cssi/SciSciGPT-SciSciNet huggingface dataset:
Morphology of lunar craters - A test of lunar erosional models

The present work is a test of published theoretical and experimental studies of crater erosion by micrometeorite bombardment which predict systematic variations in the morphology of lunar craters as a function of crater diameter and crater age. Numerical, ranking-type degradation classifications indicate that the craters on Mare Imbrium and Mare Tranquillitatis confirm these predictions by showing a systematic increase in degradation with decreasing diameter for craters smaller than a few kilometers in diameter but larger than the equilibrium diameter, and by showing fixed proportions of fresh, moderately degraded, and very degraded craters under equilibrium conditions. Furthermore, the relative ages of the two mare surfaces may be determined using a diameter/mean-degradation-number curve. These determinations of relative age and process of crater erosion are both essentially independent of the traditionally studied crater diameter/frequency relationships.
Two forms of aryl hydrocarbon receptor type 2 in rainbow trout (Oncorhynchus mykiss). Evidence for differential expression and enhancer specificity.

Two aryl hydrocarbon receptors (AhRs), rtAhR2α and rtAhR2β, were cloned from rainbow trout (rt) cDNA libraries. The distribution of sequence differences, genomic Southern blot analysis, and the presence of both transcripts in all individual rainbow trout examined suggest that the two forms of rtAhR2 are derived from separate genes. The two rtAhR2s have significant sequence similarity with AhRs cloned from mammalian species, especially in the basic helix-loop-helix and PAS functional domains located in the amino-terminal 400 amino acids of the protein. In contrast, the Gln-rich transactivation domain found in the carboxyl-terminal half of mammalian AhRs is absent from both rtAhR2s. Both clones were expressed by in vitro transcription/translation and proteins of approximately 125 kDa were produced. These proteins bind 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and are able to bind dioxin response elements in gel shift assays. rtAhR2α and rtAhR2β are expressed in a tissue-specific manner with the highest expression of rtAhR2β in the heart. Expression of rtAhR2α and rtAhR2β mRNAs is positively regulated by TCDD. Both rtAhR2α and rtAhR2β produced TCDD-dependent activation of a reporter gene driven by dioxin response elements. Surprisingly, the two receptors showed distinct preferences for different enhancer sequences. These results suggest that the two receptor forms may regulate different sets of genes, and may play different roles in the toxic responses produced by AhR agonists such as TCDD.
Representations for continuous additive functionals of super-Brownian and super-stable processes

Abstract We study a class of continuous additive functionals for super-Brownian and super-stable processes. These are given in terms of a Tanaka-like formula that generalizes the one for local times. We give representations for these additive functionals in terms of the corresponding local times. As an example, we discuss fractional Laplacians of super-Brownian local times.
Treatment for bacterial overgrowth in the irritable bowel syndrome.

In this issue, Pimentel and colleagues evaluated the efficacy of a newer broad-spectrum nonabsorbable antibiotic, rifaximin, for the irritable bowel syndrome (IBS), measuring clinical response for ...
Optical spatial solitons, the power law, and the swing effect

We continue a study of the equivalence particle principle applied to an optical spatial soliton which is a "narrow filament" that maintains its existence in a waveguide. Using this principle, expressions for acceleration, spatial frequency, spatial period and other variables for a spatial soliton can be derived from the solution of basic Nonlinear Schrodinger Equation. These results agree well with numerical simulations of the Modified Nonlinear Schrodinger Equation. If the expression of the acceleration is bounded in some cases this means the spatial soliton propagates with a swing effect. We go one step further in this theoretical study to investigate the effects of the swing effect with power law included in the Modified Nonlinear Schrodinger Equation.
The Ipod Programme on Passive Continental Margins

During the past 200 Ma (1 Ma = 106 years) the arrangement of continents and ocean basins has been reorganized from a pattern of one supercontinent, with mainly plate edge, subduction, or active continental margins bordering one essentially contiguous ocean basin, to the present configuration of dispersed continents and several oceans. Most of the world's present continental margins which were formed during that 200 Ma period are 'passive' margins lying within the interiors of lithospheric plates. Several models of rifting and evolution of these passive margins have been proposed. The objectives of IPOD include testing of these models by learning as much as we can about the history of rifting of passive continental margins, their internal structure, distribution of facies, subsidence history, and the nature of the transition and modification of the crust at the margin. These objectives cannot be attained by drilling alone, and geophysical surveying and analysis of samples from the drilling are essential parts of the overall programme.
The Interrelationships Between U.S. and Foreign Equity Market Yields: Tests of Granger Causality

This study examines the interrelationships between yields on the U.S. and several foreign market portfolios over the 1980–89 period. Tests of Granger causality are used to investigate the effects of uni-directional causality, bi-directional causality, and contemporaneous adjustment in the determination of market rates of return. The results indicate that international equity market returns are largely contemporaneously determined, and the significance of contemporaneous effects varied over time. Uni-directional and bi-directional causality were found to be relatively weak.
Hepatic regeneration in living donor liver transplantation

Key points 1. Active hepatocyte replication occurs after cadaveric transplantation to replace cells lost to ischemic and immunologic damage. Significantly more regeneration is also required after adult-to-adult living donor transplantation because of the small size of the graft. 2. The molecular mechanisms initiating regeneration are well described in animal models, which include priming with cytokines, activation of transcription factors, and expression of immediate early genes, which then cause the hepatocyte to progress through the cell cycle. 3. Certain factors have been shown to affect liver regeneration and recovery. These include ischemic injury, graft size, immunosuppression, steatosis, and donor age. Other factors that have been implicated are venous flow and gender. .4. Active regeneration in the living donor setting may affect other processes, including viral replication, the alloimmune response, drug metabolism, and recurrent hepatocellular carcinoma. More investigation is needed in these areas. Adult-to-adult living donor transplantation provides a unique opportunity to study human liver regeneration and return of normal liver function after resection.
Differential inhibition of activated tyrosine hydroxylase

Abstract Under conditions of cyclic AMP-dependent protein phosphorylation, tyrosine hydroxylase (EC 1.14.16.2; TH) is activated. Kinetic analysis reveals that, upon activation the affinity of the enzyme cofactor tetrahydrobiopterin, Vmax, as well as the Ki of its putative feedback inhibitor dopamine, are increased. Catecholic inhibitors of rat striatal TH have been assessed for the structural requirements that impart differential sensitivity to activated and control enzyme. By varying cofactor and inhibitor concentrations, Ki's were generated from Dixon plots. Structural analogs of dopamine in which the amino group was fixed in a cis conformation, i.e., 6,7-dihydroxytetrahydroisoquinolines, exhibit the same Ki for activated and nonactivated TH. However, 2-amino-6,7-dihydroxytetralin (ADTN), in which the nitrogen is extended in a fixed trans conformation of the β-rotamer, exhibited a fourfold increase in Ki upon assaying tyrosine hydroxylase under phosphorylation conditions. By systematically increasing the hydrophobicity of the substituent at C-1 of 1-carboxy-6,7-dihydroxytetrahydroisoquinolines the inhibitory potency was enhanced, suggesting the presence of a hydrophobic region near the catecholic binding site. If the hydrophobic group was rigid as in the catechol estrogens, 2-hydroxy-estradiol and 2-hydroxyestrone, the Ki was relatively low (2 × 10−5 m ) despite the absence of an amino group. Upon activation the Ki increased fourfold. These studies provide insight into the topography of the catecholic binding site on TH and to attendant changes occurring upon activation. The results suggest that the catechol binding site includes both amino group-interacting and hydrophobic regions which are influenced by enzyme activation.
Stochastic Simulations of Cellular Processes in Bacteria

Stochastic expression of genes produces heterogeneity in clonal populations of bacteria grown under identical conditions. We analyze the stochastic reaction-diffusion dynamics of selected biochemical pathways in Escherichia coli to show how individual cells vary expression of a set of genes in response to an environmental signal. The whole cells simulated under in vivo conditions include ribosomes, DNA, and large protein complexes, which take up 30-50% of the cell volume and are placed according to data from cryoelectron tomography and proteomics. using GPU processors, we simulate the dynamics for an entire cell cycle and compare the mRNA/protein distributions to those observed in single molecule experiments. We show how such distributions can be used to derive additional kinetic parameters and integrate effects of cell-to-cell variations into flux balance analysis of genome scale models of metabolic networks. The distribution of growth rates calculated for a colony of bacteria are analyzed and correlated to changes in fluxes through the metabolic network.With the availability of high-performance computing, simulations are poised to allow integration of data from structural, single-molecule, and biochemical studies into coherent computational models of cells and cellular processes. Here the calculations are performed with our Lattice Microbes software. Animation of reaction trajectories involving millions of particles is facilitated using a plugin to the VMD visualization and analysis program.“Noise contributions in an inducible genetic switch: A whole cell simulation study”, E. Roberts, A. Magis, J. Ortiz, W. Baumeister, and Z. Luthey-Schulten, Plos Comput. Biol. 7(3), e1002010 March (2011).“Determining the stability of genetic switches: Explicitly accounting for mRNA noise”M. Assaf, E. Roberts, and Z. Luthey- Schulten, Phys.Rev.Lett. 24, 248102, (2011).“Lattice Microbes: high-performance stochastic simulation method for the reaction-diffusion master equation”, E. Roberts, J. Stone, Z. Luthey-Schulten, J. Comp. Chem, (2012, in press).
Intelligent user assistance for cost effective usage of mobile phone

Cost is the governing factor which defines the penetration and adoption of mobile phones in lower strata (lower income group) of the society particularly in developing countries like India. In this paper we describe an enhancement to the mobile phone design which interacts with the user to facilitate cost-conscious usage of the mobile phone. In particular, we propose an intelligent component in the mobile phone which tracks mobile usage pattern and informs the user of deviations in usage and suggests means of using the device cost effectively.
The Protective Effect of Human Milk against Diarrhea: A Review of Studies from Bangladesh

Field studies conducted in Bangladesh in collaboration with laboratory studies in Goteborg Bethesda and Atlanta were directed toward identifying specific enteric infections in infants influenced by breastfeeding. The international Centre for Diarrheal Disease Research set up at the Dhaka Hospital examined 4000 children under 5 with diarrhea between March 1980 and February 1982. Breast feeding is the preferred feeding method in this population and is extended into the 2nd and 3rd years in the majority. Infants 6-11 months old were more likely to be breast fed than younger infants (88 vs. 77%) suggesting that breast feeding confers some protection against diarrhea in the 1st 6 months. The most frequently found enteric pathogens were rotavirus (35%) enterotoxigenic E. coli (ETEC) (14%) C. jejuni (14%) shigella (11%) G. lamblia (6%) V. cholerae (6%) and E. histolytica (2%). Children with shigellosis were significantly less likely to be breast-fed than those with other infections. Those already weaned were more likely to have shigellosis (15 vs. 9/%) or cholera (6 vs. 3%). In contrast breast feeding was more common in children with rotavirus. Rates of breastfeeding did not differ among children positive for ETEC or C. jejuni. Among children with shigellosis breast feeding was associated with a milder disease. In mother-child pairs who were contacts of index cases breast milk with higher IgA titers was protective against clinical cholera but not against colonization with V. cholerae 01. Acute and convalescent phase sera from women showed consistently high anti-cholera titers but breast milk did not in the 3- week period of the study. Shedding of G. lamblia appeared to be enhanced in breast feeding women.
Monitoring Nutrition and Glucose in Acute Brain Injury

The metabolic response to injury is well described; however, very little is understood about optimal markers to measure this response. This summary will address the current evidence about monitoring nutritional status including blood glucose after acute brain injury (ABI). An electronic literature search was conducted for English language articles describing the testing, utility, and optimal methods to measure nutritional status and blood glucose levels in the neurocritical care population. A total of 45 articles were included in this review. Providing adequate and timely nutritional support can help improve outcome after ABI. However, the optimal content and total nutrition requirements remain unclear. In addition, how best to monitor the nutritional status in ABI is still being elucidated, and at present, there is no validated optimal method to monitor the global response to nutritional support on a day-to-day basis in ABI patients. Nitrogen balance may be monitored to assess the adequacy of caloric intake as it relates to protein energy metabolism, but indirect calorimetry, anthropometric measurement, or serum biomarker requires further validation. The adverse effects of hyperglycemia in ABI are well described, and data indicate that blood glucose should be carefully controlled in critically ill patients. However, the optimal frequency or duration for blood glucose monitoring after ABI remains poorly defined. There are significant knowledge gaps about monitoring nutritional status and response to nutritional interventions in ABI; these need to be addressed and hence few recommendations can be made. The optimal frequency and duration of blood glucose monitoring need further study.
The race for the first generation of the pentazolate anion in solution is far from over.

The previous claim for the first generation of the pentazolate anion in solution was carefully reexamined; no evidence for the formation of cyclo-N5− was found under the reported conditions.
Calcite crystal growth inhibition by phosphonates

Abstract Addition of several phosphonic acid derivatives to a supersaturated calcium carbonate solution greatly reduces the rate of growth of calcite seed crystals at 25°C. The mechanism of the inhibition by phosphonates appears to involve blockage of crystal growth sites on the calcite surface. The results indicate that phosphonic acid derivatives may be useful in preventing scale formation in evaporative desalination processes.
Asystole complicating physostigmine treatment of tricyclic antidepressant overdose

Physostigmine is a commonly used therapy for the anticholinergic manifestations of tricyclic antidepressant (TCA) overdose. We describe two patients with TCA toxicity who developed asystole following the administration of physostigmine to treat seizures.
Probability-matching in the goldfish

Two groups of goldfish were trained in an instrumental situation with food reward for correct choice and guidance after incorrect choice. One group was trained in 70:30, 20:80, and 50:50 visual problems, the other in a 70:30 spatial problem. The results obtained resemble those for the African mouthbreeder.
Acceleration of 5-Methylcytosine Deamination in Cyclobutane Dimers by G and Its Implications for UV-Induced C-to-T Mutation Hotspots

Sunlight-induced C-->T mutation hotspots occur most frequently at methylated CpG sites in tumor suppressor genes and are thought to arise from translesion synthesis past deaminated cyclobutane pyrimidine dimers (CPDs). While it is known that methylation enhances CPD formation in sunlight, little is known about the effect of methylation and sequence context on the deamination of 5-methylcytosine ((m)C) and its contribution to mutagenesis at these hotspots. Using an enzymatic method, we have determined the yields and deamination rates of C and (m)C in CPDs and find that the frequency of UVB-induced CPDs correlates with the oxidation potential of the flanking bases. We also found that the deamination of T(m)C and (m)CT CPDs is about 25-fold faster when flanked by G's than by A's, C's or T's in duplex DNA and appears to involve catalysis by the O6 group of guanine. In contrast, the first deamination of either C or (m)C in AC(m)CG with a flanking G was much slower (t(1/2) >250 h) and rate limiting, while the second deamination was much faster. The observation that C(m)CG dimers deaminate very slowly but at the same time correlate with C-->T mutation hotspots suggests that their repair must be slow enough to allow sufficient time for deamination. There are, however, a greater number of single C-->T mutations than CC-->TT mutations at C(m)CG sites even though the second deamination is very fast, which could reflect faster repair of doubly deaminated dimers.
Comment on the use of GOES solar proton data and spectra in solar proton dose calculations.

Abstract There is a need to understand the calibration and response of the GOES solar particle detectors since the GOES data are being used to evaluate high energy solar particle events. We share some of our experience in utilizing these data in the analysis of solar particle ground-level events (GLEs). For the 29 September 1989 event, we have evaluated the solar proton and alpha particle spectral characteristics throughout the event. The results show that the solar cosmic ray spectrum is extremely hard at low energies with the magnitude of the slope increasing with increasing energy and with time.
In-Space Calibration of a Skewed Gyro Quadruplet

Anewapproachtogyrocalibrationispresented,wherethespacecraftdynamicsequation,attitudemeasurements, and the gyro outputs are used in a pseudolinear Kalman e lter that estimates the calibration parameters. Also an algorithm is presented for calibrating a skewed quadruplet rather than the customary triad gyro set aligned along the body coordinate axes. In particular, a new misalignment error model is derived for this case. The new calibration algorithm is applied to the EOS-AQUA satellite gyros. The effectiveness of the new algorithm is demonstrated through simulations. YRO calibration, as well as calibration of other instruments, includes two stages. During the e rst stage, the instrument er- ror parameters are estimated, and in the second stage, those errors are continuously removed from the gyro readings. In the classical approach to gyro calibration, the gyro outputs are used to maintain or compute body orientation rather than used as measurements in the context of e ltering. In inertial navigation, for example, 1 gyro errors cause erroneous computation of velocity and position, and then when the latter are compared to measured velocity and posi- tion, a great portion of the computed velocity and position errors can be determined. The latter errors are then fed into a Kalman e lter (KF) that uses the inertial navigation system error model to infer the gyro errors. Similarly, when applying the classical approach to spacecraft(SC) attitude determination, the gyro outputs are used to compute theattitude, andthentheattitude measurements 2;3 areused to determine the attitude errors, which again using a KF indicates what the gyro errors are. Several ways of treating gyro calibration have been presented in the literature. 4i6 In the approach adopted in this work, the gyro outputs are used as angular rate measurements and are compared to estimated angular rates. However,thisapproachrequires the knowl- edge of the angular rate. In the past, 7 the estimated angular rate was computed in a rather simplistic way, assuming basically that the rate was constant. In the present work, the estimated angular rate is derived using a KF whose input can be any kind of attitude mea- surement; therefore, the angular rate experienced by the SC can be continuously changing, and yet a good estimate of the rate, neces- sary for calibration, can be obtained. The calibration algorithm presented in this work was derived for a set ofquadrupletgyros. This required the derivation of anewerror model,particularly forthe gyro misalignments.Thenewcalibration algorithmwas applied to thegyro package ofthe EOS-AQUA satel- lite. The latter consists of four gyros, which are given the task of measuring the three components of the SC angular velocity vector resolved in the body Cartesian coordinates.
Pressure dependence of the fano asymmetry of optical phonons in Zn1 − xCoxSe and Zn1 − xFexSe

Abstract Effects of hydrostatic pressure on the optical phonons in ZnSe doped with Co and Fe at 10 K and up to 5 GPa are presented. Raman spectra from Zn1 − xCoxSe (x = 1.6%) show the LO phonon developing an asymmetry with increasing pressure while the asymmetry already present at 1 bar in the x = 7.4% sample increases slightly with pressure. The optical phonon in Zn1 − xFexSe (x = 8.8%) shows no modifications to its line profile for all pressures. These results are discussed in terms of a coupling between the phonons and a Raman continuum that is thought to arise through a pressure tunable p-d hybridization of the low lying crystal field levels and the valence band.
Influences of hormone replacement therapy on olfactory and cognitive function in postmenopausal women

Olfactory dysfunction can be an early sign of Alzheimer’s disease. Since hormone replacement therapy (HRT) may protect against Alzheimer’s disease in postmenopausal women, the question arises as to whether it also protects against olfactory dysfunction in such women. A total of three olfactory and 12 neurocognitive tests were administered to 432 healthy postmenopausal women with varied HRT histories. Serum levels of reproductive hormones were obtained for all subjects; APOE-e4 haplotype was determined for 77 women. National Adult Reading Test and Odor Memory/Discrimination Test scores were positively influenced by HRT. Odor Identification and Odor Memory/Discrimination Test scores were lower for women who scored poorly on a delayed recall test, a surrogate for mild cognitive impairment. The Wechsler Adult Intelligence Scale, Revised, as a Neuropsychological Instrument Spatial Span Backwards Test scores were higher in women receiving estrogen and progestin HRT and directly correlated with serum testosterone levels, the latter implying a positive effect of testosterone on spatial memory. APOE-e4 was associated with poorer odor threshold test scores. These data suggest that HRT positively influences a limited number of olfactory and cognitive measures during menopause.
Plasma Corticosteroids in Normal Individuals: With Reference to the Orcadian Rhythm, ACTH Test, Insulin Test, and Dexamethasone Suppression Test

Fluorimetrically determined plasma corticosteroids were studied in normal individuals. In female subjects the 7 a.m. mean baseline values were significantly higher than those in the male subjects. The adrenal response during the 4-hour ACTH test was significantly higher in female controls than in the male. During insulin test (0.10 i.u./kg) the maximum increase in plasma corticosteroids was 10.7 (3.7-22.8) μg/100 ml (mean and range). No difference in response was observed between male and female controls. During the 1 mg dexamethasone test plasma corticosteroids were suppressed to 2.7 (1.4-4.4) μg/100 ml (mean and range); serum corticotrophin was also significantly suppressed.
Cryogenic search for fractionally charged particles

An experiment was performed to test the hypothesis of cryogenic trapping of fractionally charged particles, suggested as a possible explanation for the results of LaRue, Fairbank, Hebard, and Phillips at Stanford. A Nb-filament source was built, which could be cooled to 4.2 /sup 0/K and rapidly heated to several hundred /sup 0/K. The source was operated in the terminal of a 700-kV Cockcroft-Walton accelerator and energy spectra of positively charged particles emerging from the filament were measured under a variety of operating conditions. No events above a background of 10/sup -2/ counts/sec were found in the energy regions where one might have expected several hundred particles of charge +(1/3)e or +(2/3)e as the source was heated. A mass range from 10 MeV/c/sup 2/ to 100 GeV/c/sup 2/ was covered in the experiment. Although negative results are rarely unambiguous, our findings exclude one class of hypotheses which might have explained the apparent fractional charges of the Stanford experiments.
Transition Metal Clusters and Isolated Atoms in Zeolite Cages

Surface science research has made much use of metal single crystals. Results have been obtained of high relevance to chemisorption and catalysis, in particular with respect to the nature of the chemisorption bonds, their dipole moments and their crystal face specificity. The coverage dependence of specific parameters and the important phenomenon of surface reconstruction have also been studied quantitatively. Among the methods used, only field ion and field electron microscopy make use of highly curved surfaces which expose a variety of crystal faces of high and low Miller indices, so that the surface migration can be studied across face boundaries [5.1–3]. Other surface science methods use macroscopic single crystals and focus on one large crystal face, usually of rather high atom density.
Chemical modification of an essential lysine at the active site of enoyl-CoA reductase in fatty acid synthetase.

Abstract Fatty acid synthetase from goose uropygial gland was inactivated by treatment with pyridoxal 5′-phosphate. Malonyl-CoA and acetyl-CoA did not protect the enzyme whereas NADPH provided about 70% protection against this inactivation. 2′-Monophospho-ADP-ribose was nearly as effective as NADPH while 2′-AMP, 5′-AMP, ADP-ribose, and NADH were ineffective suggesting that pyridoxal 5′-phosphate modified a group that interacts with the 5′-pyrophosphoryl group of NADPH and that the 2′-phosphate is necessary for the binding of the coenzyme to the enzyme. Of the seven component activities catalyzed by fatty acid synthetase only the enoyl-CoA reductase activity was inhibited. Inactivation of both the overall activity and enoyl-CoA reductase of fatty acid synthetase by this compound was reversed by dialysis or dilution but not after reduction with NaBH4. The modified protein showed a characteristic Schiff base absorption (maximum at 425 nm) that disappeared on reduction with NaBH4 resulting in a new absorption spectrum with a maximum at 325 nm. After reduction the protein showed a fluorescence spectrum with a maximum at 394 nm. Reduction of pyridoxal phosphate-treated protein with NaB3H4 resulted in incorporation of 3H into the protein and paper chromatography of the acid hydrolysate of the modified protein showed only one fluorescent spot which was labeled and ninhydrin positive and had an Rf identical to that of authentic N6-pyridoxyllysine. When [4-3H]pyridoxal phosphate was used all of the 3H, incorporated into the protein, was found in pyridoxyllysine. All of these results strongly suggest that pyridoxal phosphate inhibited fatty acid synthetase by forming a Schiff base with the ϵ-amino group of lysine in the enoyl-CoA reductase domain of the enzyme. The number of lysine residues modified was estimated with [4-3H]pyridoxal-5′-phosphate/NaBH4 and by pyridoxal-5′-phosphate/NaB3H4. Scatchard analysis showed that modification of two lysine residues per subunit resulted in complete inactivation of the overall activity and enoyl-CoA reductase of fatty acid synthetase. NADPH prevented the inactivation of the enzyme by protecting one of these two lysine residues from modification. The present results are consistent with the hypothesis that each subunit of the enzyme contains an enoyl-CoA reductase domain in which a lysine residue, at or near the active site, interacts with NADPH.
Language attrition: the fate of the start

This chapter reviews the literature on psycholinguistic aspects of language attrition over the past half decade. Descriptive data-based studies have continued to dominate during this time, providing needed groundwork for the emerging discipline. A few studies have continued theoretical threads from previous work, however, by examining attrition data from the perspectives of the regression hypothesis and markedness theory. We have also seen the beginnings of promising new lines of research which draw theoretical underpinnings from neighboring disciplines, most notably from the savings paradigm in cognitive psychology and from theories of codeswitching in bilingualism studies. Evidence on the effects in attrition of non-linguistic variables such as age, proficiency level, and literacy has continued to accumulate. Hesitation phenomena in attriter speech have begun to receive serious attention. Relearning, one of the main areas to potentially benefit from language attrition studies, is also gaining new research impetus at the turn of the century.
A Physically Consistent Formulation of Lateral Friction in Shallow-Water Equation Ocean Models

Abstract Dissipation in numerical ocean models has two purposes: to simulate processes in which the friction is physically relevant and to prevent numerical instability by suppressing accumulation of energy in the smallest resolved scales. This study shows that even for the latter case the form of the friction term should be chosen in a physically consistent way. Violation of fundamental physical principles reduces the fidelity of the numerical solution, even if the friction is small. Several forms of the lateral friction, commonly used in numerical ocean models, are discussed in the context of shallow-water equations with nonuniform layer thickness. It is shown that in a numerical model tuned for the minimal dissipation, the improper form of the friction term creates finite artificial vorticity sources that do not vanish with increased resolution, even if the viscous coefficient is reduced consistently with resolution. An alternative numerical implementation of the no-slip boundary conditions for an arbi...
“I Want to Be One Less”: The Rhetoric of Choice in Gardasil Ads

It is nearly impossible to watch television without encountering advertisements for pharmaceuticals that purport to ease a plethora of medical concerns. From restless leg syndrome to heartburn, there are new drugs available for a wide variety of health-related conditions. One of the more controversial remedies on this list is the Gardasil vaccine. Gardasil was designed by the drug company Merck to protect against 4 strains of the sexually transmitted disease human papillomavirus. According to the Gardasil website, one of the human papillomavirus strains that Gardasil protects against causes 70% of cervical cancers. Marketing Gardasil as a miracle product and an anticancer vaccine, Merck in 2006 launched a massive public relations campaign to encourage all young women between 9 and 26 years of age to receive Gardasil.
Relationship of leaf spectral reflectance to chloroplast water content determined using NMR microscopy

Nuclear magnetic resonance (NMR) microscopy and reflectance spectroscopy were used to evaluate the response of leaf spectral reflectance to chloroplast relative water content (RWC). For sun and shade leaves of maple (Acer platanoides L. var Emerald Queen), NMR determined the distribution of water through the leaf thickness and changes in distribution as leaves dried from 100% RWC to approximately 70%, 50%, and 30% RWC. Chloroplast water could be resolved only in shade leaves. Leaf and chloroplast RWC were similar at leaf RWC of 80% or greater, but chloroplast RWC was as much as 12% greater than leaf RWC when leaf RWC decreased below 50%. In contrast, the RWC of nonchloroplast water compartments was as much as 12% less than leaf RWC. Reflectance responses to leaf water content were greatest in the water absorption bands near 1450 nm, 1950 nm, and 2500 nm wavelengths, and were minimal in the near-infrared from approximately 760–1300 nm. In the 400–760 nm (visible) range, reflectance sensitivity increased substantially as chloroplast RWC decreased. Peak visible reflectance sensitivity occurred near 695 nm and 670 nm for adaxial and abaxial surfaces, respectively, and was more closely related to chloroplast than to nonchloroplast or whole leaf RWC.
Cytokines and eosinophil-derived cationic proteins upregulate intercellular adhesion molecule-1 on human nasal epithelial cells

Abstract Background: Allergic and nonallergic rhinitis with eosinophilia syndrome are characterized by tissue eosinophilia and nasal mucosal injury. Recently, it has been shown that the adherence of eosinophils and other leukocytes to epithelial cells is mediated by intercellular adhesion molecule-1 (ICAM-1) and related adherence-promoting glycoproteins. Methods: In this study we examined the constitutive expression of ICAM-1 on human nasal epithelial cells (HNECs), and the effects of interferon-γ, tumor necrosis factor-γ eosinophil major basic protein, and eosinophil cationic protein on the regulation of ICAM-1 expression on these cells. Similar studies were performed with A549 pneumocytes as comparative epithelial cells. Results: Constitutive expression of ICAM-1 was significantly higher on cultured HNECs than on A549 cells, although nasal epithelial cells in tissue specimens did not demonstrate detectable levels of ICAM-1. This spontaneous expression of ICAM-1 on cultured HNECs may explain the unique susceptibility of the nasal mucosa to rhinovirus infection, because ICAM-1 is the epithelial cell receptor for most rhinoviruses. Physiologic concentrations of major basic protein and eosinophil cationic protein stimulated significant upregulation of ICAM-1 on HNECs, which was comparable to that produced by interferon-γ and tumor necrosis factor-α. In contrast, these eosinophil constituents did not stimulate ICAM-1 upregulation on A549 alveolar epithelial cells, although A549 cells did respond to interferon-γ and tumor necrosis factor-α. Conclusion: The observation that eosinophil products upregulate ICAM-1 on HNECs suggests a positive feedback mechanism, in which the products released from migrating eosinophils might promote additional HNEC-leukocyte adherence by enhancing interactions between leukocyteβ 2 integrins (CDU11/18) and nasal epithelial ICAM-1.
Spread spectrum time-resolved photon migration imaging system: the principle and simulation results

The image quality of optical tomography depends heavily on the amount of independent information and the signal to noise ratio. Time-resolved photon migration imaging (TPMI) measures a temporal point spread function (TPSF) of light diffusing through a turbid medium. The temporal profile can generally provide more useful information for accurate image reconstruction than continuous wave (CW) and frequency domain (FD) measurements, providing that adequate signal to noise ratio has been achieved. Currently, measurement of TPSF is most commonly realized with the time-correlated single photon counting (TCSPC) technique. Nonetheless, the principle of single photon counting requires that no more than one photon is detected in each cycle. This usually results in a too long data acquisition time, or a rather low signal to noise ratio in a short time. We propose a more efficient coded excitation and correlation detection mechanism that borrows ideas from spread spectrum communications. A train of excitation pulses modulated by a pseudo-random bit sequence is used as the light source, while a cross-correlation scheme is used to retrieve the impulse response. We have simulated a TPMI system and evaluated its performance. It has been demonstrated that the data acquisition time can be reduced by several orders, in comparison with a TCSPC system.
Effect of adsorbed species on hydrogen desorption from niobium

Abstract Surface-controlled hydrogen permeation experiments were carried out on niobium under conditions such that the permeation of hydrogen was controlled by the surface reactions at the exit surface. Particular attention was paid to the effects of structure and chemistry on these surface reactions and hence on the permeation rate. Structural defects were introduced in the near-surface region by irradiation with low energy argon ions. Traps which were introduced by this process were shown to decrease the lattice diffusivity of hydrogen in the near-surface region by introducing hydrogen traps with binding energies of 10–100 kJ (mol H)−1. The effects of the adsorption of oxygen, nitrogen, chlorine, SO2, CO and H2S on the exit surface were studied. The observed decreases in the hydrogen permeation rates were interpreted on the basis of a desorption model in which the adsorbed species served to block surface sites from participating in the hydrogen desorption process. A model which describes the kinetics of permeation and desorption under these surface-controlled conditions was developed.
Rates of Crystallization of Dried Lactose‐sucrose Mixtures

The isothermal crystallization kinetics of glassy lactose/sucrose mixtures were studied at several storage temperatures (close to T g and T m ). The kinetic parameters implicit in the Avrami equation were determined. Activation energies for transport (E D ) and surface nucleation (W * ) were also found and correlated to the molar composition of the lactose/sucrose mixtures. A monotonic increase in the half crystallization time (t 1/2 ), Avrami index (n), % crystallization per day, activation energy for transport (E D ) and surface nucleation energy (W * ) and a decrease in the crystallization velocity constants (K) were related to the increase in the lactose content of lactose/sucrose mixtures
13C-Methyl isocyanide as an NMR probe for cytochrome P450 active sites

The cytochromes P450 (CYPs) play a central role in many biologically important oxidation reactions, including the metabolism of drugs and other xenobiotic compounds. Because they are often assayed as both drug targets and anti-targets, any tools that provide: (a) confirmation of active site binding and (b) structural data, would be of great utility, especially if data could be obtained in reasonably high throughput. To this end, we have developed an analog of the promiscuous heme ligand, cyanide, with a 13CH3-reporter attached. This 13C-methyl isocyanide ligand binds to bacterial (P450cam) and membrane-bound mammalian (CYP2B4) CYPs. It can be used in a rapid 1D experiment to identify binders, and provides a qualitative measure of structural changes in the active site.
Timed Petri net representation of the Synchronized Multimedia Integration Language (SMIL) of XML

A multimedia server needs to satisfy the temporal ordering of multimedia data streams when servicing a client. Multimedia data has high bandwidth requirements, and within a network a server may need to service many clients at the same time. During a presentation a client may have to wait indefinitely before receiving the next multimedia data stream. This happens because client requests are queued by a server before they can be serviced. This results in a loss of synchronization between the different multimedia objects required by a client for its presentation. In this paper we propose a technique by which clients in advance can submit to the server information of all the required multimedia objects and their temporal relationships for presentation. The technique uses an enhanced timed Petri net (TPN) to capture information of multimedia objects along with their timing and synchronization specified in the Synchronized Multimedia Integration Language (SMIL). We display a graphical representation of the temporal and synchronization information captured by the data structure representing the timed Petri net. This information can be used by a multimedia server to schedule and optimize the delivery of multimedia data streams.
Scaling, Large p(T) Distribution and Fireball Motion

Fireball properties have been investigated using results of previous analyses of inclusive $p\ensuremath{-}p$ data in terms of a Bose-type distribution modified by a scaling parameter. A discussion is presented on the relation between the scaling parameter and the longitudinal velocity of the fireball. It is found that the transverse motion may account for large-${P}_{T}$ distributions at 90\ifmmode^\circ\else\textdegree\fi{} c.m. angle and that this motion is not detectable for ${P}_{T}l1.5$ GeV/c. The fireball mass is found to increase as ${({\ensuremath{\gamma}}_{\mathrm{c}.\mathrm{m}.}\ensuremath{-}1)}^{\frac{1}{2}}$, ${\ensuremath{\gamma}}_{\mathrm{c}.\mathrm{m}.}$ being the Lorentz transformation factor from lab to c.m. system.
Daytime Precipitation Estimation Using Bispectral Cloud Classification System

Abstract Two previously developed Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) algorithms that incorporate cloud classification system (PERSIANN-CCS) and multispectral analysis (PERSIANN-MSA) are integrated and employed to analyze the role of cloud albedo from Geostationary Operational Environmental Satellite-12 (GOES-12) visible (0.65 μm) channel in supplementing infrared (10.7 mm) data. The integrated technique derives finescale (0.04° × 0.04° latitude–longitude every 30 min) rain rate for each grid box through four major steps: 1) segmenting clouds into a number of cloud patches using infrared or albedo images; 2) classification of cloud patches into a number of cloud types using radiative, geometrical, and textural features for each individual cloud patch; 3) classification of each cloud type into a number of subclasses and assigning rain rates to each subclass using a multidimensional histogram matching method; and 4) associating satellite grid...
Consciousness, Theories of

Phenomenal consciousness is the property mental states, events, and processes have when, and only when, there is something it is like for their subject to undergo them, or be in them. What it is like to have a conscious experience is customarily referred to as the experience’s phenomenal character. Theories of consciousness attempt to account for this phenomenal character. This article surveys the currently prominent theories, paying special attention to the various attempts to explain a state’s phenomenal character in terms of its representational content.
Comparing Molecular Evolution in Two Mitochondrial Protein Coding Genes (Cytochromeband ND2) in the Dabbling Ducks (Tribe: Anatini)☆

Rates of sequence evolution were estimated for the cytochrome b (cyt b) and NADH dehydrogenase subunit 2 (ND2) genes using a phylogeny of the dabbling ducks (Tribe: Anatini) and outgroups. This speciose group was densely sampled, reducing the impact of undetected homoplasy on rate comparisons. Phylogenies based on sequences of the two gene regions and various weighting schemes differed, but most of the differences involved weakly supported nodes. In addition, partition homogeneity tests show that these differences were not due to statistically significant conflict between the data sets. Cyt b and ND2 also showed similar rates and types of both nucleotide and amino acid substitutions. For both genes, substitutions between isoleucine and valine and between alanine and threonine were most common; both of these substitution types are the result of A‐G transitions at first positions of codons. Rates of sequence evolution varied substantially and significantly among nucleotide positions, and even within a given codon position (first, second, or third), rates were significantly heterogeneous among sites. Within Anatini, cyt b and ND2 show similar levels of variation and homoplasy, and are equally useful for reconstructing the species level phylogeny of this group. r 1998 Academic Press
The CFTR Ion Channel: Gating, Regulation, and Anion Permeation

Cystic fibrosis transmembrane conductance regulator (CFTR) is an ATP-gated anion channel with two remarkable distinctions. First, it is the only ATP-binding cassette (ABC) transporter that is known to be an ion channel--almost all others function as transport ATPases. Second, CFTR is the only ligand-gated channel that consumes its ligand (ATP) during the gating cycle--a consequence of its enzymatic activity as an ABC transporter. We discuss these special properties of CFTR in the context of its evolutionary history as an ABC transporter. Other topics include the mechanisms by which CFTR gating is regulated by phosphorylation of its unique regulatory domain and our current view of the CFTR permeation pathway (or pore). Understanding these basic operating principles of the CFTR channel is central to defining the mechanisms of action of prospective cystic fibrosis drugs and to the development of new, rational treatment strategies.
Space, Time, and Host Evolution Facilitate Coexistence of Competing Bacteriophages: Theory and Experiment

Abstract: We present a joint experimental/theoretical investigation into the roles of spatial structure and time in the competition between two pathogens for a single host. We suggest a natural mechanism by which competing pathogens can coexist when host evolution and competitive dynamics occur on similar timescales. Our experimental system consisted of a single bacterial host species and two competing bacteriophage strains grown on agar plates, with a serial transfer of samples of the bacteriophage population to fresh host populations after each incubation cycle. The experiments included two incubation times and two transfer protocols that either maintained or disrupted the spatial structure of the viruses at each transfer. The same bacteriophage acted as the dominant competitor under both transfer protocols. A striking difference between the treatments is that the weak competitor was able to persist in the long‐incubation experiments but not in the short‐incubation experiments. Mathematical and experime...
How do the strongest radio pulses from thunderstorms relate to lightning flashes

[1] We present a statistical analysis of thunderstorm radio frequency and optical data from the FORTE satellite to examine the relationship of strong radio frequency pulsed emissions to more conventional signals from lightning. The study is built on a FORTE database of intracloud pulsed radio signals from storms whose geolocation is provided either by coincidence with the FORTE optical imager or by coincidence with ground-based lightning-detection arrays. We show statistically that intracloud radio emissions with peak power >40 kW in the FORTE low band (26–48 MHz) have unique characteristics compared to weaker emissions, including: occurring either in isolation or at the start of leader progression but never within a progressing leader; occurring without light emission detectable by FORTE; sometimes occurring in association with a rapid (10 μs) relaxation of the electric charge; and being followed by an upward progressing leader in the cases where a leader is initiated. These strong intracloud radio pulses appear to be associated with an intracloud discharge process that is physically distinct from conventional leader progression.