cssi/SciSciGPT-SciSciNet huggingface dataset:
Use of sulfur fragments for the synthesis of nitrogen heterocycles

Abstract :This contribution contains a representative sampling from the Padwa laboratory ofthe conjugate addition of oximes with 2,3- bis (phenylsulfonyl)-1,3-butadiene followed by asubsequent dipolar cycloaddition cascade to produce a variety of alkaloids. The resultingcycloadducts are cleaved reductively to provide azapolycyclic scaffolds with strategicallyplaced functionality for further manipulation of the target compounds. Keywords : heterocyclic chemistry; nitrogen; organic synthesis; rearrangements; sulfur; tan-dem reactions. INTRODUCTION Before chemistry was a science, there was alchemy. One of the supreme quests of alchemy was to trans-mute lead into gold. Indeed, this transmutation was believed to be not only possible but also activelypracticed during the Middle Ages. The desired conversion was such a popular fad that mobs of peoplegathered to obtain the secret from a suspected alchemist who could have been beaten to death for notcomplying. It should be noted that the actual transmutation of lead into gold has indeed been achievedin recent years, since today’s particle accelerators routinely transmute elements. While it may never beeasy to transmute one element into another, in the hands of a modern-day synthetic organic chemist, itis desirable to take advantage of the unique chemistry of sulfur to synthesize nitrogen heterocycles. Theresult is bordering on alchemy, almost. For some time now, the Padwa research group has been takingadvantage of the chemistry of various thio fragments to synthesize an assortment of alkaloids. In thisshort account, a North American perspective on an aspect of heteroatom chemistry, arising from theauthor’s contributions to relevant chemical methodology and its applications in synthesis, is described.Heteroatom-containing natural products are abundant in nature and exhibit diverse and importantbiological properties [1]. Accordingly, novel strategies for the stereoselective synthesis of hetero-poly-cyclic systems found in the alkaloid kingdom continue to receive considerable attention in the field ofsynthetic organic chemistry [2]. Although methods of preparing such complex architectures such asthose shown in Fig. 1 vary widely, approaches that employ cycloaddition chemistry are particularlyattractive given the rapid introduction of molecular complexity within a single chemical operation [3].A significant improvement of the synthetic efficiency to a multitude of diverse heterocycles has beenobtained in recent years through the development of domino reactions that allow the formation of com-plex compounds, starting from simple substrates, in a single transformation consisting of several steps[4]. Domino reactions, multicomponent reactions, and the so-called “telescoping” of reactions (thesequencing of multiple transformations in a single reaction vessel through the changing of conditions
Sequential Diels−Alder Reaction of in Situ Generated 2,3-Dimethylenepyrrole and Carbodienophiles: Rapid Synthesis of 2,3,6,7-Tetrasubstituted Carbazoles

2,3,6,7-Tetrasubstituted-1,2,3,4,5,6,7,8-octahydrocarbazoles 2 were synthesized in 46−90% yields by sequential Diels−Alder reactions from N-benzyl-2,5-dimethyl-3,4-bisacetoxymethylpyrrole (1) and dienophiles such as maleic anhydride, maleimides, ethyl maleate, fumaronitrile, and ethyl acrylate. The 2,3,6,7-tetrasubstituted carbazoles 3 were then synthesized in 32−87% yields from 2 by oxidation with DDQ.
Real-Time Quantized Optical Flow

Algorithms based on the correlation of image patches can be robust in practice but are computationally intensive due to the computational complexity of their search-based nature. Performing the search over time instead of over space is linear in nature, rather than quadratic, and results in a very efficient algorithm. This, combined with implementations which are highly efficient on standard computing hardware, yields performance of 9 frame/sec on a scientific workstation. Although the resulting velocities are quantized with resulting quantization error, they have been shown to be sufficiently accurate for many robotic vision tasks such as time-to-collision and robotic navigation. Thus, this algorithm is highly suitable for real-time robotic vision research.
Secure group communication in wireless mesh networks

Wireless mesh networks (WMNs) have emerged as a promising technology that offers low-cost community wireless services. The community-oriented nature of WMNs facilitates group applications, such as webcast, distance learning, online gaming, video conferencing, and multimedia broadcasting. Security is critical for the deployment of these services. Previous work focused primarily on MAC and routing protocol security, while application-level security has received relatively little attention. In this paper we focus on providing data confidentiality for group communication in WMNs. Compared to other network environments, WMNs present new challenges and opportunities in designing such protocols. We propose a new protocol framework, Secure Group Overlay Multicast (SeGrOM), that employs decentralized group membership, promotes localized communication, and leverages the wireless broadcast nature to achieve efficient and secure group communication. We analyze the performance and discuss the security properties of our protocols. We demonstrate through simulations that our protocols provide good performance and incur a significantly smaller overhead than a baseline centralized protocol optimized for WMNs.
Reduction of magnesium orthovanadate Mg3(VO4)2

Abstract Reduction of polycrystalline and crystalline magnesium orthovanadate Mg3V2O8 by hydrogen was investigated in the temperature range of 560–920°C. A single crystal of orthorhombic Mg3V2O8 with a cation-deficient-spinel structure (25% of the magnesium atoms on octahedral sites are vacant) was transformed into cubic Mg3V2O6 which has a cation-stuffed-spinel structure (8a and 16c sites were partially occupied by magnesium and 16d sites were fully occupied by magnesium and vanadium) at 560°C in 7% H2 in N2.
A passive probe for subsurface oceans and liquid water in Jupiter’s icy moons

Abstract We describe an interferometric reflectometer method for passive detection of subsurface oceans and liquid water in jovian icy moons using Jupiter’s decametric radio emission (DAM). The DAM flux density exceeds 3000 times the galactic background in the neighborhood of the jovian icy moons, providing a signal that could be used for passive radio sounding. An instrument located between the icy moon and Jupiter could sample the DAM emission along with its echoes reflected in the ice layer of the target moon. Cross-correlating the direct emission with the echoes would provide a measurement of the ice shell thickness along with its dielectric properties. The interferometric reflectometer provides a simple solution to sub-jovian radio sounding of ice shells that is complementary to ice penetrating radar measurements better suited to measurements in the anti-jovian hemisphere that shadows Jupiter’s strong decametric emission. The passive nature of this technique also serves as risk reduction in case of radar transmitter failure. The interferometric reflectometer could operate with electrically short antennas, thus extending ice depth measurements to lower frequencies, and potentially providing a deeper view into the ice shells of jovian moons.
The effect of chronic alcohol administration on fatty acid metabolism and pyruvate oxidation of heart mitochondria

It has been proposed that the mechanism for myocardial triglyceride (TG) accumulation and diminished fatty acid oxidation in chronic alcoholic animals is mitochondrial damage and, possibly, altered palmitylcarnitine trasnferase (PCAT) activity. We have studied the fatty acid metabolism and PCAT activity of isolated heart mitochondria from 80 male rats pair-fed 52±7 days a liquid diet (35% fat) containing all essential nutrients but with ethanol or dextrin-maltose (control) as 36% of the total calories. Myocardial TG increased two to four times in alcohol-fed animals, but tissue free, acetyl- and acylcarnitine levels were unchanged. PCAT specific activity was not diminished in the alcoholic group (10.76±0.90 vs 13.38±1.60 nmol/min/mg) and Vmax and Km for carnitine were identical. Mitochondrial respiration rates with glutamate and palmityl- and acetylcarnitine were unchanged. However, pyruvate oxidation (states III and IV) in alcoholic animals was consistently reduced (200±23 and 28.3±4.0 vs 161±19 and 23.0±4.0 natoms oxygen/min/mg, respectively; P<0.001 and <0.02). These findings show that fat accumulation occurs despite the normal ability of the myocardium to transport and oxidize fatty acid. Furthermore, pyruvate dehydrogenase inhibition may be an early marker of alcohol induced myocardial damage.
Detecting Pyrolysis Products from Bacteria on Mars

A pyrolysis/sublimation technique was developed to isolate volatile amine compounds from a Mars soil analogue inoculated with approx. 10 billion Escherichia coli cells. In this technique, the inoculated soil is heated to 500 C for several seconds at Martian ambient pressure and the sublimate, collected by a cold finger, then analyzed using high performance liquid chromatography. Methylamine and ethylamine, produced from glycine and alanine decarboxylation, were the most abundant amine compounds detected after pyrolysis of the cells. A heating cycle similar to that utilized in our experiment was also used to release organic compounds from the Martian soil in the 1976 Viking gas chromatography/mass spectrometry (GC/MS) pyrolysis experiment. The Viking GC/MS did not detect any organic compounds of Martian origin above a level of a few parts per billion in the Martian surface soil. Although the Viking GC/MS instruments were not specifically designed to search for the presence of living cells on Mars, our experimental results indicate that at the part per billion level, the degradation products generated from several million bacterial cells per gram of Martian soil would not have been detected.
Underpricing, Share Overhang, and Insider Selling in Follow‐on Offerings

Prospect and information-momentum theories predict that insiders can offer fewer shares in an initial public offering (IPO) to create informational momentum and obtain higher prices in follow-on offerings. I find that dilution and insider participation in the IPO are negatively related to the number and size of follow-on offerings, consistent with the prediction. However, insider selling in follow-on offerings is positively related to IPO selling, contrary to the theories. Returns around follow-on offering announcements are more negative for newly public firms than older firms, but for newly public firms do not differ by whether the announcement comes before or after the lockup expiration date.
CIO roles and responsibilities: Twenty-five years of evolution and change

We investigated how the CIO's job has changed over the past years and found that the CIOs' role has evolved to reflect both the firm's IS infrastructure and strategy. This has led to two versions of the role: an executive-level manager focused on the firm's strategy and processes, and a technical manager focused on minimizing costs by rationalizing and leveraging the existing IS infrastructure. The degree to which a firm has standardized its IS architecture infrastructure, and the degree to which IS enables core products, services, processes, or competitive advantage of the firm impact the nature of the role.
Charged grains in Saturn’s F-Ring: interaction with Saturn’s magnetic field

Abstract Saturn’s dynamic F-Ring still presents a challenge for understanding and explaining the kinematic processes that lead to the changing structure visible in our observations of this ring. This study examines the effect of Saturn’s magnetic field on the dynamics of micron-sized grains that may become electrically charged due to interaction with plasma in Saturn’s rigidly corotating magnetosphere. The numerical model calculates the dynamics of charged dust grains and includes forces due to Saturn’s gravitational field, the plasma polarization electric field, a third order harmonic expansion of Saturn’s magnetic field, and the F-Ring’s Shepherding moons, Prometheus and Pandora.
Is pain a specific sensation

Publisher Summary This chapter discusses the analysis of pain as a specific sensation. An important clue to the peripheral pathways for pain-producing impulses was provided by morphological observations on mammalian dorsal roots. Pain became classified as a sensory quality relatively late in the evolution of ideas on sensation and consciousness. Prior to the 19th century, most authorities had followed Aristotle's view in setting pain opposite to pleasure and assigning it to the realm of emotion. As a first step in deciding whether pain has the characteristics associated with a specific sensation, it is necessary to set down attributes that might be accepted for this category. Some possible semantic problems may be avoided by starting from an unambiguous model. Vision begins with the excitation of structures in the eye, a particular and unique sense organ. Under ordinary conditions the receptive tissue of the eye has a responsiveness limited to a clearly definable set of environmental events. The receptive elements of the retina, in turn, excite a chain of nerve cells that transmit signals related to incoming light to regions of the forebrain. Consequently, a neural sequence from the receptive structure to neurons of the thalamus and cortex are dedicated to the relaying and analysis of information contained in the light reaching the eyes of the organism.
New Insights on Interstellar Gas-Phase Iron

In this paper we report on the gas-phase abundance of singly ionized iron (Fe II) for 51 lines of sight, using data from FUSE. Fe II column densities are derived by measuring the equivalent widths of several UV absorption lines and subsequently fitting those to a curve of growth. Our derivation of Fe II column densities and abundances creates the largest sample of iron abundances in moderately to highly reddened lines of sight explored with FUSE, lines of sight that are on average more reddened than lines of sight in previous Copernicus studies. We present three major results. First, we observe the well-established correlation between iron depletion and nH and also find trends between iron depletion and other line-of-sight parameters [e.g., f(H2), EB-V, and AV], and we examine the significance of these trends. Of note, a few of our lines of sight probe larger densities than previously explored and we do not see significantly enhanced depletion effects. Second, we present two detections of an extremely weak Fe II line at 1901.773 A in the archival STIS spectra of two lines of sight (HD 24534 and HD 93222). We compare these detections to the column densities derived through FUSE spectra and comment on the line's f-value and utility for future studies of Fe II. Finally, we present strong anecdotal evidence that the Fe II f-values derived empirically through FUSE data are more accurate than previous values that have been theoretically calculated, with the probable exception of f1112.
Grain boundary response of aluminum bicrystal under micro scale laser shock peening

Micro scale laser shock peening (μLSP) is a process in which compressive residual stresses are induced in a material surface to improve fatigue life and wear resistance under cyclic loading. Since the diameter of the laser spot used during the process is the same order of magnitude as grain size, the effects of anisotropy and heterogeneity have to be explicitly taken into account in any model of the process. In this study experimental and numerical studies have been performed in order to investigate the response of an aluminum bicrystal under laser shock peening. The grain boundary is shocked to investigate heterogeneity, and single crystals are shocked to study the effect of anisotropy in the absence of heterogeneity. The orientations of the crystals in the bicrystal as well as the reference single crystals have been chosen such that an approximate plane strain condition is achieved. A finite element model which accounts for the anisotropy, heterogeneity and inertia has also been developed based on single crystal micromechanics. Simulation results are compared with experimental findings. The potential benefit of μLSP as a surface treatment for improvement of fatigue life is also discussed.
A year of microseisms in southern California

[1] Microseisms are due to continuous harmonic forcing by ocean waves, whose sources vary in time, frequency, and azimuth. Using frequency-domain array beamforming, this variation is studied using one-year of continuous seismic data from 155 stations in southern California. Detailed analysis of data delineates spatiotemporal variations of sources for the primary and secondary microseisms. Both types of microseisms are generated near the coasts but the locations of excitation are different and change with season. Often sources are multiply located but can be spread out over wider areas, especially in the case of secondary microseisms. Distant storms can also be seen occasionally in the frequency range between the primary and secondary microseisms where spectral amplitudes from nearby sources are low.
Recent advancements and challenges of palladiumII-catalyzed oxidation reactions with molecular oxygen as the sole oxidant

During the past 10 years there have been significant advances in PdII-catalyzed oxidation reactions where the use of ligands has led to the development of catalytic systems capable of achieving high turnover numbers, which employ molecular oxygen as the sole stoichiometric oxidant. This Feature article will highlight some of the recent developments in direct molecular oxygen-coupled PdII-catalyzed oxidation reactions with an emphasis on enhanced catalytic systems and new reactions. Additionally, limitations of current catalytic systems, such as ligand oxidation, are presented and their implications for the development of new reactions are discussed.
Energy Criterion for Fatigue Strength of Wood Structural Members

This report describes a mathematical model for fatigue strength of cellulosic materials under sinusoidal loading. The model is based on the Reiner-Weissenberg thermodynamic theory of strength in conjunction with a nonlinear Eyring’s three-element model. This theory states that failure depends on a maximum value of the intrinsic free energy that can be stored elastically in a volume element of the material. The three-element mechanical model, which consists of a linear spring in series with a parallel array of another linear spring and an Eyring dashpot, provides a good description of rheological material properties. The strength model system was able to predict rupture occurrence of polymers and wood structural members under constant and ramp loading with satisfactory results. For sinusoidal loading, the present study shows that the strength model system can predict time at fracture as a function of applied mean stress, amplitude of cyclic stress, and stress frequency. Numerical examples with model parameters evaluated for small Douglas-fir beams are presented.
Clinical management of advanced gastrointestinal cancer.

Although advanced gastrointestinal cancer is the most commonplace problem encountered by the medical oncologist, this group of diseases has proved exceedingly resistant to past chemotherapy efforts. 5-Fluorouracil (5-FU), accepted by some as standard treatment, has provided only infrequent, incomplete, and fleeting antitumor effects, which are probably more than counterbalanced by its gastrointestinal, mucocutaneous, and hematologic antihost effects. There is no evidence that any manipulation of route or schedule of administration provides any improvement in the therapeutic ratio of 5-FU. There is no evidence that this drug contributes to patient survival when used at any stage of any type of gastrointestinal carcinoma. The search for alternative single drugs to 5-FU has been disappointing. The nitrosoureas and Mitomycin C produce occasional regressions, but they do not match the meager effectiveness of 5-FU; and they, in addition, present the difficult problem of cumulative bone marrow suppression. Recent trials with combination regimens have given some indication that the long stalemate in chemotherapy of gastrointestinal cancer may be breaking. Substantial improvements in frequency of tumor regression have been recorded for gastric carcinoma with combinations of 5-FU and BCNU, 5-FU and methyl CCNU, and 5-FU, Mitomycin C, and cytosine arabinoside; for colorectal carcinoma, with the combination of 5-FU, methyl CCNU, and vincristine; and for carcinoid tumors and islet cell carcinomas, with the combination of 5-FU and Streptozotocin. There are also suggestions that such combination chemotherapy with response rates in the 30 to 50% range may produce increased survival when compared to the untreated patient and patients treated with single-drug regimens. While the accomplishments of chemotherapy for the gastrointestinal cancer patient remain less than spectacular there is nevertheless realistic hope that a respectable contribution can now be made to multidisciplinary efforts applied at a stage of disease with minimal tumor burden.
Pelvic inflammatory disease in adolescents.

Introduction Pelvic inflammatory disease (PID), overshadowed only in the last decade by the acquired immunodeficiency syndrome, is the second most serious consequence of the ongoing epidemic of sexually transmitted disease (STD) occurring among adolescents since the mid-1960s. PID is defined as an acute clinical syndrome caused by the ascending spread of microorganisms from the lower genital tract (vagina and endocervix) to the upper genital tract (endometrium, fallopian tubes, a n d / o r contiguous structures). 1 It is an impor t an t cause of infertility, ectopic pregnancy, and chronic pain. It imposes an enormous economic burden on the national health care budget as well as a severe emotional burden on those who suffer chronic sequelae and frustrated reproductive aspirations. This chapter will provide an overview of the clinical problem of PID in adolescents with emphasis on diagnostic methods and antimicrobial treatment.
Revenge of the one family technicolor models

Abstract We describe how isospin splitting and techniquark-technilepton splitting in one-family technicolor models can reduce the predicted value of the electroweak radiative correction parameter S, without making a large contribution to the T parameter.
Area-Efficient Near-Associative Memories on FPGAs

Associative memories can map sparsely used keys to values with low latency but can incur heavy area overheads. The lack of customized hardware for associative memories in today’s mainstream FPGAs exacerbates the overhead cost of building these memories using the fixed address match BRAMs. In this article, we develop a new, FPGA-friendly, memory system architecture based on a multiple hash scheme that is able to achieve near-associative performance without the area-delay overheads of a fully associative memory on FPGAs. At the same time, we develop a novel memory management algorithm that allows us to statistically mimic an associative memory. Using the proposed architecture as a 64KB L1 data cache, we show that it is able to achieve near-associative miss rates while consuming 3--13 × fewer FPGA memory resources for a set of benchmark programs from the SPEC CPU2006 suite than fully associative memories generated by the Xilinx Coregen tool. Benefits for our architecture increase with key width, allowing area reduction up to 100 ×. Mapping delay is also reduced to 3.7ns for a 1,024-entry flat version or 6.1ns for an area-efficient version compared to 17.6ns for a fully associative memory for a 64-bit key on a Xilinx Virtex 6 device.
Turbulent Torques on Protoplanets in a Dead Zone

Migration of protoplanets in their gaseous host disks may be largely responsible for the observed orbital distribution of extrasolar planets. Recent simulations have shown that the magnetorotational turbulence thought to drive accretion in protoplanetary disks can affect migration by turning it into an orbital random walk. However, these simulations neglected the disk's ionization structure. Low ionization fraction near the midplane of the disk can decouple the magnetic field from the gas, forming a dead zone with reduced or no turbulence. Here, to understand the effect of dead zones on protoplanetary migration, we perform numerical simulations of a small region of a stratified disk with magnetorotational turbulence confined to thin active layers above and below the midplane. Turbulence in the active layers exerts decreased, but still measurable, gravitational torques on a protoplanet located at the disk midplane. We find a decrease of 2 orders of magnitude in the diffusion coefficient for dead zones with dead-to-active surface density ratios approaching realistic values in protoplanetary disks. This torque arises primarily from density fluctuations within a distance of one scale height of the protoplanet. Turbulent torques have correlation times of only ~0.3 orbital periods and apparently time-stationary distributions. These properties are encouraging signs that stochastic methods can be used to determine the orbital evolution of populations of protoplanets under turbulent migration. Our results indicate that dead zones may be dynamically distinct regions for protoplanetary migration.
Stress Measurements in Bias-Constructed Parachute Canopies During Inflation and at Steady State

This paper describes the results of an experimental study of canopy stresses in bias-constructed, solid-flat parachutes. Stresses were measured in the warp and fill directions during inflation and at steady state for different values of dynamic pressure. Omega sensors were used to measure stress. These sensors were mounted along the gore centerlines so that the warp and fill stress distributions could be determined as a function of distance from the vent. It was found that stresses in the fill direction were substantially larger than stresses in the warp direction.
Effect of Correlation on the Ferromagnetism of Transition Metals

The wave function for the electrons is investigated when a set of narrow bands (valence states) has its energies within a wide band (conduction states). The valence states are linear combinations of localized states which are attached to each lattice site. The intra-atomic Coulomb and exchange integrals for the localized states are much larger than the bandwidths of the valence states. Some of the narrow bands are neither completely empty nor completely filled. The wave function is therefore expected to be correlated, because it is disadvantageous for the electrons to crowd into the same lattice site, or take up some configuration contrary to Hund's rule. This correlation is important in trasition metals, where it is considered to be the cause of ferromagnetism. The correlated wave function is obtained by applying to the uncorrelated antisymmetrized product of Bloch functions an operator which provides each configuration of localized valence states with an appropriate amplitude and phase factor. The procedure is worked out in detail for the case of few particles (electrons or holes) in the narrow bands with the help of a diagram analysis. The localized orbits of different lattice sites do not have to be orthogonal to on another, and the computational rules are actually simplified thereby. The example of a twofold degenerate band such as the upper part of the $3d$ band in Ni is treated, and the conditions for the occurrence of ferromagnetism are stated in the case of few $3d$ holes per lattice site.
Structure-reactivity studies of the triplet-sensitized photorearrangements of allyl phosphites

The relative quantum efficiencies of allylphosphonate (7–12) formation, from the triplet-sensitized photorearrangement of allyl phosphites (1–6), can be qualitatively correlated using the 1,2-biradical model for π−π∗ excited states and considering the effect on excited state energies and lifetimes of placing the β bond in a small ring.
DUALITY IN INFINITE DIMENSIONAL FOCK REPRESENTATIONS

We construct and study in detail various dual pairs acting on some infinite dimensional Fock representations between a finite dimensional classical Lie group and a completed infinite rank affine algebra associated to an infinite affine Cartan matrix. We give explicit decompositions of a Fock representation into a direct sum of irreducible isotypic subspaces with respect to the action of a dual pair, present explicit formulas for the highest weight vectors and calculate the corresponding highest weights. We further outline applications of these dual pairs to the study of tensor products of modules of such an infinite dimensional Lie algebra.
The Energy Losses Accompanying Ionization And Resonance In Mercury Vapor...

It appears from the calculations just made that the spacial geometry for the rotating system depends on the time and space co6rdinates of the point considered, and this is at first sight in contradiction with our ordinary ideas of rotating systems. The explanation of this fact is that for a system rotating with respect to a "stationary" system there is no separation into space and time which stands out as the natural one for the entire rotating system, and consequently for this system spacial geometry is only defined when our cobrdinates have been selected. Since the equations (9) depend on co6rdinates so chosen that when t' = 0, the points on the radius vector 01 = 0 coincide with those on the radius vector 0 = 0, at t = 0 in the stationary system, it is based on co6rdinates "natural" to these spacetime points; in the sense that they are those of a stationary system coinciding with the rotating one at the space-time points considered. It will be noticed that for these points the curvature given by (13) is co2/c2. This shows that the curvature of the spacial cross-section at any space-time point in the co6rdinates "natural" to this point is constant; it is the square of the angular velocity of rotation in radians per light-second.
Assault Response Questionnaire

(1988). Assault Response Questionnaire. Issues in Mental Health Nursing: Vol. 9, No. 1, pp. 17-29.
Comparative PCET study of a donor-acceptor pair linked by ionized and nonionized asymmetric hydrogen-bonded interfaces.

A Zn(II) amidinium porphyrin is the excited-state electron donor (D) to a naphthalene diimide acceptor (A) appended with either a carboxylate or sulfonate functionality. The two-point hydrogen bond (···[H+]···) formed between the amidinium and carboxylate or sulfonate functionalities establishes a proton-coupled electron transfer (PCET) pathway for charge transfer. The two D···[H+]···A assemblies differ only by the proton configuration within the hydrogen-bonding interface. Specifically, the amidinium ion transfers a proton to the carboxylate to form a nonionized amidine−carboxylic acid two-point hydrogen network, whereas the amidinium retains both protons when bound to the sulfonate functionality, forming an ionized amidinium−sulfonate two-point hydrogen bond network. These two interface configurations within the dyads thus allow for a direct comparison of the PCET kinetics for the same donor and acceptor juxtaposed by ionized and nonionized hydrogen-bonded interfaces. Analysis of the PCET kinetics ascer...
Computed tomography for blunt abdominal trauma in the ED: a prospective study.

A study was undertaken to determine the criteria for ordering abdominal computed tomography (CT) in the emergency department (ED) for stable patients who sustained blunt trauma and to identify a patient population at high risk for having intra-abdominal injury (IAI) utilizing physical examination, decrease in hematocrit, and hematuria. Patients in a university ED who had abdominal CT from April 1995 to October 1995 were evaluated prospectively. Before the scan, the examining physician completed an entry form that included physical findings, hematocrit, hematuria, Glasgow Coma Scale score, intoxication, distracting injuries, reasons for obtaining the scan, and planned disposition. Patients were followed until discharge. A total of 196 patients were evaluated. Abdominal tenderness was present in 120 patients. Twenty-two patients had IAI. Eight required surgical intervention, and all 8 had abdominal tenderness. A total of 40 potential trauma admissions were averted by obtaining CT within the ED. The combined abnormal abdomen examination and presence of hematuria had a sensitivity of 64%, specificity of 94%, positive predictive value of 56%, and negative predictive value of 95%. Decrease of ≥5 in hematocrit was not statistically significant for detection of IAI. CT had no false negatives in this cohort. These results show that early CT scanning of stable patients who have sustained blunt trauma is an effective screen for IAI and may result in fewer total admissions, but has potential for overuse. Patients with abdominal pain and hematuria should be scanned. The benefit of a CT scan for patients without tenderness or with an isolated decrease in hematocrit is questionable.
An improved preparation of α-fluorinated propargylphosphonates and the solid phase synthesis of α-hydroxy-γ-TIPS propargylphosphonate ester

Abstract Diethyl-3-triisopropylsilyl-1-propynephosphonate was fluorinated using NFSI to give the corresponding monofluoroderivative in good yield. The synthesis of diethyl-1,1-difluoro-3-triisopropylsilylpropynephosphonate was efficiently achieved following Burton’s methodology using CuCl/Cd to promote the coupling reaction of diethyl bromodifluoromethylphosphonate with the corresponding alkynyl iodide. Although the solid phase synthesis of α-hydroxy-γ-TIPS propargylphosphonate ester was carried out successfully, its fluorination — using DAST — failed.
Selection Neglect in Mutual Fund Advertisements

Mutual fund companies selectively advertise their better-performing funds. However, investors respond to advertised performance data as if those data were unselected (i.e., representative of the population). We identify the failure to discount selected or potentially selected data as selection neglect. We examine these phenomena in an archival study (Study 1) and two controlled experiments (Studies 2 and 3). Study 1 identifies selection bias in mutual fund advertising by showing that the median performance rank for advertised funds is between the 79th and 100th percentile. Study 2 finds that both novice investors and financial professionals fall victim to selection neglect in a financial advertising task unless the advertisement makes the selective nature of available performance data transparent. Study 3 shows that selection neglect associated with a large well-known company can be debiased with a simple extrinsic sample space cue, although individual differences in statistical reasoning also matter. We argue that selection neglect results from a general tendency to ignore underlying sample spaces rather than a fundamental misunderstanding about the data selection process or the value of selected data.
Sraffa, Wittgenstein y Gramsci

Two distinct but interrelated issues are investigated here. The first concerns Sraffa's critical role in contemporary philosophy through his pivotal influence on Wittgenstein. The intellectual origins of this profound influence can be traced to the philosophical interests of the activist political circle in Italy (clustered around the journal L'Ordine Nuovo) to which both Sraffa and Antonio Gramsci belonged. The second inquiry concerns the influence of Sraffa's philosophical views on his economics. Sraffa's economic contributions can be much better understood by paying attention to the way Sraffa changed the nature of the questions asked, rather than seeking different answers to already established questions.
Utilization of mechanical diagnosis and therapy (MDT) for the treatment of lumbar pain in the presence of known lumbar transverse process fractures: a case study

Background: Spinal fractures are typically considered a contraindication to mechanical diagnosis and therapy (MDT).Objective and importance: The purpose of this case study is to illustrate how MDT was used safely and effectively to treat lumbar pain in a patient with multiple lumbar transverse process fractures.Clinical presentation: The subject was a 24-year-old female with left L2-5 transverse process fractures, sustained 10 weeks prior in a pedestrian versus motor vehicle accident.Intervention (and technique): After collaboration with her physiatrist, an MDT examination revealed a presentation consistent with the lumbar derangement syndrome.Conclusion: After three visits, utilizing patient generated forces with the extension principle of treatment, her pain, Oswestry disability index (ODI) score, and function all improved.
Proper Motions of H2O Masers in the Water Fountain Source IRAS 19190+1102

We report on the results of two epochs of Very Long Baseline Array observations of the 22 GHz water masers toward IRAS 19190+1102. The water maser emission from this object shows two main arc-shaped formations perpendicular to their NE-SW separation axis. The arcs are separated by ~280 mas in position and are expanding outward at an angular rate of 2.35 mas yr–1. We detect maser emission at velocities between –53.3 km s–1 and +78.0 km s–1, and there is a distinct velocity pattern where the NE masers are blueshifted and the SW masers are redshifted. The outflow has a three-dimensional outflow velocity of 99.8 km s–1 and a dynamical age of about 59 yr. A group of blueshifted masers not located along the arcs shows a change in velocity of more than 25 km s–1 between epochs, and may be indicative of the formation of a new lobe. These observations show that IRAS 19190+1102 is a member of the class of "water fountain" pre-planetary nebulae displaying bipolar structure.
On Data Representation and Use in a Temporal Relational DBMS

Numerous proposals for extending the relational data model to incorporate the temporal dimension of data have appeared over the past decade. It has long been known that these proposals have adopted one of two basic approaches to the incorporation of time into the extended relational model. Recent work formally contrasted the expressive power of these two approaches, termed temporally ungrouped and temporally grouped, and demonstrated that the temporally grouped models are more expressive. In the temporally ungrouped models, the temporal dimension is added through the addition of some number of distinguished attributes to the schema of each relation, and each tuple is “stamped” with temporal values for these attributes. By contrast, in temporally grouped models the temporal dimension is added to the types of values that serve as the domain of each ordinary attribute, and the application's schema is left intact. The recent appearance of TSQL2, a temporal extension to the SQL-92 standard based upon the temporally ungrouped paradigm, means that it is likely that commercial DBMS's will be extended to support time in this weaker way. Thus the distinction between these two approaches---and its impact on the day-to-day user of a DBMS---is of increasing relevance to the database practitioner and the database user community. In this paper we address this issue from the practical perspective of such a user. Through a series of example queries and updates, we illustrate the differences between these two approaches and demonstrate that the temporally grouped approach more adequately captures the semantics of historical data.
Digital libraries: new initiatives with worldwide implications

We are witnessing an explosion of digital information, some of it in unstructured repositories, some in still primitive digital libraries. This trend is certain to accelerate as the National Information Infrastructure (NII) and Global Information Infrastructure (GII) become a reality. Several digital library projects in the USA and abroad are in progress, with the goal of developing the enabling technologies for creating a single, integrated and “universal” library, composed of the large numbers of individual heterogeneous repositories. These include materials in personal information collections, collections in conventional libraries, and large data collections shared by scientists, engineers and other researchers. Six US institutions received funding for Digital Library Initiatives in the fall of 1994. In addition, the Library of Congress (LC) has a National Digital Library Project under way that is funded, in part, by private corporations and foundations to make some of its large text and image collections accessible via computer networks. Focuses on projects at Carnegie Mellon University, the University of Illinois and the Library of Congress, including how these initiatives will affect the way image and text archives are organized as we enter the next century, and their implications for the international community. Addresses the following issues: how can we encourage global intellectual access and p articipation by our citizenry? How does one locate (“navigate”) information of interest in a very large, distributed and possibly disconnected collection of libraries and archives around the world? And how can we protect the intellectual property of authors and publishers and detect violations in this new information environment?
Dyslexia (Specific Reading Disability)

Converging evidence from a number of lines of investigation indicates that dyslexia represents a disorder within the language system and more specifically within a particular subcomponent of that system, phonological processing. Recent advances in imaging technology, particularly the development of functional magnetic resonance imaging, provide evidence of a neurobiological signature for dyslexia, specifically a disruption of two left hemisphere posterior brain systems, one parieto-temporal, the other occipito-temporal, with compensatory engagement of anterior systems around the inferior frontal gyrus and a posterior (right occipito-temporal) system. Furthermore, good evidence indicates a computational role for the left occipito-temporal system: the development of fluent (automatic) reading. The brain systems for reading are malleable and their disruption in dyslexic children may be remediated by provision of an evidence-based, effective reading intervention. In addition, functional magnetic resonance imaging studies of young adults with reading difficulties followed prospectively and longitudinally from age 5 through their mid twenties suggests that there may be two types of reading difficulties, one primarily on a genetic basis, the other, and far more common, reflecting environmental influences. These studies offer the promise for more precise identification and effective management of dyslexia in children, adolescents and adults.
Quantitative PET imaging of VEGF receptor expression.

Purpose Vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) signaling pathway plays pivotal roles in regulating tumor angiogenesis. Quantitative positron emission tomography (PET) imaging of VEGFR will facilitate the planning of whether, and when, to start anti-angiogenic treatment and enable more robust and effective monitoring of such treatment.
GeV Emission from Prompt and Afterglow Phases of Gamma-Ray Bursts

We investigate the GeV emission from gamma-ray bursts (GRBs) using the results from the Energetic Gamma Ray Experimental Telescope (EGRET) and in view of the Gamma-Ray Large Area Space Telescope (GLAST). Assuming that the conventional prompt and afterglow photons originate from synchrotron radiation, we compare an accompanying inverse-Compton component with EGRET measurements and upper limits on GeV fluence, taking Klein-Nishina feedback into account. We find that the EGRET constraints are consistent with the theoretical framework of the synchrotron self-Compton model for both prompt and afterglow phases, and discuss constraints on microphysical parameters in both phases. Based on the inverse-Compton model and using EGRET results, we predict that GLAST would detect GRBs with GeV photons at a rate of ≳ 20 yr^-1 from both the prompt and afterglow phases. This rate applies to the high-energy tail of the prompt synchrotron emission and to the inverse-Compton component of the afterglow. Theory predicts that in a large fraction of the cases where synchrotron GeV prompt emission would be detected by GLAST, inverse-Compton photons should also be detected at high energies (≳ 10 GeV). Therefore, GLAST will enable a more precise test of the high-energy emission mechanism. Finally, we show that the contribution of GRBs to the flux of the extragalactic gamma-ray background measured with EGRET is at least 0.01%, and likely around 0.1%.
Continuous Hecke algebras

The theory of PBW properties of quadratic algebras, to which this paper aims to be a modest contribution, originates from the pioneering work of Drinfeld (see [Dr1]). In particular, as we learned after publication of [EG] (to the embarrassment of two of us!), symplectic reflection algebras, as well as PBW theorems for them, were discovered by Drinfeld in the classical paper [Dr2] 15 years before [EG] (namely, they are a special case of degenerate affine Hecke algebras for a finite group G introduced in [Dr2, Section 4]).
U(VI) oxygen polyhedra as pillars for building frameworks from uranophane-type layers

Solid state chemistry of uranyl-containing inorganic compounds has been enriched recently by a multiplication of papers dealing with two and three dimensional inorganic materials. This paper is a review of the compounds structurally based on uranophane–type layers in uranyl silicates, phosphates, arsenates and vanadates systems. Depending on the nature and size of the metallic or organic cation used as charge compensators or structure directing agents, various geometric isomers are obtained and described herein. The cations occupy either the interlayer space between uranophane-type sheets or different types of cavities created by a three dimensional inorganic framework built from uranophane layers pillared by U(VI) and oxygen polyhedra. The number of UO6 or UO7 pillars by [(UO2)(XO4)] structural block units of the layer give a series of compounds with the following general formula A2y/n{(UO2)1−y[(UO2)(XO4)]2} with y=0,1/3,1/2 and 1.
"Straight Arrow Science Policy" and Its Dangers

This paper pictures science as a unity of opposing forces. One such force is represented by the ideal of science as the dispassionate and unconstrained quest for truth. This ideal is both challenged and supported by another potent force; that is, the managerial ideal of the efficient use of resources in the pursuit of goals. We have explored the functions of this managerial force as it relates to science in some detail. We conclude that this concept of management is necessary to science, but also contrary to science. It is contrary in the sense that the pursuit of the managerial ideal detracts from and constrains the pursuit of the scientific ideal; but this managerial ideal must also be nourished and preserved. "They that endeavor to abolish vice, destroy also virtue; for contraries, though they destroy one another, are yet the life of one another. " (Sir Thomas Browne, Relizio Medici) And so it is with science and management.
SYNTHESIS OF FUNCTIONALIZED 3-PYRIDYL METHYL KETONES

A synthesis of 3-pyridyl methyl ketones is described that employs a palladium-catalyzed olefination of 3-bromopyridines with butyl vinyl ether followed by acid hydrolysis of the intermediate pyridyl vinyl ether in situ. This method has been applied to bromoquinoline substrates as well. The reaction is compatible with a variety of functional groups.
The CRC–NTMAC for Noisy Message Authentication

We present a new message authentication code (MAC) called the cyclic redundancy check-noise-tolerant message authentication code (CRC-NTMAC). The CRC-NTMAC improves upon the recently developed NTMAC. Unlike conventional MACs, such as the keyed-hash MAC (HMAC), the CRC-NTMAC and NTMAC tolerate a modest number of errors, such as might be caused by a noisy communications channel. Furthermore, both new MACs provide estimates of the number and locations of the errors. The CRC-NTMAC, however, provides better estimates and has a lower false acceptance probability. The CRC-NTMAC is also not based on cryptographic hash functions