cssi/SciSciGPT-SciSciNet huggingface dataset:
Flow state estimation in the presence of discretization errors

Ensemble data assimilation methods integrate measurement data and computational flow models to estimate the state of fluid systems in a robust, scalable way. However, discretization errors in the dynamical and observation models lead to biased forecasts and poor estimator performance. We propose a low-rank representation for this bias, whose dynamics is modelled by data-informed, time-correlated processes. State and bias parameters are simultaneously corrected online with the ensemble Kalman filter. The proposed methodology is then applied to the problem of estimating the state of a two-dimensional flow at modest Reynolds number using an ensemble of coarse-mesh simulations and pressure measurements at the surface of an immersed body in a synthetic experiment framework. Using an ensemble size of 60, the bias-aware estimator is demonstrated to achieve at least 70 % error reduction when compared to its bias-blind counterpart. Strategies to determine the bias statistics and their impact on the estimator performance are discussed.
Examining the role of perceived risk and benefit, shared concern for nuclear stigmatization, and trust in governments in shaping citizen risk acceptability of a nuclear power plant

This study aims to present a more balanced perspective of risk acceptability through integrating economic individualism and social constructivism and examining the impact of trust in the national a...
Covenant Amendment Fee and Value of Creditor Intervention after Covenant Violations

State-contingent control rights allow creditors to intervene after borrowers’ negative performance. Identifying the value of ex-post creditor intervention remains an empirical challenge due to the unknown counterfactual outcomes and the lack of randomly assigned treatment. In this paper, we investigate this question through examining an important form of renegotiation outcomes following covenant violations– the payment of amendment fee, which has been largely overlooked in the previous literature. Exploiting a hand-collected novel data on covenant amendments in corporate loan contracts, we first document the prevalence of nontrivial amendment fee payment made by borrowers in violation of covenants in exchange for waivers of covenant violations. We find that the amendment fee payment following covenant violation exhibits clear exclusiveness with explicit creditor intervention– only 6.9% covenant violations are followed by both amendment fee payments and creditor intervention on firm policy. This exclusiveness of amendment fee payment and creditor intervention suggests a potential time consistency issue in corporate debt contracting– creditors cannot commit to intervening after borrowers’ negative performance once been offered a side-payment for not doing so. We then examine factors that may affect the occurrence and the size of amendment fee payment following covenant violations. These factors include borrower side factors, creditor side factors and aggregate economic conditions. Eventually, we exploit variations in creditors’ share in borrowers’ outstanding liability as a measure of creditors’ skin-in-the-game to extract exogenous variations in the treatment assignment following covenant violations– whether or not interventions are undertaken. Using this instrumental variable, we identify a significantly positive real value added by creditors taking explicit actions intervening the operation of borrowers in covenant violations.
Developmental abnormalities and epigenetic alterations in medaka (Oryzias latipes) embryos induced by triclosan exposure.

Abstract Triclosan (TCS), an antibacterial and antifungal agent present in some consumer products, has been detected in the environment at varying concentrations. TCS exposure has been found to cause developmental abnormalities and endocrine disruption in various species of fish. It is not clearly understood whether TCS exposure causes epigenetic alterations in developing embryos and their germ cells. In the present study, we examined the effects of TCS exposure (0, 50, 100 and,200 μg/L) on embryonic development and primordial germ cells (PGCs), which are precursors of sperm and eggs, in medaka (Oyzias latipes). Developmental TCS exposure from 8 hours post-fertilization through 15 days post-fertilization (dpf) resulted in several developmental abnormalities, including enlarged yolk sac, decreased head trunk angle (HTA), and severe edema in the pericardial region. The male ratio increased in the 100 μg/L TCS exposure group, which was negatively correlated with the expression of cyp19ala (a gene encoding aromatase) and arα (androgen receptor alpha). Developmental 50 μg/L TCS exposure resulted in global hypomethylation in the whole body but not in the isolated PGCs. Expression of the gene encoding DNA methyltransferases (dnmt1 and dnmt3aa) was decreased by 50 μg/L TCS exposure both in the whole body and PGCs. TCS altered the expression of genes encoding enzymes involved in DNA methylation and demethylation in PGCs, suggesting epigenetic effects on germ cells. The present results demonstrate that the embryos exposed to the tested concentrations of TCS develop deformities during the early life stages and that the TCS within this range possesses an aromatase inhibitor property potential enough to alter sex ratios of developing embryos.
Biomass feedstock transport using fuel cell and battery electric trucks improves lifecycle metrics of biofuel sustainability and economy

Abstract The use of new vehicle technologies such as fuel cell hybrid electric and fully electric powertrains for biomass feedstock supply is an unexplored solution to reducing biofuel production cost, greenhouse gas emissions, and health impacts. These technologies have found success in light-duty vehicle applications and are in development for heavy-duty trucks. This study presents the first detailed stochastic techno-economic analysis and life-cycle assessment of biomass feedstock supply systems with diesel, fuel cell hybrid electric, and fully electric trucks and determines their impacts on biofuel production considering butanol as a representative biofuel. This study finds that fuel cell hybrid electric and fully electric trucks consume less energy relative to the diesel-powered truck regardless of the evaluated circumstances, including payloads of truck (loaded and empty), pavement types (gravel and paved), road conditions (normal and damaged), and road networks (local and highways). The use of fuel cell hybrid and fully electric trucks powered by H2-fuel and renewable sources of electricity, respectively, results in a large reduction in cost and carbon footprint, specifically for a long-distance hauling, and minimize other economic and environmental impacts. While the economic advantage of fuel cell hybrid electric vehicle is dependent on the price of H2-fuel and road conditions, use reduces the GHG emissions of biobutanol per 100 km-trucking-distance by 0.98–10.9 gCO2e/MJ. Results show that converting to fully electric truck transport decreases the biobutanol production cost and GHG emissions per 100 km-trucking-distance by 0.4–7.3 cents/L and 0.78 to 9.1 gCO2e/MJ, respectively. This study establishes the foundation for future investigations that will guide the development of economically, socially, and environmentally sustainable biomass feedstock supply system for cellulosic biorefineries or other goods transportation systems.
Effect of NO2 sequestered recycled concrete aggregate (NRCA) on mechanical and durability performance of concrete

Abstract The utilization of recycled concrete as an adsorbent to sequester NO2 without additives or catalysts is an innovative, cost-effective, and sustainable approach to capture NO2 from targeted industrial facilities. This paper presents the mechanical and durability performance of ordinary portland cement (OPC) concrete containing NO2 sequestered recycled concrete aggregate (NRCA). NRCA was used as a partial replacement for natural fine aggregate at 20% and 40% rates by volume. The incorporation of NRCA in concrete resulted in increased compressive strength, decreased water-permeable porosity, and reduced chloride ion migration. Moreover, test mixtures comprising 40% NRCA showed a significant chloride binding capacity compared to control concrete mixtures. Furthermore, high replacement rates of NRCA noticeably enhanced the resistance to chloride-induced corrosion of steel in concrete or at least was on par with the performance of a commercially available calcium nitrite-based corrosion inhibitor.
A review of tree-scale foraging ecology of insectivorous bark-foraging woodpeckers in North America

Abstract Woodpeckers are important forest species because they prey on tree pests and have been argued to act as keystone species through their effects as ecosystem engineers, creating breeding and shelter sites for numerous vertebrate and invertebrate taxa. We reviewed literature on tree characteristics associated with use by North American woodpeckers in the genera Campephilus, Dryobates, Dryocopus, and Picoides because forest alterations affecting this insectivorous bark-foraging guild can have cascading effects on other forest wildlife. We found that the number of studies of woodpecker tree-scale foraging was uneven across both species (ranging from 22 studies of hairy woodpeckers [Dryobates villosus] to no studies of tropical species) and ecoregions (ranging from 38 studies in Eastern Temperate Forests to no studies in Tropical Dry and Tropical Wet ecoregions). Unaltered forests were studied less than altered forests, with studies in silviculture- and wildfire-altered stands being the most commonly studied. Studies of tree characteristics largely focused on tree architecture (estimates of tree size, tree species), tree condition (live, degrading, dead, aged), foraging location (where birds foraged on trees), and environmental factors (tree burn severity, presence of bark- and wood-boring beetles, pheromone and herbicide applications), revealing four consistent patterns: 1) use of trees with relatively moderate-large diameter, 2) use of trunks more than other foraging substrates (e.g., limbs, twigs, leaves, cones, etc.), 3) use of middle portions of trees more than the lower- and upper-most portions of trees, and 4) a positive relationship between woodpecker tree use and tree use by boring beetles. Studies relating tree use to tree anatomy (e.g., bark thickness, wood hardness) and physiology (e.g., characteristics of oleoresin, phloem) were rare, including those related to tree environmental stressors (low water availability, high tree density, fire) that affect tree use by boring beetles. We emphasize the lack of studies regarding foraging ecology related to ecoregion, species, and tree characteristics as important areas for future research. We suggest land managers use studies of local foraging ecology to inform forest management when possible due to the variation in tree-scale foraging ecology among species and habitats, and provide suggestions for improving the efficiency of management-based research.
Metamaterial Integrated Radar Sensors for Location Tracking and Vital Sign Detection

This paper introduces two types of radar sensor architecture integrated with metamaterial (MTM) leaky wave antennas (LWA) that have been developed recently. The first architecture is a self-injection locked (SIL) radar sensor with MTM LWA, where the LWA is designed with −60° to +30° beam-steering angle when the frequency varies from 1.85 GHz to 2.85 GHz. The second one is MTM LWA-based homodyne radar architecture, where the LWA scans from −30° to +50° as the frequency varies from 24.3 GHz to 27.3 GHz. For proof-of-concept, two targets sitting at different places are chosen for vital sign detection by using the proposed two radar sensor architectures, respectively. Meanwhile, locations of these two targets can also be tracked accurately. Experimental results agree well with the ground truth, which verifies the validity of the proposed radar sensor architectures.
Dust Extinction and Metallicities of Star-Forming Lyman Alpha Emitting Galaxies at Low Redshift

We present the results of an optical spectroscopic study of 12 GALEX-discovered star-forming Lyman alpha emitting galaxies (LAEs) at z ~ 0.3. We measure the emission line fluxes from these galaxies by fitting their observed spectra to stellar population models in order to correct for underlying stellar absorption. We revisit earlier stellar population model fitting results, finding that excluding now-known AGNs lowers the typical stellar population age and stellar mass of this sample to ~ 300 Myr and ~ 4 x 10^9 Msol, respectively. We calculate their dust extinction using the Balmer decrement, and find a typical visual attenuation of Av ~ 0.3 mag, similar to that seen in many high-redshift LAEs. Comparing the ratio of Lyalpha/Halpha and the Lyman alpha equivalent widths to the measured dust extinction, we find that the ISMs in these objects appear to be neither enhancing nor seriously attenuating the Lyman alpha equivalent widths, as would be the case in a quasi-clumpy ISM. Lastly, we perform a detailed analysis of the gas-phase metallicities of these galaxies, and we find that most galaxies in our sample have Z < 0.4 Zsol. We find that at a fixed stellar mass, these low-redshift LAE analogs are offset by ~ 0.6 dex lower in metallicity from the general galaxy population at similar redshifts based on the local mass-metallicity relationship. This implies that galaxies with Lyman alpha in emission may be systematically more metal poor than star-forming galaxies at the same stellar mass and redshift, similar to preliminary results at z ~ 2.
Narcissistic admiration and rivalry in relation to aggressive sexual behavior among women and men

Abstract Narcissism has been linked with aggressive sexual behavior, but no extant research has specifically examined the agentic and antagonistic features of grandiose narcissism (i.e., narcissistic admiration and narcissistic rivalry, respectively) in relation to a wider array of aggressive sexual behaviors among both men and women. The purpose of this study was to investigate relationships between narcissistic admiration and narcissistic rivalry, sex, and different types of aggressive sexual behavior (i.e., coercion and seduction). College students (N = 1342) completed an online survey. Narcissistic rivalry was associated with higher levels of both coercion and seduction, while narcissistic admiration was only associated with higher levels of seduction. Sex moderated the relationship between narcissistic rivalry and aggressive sexual behavior such that women with higher levels of narcissistic rivalry were more likely to have engaged in aggressive sexual behavior. These findings indicate that narcissistic rivalry may be a significant risk factor for severe aggressive sexual behavior.
Deep learning for low frequency extrapolation of multicomponent data in elastic full waveform inversion

Full waveform inversion (FWI) strongly depends on an accurate starting model to succeed. This is particularly true in the elastic regime: The cycle-skipping phenomenon is more severe in elastic FWI compared to acoustic FWI, due to the short S-wave wavelength. In this paper, we extend our work on extrapolated FWI (EFWI) by proposing to synthesize the low frequencies of multi-component elastic seismic records, and use those "artificial" low frequencies to seed the frequency sweep of elastic FWI. Our solution involves deep learning: we separately train the same convolutional neural network (CNN) on two training datasets, one with vertical components and one with horizontal components of particle velocities, to extrapolate the low frequencies of elastic data. The architecture of this CNN is designed with a large receptive field, by either large convolutional kernels or dilated convolution. Numerical examples on the Marmousi2 model show that the 2-4Hz low frequency data extrapolated from band-limited data above 4Hz provide good starting models for elastic FWI of P-wave and S-wave velocities. Additionally, we study the generalization ability of the proposed neural network over different physical models. For elastic test data, collecting the training dataset by elastic simulation shows better extrapolation accuracy than acoustic simulation, i.e., a smaller generalization gap.
Spatial Analysis of Local Government Fiscal Condition in Nebraska

The effects of urban growth on outlying communities is a long-stand empirical question. Often couched in the concept of spread-backwash effect, Ganning, Baylis and Lee (2013) find that not until the late-1980s did empirical studies on the spread and backwash effects emerge. Most empirical investigations examine this theoretical phenomenon within the context of either population or income change. We propose to consider the spread-backwash effect from the perspective of local government fiscal health. There is a substantial body of research in the public finance literate focusing on government fiscal health/fiscal condition that is applicable and the setting of Nebraska offers a unique case-study. The U.S. state of Nebraska has approximately 1.8 million residents and the state’s population is changing (getting older and more diverse), as well as shifting to the urban centers of Omaha and Lincoln. In 1950, two-thirds of the state’s population lived outside of the metropolitan counties of Lancaster, Sarpy and Douglas. In 2050, the U.S. Census is projecting the two-thirds of the state’s population will reside in these three counties. This is raising a host of challenges and questions that residents and policy-makers are being forced to address.Methodologically, we propose a spatial neighborhood statistics model, the Markov Random Field model, to assess our central hypotheses that the further the distance from the urban center, the weaker the municipality’s fiscal condition. The study is prepared according to the procedure used by Pandey et al. (2015). While the Pandey et al. (2015) research was on E.coli flows through streams, the research design offers a good deal of applicability to this study. We will also run a set of regression models to ensure the robustness of this study. We examined the fiscal data of 69 municipalities in Nebraska that are in the Omaha-Council Bluffs MSA and the Lincoln-Beatrice MSA from 2001 to 2016. The data analysis focuses on the fiscal condition of municipalities and their proximity to the two urban centers in Nebraska, Omaha and Lincoln. The five indicators used as the dependent variables are: general revenues/general expenditures, debt per capita, debt/property valuation, net cash balances/general expenditures and property taxes/general revenues. The key independent variable of this research is the municipalities’ proximity to the Nebraska urban centers of Omaha or Lincoln, which is measured by the municipalities’ distance to the urban centers on Google Map. Other independent variables will reflect economic, demographic and institutional constructs. Our findings support the backwash effect in that, the further a city is from the urban center, the worse their fiscal condition. More specifically, the greater the distance a city is from Lincoln or Omaha, NE (urban center), the lower the city’s revenues to expenditures, the lower its net balance and the lower the city’s property tax collections as a percentage of revenues.
Confronting COVID-19 in under-resourced, African American neighborhoods: a qualitative study examining community member and stakeholders' perceptions.

OBJECTIVE: The purpose of this study was to examine perceptions of COVID-19 related to prevention, coping, and testing of African American residents in under-resourced communities in Alabama. DESIGN: Guided by the PRECEDE-PROCEED model, virtual focus groups were conducted in five urban and rural Alabama communities using secure Zoom meetings. Community residents and stakeholders (N = 36 total) participated; meetings were audio- and video-recorded, transcribed, and analyzed according to Thematic Analysis. Themes were organized by the PRECEDE portion of the model in Predisposing, Reinforcing, and Enabling barriers and facilitators in three focus areas: prevention, coping, and testing. RESULTS: Prevention barriers included apathy, difficulty with social distancing, lack of information, mixed messages from authority figures, and lack of personal protective equipment (PPE). Prevention facilitators included concerns about contracting COVID-19, clear and consistent messages from trusted sources, contact tracing, and the provision of PPE. Coping barriers included food insecurity, mental health issues, isolation, economic hardships, lack of health care access, and issues with virtual schooling and church services, which were exacerbated by the inability to connect to the internet. Facilitators to coping included religious faith, increased physical activity, and a sense of hope. Testing barriers included misunderstanding, fear, mistrust, testing restrictions, and location of testing sites. Facilitators to testing included incentives, clear information from trusted sources, convenient testing locations, and free tests. CONCLUSION: Gaining community members' perspectives can identify barriers and facilitators to prevention, coping, and testing and potentially improve outcomes. While addressing the social determinants of health (e.g. income, education, medical trust) would be an effective path by which to diminish health disparities related to COVID-19, there is an urgent need to mitigate the spread and severity of COVID-19 in vulnerable populations. Interventions should focus on downstream determinants, such as those emerging from our study.
Does NAFLD mediate the relationship between obesity and type 2 diabetes risk? evidence from the multi-ethnic study of atherosclerosis (MESA).

ABSTRACT Purpose To estimate the effect of obesity on type 2 diabetes (T2DM) risk and evaluate to what extent non-alcoholic fatty liver disease (NAFLD) mediates this association. Methods Data came from 4,522 adults ages 45–84 participating in the Multi-Ethnic Study of Atherosclerosis cohort. Baseline obesity was defined using established BMI categories. NAFLD was measured by CT scans at baseline and incident T2DM defined as fasting glucose ≥126 mg/dL or use of diabetes medications. Results Over a median 9.1 years of follow-up between 2000 and 2012, 557 new cases of T2DM occurred. After adjusting for age, sex, race/ethnicity, education, diet and exercise, those with obesity had 4.5 times the risk of T2DM compared to normal weight (hazard ratio [HR] = 4.5, 95% confidence interval [CI]: 3.0, 5.9). The mediation analysis suggested that NAFLD accounted for ~36% (95% CI: 27, 44) of the effect (direct effect HR = 3.2, 95% CI: 2.3, 4.6; indirect effect through NAFLD, HR = 1.4, 95% CI: 1.3, 1.5). Conclusions These data suggest that the association between obesity and T2DM risk is partially explained by the presence of NAFLD. Future studies should evaluate if NAFLD could be an effective target to reduce the effect of obesity on T2DM.
The effectiveness and safety profile of netarsudil 0.02% in glaucoma treatment: real-world 6-month outcomes.

To evaluate the efficacy and safety profile of netarsudil 0.02% ophthalmic solution in a tertiary glaucoma referral center. This retrospective cohort study included patients with glaucoma initiated on netarsudil 0.02% at a single institution from November 2017 to September 2018. Demographic and clinical data were collected, including intraocular pressure (IOP) and drug side effects at baseline and 1-, 3-, and 6-month follow-up visits. A total of 340 eyes of 233 patients were included; mean ± SD patient age was 69.1 ± 12.5 years. One hundred twenty (48%) eyes experienced ≥ 20% decreases in IOP at the 1-month study visit; this effect was maintained through the 6-month visit. IOP-lowering effects in patients using ≥ 3 topical glaucoma medications were similar (all p > 0.1). Eighteen (7.4%) and 7 (2.9%) patients experienced increases in IOP of ≥ 3 and ≥ 5 mmHg, respectively. Across all study visits, conjunctival hyperemia was noted at a rate of 27.6%, and though frequently reported, complaints of blurred vision (31.1%) did not manifest in significant worsening of visual acuity. The rate of drug discontinuation due to insufficient IOP-lowering and side effects was 15.6% and 24.8%, respectively. Twenty-nine (11.4%) and 82 (32.3%) eyes required additional medical and surgical/laser intervention, respectively. Commonly used as the last-line medical therapy in this case series, netarsudil safely and significantly reduced IOP in patients with glaucoma, even in those using ≥ 3 glaucoma medications. Increases in IOP of ≥ 3 mmHg occurred in a small number of patients. Subjective vision changes and conjunctival hyperemia were the most frequently reported side effects.
Disparities in sleep characteristics by race/ethnicity in a population-based sample: Chicago Area Sleep Study

Abstract Background Prior studies report less favorable sleep characteristics among non-Whites as compared with non-Hispanic Whites. However, few population-based studies have used objective measures of sleep duration, especially in more than two racial/ethnic groups. We tested whether objectively estimated sleep duration and self-reported sleep quality varied by race and whether differences were at least partially explained by the variability in clinical, psychological, and behavioral covariates. Methods Adults aged 35–64 years who self-identified as White, Black, Asian, or Hispanic were randomly sampled from Chicago, IL, and the surrounding suburbs. Our analytic sample included adults who had an apnea–hypopnea index n = 495). Daytime sleepiness was estimated using the Epworth Sleepiness Scale (ESS), and sleep quality was estimated from the Pittsburgh Sleep Quality Index (PSQI). Results Following statistical adjustment for age, gender, education, work schedule (ie, day vs. night shift), smoking status, depressive symptoms, body mass index (BMI), hypertension, and diabetes, sleep duration (minutes) was significantly (all p Conclusions Differences in sleep characteristics by race/ethnicity are apparent in a sample of adults with a low probability of sleep apnea and following adjustment for known confounders.
Portable Parallel Irregular Applications

Software developers for distributed memory multiprocessors often complain about the lack of libraries and tools for developing and performance tuning their applications. While some tools exist for regular array-based computations, support for applications with pointer-based data structures, asynchronous communication patterns, or unpredictable computational costs is seriously lacking. In this paper we describe our experience with six irregular applications from CAD, Robotics, Genetics, Physics, and Computer Science, and offer them as application challenges for other systems that support irregular applications. The applications vary in the amount and kind of irregularity. We characterize their irregularity profiles and the implementation problems that arise from those profiles. In addition to performance, one of our goals is to provide implementations that run efficiently with minimal performance tuning across machine platforms, and our designs are influenced by this desire for performance portability. Each of our applications is organized around one or two distributed data structures, which are part of the Multipol data structure library. We describe these data structures, give an overview of some key features in our underlying runtime support, and present performance results for the applications on three platforms.
Analytical solution of magnetohydrodynamic sink flow

An analytical solution to the famous Falkner-Skan equation for the magnetohydrodynamic (MHD) flow is obtained for a special case, namely, the sink flow with a velocity power index of −1. The solution is given in a closed form. Multiple solution branches are obtained. The effects of the magnetic parameter and the wall stretching parameter are analyzed. Interesting velocity profiles are observed with reversal flow regions even for a stationary wall. These solutions provide a rare case of the Falkner-Skan MHD flow with an analytical closed form formula. They greatly enrich the analytical solution for the celebrated Falkner-Skan equation and provide better understanding of this equation.
Cytodifferentiation in the accessory glands of Tenebrio molitor. VIII. Crossed immunoelectrophoretic analysis of terminal differentiation in the postecdysial tubular accessory glands

Abstract The terminal differentiation of the tubular accessory glands in the postecdysial male mealworm beetle, Tenebrio molitor, is characterized by the synthesis of four major groups of proteins as analyzed by one-dimensional SDS-poly-acrylamide gel electrophoresis. On two-dimensional gels (SDS and pI), two of these groups of proteins (A and B) are acidic in nature and have apparent MWs of 17,500 and 18,800, respectively. A third protein group (C) is heterogeneous with respect to isoelectric point (neutral to basic) and has a MW of about 21,900. The fourth class of proteins (D) is divisible into two subgroups on the basis of isoelectric points and has MWs ranging from 26,400 to 29,100. Antibodies have been produced to the soluble portion of mature tubular accessory glands. The preparations of heterologous antisera have been shown to be gland specific following absorption with bean-shaped accessory gland homogenates and ammonium sulfate fractionation. The first appearance and subsequent accumulation during postecdysial maturation of some of these proteins have been determined by crossed immunoelectrophoresis. The A and B proteins are detected immunologically, initially in the late pupa, and their quantities remain unchanged until shortly after adult eclosion. During the 8 days following adult eclosion each of these proteins increases in quantity from ∼10 to ∼7000 ng. A third immunoreactive protein appears in the 2-day old adult and increases to ∼960 ng over the following 6 days. The identity of this antigen is uncertain although it may represent either the C or the D protein. Based on crossed immunoelectrophoresis, it is evident that at least two of these tubular accessory gland antigens appear to contribute to the spermatophore.
LES of turbulence and turbulent combustion: Advances and theoretical limitations

Large Eddy Simulations account for the subgrid velocity fluctuations in a model (analytic) way. It is argued that due to small-scale intermittency, the LES models based on the Kolmogorov-Smagorinki phenomenology must fail for any mesh size Δ when the Reynolds number is large enough and Δ corresponds to the scales in the inertial range. Physically, the existing phenomenology treats very strong and weak fluctuations on the equal footing as governed by the single parameter (mean dissipation rate). This leads to unreasonably large overproduction of kinetic energy and, as a consequence, poor predictions. Intermittency disappears at the large scales and that is why the time-dependent VLES schemes are much more successfull in descibing hi Reynolds number flows. Various examples, presented in the paper support this point of view.
A network analysis of student groups in threaded discussions

As online discussion boards become a popular medium for collaborative problem solving, we would like to understand patterns of group interactions that lead to collaborative learning and better performance In this paper, we present an approach for assessing collaboration in online discussion, by profiling student-group participation We use a modularity function to compute optimal discussion group partitions and then examine usage patterns with respect to high-versus low-participating students, and high- versus low-performing students as measured by grades We apply the profiling technique to a discussion board of an undergraduate computer science course with three semesters of discussion data, comprising 142 users and 1620 messages Several patterns are identified, and in particular, we show that high achievers tend to act as ‘bridges', engaging in more diverse discussions with a wider group of peers.
An image quality measure for image communication

In this paper, we propose an image quality measure that closely resembles the image quality measure used by the human visual system. In our application, we are more concerned with localized errors due to transmission than the global errors due to compression, and we develop an approach that is appropriate for this purpose. We use psychophysical experiments to determine the visibility threshold level for each frequency component of each image block. The visibility threshold levels are adjusted according to the background variation and intensity of the image block. Only those frequency components of an error that exceed the corresponding threshold level are included in the computation of the proposed image quality measure. The proposed image quality measure gives the PSNR of the errors that are visible to the eye and the percentage area of the extent of the visible errors in the image.
Nonstandard supersymmetry breaking and Dirac gaugino masses without supersoftness

I consider models in which nonstandard supersymmetry-breaking terms, including Dirac gaugino masses, arise from $F$-term breaking mediated by operators with a $1/{M}^{3}$ suppression. In these models, the supersoft properties found in the case of $D$-term breaking are absent in general, but can be obtained as a special case that is a fixed point of the renormalization group equations. The $\ensuremath{\mu}$ term is replaced by three distinct supersymmetry-breaking parameters, decoupling the Higgs scalar potential from the Higgsino masses. Both holomorphic and nonholomorphic scalar cubic interactions with minimal flavor violation are induced in the supersymmetric Standard Model Lagrangian.
Use and exchange of genetic resources in molluscan aquaculture

Molluscs are major aquaculture species worldwide. Molluscan aquaculture accounts for approximately 27% of the total world aquaculture production. The use and exchange of genetic resources have played an important role in the development of molluscan aquaculture. The introduction and use of non-native species have been instrumental in oyster and scallop aquaculture; for example, the Pacific oyster, translocated from Japan, supports major aquaculture industries in many countries of North and South America, Europe, Asia and Africa. Bay scallops introduced from the USA account for an annual production of over 600 000 t in China. Non-native genetic materials have also been used for the genetic improvement of native species through interspecific and intraspecific hybridization. Unique genetic lines, such as disease-resistant strains, have been developed through selective breeding in some molluscs, although significantly more efforts are needed. Although the importance of genetic resources is apparent, the identification, protection and utilization of molluscan genetic resources remain a challenge.
Chapter 24. Chemotaxis

Publisher Summary Chemotaxis is not only of importance in the inflammatory accumulation of leukocytes, but is thought to be significant in the metastasis of neoplastic cells and the migration of fibroblasts involved in wound healing. Thus, drugs capable of, either selectively enhancing or depressing, chemotactic responsiveness of leukocytes and other cells are potentially of importance in a wide variety of diseases. The locomotion of leukocytes through blood vessels and into the inflammatory site is directed by a gradient of chemical substance either released from the inflammatory agent or formed endogenously. Chemotactic factors not only induce chemotaxis and other neutrophil functions, but also cause enhancement of the bactericidal activity of neutrophils against various microorganisms. The most active, until recently, and still the most widely used synthetic, chemotactic peptide is f-Met-Leu-Phe, with an ED50 for chemotaxis in the Boyden chamber assay of rabbit neutrophils of 7 x 10-11M. The classical synthesis of f-Met-Leu-Phe has been described in this chapter. The hexapeptide, f-Nle-Leu-Phe-Leu-Tyr-Lys is more active for human neutrophils, and has the added advantage that it can be radiolabeled within the tyrosyl moiety or made fluoroscent by conjugating a fluorochrome through the ɛ-NH 2 group of the lysyl residue.
18F-FDG-PET and PET/CT for Evaluating Primary Bone Tumors

Imaging is critical for the proper evaluation of patients with primary tumors of bone. There is a growing role for (18)F-fluorodeoxyglucose PET and PET/computed tomography (CT) in the grading, staging, prognostication, evaluation of therapeutic response, and detection of recurrent disease in bone. These modalities can also be used to help differentiate benign from malignant disorders of bone.
The Effects of Molecular Weight on the Single Lap Shear Creep and Constant Strain Rate Behavior of Thermoplastic Polyimidesulfone Adhesive

The bonded shear creep and constant strain rate behaviors of zero, one, and three percent endcapped thermoplastic polyimidesulfone adhesive were examined at room and elevated temperatures. Endcapping was accomplished by the addition of phthalic anhydrides. The primary objective was to determine the effects of molecular weight on the mechanical properties of the adhesive. Viscoelastic and nonlinear elastic constitutive equations were utilized to model the adhesive. Ludwik's and Crochet's relations were used to describe the experimental failure data. The effects of molecular weight changes on the above mentioned mechanical behavior were assessed. The viscoelastic Chase-Goldsmith and elastic nonlinear relations gave a good fit to the experimental stress strain behavior. Crochet's relations based on Maxwell and Chase-Goldsmith models were fit to delayed failure data. Ludwik's equations revealed negligible rate dependence. Ultimate stress levels and the safe levels for creep stresses were found to decrease as molecular weight was reduced.
SAFT-LC : An equation of state for predicting liquid-crystalline phase behavior in carbonaceous pitches

By adding an orientational free-energy term based on Maier−Saupe theory to the statistical associating fluid theory (SAFT) equation, we have developed a versatile equation of state for describing the phase behavior of carbonaceous pitches, a polydisperse class of discotic nematic liquid-crystalline materials that exhibits both thermotropic and lyotropic behavior. SAFT−liquid crystal (SAFT−LC) can be used to describe the phase behavior of carbonaceous pitches both at conditions where orientational effects are relatively minor (i.e., isotropic liquid−liquid equilibria in the presence of solvent) and at conditions where such effects dominate (e.g., the effect of pitch composition on the isotropic/nematic phase transition). SAFT−LC contains five well-behaved, adjustable parameters: three in SAFT for defining the binary interaction parameters and two in LC for describing the clearing temperature of a pitch pseudocomponent. Predictions of SAFT−LC for phase densities, product yields, and mesophase percentages o...
Microanalysis of nitrogen isotope abundances: association of nitrogen with noble gas carriers in Allende

Current research efforts to explore and account for the distribution of nitrogen isotope abundances in the ancient and present-day solar wind and in meteorites often require measurement of nitrogen abundances and isotopic compositions in very small samples of rare extraterrestrial materials. Isotopic analysis of ∼ 1 μg of N2 is possible with modern techniques of dynamic mass spectrometry, but even this high sensitivity is a limiting factor for certain critical samples. We have utilized a statistically operated mass spectrometer coupled to an ultrahigh vacuum gas extraction and processing system to lower this limit by approximately four orders of magnitude. Quantities of N2 ranging from ∼ 100 ng to < 100 pg are measurable with permil to percent precision in isotope ratios. Nitrogen and all noble gases evolved during stepwise combustion of fine-grained matrix material separated from the Allende meteorite have been meausred simultaneously in a pilot experiment using this technique. Isotopically heavy H-Xe (CCF-Xe) and isotopically light N are co-sited in a carbonaceous carrier phase, supporting a nucleosynthetic origin for15N-depleted nitrogen in Allende. The great isotopic uniformity of trapped Ar in all carrier phases indicates that simple, physical mass fractionation in gravitational escape of volatiles from the primitive nebula cannot have played a significant role in generating the nitrogen compositions observed in solar system matter.
Identifying directed links in large scale functional networks: application to brain fMRI.

Biological experiments increasingly yield data representing large ensembles of interacting variables, making the application of advanced analytical tools a forbidding task. We present a method to extract networks of correlated activity, specifically from functional MRI data, such that: (a) network nodes represent voxels, and (b) the network links can be directed or undirected, representing temporal relationships between the nodes. The method provides a snapshot of the ongoing dynamics of the brain without sacrificing resolution, as the analysis is tractable even for very large numbers of voxels. We find that, based on topological properties of the networks, the method provides enough information about the dynamics to discriminate between subtly different brain states. Moreover, the statistical regularities previously reported are qualitatively preserved, i.e. the resulting networks display scale-free and small-world topologies. Our method expands previous approaches to render large scale functional networks, and creates the basis for an extensive and -due to the presence of mixtures of directed and undirected links- richer motif analysis of functional relationships.
Nonequilibrium charge states of 60 MeV I-ions channeled in Au single crystals☆

Abstract Iodine ions (60 MeV) penetrating Au crystals in (100) planar channeling directions require ca 1200 A to reach equilibrium, implying a reduction of the charge changing cross sections. Differences in most probable charge of up to 3.6 units in 20 are observed.
Carbon dioxide extraction of residual solvents in poly(lactide-co-glycolide) microparticles.

A process for the reduction of residual solvents in spray-dried poly(lactide-co-glycolide) (PLGA)–darbepoetin alfa microparticles was developed using carbon dioxide (CO2) as an extraction solvent. CO2 was investigated in two phase states, liquid and gas. Detrimental effects on encapsulated protein integrity and microparticle morphology were observed with liquid CO2 exposure. Extraction with CO2 gas at <100 psig reduced residual solvent concentration and particle agglomeration was limited. Extraction rates and particle agglomeration increased with higher CO2 gas pressures. The CO2 pressures below which particles of polylactide (PLA) and PLGA microparticles significantly agglomerated were determined and the data used to develop extraction cycles. Extraction cycles were developed in which CO2 gas pressure was increased as residual solvent concentration decreased in order to keep extraction rates high throughout the cycle. Spray dried darbepoetin alfa–PLGA microparticles were extracted with CO2 gas and characterized for residual solvent concentration, process yield, particle size distribution, morphology, and protein integrity. The results indicated CO2 gas may be used to reduce residual solvent to ∼200 ppm with no significant detrimental effects on protein integrity or microparticle morphology.
How Accurate Is Dynamic Program Slicing? An Empirical Approach to Compute Accuracy Bounds

Dynamic program slicing attempts to find runtime dependencies among statements to support security, reliability, and quality tasks such as information-flow analysis, testing, and debugging. However, it is not known how accurately dynamic slices identify statements that really affect each other. We propose a new approach to estimate the accuracy of dynamic slices. We use this approach to obtain bounds on the accuracy of multiple dynamic slices in Java software. Early results suggest that dynamic slices suffer from some imprecision and, more critically, can have a low recall whose upper bound we estimate to be 60% on average.
An innovative analysis of taxes and corporate hedging

Abstract Theoretical research predicted that firms with convex tax schedules would hedge to minimize expected taxes. However, previous empirical research did not detect a relationship between derivative use and tax losses carry forward, which contribute to tax schedule convexity. This study aims to show that the tax incentive to hedge depends on tax losses carry forward and the ability of the firm to carry losses forward and back, which depends on the distribution of taxable income. A new measure of the tax incentive to hedge, which incorporates this, will be proposed. Hedging could be accomplished by methods other than by using derivatives. Measures of hedging activity which incorporates the effect of all methods of hedging, and which are consistent with previous theoretical research, will also be proposed. Using the new measures of the tax incentive to hedge and hedging activity, the firm’s tax incentive to hedge will be empirically established to significantly influence its hedging activity 1 .
Naloxone stimulation of luteinizing hormones release in prepubertal female rats; role of serotonergic system

Abstract The purpose of this study was to determine whether naloxone stimulated LH release via a serotonergic mechanism. Injection of naloxone hydrochloride (2 mg/kg B.W.) into 25-day old female prepubertal rats resulted in a significant elevation in serum LH 30 min later. Injection of this dose of naloxone together with morphine sulfate (2 or 5 mg/kg B.E.) resulted in inhibition of naloxone-induced LH release. When rats were first injected with 5-hydroxytryptophan (5-HTP) to increase hypothalamic serotonin content, naloxone failed to increase serum LH levels. On the other hand, when parachlorophenylalanine (PCPA) was given first to reduce hypothalamic serotonin content, naloxone-induced LH release was potentiated. Morphine failed to inhibit the naloxone-induced rise in serum LH when PCPA was first administered. Neither 5-HTP nor PCPA, when injected alone, altered serum LH values. These results suggest that naloxone promotes LH release by reducing hypothalamic serotonergic activity, and morphine inhibits LH release by increasing hypothalamic serotonergic activity. This does not exclude possible involvement of other neurotransmitters.