cssi/SciSciGPT-SciSciNet huggingface dataset:
Accurate calculations on excited states: new theories applied to the –OX, –XO, and –XO2 (X=Cl and Br) chromophores and implications for stratospheric bromine chemistry

Abstract Electronic excitation energies are determined using single-reference based theories derived from response equations involving perturbation theory and coupled-cluster theory. These methods are applied to the singlet manifold of excited electronic states of the HClO, HBrO, HOClO, HOBrO, HClO2, and HBrO2 molecules. Vertical excitation energies (VEEs) for the lowest symmetry unique triplet states are also computed using coupled-cluster theory. Both the singlet and triplet coupled-cluster VEEs are found to be in excellent agreement with experiment for HOBr and HOCl. The reliability of the various perturbation theory approaches is assessed by comparison to the linear response coupled-cluster method, and the CIS(D3) approach is found to perform the best, on average. In order to obtain reliable VEEs for these molecules, CIS(D3) is the recommended approach, unless excited state non-dynamical electron correlation is significant, in which case the recently proposed CIS(D0) technique may perform better, on average. For both the HClO2 and HBrO2 molecules, it is found that the lowest singlet excited electronic state occurs at too high an energy for it to be accessible from solar radiation in the lower stratosphere. The stratospheric chemistry implications of this, especially for bromine chemistry are discussed. It is suggested that YBrO2 molecules may in fact be the only stable stratospheric bromine reservoir species under light conditions.
Studies on the separation of pyridine nucleotides by thin-layer chromatography

Abstract Thin-layer chromatography has evolved as an analytical method having several advantages over separations using paper chromatography. The main advantages are speed of analysis and ease of recovery of the sample from the supporting media. The present report describes a thinlayer chromatographic method for the separation of oxidized and reduced diphosphopyridine and triphosphopyridine nucleotides together with data concerning the stability of these compounds under the conditions of tissue extraction procedures.
Measurement of Sticky Point Temperature of Coffee Powder with a Rheometer

Sticky point temperature is a parameter that quantifies stickiness of food and biological powders. It is traditionally measured using glass instruments. In this study, a new methodology was developed to measure sticky point temperature using a rheometer, and it was successfully used to determine sticky point temperature for coffee powder samples. The behavior of coffee sticky point temperature as a function of moisture content (%, dry basis) was observed to be non-linear, but after 16% (dry basis) moisture content, there were no changes in sticky point temperature with further increases in moisture content. An exponential prediction model for sticky point temperature = f (moisture content) was achieved with an R2 value greater than 0.93; a power law regression model also fitted well, with an R2 value of 0.97. Rheometry was shown to be a viable and convenient means to determine sticky point temperature for various coffee powders.
Significance of isotope effects for secondary-ion emission models

Differences in the ionization probabilities P of the isotopes of an element have been investigated and compared to the predictions of secondary-ion emission models. The relative differences in P for two isotopes depend inversely on the ion emission velocity v but approach a constant value for small v. Both this variation and the observed linear dependence on mass difference follow from an exponential correlation between P and v, Pproportionalexp(-v/sub 0//v), as predicted by the bond-breaking model. This agreement confirms the validity of this concept for secondary-ion emission from samples with some ionic character (halides and oxides). The parameter v/sub 0/ was determined for all ion-substrate systems investigated.
THE INCIDENTAL ACQUISITION OF SPANISH: Future Tense Morphology Through Reading in a Second Language

The present study examines the processing of Spanish future tense morphology incidentally while reading in a second language. Previous L1 and L2 reading research has demonstrated that readers can acquire new vocabulary as a result of reading, but can they also acquire formal properties of the second language grammatical system? The participants in the present study had no previous knowledge of future tense morphology such that, as they read the passage used in the study, they encountered the target form for the first time, which is an accented a on the end of an infinitive—for example, dependera “he, she, or it will depend.” Several variables were manipulated: (a) the frequency with which the target form appeared in the input passages (6, 10, or 16 exposures); (b) the learner-readers' orientation to the task (neutral, meaning oriented, or form oriented); and (c) cues to meaning (the presence or absence of future-oriented adverbials). The effects of these variables were measured on both comprehension and input processing immediately after reading, 2 weeks later, and 1 month later. Comprehension was measured with a free-written recall and a multiple-choice comprehension test. Input processing was measured with a multiple-choice form recognition test and a modified cloze-form production test. The results indicate that all three variables have some effect on comprehension and input processing.
Thermal equilibration in doped amorphous silicon.

The structure of doped amorphous silicon is shown to be in metastable thermal equilibrium above 130\ifmmode^\circ\else\textdegree\fi{}C, having temperature-dependent densities of dangling bonds and donors. The time to reach equilibrium is thermally activated, so that cooling establishes a slowly relaxing nonequilibrium state resembling a glass. The results are interpreted in terms of the recent defect-compensation model of doping.
Electron microscopic study on reassembly of plasma high density apoprotein with various lipids.

Products resulting from the sonification of mixtures of plasma high density lipoprotein apoprotein and specific lipids were studied by electron microscopy using negative staining. Sonicates of apoprotein plus lecithin produced disc-shaped structures which stacked in aggregates with a 50–55-A repeat; the discs were 100–200 A in diameter. Incorporation of unesterified cholesterol into the mixture produced structures morphologically similar to those observed in sonicates of apoprotein plus lecithin. Disc-shaped particles from sonified mixtures of apoprotein, lecithin and unesterified cholesterol were ultracentrifugally isolated in the d 1.063–1.21 g/ml fraction and were incubated with a plasma d > 1.21 g/ml fraction containing lecithin: cholesterol acyltransferase activity. Electron microscopy following the incubation procedure showed a transformation of the disc-like structures into approximately spherical particles (50–100 A diameter). Similar spherical particles were also obtained after sonification of apoprotein-lecithin-unesterified cholesterol-cholesteryl ester mixtures. Results indicate a requirement for the presence of cholesteryl esters to maintain normal morphology of plasma high density lipoproteins.
Marketing culture and marketing effectiveness in service firms

Examines the importance of the marketing culture of a service firm by pinpointing the strength of its association with marketing effectiveness. First, collects data to validate and purify a measure of marketing effectiveness. Second, undertakes a procedure to discover the nature of the relationship between the kind of marketing culture a firm has and its marketing effectiveness. The findings reveal a strong relationship between these two constructs even when the possible effects of firm size and geographical scope are removed.
Designing Online Courses: User-Centered Practices.

Abstract Teachers who develop Web-based courses must learn to act like designers; however, the type of design practice one undertakes has more than pedagogical implications. It can have political and ethical implications as well. In this article, I compare two models for design—systems and user-centered—each of which embodies different values. I argue that models of technology design can be applied to the development of Web-based courses and that various forms of user-centered design embody the values most compatible with writing instruction. While acknowledging the difficulties of enacting such models when developing Web-based courses, I present strategies for adopting a user-centered design paradigm in distance learning.
The Role of Deiodinases in Amphibian Metamorphosis

Valerie Galton's prediction over 40 years ago that deiodinases would be important in amphibian metamorphosis has been confirmed. Expression of iodothyronine deiodinase type 2 (D2) and type 3 (D3) occurs in embryogenesis at relevant locations long before the thyroid gland has developed. The expression of D2, an enzyme that synthesizes the active hormone triiodothyronine (T3) from its circulating precursor thyroxine (T4), accurately marks cells at the time that they undergo thyroid hormone-dependent changes. D2 expression in the anterior pituitary controls the maturation of the negative feed back loop between the pituitary and the thyroid gland. The expression of D3, an enzyme that inactivates the hormone, protects cells from responding to the hormone. Its constitutive expression in the dorsal ciliary marginal zone of the tadpole retina results in asymmetric replication of the ventral retina. This in turn leads to ipsilateral projections at the climax of metamorphosis as the frog develops over lapping visual fields. The genes encoding D2 and D3 appear to function in a cell autonomous manner affecting just the cells in which they are expressed. Localized deiodinases represent one of the simplest and most elegant methods to control gene expression, by regulating local concentration of the active hormone in specific cells.
The effect of instructor‐prepared handout materials on learning from lecture instruction

This study investigated the effect of organization and accuracy of detail in instructional aids on the achievement of students in a freshman college chemistry lecture course. Treatments consisted of (1) no aid, which was assumed to be low in detail and low in instructor organization; (2) a script given prior to lectures, which was assumed to be moderate in instructor organization and high in detail; and (3) outline provided prior to lectures, which was assumed to be high in instructor organization and moderate in detail. The treatments were randomly assigned to three intact classes of 54 students in freshman chemistry. All students were instructed on three different topics by means of videotaped lectures. Students were given a pretest, and following instruction on each of the three topics, they were given posttests. Results seem to indicate that the more aid in organization provided by the instructor prior to the lecture, the lower the student achievement. That is, students provided no aids achieved higher than those given a script, and those given a script achieved higher than those given an outline. The effect of amount of detail provided followed no clear pattern.
A damping boundary condition for coupled atomistic---continuum simulations

Many atomistic---continuum coupling techniques employ an overlapping subdomain to suppress spurious wave reflections. In this paper, we propose the imposition of a new damping condition on the overlapping subdomain to enhance the capability of such methods in eliminating spurious wave reflections. In this technique, the total displacements of the atoms in the overlapping subdomain are decomposed into fine and coarse scales. The fine scale displacements represent the oscillations which cannot be resolved by the continuum mesh and must be eliminated to avoid the artificial reflections. This is achieved by modifying the equations of motion of the fine scale displacements to include a damping term. The flexibility of the proposed technique is verified by applying it to the bridging scale method and bridging domain method. Numerical simulations of one- and two-dimensional problems demonstrate the effectiveness of the technique in enhancing the elimination of the spurious wave reflections in coupled atomistic---continuum techniques.
Measurement of Nuclear Spin by the Method of Molecular Beams The Nuclear Spin of Sodium

A simple method of velocity selection of arbitrary resolving power for atomic and molecular beams is described. The method consists in spreading the beam into a velocity spectrum, through the action of external fields, and then selecting a portion thereof by means of a movable selector slit. Since all the atoms of the beam of the given velocity interval are utilized, this type of selection has the maximum efficiency. In addition a method of focussing the selected beam to increase intensity and resolution is applied. A ballistic method of using the surface ionization detector was evolved extending its use to beams of exceedingly low intensity. A selected beam of slow Na atoms, obtained and measured in this fashion, was analyzed in a weak and inhomogeneous magnetic field. Four distinct peaks of equal intensity were obtained which represent the ($2i+1$) nuclear magnetic levels. The spin of the Na nucleus is accordingly equal to $\frac{3}{2}$, in units of $\frac{h}{2\ensuremath{\pi}}$.
The identification of two protease inhibitors in Drosophila melanogaster.

Abstract 1. 1. Extracts of Drosophila melanogaster larvae contain protease inhibitory activity. 2. 2. Fractionation first by heat and then by ion-exchange chromatography revealed the presence of at least two inhibitors. 3. 3. One of the inhibitors, called LTI, (Larval Trypsin Inhibitor) was a powerful inhibitor of bovine trypsin but showed no activity against bovine α-chymotrypsin. The other, called LCI (Larval Chymotrypsin Inhibitor), showed a little activity against bovine trypsin but was mostly effective against bovine α-chymotrypsin. 4. 4. The existence of LCI is difficult to explain since no trace of endogenous chymotrypsin activity is detectable in Drosophila .
Transient absorption spectra of 2-hydroxybenzophenone photostabilizers

Abstract Transient absorption spectra (400–600 nm) of 2-hydroxybenzophenone and the methyl methacrylate copolymer of 2-hydroxy, 3-allyl, 4,4'-dimethoxybenzophenone following 355 nm excitation (7–480 ps delay) are reported. A short-lived, 435 nm transient (τ ≈ 10 ps in CH 2 Cl 2 ) for both molecules is assigned to the lowest excited singlet before internal proton transfer. Weaker, broad T-T absorption is observed after 480 ps.
Digitally assisted discontinuous conduction mode 5V/100MHz and 10V/45MHz DC-DC boost converters with integrated Schottky diodes in standard 0.13µm CMOS

On-chip or on-package integration of step-up DC-DC converters in a low-voltage process can be attractive for smaller and lighter portable devices powered from single-cell batteries (i.e., NiMH, Fuel cells). To reduce the size of the off-chip components both high frequency (10 to 100s of MHz) [1, 2] and discontinuous-conduction-mode (DCM) switching have been proposed [3]. However, integration of DCM converters is challenging when the required blocking voltages across the switch and rectification stage is higher than the breakdown voltage of the standard devices. This is the case in both diode-connected MOS or CMOS controlled rectifiers for DCM boost converters [3]. Moreover, adaptive dead-time controllers are required for high-efficiency DCM operation. In this paper, we report two high-frequency DCM boost converter topologies with integrated Schottky Barrier Diodes (SBD) and a high voltage synchronous switch in a standard 0.13µm CMOS process. The SBDs are fabricated without additional processing steps to sustain ˜10V reverse voltage for high voltage operation, eliminating the need for dead-time controllers and power hungry high side drivers. The first DC-DC converter is a 100MHz digitally assisted 4-phase boost converter that delivers 240mW from a 1.2V supply with an output voltage range of 3 to 5V; and the second is a 45MHz hybrid boost converter delivering 20mW at 6-to-10V output from a 1.2V supply.
A bootstrap based analysis pipeline for efficient classification of phylogenetically related animal miRNAs

Background Phylogenetically related miRNAs (miRNA families) convey important information of the function and evolution of miRNAs. Due to the special sequence features of miRNAs, pair-wise sequence identity between miRNA precursors alone is often inadequate for unequivocally judging the phylogenetic relationships between miRNAs. Most of the current methods for miRNA classification rely heavily on manual inspection and lack measurements of the reliability of the results.
Allelotype analysis of uterine leiomyoma: Localization of a potential tumor suppressor gene to a 4‐cM region of chromosome 7q

Uterine leiomyoma is a benign smooth muscle tumor of the myometrium and is the most commonly encountered neoplasm in women of reproductive age. As for most benign tumors, the pathogenesis of leiomyoma remains obscure, especially at the molecular genetic level. The purpose of this study was to perform a genome-wide allelotype analysis to identify potential sites of tumor suppressor gene inactivation. Fifty-two cases of uterine leiomyoma were subjected to allelotype analysis by using matched pairs of tumor and blood DNA. Loss of heterozygosity (LOH) was assessed at 61 microsatellite markers distributed throughout the genome and representing all 41 chromosome arms. In general, LOH was very rare except on chromosome 7q, where LOH was observed in 34% of all informative tumors. Fine-deletion mapping with 25 microsatellite markers from the 7q22 region revealed a minimal deletion unit of approximately 4 cM, bounded by the markers D7S2453 proximally and D7S496 distally, that probably harbors a novel tumor suppressor gene involved in the etiology of this tumor.
Before and After and Superman: Andy Warhol

When 8-year-old Andy Warhol made odd shaking movements in school, hewas teased andbulliedbyhis peers.When the movements persisted and worsened, he received a diagnosis of Sydenham chorea (historically known as St. Vitus dance), an autoimmune complication of group A β-hemolytic streptococcal infection2,3; it is a neurological variant of rheumatic fever. InWarhol’s childhood, it affected about 20% of children who, like Warhol himself, had received an earlier diagnosis of scarlet fever. Although Warhol (born August 6, 1928) recalls 3 episodes during the summermonths (first epigraph), only 1 episode (with a relapse) is documented; it kept him out of school for about 8 weeks. As his movements resolved, his mother gave him comic books and movie magazines to look at, and she read to him and fed him Campbell’s Soup.Theyoungestof 3brothers,AndyWarholwasa frail child with a protective mother; the chorea made the family even more attentive tohim.Hebecameenamoredwithmovie stars and comic book heroes, particularly Popeye and Dick Tracy. Lying in bed with his Charlie McCarthy doll (first epigraph), he dreamed of becoming a movie star or hero. In 1938, a new breedof comic bookhero, the superhero, appeared in the first issue of Action Comics. Mild mannered Clark Kent’s transformationtoSupermanwasparticularlyappealing tochildren, like Warhol, who were anxious and insecure.4 Warholwaspreoccupiedwithhis physical appearance.He hadadermatological condition,probablyvitiligo,withblotchy skin, and apparently rosacea that left his nose red and enlarged. His physician noted thatWarhol had small hemangiomas on his scrotum, which were another source of embarrassment.3 It boosted his self-esteemwhen hismother tookhim for freedrawing lessonsonSaturdaymornings at the Carnegie Museum in Pittsburgh, Pennsylvania.2 Warhol’sparentsweredevoutByzantineCatholicswho immigrated to Pittsburgh from Eastern Europe. Andy attended church services each Sunday and sat before the iconostasis, a wall of icons and religious paintings meant to bring the believer face to face with a timeless spiritual presence. He was inneedof suchsupport.His fatherhadacholecystectomywith complicationsand laterbecameseverely jaundicedafterdrinking contaminated water on a job; he died at 53 years of age, whenAndywas 13yearsof age.Twoyears later, hismotherunderwent emergency surgery for colon cancerwith a fifty-fifty chance of surviving. Her convalescence took its toll too. Funds his father set aside for his education allowedAndy to enroll at the Carnegie Institute School of Technology. He graduated with a bachelor of fine arts degree in 1949 and immediatelymoved toNewYork,where his career as a commercial artist took off. Within 10 years, he was the leading commercial artist in New York City.
Associations of cord blood fatty acids with lymphocyte proliferation, IL-13, and IFN-γ

Background N-3 and n-6 polyunsaturated fatty acids (PUFAs) have been hypothesized to have opposing influences on neonatal immune responses that might influence the risk of allergy or asthma. However, both n-3 eicosapentaenoic acid (EPA) and n-6 arachidonic acid (AA) are required for normal fetal development. Objective We evaluated whether cord blood fatty acid levels were related to neonatal immune responses and whether n-3 and n-6 PUFA responses differed. Methods We examined the relation of cord blood plasma n-3 and n-6 PUFAs (n = 192) to antigen- and mitogen-stimulated cord blood lymphocyte proliferation (n = 191) and cytokine (IL-13 and IFN-γ; n=167) secretion in a US birth cohort. Results Higher levels of n-6 linoleic acid were correlated with higher IL-13 levels in response to Bla g 2 (cockroach, P = .009) and Der f 1 (dust mite, P = .02). Higher n-3 EPA and n-6 AA levels were each correlated with reduced lymphocyte proliferation and IFN-γ levels in response to Bla g 2 and Der f 1 stimulation. Controlling for potential confounders, EPA and AA had similar independent effects on reduced allergen-stimulated IFN-γ levels. If neonates had either EPA or AA levels in the highest quartile, their Der f 1 IFN-γ levels were 90% lower ( P = .0001) than those with both EPA and AA levels in the lowest 3 quartiles. Reduced AA/EPA ratio was associated with reduced allergen-stimulated IFN-γ level. Conclusion Increased levels of fetal n-3 EPA and n-6 AA might have similar effects on attenuation of cord blood lymphocyte proliferation and IFN-γ secretion. Clinical implications The implications of these findings for allergy or asthma development are not yet known.
As-vacancy interaction and ring mechanism of diffusion in Si

Vacancy-mediated diffusion of substitutional impurities in Si drastically depends on the character of the impurity-vacancy interaction. The attractive interaction which extends to at least the third nearest neighbors allows a vacancy to move along a ring of Si sites around the impurity. This process enables the impurity-vacancy pair to move and underlies the ``ring mechanism'' of diffusion. To evaluate the importance of this mechanism for As impurity in Si we performed density functional calculations of the As-vacancy interaction. We also calculated the vacancy migration barriers on the circular path around the impurity. The binding energy of the As-$V$ pair was found to be 1.17 eV. This energy decreases down to 0.36 eV when the vacancy moves onto the third-nearest-neighbor site, which is the most remote site on the ring path. We found that the migration barriers for the vacancy hops around the impurity are an order of magnitude smaller than in a bulk Si. The effective barrier along the ring path is therefore mostly determined by the difference of the binding energies on the first- and the third-nearest-neighbor sites and was found to be about 0.81 eV, in a fairly good agreement with experiment. Using ab initio binding energies and migration barriers we carried out the Monte Carlo simulation of As diffusion in silicon. We found that in a temperature range between 700 K and 1300 K the vacancy-assisted As diffusion is totally dominated by the ring mechanism.
A General and Efficient Method for the Site-Specific Dual-Labeling of Proteins for Single Molecule Fluorescence Resonance Energy Transfer

A general strategy for the site-specific dual-labeling of proteins for single-molecule fluorescence resonance energy transfer is presented. A genetically encoded unnatural ketone amino acid was labeled with a hydroxylamine-containing fluorophore with high yield (>95%) and specificity. This methodology was used to construct dual-labeled T4 lysozyme variants, allowing the study of T4 lysozyme folding at single-molecule resolution. The presented strategy is anticipated to expand the scope of single-molecule protein structure and function studies.
Mechanism of paper wet strength development by polycarboxylic acids with different molecular weight and glutaraldehyde/poly(vinyl alcohol)

In our previous research, we found that crosslinking paper using poly(carboxylic acid)s with different molecular weight or using the combination of glutaraldehyde and poly(vinyl alcohol) (PVA) significantly improved the wet strength of the paper. In this research, we studied the mechanism of paper wet strength development using crosslinking systems with different molecular weight by measuring scanning electron microscopic (SEM) images, wet strength, folding endurance, wet thickness, water retention, and Z-direction tensile strength of the treated paper. The paper crosslinked by a high-molecular weight (MW) poly(carboxylic acid) shows more swelling by water than that crosslinked by a low-MW polycarboxylic acid in the SEM micrographs even though both treated paper samples have similar wet strength. Thus, the data suggest that high-MW poly(carboxylic acid)s promote the formation of interfiber crosslinking. Crosslinking paper by glutaraldehyde, a crosslinking agent of small molecular size, improves wet strength and reduces flexibility and swellability of paper because of the formation of intrafiber crosslinking. Combining glutaraldehyde with PVA as a coreactant increases wet strength and also retains flexibility and swellability of the treated paper because of the formation of interfiber crosslinking. The hypothesis that PVA reacts with glutaraldehyde to form a polymeric pentanedialated-PVA crosslinking system and promotes the formation of interfiber crosslinking on the paper is supported by the data of wet strength, folding endurance, wet thickness, water retention, and Z-direction tensile strength of the treated paper. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 277–284, 2006
DISTRIBUTION OF SPATIAL VARIABILITY IN VIBRATION RESPONSE

Understanding the distribution of dynamic response is important in setting random vibration test levels for equipment. This paper describes how the probability distribution of a set of data could be tested. The Kolmogorov-Smirnov test statistic indicates that the third octave average PSD vibration responses on a set of components are spatially log-normal when excited by a reverberant acoustic field. Two procedures for estimating the P95/50 level are demonstrated to agree well for the component attachment sensors: one calculates the mean and standard deviation of log-transformed PSD, while the other uses a warping function with PSD mean and standard deviation calculated directly.
Whence and whither intelligence, command, and control? the certainty of uncertainty

Editors note: this article is excerpted from a publication of the Program on Information Resources Policy at Harvard University's Center for Information Policy Research. Mr. Oettinger's views are colorful and lively, and I present them as food for thought. Reader's comments are welcome.
Corrected Diffusion Approximation in Layered Tissues

We present the corrected diffusion approximation for a thin beam incident on a layered medium. This model improves upon the diffusion approximation for small source-detector separation distances and is computationally efficient.
Polyclonal B-cell activation: Severe periodontal disease in young adults

Abstract The proliferative response stimulated by the polyclonal B-cell activator staphylococcal protein A (Staph. A) was studied in cultures of peripheral blood lymphocytes obtained from young adults with severe periodontitis. The proliferative response stimulated by Staph. A was enhanced in this patient population in comparison to a control population of the same age. Differences were apparent by Day 3 in cultures stimulated by high doses of Staph. A, and were still apparent at Day 7 in cultures stimulated by low doses. Marked differences were apparent between the two groups at every Staph. A dose at Day 5 (peak response). In preliminary studies of proliferative responses in this select population, similar results were obtained using bacterial extracts from oral and nonoral organisms as the stimulators. To determine if these bacterial extracts contained polyclonal B-cell activators these same preparations were used in an assay for polyclonal antibody production. The extracts not only contained potent polyclonal B-cell activators, but in general the polyclonal antibody assays correlated with the previous proliferative assays. The most potent extracts were from Escherichia coli, followed by Bacteroides melaninogenicus, then Actinomyces viscosus, naeslundii, and israelii. These results support a hypothesis that severe periodontitis, in this select patient population, occurs as a consequence of B-cell hyperreactivity. The data further suggest the possibility that the polyclonal B-cell activators in dental plaque organisms may initiate this disease by nonspecifically stimulating B cells in the surrounding tissues. These stimulated B cells and the plasma cells derived from them could then release factors responsible for loss of periodontal support. This possible role for B cells and the potential for T cells and macrophages to regulate these responses are discussed.
Products of the Gas-Phase Reactions of Linalool with OH Radicals, NO3 Radicals, and O3

Linalool [(CH3)2CCHCH2CH2C(CH3)(OH)CHCH2] is a terpene derivative emitted from vegetation, including orange blossoms and certain trees and vegetation in the Mediter ranean area. Linalool reacts rapidly in the gas phase in the troposphere with OH radicals, NO3 radicals, and O3, with a calculated lifetime due to these reactions of ∼1 h or less. The products of these gas-phase reactions have been studied in ∼6500−7900-L Teflon chambers using gas chro matography, in situ Fourier transform infrared absorption spectroscopy, and direct air sampling atmospheric pres sure ionization tandem mass spectrometry. The products identified and their formation yields are as follows: from the OH radical reaction, acetone, 0.505 ± 0.047; 6-methyl-5-hepten-2-one, 0.068 ± 0.006; 4-hydroxy-4-methyl-5-hexen-1-al (or its cyclized isomer), 0.46 ± 0.11; from the NO3 radical reaction, acetone, 0.225 ± 0.052; 4-hydroxy-4-methyl-5-hexen-1-al (or its cyclized isomer), 0.191 ± 0.051; and a non-quantified nitrooxycarbonyl; from the O3 r...
Some modifications of Laguerre's method

Two modifications of Laguerre's method are given. They define methods for simultaneously approximating all the zeros of a given polynomial. The asymptotic behavior of the methods is studied. The possibilities of both sequential and parallel implementations of the methods are considered.
Textbooks and the Living Language1

The German Language shows the same freedom in the hands of individuals and is not standardized as is the French, for instance. C. H. Handschin, “The Germans as They Are and Will Be, Modern Language Journal, November, 1934, p. 99 ff. I should like to see others take up the cudgels for clearer, more accurate rules in our beginners' books. After all the recent pother about methods, tests, and statistics, would it not be a welcome relief to turn the spotlight back to some of the fundamental questions in the modern languages we endeavor to teach? John A. Hess, “Rules of Grammar in Beginners' German Books,” Modern Language Journal, January, 1936, p. 221 ff.
Beyond Absolutism: Guiding Principles Needed for Humanitarian Medicine: Reply

Dr. Leeds skillfully points out some of the foibles of humanitarian medicine and is correct in stating that there are usually no moral absolutes in those kinds of activities [1]. We chose to use a metaphor in our article which he finds to be faulty because of ‘‘...the complex relativism inherent to most humanitarian work.’’ Our ‘‘seven sins’’ was a way to organize the subject and to clarify our thinking about it. Perhaps we could have titled the article ‘‘The Seven Blunders...,’’ if ‘‘sins’’ seems a little harsh or negative. A primary objective of the article was to stimulate discussion about the several challenges of humanitarian medicine. It would appear that healthy dialogue has taken place because the article was published, and for this we are grateful. Perhaps, in the future, principles could be crafted, as Dr. Leeds suggests, in order to ‘‘...provide realistic guidance to managing the complexity and moral ambiguity of such work.’’ It would be gratifying and most useful if the humanitarian medicine community could come together and agree on certain fundamental goals and objectives of the work, which would be written down as a charter. These statements could be expressed in a positive way, avoiding the negativism of ‘‘sins.’’ The challenge in such an activity would not be in the gathering together of proper ideas for such a charter. Many of us are more than willing to provide credible ideas. The challenge would be to find the organization in the world with the clout and credibility to put together such an effort. Who in the world should tackle this challenge?
Identifying discursive entry points in paired-novice discourse as a first step in penetrating the paradox of learning mathematical proof

Abstract In this article, I demonstrate the efficacy of using the commognitive research framework to study the learning of mathematical proof. To this end, I present a detailed analysis of an excerpt of paired discourse by undergraduate mathematics majors working on an introductory proof task. Additionally, I draw on the excerpt to illustrate that there exists in discourse between novice interlocutors natural opportunities, especially ripe with potential, in which experts could intervene to steer the discourse toward increasing mathematical sophistication. I have named these opportunities discursive entry points and suggest their identification as significant in addressing the learning paradox as it relates to mathematical proof. Overall, the findings illustrate how rich description of the nature of learning in paired discourse, a result of the commognitive research lens, can inform reform era instructional practices.
Stokes slip flow through a lattice of parallel plates

Low Reynolds number slip flow through periodic parallel slats is studied. The efficient method of domain decomposition and eigenfunction expansion is used. It is found that even small partial slip greatly decreases the resistance of the filter and the entrance (exit) effects. On a etudie l'ecoulement avec glissement pour un faible nombre de Reynolds, sur des plaques paralleles et disposees periodiquement. La methode efficiente de decomposition de domaine et l'expansion de la fonction propre est utilisee. On a conclu que meme un petit glissement partiel reduisait de facon considerable la resistance du filtre et des effets d'entree (de sortie).
Continuous removal of dissolved oxygen by established ion‐exchangers

A way of using established ion-exchangers for the removal of dissolved oxygen is described. The efficiency and capacity for deoxygenation are given and compared with those for other resinous deoxygenators. New types of water treatment are made possible by the combination of ion exchange and deoxygenation in the one resin.
Review of strategies for minimizing bromate formation resulting from drinking water ozonation

Ozonation is a more attractive disinfection method than chlorine in that it can meet the current USEPA regulations. Indeed, ozone and its primary reactive products, the hydroxyl free radical (OH·) especially, are strong oxidizing agents, capable of substantial oxidation. However, ozonation can also lead to the formation of potentially harmful by-products, which can be dealt with either by removing the disinfection by-products themselves or by inhibiting their formation via precursor removal methods and process optimization techniques. This paper provides a review of ozonation and by-product formation chemistry, effective approaches toward the control of bromate formation, and bromate precursor removal technologies.
Q, break-even and the n/spl tau//sub E/ diagram for transient fusion plasmas

Q, break-even and the n/spl tau//sub E/ diagram are well defined and understood for steady-state fusion plasma conditions. Since many fusion experiments are transient, it is necessary to clarify the definitions for instantaneous Q values and break-even so that the n/spl tau//sub E/ diagram can be interpreted for transient plasma conditions. This discussion shows that there are two mathematically correct methods to describe the n/spl tau//sub E/ diagram for a transient plasma. The Lawson/TFTR method which is consistent with previous analyses of the Lawson cycle, and prior definitions for Q and break-even describes a transient fusion plasma in terms of Q P/sub fusion//P/sub aux/ with the plasma energy confinement time for the n/spl tau/ diagram given by /spl tau//sub E/*=W/sub p//P/sub heat/ where W/sub p/ is the total plasma kinetic energy and P/sub heat/=P/sub aux/+P/sub alpha/-P/sub brem/ is the net power heating the plasma. In the Lawson/TFTR definition break-even (P/sub fusion/=P/sub aux/) occurs at Q=1, ignition occurs at Q=infinity and the n/spl tau//sub E/* values required to achieve a given Q are the same in transient and steady-state plasmas. The JET/JT-60 method uses the definitions of Q*=P/sub fusion//(P/sub aux/-dWp/dt) and /spl tau//sub E/=Wp/(P/sub heat/-dWp/dt). This method produces the confusing result that break-even requires Q*=P/sub aux//(P/sub aux/-dWp/dt) which is >1 for many cases of interest. In addition, the n/spl tau//sub E/ value required to achieve break-even depends on dWp/dt and therefore experimental data points with different dWp/dt must be compared to different Q* curves on the Lawson diagram. For a pulsed plasma, this issue can be avoided by using the definition of fusion gain first introduced by Lawson, namely Q=fusion energy per pulse divided by auxiliary plasma heating energy supplied per pulse.
Potential Role for a Regulator of G Protein Signaling (RGS3) in Gonadotropin-Releasing Hormone (GnRH) Stimulated Desensitization

The cellular and molecular mechanisms of gonadotrope desensitization are unknown but transduction of the GnRH signal is known to involve sequentially the GnRH receptor, Gq alpha protein, phospholipase C beta-1, inositol-1,4,5-trisphosphate (IP3), and intracellular Ca+2 release. Here, we report the results of studies of a new family of proteins known as regulators of G protein signaling (RGS) that recently have been implicated in desensitization of several ligand induced processes. Using DNA-mediated transfection, we co-expressed the GnRH receptor and RGS1,2,3, or 4 in COS-1 cells. Control cells and those expressing RGS1,2, and 4 produced five fold increases in IP3 levels during the 30 sec after treatment with GnRH. In contrast, RGS3 expression suppressed by 75% the GnRH-induced IP3 responses. RGS3 was shown to bind Gq alpha protein in a model in vitro system: recombinant RGS3-glutathione-S-transferase (GST) fusion protein bound five-fold more 35S-met labeled Gq alpha protein than did with GST alone, suggesting that the mechanism of RGS3 action is attenuation of Gq alpha protein activation of phospholipase C. RGS3 mRNA and protein were observed to be expressed endogenously in the gonadotropic alpha T3-1 cell line. These results suggest a potential role for RGS3 in modulating the LH secretory responsiveness of the pituitary gonadotrope to GnRH.
Black Philly After The Philadelphia Negro

Beginning where W. E. B. Du Bois’s classic The Philadelphia Negro ends, sociologist Marcus Anthony Hunter considers the history of public housing in Philadelphia during the New Deal era. Focusing on black activism, black politics, and neighborhood change during the New Deal era, he shows that Black residents have long been citymakers, forces for progressive change
Estimating T1 from multichannel variable flip angle SPGR sequences

Quantitative estimation of T1 is a challenging but important task inherent to many clinical applications. The most commonly used paradigm for estimating T1 in vivo involves performing a sequence of spoiled gradient-recalled echo acquisitions at different flip angles, followed by fitting of an exponential model to the data. Although there has been substantial work comparing different fitting methods, there has been little discussion on how these methods should be applied for data acquired using multichannel receivers. In this note, we demonstrate that the manner in which multichannel data is handled can have a substantial impact on T1 estimation performance and should be considered equally as important as choice of flip angles or fitting strategy.
Loss of Purkinje cell‐associated benzodiazepine receptors spares a high affinity subpopulation: A study with pcd mutant mice

In order to identify the relative number of benzodiazepine (BZ) receptors in Purkinje and granule cells, the Purkinje cell degeneration (pcd) mutant mouse was used at different ages. In these mice, Purkinje cells have degenerated almost completely by 45-50 days of age. Granule cell loss occurs only later, and is most severe between 180 and 300 days. [3H]Flunitrazepam (FNZ) and [3H]ethyl-carboline-3-carboxylate (beta-CC) were used as ligands. In the 45-50-day-old pcd mice, it was found that there is approximately a 50% decrease in the number of receptors as labeled by [3H]beta-CC or [3H]FNZ, when the binding is expressed as fmol/cerebellum. The binding decreased by approximately 80% in 300-day-old pcd mice (fmol/cerebellum). [3H]FNZ was not displaced by 1 microM RO5-4864, ruling out binding to glial cells. Nonlinear regression analysis of FNZ saturation data provided evidence for two populations of receptors (high and low affinity sites). Only the low-affinity sites were reduced in number at 45 days. [3H]beta-CC saturation data showed, however, only one population of receptors. The total number of receptors (Bmax) was significantly lower for beta-CC than for FNZ in the control mice. It appears that 50% of the total BZ receptors is associated with Purkinje cells. In addition, our data on 300-day-old pcd mutants strongly suggest the existence of granule cell-associated BZ receptors.
Advances in space robotics

The problem of the remote control of space operations is addressed by identifying the key technical challenge: the management of contact forces and the principal performance parameters. Three principal classes of devices for remote operation are identified: anthropomorphic exoskeletons, computer aided teleoperators, and supervised telerobots. Their fields of application are described, and areas in which progress has reached the level of system or subsystem laboratory demonstrations are indicated. Key test results, indicating performance at a level useful for design tradeoffs, are reported.
Strangeness in neutron stars

It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which several intriguing particles processes may compete with each other. These range from the generation of hyperons to quark deconfinement to the formation of kaon condensates and H-matter. There are theoretical suggestions of even more exotic processes inside neutron stars, such as the formation of absolutely stable strange quark matter. In the latter event, neutron stars would be largely composed of strange quark matter possibly enveloped in a thin nuclear crust. This paper gives a brief overview of these striking physical possibilities with an emphasis on the role played by strangeness in neutron star matter, which constitutes compressed baryonic matter at ultra-high baryon number density but low temperature which is not accessible to relativistic heavy ion collision experiments.
DNA Polymerase λ Mediates a Back-up Base Excision Repair Activity in Extracts of Mouse Embryonic Fibroblasts

Mammalian DNA polymerase (pol) lambda is a member of the X-family of DNA polymerases and has striking enzymatic and structural similarities to mammalian DNA pol beta. Because pol beta provides two important enzymatic activities for base excision repair (BER), we examined whether pol lambda might also contribute to BER. We used extracts from mouse embryonic fibroblasts representing wild-type and null genotypes for pol beta and pol lambda. In combination with neutralizing antibodies against pol beta and pol lambda, our results show a BER deficiency in the pol lambda -/- cell extract compared with extract from isogenic wild-type cells. In addition, the pol lambda antibody strongly reduced in vitro BER in the pol beta -/- cell extract. These data indicate that pol lambda is able to contribute to BER in mouse fibroblast cell extract.
Tightly bound 2-azido-adenine nucleotides at catalytic and noncatalytic sites of the rat liver F1 ATPase label adjacent tryptic peptides of the beta subunit.

Abstract UV irradiation of rat liver F 1 ATPase, previously exposed to Mg 2+ and [β,γ- 32 P]-2-azido-ATP and separated from medium nucleotides, covalently modifies two tyrosine residues in adjacent tryptic peptides of the β subunit. This results from the occupancy by 2-azido-ATP or 2-azido-ADP of two distinct types of nucleotide binding sites, the catalytic and noncatalytic sites. The two modified peptides are identical to the ones modified by 2-azido-adenine nucleotides in the beef heart F 1 ATPase. Both catalytic and noncatalytic sites are labeled when the ATPase is exposed to [β- 32 P]-2-azido-ADP in the presence or the absence of 5′-adenylyimidodiphosphate (AMP-PNP), showing that two distinct types of ADP binding sites are present on the liver enzyme. Similar incorporation of 2-azido-adenine nucleotides is obtained when membrane-bound rat liver F 1 ATPase is incubated with Mg 2+ and [β,γ- 32 P]-2-azido-ATP.
Identifying andTesting for Insecure Paths in Cryptographic Protocol Implementations

Cryptographic protocols, which are also referred to as security protocols are used to process, store and transfer increasing volumes of information on our financial networks, health networks, and even our library systems, not to mention our conventional communication systems and our networked systems of personal and corporate computers. Users should be able to justifiably rely on their implementations to process, store, and communicate sensitive information securely. Testing is indispensable even when a security protocol is formally verified because most formal verification techniques only guarantee the correctness of the design, under certain assumptions. More importantly, no guarantees about the implementation are provided. A mathematical proof that an implementation of a security protocol conforms to its specifications is usually not feasible because it would require complicated formal semantics of the language in which it is written and the environment in which the protocol runs (the operating system and hardware)