cssi/SciSciGPT-SciSciNet huggingface dataset:
Chapter 24. The Role of Homeobox Genes in Vertebrate Embryonic Development

Publisher Summary This chapter discusses the role of homeobox genes in vertebrate embryonic development. The first vertebrate homeobox containing gene to be identified was isolated from xenopus. Subsequently, a large number of genes were isolated from three vertebrate species—xenopus, mouse, and humans. Approximately 40 mammalian genes have been isolated that contain homeobox sequences most similar to that of the Drosophila antp gene. These genes are collectively known as Hox genes and represent the largest group of vertebrate homeobox genes known to date. Many Hox gene family members are differentially expressed in the vertebrate limb bud, often with a graded pattern of expression. In xenopus, functional aspects of homeobox gene activity have been studied by ectopic expression or overexpression of these genes or by ablation of their gene products in embryos. Xenopus homeobox genes have been shown to be involved in pattern formation. Gain-of-function phenotypes have been similarly generated in mice, with ectopic expression and overexpression of homeobox gene constructs being achieved through the use of transgenic technology. Loss-of-function phenotypes can be obtained through the use of embryonic stem (ES) cells, in which genes can be mutated via homologous recombination. These gain of function and loss-of-function studies clearly illustrate the developmental importance of homeobox gene activity for proper vertebrate morphogenesis. There are, however, several naturally occurring mutations that have been identified in non- antp class homeobox genes. At least two known mouse mutations affecting morphogenesis have been shown to bear mutations in homeobox genes. There is also convincing evidence that aberrant homeobox gene expression can contribute to the genesis or progression of cancer. These data provide intriguing clues concerning the developmental role of the homeobox genes in vertebrates. It is likely that the further analysis of homeobox genes can implicate them in human disease and developmental malformation.
Islamic reflexivity and the uncritical subject

This essay examines the politics of reflexive discourse in the contemporary Muslim world, interrogating the social, affective, and material mediation of its expression. I focus on Turkey's Alevi community, for whom the encounter with modern reflexive media has proved deeply ambivalent. If available genres of public reflexive discourse enable Alevi participation in national public debate, such discursive media also sustain a disciplinary impetus, in which certain genres of argument and forms of subjectivity are valued as critical in contrast to others that are deemed to be insufficiently detached or excessively impassioned. The boundary between the critical and the uncritical, I argue, represents an ideological partition, a condition of social intelligibility, and an institutionally enforced limit to viable subjectivity. Interrogating this partitioning, I thematize a particular understanding of the politics of reflexive discourse, in which existing institutional architectures motivate the production of certain kinds of reflexive subjects at the expense of others, by disciplining affective potentials, moral sensibilities, and modes of historical consciousness. Resume Le present essai etudie la politique du discours reflexif dans le monde musulman contemporain, en interrogeant la mediation sociale, affective et materielle de son expression. Il se concentre sur la communaute alevie de Turquie, dont la rencontre avec les medias reflexifs modernes s'avere profondement ambivalente. Bien que les genres de discours reflexif public disponibles permettent aux Alevis de participer au debat public national, ils sont aussi porteurs d'une dynamique disciplinaire en cela que certains genres d'arguments et certaines formes de subjectivites seraient preferables car estimes critiques la ou d'autres sont juges trop peu detaches ou excessivement passionnees. La limite entre critique et non critique represente, selon l'auteur, une ligne de partage ideologique, une condition d'intelligibilite sociale et une limite imposee par les institutions a une subjectivite viable. En interrogeant ce cloisonnement, l'auteur explore une comprehension particuliere de la politique du discours reflexif dans laquelle les architectures institutionnelles existantes motivent la production de certains types de sujets reflectifs au detriment des autres, en disciplinant les potentiels affectifs, les sensibilites morales et les modes de conscience historique.
Lawyers, Litigation, and the U.S. Anti-Torture Campaign

This paper focuses on the anti-torture campaign that was catalyzed into existence in mid-2004 following the publication of the Abu Ghraib photos and the release of the first batch of "torture memos." Because the Bush administration essentially "legalized" torture, litigation has been the primary means of challenging the US's interrogation and detention policies and practices, and because of the complexity of issues at stake (e.g., status of enemies in the context of a "global" asymmetrical war, applicability of international humanitarian laws), anti-torture activism has been monopolized by lawyers and legal intellectuals. Unlike the contentious politics of civil rights struggles in which the victims (or would-be beneficiaries) are part of the same society as those engaging in legal activism on their behalf, with a handful of exceptions, the victims of the US torture policy are foreigners. Moreover, pervasive misrepresentations by US officials (e.g., former VP Cheney) about the efficacy and benefits of torture and indifference or hostility to victims, lawyer-dominated anti-torture activism tends to run counter to public attitudes. The empirical details and socio-legal analysis are drawn from my research on five categories of legal mobilization: 1) habeas representation of GITMO detainees; 2) defense of "high value targets" slated for prosecution; 3) civil suits against US officials and corporations on behalf of victims of US torture; 4) Freedom of Information Act litigation to make public information about the torture policy; and 5) the disputed and nascent efforts to hold the authors of the torture policy legally accountable.
Hidden control neural network identification-based tracking control of a flexible joint robot

In this paper we present a new artificial neural network (ANN) structure to compensate for the convergence problem associated with training the identification of a complex nonlinear flexible joint robot for trajectory tracking problem. The tracking control of a MIMO flexible joint robot with high velocity is complicated due to the joint flexibilities, nonlinearities, and couplings. Our scheme consists of three ANN structures. The neural network identification (NNI) is used to obtain a dynamic model of a flexible joint robot to be controlled. Once the NNI has not closely learned the dynamic model of a flexible joint robot, the other new ANN structure, called hidden control neural network identification (HCNNI), is designed to overcoming the identification convergence problem in this paper. This HCNNI allows learning to compensate for poor identification and external disturbance. A third ANN control is designed for tracking control of a flexible joint robot based upon the identification. These tasks are completed using the backpropagation neural network.
“So far away from home”: Minority women writers and the new woman

Abstract Despite indications that minority women were involved in early 20th-century feminist causes, the New Woman image from that period remains primarily white. This essay attempts to strengthen the emerging notion that women of color were also involved with the New Woman model by examining some key texts from the 1920s, a pivotal era for minority women writers: novels by Harlem Renaissance figures Jessie Fauset and Nella Larsen, the first novel by a Native American woman, Cogewea (1927) by Mourning Dave, and the first book in English by a Japanese- American, A Daughter of the Samurai (1925) by Etsu Sugimoto. Because these texts echo plot conventions of popular fiction for white women, they are contrasted with New Woman narratives from the dominant culture which posited the heroine's successful transition from female to male sphere as she found a place in the urban center of American life. In contrast, writings by minority women reject the idea of fulfilling merger in the male arena because its promises of liberation for women are demystified by the persistence of racism. Following a circular rather than a linear trajectory, minority writers move their New Woman protagonists back to the ethnic communities they initially left because life on the margin of mainstream America is reconceived as a new, more vital center for women's liberation. Perhaps because of their greater marginalization, then, women of color were able to develop a more penetrating critique of male supremacy at a time when the public arena appeared to be opening its doors to women.
PROS: Data Analysis for ROSAT

The Post-Reduction Off-line Software (PROS) is a portable X-ray analysis software system that is integrated into the Image Reduction and Analysis System (IRAF), which was developed at the National Optical Astronomy Observatories (NOAO; see Tody, this volume). The PROS consists of a suite of applications tasks and an interactive image display program, SAOimage, which runs under the X-windows system. The PROS is being developed on a network of SUN workstations by our group at the Smithsonian Astrophysical Observatory (SAO) in coordination with the IRAF development group at NOAO and the Space Telescope Science Data Analysis System (STSDAS) group at the Space Telescope Science Institute (STScI). The PROS has been written for the analysis of pointed data from the ROSAT X-ray telescope, and developed and tested using Einstein Observatory data. Goddard Space Flight Center (GSFC) has the primary responsibility for testing the PROS as part of the joint GSFC and SAO activities in support of the U.S. ROSAT Science Data Center (USRSDC). In addition, a number of sites in the community received the β-test version of the PROS for evaluation in late 1990.
A theory of commonsense knowledge

What is commonly called "commonsense knowledge" may be viewed as a collection of "dispositions": propositions with implied fuzzy logic.
Hadrons As Kerr-Newman Black Holes

The scale invariance of the source-free Einstein field equations suggests that one might be able to model hadrons as "strong gravity" black holes, if one uses an appropriate rescaling of units or a revised gravitational coupling factor. The inner consistency of this hypothesis is tested by retrodicting a close approximation to the mass of the proton from an equation that relates the angular momentum and mass of a Kerr black hole. More accurate mass and radius values for the proton are then retrodicted using the geometrodynamics form of the full Kerr-Newman solution of the Einstein-Maxwell equations. The radius of an alpha particle is calculated as an additional retrodictive test. In a third retrodictive test of the "strong gravity" hypothesis, the subatomic particle mass spectrum in the 100 MeV to 7,000 MeV range is retrodicted to a first approximation using the Kerr solution of General Relativity. The particle masses appear to form a restricted set of quantized values of the Kerr solution: n^1/2 M, where values of n are a set of discrete integers and M is the revised Planck mass. The accuracy of the 27 retrodicted masses averages 98.4%. Finally, the new atomic scale gravitational coupling constant suggests a radical revision of the assumptions governing the Planck scale, and leads to a natural explanation for the fine structure constant.
Microsoft Exchange in Business

In this clear, comprehensive guide, Russell Borland shows businesspeople how to satisfy their messaging and information-exchange needs by using Microsoft Exchange. This scenario-based book is ideal for users and power users who want a task-based, integrated way to gain an understanding of this new software,
Key to the subfamilies and genera of neotropical Ericaceae

For the first time since Drude (1897) an up-to-date key is given to all the genera of Ericaceae currently recognized in the Neotropics.
The Importance of the Nativist–Empiricist Debate: Thinking About Primitives Without Primitive Thinking

Abstract—J. P. Spencer et al. (2009) are intent on dismantling the nativist–empiricist debate and they offer three main supporting arguments. It is argued here that these arguments are simply orthogonal to the authors’ main goal. More importantly, it is argued that even the most radical empiricist must embrace some set of primitives as the basis for learning; in some cases, rich primitives may actually be the learning mechanism. The nativist–empiricist debate is crucial to a healthy dialogue that allows us to think about how learning and development occur, and is therefore vital to our scientific progress.
Inhibition of anti-Rh and anti-Lutheran sera by ribonucleic acid derivatives.

Summary The specific inhibition of anti-C, -D, -E, -Lua and -Lub sera by four ribonucleic acid derivatives - cytidine sulfate, adenylic acid, cytidylic acid and uridylic acid - is described. These substances had no inhibitory effect on any other antisera with which they were tested. It is reasoned that these inhibitors combine with the antibody by virtue of their similarity to the antigen, leaving no free antibody to effect agglutination. Their involvement in the structure of these antigens is postulated as well as the first demonstration of specificity attributable to ribonucleic acid in other than microorganisms. Resume Quatre derives de l'acide ribonucleique - le sulphate de cytidine, l'acide adenylique, l'acide cytidylique et l'acide uridylique - se sont averes capables d'inhiber l'anti-C, -D, -E, -Lua et -Lub. Ces substances n'avaient aucun pouvoir inhibiteur contre les autres anticorps examines sous ce rapport. Les auteurs pensent que ces inhibiteurs s'unissent a l'anticorps inhibe en vertu de leur ressemblance avec l'antigene homolope, et qu'ils ne laissent point d'anticorps libre de produire une agglutination. Ils postulent que ces substances font partie de la structure des antigenes en question et ils sont d'avis qu'il s'agit ici du premier exemple de specificite due a l'acide ribonucleique en dehors des microorganismes. Zusammenfassung Es wird gezeigt, das die 4 Ribonukleinsaurederivate Cytidinsulfat, Adenylsaure, Cytidilsaure und Uridylsaure Anti-C, -D, -E, -Lua und -Lub-Antikorper spezifhch zu hemmen vermogen. Auser den 5 erwahnten Isoantikorpern wurden keine anderen Blutgruppenantikorper durch diese 4 Verbindungen gehemmt. Es ist naheliegend anzunehmen, das diese 4 Verbindungen wegen ihrer chemischen Verwandtschaft mit den betreffenden Blutgruppenantigenen sich mit den Anti-korpern spezifisch binden, so das nach Absattigung der Antikorper die Erythrozytenagglutiation ausbleibt. Die Untersuchungen zeigen, das diese 4 Ribonukleinsaurederivate offenbar wesentliche Bausteine der erwahnten Antigene des Rh- und Lutheranblutgruppensystems darstellen. Im ubrigen gelang es, durch diese Untersuchungen erstmals zu zeigen, das Ribonukleinsaurei nicht nur bei Mikroorganismen als spezifitatsbestimmende Stoffe eine Rolle spielen.
Elastic Optical Path Network Architecture: Framework for Spectrally-Efficient and Scalable Future Optical Networks

SUMMARY This paper presents an elastic optical path network architecture as a novel networking framework to address the looming capacity crunch problem in internet protocol (IP) and optical networks. The basic idea is to introduce elasticity and adaptation into the optical domain to yield spectrally-efficient optical path accommodation, heightened network scalability through IP traffi co ffloading to the elastic optical layer, and enhanced
Prader-Willi syndrome and Robertsonian translocations involving chromosome 15

A case of Prader-Willi syndrome is presented in which high resolution chromosome analysis revealed not only a familial Robertsonian translocation [t(13q15q)], but also a del(15) (q11.2q13) of the chromosome 15 not involved in the translocation. While there have been numerous reports of Robertsonian translocations involving chromosome 15 in patients with Prader-Willi syndrome, in this case, the Robertsonian translocation was shown to be unrelated to the clinical findings.
Psychologists as consultants for changes of venue the use of public opinion surveys

This study reports the use of public opinion surveys to support motions to change venue. Step-bystep procedures of venue surveys are outlined, and results of their use in five capital murder trials are presented. Employing a quasi-experimental approach to the surveys allows inferences, about the likelihood of obtaining between-county differences of certain magnitudes. In addition, the use of a survey instrument with standardized subparts permits a second, novel type of contrast: comparisons previous cases. The responsiveness of this approach to the typical criticisms of venue surveys is discussed.
Suctorial feeding in a deep-sea octopus as a means of niche partitioning (Cephalopoda: Octopodidae)

Molecular phylogenetic analyses indicate that two clades of deep-sea octopuses evolved at opposite ends of the earth to become globally sympatric. Coexistence of these overtly similar, but phylogenetically distinct octopuses requires some means of niche partitioning. To investigate details of feeding, the buccal complexes of specimens of each clade, Muusoctopus and Graneledone, were sectioned at 90° to the radular ribbon. The buccal complex of Muusoctopus is the same as reported in Octopus; the radula and its bolsters extend the length of the buccal complex. In Graneledone, however, the radula and its bolsters are restricted to anterior half of the buccal complex. Posterior to the radular sac, a vertically oriented muscle, named here the buccal abductor, extends from the floor of the mouth to the base of the buccal complex. In Muusoctopus, the bolsters extend the radula to bring food into the mouth; the palps propel it to the esophagus. In Graneledone, although the bolsters extend the radula, contraction of the buccal abductor to expand the posterior mouth may be the primary food mover. The negative pressure differential created draws food into the mouth and to the entry to the esophagus. The buccal abductor may permit the ingestion of larger pieces of prey, as gut contents show. Its evolution may represent a key innovation that heightens deep-sea octopus diversity.
Calculating thermal radiation hazards in large fires

The author has developed, and discusses here, a method for assessing the thermal radiation hazards to objects from fires. A comparison of the calculations to an actual fire experience seems to indicate that the method is reasonably accurate, though somewhat conservative.
Method for creating rapid cellular temperature perturbation

Abstract A temperature perturbation in biological systems has been performed in a simple apparatus. A 5° jump in 0.5 to 0.7 ml of cell suspension was obtained with a 200 joule xenon flash within 400 msec. The jump was “chemically pure” and little or no damage of cells was detected microscopically. The response of cellular NADH to the temperature jump was an initial fast decrease in its fluorescence efficiency, followed by a delayed NADH oxidation with a half-time of several seconds. No more rapid biological relaxation was observed under the conditions studied. The advantages of using a flash heating and of a current pulse heating are discussed.
Self-Assembly of Molecule-like Nanoparticle Clusters Directed by DNA Nanocages

Analogous to the atom–molecule relationship, nanoparticle (NP) clusters (or NP-molecules) with defined compositions and directional bonds could potentially integrate the properties of the component individual NPs, leading to emergent properties. Despite extensive efforts in this direction, no general approach is available for assembly of such NP-molecules. Here we report a general method for building this type of structures by encapsulating NPs into self-assembled DNA polyhedral wireframe nanocages, which serve as guiding agents for further assembly. As a demonstration, a series of NP-molecules have been assembled and validated. Such NP-molecules will, we believe, pave a way to explore new nanomaterials with emergent functions/properties that are related to, but do not belong to the individual component nanoparticles.
Growth and decay of pulmonary function in healthy blacks and whites

We recorded maximum expiratory flow-volume curves in 3046 healthy persons, blacks and whites, age 7 and over — a representative population of lifetime nonsmokers except for some black adults males, who were healthy smokers or ex-smokers. We computed regression equations for lung function measurements (FVC, FEV1.0, FEV1.0/FVC, PEF, MEF, 50% and MEF 25%) as a function of age, height and weight terms for eight subgroups (by sex and race, and for children or adults). Objective statistical criteria were used to select the optimal equations. Simple linear regressions on age and height are inaccurate, in particular for young adults and for the elderly. Weight affects most function measurements: lung function first increases with weight (‘muscularity effect’)_ and decreases with further increases in weight (‘obesity effect’). The regression equations allow more accurate prediction of normal lung function. In addition, the lower 95% confidence limits are closer to the predicted values and are valid regardless of height, weight and age within each subgroup.
Cyanide-induced lipid peroxidation in different organs: subcellular distribution and hydroperoxide generation in neuronal cells

To evaluate hydroperoxide generation as a potential mechanism of cyanide neurotoxicity, mice were treated with KCN (7 mg/kg, subcutaneously (s.c.)) and the level of lipid peroxidation (expressed as conjugated dienes) was measured later in various organs. Brain showed elevated conjugated diene levels after cyanide but the liver, which is not considered a target for cyanide toxicity, showed no increase. The heart also showed no increase, whereas kidney conjugated dienes slowly increased to a peak 1 h after cyanide. In vitro studies show elevation of peroxidized lipids in mouse brain cortical slices following incubation with KCN (0.1 mM). Omission of calcium from the medium or pretreatment of brain slices with diltiazem (a calcium channel blocker) prevented formation of conjugated dienes by KCN. Calcium thus appears to play a critical role in cyanide-induced generation of peroxidized lipids in neuronal cells. Subcellular fractionation of brains from mice treated with cyanide showed that lipid peroxidation increased in the microsomal fraction but not in the mitochondrial fraction. Fluorescent studies using 2,7-dichlorofluorescein (a hydroperoxide sensitive fluorescent dye) show that hydroperoxides are generated rapidly after cyanide treatment of PC12 cells, a neuron-like cell, and hydroperoxide levels remain elevated for many minutes in the presence of cyanide. These results suggest that hydroperoxide generation with subsequent peroxidation of lipids may lead to changes in structure and function of certain membranes and contribute to the neurotoxic damage produced by cyanide.
Algorithmic and computational approaches to pure-tone approximations of equal-tempered musical scales

We develop formalism for generating pure-tone systems that best approximate the modulation/transposition properties of equal-tempered scales. We define six measurements to determine the closeness of scales generated by pure intervals to equal-tempered scales. Two measures apply to scales generated by single intervals and rely heavily on continued fraction analysis. We show that generated scales can be optimized to preserve the pure-tone character of the scale by compromising the modulation/transposition properties by a least amount. The other four measures are generalizations that apply to scales generated by multiple intervals. These measures are directly applied to individual scales and numerically compared. We apply this formalism to pure intervals of import in antiquity and show that this approach yields the historically important just 12-tone system as an optimum scale. Finally, we show how this formalism can be applied to the analysis of non-standard scales.
Trends in sexual risk behaviors, by nonsexual risk behavior involvement, U.S. high school students, 1991-2007.

Abstract Background Adolescent health risk behaviors often occur together, suggesting that youth involvement with one risk behavior may inform understanding of other risk behaviors. We examined the association between involvement in nonsexual risk behaviors and trends among sexual behaviors. Methods We analyzed 1991–2007 data (n = ∼125,000) from the Youth Risk Behavior Survey, a nationally representative survey of high school students in the United States. We categorized students into groups based on lifetime (Lifetime Risk Scale) and recent involvement (Recent Risk Scale) in nonsexual risk behaviors, such as smoking and drug use. We examined each group's prevalence of and trends for four sexual behaviors: ever having had sexual intercourse, having four or more lifetime partners, current sexual activity, and use of contraception at last sex. Data were examined for linear and quadratic (U-shaped) change using logistic regression. Results Sexual behaviors varied considerably between youth engaged in no risk behaviors and those in the highest risk behavior groups: sevenfold for ever having had intercourse (13% vs. 87% in 2007) and threefold for four or more lifetime sexual partners (19% vs. 57%). Despite these differences, trends in sexual risk behaviors among youth engaged in multiple nonsexual risk behaviors and those engaged in few or no risk behaviors were remarkably similar. In contrast, sexual behaviors demonstrated a very different pattern of change from that found or nonsexual behaviors: sexual experience and having multiple sexual partners declined into the early 2000s and then increased, whereas nonsexual behaviors increased over time, peaked in the late 1990s, and then declined. Conclusions Youth who engaged in little risk taking and those who engaged in considerable risk taking showed similar trends over time. However, the pattern of changes in sexual and nonsexual risk behaviors were remarkably different, raising questions about the potential impact of interventions that would reduce sexual risk taking by reducing nonsexual risk behaviors. Recent increases in sexual risk behaviors may have ominous implications for prevention of unplanned pregnancy and sexually transmitted infections among youth.
Congenital rhabdomyoma of the heart associated with arrhythmia

Summary A case of rhabdomyoma of the heart in a ten-month-old girl is reported. The most important clinical finding was a cardiac arrhythmia thought to be auricular flutter. At necropsy the tumor was found to invade the conduction system. Congenital cysts of the kidneys were also present.
A concise methodology for the stereoselective synthesis of O-glycosylated amino acid building blocks: complete 1H NMR assignments and their application in solid-phase glycopeptide synthesis.

A facile strategy for the stereoselective synthesis of suitably protected O-glycosylated amino acid building blocks, namely, Nalpha-Fmoc-Ser-[Ac4-beta-D-Gal-(1-3)-Ac2-alpha or beta-D-GalN3]-OPfp and Nalpha-Fmoc-Thr-[Ac4-beta-D-Gal-(1-3)-Ac2-alpha or beta-D-GalN3]-OPfp is described. What is new and novel in this report is that Koenigs-Knorr type glycosylation of an aglycon serine/threonine derivative (i.e. Nalpha-Fmoc-Ser-OPfp or Nalpha-Fmoc-Thr-OPfp) with protected beta-D-Gal(1-3)-D-GalN3 synthon mediated by silver salts resulted in only alpha- and/or beta-isomers in excellent yields under two different reaction conditions. The subtle differences in stereoselectivity were demonstrated clearly when glycosylation was carried out using only AgClO4 at -40 degrees C which afforded a-isomer in a quantitative yield (alpha:beta = 5:1). On the other hand, the beta-isomer was formed exclusively when the reaction was performed in the presence of Ag2CO3/AgClO4 at room temperature. A complete assignment of 1H resonances to individual sugar ring protons and the characteristic anomeric alpha-1 H and beta-1 H in Ac4Galbeta(1-3)Ac2GalN3 alpha and/or beta linked to Ser/Thr building blocks was accomplished unequivocally by two-dimensional double-quantum filtered correlated spectroscopy and nuclear Overhauser enhancement and exchange spectroscopy NMR experiments. An unambiguous structural characterization and documentation of chemical shifts, including the coupling constants for all the protons of the aforementioned alpha- and beta-isomers of the O-glycosylated amino acid building blocks carrying protected beta-D-Gal(1-3)-D-GalN3, could serve as a template in elucidating the three-dimensional structure of glycoproteins. The synthetic utility of the building blocks and versatility of the strategy was exemplified in the construction of human salivary mucin (MUC7)-derived, O-linked glycopeptides with varied degrees of glycosylation by solid-phase Fmoc chemistry. Fmoc/tert-butyl-based protecting groups were used for the peptidic moieties in conjunction with acetyl sugar protection. The transformation of the 2-azido group into the acetamido derivative was carried out with thioacetic acid on the polymer-bound glycopeptides before the cleavage step. After cleaving the glycopeptide from the resin, the acetyl groups used for sugar OH-protection were removed with sodium methoxide in methanol. Finally, the glycopeptides were purified by reversed-phase high-performance liquid chromatography and their integrity was confirmed by proton NMR as well as by mass spectral analysis. Secondary structure analysis by circular dichroism of both the glycosylated and nonglycosylated peptides revealed that carbohydrates did not exert any profound structural effect on the peptide backbone conformation.
Interactions of Foot-and-Mouth Disease Virus with Soluble Bovine αVβ3 and αVβ6 Integrins

At least four members of the integrin family of receptors, αVβ1, αVβ3, αVβ6, and αVβ8, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro. Our investigators have recently shown that the efficiency of receptor usage appears to be related to the viral serotype and may be influenced by structural differences on the viral surface (H. Duque and B. Baxt, J. Virol. 77:2500-2511, 2003). To further examine these differences, we generated soluble αVβ3 and αVβ6 integrins. cDNA plasmids encoding the individual complete integrin αV, β3, and β6 subunits were used to amplify sequences encoding the subunits' signal peptide and ectodomain, resulting in subunits lacking transmembrane and cytoplasmic domains. COS-1 cells were transfected with plasmids encoding the soluble αV subunit and either the soluble β3 or β6 subunit and labeled with [35S]methionine-cysteine. Complete subunit heterodimeric integrins were secreted into the medium, as determined by radioimmunoprecipitation with specific monoclonal and polyclonal antibodies. For the examination of the integrins' biological activities, stable cell lines producing the soluble integrins were generated in HEK 293A cells. In the presence of divalent cations, soluble αVβ6 bound to representatives of type A or O viruses, immobilized on plastic dishes, and significantly inhibited viral replication, as determined by plaque reduction assays. In contrast, soluble αVβ3 was unable to bind to immobilized virus of either serotype; however, virus bound to the immobilized integrin, suggesting that FMDV binding to αVβ3 is a low-affinity interaction. In addition, soluble αVβ3 did not neutralize virus infectivity. Incubation of soluble αVβ6 with labeled type A12 or O1 resulted in a significant inhibition of virus adsorption to BHK cells, while soluble αVβ3 caused a low (20 to 30%), but consistent, inhibition of virus adsorption. Virus incubated with soluble αVβ6 had a lower sedimentation rate than native virus on sucrose density gradients, but the particles retained all of their structural proteins and still contained bound integrin and, therefore, were not exhibiting characteristics of a picornavirus A particle.
[14C]Ethylene Metabolism during Leaf Abscission in Cotton

Changes in 14 C 2 H 4 metabolism in the abscission zone were monitored during cotton (cv. Deltapine 16) leaf abscission. Rates of 14 C 2 H 4 oxidation to 14 CO 2 and tissue incorporation in abscission zone segments cut from the second true leaf of nonabscising leaves of intact plants were similar (about 200 disintegrations per minute per 0.1 gram dry weight per 5.5 hours) and relatively constant over a 5-day period. Deblading to induce abscission caused a dramatic rise in 14 C 2 H 4 oxidation, but tissue incorporation was not markedly affected. This rise occurred well before abscission, reaching a peak of 1,375 disintegrations per minute per 0.1 gram dry weight per 5.5 hours 2 days after deblading when abscission was 40%. The rate then gradually declined, but on day 5 when abscission reached completion, it was still nearly three times higher than in segments from nonabscising leaves. Application of 0.1 millimolar abscisic acid in lanolin to the debladed petiole ends increased the per cent abscission slightly and initially stimulated 14 C 2 H 4 oxidation. In contrast, naphthaleneacetic acid applied in a similar manner delayed and markedly inhibited both abscission and 14 C 2 H 4 oxidation. Petiole segments cut 1 centimeter from the abscission zone of intact second true leaves also incorporated and oxidized 14 C 2 H 4 to 14 CO 2 but at rates two and six times higher, respectively, than that of comparable adjacent abscission zone segments. However, in marked contrast to the abscission zone segments, no changes in oxidation were observed when the leaves were debladed to induce abscission. These results demonstrate that: ( a ) prior to abscission, the ethylene oxidation, but not the tissue incorporation pathway, rapidly increases in the abscission zone; ( b ) this increase does not occur in adjacent petiole tissue; and ( c ) changes in the rate of oxidation and per cent abscission brought about by hormone treatments parallel one another. The possible significance of these changes in ethylene metabolism is discussed with respect to the hypothesis that ethylene action and metabolism are directly related.
Computer analysis of resonance profiles by the method of least squares.

The method of least squares has been applied to the analysis of resonance profiles described by the Beutler-Fano (BF) absorption cross section. To illustrate the method, parameters were determined for experimental data having BF profiles of (a) the asymmetric, enhanced absorption type; (b) the window type, and (c) the lorentzian absorption type. Systematic and random errors and correlation among the parameters were studied as a function of the slitwidth-to-resonance width ratio by applying the least squares fitting method to data computed by folding the BF transmission profile with a gaussian slit function. High correlation among the parameters and parameter fractional standard deviations of 10–20% for data with a standard deviation of 0.01 are an incentive to keep the slitwidth-to-resonance width ratio less than two for window type resonances. In addition it was found that the parameters describing a resonance could be determined with the greatest precision in a given time when the slitwidth-to-resonance width ratio was approximately 1. It was found that systematic errors greater than about 1% resulted if the number of mesh points used to approximate the convolution integral in the fitting procedure was less than at least two per resonance width. Also, for resonances whose width was equal to the slitwidth, systematic errors in the parameter values of about 10% resulted if the width of slit function used in the fitting procedure differed from the actual slit function by 10%.
Family history as a risk factor for ulcerative colitis-associated colon cancer in cotton-top tamarin.

Abstract Background & Aims: Little is currently known about the relationship between family history of colon cancer and ulcerative colitis–associated colon cancer. A nested case-control study was performed to evaluate the association between family history of colon cancer and spontaneously occurring colon cancer in cotton-top tamarins ( Saguinus oedipus ). Methods: Subjects were chosen from a colony of cotton-top tamarins held in captivity between 1968 and 1995. The cancer status of parents and grandparents was compared for 48 animals with colon cancer and 58 controls, all with histological confirmation of ulcerative colitis. Multivariate odds ratios were calculated using logistic regression. Results: A parental history of colon cancer was positively associated with risk of colon cancer (multivariate odds ratio, 2.7; 95% confidence interval, 1.1–6.3). Risk also increased as an animal's total number of family members with colon cancer increased (multivariate odds ratio, 1.7 for each increase in the total number of family members with cancer; 95% confidence interval, 1.1–2.8). Conclusions: The results suggest that cotton-top tamarins with ulcerative colitis are at significant increased risk for developing colon cancer if they have a family history of colon cancer. Further investigation of this relationship in both tamarins and humans is warranted. GASTROENTEROLOGY 1998;114:669-674
Are there morphologically abnormal early recombination nodules in the Drosophila melanogaster meiotic mutant mei-218?

Early recombination nodules have been suggested to perform a role in meiotic gene conversion recombination events. The meiotic recombination-defective mutant mei-218 greatly reduces the frequency o...
Comparison of the Recovery of Inorganic Iodide by Paper Electrophoresis or Chromatography

Recovery of carrier-free 131I- was compared after paper electrophoresis or chromatography in 3 systems: butanol-acetic acid-water (BAW), butanol-ethanol-ammonia (BEA) and butanol-dioxane-ammonia (BDA). Slightly less 131I- was recovered with any of the 3 chromatographic systems than with electrophoresis. This was caused both by spread of the 131I- on the paper and loss by evaporation. Approximately 5% of the 131I- was lost by evaporation in any of the 3 chromatography systems. If 127I-, serum or thyroid homogenate was added to the carrier-free 131I-, recovery was very similar with electrophoresis and any of the chromatography systems, but always slightly better with electrophoresis. It is concluded that paper chromatography with any of the 3 systems used is satisfactory for the quantitative determination of 131I- in thyroid homogenates or serum, but care must be taken to dry undigested homogenate for only very short periods before placing the paper strips in the developing tanks. Deiodination of thyroid ho...
Statistical Diagnosis and Tests of Factor Hypotheses

Abstract Certain symptoms are of diagnostic value because they reflect the progress of a multistage disease. To analyze such cases, a dynamic symptom/disease model is constructed. The model is seen to be consistent with observations about skewed, dependent symptom distributions for certain diseases. The uniformly most powerful unbiased test of hypotheses about the disease factor leads to a linear discriminant function. Prior knowledge of the symptom/factor relationship can be used to correct the procedure for nuisance effects or lacking such information, the model can be structured so that the test is independent of the nuisance factors.
Management of planum/olfactory meningiomas: predicting symptoms and postoperative complications.

Objective Given their location and slow growth, olfactory groove and planum sphenoidale meningiomas often grow to large sizes before they present with clinical symptoms and pose significant surgical challenges. The goal of our study is to identify which preoperative symptoms and findings on magnetic resonance imaging are correlated with specific postoperative outcomes in order to better counsel patients preoperatively. Methods We retrospectively identified 44 patients with planum/olfactory meningiomas treated at our institution from 1996 to 2006. We used univariate and multivariate regression models to analyze the effect of several magnetic resonance imaging characteristics (tumor volume, distance to optic chiasm, anterior cerebral artery encasement, paranasal sinus invasion, and sellar invasion) on preoperative symptoms and postoperative outcomes, including complication rate and tumor recurrence. Results Only brain tumor volume (>42 cm3), but not distance to the optic chiasm, is independently associated with an increased likelihood of preoperative visual symptoms. Tumors with nasal sinus invasion are significantly more likely to cause postoperative surgical complications, and tumors with anterior cerebral artery encasement are associated with a greater likelihood of both postoperative complications and tumor recurrence. Conclusions We conclude that tumors larger than 3.4 cm in diameter and those whose posterior edge is within 6–8 mm of the optic chiasm should be recommended for early surgical intervention. In terms of predicting surgical complications, nasal sinus invasion and anterior cerebral artery encasement are associated with greater-risk profiles when surgery becomes necessary. Thus, it is prudent to take these specific variables into consideration when advising patients about the risks of observation and surgery for olfactory/planum meningiomas.
Dependency of Contractile Reserve on Myocardial Blood Flow Implications for the Assessment of Myocardial Viability With Dobutamine Stress Echocardiography

Background Contractile reserve, improvement in contractile function during inotropic stimulation, is a proposed marker of viable myocardium. This study was designed to address, in patients with left ventricular dysfunction due to chronic coronary artery disease, whether contractile reserve depends on myocardial blood flow. Methods and Results We studied 19 patients, at rest and during dobutamine, with 2D echocardiography for regional mechanical function and PET for regional myocardial blood flow ([15O]water) and oxygen consumption ([11C]acetate). Of 166 myocardial segments, 21 had normal systolic function, 56 were dysfunctional but contractile reserve–positive, and 89 were dysfunctional and contractile reserve–negative. Myocardial blood flow at rest was lower in contractile reserve–negative (0.41±0.18 mL · g−1 · min−1) than in contractile reserve–positive (0.50±0.22 mL · g−1 · min−1) and normal segments (0.55±0.20 mL · g−1 · min−1, P<.009). After dobutamine infusion, blood flow increased less in contracti...
Correlation of mutagenicity of 1,1-dimethyl-3-(X-phenyl)-triazenes with molecular orbital energies and hydrophobicity

A set of 18 aryltriazenes and the antitumor drug DTIC, whose mutagenicity has been determined in the Ames test, has been studied using octanol-water partition coefficients (P) as a measure of relative hydrophobicity and MNDO molecular orbital energies and electron distributions to account for variation in their electronic characteristics. A good structure-activity relationship was found using log P in combination with either eHOMO, or qHOMO, where the latter is defined as the HOMO electron density on N1 of the triazene. The dependence of mutagenicity on hydrophobicity is similar to what had been found earlier by Venger, Hansch, Hatheway, and Amrein [4] for the aryltriazenes alone using σ+ as a descriptor of electronic characteristics. A consistent role for electronic factors is found using σ+, eHOMO and qHOMO, namely, increased mutagenicity is associated with structural variations that increase the electron donating ability of the triazenes.
Management of Fetal Tachyarrhythmias.

Fetal tachyarrhythmias are an important cause of fetal morbidity and mortality. The majority of fetal tachyarrhythmias are due to atrioventricular reentrant type of supraventricular tachycardia and atrial flutter. Fetal echocardiography remains the main tool of diagnosing and discerning the mechanism of tachyarrhythmia. The goals of therapy for fetal arrhythmias are to restore sinus rhythm, resolve heart failure, and postpone delivery before term. Although there is no anonymity in the approach to the drug treatment of fetal tachycardia, digoxin is the most commonly employed first-line antiarrhythmic drug for supraventricular tachycardia. In digoxin nonresponders, flecainide (± digoxin) controls tachyarrhythmia with high conversion rate. A combination of digoxin and sotalol has proved effective therapy for atrial flutter, but the proarrhythmic side effect of sotalol on the fetus has been a concern. Amiodarone has emerged as a second-line treatment after digoxin failure in nonhydropic fetuses and the most effective treatment for drug-refractory fetal tachycardia accompanied by hydrops. Both the fetus and mother should be closely monitored for the response and adverse effect of the treatment. The antiarrhythmic treatment for supraventricular tachycardia should be continued after birth and during infancy due to the high incidence of postnatal recurrence.
EFFECT OF CALPAIN ON THE COMPOSITION AND STRUCTURE OF POSTSYNAPTIC DENSITIES

Endogenous calcium-activated proteases, the calpains, are thought to play a role in the regulation of postsynaptic function. Here we characterize some biochemical and morphological effects of calpain on isolated postsynaptic densities (PSDs). When a PSD preparation from rat forebrain was treated with exogenous calpain, many proteins, including spectrin, tubulin and the α-subunit of calcium calmodulin-dependent protein kinase (α-CaM kinase), were proteolyzed at varying rates, while another major protein, actin, remained intact. The selectivity of calpain action became more apparent in experiments designed to achieve limited proteolysis by using a lower calpain-to-protein ratio; it was possible to obtain extensive breakdown of spectrin with no decrease in the levels of either tubulin, α-CaM kinase, or actin. Electron microscopy of freeze-substituted preparations showed that limited calpain action caused a partial unraveling of the PSD, in which the characteristic central dense lamina became wider and less dense. We interpret these changes as due to calpain-mediated breakdown of cross-bridging elements, leading to a partial unraveling of the central PSD lamina. Opening up of the PSD structure following limited calpain action could facilitate exposure of previously occluded functional sites within the PSD and contribute to the modification of the synaptic function. © 1995 Wiley-Liss, Inc.1 .
Highly fluorescent solid-state asymmetric spirosilabifluorene derivatives.

A series of four asymmetrically aryl-substituted 9,9‘-spiro-9-silabifluorene (SSF) derivatives, 2,2‘-di-tert-butyl-7,7‘-diphenyl-9,9‘-spiro-9-silabifluorene (PhSSF), 2,2‘-di-tert-butyl-7,7‘-dipyridin-2-yl-9,9‘-spiro-9-silabifluorene (PySSF), 2,2‘-di-tert-butyl-7,7‘-dibiphenyl-4-yl-9,9‘-spiro-9-silabifluorene (BPhSSF), and 2,2‘-di-tert-butyl-7,7‘-bis(2‘,2‘ ‘-bipyridin-6-yl)-9,9‘-spiro-9-silabifluorene (BPySSF) are prepared through the cyclization of the corresponding 2,2‘-dilithiobiphenyls with silicon tetrachloride. These novel spiro-linked silacyclopentadienes (siloles) form transparent and stable amorphous films with relatively high glass transition temperatures (Tg = 203−228 °C). The absorbance spectrum of each compound shows a significant bathochromic shift relative to that of the corresponding carbon analogue as a result of the effective σ*−π* conjugation between the σ* orbital of the exocyclic Si−C bond and the π* orbital of the oligoarylene fragment. Solid-state films exhibit intense violet-blue em...
Dissipative quantum tunneling in a biased double-well system at finite temperatures.

We study quantum tunneling in a biased double-well potential in the presence of Ohmic dissipation with a friction coefficient $\ensuremath{\alpha}g1$. The tunneling rate out of the metastable well is calculated in real time as a function of the temperature $T$ and bias energy $\ensuremath{\epsilon}$. The $T=0$ result agrees with a droplet-model calculation in imaginary time. At low temperatures we find an enhancement to the $T=0$ rate varying as ${(\frac{T}{\ensuremath{\epsilon}})}^{2}$.