cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of ionizing radiation on a natural plant community

Abstract An “island community” of spring and summer annuals transplanted from a granite outcrop to the gamma radiation field on the Emory University campus received ionizing radiation along a gradient ranging from 8,000 to 130,000 r at rates of 5–82 r/hr from March to August 1959. Ecological analyses of experimental and control communities over the subsequent three year period revealed both immediate and long-range effects of ionizing radiation upon individual species and community attributes. Results indicate that ionizing radiation has both stimulatory and inhibitory effects upon plant growth and that the ecological and morphological effects are reflected by species interactions at the community level. Certain post-irradiation changes in the spring flora are interpreted as resulting from a “stimulating” effect of radiation doses of 8,000–30,000 r upon Arenaria brevifolia Nutt. Following irradiation of the parental generation at these levels, the first filial generation of Arenaria was observed to increase in density, distribution, and growth at the expense of a competitive species, Diamorpha cymosa (Nutt.) Britton. These “stimulatory” effects, apparent only in the first generation, made it possible for this species to continue as the dominant species in the succeeding two generations studied. Other changes in the spring flora resulted from lethal and inhibitory effects of radiation upon plant growth. Changes in the summer flora are interpreted as resulting from the selective elimination of radiation-sensitive species and the subsequent positive selection pressure toward radiation-resistant species. Results of autecological studies indicate that the physiological tolerances of all species usually varied inversely with the level of radiation received. However, under certain conditions, plants which received radiation levels of 8,500–25,000 r exhibited environmental tolerances which surpassed those of non-irradiated controls. Whenever physiological stimulatory effects were observed they coincided with similar ecological and morphological stimulatory effects observed in the same species at radiation levels comparable to those used during community analysis. Under all experimental conditions species tolerances varied independently of dose rate. Results of autecological analyses of the post-irradiation tolerances of spring and summer annuals to a variety of environmental stresses correlate with and confirm results obtained from the community analysis. Under all environmental conditions studied, species which became dominant following the irradiation period consistently exhibited greater physiological tolerances to radiation than did the normally dominant species which they replaced.
A Phase I Trial: Dose Escalation of Melphalan in the “BEAM” Regimen Using Amifostine Cytoprotection

With the eventual goal of reducing relapse and thus improving overall survival in selected lymphoma patients, a Phase I study was performed using the cytoprotectant amifostine to permit safe dose-augmentation of melphalan in the carmustine (BCNU), etoposide, cytarabine (arabinosylcytosine), and melphalan (BEAM) regimen before autologous hematopoietic stem cell transplantation. Between 30 July 2003 and 25 November 2008, a total of 32 lymphoma patients were entered, of which 28 were evaluable. We found the melphalan dose in BEAM could be safely escalated to at least 260 mg/m2, a substantial increase from the usual dose of 140 mg/m2 in BEAM while the trial was terminated early due to poor accrual, no maximal tolerated dose or dose-limiting toxicity was found. A Phase II trial is planned.
Microsomal prostaglandin E synthase type 2 (mPGES2) is a glutathione-dependent heme protein, and dithiothreitol dissociates the bound heme to produce active prostaglandin E2 synthase in vitro.

An x-ray study indicated that microsomal prostaglandin E synthase type 2 (mPGES2) is a heme-bound protein and catalyzes prostaglandin (PG) H2 degradation, but not PGE2 formation (Yamada, T., and Takusagawa, F. (2007) Biochemistry 46, 8414–8424). In response to the x-ray study, Watanabe et al. claimed that mPGES2 is a heme-free protein and that both the heme-free and heme-bound proteins have PGE2 synthesis activity in the presence of dithiothreitol (Watanabe, K., Ito, S., and Yamamoto, S. (2008) Biochem. Biophys. Res. Commun. 367, 782–786). To resolve the contradictory results, the heme-binding scheme of mPGES2 was further characterized in vivo and in vitro by absorption and fluorescence spectroscopies. A substantial amount of heme-bound mPGES2 was detected in cell extracts. The heme content in mPGES2 was increased along with an increase in Fe3+ in the culture medium. Heme-free mPGES2 was converted to the heme-bound form by mixing it with pig liver extract, indicating that mPGES2 is capable of forming a complex with heme in mammalian cells. Heme binds to mPGES2 only in the presence of glutathione. The newly determined heme dissociation constant (2.9 nm) supports strongly that mPGES2 is a heme-bound protein in vivo. The bound heme was not dissociated by oxidation by H2O2 or reduction by glutathione or 2-mercaptoethanol. However, reduction by dithiothreitol (an artificial reducing compound) induced the bound heme to dissociate from mPGES2 and released heme-free mPGES2, which exhibited PGE2 synthesis activity in vitro. Imidazole bound to mPGES2 by stacking on the bound heme and inhibited heme oxidation by H2O2 and reduction by dithiothreitol.
Simplification in the computation of the sensitivity functions for constant coefficient linear systems

It is often necessary to compute the sensitivity functions for system parameters and initial conditions in a dynamic system. In this paper, it is shown that for constant coefficient linear systems all possible sensitivity functions can be obtained by linear transformations on the solutions to (p + 2) n th-order differential equations, where p is the number of independent inputs to the system, and n is the minimal order realization for the system. The transformations required to obtain the output sensitivities for a single-output multi-input system, which is modeled in a companion form, reduce to the identity.
Temporary anion states of the chlorobenzenes

Abstract Electron transmission spectroscopy is utilized to determine the energies of the temporary anions of chlorobenzene and the di- and tri-chlorobenzenes. The ET spectra, the results of a simple model accounting for the resonance and inductive effects of the chlorines, and ab initio calculations all indicate that the splitting between the two anion states derived from the 2 E 2u ground-state anion of benzene is small in the chlorobenzenes. At higher energies the spectra display electron capture resonances.
Comparing WISC and WISC-R Scores

The Wechsler Intelligence Scale for Children (Wechsler, 1947) was revised (Wechsler, 1974) to eliminate items which were biased, irrelevant, obsolete, or ambiguous, and to develop current normative tables. Because of its greater applicability to a wider range of children ages G through 16 yr. from different socio-economic or ethnic backgrounds, the Wechsler Intelligence Scale for Children-Revised (WISC-R) is being used widely in both public and private institutions. There are many children in the public schools' special education classes, state educational systems, and private schools who have been evaluated with the WISC who will need re-evaluation. There arises the question as to whether the two scales are equivalent. The present study was designed to examine the comparability of the two scales. METHOD Subjects Forty Caucasian students from five schools in urban North Central Texas were assigned (two males and two females) in each of 10 age levels from 6 to 15 yr. (obtained mean age of 10.91) which represent the levels of overlap between the WISC and WISC-R. Sample selection was not random in that all subjects were among lists of children to be evaluated, i.e., standard entrance evaluation in a private school and special education re-evaluation in the public schools. Selection was designed to obtain the required age distribution.
Evidence that Chlamydia pneumoniae, Strain TWAR, Is Not Sexually Transmitted

Serum specimens from 230 sexually active women were tested for antibodies to Chlamydia trachomatis and Chlamydia pneumoniae. The women were randomly selected as controls in a population-based case-control study for ectopic pregnancy. A total of 123 had antibody to C. pneumoniae and 39 had antibody to C. trachomatis. There was an association between prevalence of antibody to C. trachomatis and an increasing number of lifetime sexual partners, early age at first intercourse, and a history of gonorrheal infection. The prevalence of antibody to C. pneumoniae was not related to any of these factors. These results provide evidence that the two human species of Chlamydia have a different mode of transmission and that C. pneumoniae is not sexually transmitted.
The increasing workload in head and neck surgery: An epidemiologic analysis.

Objectives/Hypothesis: Determine if there might be an increase in the workload for head and neck surgery based on an aging population. Study Design: Cross-sectional analysis of a national database. Methods: The frequency of head and neck surgical procedures (HNSPs) performed in 2006 in the inpatient and outpatient settings in the United States were assessed using the National Hospital Discharge Summary and the National Survey of Ambulatory Surgery, respectively. From US Census Bureau statistics, age-specific HNSP rates were determined and projected to the 2020 population based on census bureau predicted changes in population demographics. The surgical workload burden was assessed in 2006 and projected to 2020 based on the predicted changes in procedure rates and resource-based relative value scale. Results: An estimated 366,050 HNSPs (142,397 inpatient vs. 223,653 outpatient) were performed in 2006 requiring a total of 2.49 million physician work relative value units (RVUs). With the expected changes in population demographics in 2020, an estimated 422,183 HNSPs will be performed (163,781 inpatient vs. 258,402 outpatient) requiring 2.88 million work RVUs in head and neck surgery. Both the HNSP rate and projected RVUs increase approximate 15.3%. Conclusions: Based on national health statistics and US census data we can anticipate a substantial increase in the workload for head and neck surgeons. Efforts should be directed at assessing manpower requirements in head and neck surgery based on the impact of an aging US population. Laryngoscope, 2011
IAMC architecture and prototyping: a progress report

Internet Accessible Mathematical Computation (IAMC) is a distributed framework to supply mathematical computing powers over the Internet. Presented are conceptual and experimental work on the IAMC architecture, a client prototype (Dragonfly), client GUI, a server prototype (Starfish), the Mathematical Computation Protocol (MCP), mathematical data encoding, and the external compute engine interface.
Fast, spatially resolved thermometry of Si and GaP crystals using pump-probe two-photon absorption

Noncontact thermometry with micron-scale lateral spatial resolution and fast time resolution is shown to be enabled by measuring the temperature dependence of two-photon absorption (TPA) on crystalline semiconductors. In the proof-of-concept experiments reported here, for studies of Si, an Er:fiber laser at λ=1.56 μm is split into pump and probe beams; where they overlap, the large TPA signal changes strongly with temperature because the two-photon energy lies between the indirect and direct bandgaps of Si. We show that the TPA coefficient increases by a factor of 2 when the temperature increases from 30 to 300 °C. For studies of GaP, we use instead a Ti:sapphire laser at 790 nm to achieve two-photon excitation above the direct bandgap. In GaP, contributions to the TPA from the dominant direct transition show less temperature dependence than for Si but the additional contribution of the indirect transition gives a similar magnitude as the temperature dependence of TPA on Si. In the current implementation ...
Rhenium geochemical cycling: Insights from continental margins

Abstract We measured rhenium (Re) in sediments (both pore waters and solid phase) from three locations on the Mid-Atlantic Bight (MAB) from the eastern margin of the United States: a northern location on the continental shelf off Massachusetts (OC426, 75 m water depth), and two southern locations off North Carolina (EN433-1, 647 m water depth and EN433-2, 2648 m water depth). These sediments underlie high oxygen bottom waters (250–270 μM), but become reducing below the sediment–water interface due to the relatively high organic carbon oxidation rates in sediments. Greater ‘reduction intensity’ is reflected by shallower oxygen penetration, greater ammonium concentrations at depth, and shallower first appearances of Mn and Fe in pore waters. This comparison suggests that for the three sites along the MAB the ‘reduction intensity’ from greatest to least is: EN433-1 > OC426 > EN433-2. All of the pore water profiles show removal of Re from pore waters. Modeled pore water Re fluxes follow the trend in reducing conditions (EN433-1: 2.0 ± 0.2 pmol/cm 2 /y, OC426: 0.9 ± 0.1 pmol/cm 2 /y, and EN433-2: 0.60 ± 0.03 pmol/cm 2 /y, respectively). Solid phase profiles show authigenic Re enrichment in sediments from all three locations, and the calculated Re accumulation rates also mirror the trend in reducing conditions, with the values decreasing from EN433-1 > OC426 > EN433-2 (1.5 ± 0.2 pmol/cm 2 /y; 0.29 ± 0.09 pmol/cm 2 /y; 0.19 ± 0.09 pmol/cm 2 /y, respectively). Controls on Re accumulation are determined from the MAB data and from the literature, and include: 1) the extent of reducing conditions, with greater removal of Re from pore waters with greater anoxic organic carbon oxidation as determined by the net dissolved ammonium production, consistent with the expected removal of pore water Re coincident with Fe(III) and sulfate reduction; 2) irrigation, which results in net removal of Re to sediments, augments the diffusive flux of Re across the sediment–water interface, and is more important in shallow, coastal sediments rather than locations from deeper water depths (MAB sites); and 3) seasonal remobilization of Re from surface sediments due to deepening oxygen penetration depth (from 0.2 cm to 1 cm), although smaller seasonal changes in oxygen penetration depth (e.g., 0.2 cm to 0.6 cm) are less conducive for remobilizing Re from sediments. There is an empirical relationship with larger Re accumulation rates present when the oxygen penetration depth is shallow. However, there is a stronger correlation between organic carbon oxidation and Re accumulation rates. This latter relationship is more appropriate, since the oxidation of labile organic matter in sediments dictates the sedimentary reducing conditions that are then conducive for Re accumulation in the solid phase.
Assessing Executive Dysfunction in Girls With Fragile X or Turner Syndrome Using the Contingency Naming Test (CNT)

The aim of this study was to examine executive function (EF) skills in girls with fragile X or Turner syndrome, using the Contingency Naming Test (CNT). The CNT is a Stroop-like task involving a 1- or 2-attribute contingency rule. We predicted that girls with fragile X would make errors reflecting poor cognitive flexibility and working memory limitations. We predicted that girls with Turner syndrome would have sufficient cognitive flexibility to perform the CNT accurately, but would have difficulty with verbal inhibition and would thus make more self-corrections than girls in a comparison group. The hypotheses were partially supported: relative to their Full Scale IQ-matched comparison group, girls with fragile X or Turner syndrome were slower on the warm-up naming task; girls with fragile X made more errors on the 1-attribute task, and girls with Turner syndrome were less efficient on both the 1- and 2-attribute tasks, without making more self-corrections. These results support previous findings of execu...
Synthesis and Structure of Perfluorocongressane

Perfluorocongressane was synthesized using elemental fluorine and characterized by mass spectra, 19F NMR, and X-ray crystallography.
Depth gradients in food-web processes linking habitats in large lakes: Lake Superior as an exemplar ecosystem

SUMMARY 1. In large lakes around the world, depth-based changes in the abundance and distribution of invertebrate and fish species suggest that there may be concomitant changes in patterns of resource allocation. Using Lake Superior of the Laurentian Great Lakes as an example, we explored this idea through stable isotope analyses of 13 major fish taxa. 2. Patterns in carbon and nitrogen isotope ratios revealed use of both littoral and profundal benthos among populations of most taxa analysed regardless of the depth of their habitat, providing evidence of nearshore–offshore trophic linkages in the largest freshwater lake by area in the world. 3. Isotope-mixing model results indicated that the overall importance of benthic food-web pathways to fish was highest in nearshore species, whereas the importance of planktonic pathways increased in offshore species. These characteristics, shared with the Great Lakes of Africa, Russia and Japan, appear to be governed by two key processes: high benthic production in nearshore waters and the prevalence of diel vertical migration (DVM) among offshore invertebrate and fish taxa. DVM facilitates use of pelagic food resources by deep-water biota and represents an important process of trophic linkage among habitats in large lakes. 4. Support of whole-lake food webs through trophic linkages among pelagic, profundal and littoral habitats appears to be integral to the functioning of large lakes. These linkages can be disrupted though ecosystem disturbance such as eutrophication or the effects of invasive species and should be considered in native species restoration efforts.
Nurturing Distributed Leadership Environments in Schools: Creative Strategies for Increasing Community Engagement and Energizing School Turnaround Efforts

This article highlights multiple ways in which kindergarten through twelfth grade (K-12) school leaders can work collaboratively with education stakeholders in elementary and secondary school settings to develop distributed leadership environments in their school communities to address the persistent and often seemingly intractable teaching and learning improvement dilemma challenges that plague many schools today. Insights gleaned from a brief examination of the distributed leadership attributes of one communal cultural tradition are utilized as the basis for generating some creative strategies for nurturing distributed leadership environments in school settings. These strategies may be useful to elementary and secondary school leaders working in a variety of educational environments who are interested in broadening their collaborative teaming and instructional support networks and energizing their school turnaround and improvement efforts.
Ultraviolet Photodetection Based on ZnO Colloidal Nanoparticles Made by Top-Down Wet-Chemistry Synthesis Process

ZnO bulk material (bandgap 3.26 eV) was reduced in size via a top-down wet-chemistry synthesis process into colloidal nanoparticles that were then coated with polyvinyl-alcohol (PVA). When the nanoparticles were excited at 340 nm, strong UV emission at 377 nm was observed, and parasitic green emission (510 nm) which normally appears in ZnO nano-material was suppressed. Quantum confinement effects of the nanoparticles were observed by a 5 nm blue shift from ZnO bulk material (380 nm) in the absorption spectrum. The same characteristics held true when the particles were deposited onto substrates to form a photoconductive detector. Point contact current-voltage characteristics of the detector were measured under darkness and 340 nm UV LED. The ratio of the UV photogenerated current to dark current was as high as 105. Spectral response of the detector demonstrates a sharp cut-off wavelength at 375 nm, with a UV responsivity equivalent to twice that of a commercial UV enhanced Si-based photodetector. The time response indicated the rise and fall time were 22s and 11s respectively. The results confirm that top-down wet-chemistry synthesized ZnO nanoparticles are suitable for small signal visible blind UV detection.
Wakefields in photonic crystal cavities

Simulations of charged particle beams in accelerator cavities show that a two-dimensional photonic crystal can be used to create a three-dimensional hybrid cavity with a single operating mode and no significant higher order modes, greatly reducing long-range wakefields. Optimizing the photonic crystal cavity to reduce radiation leakage in the desired mode (of a finite-sized structure) yields even lower wakefields. Wakefields in photonic crystal cavities are compared to those in metal pillbox cavities.
Multiple Molecules of Integration Host Factor (IHF) at a Single DNA Binding Site, the Bacteriophage Lambda Cos I1 Site

Integration host factor (IHF) is an E coli protein that binds DNA sequence-specifically and serves as a cofactor in many intracellular processes including lambda DNA packaging. In gel shift experiments, cos DNA, a DNA fragment containing the recognition signal for lambda DNA packaging, forms multiple protein-DNA complexes when combined with pure IHF. Copper(II)-1,10 orthophenanthroline footprinting of individual IHF-cos DNA complexes shows that multiple complex formation does not result from IHF binding to successive sites on the cos DNA fragment. Instead, the footprinting of DNA from two IHF-cos complexes shows protection at one site alone. DNA in the first complex is only partially protected from nucleolytic cleavage, while DNA in the second, slower-moving, complex is completely protected at the same binding site. Quantitative Western blotting experiments determined the relative stoichiometry of IHF to DNA in the two complexes. The results confirm that two molecules of IHF bind at a single site in the cos fragment. This site, cos I1, has two matches to the IHF consensus sequence, but the two matches overlap by eight of thirteen nucleotides. A search of the DNA sequence around cos, using an expanded IHF consensus sequence, has revealed additional, low-affinity consensus matches, contiguous to these. The extent of the copper(II)-1,10 orthophenanthroline footprint and the stoichiometry of the IHF-cos I1 complexes suggest that either two molecules of IHF bind to overlapping sites, or IHF binds to a site of low affinity contiguous to a strong site. Application of a thermodynamic model to the results of gel shift experiments with IHF and cos DNA suggests that multiple complex formation requires cooperative interaction between the two IHF binding sites.
On the depreciation of automobiles: An international comparison

Since older automobiles are less efficient and technologically obsolete, over-aged capital stocks are associated with higher environmental burden. Given the rapid growth of over-aged car stocks in many poor countries, the knowledge of depreciation data, depreciation patterns, and their determinants in developing countries becomes increasingly important for effective environmental policies. This paper refers to used automobile prices and generates depreciation data for a sample of 54 car models from 30 countries. We found the following results:(1) Overall, geometric depreciation appears to be a good approximation to real depreciation rates. (2) Depreciation rates are significantly lower in developing countries than in industrialized countries. (3) When using corrected prices the depreciation rates increase substantially. The average depreciation in OECD countries is 31%, whereas in non-OECD countries it is about 15%. Besides prices for new cars, the economic life of automobiles is particularly dependent on real income. In the long-run, an income increase by $1000 is likely to increase the annual depreciation rate by 2.7% in OECD countries and 3.6% in non-OECD countries.
Synthesis of N-oxides with a hepatic microsomal drug oxidase insolubilized on artificial matrices

Summary Insolubilization of a hepatic microsomal mixed function flavoprotein oxidase by covalent attachment to nylon tubing, sepharose particles, or glass beads increases the thermal stability of the purified oxidase at least one-hundred fold. This oxidase catalyzes the NADPH- and oxygen-dependent oxidation of several hundred foreign compounds and of clinically useful drugs containing amine or hydrazine functional groups. Covalent attachment of the oxidase to an insoluble support does not qualitatively change its substrate specificity but some quantitative changes are observed. Reactors containing the insolubilized enzyme can be used for the production of N-oxidized drug metabolites that are difficult to prepare by direct chemical synthesis.
An Assessment of the Faculty Engagement Program with a Leading Industry Tradeshow, IMEX America: Identification of Faculty Outcomes

University faculty plays a vital role in the preparation of the next generation entering the workforce; however, this cannot be accomplished without the support of industry professionals. The purpose of this study was to assess the Faculty Engagement program at the International Meetings Exposition America (IMEX America) and identify the educational benefits. The benefits included: curriculum strategies, research ideas, new contacts, teaching materials, and technology to implement in the curriculum.
Concentration, oxidation state, and particulate flux of uranium in the Black Sea

Abstract In contrast to its unreactive behavior in the open ocean, uranium is removed from seawater to sediments of anoxic marine basins. Four biogeochemical processes have been proposed to account for this removal: active uptake by organisms whose remains are preserved by the anoxic conditions of the sediments; complexation of U(VI) by particulate organic matter; chemical reduction of soluble U(VI) to insoluble U(IV) which is scavenged to the sediments by settling particles; and precipitation of uranium within the sediments themselves. The Black Sea is the largest anoxic marine basin in the world today. Waters below 150–200 m are anoxic and H2S levels build up to about 400 μmol 1−1 in the bottom water (maximum depth ~2200 m). Concentrations of total U and the oxidation state of dissolved U were measured throughout the water column while particulate U fluxes were determined from time series sediment trap samples collected in the deep anoxic zone. Bottom waters were depleted in U by ~40% relative to the initial U content of the water. Two independent methods gave residence times of dissolved U in the deep-water column of about 103 years. Uranium occurred throughout the water column as soluble, chemically labile (reducible) U(VI) rather than the thermodynamically favored U(IV). Uranium is neither reduced to U(IV) by the high levels of H2S nor is it rapidly scavenged from the water column as would be expected for strongly hydrolyzed tetravalent actinides like U(IV). Fluxes of particulate authigenic U measured with sediment traps are at least two orders of magnitude less than the rate of authigenic U burial in Black Sea sediments. Therefore, the first three processes listed above contribute negligibly to the deposition of U in the sediments of anoxic marine basins such as the Black Sea. The dominant removal process must involve precipitation of U in the sediments rather than scavenging from the water column.
Power flow analysis of unbalanced multiphase radial distribution systems

Abstract An alternative algorithm for power flow solution in radial distribution systems is presented. The algorithm uses a quartic equation of bus voltage magnitudes at the ends of a distribution section in a forward bus trace sequence, and the total power flows are summed up in a reverse component trace. A versatile implementation of the algorithm for the analysis of multiphase unbalanced distribution systems is described. Results of example problems solved using the algorithm are presented. A comparison of some of the special features of the algorithm with other methods reported in the literature is included.
High pressure reflux technique for growth of Hg1-xCdxTe crystals

A high pressure reflux technique has been used to grow Hg1−xCdxTe alloy crystals under controlled Hg pressures up to 80 atm. Refluxing is obtained by combining a high pressure of inert gas and a negative temperature gradient over the charge of volatile materials, making it possible to contain the charge without high-temperature seals or liquid encapsulation. The continuous evaporation and condensation process results in the separation of the inert gas and vapor species at a well-defined interface where gas and vapor have the same pressure. For Hgin1-xCdxTe crystal growth, the pressure of the inert gas at the reflux interface is adjusted to correspond to the Hg vapor pressure required to maintain stoichiometry in the charge during solidification and crystal growth. Large-diameter (up to 2.5 cm), high-quality Hgin1-xCdxTe crystals with x up to 0.60 have been grown by the technique in a high-pressure furnace. Carrier concentrations below 1015 cm-3 and electron mobilities in excess of 105 cm2/V-sec have been obtained at 77 K in annealed n-type Hg0.80Cd0.20Te. Background-limited photoconductive infrared detectors for to μm spectral region have been fabricated from this n-type material. High-performance short-wavelength (2 to 5 μm) photovoltaic detectors have been fabricated from as-grown p-type material by In ion implantation.
Computational Evidence for Self-Initiation in Spontaneous High-Temperature Polymerization of Methyl Methacrylate

This paper presents computational evidence for the occurrence of diradical mechanism of self-initiation in thermal polymerization of methyl methacrylate. Two self-initiation mechanisms of interest were explored with first-principles density functional theory calculations. Singlet and triplet potential energy surfaces were constructed. The formation of two Diels−Alder adducts, cis- and trans-dimethyl 1,2-dimethylcyclobutane-1,2-dicarboxylate and dimethyl 2-methyl-5-methylidene-hexanedioate, on the singlet surface was identified. Transition states were calculated using B3LYP/6-31G* and assessed using MP2/6-31G*. The calculated energy barriers and rate constants with different levels of theory were found to show good agreement to corresponding data obtained from laboratory experiments. The presence of a diradical intermediate on the triplet surface was identified. When MCSCF/6-31G* was used, the spin−orbit coupling constant for the singlet to triplet crossover was calculated to be 2.5 cm−1. The mechanism of ...
Th/U/Pu/Cm dating of galactic cosmic rays with the extremely heavy cosmic ray composition observer

The principal goal of ECCO, the Extremely-heavy Cosmic-ray Composition Observer, is the measurement of the age of heavy galactic cosmic-ray nuclei using the extremely rare actinides (Th, U, Pu, Cm) as clocks. ECCO is one of two cosmic-ray instruments comprising the Heavy Nuclei Explorer (HNX), which was recently selected as one of several missions for Phase A study under NASA's Small class Explorer (SMEX) program. ECCO is based on the flight heritage of Trek, an array of barium-phosphate glass tracketch detectors deployed on the Russian space station Mir from 1991–1995. Using Trek, we measured the abundances of elements with Z > 70 in the galactic cosmic rays (GCRs). Trek consisted of a 1 m2 array of stacks of individually polished thin BP-1 glass detectors. ECCO will be a much larger instrument, but will achieve both excellent resolution and low cost through use of a novel detector configuration. Here we report the results of recent accelerator tests of the ECCO detectors that verify detector performance. We also show the expected charge and energy resolution of ECCO as a function of energy.
Effect of commercial cladding on the fracture behavior of pressure vessel steel plates

Abstract The objective of this program is to determine the effect, if any, of stainless steel cladding upon the propagation of small surface cracks subjected to stress states similar to those produced by thermal shock conditions. Preliminary results from testing at temperatures 10° and 60°C below the nil-ductility-transition temperature have shown that (1) a tough surface layer (cladding and/or heat-affected zone) has arrested running flaws under conditions where unclad plates have ruptured, and (2) the residual load-bearing capacity of clad plates with large subclad flaws significantly exceeded that of an unclad plate.
Polymerization of a hydantoinylsiloxane on particles of silicon dioxide to produce a biocidal sand

The monomer 3-triethoxysilylpropyl-5,5-dimethylhydantoin has been polymerized on the surfaces of sand particles to produce an adhered film that, upon chlorination with dilute sodium hypochlorite bleach, becomes biocidal. The biocidal efficacy of this coated sand has been demonstrated in a cartridge filter experiment against the bacterial pathogens Staphylococcus aureus and Escherichia coli. Complete inactivation was observed within 1 min of contact for the former bacterium and in the interval of 1–5 min for the latter. Upon a loss of biocidal activity due to the depletion of bound chlorine, the coated sand particles can be recharged by further exposure to dilute bleach. Synthetic methods and test data are presented. Potential uses of biocidal sand include disinfection and odor control in water treatment facilities and recirculating baths. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1161–1166, 2005
Central England temperatures: long‐term variability and teleconnections

Past long-term climate variability is important for the prediction of both future climate and human impacts on climate. Teleconnections help to reveal the interactions between the components of the climate system. This research examines the central England temperature record from 1659 to 1997, both for its own variability and for its relationship to other climatic records. Results support a possible warming trend, especially in recent years. Four independent spectral analyses show several common, prominent periods of oscillation in the record, from a few years to nearly two centuries. Wavelet analysis emphasizes the non-stationary nature of this variability. Temperatures may be related to solar irradiance and sunspot numbers over long periods. They show a connection to the North Atlantic Oscillation, especially over periods of 7–8 years. However, they show no apparent relationship to the El Nino–Southern Oscillation. Copyright © 1999 Royal Meteorological Society
APP heterozygosity averts memory deficit in knockin mice expressing the Danish dementia BRI2 mutant

An autosomal dominant mutation in the BRI2/ITM2B gene causes familial Danish dementia (FDD). Analysis of FDDKI mice, a mouse model of FDD genetically congruous to the human disease since they carry one mutant and one wild-type Bri2/Itm2b allele, has shown that the Danish mutation causes loss of Bri2 protein, synaptic plasticity and memory impairments. BRI2 is a physiological interactor of Aβ-precursor protein (APP), a gene associated with Alzheimer disease, which inhibits processing of APP. Here, we show that APP/Bri2 complexes are reduced in synaptic membranes of FDDKI mice. Consequently, APP metabolites derived from processing of APP by β-, α- and γ-secretases are increased in Danish dementia mice. APP haplodeficiency prevents memory and synaptic dysfunctions, consistent with a role for APP metabolites in the pathogenesis of memory and synaptic deficits. This genetic suppression provides compelling evidence that APP and BRI2 functionally interact, and that the neurological effects of the Danish form of BRI2 only occur when sufficient levels of APP are supplied by two alleles. This evidence establishes a pathogenic sameness between familial Danish and Alzheimer's dementias.
EPR Detection of Guanine Radicals in a DNA Duplex under Biological Conditions: Selective Base Oxidation by Ru(phen)_2dppz^(3+)Using the Flash-Quench Technique

Continuous-wave X-band EPR spectroscopy has been employed in examining the guanine radical within a DNA duplex at ambient temperature using the flash-quench technique. Guanine was selectively oxidized by DNA-bound [Ru(phen)_2dppz]^(3+) (dppz = dipyridophenazine, phen = 1,10-phenanthroline) generated in situ by photolysis in the presence of [Co(NH_3)_5Cl]^(2+) as the oxidative quencher. An EPR signal centered at g_(iso) = 2.0048 is observed in experiments with poly(dG-dC) as substrate. Comparable signals are also detected with a 13-mer oligonucleotide duplex containing only one guanine base and with calf thymus DNA, but no signal is observed with poly(dA-dT) or poly(dI-dC). These observations reflect the base selectivity of the reaction in forming the guanine radical. With ruthenium hexaammine as oxidative quencher, no signal is observed, while, with methyl viologen, a strong signal with hyperfine pattern is seen, characteristic of the reduced viologen radical and indicating that [Ru(phen)_2dppz]^(3+) was generated. The guanine radical signal, once formed upon continuous irradiation in argon-saturated aqueous buffer solution (pH 7), decays with a half-life of 30 s, but vanishes instantaneously in the dark or upon introduction of oxygen. Spin trapping experiments with N-tert-butyl-α-phenylnitrone substantiate the selectivity in generating the guanine radical; in the presence of poly(dG-dC), calf thymus DNA, the 13-mer oligonucleotide but not with poly(dA-dT) and poly(dI-dC), the detected nitroxide EPR signals are the same with g_(iso) = 2.0059, 〈a_N〉 = 15.05 G, and 〈a_H〉 = 3.11 G. Upon titration of the ruthenium intercalator into poly(dG-dC), the signal intensity increases smoothly as the [base pair]/[intercalator] ratio decreases from 100 to 25, at which point the signal intensity decreases markedly; this result may be an indication of an antiferromagnetic exchange interaction between guanine radicals. Indeed, using the flash-quench technique, EPR spectroscopy of guanine radicals within DNA now will permit the evaluation of how radicals within the DNA base stack may be coupled under biological conditions.
A Collision Tumor: Primary Central Nervous System B-Cell Lymphoma and Anaplastic Astrocytoma

A collision tumor in the central nervous system (CNS) is a rare entity. We report a case of a collision tumor with primary CNS lymphoma and astrocytoma in an otherwise healthy young male and the diagnostic challenge associated with it. The tumor showed 2 histologic patterns. The predominant component consisted of anaplastic astrocytoma with gemistocytic appearance, and the lymphoma cells were kappa restricted B cells with variable cell sizes and some plasmacytoid differentiation. In situ hybridization demonstrated that the lymphoma cells were Epstein-Barr virus (EBV) positive. The patient was neurologically asymptomatic for 2 and half years following surgery, chemotherapy, and radiation.
Compiler-directed file layout optimization for hierarchical storage systems

File layout of array data is a critical factor that effects the behavior of storage caches, and has so far taken not much attention in the context of hierarchical storage systems. The main contribution of this paper is a compiler-driven file layout optimization scheme for hierarchical storage caches. This approach, fully automated within an optimizing compiler, analyzes a multi-threaded application code and determines a file layout for each disk-resident array referenced by the code, such that the performance of the target storage cache hierarchy is maximized. We tested our approach using 16 I/O intensive application programs and compared its performance against two previously proposed approaches under different cache space management schemes. Our experimental results show that the proposed approach improves the execution time of these parallel applications by 23.7% on average.
The effect of subphonetic differences on lexical access

This study investigated whether lexical access is affected by inherent acoustic variations that contribute to the identity of a phonetic feature and ultimately a phonetic segment. Two experiments were conducted to determine whether the magnitude of semantic (associative) priming in a lexical decision task is influenced when the acoustic manifestation of the initial voiceless stop consonant (specifically, voice onset time) of a prime word semantically related to a lexical decision target was systematically manipulated (e.g., prime: "king"; target: "queen"). Results showed no effect of the acoustic manipulations at the longer interstimulus interval (250 ms); however, at the shorter interstimulus interval (50 ms), the magnitude of semantic facilitation decreased as a function of the voice onset time manipulations. In addition, there was a tendency toward slower lexical decision latencies when the prime word had a real word voiced counterpart than when it did not. These results suggest that activation levels of words in the lexicon are graded, depending on the subphonetic shape of the input word. Results also suggest that words which are phonologically similar to the intended word candidate are activated to some extent, whether the input provides a relatively poor phonetic representation of the intended word or a good one.
Near infrared photoimmunotherapy for lung metastases

Lung metastases are a leading cause of cancer related deaths; nonetheless current treatments are limited. Near infrared photoimmunotherapy (NIR-PIT) is a new cancer treatment that combines the specificity of intravenously injected antibodies that target tumors with the toxicity induced by photosensitizers activated by NIR-light. Herein, we demonstrate the efficacy of NIR-PIT in a mouse model of lung metastases. Experiments were conducted with a HER2, luciferase and GFP expressing cell line (3T3/HER2-luc-GFP). An antibody-photosensitizer conjugate (APC) consisting of trastuzumab and a phthalocyanine dye, IRDye-700DX, was synthesized. In vitro NIR-PIT-induced cytotoxicity was light dose dependent. With 3D culture, repeated NIR-PIT could eradicate entire spheroids. In vivo anti-tumor effects of NIR-PIT included significant reductions in both tumor volume (p = 0.0141 vs. APC) and bioluminescence image (BLI) (p = 0.0086 vs. APC) in the flank model, and prolonged survival (p < 0.0001). BLI demonstrated a significant reduction in lung metastases volume (p = 0.0117 vs. APC). Multiple NIR-PIT doses significantly prolonged survival in the lung metastases model (p < 0.0001). These results suggested that NIR-PIT is a potential new therapy for the local control of lung metastases.
A specification-compatible Bluetooth inquiry simplification

We identify and analyze a specification-compatible method for implementing the Bluetooth inquiry function that simplifies the design while reducing the mean inquiry time. Using simulation data and independent empirical measurements, we verify a previously derived probability density function for the inquiry time of a Bluetooth device. Although the derived density matches the simulated data, it does not closely match the measured data. Assuming the manufacturer made a logical simplification to the specification, we derive the probability density function using the simplification and show it matches the empirical data. In addition to simplifying the inquiry substate implementation, the inquiry modification performs better than the specified inquiry process. We also present a simple method to mitigate a noisy channel.
Performance analysis for Bayesian microwave imaging in decision aided breast tumor diagnosis

The Markov random field is used to model the breast permittivity cross section as a propagating medium, and incorporate it into the forward electromagnetic (EM) propagation to predict the random field of the EM measurements at a received array of sensors. Given these EM field measurements, Bayesian approaches are then developed to compute the likelihood ratio for tumor detection and the a posteriori probability display of tumor localization. Quantitative performance evaluations using simulations demonstrate the advantage of using the Bayesian approach to directly process the measurement data as compared to using the Bayesian or threshold approaches to detect and localize the tumor based on the reconstructed permittivity image.
Preclinical development of cancer stem cell drugs.

Background: Despite recent progress in cancer treatment, the current cancer chemotherapy can mainly produce remission but often fails to cure cancer due to the existence of cancer stem cells. The emerging cancer stem cell hypothesis offers new insight into the failure of current cancer drugs and suggests new approaches for improved understanding of cancer biology and cancer drug development. Objective: In this review, we discuss the concept of cancer stem cells, origin of cancer stem cells and different approaches for isolating or enriching cancer stem cells. We also review the resistance of cancer stem cells to standard chemotherapy and radiation therapy and potential mechanisms for the resistance. Finally, based on the current knowledge on cancer stem cells, we discuss potential approaches for developing new drugs that target cancer stem cells and propose new methods for evaluation of cancer stem cell drugs. Conclusion: Improved cancer treatment is likely to be achieved by a combination of drugs that ki...
Efficacy and specificity of Social Cognitive Skills Training for outpatients with psychotic disorders

Psychosocial interventions that target social cognition show promise for enhancing the functional outcomes of people with psychotic disorders. This randomized controlled trial evaluated the efficacy and treatment-outcome specificity of a 24-session Social Cognitive Skills Training (SCST) that targets emotional processing, social perception, attributional bias, and mentalizing (or Theory of Mind). Sixty-eight stable outpatients with primary psychotic disorders were randomly assigned to one of four time- and group format-matched treatment conditions: (1) SCST, (2) computerized neurocognitive remediation, (3) standard illness management skills training, or (4) a Hybrid treatment that combined elements of SCST and neurocognitive remediation. The SCST group demonstrated greater improvements over time than comparison groups in the social cognitive domain of emotional processing, including improvement on measures of facial affect perception and emotion management. There were no differential benefits among treatment conditions on neurocognitive or clinical symptom changes over time. Results indicate that a targeted social cognitive intervention led to improvements in social cognition among outpatients with psychosis. Findings provide guidance for continued efforts to maximize the benefits of social cognitive interventions.