cssi/SciSciGPT-SciSciNet huggingface dataset:
Hypercholesterolemia and Experimental Vein Grafts: Accelerated Development of Intimal Hyperplasia and an Increase in Abnormal Vasomotor Function

Hypercholesterolemia is an important risk factor for the development of atherosclerosis. Late vein graft failure has been attributed to a combination of both intimal hyperplasia and atherosclerosis. This study examines the effect of hypercholesterolemia on the early morphology and vasomotor function of experimental vein grafts. Forty New Zealand White rabbits received either a 1% cholesterol diet (n = 24; HC) or a standard diet (n = 16; CON) for 4 weeks before operation and thereafter until harvest. All animals underwent a reversed vein common carotid artery bypass. The vein grafts and contralateral veins were harvested at 2 and 4 weeks after operation in both groups for either histological and morphometric analysis (n = 8 for each group) or for in vitro isometric tension studies using serotonin (5-HT), norepinephrine (NE), bradykinin (BK), and endothelin-1 (ET) and following NE precontraction, relaxation in response to acetylcholine (ACh) and sodium nitroprusside (SNP). Serum cholesterol levels were measured after 4, 6, and 8 weeks of the cholesterol diet. Serum cholesterol concentrations were 20 to 30 times higher than controls in the hypercholesterolemic animals at all times. The intimal area of the grafts in the HC group increased by twofold at 2 weeks and threefold at 4 weeks compared to corresponding controls. In contrast to the CON vein grafts, the intima of the vein grafts from HC consisted mainly of lipid-laden smooth muscle cells with scattered interspersed macrophages and occasional lipid plaques between the intima and the media. Medial areas were similar in all grafts. HC grafts became progressively more sensitive to 5-HT at 2 and 4 weeks. A supersensitivity to NE and BK developed at 4 weeks in HC grafts. There was no change in sensitivity to ET. While no graft relaxed to ACh, HC grafts contracted at low doses. All grafts responded to SNP in a dose-dependent manner. In contrast to CON veins, HC veins demonstrated an increase in sensitivity to NE and a contractile response to 5-HT (at 4 weeks only). HC veins did not relax in a dose-dependent manner in response to ACh. No changes in the morphology of HC veins were noted. HC produces changes in the structure and associated vasomotor abnormalities of vein grafts. Closely related functional changes also occur in contralateral veins. HC appears to induce intrinsic changes in smooth muscle cells which are linked to a greater proliferative and abnormal vasomotor capability. Clinically, applications of vigorous anti-HC regimens perioperatively may be beneficial in maintaining patency over the longer term.
Conceptualizing Juvenile Prostitution as Child Maltreatment: Findings from the National Juvenile Prostitution Study:

Two studies were conducted to identify the incidence (Study 1) and characteristics (Study 2) of juvenile prostitution cases known to law enforcement agencies in the United States. Study 1 revealed a national estimate of 1,450 arrests or detentions (95% confidence interval [CI]: 1,287-1,614) in cases involving juvenile prostitution during a 1-year period. In Study 2, exploratory data were collected from a subsample of 138 cases from police records in 2005. The cases are broadly categorized into three main types: (a) third-party exploiters, (b) solo prostitution, and (c) conventional child sexual abuse (CSA) with payment. Cases were classified into three initial categories based on police orientation toward the juvenile: (a) juveniles as victims (53%), (b) juveniles as delinquents (31%), and (c) juvenile as both victims and delinquents (16%). When examining the status of the juveniles by case type, the authors found that all the juveniles in CSA with payment cases were treated as victims, 66% in third-party exploiters cases, and 11% in solo cases. Findings indicate law enforcement responses to juvenile prostitution are influential in determining whether such youth are viewed as victims of commercial sexual exploitation or as delinquents.
Focusing anomalies in the vicinity of dielectric interfaces

We investigate the interface effects on high numerical aperture focusing of linearly polarized illumination. Theoretical and experimental demonstration is conducted in subsurface backside microscopy of silicon integrated circuits.
Theory of interaction intensities, buffer capacities, and pH stability in aqueous systems, with application to the pH of seawater and a heterogeneous model ocean system

Abstract The choice of convenient basic constituents for evaluating pH stability of aqueous systems is discussed, and two useful interaction parameters are defined and related to the buffer capacity: the interaction capacity, δ′ X,Y = ∂ p X ∂ TOT Y , and the interaction intensity, δ X, Y = ∂ p X ∂ pTOT Y ; for pH and TOTH, δ ′ H, H = − β H −1 , where β H is the pH buffer capacity. A method is presented for the computation of exact values of all interaction capacities and intensities through inversion of the Jacobian matrix of the system of non-linear equations describing the aqueous system. The major species of an aqueous system (H 2 O, H + , solid phases, gases, and the most abundant solute species) are shown to constitute a useful set of basic constituents for evaluation of approximate pH buffer capacities according to a simple rule: the major-minor species rule for zeroth order pH-TOTH interaction. The concepts of buffering and pH-statting are examined and contrasted; it is demonstrated that the buffer capacity of an aqueous system cannot be infinite: it is limited by the concentration of solutes in solution. The effect upon pH of variations in constituents other than H + is described in terms of first order interactions via complex formation and solid formation; approximate formulas for calculation are derived. Higher order interactions are derived from combinations of first order ones. The pH stability of the ocean system is examined in terms of an aqueous phase model including ion-association reactions and a heterogeneous model incorporating CO 2 in the gas phase, quartz, kaolinite, calcite, chlorite, and illite, in addition to the aqueous phase. There is an approximately three-fold enhancement of buffer capacity in the aqueous model as a consequence of ion-association. Only a few interaction pathways are of quantitative significance in establishing the buffer capacity. Results for the heterogeneous ocean model lend quantitative support to Sillen's notion of pH stability: the buffer capacity is about four hundred times greater than that of the aqueous phase model.
Influence of adsorbed fluids on the rolling contact deformation of MgO single crystals

Basic phenomena associated with rolling contact deformation were studied using MgO as a model bearing material. A hardened steel ball was rolled on MgO single crystals in slow-speed reciprocating motion and in high-speed circular motion. The resulting deformation was studied by dislocation etch-pit techniques. The presence of adsorbed fluids, such as silicone oil, white mineral oil, and toluene, with slow-speed sliding caused a dramatic change in slip mode and premature surface spalling compared with similar experiments in air or under water. In contrast, dimethyl formamide inhibited these slip processes. The results are consistent with the dependence of dislocation mobility on adsorbed species. High-speed hydrodynamic rolling with mineral oil lubrication produced a different slip phenomena entirely from the slow-speed rolling. The slip bands resembled those produced in tensile tests, and all slip apparently initiated at subsurface sites.
Chirped pulse amplification in Tm doped fiber using a chirped Bragg grating

Femtosecond pulses were generated and amplified via chirped pulse amplification in Tm:fiber. The mode-locked oscillator centered at 1975 nm produced 800 fs transform limited pulses with 40 pJ energy at 60 MHz repetition rate. Subsequently, a soliton self-frequency shift in a thulium-doped fiber pumped with a 793 nm diode was used to amplify pulses to 3 nJ, shift the center wavelength, and reduce the pulse duration to 150 fs. This pulse was tuned to 2020 nm to match the center wavelength of a chirped Bragg grating. The pulses were stretched to >160 ps pulses, amplified to 85 nJ in single-mode Tm:fiber and recompressed to 400 fs.
Single-event nitrous oxide losses under maize production as affected by soil type, tillage, rotation, and fertilization.

Abstract Soil nitrate (NO3) can be especially susceptible to leaching and denitrification in late spring under maize (Zea mays L.) production. This study examined the effects of tillage (untilled; tilled), fertilizer application (full season rate or starter-only at planting), rotation (maize after orchardgrass (Dactylis glomerata L.); continuous maize), and soil type (clay loam; loamy fine sand) on short-term nitrous oxide (N2O) emissions after a 50-mm late-spring simulated precipitation event. N2O emissions were measured daily for a week following the event. Soil NO3, temperature, physical properties and total N were also measured. N2O emissions peaked on the second day after a simulated rainfall event for all treatments. N2O losses were significantly higher on the clay loam compared to the loamy sand. Full season fertilizer application at planting on untilled soil resulted in 4.7 and 2.3 kg N ha−1 greater cumulative N2O losses than starter-only fertilizer application on maize-after-grass and continuous maize, respectively. Under tilled conditions, cumulative N2O losses over a week averaged 0.88 kg N ha−1 greater for the full fertilizer application compared to the starter-only application. Higher N2O losses from untilled soil were related to lower soil porosity and higher bulk density, and higher emissions under maize-after-grass were correlated with higher soil C levels. In conclusion, untilled soil and sod-based crop rotations increase late-spring N2O losses under maize production, especially with early fertilization.
Test Item Arrangement and Student Performance in Principles of Marketing Examination: A Replication Study

The use of multiple versions of objective exams which vary in test question sequences has raised concern that such a practice may unconsciously bias students' examination scores. This issue has not been explored with respect to the principles of marketing course, where the use of such a testing practice is often necessitated by crowded sections. The current experiment attempts to broaden such knowledge. It replicates previous research that explored the effect of question sequencing on exam performance of marketing students as it related to memory factors. Unlike the earlier study, question sequencing is found to have no significant effect on examination performance.
Sulfhydryl oxidase-catalyzed conversion of xanthine dehydrogenase to xanthine oxidase.

Abstract Xanthine oxidase may be isolated from various mammalian tissues as one of two interconvertible forms, viz., a dehydrogenase (NAD+ dependent, form D) or an oxidase (O2 utilizing, form O). A crude preparation of rat liver xanthine dehydrogenase (form D) was treated with an immobilized preparation of crude bovine sulfhydryl oxidase. Comparison of the rates of conversion of xanthine dehydrogenase to the O form in the presence and absence of the immobilized enzyme indicated that sulfhydryl oxidase catalyzes such conversion. These results were substantiated in a more definitive study in which purified bovine milk xanthine oxidase, which had been converted to the D form by treatment with dithiothreitol, was incubated with purified bovine milk sulfhydryl oxidase. Comparison of measured rates of conversion (in the presence and absence of active sulfhydryl oxidase and in the presence of thermally denatured sulfhydryl oxidase) revealed that sulfhydryl oxidase enzymatically catalyzes the conversion of type D activity to type O activity in xanthine oxidase with the concomitant disappearance of its sulfhydryl groups. It is possible that the presence or absence of sulfhydryl oxidase in a given tissue may be an important factor in determining the form of xanthine-oxidizing activity found in that tissue.
The use of time-lapse optical coherence tomography to image the effects of microapplied toxins on the retina.

PURPOSE We developed a novel technique for accelerated drug screening and retinotoxin characterization using time-lapse optical coherence tomography (OCT) and a drug microapplication device. METHODS Using an ex vivo rabbit eyecup preparation, we studied retinotoxin effects in real-time by microperfusing small retinal areas under a transparent fluoropolymer tube. Known retinotoxic agents were applied to the retina for 5-minute periods, while changes in retinal structure, thickness, and reflectance were monitored with OCT. The OCT images of two agents with dissimilar mechanisms, cyanide and kainic acid, were compared to their structural changes seen histologically. RESULTS We found the actions of retinotoxic agents tested could be classified broadly into two distinct types: (1) agents that induce neuronal depolarization, such as kainic acid, causing increases in OCT reflectivity or thickness of the inner plexiform and nuclear layers, and decreased reflectivity of the outer retina; and (2) agents that disrupt mitochondrial function, such as cyanide, causing outer retinal structural changes as evidenced by a reduction in the OCT reflectivity of the photoreceptor outer segment and pigment epithelium layers. CONCLUSIONS Retinotoxin-induced changes in retinal layer reflectivity and thickness under the microperfusion tube in OCT images closely matched the histological evidence of retinal injury. Time-lapse OCT imaging of the microperfused local retina has the potential to accelerate drug retinotoxicological screening and expand the use of OCT as an evaluation tool for preclinical animal testing.
Chitosan Enhances Control of Enzymatic Browning in Apple and Pear Juice by Filtration

Browning could be prevented in McIntosh apple juice by the addition of at least 200 ppm chitosan, irrespective of the chitosan product tested, followed by filtration with diatomaceous earth filter aid. Chitosan at 1000 ppm was required to prevent browning in juice from ripe Bartlett and Bosc pears. Juice from very ripe Bartlett pears did not respond to chitosan treatment. Chitosan addition interfered with the prevention of browning in apple and pear juice by centrifugation.
Handedness: an alternative hypothesis.

Handedness data collected during the Hawaii Family Study of Cognition were congruent with similar data from major published studies. Mixed-model segregation analysis did not detect a significant major gene or polygenes contributing to handedness and partitioned the total phenotypic variation into 10–20% genetic and 80–90% environmental components. No relationship between handedness and cognitive ability was detected, but significant relationships between birth stress and offspring handedness were found. There was a significant decline in the percentage of left-handed individuals grouped by advancing age. A hypothesis of handedness is proposed in which left-handedness results from a combination of genotype, birth experience, and maternal example.
Light Intensity and the Attraction of Mosquitoes to Light Traps

A method is described for evaluating the performance of light traps. The mosquito collections of light traps operated within a few feet of each other showed important differences, especially when the mosquitoes were present in large numbers. These differences were eliminated when the traps constantly changed position. There was no evidence that moving traps caught fewer mosquitoes than stationary traps. Lighted traps caught more mosquitoes than unlighted traps although the latter caught substantial numbers of Culex but not Aedes mosquitoes. The light intensity of the bulb illuminating a trap was directly related to the numbers of individuals of a species taken by that trap, except in the case of C. p. quinquefasciatus females. In fact the number of mosquitoes appeared to be directly proportional to the light intensity, with the exception noted. No repellency was noted at the highest intensities tested. Results with C. p. quinquefasciatus females were not yet clear-cut but females of this species appear to show a low attractance to light on dark nights but not on light ones. The effect of moonlight on females of this species is so pronounced that unlighted traps probably give a much better indication of abundance than lighted ones.
Radiation patterns of circular apertures with Gaussian illumination

We analyze the radiation pattern from circular apertures with Gaussian electric field distribution. Patterns are calculated using the Fraunhofer diffraction integral and we obtain a convenient expression for the FWHM beamwidth as a function of the edge taper. The aperture efficiency can be calculated for blocked and unblocked apertures in analytic form. The beam efficiency must be computed numerically, but can be obtained in a straightforward way from the beamwidth.
Inhibition of measles virus replication by cyclic AMP

Abstract The replication of measles virus was examined in cells treated with adenosine 3′,5′-monophosphate (cyclic AMP). Addition of 1 mM exogenous cyclic AMP to human amnion cell cultures (AV3) productively infected with the Edmonston strain of measles virus completely inhibited the formation of multinucleated giant cells and reduced the production of infectious virus particles by greater than 99%. While infected cyclic AMP-treated cells demonstrated measles virus antigens, discrete intracellular viral inclusion bodies were smaller and were observed much less frequently than in infected control cultures. Electron microscopy of the nucleotide-inhibited, infected cells showed that virus capsids of the “smooth” type were present in the cellular cytoplasm, but “granular” or “fuzzy” capsids were not. In addition, the association of virus nucleocapsids with the cell membrane and the budding of complete virion particles were not seen in the cyclic nucleotide-treated cultures. Analysis of infected cell immunoprecipitates by sodium dodecyl sulfate -polyacrylamide gel electrophoresis showed that the synthesis of the P and M polypeptides of the virus was significantly reduced in the nucleotide-treated infections. These data suggest that exogenous cyclic AMP inhibits the assembly of measles virions in infected AV3 cells by specifically blocking the synthesis of certain viral proteins.
A comparison of emotional approach coping (EAC) between individuals with anxiety disorders and nonanxious controls.

Emotional regulation deficits are described as a core component of anxiety disorders (ADs), yet there remains a paucity of data examining this issue in patients diagnosed with ADs. We hypothesized that help-seeking individuals with ADs would report lower levels of emotional approach coping (EAC), which includes emotional processing (EP) and emotional expression (EE), than nonanxious controls. Diagnostic interviews and a validated self-report scale assessing emotional approaches to coping (emotional approach coping scale [EACS]) were administered to 101 nonanxious controls and 92 patients with a primary AD (29 generalized anxiety disorder, 40 social anxiety disorder, and 23 panic disorder). Patients with each AD demonstrated significantly lower EAC, including both EP and EE, than nonanxious controls. Lower EAC was also associated with higher anxiety sensitivity and higher anxiety symptom severity. Overall, gender did not moderate the anxiety–EAC effect, but the results suggested that women utilize EAC to a greater degree than men. Clinical techniques designed to improve emotional coping may be beneficial to individuals with ADs.
Application of synchrotron radiation techniques to nanoscience

Abstract The development of high-brilliance synchrotron radiation sources have provided powerful new methods for probing the structure and dynamics of nanostructured materials. We shall review some of the recent applications of synchrotron radiation techniques to the study of nanomaterials. These include both scattering and real-space imaging methods and the use of coherent X-ray beams for studying nanostructures, the use of resonant magnetic scattering to study magnetic nanostructures, and the use of photon correlation spectroscopy to study their dynamics.
Efficient gröbner basis reductions for formal verification of galois field multipliers

Galois field arithmetic finds application in many areas, such as cryptography, error correction codes, signal processing, etc. Multiplication lies at the core of most Galois field computations. This paper addresses the problem of formal verification of hardware implementations of (modulo) multipliers over Galois fields of the type F 2k , using a computer-algebra/algebraic-geometry based approach. The multiplier circuit is modeled as a polynomial system in F 2k [x 1 , x 2 , … , x d ] and the verification problem is formulated as a membership test in a corresponding (radical) ideal. This requires the computation of a Grobner basis, which can be computationally intensive. To overcome this limitation, we analyze the circuit topology and derive a term order to represent the polynomials. Subsequently, using the theory of Grobner bases over Galois fields, we prove that this term order renders the set of polynomials itself a Grobner basis of this ideal - thus significantly improving verification. Using our approach, we can verify the correctness of, and detect bugs in, upto 163-bit circuits in F 2 163 ; whereas contemporary approaches are infeasible.
Dissimilar-metal and “titrant-stream” electrode systems in the potentiometric titration of millimolar concentrations of copper(II) in dimethylformamide with titanium(III)

Abstract Thirty platinum-nonplatinum electrode couples have been examined as possible end point indicators in the potentiometric titration of millimolar concentrations of copper(II) in N.N -dimethylformamide with titanium(III) in the same solvent. Molybdenum, titanium, or stainless steel gave standard deviations of less than 1%. If preconditioned, gold, tantalum, or tungsten gave similar standard deviations. Several other platinum-nonplatinum electrode couples are useful but less satisfactory. Titrations carried out with the platinum (titrant stream)-platinum (titrand) couple gave a standard deviation of less than 2%. The stainless steel (titrant stream)-stainless steel (titrand) couple is also useful but is somewhat less precise.
Growth of the high temperature, high pressure polymorph of Rh2O3 by chemical transport with HCl

Abstract The preparation of the presumed high pressure modification of Rh2O3 by chemical vapor transport is described and its structure contrasted with the closely related corundum form of the oxide.
Structured programming in assembly language

Structured design and programming techniques can be extended from high-level languages to assembly language. Over the past three years at Brown University, beginning assembly language programmers have been successfully taught these techniques using clearly defined standards. These standards and the solutions to several of the typical problems that arise in structured assembly language programming are discussed in this paper.
Polymorphisms of xenobiotic metabolizing genes in oropharyngeal carcinoma

Objective. The objective was to determine the prevalence of the polymorphisms of the microsomal epoxide hydrolase (Ephx1), glutathione S-transferase µ1 (GSTM1), θ1 (GSTT1), and π1 (GSTP1) genes in patients with oropharyngeal carcinoma. Study design. Gene polymorphisms in 137 patients with oropharyngeal carcinoma were determined by polymerase chain reaction and restriction enzyme digestion for xenobiotic metabolizing enzymes that have been implicated in the carcinogenesis of tobacco-related neoplasias and compared with a population sample of 99 persons. Results. At Ephx1 (microsomal epoxide hydrolase) codon 113, an overrepresentation of the greater activity genotype (Tyr/Tyr) was observed for male ever-smokers alone, both male and female ever-smokers, female never-smokers alone, and in both male and female never-smokers, compared with a control population sample. At codon 139, Ephx1 showed no differences. There was an overrepresentation of homozygosity for the GSTT1 (glutathione S-transferase θ1) null allele [but not for the GSTM1 (glutathione S-transferase µ1) null allele] in ever-smokers, when compared with controls. Polymorphisms at the GSTP1 (glutathione S-transferase π1) locus did not show differences versus controls, although in the never-smoker cancer sample there was a higher prevalence of the B/B genotype compared with ever-smokers. Conclusion. The Ephx1 codon 113 Tyr/Tyr variant, as well as homozygosity for the GSTT1 null allele, is associated with oropharyngeal carcinogenesis. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;93:440-5)
Time-resolved observation of product ions generated by 157 nm photodissociation of singly protonated phosphopeptides

Vacuum UV photodissociation tandem mass spectra of singly charged arginine-terminated phosphopeptides were recorded at times ranging from 300 ns to ms after photoexcitation, to investigate when the phosphate group falls off from the precursor and product ions and whether loss of phosphate can be eliminated in tandem mass spectra. For peptide ions containing phosphoserine and phosphothreonine, little loss of 98 Da from the product ions was observed up to 1 µs after photoexcitation. However, neutral losses from the precursor ions were considerable just 300 ns after photoactivation. Loss of 98 Da from product ions first appears about 1 µs after laser irradiation and becomes more common 13 µs after photoexcitation. Consistent with previous reports, phosphotyrosine was more stable than either phosphoserine or phosphothreonine.
Impact of temperature on the impedance of microwave and RF PIN diodes

A closed form linear electrothermal model for the PIN diode showing it frequency and temperature behavior is presented. The model uses PIN diode electrical parameters such as DC forward current, I-region thickness and the temperature-dependent mobility and carrier lifetime as parameters. Impedance behavior is shown over frequency and temperature as examples of the mathematical model and the model is verified with experimental. Good agreement is seen between the model and measured data. The results show that the forward bias impedance is strongly dependent on the carrier lifetime temperature coefficient that has been shown to be a function of diode cross-section and surface passivation.
Use of Ion Exchange in Recovery and Partial Purification of Morphine from Aqueous Extracts of Poppy Capsules

A cation-exchange resin has been used successfully to recover morphine from aqueous extracts of poppy capsules. With 65 ml. of extract containing 65 mg. of morphine applied per gram of resin, approximately 94 per cent of the morphine was recovered when the resin was in the sodium form and 89 per cent when in the ammonium form. The resin showed no loss of capacity after 21 cycles. The crude solid product from the column eluate contained about 54 per cent morphine. By passing the eluate from the ammonium resin through an anion exchange resin, a solid product containing 85 per cent morphine was obtained.
Folding and Hydrodynamics of a DNA i-Motif from the c-MYC Promoter Determined by Fluorescent Cytidine Analogs

The four-stranded i-motif (iM) conformation of cytosine-rich DNA has importance to a wide variety of biochemical systems that range from their use in nanomaterials to potential roles in oncogene regulation. The iM structure is formed at slightly acidic pH, where hemiprotonation of cytosine results in a stable C-C+ basepair. Here, we performed fundamental studies to examine iM formation from a C-rich strand from the promoter of the human c-MYC gene. We used a number of biophysical techniques to characterize both the hydrodynamic properties and folding kinetics of a folded iM. Our hydrodynamic studies using fluorescence anisotropy decay and analytical ultracentrifugation show that the iM structure has a compact size in solution and displays the rigidity of a double strand. By studying the rates of circular dichroism spectral changes and quenching of fluorescent cytidine analogs, we also established a mechanism for the folding of a random coil oligo into the iM. In the course of determining this folding pathway, we established that the fluorescent dC analogs tC° and PdC can be used to monitor individual residues of an iM structure and to determine the pKa of an iM. We established that the C-C+ hydrogen bonding of certain bases initiates the folding of the iM structure. We also showed that substitutions in the loop regions of iMs give a distinctly different kinetic signature during folding compared with bases that are intercalated. Our data reveal that the iM passes through a distinct intermediate form between the unfolded and folded forms. Taken together, our results lay the foundation for using fluorescent dC analogs to follow structural changes during iM formation. Our technique may also be useful for examining folding and structural changes in more complex iMs.
Lucigenin: Redox Potential in Aqueous Media and Redox Cycling with O−2 Production1☆

The use of lucigenin luminescence as a measure of [O−2] has been questioned because lucigenin has been shown to be capable of mediating the production of O−2. This being the case, lucigenin can signal the presence of O−2 even in systems not producing it in the absence of lucigenin. The reduction potential of lucigenin should be in accord with its ability to mediate O−2 production; but it has not heretofore been measured in aqueous media. The problems facing such measurement are the insolubility of the divalently reduced form, which deposits on the electrode, and the slow conformational transition that follows the second electron transfer and which interferes with reversibility. We have now used rapid scan cyclic voltammetry to determine that the reduction potential for lucigenin is −0.14 ± 0.02 V versus the normal hydrogen electrode. This value applies to both the first and the second electron transfers to lucigenin and it is in accord with the facile mediation of O−2 production by this compound.
Reconsidering Regime Type and Growth: Lies, Dictatorships, and Statistics

Some recent papers have concluded that authoritarian regimes have faster economic growth than democracies. These supposed growth benefits of autocracies are estimated using data sets in which growth rates rely heavily on data reported by each government. Governments have incentives to exaggerate their economic growth figures, however, and authoritarian regimes may have fewer limitations than democracies on their ability to do so. This paper argues that growth data submitted to international agencies are overstated by authoritarian regimes compared to democracies. If true, it calls into question the estimated relationship between government type and economic growth found in the literature. To measure the degree to which each government's official growth statistics are overstated, the economic growth rates reported in the World Bank's World Development Indicators are compared to a new measure of economic growth based on satellite imaging of nighttime lights. This comparison reveals whether or not dictators exaggerate their true growth rates and by how much. Annual GDP growth rates are estimated to be overstated by 0.5–1.5 percentage points in the statistics that dictatorships report to the World Bank.
Precise optical path length measurement through an optical fiber: Application to seafloor strain monitoring

An optical fiber strainmeter intended for measuring tectonic strains on the seafloor is under development. In this instrument, an optical fiber is stretched between two points fixed to the ocean bottom; relative displacement of these points causes a change in the elongation of the fiber. This associated change in optical path length is monitored by an electronic distance meter. The dominant sources of noise in determining the optical path length of the fiber stem from the dependence of the fiber's index of refraction on both wavelength and temperature. In a 50 day long experiment performed in the shallow ocean, a test fiber was installed along a 210 m long baseline on the bottom. The RMS variation in length was 5 mm except for two displacements of order 10 cm caused by known effects.
Factors Affecting African American Men’s Use of Online Colorectal Cancer Education

Colorectal cancer (CRC) incidence rates have decreased due to the increased use of CRC screenings that permit the detection and removal of polyps. However, CRC is still the second most common cause of cancer death among men ages 40 to 79 years; incidence and mortality rates for CRC are higher among African American (AA) men than among white men and AA women. CRC screening rates for AA men are comparable to their counterparts of other racial groups, but adherence to the screening guidelines is less, contributing to disparities in CRC mortality. Internet use is widespread and could be a channel to reach and disseminate health information to AA men; however, there are disparities in Internet use, and limited literature exists on how to best address this divide. This pilot project sought to understand African American male attitudes on colorectal cancer screening (CRCS), receipt of CRCS information, and the best strategy to provide African American men online CRCS education. Three focus groups and a feasibility trial were completed with African American men, ages of 45 to 75. Data suggest that disseminating information online is not a very effective way to reach older African American men with limited education. Although we do not recommend using websites among this population, email was more effective in getting participants to the website even though participants expressed a preference for phone messages. Recommendations for future research are provided.
Prognostic implications of echocardiography in advanced heart failure.

Purpose of reviewThe growing epidemic of systolic congestive heart failure mandates strategies to identify accurately people with high morbidity and mortality. Echocardiography remains the most widely available noninvasive tool for the assessment of cardiac structure, function, and hemodynamics. Cli
SLOUGHED PERIPHERAL ROOT CAP CELLS: YIELD FROM DIFFERENT SPECIES AND CALLUS FORMATION FROM SINGLE CELLS'

Peripheral root cap cells can be isolated by gentle agitation of the root in water for less than 60 sec. Filtration of the detached cells through a 30-Am mesh screen results in a suspension of single cells. Yields of peripheral root cap cells from 28 species in 10 families ranged from fewer than 10 per root from tobacco to more than 5,000 per root from pine. The viability of freshly isolated cells from most species, including legumes and cereals, was 85% to 95%. Cultured cells from pea and soybean exhibited cytoplasmic streaming for more than a month. When incubated at an initial density of 105 cells per ml of liquid B5(P) medium, 6% to 8% of isolated pea root cap cells divided and grew into callus.
SU‐E‐T‐519: Emission of Secondary Particles From a PMMA Phantom During Proton Irradiation: A Simulation Study with the Geant4 Monte Carlo Toolkit

Purpose: Proton therapy exhibits several advantages over photon therapy due to depth-dose distributions from proton interactions within the target material. However, uncertainties associated with protons beam range in the patient limit the advantage of proton therapy applications. To quantify beam range, positron-emitting nuclei (PEN) and prompt gamma (PG) techniques have been developed. These techniques use de-excitation photons to describe the location of the beam in the patient. To develop a detector system for implementing the PG technique for range verification applications in proton therapy, we studied the yields, energy and angular distributions of the secondary particles emitted from a PMMA phantom. Methods: Proton pencil beams of various energies incident onto a PMMA phantom with dimensions of 5 x 5 x 50 cm3 were used for simulation with the Geant4 toolkit using the standard electromagnetic packages as well as the packages based on the binary-cascade nuclear model. The emitted secondary particles are analyzed . Results: For 160 MeV incident protons, the yields of secondary neutrons and photons per 100 incident protons were ~6 and ~15 respectively. Secondary photon energy spectrum showed several energy peaks in the range between 0 and 10 MeV. The energy peaks located between 4 and 6 MeVmore » were attributed to originate from direct proton interactions with 12C (~ 4.4 MeV) and 16O (~ 6 MeV), respectively. Most of the escaping secondary neutrons were found to have energies between 10 and 100 MeV. Isotropic emissions were found for lower energy neutrons (<10 MeV) and photons for all energies, while higher energy neutrons were emitted predominantly in the forward direction. The yields of emitted photons and neutrons increased with the increase of incident proton energies. Conclusions: A detector system is currently being developed incorporating the yields, energy and angular distributions of secondary particles from proton interactions obtained from this study.« less
4-D Statistical Surface Method for Visual Change Detection in Forest Ecosystem Simulation Time Series

Rising uncertainties associated with climate change compel forest management planning to include forest ecosystem simulations. The output of such models is often of high spatio-temporal complexity and difficult to interpret for the user. This contribution describes a novel visualization method called four-dimensional (4-D) statistical surfaces, which aims at improving the visual detection of change in time series. The method visualizes attribute values as surfaces, which are interpolated and animated over time; the interactive attribute surfaces are combined with color-coding and contour lines to support absolute and relative height judgment as well as faster perception and better location of change. A design study and prototypical implementation of the visualization method is described in this contribution. Time-series simulation results of LANDIS-II, a commonly used modeling tool in forest ecology, as well as a temporal vegetation index dataset (NDVI) are visualized using 4-D statistical surfaces. Usability challenges are addressed based on explorative interviews with a small group of users. The method is not limited to ecological model output; it can be used to create three-dimensional (3-D) temporal animations of arbitrary time-series datasets where parameters are supplied in regular raster format.
Primary sequence determination of a monoclonal antibody against α-synuclein using a novel mass spectrometry-based approach

Abstract A novel mass spectrometry-based workflow for de novo sequencing of a full-length monoclonal antibody (LB509) against α-synuclein is presented. This approach combines chemical modification of cysteine residues, multiple enzymatic digestion, stable isotope labeled amino acids in cell culture (SILAC), liquid chromatography coupled tandem mass spectrometry (LC/MS/MS) analysis including collision-induced dissociation (CID), higher energy collision-induced dissociation (HCD), and de novo sequencing software for data interpretation. The introduction of aminoethyl-8 (A-8) reagent which renders cysteine residues in the antibody to become substrates for trypsin digestion significantly increases the sequence coverage of the antibody, especially in the complementarity determining regions (CDRs). Incorporation of SILAC helps to distinguish minor sequence variations between original and deduced sequences. Methods in obtaining detailed sequence characterization are described, highlighting the advantage of using multiple fragmentation schemes, CID in ion trap and HCD in C-trap. Complete primary sequence for LB509 has been construed and the antibody generated exhibits specific binding to α-synuclein. The development and implementation of this technology enables an alternative approach for generating therapeutic candidate and reagent antibodies.
Pathogenetic implications of DNA nondiploidy in colorectal cancers

PURPOSE: Several studies propose that proximal and distal colorectal cancers have a different pathogenesis. We tested the hypothesis using flow cytometric DNA analysis. METHODS: DNA analysis was performed in 719 patients with colorectal cancer. In addition, histopathologic data were re-evaluated in a blinded fashion by a single pathologist. RESULTS: Distal tumors were more often nondiploid than were proximal tumors (61 vs.49 percent;P =0.015). Compared with the proximal tumor, distal tumors were smaller ( P =0.0001) and had less desmoplastic reaction (39 vs.53 percent;P =0.0001). Tumor location had no significant associations with the remaining parameters, including mucin production, perineural invasion, blood/lymphatic vessel invasion, lymphocytic infiltration, histologic grade, tumor stage, gross appearance, age, and gender. CONCLUSIONS: The unequal distribution of ploidy suggests distinct pathogenetic mechanisms at proximal and distal sites.
Dynamic properties of metal matrix composites: a comparative study

Abstract Three distinctly different metal matrix composites have been tested at strain rates from quasi-static to ≈3000 s −1 . It was found that the high strain rate response of each composite was determined primarily by (a) the response of the matrix in the absence of any reinforcement and (b) the damage formation and accumulation processes during deformation. High strain rate behavior of the short fiber composite was dominated by the matrix behavior at low strains but by fiber damage at high strains. The behavior of a whisker reinforced composite was dominated by the matrix properties at all strains. Re-loading tests produced increased fracture strains, indicating that adiabatic heating accelerates fracture of composites by permitting the development of local strain instabilities.
Adaptive Linear Turbo Equalization Over Doubly Selective Channels

Over the last decade, tremendous gains, leading to near-capacity achieving performance, have been shown for a variety of communication systems through the application of the turbo principle, i.e., the exchange of extrinsic information between constituent algorithms for tasks such as channel decoding, equalization, and multiple-input-multiple-output (MIMO) detection. In this paper, we study the practical application of such an iterative detection and decoding (IDD) framework to underwater acoustic communications. We explore complexity and performance tradeoffs of a variety of turbo equalization (TEQ)-based receiver architectures. First, we elaborate on two popular but suboptimal turbo equalization techniques: a channel-estimate-based minimum mean-square error TEQ (CE-based MMSE-TEQ) and a direct-adaptive TEQ (DA-TEQ). We study the behavior of both TEQ approaches in the presence of channel estimation errors and adaptive filter adjustment errors. We confirm that after a sufficient number of iterations, the performance gap between these two TEQ algorithms becomes small. Next, we demonstrate that an underwater receiver architecture built upon the least mean squares (LMS) DA-TEQ technique can leverage and dramatically improve the performance of the conventional implementation based on the decision-feedback equalizer at a feasible complexity. To maintain performance gains over time-varying channels, the slow convergence speed of the LMS algorithm has been improved via two methods: 1) repeating the weight update for the same set of data with decreasing step size and 2) reducing the dimensionality of the equalizer by capturing sparse channel structure. This receiver architecture was used to process collected data from the SPACE 08 experiment (Martha's Vineyard, MA). Receiver performance for different modulation orders, channel codes, and hydrophone configurations is examined at a variety of distance, up to 1 km from the transmitters. Experimental results show great promise for this approach, as data rates in excess of 15 kb/s could readily be achieved without error.
A Demonstration of the Efficiency of Developmental Learning

Previous research has suggested that developmental learning can make the learning of advanced sensorimotor and cognitive skills possible. In this paper, we demonstrate that developmental learning based on skill progression is also more efficient than traditional divide-and-conquer methods. Using a model based on the skills of reaching and pointing to visual targets, we demonstrate an implementation for a humanoid robot that is more efficient at learning joint attention skills than other published methods. This efficiency results from (1) a structured set of learning tasks that progresses from low-dimensional to high-dimensional problems and (2) a greater exploitation of the learning environment that does not follow from the completely task-based decomposition that divide-and-conquer provides.
Magnesium Sulfate Is a Poor Inhibitor of Oxytocin-Induced Contractility in Pregnant Sheep

The aim of this study was to determine if magnesium sulfate has a direct inhihitory effect in vivo on oxytocin-induced myometnal contractility. We used 13 preterm non-laboring sheep to evaluate the ability of magnesium sulfate to inhibit oxytocin-induced contractions. In each of seven animals, we achieved three sequential steady state concentrations of magnesium (3.5, 5.5, and 8.3 mEq/L). A bolus of oxytocin was given before magnesium infusion and after 140 min at each steady state concentration. The myometrial response to each oxytocin injection was quantified. In six other animals, we infused magnesium sulfate over 24 h and achieved an average concentration of 7.7 mEq/L. Oxytocin boluses were given after 4 and 24 h of magnesium infusion and the myometrial response was quantified. Magnesium sulfate did not significantly reduce oxytocin-induced contractility with either short (2 h) or prolonged (24 h) infusion. There was no dose related contraction inhibition by magnesium sulfate over concentrations rangi...
Developing evolutionary neural controllers for teams of mobile robots playing a complex game

This research develops methods of automating the production of behavioral robotics controllers. Population-based artificial evolution was employed to train neural network-based controllers to play a robotic version of the team game Capture the Flag. The robot agents used processed video data for sensing their environment. To accommodate the 35 to 150 sensor inputs required, large neural networks of arbitrary connectivity and structure were evolved. An intra-population competitive genetic algorithm was used and selection at each generation was based on whether the different controllers won or lost games over the course of a tournament. This paper focuses on the evolutionary neural controller architecture. Evolved controllers were tested in a series of competitive games and transferred to real robots for physical verification.
Metabolism of the Bile Acid Analogues 7,β-Methyl-Cholic Acid and 7α-MethylUrsocholic Acid

The metabolism of two new bile acid analogues, 7,β-methyl-cholate and 7α-methyl-ursocholate; was compared with that of cholate in the hamster. After intraduodenal administration of 14 C-labeled compounds into bile fistula hamsters, radioactivity was exclusively recovered in bile; the more hydrophobic bile acid was absorbed more rapidly. Hepatic extraction of intravenously infused compounds was efficient and administered analogues became major biliary bile acids. Amidation of cholate was essentially complete, whereas 39% of 7β-methyl-cholate and 65% of 7α-methyl-ursocholate were secreted in unconjugated form. After intragastric administration of the compounds, radioactivity was quantitatively recovered in feces. Cholate was 7-dehydroxylated to deoxycholate, whereas 31% of 7β-m ethyl -chol ate and 78% of 7α-methyl -ursocholate were recovered unchanged. Fifty percent of 7β-methyl -cholate and 15% of 7α-methyl-ursocholate were transformed into ketonic derivatives, without loss of the 7hydroxyl group. It is concluded that the introduction of the 7-methyl group did not interfere with intestinal absorption, hepatic extraction, and biliary secretion but did affect enzymatic amidation and bacteria] 7-dehydroxylation of the analogues.