cssi/SciSciGPT-SciSciNet huggingface dataset:
Large Eddy Simulation of Fully Developed Flow and Heat Transfer in a Rotating Duct With 45° Ribs

This paper concerns itself with investigating the effect of rotation on flow and heat transfer in a 45° ribbed square duct. Large-Eddy Simulations (LES) are used to investigate why rotation does not have any effect on heat transfer augmentation unlike 90 degree ribs, in which considerable changes are observed in augmentation at the trailing and leading walls of the duct. It is found that unlike 90 degree ribbed ducts, in which the heat transfer augmentation is strongly dependent on streamwise momentum, spanwise momentum dominates heat transfer in skewed ribs. Since Coriolis forces under orthogonal rotation about the z-axis do not directly contribute to spanwise momentum, they do not have as much of an effect on heat transfer at the ribbed walls at the trailing and leading sides. However, because of the augmentation of turbulence at the trailing side, the vortices which are produced in the separated shear layer of the rib and which move from the inside to the outside of the duct, break down and diffuse before they can impinge on the outer wall. Turbulence attenuation at the leading wall has the opposite effect which allows the vortices to maintain their coherence and impinge on the outer wall. This effect taken together with the streamwise flow being pushed to the leading side, produces an extended region of high heat transfer at the outer wall near the leading side. This is countered by lower heat transfer at the trailing side of the outer wall. Hence, although local variations are present due to rotation, the overall augmentation remains the same.Copyright © 2006 by ASME
Maps, routes, and the hippocampus: a neural network approach.

This study describes hippocampal participation in maze navigation in terms of a real-time, biologically plausible neural network. The system is composed of (1) a goal-seeking mechanism, (2) a cognitive map system, and (3) a route system. The goal-seeking mechanism displays exploratory behavior until either the goal is found or a sufficiently strong prediction of the goal is generated. The cognitive map is a topological map that stores associations between places and views of accessible places, and between places and reward. The route system establishes associations between cues and reward. Both systems compete with each other to establish associations with the reward, with the cognitive system generally overshadowing the route system. In agreement with previous models, it is assumed that the hippocampus modulates the storage of cognitive maps in cortical areas and mediates the competition between cognitive maps and route systems. In agreement with previous models, it is assumed that the hippocampus modulates the storage of cognitive maps in cortical areas and mediates the competition between cognitive maps and route systems. After hippocampal lesions, animals navigate through mazes making use of the route system. Computer simulations show that the network effectively describes latent learning, detour behavior, and place learning in normal and hippocampal-and cortical-lesioned animals.
Artificial Societies and Generative Social Science

What is anartificial society? What can such models offer the social sciences in particular? We address these general questions, drawing brief illustrations from the specific artificial society we call “Sugarscape.”
Spectral displacement techniques for studying the binding of spectroscopically transparent ligands to cyclodextrins.

Abstract A spectroscopic displacement method is used to determine association constants of β-cyclodextrin with compounds that are spectroscopically transparent. These compounds are adamantanecarboxylate and structurally related compounds. Association constants obtained are compared to values obtained by other methods. It is shown that for all types of displacement techniques a distinction must be made between free and total concentrations of ligand in cases of strong binding.
Emergence from nonrelativistic strong-field rescattering to ultrastrong-field laser-atom physics: A semiclassical analysis

We discuss a rescattering deflection parameter to gauge the progression from strong- to ultrastrong-field rescattering dynamics. Our analytical and numerical treatments of rescattering quantify the change from nonrelativistic, dipole approximation strong-field dynamics to an ultrastrong-field interaction where $v∕c\ensuremath{\ne}0$ and ${\mathbf{B}}_{\text{laser}}\ensuremath{\ne}0$. At the threshold between these two regimes the Lorentz deflection reduces the returning electron flux at the core and suppresses rescattering related phenomena. Both radiation and nonsequential ionization from rescattering are studied. We show the ultrastrong-field regime can occur at intensities as low as ${10}^{14}\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$ for mid-IR $(2\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}5\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m})$ wavelengths or as high as ${10}^{18}\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$ for UV radiation.
Continuous Curd Tension Measurements During Milk Coagulation

Abstract A Brookfleld LVT-Helipath viscometer has been adapted for curd tension studies. A sharp leading edge was machined on a TF bar spindle crosswire. The spindle was subsequently calibrated against an unmodified TF spindle so that results could be reported in centipoises or dyne-centimeters. Standardized enzyme coagulants were inoculated into whole milk and Berridge-test substrate. Different coagulants caused considerable variation in the rate of increase in curd firmness in whole milk but not in Berridge substrate. In addition, coagulation time in whole milk did not correlate with curd tension. An improved substrate for measuring coagulation time is needed to improve correlation. The viscometer was useful for studying curd formation by direct-acidification. Continuous measurement throughout milk heating and curd formation was possible.
Resolution of focal CT hypodense lesions in patients with subarachnoid hemorrhage

Cerebral infarction in the setting of vasospasm due to subarachnoid hemorrhage (SAH) is a known complication of aneurysmal rupture. Computed tomography (CT) has been instrumental in making this diagnosis; however, focal hypodense lesions on CT scan do not always represent infarcted tissue. Two patients are presented here who had CT hypodense lesions in regions of cerebral vasospasm following subarachnoid hemorrhage.
Differential proliferation of erythroid and granuloid spleen colonies following sublethal irradiation of the bone marrow donor.

Spleen colonies produced by sublethally irradiated mouse bone marrow cells were compared to those produced by unirradiated marrow cells in lethally irradiated mice. Sublethally irradiated marrow cells gave rise to many fewer spleen colonies. At seven days of colony age, the ratio of erythroid colonies to granuloid colonies was lower (< 1) than for colonies formed by unirradiated marrow (2 to 3 or more). Delay of harvest of colonies to day 10 or 12 resulted in 6 to 11 fold increase in the ratio of erythroid to granuloid colonies due largely to the belated appearance of erythroid colonies.
Atrial Fibrillation in Patients with Implantable Defibrillators

Atrial fibrillation (AF) is common in patients who have implantable defibrillators and presents some unique challenges and opportunities. AF burden can be assessed more accurately, allowing for evaluation of therapy efficacy (drugs or ablation). It remains to be shown whether home monitoring of defibrillators to detect and treat AF more quickly can reduce cardiovascular and stroke end points. One major goal will be to reduce inappropriate shocks from atrial fibrillation. Otherwise, the goals of therapy remain the same—reduction of symptoms (including heart failure exacerbation and inappropriate implantable cardioverter defibrillator therapies) by controlling rate or rhythm and anticoagulation for stroke prophylaxis.
The Association between Overweight and Illegal Drug Consumption in Adolescents: Is There an Underlying Influence of the Sociocultural Environment?

Background The aims of the study were to: a) Examine the distribution of gender-stratified body mass index (BMI), eating attitudes and use of addictive substances, under the hypothesis of a confluent prevalence of weight abnormalities, eating disorders and substance abuse. b) Demonstrate the extent to which family, peer-related and psychosocial factors are common elements in categories of compulsive behaviour. Methodology/Principal Findings In the present cross-sectional study, data were collected through self reported questionnaires administered to a large sample of 33,185 15–19 years old adolescents (ESPAD®Italia), divided into weight categories based on the BMI percentile distribution. Multinomial analyses were adopted to address the influence of social, family, leisure time factors, Eating Attitude Test (EAT26) on the association between weight categories and drug use. Recent drugs use was more frequent in overweight and underweight adolescents (p<0.05), especially in females. An EAT26 score ≥20 was more common in overweight adolescents. Multinomial analysis abolished the relationship between overweight and the use of most drugs, implicating self-esteem, parents' educational level, and friendships as mediators of the association. Within the overweight category, adolescents reporting recent drug use, showed greater frequency of having drug-abusing friends (~80%), and severe problems with parents and school (~30%) compared to overweight adolescents without recent drug use. Conclusion The frequent association of overweight and substance use and the presence of common underlying social factors, highlights the need for an interdisciplinary approach involving individual-focused treatment models as well as public health, social and environmental changes to reduce food- and substances-related problems.
REFRACTORIES FOR USE IN SULPHATE‐RECOVERY FURNACES OF THE PULP AND PAPER INDUSTRIES*

The paper gives a short review of the soda-recovery methods used in the Kraft process. The tests made to determine the relative merits of different refractories were (1) P.C.E. determinations of soda-refractory mixtures, (2) simulative-service slag tests, and (3) petrographic analyses. Tests indicate that resistance is produced by (1) an impervious crystalline structure, such as soapstone for the low temperatures and electro-cast mullite for the high temperatures, or (2) chemical inertness in contact with soda, such as is found with purer forms of magnesia.
A novel dimensional reduction approach for structural damage diagnosis using feature similarity

Dimensionality reduction is an essential data preprocessing technique for feature extraction, clustering and data classification in the area of Structural Health Monitoring (SHM). This paper presents a novel data-driven model for feature extraction and its application to damage identification by means of experimental case studies. The method obtains similarity matrix indices for individual dimensional reduction techniques whereby maximum compression of information is obtained and redundancy therein is removed by creating an ensemble of these indices. A systematic comparison of this novel technique to existing linear and nonlinear dimensional reduction methods is given. First case study investigates the aeroacoustic properties of a scaled wing model with penetrating impact damage. In the experimental vibration case study, we use the response of surface mounted accelerometers to detect and quantify damage of an aluminum plate. The dimensional reduction methods will be used to improve the efficiency and effectiveness of damage classifier. In this study, damage identification performances are evaluated using a one-class k-Nearest Neighbor classifier. Classification performance is measured in terms of rate of detection and false alarm via receiver operating characteristic (ROC) curves. The robustness of the damage detection approach to uncertainty in the input data is investigated using probabilistic-based confidence bounds of prediction accuracy. Experimental results show that proposed approach yields significant reduction of false-diagnosis and increasing confidence levels in damage detection.
Conformational Changes in Troponin Within the Cardiac Myofilament

We have an engineered FRET assay in cardiac troponin that monitors the main structural change in troponin during activation. We report the results of different methods for exchanging the construct into myofibrils isolated from adult mouse ventricular cardiomyocytes. Fluorescence lifetime imaging (FLIM) revealed heterogeneous activation of troponin between the A- and I-bands in rigor myofibrils. This suggests that strongly-bound cross bridges play a role in the activation of the cardiac myofilament. These measurements are a precursor to single pair FRET measurements of the activation of troponin within the cardiac myofilament.
Electro-optic polymers for THz applications

Electro-optic (EO) polymers are promising materials to be used as THz emitters and sensors due to their high nonlinear coefficients and good phase-matching conditions. We demonstrate efficient THz generation from an 80 μm thick EO polymer emitter which is equivalent to that of a 1000 μm thick ZnTe standard. Also, this kind of EO polymer allows a generation up to 20 THz with ultra-short laser pulses. We have observed resonance-enhanced THz generation in another kind of EO polymer composite near its absorption maximum. Due to a sharp resonance of the EO coefficient near the absorption maximum of the material, the amplitude of THz field generated from a 3.1 μm thick film of this composite is 15% larger than that from a 1000 μm thick ZnTe standard. The estimated EO coefficient of this composite at 800 nm is over 1200 pm/V.
Release of NOx from sunlight‐irradiated midlatitude snow

Photochemical production and release of gas-phase NOx (NO + NO2) from the natural snowpack at a remote site in northern Michigan were investigated during the Snow Nitrogen and Oxidants in Winter study in January 1999. Snow was collected in an open 34 L chamber, which was then sealed with a transparent Teflon cover and used as an outdoor flow and reaction chamber. Significant increases in NOx mixing ratio were observed in synthetic and ambient air pulled through the sunlit chamber. [NOx] enhancements were correlated to ultraviolet sunlight intensity, reaching ∼300 pptv under partially overcast midday, midwinter conditions. These findings are consistent with NOx production from photolysis of snowpack NO3−; the observed NOx release implies production of significant amounts of OH within the snow. Snowpack NO3− photolysis may therefore significantly alter boundary layer levels of both NOx and oxidized compounds over wide regions of the atmosphere.
Enhanced Radiosensitivity of Androgen-Resistant Prostate Cancer: AZD1152-Mediated Aurora Kinase B Inhibition

Aurora kinase B (AURKB) is critical to the process of mitosis, aiding in chromosome condensation by phosphorylating histone H3. We investigated the effects of AZD1152, an AURKB inhibitor, on radiosensitivity of androgen-insensitive prostate cancer cells. The goal of this study was to test whether AZD1152 increases the susceptibility of hormone-refractory prostate cancer cells to radiation-induced DNA damage and to determine the conditions of AZD1152 treatment that maximize radiosensitization. PC3 and DU145 cells were treated with various AZD1152 doses for various durations to elucidate the conditions that yielded maximal increases in G2/M-phase and polyploid cells. To assess DNA damage, γ-H2AX phosphorylation was quantified for cells grown under radiosensitizing conditions and subjected to either no radiation or 5 Gy radiation. Radiosensitivity was determined by clonogenic assays. Cell cycle effects in both cell lines were maximized by treatment with 60 nM AZD1152 for 48 h. AZD1152-treated cells exhibited...
Hope, learning goals, and task performance

This paper examines the relationships among hope in its trait and state forms, goal orientation, verbal persuasion, and task performance. Results of a laboratory experiment involving 212 undergraduate students indicated that learning goal orientation was positively related to trait hope. Findings further indicated that trait hope was positively related to performance on an anagram task through the mediating variable of state hope; moreover state hope was influenced by negative verbal persuasion but unaffected by positive verbal persuasion.
Effect of damping on the structure of the time-optimal control profile

Conclusion A simple guidance law for operation of dual-fuel SSTO launch vehicles has been developed and used to determine the optimal value of the transition Mach number from dual fuel to single fuel. For the example considered, the optimal transition Mach number was 9.0 along a fixed trajectory. Along an optimal trajectory, the best transition Mach number was 9.6; the optimal trajectory had higher dynamic pressure than the fixed, particularly in dual-fuel mode. In the future, the guidance method described in this Note easily could be extended to optimize other propulsion system parameters, such as flow rates of individual propellants in multipropellant engines. Because the guidance algorithm is internal to the trajectory optimization routine, its use will save many iterations of a preliminary design computer code relative to treating these parameters as external design variables. The guidance law is highly accurate, robust, and simple to implement, also making it ideal for use in a real-time onboard control system for an SSTO launch vehicles.
Clustering short texts using wikipedia

Subscribers to the popular news or blog feeds (RSS/Atom) often face the problem of information overload as these feed sources usually deliver large number of items periodically. One solution to this problem could be clustering similar items in the feed reader to make the information more manageable for a user. Clustering items at the feed reader end is a challenging task as usually only a small part of the actual article is received through the feed. In this paper, we propose a method of improving the accuracy of clustering short texts by enriching their representation with additional features from Wikipedia. Empirical results indicate that this enriched representation of text items can substantially improve the clustering accuracy when compared to the conventional bag of words representation.
Clinical Trial Results Applied to Management of the Individual Cancer Patient

The application of clinical trial results to the management of the individual cancer patient is not always straightforward. The results of a clinical trial indicate the "average" effect of an intervention, often expressed in terms of an absolute risk reduction, which is an estimate of the likelihood of benefit for a particular patient. However, within any clinical trial, there might be differences between groups of patients in underlying pathology, genetics, or biology, and some patients might benefit more from a new treatment than others. Thus, within a clinical trial, it might also be useful to group together patients with similar characteristics, and test for subgroup interaction. The test for interaction will indicate whether the magnitude of benefit differs from one prognostic subgroup to the next (a quantitative interaction). Much less common are qualitative interactions, in which a new treatment is beneficial in one subgroup but harmful in another. If the test for subgroup interaction is significant, then the effects of treatment may indeed differ between subgroups of patients, but this should be confirmed in other trials before a treatment is implemented in clinical practice.
A Simple and Universal Gel Permeation Chromatography Technique for Precise Molecular Weight Characterization of Well-Defined Poly(ionic liquid)s

Poly(ionic liquid)s (PILs) are an important class of technologically relevant materials. However, characterization of well-defined polyionic materials remains a challenge. Herein, we have developed a simple and versatile gel permeation chromatography (GPC) methodology for molecular weight (MW) characterization of PILs with a variety of anions. PILs with narrow MW distributions were synthesized via atom transfer radical polymerization, and the MWs obtained from GPC were further confirmed via nuclear magnetic resonance end group analysis.
A scalable parallel genetic algorithm for x-ray spectroscopic analysis

We use a parallel multi-objective genetic algorithm to drive a search and reconstruction spectroscopic analysis of plasma gradients in inertial confinement fusion (ICF) implosion cores. In previous work, we had shown that our serial multi-objective Genetic Algorithm was a good method to solve two-criteria X-ray spectroscopy diagnostics problems. However, this serial version was slow and we therefore could not incorporate better physics and more criteria to solve larger problems and handle larger data sets. In this paper, we develop and use a parallel multi-objective genetic algorithm based on a master-slave model to solve three criteria spectroscopic analysis problems. The algorithm works well in reconciling experimental observations with theoretical physics model parameters. In addition, theoretical analysis and experimental results on the parallelized version show good scalability with up to 150 processors. This reduces the time for running the GA from 9.6 hours to 5.9 minutes.
Genetic interference reduces the evolvability of modular and non-modular visual neural networks

The aim of this paper is to propose an interdisciplinary evolutionary connectionism approach for the study of the evolution of modularity. It is argued that neural networks as a model of the nervous system and genetic algorithms as simulative models of biological evolution would allow us to formulate a clear and operative definition of module and to simulate the different evolutionary scenarios proposed for the origin of modularity. I will present a recent model in which the evolution of primate cortical visual streams is possible starting from non-modular neural networks. Simulation results not only confirm the existence of the phenomenon of neural interference in non-modular network architectures but also, for the first time, reveal the existence of another kind of interference at the genetic level, i.e. genetic interference, a new population genetic mechanism that is independent from the network architecture. Our simulations clearly show that genetic interference reduces the evolvability of visual neural networks and sexual reproduction can at least partially solve the problem of genetic interference. Finally, it is shown that entrusting the task of finding the neural network architecture to evolution and that of finding the network connection weights to learning is a way to completely avoid the problem of genetic interference. On the basis of this evidence, it is possible to formulate a new hypothesis on the origin of structural modularity, and thus to overcome the traditional dichotomy between innatist and empiricist theories of mind.
Evidence for insulin synthesis in normal mouse seminal vesicle based on in situ RNA-DNA hybridization.

Cultured seminal vesicle epithelial cells exhibited cytoplasmic immunoreactivity following treatment with anti-insulin antisera. In addition, these cultured epithelial cells were found, by in situ hybridization with a radiolabeled insulin complementa y deoxyribonucleic acid (cDNA) probe, to contain an insulin or insulin-like messenger ribonucleic acid (mRNA). Autoradiograms of the hybridized cells exhibited heavy labeling over the cytoplasm and minimal distribution of grains over the nuclei and background areas. These observations indicate that cultured mouse seminal vesicle epithelium contains an insulin or insulin-like peptide as well as the mRNA that is required for its synthesis.
Forward propulsion asymmetry is indicative of changes in plantarflexor coordination during walking in individuals with post-stroke hemiparesis

Abstract Background A common measure of rehabilitation effectiveness post-stroke is self-selected walking speed, yet individuals may achieve the same speed using different coordination strategies. Asymmetry in the propulsion generated by each leg can provide insight into paretic leg coordination due to its relatively strong correlation with hemiparetic severity. Subjects walking at the same speed can exhibit different propulsion asymmetries, with some subjects relying more on the paretic leg and others on the nonparetic leg. The goal of this study was to assess whether analyzing propulsion asymmetry can help distinguish between improved paretic leg coordination versus nonparetic leg compensation. Methods Three-dimensional forward dynamics simulations were developed for two post-stroke hemiparetic subjects walking at identical speeds before/after rehabilitation with opposite changes in propulsion asymmetry. Changes in the individual muscle contributions to forward propulsion were examined. Findings The major source of increased forward propulsion in both subjects was from the ankle plantarflexors. How they were utilized differed and appears related to changes in propulsion asymmetry. Subject A increased propulsion generated from the paretic plantarflexors, while Subject B increased propulsion generated from the nonparetic plantarflexors. Each subject's strategy to increase speed also included differences in other muscle groups (e.g., hamstrings) that did not appear to be related to propulsion asymmetry. Interpretation The results of this study highlight how speed cannot be used to elucidate underlying muscle coordination changes following rehabilitation. In contrast, propulsion asymmetry appears to provide insight into changes in plantarflexor output affecting propulsion generation and may be useful in monitoring rehabilitation outcomes.
Nitric Oxide Produced by THAL Nitric Oxide Synthase Inhibits TGF

Nitric oxide (NO) produced by neuronal NO synthase (nNOS) in the macula densa decreases tubuloglomerular feedback (TGF). NO produced by NOS in the thick ascending limb (THAL) inhibits NaCl transport. We hypothesized that NO produced by NOS in the THAL reaches the macula densa and inhibits TGF. Rabbit afferent arterioles and attached macula densa were simultaneously microperfused in vitro. TGF response was determined by measuring afferent arteriole diameter before and after increasing NaCl in the macula densa perfusate. When the nNOS inhibitor 7-nitroindazole (7-NI) (10 μmol/L) was added to the macula densa lumen, it increased TGF from 2.3±0.2 to 3.5±0.5 μm ( P N ω -nitro-l-arginine methyl ester (L-NAME) (1 mmol/L) enhanced TGF from 2.6±0.3 to 4.0±0.5 μm ( P
Researcher: an overview

Described in this paper is a computer system, RESEARCHER, being developed at Columbia that reads natural language text in the form of patent abstracts and creates a permanent long-term memory based on concepts generalized from these texts, forming an intelligent information system. This paper is intended to give an overview of RESEARCHER. We will describe briefly the four main areas dealt with in the design of RESEARCHER: 1) knowledge representation, where a canonical scheme for representing physical objects has been developed, 2) memory-based text processing, 3) generalization and generalization-based memory organization that treats concept formation as an integral part of understanding, and 4) generalization-based question answering.
An HPLC Method for the Quantitation of Quinidine and its Metabolites in Plasma: An Application to a Quinidine-Phenytoin Drug Interaction Study

A rapid and simple method is described for the separation of quinidine (Q), its metabolites 3-hydroxyquinidine (30HQ) and 2'oxoquinidinone (QD) as well as the quinidine salt contaminant, dihydroquinidine (DHQ) in plasma by high pressure liquid chromatography (HPLC). A silica column was used with methanol: 1 N ammonium nitrate: 2 N ammonium hydroxide (28:1:1 v/v) as the mobile phase to separate the compounds and a fluorescence spectrophotometer for detection. Application of this method is demonstrated by the analysis of human plasma samples collected from a volunteer during a phenytoin-quinidine drug interaction study.
PHOTOSYSTEM I: Function and Physiology

▪ Abstract Photosystem I is the light-driven plastocyanin-ferredoxin oxidoreductase in the thylakoid membranes of cyanobacteria and chloroplasts. In recent years, sophisticated spectroscopy, molecular genetics, and biochemistry have been used to understand the light conversion and electron transport functions of photosystem I. The light-harvesting complexes and internal antenna of photosystem I absorb photons and transfer the excitation energy to P700, the primary electron donor. The subsequent charge separation and electron transport leads to the reduction of ferredoxin. The photosystem I proteins are responsible for the precise arrangement of cofactors and determine redox properties of the electron transfer centers. With the availability of genomic information and the structure of photosystem I, one can now probe the functions of photosystem I proteins and cofactors. The strong reductant produced by photosystem I has a central role in chloroplast metabolism, and thus photosystem I has a critical role in...
Political Institutions and Satisfaction with Democracy: A Cross-National Analysis of Consensus and Majoritarian Systems

Do political institutions affect citizen satisfaction with democracy? If so, how? Using cross-sectional survey data for eleven European democracies together with data on the type of democracy in which individuals live, we demonstrate that the nature of representative democratic institutions (measured by Arend Lijphart's consensus-majority index of democracies) mediates the relationship between a person's status as part of the political minority or majority and his or her satisfaction with the way the system works. Specifically, we find that (1) the losers of democratic competition show lower levels of satisfaction than do those in the majority and (2) losers in systems that are more consensual display higher levels of satisfaction with the way democracy works than do losers in systems with majoritarian characteristics. Conversely, winners tend to be more satisfied with democracy the more a country's political institutions approximate pure majoritarian government.
Some Comments on the Relevance of Charge Transfer for the 300 nm Transition in β, γ Unsaturated Ketones

When two (or more) chromophores are brought sufficiently close together in a single molecule, it is commonly observed that the absorption spectrum of the coupled system is not merely a superposition of the spectra of the separate species. For specifying the nature of the transitions of the composite system, a very definite interpretative convenience is achieved through the approach of Longuet-Higgins & Murrell (1955). In their formulation, the basis states employed for a description of the states of the combined system are classified as either ‘locally excited’ or ‘charge transfer’. Locally excited states are those associated with electronic promotions within a single chromophore, and charge transfer states are those that arise from the promotion and transfer of an electron from a filled orbital on one chromophore to an unfilled orbital on another. The electronic states of the coupled system can then be characterized as some linear combination of the interchromo-phoric charge transfer states and the locally excited states characteristic of the separate chromophores. Therefore, the extent to which charge transfer and/or local excitations contribute to transitions of the coupled system is readily given by the coefficients in the linear combination of charge transfer and locally excited states that go to specify a state of the polychromophoric species. Of course, such information is also available, in principle, in an orbital approach. However, it is not nearly so manifest there. The Longuet-Higgins & Murrell method has been applied to the following series of compounds (Moscowitz et al . 1964; Hansen 1964; Mislow 1962): ( + )-(1R)-5-methylenebicyclo[2. 2. 1]hept-2-ene (I), ( + )-(1R)-bicyclo[2. 2. 2]oct-5-ene-2-one (II), and bicyclo[2. 2. 1]hept-2-7-dione (III). The motivation, in part, was to test the extent of validity of a fundamental assumption commonly employed in theo­retical treatments of optically active helical polypeptides (Tinoco 1961), namely, that charge transfer is of negligible importance for the near ultraviolet optical properties of the helical polypeptides, and that electrostatic coupling (without charge transfer) of the locally excited states of the ordered amide monomers is primarily responsible for the enhanced optical activity in the helical conformations relative to the random coil forms.
Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial.

Context The herbal product Ginkgo biloba is taken frequently with the intention of improving cognitive health in aging. However, evidence from adequately powered clinical trials is lacking regarding its effect on long-term cognitive functioning. Objective To determine whether G biloba slows the rates of global or domain-specific cognitive decline in older adults. Design, Setting, and Participants The Ginkgo Evaluation of Memory (GEM) study, a randomized, double-blind, placebo-controlled clinical trial of 3069 community-dwelling participants aged 72 to 96 years, conducted in 6 academic medical centers in the United States between 2000 and 2008, with a median follow-up of 6.1 years. Intervention Twice-daily dose of 120-mg extract of G biloba (n = 1545) or identical-appearing placebo (n = 1524). Main Outcome Measures Rates of change over time in the Modified Mini-Mental State Examination (3MSE), in the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS-Cog), and in neuropsychological domains of memory, attention, visual-spatial construction, language, and executive functions, based on sums of z scores of individual tests. Results Annual rates of decline in z scores did not differ between G biloba and placebo groups in any domains, including memory (0.043; 95% confidence interval [CI], 0.034-0.051 vs 0.041; 95% CI, 0.032-0.050), attention (0.043; 95% CI, 0.037-0.050 vs 0.048; 95% CI, 0.041-0.054), visuospatial abilities (0.107; 95% CI, 0.097-0.117 vs 0.118; 95% CI, 0.108-0.128), language (0.045; 95% CI, 0.037-0.054 vs 0.041; 95% CI, 0.033-0.048), and executive functions (0.092; 95% CI, 0.086-0.099 vs 0.089; 95% CI, 0.082-0.096). For the 3MSE and ADAS-Cog, rates of change varied by baseline cognitive status (mild cognitive impairment), but there were no differences in rates of change between treatment groups (for 3MSE, P = .71; for ADAS-Cog, P = .97). There was no significant effect modification of treatment on rate of decline by age, sex, race, education, APOE*E4 allele, or baseline mild cognitive impairment (P > .05). Conclusion Compared with placebo, the use of G biloba, 120 mg twice daily, did not result in less cognitive decline in older adults with normal cognition or with mild cognitive impairment. Trial Registration clinicaltrials.gov Identifier: NCT00010803
Reducing the latency and area cost of core swapping through shared helper engines

Technologies scaling trends and the limitations of packaging and cooling have intensified the need for thermally efficient architectures and architecture-level temperature management techniques. To combat these trends, we explore the use of core swapping on microcore architecture, a deeply decoupled processor core with larger structures factored out as helper engines. The microcore architecture presents an ideal platform for core swapping thanks to helper engines that maintain the state of each process in a shared fabric surrounding the cores, reducing the impact of core swapping 43% on average while showing promising thermal reduction. It also has favorable performance when compared to other thermal management techniques. Furthermore, we evaluate alternative approaches to spending the area overhead of the additional microcore, including larger microcores, CMP cores, and SMT cores with different thermal management techniques.
Bivalirudin Dosing Adjustments for Reduced Renal Function with or without Hemodialysis in the Management of Heparin-Induced Thrombocytopenia

Background:While not approved by the Food and Drug Administration for treatment of heparin-induced thrombocytopenia (HIT), except in patients undergoing percutaneous interventions, the direct thrombin inhibitor bivalirudin is a treatment option that is gaining use. An initial dose of bivalirudin 0.15–0.2 mg/kg/h, adjusted to an activated partial thromboplastin time (aPTT) of 1.5–2.5 times the baseline value, has been suggested. Initial dosing in patients with renal dysfunction, including those on hemodialysis, is unclear.Objective:To evaluate initial bivalirudin dosing requirements in patients with and without renal dysfunction, including patients on different forms of dialysis.Methods:A retrospective analysis of 135 patients treated with bivalirudin for HIT between June 2004 and October 2009 was conducted at a tertiary care medical center. The patients were divided into groups, based on renal function. Patients receiving dialysis were divided into 3 subgroups based on the mode of hemodialysis: intermitte...
Signals and linear systems: a teaching approach based on learning styles concepts

The exclusive teaching of continuous-time concepts before discrete-time concepts in undergraduate signals and linear systems is advocated when circuit analysis is a prerequisite. The reasons for this approach are based on learning styles concepts of inductive/deductive organization, sequential/global understanding and sensory/intuitive perception. This approach is promoted because it: (1) supports inductive progression of material; (2) addresses the needs of students who learn through sensing; and (3) supports both global and sequential learners. Arguments are made that the presentation of continuous-time concepts first promotes the deepest understanding of the material in the largest number of students. >
Application of synchrotron radiation for measurement of iron red-ox speciation in atmospherically processed aerosols

In this study, ambient atmospheric particulate matter samples were collected using a size-resolved impactor sampler from three urban sites. The purpose of this study is to gain a better understanding of transformations of aerosol-bound iron as it is processed in the atmosphere. Thus, the aerosol samples were artificially aged to represent long-term transport (10 to 40 days) or short-term transport (1 to 10 days) and were measured for iron at several time points. At each time point, iron was measured in each size fraction using three different techniques; 1) inductively coupled plasma-mass spectrometry (ICPMS) for total iron, 2) x-ray absorbance near edge structure (XANES) spectroscopy for the measurement of total Fe(II) and Fe(III), and 3) a wet-chemical method to measure soluble Fe(II) and Fe(III). Prior to aging, the XANES spectroscopy results show that a majority (>60% for each size fraction) of the total iron in the PM is in the form of Fe(III). Fe(III) was shown to be a significant fraction of the soluble iron (sometimes >50%), but the relative significance of Fe(III) was found to vary depending on the site. Overall, the total soluble iron depended on the sampling site, but values ranged from less than 1% up to about 20% of the total iron. Over the course of the 40 day aging period, we found moderate changes in the relative Fe(II)/Fe(III) content. A slight increase was noted in the coarse (>2.5 µm) fraction and a slight decrease in the 0.25 to 0.5 µm fraction. The soluble fraction generally showed (excepting one day) a decrease of soluble Fe(II) prior to 10 days of aging, followed by a relatively constant concentration. In the short-term transport condition, we found that the sub-micron fraction of soluble Fe(II) spikes at 1 to 3 days of aging, then decreases to near the initial value at around 6 to 10 days. Very little change in soluble Fe(II) was observed in the super-micron fraction.
Nested parallelism in transactional memory

This paper investigates adding transactions with nested parallelism and nested transactions to a dynamically multithreaded parallel programming language that generates only series-parallel programs. We describe XConflict, a data structure that facilitates conflict detection for a software transactional memory system which supports transactions with nested parallelism and unbounded nesting depth. For languages that use a Cilk-like work-stealing scheduler, XConflict answers concurrent conflict queries in O(1) time and can be maintained efficiently. In particular, for a program with T1 work and a span (or critical-path length) of T∞, the running time on p processors of the program augmented with XConflict is only O(T1/p + pT∞).Using XConflict, we describe CWSTM, a runtime-system design for software transactional memory which supports transactions with nested parallelism and unbounded nesting depth of transactions. The CWSTM design provides transactional memory with eager updates, eager conflict detection, strong atomicity, and lazy cleanup on aborts. In the restricted case when no transactions abort and there are no concurrent readers, CWSTM executes a transactional computation on p processors also in time O(T1/p + pT∞). Although this bound holds only under rather optimistic assumptions, to our knowledge, this result is the first theoretical performance bound on a TM system that supports transactions with nested parallelism which is independent of the maximum nesting depth of transactions.
Individuals, Corporations and the Pedagogy of Citizenship

This essay examines access to and experiences in the market for citizenship (writ large to include legal, cultural, social, and political) across three broad categories: black Americans, immigrants, and corporations. Drawing on the critiques reanimated by the killings of youth, like Michael Brown in Ferguson, Missouri, the essay suggests that, while black Americans enjoy full legal citizenship, they, nevertheless, face often insurmountable obstacles in accessing and negotiating the market for arguably more valuable forms of citizenship. Contrasting the position of a range of noncitizens -- from pop stars to migrant workers -- the essay reaffirms the common wisdom that for immigrants, the market for citizenship is an unpredictable and unreliable lottery. Then, recounting the story of Burger King's partial expatriation, it illustrates that corporations participate in a market for citizenship that is flexible and negotiable, not unlike traditional markets. Although, the stories this essay tells and the discourses associated with them are well known, their juxtaposition reveals a new question. What is the lesson taught by these disparate experiences? Describing law as a societal pedagogy, the essay suggests a heuristic through which that question may begin to be explored.
Lightweight mirror construction optimization

Large, lightweight mirrors are a critical component in space based imaging applications. These mirrors have traditionally required long manufacturing cycle times with associated high costs. In this paper, the key cost and schedule drivers for the production of large, lightweight mirrors will be reviewed along with enabling solutions that could provide significant cost and schedule reductions while maintaining the high quality performance required for these challenging applications. The technologies include advancements in replication, construction, and bonding. Initial feasibility tests and associated results will be presented.
Abstract 18429: Transmembrane Protein 88: A Wnt Regulatory Protein That Specifies Cardiomyocyte Development

Genetic regulation of the cell fate transition from lateral plate mesoderm to the specification of cardiomyocytes requires suppression of Wnt/β-catenin signaling, but the mechanism for this is not well understood. By analyzing gene expression and chromatin dynamics during directed differentiation of human embryonic stem cells (hESCs), we identified a suppressor of Wnt/β-catenin signaling, transmembrane protein 88 (TMEM88), as a potential regulator of cardiovascular progenitor cell (CVP) specification. During the transition from mesoderm to the CVP, TMEM88 has a chromatin signature of genes that mediate cell fate decisions, and its expression is highly up-regulated in advance of key cardiac transcription factors in vitro and in vivo. In early zebrafish embryos tmem88a is expressed broadly in the lateral plate mesoderm including the bilateral heart fields, and morpholino-mediated reduction in its expression yields small hearts with defective looping. Short hairpin RNA targeting of TMEM88 during hESC cardiac differentiation increases Wnt/β-catenin signaling, confirming its role as a suppressor of this pathway. TMEM88 knockdown has no effect on Nkx2.5 or GATA4 expression, but 80% of genes most highly induced during CVP development have reduced expression, suggesting adoption of a new cell fate. In support of this, analysis of later stage cell differentiation showed that TMEM88 knockdown inhibits cardiomyocyte differentiation and promotes endothelial differentiation. Taken together, TMEM88 is critical for heart development and acts downstream of GATA factors in the pre-cardiac mesoderm to specify lineage commitment of cardiomyocyte development through inhibition of Wnt/s-catenin signaling.
The Influence of Neurocognitive Impairment on HIV Risk Behaviors and Intervention Outcomes among High-Risk Substance Users: A Systematic Review

Neurocognitive impairment (NCI) among high-risk substance users poses a substantial barrier to reducing risk behaviors in this populations. Previous work suggest that NCI is intertwined in a close, reciprocal relationship with risk behaviors. Not only does substance use worsen cognitive impairment, but cognitive impairment may also reduce the efficacy of interventions aimed at reducing risk and improving medication adherence. In this systematic review, we examine the potential impact of substance abuse and cognitive functioning in the context of HIV risk behaviors and risk-reduction intervention outcomes. The findings thus far suggest that, in order to be effective, risk-reduction interventions must take into account the impact of NCI on learning, memory, and behavior.
Aerodynamic Forces on an Airdrop Platform

attack over the range -10o to 178o and with the plate undergoing dynamic pitching which was scaled from full-size platform motion. The results showed that the dynamic pitching of the plate significantly increased the lift and drag coefficients of the plate when compared against the plate at static angles of attack. The peak lift coefficient was increased by 72% and the maximum drag coefficient was increased by 350%. Although the peak lift coefficient occurred at the same angle of attack in both cases, the peak drag coefficient was delayed by ~42o with the dynamically pitching plate.