cssi/SciSciGPT-SciSciNet huggingface dataset:
Colloidal silver formation at the surface of float glass

Abstract The formation of colloidal silver during the heating in air of silver films on float glass has been observed. The presence of colloidal silver gives to a yellow color and an absorption band centered at 400–420 nm. The results of this study indicate that the formation of colloidal silver is strongly dependent upon the concentration of stannous tin in the glass. The optical density of the absorption band induced in the glass is much greater for samples silvered on the tin-rich face of the glass and varies with the thermal history of the sample. Removal of the outer few micrometers of the glass surface results in a radical change in the amount of colloidal silver formed. Silver colloids are formed only if the sample is heated in an atmosphere containing oxygen, suggesting that the silver must be ionized before it will diffuse into the glass. The colloid formation process has an activation energy of approximately 30 kcal/mol, which is very near that reported for silver-sodium interdiffusion in similar glasses.
Oligodendrocyte/myelin-immunoreactivity n the developing olfactory system

Abstract Immunocytochemistry was used to characterize oligodendrocyte maturation in the developing mammalian olfactory system. Postnatal day 10–16, 20, 30 and adult rats were examined, as well as postnatal day 20, 30, 40 and adult Monodelphis domestica (the grey, short-tailed opossum). In rats, oligodendrocyte/myelin-immunoreactivity first appears in the accessory olfactory bulb by day 11, with labeling rapidly increasing throughout the entire bulb over the next five days. An adult pattern of immunoreactivity, characterized by dense labeling in the granule cell layer, sparse immunoreactivity in the external plexiform layer, and staining along the periphery of glomeruli, is attained by day 30. Staining is apparent in both the lateral olfactory tract and anterior commissure by day 11, and becomes heavy by day 20. While patterns of oligodendrocyte/myelin-immunoreactivity in the adult Monodelphis and rat bulb are similar, staining first appears much later in the opossum (around day 30), and maturation occurs more slowly. For example, rostral-caudal gradients in the development of staining in the anterior commissure were noted which were not seen in the rat. These differences emerge because Monodelphis' slower growth allows more resolution into developmental sequences. Finally, in rats, unilateral naris closure on the day after birth, which significantly alters normal patterns of bulb development, has no effect on the pattern and level of immunoreactivity even after long (30 day) survival periods. In both normal and naris occluded rats, oligodendrocyte/myelin-immunoreactivity is found in caudal aspects of the rat bulb on day 11 and subsequently progresses throughout the entire bulb over the next five days. Patterns in the Monodelphis bulb mirror those observed in the rat, however, staining appears later and progresses more slowly, suggesting Monodelphis is a useful animal for examining early myelin formation.
Interaural Level Difference Discrimination Thresholds for Single Neurons in the Lateral Superior Olive

The lateral superior olive (LSO) is one of the earliest sites in the auditory pathway that is involved in processing acoustical cues to sound location. Here, we tested the hypothesis that LSO neurons can signal small changes in interaural level differences (ILDs), a cue to horizontal sound location, of pure tones based on discharge rate consistent with psychophysical performance in the discrimination of ILDs. Neural thresholds for ILD discrimination were determined from the discharge rates and associated response variability of single units in response to 300 ms tones in the LSO of barbiturate-anesthetized cats using detection theory. Neural response variability was well described by a power function of the mean rate, both in individual neurons and collectively; LSO neurons were less variable than expected from a Poisson process. Compared with psychophysical data, the best-threshold ILDs of single LSO neurons were comparable with or better than behavior over the full range of frequencies (0.3–35 kHz) and pedestal ILDs (±25 dB) explored in this study. With a pedestal ILD of 0 dB, ILD increments of 1 dB could be discriminated by some neurons, with a median of 4.35 dB across neurons. For pedestal ILDs away from 0 dB, the best-threshold ILDs were as low as 0.5 dB, with a median of 2.3 dB. These findings support the hypothesis that the LSO plays a role in the extraction of ILD, and that the representation of ILD by LSO neurons may set a lower bound on the behavioral sensitivity to ILDs.
A Stochastic Process and Generalized Distributions for the Study of Oviposition Evolution of a Parasite

This paper considers a generalized birth process {Xm(t), t > 0} and presents a new stochastic model for the number of eggs laid by a parasite on a host. Also, given an underlying distribution for the number of visits between parasites and a host, this distribution is generalized by the distribution of the number of eggs per visit laid on the host. If a certain number of eggs are already present on the host, a parasite such as a Japanese weevil, may avoid oviposition in subsequent visits (see JANARDAN (1980)) to the same host. A class of generalized distributions are presented to model such situations. The case of a single egg laying parasite and a Poisson distribution for the number of visits of the parasite to the same host yields a distribution of particular interest. In order to develop this model, certain lemmas are derived. Finally a characteristic property of this stochastic model is presented.
Importance of Angular Correlations between Atomic Electrons

We present the results of some new calculations on two atomic problems---the correlation energy in the ground state of 2-electron atoms, and elastic scattering of slow electrons from hydrogen atoms---to show the relative importance of various angular components of the complete wave function. We conclude that, as a general rule, the use of just (relative) $s$ and $p$ waves will give quite accurate answers---with only a few percent errors at most; but to obtain higher precision one should abandon the Legendre polynomial expansion and use the coordinate ${r}_{12}$.
Factors related to medication adherence among homeless women and children

Objective The primary objective of this study was to examine factors related to medication adherence among homeless women and children. A secondary purpose was to describe the medication informational needs of homeless women. Method Fifty-seven women at six different shelters for homeless women in Wake County, North Carolina were interviewed during the summer of 2001. Key findings Fifty-eight per cent of women reported having at least one medical condition and 84% of the women had taken at least one medication during the past week. Twenty-six per cent of women said that during the last week they had not taken a medication on purpose and 30% purposively cut back on a medication. A woman with a substance abuse problem was five times more likely to purposively not take a medication. Almost half of the women who had children living with them had a child that had taken medication during the past week. The primary reasons cited for not using medications as directed were access issues. Fifty-eight per cent of the women wanted to learn more about their or their children's medications. The majority of women preferred to receive more verbal and written drug information. Conclusions Pharmacists need to work with local homeless shelters and the women in these shelters to help make sure that they receive needed medications and information for themselves and their children.
The effects of intragroup forces on intergroup conflict resolution

Abstract Forces which are part of a representative's role as he negotiates intergroup disputes were examined in a laboratory experiment. Prenegotiation experience, cohesiveness, and evaluation potential were manipulated in the context of a union management bargaining problem to determine their effect on the length of time needed to reach agreement. It was found that the effects of prenegotiation experience in previous research were likely to be confounded with the latter two independent variables. Further, these variables interact in complex ways to produce longer negotiation times for representatives who faced postnegotiation evaluation by a cohesive group.
Robust background modeling for enhancing object tracking in video

Automated event recognition in video data has numerous practical applications. The ability to recognize events in practice depends on accurate tracking of objects in the video data. Scene complexity has a large effect on tracker performance. Background models can address this problem by providing a good estimate of the image region surrounding the object of interest. However, the utility of the background model depends on accurately representing current imaging conditions. Changing imaging conditions, such as lighting and weather, render the background model inaccurate, degrading the tracker performance. As a preprocessing step, developing a set of robust background models can substantially improve system performance. We present an approach to robustly modeling the background as a function of the data acquisition conditions. We will describe the formulation of these models and discuss model selection in the context of real-time processing. Using results from a recent experiment, we demonstrate empirically the performance benefits from using the robust background modeling.
Genetically defined peptidases of maize. I. Biochemical characterization of allelic and nonallelic forms.

A number of biochemical properties have been investigated for both allelic and nonallelic forms of maize peptidases. Four aminopeptidases exist in maize (LAP-A, LAP-B, LAP-C, and LAP-D) and are the products of four diallelic loci. The aminopeptidases fall into two biochemical groups on the basis of these studies. LAP-A and LAP-D have comparatively low apparent Km (Kapp) values for arginine-naphthylamide derivatives and high velocities for arginine-naphthylamide and lysine-naphthylamide. LAP-B and LAP-C, on the other hand, have lower Kapp values for leucine-naphthylamide and higher velocities for nonpolar amino acid-naphthylamides than for arginine-naphthylamide. LAP-A and LAP-D are also relatively more heat stable than LAP-B and LAP-C and have somewhat higher molecular weights (71,500) than LAP-B and LAP-C (63,500). In determining molecular weights of the peptidases, use was made of their differential substrate specificities toward amino acid-naphthylamides. Some properties of genetically defined maize endopeptidase are also presented. Maize endopeptidase is inhibited by the sulfhydryl reagents N-ethylmaleimide and p-chloromercuribenzoate (pCMB), and by tosyl lysine chloromethyl ketone. Maize aminopeptidase activity is inhibited by N-ethylmaleimide, pCMB, and EDTA (ethylenediamine tetraacetic acid).
Localization of sodium pump sites in frog urinary bladder.

Abstract [3H]Ouabain binding in frog and toad urinary bladder was investigated by short-circuit current (SCC), scintillation counting and authoradiographic techniques. SCC data and analysis of tissue digests following serosal exposure to ouabain showed that ouabain binding and inhibition of Na+ transport was completely reversible in toad bladder whereas, in frog bladder, [3H] ouabain was tightly bound and Na+ transport remained suppressed even after a 60-min washout. Mucosal exposure of frog bladder to [3H]ouabain or serosal exposure after preincubation with unlabeled ouabain led to a marked reduction in binding. Specificity of binding was assessed further by adjusting the concentration of cecrtain (Na+−K+)-ATPase ligands (K+, ATP) to levels known to reduce ouabain binding. High K+ concentrations and depletion of endogenous ATP by incubation under anoxic conditions resulted in a significant drop in [3H]ouabain binding. Autoradiographic analysis showed that grains are localized primarily to the basolateral plasma membranes of the granular cells, providing direct morphological evidence for the location of Na+ pumps at these sites. Although autoradiographs did not provide sufficient resolution to rule out unequivocally ouabain binding to the mitochondria-rich cell, morphological evidence suggests that grain densities are significatly higher between adjacent granular cells than between granular cell-mitochondria-rich cell interfaces.
Electrophoretic deposition of CdSe nanocrystal films onto dielectric polymer thin films

Abstract The electrophoretic deposition of cadmium selenide (CdSe) nanocrystal films from a stable hexane suspension onto a dielectric polymer film is reported. The electrodes were prepared by spin casting a ~ 30 nm thick smooth, defect-free, polystyrene film on silicon substrates. Scanning electron microscopy and atomic force microscopy showed that the CdSe films deposited atop polystyrene possessed morphology comparable to CdSe films deposited on the bare silicon electrodes. Factors affecting deposition, such as nanocrystal charging in suspension and wetting of electrode surfaces, are reviewed. This approach to preparing nanocrystal films onto homogeneous dielectric layers will facilitate the fabrication of novel polymer-nanocrystal composites.
The social contexts of some very low frequency calls of African elephants

Several types of low frequency calls made by African elephants, Loxodonta africana, and the contexts in which they occurred are described. These calls had fundamental frequencies ranging from 14–35 Hz and sound pressure levels as high as 103±3dB (re 20 μPa) at 5 m from the source. Very low frequency sounds are subject to very little environmental attenuation, suggesting that sounds at the frequencies and sound pressure levels measured from elephants may be audible to conspecifics several km away. Long-term records on the behavior of elephants and on the contexts of specific call types suggest that elephants make use of infrasound in the spatial coordination of groups and as they search for mates.
Specific effects and biofeedback versus biofeedback-assisted self-regulation training

In any field, clear and logical conceptualizations are the basis of accurate models----correct research design----correct results----correct conclusions----advancement in the field. Faulty conceptualizations----faulty models----faulty research design----faulty results----faulty conclusions----confusion. In analyzing the conceptualizations of "biofeedback" as expressed by John Furedy (1987) in, "Specific versus Placebo Effects in Biofeedback Training: A Critical Lay Perspective," we focus on two issues: Does biofeedback have a treatment effect? Is biofeedback necessary for the training effect? In discussing issue (1) we describe the multiple meanings of "biofeedback" and raise the fundamental question: Is biofeedback a treatment? We argue that faulty conceptualizations of clinical biofeedback (1) assume that the treatment in clinical biofeedback is "biofeedback" with specific effects, (2) assume that the scientific basis of biofeedback is dependent upon demonstrations of these specific effects through double-blind design that distinguish "specific" from "placebo effects," and (3) trivialize clinical research by attempting to determine the usefulness of biofeedback information--usefulness that is already understood logically by professionals and consumers and demonstrated by clinical studies in the laboratory and in the clinic. We further argue that accurate conceptualizations of clinical biofeedback (1) identify self-regulation skills as the treatment with specific effects of physiological change and symptom reduction, and (2) describe the use of information from biofeedback instruments as scientific verification of self-regulation skills. Finally, the scientific basis of clinical biofeedback is based on (1) evidence from experimental and clinical control studies that have demonstrated the effectiveness of self-regulation skills for symptom alleviation, and (2) the use of biofeedback instruments to verify the acquisition of self-regulatory skills, thus fulfilling the scientific dictum of verifiability.
Expression of a cardiac myosin gene in non-heart tissues of developing frogs

Direct developing frogs, like Eleutherodactylus coqui, provide opportunities to investigate limb early development in anuran amphibians that are less available in species with tadpoles. We have found that myosin heavy chain 6 (myh6), a myosin gene usually considered heart-specific in Xenopus and other animals, is expressed in limbs of E. coqui embryos. The gene for microRNA(miR)-208 is contained in an intron of the E. coqui myh6 gene as in mammals, and miR -208 was detected as a microRNA, more highly expressed in a microarray of E. coqui limb buds, compared to Xenopus laevis limb buds. Myh6 is also expressed in several muscles of tadpoles and froglets of Xenopus tropicalis. These connections raise the possibility of an involvement of myh6 and miR-208 in the thyroid dependent metamorphosis of anurans.
Human protoporphyrinogen oxidase: relation between the herbicide binding site and the flavin cofactor.

Protoporphyrinogen IX oxidase (protox) catalyzes the oxidation of protoporphyrinogen IX to protoporphyrin IX in the penultimate step of heme and chlorophyll biosynthesis in animals and plants. Protox is the target of light-dependent peroxidizing herbicides and is inhibited at nanomolar levels by several chemical classes including tetrahydrophthalimides (discussed below) and diphenyl ethers (e.g., acifluorfen) usually with little selectivity between the mammalian and plant enzymes. The herbicide binding site is examined here with a photoaffinity radioligand optimized on the basis of structure−activity relationships. A radiosynthetic procedure is described for this new herbicidal probe, N-(5-azido-4-chloro-2-fluorophenyl)-3,4,5,6-[3H]tetrahydrophthalimide ([3H]AzTHP), resulting in high specific activity (2.6 TBq/mmol). Human protox expressed in Escherichia coli and purified by affinity chromatography is used with [3H]AzTHP to characterize the herbicide/substrate binding site. Specific binding of [3H]AzTHP t...
A sequence preference for nucleation of α‐helix—crystal structure of Gly‐L‐Ala‐L‐Val and Gly‐L‐Ala‐L‐Leu: Some comments on the geometry of leucine zippers

The synthetic peptide Gly-L-Ala-L-Val (C10H19N3O4.3H2O; GAV) crystallizes in the monoclinic space group P21, with a = 8.052(2), b = 6.032(2), c = 15.779(7) A, beta = 98.520(1) degree, V = 757.8 A3, Dx = 1.312 g cm-3, and Z = 2. The peptide Gly-L-Ala-L-Leu (C11H21N3O4.3H2O; GAL) crystallizes in the orthorhombic space group P212121, with a = 6.024(1), b = 8.171(1), c = 32.791(1) A, V = 1614 A3, Dx = 1.289 g cm-3, and Z = 4. Their crystal structures were solved by direct methods using the program SHELXS-86, and refined to an R index of 0.05 for 1489 reflections for GAV and to an R index of 0.05 for 1563 reflections for GAL. The tripeptides exist as a zwitterion in the crystal and assume a near alpha-helical backbone conformation with the following torsion angles: psi 1 = -150.7 degrees; phi 2, psi 2 = -68.7 degrees, -38.1 degrees; phi 3, psi 32 = -74.8 degrees, -44.9 degrees, 135.9 degrees for GAV; psi 1 = -150.3 degrees; phi 2, psi 2 = -67.7 degrees, -38.9 degrees; phi 3, psi 31, psi 32 = -72.2 degrees, -45.3 degrees, 137.5 degrees for GAL. Both the peptide units in both of the tripeptides show significant deviation from planarity [omega 1 = -171.3(6) degrees and omega 2 = -172.0(6) degrees for GAV; omega 1 = -171.9(5) degrees and omega 2 = -173.2(6) degrees for GAL]. The side-chain conformational angles chi 21 and chi 22 are -61.7(5) degrees and 175.7(5) degrees, respectively, for valine, and the side-chain conformations chi 12 and chi 23's are -68.5(5) degrees and (-78.4(6) degrees, 159.10(5) degrees) respectively, for leucine. Each of the tripeptide molecule is held in a near helical conformation by a water molecule that bridges the NH3+ and COO- groups, and acts as the fourth residue needed to complete the turn by forming two hydrogen bonds. Two other water molecules form intermolecular hydrogen bonds in stabilizing the helical structure so that the end result is a column of molecules that looks like an alpha-helix.
Ion structure determination through collisions of ions of high kinetic energy

Through studies on [C6H6]+ and [C6H5]+ it is shown that charge stripping provides information on ion structure which is complementary to that given by collision-induced dissociation. Stripping involves a more uniform sampling over the range of ion internal energies than does collision-induced dissociation which preferentially samples higher energy ions.
Response to Letters Regarding Article, “Predictors of Abdominal Aortic Aneurysm Sac Enlargement After Endovascular Repair”

We appreciate the comments and interest that our study has generated. Dr De Rango and colleagues and Dr Fillinger highlight key features of our study that are essential for the accurate interpretation of these data. Both letters underscore the potential impact of selection bias in the M2S dataset. This limitation of selection bias was acknowledged clearly in our article.1 However, other than industry-sponsored trials intended for regulatory submissions in which all patients underwent endovascular aortic aneurysm repair (EVAR) within specific industry guidelines, no large multicenter studies that included a wide cross section of patients have been published in which reproducible, well-defined, standardized methods of 3D computerized tomography image analysis were used both before and after device implantation. In fact, the number of patients analyzed in this study is many orders of magnitude larger than any published on the anatomic determinants and rates of aortic sac enlargement after EVAR. Furthermore, single-center case series …
FGF signaling regulates otic placode induction and refinement by controlling both ectodermal target genes and hindbrain Wnt8a

Abstract The inner ear epithelium, with its complex array of sensory, non-sensory, and neuronal cell types necessary for hearing and balance, is derived from a thickened patch of head ectoderm called the otic placode. Mouse embryos lacking both Fgf3 and Fgf10 fail to initiate inner ear development because appropriate patterns of gene expression fail to be specified within the pre-otic field. To understand the transcriptional “blueprint” initiating inner ear development, we used microarray analysis to identify prospective placode genes that were differentially expressed in control and Fgf3−/−;Fgf10−/− embryos. Several genes in the down-regulated class, including Hmx3, Hmx2, Foxg1, Sox9, Has2, and Slc26a9 were validated by in situ hybridization. We also assayed candidate target genes suggested by other studies of otic induction. Two placode markers, Fgf4 and Foxi3, were down-regulated in Fgf3−/−;Fgf10−/− embryos, whereas Foxi2, a cranial epidermis marker, was expanded in double mutants, similar to its behavior when WNT responses are blocked in the otic placode. Assays of hindbrain Wnt genes revealed that only Wnt8a was reduced or absent in FGF-deficient embryos, and that even some Fgf3−/−;Fgf10−/+ and Fgf3−/− embryos failed to express Wnt8a, suggesting a key role for Fgf3, and a secondary role for Fgf10, in Wnt8a expression. Chick explant assays showed that FGF3 or FGF4, but not FGF10, were sufficient to induce Wnt8a. Collectively, our results suggest that Wnt8a provides the link between FGF-induced formation of the pre-otic field and restriction of the otic placode to ectoderm adjacent to the hindbrain.
Noblesse oblige emerges (with time): Power enhances intergenerational beneficence

Abstract Across four experiments, we examine how the experience of power affects intergenerational decision-making. We argue, and empirically demonstrate, that the experience of power enhances intergenerational beneficence. This effect emerges because the experience of power in intergenerational dilemmas prompts a sense of social responsibility among powerholders. In particular, the experience of power in intergenerational contexts leads people to feel an obligation to look out for the long-term interests of others, which in turn enhances generosity to future others. Thus, the positive effect of power on intergenerational beneficence is mediated by a sense of responsibility to look after others’ long-term interests.
Studies of the oligomerization and properties of oligonucleotide analogs bearing (3′->5′) phosphoramidate backbone

In our search for a model of a non-enzymatic template-directed self-replicating system we have studied the oligomerization of 5'phosphoryl-(3'-amino-3'-deoxycytidylyl)-(3'->5')(N->P)-3'-amino-3'deoxyguanosine [PCNPGNH2] and 5'-phosphoryl-(3'-amino-3'-deoxyguanylyl)-(3'->5')(N->P)-3'-amino-3'-deoxycytidine [PGNPCNH2]. These hitherto unknown phosphoramidate analogs of dinucleoslde diphosphates were synthesized and characterized by spectrometric and enzymatic methods. Oligomerization reactions were carried out in aqueous solutions and presence of water soluble earbodiimides.
Building imperial youth? Reflections on labour and the construction of working‐class childhood in late Victorian England

This article looks at the philanthropic practice of juvenile emigration which resulted in the relocation of over 100,000 children from England to the colonies for insights into changing ideas of childhood and labour. After providing a brief introduction to juvenile emigration and the social benefits associated with childhood, this paper demonstrates how philanthropists between 1874 and 1900 increasingly divided children into two cohorts defined by age and work responsibilities. When philanthropists promoted emigration for children under the age of eight, they claimed it provided healthy domestic environments in which innocent "little ones" would be nurtured by adoptive families. For these children, labour ceased to be associated with emigration. Instead, because of their young age, they were entitled to a condition of complete socioeconomic dependency. However, for children above school age, who were increasingly identified as "youth", emigration was understood to be an avenue to economic independence; in an age of anxiety about international competition, creating independent workers became a vital consideration. For these "at risk" youth, emigration was progressively designed to be an educative experience preparing them to contribute to the economic strength of Britain.
Using behavioral mapping to examine the validity of the IPIP-IPC.

Behavioral mapping, a method designed to relate behaviors to circumplex models, was used to examine the predictive validity of the International Personality Item Pool–Interpersonal Circumplex (IPIP-IPC). In this study, 96 participants first completed the IPIP-IPC and then were videotaped in a social interaction with a confederate. At the conclusion of this interaction, the Riverside Behavioral Q-Sort was used to code 64 different behaviors expressed by the participants. Results indicated that participants’ Riverside Behavioral Q-Sort interpersonal behaviors occurred in a manner predicted by their IPIP-IPC scores. Such findings suggest that the IPIP-IPC can predict a multitude of interpersonal behaviors expressed during a dyadic interaction.
Management Vs. Political Perspectives on Transit Policymaking

Over a thirty year period the American transit industry has been transformed from private to public ownership, and financial support for transit has come to be domi nated by a political perspective rather than a management perspective Examples of the politicization of transit policy are drawn from four areas: (1) fare policies designed to encourage ridership use in low density suburbs while penalizing inner-city residents taking short trips, (2) service increased for peak hour com muters and decreased in the off-peak despite adverse economic consequences, (3) emphasis on accessible "mainstream" service for the handicapped rather than more cost-effective separate services, and (4) technical forecasts of transit patronage and cost guided by political uses of the forecasts rather than their accuracy. While researchers have carefully enumerated the economic consequences of transit policy, political concerns are more likely to deter mine those policies
A Human Fetal Prostate Xenograft Model of Developmental Estrogenization

Prostate cancer is a common disease in older men. Rodent models have demonstrated that an early and later-life exposure to estrogen can lead to cancerous lesions and implicated hormonal dysregulation as an avenue for developing future prostate neoplasia. This study utilizes a human fetal prostate xenograft model to study the role of estrogen in the progression of human disease. Histopathological lesions were assessed in 7-, 30-, 90-, 200-, and 400-day human prostate xenografts. Gene expression for cell cycle, tumor suppressors, and apoptosis-related genes (ie, CDKN1A, CASP9, ESR2, PTEN, and TP53) was performed for 200-day estrogen-treated xenografts. Glandular hyperplasia was observed in xenografts given both an initial and secondary exposure to estradiol in both 200- and 400-day xenografts. Persistent estrogenic effects were verified using immunohistochemical markers for cytokeratin 10, p63, and estrogen receptor α. This model provides data on the histopathological state of the human prostate following estrogenic treatment, which can be utilized in understanding the complicated pathology associated with prostatic disease and early and later-life estrogenic exposures.
Biomimetic synthesis of dalrubone and of a new pigment from Dalea emoryi

The isolation of two unusual pigments from Dalea emoryi, dalrubone 2 and its S-methoxy analog together with coumarin and S-methoxycoumarin was recently reported by Dreyer et al. [l]. The structure of dalrubone and the co-occurrence of coumarin suggest that its biosynthesis in Dalea species may involve Cand Omethylation of tlavylium salt intermediates such as 1, although anthocyanidins or flavylium salts with this unusual oxygenation pattern have not yet been reported from any natural sources. In order to test this hypothesis we have prepared flavylium salt 1 employing a general synthetic method described by Michaelidis and Wizinger [2] and have methylated it under a variety of conditions. Methylation of 1 with Me1 in refluxing methanolic NaOMe (mole ratio 1: 10 :6) gave a complex mixture of Et,O-soluble products most of which were acidic and removed by extraction with aqueous base. Repeated column chromatography of the alkali-insoluble fraction yielded small amounts of two pure pigments. The orange, less polar pigment possessed spectral properties (UV, MS, PMR, IR) and TLC behaviour in a number of solvent systems identical to those reported [l] for dalrubone, and this identity was confirmed by direct comparison with an authentic sample. The yellow, more polar pigment has the molecular formula Cr9H1s04 (MS), and 3 IR absorption bands in the carbonyl region at 1720, 1675 and 1636cm-’ but no OH absorptions. The PMR spectrum in CDCl, was comprised of a pair of AB doublets at 68.35 and 7.71 (J = 10 Hz) indicative of a cis disubstituted olefin, a 4 proton multiplet in the aromatic region at 67.35-7.64, and a 12 proton singlet at 61.39 caused by 4 equivalent Me groups. These data suggest structure 3 for the yellow pigment. This structural assignment was further confirmed by a study of the MS fragmentation pattern which can be rationalized as shown in Scheme 1. Additional support for the scheme was provided by a study of metastable peaks which were observed for all of the transformations shown except m/e 171 + 170. To further support the proposal that biosynthesis of Dalea pigments involves methylation of 2’-hydroxyflavylium intermediates, a sample of D. emoryi was extracted with CH among these were treatment of 1 with (a) Me1 and BaO in DMF (b) Et,O-CH,N*
Directional effects on size transposition in preschool children.

Abstract Forty-four preschool children were used in a replication of the Kuenne (1946) study, with the direction of transposition changed to make the larger stimulus positive. A prediction of no differential amount of transposition on a far test, between younger and older Ss, was verified. The difference in results from the previous study was considered to be due to two factors: (a) S preference for larger stimulus, and (b) greater ease of discrimination between pairs of larger stimuli. It is suggested that the Kuenne results do not demonstrate a difference in the transposition process which is dependent upon verbal mediation but rather on the development with age of perceptual selectivity and ordering which gradually counteract various biasing factors in the perceptual behavior of young children.
An evaluation of the involvement of polyamines in modulating MCF-7 human breast cancer cell proliferation and progesterone receptor levels by estrogen and antiestrogen

Abstract The present studies were undertaken to determine the importance of the polyamine biosynthetic pathway in cellular proliferation and hormone-regulated progesterone receptor synthesis in estrogen receptor-containing breast cancer cells. Treatment of MCF-7 cells with difluoromethylornithine (DFMO), the irreversible inhibitor of the enzyme ornithine decarboxylase (ODC), prevented estradiolinduced cell proliferation in a dose-dependent fashion. DFMO inhibition of estradiol-induced cell proliferation was completely recoverable by the addition of exogenous putrescine while putrescine alone did not stimulate proliferation of control cells. ODC activity was 4-fold greater in estrogen-treated cells and DFMO (5 mM) fully inhibited ODC activity. DFMO was able to suppress only slightly further the proliferation of antiestrogen (tamoxifen) treated cells and putrescine was able to recover this DFMO inhibition. In contrast to the suppressive effect of DFMO on cell proliferation, DFMO had no effect on the ability of estrogen to stimulate increased (4-fold elevated) levels of progesterone receptor. Hence, while ODC activity appears important for estrogen-induced cell proliferation, inhibition of the activity of this enzyme has no effect on the ability of estradiol to increase cellular progesterone receptor content.
Protonation of coordinated 2-methylpyrazine and 4,4′-bipyridine as a probe of π-donor potential of ruthenium(II) polyaminopolycarboxylate complexes

The proton dissociation pKa data for RuII(hedta)(LH) and Ru 2 II (ttha)(LH)2 complexes were measured by the spectrophotometric titration mid-point method using the difference in the MLCT spectra for the protonated and deprotonated complexes with L=2-methylpyrazine (2-Mepz) and 4,4′-bipyridine (4,4′-bpy). The pK a ′ s were as follows at 22° C, μ=0.10 (NaCl): Ru(hedta)(2-MepzH), 3.45; Ru2(ttha)(2-MepzH)2, 3.25; Ru(hedta)(4,4′-bpyH), 4.5; Ru2(ttha)(4,4′-bpyH)2, 4.51. The two series (2-Mepzversus 4,4′-bpy) lead to a divergent prediction of the ability of RuII (polyaminopolycarboxylates) to serve as π-donor metal centers in comparison with RuII(NH3) 5 2+ . The results with 4,4′-bpy ligation, where the site of protonation is more isolated from electrostatic effects of the ruthenium center, appear to give the more correct interpretation, consistent with their capacity to make good π-complexes with olefins and pyrimidine nucleobases, that RuII(polyaminopolycarboxylates) are better π-donor metal centers than Ru(NH3) 5 2+ ·ΔpK*, the difference between ground state and excited state pK a ′ s, are used to establish the π-donating order of RuII(polyaminopolycarboxylates) as compared to Ru(NH3) 5 2+ and Ru(CN) 5 3− . The π-donor effect of the ruthenium(II) center in Ru 2 II (ttha)(1,3-butadiene) 2 2− is observed to influence the ligand electronically up to five bonds away from the site of metallation.
Phylogenetic MCMC Algorithms Are Misleading on Mixtures of Trees

Markov chain Monte Carlo (MCMC) algorithms play a critical role in the Bayesian approach to phylogenetic inference. We present a theoretical analysis of the rate of convergence of many of the widely used Markov chains. For N characters generated from a uniform mixture of two trees, we prove that the Markov chains take an exponentially long (in N) number of iterations to converge to the posterior distribution. Nevertheless, the likelihood plots for sample runs of the Markov chains deceivingly suggest that the chains converge rapidly to a unique tree. Our results rely on novel mathematical understanding of the log-likelihood function on the space of phylogenetic trees. The practical implications of our work are that Bayesian MCMC methods can be misleading when the data are generated from a mixture of trees. Thus, in cases of data containing potentially conflicting phylogenetic signals, phylogenetic reconstruction should be performed separately on each signal.
Adenosine signaling in normal and sickle erythrocytes and beyond.

Sickle cell disease (SCD) is a debilitating hemolytic genetic disorder with high morbidity and mortality affecting millions of individuals worldwide. Although SCD was discovered more than a century ago, no effective mechanism-based prevention and treatment are available due to poorly understood molecular basis of sickling, the fundamental pathogenic process of the disease. SCD patients constantly face hypoxia. One of the best-known signaling molecules to be induced under hypoxic conditions is adenosine. Recent studies demonstrate that hypoxia-mediated elevated adenosine signaling plays an important role in normal erythrocyte physiology. In contrast, elevated adenosine signaling contributes to sickling and multiple life threatening complications including tissue damage, pulmonary dysfunction and priapism. Here, we summarize recent research on the role of adenosine signaling in normal and sickle erythrocytes, progression of the disease and therapeutic implications. In normal erythrocytes, both genetic and pharmacological studies demonstrate that adenosine can enhance 2,3-bisphosphoglycerate (2,3-BPG) production via A2B receptor (ADORA2B) activation, suggesting that elevated adenosine has an unrecognized role in normal erythrocytes to promote O2 release and prevent acute ischemic tissue injury. However, in sickle erythrocytes, the beneficial role of excessive adenosine-mediated 2,3-BPG induction becomes detrimental by promoting deoxygenation, polymerization of sickle hemoglobin and subsequent sickling. Additionally, adenosine signaling via the A2A receptor (ADORA2A) on invariant natural killer T (iNKT) cells inhibits iNKT cell activation and attenuates pulmonary dysfunction in SCD mice. Finally, elevated adenosine coupled with ADORA2BR activation is responsible for priapism, a dangerous complication seen in SCD. Overall, the research reviewed here reveals a differential role of elevated adenosine in normal erythrocytes, sickle erythrocytes, iNK cells and progression of disease. Thus, adenosine signaling represents a potentially important therapeutic target for the treatment and prevention of disease.
A Framework for Reliability Assessment in Multilevel Phase-Change Memory

Multilevel-cell (MLC) storage is the preferred way for achieving increased capacity and thus lower cost-per-bit in memory technologies. In phase-change memory (PCM), MLC storage is hampered by noise and resistance drift. In this paper the issue of reliability in MLC PCM devices is addressed at the array level. The purpose of this study is to identify the dominant reliability issues in PCM arrays and to provide a practical methodology to assess the reliability and predict the retention of multilevel states. Experimental data are used to derive and fit simple empirical models which can be used to assess the device reliability over the course of time.
Toward Reconciling STEM and SAXS Data from Ionomers by Investigating Gold Nanoparticles

To date, the sizes of the nanoscale ionic aggregates present in ionomers as determined by scanning transmission electron microscopy (STEM) experiments are inconsistent with small-angle X-ray scattering (SAXS) data interpreted by the Yarusso−Cooper model. To address this discrepancy, we have investigated a pair of model nanoparticles (11- and 55-atom Au clusters) with both STEM and SAXS. To mimic ionic aggregates, these nanoparticles were supported by amorphous PS films of predetermined thickness. While the size of the STEM probe was inconsequential to the resolution and measurement of the particles, the optimal specimen thickness was determined to be less than 50 nm. SAXS was performed on dilute solutions of the nanoparticles and fit using a monodisperse, noninteracting hard-sphere form factor model. For Au 11, STEM finds a diameter of 1.3 ± 0.14 nm and SAXS finds a diameter of 1.4 nm. Similarly, both STEM and SAXS determine a diameter of 1.7 nm for Au 55. For a combined system of Au 11 and Au 55, STEM da...
Symptomatic Unilateral Cannon “a” Waves in a Patient with a Ventricular Pacemaker

A 64-year-old woman was referred because of intermittent pulsations of the left side of the neck, face, and scalp that were first noticed after the insertion of a ventricular pacemaker. The pacemaker had been inserted because of symptomatic 2:1 atrioventricular Mock. Right cardiac catherization showed cannon "a" waves, and phlebographic studies revealed stenosis of the right innominate and internal jugular veins. The symptoms were abolished by conversion to an atrial synchronous pacing system. Comments are offered on the hemodynamic findings, the "pacemaking syndrome," and the use of atrial synchronous pacing.
Radiotherapy for malignancy in patients with scleroderma: The Mayo Clinic experience.

Purpose: To determine the frequency of acute and chronic adverse effects in patients with scleroderma who receive radiotherapy for treatment of cancer. Methods and Materials: Records were reviewed of 20 patients with scleroderma who received radiotherapy. Acute and chronic toxic effects attributable to radiotherapy were analyzed, and freedom from radiation-related toxicity was calculated. Results: Of the 20 patients, 15 had acute toxic effects, with Grade 3 or higher toxicity for 3 patients. Seven patients had self-limited Grade 1 or 2 radiation dermatitis, and no patient had Grade 3 or higher radiation dermatitis. Thirteen patients had chronic toxic effects, with Grade 3 or higher chronic toxicity for 3 patients. The median estimated time to any grade chronic toxicity was 0.4 years, and the median estimated time to Grade 3 or higher chronic toxicity has not been reached. Conclusions: The results suggest that although some patients with scleroderma treated with radiation experience considerable toxic effects, the occurrence of Grade 3 or higher toxicity may be less than previously anticipated.
VacA from Helicobacter pylori: a hexameric chloride channel.

VacA is a unique protein toxin secreted by the human pathogen Helicobacter pylori. At a neutral pH, the cytotoxin self-associates into predominantly dodecameric complexes. In this report, we show that at an acidic pH, VacA forms anion selective channels in planar phospholipid bilayers. Similar to several other chloride channels, the VacA channel exhibits a moderate selectivity for anions over cations (PCl:PNa=4.2:1), inhibition by the blocker 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid and a permeability sequence, SCN−≫I−>Br−>Cl−>F, consistent with a ‘weak field strength’ binding site for the permeant anion. Single channel recordings reveal rapid transitions (486 s−1) between the closed state and a single open state of 24 pS (+60 mV, 1.5 M NaCl). Evaluation of the rate of increase in macroscopic current as well as atomic force microscopy suggest that this VacA channel is a hexamer, formed by the assembly of membrane-bound monomers. Not only are these VacA channels likely to play an important role in the pathological activity of this toxin, but they may also serve as a model system to further investigate the mechanism of anion selectivity in general.
Cyclic product codes and their implementation

In many communication systems, variable-redundancy coding schemes are highly desirable either due to the fact that messages of various degrees of importance are present, or due to some change in the real communication channel. A class of “cyclic product codes” presented in this paper is capable of operating in variable redundancy modes. In the simplest case, the generator polynomial in the high redundancy mode is g(x) = g1(x)g2(x), while the generator polynomial in the low redundancy mode is only g1(x). It is shown that efficient product codes can be constructed offering different degrees of protection against independent errors, burst errors, and multiple burst errors. It is also shown that particularly simple implementation for cyclic product codes is possible. In fact, the complexity of the entire decoder can be made roughly the same as that of the decoder for the high redundancy code alone. Hence, the implementation of low-redundancy codes is accomplished with little extra cost.
Metastases to the kidney: A clinicopathological study of 43 cases with an emphasis on deceptive features

Aims To review our experience with metastases to the kidney in surgical pathology material. Methods and results The clinicopathological features of all metastases to the kidney in surgical pathology cases between May 1987 and May 2013 at our institution were reviewed. Autopsy cases were excluded. Forty-three cases (16 nephrectomies, 25 biopsies, and two fine needle aspirations) were included; the primary malignancy was diagnosed prior to/concurrently with the metastasis in nearly all cases. Common primary sites included the lung, breast, female genital tract, and head and neck; the majority were carcinomas. A primary renal tumour was suspected prior to the pathological diagnosis in 35% of cases. Unusual features included: common unilateral (77%) and unifocal (70%) involvement, lack of other distant organ metastases (37%), >10 years between primary and metastasis diagnoses (19%), lack of a discrete mass (5%), and renal vein extension (19% of resections). The most common dilemma was excluding urothelial or high-grade renal cell carcinoma; however, metastases from the thyroid commonly mimicked low-grade renal cell carcinomas. Conclusions In surgical pathology material, metastases to the kidney most commonly present as solitary unilateral masses, and in a substantial subset of cases mimic a primary renal tumour.
Transonic Flow about Two-Dimensional Airfoils by Relaxation Procedures

A successive over-relaxation procedure has been developed to treat the inviscid, fully nonlinear, potential equations governing compressible flow. The procedure is designed to compute embedded shock waves and adjust to the Kutta condition during the course of the iterations. Adjustment to the Kutta condition, convergence rate control and other data handling are accomplished in a practical fashion by means of interacting graphics provided by a cathode-ray tube coupled to the computer. The procedure has been applied to blunt-nosed, lifting airfoils in a subsonic freestream. Calculated results are compared to exact theories and experiment.
The formation of Saturn's satellites and rings, as influenced by Saturn's contraction history

The paper investigates constraints imposed on the ice content of Saturn's satellites and rings by the planet's high luminosity during the early part of its quasi-equilibrium contraction phase. It is assumed that the addition of ices to the satellites was not completed until after the start of the quasi-equilibrium contraction and that the condensation of ices ceased at the same time within the primordial nebulae of Jupiter and Saturn. Using previously derived limits on the time of condensation cessation for Jupiter's system, the following tentative conclusions are made: (1) Titan is the innermost satellite at whose position a methane-containing ice could condense; (2) water ice could have condensed at the positions of all the satellites; (3) the systematic decrease in the mass of the regular satellites with decreasing distance from the planet may have been caused, in part, by the larger time intervals, for the closer satellites, between the start of contraction and the first condensation of ices at their positions; and (4) ammonia ices, primarily NH4SH, were able to condense at the positions of all but the innermost satellites. It is also shown that water ice could have condensed in the region of the rings near the end of the condensation period.