cssi/SciSciGPT-SciSciNet huggingface dataset:
Linear and hyperbranched polycarbosilanes with Si-CH2-Si bridging groups: a synthetic platform for the construction of novel functional polymeric materials

Work carried in the authors’ laboratory on Si‐ CH2‐Si bridged polycarbosilanes is reviewed. In pursuit of high-yield polymeric precursors to silicon carbide, convenient synthetic routes to both linear and hyperbranched polycarbosilanes having a ‘[SiH2CH2]n’ compositional formula have been developed. The linear [SiH2CH2]n polymer was prepared by ring-opening polymerization of a substituted disilacyclobutane, and was studied both as an analogue of polyethylene and as a high-yield precursor to SiC. Elaboration of the methods employed to prepare this polymer has yielded a wide range of new poly(silylenemethylene)s (PSMs) of the type [SiRR’CH2]n, where R and R’ can be a wide range of different groups, including a series of symmetrically disubstituted polymers with R=R ’= F, alkyl and alkoxy which form crystalline solid phases and various amorphous, atactic polymers having different R and R’ groups. By using (Si)‐Cl replacement reactions analogous to those developed previously for polydichlorophosphazene, as well as hydrosilation reactions similar to those used for [Si(H)(Me)O]n, a series of side-chain polymers having various groups attached to Si through Si‐C or Si‐O bonded linkages were obtained. Similar polymer modification reactions have recently been developed for the branched oligomer/polymer analogue of these linear polycarbosilanes, leading to hyperbranched species with functional substituents, including a di(ethyleneoxy) methyl ether-terminated derivative which readily dissolves lithium salts. The results of studies of these novel ‘inorganic/organic’ hybrid polycarbosilanes are described and their properties are compared with those of related carbon-backbone and siloxane polymers. # 1998 John Wiley & Sons, Ltd.
Alkali metal ion mediated cyclization of 4,4'-(3,6-dioxaocta-1,8-diyloxy)-bis(benzophenone)

Abstract The effect of alkali metal ions on the ratio of cyclization to polymer formation was investigated. The presence of potassium ions enhances the formation of macrocycles, while lithium ions suppress the reaction.
On winds in the upper atmosphere

The observations of the drift of meteor-trains have been summarized by Trowbridge (Mon. Weath. Rev., v. 35, 390, 1907), and by Kahlke (Ann. Hydrogr., v. 49, 294, 1921). Data of 74 trains in the northern hemisphere were assembled which showed that in the atmospheric levels from about 30 to 80 km there prevails an easterly wind in the late afternoon, and that at night in the levels from about 80 to 110 km westerly winds predominate in November and August; during other months the winds are either variable or the data are too fragmentary to permit trustworthy conclusions. The observations afford on the whole only a glimpse of air circulation in the upper atmosphere. One would like to know more about it and further observations of meteor-trains would be of great interest.
2-Cyanoethylzinc iodide: A new reagent with reactivity umpolung

Abstract 2-Cyanoethylzinc iodide 1 generated in over 90% yield from 3-iodopropionitrile and zinc in THF can be transmetallated to the copper and titanium derivatives 3 and 4 which react in good yields, respectively, with acyl chlorides, enones, allylic halides and benzaldehyde.
Scalar absorption and the breaking of the world-volume conformal invariance

Abstract We investigate a version of fixed scalars for nondilatonic branes which correspond to dilatations of the brane world-volume. We obtain a cross section whose world-volume interpretation falls out naturally from an investigation of the breaking of conformal invariance by the irrelevant Born-Infeld corrections to Yang-Mills theory. From the same irrelevant world-volume operator we obtain the leading correction to the cross sections of minimal scalars. This correction can be obtained in supergravity via an improved matching of inner and outer solutions to the minimal wave equation.
COMPUTER GRAPHICS IN SIMULATION OF CARDIOVASCULAR TRANSPORT PHENOMENA.

Abstract Simulation is a necessary tool if we are to understand better the complexities involved in cardiovascular transport. While some of the phenomena modeled can be described analytically, perusal of the equations alone often doesn't result in full appreciation of the model system. It therefore becomes pertinent to utilize computer graphics in order to enhance simulation of physiologic transport processes. Graphic representation not only facilitates interaction between the investigator and the simulation, it provides a juxtaposition of the model to the real system, as well as a simplification of relationships between various features of the model. Increased mathematical sophistication required in the investigation of cardiovascular transport phenomena often makes traditional graphic representation cumbersome. Therefore several different types of graphics have been utilized, including 2-, 3-, and 4-dimensional displays. The methods and algorithms for these displays have been generalized to make them easy to use over a broad spectrum of applications. In some cases we have generated motion pictures of sequential model solutions which have increased and accelerated model comprehension, as well as been valuable for teaching purposes.
A Flat Photoionization Rate at 2 ≤ z ≤ 4.2: Evidence for a Stellar-Dominated UV Background and against a Decline of Cosmic Star Formation beyond z ~ 3

We investigate the implications of our measurement of the Lyα forest opacity at redshifts -->2 ≤ z ≤ 4.2 from a sample of 86 high-resolution quasar spectra for the evolution of the cosmic ultraviolet luminosity density and its sources. The derived hydrogen photoionization rate Γ is remarkably flat over this redshift range, implying an increasing comoving ionizing emissivity with redshift. Because the quasar luminosity function is strongly peaked near -->z ~ 2, star-forming galaxies likely dominate the ionizing emissivity at -->z 3. Our measurement argues against a star formation rate density declining beyond -->z ~ 3, in contrast to existing state-of-the-art determinations of the cosmic star formation history from direct galaxy counts. Stellar emission from galaxies therefore likely reionized the universe.
Synthetic studies directed toward streptenol D: enantioselective preparation of the 3,5-diacetoxy-6E,8E-decadiene segment

Abstract The enantioselective preparation of 2-(3′ R ,5′ R -diacetoxy-6 E ,8 E -decadienyl)-1,3-dioxane, (+)- 13 , is described. This synthesis of the skeleton of streptenol D utilizes the ability of a diene-complexed (tricarbonyl)iron unit to serve as a protecting and stereodirecting functionality.
ATP excites a subpopulation of rat dorsal horn neurones

Abstract 1. Intracellular recordings were made from dorsal horn neurones grown in dissociated cell culture for periods of 4–12 weeks. 2. Results showed that a subpopulation of dorsal horn neurones that are likely to be involved in the processing and regulation of sensory stimuli were potently and selectively excited by ATP. 3. In dissociated cell culture, the identification and origin of dorsal hown neurones that respond to ATP were unclear.
Effect of Non-equilibrium Surface Thermochemistry in Simulation of Carbon Based Ablators

This study demonstrates that coupling of a material thermal-response code and a flow solver using a nonequilibrium gas/surface-interaction model provides time-accurate solutions for the multidimensional ablation of carbon-based charring ablators. The material thermal-response code used in this study is the two-dimensional implicit thermal response and ablation program, which predicts the charring-material thermal response and shape change on hypersonic space vehicles. Its governing equations include total energy balance, pyrolysis-gas mass conservation, and a three-component decomposition model. The flow code solves the reacting Navier–Stokes equations using the data-parallel-line-relaxation method. Loose coupling between the material-response and flow codes is performed by solving the surface mass balance in the flow code and the surface energy balance in the material-response code. Thus, the material surface recession is predicted by finite rate gas/surface-interaction boundary conditions implemented in...
Immigrant earnings, relative to what? The importance of earnings function specification and comparison points

Immigrant relative earnings estimates are sensitive to the choice of comparison point and the specification of earnings. Non-sample mean comparisons (Borjas, 1985) understate relative earnings. Simple earnings specifications (linear education, quadratic experience) overstate relative earnings for both poorly and well-educated immigrants. Specifications which ignore omitted variables understate the relative earnings of poorly educated immigrants and overstate those of well-educated ones. Although measures of assimilation and changes in immigrant quality are insensitive to earnings specification, they indicate strong earnings growth for post-1964 immigrants, an overall decrease in immigrant quality, and an increase in Mexican immigrant quality.
Young red supergiants and the near-infrared light appearance of disk galaxies

Disk galaxies often show prominent nonaxisymmetric features at near-infrared (NIR) wavelengths. Such features may indicate variations in the surface density of stellar mass, contributions from young red supergiants in star-forming regions, or substantial dust obscuration. To distinguish among these possibilities, we have searched for spatial variations in the 2.3 μm photometric CO index within the disks of three nearby galaxies (NGC 278, NGC 2649, and NGC 5713). This index measures the strength of the absorption bands of molecular CO in stellar atmospheres and is strong in cool, low surface gravity stars, reaching the largest values for red supergiants. We observe significant spatial CO index variations in two galaxies (NGC 278 and NGC 5713), indicating that the dominant stellar population in the NIR is not everywhere the same. Central CO index peaks are present in two galaxies; these could be due to either metallicity gradients or to recent star formation activity. In addition, significant azimuthal CO index variations are observed in NGC 278. Because strong azimuthal metallicity gradients are physically implausible in disk galaxies, these features are most naturally explained by the presence of a young stellar population. The fraction of 2 μm light due to young stellar populations in star-forming regions can be calculated from our data. Overall, young stellar populations can contribute ~3% of the NIR flux of a (normal) galaxy, which is consistent with other global properties (e.g., the near-IR Tully-Fisher relation). Locally, this fraction may rise to ~33%. Thus, young stars do not dominate the total NIR flux, but can be locally dominant in star-forming regions, and can bias estimates of spiral arm amplitude or other nonaxisymmetric structures in galaxies' mass distributions.
Asymmetric Synthesis of α-Amino Allyl, Benzyl, and Propargyl Silanes by Metalation and Rearrangement

Metalation of a Boc-protected N-silylamine α to nitrogen results in migration of the silicon from nitrogen to carbon (reverse aza-Brook rearrangement), yielding an α-amino silane. The Boc group acts initially as a metalation-directing group and then to stabilize the nitrogen anion, providing a driving force for the rearrangement. In the presence of (−)-sparteine, the new chiral center is formed in >90% ee from allyl, benzyl, and propargylamines.
Does Judicial Efficiency Lower the Cost of Credit

The authors investigate the effect of judicial efficiency on banks' lending spreads for a large cross section of countries. They measure bank interest rate spreads for 106 countries at an aggregate level, and for 32 countries at the level of individual banks. The authors find that-after controlling for a number of other country characteristics-judicial efficiency, in addition to inflation, is the main driver of interest rate spreads across countries. This suggests that in addition to improving the overall macroeconomic climate in a country, judicial reforms, through a better enforcement of legal contracts, are critical to lowering the cost of financial intermediation for households and firms.
Mathematics of gravitational lensing: multiple imaging and magnification

The mathematical theory of gravitational lensing has revealed many generic and global properties. Beginning with multiple imaging, we review Morse-theoretic image counting formulas and lower bound results, and complex-algebraic upper bounds in the case of single and multiple lens planes. We discuss recent advances in the mathematics of stochastic lensing, discussing a general formula for the global expected number of minimum lensed images as well as asymptotic formulas for the probability densities of the microlensing random time delay functions, random lensing maps, and random shear, and an asymptotic expression for the global expected number of micro-minima. Multiple imaging in optical geometry and a spacetime setting are treated. We review global magnification relation results for model-dependent scenarios and cover recent developments on universal local magnification relations for higher order caustics.
Interactive graphics nonlinear constrained optimization

Abstract An interactive computer graphics environment is used to perform nonlinear constrained optimization analysis. It is found that by combining the power of a digital computer with the subtility of engineering judgment—during program execution—final results can be substantially better than the ones achieved by the numerical algorithm by itself.
The Han-Kobayashi region for a class of Gaussian interference channels with mixed interference

A simple encoding scheme based on Sato's non-na¨ive frequency division is proposed for a class of Gaussian interference channels with mixed interference. The achievable region is shown to be equivalent to that of Costa's noiseberg region for the onesided Gaussian interference channel. This allows for an indirect proof that this simple achievable rate region is indeed equivalent to the Han-Kobayashi (HK) region with Gaussian input and with time sharing for this class of Gaussian interference channels with mixed interference.
Gauge symmetry in background charge conformal field theory

Abstract We present a mechanism to construct four-dimensional charged massless Ramond states using the discrete states of a fivebrane Liouville internal conformal field theory. This conformal field theory has background charge, and admits an inner product which allows positive norm states. A connection among supergravity soliton solutions, Liouville conformal field theory, non-critical string theory and their gauge symmetry properties is given. A generalized construction of the SU (2) super Kac-Moody algebra mixing with the N = 1 super Virasoro algebra is analyzed. How these Ramond states evade the DKV no-go theorem is explained.
Dynamic sculpting and animation of free-form subdivision solids

This paper presents a sculptured solid modeling system founded upon dynamic Catmull-Clark subdivision-based solids of arbitrary topology. Our primary contribution is that we integrate the geometry of sculptured free-form solids with the powerful physics-based modeling framework by augmenting pure geometric entities with material properties such as mass, damping, and stiffness distributions and with physical behaviors such as elasticity, plasticity, and natural deformation under external forces. Our novel dynamic model of free-form solids frees users from having to deal with low-level central point operations and permits them to interact with subdivision-based virtual clay in a more natural and intuitive fashion via "forces".
Redshifts for 2410 Galaxies in the Century Survey Region

The Century Survey strip covers 102 deg2 within the limits 85 ≤ α ≤ 165, 290 ≤ δ ≤ 300, equinox B1950.0. The strip passes through the Corona Borealis supercluster and the outer region of the Coma cluster. Within the Century Survey region, we have measured 2410 redshifts that constitute four overlapping complete redshift surveys: (1) 1728 galaxies with Kron-Cousins Rph ≤ 16.13 covering the entire strip, (2) 507 galaxies with Rph ≤ 16.4 in right ascension range 8h32m ≤ α ≤ 10 h45m, equinox B1950.0, (3) 1251 galaxies with absorption- and K-corrected RCCDc ≤ 16.2 (where "c" indicates "corrected") covering the right ascension range 85 ≤ α ≤ 135, equinox B1950.0, and (4) 1255 galaxies with absorption- and K-corrected VCCDc ≤ 16.7 also covering the right ascension range 85 ≤ α ≤ 135, equinox B1950.0. All these redshift samples are more than 98% complete to the specified magnitude limit. We derived samples 1 and 2 from scans of the POSS1 red (E) plates calibrated with CCD photometry. We derived samples 3 and 4 from deep V and R CCD images covering the entire region. We include coarse morphological types for all the galaxies in sample 1. The distribution of (V-R)CCD for each type corresponds appropriately with the classification.
What is the correct value for the brain--blood partition coefficient for water?

A knowledge of the brain-blood partition coefficient (γ) for water is usually required for the measurement of CBF with [15O]water. The currently accepted value for whole-brain Λ, 0.95–0.96 ml/g, calculated from brain and blood water content data, is incorrect because in the calculation, the blood water content was not adjusted for the density of blood. The correct value is 0.90 ml/g. Variations in brain or blood water content affect Λ. Thus, Λ changes during development of the brain and varies regionally in it, even among different gray matter structures, owing to variation in brain water content. In addition, Λ would be expected to vary with the hematocrit, owing to changes in blood water content. The impact of using an incorrect value for Λ will depend on the sensitivity of the CBF measurement technique used to errors in Λ.
DIFFERENTIATION OF GENUS PSEUDOMONAS AND RELATED AEROBIC BACTERIA

As an aid to ecological research of microorganisms, a differentiation of aerobic bacteria, mainly genus Pseudomonas, was studied. On 28 genera, 114 species and 350 strains of type cultures, cultural and biochemical characteristics, such as assimilation of nitrate, ammonium, glutamate, succinate, glucose, and p-hydroxy-benzoate, reaction to B. C. P. milk, formation of soluble pigments, coloration on nutrient agar slant etc., were tested. The results are shown on Table 3, and the author described a differential key of aerobic bacteria, which illustrated on Table 4. The bacteria belonged to Gram negative group, such as Pseudomonas, Achromobacter, Flavobacterium, Escherichia, Aerobacter etc., are biochemically simple, and would be differentiated by this key. On the other hand, the bacteria of Gram positive, such as Micrococcus, Sarcina, Brevibacterium, Bacillus etc., are nutritionally more complex than that of Gram negative group, and would not easily differentiated by this procedure. Furthermore, some problems of bacterial taxonomy were discussed on the basis of the relationship between bacterial flagellation and biochemical characteristics.
Fate of the sterile neutrino

Abstract In light of recent Super-Kamiokande data and global fits that seem to exclude both pure ν μ → ν s oscillations of atmospheric neutrinos and pure ν e → ν s oscillations of solar neutrinos (where ν s is a sterile neutrino), we reconsider four-neutrino models to explain the LSND, atmospheric, and solar neutrino oscillation indications. We argue that the solar data, with the exception of the 37 Cl results, are suggestive of ν e → ν s oscillations that average to a probability of approximately 1 2 . In this interpretation, with two pairs of nearly degenerate mass eigenstates separated by order 1 eV, the day-night asymmetry, seasonal dependence, and energy dependence for 8 B neutrinos should be small. Alternatively, we find that four-neutrino models with one mass eigenstate widely separated from the others (and with small sterile mixings to active neutrinos) may now be acceptable in light of recently updated LSND results; the 37 Cl data can be accommodated in this model. For each scenario, we present simple four-neutrino mixing matrices that fit the stated criterion and discuss future tests.
Ultraviolet spectropolarimetry of high-redshift quasars with the Hubble Space Telescope

Ultraviolet spectropolarimetry of three bright high-redshift low polarization quasars (LPQ's) was obtained with the Faint Object Spectrograph of the Hubble Space Telescope. Two of the quasars, PG 1634+706 and PG 2302+029, had polarizations of rho is approximately equal to 0.5-1.0 percent throughout the ultraviolet, and showed no significant variation of polarization amplitude or position angle with wavelength. PG 2302+029 was also marginally (2.4 sigma) circularly polarized in the optical continuum. For the highest redshift quasar, PG 1222+228 (Ton 1530), the polarization was measured down to rest wavelengths below 800 A. Although the continuum of PG 1222+228 was weakened by Lyman limit absorption from an intergalactic gas cloud, the polarization increased sharply from 1 percent to about 4.5 percent, a change of 4 sigma significance. This abrupt rise in polarization does not appear attributable to any known instrumental artifact. These UV polarizations were only slightly less than those previously observed for these same objects in the optical. The polarization spectra were flat with a typical slope of the polarized flux pF(sub upsilon) varies as upsilon(exp -0.8 plus or minus 0.5). Unlike the polarization spectra of several high luminosity Seyfert 1 nuclei studied previously, such a flat wavelength dependence of polarization cannot be explained by scattering from dust grains. The hypotheses that the polarization in these quasars is produced by transmission through aligned interstellar grains (in the Milky Way or the host galaxy), or by a synchrotron power law component, also appear to be ruled out. These observed spectra are consistent with a wavelength-independent polarization proportional to the total nonstellar light or, possibly, to the contribution of the blue thermal component.
Gravity-Induced Angular Motion of a Spinning Missile

Abstract : The usual analysis of the steady state angular motion of a dynamically stable spinning missile assumes a quasi-steady state calculation of a gravity-induced trim angle. A condition for the validity of this quasi-steady state assumption is derived. When this condition is not satisfied, the gravity- induced angular motion must be described differently for three distinct portions of the trajectory: the upleg, near apogee, and the downleg. The accuracy of this description is checked by comparison with numerical integrations. Finally the influence of cubic static and Magnus moments on the motion is determined and a revised point mass trajectory model is constructed.
Light hadronic physics using domain wall fermions in quenched lattice QCD

Abstract In the past year domain wall fermion simulations have moved from exploratory stages to the point where systematic effects can be studied with different gauge couplings, volumes, and lengths in the fifth dimension. Results are presented here for the chiral condensate, the light hadron spectrum, and the strange quark mass. We focus especially on the pseudoscalar meson mass and show that, in small volume, the correlators used to compute it can be contaminated to different degrees by topological zero modes. In large volume a nonlinear extrapolation to the chiral limit, e.g. as expected from quenched chiral perturbation theory, is needed in order to have a consistent picture of low energy chiral symmetry breaking effects.
Anisotropy of the third-order nonlinear-optical susceptibility in a degenerate-ground-state conjugated polymer: trans -(CH ) x

We present the results of a series of third-harmonic-generation (THG) measurements on the conjugated polymer polyacetylene which probe the magnitude and the origin of the third-order nonlinear-optical susceptibility of this material. By performing reflection THG measurements relative to a silicon standard, we have unambiguously determined the magnitude of the third-order susceptibility associated with tripling the fundamental of the Nd:YAG laser to be ${\ensuremath{\chi}}_{?}^{(3)}$(3\ensuremath{\omega};\ensuremath{\omega},\ensuremath{\omega},\ensuremath{\omega}/B) =(4\ifmmode\pm\else\textpm\fi{}2)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}10}$ esu, where ${\ensuremath{\chi}}_{?}^{(3)}$ refers to that component of the third-order susceptibility tensor with all indices parallel to the chain direction. By measuring anisotropic THG in oriented films, we have shown that this component dominates. The magntiude and anisotropy are directly compared with results obtained from single crystals of polydiacetylene-(toluene-sulfonate) measured in the same apparatus. Finally, we have measured THG in both cis-rich and trans isomers of the same sample. We found that the measured response of the cis-rich samples scales with the residual trans content of the sample; ${\ensuremath{\chi}}_{?}^{(3)}$ of the trans isomer is 15--20 times larger than that of the cis isomer. This symmetry-specific aspect of ${\ensuremath{\chi}}^{(3)}$ implies a mechanism which is sensitive to the existence of a degenerate ground state, as in trans-(CH${)}_{\mathrm{x}}$; it is consistent with the virtual generation of nonlinear solitons as a mechanism for the large measured third-order nonlinear-optical susceptibility of polyacetylene.
EpiChord: Parallelizing the Chord lookup algorithm with reactive routing state management

EpiChord is a DHT lookup algorithm that demonstrates that we can remove the O(log n)-state-per-node restriction on existing DHT topologies to achieve significantly better lookup performance and resilience using a novel reactive routing state maintenance strategy that amortizes network maintenance costs into existing lookups and by issuing parallel queries. Our technique allows us to design a new class of unlimited-state-per-node DHTs that is able to adapt naturally to a wide range of lookup workloads. EpiChord is able to achieve O(1)-hop lookup performance under lookup-intensive workloads, and at least O(log n)-hop lookup performance under churn-intensive workloads even in the worst case (though it is expected to perform better on average). Our reactive routing state maintenance strategy allows us to maintain large amounts of routing state with only a modest amount of bandwidth, while parallel queries serve to reduce lookup latency and allow us to avoid costly lookup timeouts. In general, EpiChord exploits the information gleaned from observing lookup traffic to improve lookup performance, and only sends network probes when necessary. Nodes populate their caches mainly from observing network traffic, and cache entries are flushed from the cache after a fixed lifetime. Our simulations show that with our approach can reduce both lookup latencies and path lengths by a factor of 3 by issuing only three queries asynchronously in parallel per lookup. Furthermore, we show that we are able to achieve this result with minimal additional communication overhead and the number of messages generated per lookup is no more than that for the corresponding sequential Chord lookup algorithm over a range of lookup work-loads. We also present a novel token-passing stabilization scheme that automatically detects and repairs global routing inconsistencies.
Sequence, genetic, and lacZ fusion analyses of a nifR3–ntrB–ntrC operon in Rhodobacter capsulatus

Transcription of Rhodobacter capsulatus genes encoding the nitrogenase polypeptides (nifHDK) is repressed by fixed nitrogen and oxygen. Regulatory genes required to sense and relay the nitrogen status of the cell are glnB, ntrB (nifR2), and ntrC (nifR1). R. capsulatus nifA1 and nifA2 require ntrC for activation when fixed nitrogen is limiting. The polypeptides encoded by nifA1 and nifA2 along with the alternate sigma factor RpoN activate nifHDK and the remaining nif genes in the absence of both fixed nitrogen and oxygen. In this study we report the sequence and genetic analysis of the previously identified nifR3-ntrB-ntrC regulatory locus. nifR3 is predicted to encode a 324-amino-acid protein with significant homology to an upstream open reading frame cotranscribed with the Escherichia coli regulatory gene, fis. Analysis of ntrC-lacZ fusions and complementation data indicate that nifR3 ntrBC constitute a single operon. nifR3-lacZ fusions are expressed only when lacZ is in the proper reading frame with the predicted nifR3 gene product. Tn5, a kanamycin-resistance cassette, and miniMu insertions in nifR3 are polar on ntrBC (required for nif transcription). This gene organization suggests that the nifR3 gene product may be involved in nitrogen regulation, although nifR3 is not stringently required for nitrogen fixation when ntrBC are present on a multicopy plasmid. In addition, a R. capsulatus strain with a 22-nucleotide insert in the chromosomal nifR3 gene was constructed. This nifR3 strain is able to fix nitrogen and activate nifA1 and nifA2 genes, again supporting the hypothesis that nifR3 is not stringently required for ntrC-dependent gene activation in R. capsulatus.
ANOMIE, SOCIAL CHANGE AND CRIME A Theoretical Examination of Institutional-Anomie Theory

Explicating Institutional-Anomie theory relative to the sociologies of Durkheim, Merton and Polanyi, I find that this theory goes beyond Merton by using a strain of thought that is critical of liberal society. By bringing in the notion of the disembedded market economy, a central notion in the institutionalism of Polanyi and Durkheim, this theory links crime, anomie, and contemporary social change. I also discuss some of the limitations of linking crime with societal level processes in a Durkheimian rather than Mertonian manner. The classical sociological notion of anomie has long been a conceptual tool to under stand the relationship between social structure, culture and deviant behaviour. Central to different versions of anomie theory is the premise that humans are normative beings. People act and think on the basis of commonly shared definitions and traditions. To a greater and lesser extent the common meanings that emerge in social life have senti mental value for people; they constitute morality and ethics. Shared cultural values define and sanction people's goals and the means they use in reaching the goals. Anomie results when the power of social values to regulate the ends and the means of human conduct is weakened. But anomie perspectives are not a unified body of theory. While Durkheim is usually seen as the founder of the sociological tradition of anomie theory, his notion of anomie changed fundamentally in the hands of American sociology (Orru 1987; Besnard 1990). Durkheim's (1951) understanding of anomie derives from his concern about the disruptive tendencies of fundamental features of modern, industrial society. Durkheim argues that specific features of industrial society, particularly in the sphere of economic activity, produce a chronic state of normative deregulation. As a result, valued goals become ill conceived and the society fails to provide people with normative limits on their desires. In contrast, American anomie theorists have not emphasized anomie as the widespread lack of socially valued goals. Thus Merton's (1967/1994) influential essay, Social Structure and Anomie, does not cast in doubt the fundamental cultural ends of the society, that is, the normative ends of action. In Merton's theory social values are clearly defined in the mainstream egalitarian ideology and in the universal emphasis on monetary success. On the cultural level, Merton emphasizes the lack of equilibrium between socially described means and ends of action. Anomie is caused by the imbalance
Ultrafine titania by flame spray pyrolysis of a titanatrane complex

Ultrafine titania particles can be produced by flame spray pyrolysis of a chelated metal alkoxide. The precursor can be made by reacting a titanium hydrosol with triethanolamine in ethylene glycol. The chelate, dissolved in ethanol, is misted as an aerosol into an oxidizing flame where it undergoes combustion. The combustion process generates particles, probably by a gas phase condensation process, that are discrete single crystals that exhibit some faceting. The powder is a mixture of anatase and rutile (<10%), with a 45±5 m2 g−1 BET surface area. The calculated equivalent spherical diameter (34+4 nm) is consistent with typical particle sizes found in TEM micrographs. The particles are briefly compared with commercial ultrafine particles produced by flame hydrolysis of TiCl4 and by Ti vapor condensation.
Mathematical analysis of involvement ratio between central and peripheral COX-2 in rat pain models with two types of COX-2 inhibitors with different distribution, celecoxib and CIAA

Abstract The purpose of this study is to clarify involvement ratios between central and peripheral cyclooxygenase (COX)-2 in rat inflammatory pain models, by evaluating celecoxib and [6-chloro-2-(4-chlorobenzoyl)-1 H -indol-3-yl]acetic acid (CIAA) on carrageenan-induced mechanical and thermal hyperalgesia. Celecoxib and CIAA exhibited ID 30 values with 1.5 and 7.7 mg/kg on mechanical hyperalgesia, respectively, and ID 25 values with 0.54 and 36 mg/kg on thermal hyperalgesia, respectively. By solving quadratic functional analysis with prostaglandin E 2 (PGE 2 ) inhibitory activities, it was calculated that involvement ratios between central and peripheral COX-2 involvement were 0.47 and 0.53 on mechanical hyperalgesia, and 0.97 and 0.03 on thermal hyperalgesia, respectively. These data suggest that central and peripheral COX-2 are equally involved in mechanical hyperalgesia, while central COX-2 is predominantly involved in thermal hyperalgesia.
Income Inequality, Taxation, and Growth

Much recent theoretical and empirical research has focused on the relationship between income distribution and economic growth. The fiscal policy approach argues that inequality is linked to pressure for redistributionary taxation, leading to low capital investment and, therefore, growth. Empirical analyses are consonant with this view in that the long-run relationship between inequality and growth is negative. However, several empirical inconsistencies with the fiscal policy approach do emerge: (a) there exists a short-run, positive relationship between income inequality and growth and (b) the relationship between inequality and taxation is mixed, at best. This paper presents a simple theoretical model that reconciles the intuitively appealing fiscal policy approach with the empirical findings.
A note on the functional estimation of values of hidden variables: an extended module for expert systems

The paper describes an extension of our work on the Generalized Production Rules System. In its original form, it could estimate at a given point of time or space the value of hidden variables---variables that can be measured only intermittently or periodically. In contrast, open variables are readily measurable any time. The system establishes stochastic, causal relations, generalized production rules, between known values of hidden variables and certain mathematical properties of the open variables' behavior. These rules are then used to make the point estimates.We have now provided the system with the additional ability to estimate the functional behavior of the hidden variables. The system can serve as a domain-independent module to a knowledge-based expert system in need of such numerical estimates.
Dose, exposure time and resolution in serial X-ray crystallography.

The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed serial crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. The incident X-ray fluence (energy/area) is evaluated that is required to obtain a given resolution from (i) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (ii) explicit simulation of diffraction patterns for a GroEL–GroES protein complex, and (iii) the spatial frequency cut-off of the transfer function following iterative solution of the phase problem, and reconstruction of an electron density map in the projection approximation. These calculations include counting shot noise and multiple starts of the phasing algorithm. The results indicate counting time and the number of proteins needed within the beam at any instant for a given resolution and X-ray flux. An inverse fourth-power dependence of exposure time on resolution is confirmed, with important implications for all coherent X-ray imaging. It is found that multiple single-file protein beams will be needed for sub-nanometer resolution on current third-generation synchrotrons, but not on fourth-generation designs, where reconstruction of secondary protein structure at a resolution of 7 A should be possible with relatively short exposures.
DETECTION OF T AND B LYMPHOCYTE ANTIGENS ON TWO MAJOR NULL CELL SUBSETS

Rabbit antiaera to autologous T and B lymphoblast cell lines HSB-2 and SB, after reciprocal absorption, were found to detect human T and B lymphocyte antigens (HTLA and HBLA antigens). When tested by indirect immunofluorescence and C' dependent cytotoxicity, the anti-T cell line serum reacted with T cells but not B cells whereas the anti-B cell line serum reacted with B cells but not T cells. These two antisera also reacted with peripheral blood null cells prepared by nylon column filtration and E rosette depletion. The sum of the percentages of null cells reacting with each antiserum approximated 100%. Null cell suspensions depleted of cells reacting with one antiserum showed a reciprocal increase in cells reacting with the opposite antiserum. These findings indicate that most, if not all, null cells express either HTLA or HBLA antigens. It appears therefore that some null cells are related to the T cell line of differentiation whereas others are related to the B cell line of differentiation. (Supported by USPHS NIH Grant CA 17534 and Contract l-CP-33333. J. Kaplan is recipient of NIH Research Career Development Award CA 00188).
Implications of recent observational discoveries for the nature and origin of gamma-ray bursts

Abstract The discoveries that GRBs have X-ray, optical and radio afterglows have connected the study of GRBs to the rest of astronomy, and revolutionized the field. In this review, I discuss the implications that the observation of these afterglows have for burst energies and luminosities, and for models of the bursts and their afterglows. I describe recent evidence linking the long, softer, smoother GRBs detected by BeppoSAX and core collapse supernovae. Finally, I summarize recent work showing that, if these GRBs are due to the collapse of massive stars, they may provide a powerful probe of the very high redshift universe.
Renegotiating Vocational Instruction.

Recent research by the author and others suggests that secondary vocational instruction may often fail to develop students' analytical and critical thinking skills. This failure, it is argued, is manifest in teacher-student “negotiation” as set in a complex social, economic, and institutional context. The article focuses on how vocational education might be reformed to address this problem. Discussed are the need for instruction in problem solving and decision making, more basic skill instruction, student involvement in the group management of entrepreneurial projects, development of critical thinking skills for the purpose of improving workplaces and society, revision of vocational teacher preparation, and a restructuring of the ways in which secondary vocational education is offered. Vocational education is redefined as academically integrated, experiential coursework in which a diverse group of students is educated broadly for work, learning, and life.
Current Considerations on the Use of One-to-One Instruction with Autistic Students Review and Recommendations

One-to-one instruction was utilized in the 1960s to determine the feasibility of teaching autistic children and remains a widely recommended teaching procedure in the 1980s. While this teaching paradigm is of obvious value in the education of autistic students, it also presents some serious problems, particularly in the areas of generalization, social skill development, and teacher efficiency. Alternatives to one-to-one instruction include individualized instruction in a group, group instruction, and peer tutoring. This paper discusses each of these instructional methods, their advantages and disadvantages, recommendations for their use, and areas for future research.
Proteomic Mapping of Mitochondria in Living Cells via Spatially Restricted Enzymatic Tagging

Microscopy and mass spectrometry (MS) are complementary techniques: The former provides spatiotemporal information in living cells, but only for a handful of recombinant proteins at a time, whereas the latter can detect thousands of endogenous proteins simultaneously, but only in lysed samples. Here, we introduce technology that combines these strengths by offering spatially and temporally resolved proteomic maps of endogenous proteins within living cells. Our method relies on a genetically targetable peroxidase enzyme that biotinylates nearby proteins, which are subsequently purified and identified by MS. We used this approach to identify 495 proteins within the human mitochondrial matrix, including 31 not previously linked to mitochondria. The labeling was exceptionally specific and distinguished between inner membrane proteins facing the matrix versus the intermembrane space (IMS). Several proteins previously thought to reside in the IMS or outer membrane, including protoporphyrinogen oxidase, were reassigned to the matrix by our proteomic data and confirmed by electron microscopy. The specificity of peroxidase-mediated proteomic mapping in live cells, combined with its ease of use, offers biologists a powerful tool for understanding the molecular composition of living cells.
Coupled model simulations of boreal summer intraseasonal (30–50 day) variability, Part 1: Systematic errors and caution on use of metrics

Boreal summer intraseasonal (30–50 day) variability (BSISV) over the Asian monsoon region is more complex than its boreal winter counterpart, the Madden–Julian oscillation (MJO), since it also exhibits northward and northwestward propagating convective components near India and over the west Pacific. Here we analyze the BSISV in the CMIP3 and two CMIP2+ coupled ocean–atmosphere models. Though most models exhibit eastward propagation of convective anomalies over the Indian Ocean, difficulty remains in simulating the life cycle of the BSISV, as few represent its eastward extension into the western/central Pacific. As such, few models produce statistically significant anomalies that comprise the northwest to southeast tilted convection, which results from the forced Rossby waves that are excited by the near-equatorial convective anomalies. Our results indicate that it is a necessary, but not sufficient condition, that the locations the time-mean monsoon heat sources and the easterly wind shear be simulated correctly in order for the life cycle of the BSISV to be represented realistically. Extreme caution is needed when using metrics, such as the pattern correlation, for assessing the fidelity of model performance, as models with the most physically realistic BSISV do not necessarily exhibit the highest pattern correlations with observations. Furthermore, diagnostic latitude-time plots to evaluate the northward propagation of convection from the equator to India and the Bay of Bengal also need to be used with caution. Here, incorrectly representing extratropical–tropical interactions can give rise to “apparent” northward propagation when none exists in association with the eastward propagating equatorial convection. Despite these cautions, the use of multiple cross-checking diagnostics enables the fidelity of the simulation of the BSISV to be meaningfully assessed.
Synthetic studies on the ginkgolides: total synthesis of (.+-.)-bilobalide

Two syntheses of the C15 ginkgolide, bilobalide, are presented. One approach results in a formal synthesis by intersecting an intermediate in the Corey synthesis, while a second approach results in a completed total synthesis which is considerably shorter than the first. Both approaches rely on a stereoselective intramolecular [2+2] photocycloaddition to control much of the stereochemistry. A diastereoselective aldol condensation serves to establish the relative stereochemical relationship between the secondary and tertiary alcohols in the second approach. This circumvents problems of incorporation of the tertiary carbinol which were encountered in both previous appraches
Langmuir waves upstream of interplanetary shocks: Dependence on shock and plasma parameters

[1] We have examined 178 interplanetary shocks observed by the Wind spacecraft to establish which shock and plasma parameters are favorable for the production of upstream Langmuir waves and therefore to determine which shocks are likely to generate interplanetary Type II radio bursts. Of the 178 shocks included in this study, 43 produced upstream Langmuir waves, as evinced by enhancements in wave power near the plasma frequency. The large number of observed shocks permits the use of statistical tests to determine which parameters control the upstream activity. The best predictor of activity is the de Hoffmann-Teller speed, a result consistent with the fast Fermi model of electron acceleration. Several other parameters, including the magnetic field strength and the level of solar activity (but not the Mach number), are also correlated with upstream activity. These additional parameters may be associated with an increased level of shock front curvature or upstream structure, leading to the formation of upstream foreshock regions, or with the generation of an upstream electron population favorable for shock reflection.
The TRENDS High-contrast Imaging Survey. V. Discovery of an Old and Cold Benchmark T-dwarf Orbiting the Nearby G-star HD 19467

The nearby Sun-like star HD 19467 shows a subtle radial velocity (RV) acceleration of –1.37 ± 0.09 m s^(–1) yr^(–1) over a 16.9 yr time baseline (an RV trend), hinting at the existence of a distant orbiting companion. We have obtained high-contrast images of the star using NIRC2 at Keck Observatory and report the direct detection of the body that causes the acceleration. The companion, HD 19467 B, is ΔK_s = 12.57 ± 0.09 mag fainter than its parent star (contrast ratio of 9.4 × 10^(–6)), has blue colors J – K_s = –0.36 ± 0.14 (J – H = –0.29 ± 0.15), and is separated by ρ = 1."± 0."004 (51.1 ± 1.0 AU). Follow-up astrometric measurements obtained over a 1.1 yr time baseline demonstrate physical association through common parallactic and proper motion. We calculate a firm lower-limit of m ⩾ 51.9^(+3.6)_(-4.3)M_J for the companion mass from orbital dynamics using a combination of Doppler observations and imaging. We estimate a model-dependent mass of m=56.7^(+4.6)_(-7.2)M_(Jup) from a gyrochronological age of 4.3^(+1.0)_(-1.2) Gyr. Isochronal analysis suggests a much older age of 9 ± 1 Gyr, which corresponds to a mass of m = 67.4^(+0.9)_(-1.5)M_J. HD 19467 B's measured colors and absolute magnitude are consistent with a late T dwarf [≈T5-T7]. We may infer a low metallicity of [Fe/H] =–0.15 ± 0.04 for the companion from its G3V parent star. HD 19467 B is the first directly imaged benchmark T dwarf found orbiting a Sun-like star with a measured RV acceleration.