cssi/SciSciGPT-SciSciNet huggingface dataset:
Review of the recent controlled experiments for study of local reconnection physics

The present paper reviews the recent laboratory experiments on magnetic reconnection focussing on the local features of the reconnection region. It is very important to recognize that magnetohydrodynamics (MHD) often breaks down locally in the thin reconnection layer, while globally, the reconnecting plasma has large Lundquist number and is well approximated by MHD equations. Precise measurements of the neutral sheet profile can provide important clues to help understand the non-MHD physics mechanisms of reconnection. Thanks to significant progress in data acquisition technology, the detailed magnetic field structure of the neutral sheet has been measured in laboratory plasmas. Extensive data have been accumulated in highly conductive MHD plasmas with large Lundquist numbers S = 10–1000. In this review we primarily focus on the physics data of the neutral sheet from the most recent laboratory experiments.
A near-optimal adaptive algorithm for maximizing modularity in dynamic scale-free networks

We introduce A$$^3$$3CS, an adaptive framework with approximation guarantees for quickly identifying community structure in dynamic networks via maximizing Modularity Q. Our framework explores the advantages of the power-law distribution property found in many real-world complex systems. The framework is scalable for very large networks, and more excitingly, possesses approximation factors to ensure the quality of its detected community structure. To the best of our knowledge, this is the first framework that achieves approximation guarantees for the NP-hard Modularity maximization problem, especially on dynamic scale-free networks. To certify our approach, we conduct extensive experiments in comparison with other adaptive methods on both synthesized networks with known community structures and real-world traces including ArXiv e-print citation and Facebook social networks. Excellent empirical results not only confirm our theoretical results but also promise the practical applicability of A$$^3$$3CS in a wide range of dynamic networks.
Electron Transfer Dissociation: Effects of Cation Charge State on Product Partitioning in Ion/Ion Electron Transfer to Multiply Protonated Polypeptides.

Abstract The effect of cation charge state on product partitioning in the gas-phase ion/ion electron transfer reactions of multiply protonated tryptic peptides, model peptides, and relatively large peptides with singly charged radical anions has been examined. In particular, partitioning into various competing channels, such as proton transfer (PT) versus electron transfer (ET), electron transfer with subsequent dissociation (ETD) versus electron transfer with no dissociation (ET,noD), and fragmentation of backbone bonds versus fragmentation of side chains, was measured quantitatively as a function of peptide charge state to allow insights to be drawn about the fundamental aspects of ion/ion reactions that lead to ETD. The ET channel increases relative to the PT channel, ETD increases relative to ET,noD, and fragmentation at backbone bonds increases relative to side-chain cleavages as cation charge state increases. The increase in ET versus PT with charge state is consistent with a Landau–Zener based curve-crossing model. An optimum charge state for ET is predicted by the model for the ground state-to-ground state reaction. However, when the population of excited product ion states is considered, it is possible that a decrease in ET efficiency as charge state increases will not be observed due to the possibility of the population of excited electronic states of the products. Several factors can contribute to the increase in ETD versus ET,noD and backbone cleavage versus side-chain losses. These factors include an increase in reaction exothermicity and charge state dependent differences in precursor and product ion structures, stabilities, and sites of protonation.
An empirical examination of the preference structure for the distribution of earnings

Abstract A perplexing diversity of theory has persisted concerning the topic of earnings distribution. Empirical studies to date have only added additional inconsistencies. The contradictory findings of earlier studies suggest that shareholders' distribution perferences may not be identical across firms and over time. This study empirically examines the aggregate preference structure for the distribution of earnings by extending existing methodologies to a dynamic model. In the final model tested, distribution perferences are measured in the context of other economic variables. A sample of 97 widely held firms observed over 20 semiannual periods from 1968 to 1977 provided the data base for this study. The results here suggest that the aggregate preferences for the distribution of earnings are dynamic and depend on the relative level of other variables. All of the adjunct variables selected for inclusion in the model—risk, growth, and market environment—were found to have a significant impact on the level of preferences. In each case, the direction of effect was consistent with intuitive positions of those supporting dividend relevance.
Dynamics of Leading-Strand Lesion Skipping by the Replisome

The E. coli replisome stalls transiently when it encounters a lesion in the leading-strand template, skipping over the damage by reinitiating replication at a new primer synthesized downstream by the primase. We report here that template unwinding and lagging-strand synthesis continue downstream of the lesion at a reduced rate after replisome stalling, that one replisome is capable of skipping multiple lesions, and that the rate-limiting steps of replication restart involve the synthesis and activation of the new primer downstream. We also find little support for the concept that polymerase uncoupling, where extensive lagging-strand synthesis proceeds downstream in the absence of leading-strand synthesis, involves physical separation of the leading-strand polymerase from the replisome. Instead, our data indicate that extensive uncoupled replication likely results from a failure of the leading-strand polymerase still associated with the DNA helicase and the lagging-strand polymerase that are proceeding downstream to reinitiate synthesis.
Low-frequency damped electroretinographic wavelets in young asymptomatic patients with dominant retinitis pigmentosa: a new electroretinographic finding.

Abstract Objective To describe a previously unreported electroretinographic (ERG) pattern in early retinitis pigmentosa (RP). Design Two case reports. Participants Two unrelated young asymptomatic patients with autosomal-dominant retinitis pigmentosa were studied. Main outcome measures Clinical findings and ERG responses were assessed. Results No ERG responses were detected scotopically with low-luminance stimuli. With increasingly brighter stimuli, a series of three to five low-frequency damped wavelets developed under both scotopic and photopic conditions. The period of the wavelets was 25 to 37 msec. Conclusions Low-frequency damped ERG wavelets occur in some young asymptomatic patients with autosomal-dominant RP. The ERG pattern suggests that these wavelets are predominantly cone-generated.
Dispersal and recruitment limitation in native versus exotic tree species: life‐history strategies and Janzen‐Connell effects

Life-history traits of invasive exotic plants are typically considered to be exceptional vis-a-vis native species. In particular, hyper-fecundity and long range dispersal are regarded as invasive traits, but direct comparisons with native species are needed to identify the life-history stages behind invasiveness. Until recently, this task was particularly problematic in forests as tree fecundity and dispersal were difficult to characterize in closed stands. We used inverse modelling to parameterize fecundity, seed dispersal and seedling dispersion functions for two exotic and eight native tree species in closed-canopy forests in Connecticut, USA. Interannual variation in seed production was dramatic for all species, with complete seed crop failures in at least one year for six native species. However, the average per capita seed production of the exotic Ailanthus altissima was extraordinary:  40 times higher than the next highest species. Seed production of the shade tolerant exotic Acer platanoides was average, but much higher than the native shade tolerant species, and the density of its established seedlings ( 3 years) was higher than any other species. Overall, the data supported a model in which adults of native and exotic species must reach a minimum size before seed production occurred. Once reached, the relationship between tree diameter and seed production was fairly flat for seven species, including both exotics. Seed dispersal was highly localized and usually showed a steep decline with increasing distance from parent trees: only Ailanthus altissima and Fraxinus americana had mean dispersal distances  10 m. Janzen-Connell patterns were clearly evident for both native and exotic species, as the mode and mean dispersion distance of seedlings were further from potential parent trees than seeds. The comparable intensity of Janzen-Connell effects between native and exotic species suggests that the enemy escape hypothesis alone cannot explain the invasiveness of these exotics. Our study confirms the general importance of colonization processes in invasions, yet demon strates how invasiveness can occur via divergent colonization strategies. Dispersal limitation of Acer platanoides and recruitment limitation of Ailanthus altissima will likely constitute some limit on their invasiveness in closed-canopy forests.
Analysis of a nonadiabatic flame propagating through gradients of fuel or temperature

Using the analytic techniques of large activation energy asymptotics applied to a slowly-varying flame, an equation is derived that describes the burning rate of an unsteady nonadiabatic flame traveling through shallow gradients in fuel concentration or temperature. Solutions of this equation show that (1) the transient burning rate responds more slowly to these gradients than does the local steady-state burning rate, (2) an unsteady flame in an inhomogeneous mixture propagates into a region where the mixture is outside of the homogeneous flammability limits predicted by the steady theory, and (3) the burning rate of the unsteady flame approaches zero at a finite position in the gradient, even with a single-step Arrhenius reaction mechanism. This behavior arises from the accumulation, of enthalpy in the preheat zone, which in turn arises from the differing rates of heat conduction and mass diffusion.
Effects of γ-hydroxybutyrate (GHB) and its metabolic precursors on delayed-matching-to-position performance in rats

Abstract The purpose of the present study was to provide further information about the effects of γ-hydroxybutyrate (GHB) on memory. Initially, the acute effects of gamma-butyrolactone (GBL, 75-200 mg/kg IP), 1,4-butanediol (1,4-BD, 100–300 mg/kg IP), and ethanol (1.0–3.0 g/kg, oral), as well as GHB (100–300 mg/kg IP), were examined in rats responding under a delayed-matching-to-position (DMTP) procedure with delays from 0 to 32 s. Acute administration of all four drugs reduced the number of trials completed and also reduced accuracy during delay trials, but not during trials without a delay. Some tolerance developed to the disruptive effects of GHB following exposure to 300 mg/kg/day for 29 consecutive days. These data indicate that GHB can disrupt working memory and speed of responding, and that tolerance can develop to these effects. Moreover, the acute effects of GHB under the DMTP procedure resemble those of its metabolic precursors, GBL and 1,4-BD, and of the prototypical CNS depressant drug, ethanol.
Re-interpretation of Wexfordia hookense from the Upper Devonian of Ireland as an arborescent lycophyte

New collections of pyritized axes of the lycophyte Wexfordia hookense have been made from the Upper Devonian (uppermost Famennian) type locality at Sandeel Bay, County Wexford, in south-eastern Ireland. The specimens reveal additional histological features that permit reinterpretation of the morphology of this taxon and reevaluation of its taxonomic affinities. Wexfordia is shown to possess both secondary xylem, with narrow, uni- to biseriate rays, and periderm. The range of variation in relative amounts of primary and secondary xylem can be correlated with position in the mature plant. This evidence indicates that Wexfordia was a small tree rather than an herbaceous form. Fine structure of tracheids and additional anatomical features strongly support affinities with Carboniferous arborescent Isoetales, rather than Devonian Protolepidodendrales, and further support the hypothesis that radiation in this lineage was well underway prior to the Carboniferous. © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society, 2004, 144, 275–287.
The breadth of imaging findings of groove pancreatitis

The pathogenesis of groove pancreatitis involves progressive cystic degeneration of hamartomatous pancreas rests which lie within the duodenal wall. Hamartomatous pancreatic rests can occur in other locations, but when located within the pancreaticoduodenal groove can lead to a particular clinical presentation following the development of fibrotic and inflammatory tissue. Although this is not a disease of the pancreas itself, the pancreatic duct and biliary system is frequently secondarily involved in this regional process. Identification of this entity and its varied appearances as a distinct pathology is essential given the unique management issues of groove pancreatitis.
Stepping out of bounds: Performing feminist pedagogy within a dance education community

Sprague (1992) asserts that communication scholars “should be leading other teacher educators”; in communication‐focused research that can better explain how teachers’ behaviors contribute to students’ development of critical consciousness. One useful way of highlighting teachers’ pedagogical behaviors is by viewing them as social performances that can either encourage or subvert students’ abilities and desires to transform society. This critical ethnography examines a dance education culture to see whether or not instructors within this culture perform behaviors that support their espoused critical feminist pedagogical philosophy. Although the authors argue that many of the instructors’ performances help construct a culture in which this philosophy is enacted, they conclude that embedded within some of the instructors’ performances are communicative actions that constrain greatly the development of a truly critical feminist pedagogy.
The Role of Certain Organic Sulfur Compounds as Preventive Antioxidants

Abstract The mechanism of autoxidation of organic materials by elemental oxygen is a free radical chain reaction initiated by hydroperoxide decomposition to form alkoxy and peroxy radicals. Chain scission and crosslinking reactions occur, along with the formation of hydroperoxide, resulting in degradation of properties of polymeric materials. The presence of unsaturation in natural and synthetic rubbers makes them particularly vulnerable to autoxidation, and antioxidants are thus essential to provide protection against oxidative degradation. There are two ways in which antioxidants can function to retard autoxidation. Preventive antioxidants act in some way to reduce the rate of initiation, while chain-breaking antioxidants intercept the chain-propagating peroxy free radicals and thus terminate the chain mechanism. Both types include a variety of compounds and possible modes of action as indicated in the following classification:
Video lecture capture (VLC) system: A comparison of student versus faculty perceptions

A Video Lecture Capture (VLC) system was implemented to address issues relating to retention, and to reverse the trend of high drop, failure, and withdrawal (DFW) rates. The purpose of this study was to examine student perceptions of how using VLC impacted their academic performance. Areas of interest surrounded students' perceived benefits, value, and helpfulness of using the system. In addition, the study probed the concern of many about the impact using VLC would have upon class attendance. Finally the study compared students' perceptions about their performance as a result of using VLC with faculty perceptions about their students' performance as a result of using VLC. It was hypothesized that there is a significant difference between student and faculty perceptions.
Interaction of Carbon Monoxide with Small Gold Clusters Inside TS-1 Pores

We report a two-layer, quantum mechanics/molecular mechanics analysis of CO adsorption on Au1-5 clusters located near T6-Ti-nondefect, T6-Si-nondefect, T6-Ti-defect, and T6-Si-defect sites in TS-1, augmented with thermochemistry at 298.15 K and 1 atm. The BPW91/LANL2DZ:UFF level of theory overestimates the adsorption energies compared to the BPW91/LANL2DZ/6-311+G(d, p):UFF level. In all the cases cluster−CO geometries are planar, and CO adsorption is thermodynamically favorable. The adsorbed CO is anionic, and the red-shift in the C−O stretching frequency, due to back-donation of electron density to the 2π* antibonding orbital in CO, is consistent with the elongation of the C−O bond. The Mulliken charge on adsorbed CO versus ΔEads of CO shows approximate linear correlation when both the quantities are plotted on a per Au atom basis, suggesting that the charge-transfer to adsorbed CO contributes significantly to ΔEads. The total charge on the cluster−CO adduct matches almost quantitatively with the negativ...
Natural cyclotron harmonic radiation from the ionosphere

Summary form only given. Earth's auroral ionosphere emits several types of spontaneous emissions, including auroral hiss, medium frequency burst, and roar. Auroral roar occurs at harmonics of the electron cyclotron frequency. The most commonly observed harmonic is 2fce, first reported in the 1970's. Since the 1990's, the 3fce harmonic has also been regularly observed from ground level. These emissions both favor pre-midnight magnetic local times and require darkness for observation at ground-level. Significant evidence has accumulated that they result from mode conversion of upper hybrid waves excited where the upper hybrid frequency matches the cyclotron harmonic. Satellite and rocket observations of the 2fce emission support that mechanism. Recently, two papers report observations of 4fce and 5fce emissions in Svalbard and in Antarctica. These higher harmonic emissions also favor pre-midnight magnetic local times but require sunlit ionosphere for observation. For all harmonics observed so far, the frequency scales linearly with the strength of the geomagnetic field at the observing station. Combining data from multiple stations allows estimation of source altitudes. Observations of the harmonics at a given station also provides a method for remotely sensing the ionospheric density.
A kinetic description of the concurrent process of nucleation, growth and coarsening

Phase transformations are often initialized by nucleation and growth of the nuclei of new phase inside the original one. Direct clues for revealing the microscopic mechanisms of nucleation and growth are furnished by macroscopic kinetic observations. Thus, a correct kinetic description of the nucleation and growth phenomena is important to both experimental and theoretical efforts aiming at understanding the phenomena. A kinetic description has been developed which can be used to describe the nucleation process, the growth process and the coarsening process or the concurrent nucleation, growth and coarsening process. The new kinetic description has already been employed to understand the kinetic behavior of supercritical crystallites. It is critical to the development of a new method for exploring directly the free energy, enthalpy and entropy barrier to nucleation of crystallites in amorphous matrix, as will be reported in a future work.
Spectrum attributes of frequency-steerable phased array antennas

When considering phased array radar systems it is important to consider the possible differences in the spectral content of radar emissions when comparing boresight to off-boresight. This detail is important as it can accentuate potential electromagnetic interference (EMI) effects between radar and other devices competing for space in a crowded spectrum. In order to analyze the potential impact of off-boresight radar emissions to other electronic devices, a MATLAB and electromagnetic model of a simple eight element slotted waveguide linear array operating at 3.5 GHz was simulated with an element spacing of a half-wavelength. The model was stimulated utilizing continuous wave (CW), pulsed amplitude, and linear Frequency Modulated Continuous-Wave (FMCW) waveforms. The spectral content of these emissions in the far-field was assessed at a variety of angles with respect to boresight. It was concluded that the eletromagnetic emissions power may be under measured if out of band emissions of a waveguide slot array are measured only at boresight resulting in compliance testing issues. This could result in the interference to other electronic devices being underestimated.
INDUCTION OF CHLOROSIS BY ULTRAVIOLET LIGHT IN NON‐IRRADIATED PLANT TISSUES*

Summary (1) Prolonged irradiation of portions of bean Ieaves with U.V. radiation of 2537 A results in (a) the development of chlorosis in adjacent non-irradiated portions of such leaves and (b) pronounced histological changes in epidermal and sub-epidermal layers of irradiated areas. (2) Induction of chlorosis is not associated with gross cell damage of non-irradiated tissues, but appears to be due to a specific effect on chlorophyll synthesis. (3) Some evidence is presented for the production of a diffusible water-soluble material by irradiated leaf portions which is responsible for the induction of chlorosis in adjacent portions of leaves not exposed to U.V. (4) The variety of responses of chloroplasts to U.V. irradiation is discussed.
Lipase-catalyzed synthesis of partial acylglycerols of acetoacetate†

Immobilized Rhizomucor miehei lipase (Lipozyme RMIM) was employed in the synthesis of partial acylglycerols of acetoacetate (C 4 H 6 O 3 , 3-oxobutanoic acid). Both 1(3)-sn-monoacetoacetyl glycerol (MAcG) and 1,3-sn-diacetoacetyl glycerol (DAcG) resulting from esterification of glycerol with ethylacetoacetate were isolated and identified by 1 H and 13 C NMR. An HPLC method for the separation and quantitation of these species was developed. The effects on product yield of coordinate variations in the amounts of enzyme, water, ethyl acetoacetate, and the ratio of immobilizing silica to glycerol were explored. This allowed creation of predictive equations relating these variables to product yield. Reaction conditions were thereby identified and validated under which maximum yields of MAcG and/or DAcG or total ester were predicted. The production of both MAcG and DAcG was markedly sensitive to water, with optimal yields obtained within a narrow range of added water contents. Substantial excesses of ethylacetoacetate ameliorated the inhibitory effect of water. MAcG was effectively produced with the lowest amount of RMIM investigated. It was necessary to use larger amounts of lipase to achieve high yields of DAcG, and even then actual yields were only 30% of theoretical maximum. In the absence of silica only MAcG was produced. Practical applications: Aceotacetyl esters of glycerol are potential prochiral building blocks for further chemical synthesis and exhibit the chemical reactivity of both the acetoacetyl moiety and of glycerol. They are thus of potential use in, for example, the production ofbiopolymers exhibiting any of a variety of features and functionalities. The use of enzymatic catalysis rather than chemical synthesis for their production offers advantages of reduced degradation and contamination due to the gentler reaction conditions characteristic of enzymatic catalysis, as well as a potential reduction in the costs to procure and dispose of catalyst.
Introduction to American Government: What is it Good for? Absolutely Everything

For those times when political science is again confronted with questions about its usefulness, we suggest that the classroom is a central arena for our discipline to reassert its relevance to the society in which we live. In particular, given the existence of our open and accessible political system, we argue that the introductory course taught as a general education requirement by nearly every political science department provides unique advantages for political science to justify itself as a relevant and necessary endeavor in comparison with most other academic disciplines. However, to truly take advantage of the unique position of political science we need to reevaluate some of our most basic assumptions about the reasons we have for teaching these introductory classes. Incorporating the latest research in teaching methods and theories of learning, we totally redesigned an introductory course from the ground up, basing this course around semester-long group projects geared towards enhancing the intern...
THERMODYNAMIC PROPERTIES OF ZIRCONIUM--CADMIUM AND CERTAIN OTHER SOLID SOLUTIONS.

Abstract The experimental work reported here has to do with the zirconium-rich zirconium-cadmium alloys. The phase diagram has been determined up to a concentration of 20 at. % Cd. Lattice parameters have been measured for the hexagonal phase. The vapor pressure of cadmium in equilibrium with the solid solution has been measured for both the hexagonal and cubic phases as a function of temperature and concentration. These data are considered together with earlier data on the Zr-Ag, Zr-In, Zr-Sn and Zr-Sb primary substitutional solid solutions. Empirical relations are found between the hexagonal ( c a ) ratio, the temperature of the transformation from cubic to hexagonal zirconium and the electronic specific heat coefficient on the one hand and the concentration of principal quantum number 5 electrons on the other. These simple relations suggest the possibility that the principal quantum number 5 electrons are entering a rigid conduction band in zirconium. In order to investigate this possibility, we have calculated the partial molal energy of cadmium in zirconium from the vapor pressure measurements. We have also done this for certain other solutions for which vapor pressure data have been published. We conclude that the rigid band model is a bad approximation and point out that this is in accord with recent quantum mechanical calculations. Furthermore, the effect of cadmium on the transformation temperature of zirconium is the resultant of two opposite and nearly balanced effects—an absolute zero energy effect which tends to stabilize the cubic form and an entropy effect which tends to stabilize the hexagonal form. Finally, it is shown that, for most of the solutions considered here, the energy of a Wigner-Seitz polyhedron is independent of concentration within experimental error.
Cathodic electrodeposition of mixed molybdenum tungsten oxides from peroxo-polymolybdotungstate solutions.

Mixed molybdenum tungsten trioxide films of varying stoichiometry (MoxW1 - xO3, 0 < x < 1) were prepared by cathodic electrodeposition on indium tin oxide (ITO)-coated glass substrates from aqueous peroxo-polymolybdotungstate solutions. Electrochemical quartz crystal microbalance (EQCM), cyclic voltammetry, and chronocoulometry were used to gain insight into the electrodeposition mechanism. The compositional and structural properties were characterized for MoxW1 - xO3 films deposited at intermediate potentials (−0.35 V vs Ag/AgCl) and sintered at 250 °C using energy-dispersive spectroscopy, X-ray diffraction, and Raman spectroscopy. These studies reveal that films consist of homogeneously mixed MoxW1 - xO3, with an enriched Mo content ranging in composition from 0.4 < x < 0.7 depending upon the mol % Mo present in the deposition solution. Chronoamperometry and spectroelectrochemical measurements were conducted to estimate lithium ion diffusion coefficients and coloration efficiencies for the mixed metal o...
The dynamics of cost‐plus pricing

Researchers report a sizable number of companies that use cost-plus pricing. While such a policy is normatively suspect, it is simple, conventional, and occasionally mandated by regulation. This paper investigates cost-plus pricing as a dynamic adjustment process. As a dynamic policy, cost-plus pricing is more flexible than has commonly been realized. When firms have constant or decreasing average costs, dynamic cost-plus pricing typically exhibits rapid convergence to the attracting member of a pair of fixed points. If the average cost function is sufficiently U-shaped, complicated and chaotic dynamics can emerge.
Rb Loss Causes Cancer by Driving Mitosis Mad

Aneuploidy is a hallmark of most human cancers, but whether it is a cause or a consequence of cellular transformation remains a subject of debate. The spindle checkpoint functions to prevent aneuploidy and plays a central role in this discussion. The checkpoint gene Mad2 is activated by E2F1 and overexpressed in cells lacking a functional Rb pathway. In this issue of Cancer Cell, Sotillo and coworkers report that Mad2 overexpression leads to chromosomal instability and tumorigenesis, indicating that Mad2 contributes to cancer development after Rb mutation. In a second paper, Weaver et al. report that aneuploidy has both tumor-promoting and -suppressing properties.
Quantitative protein synthetic rates in various tissues of a temperate fish in vivo by the method of phenylalanine swamping

1. A single high-dose injection of 14C- (or 3H-) phenylalanine was used for measurement of protein synthetic rates in tissues of toadfish, Opsanus tau, in vivo. 2. Average rates at 20 degrees C, as per cent of tissue protein synthesized per day, were as follows: liver, 14; head kidney, 15; gill, 7.7; spleen 5.0; heart, 2.3; testis, 1.4; epaxial and pectoral muscle, 0.20-0.23. Elevated rates in muscle (0.71%/day) were found in fed fish. 3. Temperature dependency (Q10) in the 10-20 degrees C range averaged 6-7 for tissues with high rates of protein turnover, and 3-4 in heart and muscle after two-weeks acclimation.
CHEMICAL PACEMAKERS : III. ACTIVATION ENERGIES OF SOME RATE-LIMITING COMPONENTS OF RESPIRATORY SYSTEMS.

1. In a previous paper it was found that 11,200 calories is obtained for the energy of activation in the oxidation of succinate to fumarate in the presence of crude beef heart extract when succino-dehydrogenase was made the limiting factor. 16,000 calories was obtained with this preparation when cytochrome-cytochrome oxidase was made the limiting factor. In the present paper activation energies of the components of this enzyme system are further studied. 2. Oxidation of p-phenylenediamine catalyzed by the extract and known not to involve the dehydrogenase component yields Arrhenius equation plots indicating a pacemaker reaction with a micro of 9,500 calories. 3. An activation energy of 17,500 calories is obtained for the oxidation of succinate to fumarate in the presence of the beef heart extract partially poisoned by pyrophosphate. Evidence is presented that this value corresponds to a link in the respiratory chain other than that of succino-dehydrogenase or cytochrome c-cytochrome oxidase. 4. Addition of a suitable amount of cresyl blue to a beef heart extract reaction mixture, completely inhibited by cyanide, restores the oxidation of succinate to normal in the presence of pure oxygen. In this system, in which the dye is substituted for the oxidase, when the enzyme extract (dehydrogenase) is made the limiting factor, a micro of 18,500 calories is obtained; when cresyl blue is made the limiting factor, the micro value is 22,000 calories. 5. Results of these experiments indicate that energies of activation are associated not with the enzyme as such, but with the particular reaction steps involving them as catalysts.
Relativistic shells: Dynamics, horizons, and shell crossing

We consider the dynamics of timelike spherical thin matter shells in vacuum. A general formalism for thin shells matching two arbitrary spherical spacetimes is derived and subsequently specialized to the vacuum case. We first examine the relative motion of two dust shells by focusing on the dynamics of the exterior shell, whereby the problem is reduced to that of a single shell with different active Schwarzschild masses on each side. We then examine the dynamics of shells with nonvanishing tangential pressure p, and show that there are no stable\char22{}stationary, or otherwise\char22{}solutions for configurations with a strictly linear barotropic equation of state, $p=\ensuremath{\alpha}\ensuremath{\sigma},$ where $\ensuremath{\sigma}$ is the proper surface energy density and $\ensuremath{\alpha}\ensuremath{\in}(\ensuremath{-}1,1).$ For arbitrary equations of state, we show that, provided the weak energy condition holds, the strong energy condition is necessary and sufficient for stability. We examine in detail the formation of trapped surfaces, and show explicitly that a thin boundary layer causes the apparent horizon to evolve discontinuously. Finally, we derive an analytical (necessary and sufficient) condition for neighboring shells to cross, and compare the discrete shell model with the well-known continuous Lema\^{\i}tre-Tolman-Bondi dust case.
Site-specific labeling of Saccharomyces cerevisiae ribosomes for single-molecule manipulations

Site-specific labeling of Escherichia coli ribosomes has allowed application of single-molecule fluorescence spectroscopy and force methods to probe the mechanism of translation. To apply these approaches to eukaryotic translation, eukaryotic ribosomes must be specifically labeled with fluorescent labels and molecular handles. Here, we describe preparation and labeling of the small and large yeast ribosomal subunits. Phylogenetically variable hairpin loops in ribosomal RNA are mutated to allow hybridization of oligonucleotides to mutant ribosomes. We demonstrate specific labeling of the ribosomal subunits, and their use in single-molecule fluorescence and force experiments.
Decisional capacity in pregnancy: a complex case of pregnancy termination.

Perinatal psychiatric illness is common and can carry significant morbidity and mortality for mother, fetus, child, and family. Among women pregnant in the past year, up to 25.3% meet criteria for a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition psychiatric disorder, 8% meet criteria for a new psychiatric disorder, and 0.4% meet criteria for a psychotic disorder. Maternal schizophrenia and acute psychosis during pregnancy have been associated with higher risks of adverse pregnancy and birth outcomes, unplanned and unwanted pregnancies, parenting difficulties, and loss of custodial or parental rights. Perinatal psychiatric illness may impair a woman's judgment, self-care, decision-making, giving rise to sensitive and complex legal and ethical issues related to psychiatric, obstetric, and neonatal care. Although the literature on perinatal psychiatric illness is growing rapidly, there is a relative absence of information on the complex legal and ethical issues that may arise in the care of these patients, especially regarding the question of pregnancy termination.
Competing phytoplankton undermines allelopathy of a bloom-forming dinoflagellate

Biotic interactions in the plankton can be both complex and dynamic. Competition among phytoplankton is often chemically mediated, but no studies have considered whether allelopathic compounds are modified by biotic interactions. Here, we show that compounds exuded during Karenia brevis blooms were allelopathic to the cosmopolitan diatom Skeletonema costatum, but that bloom allelopathy varied dramatically among collections and years. We investigated several possible causes of this variability and found that neither bloom density nor concentrations of water-borne brevetoxins correlated with allelopathic potency. However, when we directly tested whether the presence of competing phytoplankton influenced bloom allelopathy, we found that S. costatum reduced the growth-inhibiting effects of bloom exudates, suggesting that S. costatum has a mechanism for undermining K. brevis allelopathy. Additional laboratory experiments indicated that inducible changes to K. brevis allelopathy were restricted to two diatoms among five sensitive phytoplankton species, whereas five other species were constitutively resistant to K. brevis allelopathy. Our results suggest that competitors differ in their responses to phytoplankton allelopathy, with S. costatum exhibiting a previously undescribed method of resistance that may influence community structure and alter bloom dynamics.
Research evaluation and diagnosis of possible Alzheimer’s disease over the last two decades: II

Objective: To describe the experience of a research clinic diagnosing possible AD during the last two decades. Background: The National Institute of Neurological and Communicative Disorders and Stroke–Alzheimer’s Disease and Related Disorders Association criteria for possible AD are generally used to indicate that a patient has AD in association with another disease process that could by itself cause dementia. There are no studies describing how these criteria should be applied, and there are no descriptions of functional and cognitive progression or survival in possible AD. Methods: The authors examined the clinical characteristics of 267 patients diagnosed with possible AD at the AD Research Center of Pittsburgh from 1983 to 2000 and the likelihood of arriving at four endpoints: Mini-Mental State Examination score of ≤ 9, Blessed Dementia Rating Scale for activities of daily living score of ≥ 12, nursing home admission, and death. Results: The possible AD classification has been simplified in six categories: possible AD with cerebrovascular disease (CVD) (69%), with history of alcohol abuse (15%), with history of depression (7%), with thyroid disease (4%), with history of head trauma (6%), with vitamin B12 deficiency (6%), and with other disease process that may have affected the clinical presentation of AD (4%). The presence of CVD, history of alcohol abuse, and history of depression concomitant with the onset of dementia were associated with time to death. Neither thyroid disease, history of head trauma, nor vitamin B12 deficiency were associated with any of the four endpoints. Conclusion: This cohort showed that comorbid conditions that can affect cognition delineate clearly defined subgroups in AD. The presence of environmental or other brain disorders sufficient to produce dementia appears to affect physical survival in patients with AD, but not functional and cognitive decline or institutionalization.
Deforestation of montane cloud forest in the Central Highlands of Guatemala: contributing factors and implications for sustainability in Q’eqchi’ communities

Cloud forest in the Central Highlands of Guatemala provides important ecosystem services for the Q’eqchi’ Maya but has been disappearing at an increasing rate in recent decades. This research documents changes in cloud forest cover, explores some contributing factors to deforestation, and considers forest preservation and food security implications for Q’eqchi’ communities. We used a transdisciplinary framework that synthesized remote sensing/GIS analysis of land cover change, focus group dialogs, and surveys. Expansion of subsistence agriculture is a key proximate cause of cloud forest removal, followed by extraction of fuelwood and larger-scale logging operations. Predisposing environmental factors such as rugged topography, steep slopes, and poor soils contribute to low agricultural productivity that contributes to increased conversion of forest to agricultural land. The key underlying driving forces for deforestation locally are population growth and subdivision of land. Population growth is increasin...
The influence of moment of inertia on baseball/softball bat swing speed

The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent, the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets, balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured speeds, from 22 to 31 m s−1, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest the importance of additional degrees of freedom in determining swing speed.
QQML 2009 International Conference: ''Qualitative and Quantitative Methods in Libraries''

Purpose – This review reports on the first Qualitative and Quantitative Methods in Libraries International Conference held in Chania, Crete, Greece.Design/methodology/approach – The methodological approach is anthropological participant observation.Findings – Approximately 150 attendees from 50 different countries participated and exchanged ideas, methodologies, and techniques related to library research.Practical implications – Presentation of research related to various types of libraries is a way to disseminate research results as well as promote and stimulate further research.Originality/value – There is a need to expand the body of both qualitative and quantitative LIS research related to library research, particularly the evaluation of library services.
Absolute orientation of molecules at interfaces.

A method to determine the absolute orientation of molecules at liquid interfaces by sum frequency generation (SFG) is reported. It is based on measurements of the orientations of two nonparallel vibrationally active chromophores in the molecule of interest combined with a rotation matrix formulation to obtain the absolute molecular orientation. We chose m-tolunitrile, a planar molecule adsorbed to the air/water interface, as a proof-of-method experiment. Quantitative analysis of different polarization sum frequency intensities facilitate unique peak assignments of the methyl and nitrile groups of m-tolunitrile. The SFG analysis of the measurement yields a nitrile group tilting at 53° to the surface normal, and the C3 axis of the methyl group is almost upright at 23° with respect to the surface normal. Using a rotation matrix formulation, we found that the angle between the surface plane and the m-tolunitrile molecular plane is 70°.
Na-K-2Cl cotransporters are present and regulated in simian eccrine clear cells

In freshly dissociated rhesus palm eccrine clear cells, regulatory volume increase (RVI) was studied using image analysis as a measure of Na-K-2Cl cotransport activity. Pseudo-RVIs, as well as RVI during methacholine (MCh)-induced cell shrinkage, were observed in clear cells and were inhibited by 100 microM bumetanide or in Na-free medium, but were not inhibited by amiloride or ouabain. RVI in hypertonic medium and RVI after MCh-induced cell shrinkage were accelerated by adenosine 3',5'-cyclic monophosphate (cAMP)-elevating agents (forskolin+isoproterenol) and inhibited by phorbol ester. RVI in hypertonic medium was enhanced by a phosphatase inhibitor, okadaic acid. mRNA for Na-K-2Cl cotransporter (NaKCC) was demonstrated in freshly isolated rhesus sweat secretory coils by polymerase chain reaction (PCR) after reverse transcription using a set of primers derived from the published human NaKCC (hNaKCC) 1 sequence, i.e., nucleotides 2,043-2,810. The deduced amino acid sequence of the PCR-amplified 767-base pair segment was identical to that of hNaKCC 1 from a human colon cell line (T84). The data are interpreted to indicate that NaKCC, showing strong homology to secretory type hNaKCC 1, is present in rhesus eccrine secretory coils and may participate in the cotransport component of eccrine sweat secretion and cell volume regulation, especially during cholinergic stimulation. The data also raise the possibility that sweat gland NaKCC may be upregulated by cAMP-mediated protein phosphorylation and downregulated by protein kinase C.
Identification of cancer specific high affinity targeting ligands by screening One-bead-one-compound and small molecule combinatorial libraries

A220 Drug discovery is a difficult and time consuming process that involves the identification of potent therapeutic agents with good bio-availability, metabolic stability, and low toxicity. An important first step in this process is the identification of molecules that bind with high affinity and selectivity to the biological target. In the “one bead one compound” combinatorial library method, millions of random peptides can be generated rapidly, such that each bead displays only one peptide entity. When live cancer cells are co-cultured with these peptide-bead libraries, beads with cell adhesion peptides will be covered entirely by the cells. These positive peptide-beads are then isolated for sequence analysis. Using this high throughput screening approach, we evaluated four different peptide libraries and identified several peptides that bind to pancreatic cancer cells. We also constructed, solution phase small molecule combinatorial chemistry libraries with highly diverse 9216 membered small molecule having 2,4-dinitrobenzene as base structure. This was screened concurrently against pancreatic cancer cells and normal cells to identify pro-apoptotic compounds. This library was distributed to multiple 96 well plates with 8 compounds per well at a final concentration of 12.5 µM, 25 µM, 37.5 µM and 50 µM per compound. Several plates were made in replicas and one type of cell was used per plate. Approximately 100 cells (cancer or normal ductal cells) were added to each well and cell growth was monitored every day for five days. Immortalized pancreatic ductal cells (p-TERI-HPNE) and low passage pancreatic cancer cells XPA1,and XPA3 were used for this study. The compounds that induced apoptosis in only cancer cells but not normal cells were re-tested. Those compounds that were re-tested positive in three consecutive times were further characterized. Apoptotic and migration assays were performed. Three compound-wells showed specific growth inhibition on cancer cells and not normal cells. These active molecules may have therapeutic potential for pancreatic cancer, either alone or in combination with other therapies. This work is supported by grant R03 CA129786-01, DOD-CM064046 and Children’s Miracle Network grant.
Photophysics of Open C60 Derivatives

In this report we examine the photophysical properties of two novel C60 derivatives. These compounds consist of a ring-opened C60 derivative (2) and its dihydro precursor (1), both of which include an orifice. The ground-state absorption spectra and the triplet−triplet absorption spectra were recorded for both derivatives. Extinction coefficients for the ground-state absorption (e) and the triplet excited state (ΔeT-T) were calculated. The derivatives have triplet energies (ET) lower than that of C60, and the triplet quantum yields (φT) are somewhat lower than that of C60. These compounds remain good photosensitizers for the formation of singlet oxygen, with high quantum yields (φΔ). Thus, in many respects the photophysics of these buckyballs with an orifice still resemble pristine fullerenes.