cssi/SciSciGPT-SciSciNet huggingface dataset:
Cultivation and Growth Characteristics of a Diverse Group of Oligotrophic Marine Gammaproteobacteria

Forty-four novel strains of Gammaproteobacteria were cultivated from coastal and pelagic regions of the Pacific Ocean using high-throughput culturing methods that rely on dilution to extinction in very low nutrient media. Phylogenetic analysis showed that the isolates fell into five rRNA clades, all of which contained rRNA gene sequences reported previously from seawater environmental gene clone libraries (SAR92, OM60, OM182, BD1-7, and KI89A). Bootstrap analyses of phylogenetic reliability did not support collapsing these five clades into a single clade, and they were therefore named the oligotrophic marine Gammaproteobacteria (OMG) group. Twelve cultures chosen to represent the five clades were successively purified in liquid culture, and their growth characteristics were determined at different temperatures and dissolved organic carbon concentrations. The isolates in the OMG group were physiologically diverse heterotrophs, and their physiological properties generally followed their phylogenetic relationships. None of the isolates in the OMG group formed colonies on low- or high-nutrient agar upon their first isolation from seawater, while 7 of 12 isolates that were propagated for laboratory testing eventually produced colonies on 1/10 R2A agar. The isolates grew relatively slowly in natural seawater media (1.23 to 2.63 day(-1)), and none of them grew in high-nutrient media (>351 mg of C liter(-1)). The isolates were psychro- to mesophilic and obligately oligotrophic; many of them were of ultramicrobial size (<0.1 micro m(3)). This cultivation study revealed that sporadically detected Gammaproteobacteria gene clones from seawater are part of a phylogenetically diverse constellation of organisms mainly composed of oligotrophic and ultramicrobial lineages that are culturable under specific cultivation conditions.
Analyzing carrier escape mechanisms in InAs/GaAs quantum dot p-i-n junction photovoltaic cells

Intermediate band solar cells (IBSCs) are third-generation photovoltaic (PV) devices that can harvest sub-bandgap photons normally not absorbed in a single-junction solar cell. Despite the large increase in total solar energy conversion efficiency predicted for IBSC devices, substantial challenges remain to realizing these efficiency gains in practical devices. We evaluate carrier escape mechanisms in an InAs/GaAs quantum dot intermediate band p-i-n junction PV device using photocurrent measurements under sub-bandgap illumination. We show that sub-bandgap photons generate photocurrent through a two-photon absorption process, but that carrier trapping and retrapping limit the overall photocurrent. The results identify a key obstacle that must be overcome in order to realize intermediate band devices that outperform single junction photovoltaic cells.
Total and partial photoionization cross-sections of O2 from 100 to 800 Å

Abstract The branching ratios and absolute values of the total and partial photoionization cross-sections for producing O 2 + in its various electronic states are given as a function of wavelength in the range 100–800 A. Cross-sections for dissociative ionization are given based on the premise that some of the bound ionic states predissociate. Photoelectron spectroscopy and absorption techniques utilizing a double ionization chamber were used to obtain the data.
Population structure in old-growth and managed northern hardwoods: an examination of the balanced diameter distribution concept

Abstract Silvicultural guidelines for uneven-aged management have traditionally been based on the regulation of `balanced' stand structures that allow for periodic yields at regular intervals while providing adequate growing space for multiple cohorts. To evaluate certain assumptions behind the `balanced' diameter distribution concept, we investigated differences in the size structure, canopy recruitment, and growing space allocation among 31 old-growth, managed uneven-aged (selection), and even-aged northern hardwood stands in north-central Wisconsin and adjacent western Upper Michigan. The frequency of stands meeting criteria for balanced uneven-aged structure was substantially affected by whether diameter distributions were plotted for all crown classes combined (traditional approach) or whether the distributions included only trees with crowns exposed overhead to skylight. While all 10 old-growth stands and 11 of the 15 selection stands met the traditional criteria for balanced structure, only 50% and 27%, respectively, met the more stringent criteria for balanced structure that included evidence of substantial gap sapling recruitment. Both negative exponential and rotated sigmoid diameter distributions were found among individual old-growth and selection stands. However, all old-growth stands classified as balanced (based on exposed canopy trees) had rotated sigmoid diameter distributions for all species pooled and for sugar maple only. Negative exponential distributions were also observed in some `balanced' stands, but only among the selection stands. Aggregate crown area distributions in old-growth and selection stands with reasonably smooth reverse-J diameter distributions provided support for a modified interpretation of the equal area allocation hypothesis. While the aggregate exposed crown area occupied by each size class tended to be lower for small trees than for medium and large trees, total crown area distribution for trees with partially or fully exposed crowns did approximate a nearly uniform distribution.
Allopurinol Enhances the Contractile Response to Dobutamine and Exercise in Dogs With Pacing-Induced Heart Failure

Background—Superoxide (O2−) generated by enhanced xanthine oxidase (XO) activity may contribute to the increased myocardial oxidative stress in heart failure (CHF). Because blocking XO with allopurinol augments myofilament Ca2+ sensitivity in reperfusion injury and CHF, we hypothesized that it may improve adrenergic inotropic responsiveness in CHF. Methods and Results—We studied the effect of allopurinol on the contractile response to dobutamine and exercise in 7 chronically instrumented conscious dogs before and after producing CHF by rapid pacing. Left ventricular (LV) contractile performance was measured by the slopes of the LV end-systolic pressure-volume relation (EES) and stroke work–end-diastolic volume relation (MSW). Before CHF, allopurinol produced no change in LV contractile performance and did not alter the response to dobutamine or exercise. After CHF, allopurinol produced significant (P<0.05) increases in EES (5.0±0.6 versus 3.3±0.6 mm Hg/mL) and MSW. Dobutamine and allopurinol produced grea...
Ethics Regulation Across Professions

Gifting, a private act of friendship and charity among individuals that has deep cross-cultural roots, is increasingly seen as a morally problematic practice in many professions. Gifting done within the context of employment is now the subject of regulation in many professions as part of a broader effort to promote independence, impartiality, and objectivity. Based upon a survey of more than twenty professional associations and fields of employment, this commentary examines the historical roots of gifting, why it poses an ethical problem, and how many organizations across the public, private, and nonprofit sectors are adopting policies to address this practice. Overall, three conclusions are reached. First, because gifting creates a sense of dependency, reciprocity, or indebtedness, its practice within a professional setting causes potential or real conflicts of interest, regardless of the size or type of the gift. Second, because of the problems that gifting poses, many professions have already recognize...
Long-term use of hydroxypropyl cellulose ophthalmic insert to relieve symptoms of dry eye in a contact lens wearer: case-based experience.

Objectives:To report a case in which hydroxypropyl cellulose ophthalmic inserts were successfully used for the treatment of dry eye disease in a contact lens (CLs) wearer for more than 25 years.Methods:Review of clinical findings in a female CL wearer with dry eye spanning more than 30 years. The pa
The Measurement of Very-Low Partial Pressures

The measurement of partial pressures in the ultra high and extreme high vacuum ranges (below about 10-6 Pa) is important for residual gas analysis and the measurement of low-pressure constituents (both contaminants and deliberate additions) in higher-pressure process gases. Mass-spectrometer type instruments-partial pressure or residual gas analyzers (PPAs and RGAs) -are generally used for this purpose. Typically, these instruments consist of an electron-impact ionizer, a quadrupole mass filter, and an ion detector. This paper discusses these elements and other factors that determine the very-low-pressure performance of these instruments-detection limits, mass resolution, and stability and pressure-dependence of the sensitivity. Particular attention is paid to ion-source design and operating parameters, the coupling of ions between the ionizer and the mass analyzer, and the influence of the total pressure on partial pressure sensitivities.
Pharmacokinetic mapping for lesion classification in dynamic breast MRI.

Purpose: To prospectively investigate whether a rapid dynamic MRI protocol, in conjunction with pharmacokinetic modeling, could provide diagnostically useful information for discriminating biopsy-proven benign lesions from malignancies. Materials and Methods: Patients referred to breast biopsy based on suspicious screening findings were eligible. After anatomic imaging, patients were scanned using a dynamic protocol with complete bilateral breast coverage. Maps of pharmacokinetic parameters representing transfer constant (Ktrans), efflux rate constant (kep), blood plasma volume fraction (vp), and extracellular extravascular volume fraction (ve) were averaged over lesions and used, with biopsy results, to generate receiver operating characteristic curves for linear classifiers using one, two, or three parameters. Results: Biopsy and imaging results were obtained from 93 lesions in 74 of 78 study patients. Classification based on Ktrans and kep gave the greatest accuracy, with an area under the receiver operating characteristic curve of 0.915, sensitivity of 91%, and specificity of 85%, compared with values of 88% and 68%, respectively, obtained in a recent study of clinical breast MRI in a similar patient population. Conclusion: Pharmacokinetic classification of breast lesions is practical on modern MRI hardware and provides significant accuracy for identification of malignancies. Sensitivity of a two-parameter linear classifier is comparable to that reported in a recent multicenter study of clinical breast MRI, while specificity is significantly higher. J. Magn. Reson. Imaging 2010;31:1371–1378. © 2010 Wiley-Liss, Inc.
Fragile X syndrome: genetic predisposition to psychopathology.

Fragile X syndrome is a newly recognized X-linked disorder which has been associated with a high prevalence of psychiatric disturbance, particularly attention deficit disorder and autism. The present study involved the neuropsychiatric evaluation of 14 males with the disorder who were between the ages of 3 to 27 years. Pervasive hyperactivity, impulsivity, and attentional deficits were found among all of the subjects, while a significant degree of anxiety was manifested by more than half. Although the majority of subects exhibited poor eye contact, atypical speech and language functioning, and stereotyped behavior, only one met DSM-III diagnostic criteria for a persistent pervasive developmental disorder. Gaze aversion, noted among half of the subjects, was attributed to underlying anxiety rather than to autistic social dysfunction because of the otherwise socially engaged and affectionate behavior exhibited by the subjects. Failure to make this distinction in the context of cognitive and linguistic impairments associated with fragile X syndrome may account for the high rates of autism reported by other investigators.
PITBUL: a physics-based modeling package for imaging and tracking of airborne targets for HEL applications including active illumination

Aimpoint acquisition and maintenance is critical to high energy laser (HEL) system performance. This study demonstrates the development by the AFIT/CDE of a physics-based modeling package, PITBUL, for tracking airborne targets for HEL applications, including atmospheric and sensor effects and active illumination, which is a focus of this work. High-resolution simulated imagery of the 3D airborne target in-flight as seen from the laser position is generated using the HELSEEM model, and includes solar illumination, laser illumination, and thermal emission. Both CW and pulsed laser illumination are modeled, including the effects of illuminator scintillation, atmospheric backscatter, and speckle, which are treated at a first-principles level. Realistic vertical profiles of molecular and aerosol absorption and scattering, as well as optical turbulence, are generated using AFIT/CDE’s Laser Environmental Effects Definition and Reference (LEEDR) model. The spatially and temporally varying effects of turbulence are calculated and applied via a fast-running wave optical method known as light tunneling. Sensor effects, for example blur, sampling, read-out noise, and random photon arrival, are applied to the imagery. Track algorithms, including centroid and Fitts correlation, as a part of a closed loop tracker are applied to the degraded imagery and scored, to provide an estimate of overall system performance. To gauge performance of a laser system against a UAV target, tracking results are presented as a function of signal to noise ratio. Additionally, validation efforts to date involving comparisons between simulated and experimental tracking of UAVs are presented.
Rheumatoid Pleural Effusion in the Absence of Arthritic Disease

Rheumatoid pleural effusion is an unusual complication of rheumatoid disease that typically presents subsequent to other more common manifestations of rheumatoid illness. The case of a 72-year-old woman with a rheumatoid pleural effusion is discussed. The patient presented with dyspnea, but without any history of rheumatoid arthritis. The patient was treated by thoracentesis, followed by video-thoracoscopy and pulmonary decortication. Postoperatively, the patient's effusion partially reaccumulated. Steroid therapy resulted in prompt and permanent resolution of the effusion. The patient remains asymptomatic 1 year after her presentation. The biochemical, serologic, and cytologic characteristics of rheumatoid effusions are reviewed.
A wind-mixed layer model for solar ponds

Abstract A computer model is described which may be used for predicting transient salinity and temperature profiles in a salt gradient solar pond. It is intended for use in modeling large surface area ponds where wind-mixing would be expected to play an important part in the dynamics of the upper layer. The formulation predicts the depth of the upper convecting zone using a mixed-layer model which incorporates the wind-mixing algorithm described by Bloss and Harleman [1,2]. This is in contrast to earlier solar pond models which have generally assumed a constant value for this layer depth. Results have been obtained for a number of 1-yr simulations of a large hypothetical pond in Richmond, Virginia, and these have been used in testing the sensitivity of the model to several of the input parameters, including the radiation term and the form of the wind-mixing algorithm. The model output is also compared with field data from an operating solar pond and good agreement is found. Results have indicated that some measures will have to be taken to counteract the mixing action due to wind stress, if the upper mixed layer depth is to be maintained at an acceptable level. The model is expected to be useful in large-scale pond design.
New lens on gender-based violence

Your October, 2013, articles bring a welcome scientifi c lens to genderbased violence in the Asia-Pacific region. Indeed, gender-based violence is so widespread it merits closer examination through the lens of development economics as well. Women in poverty often confront multiple difficulties in avoiding or escaping gender-based violence. They might have less financial independence and fewer exit routes, and they often live amid social norms that at best turn a blind eye to their suff ering. Fear of encountering violence deters many women from seeking employment. The vicious cycle of inequality, poverty, and violence continues. To address this pervasive rights abuse and its concomitant psychological, social, and economic costs, the World Bank Group is expanding its gender-related work to advance our twin goals of ending poverty and boosting shared prosperity. Indeed, the costs of gender-based violence, even according to conservative estimates of lost productivity, range from 1·2% of gross domestic product (GDP) in Brazil and Tanzania to 2% of GDP in Chile—as much as most governments spend on primary education. In collaboration with key partners, we are investing in knowledge and data on women and girls. This investment includes new work on women’s agency and participation, which takes as its starting point the view that freedom from violence is perhaps the most fundamental expression of agency. First, we are analysing the costs of violence and reviewing what interventions work and why. Second, we are bringing fi nancing to operations on the ground. In just the past year, ten new projects with an exclusive or priority focus on sexual and gender-based violence totalling almost US$19 million have been approved. Third, we are partnering with the private sector and civil society. In places such as Papua New Guinea, with its astonishingly high rates of gender-based violence, our “traditional” investments in areas such as mining and infrastructure all comprise explicit gender elements. Recent interviews with girls in the Pacifi c Island state as part of a global survey on development priorities suggest that they can imagine something better. “I want my future to be much safer”, one girl said, while another urged her government “to give fi rst priority to young women and girls...They should allow women to run the government.” Empowering women and girls can be catalytic in lifting families and communities out of poverty. Tackling the epidemic violence against them is vital to that equation.
Acidosis inhibits oxidative phosphorylation in contracting human skeletal muscle in vivo

This study tested the hypothesis that acidic pH inhibits oxidative ATP supply during exercise in hand (first dorsal interosseus, FDI) and lower limb (leg anterior compartment, LEG) muscles. We measured oxidative flux and estimated mitochondrial capacity using the changes in creatine phosphate concentration ([PCr]) and pH as detected by 31P magnetic resonance (MR) spectroscopy during isometric exercise and recovery. The highest oxidative ATP flux in sustained exercise was about half the estimated mitochondrial capacity in the LEG (0.38 ± 0.06 vs. 0.90 ± 0.14 mm ATP s−1, respectively), but at the estimated capacity in the FDI (0.61 ± 0.05 vs. 0.61 ± 0.09 mm ATP s−1, respectively). During sustained exercise at a higher contraction rate, intracellular acidosis (pH 0.24 mm) and avoiding acidosis using burst exercise. This exercise raised oxidative flux (0.69 ± 0.05 mm ATP s−1) to nearly twice that found with sustained exercise in the LEG and matched (0.65 ± 0.11 mm ATP s−1) the near maximal flux seen during sustained exercise in the FDI. Thus both muscles reached their highest oxidative fluxes in the absence of acidosis. These results show that acidosis inhibits oxidative phosphorylation in vivo and can limit ATP supply in exercising muscle to below the mitochondrial capacity.
Seasonal comparisons of weight loss for two types of Typha glauca Godr. leaf litter

Abstract Samples of living (2.8% N, 0.3% P) and naturally senesced (0.6% N, 0.05% P) leaves of cattail (Typha glauca Godr.) were collected from a shallowly flooded stand during July 1979 and February 1980, respectively. Decomposition patterns of the two litter types were compared by adding and removing litter samples from the Delta Marsh, Manitoba, Canada at various intervals during the growing season. Green leaf material, collected just before flowering, decomposed more rapidly than senesced litter during all time periods. Simple exponential decomposition rates differed significantly; −0.0241 day−1 for green litter vs. −0.0110 day−1 for senesced litter. Initial rates of organic dry wt. loss were not different between seasons for either litter type, but initial rates declined faster later in the summer. Less organic weight was lost during late summer after 2 and 30 days of incubation for both types of litter. However, seasonal effects could not be detected after longer treatment periods. During late summer, siltation of wind-suspended sediments apparently impeded decomposition by depressing oxygen levels and invertebrate activity in the litter samples. We estimate that up to 21 and 36 times more N and P, respectively would be released from litter toppled by muskrat feeding activity than by natural toppling of dead plant material during the growing season.
Continued Studies of the Status, Socialization, and Relationships of Isle Royale Wolves, 1967 to 1970

Studies of the wolf ( Canis lupus ) and its prey in Isle Royale National Park commenced in 1958. Numbers, pack structures, and observed relationships are reported herein for winter periods of the 4 years, 1967 to 1970. An important feature of the period was the immigration of a pack of seven wolves in 1967. Four of the seven were black and thus identifiable. This addition raised wolf numbers on Isle Royale to at least 28. Through mortality not compensated for by recruitment, and possibly by the egress of a pack of six to Canada, the population was reduced to 15 in 1968. Estimates for the winters of 1969 and 1970 were 17 and 18, respectively. In 2 years considered to be environmentally favorable, there were unexpectedly small population gains toward an earlier mean of 24. In the period 1967 to 1970 the common size for major packs on the island was six or seven, and evidence is accumulating that the area may not accommodate more than a single breeding group. The smaller packs did not evidence any decrease in predation efficiency relative to that observed for a large pack of 16 prior to 1967. Territorial antagonism, however, between the largest pack and a group of four apparently resulted in a clash in 1969 during which one of the four was killed. In the winter of 1970 the dominant pack contained eight wolves at the highest count. The alpha male in this pack was a large gray animal that appeared bonded with the same female in 1969 and 1970. The pair was closely attended in 1970 by a large black male that evidently was the beta animal in the male hierarchy.
13 P - Ontogeny of human natural killer (NK) cells: cytolytic mechanisms

NK cells are important effectors in graft rejection and against tumor cells. The development of this lytic arsenal during ontogeny remains unclear. We have shown that NK cells can be obtained from human adult bone marrow stern cells and progenitors cultured with SCF, IL-1α and IL2 (1,000 U/ml) with up to 96% at 4 weeks of culture; in some experiments IL7 (1,000 U/ml) was used instead of IL2. Expression of NK cell markers and lytic activity against K562 targets increased in parallel in cultures with IL2. NK cells grown in IL7 were, however, devoid of lytic activity. We used this system to detect Granzyme A (GA) (a tryptase commom to NK and T Iymphocites) and Hu-Met-1 (a met-ase constitutively exprassed in mature human NK cells) expression, early (2 weeks) and at the end of culture (4 weeks). After depletion of CD3+ cells, total RNA was extracted and RT-PCR performed. The sense primers were designed to amplify the sequence that codes for the aminoacid rasidues of the unprocessed protein. The amplified products were detected in an ethidium bromide gel electrophoresis and their specificity confirmed by Southern blot analysis using a specific probe. As early as two weeks, GA transcrips were detected in IL2-cultured cells (CD56+/3-cells: 15.3%±4.9%; % lysis of K562 targets: 10.4%±8.9% at 2.5:1 E:T ratio). In cultures with IL7 GA mRNA was only amplified later in culture (4 weeks). HU-Met-1 was not detected at any time of analysis in IL2 or IL7 culturas. We conclude that GA expression occurs early during NK ontogeny but it's presence doesn’t correlate with lytic function. These effectors are immature since Hu-Met-1 expression was not detected; which suggests that other factors may be necessary for terminal maturation of fully cytotoxic NK cells.
The effect of ammonium chloride and sodium bicarbonate ingestion on the physical working capacity at the fatigue threshold.

The purpose of this investigation was to examine the effect of ammonium chloride (NH4Cl) and sodium bicarbonate (NaHCO3) ingestion on the physical working capacity at the fatigue threshold (PWCFT). Eighteen adult males (mean age, SD=23, 2 years) volunteered for two experiments (experiment 1,n=9 ; experiment 2,n=9). In both experiments, the subjects orally ingested 0.3 g · kg−1 body weight of NH4Cl and NaHCO3 over a 3-h period in random order on days separated by 72 h or more. In experiment 1, following ingestion of the substance, the subjects performed a discontinuous incremental cycle ergometer test to the onset of PWCFT which was estimated from integrated electromyography voltages at the vastus lateralis muscle. In experiment 2, the subjects performed a continuous PWCFT test. The results of these experiments indicated that NH4Cl and NaHCO3 ingestion had no significant (P>0.05) effect on PWCFT (experiment 1: NH4Cl=257, SD 26 W; NaHCO3=256, SD 22 W;t=0.06;r=0.866; experiment 2: NH4Cl=231, 14 W; NaHCO3=216, 16 W;t=1.78;r=0.857).
Annular Honeycomb-Stator Turbulent Gas Seal Analysis Using a New Friction-Factor Model Based on Flat Plate Tests

A new empirical friction-factor model for honeycomb surfaces based on flat plate test results has been developed as a function of Mach number and dimensionless pressure and honeycomb geometry variables. A rotordynamic analysis for centered, turbulent-annular-honeycomb-stator seals has been developed incorporating the new empirical friction-factor model for honeycomb-stator surfaces. The results of the new analysis in predicting the rotordynamic and leakage characteristics have been compared to: (a) Moody’s friction-factor model analysis, and (b) experimental data for short (L/D = 1/6, 25.4 mm long) seal. The comparisons show that the new honeycomb friction-factor model greatly improves the predictions of leakage and rotordynamic coefficients compared to Moody’s friction-factor model, especially, for direct and cross-coupled stiffness.
Simultaneous and sensitive measurement of nicotine, cotinine, trans-3′-hydroxycotinine and norcotinine in human plasma by liquid chromatography-tandem mass spectrometry

Abstract An LC-MS/MS method for the simultaneous quantification of nicotine, cotinine, trans-3′-hydroxycotinine and norcotinine in human plasma was developed and fully validated. Potential endogenous and exogenous interferences were extensively evaluated and limits of quantification were determined by decreasing analyte concentration. Analytical ranges were 1–500 ng/mL for nicotine and cotinine, 5–500 ng/mL for trans-3′-hydroxycotinine and norcotinine. Mean intra- and inter-assay analytical recoveries were between 101.9 and 116.8%, and intra- and inter-assay imprecision were less than 11% RSD for all analytes: parameters were evaluated at three different concentrations across the linear range of the assay. Extraction efficiency was ≥70% for all analytes. This validated method is useful for the determination of nicotine and metabolites in human plasma to support research on the role of nicotine biomarkers on neuronal systems mediating cognitive and affective processes and to differentiate active, passive and environmental exposure.
CDK6 blocks differentiation: Coupling cell proliferation to the block to differentiation in leukemic cells

Cell proliferation and differentiation are highly coordinated during normal development. Many tumor cells exhibit both uncontrolled proliferation and a block to terminal differentiation. To understand the mechanisms coordinating these two processes, we have investigated the relation between cyclin-dependent kinase (CDK) activities and the block to differentiation in murine erythroleukemia (MEL) cells. We found that CDK6 (but not CDK4) is rapidly downregulated as MEL cells are induced to re-enter erythroid differentiation and that maintenance of CDK6 (but not CDK4) activity by transfection blocks differentiation. Moreover, we found that PU.1, an Ets transcription factor that is oncogenic in erythroid cells and also can block their differentiation, controls the synthesis of CDK6 mRNA. These results suggest a mechanism for coupling proliferation and the block to differentiation in these leukemic cells through the action of an oncogenic transcription factor (PU.1) on a key cell cycle regulator (CDK6). Our findings suggest that studying the relative roles of CDK6 and CDK4 in other types of malignant cells will be important in designing approaches for cell cycle inhibition and differentiation therapy in cancer.
II. Kinetic Pathways of Switching Optical Conformations in DsRed by 2D Fourier Imaging Correlation Spectroscopy

The kinetics of biomolecular conformational transitions can be studied by two-dimensional (2D) magnetic resonance and optical spectroscopic methods. Here we apply polarization-modulated Fourier imaging correlation spectroscopy (PM-FICS) to demonstrate a new approach to 2D optical spectroscopy. PM-FICS enables measurements of conformational fluctuations of fluorescently labeled macromolecules on a broad range of time scales (10 -3 -10 2 s). We examine the optical switching pathways of DsRed, a tetrameric complex of fluorescent protein subunits. An analysis of PM-FICS coordinate trajectories, in terms of 2D spectra and joint probability distributions, provides detailed information about the transition pathways between distinct dipole-coupled DsRed conformations.
PREDICTION OF INTERCITY FREIGHT FLOWS I. THEORY

Abstract This paper presents the conceptual framework for a predictive network equilibrium model of a freight transportation system in which the generation, distribution, modal split and assignment of freight movements are performed simultaneously. A neoclassical profit maximization model is stated for the supply-side of the transportation market, the demand-side is represented by a spatial price equilibrium model, and the economic mechanism which integrates the supply and demand submodels is described. The theoretical limitations imposed on the model by the requirement that it be capable of solving large-scale problems are also addressed.
Methylammonium uptake by Rhodobacter capsulatus

The ammonium uptake system of Rhodobacter capsulatus B100 was examined using the ammonium analog methylammonium. This analog was not transported when cells were grown aerobically on ammonium. When cultured on glutamate as a nitrogen source, or when nitrogen-starved, cells would take up methylammonium. Therefore, in cells grown under nitrogen-limiting conditions, a second system of ammonium uptake (or a modified form of the first) is present which is distinguished by its capacity for transporting the analog in addition to ammonium. The methylammonium uptake system exhibited saturation kinetics with a Km of 22 μM and a Vmax of about 3 nmol per min · mg protein. Ammonium completely inhibited analog transport with a Ki in the range of 1 μM. Once inside the cell methylammonium was rapidly converted to γ-N-methylglutamine; however, a small concentration gradient of methylammonium could still be observed. Kinetic parameters reflect the effects of assimilation.
The effects of nitroglycerin-methoxamine combination on infarct size in conscious dogs

Abstract The effect of nitroglycerin combined with methoxamine in reducing infarct weight was studied in conscious dogs. Ten minutes after permanent left anterior descending (LAD) coronary artery occlusion, 10 dogs received nitroglycerin (450 μg bolus IV, then 300 μg/min for 4 hours) and methoxamine as needed to maintain blood pressure and heart rate. No dogs were in heart failure. Ten control dogs received saline solution. Dogs were sacrificed 3 days later. The region at risk of infarction was delineated by simultaneously perfusing the aortic root with Evans blue and the distal LAD artery with saline solution under equal pressures. Slices of stained hearts were incubated with tetrazolium to identify infarct. Total weight of left ventricle (LV), risk region, and infarct was measured. Nitroglycerin-treated dogs showed no difference from control dogs in infarct weight (26.2 ± 5.9 gm ± SE vs 27.7 ± 5.6 gm), percent risk region/LV (36.0 ± 1.4% vs 37.9 ± 3.1%), or percent infarct/LV (23.5 ± 5.2% vs 24.8 ± 4.9%). In a subgroup with risk region/LV ≤ 35%, nitroglycerin reduced infarct weight by 45% (8.8 ± 8.5% vs 15.9 ± 7.9%), percent infarct/LV by 49% (7.1 ± 6.8% vs 13.8 ± 6.6%), and percent infarct/risk region by 41% (23.0 ± 22.0% vs 38.9 ± 15.9%). Because of the small number of dogs in the study, differences were not significant. In dogs with risk region/LV > 35%, nitroglycerin had no effect. Thus, in dogs without overt heart failure, nitroglycerin may salvage ischemic tissue within small areas at risk of infarction, but the results are not definitive. However, our results clearly demonstrate that in the absence of failure, nitroglycerin does not reduce the size of large infarcts.
Quantitative Measurement of Errors in Reading Arabic

Teaching children how to read, viewed through an historical scheme, shows certain trends. The "whole" method was used as a reaction against the old phonic method in the early twentieth century. Later on, the "experience approach," which is associated with "progressive education," supplemented the "whole" method. Then came the Gestalt theory, which was used as a theoretical basis for learning word "wholes." However, "the most prominent criticism of instruction in the 1940's and 1950's centered around the place of phonics in the teac ing of reading."' The crucially important fact which is drawn from the historical evalua-
Effect of control measures on pest populations subject to regulation by parasites and pathogens.

Abstract The effects of control measures on a disease regulated pest population are analyzed using the May-Anderson model of infectious disease. Control measures that increase the pest death rate (e.g. pesticides) increase the threshold pest population required for spread of the pathogen and lengthen the time required for the pathogen to control the pest. In contrast, control measures that decrease the pest birth rate (e.g. sterile males) do not interfere with pest regulation by pathogens.
Generation of MIL-HDBK-5 design allowables for aramid/aluminum laminates

ARALL® laminates are the first commercial members of a family of fibrous-metal structural laminates featuring high strength, low density, and high resistance to fatigue and fracture. (ARALL is a registered trademark for ALCOA and AKZO.) These materials are bonded arrangements composed of alternating layers of thin aluminum sheet and epoxy adhesive impregnated with strong aramid fibers. Consideration of ARALL laminates for aerospace applications will require the generation of basic strength property design allowables. This article presents results of a program conducted to establish ARALL laminate design allowable information based on modified MIL-HDBK-5 procedures. Experimental and analytical practices employed to obtain 5-basis minimum properties for tension, compression, in-plane shear and bearing are described. Observations on specimen failure modes for the individual property determinations are presented.
Deterministic versus probabilistic seismic hazard analysis for critical structures

Abstract Probabilistic seismic hazard analysis has been practically unchallenged since its inception three decades ago. However, information has been accumulating which shows convincingly that PSHA is a defective procedure. Its greatest weakness is the dependence of the probability theory on the Gutenberg-Richter magnitude and a recurrence relation which can no longer be regarded as a power law. Remedies that rely on incorporating paleoseismic information and characteristic earthquakes into the probability calculation introduce other errors resulting from fragmentary data and the known non-uniformity of earthquake occurrence in space and time. The worst corrective for probability is the method developed by the Electric Power Research Institute and the Lawrence Livermore National Laboratory that averages multiple expert opinions. Expert opinions cannot be averaged meaningfully because the criteria for different models are nonequivalent. On the other hand, the deterministic procedure for earthquake hazard evaluation avoids the above defects by eliminating the falsely precise time element in the probabilistic estimation. Geologic time for recurrence is used, according to accepted criteria such as a single movement in the past 12,000 years or multiple movements in 500,000 years. For a critical project, where the consequences of failure are intolerable and protection is needed against the worst that can be reasonably expected to occur (the maximum credible earthquake), the deterministic method is strongly recommended.
The mechanical respirator in poliomyelitis

Summary The respirator in poliomyelitis should be used as a means of giving physiologic rest in early and moderate paralysis of the respiratory muscles. The dramatized use of the respirator as an emergency lifesaving machine has occurred at the expense of interest in its more prosaic, but perhaps more valuable, function as a splint for weakened respiratory muscles. The early signs of respiratory weakness are often undetected, and the patient is given either no respiratory treatment at all, or none until a degree of fatigue occurs which would be considered a sign of intolerable neglect, were the muscles those of the arms. No clear distinction is made by many physicians between the various causes of respiratory failure in poliomyelitis. The respirator is seldom of use except where the intercostal muscles or diaphragm are paralyzed. Most cases of “bulbar” poliomyelitis are not helped. Two new types of machines for artificial respiration are described and their different advantages discussed. It is suggested that a national coordinated program for the handling of respiratory paralysis in poliomyelitis be planned as the only practical manner of meeting this problem.
Nitrate reduction with Halomonas campisalis. Kinetics of denitrification at pH 9 and 12.5% NaCl.

Regeneration of ion exchange resins with NaCl produces brine containing high concentrations of nitrate that can be difficult to remove using standard biological, physical, or chemical technologies. In this study, Halomonas campisalis (ATCC #700597) (Mormile et al., 1999) was shown to completely reduce nitrate at 125 g/L NaCl and pH 9. This organism was also used in experiments to determine nitrate-reduction rates and biomass yields. Kinetic parameters were measured separately with glycerol, lactate, acetate, ethanol, and methanol. The specific nitrate-reduction rate coefficient was highest in cultures amended with acetate, while lactate and glycerol (a natural osmoticum in hypersaline environments) had lower reduction rates. No evidence of nitrate reduction was observed when ethanol or methanol was provided as an electron donor. Kinetic modeling provided values for nitrate and nitrite-reduction rate coefficients and for biomass yields. Measured rates and yields were similar to reported parameters obtained from non-halophilic nitrate-reducing cultures under low salt concentrations. Therefore, for highly saline solutions, the use of halophiles to selectively remove nitrate from these brines may represent a viable treatment option.
Particle motion in the fountain flow region during filling of a tube with a viscoelastic fluid

We present the results of an investigation of particle motion behind the advancing free surface during the filling of an initially empty tube with a viscoelastic fluid. Particle motion in the vicinity of an advancing free surface (the fountain flow region) is of significance in a number of processes used to form composite materials, notably injection and compression molding. This motion determines, to a large extent, the distribution of the reinforcing phase in the molded part. We show experimentally that an isolated spherical particle moves behind the interface in characteristic orbits, remaining in close proximity to the advancing free surface. This is in stark contrast to what happens in a Newtonian fluid. In that case, the particle is deposited on the tube walls by the fountain flow and never again reaches the faster moving free surface. The particle motion behind the interface is modeled with a combination of equations that describe the advection of the particle due to convective/fountain flow and its lateral migration due to viscoelasticity. This model neglects the finite size of the particle and is thus unable to capture the full details of the observed motion. However, the qualitative agreement between the experimental results and the modeling predictions suggests that the observed particle motion is the result of the combined effect of viscoelasticity and fountain flow.
Comparative analysis of electron-phonon relaxation in a semiconducting carbon nanotube and a PbSe quantum dot

The key features of the phonon-induced relaxation of electronic excitations in the (7,0) zig-zag carbon nanotube (CNT) and the Pb 16 Se 16 quantum dot (QD) are contrasted using a time-domain ab initio density functional theory (DFT) simulation. Upon excitation from the valence to the conduction band (CB), the electrons and holes nonradiatively decay to the band-edge in both materials. The paper compares the electronic structure, optical spec- tra, important phonon modes, and decay channels in the CNT and QD. The relaxation is faster in the CNT than in the QD. In the PbSe QD, the electronic energy decays by coupling to low-frequency acoustic modes. The decay is nonexponential, in agreement with non- Lorentzian line-shapes observed in optical experiments. In contrast to the QD, the excitation decay in the CNT occurs primarily via high-frequency optical modes. Even though the holes have a higher density of states (DOS), they relax more slowly than the electrons, due to bet- ter coupling to low-frequency vibrations. Further, the expected phonon bottleneck is not ob- served in the QD, as rationalized by a high density of optically dark states. The same argu- ment applies to the CNT. The computed results agree well with experimentally measured ultrafast relaxation time-scales and provide a unique atomistic picture of the electron-phonon relaxation processes.
Remarks on a paper by Aref and Flinchem

It is shown that the vortex filament in background shear considered in Aref & Flinchem (1984) is unstable to infinitesimal disturbances, and that the numerical results described therein are consistent with the characteristics of the instability.
Reactive Arthritis and Reiter's Syndrome Following an Outbreak of Gastroenteritis Caused by Salmonella enteritidis

Reactive arthritis and Reiter's syndrome have been reported following gastroenteritis. Prevalence studies for these conditions are uncommon, and the prevalence of Reiter's syndrome after Salmonella enteritidis infection has not been previously reported. After a large outbreak of S. enteritidis gastroenteritis, a survey of persons exposed to the implicated food source was conducted, and those with reactive arthritis were evaluated for possible risk factors. Among 481 persons responding to the questionnaire, 217 cases of S. enteritidis gastroenteritis were identified (31 confirmed and 186 clinical cases; attack rate, 45%). Twenty-nine percent of the cases had symptoms of reactive arthritis, 3% had symptoms of Reiter's syndrome, and 10% had reactive arthritis with oral ulcers. Markers for severe illness (diarrhea > or =7 days, emergency room visit or hospitalization, and antibiotic treatment) were statistically significant but colinear factors associated with reactive arthritis. Increased awareness of postdysenteric reactive arthritis and Reiter's syndrome is recommended.
An Adaptive Data Prefetcher for High-Performance Processors

While computing speed continues increasing rapidly, data-access technology is lagging behind. Data-access delay, not the processor speed, becomes the leading performance bottleneck of high-end/high-performance computing. Prefetching is an effective solution to masking the gap between computing speed and data-access speed. Existing works of prefetching, however, are very conservative in general, due to the computing power consumption concern of the past. They suffer in effectiveness especially when applications' access pattern changes. In this study, we propose an Algorithm-level Feedback-controlled Adaptive (AFA) data prefetcher to address these issues. The AFA prefetcher is based on the Data-Access History Cache, a hardware structure that is specifically designed for data prefetching. It provides an algorithm-level adaptation and is capable of dynamically adapting to appropriate prefetching algorithms at runtime. We have conducted extensive simulation testing with Simple Scalar simulator to validate the design and to illustrate the performance gain. The simulation results show that AFA prefetcher is effective and achieves considerable IPC (Instructions Per Cycle) improvement in average.
FIBRE BEAM–COLUMN MODEL FOR NON‐LINEAR ANALYSIS OF R/C FRAMES: PART I. FORMULATION

A companion paper presents the formulation of a fibre beam-column element for the non-linear static and dynamic analysis of R/C frames. This paper illustrates the application of the proposed element in the simulation of the hysteretic behaviour of several R/C beam and column specimens. The specimens are subjected to uniaxial and biaxial loading histories with varying axial load. The proposed element shows computationally stable and robust numerical behaviour, while being able to describe very well the hysteretic behaviour of the reinforced concrete members under the imposed complex loading histories.