cssi/SciSciGPT-SciSciNet huggingface dataset:
A simple, cost-effective, and novel method for determining the efficiency of industrial and commercial noise-canceling earmuffs

Context: There are several ways to assess the noise reducing efficiency of earmuffs, but they usually involve using human participants and/or specialized equipment. Objective: The current study was designed to develop a less labor-intensive, cost-effective, participant-free first-pass method for measuring the efficiency of earmuffs. Methods: We evaluated the noise-cancelling ability of five different types of earmuffs (3M: Optime 98, Optime 105; iDEA USA V201; Tronsmart Encore S6; Bose QuietComfort 35) under laboratory and field conditions. We compared our results to the microphone-in-real-ear (MIRE) method. Lastly, a survey of college-aged students was also conducted to determine which earmuffs were the most comfortable and provided the best fit. Results: Of the five earmuffs studied, the Optime 98 and Bose earmuffs were most effective at reducing noise levels in both the laboratory and field. These earmuffs also received the highest scores for comfort, fit, and perceived ability to reduce noise, with Bose being slightly more preferred than Optime 98. The MIRE method provided the same overall results as the laboratory and field tests. Conclusion: Our method for evaluating the noise-canceling ability of earmuffs could be used to supplement more complicated testing procedures as a first-pass method.
Inference for variance components in linear mixed-effect models with flexible random effect and error distributions.

In many biomedical investigations, parameters of interest, such as the intraclass correlation coefficient, are functions of higher-order moments reflecting finer distributional characteristics. One...
Explaining Attitudes Toward Refugees and Immigrants in Europe

While there is a large literature on attitudes toward immigrants, scholars have not systematically examined the determinants of attitudes toward refugees. Often, refugees are simply treated as a su...
Towards scalable soft e-skin: Flexible event-based tactile-sensors using wireless sensor elements embedded in soft elastomer

Scalable, high-density electronic skins (e-skins) are a desirable goal of tactile sensing. However, a realization of this goal has been elusive due to the trade-off between spatial and temporal resolution that current tactile sensors suffer from. Additionally, as tactile sensing grids become large, wiring becomes unmanageable, and there is a need for a wireless approach. In this work, a scalable, event-based, passive tactile sensing system is proposed that is based on radio-frequency identification (RFID) technology. An RFID-based tactile sensing hand is developed with 19 pressure sensing taxels. The taxels are read wirelessly using a single ‘hand-shaped’ RFID antenna. Each RFID tag is transformed into a pressure sensor by disconnecting the RFID chip from its antenna and embedding the chip and antenna into soft elastomer with an air gap introduced between the RFID chip and its antenna. When a pressure event occurs, the RFID chip contacts its antenna and receives power and communicates with the RFID reader. Thus, the sensor is transformed into a biomimetic event-based sensor, whose response is activated only when used. Further, this work demonstrates the feasibility of constructing event-based, passive sensing grids that can be read wirelessly. Future tactile sensing e-skins can utilize this approach to become scalable and dense, while retaining high temporal resolution. Moreover, this approach can be applied beyond tactile sensing, for the development of scalable and high-density sensors of any modality.
Na +-K +-ATPase Functions in the Developing Hippocampus: Regional Differences in CA1 and CA3 Neuronal Excitability and Role in Epileptiform Network Bursting

Despite the extensive literature showing the importance of the Na+-K+ pump in various neuronal functions, its roles in the developing brain are not well understood. This study reveals that the Na+-...
Electrochemical reduction of Cr(VI) in water: lessons learned from fundamental studies and applications

Converting toxic Cr(vi) to benign Cr(iii) would offer a solution to decontaminate drinking water. Electrochemical methods are ideally suited to carry out this reduction without added external reductants. Achieving this transformation at low overpotentials requires mediating the transfer of protons and electrons to Cr(vi). In this review thermodynamic parameters will be discussed to understand Cr(vi) speciation in water and identify reduction pathways. The electrochemical reduction of Cr(vi) at bare electrodes is reviewed and mechanistic considerations are discussed. Works on modified electrodes are compared to identify key parameters influencing the reduction. An overview of current applications to Cr(vi) reduction is briefly discussed to link fundamental studies to applications.
Secured Creditor Control and Bankruptcy Sales: An Empirical View

Since the early 2000s, the conventional view held by bankruptcy scholar is that the bulk of Chapter 11 cases re dominated by secured creditors, especially in large cases with more than $20 million of debt. It has been claimed that this creditor domination is so complete that it has been called “The End of Bankruptcy.” It is often claimed that this domination in turn has greatly increased sales of entire businesses under section 363 of the Bankruptcy Code in lieu of traditional reorganization. Analysis of a dataset from a cross section of 2006 Chapter 11 cases reveals that secured creditor control is important, but it is certainly not as pervasive as is commonly believed. This Article makes two major points: first, that the conventional picture of secured creditor control and section 363 sales is misleading and overstated; second, that the focus on very large cases instead of a cross section of Chapter 11 cases leaves a hole in the current research because our data suggest that dominant security interests are not strongly related to the size of the case. The data also make it clear that much more research will be necessary to understand the effects of secured credit on Chapter 11 cases and their outcomes.
Two-dimensional HYSCORE spectroscopy reveals a histidine imidazole as the axial ligand to Chl3A in the M688HPsaA genetic variant of Photosystem I.

Abstract Recent studies on Photosystem I (PS I) have shown that the six core chlorophyll a molecules are highly coupled, allowing for efficient creation and stabilization of the charge-separated state. One area of particular interest is the identity and function of the primary acceptor, A0, as the factors that influence its ultrafast processes and redox properties are not yet fully elucidated. It was recently shown that A0 exists as a dimer of the closely-spaced Chl2/Chl3 molecules wherein the reduced A0 − state has an asymmetric distribution of electron spin density that favors Chl3. Previous experimental work in which this ligand was changed to a hard base (histidine, M688HPsaA) revealed severely impacted electron transfer processes at both the A0 and A1 acceptors; molecular dynamics simulations further suggested two distinct conformations of PS I in which the His residue coordinates and forms a hydrogen bond to the A0 and A1 cofactors, respectively. In this study, we have applied 2D HYSCORE spectroscopy in conjunction with molecular dynamics simulations and density functional theory calculations to the study of the M688HPsaA variant. Analysis of the hyperfine parameters demonstrates that the His imidazole serves as the axial ligand to the central Mg2+ ion in Chl3A in the M688HPsaA variant. Although the change in ligand identity does not alter delocalization of electron density over the Chl2/Chl3 dimer, a small shift in the asymmetry of delocalization, coupled with the electron withdrawing properties of the ligand, most likely accounts for the inhibition of forward electron transfer in the His-ligated conformation.
Internal Structure; Effect of Hydrogen Bonding on Side-Chain Reactivity

This chapter describes the internal structure of protein solutions and the effect of hydrogen bonding on side-chain reactivity. It discusses the effects that arise from internal hydrogen bonding. These phenomena are in addition to the trivial electrostatic effects embodied and the statistical effects arising from the fact that many groups of a given kind ionize in a given pH region. However, other effects such as local electrostatic effects and hydrophobic bonding can also give rise to anomalies in the binding of protons and other small ions and molecules to proteins. Ultimately, criteria will have to be established to distinguish between these various effects. Titration curves, in providing information about anomalous reactivity of side-chain groups, may give clues about internal hydrogen bonding. This is only one of several different methods for locating hydrogen bonds in a protein molecule.
Estimating Market Power and Strategies: Strategic Reasons for a Dynamic Estimation Model

Until now, we have discussed estimating market power under the assumption that firms engage in a sequence of static games: In each period, a firm maximizes its current profit given its belief about how its rivals behave and assuming that actions in other periods do not affect behavior in this period. We now examine how to model games in which firms interact over many periods: where they play a dynamic game. Each firm maximizes its expected present discounted value of the stream of its future profits. When each firm solves a dynamic optimization problem in which its payoff depends on the behavior of other firms, the industry equilibrium is the solution to a dynamic game. We want to use observations on firms' behavior to measure the extent of competition in a dynamic game. The manner in which we estimate market power depends on the reason for the dynamics: the type of game that firms play. We distinguish between two types of reasons – strategic and fundamental – why firms might play a dynamic game rather than a sequence of static games. If dynamic interactions arise because firms think that their rivals will respond in the future to their current action, we say that the reason for the dynamics is strategic. If a firm solves a dynamic rather than a static problem because its current decision affects a stock variable that affects its future profits, we say that the reason for the dynamics is fundamental.
Rearrangement of snRNA structure during assembly and function of the spliceosome.

Publisher Summary This chapter discusses the idea that spliceosomal ribonucleic acid (RNA) works in fundamentally the same way in all systems is used to develop a cohesive representation of the rearrangement of the most conserved RNA–RNA interactions during splicing. The core of the spliceosome contains a highly conserved RNA structure, suggesting that the chemical events of splicing are based heavily on RNA–RNA interactions. Yet, spliceosomes from different organisms are not exactly the same. Most studies on splicing have used human (HeLa) cells or the yeast, Saccharomyces cerevisiae. Differences in splicing, and the intrinsic strengths and weaknesses of the experimental materials, have restricted some findings to one or other system, but the conservation of small nuclear RNA (snRNA), splicing factor structure, and hnction means that the yeast and human spliceosomes are very similar. Some RNA–RNA interactions are essential in both systems. Some make more important contributions to the function in one system than in the other, at least as assayed in the laboratory. Other interactions have not yet been shown to contribute to the function, but are inferred to be critical for success in the ultimate bioassay evolution.
Engineering Managed Care Automation via the Treatment Planning Process: A Bottom-up Approach

This paper describes implementing technology used for developing a personalized treatment plan using a specific treatment planning process and methodology. This methodology involves defining categories of treatment, goals that a program can assist patients to achieve, client objectives that evidence movement towards achieving specific goals, and interventions that can be performed by the program to accomplish these objectives. Each goal is issued a start and end (review) date. At the review date, whether a patient accomplished the goal or not will be assessed by a clinician using acceptable testing methods. Staff intervene according to the objectives for which the intervention has been designated and chart against these objectives by comments and assigning a progress indicator. Using this methodology which includes these two disjoint measures, care facilities can utilize technology to employ a paperless system that will standardize the process for developing a person-centered plan, identify program and staff deficiencies, evaluate the effectiveness of changes made to the program with respect to staff and patients, and capture information necessary to produce detailed billing. Software that implements this method has successfully been employed at the Rose Hill Center for Psychiatric Treatment & Rehabilitation in less than six months. Facilities using this software can transfer patients between programs and keep a longitudinal patient record. Funding has been granted to use this software to study best practices in the treatment of schizophrenia and schizoaffective disorder.
Research Directions for Big Data Graph Analytics

In the era of big data, interest in analysis andextraction of information from large data graphs is increasingrapidly. This paper examines the field of graph analytics fromsomewhat of a query processing point of view. Whether it bedetermination of shortest paths or finding patterns in a datagraph matching a query graph, the issue is to find interestingcharacteristics or information content from graphs. Many ofthe associated problems can be abstracted to problems onpaths or problems on patterns. Unfortunately, seemingly simpleproblems, such as finding patterns in a data graph matching aquery graph are surprisingly difficult. In addition, the iterativenature of algorithms in this field makes the simple MapReducestyle of parallel and distributed processing less effective. Still,the need to provide answers even for very large graphs isdriving the research. Progress, trends and directions for futureresearch are presented
Design tradeoffs in a hardware implementation of the k-means clustering algorithm

Hyperspectral imagery provides exquisitely detailed information but poses a serious challenge to the image analyst. Massive quantities of data must be reduced in a way that identifies useful features. Pixel clustering algorithms provide one approach: each pixel is assigned to a class based on the spectral similarity of that pixel to other members of the class. An image where each pixel is represented by its class provides a single picture (not hundreds of channels) for the analyst to interpret. Opportunities for fine-grain parallelism in this computationally intensive calculation motivate the consideration of specialized hardware. We are developing an FPGA-based implementation of the k-means clustering algorithm, because FPGAs can provide considerable speedup yet are sufficiently flexible to permit the testing of variants and tradeoffs. Assigning pixels to classes requires a definition of spectral similarity. The standard choice is the Euclidean distance. We consider two alternative distances: the Manhattan (sum of the absolute coordinate differences) and the Max (maximum of the absolute differences). The Euclidean distance is optimal in the sense of minimizing within-class variance, but requires computing many squares. The Manhattan and Max distances eliminate this squaring, and furthermore reduce the number of bits needed to store intermediate calculations. We conducted two sets of experiments to assess the tradeoff between quality of clustering and efficiency of hardware implementation. The first considered an idealized setup for assessing mis-classification rates and their effect on within-class variance. The second evaluated within-class variance for real 224-channel AVIRIS data sets. Both experiments confirmed that the highest quality clusters are achieved using the Euclidean metric, and quantified the difference.
Fritz Schmidt, Henry Sweeney and Stabilised Accounting

Abstract Dean and Clarke (1989) argue that the German Betriebswirtschafl theorist Fritz Schmidt, who was the author of the first comprehensive replacement cost model in the literature, had a greater influence on the development of Henry Sweeney's stabilised accounting ideas than the price-level-adjustment proponents, Eugen Schmalenbach and Walter Mahlberg. This paper argues that to identify Sweeney's stabilisation ideas with Schmidt's—even those incorporating replacement costs—is misleading. Sweeney's economic orientation was fundamentally different from Schmidt's and for this reason Sweeney never fully accepted Schmidt's model. Sweeney's and Schmidt's differing economic orientations reflect national attitudinal differences that have manifested themselves in more recent inflation accounting developments.
Clinical Outcome of Total Hip Arthroplasty Using the Normalized and Proportionalized Femoral Stem With a Minimum 20-Year Follow-Up

Currently, there are several femoral stem designs available for use, but few have an extended track record. We have previously reported on 10- and 15-year outcome studies of total hip arthroplasty (THA) using a cemented normalized and proportionalized femoral stem from a single surgeon series. This is a follow-up study reporting the minimum 20-year outcome of this femoral stem design. The study began with THA performed in a consecutive series of 184 patients; stem fixation was achieved using first-generation cementing techniques. The overall early complication rate was 10%. There were 23 patients (31 hips) who had been followed-up for a minimum 20-year period (average 21.3 years). Mean d'Aubigne and Postel scores improved from 5.9 to 11.3; mean Harris hip scores improved from 43.8 to 92.8. Kaplan-Meier survivorship was 93% at 20 years (95% confidence interval); there were no stem failures. The use of a cemented normalized and proportionalized femoral stem in primary THA provides satisfactory long-term clinical and radiological outcomes in patients.
Milk Test for Ketosis in Dairy Cows

Summary Twenty cows considered susceptible to ketosis were tested with a qualitative milk test for ketosis at weekly intervals for 4 wk. following calving. The results were compared with the quantitative levels of ketones in the blood and milk and the outward symptoms of ketosis. The milk test gave a conservative but accurate indication of the degree of ketosis. Fifty per cent of the cows maintained negative milk tests and showed no symptoms of ketosis. Forty per cent showed at least one mildly positive milk test, but did not require ketosis treatment. Ten per cent showed markedly positive milk tests and required treatment. There was a correlation coefficient of +0.87 between the blood and milk levels of the ketone fraction made up of acetoacetic acid and acetone. A lower correlation coefficient of +0.36 between the blood and milk levels of betahydroxybutyric acid could be attributed to utilization of this acid by the mammary gland. Total milk ketones were a little less than one-half the blood ketones.
Creep and drying shrinkage of calcium silicate pastes II. Induced microstructural and chemical changes

Abstract Structural changes occurring during creep and shrinkage of pure calcium silicate pastes were investigated. The tests included determination of pore structure and surface area by adsorption of H 2 O and N 2 . Helium inflow tests were also carried out. The degree of silicate polymerization was analyzed using the trimethylsilyl method. Penetration of He and H 2 O into the pore system is unaffected by the creep and shrinkage of the pastes. At low degrees of hydration drying decreases the N 2 surface area S(N 2 ), and increases the amount of highly polymerized silicate, while loading does not affect S(N 2 ) but inhibits the additional polymerization that can occur on drying. At high degrees of hydration, drying causes a slight reduction in S(N 2 ) while loading increases it. Drying, and especially loading and drying, promote silicate polymerization while loading without any drying does not induce significant changes.
A statistical framework for expression-based molecular classification in cancer

Summary. Genome-wide measurement of gene expression is a promising approach to the identification of subclasses of cancer that are currently not differentiable, but potentially biologically heterogeneous. This type of molecular classification gives hope for highly individualized and more effective prognosis and treatment of cancer. Statistically, the analysis of gene expression data from unclassified tumours is a complex hypothesis-generating activity, involving data exploration, modelling and expert elicitation. We propose a modelling framework that can be used to inform and organize the development of exploratory tools for classification. Our framework uses latent categories to provide both a statistical definition of differential expression and a precise, experiment-independent, definition of a molecular profile. It also generates natural similarity measures for traditional clustering and gives probabilistic statements about the assignment of tumours to molecular profiles.
Degenerate Hopf bifurcation and isolated periodic solutions of the Hodgkin-Huxley model with varying sodium ion concentration.

Points of degenerate Hopf bifurcation in the Hodgkin-Huxley model are found as parameters temperature T and voltage level of sodium V Na are varied. Local techniques of degenerate Hopf bifurcation analysis are used to show the existence of families of periodic solutions of the model: isolated branches of periodic solutions (i.e. branches not connected to the stationary branch) are found in addition to Hopf branches. Purely numerical techniques are used to show that the isolas persist for V Na up to a value slightly greater than 114 mV. Under some conditions there are multiple stable periodic solutions, so “jumping” between action potentials of different amplitudes might be observed.
Spectroscopic Analysis of the Structure of Silicate Glasses along the Joint xMAlO2‐(1–x)SiO2(M = Li, Na, K, Rb, Cs)

Infrared spectroscopic studies of charge-coupled substitution in silicate glasses and crystals along the joints xMAlO2(1 –x)SiO2 (M = Li, Na, K, Rb, and Cs; 0.10 ≤x≤ 0.60) were carried out in the range 2000 to 200 cm−1 Three major absorption bands appeared in the 1100-, 800-, and 500-cm−1 regions. For a specific value of x, the observed changes in frequency, intensity, and bandwidth decreased in the order Li > Na > K > Rb > Cs and the apparent disorder in the glass structure caused by the substituted aluminum increased in the direction K < Na < Li. The 800-cm−1 band splits at SiO2≃ 0.75 mol, which has been interpreted in terms of the number of AlO4 tetrahedra in the structure. Most of the substituted aluminum in the glasses and the crystals was found to be in the fourfold coordination.
Kinetic and thermodynamic characterization of DNA duplex-hairpin interconversion for two DNA decamers: d(CAACGGGTTG) and d(CAACCCGTTG)

The duplex-hairpin interconversion of two DNA decamers, d(CAACGGGTTG) and d(CAACCCGTTG), has been characterized thermodynamically and kinetically by using uv-melting and nmr relaxation methods. Separately, each decamer shows slow exchange between hairpin and duplex conformations. The hairpin conformations have melting points of 47 and 50 degrees C, respectively, and exhibit similar thermodynamic stabilities. The enthalpies of duplex formation, measured by nmr, were found to be very similar (delta HDH = 26 +/- 3 kcal/mole) for both decamers at low salt concentrations (< 50 mM NaCl). However, as the salt concentration was increased the behavior of delta HDH and kinetics is significantly different for each decamer. The d(CAACGGGTTG) decamer forms a duplex containing two central G.G mismatches at high salt and DNA concentration. Based upon the measurement of high interconversion activation energies and a decrease in hairpin formation rate with increasing salt, the interconversion between hairpin and duplex was concluded to proceed by complete strand dissociation. In contrast, the d(CAACCCGTTG) decamer was determined to form a duplex with two centrally located C.C mismatches at pH values less than 6.2, consistent with the formation of a hemiprotonated C+.C mismatch. At pH values greater than 6.4, the hairpin-duplex equilibrium is almost completely shifted toward the hairpin conformation at DNA concentrations of 0.5-7.0 mM and salt concentrations of 10-100 mM. The interconversion of duplex and hairpin conformations was ascertained by means of both kinetic and thermodynamic measurements to proceed by a slightly different mechanism than its complementary decamer. Although the interconversion proceeds by complete strand separation as suggested by high duplex-hairpin interconversion activation enthalpies, the increasing hairpin formation rate with increasing ionic strength as well as the delta HDH dependence on salt indicate that an intermediate internally bulged duplex (no C+.C formation) is stabilized by increasing ionic strength. These data support an interconversion mechanism where an intermediate internally bulged duplex may be the rate limiting step before strand separation.
Lumbar nerve rootlet entrapment by an iatrogenically spliced percutaneous intra-thecal lumbar cerebrospinal fluid catheter.

Background Complications associated with the use of percutaneous intra-thecal lumbar indwelling spinal catheters include infection, hematoma, neurologic dysfunction, and persistent undesired retention among others. A case of iatrogenic splicing associated with neurologic dysfunction with the use of a percutaneous intra-thecal indwelling spinal catheter is presented in this study.
Active-site determination of a pyrimidine dimer glycosylase.

Abstract One mechanism for the repair of UV-induced DNA damage is the base excision repair pathway. The initial step in this pathway and the specificity for the type of damage that is to be repaired reside in DNA glycosylase/abasic (AP) lyases. Cleavage of the glycosyl bond of the 5′ pyrimidine of a cyclobutane pyrimidine dimer is hypothesized to occur through the destabilization of the glycosyl bond by protonation of the base or sugar with a concomitant nucleophilic attack on C1′ of the deoxyribose moiety. Based on mechanistic biochemical information from several glycosylase/AP lyases and the structural information on the bacteriophage T4 pyrimidine dimer glycosylase (T4-pdg), the catalytic mechanism has been investigated for the Chlorella virus pyrimidine dimer glycosylase (cv-pdg). As predicted from modeling studies and reaction mechanisms, the primary amine that initiates the nucleophilic displacement reaction could be trapped as a covalent imine intermediate and its identity determined by sequential Edman degradation. The primary amine was identified as the α-amino group on the N-terminal Thr2. Site-directed mutagenesis was subsequently used to confirm the conclusions that the α-amino group of cv-pdg is the active-site nucleophile.
Evaluation of three different laser systems for the determination of lead by laser excited atomic fluorescence spectrometry with graphite tube atomizers

Abstract Three laser pumped dye laser systems were used in combination with graphite tube electrothermal atomization to detect ultratrace quantities of lead atoms in pure aqueous solutions. The frequency doubled radiation of a dye laser pumped by either a frequency doubled Nd:YAG laser, a nitrogen laser or a Cu vapor laser, was used as a light source in the atomic fluorescence study. The fluorescence was collected at 90° with a combination of a plane mirror, having a 0.2 cm diameter hole in its center to pass the laser beam, a spherical lens, and a monochromator or an interference filter. The direct line fluorescence measured at 405.78 nm gave detection limits in the femtogram to subfemtogram range. The best case occurred when the high repetition rate Cu vapor laser was used where a 0.5 fg detection limit was obtained.
Modeling Surface Transfer of Listeria monocytogenes on Salami during Slicing

: Listeria monocytogenes has been implicated in several listeriosis outbreaks linked to the consumption of presliced ready-to-eat (RTE) deli meats, which has drawn considerable attention in regard to possible cross-contamination during slicing operation at retail and food service environments. Salami with 15% fat (a moderate fat content deli item) was used to investigate the transfer of L. monocytogenes between a meat slicer and salami slices and to understand its impact on food safety. A 6-strain cocktail of L. monocytogenes was inoculated onto a slicer blade to an initial level of approximately 3, 5, 6, 7, or 9 log CFU/blade (or approximately 2, 4, 5, 6, or 8 log CFU/cm2 of the blade edge area), and then the salami was sliced to a thickness of 1 to 2 mm (case I). For another cross-contamination scenario, a clean blade was first used to slice salami loaf that was previously surface-inoculated with L. monocytogenes (approximately 3, 5, 6, 7, 8, or 9 log CFU/100 cm2 area), followed by slicing the uninoculated salami loaf (case II). The salami slicing rate was maintained at an average of 3 to 4 slices per minute in all the tests. The results showed that the empirical models developed in this study were reasonably accurate in describing the transfer trend/pattern of L. monocytogenes between the blade and salami slices if the inoculum level was > 5 log CFU on the salami or blade. With an initial inoculum at 3 or 4 log CFU, the experimental data seemed to suggest a rather random pattern of bacterial transfer between blade and salami. The currently developed models are microbial load (n), sequential slice index (X), and contamination route dependent, which might limit their applications to certain conditions. However, the models may be further applied to predict the 3 or 4 log CFU level (and below) cross-contamination of salami slicing process. Considering only few data are available in the literature regarding food pathogen surface transfer, the empirical models may provide a useful tool in building risk assessment procedures.
Comparison of Glycoalkaloid Content of Fresh and Freeze-Dried Potato Leaves Determined by HPLC and Colorimetry

As part of a program to control the biosynthesis of Solanum glycoalkaloids in potatoes, we used an HPLC assay to measure the specific α-chaconine and α-solanine content of greenhouse-grown potato leaves at different stages of maturity. Comparative studies were done with the bromophenol blue titration assay for total glycoalkaloids. We found that foliar glycoalkaloids can be extracted with 5% aqueous acetic acid, that analysis of glycoalkaloids with freeze-dried leaf powders was more reproducible than with fresh leaves, and that the bromophenol colorimetric method gave higher values than HPLC. As little as one leaf from a growing plantlet can be analyzed with the HPLC assay. Large variations in both α-chaconine and α-solanine contents of fresh leaves suggest that potato foliar glycoalkaloids should be determined by HPLC from freeze-dried rather than fresh leaves. Keywords: Glycoalkaloids; α-chaconine; α-solanine; potato leaves; biosynthesis; high-performance liquid chromatography; colorimetry; transgenic p...
Ion cyclotron emission due to fast Alfvén-wave radiative instabilities in tokamaks induced by newly born fusion products

The velocity distribution functions of newly born (t = 0) charged fusion products (protons in DD and alpha particles in DT plasmas) of tokamak discharges can be approximated by a monoenergetic ring distribution with a finite v∥ such that v⊥ v∥ V j where 1/2 M j V 2 j = E j , the directed birth energy of the charged fusion-product species j of mass M j . As the time t progresses, these distribution functions will evolve into a Gaussian in velocity (i.e. a drifting Maxwellian type), with thermal spreads given by the perpendicular and parallel temperatures T⊥(t) = T∥ j (t), with T j (t) increasing as t increases and finally reaching an isotropic saturation value of T⊥ j (t τ j ) = T∥ j (t τ j ) = T j (t τ j ) [M j T d E j /(M j + M)] 1/2 . Here T d is the temperature of the background deuterium plasma ions, M is the mass of a triton or a neutron for j = protons and alpha particles respectively, and τ j 1/4τ sj is the thermalization time of the fusion product species j in the background deuterium plasma, with T sj the slowing-down time. For times t of the order of T j , the distributions can be approximated by a Gaussian in the total energy (i.e. a Brysk type). Then, for times t ≥ T sj , the velocity distributions of the fusion products will relax towards their appropriate slowing-down distributions. Here we shall examine the radiative stability of all these (i.e. a monoenergetic ring, a Gaussian in velocity, a Gaussian in energy, and the slowing-down) distributions.
Macros that work

This paper describes a modified form of Kohlbecker’s algorithm for reliably hygienic (capture-free) macro expansion in block-structured languages, where macros are source-tosource transformations specified using a high-level pattern language. Unlike previous algorithms, the modified algorithm runs in linear instead of quadratic time, copies few constants, does not assume that syntactic keywords (e.g. if) are reserved words, and allows local (scoped) macros to refer to lexical variables in a referentially transparent manner. Syntactic closures have been advanced as an alternative to hygienic macro expansion. The problem with syntactic closures is that they are inherently low-level and therefore difficult to use correctly, especially when syntactic keywords are not reserved. It is impossible to construct a patternbased, automatically hygienic macro system on top of syntactic closures because the pattern interpreter must be able to determine the syntactic role of an identifier (in order to close it in the correct syntactic environment) before macro expansion has made that role apparent. Kohlbecker’s algorithm may be viewed as a book-keeping technique for deferring such decisions until macro expansion is locally complete. Building on that insight, this paper unifies and extends the competing paradigms of hygienic macro expansion and syntactic closures to obtain an algorithm that combines the benefits of both. Several prototypes of a complete macro system for Scheme have been based on the algorithm presented here.
THE OTHER SIDE OF SILENCE: RACHEL CARSON'S VIEWS OF ANIMALS

The publication of Rachel Carson’s Silent Spring in 1962 is widely regarded as one of the major events that launched the modern environmental movement. Silent Spring is a compelling blend of stories, natural history, human values, and biological facts. In this essay we consider Carson’s attitude toward animals in Silent Spring and in other texts. Despite the facts that she was raised to love Nature and animals, little direct attention has been given to Carson’s views about our moral responsibilities to, and the moral standing of animals. Carson favored responsible stewardship, was more of an animal welfarist and environmentalist/conservation biologist who privileged ecosystems and species than an animal activist who privileged individuals, and she did not advocate an animal rights agenda. There is clear tension in Carson’s text. Often she seemed troubled by attempting to come across as a moderate and practical scientist and some of her words, when considered out of context, could lead one to label Carson as an animal rightist. While some of Carson’s text favors human-centered interests, she did not believe that only humans counted. Her warnings about silent springs — silent seasons — must be taken seriously, perhaps even more seriously than when they were penned more than four decades ago. Surely, on the other side of silence, await magic, awe, and Nature’s cacophony of sounds — along with a panoply of innumerable other sensory (visual and olfactory) experiences that help us to feel at one with all of Nature. We must be careful never to allow Nature to be silenced. Carson was a passionate and extremely influential activist, and there is no doubt that if there were a world of Rachel Carson’s in charge of our global environmental policies, we and our fellow animals would surely be in much better shape than we currently are.
A general theory for dynamic instability of tube arrays in crossflow

A general theory of fluidelastic instability for a tube array in crossflow is presented. Various techniques to obtain the motion-dependent fluid-force coefficients are discussed and the general instability characteristics are summarized. The theory is also used to evaluate the results of other mathematical models for crossflow-induced instability.
SID-5 Is an Endosome-Associated Protein Required for Efficient Systemic RNAi in C. elegans

Summary In the nematode C. elegans , RNAi silencing signals are efficiently taken up from the environment and transported between cells and tissues [1–3]. Previous studies implicating endosomal proteins in systemic RNAi lack conclusive evidence [4, 5]. Here, we report the identification and characterization of SID-5, a C. elegans endosome-associated protein that is required for efficient systemic RNAi in response to both ingested and expressed double-stranded RNA (dsRNA). SID-5 is detected in cytoplasmic foci that partially colocalize with GFP fusions of late endosomal proteins RAB-7 and LMP-1. Furthermore, knockdown of various endosomal proteins similarly relocalizes both SID-5 and LMP-1::GFP. Consistent with a non-cell-autonomous function, intestine-specific SID-5 expression restored body wall muscle (bwm) target gene silencing in response to ingested dsRNA. Finally, we show that sid-5 is required for the previously described sid-1 -independent transport of ingested RNAi triggers across the intestine [6]. Together, these data demonstrate that an endosome-associated protein, SID-5, promotes the transport of RNAi silencing signals between cells. Furthermore, SID-5 acts differently than the previously described SID-1, SID-2, and SID-3 proteins [3, 6–8], thus expanding the systemic RNAi pathway.
Metabolic changes induced by tissue injury: in vitro studies with rat liver slices.

To study the metabolic response to tissue injury, in vitro studies with rat liver slices have been conducted. Liver slices, from fasted rats which had undergone standard midline laparotomy 24 hr before, showed a 14-fold increase in the incorporation of acetate-2-14C into cholesterol, with no change in the conversion of the acetate to other lipid fractions or 14CO2. The fate of L-alanine-14C has also been determined. The same physical injury brought about a 7-fold increase in the production of cholesterol-14C, a 66 per cent increase in the incorporation of the alanine into liver proteins, and a 35 per cent increase in the evolution of lactic acid-14C. The radioactivity of other lipid classes, 14CO2, glucose or glycogen was not significantly different from the corresponding control values. These data are compatible with a striking and specific stimulating action of surgical injury upon cholesterogenesis. In addition, though the known effect of physical injury in the peripheral tissues is excessive breakdown of proteins, the results suggest enhanced hepatic protein synthesis after injury.
A Q-Band/W-Band Dual-Band Power Amplifier in 0.12 µm SiGe BiCMOS Process

A three-stage dual-band power amplifier is demonstrated in 0.12 um silicon germanium (SiGe) BiCMOS process at both Q-band and W-band. The first two stages are pseudo-differential pre-amplifiers with a high-impedance dual-band load. The final stage is a single-ended power amplifier with an appropriate impedance to produce output power. The collector-emitter junction breakdown voltage of the amplifier is extended with a low-impedance base current biasing network. The amplifier achieves a peak power-added efficiency (PAE) of 15% with 14 dBm maximum saturated power (Psat) at 43 GHz and 9 dBm Psat at 82 GHz. The effective chip area is 1mm2 including input and output RF GSG pads.
The muscle activation of the erector spinae during hyperextension with and without the pelvis restrained

Abstract The purpose of this study was to determine if pelvic restraint during hyperextension on a variable angle Roman chair (VARC) changes the muscle activation of the erector spinae musculature. Seventy volunteers (18–35 years) performed hyperextension exercises on the VARC with and without the pelvis restrained. Surface electromyography (EMG) was used to measure the muscle activation of the erector spinae at the third lumbar vertebra (L3). Total root mean square (RMS) for eccentric and concentric phases were amplitude normalized to a maximal voluntary isometric contraction (MVIC). A post test questionnaire was used to determine the subjective feeling of localized fatigue. The EMG data were analyzed with a Multivariate Hotelling's T 2 test and univariate t -tests. The questionnaire data were analyzed using McNemar's test. Alpha was set at 0·05. A statistically significant ( p
Survey approach to estimating demand for physician assistants

A national probability sample of physicians was surveyed by mail to provide an estimate of the number of job openings for physician assistants (PAs). The responses were used to undertake an empirical analysis of the factors which influence a physician's decision to hire a PA. Estimates were adjusted to account for survey non-response. This approach may be useful for estimating the employment demand for other types of health workers employed by physicians. It was found that in 1976 there was an unconditional demand for 20,338 PAs and a further conditional demand for 3417 PAs. This contrasts sharply with the fact that as a march 1977 only 4845 PAs had graduated from training programs. Approximately 53% of this employment demand was from physicians in the primary care specialties (general/family practice. Obstetrics/gynecology, internal medicine, and pediatrics). Of note was the finding that physicians expected to pay PAs a lower salary than was being received in the market place. Further, 27% of physicians not willing to hire PAs indicated lack of knowledge about them as the main reason for not hiring.
Introduction to the general principles of hormone-receptor interactions

This review presents a concise overview of the historical development of receptor theory and the molecular mechanisms of action of the three broad classes of hormones, steroids, tyrosine derivatives, and polypeptides. Key terms required for understanding the basic terminology and concepts currently utilized in membrane receptor research are defined. The basic information should enable the reader to critically assess and understand more detailed discussions of hormone-receptor interactions and their application to clinical medicine.
Mutagenicity of ascorbic acid for the plant Arabidopsis

Abstract Mutagenicity of ascorbic acid and ascorbate has been demonstrated in Arabidopsis. The grequency of mutation at a very large number of loci consistently exceeded the spontaneous level when mature seeds were treated with 0.05–2.00% solution of this vitamin although the induced rate of mutation was apparently not much affected by the concentrations within this range. In six experiments the mutational events were scored by the phenotype of immature embryos. In another series of experiments, seedling mutations were assessed in M 2 generations involving over 330 000 genomes treated and approximately equal size concurrent control. Although the induced rate of mutation was low (0.00024 over all loci) in the latter series, it was highly significantly above the spontaneous level (0.00010).
Squamous-cell carcinoma of the anus in HIV-positive patients.

PURPOSE: Patients diagnosed as having anal cancer and human immunodeficiency virus (HIV)-positive disease were evaluated for response to treatment and its associated toxicity. METHODS: We studied nine HIV-positive patients with squamous-cell carcinoma of the anus. Among them, three patients had acquired immunodeficiency syndrome (AIDS). The stage of disease at presentation included: one Stage 0, two Stage I, two Stage II, and four Stage III patients. Seven patients received combined modality treatment,i.e.,radiation therapy and chemotherapy, and two patients received radiation therapy alone. The radiation therapy field included the pelvis and a conedown boost. Chemotherapy consisted of two cycles of 5-fluorouracil and mitomycin C. Patients have been followed from 2 to 42 (median, 8) months. RE-SULTS: Seven patients achieved a complete response clinically. All Stage I/II patients and one of four Stage III patients remain alive and have no evidence of disease. Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer Grades 3 and 4 skin toxicity were noted in six patients, and Grades 2 and 3 myelosuppression were noted in eight patients. The response rates achieved are comparable to the experience in non-HIV patients reported in the literature, but toxicity seems to be increased. CONCLUSION: It would seem reasonable to offer combined modality treatment to early stage, HIV-positive patients with good performance status and a history of minor opportunistic infections. The value of combined modality in AIDS patients and those who present with advanced stages of the disease is questionable.
X-ray detector using superconducting aluminum tunnel junctions

We report on tests of a prototype detector for 6-keV X-rays, using series arrays of tunnel junction. Tests with higher-energy particles indicate an energy resolution of 4 keV, at 0.3K and with a warm pre-amp. At lower temperatures and with a cooled FET, the resolution should approach 100 eV.
Sensitive determination of hexamethylene triperoxide diamine explosives, using electrogenerated chemiluminescence enhanced by silver nitrate.

Sensitive detection and quantification of hexamethylene triperoxide diamine (HMTD), which is one of commonly used explosives by terrorists, was presented on the basis of electrogenerated chemiluminescence (ECL) technology coupled with silver nitrate (AgNO3) enhancement in acetonitrile at a platinum electrode. Upon anodic potential scanning, HMTD irreversibly oxidized at ∼1.70 V vs Ag/Ag+ (10 mM) at a scan rate of 50 mV/s, and the ECL profile was coincident with the oxidation potential of HMTD in the presence of ruthenium(II) tris(bipyridine) (Ru(bpy)32+) luminophore species, which showed a half-wave potential of 0.96 V vs Ag/Ag+. The addition of small amounts of AgNO3 (0.50−7.0 mM) into the HMTD/Ru(bpy)32+ system resulted in significant enhancement in HMTD ECL production (up to 27 times). This enhancement was determined to be largely associated with NO3− and was linearly proportional to the concentrations of NO3− and Ag+ in solution. Homogeneous chemical oxidations of HMTD by electrogenerated NO3• and Ag(...
Coupling crystallography and Computational biochemistry in understanding heme enzyme structure and function

Computational methods and crystallography have been coupled to study structure–function relationships in cytochrome c peroxidase (CCP) and nitric oxide synthase (NOS). NOS is an important drug target and the structural details of NOS–inhibitor interactions are essential if structure-based drug design is to be of any use in the development of therapeutic agents targeted to NOS. The structure of 7-nitroindazole, a potent NOS inhibitor, complexed to one NOS isoform left some ambiguity in the precise orientation of the inhibitor. Various computational approaches were used to resolve this ambiguity as well as revealing the energetic basis for tight binding. With CCP site directed mutagenesis, crystallography and various computational tools have been used to understand why CCP is unique among the peroxidases in its ability to stabilize a tryptophan cation radical during catalysis. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002