cssi/SciSciGPT-SciSciNet huggingface dataset:
Selective expression of xenotropic virus in congenic HRS/J (hairless) mice

GENETIC factors strongly influence susceptibility to leukaemia in mice. In some instances leukaemogenesis hinges on only a few genes, or even a single gene1. The hairless mutation is an example of this. Homozygotes for this autosomal recessive gene (hr/hr) have a high incidence of thymic leukaemia (45% at 8–10 months), whereas the incidence in heterozygotes (hr/ +) is low (1% at 8–10 months)2. The leukaemogenic effect produced by homozygocity for hr is unknown. Here we report that thymuses of hr/hr mice produce high titres of xenotropic viruses, whereas thymuses of hr/ + mice do not. Furthermore, viruses with a broadened host range were isolated from thymuses of preleukaemic hr/hr mice, but not from any tissue of hr/ + mice. We propose that the mutant gene hr specifies circumstances that augment production of xenotropic virus by the thymus. This phenomenon may be an important step in the development of thymic leukaemia.
A comparison of costs of universal versus targeted lead screening for young children.

Abstract The purposes of this study were to compare universal blood lead screening for young children versus targeting by a risk assessment questionnaire and to examine the cost implications of each approach. Costs reflect the total number of blood tests required and cost of specimen collection, handling, and testing per elevated case. The setting included the metropolitan areas of Minneapolis and St. Paul, Minnesota. Children ( N =9603) from 17 community organizations had blood tests. In addition, each child's parent or guardian completed a questionnaire assessing potential risk for lead poisoning. Four different screening approaches are presented. Each screening approach is presented with associated costs of overall screening and cost per child identified at blood levels of ≥10 μg/dl ( N =1140) and ≥15 μg/dl ( N =317). Based on the screening strategy selected and an estimate of $17 per blood test, total screening costs ranged from $91,596 to $165,945. The cost per child identified with elevated lead levels ranged from $361 to $523 at ≥15 and $105 to $146 at ≥10. Nine to 13% of children would not have been detected by policies other than universal screening. A geographically based approach was able to detect 90% of children with elevated blood levels at two-thirds the cost of universal screening. Blood tests would be taken for all children living within city limits. Those residing elsewhere would be tested only if answers to questionnaire items pertaining to age of housing, prior history of lead poisoning, or eating paint chips indicated risk. The new CDC guidelines suggest that screening be based on an assessment of housing, population demographics, and community risk and resources. This paper presents such an assessment.
An improved scintillation cocktail of high-solubilizing power.

Abstract A scintillation cocktail containing 25% Triton X-114 in xylene is considered for a broad range of scintillation counting applications. The cocktail gives good counting efficiencies for 3H (47%) and 14C (93%). It will accept up to 30% (v/v) aqueous sample. The scintillation fluid is also used effectively with samples which are difficult to solubilize, such as the degradation products from the solubilization of polyacrylamide gels. The cocktail can be formulated for less than $2.00 per gallon.
Comparison of the red blood cell Ca2(+)-ATPase in ghost membranes and after purification.

We have compared properties of the red blood cell Ca2+-ATPase in two types of preparations: red cell membrane ghosts (enzyme in unfractionated membranes) and after purification (detergent-soluble enzyme). The Ca2+-ATPase activity was studied with respect to its requirement for: calmodulin, calcium, magnesium, monovalent cations, ionic strength, pH, and temperature. Sensitivity of the Ca2+-ATPase activity in the two preparations to anticalmodulin drugs and to engineered calmodulins with amino acid substitutions was determined. Finally, stoichiometry of the formation of phosphorylated enzyme intermediate (EP) and titrations of the ATP binding region with fluorescein 5′-isothiocyanate (FITC) were characterized. For the first time a high phosphorylation level of 2.0–2.4 mmol EP/mg of purified enzyme is reported.
Biological degradation of explosives and chemical agents

Hazardous energetic organo-nitro compounds are found as contaminants in many environments. A series of nitro aromatics, nitrate esters and nitro amines, all characteristic of this class, has been studied for their susceptibility to biological transformation. Biotransformation pathways for each of these compounds have been identified and are summarized. Implications for these findings in light of current contamination issues is discussed. The detoxification of organophosphate chemical agents focuses on the investigation of organophosphate degrading enzymes from bacteria. Certain of these enzymes, active both in solution and when immobilized onto a solid surface, are very successful in hydrolyzing and detoxifying various organophosphate chemical agents. The relationship of this research to the critical concerns of the agricultural industry regarding detoxification of organophosphorous pesticides is discussed.
Onset of failure in finitely strained layered composites subjected to combined normal and shear loading

Abstract A limiting factor in the design of fiber-reinforced composites is their failure under axial compression along the fiber direction. These critical axial stresses are significantly reduced in the presence of shear stresses. This investigation is motivated by the desire to study the onset of failure in fiber-reinforced composites under arbitrary multi-axial loading and in the absence of the experimentally inevitable imperfections and finite boundaries. By using a finite strain continuum mechanics formulation for the bifurcation (buckling) problem of a rate-independent, perfectly periodic (layered) solid of infinite extent, we are able to study the influence of load orientation, material properties and fiber volume fraction on the onset of instability in fiber-reinforced composites. Two applications of the general theory are presented in detail, one for a finitely strained elastic rubber composite and another for a graphite–epoxy composite, whose constitutive properties have been determined experimentally. For the latter case, extensive comparisons are made between the predictions of our general theory and the available experimental results as well as to the existing approximate structural theories. It is found that the load orientation, material properties and fiber volume fraction have substantial effects on the onset of failure stresses as well as on the type of the corresponding mode (local or global).
The CH2+ cation

Abstract A tentative identification is proposed of the state of CH2+ which has been detected in energy loss experiments with a lifetime of at least 3 μs. An empirical modification of a calculated potential energy curve is made which yields a well about 1 eV deep in the repulsive curve of the ground electronic state near 1.21 A. An elastic scattering resonance level occurs at the measured excitation energy and has a width corresponding to a lifetime of 3.2 μs.
Corneal injury thresholds for exposures to 1.54-μm radiation

Corneal epithelial injury thresholds have been determined for exposures to 1.54 μm infrared radiation having durations from 1 to 100 sec and beam diameters from 0.5 to 7 mm. For 1 sec exposures, measured thresholds range from 12 W/cm 2 (5 mm diameter beam ) to 67 W/cm 2 (0.5 mm diameter). For 2 sec exposures, they range from 9 W/cm 2 (7mm diameter) to 57 W/cm 2 (0.5 mm diameter). For 10 sec exposures, they range from 3.7 W/cm 2 (7mm diameter) to 33 W/cm 2 (0.5 mm diameter). For 100 sec exposures, they are 1.4 W/cm 2 (7mm diameter) and 3.7 W/cm 2 (2mm diameter). The dependence of the measured thresholds on laser beam diameter provides strong evidence supporting a critical temperature damage model. These measured thresholds are greater than 10 times the maximum permissible exposure (MPE) in ANSI Z-136.5-2000.
INTRACARDIAC NEEDLE BIOPSY OF THE VENTRICULAR SEPTUM.

Abstract This report describes a myocardial biopsy technic for safely securing enough tissue for biochemical and microscopic study of heart disease. The technic relies on a catheter-sheathed, curved biopsy needle containing a retractable cutting device.
Modulation of Gear Tooth Loading Due to Traveling Wave Vibration

The first reduction gear set in a turboprop engine gearbox was changed from a spur configuration to helical in order to reduce dynamic load and tooth stress. During initial strain gage testing, a low frequency modulation (approximately 70 Hz) of the tooth engagement strain was observed. The modulation had not been present during previous strain gage tests of the gears in their original spur configuration. The expected decrease in dynamic load and tooth stress was not realized due to the low frequency modulation. Post test inspection revealed indications of end loading on both the forward and aft ends of the gear teeth. Additionally, a 22/rev standing wear pattern developed on the aft face of the bull gear rim where it contacts the high-speed pinion bearing thrust collar. Detailed analysis of the strain gage data coupled with traveling wave theory identified the source of the modulation as 19/rev response of a forward traveling three nodal diameter mode of the bull gear at approximately 2,500 Hz. An analytical simulation of the high-speed pinion tooth mesh multiplied by a signal representing a forward traveling three nodal diameter response of the bull gear exactly matched the observed modulation. Design-of-experiment engine tests using proximity probes to measure bull gear vibration identified improper contact at the bull gear thrust collar as the excitation of the three nodal diameter mode. A verification strain gage test with proper contact showed no modulation in tooth engagement.Copyright © 2003 by ASME
Femtosecond spontaneous-emission studies of reaction centers from photosynthetic bacteria.

Abstract Spontaneous emission from reaction centers of photosynthetic bacteria has been recorded with a time resolution of 50 fs. Excitation was made directly into both the special-pair band (850 nm) and the Qx band of bacteriochlorophylls (608 nm). Rhodobacter sphaeroides R26, Rhodobacter capsulatus wild type, and four mutants of Rb. capsulatus were studied. In all cases the fluorescence decay was not single exponential and was well fit as a sum of two exponential decay components. The short components are in excellent agreement with the single component detected by measurements of stimulated emission. The origin of the nonexponential decay is discussed in terms of heterogeneity, the kinetic scheme, and the possibility of slow vibrational relaxation.
Design of Muon Storage Rings for Neutrino Oscillations Experiments

A muon storage ring can provide electron and muon neutrino (?e,??) beams of precisely knowable flux which are excellent probes for ? oscillations. Constraints on storage ring and injection design are described. Sample muon storage rings are presented and compared with parasitic use of the Fermilab p? precooler as a ? storage ring. "Stochastic injection" with injected pion beam decaying to circulating muon beam is favored. A practical possibility may be a low-energy (1 GeV) ring matched to a medium energy proton injector (8 GeV Booster).
A dynamic duo: pairing click chemistry and postpolymerization modification to design complex surfaces.

ConspectusAdvances in key 21st century technologies such as biosensors, biomedical implants, and organic light-emitting diodes rely heavily on our ability to imagine, design, and understand spatially complex interfaces. Polymer-based thin films provide many advantages in this regard, but the direct synthesis of polymers with incompatible functional groups is extremely difficult. Using postpolymerization modification in conjunction with click chemistry can circumvent this limitation and result in multicomponent surfaces that are otherwise unattainable.The two methods used to form polymer thin films include physisorption and chemisorption. Physisorbed polymers suffer from instability because of the weak intermolecular forces between the film and the substrate, which can lead to dewetting, delamination, desorption, or displacement. Covalent immobilization of polymers to surfaces through either a “grafting to” or “grafting from” approach provides thin films that are more robust and less prone to degradation. ...
Theory of high gain harmonic generation: an analytical estimate

We discuss the theory of the High Gain Harmonic Generation (HGHG). First, we describe an analytical estimate using the HGHG parameters in the DUVFEL project at BNL as an example. We show that the effective energy spread in a chicane dispersion section is found to be very small, and the effect of finite emittance can be neglected during the calculation of coherent harmonic generation. Then we discuss some issues such as the intensity stability, and how to use HGHG to obtain information about local energy spread. We compare these issues with recent experimental results in the infrared. We discuss some of the key issues in the cascading HGHG scheme and its possible limitations.
Selecting Books for Children Birth through Four: A Developmental Approach.

The selection of books to read to young children matters enormously in the role books play for enriching children’s lives. This paper reviews the scientific evidence for the appropriate selection of books, and argues that care in selecting books targeted to children’s developing skills will enhance the power and the pleasures of reading to young children.
Systematic Review of Patient-specific Instrumentation in Total Knee Arthroplasty: New but Not Improved

Background Patient-specific cutting blocks have been touted as a more efficient and reliable means of achieving neutral mechanical alignment during TKA with the proposed downstream effect of improved clinical outcomes. However, it is not clear to what degree published studies support these assumptions.
Kinetics studies of the reactions of KMnO4 and of KIO4 in alkali halide disks

Abstract The kinetics of the solid state reactions of KMnO4 in alkali halide matrices and KIO4 in alkali halide matrices were studied. All reactions were found to be first order with respect to the species being reduced. Rate constants were determined at 25, 50 and 100°C, and activation energies were determined for the reactions of KMnO4 in KI and KIO4 in KI. At 25°C, the rate constants for the reaction of KMnO4 in KI and KMnO4 in RbI were approximately the same. But the rate constant at 25°C for the reaction of KIO4 with I− was about 2 1 2 times larger in a RbI disk than in a KI disk. Possible mechanisms for the solid state processes are suggested.
Monitoring organic contaminants in eggs of glaucous and glaucous-winged gulls (Larus hyperboreus and Larus glaucescens) from Alaska.

Abstract Gull eggs have been used to monitor contaminants in many parts of the world. The Seabird Tissue Archival and Monitoring Project (STAMP) is a long-term program designed to track trends in pollutants in northern marine environments using seabird eggs. Glaucous and glaucous-winged gull ( Larus hyperboreus and Larus glaucescens ) eggs collected in 2005 from seven Alaskan colonies were analyzed for organic contaminants. Concentrations ranged from below detection limits to 322 ng g −1 wet mass in one egg for 4,4′-DDE and differed among the samples collected in the Gulf of Alaska and Bering and Chukchi Seas. Chick growth and survival rates may be affected by the contaminant levels found in the eggs, but the eggs should be safe for human consumption if they are eaten in small quantities. STAMP plans to continue collecting and banking gull eggs for future real-time and retrospective analyses.
The measurement of role taking in young adults

Sociometry is presented as an alternative way of measuring role taking, specifically, an alternative to an often used projective measure, the Role-Taking Task (RTT). Study 1 assesses role taking in 161 college students. In this study, a sociometric measure, the Peer Role-Taking Questionnaire (PRTQ) was shown to correlate with class year, group status, social choice, and friendship. In contrast, the RTT correlated weakly with grade point average and some personality test measures. In Study 2, the PRTQ, and not the RIT, was associated with interaction skills in a sample of 39 college nursing students. The PRTQ and RTT did not correlate with each other in either study. The validity and reliability of these two role-taking measures are discussed. It is suggested that researchers need to examine the adequacy of the role-taking measures they use.
Is your household prepared for a disaster such as fire, flood, earthquake, blackout, or a terrorist attack in your community?

Study objectives: The purpose of this study is to determine the level of individual household preparedness for a disaster. Methods: This was a prospective survey of a convenience sample of English-speaking adults in the emergency department waiting area (includes patients and visitors) during a 3-month period in 2004. The survey asked for the following information: demographics: whether the individual had a specific disaster plan in effect for their family, knowledge of disaster plans at their place of work or their children's school or daycare center; whether they had essential supplies, medications, batteries, battery-powered radios, smoke detectors, or carbon monoxide detectors at home; and whether they had a communication plan in effect. These are current recommendations by the Department of Homeland Security and the American Red Cross. Results: A total of 414 surveys were completed, with these results: 78% of participants were between 30 to 69 years of age, 56% were women, 70% white, 64% married, 87% with high school or greater level of education, 50% with children in the household, and 30% with household income greater than $100,000 per year. We obtained the following results: 59% reported having done no specific disaster planning for the family, 45% have no knowledge of disaster plans at work, 38% of participants with children in the household are not aware of their school or daycare disaster plans, and 65% of participants have no portable easy-to-carry container with essential supplies. However, after the extensive blackout in the Northeast in 2003, 49% reported changing their degree of preparedness. At home, 88% reported having a battery- powered radio, and 93% reported having a flashlight. Fifty-five percent of participants reported having "special needs" items such as formula and medications in the house in case of an emergency. We found that 88% of households have smoke detectors, but only 43% have carbon monoxide detectors. We obtained the following results about communication plans in case of an emergency: 60% do not have a designated place to meet outside the neighborhood, and 60% do not have a designated out-of-state family member or friend as a contact. Of those people surveyed who have a designated contact, only 49% of the time does every household member know the telephone number of the contact, and only 39% of the time does every household member know the e-mail address of that contact. Conclusion: Although there have been significant government efforts to improve disaster planning at the state and federal level, 59% of households have not done any planning for a disaster at home, 45% of households are not aware of a workplace plan, and 38% are not aware of their children's school or daycare plan for a disaster. We found that the majority of people do not have a designated place or person to contact in case of an emergency, as has been recommended by the American Red Cross.
The best health care system in the world

"AMERICANS enjoy the best health care system in the world." So says President Bush, and many physicians agree with this claim. But frequent repetition doesn't make it true. What kind of evidence would an objective observer examine to evaluate different systems of health care? Is it possible to determine the best system unambiguously, or does the choice depend on the criteria used? The "best" health care system may be like the "best" spouse—it all depends on what one is looking for. Physicians, for instance, may assign values to system characteristics that differ markedly from those assigned by the public. Even within the profession, each specialty may have a different point of view and reach different conclusions about the system, eg, radiologists vs family physicians. Naoki Ikegami, a Japanese psychiatrist, has suggested three criteria for assessing "best medical practice": (1) maintenance of technical standards in diagnosis and treatment; (2) preventive measures
Evaluation of different RT enzyme standards for quantitation of retroviruses using the single-tube fluorescent product-enhanced reverse transcriptase assay

PCR-based reverse transcriptase (RT) assays are highly sensitive for broad detection of retroviruses. These assays are currently used for demonstrating the absence of retroviral contamination in vaccines and can also be applied to clinical and laboratory research to investigate low-virus replication. A single-tube fluorescent product-enhanced reverse transcriptase assay (STF-PERT) has been published that was highly sensitive for retrovirus detection (<10 virions), with enhanced reproducibility and increased efficiency [Sears, J.F., Khan, A.S., 2003. Single-tube fluorescent product-enhanced reverse transcriptase assay with AmpliWax (STF-PERT) for retrovirus quantitation. J. Virol. Meth. 108, 139-142]. In this report, the step-by-step setup and performance of the STF-PERT assay is described and sensitivity, reproducibility and specificity of the assay reported using three different RTs as standards: avian myeloblastosis virus (AMV) RT, murine leukemia virus (MMLV) RT, and human immunodeficiency virus type 1 (HIV-1) RT. Evaluation of virus stocks showed about 1-2 logs difference in RT detection and retrovirus quantitation with the different RT enzyme standards; in general, virus determination using HIV-1 RT was comparable to using the relevant virus RT.
Differential gradients of interaction affinities drive efficient targeting and recycling in the GET pathway

Efficient and accurate localization of membrane proteins requires a complex cascade of interactions between protein machineries. This requirement is exemplified in the guided entry of tail-anchored (TA) protein (GET) pathway, where the central targeting factor Get3 must sequentially interact with three distinct binding partners to ensure the delivery of TA proteins to the endoplasmic reticulum (ER) membrane. To understand the molecular principles that provide the vectorial driving force of these interactions, we developed quantitative fluorescence assays to monitor Get3–effector interactions at each stage of targeting. We show that nucleotide and substrate generate differential gradients of interaction energies that drive the ordered interaction of Get3 with successive effectors. These data also provide more molecular details on how the targeting complex is captured and disassembled by the ER receptor and reveal a previously unidentified role for Get4/5 in recycling Get3 from the ER membrane at the end of the targeting reaction. These results provide general insights into how complex protein interaction cascades are coupled to energy inputs in biological systems.
A Fast HPLC Analysis Of Catecholamines and Indoleamines in Avian Brain Tissue

Abstract A fast HPLC method for the determination of monoamine levels in avian brain tissue, using a short 3 micron column and electrochemical detection, is presented. This system simultaneously analyzes 18 catecholamines, indoleamines, metabolites, and internal standards, without further sample preparation, in 20 minutes. Contrary to reports involving the mammalian species, incubation of the tissue homogenate with ascorbate oxidase and/or urate oxidase does not significantly alter the analysis under the reported conditions. The assay was used to evaluate differences in the neurochemical content of brain tissue from chickens divergently selected for 42 day exponential growth rate.
LOGARITHMIC TRANSFORMATION OF MAGNITUDE ESTIMATION DATA AND COMPARISONS OF SCALING METHODS

. Recent studies comparing magnitude estimation to other scaling methods have been criticized for failure to submit the data to logarithmic transformation before statistical analysis, a procedure which can improve the ability of magnitude estimation scaling to differentiate among products. Data from one of these studies was available for re-analysis, which was conducted both with and without logarithmic transformation of magnitude estimation, category scales and line scales. The ability of magnitude estimation to differentiate among products was improved by log transformation, while the other methods were not. Improvements were associated in pan with reductions in positive skew and improved approximation of the normal distribution. In spite of this improvement, magnitude estimation remained slightly inferior to the other methods especially in the hands of an untrained consumer sample.
Advances in High Throughput Supercritical Fluid Chromatography

Supercritical fluid chromatography (SFC) has long been touted as the separation of choice for high throughput applications and, after nearly a decade, is finally considered mainstream in the analytical chemistry community. Applications range from microscale analysis of complex mixtures to macroscale purification of chiral enantiomers in a variety of industries, such as pharmaceuticals, foods, cosmetics, agrochemicals, petrochemical and natural products. The inherent speed, efficiency, and versatility of SFC have transformed the perceptions of the technology from novelty to integral tool for the modern analytical lab, especially those labs wanting to maximize throughput. However, maneuvering SFC through the transition from single samples to array-like libraries has strained the development of instrumentation to meet the challenging demands. This review presents the major developments and applications useful to those embarking on using SFC for high throughput applications in other fields.
A Closed-loop Model-based Design Approach based on Automatic Verification and Transformation

Domain-specific modeling languages effectively constrain structural concepts, but constraints that are not easily captured with structural constraints are still important to fix at design time. In practice these kinds of constraints are implicitly left to be carried out by the domain modelers. This paper explores the process of incorporating system behavioral (not just structural) constraints into a DSML, and studies the way of generating feasible transformation solutions if those constraints fail, based on a transformation library constructed in advance. Our approach is to carry out the verification process through code generation, but utilize the results of verification as an input to a model transformation generator. The output transformation then operates on the original model. As a case study, we applied the approach to finite state machine (FSM) models that control a cyber-physical system.
Evaluation of user interaction with daylighting simulation in a tangible user interface

Abstract We present a study of a tangible user interface for design and simulation applied to architectural daylighting analysis. This tool provides an intuitive way for architects and future occupants of a building to quickly construct physical models and interactively view in them a projected simulation of resulting daylighting. A user study was conducted of both architecture students and non-architects in a set of analysis and design exercises. The study investigates the effectiveness of this interface as an educational tool, the precision and accuracy of the constructed physical models, and its effectiveness for creative design exploration. The four part study investigates users' intuitions about daylighting and their interaction with the tangible user interface for analysis of an existing space. These exercises revealed and corrected misconceptions in many of the participants' intuitions about daylighting, and overall the participants praised the ease-of-use of the tool and expressed interest in this simulation tool for daylighting analysis in architectural design.
Osteogenic differentiation of human mesenchymal stem cells through alginate-graft-poly(ethylene glycol) microsphere-mediated intracellular growth factor delivery.

Abstract The intracellular delivery of growth factors increases opportunities for controlling cell behavior and maintaining tissue homeostasis. Recently, VEGFA was reported to enhance osteogenic differentiation of mesenchymal stem cells (MSCs) through an intracrine mechanism, suggesting a new strategy to promote bone tissue formation in osteoporotic patients. The goal of this study was to design and fabricate ligand-conjugated alginate-graft-poly(ethylene glycol) microspheres for intracellular delivery and release of VEGFA in primary human MSCs to enhance osteogenic differentiation as a potential therapeutic. Three types of microspheres were synthesized and characterized by scanning electron microscopy, in vitro drug release kinetics, MSC uptake and internalization: alginate alone (Alg), alginate-graft-poly(ethylene glycol) (Alg-g-PEG) and alginate-graft-poly(ethylene glycol)-S-S-arginine-glycine-aspartic acid (Alg-g-RGD). Each of the different microsphere formulations successfully transported bioactive VEGFA into primary human MSCs within 48 h of culture, and significantly enhanced osteogenic differentiation compared to control treatments with empty microspheres (intracellular control) or non-encapsulated VEGFA (extracellular control). Adipogenic differentiation was not affected by the presence of VEGFA intracellularly or extracellularly. These results demonstrating the internalization of alginate-based microspheres and intracellular delivery of VEGFA support the efficacy of using this drug delivery and intracrine mechanism to control the fate of human MSCs and enhance osteogenic differentiation.
Equivalence Classes for the Double-Digest Problem with Coincident Cut Sites

ABSTRACT When restriction sites are modeled by a random process, the number of solutions to the doubledigest problem (DDP) increases exponentially with the length of the DNA molecule. Cassette transformations define equivalence classes on the set of solutions to the DDP for the case of no coincident cut sites. Pevzner (1994) completely characterized the solutions to the DDP in the case of no coincident cut sites by associating solutions to DDP with alternating Eulerian paths in an edge-bicolored graph. In this paper we extend the definition of cassettes and their transformations to the general case allowing coincident cut sites. Solutions to the DDP in the general case are again characterized by associating solutions to the DDP with alternating Eulerian cycles in an extended graph.
Short axial length broad-band horns

Ever-increasing antenna frequency bandwidth requirements for countermeasures applications and electromagnetic compatibility measurements have provided the impetus for the development of a series of very broad-band horns. In addition to the broad bandwidth, a substantial reduction in axial length over that of earlier models has been achieved for the two designs discussed in this communication. The first horn described covers the frequency range from 1.0-12.0 GHz with the flared portion of the horn having an axial length of 6 in as compared with 12 in for an earlier model. Although horn antennas are not commonly considered for use at frequencies as low as 0.2 GHz, the short axial length design appeared to be an attractive approach in developing a very reasonably sized antenna operating in the 0.2-2.0 GHz range. The technique of fabricating the H plane walls in the form of a grid was used in both designs as a means of maintaining the required H -plane half-power beamwidths. The grid for the 1.0-12.0 GHz horn is of printed circuit form while the grid elements of the lower frequency horn are made of aluminum tubing. Electrical characteristics of both designs are presented, as well as some additional data for recent advances which indicate that a further reduction in axial length or an increase in bandwidth can be achieved with only a moderate rise in VSWR in the lower portion of the frequency range.
Enabling search for facts and implied facts in historical documents

Building a database of facts extracted from historical documents to enable database-like query and search would reduce the tedium of gleaning facts of interest from historical documents. We propose a solution in which historical documents themselves constitute the stored database. In our solution, we use information-extraction techniques to produce a conceptualized external annotation of facts found in each document, and we superimpose the conceptualization over the document collection. The annotation process populates the conceptualization producing a repository of extracted facts, and a reasoner obtains inferred facts from these extracted facts. Our query interface accepts free-form queries and converts them to formal queries over the extracted and inferred facts. Displayed results include, in addition to standard query results, images of original documents with results highlighted along with reasoning chains for inferred facts grounded in these highlighted facts. Along with giving the implementation status of our proof-of-concept prototype, we present results for extraction accuracy and efficiency and point to current and future work needed to enable a practical solution for the envisioned historical-document database.
Voronoi cell properties from simulated and real random spheres and points

Results are reported of a computer-aided study of the properties of Voronoi cells generated from randomly placed impenetrable uniform spheres which saturate a space and of Poisson points in three-dimensional space. An empirical expression is suggested for the volume distribution function and an expression for the probability of thenth nearest neighbor of a Voronoi cell nucleus forming a cell face. Comparison is made with the work of Meijering [Philips Res. Rep.8:270 (1953)], Finney [Proc. R. Soc. (London)A319:479, 495 (1970)], Kiang [Z. Astrophys.64:433 (1966)], and others. Radial distributions, coordination number, and packing density are discussed for the spheres.
Value of Holter monitoring in assessing cardiac arrhythmias in symptomatic patients.

Abstract Holter electrocardiographic monitoring in 55 symptomatic patients with syncope, palpitations or dizziness uncovered significant arrhythmias in 30 patients (55 percent). By providing an observation period of at least 24 hours including a period of sleep, the procedure aided detection and diagnosis in both symptomatic and asymptomatic patients of transient arrhythmias or conduction abnormalities not documented by routine electrocardiograms. Bradyarrhythmias accounted for the majority of arrhythmias recorded in 21 of 30 symptomatic patients (70 percent); 15 had sinus bradycardia (35 to 55 beats/min) alone and 6 also had long episodes of sinus arrest of up to 5 seconds. Two had sinus bradycardia with periods of atrioventricular block with Wenckebach phenomenon. Five patients had a tachycardia-bradycardia syndrome; three had other episodic arrhythmias and one had pacemaker failure. In 15 (60 percent) of the 25 patients without arrhythmias, monitoring did not document the cause of symptoms. Holter monitoring is of considerable value in assessing the efficacy and adequacy of drug treatment, especially in patients with known heart disease, and in detecting pacemaker malfunction. However, very long periods of monitoring may be needed to make a diagnosis in those with only sporadic symptoms.
Verification and Intercomparison of Multimodel Simulated Land Surface Hydrological Datasets over the United States

AbstractSeveral land surface datasets, such as the observed Illinois soil moisture dataset; three retrospective offline run datasets from the Noah land surface model (LSM), Variable Infiltration Capacity (VIC) LSM, and Climate Prediction Center leaky bucket soil model; and three reanalysis datasets (North American Regional Reanalysis, NCEP/Department of Energy Global Reanalysis, and 40-yr ECMWF Re-Analysis), are used to study the spatial and temporal variability of soil moisture and its response to the major components of land surface hydrologic cycles: precipitation, evaporation, and runoff. Detailed analysis was performed on the evolution of the soil moisture vertical profile. Over Illinois, model simulations are compared to observations, but for the United States as a whole some impressions can be gained by comparing the multiple soil moisture–precipitation–evaporation–runoff datasets to one another. The magnitudes and partitioning of major land surface water balance components on seasonal–interannual ...
Non-SH2/PDZ reverse signaling by ephrins

Great strides have been made regarding our understanding of the processes and signaling events influenced by Eph/ephrin signaling that play a role in cell adhesion and cell movement. However, the precise mechanisms by which these signaling events regulate cell and tissue architecture still need further resolution. The Eph/ephrin signaling pathways and the ability to regulate cell-cell adhesion and motility constitutes an impressive system for regulating tissue separation and morphogenesis [1, 2]. Moreover, the de-regulation of this signaling system is linked to the promotion of aggressive and metastatic tumors in humans [2]. In the following section, we discuss some of the interesting mechanisms by which ephrins can signal through their own intracellular domains (reverse signaling) either independent of forward signaling or in addition to forward signaling through a cognate receptor. In this review we discuss how ephrins (Eph ligands) “reverse signal” through their intracellular domains to affect cell adhesion and movement, but the focus is on modes of action that are independent of SH2 and PDZ interactions.
Distinct activation states of α5β1 integrin show differential binding to RGD and synergy domains of fibronectin

α5β1 integrin can occupy several distinct conformational states which support different strengths of binding to fibronectin [Garcia, A. J., et al. (1998) J. Biol. Chem. 273, 34710−34715]. Using a model system in which specific activating monoclonal antibodies were used to achieve uniform activated states, the binding of α5β1 to full-length wild-type fibronectin and mutants of fibronectin in the defined RGD and PHSRN synergy sites was analyzed using a novel method that measures the strength of the coupling between integrin and its ligand. Neither TS2/16- nor AG89-activated α5β1 showed significant mechanical coupling to RGD-deleted fibronectin. However, peptide competition assays demonstrated a 6-fold difference in the binding affinities of these two states for RGD. The mutant synergy site reduced the AG89 (low)-activated state to background levels, but the TS2/16-activated state still retained approximately 30% of the wild-type activity. Thus, these two active binding states of α5β1 interact differently wi...
Tissue engineering in cleft palate and other congenital malformations.

Contributions from multidisciplinary investigations have focused attention on the potential of tissue engineering to yield novel therapeutics. Congenital malformations, including cleft palate, craniosynostosis, and craniofacial skeletal hypoplasias represent excellent targets for the implementation of tissue engineering applications secondary to the technically challenging nature and inherent inadequacies of current reconstructive interventions. Apropos to the search for answers to these clinical conundrums, studies have focused on elucidating the molecular signals driving the biologic activity of the aforementioned maladies. These investigations have highlighted multiple signaling pathways, including Wnt, fibroblast growth factor, transforming growth factor-β, and bone morphogenetic proteins, that have been found to play critical roles in guided tissue development. Furthermore, a comprehensive knowledge of these pathways will be of utmost importance to the optimization of future cell-based tissue engineering strategies. The scope of this review encompasses a discussion of the molecular biology involved in the development of cleft palate and craniosynostosis. In addition, we include a discussion of craniofacial distraction osteogenesis and how its applied forces influence cell signaling to guide endogenous bone regeneration. Finally, this review discusses the future role of cell-based tissue engineering in the treatment of congenital malformations.
Endothelial cell regulation of nitric oxide production during hypoxia in coronary microvessels and epicardial arteries.

Nitric oxide (NO) synthesized by endothelial cell nitric oxide synthase (eNOS) elicits vasodilation of resistance-sized coronary microvessels. Since coronary blood flow increases during hypoxia, we tested the hypotheses that: (1) hypoxia results in increased blood flow through increased NO production mediated by the upregulation of both eNOS mRNA and protein and (2) the regulation of NO production in response to hypoxia differs in microvascular endothelial cells and nonresistance, epicardial endothelial cells. Monocultures of vascular endothelium from resistance (∼100 μ) and nonresistance epicardial arteries were established and characterized. Nitric oxide was quantitated using a chemiluminescence method. Hypoxia (pO2 = 10 mmHg) significantly increased NO production in both cell lines, with less NO produced in microvascular endothelium. Western blots demonstrated that hypoxia caused a time-dependent increase in eNOS protein in both lines, with an average 2.5-fold increase in nonresistance, epicardial endothelial cells compared to an average 1.7-fold increase in protein from microvascular endothelium. Total mRNA recovery increased 2.4 ± 0.6-fold within 30 min of hypoxia in nonresistance, epicardial endothelial cells with no increase in microvascular endothelial cells. Although hypoxia increased NO production in both populations of endothelial cells, the increase in NO production and eNOS protein in microvascular endothelium was less compared to nonresistance, epicardial endothelial cells. Furthermore, there was no significant upregulation of total mRNA for eNOS in microvascular endothelium. The data indicate that increased NO production in microvascular endothelium during hypoxia may be through translational or posttranslational modifications of the enzyme, whereas transcriptional upregulation may account for the increased NO production in nonresistance, epicardial endothelial cells. Oxygen-sensitive response mechanisms that modulate NO production may be different in endothelium from different coronary artery vascular beds. J. Cell. Physiol. 182:359–365, 2000. © 2000 Wiley-Liss, Inc.
EBV Latent Membrane Protein 1 Activates Akt, NFκB, and Stat3 in B Cell Lymphomas

Latent membrane protein 1 (LMP1) is the major oncoprotein of Epstein-Barr virus (EBV). In transgenic mice, LMP1 promotes increased lymphoma development by 12 mo of age. This study reveals that lymphoma develops in B-1a lymphocytes, a population that is associated with transformation in older mice. The lymphoma cells have deregulated cell cycle markers, and inhibitors of Akt, NFκB, and Stat3 block the enhanced viability of LMP1 transgenic lymphocytes and lymphoma cells in vitro. Lymphoma cells are independent of IL4/Stat6 signaling for survival and proliferation, but have constitutively activated Stat3 signaling. These same targets are also deregulated in wild-type B-1a lymphomas that arise spontaneously through age predisposition. These results suggest that Akt, NFκB, and Stat3 pathways may serve as effective targets in the treatment of EBV-associated B cell lymphomas.
Tissue engineering: construction of a multicellular 3D scaffold for the delivery of layered cell sheets.

Many tissues, such as the adult human hearts, are unable to adequately regenerate after damage.2,3 Strategies in tissue engineering propose innovations to assist the body in recovery and repair. For example, TE approaches may be able to attenuate heart remodeling after myocardial infarction (MI) and possibly increase total heart function to a near normal pre-MI level.4 As with any functional tissue, successful regeneration of cardiac tissue involves the proper delivery of multiple cell types with environmental cues favoring integration and survival of the implanted cell/tissue graft. Engineered tissues should address multiple parameters including: soluble signals, cell-to-cell interactions, and matrix materials evaluated as delivery vehicles, their effects on cell survival, material strength, and facilitation of cell-to-tissue organization. Studies employing the direct injection of graft cells only ignore these essential elements.2,5,6 A tissue design combining these ingredients has yet to be developed. Here, we present an example of integrated designs using layering of patterned cell sheets with two distinct types of biological-derived materials containing the target organ cell type and endothelial cells for enhancing new vessels formation in the “tissue”. Although these studies focus on the generation of heart-like tissue, this tissue design can be applied to many organs other than heart with minimal design and material changes, and is meant to be an off-the-shelf product for regenerative therapies. The protocol contains five detailed steps. A temperature sensitive Poly(N-isopropylacrylamide) (pNIPAAM) is used to coat tissue culture dishes. Then, tissue specific cells are cultured on the surface of the coated plates/micropattern surfaces to form cell sheets with strong lateral adhesions. Thirdly, a base matrix is created for the tissue by combining porous matrix with neovascular permissive hydrogels and endothelial cells. Finally, the cell sheets are lifted from the pNIPAAM coated dishes and transferred to the base element, making the complete construct.
Rates of dissolution of constituent organic contaminants from coal liquefaction oil films into water

Abstract To facilitate development of a model for dissolution of toxic contaminants from synthetic coal liquids in the event of an accidental riverine spill, dissolution rates from oil films overlying water in a stirred laboratory extractor were measured by solvent partitioning and gas chromatography. Major water-soluble contaminants identified in five coal liquids were phenol, aniline and their C1–C3 alkylated derivatives. First-order rate constants for approach to equilibrium were related to the oil-water partition coefficient in an inverse nonlinear relationship; data agreed well with a two-film model developed and verified previously. Overall mass transfer coefficients varied nearly 103 from phenol to naphthalene in one oil. Oil-phase mass transfer coefficients were inversely related to oil viscosity. Results indicate that under riverine turbulence conditions in which spilled oil is not dispersed by mixing into the water column, phenols and anilines in coal liquids will dissolve far more rapidly than one- and two-ring aromatic hydrocarbons.
Theoretical study of the two tautomers of 2-(diphenylacetyl)-1,3-indandione 1-(p-dimethylamino)benzaldazine)

Abstract Two tautomers, the keto and enol forms, of 2-(diphenylacetyl)-1,3-indandione 1-( p -(dimethylamino) benzaldazine) (DIPAIN) are studied. Earlier chemometric studies of fluorescence enhancement DIPAIN has shown that the enhancement is associated with the ability of a compound that has a minimum length of 7.2 A and lipophilic groups to form a molecular complex with DIPAIN. This paper examines molecular structure of DIPAIN and possible cavities within the molecule itself. Both forms of DIPAIN are optimized at the Hartree-Fock level using a 3–21G basis set. Cavity sizes of the two forms are examined. The aminobenzaldehyde ring moiety is shown to be co-planar with the C-N-N central π system in both forms, and a cavity of approximately 7.2 A is found adjacent to the central C-N-N π system.