cssi/SciSciGPT-SciSciNet huggingface dataset:
Algebraic aspects of relational database decomposition

An algebraic framework for investigating the problem of decomposing a relational database schema into components is developed. It is argued that the views of a relational schema which are to be the components of a decomposition should form a finite atomic Boolean algebra. The unit of the algebra is the identity view, and the zero is the null view. The join operation in this algebra is to be a generalization of the usual concept of join; the resulting view should contain precisely the representation contained in the two component views as a unit. The meet operation in this algebra is to measure the interdependence of the components, and is to be zero if and only if they are independent. A decomposition of the schema is then to be a decomposition of the identity component, with the ultimate decomposition the one consisting entirely of atoms.The thrust of the results is in two directions. First, the general properties of relational schemata particular to this problem are developed, within the framework of first-order logic. The key formulations are those of abstract meet and join of schemata. Using these formulations, it is shown that a completely general decomposition theory is impossible. The second part of the work islolates a relatively large class of schemata which do admit reasonable decompositions. These schemata include all of the usual decomposition problems, including project-join decompositions and horizontal decompositions of schemata constrained by universal Horn sentences.
Welfare and the Achievement of Goals

I defend the view that an individual's welfareis in one respect enhanced by the achievementof her goals, even when her goals are crazy,self-destructive, irrational or immoral. This``Unrestricted View'' departs from familiartheories which take welfare to involve only theachievement of rational aims, or of goals whoseobjects are genuinely valuable, or of goalsthat are not grounded in bad reasons. I beginwith a series of examples, intended to showthat some of our intuitive judgments aboutwelfare incorporate distinctions that only theUnrestricted View can support. Then, I show howthe view can be incorporated into a broadertheory of welfare in ways that do not produceimplausible consequences. This in hand, Ifinish by providing a more philosophicalstatement of the Unrestricted View and the casein its favor, and respond to some objections.
A New Approach to Model and Directly Control Co-Transcriptional RNA Folding

RNAs are synthesized exclusively in a 5' to 3' direction and it is well established that many (particularly long noncoding, but also riboswitch) RNAs begin to fold before the transcript is fully synthesized. Indeed, in many cases, directional folding is thought to limit the formation of nonproductive, nonnative structures that might arise from a more random condensation of secondary and tertiary structures or to facilitate formation of necessary (and transient on pathway) folding intermediates. Site-specifically programmed pauses in transcription are often necessary to direct these interactions.Using tools from synthetic biology and nucleic acid nanotechnology, we are developing an alternative approach to direct and control 5' to 3' sequential RNA folding. The approach allows the introduction of pauses into the sequential release and allows the experimenter to halt and then resume RNA release/folding. Initial studies use the malachite green binding RNA aptamer, with a simple fluorescence readout of formation of the final structure. Subsequent studies will footprint intermediates with a variety of probes to follow the progress of folding and detect intermediates.View Large Image | View Hi-Res Image | Download PowerPoint Slide
Mechanical Entropy and Its Implications

It is shown that the classical laws of thermodynamics require that mechanical systems must exhibit energy that becomes unavailable to do useful work. In thermodynamics, this type of energy is called entropy. It is further shown that these laws require two metrical manifolds, equations of motion, field equations, and Weyl's quantum principles. Weyl's quantum principle requires quantization of the electrostatic potential of a particle and that this potential be non-singular. The interactions of particles through these non-singular electrostatic potentials are analyzed in the low velocity limit and in the relativistic limit. It is shown that writing the two particle interactions for unlike particles allows an examination in two limiting cases: large and small separations. These limits are shown to have the limiting motions of: all motions are ABOUT the center of mass or all motion is OF the center of mass. The first limit leads to the standard Dirac equation. The second limit is shown to have equations of which the electroweak theory is a subset. An extension of the gauge principle into a five-dimensional manifold, then restricting the generality of the five-dimensional manifold by using the conservation principle, shows that the four-dimensional hypersurface that is embedded within the 5-D manifold is required to obey Einstein's field equations. The 5-D gravitational quantum equations of the solar system are presented.
Neuregulin expression after focal stroke in the rat

Upregulation of neuregulin has been demonstrated in traumatic brain injury, but a role for neuregulin in ischemic brain injury has not been investigated. Therefore, we used a rat permanent middle cerebral artery occlusion model to examine the distribution of neuregulin after the onset of ischemic stroke. We found an increase in immunohistochemical staining for neuregulin in the penumbral regions of the cortex. The increase in neuregulin appeared to be neuronal. There was no neuregulin co-localization with astrocytes or macrophages. These results demonstrate that neuregulin is induced in neurons following ischemic stroke and may be involved in neuroprotection and repair.
What's a word worth?

Geotaxis denotes automatic, reliable orientation and movement in relation to a gravitational stimulus. It is, by definition, dependent on perception of gravitational cues or of stimuli that arise from gravitational forces, such as proprioceptive cues. Recent empirical re-examinations of negative geotaxis in infant rats, briefly reviewed in our commentary, indicate that the behavior of rats on an inclined plane is not geotaxis. Depending on factors such as the angle of incline or the substrate material, a rat pup may be observed to orient up, down, or in no particular direction. Absent is a robust, reliable and valid gravity-oriented response by infant rodents on inclined surfaces. There was no substantive disagreement expressed by the commentators on these points. The discrepancy between the specificity of the term, geotaxis, and the general absence of an oriented response to gravitational cues bothers each of the commentators and us in different ways and to varying degrees. Despite these differences, it was gratifying that a common theme in each of the Open Peer Commentaries is a basic concern with the conduct of science. Krieder and Blumberg drew a parallel between lack of terminological rigor and the absence of methodological standardization in testing infant rodents’ performance on an inclined surface. They see dual benefits to the use of standardized methods. First would be consistency, so that results from different laboratories could be compared legitimately. This is essentially impossible today, due to the wide variation of what is performed under the label of tests of negative geotaxis (see Kreider and Blumberg’s Peer Commentary).
The interactive effects of plant microbial symbionts: a review and meta-analysis

In nature, plants often associate with multiple symbionts concurrently, yet the effects of tripartite symbioses are not well understood. We expected synergistic growth responses from plants associating with functionally distinct symbionts. In contrast, symbionts providing similar benefits to a host may reduce host plant growth. We reviewed studies investigating the effect of multiple interactions on host plant performance. Additionally, we conducted a meta-analysis on the studies that performed controlled manipulations of the presence of two microbial symbionts. Using response ratios, we investigated the effects on plants of pairs of symbionts (mycorrhizal fungi, fungal endophytes, and nitrogen-fixers). The results did not support the view that arbuscular mycorrhizal (AM) fungi and rhizobia should interact synergistically. In contrast, we found the joint effects of fungal endophytes and arbuscular mycorrhizal fungi to be greater than expected given their independent effects. This increase in plant performance only held for antagonistic endophytes, whose negative effects were alleviated when in association with AM fungi, while the impact of beneficial endophytes was not altered by infection with AM fungi. Generalizations from the meta-analysis were limited by the substantial variation within types of interactions and the data available, highlighting the need for more research on a range of plant systems.
A diamagnetically stabilized horizontally levitated electromagnetic vibration energy harvester

This article investigates a horizontal diamagnetic levitation (HDL) system for vibration energy harvesting. In this configuration, two large magnets, alias lifting magnets, are arranged co-axially at a distance such that in between them a magnet, alias floating magnet, is passively levitated at a laterally offset equilibrium position. The levitation is stabilized in the horizontal direction by two diamagnetic plates made of pyrolytic graphite placed on each side of the floating magnet. This HDL configuration permits large amplitude vibration of the floating magnet and exploits the ability to tailor the geometry to meet specific applications due to its frequency tuning capability. Theoretical modeling techniques are discussed followed by an experimental setup to validate it. At an input root mean square (RMS) acceleration of 0.0434 m/s 2 (0.0044 g rms ) and at a resonant frequency of 1.2 Hz, the prototype generated a RMS power of 3.6 μW with an average system efficiency of 1.93%. Followed by the validation, parametric studies on the geometry of the components are undertaken to show that with the optimized parameters the efficiency can be further enhanced.
Geometric generalizations of the power of two choices

A well-known paradigm for load balancing in parallel and distributed systems is the "power of two choices," whereby an item is stored at the less loaded of two (or more) random alternative servers. We investigate the power of two choices in natural settings where items and servers reside in a geometric space and each item is associated with the server that is its nearest neighbor. This is the setting for example in the Chord distributed hash table, where the geometric space is determined by clockwise distance on a one-dimensional ring. For example, our analysis shows that when $n$ items are placed at n servers with d choices per item, the maximum load at any server is log log n/ log d + O(1) with high probability, only an additive constant more than when servers are chosen uniformly at random. Our proofs are quite general, showing that the power of two choices works under a variety of distributions, with most geometric constructions having at most an additive O(1) penalty. We also show that these techniques still work under highly unbalanced distributions, and give sharp bounds on the necessary number of choices. Finally, we provide simulation results demonstrating the load balance that results as the system size scales into the millions.
Building a “Family-Friendly” Metropolis: Sexuality, the State, and Postwar Housing Policy

This article explores the role normative sexuality played in housing policies in the San Francisco Bay Area after World War II. Beginning in the 1940s, policymakers made it easier for married Ameri...
Permissive Action of Growth Hormone on the Renal Response to Dietary Phosphorus Deprivation

Animal studies have shown that GH is necessary for the increased renal production of calcitriol during dietary phosphorus deprivation (PD). These studies suggest that this adaptive change in vitamin D metabolism is mediated through insulin-like growth factor-I (IGF-I) and/or insulin. We subjected 16 GH-deficient children to 96 h of severe dietary PD twice, first before and again during recombinant GH replacement. Half of the children received low dose and half received high dose replacement with recombinant GH. We measured renal tubular reabsorption maximum for phosphate corrected for glomerular filtration rate (TmP/GFR), PTH, IGF-I, calcidiol, and calcitriol pre- and postdietary PD, both off and on GH. We also assessed insulin secretion during an oral glucose load (OGTT) off and on GH. Basal PTH, calcidiol, calcitriol, and fasting blood sugar were unaffected by GH therapy. PD did not affect PTH or calcidiol either off or on GH. Basal TmP/GFR rose on GH therapy (4.8 ± 0.2 to 6.3 ± 0.4 mg/dL) and with PD (...
Effects of Sp1 overexpression on cultured human corneal stromal cells.

Sp1, a transcription factor, is upregulated in keratoconus, a cornea-thinning disease. Keratoconus corneas have also been shown to contain increased levels of degradative enzymes such as cathepsin B and decreased proteinase inhibitors such as α1-proteinase inhibitor (α1-PI). We transfected cultured human corneal stromal cells to overexpress Sp1. The resulting effects on cathepsin B and α1-PI levels as well as the cellular proliferative and apoptotic activities were examined by Western blotting and cytochemical staining. It was found that the Sp1 transfected cells contained a greater amount of cathepsin B than did mock transfected controls. The activity of cathepsin B was also increased. By contrast, the protein level of α1-PI was lowered in corneal stromal cells upon Sp1 overexpression. The Sp1-induced alterations thus mimicked closely those observed in keratoconus, supporting the notion that Sp1 upregulation may be a key factor contributing directly to the disease development. Furthermore, the apoptotic activity was unaffected in Sp1 transfectants but the proliferation was inhibited, consistent with the idea that Sp1 may play a role in differentiation of corneal cells.
Percutaneous retrieval of a surgical laparotomy sponge from the peritoneal cavity.

Percutaneous retrieval of an extravascular foreign bodyis an uncommon procedure. This report describes the successful retrieval of a 46 X 46-cm laparotomy sponge from the peritoneal cavity using a Nitinol Gooseneck Snare system. This technique can eliminate the need for exploratory surgery and may be particularly useful in poor operative candidates.
Molecular characterization, functional expression, and developmental profile of an ether à-go-go K+ channel in the tobacco hornworm Manduca sexta.

A very large number of evolutionarily conserved potassium channels have been identified but very little is known about their function or modulation in vivo. Metamorphosis of the tobacco hornworm, Manduca sexta, is a compelling model system for such studies because it permits analysis to be conducted at the level of identified neurons whose roles in simple behaviors and endocrine regulation are known. We present here the characterization of the first ion channel to be cloned from this animal. Partial genomic sequence for Manduca sexta ether a-go-go (Mseag) and a cDNA clone encoding the Mseag open reading frame were obtained. Genomic Southern analysis indicates that Manduca contains a single member of the eag subfamily per haploid genome. When expressed in Xenopus oocytes, MsEag channels conduct a voltage-dependent, K+ selective outward current with an inactivating component that closely resembles the Drosophila eag current. Mseag transcripts were restricted to the nervous system, adult antenna, and one set of larval skeletal muscles. Steroid hormonal regulation of Mseag expression is suggested by the temporal correlation of developmental changes in transcript expression with the changing steroid titers that promote metamorphosis. These results provide the foundation for functional and modulatory studies of the Eag family of K+ channels in Manduca, which will complement the genetic analysis in Drosophila.
The attenuation of central angiotensin II-dependent pressor response and intra-neuronal signaling by intracarotid injection of nanoformulated copper/zinc superoxide dismutase

Adenoviral-mediated overexpression of the intracellular superoxide (O(2)(*-)) scavenging enzyme copper/zinc superoxide dismutase (CuZnSOD) in the brain attenuates central angiotensin II (AngII)-induced cardiovascular responses. However, the therapeutic potential for adenoviral vectors is weakened by toxicity and the inability of adenoviral vectors to target the brain following peripheral administration. Therefore, we developed a non-viral delivery system in which CuZnSOD protein is electrostatically bound to a synthetic poly(ethyleneimine)-poly(ethyleneglycol) (PEI-PEG) polymer to form a polyion complex (CuZnSOD nanozyme). We hypothesized that PEI-PEG polymer increases transport of functional CuZnSOD to neurons, which inhibits AngII intra-neuronal signaling. The AngII-induced increase in O(2)(*-), as measured by dihydroethidium fluorescence and electron paramagnetic resonance spectroscopy, was significantly inhibited in CuZnSOD nanozyme-treated neurons compared to free CuZnSOD- and non-treated neurons. CuZnSOD nanozyme also attenuated the AngII-induced inhibition of K(+) current in neurons. Intracarotid injection of CuZnSOD nanozyme into rabbits significantly inhibited the pressor response of intracerebroventricular-delivered AngII; however, intracarotid injection of free CuZnSOD or PEI-PEG polymer alone failed to inhibit this response. Importantly, neither the PEI-PEG polymer alone nor the CuZnSOD nanozyme induced neuronal toxicity. These findings indicate that CuZnSOD nanozyme inhibits AngII intra-neuronal signaling in vitro and in vivo.
The effects of awareness on cortical evoked potentials to conditioned affective stimuli.

A previous paper of ours (Begleiter, Gross, & Kissin, 1967) demonstrated that it was possible to condition affective meaning to meaningless figures (CS), and significantly alter visual evoked potential (VEP) amplitudes and latencies to them, without the S's awareness of the CS–UCS relationship (Experiment I, totally unaware). In the present study some Ss were deliberately informed that a CS–UCS connection existed; however, the exact nature of their relationship was not divulged (Experiment II, slightly aware). Other Ss were explicitly informed of the correct CS–UCS contingency, and entire conditioning paradigm (Experiment III, fully aware). One physiological (VEP) and two behavioral (interflash interval and semantic differential) indices of conditioning were obtained during an extinction procedure, and demonstrated significant differences between CRs in Experiment II, but none in Experiment III. VEP amplitudes to positive and negative CSs were enhanced in Experiment II, and suppressed in Experiment I, in comparison to the neutral CS. This effect was most marked in responses to the negative CS. It is suggested that level of awareness of the CS–UCS contingency might be reflected in our physiological index of conditioning - VEP amplitude.
Thermal Conductivity of Doped and Pure Cadmium Sulfide

The thermal conductivity as a function of temperature has been measured from 1.4 to 80\ifmmode^\circ\else\textdegree\fi{}K for doped and pure cadmium sulfide single crystals. The experimental results for the pure crystals indicate that the thermal conductivity is isotropic and can be successfully analyzed using the Debye thermal conductivity integral. Isoelectronic, substitutional impurities (Co, Mn, Ni, Se, and Zn) were introduced in the melt in concentrations up to 500 ppm. The Debye integral, assuming phonon scattering by dislocations as well as the impurities, gives a good fit to the experimental data for all but the Se-doped crystal. Phonon scattering by magnetic levels was also considered and may explain the low-temperature depression of the thermal conductivity in the 500-ppm Co-doped sample.
The Kansas Academy of Science - Née State Natural History Society

There were several involved and responsible for founding the organization. The ‘founding fathers’ were John D. Parker, a Congregational minister, natural scientist, and the instigator, Francis H. Snow, a natural scientist and strong advocate, with support from Benjamin F. Mudge, a lawyer with interest in natural science, and John Fraser, military general and mathematician (Bonwell, 1969; Merriam, 2012). All were associated with universities Parker at Lincoln (Washburn) College in Topeka, Snow and Fraser at KU in Lawrence, and Mudge at Kansas State Agriculture College (K-State) in Manhattan.
Iron chelators and iron toxicity.

Abstract Iron chelation may offer new approaches to the treatment and prevention of alcoholic liver disease. With chronic excess, either iron or alcohol alone may individually injure the liver and other organs. In combination, each exaggerates the adverse effects of the other. In alcoholic liver disease, both iron and alcohol contribute to the production of hepatic fibrosis through their effects on damaged hepatocytes, hepatic macrophages, hepatic stellate cells, and the extracellular matrix. The pivotal role of iron in these processes suggests that chelating iron may offer a new approach to arresting or ameliorating liver injury. For the past four decades, deferoxamine B mesylate has been the only iron-chelating agent generally available for clinical use. Clinical experience with deferoxamine has demonstrated the safety and effectiveness of iron chelation for the prevention and treatment of iron overload. Determined efforts to develop alternative agents have at last resulted in the development of a variety of candidate iron chelators that are now in or near clinical trial, including (a) the hexadentate phenolic aminocarboxylate HBED [ N , N ′-bis(2-hydroxybenzyl)ethylenediamine- N , N ′-diacetic acid], (b) the tridentate desferrithiocin derivative 4′-OH-dadmDFT [4′-hydroxy-( S )-desazadesmethyl-desferrithiocin; ( S )-4,5-dihydro-2-(2,4-dihydroxyphenyl)-4-thiazolecarboxylic acid], (c) the tridentate triazole ICL670A [CGP72 670A; 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid], and (d) the bidentate hydroxypyridin-4-one deferiprone [L1, CP20; 1,2-dimethyl-3-hydroxypyridin-4-one]. These agents may provide new pharmacological means of averting or ameliorating liver damage in alcoholic liver disease by binding, inactivating, and eliminating the reactive forms of iron that contribute to oxidative injury of cellular components, are involved in signal transduction, or both.
Time-resolved observations of water oxidation intermediates on a cobalt oxide nanoparticle catalyst

In any artificial photosynthetic system, the oxidation of water to molecular oxygen provides the electrons needed for the reduction of protons or carbon dioxide to a fuel. Understanding how this four-electron reaction works in detail is important for the development of improved robust catalysts made of Earth-abundant materials, like first-row transition-metal oxides. Here, using time-resolved Fourier-transform infrared spectroscopy and under reaction conditions, we identify intermediates of water oxidation catalysed by an abundant metal-oxide catalyst, cobalt oxide (Co3O4). One intermediate is a surface superoxide (three-electron oxidation intermediate absorbing at 1,013 cm(-1)), whereas a second observed intermediate is attributed to an oxo Co(IV) site (one-electron oxidation intermediate absorbing at 840 cm(-1)). The temporal behaviour of the intermediates reveals that they belong to different catalytic sites. Knowledge of the structure and kinetics of surface intermediates will enable the design of improved metal-oxide materials for more efficient water oxidation catalysis.
Atmospheric Excitation of the Earth's Wobble

Summary Hassan (1960) has computed mean monthly values of the atmosphere's moments and products of inertia for the period 1873 to 1950, using all available station-level pressures. On the basis of these time series the excitation of the seasonal and 14-month (Chandler) wobble is discussed. With respect to the seasonal wobble, our calculations confirm the conclusion by Jeffreys and others that it is due largely to atmospheric excitation. By working directly with station-level pressures we have avoided the procedure followed previously of removing the sea-level correction from sea-level pressure charts (thus “uncorrecting” for a large and undesirable correction). Our amplitudes are 25 per cent smaller than those given by Jeffreys (1959). With respect to the Chandler wobble, it has been suggested by Jeffreys (1940), Rudnick (1956), and by Munk & MDonald (1960) that this represents a resonance amplification of the irregular (nonseasonal) variation in atmospheric inertia. The computed spectral density of the atmospheric variation at the Chandler frequency falls short by one to two orders of magnitude to meet the requirement of this hypothesis. Excitation by irregular motion in the core is briefly considered. Here the electromagnetic coupling (limited by conductivity in the lower mantle) appears to be far too weak to account for the observed wobble. The excitation of the Chandler wobble must be considered an unsolved problem.
A brief overview of executive stock options in reducing the agency problem of excessive risk aversion

Purpose – The purpose of this paper is to discuss how executive stock options help in reducing agency costs in the firm and to address problems experienced by the firm when stock options are used as incentives. Design/methodology/approach – The paper initially discusses types of agency problems caused by company managers and then explains why stock options can reduce the problem of excessive risk aversion displayed by some managers. It then addresses the problems that may occur with the introduction of executive stock options by the firm and finally offers methods to reduce these problems. Findings – The paper explains the methods available to reduce the problems caused by executive stock options such as indexing the stock options to the S&P 500 index and structuring the Board of Directors in a manner that helps ensure the stock options are used appropriately. Originality/value – This paper is valuable to firms using executive stock options as incentives to managers. It outlines the problems stock options can help solve and the problems which may occur by their use. In addition, the ways to reduce the problems produced by executive stock options in the firm are discussed.
Nanotechnology in cancer prevention, detection and treatment: bright future lies ahead

This paper is an overview of advances and prospects in applications of nanotechnology for cancer prevention, detection and treatment. We begin with a brief description of the underlying causes of cancer. Then we address preventive treatment, disease-time treatment, and diagnosis in the context of some of the most recent advances in nanotechnology. Nanoparticle science is also briefly addressed as the foundation upon which most nanotechnology cancer therapy is based. It is demonstrated how nanotechnology can help solve one of the most challenging and longstanding problems in medicine, which is how to eliminate cancer without harming normal body tissue.
Inhibition of purine nucleoside phosphorylase by 8-aminoguanosine: selective toxicity for T lymphoblasts

The guanosine analog 8-aminoguanosine is an effective inhibitor of the purine degradative enzyme purine nucleoside phosphorylase, both in vitro and in intact lymphoid cells. In a human lymphoblast tissue culture system, 8-aminoguanosine, in combination with low concentrations of 2'-deoxyguanosine, causes toxicity toward T cells but not B cells. The selective T cell toxicity correlates with increased accumulation of deoxyguanosine triphosphate in the treated T lymphoblasts.
On the occurrence of substitutional and triple defects in intermetallic phases with the B2 structure

Abstract Theoretical models for the thermodynamic properties of intermetallic B2 phases are employed to explain a priori the empirical observation that B2 phases with a small enthalpy of formation exhibit substitutional defects, whereas B2 phases with a large enthalpy of formation exhibit triple defects. The following expressions for the concentration of anti-structure atoms (NβA/N) as a function of the enthalpy of formation ΔH∝ of the stoichiometric compound, the enthalpy of formation of vacancies ΔHv, and the temperature T, are derived: substitutional defects: (NβA/N)s = 0.5 exp[(ΔH∝)(2/RT)] triple defects: (N β A /N) t = 0.315 exp [( 2 3 ΔH ∝ − 1 3 ΔH v )2/RT)] . These equations indicate that the formation of substitutional defects, which depends solely on ΔH∝, becomes more difficult with increasing ΔH∝. On the other hand, the formation of triple defects, which depends on both ΔH∝ and ΔHv, becomes comparatively easier, assuming that ΔHv has approximately the same value for all B2 phases. It is predicted that some B2 phases might exhibit a hybrid behavior, with both defect types occurring in comparable concentrations.
Discharge-Chamber Sputtering in Mercury Ion Thrusters

Discharge-chamber sputter erosion has been investigated in two electron-bombardment mercury ion thrusters at 8-cm and 12-cm beam diameter (respectively, the SIT-8 and the SIT-12 thrusters). Sputter erosion is found to be concentrated primarily on the screen electrode and is due primarily to singly charged mercury ions, Hg + . A model of discharge-cha mber sputter-erosion has been developed that predicts erosion rates that are in good agreement with observed rates. A three fold reduction in the rate of total mass erosion has been achieved in both the SIT-8 and SIT-12 thrusters by biasing the thruster shell (including screen electrode) at keeper potential rather than at cathode potential. PUTTER erosion of discharge-cha mber surfaces has been identified as an important life-limiting process in electron- bombardment mercury ion thrusters.1'2 Present mercury thruster designs incorporate features that reduce the failure hazard posed by sputter erosion3; these measures appear to be adequate for small (8-cm-diameter) thrusters, but further improvement is needed in large (30-cm-diameter) thrusters intended for primary-propulsion application. Details of the discharge processes that cause sputter erosion have, however, remained largely unexplored. This paper describes the results of an investigation of discharge-cha mber sputter erosion and the development of several analytical and diagnostic tools that have been used to advantage in this investigation. In addition, a straightforwar d modification in discharge-cha mber design is described that has resulted in a three fold reduction in the rate of total mass erosion measured in operation of an 8-cm and a 12-cm mercury ion thruster. of the ion thruster fires downward into a frozen mercury collector, which was installed to avoid the experimental uncertainties that might result from backsputtering of nonvolatile material from a conventional solid-metal collector. Typical facility pressures (with an operating thruster) are in the range of 1 to 5 x 10 ~4 Pa. Several of the most important diagnostic measurements are described in greater detail in the following.
The Derivatives Revolution After Thirty Years

The growth of derivatives of all kinds, exchange-traded as well as over-the-counter deals, has been phenomenal during the last thirty years. Derivatives have grown because they have offered a cheap way of managing the risks that have plagued businesses for decades, if not centuries. The emergence of the whole new derivatives industry should be particularly gratifying to academics because academic research, so often derided as useless and impractical, has played such a major role in its development.
The Lincoln‐Douglas debates revisited: The evolution of public argument

The Lincoln‐Douglas debates of 1858 are models not of statesmanship and eloquence, as is sometimes thought, but of strategies and tactics of rhetorical invention in the context of the public forum. The debates were marked by four patterns of argument: conspiratorial, legal, historical, and moral. The dynamics of each pattern are explored and speculations are offered about the transformation of controversial questions in the crucible of public debate.
Efficient Estimation With Panel Data When Instruments Are Predetermined: An Empirical Comparison of Moment-Condition Estimators

I examine the empirical performance of instrumental variables estimators with predetermined instruments in an application to life-cycle labor supply under uncertainty. The estimators studied are two-stage least squares, generalized method-of-moments (GMM), forward filter, independently weighted GMM, and split-sample instrumental variables. I compare the bias/efficiency trade-off for the estimators using bootstrap algorithms suggested by Freedman and by Brown and Newey. Results indicate that the downward bias in GMM is quite severe as the number of moment conditions expands, outweighing the gains in efficiency. The forward-filter estimator, however, has lower bias and is more efficient than two-stage least squares.
Mechanism of PKR Activation: Dimerization and Kinase Activation in the Absence of Double-stranded RNA

The kinase PKR is a central component of the interferon antiviral pathway. PKR is activated upon binding double-stranded (ds) RNA to undergo autophosphorylation. Although PKR is known to dimerize, the relationship between dimerization and activation remains unclear. Here, we directly characterize dimerization of PKR in free solution using analytical ultracentrifugation and correlate self-association with autophosphorylation activity. Latent, unphosphorylated PKR exists predominantly as a monomer at protein concentrations below 2 mg/ml. A monomer sedimentation coefficient of s(20,w)(0)=3.58 S and a frictional ratio of f/f(0)=1.62 indicate an asymmetric shape. Sedimentation equilibrium measurements indicate that PKR undergoes a weak, reversible monomer-dimer equilibrium with K(d)=450 microM. This dimerization reaction serves to initiate a previously unrecognized dsRNA-independent autophosphorylation reaction. The resulting activated enzyme is phosphorylated on the two critical threonine residues present in the activation loop and is competent to phosphorylate the physiological substrate, eIF2alpha. Dimer stability is enhanced by approximately 500-fold upon autophosphorylation. We propose a chain reaction model for PKR dsRNA-independent activation where dimerization of latent enzyme followed by intermolecular phosphorylation serves as the initiation step. Subsequent propagation steps likely involve phosphorylation of latent PKR monomers by activated enzyme within high-affinity heterodimers. Our results support a model whereby dsRNA functions by bringing PKR monomers into close proximity in a manner that is analogous to the dimerization of free PKR.
Phonon-induced spectral linewidths in crystals

Abstract The phonon-induced linewidths of spectral lines in paramagnetic crystals have been calculated. The agreement between theory and experiment is good.
2,6-Di(pyrimidin-4-yl)pyridine Ligands with Nitrogen-Containing Auxiliaries: The Formation of Functionalized Molecular Clefts upon Metal Coordination

A series of ligands (1−4) based on a 2,6-di(pyrimidin-4-yl)pyridine scaffold have been synthesized, and their abilities to form complexes with Zn(II) and Cu(II) have been determined using UV/vis spectroscopy in buffered aqueous solution (0.01 M N-[2-hydroxyethyl]piperazine-N‘-[3-ethanesulfonic acid] (HEPES) at pH = 6.8). The Zn(II) complex of 1 was determined to have a formation constant of 8.4 × 103 M-1 while the formation constant of the Cu(II) complex was found to be 1 × 106 M-1. The presence of auxiliary amines in 2 increased the stability of the Zn(II) complex relative to that of 1 by a factor of over 40, suggesting possible coordination of the auxiliaries to the Zn(II) center. The guanidinium and 2-amino-4,5-dihydro-imidazolinium groups of 3 and 4 considerably diminished the stability of the Zn(II) and Cu(II) complexes relative to those of 1. X-ray crystal structures of 1-Zn, 3-Zn, 4, and 4-Zn were obtained and are discussed. A significant increase in the stability of 3-Zn, but not in the stability ...
Three Dimensional Profile Simulation For Positive Photoresists

E. Barouch, B. Bradie and S.V. BabuClarkson University, Departments of Mathematics and Computer Science and Chemical EngineeringPotsdam, New York 13676ABSTRACTThe least action principle algorithm is extended to model the development of a three dimensional latentimage in an exposed resist The photoactive compound (PAC) concentration is determined in a model resistfilm from the exact solution of Dill's equations for the exposure -bleaching process for the case of a matchedsubstrate. The procedure is valid for all mask shapes and is illustrated with an elliptical symmetry imposedupon the incident light intensity. Utilizing these PAC gradients, the three dimensional least action principlealgorithm is employed to compute developed resist profiles.1. INTRODUCTIONAccurate simulation of developed positive photoresist profiles is an integral part of the optimizationprocess for improved photoresist performance in VLSI lithography. For two dimensional profile simulations,the two most widely used general lithographic simulation systems, SAMPLE1 and PROLITH2, employ thestring development algorithm3. Recently, a new development algorithm, which is based upon the principle
On fuzzy preference relations

Triangular norms, conorms, and negation functions are used as interpretations for propositional connectives in a multiple-valued logic model for fuzzy binary relations of weak preference, strict preference, and indifference. It is shown that the Law of Contradiction is a necessary condition for the very existence of reflexive transitive fuzzy binary relations. Basic properties of indifference and strict preference relations are established including transitivity of a strict preference.
Quasi-Newton full-waveform inversion with a projected Hessian matrix

ABSTRACTWe present a method, in realistic-size full-waveform inversion (FWI), to explicitly construct a projected Hessian matrix and its inverse matrix, which we subsequently used to solve FWI with a quasi-Newton method. Newton’s method is practically unfeasible in solving realistic-size FWI problems because of the prohibitive cost (computing time and memory consumption) of calculating the Hessian matrix and the inverse Hessian. Therefore, the Gauss-Newton method and various quasi-Newton methods are proposed to approximate a Hessian matrix. Particularly, current quasi-Newton FWI (QNFWI) commonly uses the limited-memory BFGS (L-BFGS) method, which, however, only implicitly approximates an inverse Hessian. We repose FWI as a sparse optimization problem in a sparse model space, which contains substantially fewer model parameters that are constrained by structures of the model. With respect to fewer parameters in the sparse model, we can avoid the “limited-memory” approximation and are able to explicitly comp...
Two adenovirus mRNAs have a common 5′ terminal leader sequence encoded at least 10 kb upstream from their main coding regions

Abstract The messenger RNAs encoding two late adenovirus serotype 2 (Ad2) proteins, fiber and 100K, were purified by hybridization to restriction endonuclease fragments of Ad2 DNA followed by electrophoresis on polyacrylamide gels containing 98% formamide. The 5′ terminal oligonucleotides generated by RNAase T1 digestion of the messengers were selected by dihydroxyboryl-cellulose chromatography. Both mRNAs gave an identical 5′-undecanucleotide with the general structure 7mG 5′ ppp 5′ A m C (m) U(C 4 ,U 3 )G. This undecanucleotide could be removed by mild RNAase treatment from the mRNA after hybridization to DNA fragments containing the main coding sequence of the messenger. In contrast, a small region defined by Bal I-E (14.7–21) protects this undecanucleotide from RNase. A second region contained within both Hind III-B (17–31.5) and Hpa I-F (25.5–27.9), although unable to protect the undecanucleotide, hybridizes to both fiber and 100K mRNAs and protects a similar sequence of 100–150 nucleotides. These observations suggest that both mRNAs contain a long common sequence, complementary to at least two different sites on the Ad2 genome remote from the start of these two genes. The implications of these findings are discussed, and a general mechanism is presented for the biosynthesis of mRNAs from larger precursor molecules, based on intramolecular ligation.
Cervical spine fractures in the elderly

Background Cervical spine fractures in the elderly are relatively common. The management of such injuries may be complicated by underlying medical debility and osteopenia as well as reduced tolerance to halo immobilization. Methods Over a 1-year period, 43 cervical spine fractures were treated at our institution. Ten (23%) were in persons 70 years of age or older. This retrospective analysis describe the clinical features, treatment, and outcome of these 10 elderly patients. All fractures in this patient population involved the atlantoaxial complex, including five combination C1-C2 fractures. Six patients were treated with early halo immobilization and three were initially managed with a rigid cervical collar. Three patients required posterior cervical fusion. Results Of the six patients undergoing halo immobilization, five progressed to osseous union. Three patients were immobilized in a Philadelphia collar resulting in one osseous union, one nonunion, and one death. Three patients underwent posterior cervical fusion with subsequent osseous union in all three. Conclusions Although external immobilization with a halo device is our treatment of choice for most C1 and C2 fractures in elderly patients, a Philadelphia collar is useful in select cases when halo immobilization or early surgical fusion is contraindicated. Posterior cervical fusion can be safely and effectively performed in elderly patients and should be strongly considered for initial therapy in the elderly with fracture types unlikely to progress to osseous union with external immobilization alone.
Pim-2 phosphorylation of p21Cip1/WAF1 enhances its stability and inhibits cell proliferation in HCT116 cells

Abstract Pim-2 kinase is one of the three highly conserved Pim family members which are known to be involved in cell survival and cell proliferation. Here we demonstrate that like Pim-1, Pim-2 also phosphorylates the cell cycle inhibitor p21Cip1/WAF1 (p21) on Thr145 in vitro and in vivo. Overexpression of Pim-2 in HCT116 cells leads to the increased stability of p21 and results in enhanced levels of both exogenous and endogenous p21 proteins. Knockdown of Pim-2 expression via siRNA results in reduced level of endogenous p21, indicating that like Pim-1, Pim-2 is another legitimate p21 kinase. However, Pim-2 has no influence on the nuclear localization of p21 in HCT116 cells. In addition, Pim-2 is able to arrest the cell cycle at G1/S phase and inhibit cell proliferation through phosphorylation of p21 in HCT116 cells. These data suggest that Pim-2 phosphorylation of p21 enhances p21's stability and inhibits cell proliferation in HCT116 cells.
Multi-angle fast neutron time-of-flight system

Abstract A multi-angle fast neutron time-of-flight system operating in the nsec range is described. The system consists of: a. up to ten simultaneously operational detectors situated at scattering angles of 20° to 150° and at flight paths of 1.5 to 3.5 m; b. analog circuit components inclusive of time-to-pulse height converters and neutron-gamma-ray discriminators; c. information routing and gating circuitry; d. multi-dimensional analog to digital conversion apparatus; e. a dual digital computer configuration and f. a pulsed and bunched Van de Graaff accelerator. The system concept, components, operation including on-line information storage, processing, automated control, and off-line data processing are discussed. Examples of representative experimental applications are given.
Lightweight power aware and scalable movement monitoring for wearable computers: a mining and recognition technique at the fingertip of sensors

Activity monitoring using Body Sensor Networks(BSN) has gained much attention from the scientific community due to its recreational and medical applications. Suggested techniques for activity monitoring face two major problem. First, systems have to be trained for the individual subjects due to the heterogeneity of the BSN data. While most solutions can address this problem on a small data set, they have no mechanics for automatic scaling of the solution as the data set increases. Second, the battery limitations of the BSN severely limit the maximum deployment time for the continuous monitoring. This problem is often solved by shifting some processing to the local sensor nodes to avoid a very heavy communication cost. However, little work has been done to optimize the sensing and processing cost of the action recognition. In this paper, we propose an action recognition approach based on the BSN repository. We show how the information of a large repository can be automatically used to customize the processing on sensor nodes based on a limited and automated training process. We also investigate the power cost of such a repository mining approach on the sensor nodes based on our implementation. To assess the power requirement, we define an energy model for data sensing and processing. We demonstrate the relationship between the activity recognition precision and the power consumption of the system during continuous action monitoring. We demonstrate the energy effectiveness of our approach with a classification accuracy constraint based on limited data repository.