cssi/SciSciGPT-SciSciNet huggingface dataset:
Uveitis Reactivation in Children Treated With Tumor Necrosis Factor Alpha Inhibitors

Purpose To evaluate reactivation of pediatric uveitis during/following treatment with tumor necrosis factor alpha inhibition (anti-TNFα). Design Retrospective cohort study. Methods We assessed the incidence of uveitis reactivation in children ≤18 years who had achieved uveitis quiescence under anti-TNFα. Survival analysis was used to calculate reactivation rates while still on (primary outcome), and following discontinuation of (secondary outcome), anti-TNFα. Potential predictive factors were assessed. Results Among 50 children observed to develop quiescence of uveitis under anti-TNFα, 39 met criteria to be "at risk" of the primary (19 for the secondary) outcome. 60% were female, ∼half had juvenile idiopathic arthritis, and most were treated with infliximab. Overall, the estimated proportion relapsing within 12 months was 27.8% (95% confidence interval [CI]: 15.9%–45.8%); the estimated probability of reactivation was higher following (63.8% [95% CI: 38.9%–87.7%]) vs before (21.6% [95% CI: 10.8%–40.2%]) anti-TNFα discontinuation. Among those who discontinued anti-TNFα, the likelihood of reactivation was higher for those treated with adalimumab vs infliximab (hazard ratio [HR] 13.4, P = .01, 95% CI: 2.2–82.5) and those with older age at uveitis onset (HR 1.3, P = .09, 95% CI: 1.0–1.7). The duration of suppression, on medication, did not significantly affect the likelihood of reactivation when quiescence was maintained for ≥1.5 years. Conclusions Approximately 75% of children remaining on anti-TNFα following achievement of uveitis quiescence remain quiescent at 1 year. However, most reactivate following anti-TNFα discontinuation. These results suggest that infliximab more often is followed by remission, off medication, than adalimumab. The data do not suggest that maintenance of suppression for more than 1.5 years decreases the reactivation risk.
SU-GG-T-126: Robust Optimization for Lung Treatment in the Presence of Dosimetric Errors

Purpose: Intensity modulated radio therapy (IMRT) has the ability to deliver highly conformal dose distributions to tumors of complex shape. Uncertainties, such as breathing motion, can substantially degrade the quality of an otherwise optimized treatment plan. Furthermore, the quality of robustly optimized plans significantly depend on how well the underlying dose calculation matches the actual delivered dose to the treated organ.Method and Materials: We present two planing concepts for IMRT using robust optimization techniques. The first concept relies on pencil beam based calculation of the delivered dose. The second method employs Monte Carlo dose calculation. The robust optimization techniques seeks to minimize the expectation value of the deviation of the delivered and prescribed dose with an uncertainty model relying on several random variables. Results: When comparing the deposited dose of one pencil beam using Monte Carlo calculations of up to 10∧7 particles to dose calculations using pencil beam based algorithms, we observe a significant laterally scattered dose that is not capture with simple pencil beam algorithms, amounting to up to 30%. Furthermore, a comparison of the dose before and after sequencing reveals errors of up to 5%. We developed a novel robust optimization algorithm that provides optimized IMRT plans which are inherently robust against dosimetric errors. Conclusion: If the treated structure does not reveal significant inhomogeneities, using a computationally less expensive pencil beam calculation can allow for other ways treatment optimizations, such as beam‐angle optimization, that are otherwise not accessible without extensive approximations.
Selection for resistance to Bacillus thuringiensis subspecies israelensis in field and laboratory populations of the mosquito Aedes aegypti.

Abstract One laboratory and two wild populations of the yellow fever mosquito, Aedes aegypti , were used in an attempt to artificially select for resistance to Bacillus thuringiensis subsp. israelensis . After 14 generations of LC 50 selection pressure, a small but statistically significant shift (twofold increase) in response was observed in the F 15 generation of one wild strain only. Regression lines, LC 50 values, and slopes of parental populations between strains did not differ significantly.
Short-term memory for sentences

Short-term memory for active and passive sentences at two levels of grammatical complexity was tested at four retention intervals, 0, 10, 20, and 40 sec. Sentence forgetting was analyzed in terms of differential word-class forgetting. It was hypothesized that S s selectively focus on key word classes, with grammatical structure as the guide to selection, and generate recall sentences around retained elements.
Transmitting Medical Imagery over 2-Meter Amateur Packet Radio Networks using TCP Reno and UDP

The United States Federal Communications Commission permits licensed amateur radio operators to transmit data using the 144.1 MHz - 148.0 MHz radio frequencies that comprise the amateur 2-meter band. Unfortunately, significant time is needed to transmit large files over 2-meter amateur packet radio networks because the required terminal node controllers (i.e. radio modems) transmit data at a standard rate of 1200 bps. In this paper, we evaluate the performance of the Reno variant of the transmission control protocol and the user datagram protocol when both are used to transmit medical imagery over ns-2 simulated 2-meter amateur packet radio networks. Specifically, we obtain file transmission times while varying protocol segment sizes and channel bit error rates, and find that smaller segment sizes are best for transmitting medical imagery when the bit error rate increases. We also discuss image quality measures as they relate to medical imagery transmitted using the user datagram protocol.
A Theory of Armament

I develop a theory explaining how states decide how much armament to acquire. The theory treats states as unitary optimizers choosing between guns and butter, and it offers a novel exposition of the role intentions play in armament decisions-how they are perceived, and how their assessment interacts with the assessment of power. One of the results deduced from the theory is that if statesmen worry about intentions more than about power, then high arms levels possessed by one state will be matched by low arms levels possessed by another, this prediction sharply contradicts conventional wisdom about the nature of arms-races. Statistical analysis of the Superpowers' cold war interaction-which supports the theory-is briefly discussed.
Studies of Auxin Protectors VIII. Evidence that Auxin Protectors Act as Cellular Poisers

Auxin protectors completely inhibit the peroxidase-catalyzed oxidation of indoleacetic acid (IAA). Presumably only when the protector substance itself has been oxidized, does IAA oxidation begin. Reduced nicotinamide-adenine dinucleotide (NADH) mimics the native auxin protectors: In the presence of NADH, the peroxidase-catalyzed oxidation of IAA does not begin until almost all the NADH has been oxidized. Auxin protectors slow the oxidation of NADH in the presence of the peroxidase complex (enzyme plus manganese). However, in the absence of the peroxidase complex, protectors actually accelerate the spontaneous oxidation of NADH. Protectors can also accelerate the oxidation of the dye 2,6-dichlorophenol-indophenol, especially in the presence of manganese. Protector oxidized by boiling with traces of hydrogen peroxide will act as an electron acceptor in the peroxidase-catalyzed oxidation of NADH. The reversible redox role of auxin protectors implies that they can act as cellular poisers.
Chromoendoscopy in Inflammatory Bowel Disease

Chromoendoscopy is an evolving but increasingly used diagnostic modality in the detection of dysplasia in ulcerative and Crohn's colitis. The history of chromoendoscopy is reviewed. The characteristics of various dye stains are discussed. Strategies for application of dye stains and the subsequent endoscopic examination are outlined. Implications for our understanding of the natural history of dysplasia and cancer in colitis with these enhanced techniques are explored.
Blood-gas transfer in an axial flow annular exchanger

The rates of hemoglobin saturation and carbon dioxide reduction in blood flowing in an annular-shaped membrane exchanger were studied theoretically by considering two limiting cases: the fluid-limited case and the wall-limited case. The blood is assumed to flow axially with a fully developed laminar profile. In the fluid-limited analysis the membrane wall is assumed to be infinitely permeable, so the efficiency of the oxygenator depends solely on the rate of gas transport within the blood. In the wall-limited case the blood is assumed to have infinite transport ability, thus the efficiency of the oxygenator is limited by the diffusion rate through the wall. For realistic radii ratio, the oxygenator is fluid limited, thus suggesting the need for enhanced blood mixing. In the fluid-limited case the rate of gas transport depends on the radii ratio and a dimensionless length, which is independent of the cylinder sizes. If PO2 = 715 mm. Hg and PCO2 = 0 mm. Hg are maintained at both walls, oxygenation is the slower process. For the same flow rate the length required for complete hemoglobin saturation in the annulus with an inner to outer radius ratio of 0.95 is 1/65 of that required in a circular tube.
Paradise Lost and the Concept of Creation

����� ��� SCHOLARS HAVE LONG RECOGNIZED that the process of creation is crucial to Milton’s poetry. Almost sixty years ago W. B. C. Watkins affirmed that creation is “deeply interfused” in Milton’s Paradise Lost. Pointing out that Milton “never lets us forget from beginning to end the Divine creative process,” Watkins concludes that creation “is both [the] substance and structure of his epic.” 1 Subsequent critics have confirmed this claim, commenting at length upon the ways in which acts of creation anchor Milton’s epic. As Michael Lieb points out: “Creation is so important to the action of Paradise Lost, [that] most scholars have had something to say about its presence in Milton’s epic.” 2 Lieb’s own book-length engagement with Paradise Lost emerges from the insight that “the idea of creation in all its aspects” serves as the “common referent by which the oppositions of the poem find expression.” 3 In spite of all this critical attention, however, I believe that we have yet to take the full measure of Milton’s interest in acts of creation. For Milton, creation is more than a compelling metaphor or elaborate image of divine power. Rather, creation constitutes the very essence of deity. This state of affairs arises from Milton’s single-minded subscription to a materialist monism which asserts that all life originates in and is composed of one and the same substance. According to Milton, the universe was not created ex nihilo but rather de deo; everything was fashioned from the singular substance of the Father. The Father’s substance thus constitutes the “one first matter” out of which “all things proceed” (5.469–72). 4 This de deo genesis ennobles each and every existent, for it provides a material link between creation and the Creator. Since everything is to some degree a part of the Father, everything is to some degree divine. In the same way that Milton’s monist logic lends a touch of godliness to all of creation, however, it simultaneously unsettles orthodox ideas about the identity of God.
PLASMA IMPURITY CONTENT, GAS FUELING, AND EXHAUST ON DIII-D OVER EXTENDED PERIODS BETWEEN BORONIZATIONS

During the 2006 and 2007 DIII-D experimental campaigns the rate of boronization events was reduced significantly from past campaigns with no detrimental effects on discharges, including high-performance hybrid and advanced tokamak discharges. Boronizations were completed early in both campaigns due to preceding entry vents. Over the 3-month duration of each campaign, a database of edge and core impurity emission and fueling/exhaust rates from many hybrid discharges was developed that demonstrated little secular change over 7000 plasma-seconds of operations. After 6000 s, a set of seven sequential hybrid discharges was executed with no between-shot helium glow-discharge cleaning. While small effects on fueling and exhaust are observed, density remains controlled and fusion performance is held constant. These results, obtained with the all graphite wall on DIII-D, are promising for the next generation of superconducting, long-pulse tokamaks, where studies of stationary, high performance will be of great interest.
From client/server to intranet

An intranet puts a new layer into a client/server (C/S) architecture, the Web server, which acts as the gateway to the application logic and data. It is three‐tier computing, where these functions are performed on separate servers. The servers store everything and perform the bulk of the querying and the data presentation. Although there is great potential using an intranet to develop applications, there are certain challenges, including: security, privacy, currency, and performance. There is progress with security but performance with high volume transaction processing is still unproved. There have been a lot of mistakes with C/S and the danger here is to go down the same road with the intranet. To avoid this, this study explores the managerial and technical issues involved in developing a corporate intranet. Inspired with the success of Internet, intranet is proved to be an extension of and an enhancement to C/S. Client/server is not dead just as the mainframe is not dead; but the C/S model is being changed by the intranet.
Simulation of models involving mixed selfing and random mating. I. Stochastic variation in outcrossing and selection parameters.

Simulation of models involving mixed selfing and random mating I. Stochastic variation in outcrossing and selection parameters
X-ray absorption in neon modulated by a strong laser pulse

We have measured the absorption of x-rays in neon gas in the presence of a strong laser pulse. The femtosecond x-rays were tuned to energies near the neon 1s-3p resonance, and the laser intensity of 1013 W/cm2 was below the intensity required to alone ionize neon. We observed strong modification of the x-ray absorption when the neon was subjected to laser light that was temporally overlapped with the x-rays.
MOTOR PERFORMANCE UNDER STRESS AS A FUNCTION OF THE AMOUNT OF PRACTICE

The effects of stress on performance are far from clear (Beam, 1955; Castanda & Lipsett, 1950; Farber & Spence, 1953). Stress has been shown to either improve or impair performance depending upon varying experimental conditions. Two factors that appear important in determining the effects of stress are the relative difficulry of the skill to be performed and the degree of proficiency in the skill when stress is inuoduced. Using a motor skill (balancing on a pivoted platform) that permitted the relative level of difficulty to be varied, Ryan (1961b) found that after 12 practice uials threat of electric shock had no deleterious effects on performance of an easier skill but impaired performance on a more difficult skill. Earlier Deese and Lazarus ( 1952 ), investigating the effects of failure-stress on rotary pursuit performance, found that stress introduced early produced a small decrement in performance, while failure-stress introduced late in learning produced a small facilitation. If the assumption can be made that skills become easier as learning progresses, these studies support each other. In Ryan's study stress had no effect on the easy skill but impaired the more difficult one. In the smdy by Deese and Lazarus stress had no effect on performance late in learning when the task would be assumed to be easiest, but early in learning when the task would be assumed ro be more difficult stress impaired performance. From chis it appears that the relative ease of performance may be a crucial factor in determining the effects of stress on performance, with stress having its most disruptive effect early in learning when performance appears most difficult, then becoming less disruptive as learning progresses. From this hypothesis the prediction would be that performance on the difficult motor skill used in the Ryan study (1961b) would not be expected to show the same deleterious effect under stress late in learning as it did earlier. METHOD Silbject~.-Ss were 40 male university students, all volunteers, from various areas of specialization. None had previous experience in performing similar tasks.
Conformational energetics of cationic backbone rearrangements in triterpenoid biosynthesis provide an insight into enzymatic control of product

2,3-(S)-Oxidosqualene (C30H50O) serves as a versatile starting point for the remarkable biosynthesis of many isomeric naturally occurring triterpenoids of formula C30H50O. These biosyntheses all involve polycyclization via cationic intermediates. The fully cyclized primary products then are converted to various structures by cationic rearrangements involving the polycyclic backbone. The energetics of these rearrangements has been examined by B3LYP 6−31 G* DFT calculations and by ab initio Hartree−Fock calculations at the 6−31G* or 3−21G(*) level. The results have led to the conclusion that the biosynthesis of friedelin, the most drastically rearranged of the pentacyclic triterpenes, involves a complex nonstop process, with no stable intermediates between 2,3-(S)-oxidosqualene and friedelin. It is proposed that this single-reaction biosynthesis consists of pentacyclization to the lupanyl cation followed directly by a sequence of 10 suprafacial 1,2-shifts of carbon and hydrogen, driven by the large exergoni...
Prolactin concurrently activates src-PLD and JAK/Stat signaling pathways to induce proliferation while promoting differentiation in embryonic astrocytes.

Abstract In normal development, embryonic astrocytes progress through their cell lineage by acquiring differentiation, by apoptosis, and by proliferation. In this study, we show that embryonic astrocytes may maintain and make gains in differentiation as they simultaneously progress through one cell cycle when induced by prolactin (PRL). Prolactin induced the majority of astrocytes to incorporate bromodeoxyuridine (BrdU) with a four-fold increase over controls after 18 h of exposure. Investigating possible mitogenic signaling pathways we show for the first time that prolactin is coupled to a sustained phospholipase D (PLD) activation, with an efficacy similar to the phorbol ester and astrocytic mitogen 12-tetradecanoylphorbol-13-acetate (TPA). Both cyclosporine and suramin abolished this activation. Staurosporine and calphostin C also inhibited the PRL effect by 50%, consistent with involvement of protein kinase C-(PKC)- α , the major PKC isoform in astrocytes. Genistein and PP1 blocked the activation indicating additional regulation by cytosolic tyrosine kinases. This profile of PLD activation was suggestive of a PLD I isoform and a mitogenic response. Upon completion of the cell cycle, analysis of glia fibrillary acidic protein (GFAP) and vimentin abundance, and glutamine synthetase (GS) activity showed that astrocytes had gained in expression of differentiation markers. Moreover, the intensity of GFAP immunofluorescence was greater per cell, as was the length of the cell processes. In exploring the signaling for prolactin-induced differentiation we found that prolactin activated the tyrosine kinase Janus kinase (JAK) 2 and significantly stimulated tyrosine, phosphorylation of the prolactin receptor. Stat 1 and 3 were also activated presumably downstream to JAK2 activation. A rapid translocation of the cytosolic Stats over the nucleus was seen in nearly every astrocyte corresponding well with the gains in GFAP per cell. The Stats translocation did not depend on MEK-ERK inhibition by PD98059, inhibition of p38 by 1 μm SB203580, or Src kinase family inhibition by PP1. Our results demonstrate the ability of PRL to concurrently induce activation of PLD, a mitogenic signaling pathway in astrocytes, and prolonged stimulation of Stat1, compatible with the increased GFAP upregulation and cell differentiation. Considered together this data may provide an explanation on the fast gain in both numbers and differentiation in the astrocytic population during development (HD 09402, CRF).
Purification and characterization of aminoglycoside phosphotransferase APH(6)-Id, a streptomycin-inactivating enzyme

As part of an overall project to characterize the streptomycin phosphotransferase enzyme APH(6)-Id, which confers bacterial resistance to streptomycin, we cloned, expressed, purified, and characterized the enzyme. When expressed in Escherichia coli, the recombinant enzyme increased by up to 70-fold the minimum inhibitory concentration needed to inhibit cell growth. Size-exclusion chromatography gave a molecular mass of 31.4 ± 1.3 kDa for the enzyme, showing that it functions as a monomer. Activity was assayed using three methods: (1) an HPLC-based method that measures the consumption of streptomycin over time; (2) a spectrophotometric method that utilizes a coupled assay; and (3) a radioenzymatic method that detects production of (32)P-labeled streptomycin phosphate. Altogether, the three methods demonstrated that streptomycin was consumed in the APH(6)-Id-catalyzed reaction, ATP was hydrolyzed, and streptomycin phosphate was produced in a substrate-dependent manner, demonstrating that APH(6)-Id is a streptomycin phosphotransferase. Steady-state kinetic analysis gave the following results: K(m)(streptomycin) of 0.38 ± 0.13 mM, K(m)(ATP) of 1.03 ± 0.1 mM, V(max) of 3.2 ± 1.1 μmol/min/mg, and k(cat) of 1.7 ± 0.6 s(-1). Our study demonstrates that APH(6)-Id is a bona fide streptomycin phosphotransferase, functions as a monomer, and confers resistance to streptomycin.
Amino acid concentrations in rat cochlear nucleus and superior olive

Distributions of 10 amino acids were mapped in the cochlear nucleus and superior olive of rats by microdissection of freeze-dried sections combined with high performance liquid chromatography. Glutamate concentrations were relatively high in regions containing granule cell bodies, axons and terminals, whereas aspartate concentrations were higher in the rest of the cochlear nucleus. The distribution of glutamine, a metabolic precursor of glutamate, correlated highly with that of glutamate. In the superior olive, glutamate concentrations were similar among the nuclei, whereas aspartate concentrations were higher in the more dorsal nuclei. Glycine concentrations were relatively high in dorsal portions of the cochlear nucleus and superior olive and were much higher in all regions than those of γ-aminobutyrate (GABA). Both GABA and taurine showed decreasing gradients from superficial to deep layers of the dorsal cochlear nucleus. Concentrations of serine, threonine, arginine and alanine were generally lower than those of the other six amino acids. The results support other evidence for prominent roles of glutamate and glycine as neurotransmitters in the cochlear nucleus and superior olive. They support a neurotransmitter role also for GABA, especially in the superficial layers of the dorsal cochlear nucleus, but less in the superior olive. The literature related to our results is reviewed.
Simple Available Bandwidth Utilization Library for High-Speed Wide Area Networks

The growth of high-speed wide area networks (WANs) has enabled the emergence of new classes of data intensive, wide area computing applications, such as the remote analysis and exploration of data and distributed data mining. The de facto standard for reliable data transfers is the Transmission Control Protocol (TCP). Despite improvements in TCP over the years (to reduce overhead and achieve higher throughput), it is still a common experience for the end-to-end data rates of wide area data mining and data analysis applications to be inefficient. This paper introduces a library called SABUL (Simple Available Bandwidth Utilization Library) which merges features of UDP and TCP to produce a light-weight protocol with flow control, rate control and reliable transmission mechanisms that is designed for data intensive applications over wide area high performance networks. In this paper, we describe the library and give experimental evidence of its effectiveness.
Triglycerides and coronary risk.

Despite extensive research, it has not yet been determined whether triglycerides represent an independent risk factor for coronary heart disease (CHD). The association has been obscured by imprecision in triglyceride measurements, individual variability, and complex interactions between triglycerides and other lipid-nonlipid parameters. Recent large-scale epidemiologic data indicate that elevated fasting triglycerides represent a useful marker for risk of coronary heart disease. The strong interrelationships of triglyceride level, high-density lipoprotein (HDL) level, and low-density lipoprotein (LDL) particle size with CHD risk suggest a metabolic interaction between the triglyceriderich and cholesterol ester-rich lipoproteins in increasing risk of myocardial infarction. Limited data from clinical trials suggest that intervention with agents that lower triglycerides and raise HDL tend to reduce event rates among those with elevated and normal LDL levels. Many important issues defining the role of triglycerides in the primary and secondary prevention of CHD need further evaluation. These issues include the degree of risk associated with high triglyceride levels in various age, gender, racial, and ethnic subgroups, and the prognostic significance of postprandial versus fasting triglyceride levels. Further, primary and secondary intervention trials that more specifically address the clinical benefit of reducing triglyceride levels are warranted. Ultimately, screening and treatment guidelines may have to be modified to allow greater focus on fasting-triglyceride levels. Although current guidelines do not mandate screening for elevated triglyceride levels in the general population, obtaining triglyceride levels in those with known CHD or with other risk factors can provide valuable prognostic information and therefore be of aid in therapeutic decisions.
A pair of male fraternal twins with contrasting manifestations of Rh hemolytic disease.

A pair of male, Negro, fraternal twins are described, both of whom were affected with Rh hemolytic disease. In one twin, the manifestations were typical; jaundice appeared early, exchange transfusion was carried out, and this was followed by prompt and complete recovery. In the second twin, who was treated expectantly, jaundice appeared later and followed the protracted course of the so-called «inspissated bile» syndrome, i. e., the stools were acholic, there was bile in the urine, and most of the serum bilirubin was of the direct reacting type. Of interest was the finding that the occurrence of the syndrome was presaged by the presence of excessive amounts of direct reacting bilirubin in the cord serum. This twin also recovered completely, but convalescence was more prolonged. The observations on these twins provide further evidence that the constitution of the baby, in addition to the maternal Rh antibody titer determine the nature and severity of the manifestations in an erythroblastotic baby.
Carboxylate‐containing chain‐extended polyurethanes

Polyurethanes based on methylene bis(p-phenyl isocyanate), bis(hydroxymethyl) propanoic acid, and poly (tetramethylene oxide) were synthesized, and their morphology and physical properties investigated. The acid polyurethanes exhibited very poor phase separation and mechanical properties, but upon neutralization with alkali metals phase separation improved dramatically and the materials resembled tough elastomers. The choice of cation played a much less important role than hard segment content in determining morphology and properties. Small-angle x-ray scattering patterns of these ionic polyrethanes exhibit two peaks, one characteristic of scattering between the hard and soft domains and the other reflecting scattering from aggregates of ionic groups residing within the hard domains. While ionic aggregation is the primary driving force for phase separation in these materials, their morphology more closely resembles that for nonionic polyurethanes than that for conventional ionomers, because the ionic groups exist in blocks composed primarily of rigid diisocyanate residues.
Wearable Biomedical Systems: Research to Reality

The field of wearable biomedical systems (WBS) has of late been generating a lot of interest in the research and business communities since its early beginnings in the mid-nineties. However, the technology is yet to enter the marketplace and realize its original goal of enhancing the quality of life for individuals through enhanced real-time biomedical monitoring. In this paper, we propose a framework for analyzing the transition of WBS from research to reality. We begin with a look at the evolution of the field and describe the key components of a WBS. We then analyze the key issues encompassing the technical, medical, economic, public policy and business facets from the viewpoints of various stakeholders in the continuum. We conclude with a plan of action for transitioning WBS from "research to reality."
Increased gallbladder-related mortality among Hispanics: does education play a role?

Objective. Hispanics, particularly Mexican Americans, are known to have a higher incidence of mortalities whose underlying cause is a gallbladder‐related disorder. These analyses evaluate the role ...
The effects of N-cadherin misexpression on morphogenesis in xenopus embryos

N-cadherin is a calcium-dependent, cell adhesion molecule that has been proposed to play a role in morphogenesis in vertebrate embryos. Throughout early neural development, N-cadherin is expressed during the morphogenetic changes that occur when ectoderm, in response to neural induction, forms a neural plate and tube. To study the role of N-cadherin in these processes, cDNA clones encoding Xenopus laevis N-cadherin were isolated and used to study the expression of N-cadherin in frog embryos. These studies showed that N-cadherin RNA is not expressed at detectable levels in early cleavage embryos or in isolated ectoderm in the absence of neural induction. However, N-cadherin RNA rapidly appeared in ectoderm exposed to a heterologous neural inducer, indicating that N-cadherin expression, as an early response to induction, precedes the morphogenetic events associated with early neural development. The role of N-cadherin in these morphogenetic events was studied by ectopically expressing N-cadherin in the ectoderm of embryos prior to induction. The ectopic expression of this protein in ectoderm led to the formation of cell boundaries and to severe morphological defects. These results are consistent with the hypothesis that the morphogenetic changes associated with early neural development are controlled, in part, by the induced expression of N-cadherin in the neural plate.
Matching feature points for telerobotics

A system that quickly and reliably matches points from images of the same scene, taken by three different cameras, is presented. The first step consists of weak calibration of the camera system. Feature points are then iteratively selected and matched in the first two images, guided by a fundamental matrix. Each correspondence is then validated by computing the position of matches in the third image using a trifocal tensor, and enforcing a constraint on the disparity of neighboring matches.
Asynchronous multiuser CDMA detector made simpler: novel decorrelator, combiner, canceller, combiner (DC/sup 3/) structure

A code division multiple access (CDMA) detector that employs a combination of a decorrelator and an adaptive interference canceller was proposed by Siveski, Bar-Ness and Chen (1994) for the synchronous channel. For the asynchronous channel, the one-shot approach was suggested. It requires a (2K-1) dimensional decorrelator and a canceller (K is the number of users) and must be repeated once for every user if adequate performance for all users is sought. Instead, we propose in this paper a decorrelator, data combiner, canceller, data combiner arrangement. Using maximum signal-to-noise ratio (SNR) combining at both data combining stages, we show that the resulting decorrelator canceller performs with an asynchronous channel as does that for the synchronous case.
Supercolonies of billions in an invasive ant: What is a society?

All societies are characterized by the capacity of their members to distinguish one another from outsiders. Ants are among the species that form ‘‘anonymous societies’’: members are not required to tell each other apart as individuals for the group to remain unified. Rather, each society depends on shared cues recognized by all its members. These cues permit societies to reach populations in the low millions in certain ant and termite species, and to grow indefinitely populous, expansive, and possibly long lasting in a few other ant species, which are described as having supercolonies. Anonymous societies are contrasted with ‘‘individual recognition societies’’ such as those of most vertebrates, which are limited to a few individuals by the necessity that the members individually recognize each other. The shared recognition cues of ants provide clear criteria for defining colonies and are what enables a supercolony to remain a single society no matter how large it becomes. I examine the often conflicting ideas about the best studied ant with supercolonies, the Argentine ant (Linepithema humile). Its invasive supercolonies, containing in some cases billions of workers and queens spread over hundreds of square kilometers, can be most parsimoniously understood as single colonies that have had an opportunity to expand across regions of suitable habitat because of a lack of well-matched competitors. This capacity for unrestricted growth is the defining characteristic of supercolonies. There is no evidence that the local patchiness of nests and patterns of worker and food traffic within these wide-ranging populations are so invariant that supercolonies do not exist but instead are collections of numerous independent nest clusters that should be called ‘‘colonies.’’ Nor is there evidence for the hypothesis that invasive supercolonies have been able to grow large and successful overseas only as a result of evolving through genetic drift or selection to become fundamentally different from the smaller colonies typical of the species’ region of origin around northern Argentina. The most unique feature of the Argentine ant, however, is not that its colonies are anonymous or that they can grow indefinitely large—though the last trait is found only in a few ant species and humans. Rather, it is that Argentine ant colonies do not interbreed. Indeed, the only fighting among Argentine ants occurs along colony borders, which even reproductives seldom, if ever, cross and survive. For this reason, each Argentine ant supercolony acts as virtually a sibling species. Key words: Argentine ant, polydomy, recognition system, reproductive isolation, society, speciation, supercolony, unicolonial. [Behav Ecol]
Continuity and Change in the Constitutional Experience of the German Jews

Despite the progress of Emancipation in the nineteenth centu ry, German Jews were required to belong to legally recognized Jewish communities. Even after this requirement was lifted, Jew ish communal life remained strong. The community structure that the Prussian state expected the Jews to implement was modeled after German civil administration. This framework, however, re sembled both medieval German and medieval Jewish models. Thus, German Jews, while modernizing their own communal insti tutions, continued to maintain both their own and their German neighbors' political traditions. The German Jewish communal constitutions attest to a Jewish political tradition of adaptation to prevailing non-Jewish norms, as well as retention of ancient Jew ish elements.
Realistic Models of Hydrogenated Amorphous Si

We have recently produced experimentally plausible structural models of 12a-Si:H. We discuss the structural, vibrational and electronic properties of these models, and indicate how such structures can be obtained.
Host-Dependent Induction of Phage Mutants and Lysogenization.

Abstract Temperate phage P2 froms plaques with equal efficiency on its hosts Escherichia coli strain C and Shigella dysenteriae strain Sh. When the host was irradiated with ultraviolet light (UV), strain C was found to have a greater capacity than strain Sh to give rise to plaques after infection with either unirradiated or irradiated phage P2. When strain C, irradiated with relatively small doses of UV, was infected with UV-irradiated phage P2, the survival of the phage was greatly increased, compared to that obtained on either unirradiated strain C or Sh, or similarly irradiated strain Sh. Concomitantly, an increased proportion of clear plaque-type mutants was found among the survivors. Ninety-eight such mutants were classified according to their ability to establish lysogeny in either strain Sh or C, and to cooperate with each other in mixed infection to increase the frequency of establishment of lysogeny. Three classes were obtained, the members of one of which had two unusual characteristics: they were able to establish lysogeny in strain C, but not in strain Sh; they gave rise, both spontaneously and after UV treatment, to variants able to establish lysogeny in both strains. A hybrid of strains Sh and C, which was able to be lysogenized by the above class of mutants, retained the same capacity for phage P2 as strain Sh, indicating that these two differences between the strains are independent of each other.
Untreated Hypertension Decreases Heritability of Cognition in Late Middle Age

Hypertension is a risk factor for cognitive decline, but the mechanisms underlying the effects of hypertension on cognition, particularly in midlife, are unclear. We examined whether hypertension modifies genetic influences on individual differences in cognition. Nine cognitive domains and general cognitive ability were assessed in a sample of 1,237 male twins aged 51–60 who were divided into three blood pressure groups: non-hypertensive; medicated hypertensive; and unmedicated hypertensive. Heritability was significantly lower among unmedicated hypertensives compared to medicated hypertensives and non-hypertensives for visual-spatial ability (p = 0.013) and episodic memory (p = 0.004). There were no heritability differences between non-hypertensives and medicated hypertensives. In addition, there were no significant differences in mean level cognition across the three blood pressure groups. These results suggest that in middle-aged men, untreated hypertension suppresses normal genetic influences on individual differences in certain domains of cognition prior to the emergence of hypertension-related effects on cognitive performance. These results further suggest that antihypertensive medication may protect against or reverse this effect.
Constrained opinion dynamics: freezing and slow evolution

We study opinion formation in a population of leftists, centrists and rightist. In an interaction between neighbouring agents, a centrist and a leftist can become both centrists or leftists (and similarly for a centrist and a rightist), while leftists and rightists do not affect each other. The evolution is controlled by the initial density of centrists ρ0. For any spatial dimension the system reaches a centrist consensus with probability ρ0, while with probability 1 − ρ0 the final state is either an extremist consensus, or a frozen population of leftists and rightists. In one dimension, we determine the opinion evolution by mapping the system onto a spin-1 Ising model with zero-temperature Glauber kinetics. The approach to the final state is governed by a t−ψ long-time tail, with ψ → 2ρ0/π as ρ0 → 0. In the one-dimensional frozen state, the length distribution of single-opinion domains has an algebraic small-size tail x−2(1−ψ) and the average domain length is L2ψ, where L is the length of the system.
Co-occurrence of 1,4-dioxane with trichloroethylene in chlorinated solvent groundwater plumes at US Air Force installations: Fact or fiction

Increasing regulatory attention to 1,4-dioxane has prompted the United States Air Force (USAF) to evaluate potential environmental liabilities, primarily associated with legacy contamination, at an enterprise scale. Although accurately quantifying environmental liability is operationally difficult given limited historic environmental monitoring data, 1,4-dioxane is a known constituent (i.e., stabilizer) of chlorinated solvents, in particular 1,1,1-trichloroethane (TCA). Evidence regarding the co-occurrence of 1,4-dioxane and trichloroethylene (TCE), however, has been heavily debated. In fact, the prevailing opinion is that 1,4-dioxane was not a constituent of past TCE formulations and, therefore, these 2 contaminants would not likely co-occur in the same groundwater plume. Because historic handling, storage, and disposal practices of chlorinated solvents have resulted in widespread groundwater contamination at USAF installations, significant potential exists for unidentified 1,4-dioxane contamination. Therefore, the objective of this investigation is to determine the extent to which 1,4-dioxane co-occurs with TCE compared to TCA, and if these chemicals are co-contaminants, whether or not there is significant correlation using available monitoring data. To accomplish these objectives, the USAF Environmental Restoration Program Information Management System (ERPIMS) was queried for all relevant records for groundwater monitoring wells (GMWs) with 1,4-dioxane, TCA, and TCE, on which both categorical and quantitative analyses were carried out. Overall, ERPIMS contained 5788 GMWs from 49 installations with records for 1,4-dioxane, TCE, and TCA analytes. 1,4-Dioxane was observed in 17.4% of the GMWs with detections for TCE and/or TCA, which accounted for 93.7% of all 1,4-dioxane detections, verifying that 1,4-dioxane is seldom found independent of chlorinated solvent contamination. Surprisingly, 64.4% of all 1,4-dioxane detections were associated with TCE independently. Given the extensive data set, these results conclusively demonstrate for the first time that 1,4-dioxane is a relatively common groundwater co-contaminant with TCE. Trend analysis demonstrated a positive log-linear relationship where median 1,4-dioxane levels increased between approximately 6% and approximately 20% of the increase in TCE levels. In conclusion, this data mining exercise suggests that 1,4-dioxane has a probability of co-occurrence of approximately 17% with either TCE and/or TCA. Given the challenges imposed by remediation of 1,4-dioxane and the pending promulgation of a federal regulatory standard, environmental project managers should use the information presented in this article for prioritization of future characterization efforts to respond to the emerging issue. Importantly, site investigations should consider 1,4-dioxane a potential co-contaminant of TCE in groundwater plumes.
Expression of the T-lymphocyte activation gene, F5, by mature neurons.

F5 was first identified as an mRNA expressed by activated but not resting T-lymphocytes. Subsequent studies suggested that it also is selectively expressed by mature neurons. Although the F5 protein coding sequence is highly conserved, the function of the F5-encoded protein is unknown. The present studies were undertaken to define the anatomic distribution, cellular specificity, and developmental pattern of F5 mRNA expression in the mouse nervous system, addressing specifically the question of whether the expression pattern of F5 corresponds to that of known ligand-receptor or signal-transduction systems. The use of a nonradioactive in situ hybridization method and paraffin-embedded sections provided excellent morphological preservation and a high degree of cellular resolution. F5 mRNA was detected in the central nervous system, peripheral nervous system, and retina in cells having the location and morphological features of neurons. Combined in situ hybridization histochemistry for F5 mRNA and immunofluorescence staining for cell-specific markers confirmed that neurons expressed F5 mRNA but astrocytes did not. The neuronal expression of F5 mRNA had two interesting features. First, the level of expression appeared to correlate directly with the size of the neuronal perikarya, the length of the axonal projection, or the extent of dendritic arborization. Second, F5 mRNA appeared late in post-natal development. These observations are of interest because of preliminary data suggesting that F5 may function as a substrate for protein kinase C, which demonstrates a similar expression pattern in the nervous system. © 1992 Wiley-Liss, Inc.
Morphometric and cytochemical analysis of lysosomes in rat Peyer's patch follicle epithelium: Their reduction in volume fraction and acid phosphatase content in M cells compared to adjacent enterocytes

M cells are specialized epithelial cells over lymphoid follicles in Peyer's patches which take up viruses, bacteria, and antigenic macromolecules from the intestinal lumen. Unlike ordinary enterocytes which sequester pinocytosed material in lysosomes, M cells transport such material across the epithelium to antigen-processing areas in lymphoid follicle domes, suggesting a difference in lysosomal activity or a different route for movement of endocytic vesicles. Ileal Peyer's patches in rats were examined by electron microscopy to identify lysosomes by acid phosphatase activity. Acid phosphatase was found in dense bodies in enterocytes but not in M cells. Stereological analysis showed the volume fraction occupied by dense bodies in M cells to be 16 times less than in enterocytes (P less than .0005), even though the volume fractions of cytoplasm occupied by mitochondria in M cells and enterocytes were not significantly different. The small volume fraction of dense bodies and the absence of acid phosphatase activity in M cells thus correlate with absence of lysosomal degradation of luminal microorganisms during transport into lymphoid follicles by M cells and may provide not only a complete array of microbial antigens for initiation of immune responses, but also a route through the mucosal barrier for microorganisms which can evade local containment mechanisms.
Meningococcus genome informatics platform: a system for analyzing multilocus sequence typing data

The Meningococcus Genome Informatics Platform (MGIP) is a suite of computational tools for the analysis of multilocus sequence typing (MLST) data, at http://mgip.biology.gatech.edu. MLST is used to generate allelic profiles to characterize strains of Neisseria meningitidis, a major cause of bacterial meningitis worldwide. Neisseria meningitidis strains are characterized with MLST as specific sequence types (ST) and clonal complexes (CC) based on the DNA sequences at defined loci. These data are vital to molecular epidemiology studies of N. meningitidis, including outbreak investigations and population biology. MGIP analyzes DNA sequence trace files, returns individual allele calls and characterizes the STs and CCs. MGIP represents a substantial advance over existing software in several respects: (i) ease of use--MGIP is user friendly, intuitive and thoroughly documented; (ii) flexibility--because MGIP is a website, it is compatible with any computer with an internet connection, can be used from any geographic location, and there is no installation; (iii) speed--MGIP takes just over one minute to process a set of 96 trace files; and (iv) expandability--MGIP has the potential to expand to more loci than those used in MLST and even to other bacterial species.