cssi/SciSciGPT-SciSciNet huggingface dataset:
A neutron reflectometry study of human serum albumin adsorption in situ

Reflectometry is used to characterize silicon-wafer-supported NH3+-terminated self-assembled silane monolayers (SAMs) and silicon oxide (SiOx) surfaces against air, water, and human serum albumin (HSA) solutions. X-ray reflectometry (XR) of the NH3+-terminated SAM in air revealed a 14 A thick, close-packed silane monolayer consistent with an all-trans extended hydrocarbon chain packing tilted about 30° with respect to the surface normal. Neutron reflectometry (NR) of the NH3+ surface against D2O was consistent with (XR) results if it was assumed that labile protons exchange with deuterium resulting in an interface comprised largely of ND3+. NR results obtained with the SiOx surface against D2O were interpreted in terms of a porous, hydrated oxide layer about 20 A thick. NR of HSA adsorbed from D2O buffer onto NH3+ terminated SAM surfaces revealed a two-layer adsorption regime. The first layer directly adjacent to the solid surface was about 40 A thick and was essentially independent of bulk liquid concent...
P1-S6.44 HIV vaccine clinical trial adherence and retention: high-risk drug-using women

Background Clinical trial protocol adherence and retention are often considered challenges that are especially difficult to achieve among certain high-risk populations. The HIV infection rate among heterosexual African-American women is increasing, making their participation in clinical trials of HIV behavioural and biomedical prevention interventions more important. We identify drug use and sex risk factors associated with adherence to protocol and study retention among this population during the course of an HIV vaccine trial. Methods Data from participants at the Philadelphia, PA site for the HIV Vaccine Trials Network (HVTN) 502 study testing the Merck Adenovirus 5 gag-pol-nef HIV vaccine were used to examine factors associated with adherence (receipt of three vaccines) and retention (present for 12-month appointment). Enrollees included 123 HIV-negative women 18–45 years of age reporting regular use of crack cocaine and frequent unprotected sex, who were randomly assigned to receive three injections of either the study vaccine or a placebo vaccine. Results Study participants had a mean age of 37 years and 91% were African–American. Overall adherence to study protocol was 89% and study retention at one year was 93.5%. Analyses found no association between drug use and high-risk sex behaviours and poorer rates of adherence and retention. In fact, participants who used recreational drugs at baseline were more likely than those who did not to adhere to study protocol (92% vs 75%, p Conclusions Factors commonly assumed to interfere with trial participation were not associated with adherence to study protocol or retention. These findings suggest that drug use and sexual risk behaviours do not impede completion of vaccinations and protocol required visits in clinical trials of experimental HIV vaccines.
Serum Carboxymethyl-Lysine, a Dominant Advanced Glycation End Product, Is Associated With Chronic Kidney Disease: The Baltimore Longitudinal Study of Aging

Objective Advanced glycation end products (AGEs) are modifiable risk factors for renal disease that were primarily studied in persons with diabetes or endstage renal disease. Our objective was to characterize the relationship between AGEs and renal function in community-dwelling adults. Design The presence of serum L-carboxymethyl-lysine (CML), a dominant AGE, was compared with renal function in a cross-sectional analysis. Setting This study was part of the Baltimore Longitudinal Study of Aging in Baltimore, Maryland. Patients or Other Participants Participants included community-dwelling men and women, aged 26 to 93 years, seen during a regular follow-up visit to the Baltimore Longitudinal Study of Aging between 2002 and 2007. Main Outcome Measures The main outcome measures included chronic kidney disease (CKD) at stage ≥3 of the National Kidney Foundation classification (estimated glomerular filtration rate [eGFR] of Results Of 750 adults, 121 (16.1%) had CKD. Serum CML was associated with CKD (odds ratio expressed per one standard deviation, 1.37; 95% confidence interval, 1.11 to 1.67; P = .003) in a multivariate logistic regression model adjusting for age, race, smoking, and chronic diseases. Serum CML was associated with eGFR (mL/minute/1.73 m2) (β = −2.21, standard error = 0.57, P = .0001) in a multivariate linear regression model, adjusting for age, race, smoking, and chronic diseases. After excluding patients with diabetes, serum CML was associated with CKD (odds ratio per one standard deviation, 1.38; 95% confidence interval, 1.12 to 1.70; P = .003) and eGFR (β = −2.09, standard error = 0.59, P = .0005), adjusting for the same covariates. Conclusion Serum CML, a dominant AGE, is independently associated with CKD and eGFR.
Aminolevulinic acid dehydratase activity in American dippers (Cinclus mexicanus) from a metal‐impacted stream

Blood samples collected from adult and nestling American dippers (Cinclus mexicanus) along the Arkansas River (CO, USA), a stream impacted by discharges from historical mining operations, and a reference stream were analyzed for lead concentration and δ-aminolevulinic acid dehydratase (ALAD) activity. Median ALAD activities of adult and nestling dippers from the Arkansas River were found to be significantly different from median ALAD activities of reference adults and nestlings (p = 0.002 and p = 0.028). Median ALAD activity for adult dippers from the Arkansas River was more than 50% lower relative to reference adults and activity approached a level close to 50% lower in nestlings from the same site. Median blood lead concentrations from adult (range 15.4–386.0 ppb) and nestling (range 12.1–323.0 ppb) dippers from the Arkansas River were found to be significantly different from median blood lead concentrations of reference adult (range 4.2–29.6 ppb) and nestling (range 4.2–8.2 ppb) dippers (p < 0.001 and p = 0.011). The median hematocrit level in adult dippers did not vary between sites (p = 0.73), whereas the median hematocrit level of nestling dippers from the reference site was significantly lower compared to Arkansas River nestlings (p = 0.042). Blood lead concentration in both adult and nestling dippers was found to be significantly correlated with invertebrate lead concentration (r = 0.81, p < 0.001 and r = 0.62, p = 0.01, respectively). Highly significant negative correlations were observed between blood lead concentration and ALAD activity in both adult and nestling dippers (r = −0.86, p < 0.001 and r = −0.84, p < 0.001, respectively). This study suggests that dippers (both adults and nestlings) from the Arkansas River have significantly lower ALAD activity and significantly higher blood lead concentrations compared to reference values. The measurement of ALAD activity may be a sensitive and accurate biomarker for environmental lead exposure in dippers.
High level ab initio and density functional theory study of bond dissociation energy and enthalpy of formation for hypochloric and hypobromic acids

Abstract The accuracy of high level ab initio, gradient-corrected density functional, and hybrid density functional theory methods were evaluated for computational bond dissociation energies and enthalpies of formation in the gas phases of small polar molecular systems. These are of particular interest for atmospheric and combustion chemistry. Examples used in this study are hypochloric acid and hypobromic acid. The former is selected because its very accurate experimental energies are readily available and the latter, selected because accurate experimental data are not available. The reliability of these methods for the computation of energies for these systems is discussed.
Neural Tube Defects

The term "neural tube defects" refers to a biologically interrelated series of malformations of the central nervous system and overlying tissues. There is an abnormality in morphogenesis of the brain and/or spinal cord, associated with varying degrees of absence or malformation of the meninges, bone, muscle, and skin. In addition to morphologic similarities, these lesions are related epidemiologically and probably genetically. The terminology is complex, but the lesions can be placed in a simple framework. The Table outlines the most common defects. The malformation occurs early in embryonic development, since the gross structure of the central nervous system has been completed by the 26th gestational day. There are numerous theories of pathogenesis and there is a good deal of subprimate teratologic research, but no single etiologic hypothesis is widely accepted or rigorously proven. Despite this, clinical risk factors have been clearly defined and empiric techniques for prenatal diagnosis have been developed. FREQUENCY AND EPIDEMIOLOGY Neural tube defects represent one of the most common groups of major congenital malformations. Each year approximately 6,000 to 8,000 infants are born with these conditions in the United States. Incidence rates vary among different groups from 0.6 to 4.1/1,000 total births for anencephaly. The risk is not uniformly spread over the entire population; a number of factors are related to initial occurrence and recurrence.
A 46-year-old woman with chin pain and a fainting spell.

History of the present illness The patient had a history of primary central nervous system (CNS) lymphoma that had recurred in the past but had been in remission for 2 years. She was admitted to the hospital in August 2008, following a syncopal episode. For several weeks prior to her syncope, she had experienced generalized malaise and the sensation of total body weakness. On the day of admission, she was nauseated and had one episode of non-bloody emesis. As the day progressed, she felt lightheaded and eventually lost consciousness while walking to the bathroom. In the emergency department, she was suspected of dehydration. However, an electrocardiogram revealed complete heart block (CHB). A temporary transjugular pacing wire was placed, intravenous fluids were started, and she was admitted to the Cardiac Unit. The patient stated that she had been completely well until 2 months before admission, when she began to experience easy fatigability. One month before admission, she developed a series of episodes of myalgias that involved her shoulders and neck. These symptoms responded to acetaminophen. She had also experienced periodic night sweats during this time. Two weeks before admission, the patient presented to her oncologist with the symptom of chin pain that radiated bilaterally toward the angle of her mandible. The pain was described as “sharp and shooting.” It sometimes appeared to be worsened by jaw movement. The patient indicated that chewing exacerbated the pain, starting with the first bite. Her oncologist had obtained a brain magnetic resonance imaging (MRI) study to exclude a lymphoma recurrence. The MRI study was interpreted as showing no new lesions. The pain did not respond to nonsteroidal antiinflammatory drugs and had been present for 2 weeks at the time of her syncope.
Functional and structural differences in ribosomal subunits isolated from monomers and polysomes of Acheta domesticus.

Abstract 1. 1. Two types of ribosomal subunit preparations, one consisting of particles originally derived from polysomes as well as those from 80 S monomers, in approximatel equal proportions, and the other of subunits derived from 80 S monomers only, were isolated from Acheta domesticus nymphs. 2. 2. The two preparations have identical reassociation characteristics at higher Mg 2+ levels, undegraded RNA and comparable abilities for ApUpG-directed binding of formyl-methionyl-tRNA. 3. 3. They differ in that the polysomally derived subunits have a significantly enhanced capacity for poly(U)-directed binding and incorporation of phenylalanine and the presence of enhanced quantities of specific 40 S and 60 S subunit proteins.
Temperature variation effects on sparse representation of guided-waves for damage diagnosis in pipelines

Multiple ultrasonic guided-wave modes propagating along a pipe travel with different velocities which are themselves a function of frequency. Reflections from the features of the structure (e.g., boundaries, pipe welding, damage, etc.), and their complex superposition, adds to the complexity of guided-waves. Guided-wave based damage diagnosis of pipelines becomes even more challenging when environmental and operational conditions (EOCs) vary (e.g., temperature, flow rate, inner pressure, etc.). These complexities make guided-wave based damage diagnosis of operating pipelines a challenging task. This paper reviews the approaches to-date addressing these challenges, and highlights the preferred characteristics of a method that simplifies guided-wave signals for damage diagnosis purposes. A method is proposed to extract a sparse subset of guided-wave signals in time-domain, while retaining optimal damage information for detection purpose. In this paper, the general concept of this method is proved through an extensive set of experiments. Effects of temperature variation on detection performance of the proposed method, and on discriminatory power of the extracted damage-sensitive features are investigated. The potential of the proposed method for real-time damage detection is illustrated, for wide range of temperature variation scenarios (i.e., temperature difference between training and test data varying between -2°C and 13°C).
A review of the multi-level adaptations for maximizing aerobic dive duration in marine mammals: from biochemistry to behavior

Marine mammals exhibit multi-level adaptations, from cellular biochemistry to behavior, that maximize aerobic dive duration. A dive response during aerobic dives enables the efficient use of blood and muscle oxygen stores, but it is exercise modulated to maximize the aerobic dive limit at different levels of exertion. Blood volume and concentrations of blood hemoglobin and muscle myoglobin are elevated and serve as a significant oxygen store that increases aerobic dive duration. However, myoglobin is not homogeneously distributed in the locomotory muscles and is highest in areas that produce greater force and consume more oxygen during aerobic swimming. Muscle fibers are primarily fast and slow twitch oxidative with elevated mitochondrial volume densities and enhanced oxidative enzyme activities that are highest in areas that produce more force generation. Most of the muscle mitochondria are interfibriller and homogeneously distributed. This reduces the diffusion distance between mitochondria and helps maintain aerobic metabolism under hypoxic conditions. Mitochondrial volume densities and oxidative enzyme activities are also elevated in certain organs such as liver, kidneys, and stomach. Hepatic and renal function along with digestion and assimilation continue during aerobic dives to maintain physiological homeostasis. Most ATP production comes from aerobic fat metabolism in carnivorous marine mammals. Glucose is derived mostly from gluconeogenesis and is conserved for tissues such as red blood cells and the central nervous system. Marine mammals minimize the energetic cost of swimming and diving through body streamlining, efficient, lift-based propulsive appendages, and cost-efficient modes of locomotion that reduce drag and take advantage of changes in buoyancy with depth. Most dives are within the animal’s aerobic dive limit, which maximizes time underwater and minimizes recovery time at the surface. The result of these adaptations is increased breath-hold duration and enhanced foraging ability that maximizes energy intake and minimizes energy output while making aerobic dives to depth. These adaptations are the long, evolutionary legacy of an aquatic lifestyle that directly affects the fitness of marine mammal species for different diving abilities and environments.
Closure Provides No Relief from the Problem of Easy Knowledge

Closure principles loom large in recent internalist critiques of epistemic externalism. Cohen (Philos Phenomenol Res 65:309–329, 2002, Philos Phenomenol Res 70:417–430, 2005), Vogel (J Philos 97:602–623, 2000), and Fumerton (Meta-Epistemology and skepticism. Rowman and Littlefield, Lanham, 1995) argue that, given closure, epistemic externalism is committed to the possibility of implausibly easy knowledge. By contrast, Zalabardo (Philos Rev 114:33–61, 2005) proposes that epistemic closure actually precludes the possibility of easy knowledge, and appeals to closure principles to solve the problem of easy knowledge. In my view, disagreement over closure’s bearing on externalism and the problem of easy knowledge is rooted in a failure to bear in mind the familiar distinction between ex ante and ex post forms of epistemic justification and warrant. When this distinction is kept in focus, the result is clear: epistemic closure provides no relief from the problem of easy knowledge.
Case Study: Particle Velocimetry in a Model of Lake Ogallala

In a case study of Lake Ogallala, a reservoir in central Nebraska, large scale particle tracking velocimetry (LSPTV) is used to measure surface velocities in a physical model of the lake. Knowledge of flow patterns in the lake is essential for predicting the transport of dissolved oxygen (DO). A preliminary comparison with acoustic Doppler velocimetery (ADV) measurements shows that both LSPTV and large scale particle image velocimetry (LSPIV) accurately measure surface velocities. In the present study, LSPTV works better near flow boundaries and in regions with high velocity gradients since smaller sampling areas are possible, and unlike LSPIV measurements, LSPTV measurements are unbiased. Discharges measured at eight different transects using LSPTV were within 6% of the discharge measured with an orifice, the worst correlation occurring where the bathymetry was slightly nonuniform (making application of the 1/7-power law suspect). In the prototype, DO content periodically drops to unacceptable levels throughout most of the Keystone Basin (a subbasin of Lake Ogallala). Predicted flow patterns suggest that low DO problems are exacerbated in regions with low velocities since oxygen consumed by macrophytes during nighttime hours is not quickly replenished.
Charge fluctuations in e + e - annihilations

We consider what can be learned about the nature of the annihilation process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}$ hadrons from the measurement of the mean-square charge transfer between right and left c.m. hemispheres. Predictions of parton models, where this quantity goes to a finite constant, and fireball models, where it grows with multiplicity, are compared. We conclude that it should be possible to discriminate between these two classes of models at SPEAR energies. We also comment on difficulties associated with testing in ${e}^{+}{e}^{\ensuremath{-}}$ annihilations Feynman's conjecture that quark quantum numbers remain in the parton fragmentation region.
Immunochemical evidence for a role of cytochrome P-450 in liver microsomal ethanol oxidation.

Abstract Antibodies to cytochrome P -450 isozyme 3a, the ethanol-inducible isozyme in rabbit liver, were used to determine the role of this enzyme in the microsomal oxidation of alcohols and the p -hydroxylation of aniline. P -450 isozymes, 2, 3b, 3c, 4, and 6 did not crossreact with anti-3a IgG as judged by Ouchterlony double diffusion, and radioimmunoassays indicated a crossreactivity of less than 1%. Greater than 90% of the activity of purified form 3a toward aniline, ethanol, n -butanol, and n -pentanol was inhibited by the antibody in the reconstituted system. The catalytic activity of liver microsomes from control or ethanol-treated rabbits was unaffected by the addition of either desferrioxamine (up to 1.0 m m ) or EDTA (0.1 m m ), suggesting that reactions involving the production of hydroxyl radicals from H 2 O 2 and any contaminating iron in the system did not make a significant contribution to the microsomal activity. The addition of anti-3a IgG to hepatic microsomes from ethanol-treated rabbits inhibited the metabolism of ethanol, n -butanol, n -pentanol, and aniline by about 75, 70, 80, and 60%, respectively, while the inhibition of the activity of microsomes from control animals was only about one-half as great. The rate of microsomal H 2 O 2 formation was inhibited to a lesser extent than the formation of acetaldehyde, thus suggesting that the antibody was acting to prevent the direct oxidation of ethanol by form 3a. Under conditions where purified NADPH-cytochrome P -450 reductase-catalyzed substrate oxidations was minimal, the P -450 isozymes other than 3a had low but significant activity toward the four substrates examined. The residual activity at maximal concentrations of the antibody most likely represents the sum of the activities of P -450 isozymes other than 3a present in the microsomal preparations. The results thus indicate that the enhanced monooxygenase activity of liver microsomes from ethanol-treated animals represents catalysis by P -450 isozyme 3a.
Broken symmetries in scanning tunneling images of carbon nanotubes

Scanning tunneling images of carbon nanotubes frequently show electron distributions that break the local sixfold symmetry of the graphene sheet. We present a theory of these images that relates these anisotropies to the off-diagonal correlations in the single-particle density matrix, and allows one to extract these correlations from the observed images. The theory is applied to images of the low-energy states reflected at the end of a tube or by point defects, and to states propagating on defect free semiconducting tubes. The latter exhibit a switching of the anisotropy in the tunneling image with the sign of the tunneling bias. @S0163-1829~99!50920-X# Scanning tunneling microscopy and spectroscopy is a powerful tool for studying the structural and electronic properties of carbon nanotubes at the atomic scale. Several experimental groups have reported tunneling images of isolated single wall carbon nanotubes 1,2 and of tubes packed into bundles or ‘‘ropes.’’ 3 In some cases these measurements have allowed a direct determination of the diameters and wrapping vectors for the tubes and these observations, combined with scanning tunneling spectroscopy, have confirmed the idea that the semiconducting or conducting behavior of a tube is controlled by its wrapping vector. 1,2
Some convergence theorems for stochastic learning models with distance diminishing operators

Abstract A broad mathematical framework is considered that includes stochastic learning models with distance diminishing operators for experiments with finite numbers of responses and simple contingent reinforcement. Convergence theorems are presented that subsume most previous results about such models, and extend them in a variety of ways. These theorems permit, for example, the first treatment of the asymptotic behavior of the general linear model with experimenter-subject controlled events and no absorbing barriers. Some new results are also given for certain two-process discrimination learning models and for models with finite state spaces.
Cardiopulmonary Changes in the Crying Neonate

To determine hemodynamic effects of crying, 12 newborn infants recovering from the respiratory distress syndrome (RDS) were studied. When crying, the range of inspiratory esophageal pressure was -18.8 to -32.5 cm H2O and the range of espiratory pressure was +6.2 to 34.4 cm H2O. The esophageal pressure remained positive for a mean value of 66% of the respiratory cycle. There was a mean significant increase in heart rate of 19 beats/min. The systolic and diastolic blood pressures increased significantly at the beginning of strain to 115 and 135% of the respective control values. There was a progressive decrease in systolic and diastolic pressures during the period of strain and the systolic pressures reached values significantly less than control. With the decrease in systolic and diastolic pressures, there were pronounced reductions in pulse pressures. Three infants reached pulse pressure values less than 1% of control when cries were sustained for nine cardiac cycles. There was a significant mean decrease in arterial oxygen tension (PaO2) of 16.8 mm Hg. There were no changes in arterial carbon dioxide tension (PaCO2), pH, or base excess.
Dennett's misremenberings

Critique de l'argument contre l'ecran cartesien des images visuelles developpe par D. Dennett dans son ouvrage intitule «Consciousness explained» (1991). Examinant les donnees empiriques de l'experience visuelle et les principes verificationnistes utilises par Dennett, d'une part, et presentant la theorie causale de la memoire, de la perception et de la reference developpee par C. B. Martin et M. Deutscher, d'autre part, l'A. montre que la meilleure option que Dennett puisse prendre est d'adopter une conception forte de la causalite, au-dela de la difference entre l'histoire-P(re-organisationnelle) et l'histoire-R(evisionniste) de l'ecran cartesien et au-dela de la distinction logique etablie entre la memoire et la fausse memoire
A synthetic route to valienamine: An interesting observation concerning stereoelectronic preferences in the SN2′ reaction

Abstract Intramolecular allylic displacement of a spiroepoxide is used to reach (+)-valienamine.
Do's and don'ts of simultaneous instruction to on-campus and distance students via videoconferencing

Abstract Achieving the transition from Bibliographic Instruction (BI) to Information Literacy (IL) is particularly hard for institutions because it requires librarians to actively collaborate with a variety of administrative programs and this is all the more challenging when serving distance students. At Nova Southeastern University, the Speech-Language Pathology (SLP) department employs several delivery methods to impart graduate education. This case study describes transition from one-shot library BI to a three-day format for the SLP program, with instruction that builds sequentially and developmentally, incorporating a variety of assessment techniques (e.g., in-class exercises, puzzles, quizzes, take-home assignments). The paper discusses the innovative delivery of the course format: the issues and challenges of teaching local and distance students simultaneously via compressed video. Solutions are offered based on the presenters' experience of what worked and what did not, the quality of teaching and ...
Kinetic studies of a catalyzed metalloporphyrin formation

Kinetics of the incorporation of mercury(II) ion in tetra (p-trimethylammoniumphenyl)porphine have been investigated in aqueous solution at 30.0°C and 0.2 M (NaNO3) ionic strength. The reaction was found to be first order each in mercury(II) and the porphyrin. The forward (formation) and the reverse (dissociation) rate constants were found to be 1.9 ± 0.2 × 103 M−1 s−1 and 7 ± 2 × 106 M−1 s−1, respectively. Kinetics of zinc(II) incorporation in tetra(p-trimethylammoniumphenyl)porphine catalyzed by mercury(II) were also investigated. This catalysis is explained in terms of steady-state formation of mono mercury(II) porphyrin followed by zinc(II) displacement of mercury(II) ion from the porphyrin. Such a mechanism also illustrates the importance of porphyrin core deformation to metal incorporation.
Factors Affecting Selection of Mates of Sires in Arteficial Service

Abstract Matings of 10,922 registered Holstein cows from 1964 through 1967, to 142 sires, were identified through two artificial insemination organizations. Each sire had a minimum of 10 mates. Mates' mature equivalent records were used to compute bias in sires' Predicted Differences due to nonrandom selection of mates. The mean bias was 13.2 and .6kg for milk and fat with standard deviations of 14.7 and .6kg. Rank correlations between Predicted Differences, uncorrected and corrected for the bias, were .996 and .992 for milk and fat for the 126 bulls with published proofs. Price by itself accounted for approximately one-half of the variation in bias. Multiple regression of bias on a subjective popularity score and type and production proof data indicated that price and sire's type score were the most important factors in predicting bias.
Avalanches in a stochastic model of spiking neurons.

Neuronal avalanches are a form of spontaneous activity widely observed in cortical slices and other types of nervous tissue, both in vivo and in vitro. They are characterized by irregular, isolated population bursts when many neurons fire together, where the number of spikes per burst obeys a power law distribution. We simulate, using the Gillespie algorithm, a model of neuronal avalanches based on stochastic single neurons. The network consists of excitatory and inhibitory neurons, first with all-to-all connectivity and later with random sparse connectivity. Analyzing our model using the system size expansion, we show that the model obeys the standard Wilson-Cowan equations for large network sizes ( neurons). When excitation and inhibition are closely balanced, networks of thousands of neurons exhibit irregular synchronous activity, including the characteristic power law distribution of avalanche size. We show that these avalanches are due to the balanced network having weakly stable functionally feedforward dynamics, which amplifies some small fluctuations into the large population bursts. Balanced networks are thought to underlie a variety of observed network behaviours and have useful computational properties, such as responding quickly to changes in input. Thus, the appearance of avalanches in such functionally feedforward networks indicates that avalanches may be a simple consequence of a widely present network structure, when neuron dynamics are noisy. An important implication is that a network need not be “critical” for the production of avalanches, so experimentally observed power laws in burst size may be a signature of noisy functionally feedforward structure rather than of, for example, self-organized criticality.
Effect of self-association of αs1-casein and its cleavage fractions αs1-casein(136–196) and αs1-casein(1–197), on aromatic circular dichroic spectra: comparison with predicted models

Abstract The self-association of native αs1-casein is driven by a sum of interactions which are both electrostatic and hydrophobic in nature. The dichroism of aromatic side chains was used to derive regio-specific evidence in relation to potential sites of αs1-casein polymerization. Near-ultraviolet circular dichroism (CD) revealed that both tyrosine and tryptophan side chains play a role in αs1-casein associations. Spectral evidence shows these side chains to be in an increasingly nonaqueous environment as both ionic strength and protein concentration lead to increases in the degree of self-association of the protein from dimer to higher oligomers. Near-UV CD investigation of the carboxypeptidase A treated peptide, αs1-casein(1–197), indicated that the C-terminal residue (Trp199) may be superficial to these interactions, and that the region surrounding Trp164 is more directly involved in an aggregation site. Similar results for the cyanogen bromide cleavage peptide αs1-casein(136–196) indicated the presence of strongly hydrophobic interactions. Association constants for the peptides of interest were determined by analytical ultracentrifugation, and also were approximated from changes in the near-UV CD curves with protein concentration. Sedimentation equilibrium experiments suggest the peptide to be dimeric at low ionic strength; like the parent protein, the peptide further polymerizes at elevated (0.224 M) ionic strength. The initial site of dimerization is suggested to be the tyrosine-rich area near Pro147, while the hydrophobic region around Pro168, containing Trp164, may be more significant in the formation of higher-order aggregates.
Late hypertension after liver transplantation: A comparison of cyclosporine and tacrolimus (FK 506)

Hypertension frequently develops early after liver transplantation when cyclosporine-based immunosuppression is used. However, initial experience with tacrolimus has suggested that its use leads to a lower early incidence of hypertension. In this study, the blood pressure status of patients treated with cyclosporine (n = 131) and those treated with tacrolimus (n = 28) was compared 24 months after liver transplantation. At this time interval, the prevalence of hypertension in the cyclosporine and tacrolimus groups were 82% and 64%, respectively (P < .05). For those patients who were hypertensive by 24 months, onset was delayed in the tacrolimus group compared with the cyclosporine group: 40% versus 71% and 73% versus 93% at 1 and 12 months, respectively (P < .05). Within the cyclosporine group, patients with hypertension were heavier than those with normal blood pressure, 84.7 +/- 1.8 versus 73.4 +/- 4.0 kg, respectively (P < .05). Within the tacrolimus group, hypertensive patients had lower glomerular filtration rates and higher renal vascular resistances compared with normotensive patients, 74 +/- 12 versus 47 +/- 6 mL/min and 15,711 +/- 2,445 versus 28,830 +/- 4,310 dyne/s/cm5/m2, respectively (P < .05). There were no within-group differences for age, gender, pretransplant history of hypertension, family history of hypertension, graft function, or daily doses of prednisone, cyclosporine, or tacrolimus. These results indicate that, compared with cyclosporine, the onset of hypertension after liver transplantation is delayed and less prevalent with tacrolimus. Additionally, hypertension is associated with increased body weight in cyclosporine-treated patients and with more severe renal dysfunction in patients receiving tacrolimus. The relationships of these findings to the development of posttransplant hypertension requires further study.
Investigations of microwave plasmas - Applications in electrothermal thruster systems

Experimental studies which have been conducted to develop understanding of plasma processes used for spacecraft propulsion are reviewed. The techniques discussed are calorimetry and volume measurements using the TM 011 and TM 012 modes in the microwave cavity system. The use of plasmas in electrical propulsion and microwave induction is reviewed. Plasma containment, microwave power production, energy distribution, and the pressure and flow dependence of the energy distribution are addressed. The plasma dimensions and their dependence on pressure, flow, and power are considered.
Using Declarative Specifications and Case-based Planning for System Synthesis

Synthesis of pragmatic systems from high-level specifications requires representation and application of both functional requirements and constraints. This work presents a language for representing requirements and constraints in VHDL design representations and a prototype care-based synthesis system. VSPEC is an annotation language for VHDL developed to support axiomatic representation of requirements for system synthesis. VSPEC descriptions serve as synthesis goals and verification criteria. A prototype case-based synthesis system is also presented that uses VSPEC requirements as goal statements and descriptions of potential solutions. This prototype system demonstrates how synthesis can be performed at the systems level and how constraints can be used to implement a simple concurrent engineering process.
Effect of the phenyl ring orientation in the polystyrene buffer layer on the performance of pentacene thin-film transistors

Abstract The phenyl groups of polystyrene (PS) thin films untreated and thermally treated at 80 and 120 °C assume tilt angles of 27°, 39° and 62°, respectively. The PS films were inserted between SiO 2 and organic semiconductors as buffer layers for organic thin-film transistors (OTFTs). The results showed that a flat orientation of phenyl ring at the surface of the PS films optimized the surface energy of PS film, resulting in higher crystallinity of pentacene films deposited onto it and an improved interconnection between the pentacene crystalline domains. The device with the PS film thermally treated at 120 °C showed superior performance, affording a mobility as high as 4 cm 2 /V s, an on/off ratio of about 10 7 –10 8 and a threshold voltage of about 6.5 V in the saturation region.
Bone Mineral Density and Dietary Intake in Patients with Crohn's Disease

Abstract Individuals diagnosed with Crohn's disease are at an increased risk for developing low bone density. The exact cause of low bone mineral density in Crohn's disease patients has not been determined. The purpose of this study was to assess the incidence of low bone mineral density in premenopausal women with Crohn's disease and to determine the role diet plays in bone mineral density for this population. Bone mineral density of the lumbar spine (L2−L4), proximal femur, and forearm was measured in 51 female controls and 50 females with Crohn's disease using dual energy X-ray absorptiometry (Lunar DPX-Plus, Madison, WI). Dietary intake for all Crohn's disease participants was analyzed using both 3-d dietary records and a food frequency questionnaire. When compared to healthy controls, bone mineral density values of Crohn's disease participants were decreased for all sites, particularly the spine (1.169 ± 0.114, p = 0.054), Ward's area (0.831 ± 0.128, p = 0.052), and the femoral neck (0.927 ± 0.100, p = 0.01). Factors associated with lower bone density in Crohn's participants were weight, corticosteroid usage, length and age of diagnosis, history and length of resection, and dietary intakes of magnesium, copper, magnesium, vitamin K, and zinc. The results of this study indicate for the first time that diet plays a role in the development of low bone density in premenopausal women with Crohn's disease.
Rural and urban Midwestern United States contraception practices.

To address a paucity of demographic data on rural United States contraception practices, 370 randomly selected menstruating women, age 13-55 years, living in rural and urban Illinois and Missouri answered interview questions. Women with relatively few children and living in urban areas were likely to practice contraception more than those with relatively few children and living in rural areas, p 0.05. Urban-rural differences in contraception practices may be a function of life style choices (e.g. urban women may practice contraception to postpone having children, whereas rural women may practice contraception to prevent having more children after families are complete). Results do not strongly support that locale differences in contraception practices are a function of concern about contracting STDs.
Neural network approach for the derivation of chlorophyll concentration from ocean color

Using a dataset consisting of 9000 reflectance spectra simulated using HYDROLIGHT 5 for a broad range of observable natural water conditions, we have developed three neural networks (NNs) working in parallel to model the inverse problem for both oceanic and coastal waters. These NNs are used to relate the water leaving remote sensing reflectance ( Rrs ) at available MODIS visible wavelengths (412, 443, 488, 531, 547 and 667nm) to the phytoplankton ( a ph ), non-phytoplankton particulate ( a dm ), dissolved ( a g ) absorption and particulate backscattering ( b bp ) coefficients at 443nm. These reflectance derived parameters ( a ph (443), a dm (443), a g (443), b bp (443)) are then combined with the measured reflectance values and used as input to a fourth NN, (IOP NN [Chl]), to derive chlorophyll concentration ([Chl]). Unlike NNs previously developed by us that were trained on a synthetic dataset and then tested on the NASA Bio-Optical Marine Algorithm Dataset (NOMAD), the (IOP NN [Chl]) network was both trained and tested solely on NOMAD. Although the inherent optical properties (IOP) can be derived from the optical signal through their direct relation to the Rrs , the relationship of [Chl] to IOP varies with location and season, and is therefore difficult to model globally. In order to demonstrate that the inclusion of derived IOP estimates along with radiance measurements can improve the retrieval of [Chl], we construct a neural network that is trained to derive [Chl] from reflectance measurements only We also compare our [Chl] product to that obtained from the current OC3 algorithm implemented by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS). Finally, we apply our algorithm to MODIS data and present and analyze the global seasonal variability for all three parameters.
RNASEL and MIR146A SNP-SNP Interaction as a Susceptibility Factor for Non-Melanoma Skin Cancer

Immunity and inflammatory pathways are important in the genesis of non-melanoma skin cancers (NMSC). Functional genetic variation in immune modulators has the potential to affect disease etiology. We investigated associations between common variants in two key regulators, MIR146A and RNASEL, and their relation to NMSCs. Using a large population-based case-control study of basal cell (BCC) and squamous cell carcinoma (SCC), we investigated the impact of MIR146A SNP rs2910164 on cancer risk, and interaction with a SNP in one of its putative targets (RNASEL, rs486907). To examine associations between genotype and BCC and SCC, occurrence odds ratios (OR) and 95% confidence intervals (95%CI) were calculated using unconditional logistic regression, accounting for multiple confounding factors. We did not observe an overall change in the odds ratios for SCC or BCC among individuals carrying either of the RNASEL or MIR146A variants compared with those who were wild type at these loci. However, there was a sex-specific association between BCC and MIR146A in women (ORGC = 0.73, [95%CI = 0.52-1.03]; ORCC = 0.29, [95% CI = 0.14-0.61], p-trend<0.001), and a reduction in risk, albeit not statistically significant, associated with RNASEL and SCC in men (ORAG = 0.88, [95%CI = 0.65-1.19]; ORAA = 0.68, [95%CI = 0.43-1.08], p-trend = 0.10). Most striking was the strong interaction between the two genes. Among individuals carrying variant alleles of both rs2910164 and rs486907, we observed inverse relationships with SCC (ORSCC = 0.56, [95%CI = 0.38-0.81], p-interaction = 0.012) and BCC (ORBCC = 0.57, [95%CI = 0.40-0.80], p-interaction = 0.005). Our results suggest that genetic variation in immune and inflammatory regulators may influence susceptibility to NMSC, and novel SNP-SNP interaction for a microRNA and its target. These data suggest that RNASEL, an enzyme involved in RNA turnover, is controlled by miR-146a and may be important in NMSC etiology.
Crystal structure and mechanism of a carbon-carbon bond hydrolase.

Abstract Background: Fumarylacetoacetate hydrolase (FAH) catalyzes the final step of tyrosine and phenylalanine catabolism, the hydrolytic cleavage of a carbon–carbon bond in fumarylacetoacetate, to yield fumarate and acetoacetate. FAH has no known sequence homologs and functions by an unknown mechanism. Carbon–carbon hydrolysis reactions are essential for the human metabolism of aromatic amino acids. FAH deficiency causes the fatal metabolic disease hereditary tyrosinemia type I. Carbon–carbon bond hydrolysis is also important in the microbial metabolism of aromatic compounds as part of the global carbon cycle. Results: The FAH crystal structure has been determined by rapid, automated analysis of multiwavelength anomalous diffraction data. The FAH polypeptide folds into a 120-residue N-terminal domain and a 300-residue C-terminal domain. The C-terminal domain defines an unusual β -strand topology and a novel ‘mixed β -sandwich roll' structure. The structure of FAH complexed with its physiological products was also determined. This structure reveals fumarate binding near the entrance to the active site and acetoacetate binding to an octahedrally coordinated calcium ion located in close proximity to a Glu–His dyad. Conclusions: FAH represents the first structure of a hydrolase that acts specifically on carbon–carbon bonds. FAH also defines a new class of metalloenzymes characterized by a unique α / β fold. A mechanism involving a Glu–His–water catalytic triad is suggested based on structural observations, sequence conservation and mutational analysis. The histidine imidazole group is proposed to function as a general base. The Ca 2+ is proposed to function in binding substrate, activating the nucleophile and stabilizing a carbanion leaving group. An oxyanion hole formed from sidechains is proposed to stabilize a tetrahedral alkoxide transition state. The proton transferred to the carbanion leaving group is proposed to originate from a lysine sidechain. The results also reveal the molecular basis for mutations causing the hereditary tyrosinemia type 1.
The Meaning of Negative Premises in Transition System Specifications II

This paper reviews several methods to associate transition relations to transition system specifications with negative premises in Plotkin''s structural operational style. Besides a formal comparison on generality and relative consistency, the methods are also evaluated on their taste in determining which specifications are meaningful and which are not.
Ultra low power electronics for medicine

Summary form only given. We discuss how programmable analog electronics may be used to lower overall power consumption over traditional A-to-D-then-DSP architectures in portable medical applications. One example includes a bionic ear processor for the deaf whose power consumption is an order of magnitude below the best designs today, that are unbeatable even at the end of Moore's law, and which enable 30 year operation on an implanted 100mAh rechargeable battery. Another example includes an ultra low power portable pulse oximeter for measuring oxygen saturation, an important vital sign. This paper discusses implications for future medical applications that are battery free and that operate by rectifying ambient RF energy, for example for cardiac monitoring. Medical applications in the future are likely to benefit greatly from ultra low power electronics especially in implanted, home care, surgical, and emergency monitoring.
Developmental and Thermal Regulation of the Maize Heat Shock Protein, HSP101

The plant heat stress protein, Hsp101, and the yeast ortholog, Hsp104, are required to confer thermotolerance in plants and yeast (Saccharomyces cerevisiae), respectively. In addition to its function during stress, Hsp101 is developmentally regulated in plants although its function during development is not known. To determine how the expression of Hsp101 is regulated in cereals, we investigated the Hsp101 expression profile in developing maize (Zea mays). Hsp101 protein was most abundant in the developing tassel, ear, silks, endosperm, and embryo. It was less abundant in the vegetative and floral meristematic regions and was present at only a low level in the anthers and tassel at anthesis, mature pollen, roots, and leaves. As expected, heat treatment resulted in an increase in the level of Hsp101 protein in several organs. In expanding foliar leaves, husk leaves, the tassel at the premeiosis stage of development, or pre-anthesis anthers, however, the heat-mediated increase in protein was not accompanied by an equivalent increase in mRNA. In contrast, the level of Hsp101 transcript increased in the tassel at anthesis following a heat stress without an increase in Hsp101 protein. In other organs such as the vegetative and floral meristematic regions, fully expanded foliar leaves, the young ear, and roots, the heat-induced increase in Hsp101 protein was accompanied by a corresponding increase in Hsp101 transcript level. However, anthers at anthesis, mature pollen, developing endosperm, and embryos largely failed to mount a heat stress response at the level of Hsp101 protein or mRNA, indicating that Hsp101 expression is not heat inducible in these organs. In situ RNA localization analysis revealed that Hsp101 mRNA accumulated in the subaleurone and aleurone of developing kernels and was highest in the root cap meristem and quiescent center of heat-stressed roots. These data suggest an organ-specific control of Hsp101 expression during development and following a heat stress through mechanisms that may include posttranscriptional regulation.