cssi/SciSciGPT-SciSciNet huggingface dataset:
On a new approach to the design of tracking controllers for nonlinear dynamical systems

The nonlinear autoregressive moving-average (NARMA) model is now well established for identifying nonlinear systems using input-output data. In this paper a method of designing a controller based on the NARMA model is proposed. The controller is shown to be the solution to an implicit algebraic equation, so that the controller can be determined without explicit use of past values of inputs and outputs as in traditional methods. Simulation studies are presented to demonstrate that the method proposed is significantly better than other methods currently in use. The resulting controller provides a satisfactory starting point for online adaptation in practical applications.
Electron transport of a linac coherent light source (LCLS) using the SLAC linac

A linac configuration providing a low emittance high peak current electron beam is under study for a potential Linac Coherent Light Source (LCLS) based on the SLAC accelerator. The parameters of the final electron bunch are nearing the technological limits of present accelerators in both transverse and longitudinal phase space. In this note we describe a layout of the RF gun, linac, and bunch compressors to deliver the required bunch properties. >
Family Violence, Anger Expression Styles, and Adolescent Dating Violence

How partner violence is transferred across generations is relatively unexplored. This paper proposes that anger expression style (constructive, destructive direct, destructive indirect) mediates the relationship between exposure to family violence and dating violence perpetration by adolescents. Data are from 1,965 completed self-administered questionnaires given to eighth- and ninth-grade students in a primarily rural county in North Carolina in 1994. Results varied by gender and type of exposure to family violence. For females, destructive direct and destructive indirect anger expression styles mediated the relationship between experiencing family violence and dating violence perpetration. For males, this relationship was mediated primarily by destructive direct anger expression style. The association between witnessing family violence and dating violence perpetration for females was mediated by destructive direct anger expression style only. Witnessing family violence was not associated with dating violence perpetration for males, and therefore could not be mediated. This study suggests that adolescents exposed to family violence learn anger expression styles that put them at risk of being perpetrators of dating violence. Further research is needed to identify other mediators that explain how partner violence is transferred across generations.
Amorphous ferrimagnets in large magnetic fields

Abstract In the amorphous rare earth-transition metals the rare earth sublattice is asperomagnetic with the transition metal spins aligned antiparallel to the rare earth moment. Application of a magnetic field produces an angled phase between two critical fields as in crystalline ferrimagnets, but with the rare earth moment dependent on field.
Influence of pH, tungstate and picrate on precipitation of plasma proteins.

Abstract A procedure for subdividing and analyzing small segments of an electrophoretic pattern is presented. Electrophoretic patterns of human plasma adjusted to varying pH values (7.6-2.0) with HCl are described. The concentrations and properties of the globulin components are markedly affected as the pH values decrease. Electrophoretic analyses of fractions obtained after treatment of human plasma with tungstate and picrate are presented. Specific components do not appear to be selectively separated by these alkaloidal reagents.
New manifolds for superstring compactification

We construct new manifolds with SU(3) holonomy that are candidate vacua for superstring theory and give a detailed explanation of the techniques involved. Some of these manifolds have a non-abelian fundamental group and thus can lead to a rank five low energy gauge group. Models with an odd number of generations are obtained.CP violation is discussed in this context and shown to occur generically. Topological features of the Yukawa couplings are also discussed.
Representation of Lesbian and Gay Men in Federal, State, and Local Bureaucracies

Americans increasingly view lesbians and gay men as a legitimate minority, entitled to equal employment opportunities and perhaps to adequate representation in government. Scholars of public administration have extensively studied whether women and racial minorities receive fair representation and pay in the public sector, but we have generally ignored lesbians and gay men, largely because we lack data on the sexual orientation of government employees. Using a 5 percent sample of the 2000 Census, this paper provides new insights into one group of lesbian and gay employees: full-time workers with same-sex unmarried partners. It first determines whether they are as likely to hold jobs in the public and nonprofit sectors as workers who are married, have different-sex unmarried partners, or have never been married. Second, it explores whether lesbians' and gay men's representation is concentrated in particular occupations. It then examines whether workers with same-sex partners earn as much as other workers, and whether any disparities can be explained by race, gender, education, age, occupation, and location.
A Generalized Subspace Least Mean Square Method for High-resolution Accurate Estimation of Power System Oscillation Modes

Abstract A generalized subspace least mean square method is presented for accurate and robust estimation of oscillation modes from exponentially damped power system signals. The method is based on the orthogonality of signal and noise eigenvectors of the signal autocorrelation matrix. Performance of the proposed method is evaluated using Monte Carlo simulation and compared with the Prony method. Test results show that the generalized subspace least mean square method is highly resilient to noise and significantly dominates the Prony method in tracking power system modes under noisy environments.
Surface complexation modeling of Pb(II) adsorption on mixtures of hydrous ferric oxide, quartz and kaolinite

Abstract Pb adsorption is measured on hydrous ferric oxide (HFO), kaolinite and quartz as a function of pH (∼ 2–10), ionic strength (0.001 to 0.1 M NaNO 3 ) and sorbate concentration (1 to 100 µM Pb on 2 g/L solid). The data are used to parameterize diffuse layer surface complexation models (DLMs) for each solid. Pb adsorption edges on HFO show little dependence on ionic strength and are described well by a DLM with Pb forming a monodentate complex on strong and weak surface sites. In contrast, Pb adsorption edges on quartz are strongly dependent on ionic strength and sorbate/sorbent ratios. A single-site DLM with a monodentate Pb complex describes Pb adsorption on quartz well over relatively restricted solution conditions, but cannot reproduce the observed dependence on ionic strength and Pb loading. As for quartz, Pb adsorption on kaolinite depends strongly on ionic strength and Pb loading. Several model approaches are tested, but none produces a good fit to the data over the full range of measured conditions. The best of the tested DLMs for kaolinite assumes Pb binding to a permanent charge (face) site and formation of a monodentate complex on a variable-charge (edge) site. A simple component additivity approach, assuming no mineral–mineral interactions and using models developed for the three pure sorbents generally produces good predictions of Pb adsorption for mixed solid systems. With the possible exception of the HFO and kaolinite system, mineral–mineral interactions between quartz, kaolinite and HFO appear to be smaller than the uncertainties associated with the pure sorbent models.
Written expression—The last skill acquired

These dyslexic youngsters were particularly weak in syntax. The level of productivity, the abstractness and originality of ideas were diverse. Results of Table 1 differed somewhat from Myklebust’s study and warrant further attention with larger groups of children. The subtle difficulties noted in spontaneous oral language should be explored further. Case 4 had the most difficulty with oral language. It is quite possible that written work is helping him monitor and clarify his oral language. With Case 3, the opposite seems true—oral language is perhaps aiding him in the sequencing of written language. In many respects, this paper has raised a myriad of questions and offered no answers. I believe, however, that it illustrates that written language is, indeed, the very last skill acquired by many youngsters.
Changing fluorescence in a streaming barium plasma due to an axial magnetic field

The present investigations consider the case of a low-density laser-produced plasma expanding into a vacuum in the presence of an axial magnetic field. The time-integrated line intensities of neutral and singly ionized barium have been measured for magnetic fields up to 300 G. These measurements reveal three prominent changes in the intensities of individual lines as a function of increasing magnetic field: extinction, growth, and severe attenuation followed by enhancement. Measurements support a model that predicts the quenching of higher-lying transitions and the enhancement of lower-lying transitions for increasing magnetic fields.
An Alternate Statistic for Testing the Slow Change Assumption of the Shine-Bower Error Term.

It is indicated that the Mean Square Successive Difference test is not always suitable for testing the slow change assumption of the Shine-Bower error term. A more suitable alternate statistic is presented. The two statistics are compared.
Lysine production from methanol at 50°C using Bacillus methanolicus : modeling volume control, lysine concentration, and productivity using a three-phase continuous simulation

A simulation was developed based on experimental data obtained in a 14-L reactor to predict the growth and L-lysine accumulation kinetics, and change in volume of a large-scale (250-m(3)) Bacillus methanolicus methanol-based process. Homoserine auxotrophs of B. methanolicus MGA3 are unique methylotrophs because of the ability to secrete lysine during aerobic growth and threonine starvation at 50 degrees C. Dissolved methanol (100 mM), pH, dissolved oxygen tension (0.063 atm), and threonine levels were controlled to obtain threonine-limited conditions and high-cell density (25 g dry cell weight/L) in a 14-L reactor. As a fed-batch process, the additions of neat methanol (fed on demand), threonine, and other nutrients cause the volume of the fermentation to increase and the final lysine concentration to decrease. In addition, water produced as a result of methanol metabolism contributes to the increase in the volume of the reactor. A three-phase approach was used to predict the rate of change of culture volume based on carbon dioxide production and methanol consumption. This model was used for the evaluation of volume control strategies to optimize lysine productivity. A constant volume reactor process with variable feeding and continuous removal of broth and cells (VF(cstr)) resulted in higher lysine productivity than a fed-batch process without volume control. This model predicts the variation in productivity of lysine with changes in growth and in specific lysine productivity. Simple modifications of the model allows one to investigate other high-lysine-secreting strains with different growth and lysine productivity characteristics. Strain NOA2#13A5-2 which secretes lysine and other end-products were modeled using both growth and non-growth-associated lysine productivity. A modified version of this model was used to simulate the change in culture volume of another L-lysine producing mutant (NOA2#13A52-8A66) with reduced secretion of end-products. The modified simulation indicated that growth-associated production dominates in strain NOA2#13A52-8A66. (c) 1996 John Wiley & Sons, Inc.
The function of FOXO1 in the late phases of the cell cycle is suppressed by PLK1-mediated phosphorylation

Polo-like kinase 1 (PLK1) plays crucial roles in multiple stages of cell division. Our previous studies suggest that global transcriptional regulation by PLK1 may contribute to its multiple functions. PLK1 depletion is associated with a decrease in cell viability and the induction of apoptosis; however, the underlying mechanisms are not completely understood. Here, we report that forkhead box protein O1 (FOXO1) is a novel physiological substrate of PLK1. FOXO1 is at the interface of crucial cellular processes, orchestrating programs of gene expression that regulate apoptosis, cell cycle progression, and oxidative-stress resistance. PLK1 interacts with and phosphorylates FOXO1, mainly at the G 2/M phase of the cell cycle. PLK1-mediated phosphorylation leads to the impairment of FOXO1's transcriptional activity in an Akt-independent manner. By immunofluorescence staining and subcellular fractionation, we demonstrate that PLK1-induced FOXO1 phosphorylation causes its nuclear exclusion. Furthermore, PLK1-mediated phosphorylation of FOXO1 negatively regulates its pro-apoptotic function and abrogates its ability to delay entry into and progression through G 2/M transition. Therefore, our results suggest that PLK1 abrogates the inhibitory effects of FOXO1 on cell growth and survival to ensure timely cell cycle progression. This study not only reveals a novel and major regulatory mechanism of FOXO1 at the late phases of the cell cycle, but also provides new insight into the molecular mechanisms by which PLK1 inhibition leads to growth arrest and cell death.
The cartel of good intentions: The problem of bureaucracy in foreign aid

Well-meaning national and international bureaucracies dispense foreign aid under conditions in which bureaucracy fails. The environment that created aid bureaucracies led those organizations to (a) define their output as money disbursed rather than service delivered, (b) produce many low-return observable outputs (glossy reports and "frameworks") and few high-return less observable activities like ex - post evaluation, (c) engage in obfuscation, spin control, and amnesia (always describing aid efforts as "new and improved") exhibiting little learning from the past, (d) put enormous demands on scarce administrative skills in poor countries. To change this unhappy equilibrium, policymakers in rich and poor countries should experiment with decentralized markets, matching those who want to help the poor with the poor themselves freely expressing their needs and aspirations.
Concentration Dependence of Lidocaine-induced Irreversible Conduction Loss in Frog Nerve

Background:Concentration is a causal factor in local anesthetic nerve toxicity. Therefore, it is essential to define a concentration below which injury does not occur. We explored the relation of lidocaine concentration and nonreversible block after drug washout in frog sciatic nerve.Methods:Frog sc
Phosphorylation of tris(hydroxymethyl)aminomethane by human erythrocytes.

Abstract Whole human blood was incubated for periods of up to 96 hr at 37 °. Control of pH within the limits of 7.1–7.5 was achieved by the addition of pH 8.5 isotonic Tris buffer. Glucose, inorganic phosphate, adenine, and pyruvate were added as necessary to maintain the intracellular ATP level near that of fresh erythrocytes. During the prolonged incubation, an unusual phosphate ester accumulated within the erythrocytes. In samples incubated for 2–4 days, the final intracellular level of this compound ranged from 3.1 to 5.8 μmoles/ml cells. These values represent concentrations two to five times that of ATP. Isolation and purification of the phosphate ester was accomplished using anion and cation-exchange chromatography. The isolated phosphate ester was shown to be identical to synthetic phosphoryl-Tris using: (1) anion-exchange chromatography; (2) paper chromatography; and (3) infrared spectrophotometry. The synthesis and properties of phosphoryl-Tris are described.
Nuclear Quadrupole Interaction in Pure Metals

Calculations of the ionic part of the electric field gradient at the nuclei of certain metals are combined with available experimental data to obtain information about the electronic structures of the metals, or estimates of nuclear quadrupole moments. The metals considered are Be, Sc, Re, La, Mg, Co, Zn, and Cd, which have the hexagonal close-packed structure, and indium, which has a centered tetragonal structure. Some comparison is made with other information about the shapes of the Fermi surfaces and a pertinent experiment on Zn is suggested.
Validity of the Childhood Trauma Questionnaire in an Adolescent Psychiatric Population

ABSTRACT Objective To present initial findings on the validity of a recently developed maltreatment inventory, the Childhood Trauma Questionnaire (CTQ), in a sample of adolescent psychiatric patients. Method Three hundred ninety-eight male and female adolescents (aged 12 to 17 years) admitted to the inpatient service of a private psychiatric hospital were given the CTQ as part of a larger test battery. Structured interviews were also conducted with the primary therapists of 190 of the patients to obtain ratings of abuse and neglect based on all available data, including clinical interviews with patients and their relatives and information from referring clinicians and agencies. Results Principal-components analysis of the CTQ items yielded five rotated factors-emotional abuse, emotional neglect, sexual abuse, physical abuse, and physical neglect-closely replicating the factor structure in an earlier study of adult patients. The internal consistency of the CTQ factors was extremely high both in the entire sample and in every subgroup examined. When CTQ factor scores were compared with therapists' ratings in a series of logistic regression analyses, relationships between the two sets of variables were highly specific, supporting the convergent and discriminant validity of the CTQ. Finally, when therapists' ratings were used as the validity criterion, the CTQ exhibited good sensitivity for all forms of maltreatment, and satisfactory or better levels of specificity. Conclusions These initial findings suggest that the CTQ is a sensitive and valid screening questionnaire for childhood trauma in an adolescent psychiatric inpatient setting.
Women as farm landlords: does gender affect environmental decision-making on leased land?

The 1988 Agricultural Economics and Land Ownership Survey allows a more thorough analysis of the role of women as farmland owners. Women farmland owners are predominately nonoperators—that is, they rent their land to others. This analysis focuses on whether gender affects landlord participation in the selection of fertilizer and chemicals on leased land. Findings indicate that women landlords are less likely than men to participate in this management decision.
Teratogenicity following inhalation exposure of rats to a high-boiling coal liquid

On days 12-16 of gestation pregnant rats were exposed to heavy distillate (HD), the highest-boiling material derived from the solvent refined coal-II (SRC-II) process, and the litters were examined at day 21. Adverse biological effects were observed in the group of animals exposed to an aerosol concentration of 0.66 mg 1-1 [1.8 microgram, mass medium aerodynamic diameter (MMAD)]; groups of animals exposed to lower aerosol concentrations (0.084 and 0.017 mg 1-1) were largely unaffected. Embryo lethality during mid- and late gestation appeared attributable to the coal liquid exposure. Fetuses from pregnant rats in the high exposure group were smaller in weight and length than fetuses from control animals, and skeletal ossification was reduced. Increased incidences of small lungs and cleft palate were observed in fetuses from the high exposure group. Pregnant rats in the high-exposure group gained less weight than controls during gestation; the reduced weight gain was accounted for by the reduced size of the fetuses and placentas. Even though maternal body weight (exclusive of the products of conception) was unaffected by the exposure, the weights of the maternal thymus, lung and spleen were altered in the high exposure group.
Learning the shape of information: a longitudinal study of Web-news reading

A concept called shape is proposed to experimentally examine the development of users' mental representations of information spaces over time. Twenty five novice users are exposed to two differently designed news web sites over five sessions. The longitudinal impacts on users' comprehension, usability, and navigation are examined.
Revision des Atomgewichtes von Cadmium. III. Mitteilung. Die Elektrolytische Bestimmung von Cadmium in Cadmiumchlorid

1. Die Kristallisation von Cadmiumbromid erwies sich als ein sehr wirksames und schnell ausfuhrbares Verfahren zur Reinigung von Cadmiummaterial.
Superlattice Structure and Precipitates in O+ and Zr+ Ion Coimplanted SrTiO3: a Model Waste Form for 90Sr

There are high yields of 90Sr radionuclide present in the spent fuels from nuclear power plants. Permanent disposal of the nuclear waste requires immobilization of the highly radioactive materials. We investigate strontium titanate as a model waste form for 90Sr. Coimplantation with O+ and Zr+ ions, followed by annealing at 1423 K, was performed to simulate 90Sr to 90Zr decay. The microstructures were examined using a state-of-the-art aberration-corrected scanning transmission electron microscope (STEM) with a spatial resolution of better than 0.1 nm. At low Zr concentrations, we observe formation of a ZrO-Sr superlattice structure. Ab initio calculations indicate that this atomic configuration is energetically favorable. At higher Zr concentrations, we observe precipitates of ZrO2 with a coherently strained interface or a monolayer of disordered interfacial structure. Chemical and charge effects in the model waste form of 90SrTiO3 are discussed.
GROWTH FACTORS FROM PLATELETS, MONOCYTES, AND ENDOTHELIUM: THEIR ROLE IN CELL PROLIFERATION*

Of the various biological roles assigned to growth factors at the beginning of this article, the factors described here are largely associated with the response to injury. These represent a special type of factor since two of them, PDGF and MDGF, are carried in the circulation by the platelet and the monocyte respectively, and can therefore be delivered to sites where a proliferative response would be an important event in the restitution of tissue continuity. The role of the endothelial-derived growth factor in these phenomena is not clear at present. Atherosclerosis has been suggested to represent a protective proliferative response that has gone awry and become disease. In this instance both PDGF and MDGF could play important roles, since platelets have been associated with the early injury phenomenon and macrophages appear to be present in virtually all phases of the development of the lesions of atherosclerosis from the fatty streak to the fibrous plaque and the complicated lesion. In each of these circumstances the macrophage may be important in lesion progression and possibly in lesion initiation. PDGF may also be important in initiation of some lesions, and in some instances would undoubtedly participate in the fibroproliferative response that occurs during organization of a thrombus.
Role of endogenous ceruloplasmin in low density lipoprotein oxidation by human U937 monocytic cells.

Oxidation of lipids and lipoproteins by macrophages is an important event during atherogenesis. Activation of monocytic cells by zymosan and other agonists results in the release of multiple oxidant species and consequent oxidation of LDL. We now show evidence that ceruloplasmin, a copper-containing acute phase reactant, is secreted by zymosan-activated U937 monocytic cells, and that the protein has an important role in LDL oxidation by these cells. In one approach, ceruloplasmin has been shown to exhibit oxidant activity under the appropriate conditions. Exogenous addition of purified human ceruloplasmin stimulates U937 cell oxidation of LDL to nearly the same extent as activation by zymosan. In contrast to previous cell-free experiments (Ehrenwald, E., G.M. Chisom, and P.L. Fox. 1994. Intact human ceruloplasmin oxidatively modifies low density lipoprotein. J. Clin. Invest. 93:1493-1501.) in which ceruloplasmin by itself (in PBS) oxidizes LDL, under the conditions of the current experiments (in RPMI 1640 medium) ceruloplasmin only oxidizes LDL in the presence of cells; the mechanism by which cells overcome the inhibition by medium components has not been ascertained. As further evidence for a role of ceruloplasmin, activation of U937 cells with zymosan induces ceruloplasmin mRNA and ceruloplasmin protein synthesis after a 5-6 h lag that is consistent with that preceding LDL oxidation. Finally, neutralization by a highly specific polyclonal antibody to human ceruloplasmin inhibits LDL oxidation by at least 65%. Moreover, multiple antisense oligodeoxynucleotides targeted to different regions of the ceruloplasmin mRNA block LDL oxidation by up to 95%. The specific action of the antisense oligonucleotides has been verified by showing inhibition of ceruloplasmin synthesis and by the ability of exogenous ceruloplasmin to overcome the inhibition. In summary, these results are consistent with a mechanism in which cell-derived ceruloplasmin participates in oxidation of LDL by U937 monocytic cells. The data also show that cellular factors in addition to ceruloplasmin, possibly active oxygen species and/or lipoxygenases, are essential and act synergistically with ceruloplasmin to oxidize LDL.
Surgical implications and results of combined aortic valve replacement and myocardial revascularization.

Abstract To better define the indications for and results of simultaneous aortic valve replacement and myocardial revascularization, a cohort of 271 patients with angiographically defined coronary anatomy who underwent xenograft bioprosthetic aortic valve replacement were analyzed. Two hundred and twelve patients had predominant aortic stenosis, and 55 had pure aortic regurgitation. Discordance between the clinical assessment of angina and the angiographic assessment of coronary artery disease was apparent in 39 percent of the patients with aortic stenosis and 45 percent of the patients with aortic regurgitation. Thirty-seven percent of patients in the aortic stenosis subgroup without angina and 41 percent of patients in the aortic regurgitation subgroup without angina had hemodynamically significant coronary artery disease. Concomitant coronary artery bypass grafting and aortic valve replacement were performed in 101 patients. The incidence of perioperative myocardial infarction and operative death was significantly greater ( P It is concluded that angina pectoris in patients with aortic valve disease is not a reliable indicator of coronary artery disease and that patients with coronary disease who undergo aortic valve replacement have an increased risk. It is inferred from this study that preoperative coronary arteriography is advisable in most adults undergoing the evaluation of aortic valve disease and that simultaneous aortic valve replacement and myocardial revascularization may provide some protection against late attrition due to the combined effects of coexistent aortic valve and coronary artery disease.
The extent of Russell's modal views

Russell has recently been held to have had a modal logic, a full modal theory and a view of naming that anticipates Kripke's intuitions on rigid designation. It is argued here that no such claims are warranted. While Russell was not altogether silent on matters modal, he did not advance an identifiable modal logic or anything more than a modest modal theory. His view of naming involves a notion of guaranteed reference. But what Kripke's intuitions about rigidity primarily pertain to is fixed reference, something demonstrably different.
Oxidation of Polycrystalline Copper Thin Films at Ambient Conditions

Qualitative and quantitative studies of the oxidation of polycrystalline copper (Cu) thin films upon exposure to ambient air conditions for long periods (on the order of several months) are reported in this work. Thin films of Cu, prepared by thermal evaporation, were analyzed by means of X-ray photoelectron spectroscopy (XPS) to gain an understanding on the growth mechanism of the surface oxide layer. Analysis of high-resolution Cu LMM, Cu2p3/2, and O1s spectra was used to follow the time dependence of individual oxide overlayer thicknesses as well as the overall oxide composite thickness. Transmission electron microscopy (TEM) and spectroscopic ellipsometry (SE) were used to confirm the results obtained from XPS measurements. Three main stages of copper oxide growth were observed: (a) the formation of a Cu2O layer, most likely due to Cu metal ionic transport toward the oxide−oxygen interface, (b) the formation of a Cu(OH)2 metastable overlayer, due to the interactions of Cu ions with hydroxyl groups pr...
A validated liquid chromatography/tandem mass spectrometry assay for cis-amminedichloro(2-methylpyridine)platinum(II) in human plasma ultrafiltrate.

The clinical use of platinum drugs as anticancer agents has encountered problems when relating pharmacokinetic profiles with efficacy and toxicity is attempted. This has been mainly due to the lack of specific and sensitive analytical methodology to examine concentrations of the unbound drug in plasma. The presence of a carbocyclic ring on the new drug, cis-amminedichloro(2-methylpyridine)platinum(II) (ZD0473) suggested that it would be possible to develop the first stable isotope dilution LC/MS assay for a platinum drug in human plasma ultrafiltrate samples. The dichloro form of the drug exists in equilibrium with at least two aquated forms in plasma. The molecular form of the drug, therefore, depends on the length of time that the plasma sample is maintained at room temperature before freezing. Therefore, we have developed a method that quantitatively converts the aquated species back to the dichloro form of the parent drug so that a single molecular species can be analyzed. Selected reaction monitoring...
Short-term responses of native bees to livestock and implications for managing ecosystem services in grasslands

Rangelands are significant providers of ecosystem services in agroecosystems world-wide. Yet few studies have investigated how different intensities of livestock grazing impact one important provider of these ecosystem services—native bees. We conducted the first large-scale manipulative study on the effect of a gradient of livestock grazing intensities on native bees in 16 40-ha pastures in the Pacific Northwest Bunchgrass Prairie. Each pasture was exposed to one of four cattle stocking rates for two years and grazing intensity was quantified by measuring utilization. We measured soil and vegetation characteristics related to floral and nesting resources as well as several metrics of the bee community. Increased grazing intensity significantly reduced vegetation structure, soil stability, and herbaceous litter and significantly increased soil compaction and bare ground. Native bees responded with changes in abundance, richness, diversity, and community composition. Responses varied with taxa and time of season. Bumble bees were sensitive to grazing intensity early in the season, showing reduced abundance, diversity, and/or richness with increased intensity, potentially because of altered foraging behavior. In contrast, sweat bees appeared unaffected by grazing. These results show that native bee taxa vary in their sensitivity to livestock grazing practices and suggest that grazing may potentially be a useful tool for managing pollination services in mosaic agroecosystems that include rangelands.
Angular distributions of solar protons and electrons

High angular-resolution measurements of directional fluxes of solar particles in space have been obtained with detectors aboard OGO-5 during the cosmic ray event of Nov. 18, 1968. This is the only case on record for which sharply-defined directional observations of protons and electrons covering a wide rigidity range (0.3 MV to 1.5 GV) are available. The satellite experiment provided data for determining pitch-angle distributions with respect to the direction of the local interplanetary magnetic field lines during the lengthy highly anisotropic phase of the event. The results have been interpreted in the light of the temporal flux profiles and the state of the interplanetary medium.
An Extraordinarily Distorted cyclo-Tetrastibine. Crystallographic Structure of a New Polymorph of cyclo-(σ-C5Me5Sb)4

A new crystalline polymorph of cyclo-(Cp*Sb)4 has been crystallographically characterized that contains the mostly acutely angled four-membered, homoatomic ring system known (Sb−Sb−Sb = 76.1(1)°). In the previously reported form, the Cp* and Sb4 ring centroids (viewed along the C−Sb bond) are anti; in the new form the Cp* ring rotates over 100° to a more crowded gauche form. The new form melts at a temperature 72 °C higher than the one previously reported and is about 15% more dense. While the Sb−Sb ring distances are normal (2.836(1) A), the transannular Sb···Sb distances are the shortest known for antimony (3.518(1) A) and apparently provide a stabilization that compensates for the extreme ring distortion.
A spatially distributed computational model of brain cellular metabolism

Abstract This paper develops a three-dimensional spatially distributed model of brain cellular metabolism and investigates how the locus of the synaptic activity in reference to the capillaries and diffusion affects the behavior of the model, a type of analysis which is impossible to carry out in spatially lumped models, which are shown to be consistent spatially averaged approximations of the distributed model. To avoid a geometrically detailed modeling of the complex structure of the tissue consisting of different cell types and the extracellular space, the distributed model is based on a novel multi-domain formulation of reaction–diffusion equations, accounting also for separate mitochondria. The model reduction relating the spatially distributed model and lower dimensional reduced models, including the well-mixed spatially lumped compartment model, is carefully explained. We illustrate the effects of losing the spatial resolution with a computed example which is based on a reduced one-dimensional distributed radial model, and look into how the model behaves when the locus of the synaptic activity in reference to the capillaries is changed. By averaging the fluxes and concentrations in the distributed radial model to correspond to quantities in a lumped model, and further by estimating the parameters in the lumped, we conclude that varying the locus of the synaptic activity in reference to the capillaries alters significantly the lumped model parameters. This observation seems to be consequential for parameter estimation procedures from data when the spatial resolution is insufficient to determine the locus of the activity, indicating that the model uncertainty is an inherent feature of lumped models.
The transcription factor Egr3 modulates sensory axon-myotube interactions during muscle spindle morphogenesis.

The Egr family of zinc-finger transcription factors, consisting of Egr1, Egr2, Egr3, and Egr4, are involved in cellular growth and differentiation. Adult Egr3-deficient mice are ataxic and lack muscle spindle proprioceptors that normally develop at the sites of Ia afferent-myotube contacts during embryogenesis. To resolve whether spindles form and then degenerate, or whether they never form in the absence of Egr3, we examined the spatiotemporal expression of Egr3 relative to spindle development. In wild type mice, Egr3 was expressed in developing myotubes shortly after they were innervated by Ia afferents and its expression was controlled by innervation because it dissipated following nerve transection. In Egr3-deficient mice, myotubes received Ia afferent innervation and assembled normally into spindles during embryogenesis. However, newborn Egr3-deficient spindles had few internal myonuclei in intrafusal fibers and thin capsules. Moreover, slow-developmental myosin heavy chain was not induced in embryonic Egr3-deficient spindles suggesting that impairments in differentiation were present before they could be detected morphologically. After birth, sensory and motor innervation withdrew from the Egr3-deficient spindles, and the spindles disassembled. In spite of the spindle disassembly and retraction of afferents from muscles, the cell bodies of proprioceptive neurons within dorsal root ganglia were retained. We conclude that Egr3 has an essential role in regulating genes required for the transformation of undifferentiated myotubes into intrafusal fibers, and hence for the phenotypic differentiation of spindles.
Stratigraphic effects of change from internal to external drainage in an extending basin, southeastern Nevada

Observations from southern White River Valley, southeastern Nevada, shed light on sediment dispersal and geomorphic development during and after extensional faulting that formed the valley. Fine-grained lacustrine and alluvial sediments of the late Neogene White River Narrows Formation were deposited in a subsiding half graben, while coeval coarse-grained deposits were confined to within 1 km of the active fault. The syntectonic deposits are overlain along an erosional unconformity by post-tectonic, uniformly coarse-grained, alluvial-plain and fluvial-terrace deposits. This sequence conforms to a recent proposal that fine-grained intervals in extensional basins are deposited syntectonically, whereas coarse-grained intervals are deposited during post-tectonic progradation of marginal clastic wedges. The stratigraphy and geomorphology of the study area suggest that post-tectonic progradation of coarse clastic sediment resulted from incorporation of the White River Valley into the Colorado River drainage system. Meadow Valley Wash also links previously closed, young but presently quiescent, extensional basins to the Colorado River system. By contrast, most nearby basins that contain Quaternary scarps remain internally drained. Maintenance of internal drainage by active subsidence therefore may have been important in ponding of coarse-grained sediments next to the fault. After tectonic subsidence ceased, the basin drainage became southward. This action resulted in post-tectonic progradation of coarse-grained clastic deposits as sediment-dispersal systems responded to the new external base level. Regional comparisons, however, indicate that, depending on local rates of tectonic subsidence and erosion, a basin may become externally drained syntectonically, which can cause syntectonic deposits to be coarse grained. In addition, a basin may remain closed long after tectonic activity ceases, causing fine-grained deposits to continue to accumulate in a quiescent basin. We conclude that the interplay between internal and external drainage, which depends not only on the rate of local fault activity, but also regional tectonics, climate, and other factors, is a significant factor in the stratigraphic evolution of continental extensional basins.
Composition ofNeurospora crassa vacuolar membranes and comparison to endoplasmic reticulum, plasma membranes, and mitochondrial membranes

Abstract We have determined the carbohydrate and lipid contents of vacuolar membranes from Neurospora crassa , and have compared them to mitochondrial membranes, endoplasmic reticulum, and plasma membranes. These four membrane fractions were clearly distinct from each other in polypeptide composition, as judged by polyacrylamide gel electrophoresis. The vacuolar membranes proved unusual in two respects: the contained very high amounts of carbohydrate and were the only membranes with significant levels of phosphatidylserine. As in other eucaryotic cells, the mitochondrial membranes were unique in having high amounts of cardiolipin but virtually no sterol. Although the endoplasmic reticulum and plasma membranes were qualitatively similar to each other, the plasma membranes could be distinguished by a higher carbohydrate content, whereas the endoplasmic reticulum had a characteristically high ratio of phosphatidylcholine to phosphatidylethanolamine. The fatty acid compositions of all four membranes were similar, except that mitochondrial membranes contained about half as much saturated fatty acids as the other three fractions.
Expression Cloning of Three Rhizobium leguminosarum Lipopolysaccharide Core Galacturonosyltransferases

Abstract The lipid A and core regions of the lipopolysaccharide in Rhizobium leguminosarum, a nitrogen-fixing plant endosymbiont, are strikingly different from those of Escherichia coli. In R. leguminosarum lipopolysaccharide, the inner core is modified with three galacturonic acid (GalA) moieties, two on the distal 3-deoxy-d-manno-octulosonic acid (Kdo) unit and one on the mannose residue. Here we describe the expression cloning of three novel GalA transferases from a 22-kb R. leguminosarum genomic DNA insert-containing cosmid (pSGAT). Two of these enzymes modify the substrate, Kdo2-[4′-32P]lipid IV2 and its 1-dephosphorylated derivative on the distal Kdo residue, as indicated by mild acid hydrolysis. The third enzyme modifies the mannose unit of the substrate mannosyl-Kdo2-1-dephospho-[4′-32P]lipid IV2. Sequencing of a 7-kb subclone derived from pSGAT revealed three putative membrane-bound glycosyltransferases, now designated RgtA, RgtB, and RgtC. Transfer by tri-parental mating of these genes into Sinorhizobium meliloti 1021, a strain that lacks these particular GalA residues, results in the heterologous expression of the GalA transferase activities seen in membranes of cells expressing pSGAT. Reconstitution experiments with the individual genes demonstrated that the activity of RgtA precedes and is necessary for the subsequent activity of RgtB, which is followed by the activity of RgtC. Electrospray ionization-tandem mass spectrometry and gas-liquid chromatography of the product generated in vitro by RgtA confirmed the presence of a GalA moiety. No in vitro activity was detected when RgtA was expressed in Escherichia coli unless Rhizobiaceae membranes were also included.
Human papillomavirus type 18 in conjunctival intraepithelial neoplasia.

Human papillomaviruses are oncogenic viruses that have been found in a variety of epithelial neoplasias. We sought to confirm their presence in conjunctival intraepithelial neoplasia. Five tumors were studied with a polymerase chain-reaction assay designed to detect the E6 region of human papillomavirus types 16 and 18. Human papillomavirus type16 DNA was found in four of the five tumors, including two tumors that contained both type-16 and type-18 DNA. Viral DNA was not present in the fifth tumor.
Perfecting your spread plate technique.

The Spread Plate Technique, in conjunction with serial dilutions, is a valuable research tool. In this example, dye is used to accentuate the visible volume of each aliquot and the dispersion pattern on the agar. With the utilization of a second dye, each agar plate can be used twice. The immediate feedback and personal evaluation of these techniques provide an active learning experience that students remember.
Nitric oxide alters chondrocyte function by disrupting cytoskeletal signaling complexes.

Components of osteoarthritis include increases in pericellular fibronectin and in chondrocyte beta1 integrin expression. Events which follow ligation of fibronectin to its chondrocyte-receptor, the integrin alpha5beta1 include an assembly of a subplasmalemmal actin/rho A/focal adhesion kinase signaling complex. In addition, nitric oxide (NO), a potential mediator of cartilage pathophysiology disrupts the cytoskeletal signaling complex associated with integrin signaling. In these studies, we examined the relationship among integrin signaling, biosynthesis of S-35 sulfate containing proteoglycans and release of YKL-40 (a secretory glycoprotein) by comparing cell responses using cells plated on a fibronectin-coated or polyHEME coated surfaces. We report that the release of proteoglycan and glycoprotein require anchorage dependent signals by integrin costimulation. NO which disrupts the integrin signaling complex attenuates both cell responses. Taken together NO may serve as a nonspecific 'brake' to prevent anabolic and catabolic injury responses.
Opiate receptor supersensitivity produced by chronic naloxone treatment: dissociation of morphine-induced antinociception and conditioned taste aversion

In three separate experiments, rats were used to assess the effects of chronic administration of naloxone on specific binding of 3H-naloxone in various regions of the central nervous system (CNS) and on the efficacy of morphine to produce antinociception and a conditioned taste aversion. Chronic naloxone treatment increased opiate binding in medulla-pons, midbrain, hypothalamus, hippocampus, striatum, and prefrontal cortex, but not in either spinal cord or cerebellum. In those CNS regions exhibiting increased opiate binding, the duration of increased binding following termination of the naloxone treatment differed between regions. In conjunction with the increase in opiate binding, the efficacy of morphine to produce antinociception was potentiated, while the efficacy to produce a conditioned taste aversion was unchanged. Moreover, the administration of naloxone during behavioral testing blocked completely the antinociceptive effect, but not the aversive effect, of morphine. These results indicate that morphine-induced antinociception and conditioned taste aversion may be dissociated neuropharmacologically.
Digital computer-assisted warfarin therapy: Comparison of two models

Abstract An interactive computer program developed to assist clinicians in selecting appropriate maintenance warfarin doses is described. The program uses two previously described mathematical models to which actual patient data is iteratively fit. Preliminary results of a clinical evaluation of the program and comparison of the two models are presented, and the potential clinical applications are discussed.
Maximizing diversity in synthesized hyperspectral images

Maximum diversity in sample data is required in order to ensure that results from such are representative of the entire domain. In cases where the generation of data is computationally expensive, such as image synthesis, the number of samples should be kept to a minimum with a higher density in regions of transition with respect to image variation. Our objective is to synthesize a set of hyperspectral images to evaluate the performance of ATRs. We use the Digital Imaging and Remote Sensing Image Generation (DIRSIG) model, an image synthesizing software, to generate the images. The nature of a synthesized image is determined by numerous input parameters to DIRSIG. It is required that the resulting image set be diverse with respect to the degree of difficulty for the ATRs under test. We model each synthesized image as a function of the input parameters to DIRSIG, each parameter being a possible source of variation in the image. We compute a Complexity Measure (CM) for each image that represents the degree of difficulty for an ATR. A gradient based sampling scheme is infeasible to determine the regions of transitions in the CM in the multiparameter space because of the computational cost of synthesizing each image. We thus present a sampling algorithm based on an active walker model, in which the step size is adapted based on the distribution of the CM values from the already synthesized images. We sample a variety of multi-dimensional functions with this algorithm, and confirm the improved reconstruction accuracy from samples obtained using it compared to even and random sampling. When applied to sampling the CM multi-parameter space, our adaptive sampling algorithm produces a more diverse image set with respect to degree of difficulty than the random and even sampling schemes.