cssi/SciSciGPT-SciSciNet huggingface dataset:
The Stone gamut: a coordinatization of mathematics

We give a uniform representation of the objects of mathematical practice as Chu spaces, forming a concrete self dual bicomplete closed category and hence a constructive model of linear logic. This representation distributes mathematics over a two dimensional space called the Stone gamut. The Stone gamut is coordinatized horizontally by coherence, ranging from -1 for sets to 1 for complete atomic Boolean algebras (CABA's), and vertically by complexity of language. Complexity 0 contains only sets, CABA's, and the inconsistent empty set. Complexity 1 admits noninteracting set CABA pairs. The entire Stone duality menagerie of partial distributive lattices enters at complexity 2. Groups, rings, fields, graphs, and categories are all entered by level 16, and every category of relational structures and their homomorphisms eventually appears. The key is the identification of continuous functions and homomorphisms, which puts Stone Pontrjagin duality on a uniform basis by merging algebra and topology into a simple common framework.
An Information-Based Approach to Change-Point Analysis with Applications to Biophysics and Cell Biology

This article describes the application of a change-point algorithm to the analysis of stochastic signals in biological systems whose underlying state dynamics consist of transitions between discrete states. Applications of this analysis include molecular-motor stepping, fluorophore bleaching, electrophysiology, particle and cell tracking, detection of copy number variation by sequencing, tethered-particle motion, etc. We present a unified approach to the analysis of processes whose noise can be modeled by Gaussian, Wiener, or Ornstein-Uhlenbeck processes. To fit the model, we exploit explicit, closed-form algebraic expressions for maximum-likelihood estimators of model parameters and estimated information loss of the generalized noise model, which can be computed extremely efficiently. We implement change-point detection using the frequentist information criterion (which, to our knowledge, is a new information criterion). The frequentist information criterion specifies a single, information-based statistical test that is free from ad hoc parameters and requires no prior probability distribution. We demonstrate this information-based approach in the analysis of simulated and experimental tethered-particle-motion data.
Metabolism of Entamoeba histolytica Schaudinn, 1903

Publisher Summary This chapter focuses on the metabolism of typical Entamoeba histolytica originally isolated from human infections. It presents evidence that E. histolytica, grown axenically, have a complete but circumscribed, metabolic capability; and that when living in contact with other cells, they have a faculty for expanding their metabolic competence. The chapter addresses the possible modes of transfer of activities from associated cells to the amoeba and evidence that pathogenicity is thereby influenced. It also considers growth factors and nutrients, metabolic regulation, and speculative views on the ways the metabolism of amoebae may shed light on primitive metabolic pathways. The chapter illustrates allosteric modulation or some system for the regulation of amoebic glycolytic enzymes. However, the results of probing for regulatory features have been disappointing. They have yielded only thermodynamic explanations of enzyme regulation—that the rate of a reversible reaction slows as equilibrium is approached. An understanding of the pathogenicity of the organism is likely to come from the investigation of the interactions among amoebae, the host, and the associate organisms of the gut.
Interval Computations as an Important Part of Granular Computing: An Introduction

This chapter provides a general introduction to interval computations, especially to interval computations as an important part of granular computing. This introduction is aimed at researchers who would like to learn more – and eventually to use – the main ideas and techniques of granular computing. We explain how intervals naturally appear in data processing, which techniques exist for processing intervals, and how these techniques have been historically developed.
Isolation, characterization, and biological activity of retinyl phosphate from hamster intestinal epithelium

Epithelial cells from hamster small intestine, in short term culture, incorporated [carbinol-14C]retinol into a compound that is identical to synthetic retinyl phosphate, as judged by chromatography on DEAE-cellulose, silicic acid, and thin layers of silica gel. The biological compound displays the same absorption spectrum as does synthetic retinyl phosphate with a maximum at 325 nm. Hydrolysis with mild alkali yields anhydroretinol, as it does for synthetic retinyl phosphate, with absorption maxima at 388, 368, and 346 nm. Enzymic hydrolysis by alkaline phosphatase releases 9% of the radioactivity as [14C]retinol. Under the same conditions, 9% of synthetic retinyl phosphate is hydrolyzed to retinol. The biological compound was tested for biological activity. At a concentration of 5.5 × 10-8 M it was as active as retinol and retinyl phosphate in reversing keratinization induced in hamster tracheal epithelium by vitamin A deficiency. It is concluded that hamster intestinal cells synthesize retinyl phosphate.
Framing an Emerging Issue: How U.S. Print and Broadcast News Media Covered Sex Trafficking, 2008–2012

Sex trafficking has increasingly become a topic on the public and political agenda. This study revealed that coverage of sex trafficking in U.S. print and broadcast media from 2008–2012 was largely episodic, focused on crime and policy frames, privileged official sources, and neglected survivors’ voices. However, findings suggest a shift toward thematic framing as the issue became more widely understood by the public and policymakers.
New precursors for the CVD of zirconium and hafnium oxide films

Alternatives to tetrakis(dialkylamido)zirconium and hafnium for use as precursors to zirconium and hafnium oxide films are examined. Tetrakis(trimethylhydrazido)zirconium and hafnium, Zr(NMeNMe 2 ) 4 and Hf(NMeNMe 2 ) 4 , and Hf[ t BUNCH 2 CH 2 N- t Bu] 2 are used with oxygen as precursors to zirconium and hafnium oxide films in a low-pressure CVD process at substrate temperatures <400 °C. The as-deposited films are amorphous, featureless, and transparent on glass. X-ray photoelectron spectroscopy (XPS) data shows that the films deposited using the hydrazido complexes and oxygen as precursors are carbon- and nitrogen-free, while the films obtained from Hf[ t BUNCH 2 CH 2 N- t Bu] 2 and oxygen have a composition HfO 1.6 C 0.06 N 0.2 . A thin (<1500 A) zirconium oxide film remains amorphous after annealing for 2 h at 950°C. The X-ray crystal structure of Hf[ t BuNCH 2 CH 2 N- t Bu] 2 , which was synthesized along with its Zr congener from MCl 4 and Li 2 [ t BuNCH 2 CH 2 N + t Bu], reveals that it has an elongated tetrahedral geometry in the solid state.
Inverse bremsstrahlung acceleration in an electrostatic wave

1407_70It is shown that the acceleration by net inverse bremsstrahlung of a laser light is a classical phenomenon in which high-energy electrons, whose momenta and energies are modulated by the laser light, obey strictly the momentum and energy conservation laws and the time-reversal invariance of the transition probability. Net inverse bremsstrahlung acceleration of high-energy electrons traveling in a strong laser light and an electrostatic wave propagating in an oblique direction with respect to the laser light is investigated by using the relativistic quantum-kinetics based on the Dirac equation. The quantum kinetics treats the classical phenomenon exhibited by high-energy electrons through the correspondence principle. The dc force in the laser light direction by the net inverse bremsstrahlung is independent of the spread of the electron beam energy, and increases with the electron beam energy. Also, the dc force increases with the laser intensity if the potential amplitude of the laser wave is smaller than the electron rest energy.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A Linkage Study of Panic Disorder

We tested for linkage between panic disorder and a battery of 29 genetic markers in 26 families. Linkage between panic disorder and 18 of the marker loci could be excluded at a recombination fraction of 0.00, nine at a recombination fraction of 0.05, and four at a recombination fraction of 0.10. The 18 loci are distributed over ten chromosomes. One locus was suggestive of linkage. The maximum lod score for alpha-haptoglobin was 2.27 at a recombination fraction of 0.0, representing odds in favor of linkage of 186.1. alpha-Haptoglobin has been mapped to chromosome 16q22. The results demonstrate that linkage studies of psychiatric disorders can yield informative results by identifying tentative linkages that merit further investigation and by excluding regions of the genome from future linkage searches.
Are US informed consent requirements driving resuscitation research overseas

Following a 2-year federally imposed moratorium on acute resuscitation research due to concern regarding the inability of patients in cardiac arrest to provide prospective, informed consent to participate in such research, the United States federal government in 1996 released regulations with provisions for exemption of prospective informed consent in certain types of emergency research. While very few acute resuscitation research studies have been attempted in the United States since that time, such research has continued overseas. We discuss one large multi-center, out-of-hospital trial of a device intended to improve the hemodynamics of cardiopulmonary resuscitation. After pilot implementation overseas, this trial could not be conducted in the United States, largely due to the difficulties and costs involved in implementing the requirements of the 1996 regulations. A recent European Union directive on the conduct of clinical trials may halt European research on patients who are unable to provide prospective, informed consent. The directive contains no provisions for exceptions or waiver of informed consent, and may hinder acute resuscitation research in Europe to an even greater degree than the 1996 regulations have in the United States.
Paleomagnetism of Late Pleistocene-Holocene Sediments, Gulf of Mexico: ABSTRACT

Detailed paleomagnetic studies have been made on 15 sediment cores selected along north-south lines in the eastern and western Gulf of Mexico. The piston cores were sampled at 20-cm intervals immediately upon extrusion and measurements of natural remanent magnetization (NRM) were made using a 5hZ spinner magnetometer. Excursions of the geomagnetic field are recorded at 2 levels in many cores. Extrapolation of the ZY boundary in the western Gulf indicates that the younger feature is between 13.5 and 17.5 × 103 years BP, and is consistent with the age determination of the Laschamp event. Dates are not available for the eastern Gulf cores, but the depth of the paleomagnetic feature correlates with the expected sedimentation rates. The older feature is less di tinct and further extrapolation of the ZY boundary places it between 20.0 and 24.0 × 103 years BP. This age is within the range of a geomagnetic feature that is not the Laschamp. These results show that with extreme care, paleomagnetic measurements may be used as a stratigraphic tool in the Gulf of Mexico. Several points should be considered. First, because of the high sedimentation rates, the 2 young features described herein are the only ones expected in piston cores from this region. Second, direction scatter is quite pronounced in the upper 1/2 m and lower few centimeters of several cores. Correlations at these levels are difficult. Finally, as measurement of the geomagnetic features described lasted for only a short time and did not traverse a full 180°, dense sampling is recommended to assure their definition. End_of_Article - Last_Page 1897------------
Claromatic Carbon Nanostructures

Eric Clar’s qualitative ideas for benzenoids are described in application to various novel nanostructures: graphene, edges in graphene, carbon nanotubes, carbon nanocones, and carbon nanotori. The specially singled out most highly aromatic species with Clar structures consisting entirely of aromatic sextets are proposed to be termed “claromatic”. Several such claromatic nanostructures are identified as manifesting special properties. A molecular structural “(h,k)” characterization for benzo/grapheneic nanostructures is shown to link up neatly with Clar’s ideas.
tRNA Traffic Meets a Cell-Cycle Checkpoint

The molecular pathways linking DNA-damage checkpoint proteins to cell-cycle progression remain largely unresolved. Findings by Ghavidel et al. (2007) reported in this issue suggest that tRNA trafficking and the transcription factor Gcn4 are key intermediates in the process by which yeast cells detect DNA damage and delay cell-cycle progression at the G1 to S phase transition.
The Rationality of Rural Lite: Economic and Cultural Change In Tuscany

The Rationality of Rural Lite: Economic and Cultural Change In Tuscany. JEFF PRATT. Chur, Switzerland: Harwood Academic Publishers, 1994. x + 219 pp., illustrations, appendix, notes, bibliography, index.
The Use of Peer Optic Nerve Photographs for Teaching Direct Ophthalmoscopy

NOTICE: This is the author’s version of a work that was accepted for publication in Ophthalmology: Journal of The American Academy of Ophthalmology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in PUBLICATION, Vol 120, Issue 4, (2013) DOI: 10.1016/j.ophtha.2012.09.020
The role of the tail in channel passage by the sand skink, Neoseps reynoldsi

Thirteen sand skinks, Neoseps reynoldsi, were observed and videotaped traversing variously spaced plexiglass channels and spacings of pins to investigate locomotory patterns of a slender elongate lizard, with reduced limbs. Five individuals were recorded both before and after tail autotomy. Neoseps moves its limbs in locomotion on a flat surface; the hindlimbs participate in propulsion and their position, relative to their body, reflects the curvature of the trunk. Distance between pins, width of the plexiglass channel, and surface texture influence locomotory patterns. Individuals move more rapidly in wide channels, and movement is most irregular in channels with sandpaper floors. Whether on a plexiglass or a sandpaper floor, individuals travel more rapidly down the 2cm wide channel than the 1 cm channel. Fewer bends in the trunk in the wider channels may allow for more rapid movement. Autotomy of the tail slows movement on a plexiglass or sandpaper floor. The anterior portion of the tail contributes to the establishment of a static friction site that is jerked toward the head during locomotion, advancing the center of gravity in that direction. From the new site the trunk can be straightened by pushing against the friction site. The posterior portion of a tailless individual slides backward as the trunk is straightened, slowing their forward movement. The backward slide may reflect the lower mass and reduced static friction of the partial tail. In channels, Neoseps uses limbed concertina rather than simple concertina to generate a propulsive force. Evolutionarily, it appears that elongation of the tail and trunk did not incorporate the capacity for lateral undulation; as the curves of the trunk and tail seem preprogrammed and do not adjust to local points of contact.
Tidal freshwater wetland zonation: seed and seedling dynamics

Abstract Zonation patterns of seed rain (input), persistent seed bank (seeds persisting for 1 year or longer), field seedlings, and seed production were studied in a New Jersey tidal freshwater wetland along transects extending from a tidal stream bank 30 m into the high marsh. Species diversity was highest along the stream channel and lowest at the farthest high marsh sites. Seed rain and persistent seed bank densities were similar across the transect. Although species composition varied considerably among life history categories, generally field seedlings mirrored the species composition of the seed rain. Seed rain, seed bank, seedlings observed in the field, and seed production patterns varied between species, across sites for a species, and between years. Sites varied in the proportion of estimated seed production represented as seedlings either in greenhouse (5–99%) or field (2–24%) samples. Tidal transport influenced dispersal of seeds and the persistent seed bank.
FARMERS' PERCEPTIONS, PRACTICES AND PERFORMANCE IN A SAHELIAN IRRIGATED RICE SCHEME

Combined socio-economic and agronomic surveys were conducted during two growing seasons with 20 rice (Orgyza sativa) farmers in the irrigation scheme of Guede, northern Senegal. Farmers' knowledge of recommended cropping practices was relatively poor. The surveys identified sub-optimal timing of N fertilizer application and late harvesting as major constraints. Before the start of the second season, farmers were given field-specific recommendations on timing of key crop-management interventions. Average yield compared with the first season increased by more than 1 t ha -1 , which was attributed to a slightly higher recovery efficiency of fertilizer N (REN) (average: 0.47 kg crop N kg -1 fertilizer N), a change in cultivars used (resulting in a better uptake of indigenous soil N) and more favourable weather conditions in general. It is concluded that if farmers are given better access to information, improved rice technologies, inputs and decision making, rice production on irrigated land in West Africa may leap forward rapidly, as potential production gains are still large.
The case of the 2006 War in Lebanon: reparations? Reconstruction? Or both?

The Lebanese government took an interesting path to recovery after the July 2006 War. It embarked on a mission to both compensate the victims of the war – a challenge to the traditional reparation model – and to rebuild the country. This article examines the Lebanese case by presenting the path the national government took in the aftermath of the war, analysing Lebanon's decision to create a unique scheme – the adoption method – in its road to recovery, investigating the advantages and disadvantages of their approach, and last but not least providing some lessons learned on how individual reparations can be provided for victims of international humanitarian law in cases where there is no agreement in place.
Firearms and the mentally ill: A legislative overview and jurisprudential analysis

This article examines federal and state laws that prohibit the mentally ill from possessing firearms and assesses the jurisprudence that has developed as courts have applied the federal law. It argues that although there is little or no empirical data linking the mentally ill with firearms violence, legislative activity and popular political debate invariably include such restrictions on the mentally ill. Notwithstanding the proliferation of firearms and antecedent violence, this article suggests that legislators and policy-makers must separate this issue from the broader and more emotional issue of "gun control" in order to effectuate better public policy and simultaneously protect the constitutional rights of the mentally ill. Language: en
Characterization of biomolecular nanoconjugates by high-throughput delivery and spectroscopic difference.

Aim: Nanoparticle conjugates have the potential for delivering siRNA, splice-shifting oligomers or nucleic acid vaccines, and can be applicable to anticancer therapeutics. This article compares tripartite conjugates with gold nanoparticles or synthetic methoxypoly(ethylene glycol)-block-polyamidoamine dendrimers. Materials & methods: Interactions with model liposomes of a 1:1 molar ratio of tripalmitin:cholesterol or phospholipid:cholesterol were investigated by high-throughput absorbance, as well as fluorescence difference and cellular luminescence assays. Results: Spectral differences and dynamic light-scattering spectroscopy shifts demonstrated the interaction of conjugates with liposomes. Biological activity was demonstrated by upregulation of gene expression via splice-shifting oligomers, delivery of anti-B-Raf siRNA in cultured human cancer cells or tuberculosis antigen 85B plasmid expression vector in a coculture model of antigen presentation. Conclusion: The data suggests that gold nanoparticles a...
Drawing Inferences From Policy Experiments Issues of External Validity and Conflict of Interest

The article argues that the sctentific credibility and policymaking utility of policy evaluation research is threatened by inappropriate inference strategies. These inference strategies are a consequence of a system of incentives and a methodology that encourage vague, ambiguous, or nonspecification of primary inferences and extended or unwar ranted tangential inferences. The result is policy research designed more to promote the enterprise of policy research than to assist in the useful application of research in policymaking settings. These points are illustrated through an analysis of the inference strategy pursued in the Police Foundation's Kansas City Preventive Patrol Experiment. One solution to the problem of inappropriate inferencing is for policy researchers to adopt the practice ofspecifying an illustrative range of potential primary inferences at the initial stages of analysis.
Nonglaucomatous excavation of the optic disc.

• In order to test the hypothesis that glaucomatous and nonglaucomatous optic disc cupping can be distinguished ophthalmoscopically, three ophthalmologists experienced in assessing optic dics were asked to view fundus stereophotographs as "unknowns." Of 29 eyes with nonglaucomatous optic atrophy, 13 (44%) were misdiagnosed as showing glaucoma by at least one observer. Of four optic disc features specifically analyzed, neuroretinal rim pallor proved to be 94% specific for nonglaucomatous atrophy, while focal or diffuse obliteration of the neuroretinal rim was 87% specific for glaucoma. These two signs are the most useful in making the distinction. Thinning of the rim was more common in glaucoma than in nonglaucomatous atrophy, but was only 47% specific for glaucoma. Laminar dots were present in both types of excavation.
A Pattern Recognition Based Method for IC Failure Analysis

Random fluctuations which are inherent in the IC manufacturing process cause production yields to be significantly less than 100 percent. Yield drop is caused by two types of faults, catastrophic and parametric. This paper deals with the diagnosis of parametric faults which occur during the manufacturing of IC's and cause the yield to drop below some acceptable level. A statistical pattern recognition approach to IC failure analysis is developed in this paper. Identification of faults is based on the analysis of the joint probability density function of circuit performances. A number of alternative approaches to IC failure analysis are developed and their efficiency is discussed. Also a complete statistical pattern recognition system with learning capability is proposed and all the stages of its development are discussed. An efficient method for fault simulation which is based upon statistical process simulation is proposed. The performance of the algorithms proposed in this paper has been successfully verified for data collected from commercial fabrication processes and from computer simulation.
Criticality safety assessment for a conceptual high-level-waste repository in water-saturated geologic media

An assessment for the criticality safety of a conceptual repository for vitrified high-level radioactive waste from reprocessed fuel of commercial light water reactors in a water-saturated granitic rock has been performed by quantitatively estimating the mass of fissile {sup 235}U existing in the entire far field as the performance measure. The uncertainties associated with the performance measure have been obtained by a statistical analysis with the Latin hypercube sampling method. With the assumed probability distribution functions for the model parameters, the mass of {sup 235}U released from the repository and existing in the far field at 100 million years is estimated to be < 40 kg with a 90% confidence level. This implies that all {sup 235}U existing in the entire far field at that time must accumulate in a single location for an overmoderated criticality event to occur in granitic rock.
Predictors of Resistance to Persuasion: Propensity of Persuasive Attack, Pretreatment Language Intensity, and Expected Delay of Attack

Summary This investigation extended earlier research investigating predictors of resistance to persuasion. Ss were 113 male and female college students enrolled in undergraduate social science courses. The first hypothesis predicted a curvilinear relationship between propensity of attack (i.e., likelihood of having present attitudes attacked) and expected time delay of the attack in conferring resistance to persuasion. As predicted, in the condition of 50% probability of subsequent attack and no expected delay, maximum resistance to persuasion obtained; moreover, as hypothesized, resistance to persuasion decreased as expected delay increased. The predicted main effect for the superiority of moderately intense language in pretreatment messages did not receive support.
An idealized concept of the true cladistic character

Abstract Estimating evolutionary relationships is basic to the objectives of systematics. Comparative data, structured as taxonomic characters, are usually the essential considerations on which such estimates are founded. Some taxonomic characters are more useful than others for structuring plausible estimates of evolutionary relationship. Thus, one of the primary challenges to the systematist is the construction of taxonomic characters most useful for this purpose. Since taxonomic characters are the result of action on the part of the systematist, they must be defined operationally. It is our hope, however, that these operationally defined characters will conform to an ideal that, itself, cannot be operationally defined insofar as the concept depends on history that is, usually, inherently unknowable. It is, nonetheless, essential to our conceptual methods that this ideal concept be well defined. Here we present a series of definitions leading to a clear ideal concept of true cladistic character . This series includes definitions of the concepts: evolutionary unit, qualitative taxonomic character, monophyletic group, divergent character, true cladistic character, operational cladistic character, and the post-factum ideal relation between an operational cladistic character and an estimate of cladistic history. A concise characterization of true cladistic character is presented and proved.
Role of Group Affiliation and Gender on Attitudes Toward Women in the Military

The current study examined attitudes of West Point cadets (N = 218), Reserve Officer Training Corps (ROTC) cadets (N = 509), and non-military-affiliated students from civilian colleges (N = 598) to...
The social biology of human populations: Spontaneous group formation conforms to evolutionary predictions of adaptive aggregation patterns

Abstract Two experiments tested whether city commuter and pedestrian groups conformed with ecological predictions of adaptive group size, age, and sex composition. It was predicted that individuals with the greatest reproductive potential would optimize mating contacts and minimize competitive interference by segregating into small, mixed-sex groups, whereas more vulnerable individuals, too young or old for optimum fertility, would tend to aggregate independently of gender in larger groups, which may offer advantages for foraging and predator avoidance. To maximize reproductive potential, mature males should prefer grouping with young women of high fertility, whereas older women should prefer younger men. In Experiment 1, 2,432 persons in three cities were observed on buses, automobiles, and sidewalks, in yoked observations. As predicted, reproductively immature preschool and grade-school children formed larger groups than mature adults ( p p p p p p p p p
Single pulse shock tube studies of pulverized coal ignition

The ignition behavior of sized samples of pulverized coal has been studied using a modified single pulse shock tube. Ignition delays and particle temperature history were recorded optically while batch samples of evolved gases were sampled prior to and after ignition and analyzed by gas chromatography. Significant pre-ignition pyrolysis in the form of low molecular weight hydrocarbons was detected in all samples tested. Although the ignition delay of two similarly sized samples (Illinois no. 6 and Pittsburgh Seam) were substantially different, the volatile compositions were similar with the Pittsburgh having a somewhat higher yield at all conditions studied. Activation energies, determined from surface oxidation rate data, were used to successfully model the temperature dependence of the ignition delay of both smaller coals (number mean diameter 3.3 μ m for Pittsburgh and 4.1 μ m for Illinois no. 6). This heterogeneous theory failed for the larger Pittsburgh coal (14.9 μ m mean number diameter) as it consistently overpredicted the ignition delay. Inasmuch as the oxidation of pre-ignition hydrocarbons prior to ignition of the solid phase was observed only for the large Pittsburgh coal, the discrepency can be explained plausibly on the basis of the gas phase volatiles participating in the ignition of the larger particles.
Nobel Lecture: From the Big Bang to the Nobel Prize and beyond

NASA's Cosmic Background Explorer satellite mission, the COBE, laid the foundations for modern cosmology by measuring the spectrum and anisotropy of the cosmic microwave background radiation and discovering the cosmic infrared background radiation. I describe the history of the COBE project, its scientific context, the people who built it, and the scientific results. The COBE observed the universe on the largest scales possible by mapping the cosmic microwave and infrared background radiation fields and determining their spectra. It produced conclusive evidence that the hot Big Bang theory of the early universe is correct, showed that the early universe was very uniform but not perfectly so, and that the total luminosity of post--Big Bang objects is twice as great as previously believed. The COBE concept was developed by a Mission Definition Study Team appointed by NASA in 1976, based on three competing proposals submitted in 1974. The COBE was built in-house by Goddard Space Flight Center, with a helium cryostat provided by Ball Aerospace, and was launched on a Delta rocket built by McDonnell Douglas. It is in a circular orbit $900\phantom{\rule{0.3em}{0ex}}\mathrm{km}$ above the Earth, in a plane inclined 99\ifmmode^\circ\else\textdegree\fi{} to the equator and roughly perpendicular to the line to the Sun. It carried three instruments, a far infrared absolute spectrophotometer (FIRAS), a differential microwave radiometer with three channels (DMR), and a diffuse infrared background experiment (DIRBE). The helium cryostat cooled the FIRAS and DIRBE for $10\phantom{\rule{0.3em}{0ex}}\text{months}$ until the helium was exhausted, but operations continued for a total of $4\phantom{\rule{0.3em}{0ex}}\text{years}$. Subsequent observations have confirmed the COBE results and led to measurements of the main cosmological parameters with a precision of a few percent.
Effect of quantum dot size and size distribution on the intersublevel transitions and absorption coefficients of III-V semiconductor quantum dot

The intersublevel absorption peak energy and absorption coefficient of non-uniform quantum dot (QD) ensembles are calculated analytically. The effect of size variations and size distribution of QDs on their energy states is analyzed. The dots are considered as a quantum box with finite potential at the barriers and the size distribution described by a Gaussian function. The influence of the aspect ratio (base to height ratio) of the QDs on the optical transitions is studied. Our model predicts the dot size (height and base) accurately to determine the absorption peaks and corresponding absorption coefficient. We also compute the absorption coefficient of the QD with different size distributions to verify the results calculated using this model with the reported experimental and other theoretical results.
Effects of regional ischaemia, with or without reperfusion, on endothelium dependent coronary relaxation in the dog.

Objective: The aim was to establish whether the duration of coronary ischaemia and coronary ischaemia with reperfusion selectively reduced the magnitude of relaxation mediated by endothelium dependent relaxing factor (EDRF) in response to thrombin, compared with relaxation produced by acetylcholine and calcimycin. Methods: Adult male dogs, anaesthetised with sodium pentobarbitone (30 mg·kg−1 intravenously) were used. Coronary artery occlusions were maintained for either 15 or 45 min; in half the dogs from each timepoint, occlusion was followed by 60 min reperfusion. At the end of each in situ period, coronary arteries were removed from both ischaemic and non-ischaemic regions, cut into rings, and hung in isolated organ baths. Dose-response relationships to the EDRF dependent vasodilators thrombin, acetylcholine, and calcimycin, and to the EDRF independent vasodilator isoprenaline, were then established. Results: Thrombin (0.003-0.3 units.ml−1) caused dose dependent relaxation in all tissues. Relaxant responses (Emax) in the non-ischaemic vessels from both 15 and 45 min treatment groups were used as control data for the responses in ischaemic vessels. Maximum responses were not different in the non-ischaemic groups from either 15 or 45 min studies, at 82.7(SEM 3.7)% after 15 min, and 82.1(2.4)% after 45 min. There was a small but significant reduction in Emax after 15 min and 45 min ischaemia, to 74.4(3.2)% and 74.4(3.0)% respectively. Sixty minutes reperfusion provoked a further reduction in Emax to 64.9(3.8)% after 45 min ischaemia, but not after 15 min ischaemia [70.3(4.2)%]. Neither 15 nor 45 min interventions altered Emax of relaxation to acetylcholine or calcimycin (>88.0% in each group). Similarly there were no significant differences between groups to the relaxation stimulated by isoprenaline (Emax >90.0%). Conclusions: The data suggest that loss of EDRF dependent relaxation to thrombin is more sensitive to ischaemia than the relaxation produced by either acetylcholine or calcimycin, and appears to be manifested early in the onset of ischaemic injury.
Intrachain contact dynamics in unfolded cytochrome cb562.

We have investigated intrachain contact dynamics in unfolded cytochrome cb_(562) by monitoring heme quenching of excited ruthenium photosensitizers covalently bound to residues along the polypeptide. Intrachain diffusion for chemically denatured proteins proceeds on the microsecond time scale with an upper limit of 0.1 μs. The rate constants exhibit a power-law dependence on the number of peptide bonds between the heme and Ru complex. The power-law exponent of −1.5 is consistent with theoretical models for freely jointed Gaussian chains, but its magnitude is smaller than that reported for several synthetic polypeptides. Contact formation within a stable loop was examined in a His63-heme ligated form of the protein under denaturing conditions. Loop formation accelerated contact kinetics for the Ru66 labeling site, owing to reduction in the length of the peptide separating redox sites. For other labeling sites within the stable loop, quenching rates were modestly reduced compared to the open chain polymer.
Sensitivity of blacknose dace (Rhinichthys atratulus) to moderate acidification events in Shenandoah National Park, U.S.A.

Shenandoah National Park (SNP) receives more acid deposition than any other national park in the United States of America. As part of an effort to assess the impact of acidification upon fish in the park, in situ sub-lethal stress bioassays (measured by monitoring hematocrit) were conducted with acid sensitive blacknose dace Rhinichthys atratulus. Study streams experienced moderate acidification events that resulted in reduced pH (the largest reductionbeing 6.18 to 5.37) and increased total monomeric aluminum (TMA) concentration (the largest being 15 to 39 μg L-1). Although some of these acidification events were within the pH and TMA range expected to result in blacknose dace stress, none was detected by monitoring hematocrit. In an acid-sensitive stream, mean baseflow (pre-event) hematocrit ± SD, was 33.5±4.5%, and hematocrit during the largest event was 31.5±4.9%, A moderate acidification event also occurred in a less acid sensitive stream; pH dropped from 7.18 to 6.38 but TMA remained below 10 μg L-1. Mean hematocrit during baseflowin this stream was 32.3±2.8%, and hematocrit during event flow was 34.1±5.0%. At the time of this bioassay, acidificationevents that would result in acute toxicity for most species of fish did not occur, however the conditions documented in this investigation do not represent the most acute acidification events that have been observed in SNP. It should be noted that a chronic sub-lethal stress, measured by condition indices, has been observed among blacknose dace in SNP streams.
A monte carlo model for the simulation of temperature-programmed desorption spectra

Abstract A Monte Carlo model has been developed for describing the temperature-programmed desorption of adsorbates from single crystal surfaces. This model takes into account the effects of surface diffusion and the influence of metal-adsorbate (M-A) and adsorbate-adsorbate (A-A) interactions on the coverage dependence of the activation energy for desorption. The inclusion of M-A and A-A interactions has a pronounced effect on the shape of the predicted TPD spectrum. Where only a single peak is observed in the absence of M-A and A-A interactions, multiple peaks are found when these interactions are included. The inclusion of M-A and A-A interactions is also shown to produce a nonlinear decline in the activation energy for desorption as a function of increasing adsorbate coverage. Simulated TPD spectra for CO desorption from a Pd(100) surface and for H 2 desorption from Mo(100) and Ni(111) surfaces, obtained using the Monte Carlo model, are in satisfactory agreement with those observed experimentally. An important feature of the model is that it describes correctly the observed dependence of the activation energy on adsorbate coverage.
Force variations in the distal radius and ulna: effect of ulnar variance and forearm motion.

Purpose To better define normal wrist joint forces during wrist motion and forearm motion at specific wrist and forearm positions and to see if there is a relationship between these forces and the amount of ulnar variance. A secondary purpose was to determine the relationship between the thickness of the articular disk of the triangular fibrocartilage complex and the amount of force transmitted through the distal ulna. Methods Multi-axis load cells were attached to the distal radius and ulna of 9 fresh cadaver forearms. The axial radial and ulnar compressive forces were recorded while each wrist was moved through wrist and forearm motions using a modified wrist joint simulator. During each motion, the tendon forces required to cause each motion were recorded. The ulnar variance and triangular fibrocartilage complex articular disc thickness were measured. Results The axial force through the distal ulna and the wrist extensor forces were greatest with the forearm in pronation. No relationship was found between the amount of force through the distal ulna and the amount of ulnar variance. A strong inverse relationship was found between the triangular fibrocartilage complex thickness and the ulnar variance. Conclusions Wrists with positive ulnar variance have generally been thought to transmit greater loads across the distal ulna, which has been felt to predispose these wrists to the development of ulnar impaction. The results of this study appear to show that all wrists have similar loading across the distal ulna regardless of ulnar variance. By comparison, pronation relatively increases loading across the distal ulna. Clinical relevance Because these results suggest that within reasonable ranges of ulnar variance loading across the distal ulna is independent of ulnar variance, the clinically observed incidence of ulnar impaction is more likely the result of increased wear on a thinner and less durable triangular fibrocartilage complex than due to increased distal ulna loading in ulnar positive variant wrists.
Modulation of human T-cell suppressor activity by beta endorphin and glycyl-L-glutamine.

Abstract β-endorphin (10 −7 M) induced suppressor cell activity in human peripheral blood lymphocyte cultures comparable to that of concanavalin A (Con A) (60 μg/ml). β-endorphin and Con A, when used together during the induction portion of the suppressor assays, displayed synergistic activity. In contrast, glycyl- L -glutamine, the carboxy terminal dipeptide of β-endorphin, inhibited development of Con A induced suppressor activity. It appears that the previously reported suppressive effects of β-endorphin on immune function may be achieved by activation of specific suppressor T cell populations.
Evidence for peak structure in e++ Th interactions

Abstract Thorium and tantalum targets were bombarded with positrons from a radioactive source having an endpoint energy of 1.9 MeV. Electron and positron kinetic energy were measured in coincidence using mini-orange magnetic spectrometers. Evidence for peak structure at 340 keV was found in the spectra from the thorium target, and is discussed in the context of peaks observed near this energy in collisions of high- Z nuclei.
Clinical use of first-trimester aneuploidy screening in a United States population can replicate data from clinical trials

Objective The clinical application of first-trimester aneuploidy screening remains controversial in the United States. The aim of our study was to evaluate the performance of maternal age, fetal nuchal translucency measurements, pregnancy-associated plasma protein A, and free beta-human chorionic gonadotrophin used in aneuploidy screening in a single institution outside of a clinical trial. Study design Four thousand eight hundred eighty three patients underwent first-trimester aneuploidy screening at 11 to 13 6/7 weeks of gestation (fetal crown-rump length 45 mm to 84 mm) at our institution between January 2003 and September 2004. Measurement of nuchal translucency was performed according to the Fetal Medicine Foundation standards and was included in the overall risk assessment performed by NTD Laboratories. Measurement of pregnancy-associated plasma protein A and free beta-human chorionic gonadotrophin on maternal dried whole blood samples was conducted by NTD Laboratories and was reported as gestational-specific multiples of the median adjusted for ethnicity. Risk adjustment for trisomy 21 and trisomy 18 was done with a standard algorithm using maternal age, serum biochemistry, and nuchal translucency. Only singleton gestations (N = 4615) were included in the analysis. Results The median maternal age was 33.0 years (interquartile range 31.0 to 36.0) and the median crown-rump length was 61.2 mm (interquartile range 55.7 to 67.2) at the time of screening. There were a total of 22 fetuses diagnosed with trisomy 21 and 8 with trisomy 18. The detection rates for trisomy 21 for a 5% false-positive rate and 1% false-positive rate were 90.9% (20 of 22) and 77.3% (17 of 22), respectively. Similarly, the detection rates for trisomy 18 at a 5% false-positive rate and a 1% false-positive rate were 100% (8 of 8) and 100% (8 of 8), respectively. Conclusion Non-investigational use of first-trimester aneuploidy screening for trisomy 21 and trisomy 18 can replicate results from investigational trials.
Predicting Final Eye Position Halfway Through a Saccade

When the visual environment is to be changed during a saccadic eye movement, it is useful to predict the final eye position before the eye comes to rest. We have built a microcomputer-based instrument to make such predictions. Two techniques were used: one based on the saccadic peak-velocity versus magnitude relationship, and the second based on peak-velocity occurring in the middle of the saccade. The second technique has been tailored to take advantage of the differences between temporal and nasal saccades. Depending on saccade duration, final eye position was predicted 4 to 60 ms before the end of the saccade.
Low band gap dithieno[3,2-b:2′,3′-d]silole-containing polymers, synthesis, characterization and photovoltaic application

A series of low band gap silole-containing polymers were synthesized with different alkyl side chains and a power conversion efficiency (PCE) of 3.43% was obtained.
Amylin-induced downregulation of hippocampal neurogenesis is attenuated by leptin in a STAT3/AMPK/ERK-dependent manner in mice.

Aims/hypothesis Both leptin and insulin sensitivity have been linked with pathophysiological processes involving the central nervous system in general, and the hippocampus in particular, but the role of leptin in hippocampal neurogenesis has not yet been elucidated. Also, no previous studies have evaluated whether amylin or the endogenous insulin sensitiser adiponectin interact with leptin to alter hippocampal neurogenesis in mouse hippocampal neuronal (HN) cells or investigated the role of leptin, amylin or adiponectin signalling in mouse HN cells.
Supporting active learning and example based instruction with classroom technology

This paper describes an application of classroom technology in support of teaching through the use of examples and active learning techniques. Here we report on using Classroom Presenter, a Tablet PC based classroom interaction syst, in a senior level course in Algorithms -- a domain for which the instructor believes working on sample probls is critical to student learning in the classroom. The role of the technology was to integrate activities into the lecture so that students have the opportunity to work with concrete examples in class, while the instructor can collect and review student work in real time, incorporating selected student answers into the discussion. In this paper, we describe the pedagogical goals of the instructor, the types of activities used to achieve those goals, and the role that technology played in supporting those goals and activities. The contributions of the paper are in showing how classroom technology can be used to support pedagogical choices, as well as in phasizing the value of having clear pedagogical goals when incorporating a new technology in the classroom. We believe the application of technology as illustrated in this work could bring similar benefits to the instruction in other disciplines.