cssi/SciSciGPT-SciSciNet huggingface dataset:
Molecular pathways of pannexin1-mediated neurotoxicity

Pannexin1 (Panx1) forms nonselective membrane channels, structurally similar to gap junction hemichannels, that is permeable to ions, nucleotides and other small molecules below 900 Da. Panx1 activity is implicated in paracrine signaling and inflammasome regulation. Recent studies in different animal models showed that Panx1 overactivation correlates with a selective demise of several types of neurons, including retinal ganglion cells, brain pyramidal and enteric neurons. The list of Panx1 activators includes extracellular ATP, glutamate, high K+, Zn2+, fibroblast growth factors (FGFs), pro-inflammatory cytokines and elevation of intracellular Ca2+. Most of these molecules are released following mechanical, ischemic or inflammatory injury of the CNS, and rapidly activate this channel. As a result, prolonged opening of Panx1 channel induced by these “danger signals” trigger a cascade of neurotoxic events capable of killing cells. The most vulnerable cell type are neurons that express high levels of Panx1. Experimental evidence suggests that Panx1 channels mediate at least two distinct neurotoxic processes: increased permeability of the plasma membrane and activation of the inflammasome in neurons and glia. Importantly, either pharmacological or genetic inactivation of Panx1 suppresses both these processes, providing a marked protection in several disease and injury models. These findings indicate that external danger signals generated after diverse types of injuries converge to activate Panx1. In this review we discuss molecular mechanisms associated with Panx1 toxicity and the crosstalk between different pathways.
Structural changes in Kenya's broadcasting system: A manifesta tion of presidential authoritarianism

Between December 1988 and March 1990, the government of Kenya restructured its broadcasting system. Examination of government documents and press reports viewed from the perspective of literature on authoritarian politics in Africa indicates that the structural changes were part of a strategy intended to enhance the image and authority of President Moi, breath new life into the ruling party and attract foreign investors. The strategy did attract foreign aid and investment in the media and did give the president a more efficient propaganda tool and tighter control over the state's broadcasting system. But, the aid increased the nation's external debt; the regime's propaganda alienated the public, and the second TV channel served to encourage open debate and multi-party politics which undermined the president's authority.
The Urea−Hydrogen Peroxide Complex: Solid-State Oxidative Protocols for Hydroxylated Aldehydes and Ketones (Dakin Reaction), Nitriles, Sulfides, and Nitrogen Heterocycles

An efficient solid-state oxidation of organic molecules is described using a stable, inexpensive, and easily handled reagent, the urea−hydrogen peroxide adduct. The generality of the reaction has been demonstrated in oxidation of several molecules, namely hydroxylated aldehydes and ketones (to hydroxylated phenols), sulfides (to sulfoxides and sulfones), nitriles (to amides), and nitrogen heterocycles (to N-oxides).
An Approach to the Minimization of Misclassification in the Repair of Equipment

A problem which can be quite costly to an agency involved with repairable equipment on a large scale is the misclassification which can arise when repair work is initiated. Often, a piece of equipment finds its way to the repair shop even though it has not experienced a failure. On the other hand, a failed component may not be repaired properly because the cause of failure is not properly diagnosed; thus a delay will occur in returning the component to service. A mathematical model is developed which accounts for the two misclassification possibilities and a procedure is given which minimizes the misclassification probabilities, contingent on a fixed amount of available capital for this purpose. The model is of the Markov type with the simplifying assumption of constant transition rates (over time) among the various states.
Elders Caring for Elders: The Role of Religious Involvement and Spiritual Rewards on Caregiver Stress, Resources, and Health

The current study investigates the relationships between three indicators of religious involvement and three aspects of spiritual caregiving awards and multiple measures of caregiver stress, internal and external resources, and physical and mental health among older (60+) African American caregivers of elders. Findings show that both factors are associated with the three caregiving areas, although spiritual rewards emerged as having more linkages than religious involvement. Further analysis showed significant relationships between the two independent variables of religious involvement and spiritual rewards, suggesting possible interactive effects on the caregiving experience. Implications for social work practice and research are highlighted.
Merleau-Ponty's Pragmatist Ethics

Utilizing a characterization of pragmatism drawn from Joseph Margolis, and with reference to the thought of C. S. Peirce and John Dewey, this paper first exposes a pragmatist conception of rationality within the French philosophy of Maurice Merleau-Ponty. It then explores how this praxical, biologically rooted understanding of rationality leads Merleau-Ponty to espouse the same broadly pragmatist conception of ethical life that we find in a recent work from Joseph Margolis: one that repudiates fixed principles and absolute ends in order to prompt us, under the pressing exigencies of life, to learn from radically different ways of thinking, thus committing us to negotiating peaceful solutions to our moral and political conflicts across diverse rational perspectives in a manner that, although taking us far from any form of objectivism, nevertheless refuses to renounce all claims to objectivity.
The influence of physical education on physical activity levels of urban elementary students.

Abstract The purpose of this study was to examine the role of physical education in shaping physical activity patterns. Seventy-one Hispanic and African American elementary students participated in the study. Students attended one 30- and one 60-min physical education class weekly. Pedometer steps were used to estimate physical activity. Data suggest that students did not engage in enough physical activity on a daily basis to incur health benefits. There were significant step differences in 0-, 30-, and 60-min physical education days, with the most steps occurring on 60-min days. Results from the study suggest physical education may be an important source of physical activity for Hispanic and African American students, especially girls, and may influence participation in physical activity outside of class.
Spectroscopic analyses of the noncovalent self-assembly of cyanines upon various nucleic acid scaffolds.

We utilized self-assembly of cyanine chromophores to study the conformational changes in various types of nucleic acid scaffolds: single and double stranded DNA, linear or circular DNA and RNA. We identified a chromophore that became highly fluorescent after aggregating upon nucleic acids. Fluorescence from the aggregate was instantaneous after self-assembly. Temporal emission profiles displayed a biphasic trend demonstrating kinetic dependence for assembly and disassembly. Absorption spectra of the aggregate showed a red-shifted “shoulder” peak indicative of J-aggregate. Fluorescence from J-aggregates was also red-shifted. We utilized cyanine self-assembly to quantize various nucleic acids. The limits of detection and quantization for φX174 DNA were 3 and 9 fmol, respectively. We similarly determined the sensitivity for various nucleic acids and established the optimum conditions for self-assembly. Collectively, the effects of methanol, salt, and full width at half maximum for cyanine fluorescence on DNA or carboxymethylamylose scaffolds, all suggested noncovalent, electrostatic, and hydrophobic forces were involved in supramolecular self-assembly. Our results facilitate a better understanding of supramolecular self-assembly.
Linear stability of Poiseuille flow in a circular pipe

Correction of an error in the matrix elements used by Salwen & Grosch (1972) has brought the results of the matrix-eigenvalue calculation of the linear stability of Hagen–Poiseuille flow into complete agreement with the numerical integration results of Lessen, Sadler & Liu (1968) for azimuthal index n = 1. The n = 0 results were unaffected by the error and the effect of the error for n > 1 is smaller than for n = 1. The new calculations confirm the conclusion that the flow is stable to infinitesimal disturbances.Further calculations have led to the discovery of a degeneracy at Reynolds number R = 61·452 ± 0·003 and wavenumber α = 0·9874 ± 0·0001, where the second and third eigenmodes have equal complex wave speeds. The variation of wave speed for these two modes has been studied in the vicinity of the degeneracy and shows similarities to the behaviour near the degeneracies found by Cotton and Salwen (see Cotton 1977) for rotating Hagen-Poiseuille flow. Finally, new results are given for n = 10 and 30; the n = 1 results are extended to R = 106; and new results are presented for the variation of the wave speed with αR at high Reynolds number. The high-R results confirm both Burridge & Drazin's (1969) slow-mode approximation and more recent fast-mode results of Burridge.
Rational spectral densities and strong mixing

Abstract This article is concerned with stationary random fields with rational spectral densities. The dichotomy between the one-parameter and multiparameter cases is explored, particularly in terms of a strong mixing condition. The rich variety of behavior exhibited by the multiparameter case is demonstrated.
Intermittent methylphenidate during adolescent development produces locomotor hyperactivity and an enhanced response to cocaine compared to continuous treatment in rats.

The consequences of chronic methylphenidate (MPH) administration in adolescents for the treatment of attention-deficit/hyperactivity disorder (ADHD) remain to be fully understood. Studies in rats indicate that the pharmacokinetics of psychostimulant administration can powerfully influence the behavioral and neural consequences of chronic treatment. The purpose of the present study was to assess the effects of intermittent (0.8 or 1.6 mg/kg, s.c., twice daily) versus continuous (1.6 or 3.2 mg/kg/day via osmotic minipump) MP administration across four weeks of adolescent development in rats. Results indicate that intermittent treatment produced hyperactivity in a novel open field and increased sensitivity to both the reinforcing and locomotor-activating effects of cocaine. In contrast, continuous MPH resulted in a hypoactive response to the novel open field and a reduced sensitivity to both operant and non-contingent cocaine. To the extent that the continuous release condition models the sustained-release formulations utilized in human ADHD treatment, we interpret these data to indicate that sustained-release formulations are less likely to advance a risk of subsequent substance abuse.
A rule-based approach to predict forging volume for cost estimation during product design

The cost of manufacturing a part is an important consideration as it is being designed. However, early in the design process, not all of the design details of a part are decided, so the cost must be estimated from a limited amount of data. Raw material typically represents a significant portion of the part’s final cost, especially when parts are formed by forging, which requires a significant amount of additional material to be added to the final part. Therefore, an accurate estimate of the volume of the forging die is needed from limited information about the part geometry. This paper describes a rule-based system to quickly estimate the geometry (and thus, the volume) of the forging die that will be needed for an axisymmetric part based on its geometry. Tests of the methodology on aircraft engine components demonstrate that the methodology produces accurate estimates of the billet weight.
Modeling of transport delay for adaptive antiarrhythmic drug infusion

We have examined a model of early drug distribution to be used in adaptive antiarrhythmic drug delivery. This two-compartment model includes a simple time delay to compensate for the dynamics of drug transport and mixing. The model parameters for 19 patients were found by non-linear regression. The average model time-delay was found to be 70 seconds for the Class 1A antiarrhythmic drugs disopyramide and procainamide. The two-compartment model with time-delay was found to be a suitable model for use with an adaptive control scheme.
Determination of neural state classification metrics from the power spectrum of human ECoG

Brain electrical activity exhibits scale-free dynamics that follow power law scaling. Previous works have shown that broadband spectral power exhibits state-dependent scaling with a log frequency exponent that systematically varies with neural state. However, the frequency ranges which best characterize biological state are not consistent across brain location or subject. An adaptive piecewise linear fitting solution was developed to extract features for classification of brain state. Performance was evaluated by comparison to an a posteriori based feature search method. This analysis, using the 1/ƒ characteristics of the human ECoG signal, demonstrates utility in advancing the ability to perform automated brain state discrimination.
The Physics of Semiconductors: With Applications to Optoelectronic Devices

1. Basic concepts in quantum mechanics 2. One dimensional potential problems 3. Three dimensional potential problems 4. Approximation methods in quantum mechanics 5. Equilibrium statistical mechanics 6. Nonequilibrium statistical mechanics 7. Multielectron systems and crystalline symmetries 8. Motion of electrons in a periodic potential 9. Phonons and the electron-phonon interaction 10. Generation and recombination processes in semiconductors 11. Junctions 12. Semiconductor photonic detectors 13. Optoelectronic emitters 14. Field effect devices.
Longitudinal relationship among growth, nutritional status, and pulmonary function in children with cystic fibrosis: analysis of the Cystic Fibrosis Foundation National CF Patient Registry.

Objective: To determine prospectively the relationship among growth, nutritional status, and pulmonary function over a 4-year period in a large cohort of children with cystic fibrosis (CF). Study design: CF Foundation National CF Patient Registry data collected from 1991 to 1995 for 968 children (507 male) aged 5 to 8 years with pancreatic insufficiency and forced expiratory volume in 1 second within 60% to 140% of predicted values (FEV1%) were analyzed longitudinally. Variables hypothesized to affect FEV1% included age, sex, z scores for height, weight, percent of height-appropriate body weight, and annual number of days hospitalized. Results: The significant decline in FEV1% was curvilinear and dependent on baseline FEV1%; children with initial FEV1% ≥90 declined 2.6 U/y more than those with initial FEV1% <90. Boys gained but girls declined in z scores for height. Girls decreased in z scores for weight at a greater rate than boys. The z scores for weight and percent of height-appropriate body weight were significantly associated with longitudinal changes in FEV1%, after adjustment was done for hospitalizations. Conclusions: Growth, nutritional status, and pulmonary function are not stable in prepubertal children with CF and pancreatic insufficiency. Important sex-related differences in growth occur before puberty. Growth and nutritional status are associated with changes in FEV1%, suggesting that nutritional intervention may slow the decline in pulmonary function in children with CF. (J Pediatr 2000;137:374-80)
Contribution of net hepatic glycogen synthesis to disposal of an oral glucose load in humans.

Abstract The contribution of hepatic glycogen synthesis to whole body glucose disposal after an oral glucose load was examined using 13C nuclear magnetic resonance (NMR) spectroscopy to measure liver glycogen content in healthy, volunteers after an overnight fast. In group 1 (n = 14), hepatic glycogen synthesis was measured using 13C-NMR spectroscopy for 240 minutes after ingestion of 98 ± 1 g glucose. Liver volumes were measured using magnetic resonance imaging (MRI). To assess the direct (glucose → glucose-6-P → glucose-1-P → uridine diphosphate (UDP)-glucose → glycogen) and indirect (3-carbon units → → glycogen) pathways of liver glycogen synthesis, group 2 (n = 6) was studied with an identical glucose load enriched with [1-13C]glucose along with acetaminophen to noninvasively assess the 13C enrichment in hepatic UDP-glucose. The fasting hepatic glycogen content was 305 ± 17 mmol/L liver, and the liver volume was 1.46 ± 0.07 L. For the initial 180 minutes after ingestion of glucose, hepatic glycogen concentrations increased linearly (r = .94, P = .0006) achieving a maximum concentration of 390 ± 7 mmol/L liver and then remained constant until the end of the study. The mean maximum rate of net hepatic glycogen synthesis was 0.48 ± 0.07 mmol/L liver-minute. Total liver glycogen synthesis could account for 16.7 ± 3.8 g (17% ± 4%) of the glucose ingested, and of this, 10.5 ± 2.4 g (63% ± 7%) was synthesized by the direct pathway. In conclusion, after ingestion of 98 g of glucose: (1) 16.7 ± 3.8 g (17% ± 4%) glucose was stored in the liver as glycogen, and (2) 63% ± 7% (10.5 ± 2.4 g) of this glycogen was formed via the direct pathway.
An evaluation of a new mechanized endodontic device: The Endolift

Four methods of canal preparation are tested: hand instrumentation with preflaring and step back, Giromatic, Union Broach Endo Angle, and the Kerr Endolift. The preparations are analyzed with plastic blocks and extracted human teeth. Hand instrumentation with preflaring and step-back is superior to and safer than the mechanized endodontic devices. With proper care and technique, some mechanized endodontic devices can produce adequate canal preparations.
NEPHROSTOMY TUBE DRAINAGE WITH PYELOPLASTY: IS IT NECESSARILY A BAD CHOICE?

Purpose: Despite continued controversy regarding the optimal method of urinary diversion after dismembered pyeloplasty in children, we have treated the majority of our patients with postoperative n...
Biphotonic stimulation of emission and matrix effects in lead sulfide in solid argon

Abstract Vibronic emission spectra stimulated by laser radiation are reported for PbS in argon matrices. Biphotonically induced emission bands largely from the V ′ = 0 levels of the B and D states have been observed and in the B → X system, V ′ → 0 bands for V ′ up to 7 also appear. The A → X and a → X emissions by single photon stimulation have been reexamined and the zero-phonon quasilines as well as the multiphonon envelops have been measured. In the A → X band system, zero-phonon lines for 34 S as well as for 32 S can be seen. Series of additional emission peaks appearing in the A → X system are tentatively interpreted as due to a localized vibration of the PbS molecule in a potential describing its cage in the argon matrix lattice.
Assessing Aquatic Ecotoxicological Risks Associated with Fluorescent Dyes Used for Water-Tracing Studies

Hydrological tracer testing is the most reliable diagnostic technique available for identifying and quantifying hydrodispersive transport processes. As such, hydrologic tracing is an essential tool that is commonly used to establish flow trajectories, to understand solute-transport processes, and to develop human health and ecological risk assessments. Unfortunately, the use of anthropogenic materials to trace the flow of water may also impart another source of risk to human health and the environment. In general, attempts are usually made to deliberately release tracer agents at concentrations far below their recognized toxic levels. Ecotoxicologically safe levels for injection concentrations of fluorescent tracer agents are generally set at levels far below that which are necessary to maintain measurable downstream concentrations. Appropriate tracer test design is important, because incorrect tracer-mass estimates may result in the release of larger tracer masses than are necessary and that exceed expected environmental concentrations (EECs). To maintain tracer concentrations at or below accepted levels, optimal tracer-test design is essential and may be achieved using the Efficient Hydrologic Tracer-Test Design methodology. By applying an optimal tracer-test design, it is more likely that downstream tracer EECs will be maintained at or below accepted concentrations while maintaining sufficiently high downstream EECs necessary for positive tracer detection.
Social Calls Produced within and near the Roost in Two Species of Tent-Making Bats, Dermanura watsoni and Ectophylla alba

Social animals regularly face the problem of relocating conspecifics when separated. Communication is one of the most important mechanisms facilitating group formation and cohesion. Known as contact calls, signals exchanged between conspecifics that permit group maintenance are widespread across many taxa. Foliage-roosting bats are an excellent model system for studying the evolution of contact calling, as there are opportunities to compare closely related species that exhibit major differences in ecology and behavior. Further, foliage-roosting bats rely on relatively ephemeral roosts, which leads to major challenges in maintaining group cohesion. Here, we report findings on the communication signals produced by two tent-making bats, Dermanura watsoni and Ectophylla alba. We found that both species produced calls in the early morning near the roost that were associated with roostmate recruitment. Calling often ended once other bats arrived at the tent, suggesting that calls may be involved in roostmate recruitment and group formation. The structure and function of these calls are described and future research directions are discussed.
Potentially Available Nitrogen and Phosphorus Along a Chaparral Fire Cycle Chronosequence

The objectives were to examine the effect of time, aspect, and soil horizon on N and P availabilities across a 4- to 85-yr-old post-fire chaparral chronosequence. Nitrogen and P availabilites were measured with plant bioassays, soil incubations, soil chemical extractions, and field leaf analyses. The A horizons contained significantly higher levels of available N and P than B horizons. In general, N availability was higher in north aspect stands than in south aspects stands, while P availability was higher in south aspect stands than in north aspect stands. Nitrogen availability increased with increasing stand age up to 50 to 60 yr (aggradation phase); beyond 60 yr, N availability declined (degradation phase). Phosphorus availability decreased logarithmically with increasing age. Declining N availability in the older stands was due to declining total soil N and a decline in the fraction available; the declining P availability in the older stands was due to a decline in the fraction available. The lowering of both soil and plant N and P concentrations in older stands may contribute to stand senescence. Contribution from the Systems Ecology Res. Group. This work was funded by NSF Grant DEB-8025977 to San Diego State Univ.
Neuroprotective effects of geranylgeranylacetone in experimental traumatic brain injury.

Geranylgeranylacetone (GGA) is an inducer of heat-shock protein 70 (HSP70) that has been used clinically for many years as an antiulcer treatment. It is centrally active after oral administration a...
Exploration of Molecular Interactions in Cholesterol Superlattices: Effect of Multibody Interactions

Experimental evidences have indicated that cholesterol may adapt highly regular lateral distributions (i.e., superlattices) in a phospholipid bilayer. We investigated the formations of superlattices at cholesterol mole fraction of 0.154, 0.25, 0.40, and 0.5 using Monte Carlo simulation. We found that in general, conventional pairwise-additive interactions cannot produce superlattices. Instead, a multibody (nonpairwise) interaction is required. Cholesterol superlattice formation reveals that although the overall interaction between cholesterol and phospholipids is favorable, it contains two large opposing components: an interaction favoring cholesterol-phospholipid mixing and an unfavorable acyl chain multibody interaction that increases nonlinearly with the number of cholesterol contacts. The magnitudes of interactions are in the order of kT. The physical origins of these interactions can be explained by our umbrella model. They most likely come from the requirement for polar phospholipid headgroups to cover the nonpolar cholesterol to avoid the exposure of cholesterol to water and from the sharp decreasing of acyl chain conformation entropy due to cholesterol contact. This study together with our previous work demonstrate that the driving force of cholesterol-phospholipid mixing is a hydrophobic interaction, and multibody interactions dominate others over a wide range of cholesterol concentration.
Postinstability Models in Dynamics

This paper is devoted to the concept of instability in dynamical systems with the main emphasis on orbital, Hadamard, and Reynolds instabilities. It demonstrates that the requirement about differentiability in dynamics in some cases is not consistent with the physical nature of motions, and may lead to unrealistic solutions. Special attention is paid to the fact that instability is not an invariant of motion: it depends upon frames of reference, the metric of configuration space, and classes of functions selected for mathematical models of physical phenomena. This leads to the possibility of elimination of certain types of instabilities (in particular, those which lead to chaos and turbulence) by enlarging the class of functions using the Reynolds-type transformation in combination with the stabilization principle: the additional terms (the so-called Reynolds stresses) are found from the conditions that they suppress the original instability. Based upon these ideas, a new approach to chaos and turbulence as well as a new mathematical formalism for nonlinear dynamics are discussed.
Health-related service utilization and HIV risk behaviors among HIV infected injection drug users and crack smokers

This study was designed to assess utilization of health-related services and HIV risk related behaviors by HIV infected drug users one year prior to and two years following the availability of Ryan White Title I funding. Using a cross-sectional design, a total of 777 drug injectors and crack smokers from five US cities were surveyed, over three waves of data collection, about their use of drug treatment, medical services, housing, mental health, and case management and about their sex and drug-related risk behaviors. For all service categories and in each wave, including the year prior to Title I funding, HIV risk behaviors were lower among those who used health-related services, with the exception of housing. Use of services did not increase significantly following the disbursement of Title I funds except for housing and case management. These findings suggest that it may be necessary to increase the attractiveness of health-related services, not just funding for services, for HIV infected substance abusers.
Modeling aeolian transport of soil-bound plutonium: considering infrequent but normal environmental disturbances is critical in estimating future dose

Dose assessments typically consider environmental systems as static through time, but environmental disturbances such as drought and fire are normal, albeit infrequent, events that can impact dose-influential attributes of many environmental systems. These phenomena occur over time frames of decades or longer, and are likely to be exacerbated under projected warmer, drier climate. As with other types of dose assessment, the impacts of environmental disturbances are often overlooked when evaluating dose from aeolian transport of radionuclides and other contaminants. Especially lacking are predictions that account for potential changing vegetation cover effects on radionuclide transport over the long time frames required by regulations. A recently developed dynamic wind-transport model that included vegetation succession and environmental disturbance provides more realistic long-term predictability. This study utilized the model to estimate emission rates for aeolian transport, and compare atmospheric dispersion and deposition rates of airborne plutonium-contaminated soil into neighboring areas with and without environmental disturbances. Specifically, the objective of this study was to utilize the model results as input for a widely used dose assessment model (CAP-88). Our case study focused on low levels of residual plutonium found in soils from past operations at Los Alamos National Laboratory (LANL), in Los Alamos, NM, located in the semiarid southwestern USA. Calculations were conducted for different disturbance scenarios based on conditions associated with current climate, and a potential future drier and warmer climate. Known soil and sediment concentrations of plutonium were used to model dispersal and deposition of windblown residual plutonium, as a function of distance and direction. Environmental disturbances that affected vegetation cover included ground fire, crown fire, and drought, with reoccurrence rates for current climate based on site historical patterns. Using site-specific meteorology, accumulation rates of plutonium in soil were modeled in a variety of directions and distances from LANL sources. Model results suggest that without disturbances, areas downwind to the contaminated watershed would accumulate LANL-derived plutonium at a relatively slow rate (<0.01 Bq m−2 yr−1). However, model results under more realistic assumptions that include environmental disturbances show accumulation rates more than an order-of-magnitude faster. More generally, this assessment highlights the broader need in radioecology and environmental health physics to consider infrequent but normal environmental disturbances in longer-term dose assessments.
Sensitivity study of meteorological parameters on mineral aerosol mobilization, transport, and distribution

[1] Predicting mineral aerosol distributions is a difficult task due to the episodic nature of the sources and transport. Here we show comparisons between a 22-year simulation of mineral aerosols and satellite and in situ observations. Our results suggest that the model does a good job of predicting atmospheric mineral aerosol distributions, with some discrepancies. In addition, there are differences between our model results and previously published results [e.g., Ginoux et al., 2001]. We conduct several tests of the sensitivity of mineral aerosol simulations to the meteorological data sets and mobilization parameterizations in order to understand the differences. Comparisons between model simulations using National Center for Atmospheric Research/National Center for Environmental Prediction (NCEP/NCAR) and National Aeronautics and Space Administration Data Assimilation Office (NASA DAO) reanalysis data sets show that the model results with the two data sets are fairly consistent but with some important differences. The sensitivity analysis shows that differences between simulated dust near Australia are likely due to differences in both source parameterization and surface winds. Differences over East Asia are dominated by differences in meteorology. The sensitivity analysis also shows that we cannot tell from comparisons with observations whether the cultivation source is active nor eliminate it because of the large uncertainty in meteorology and source parameterization.
In vivo quantification of T1ρ using a multislice spin-lock pulse sequence

A multislice spin-lock (MS-SL) pulse sequence is implemented on a clinical scanner to acquire multiple images with spin-lock-generated contrast of the knee joints of six healthy human subjects. The MS-SL sequence produces images with T1ρ contrast with an additional factor of intrinsic T2ρ weighting, which hinders direct measurement of T1ρ. A method is presented to compensate the MS-SL-generated data with regard to T2ρ in an effort to accurately calculate multislice T1ρ maps in a feasible experimental time. The T2ρ-compensated multislice T1ρ maps produced errors in the measurement of T1ρ in healthy patellar cartilage of ∼5% compared to the gold standard measurement of T1ρ acquired with single-slice spin-lock pulse sequence. The MS-SL sequence has potential as an important clinical tool for the acquisition of multislice T1ρ-weighted images and/or quantitative multislice T1ρ maps. Magn Reson Med 52:1453–1458, 2004. © 2004 Wiley-Liss, Inc.
Multivariate subexponential distributions

We present a formulation of subexponential and exponential tail behavior for multivariate distributions. The definitions are necessarily in terms of vague convergence of Radon measures rather than of ratios of distribution tails. With the proper setting, we show that if all one dimensional marginals of a d-dimensional distribution are subexponential, then the distribution is multivariate subexponential. Known results for univariate subexponential distributions are extended to the multivariate setting. Point process arguments are used for the proofs.
Culture of responsibility

The current crisis with the Ebola virus vividly illustrates the priority that must be given to infectious diseases because of their potentially devastating consequences to individuals and to society. Few would argue against the need for more research on Ebola and the expedited development of a cure; however, recent incidents in biocontainment laboratories and the proliferation of such facilities globally raise concerns about safety and have split the scientific community. Scientists who defend research on dangerous pathogens as vital to protecting populations are opposed by those who fear the potential devastation caused by the intentional or unintentional release of pathogens from the lab. Achieving a “culture of safety,” so often alluded to after recent lapses in biosafety procedures, demands adopting a “culture of responsibility” as well.
Descriptive epidemiology of ovarian cancer in the United States, 1992-1997.

Descriptive Epidemiology of Ovarian Cancer in the United States, 1992-1997 Marc T. Goodman and Holly L. Howe Ovarian cancer is relatively uncommon, and therefore little has been published to date regarding racial or ethnic variations in the incidence or mortality of this malignancy. As the U.S. population becomes more diverse, the interest in health problems and disparities in outcomes among minority and economically disadvantaged groups will continue to increase. In this supplement, the authors focus on epidemiology, pathology and classification issues, multiple primary tumors, staging, and incidence and mortality for race/ethnic groups. The authors also focused on epidemiologic differences between borderline tumors of low malignant potential and carcinomas.
Nonlinear correlation for estimating the motion of multiple objects in image sequences

A nonlinear correlation algorithm is proposed for estimating the motion of objects from an image pair. This algorithm requires no a priori information on the number, size, or shape of the moving objects and does not require feature extraction or segmentation of either image. The algorithm directly yields information on the number of moving objects, the motion of the objects, and the size of the objects. Additional processing can be performed to yield the centroid of the objects in either frame. The utility of the resulting algorithm is demonstrated by application to a pair of example image sequences.
Chinese and north Americans: An epistemological exploration of intercultural communication

Based on relevant works from various disciplines (rhetoric, sociology, cognitive science, linguistics, and anthropology), this article proposes that the external world, known through species‐specific human mental capabilities, has provided all cultures with almost identical basic knowledge mutating into several structures of consciousness. It is argued that this process of knowing renders communication possible among people from diverse cultures, despite their differences. Within this theoretical frame, a qualitative analysis is offered to contrast the Chinese with the North American cultures, tracing down to a ground common to both. Three basic domains—time, space, and ego, relating to views on nature, the individual, and society— are examined in order to establish a connection to cultural traditions/conventions for social interaction. Further examination of data from interviews and participant observations locates some common difficulties in intercultural interaction between Chinese and North Americans ...
Automated Situation-Aware Service Composition in Service-Oriented Computing

Service-based systems have many applications, such as e-business, health care, and homeland security. In these systems, it is necessary to provide users the capability of composing services into workflows providing higher-level functionality. In dynamic service-oriented computing environments, it is desirable that service composition is automated and situation-aware to generate robust and adaptive workflows. In this paper, an automated situation-aware service composition approach is presented. This approach is based on the a-logic, a-calculus, and a declarative model for situation awareness (SAW). This approach consists of four major components: (1) analyzing SAW requirements using our SAW model, (2) translating our SAW model representation to a-logic specifications and specifying a control flow graph in a-logic as the service composition goal, (3) automated synthesis of a-calculus terms defining situation-aware workflow agents based on a-logic specifications for SAW requirements and the control flow graph, and (4) compilation of a-calculus terms to executable components.
Application-aware management of parallel simulation collections

This paper presents a system deployed on parallel clusters to manage a collection of parallel simulations that make up a computational study. It explores how such a system can extend traditional parallel job scheduling and resource allocation techniques to incorporate knowledge specific to the study.Using a UINTAH-based helium gas simulation code (ARCHES) and the SimX system for multi-experiment computational studies, this paper demonstrates that, by using application-specific knowledge in resource allocation and scheduling decisions, one can reduce the run time of a computational study from over 20 hours to under 4.5 hours on a 32-processor cluster, and from almost 11 hours to just over 3.5 hours on a 64-processor cluster.
Mutagenesis and Expression of amo, Which Codes for Ammonia Monooxygenase in Nitrosomonas europaea

Nitrosomonas europaea has two copies of the operon encoding ammonia monooxygenase (AMO). The nucleotide sequences of the two copies of amoA were obtained, and they were found to differ by one nucleotide. To determine if both copies of amoA were functional, insertional mutagenesis was performed to inactivate either copy of amoA alone. A DNA cassette containing the lacZ and kan genes inserted into amoA was constructed. Mutagenesis was done by using transformation and homologous recombination to mobilize the cassette into the chromosomal copies of amoA. Mutations were obtained in both copies of amoA. Either copy of amoA was sufficient to support growth when the other copy was disrupted. However, inactivation of one copy of amoA, but not the other, resulted in slower growth. Measurements of ammonia-dependent O2 consumption, which depends on AMO, confirmed that the slower-growing mutant had lower activity while the faster-growing mutant had near wild-type levels of activity. Similarly, as measured by [14C]acetylene label incorporation, there was less active AMO present in the slower-growing mutant than in the faster-growing mutant or in the wild type. Northern blot analysis of transcription likewise showed that the slower-growing mutant had less full-sized AMO mRNA.
Retention of suspended sediment and phosphorus on a freshwater delta, South Lake Tahoe, California

The Upper Truckee River and Trout Creek, two major tributaries inflowing to Lake Tahoe, join to form what was historically the largest wetland in the Sierra Nevada mountain range that separates California and Nevada (USA). In the 1950s the delta floodplain of the Upper Truckee River was greatly reduced in area (38%) by urban development and the diversion of the river into a single excavated channel. Conversely, Trout Creek still flows through a wide marsh system with significant overbank flooding before entering Lake Tahoe. This study hypothesized that river channel reaches that are not incised within the delta floodplain retain more sediment and nutrients as a result of greater floodplain connectivity, compared to more incised and excavated reaches. Suspended sediment (SS) and total phosphorus (TP) load data from the delta formed by the Upper Truckee River and Trout Creek were collected using flow stage sensors, turbidometers and depth-integrated samples. During the spring snowmelt flow events monitored in 2003, SS load was reduced by 13–41% for the Upper Truckee River and by 68–90% for Trout Creek. Similar reductions in TP load were observed: 13–32% for the Upper Truckee River and 61–84% for Trout Creek. Monitoring of Trout Creek indicated a reduction in load per unit volume of 20–34% in a moderately incised reach versus a reduction of 51–77% in a non-incised marsh reach containing lagoons, braided channels and backwater areas created by a beaver dam. Smaller particle sizes, <10 μm, were retained in the lower marsh reach with similar efficiencies as larger particle sizes. If retention rates from the Trout Creek portion of the marsh are applied to the Upper Truckee River, sediment loading to Lake Tahoe for 2003 would have been reduced by 917 tons of SS.
Structural characterization of Clostridium acetobutylicum 8-oxoguanine DNA glycosylase in its apo form and in complex with 8-oxodeoxyguanosine.

Abstract DNA is subject to a multitude of oxidative damages generated by oxidizing agents from metabolism and exogenous sources and by ionizing radiation. Guanine is particularly vulnerable to oxidation, and the most common oxidative product 8-oxoguanine (8-oxoG) is the most prevalent lesion observed in DNA molecules. 8-OxoG can form a normal Watson–Crick pair with cytosine (8-oxoG:C), but it can also form a stable Hoogsteen pair with adenine (8-oxoG:A), leading to a G:C → T:A transversion after replication. Fortunately, 8-oxoG is recognized and excised by either of two DNA glycosylases of the base excision repair pathway: formamidopyrimidine–DNA glycosylase and 8-oxoguanine DNA glycosylase (Ogg). While Clostridium acetobutylicum Ogg (CacOgg) DNA glycosylase can specifically recognize and remove 8-oxoG, it displays little preference for the base opposite the lesion, which is unusual for a member of the Ogg1 family. This work describes the crystal structures of CacOgg in its apo form and in complex with 8-oxo-2′-deoxyguanosine. A structural comparison between the apo form and the liganded form of the enzyme reveals a structural reorganization of the C-terminal domain upon binding of 8-oxoG, similar to that reported for human OGG1. A structural comparison of CacOgg with human OGG1, in complex with 8-oxoG containing DNA, provides a structural rationale for the lack of opposite base specificity displayed by CacOgg.
The homotopy groups of SE(2) at p⩾5 revisited

Abstract We present a new technique for analyzing the v 0 -Bockstein spectral sequence studied by Shimomura and Yabe. Employing this technique, we derive a conceptually simpler presentation of the homotopy groups of the E ( 2 ) -local sphere at primes p ⩾ 5 . We identify and correct some errors in the original Shimomura–Yabe calculation. We deduce the related K ( 2 ) -local homotopy groups, and discuss their manifestation of Gross–Hopkins duality.
Lorentzian path integral for minisuperspace cosmology.

The path integral for minisuperspace models of cosmology is defined as a sum over Lorentzian geometries, and is a Green function for the Wheeler-DeWitt operator. It is shown to be a symmetric function of the initial and final configurations, and its real part is a solution to the Wheeler-DeWitt equation. The Lorentzian path integral is computed explicitly for the de Sitter minisuper-space model and is convergent. The resulting Green function is then related to the solutions of the Wheeler-DeWitt equation known as the Hartle-Hawking and tunneling wave functions of the Universe. The real part of this Green function is a product of Hartle-Hawking wave functions.
Effect of liver disease and transplantation on urea synthesis in humans: relationship to acid-base status.

It has been suggested that hepatic urea synthesis, which consumes HCO 3 − , plays an important role in acid-base homeostasis. This study measured urea synthesis rate (Ra urea) directly to assess it...
Impact of Positive Margins on Survival in Patients Undergoing Esophagogastrectomy for Esophageal Cancer.

Background Multimodality treatment that includes esophagogastrectomy may represent the best option for curing accurately staged patients with esophageal cancer. We analyzed the impact of incomplete resection on outcomes after esophagogastrectomy for esophageal cancer. Methods The incidence of positive margins for patients who underwent esophagogastrectomy without induction therapy for pathologic T1-3N0-1M0 esophageal cancer of the mid and lower esophagus from 2003 to 2006 in the National Cancer Database was analyzed with multivariate logistic regression. The impact of positive margins on survival was assessed using Kaplan-Meier and Cox proportional hazards analysis. Results Positive margins occurred in 342 of 3,125 patients (10.9%) who met study criteria. Increasing clinical T status was an independent predictor of positive margins in multivariate analysis, but the chance of positive margins decreased with larger facility case volumes. The presence of clinical nodal disease was not predictive of an incomplete resection. The 5-year survival of patients with positive margins (13.8%, 95% confidence interval [CI]: 10.5% to 18.1%) was significantly worse than that for patients with negative margins (46.3%, 95% CI: 44.4% to 48.3%, p p p p Conclusions Positive margins are associated with poor survival, and adjuvant therapy only marginally improved prognosis. Future studies are needed to better evaluate whether induction therapy can lower the incidence of positive margins.
Studies of ferrite materials for the AGS Booster Synchrotron

The BNL (Brookhaven National Laboratory) Booster Synchrotron injects heavy ion and proton beams of increased intensity into the Alternating Gradient Synchrotron (AGS). Its accelerating cavities are sweep-tuned by varying the permeability of ferrite core rings within the cavities. Core material selection criteria and evaluation are discussed. Measurements of permeability, loss, and permittivity are presented. >
Quasi-optical components and subsystems for communications

Although most wireless communications systems are now digital, they still require analog front ends, since the transmitted signal is a modulated sinusoid. Optimization of the analog transmitter and receiver can improve the digital system performance. In this paper we describe a new approach to what we believe are more reliable, less expensive, and more compact front ends for microwave and millimeter-wave communications, This new approach is based on quasi-optical components, which are printed surfaces loaded with active and/or passive devices. The results presented here describe components which perform all of the functions that a quasi-optical transceiver requires: signal generation, amplification, reception, modulation and beam control.