cssi/SciSciGPT-SciSciNet huggingface dataset:
Cleavage behavior of calicheamicin gamma 1 and calicheamicin T.

Abstract Calicheamicin gamma 1 is a potent antitumor antibiotic that cleaves DNA with a high degree of specificity; there is much interest in the recognition process. We have investigated the DNA-cleaving properties of calicheamicin T, a truncated derivative of calicheamicin. We show that calicheamicin T cleaves DNA in a double-stranded fashion, indicating that the first two sugars are sufficient to facilitate binding of the aglycone in the minor groove. However, calicheamicin T cleaves DNA nonselectivity. This result suggests that cyclization kinetics do not determine the cleavage specificity of the intact drug. Instead, cleavage specificity probably reflects binding specificity. Because of the recognition sites reported in the original cleavage paper, calicheamicin has been assumed to recognize oligopyrimidine DNA sequences containing G-C base pairs. We show here that calicheamicin also cuts efficiently at A.T tracts, sometimes in preference to G.C-rich homopyrimidine tracts. Crystallographic data and experiments with chemical probes indicate that DNA sequences including G.C base pairs have significantly different local conformations from DNA sequences containing several (four or more) sequential A.T base pairs. This difference makes it unlikely that calicheamicin simply senses inherent groove conformation and suggests that there is some degree of "induced fit." The ability to recognize both A.T- and G.C-rich oligopyrimidine sequences with a high degree of specificity makes calicheamicin an unusual minor-groove binder.
Gonadotrophic Regulation of Precursor Incorporation Into Ovarian RNA, Protein, and Acid-Soluble Fractions. II. Changes in Nucleotide Labeling, Nuclear RNA Synthesis, and Effects of RNA and Protein Synthesis Inhibitors

Within the first hour after sc LH administration, in vivo incorporation of 3H-cytidine into nucleotides and RNA of the immature rat ovary was appreciably increased; at the same time, amino acid uptake and incorporation into protein was also increased. The relative increase in 14C counts, identified as cytidine or CTP, in the acid-soluble fraction was comparable to the increased labeling of RNA. Subcellular fractionation of ovaries which were subjected to LH treatment and 1 hr in vivo labeling showed a corresponding increase in labeling in both RNA and protein components of all subcellular fractions. A 1 or 4 hr LH treatment showed no difference in nuclear RNA polymerase activity in the ovary. Actinomycin D blocked the LH effect on in vivo 3H-leucine incorporation into protein, and, in turn, cycloheximide blocked the LH effect on cytidine-2-14C incorporation into RNA. We conclude that the ovarian response to LH is complex and involves changes in in vivo precursor uptake as well as RNA and protein synthesis...
"Midwives are nice, but . . .": perceptions of midwifery and childbirth in an undergraduate class.

Introduction The purpose of this study was to explore college students' beliefs about childbirth and midwifery. Methods A critical qualitative analysis was used to identify common themes that occurred in an online class discussion about midwifery. Results This population of 459 college students drew on the larger social discourse of the medical model of childbirth to frame their discussion of childbirth and midwives. Common beliefs that emerged from class discussions included the perceived dangerous nature of childbirth, the necessity for technologic interventions in childbirth, and doubts about the quality of midwifery training and practice. Discussion To promote midwifery among this population, advocates should continue public education efforts through a variety of media and communication strategies, with an emphasis on the safety of midwifery care.
Copper absorption in young men fed adequate and low zinc diets

Copper absorption was measured at two levels of dietary zinc in six healthy young men who were confined to a metabolic unit for a 75 d study of zinc utilization. A diet of conventional foods was fed, providing either 16.5 or 5.5 mg zinc and 1.3 mg copper daily. Copper absorption was determined by feeding 65Cu, a stable isotope of copper, once during the 16.5 mg Zn diet and near the beginning and end of the 5.5 mg Zn diet. Apparent copper absorption averaged 48.1% when the 16.5 mg Zn diet was fed. This was significantly higher than the averages of 37.2 and 38.5% when the 5.5 mg Zn diet was fed. Absorption also differed significantly among subjects. Fecal copper did not differ between diets or among subjects. All subjects were in positive copper balance at both levels of dietary zinc. These results suggest that a dietary zinc intake slightly above the Recommended Dietary Allowance of 15 mg/d does not increase fecal copper loss and does not interfere with copper absorption.
Insulin Regulation of Fatty Acid Synthase Gene Transcription: Roles of USF and SREBP-1c

The transcriptional regulation of lipogenesis is a highly coordinated process occurring in concert with transcriptional as well as post-transcriptional regulation of enzymes involved in glycolysis and gluconeogenesis. Fatty acid synthase (FAS) plays a central role in de novo lipogenesis by converting acetyl-CoA and malonyl-CoA into the final end product, palmitate, which can subsequently be esterified into triacylglycerols and then stored in adipose tissue. Ultimately, this helps to prevent buildup of excess glucose in other types of cells and tissues, the effects of which can be readily observed in the pathophysiology of disease states such as Type-11 diabetes and obesity. Thus, elucidating the transcriptional mechanisms of lipogenic enzyme genes is important for understanding the normal regulation of lipogenesis and ultimately the dysregulation that may occur in certain metabolic disease. In this review, we discuss advances in our understanding of the regulation of lipogenesis at the genetic level, with a special emphasis on the common cis- and trans-acting factors involved in regulation of FAS. Two transcription factors, Upstream Stimulatory Factor (USF) and Sterol Regulatory Element Binding Protein-lc (SREBP-lc), seem to play a dominant and possibly cooperative role in regulating FAS transcription.
Possible Implications of the Quantum Theory of Gravity: An Introduction to the Meduso-Anthropic Principle

If we assume that the constants of nature fluctuate near the singularity when a black hole forms (assuming, also, that physical black holes really do form singularities) then a process of evolution of universes becomes possible. We explore the implications of such a process for the origin of life, interstellar travel, and the human future.
Intelligent Polymerized Crystalline Colloidal Arrays: Novel Chemical Sensor Materials

We report the development of a novel sensing material that reports on analyte concentrations via diffraction of visible light from a polymerized crystalline colloidal array (PCCA). The PCCA is a mesoscopically periodic crystalline colloidal array (CCA) of spherical polystyrene colloids polymerized within a thin, intelligent polymer hydrogel film. CCAs are brightly colored, and they efficiently diffract visible light meeting the Bragg condition. The intelligent hydrogel incorporates chemical molecular recognition agents that cause the gel to swell in response to the concentration of particular analytes; the gel volume is a function of the analyte concentration. The color diffracted from the hydrogel film is, thus, a function of analyte concentration: the swelling of the gel changes the periodicity of the CCA, which results in a shift in the diffracted wavelength. We have fabricated a sensor, utilizing a crown ether as the recognition agent, that detects Pb2+ in the 0.1 μM−20mM (∼20 ppb−∼4000 ppm) concenra...
Laser scanning microscopy

In conventional light microscopy, images are formed either by direct imaging of the object at a desired magnification or by imaging the object onto a remote surface and converting the illuminance at that surface to an electrical signal. In laser scanning microscopy, the object or specimen surface is scanned point by point by a focused laser beam. The actual image or other pertinent characteristic of the object is then generated by an electronic system. Use of such scanned laser systems exists today in biomedical research, in the semiconductor microelectronics industry, and in varied other industrial inspection applications. In this paper, we review the basic principles of laser scanning microscopy, discuss advantages as compared to more conventional light microscopy, and illustrate the technique with examples of systems in use today.
Parameter Optimization of relaxed Ordered Subsets Pre-computed Back Projection (BP) based Penalized-Likelihood (OS-PPL) Reconstruction in Limited-angle X-ray Tomography

This paper presents a two-step strategy to provide a quality-predictable image reconstruction. A Pre-computed Back Projection based Penalized-Likelihood (PPL) method is proposed in the strategy to generate consistent image quality. To solve PPL efficiently, relaxed Ordered Subsets (OS) is applied. A training sets based evaluation is performed to quantify the effect of the undetermined parameters in OS, which lets the results as consistent as possible with the theoretical one.
Gesture, speech, and sign . Lynn Messing and Ruth Campbell (Eds.). New York: Oxford University Press, 1999. Pp. 227.

The study of gesture, especially its relationship to spoken and signed languages, has become a broadly studied topic for researchers from various fields, including neuropsychology, cognitive psychology, evolutionary psychology, human development, and communication disorders. One possible reason for the wide interest in gesture is its universality. People of all ages and cultures use gestures for various purposes. Young language-learning, hearing children often use gestures alone or in combination with speech to help express themselves to their interlocutors, for example, pointing to a desired object while saying “mine.” As a more striking example, deaf children in Nicaragua who had previously been unexposed to any conventional sign language, used gestures to develop home-sign systems that eventually developed into Nicaraguan Sign Language (Kegl, Senghas, & Coppola, 1999). On the other hand, gestures are often used in situations where the underlying purpose of the gesture is less clear. For example, people who are blind from birth are nonetheless found to gesture in conversation (Iverson & Goldin-Meadow, 1997), and adults gesture frequently, and often subconsciously, during conversations with one another. Despite their omnipresence, we know relatively little about gestures' origins, their relationship to language, and, in some instances, the purposes they serve.
AN APPROXIMATE CELL MODEL FOR LIQUID HYDROGEN, II.

In a previous publication' (hereafter called I), an approximate cell model was formulated and applied to liquid hydrogen. In this approximate model the potential well of Lennard-Jones and Devonshire2 was approximated by a parabolic well split by a region of constant potential. This approximate cell model appears to preserve the essential features of the Lennard-Jones and Devonshire theory but does not involve the computational difficulties of the exact method of Levelt and Hurst. In this publication the variation of thermodynamic properties among the H2 isotopes is reported. Comparison of Tabulated Properties and Conclusions. -In Table 1 the reduced internal entropy is tabulated for the five H2 isotopes. The reduced thermodynamic functions have been defined in I and the potential parameters (e/k = 37.000K, T = 2.928 A) have been assumed to be the same for all five liquids. The appropriate values of the quantum parameters of these five liquids, obtained from Hirschfelder et al.,4 have also been included in Table 1. The communal entropy correction has been introduced and, therefore, the internal entropy tends to zero at high temperatures and low densities. In Tables 2 and 3 the reduced internal energy and the reduced internal specific heat are tabulated. The internal energy and specific heat are in reasonable agreement with the calculations of Levelt and Hurst.' The agreement of the internal entropy with the calculations of Levelt and Hurst is less satisfactory. As was reported in I, this approximate cell model does not give satisfactory values for volume derivatives. However, it does give reasonable results for the quantum correction. If the quantum correction to the reduced pressure is added to the reduced pressures, calculated by Hirschfelder et al.,4 for the classical cell theory, a good estimate of the critical constants may be obtained. The calculated and experimental critical constants of the five H2 isotopes are given in Table 4. The experimental critical constants for H2, HD and D2 were obtained by Hoge and Lassiter." The "experimental" critical constants of DT and T2 are given in parentheses, since they are estimates given by Friedman et al." based on an assumed linear variation of the critical properties with X*. For comparison, the calculated and experimental critical constants for a classical liquid have also been included. The calculated
Changing the fragmentation pattern of molecules in helium nanodroplets by co-embedding with water

Individual amino acid molecules embedded in helium nanodroplets fragment extensively when the beam is ionized by electron bombardment. However, we find that when glycine and tryptophan are picked up right after, or right before, a small amount of water, the mass spectra become significantly altered. For glycine, the detected ions consist almost entirely of intact protonated amino acids, with or without a few water molecules attached. In other words, the presence of water exerts a striking “buffering” effect on the ionization-induced fragmentation. For tryptophan the effect is weaker but also present. In both cases, the hydroxyl group lost upon ionization overwhelmingly comes from the water partner (in strong contrast to the situation observed when amino acids are picked up by neat water clusters). A complementary experiment involving DCl molecules co-embedded with water shows that in this case Cl and/or DCl invariably leave the droplet upon ionization. The observed patterns may be steered by the analytes' dipole moments or by solvation effects.
Biosynthesis of asymmetric citric acid; a substantiation of the Ogston concept.

A. G. OGSTON1, in a recent note in Nature on the “Interpretation of Experiments on Metabolic Processes, using Isotopic Tracer Elements", introduced the important concept that an enzyme might be able to distinguish between the chemically ‘identical’ groups of a symmetrical compound. Ogston pointed to the dangers of the contrary assumption, and as one example he questioned the conclusion that citric acid was not an intermediate in the Krebs cycle of oxidations in so far as this conclusion was based upon the finding that the fixation of isotopically labelled carbon dioxide led to the formation of asymmetrically labelled α-keto-glutaric acid. It had been assumed2,3,4 that if citric acid were on the pathway leading to α-ketoglutaric acid, the latter would have had isotopic carbon equally distributed between the two carboxylic acid groups.
Kinetics of the low temperature thermal decomposition of ammonium perchlorate and its catalysis by copper ion

Abstract The low temperature thermal decomposition of ammonium perchlorate is found to be initiated by a single stage nucleation process at a lattice defect site on the surface of the crystal. An aging effect in the form of a decrease in the decomposition rate with storage time at room temperature was observed. Sample impurities and as little as 0.04% copper chloride significantly accelerate the decomposition but do not alter the nucleation process or the rate-determining step. The reaction stoichiometry is changed by copper chloride but not by recrystallization. It is suggested that catalysis occurs through the formation of ammine complexes which tie up the ammonia on the crystal surface and thereby prevent the reversal of the proton transfer reaction.
Fibronectin accumulation within cardiac myocytes in rats with elevated plasma angiotensin II

Abstract Elevation in plasma angiotensin II (AngII) is associated with cardiac myocyte necrosis. Myocyte necrosis followed by wound healing and fibrosis represents a structural remodeling of the myocardium thought to contribute to abnormal myocardial function. Fibronectin (FN) is generally considered an early component of the healing process that precedes collagen accumulation. To better understand the time course of this remodeling process involving both cardiac myocytes and extracellular matrix, (i.e., FN and collagen), we used two animal models: (1) endogenous activation of the renin-angiotensin system by surgical induction of renovascular hypertension and (2) exogenous AngII administration (150 ng/min/kg). Animals were killed at different time points within the first two weeks. Both “cellular” (cFN) and “plasma” (pFN) FN immunolabeling were compared with collagen distribution (picrosirius red stain), together with histopathologic (hematoxylin-eosin stain) and ultrastructural examination of cardiac myocytes. In each experimental group, the pattern and time course of FN immunolabeling was coincident with histopathologic evidence of myocyte injury and/or remodeling. We found different patterns of FN labeling of cardiac myocytes: (a) homogenous intracellular distribution in necrotic myocytes, most obvious on days 1 and 2; (b) patchy intracellular distribution in nonnecrotic myocytes starting on day 4; and (c) marking internalized capillaries. Both FNs were codistributed throughout the myocardium of each ventricle; however, cFN was less pronounced and not seen in mature scars. Ultrastructural examination revealed different kinds of intramyocytic inclusions, characterized by vacuoles containing fibrillar/flocculent material, remnants of unknown origin, or internalized capillaries. We conclude that FNs are markers of cardiac myocyte necrosis and early interstitial remodeling and that renovascular hypertension and AngII administration exhibit the same time course and pattern of FN and collagen expression.
The Pyridine Ring and the Problem of its Biosynthesis

THE relationships of anthranilic acid and tryptophane to nicotinic acid are well established in a number of organisms1 and it has been suggested that in the higher plants the pyridine ring may be formed in a like manner2. It has been shown, however, that tryptophane-3-14C is not a precursor of damascenine in Nigella damascena L., nor did it give rise to radioactive trigonelline when fed to pea seedlings3. It is possible that in the two plants studied the enzyme system necessary for the initial oxidation of tryptophane to kynurenine is lacking and that the hydroxyanthranilic acid in one case (damascenine) and the pyridine ring in the other (trigonelline) are synthesized from different precursors and by a different pathway.
Ex Situ Thermal Cycle Annealing of Molecular Beam Epitaxy Grown HgCdTe/Si Layers

We present the results of ex situ thermal cycle annealing (TCA) of molecular beam epitaxy grown mercury cadmium telluride (HgCdTe) on Cd(Se)Te/Si(211) composite substrates. We examined the variation in the etch pit density (EPD) and overall crystalline quality with respect to annealing temperature, number of annealing cycles, total annealing time, pre-annealed EPD/crystal quality, buffer layer quality, and buffer layer lattice constant. Using TCA we observed an order of magnitude reduction in the dislocation density of the HgCdTe layers and a corresponding decrease in x-ray full width at half maximum, when the as-grown layer EPD was on the order of 1 × 107 cm−2. Among all the parameters studied, the one with the greatest influence on reducing EPD was the number of annealing cycles. We also noticed a saturation point where the HgCdTe/Si EPD did not decrease below ∼1 × 106 cm−2, regardless of further TCA treatment or the as-grown EPD value.
Consumer purchase intention for organic personal care products

Purpose – Using the theory of planned behavior (TPB) to examine the effects of consumer values and past experiences on consumer purchase intention of organic personal care products, this study aims to consider further the moderating effect of perceived behavioral control on the attitude‐intention relationship.Design/methodology/approach – An online survey was conducted with 207 online panel members, and multiple regression analysis was used to test the relationships among the variables.Findings – The results indicate that environmental consciousness and appearance consciousness positively influence attitude toward buying organic personal care products. The addition of past experiences as a predictor of purchase intention and perceived behavioral control as a moderator of the attitude‐purchase intention relationship yielded an improvement on the TPB model.Practical implications – This study suggests that retailers can develop effective marketing strategies emphasizing ecological beauty, product safety, and...
Theoretical exploration of gas lasers using time-dependent 3D Navier-Stokes simulation

Theoretical models for chemical lasers depend on a variety of assumptions and empirical data to provide closure and simplify solution of the governing equations. Among the various assumptions and empirical data that have been built into models for chemical lasers are assumptions regarding flow steadiness in the time domain and geometric similarity of the spatial domain. The work discussed here is directed toward elucidating and increasing the understanding of these assumptions commonly used in chemical laser simulation and the impact of their usage upon the predictions of these models. These efforts in turn are directly linked to efforts to achieve improved chemical laser efficiencies and performances as excursions outside the assumed to be 'well understood' traditional operational parameter space are increasingly necessary.
Characterization of p51/52, a cell-growth regulated protein of WI-38 cells.

Abstract A number of proteins have been identified whose expression or activity is regulated by cell growth. We have produced a monoclonal antibody against a new cell-growth regulated protein found in normal human fibroblasts. We have shown that this antibody recognizes a 51 52 -kDa doublet (p51/52) found mainly in normal cells. This doublet is sensitive to degradation by the calcium-activated protease, calpain, breaking down to a 37 38 -kDa doublet. The relative amount of the two members of the 51 52 -kDa doublet changes when serum-starved cells reenter the cell cycle. Quiescent cells express mainly the 51-kDa form; the 52-kDa form becomes more abundant upon refeeding serum-starved cells. Transformed cells express either very small amounts of this doublet, and then predominantly the 52-kDa form, or no detectable amount of either form. These characteristics distinguish this molecule from several other known growth-regulated proteins such as statin and the anti-oncogene p53.
Shear yield and flow behavior of a zirconium-based bulk metallic glass

Abstract A series of plate-impact combined compression-and-shear experiments are conducted to investigate the effect of normal stress and hydrostatic pressure on the shear yield and flow behavior of a zirconium-based bulk metallic glass (BMG), Zr41.25Ti13.75Ni10Cu12.5Be22.5. The experiments involve skew impact of a thick tungsten carbide (WC) flyer with a stationary WC target plate that sandwiches a thin BMG specimen. The experimental results are combined with the results of a previous study by Lewandowski and Lowhaphandu (2002) , where the yield and fracture behavior of the same composition BMG at hydrostatic pressures up to 1 GPa were analyzed using a simple Mohr–Coulomb type model, to understand the effects of normal stress and hydrostatic pressure on the yield and flow behavior of the BMG. The results indicate that, within experimental errors, the normal stress as well as the hydrostatic pressure up to 8.8 GPa have a negligible influence on the shear yield and flow behavior of the BMG.
Flow adsorption calorimetry of surfactants as a function of temperature, salinity, and wettability☆

Abstract Surfactant adsorption and the enthalpy thereof have been evaluated using flow adsorption calorimetry. This technique permits the simultaneous determination of both the quantity and the enthalpy of adsorption. Temperature, salinity, surfactant type, and the wettability of the adsorbent surface were all shown to have an effect on both the amount of and the enthalpy of adsorption. In general, there was a decrease in adsorption as temperature increased and an increase in adsorption as salinity increased, up to a maximum. Similarly, the molar enthalpy of adsorption increased with increasing temperature and decreased with increasing salinity. The molar enthalpy of adsorption for all surfactant types was higher for oil-wet than for water-wet material. A Langmuir isotherm adequately described the adsorption of cationic surfactant on an oil-wet surface for all temperatures and salinities reported in this study.
Biases in optimal pricing with network externalities

Access and usage externalities affect consumer welfare and behavior in regulated communications networks, but nobody has ever adjusted prices to allow for externalities with a binding revenue constraint. If we fail to account for network externalities when we set (profit-constrained) welfare-maximizing access and usage prices, are the resulting prices too high or too low? This article demonstrates that the outcome depends upon what size of customer is likely to exit the network. It determines ranges where the access price increases and the usage price decreases, as well as the reverse.
Sequence conversion during postreplicative adenovirus overlap recombination

Abstract Sequence conversion efficiently transfers genetic information in high yield during postreplicative adenovirus overlap recombination. This process is intrinsically nonreciprocal, depends on adenovirus-specific strand-displacement replication by both partner molecules, and requires that complementary sequences on displaced strands must exceed a minimal length to form a heteroduplex intermediate.
Women's Reproductive Rights, Modernization, and Family Planning Programs in Developing Countries: : A Causal Model

Ongoing debates on women's reproductive rights in world conferences and conventions have heightened the need for empirical research and theoretical explanations of women's reproductive rights. The study examines the effects of family planning programs and the processes of modernization on women's reproductive rights. The study involves 101 developing countries. Using linear structural equation analysis, the study finds that family planning programs reduce population growth. However, population decline does not influence women's reproductive rights. The most important determinant of reproductive rights is gender equality. Socioeconomic development has a positive effect on women's educational attainment, but is negatively related to gender equality. The direct effect of women's education on reproductive rights is negative. Theoretical and policy implications of the findings are presented.
Colon polyp detection using smoothed shape operators: Preliminary results

Computer-aided detection (CAD) algorithms identify locations in computed tomographic (CT) images of the colon that are most likely to contain polyps. Existing CAD methods treat the CT data as a voxelized, volume image. They estimate a curvature-based feature at the mucosal surface voxels. However, curvature is a smooth notion, while our data are discrete and noisy. As a second order differential quantity, curvature amplifies noise. In this paper, we present the smoothed shape operators method (SSO), which uses a geometry processing approach. We extract a triangle mesh representation of the colon surface, and estimate curvature on this surface using the shape operator. We then smooth the shape operators on the surface iteratively. Throughout, we use techniques explicitly designed for discrete geometry. All our computation occurs on the surface, rather than in the voxel grid. We evaluate our algorithm on patient data and provide free-response receiver-operating characteristic performance analysis over all size ranges of polyps. We also provide confidence intervals for our performance estimates. We compare our performance with the surface normal overlap (SNO) method for the same data. A preliminary evaluation of our method on 35 patients yielded the following results (polyp diameter range; sensitivity; false positives/case): (10mm; 100%; 17.5), (5-10 mm; 89.7%, 21.23), (<5 mm; 59.1%; 23.9) and (overall; 80.3%; 23.9). The evaluation of the SNO method yielded: (10 mm; 75%; 17.5), (5-10 mm; 43.1%; 21.23), (<5 mm; 15.9%; 23.9) and (overall; 38.5%; 23.9).
CONSIDERING BUILD-LATER AS AN ALTERNATIVE IN MAJOR TRANSIT INVESTMENT ANALYSES

How the stream of benefits, discount rate, and other parameters of a major transit project affect its optimal timing are examined. A theoretical model of the timing of public infrastructure projects is used. The model takes into account the net benefits of a project, the variation of benefits with project age and timing of investment, construction cost and its growth, and discount rate. The model is used to examine three questions: Under what conditions is build-later optimal? How do changes in the discount rate and other parameters of an investment affect its optimal timing? How significantly do differences in the stream of net benefits from an investment affect its optimal timing? The first two questions are examined analytically, and the last question is examined numerically. When the stream of net benefits stays constant, declines, or shifts parallel with the timing of investment, build-later is not optimal. When the stream of net benefits grows over time, however, build-later can be optimal. A necess...
Effects of Plasma Boundaries in Plasma Oscillations

The discussion of electron plasma oscillations is extended to include some of the effects of boundaries. It is first shown that an electron taking part in a traveling plasma oscillation will be reflected at a sheath of infinitesimal thickness with velocity appropriate to the oscillation traveling in the reverse direction. This means that standing waves may be built up without loss at the sheaths. This approach is extended to sheaths where a finite time of penetration is necessary before reflection occurs and also to the case of reflection at metallic electrodes. In both cases expressions for the damping are derived and it is concluded that for low pressure discharges damping resulting from imperfect reflection from electrode sheaths may be comparable with collision damping but that damping arising from conducting electrodes is unimportant.The excitation of the plasma by sharp beams is considered briefly and expressions are derived for the energy transfer of a beam to growing and of stationary amplitudes. It is pointed out that beams should excite oscillations only when a regular geometry exists. With irregular geometry bunching pulses are to be expected, of the type observed by Merrill and Webb. A detailed analysis is given of the bunching and of the Merrill and Webb experiments. Good agreement is obtained if one assumes that the pulses are maintained because high harmonic waves in the pulse cannot be shielded out by the plasma. These feed back energy towards the cathode and continuously modulate the beam.
Some Thoughts on Affirmative Action Here and in India: Galanter's Competing Equalities

During the time that the British Empire included much of India, Canada, and the United States, Lord Mansfield declared that slavery was abhorrent to the common law and, with a stroke of his quill, freed several thousand black slaves in England.' Mansfield's decision in Sommersett's case was in the eighteenth-century tradition that recognized individual rights against state power. It helped to usher in a world where slavery and subordination were no longer normal. That individualist tradition took deepest root in America, where we established a system of individual equality but simultaneously created inferior classes by establishing slavery and subordinating, in different ways, women and native Americans. We have struggled for more than half our history to rid ourselves of these shadows. In the last quarter century, we have come to recognize that the principle of individual equality is a necessary but inadequate response to social conditions generated by slavery and subordination. We have begun an effort to raise the status of subordinated groups. These activities parallel efforts in India and Canada to improve the substantive conditions of members of subordinated groups. In India, Canada, and the United States today, these postMansfield questions are being addressed in ways that conform to national customs and perceptions yet are understandable as emanations of the common law tradition.
Predictors of alcohol and tobacco use prior to and during pregnancy in the US: the role of maternal stressors

The purpose of the study was to understand the association between stressful life events prior to conception (PSLEs) and women's alcohol and tobacco use prior to and during pregnancy, and the continuation of such use through pregnancy. Data were from the Early Childhood Longitudinal Study-Birth Cohort (n = 9,350). Data were collected in 2001. Exposure to PSLEs was defined by indications of death of a parent, spouse, or previous live born child, divorce or marital separation, or fertility problems prior to conception. Survey data determined alcohol and tobacco usage during the 3 months prior to and in the final 3 months of pregnancy. Weighted regressions estimated the effect of PSLEs on alcohol and tobacco use at each time point and on the continuation of use, adjusting for confounders. Experiencing any PSLE increased the odds of tobacco use prior to (adjusted odds ratio [AOR] 1.52, 95 % confidence interval (CI) 1.23-1.87) and during pregnancy (AOR 1.57, 95 % CI 1.19-2.07). Women exposed to PSLEs smoked nearly five additional packs of cigarettes in the 3 months prior to pregnancy (97 cigarettes, p = 0.011) and consumed 0.31 additional alcoholic drinks during the last 3 months of pregnancy than unexposed women. PSLEs are associated with tobacco use before pregnancy and alcohol and tobacco use during pregnancy. Alcohol and tobacco screening and cessation services should be implemented prior to and during pregnancy, especially for women who have experienced PSLEs.
Thermal injury: Defects in immune response induction

Abstract The immunocompetence of leukocyte subpopulations from mice which had received a 10% scald burn has been examined following injury. Leukocytes from the burned animals were reduced 80% in their ability to generate de novo antibody-forming cells in vitro . When leukocytes from the injured animals were supplied with the immunologically active factors produced by normal A and T leukocytes, their immunocompetence was restored. These experiments indicate that: (i) Thermal injury directly reduces the immune activity of leukocytes; (ii) the thermal-induced leukocyte injury is time dependent; and (iii) the leukocyte subpopulation affected is not the antibody-forming B cell.
A theorem on regular infinitely divisible cox processes

Abstract If a regular infinitely divisible (Poisson cluster) point process is Coxian (doubly stochastic Poisson, subordinated Poisson), then the number of points per cluster either takes on each positive integer value with positive probability or is identically equal to one. In particular, a Gauss-Poisson process can not be Coxian.
Web 2.0 for Language Learning: Benefits and Challenges for Educators

This literature review study explores 43 empirical research studies that report on the integration of Web 2.0 tools into language learning and evaluate the actual impact of their use. In particular, this review aims to identify the specific Web 2.0 tools integrated in the educational settings, theoretical underpinnings that are commonly used to frame the research, methodologies and data analysis techniques that scholars employ to analyze their research data, the benefits and challenges scholars spotted in their research findings, the pedagogical implications in using Web 2.0 for language learning and future research directions that scholars offer from their research.
Ontogeny of Langerhans Cells

Results of transplantation and chimera studies indicate that epidermal Langerhans cells are derived from precursor cells originating in bone marrow.
Observation of Resonant Transfer and Excitation to Specific LS -Coupled States in O 5 + + He Collisions by High-Resolution, 0° Auger-Electron Spectroscopy

Conclusive evidence is presented for resonant transfer and excitation to specific intermediate states in collisions of Li-like ${\mathrm{O}}^{5+}$ with He. Using the technique of high-resolution 0\ifmmode^\circ\else\textdegree\fi{} Auger-electron spectroscopy, we observed a maximum in the cross section for production of Be-like $1s2s2{p}^{2}^{3}D$ and $1s2s2{p}^{2}^{1}D$ states as a function of incident ion energy. The peak appears at \ensuremath{\sim}13 MeV with a width of \ensuremath{\sim}7 MeV and is in good agreement with the impulse-approximation model for resonant transfer and excitation.
Temporal variation in winter flounder recruitment at the southern margin of their range: is the decline due to increasing temperatures?

The southern-most stock of winter flounder (Pseudopleuronectes americanus), a cold temperate species of the Northwest Atlantic, has not recovered from overfishing despite continued restrictive measures, and appears to be contracting northward. We regressed larval and settled juvenile abundance (after accounting for adult and larval contribution to variation, respectively) on temperature over several decades from collections in New Jersey, the United States, at the southern edge of their range to determine if increasing temperatures during the first year of life were responsible for this contraction. A significant stock–recruitment relationship at both stages was moderate, explaining 27.5% of the variance for larvae on adults and 20.6% for juveniles on larvae. There was no significant effect of average monthly temperature in explaining variance of the residuals for larvae, or of degree day on explaining the abundance of residuals for juveniles over a months-long settlement period. However, in both cases, residuals were widely distributed at cold temperatures, while they were always low at warm temperatures. Thus, years in which spring temperatures were warm (5–7C for February, 7–9 for March, and 11–20 for May) always experienced poor recruitment. This threshold effect may result from an intersection with predators in response to temperature, and this may play a more important role than heat stress in determining recruitment success.
Hematologic disorders and growth factor support in HIV infection

HIV disease highlights the continuum that links hematology to immunology. It is thought that the direct cellular interactions of HIV-1 are quite restricted. Yet a pancellular abnormality of the blood and immune systems develops that alters not just host defense but also the oxygen-carrying and coagulation function of these systems as well. Although the CD4+ T lymphocyte legitimately remains the focus of attention regarding the pathophysiology of AIDS, this article reviews the manifestations and possible mechanisms by which HIV-1 affects other dimensions of the lymphohematopoietic system.
Data offloading techniques in 3GPP Rel-10 networks: A tutorial

The realization of high data rates in LTE technology over an all IP network means an ever increasing load on packet data networks. 3GPP has defined data offloading as a key solution to cope with this challenge. Data offloading has been a critical area of study in 3GPP Release-10. The 3GPP Evolved Packet Core (EPC) has been defined to be expansive; for example, it is designed to work in conjunction with non-3GPP access networks, femto cells etc., This diversity causes more scenarios to tackle, but it also provides solutions in the ways of offloading data from the EPC. This article is a tutorial on three such mechanisms, namely Local IP Access (LIPA), Selected IP Traffic Offload (SIPTO) and IP Flow Mobility (IFOM). The article starts with an overview of data offloading methods. The basics and key concepts of each method are summarized before giving the requirements, architecture and procedures with high-level message flows. The article ends with a brief evaluation of the mechanisms and references for the reader interested in further reading.
Phosphorus addition reduces invasion of a longleaf pine savanna (Southeastern USA) by a non-indigenous grass (Imperata cylindrica)

Imperata cylindrica is an invasive C4 grass, native to Asia and increasing in frequency throughout the tropics, subtropics, and southeastern USA. Such increases are associated with reduced biodiversity, altered fire regimes, and a more intense competitive environment for commercially important species. We measured rates of clonal spread by I. cylindrica from a roadside edge into the interior of two longleaf pine savannas. In addition, we measured the effects of fertilization with nitrogen and phosphorus on clonal invasion of one of these sites. Clonal invasion occurred at both sites and at similar rates. Older portions of an I. cylindrica sward contained fewer species of native pine-savanna plants. Clonal growth rates and aboveground mass of I. cylindrica were reduced by the addition of phosphorus relative to controls by the second growing season at one site. As a group, native species were not affected much by P-addition, although the height of legumes was increased by P addition, and the percent cover of legumes relative to native non-legumes decreased with increasing expected P limitation (i.e., going from P-fertilized to controls to N-fertilized treatments). Clonal invasion was negatively correlated with the relative abundance of legumes in control plots but not in P-fertilized plots. Species richness and percent cover of native plants (both legumes and non-legumes) were dramatically lower in N-fertilized plots than in controls or P-fertilized plots. Species richness of native plants was negatively correlated with final aboveground mass of I. cylindrica in control and P-fertilized plots, but not in N-fertilized plots. The results suggest that I. cylindrica is a better competitor for phosphorus than are native pine-savanna plants, especially legumes, and that short-lived, high-level pulses of phosphorus addition reduce this competitive advantage without negatively affecting native plant diversity. Ratios of soil P to N or native legume to non-legume plant species may provide indicators of the resistance of pristine pine savannas to clonal invasion by I. cylindrica.
Long-Term Stability of the Wechsler Intelligence Scale for Children-Third Edition among Students with Disabilities

Long-term stability of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) was investigated for children with specific learning disability (SLD), serious emotional disability (SED...
Incidence of Thyroid Cancer in Women in Relation to Previous Exposure to Radiation Therapy and History of Thyroid Disease

Female residents of 13 counties of Western Washington, in whom papillary, follicular, or mixed papillary-follicular thyroid carcinomas had been diagnosed between 1974 and 1979 were interviewed regarding their medical and reproductive histories and past exposure to radiation treatments. For comparison, a random sample of women from the same population was interviewed. Women who had received radiation treatments to the head or neck prior to 5 years before interview were 16.5 times (95% confidence interval = 8.1-33.5) more likely than unexposed women to develop cancer. The relative risk (RR) was highest for papillary cancer (19.4) but also was elevated substantially for follicular and mixed papillary-follicular tumors. Women first irradiated at age 19 years or younger had a much higher RR than did women irradiated at age 20 or older. Regardless of prior radiation exposure, women who ever had had a goiter were at increased risk of developing thyroid cancer. Women who had ever developed a goiter had 17 times the risk of developing follicular cancer and almost 7 times the risk of developing papillary cancer as compared with women who never had had a goiter. Risk of thyroid cancer was elevated even among women who had had a history of goiter many years prior to diagnosis. A history of thyroid nodules was also a risk factor for papillary and mixed thyroid cancer. Neither a history of hypothyroidism nor hyperthyroidism was found to increase the risk of thyroid cancer.
Suppression of Stimulated Brillouin scattering in high power, low phase noise RF-photonic links

Stimulated Brillouin scattering (SBS) degrades the performance of ultra-low phase noise RF-photonic links by limiting the optical power that can be transmitted through the optical fiber. While SBS can be suppressed with a variety of methods, existing techniques conflict with the demands of RF-photonic links that require the lowest phase noise. In this work, we present a new technique that is compatible with these systems. We demonstrate that by concatenating spools of Corning SMF-28 fiber with different Brillouin frequency shifts, it is possible to decrease the total power reflected in the SBS process by at least 7 dB. This corresponds to an increase in the optical power that can be transmitted through the fiber.
A FemmeNist ManiPedifesto

This is an autoethnography about the role of nail salons in relation to my own evolving feminist and femme consciousness. Through a story of desire, grief, isolation, and recuperation, I explore th...
Imposing Local Magnetic Fields to Control Magnetotactic Bacteria Through Combining Microfabrication and Magnetism

The ability to impose localized magnetic fields on magnetic bacteria has a variety of applications including in biophysics, nature inspired materials, and non-destructive sensors. Herein we demonstrate our ability to locally direct swimming magnetotactic bacteria, Magnetospirillum magneticum strain AMB-1, through microfabricated magnetic field concentrators. To accomplish this, a pair of Helmholtz coils was built to magnetize microfabricated permalloy structures of shapes including circles, squares, and triangles, which may affect the local magnetic fields near the structures. The permalloy structures were fabricated through photolithography and depositing a thin film of NiFe on a master mold. The substrate was a #1 glass coverslip that permitted us to observe the interactions of the magnetotactic bacteria with the permalloy structures. These microfabricated structures were positioned at the center and along the axes of the Helmholtz coils. The response of the bacteria around the structure was quantified through analyzing the images of the bacteria in terms of orientation and velocity. The results indicate that the AMB-1 appeared to cross or stop at the regions on the structures possessing higher magnetic field intensity relative to the surroundings. Furthermore, the bacteria appeared to alter their orientation as they approached sharp corners of the structures. We also developed a model using Finite Element Method Magnetics (FEMM) to investigate the regions of local magnetic field gradients, which indicated higher magnetic fields at the protrusions and the sharp points of the magnetic structures. This work supports the idea of using these magnetotactic bacteria as an aqueous non-destructive sensor and also has implications in fields including physics, biology, material science, and engineering.