cssi/SciSciGPT-SciSciNet huggingface dataset:
Conformational Transitions Associated with the Release of the Buried Tryptophan Residues of α1-Acid Glycoprotein

Abstract A study on α1-acid glycoprotein by various techniques was carried out to investigate certain conformational transitions associated with the release of the buried tryptophan residues of this protein. The reactive tryptophan residues of α1-acid glycoprotein were determined with Koshland's reagent (2-hydroxy-5-nitrobenzylbromide). As solvents, sodium acetate buffers, pH 4.4, containing increasing concentrations of 2-chloroethanol or guanidine hydrochloride were used. In sodium acetate buffer alone, 2 of the 4 tryptophan residues were found to be reactive. In the presence of 50% 2-chloroethanol or 3 m guanidine hydrochloride, or after incubation at pH 13 for 30 min, all 4 residues reacted with Koshland's reagent. These results, together with the changes in the specific optical rotation and optical rotatory dispersion observed in the mentioned solvents, are discussed in relation to the changes in the structure of this protein induced by these solvents. In 2-chloroethanol a reversible transition of the β conformation of the native protein to a conformation that has properties similar to those of an α-helical structure was observed. In guanidine hydrochloride the conformation of α1-acid glycoprotein was also reversibly altered, but yielded a random coil structure. Incubation at pH 13 caused irreversible denaturation. Further, this study showed that the sialyl residues of this typical glycoprotein do not significantly influence the conformational transitions of its polypeptide chain. In a correlated study, the optical rotatory dispersion of the glycopeptide mixture derived from native α1-acid glycoprotein was determined and shown to account for only a small percentage of the optical rotatory dispersion of the glycoprotein. Hence, the Cotton effect of glycoproteins is essentially due to the conformation of their polypeptide moieties.
The relationship of performance characteristics to basic parameters of polymers. I. A collaborative study of polystyrene using torsion pendulum and impact methods

In July, 1963, a working party of I.U.P.A.C. was set up to consider collaborative investigations in the general area indicated by the main title of this paper, and joint studies were started with three polymers: polystyrene, polyvinyl chloride, and polyethylene. This paper gives an account of the work done to date with polystyrene. The paper shows the detailed torsion pendulum results of six laboratories with the use of the same toughened polystyrene. The significance of frequency of vibration in raising the temperature of maximum damping of the rubbery component is clearly brought out and the degree of agreement shown between laboratories is good. A smaller number of collaborators made impact strength and torsion pendulum studies over a range of temperatures on polystyrene and another toughened polystyrene. The dependence of the brittle–tough transition temperature on estimated rate of elongation of the breaking filament is correlated with the dependence of the temperature of maximum damping of the rubbery component on frequency.
Electric field dependent dielectric properties and high tunability of BaZrxTi1−xO3 relaxor ferroelectrics

This letter reports the E-field tunable behavior of the environmental friendly lead-free perovskite BaZrxTi1−xO3 (x=0.50 and 0.60) relaxor ceramics in the temperature range from 300to30K. dc electric field dependence of dielectric behavior of the ceramics has been studied. The results have been analyzed in relation to tunability (%) and K factor of the tunable dielectric materials. It is shown that manipulating the Zr:Ti concentration in BaZrxTi1−xO3 ceramics and optimizing the applied dc bias field the properties for specific applications in tunable filters, phase shifters, antennas, etc., can be tailored in the temperature range from 100to300K.
Stock Option Exercise, Earnings Management, and Abnormal Stock Returns

This essay uses a large sample to examine whether stock option plans provide incentives to executives to manage earnings when exercising their options. The evidence presented is consistent with a hypothesis where managers use accruals to shift earnings to increase the stock price prior to and during option exercise periods. However, the results indicate that the magnitude of earnings management related to stock options may be limited. Reported income peaks at the earnings announcement immediately preceding option exercise activity and is followed by both reversals in income and discretionary accruals as well as negative abnormal stock returns during the post-exercise period for up to one year. Current discretionary accruals range from 0.3% to 0.62% of assets, depending upon the accrual model, during the quarterly earnings announcement immediately preceding option exercise activity. Over the two quarters following option exercise, sample firms experience small but statistically significant reversals in discretionary accruals and on average experience negative abnormal returns of approximately -3%. The magnitude of the return reversals is shown to be cross-sectionally positively related to the magnitude of the pre-exercise discretionary accrual proxies, even after adjusting for the Sloan anomaly. I find similar evidence for a sample of firms that experience option expiration but weaker evidence of earnings management for stock sales unrelated to stock option exercise.
Root Architecture and Plant Productivity.

Water and nutrient availability limit plant growth in a11 but a very few natural ecosystems. They limit yield in most agricultural ecosystems, and in the United States and other industrialized nations, intensive irrigation and fertilization have generated serious environmental problems. The acquisition of soil resources by plant root systems is therefore a subject of considerable interest in agriculture and ecology, as well as a complex and challenging problem in basic plant biology. Symbioses between roots and otlier organisms (notably mycorrhizas and N-fixing bacteria), modification of the rhizosphere through root exudates, and the uptake and transport characteristics of root axes are a11 important dimensions of this problem that are being actively researched by plant biologists. Another aspect of this problem that has received less attention, despite its probable importance, is root architecture. Recent methodological innovations present opportunities for improved under.standing of the functional importance of root architecture in the efficient acquisition of soil resources and plant adaptation to suboptimal soil conditions. The purpose of this Update is to briefly summarize conceptual issues and recent developments in the study of root architecture and to propose a framework for understanding its physiological basis.
Type I Elements Mediate Replication Fork Pausing at Conserved Upstream Sites in the Tetrahymena thermophila Ribosomal DNA Minichromosome

Two-dimensional gel electrophoresis was used to study replication of the Tetrahymena thermophila ribosomal DNA (rDNA) minichromosome. During vegetative growth, the rDNA is replicated exclusively from origins in the 5' nontranscribed spacer (NTS). Whereas replication fork movement through the rest of the chromosome appears to be continuous, movement through the 5' NTS is not. Replication forks arrest transiently at three prominent replication fork pausing sites (RFPs) located in or immediately adjacent to nucleosome-free regions of the 5' NTS. Pausing at these sites is dramatically diminished during replication in Escherichia coli, suggesting that chromatin organization or Tetrahymena-specific proteins may be required. A conserved tripartite sequence was identified at each pausing site. Mutations in type I elements diminish pausing at proximal RFPs. Hence, type I elements, previously shown to control replication initiation, also regulate elongation of existing replication forks. Studies with rDNA transformants revealed a strong directional bias for fork pausing. Strong pausing only occurred in forks moving toward the rRNA-coding region. We propose that fork pausing in the 5' NTS evolved to synchronize replication and transcription of the downstream rRNA genes.
Simplified Highly-Accelerated Life Testing on components for product-level vibration reliability enhancement

The current trend towards the placement of electronics hardware in harsh vibration environments with the simultaneous need to control costs by using 'off-the-shelf' electronics components has introduced additional challenges. The need therefore exists for a means to rapidly and cost-effectively test the vibration robustness of individual components and assemblies. To address this particular need, specialized hardware has been developed along with the associated methodology. The hardware developed essentially consists of a simple mechanical vibration amplifier controlled using a closed-loop feedback system, by means of which extreme vibration levels (in excess of 250 Gs) can be achieved using a low power vibration shaker system. The methodology of testing consists of a simplified form of the Highly-Accelerated Life Testing (HALT) methodology and involves subjecting components under consideration to high levels of vibration and testing to the point of failure. Based on test results, a relative assessment can be rapidly made for various changes in product configuration. This is best illustrated by an example where several configuration variations were tested using this methodology to solve a capacitor failure problem. The techniques described here can potentially be applied to a wide range of electronics components. As can be inferred from the example in the paper, these techniques offer the potential for considerable cost-savings in the form of minimizing product-level testing, along with improvement in the reliability of the end product.
The Use of Computer-Monitored Data in Information Science and Communication Research.

As computer-based information retrieval and communication systems become more commonplace, researchers have a greater opportunity to evaluate the uses and impacts of new communication technologies. The systems and the kinds of data now available are discussed along with advantages and disadvantages of using computer-monitored data.
Theory of superfluids with population imbalance: Finite-temperature and BCS-BEC crossover effects

In this paper we present a very general theoretical framework for addressing fermionic superfluids over the entire range of BCS to Bose Einstein condensation (BEC) crossover in the presence of population imbalance or spin polarization. Our emphasis is on providing a theory which reduces to the standard zero temperature mean-field theories in the literature, but necessarily includes pairing fluctuation effects at nonzero temperature within a consistent framework. Physically, these effects are associated with the presence of preformed pairs (or a fermionic pseudogap) in the normal phase, and pair excitations of the condensate, in the superfluid phase. We show how this finite $T$ theory of fermionic pair condensates bears many similarities to the condensation of point bosons. In the process we examine three different types of condensate: the usual breached pair or Sarma phase and both the one- and two-plane-wave Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) states. The last of these has been discussed in the literature albeit only within a Landau-Ginzburg formalism, generally valid near ${T}_{c}$. Here we show how to arrive at the two-plane-wave LOFF state in the ground state as well as at general temperature $T$.
The structure of phosphorus-selenium glasses I. Concentration dependence of the short- and intermediate-range order☆

Abstract The structures of phosphorus-selenium glasses PxPe1−x with x=0 (pure selenium), 0.05, 0.15, 0.25, 0.40 and 0.50 have been investigated with neutron diffraction, extented, X-ray absorption fine structure measurements, and Raman and infrared spectroscopy. The behavior of the near-neighbor coordination at r∼2.3 A as a function of x suggests a picture in which P4Sen molecular units are linked together by Se atoms or chains. The diffraction patterns exhibit anomalous peaks at Q ∼ 1.2A which rise dramatically as P is added to the Se glass; these peaks can also be understood on a molecular picture. The Raman spectra at the larger P concentrations are characterized by series of relatively sharp peaks which also suggest molecular units and for x = 0.5 bear a close correspondence to the spectrum of crystalline P4Se3.
Narrative Middles: Navigating the Nineteenth-Century British Novel

What's so bad about being a “large loose baggy monster,” anyway? Caroline Levine and Mario Ortiz-Robles's original collection asks a version of this question in proposing that what Henry James like...
Fuel Gas Purification with Permselective Membranes

Abstract Production of fuel gas from biomass and recovery of flared gas from landfills, oil fields, coal mines, is hampered by the high cost of gas purification for the removal of C02 and H2S. Membranes offer a potentially simple and attractive technique for on-site gas purification. Two membrane approaches have been considered for fuel gas purification-polymer films and facilitated transport-each with its own unique advantages. Polymer films can be made extremely thin (<500A), and thus have high gas throughput and a very low membrane area requirement. Ultrathin polymer membranes have been found to be extremely attractive for purification of gas produced from waste or in remote site applications. Of particular interest is biogas produced from anaerobic digestion of sewage, municipal waste, agricultural waste, and landfills. Membrane purification is expected to cost less than half of that for conventional scrubbing processes. Additionally, the gas is purified and dried at the same time. Laboratory tests co...
Gaussian Behavior of the Electroencephalogram: Changes during Performance of Mental Task

The probability distribution of the amplitude of scalp electroencephalogram has been investigated in an adult subject in the idle state, and during performance of a mental arithmetic task. Based on a large sample, the electroencephalogram in this subject in the idle state follows a Gaussian (normal) probability function 66 percent of the time. During performance of the arithmetic task, the portion of Gaussian electroencephalogram decreases to 32 percent. The probability function characterizing gross electroencephalographic activity is determined by the degree of mutual interaction of individual cellular generators of wave activity in the tissue underneath the recording electrode. The data imply an increase in the cooperative activity of cortical neuronal elements during performance of a mental task.
Prevention of Transplant Rejection: Can Tolerance be Achieved with Immunosuppressive Treatment?

Successful solid organ transplantation is generally attributed to the increasingly precise ability of drugs to control rejection. However, it was recently shown that a few donor haematolymphoid cells can survive for decades in recipients of successful organ allografts, a phenomenon called microchimaerism. The association for decades of haematolymphoid chimaerism with allograft tolerance in experimental transplantation suggests that immunosuppressive drugs merely create a milieu that enables an allograft and its complement of passenger leucocytes to prime the recipient for graft acceptance.Exploitation of this concept requires a fundamental shift in the classical view of passenger leucocytes only as initiators of rejection. Microchimaerism has taught us that solid organ transplantation involves the transfer of two donor organ systems to the recipient: the allograft parenchyma and the donor haematolymphoid system in the form of donor stem cells contained within the passenger leucocyte compartment. Each has the potential to integrate with the corresponding recipient system and carry out normal physiological functions, such as immunological self definition. Resistance to initial integration by mature T cells requires some form of immunosuppression, but maintenance of donor immune system function will depend on renewable supply of cells, which can be provided by engrafted progenitors. Successful clinical application will depend on the development of low morbidity methods to enhance engraftment of donor haemopoietic stem cells.
Extrinsic upper bounds for λ1

Si M est compact alors il existe c∈R tel que λ 1 (M)≤c+(n∫M Hu 2)/volM pour toutes les sous-varietes M compactes connexes a n dimensions isometriquement immergees de M. (λ 1 (M)) est la premiere valeur propre du laplacien de M
Type A behavior and temporal judgment

Type A behavior is related to the development of coronary heart disease. Type A college students were compared with Type Bs on several time-related measures. The findings differ from what is expected on the basis of previous research and theories. Type As show greater variability and absolute error than do Type Bs in the production of a 60- or 300-sec duration, as well as marginally greater productions. Type As did not arrive earlier for the experiment and were not wearing a watch more frequently than were Type Bs. The results reveal difficulties in judging duration, which may help in understanding the Type A behavior pattern.
Facial expression and face orientation processing in schizophrenia

Schizophrenia patients exhibit deficits in recognition and identification of facial emotional expressions, but it is unclear whether these deficits result from abnormal affective processing or an impaired ability to process complex visual stimuli such as faces. Participants comprised 16 outpatients with schizophrenia and 22 matched healthy control subjects who performed two computerized visual matching tasks (facial emotional expression and orientation). Accuracy and reaction time were recorded. Clinical symptoms were assessed in the patients using the Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Positive Symptoms (SAPS), and Scale for the Assessment of Negative Symptoms (SANS). Social functioning as measured by the Zigler social competence scale was indexed in all participants. Patients with schizophrenia were less accurate than control participants on both facial emotion and orientation matching tasks, but there was no diagnosis-by-task interaction. Clinical symptoms of the patients were associated with deficits on emotion and orientation matching tasks. Worse social functioning was correlated with facial emotion matching errors across both groups. Patients with schizophrenia show general deficits in processing of faces, which is in turn associated with worse symptoms and reduced social functioning.
Self-repairing poly(phenylenesulfide) coatings in hydrothermal environments at 200 °C

Usefulness of hydraulic calcium aluminate (CA) fillers, containing monocalcium aluminate (CaO.Al2O3) and calcium bialuminate (CaO.2Al2O3) reactants as the major phases, in healing and repairing micro-sized cracks generated on the surfaces of poly(phenylenesulfide) (PPS) coating was evaluated by exposing the cleaved coatings to a simulated geothermal environment. CA fillers with a grain size of <40 μm were incorporated into the PPS coatings. The cleaved PPS coatings containing fillers then were exposed for up to 20 days in a 200 °C CO2-laden brine. The decalcification–hydration reactions of the CaO.Al2O3 and CaO.2Al2O3 reactants disclosed in the cracks led to the rapid growth of boehmite crystals, while the crystalline calcite phase formed by the carbonation of these reactants was leached out of cracks because of the formation of water-soluble calcium bicarbonate. During exposure for 24 h, the block-like boehmite crystals, ∼4 μm in size, densely filled and sealed the open cracks; this was reflected in an increase in pore resistance to two orders of its magnitude compared with that of cleaved coatings without fillers. Extending the exposure time to 20 days resulted in no change in pore resistance, suggesting that the sealing of the cracks by boehmite crystals played an essential role in reconstituting and restoring the function of the failed coatings as corrosion-preventing barrier. Therefore, CA-filled PPS coatings are able to self-heal and -repair cracks generated on the surfaces of coating films in hydrothermal environments.
Investigating the role of FUS exonic variants in Essential Tremor

Essential Tremor is the most common form of movement disorder. Aggregation in families suggests a strong genetic component to disease. Linkage and association studies have identified several risk loci but the specific causal variants are still unknown. A recent study using whole exome sequencing identified a rare nonsense variant in the FUS gene (p.Q290X) that segregated with Essential Tremor in a large French Canadian family. In addition, two other rare FUS variants were identified (p.R216C and p.P431L) in Essential Tremor patients however co-segregation analysis with disease was not possible. In the present study, we sequenced all 15 exons of FUS in 152 familial probands with Essential Tremor and genotyped three reported FUS variants in 112 sporadic Essential Tremor patients and 716 control subjects recruited at Mayo Clinic Florida. Only known synonymous SNPs unlikely to be pathogenic were detected in our sequencing and not any of the recently identified mutations or novel ones. We conclude that the FUS mutations associated with risk of Essential Tremor are probably a rare occurrence.
TU-D-BRB-02: Failure Modes and Effects Analysis Applied to HDR Treatment Planning

Purpose: To apply Failure Modes and Effects Analysis (FMEA) to HDR treatment planning in order to identify the most likely and significant sources of error in the process. Methods and Materials: We have made a list of 24 failure modes grouped into six categories (imaging, catheter reconstruction, dwell position activity, dose points/normalization, optimization/dose, and evaluation) based on our experience with the Nucletron Plato and Oncentra planning systems. Each mode was then rated on a 1–5 scale for severity, likelihood of occurrence, and probability of escaping detection. An overall ranking is formed from the product of the 3 scores (1–125). Severity was ranked according to potential harm to the patient (notably underdosing was not considered) and was based on the NCI Common Terminology Criteria for Adverse Events handbook v 4.0. The authors assigned scores independently and the resulting rankings were averaged. We have also analysed 36 recent reported medical events related to HDR treatment planning listed on the NRC website and compared with our own rankings. Results: Failure modes associated with image sets, catheter reconstruction, indexer length and incorrect dose points had the highest ranking in our analysis (scores > 20). The most often cited failure modes in the NRC reports examined were indexer length (17/36) and incorrect dose points (6/36). Several of our high‐ranking modes are not associated with reported events. Conclusion: It is a useful exercise to identify failure modes locally and analyse the efficacy of the local quality assurance program. Comparison with nationally reported failures can help direct the local analysis, but the absence or small number of reports for failure modes with a high score may be due to low detectability. Such modes obviously cannot be ignored.
Do multivitamin supplements modify the relationship between prenatal alcohol intake and miscarriage

Objective To determine whether multivitamin supplements modify the relationship between alcohol consumption during pregnancy and the risk of miscarriage. Study Design We used data from a population-based cohort study of pregnant women (n = 1061; response rate = 39%). Participants were asked about their alcohol consumption and vitamin intake during pregnancy. Results Among multivitamin nonusers, women who drank alcohol during their pregnancy were more likely to have a miscarriage compared with women who abstained (adjusted hazard ratio, 1.67; 95% confidence interval, 1.04–2.69). However, among multivitamin users, there was no difference in the risk of miscarriage between alcohol consumers and abstainers. Results suggest the volume of alcohol as well as the timing of multivitamin supplementation may also be important. Conclusion Our findings suggest that a woman of childbearing years might decrease her risk of miscarriage associated with alcohol intake by taking multivitamin supplements. However, our findings should be interpreted with caution and future research replicating these findings is necessary.
Virtual Reality Pain Control During Burn Wound Debridement in the Hydrotank

Objective Most burn-injured patients rate their pain during burn wound debridement as severe to excruciating. We explored the adjunctive use of water-friendly, immersive virtual reality (VR) to distract patients from their pain during burn wound debridement in the hydrotherapy tank (hydrotank). Setting This study was conducted on inpatients at a major regional burn center. Patients Eleven hospitalized inpatients ages 9 to 40 years (mean age, 27 y) had their burn wounds debrided and dressed while partially submerged in the hydrotank. Intervention Although a nurse debrided the burn wound, each patient spent 3 minutes of wound care with no distraction and 3 minutes of wound care in VR during a single wound care session (within-subject condition order randomized). Outcome measures Three 0 to 10 graphic rating scale pain scores (worst pain, time spent thinking about pain, and pain unpleasantness) for each of the 2 treatment conditions served as the primary dependent variables. Results Patients reported significantly less pain when distracted with VR [eg, "worst pain" ratings during wound care dropped from "severe" (7.6) to "moderate" (5.1)]. The 6 patients who reported the strongest illusion of "going inside" the virtual world reported the greatest analgesic effect of VR on worst pain ratings, dropping from severe pain (7.2) in the no VR condition to mild pain (3.7) during VR. Conclusions Results provide the first available evidence from a controlled study that immersive VR can be an effective nonpharmacologic pain reduction technique for burn patients experiencing severe to excruciating pain during wound care. The potential applications of VR analgesia to other painful procedures (eg, movement or exercise therapy) and other pain populations are discussed.
Friction and Faulting Editor’s Note

Combining the topics of rock friction and faulting in one volume is an expression of a certain optimism that information obtained on frictional properties, which comes primarily from relatively small laboratory samples, is relevant to slip on those faults of greatest interest to us, the relatively large ones found in the earth. Probably most workers in this general area believe or hope that this is true, but there is still debate concerning how much progress has been made in relating the laboratory measurements to the earth and how reasonable it is to expect that more progress can be made in the future. The scientific fascination and challenges of these complex topics are enhanced by the possibility they offer for understanding the mechanics of earthquakes that may lead to a workable earthquake prediction program. It is worth reflecting on the similarities and differences between the laboratory and the field settings and on what must be done to understand the mechanics of faulting using laboratory friction data. The articles in this volume are representative of the types of studies that must be combined to attain this goal.
Schistosoma mansoni: assessment of effects of oleic acid, cercarial age and water temperature on parasite-host attraction.

Although the lifecycle of Schistosoma spp. and pathophysiology of schistosomiasis have been established, the mechanism by which cercariae find their host is not well understood. Speculatively, host infection by random and accidental host contact is not as biologically plausible as a biochemical mechanism of mammalian attraction. A few studies have indicated that biochemical cues and temperature gradients may play a role in host identification, attraction and attachment triggers. This study aimed to elucidate these mechanisms more specifically through evaluation of biochemical, age and temperature influences leading to Schistosoma mansoni cercariae attraction and attachment behaviors. Oleic acid, a common unsaturated free fatty acid in the outer layer of human skin, was tested for cercariae attraction across biologically relevant concentrations. Influence of media type (beeswax, nail varnish and agar), age-dependent behavior variability and environmentally appropriate temperatures (22 and 30 °C) were also evaluated. Results indicated that oleic acid at concentrations of 0.3, 0.9 and 1.8 g/mL in beeswax significantly increased median attachment to media (median attachment of 7.50%, 4.20% and 3.71%, respectively, P 0.05). Biochemical, age and environmental factors influencing cercarial host attraction and attachment behavior have been elucidated by this study. This information will inform further development of devices for environmental surveillance and potentially improve cercarial exposure prevention strategies.
Autoimmune Disease and Histocompatibility Antigen

Excerpt To the editor: The report by Van Thiel and associates (1) is an excellent example of a thorough family study, and adds the syndrome of selective immunoglobulin A deficiency with malabsorpti...
Enhancement of ketosis by 16,16 dimethylpostaglandin E2 during the genesis of diabetic ketoacidosis in rats

Abstract We examined the effects of 16,16 dimethylprostaglandin E2 (DMPGE2) on the development of diabetic ketoacidosis (DKA) in rats. Animals received DMPGE2, 200 or 300 μg/kg body weight subcutaneously in 0.5 ml saline, or the saline carrier alone at 0, 12, 24 and 36 hours after administration of streptozotocin. At 40 hours, blood was obtained for measurement of plasma free fatty acids (FFAs) and ketone bodies. DMPGE2 produced a dose-related decrease in plasma FFA levels at 40 hours. FFA levels were 2.76 ± 0.39 meq/L (mean ± SEM) with saline, 1.72 ± 0.22 meq/L with 200 μg/kg DMPGE2 (p in vivo and in vitro . Despite suppression of lipolysis, DMPGE2 enhanced the development of ketosis during the genesis of DKA. The beta-hydroxybutyrate level was 5.89 ± 0.60 mM with saline, 8.15 ± 1.02 mM with 200 μg/kg DMPGE2 and 11.17 ± 0.60 mM with 300 μg/kg DMPGE2 (p This study demonstrates that this analog of prostaglandin E2 promotes the development of ketosis during the genesis of DKA despite decreased substrate availability. This may be due to enhancement of hepatic ketogenesis, impairment of ketone disposal, or both.
Petrov-Galerkin method for multidimensional time-dependent convective-diffusion equations

A Petrov—Galerkin finite element method for two and three-dimensional time dependent convection-diffusion equations is presented in the context of two space dimensions. The method involves perturbed weighting functions in the weighted residuals formulation, that are bilinear in space and quadratic in time and depend on two parameters which are calculated according to a local analysis for the one dimensional case. The perturbations to the weighting functions can be interpreted as an added local anisotropic balancing diffusion and an added dispersion in the direction of the convective motion. The effectiveness of the method is shown through several examples involving the convective and diffusive transport of scalar distributions in known velocity fields.
Diet of Lake Trout and Burbot in Northern Lake Michigan During Spring: Evidence of Ecological Interaction

Abstract We used analyses of burbot ( Lota lota ) and lake trout ( Salvelinus namaycush ) diets taken during spring gill-net surveys in northern Lake Michigan in 2006–2008 to investigate the potential for competition and predator–prey interactions between these two species. We also compared our results to historical data from 1932. During 2006–2008, lake trout diet consisted mainly of alewives ( Alosa pseudoharengus ) and rainbow smelt ( Osmerus mordax ), whereas burbot utilized a much wider prey base including round goby ( Neogobius melanostomus ), rainbow smelt, alewives, and sculpins. Using the Schoener's diet overlap index, we found a higher potential for interspecific competition in 1932 than in 2006–2008, though diet overlap was not significant in either time period. No evidence of cannibalism by lake trout or lake trout predation on burbot was found in either time period. In 2006–2008, however, lake trout composed 5.4% (by weight) of burbot diet. To determine whether this predation could be having an impact on lake trout rehabilitation efforts in northern Lake Michigan, we developed a bioenergetic-based consumption estimate for burbot on Boulder Reef (a representative reef within the Northern Refuge) and found that burbot alone can consume a considerable proportion of the yearling lake trout stocked annually, depending on burbot density. Overall, we conclude that predation, rather than competition, is the more important ecological interaction between burbot and lake trout, and burbot predation may be contributing to the failed lake trout rehabilitation efforts in Lake Michigan.
Central points and central lines in the plane of a triangle

(1994). Central Points and Central Lines in the Plane of a Triangle. Mathematics Magazine: Vol. 67, No. 3, pp. 163-187.
VOLTAGE-DEPENDENT OPENING OF HCN CHANNELS: FACILITATION OR INHIBITION BY THE PHYTOESTROGEN, GENISTEIN, IS DETERMINED BY THE ACTIVATION STATUS OF THE CYCLIC NUCLEOTIDE GATING RING

Abstract Investigation of the mechanistic bases and physiological importance of cAMP regulation of HCN channels has exploited an arginine to glutamate mutation in the nucleotide-binding fold, an approach critically dependent on the mutation selectively lowering the channel's nucleotide affinity. In apparent conflict with this, in intact Xenopus oocytes, HCN and HCN-RE channels exhibit qualitatively and quantitatively distinct responses to the tyrosine kinase inhibitor, genistein — the estrogenic isoflavonoid strongly depolarizes the activation mid-point of HCN1-R538E, but not HCN1 channels (+ 9.8 mV ± 0.9 versus + 2.2 mV ± 0.6) and hyperpolarizes gating of HCN2 (− 4.8 mV ± 1.0) but depolarizes gating of HCN2-R591E (+ 13.2 mV ± 2.1). However, excised patch recording, X-ray crystallography and modeling reveal that this is not due to either a fundamental effect of the mutation on channel gating per se or of genistein acting as a mutation-sensitive partial agonist at the cAMP site. Rather, we find that genistein equivalently moves both HCN and HCN-RE channels closer to the open state (rendering the channels inherently easier to open but at a cost of decreasing the coupling energy of cAMP) and that the anomaly reflects a balance of these energetic effects with the isoform-specific inhibition of activation by the nucleotide gating ring and relief of this by endogenous cAMP. These findings have specific implications with regard to findings based on HCN-RE channels and kinase antagonists and general implications with respect to interpretation of drug effects in mutant channel backgrounds.
Nonnucleoside reverse transcriptase inhibitor pharmacokinetics in a large unselected cohort of HIV-infected women.

Background: Small intensive pharmacokinetic (PK) studies of medications in early-phase trials cannot identify the range of factors that influence drug exposure in heterogenous populations. We performed PK studies in large numbers of HIV-infected women on nonnucleoside reverse transcriptase inhibitors (NNRTIs) under conditions of actual use to assess patient characteristics that influence exposure and evaluated the relationship between exposure and response. Methods: Two hundred twenty-five women on NNRTI-based antiretroviral regimens from the Women's Interagency HIV Study were enrolled into 12-hour or 24-hour PK studies. Extensive demographic, laboratory, and medication covariate data were collected before and during the visit to be used in multivariate models. Total NNRTI drug exposure was estimated by area under the concentration-time curves. Results: Hepatic inflammation and renal insufficiency were independently associated with increased nevirapine exposure in multivariate analyses; crack cocaine, high fat diets, and amenorrhea were associated with decreased levels (n = 106). Higher efavirenz exposure was seen with increased transaminase, albumin levels, and orange juice consumption; tenofovir use, increased weight, being African American, and amenorrhea were associated with decreased exposure (n = 119). With every 10-fold increase in nevirapine or efavirenz exposure, participants were 3.3 and 3.6 times as likely to exhibit virologic suppression, respectively. Patients with higher drug exposure were also more likely to report side effects on therapy. Conclusions: Our study identifies and quantitates previously unrecognized factors modifying NNRTI exposure in the "real-world" setting. Comprehensive PK studies in representative populations are feasible and may ultimatley lead to dose optimization strategies in patients at risk for failure or adverse events.
Turbulent mass flux measurements using a laser/hot-wire technique

Abstract A laser-Doppler anemometer and a hot-wire type concentration probe are used to measure the velocity and species concentration fields simultaneously in an axisymmetric sudden-expansion flow. The presence of the probe has a negligible effect on the Doppler signals. Furthermore, the presence of small liquid droplets in the flow does not affect the hot-wire measurements. Resulting measurements of axial velocity and species concentration are compared with corresponding data obtained by applying the LDA and hot-wire probe separately to measure the flow properties. Excellent agreement is obtained. Therefore, the measured mass flux is valid and reliable. The technique is used to examine the behavior of the turbulent mass flux in an axisymmetric sudden-expansion flow.
AUTOMATIC CHARACTERIZATION OF SPEAKING STYLES IN EDUCATIONAL VIDEOS

Recent studies have shown the importance of using online videos along with textual material in educational instruction, especially for better content retention and improved concept understanding. A key question is how to select videos to maximize student engagement, particularly when there are multiple possible videos on the same topic. While there are many aspects that drive student engagement, in this paper we focus on presenter speaking styles in the video. We use crowd-sourcing to explore speaking style dimensions in online educational videos, and identify six broad dimensions: liveliness, speaking rate, pleasantness, clarity, formality and confidence. We then propose techniques based solely on acoustic features for automatically identifying a subset of the dimensions. Finally, we perform video re-ranking experiments to learn how users apply their speaking style preferences to augment textbook material. Our findings also indicate how certain dimensions are correlated with perceptions of general pleasantness of the voice.
Reperfusion injury of postischemic tissues

Reperfusion injury, occurring when blood circulation is restored to previously ischemic tissues, is now demonstrable as a pathophysiologic entity distinct from the primary ischemic injury that develops during ischemia per se. The primary pathogens that cause reperfusion injury are thought to be partially reduced oxygen species, including superoxide radicals, hydrogen peroxide, and hydroxyl radicals, which initiate lipid peroxidation and other deleterious oxidation reactions during the reperfusion period. Antioxidant drugs, given at the end of ischemia or at the very onset of reperfusion, can improve the postischemic function of isolated organs and the survival of intact animals subject to a cycle of circulatory arrest and reperfusion, suggesting that reperfusion injury is both a real and a preventable pathophysiologic entity.
More information relating to the high-altitude use of color infrared film

Abstract Use of EA-4 processing for color infrared film and observed deviationsfrom normal sensitometric characteristics modify the previously made recommendations for the use of auxiliary minus-visual filters with the film system. With this processing, the need to equalize dye-forming layer sensitivities to combat the color shift due to air luminance can be satisfied with filters that attenuate less the visual wavelengths. Loss of cyan sensitivity due to aging, on the other hand, increases the attenuation need. Simple tests are suggested whereby the user can ascertain the sensitometric characteristics of his film.
Carbamazepine level-A in vivo-in vitro correlation (IVIVC): a scaled convolution based predictive approach.

A method is presented for prediction of the systemic drug concentration profile from in vitro release/dissolution data for a drug formulation. The method is demonstrated using four different tablet formulations containing 200 mg carbamazepine (CZM), each administered in a four way cross-over manner to 20 human subjects, with 15 blood samples drawn to determine the resulting concentration profile. Amount versus time dissolution data were obtained by a 75 rpm paddle method for each formulation. Differentiation, with respect to time, of a monotonic quadratic spline fitted to the dissolution data provided the dissolution rate curve. The dissolution curve was through time and magnitude scaling mapped into a drug concentration curve via a convolution by a single exponential, and the estimated unit impulse response function. The method was tested by cross-validation, where the in vivo concentration profiles for each formulation were predicted based on correlation parameters determined from in vivo-in vitro data from the remaining three formulations. The mean prediction error (MPE), defined as the mean value of 100% x(observed-predicted)/observed was calculated for all 240 cross-validation predictions. The mean values of MPE were in the range of 10-36% (average 22%) with standard deviations (S.D.s) in the range of 9-33% (average 13%), indicating a good prediction performance of the proposed in vivo-in vitro correlation (IVIVC) method.
Decay of Concentration Functions for Adapted Probabilities on Discrete Groups

Given a probability measure, μ , on a locally compact group, necessary and sufficient support conditions which ensure that the concentration functions associated with μ converge to zero have previously been determined. In this note the rate of this convergence when μ is adapted on a discrete group G is shown to depend on the volume growth rate of N μ , the smallest normal subgroup a coset of which contains the support of μ .
Hippocampal neurogenesis is associated with migratory behaviour in adult but not juvenile sparrows (Zonotrichia leucophrys ssp.)

It has been hypothesized that individuals who have higher demands for spatially based behaviours should show increases in hippocampal attributes. Some avian species have been shown to use a spatially based representation of their environment during migration. Further, differences in hippocampal attributes have been shown between migratory and non-migratory subspecies as well as between individuals with and without migratory experience (juveniles versus adults). We tested whether migratory behaviour might also be associated with increased hippocampal neurogenesis, and whether potential differences track previously reported differences in hippocampal attributes between a migratory (Zonotrichia leucophrys gambelii) and non-migratory subspecies (Z. l. nuttalli) of white-crowned sparrows. We found that non-migratory adults had relatively fewer numbers of immature hippocampal neurons than adult migratory birds, while adult non-migrants had a lower density of new hippocampal neurons than adult and juvenile migratory birds and juvenile non-migratory birds. Our results suggest that neurogenesis decreases with age, as juveniles, regardless of migratory status, exhibit similar and higher levels of neurogenesis than non-migratory adults. However, our results also suggest that adult migrants may either seasonally increase or maintain neurogenesis levels comparable to those found in juveniles. Our results thus suggest that migratory behaviour in adults is associated with maintained or increased neurogenesis and the differential production of new neurons may be the mechanism underpinning changes in the hippocampal architecture between adult migratory and non-migratory birds.
Fuzzy-logic-based controller for optical resonators

The beam characteristics of a laser depend on various factors such as temperature, mechanical deficiencies of mounts, tolerance specifications, etc. As such, there is a tendency for the beam characteristics to deviate from the desired characteristics. This paper describes the development of a fuzzy-logic based controller to obtain and maintain specific output beam characteristics of an optical resonator.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Late Whiplash Syndrome: A Clinical Science Approach to Evidence-Based Diagnosis and Management

The purpose of this article is to narrow the gap that exists in the clinical application of scientific research and empiric evidence for the evaluation and management of late whiplash. Considering that 14% to 42% of patients are left with chronic symptoms following whiplash injury, it is unlikely that only minor self-limiting injuries result from the typical rear-end impact. As psychosocial issues play a role in the development of persistent whiplash symptoms, discerning the organic conditions from the biopsychosocial factors remains a challenge to clinicians. The term "whiplash" represents the multiple factors associated with the event, injury, and clinical syndrome that are the end-result of a sudden acceleration-deceleration trauma to the head and neck. However, contentions surround the nature of soft-tissue injuries that occur with most motor vehicle accidents and whether these injuries are significant enough to result in chronic pain and limitations. The stark contrast in litigation for whiplash that exists among industrialized nations and less developed countries suggests another factor that could influence one's interpretation of symptoms' chronicity associated with Late Whiplash Syndrome. There are no gold standard tests or imaging techniques that can objectify whiplash-associated disorders. A lack of supporting evidence and disparity in medico-legal issues have created distinct camps in the scientific interpretations and clinical management of late whiplash. It is likely that efforts in research and/or clinical practice will begin to explain the disparity between acute and chronic whiplash syndrome. Recent evidence suggests that Late Whiplash Syndrome should be considered from a different context. The purpose of this article is to expound on several of the significant findings in the literature and offer clinical applications for evaluation and management of Late Whiplash Syndrome.
3D profilometer employing white-light interferometry for microstructures with large-bevel inclines in brightness-enhanced films

This study employed white-light interferometry to measure the three-dimensional (3D) profiles, roughness, and dimensions of brightness-enhanced films (BEFs) that exhibited roof-shaped profiles with large-bevel inclines that could not be successfully measured by conventional optical inspection. A scanning white-light interferometer (SWLI) was used to obtain image information from both the symmetrical sides of inclines in the BEFs. A feasible structure with an angle-tuning mechanism was also introduced to enable the scanning white-light interferometer to rotate the angle of vision according to the bevel angle of the incline in the BEF. Further, the profiles of the BEFs could be reconstructed successfully through a series of image processing techniques. Now, the allowable bevel angle of the inclines in the BEF is not greater than 45°. The experimental results confirmed that this approach can successfully measure the 3D profiles of large-bevel inclines of microstructures as well as the roughness and dimensions of BEFs.