cssi/SciSciGPT-SciSciNet huggingface dataset:
Increased risk for gestational diabetes mellitus associated with insulin receptor and insulin-like growth factor II restriction fragment length polymorphisms

Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset or first recognition during pregnancy. We have examined restriction fragment length polymorphisms (RFLPs) near "candidate diabetogenic genes" as one approach to identify molecular markers for GDM genes. Genotypes for insulin hypervariable region (HVR), insulin-like growth factor II (IGF2), insulin receptor (INSR), and glucose transporter (GLUT1) RFLPs were studied in 96 GDM and 164 control subjects, matched to GDM for race, age, and gravidity. Logistic regression analysis was used to explore the relationship between genotypes at these candidate gene loci and GDM, while adjusting for the effects of potential confounding variables. Among black subjects, the INSR allele 1 (P = 0.001) and interactions between INSR allele 1 with body mass index (BMI) (P = 0.002) and history of DM in subject's mother (P = 0.004) contributed significantly to GDM risk. Among Caucasian subjects, a similar relationship between the INSR allele 1 (P = 0.007) and INSR allele 1-BMI interactions (P = 0.011) on GDM risk were observed. In Caucasians, an additional significant risk factor was determined by an INSR allele 1-IGF2 allele 2 interaction (P = 0.018). No risk factors were identified in Hispanic subjects. These data continue to support the hypothesis that GDM is a heterogeneous disorder with respect to phenotypic and genotypic features. Furthermore, our data suggest that risk for GDM in black and Caucasian subjects is not due to obesity perse but to interactions between obesity and INSR alleles. In Caucasian women, INSR and IGF2 alleles interact to confer additional risk for GDM. Thus genes underlying susceptibility to GDM in some women may be similar to genes conferring risk to NIDDM, while in others novel genes may contribute to GDM risk.
Non-adiabatic dynamics modeling framework for materials in extreme conditions

Modeling non-adiabatic phenomena and materials at extremes has been a long-standing challenge for computational chemistry and materials science, particularly for systems that undergo irreversible phase transformations due to significant electronic excitations. Ab initio and existing quantum mechanics approximations to the Schrodinger equation have been limited to ground-state descriptions or few excited electronic states, less than 100 atoms, and sub-picosecond timescales of dynamics evolution. Recently, the electron force field (eFF) introduced by Su and Goddard (2007) presented a cost-efficient alternative to describe the dynamics of electronic and nuclear degrees of freedom. eFF describes an N-electron wave function as a Hartree product of one-electron floating spherical Gaussian wave packets propagating via the time-dependent Schrodinger equation under a mixed quantum–classical Hamiltonian evaluated as sum of self- and pairwise potential interactions. Local Pauli potential corrections replace the need for explicit anti-symmetrization of total electronic wavefunction, a wavefunction kinetic energy term accounts for Heisenberg’s uncertainty, and classical electrostatics complete the total eFF energy expression. However, due to the spherical symmetry of the underlying Gaussian basis functions, the original eFF formulation is limited to low-Z numbers with electrons of predominant s-character. To overcome this, we introduce here a formal set of potential form extensions that enable accurate description of p-block elements in the periodic table. The extensions consist of a model representing the core electrons of an atom together with the nucleus as a single pseudo particle with wave-like behavior, interacting with valence electrons, nuclei, and other cores through effective core pseudopotentials (ECPs). We demonstrate and validate the ECP extensions for complex bonding structures, geometries and energetics of systems with p-block character (containing silicon, oxygen, carbon, or aluminum atoms and combination thereof) and apply them to study materials under extreme mechanical loading conditions.
Heats of activation for the exosmotic flow of water across the membrane of leucocytes and leukemic cells

The permeability of the membranes of different types of leucocytes from several mammalian species to the exosmotic flow of water has been measured at different temperatures. Heats of activation for the process have been calculated. Results indicate that the leucocyte has an unusually high heat of activation for the osmotic movement of water across its outer membrane, ranging between 13 to 18 kcal/mole. Unconstrained water movement usually has values between 3 to 5 kcal/mole. This property characterizes all leucocytes examined to date, regardless of species or type. It is apparent that water is intimately associated with the outer boundary of the cell and that this association is quite sensitive to the structural changes which must occur in response to changes in temperature.
Betamethasone Increases Pulmonary Compliance in Part by Surfactant-Independent Mechanisms in Preterm Rabbits

ABSTRACT. Antenatal exposure to corticosteroids is known to increase the pulmonary compliance of preterm animals. We wished to determine whether this was due solely to alteration in lung surfactant content. Rabbit does were injected with either vehicle alone or betamethasone on days 25 and 26 of gestation. Fetuses were delivered at 27 days and given either 50% lactated Ringer's or intratracheal natural surfactant prior to their first breath. Fetuses were mechanically ventilated at a tidal volume of 12 ml/kg for 60 min with periodic compliance measurements. Following ventilation an alveolar lavage was collected for phosphatidylcholine determination. Some fetuses did not undergo ventilation but had saline compliance studies instead. Fetuses given intratracheal surfactant had a higher dynamic compliance than fetuses exposed to antenatal corticosteroids (0.55 ± 0.01 versus 0.48 ± 0.02 ml/cm H2O/kg, respectively). Fetuses exposed to antenatal corticosteroids and given intratracheal surfactant had a dynamic compliance (0.66 ± 0.02) that was greater than those exposed to either single therapy. This was found despite an alveolar surfactant content equal to that in fetuses receiving intratracheal surfactant alone. Saline compliance at birth was significantly greater for fetuses exposed antenatally to steroids. These data imply the existence of a nonsurfactant mechanism by which antenatal corticosteroids increase fetal pulmonary compliance.
Magnetostatic resonances in axially magnetised YIG rods

Abstract Magnetostatic-resonance measurements have been performed on axially magnetised YIG rods. It is shown that the results can be represented by a parameter, having values for short rods, significantly larger than the theoretical value for an infinitely long rod.
Real time non-invasive imaging of receptor-ligand interactions in vivo.

Non-invasive longitudinal detection and evaluation of gene expression in living animals can provide investigators with an understanding of the ontogeny of a gene's biological function(s). Currently, mouse model systems are used to optimize magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and optical imaging modalities to detect gene expression and protein function. These molecular imaging strategies are being developed to assess tumor growth and the tumor microenvironment. In addition, pre-labeling of progenitor cells can provide invaluable information about the developmental lineage of stem cells both in organogenesis and tumorigenesis. The feasibility of this approach has been extensively tested by targeting of endogenous tumor cell receptors with labeled ligand (or ligand analog) reporters and targeting enzymes with labeled substrate (or substrate analog). We will primarily discuss MRI, PET, and SPECT imaging of cell surface receptors and the feasibility of non-invasive imaging of gene expression using the tumor microenvironment (e.g., hypoxia) as a conditional regulator of gene expression.
In situ atomic force microscopy studies of protein and virus crystal growth mechanisms

In situ atomic force microscopy was utilized in studies of the growth mechanisms of six protein and virus crystals. It was demonstrated that those macromolecules utilize all of the growth mechanisms found in the crystallization of conventional molecules. These include growth on screw dislocations and by two- and three-dimensional nucleation. In addition the mechanism of normal growth was observed as well. Estimates for the fundamental parameters (free energy of the step edge, α, and kinetic coefficient of steps, β) for the crystallization of some macromolecules were obtained and compared with those known for inorganic crystals grown from solution.
Calibrated intercepts for solar radiometers used in remote sensor calibration

Calibrated solar radiometer intercepts allow spectral optical depths to be determined for days with intermittently clear skies. This is of particular importance on satellite sensor calibration days that are cloudy except at the time of image acquisition. This paper describes the calibration of four solar radiometers using the Langley-Bouguer technique for data collected on days with a clear, stable atmosphere. Intercepts are determined with an uncertainty of less than six percent, corresponding to a maximum uncertainty of 0.06 in optical depth. The spread of voltage intercepts calculated in this process is carried through three methods of radiometric calibration of satellite sensors to yield an uncertainty in radiance at the top of the atmosphere of less than one percent associated with the uncertainty in solar radiometer intercepts for a range of ground reflectances.
Apparent Molar Volume of Solubilized Water in AOT/Isooctane/Water Reverse Micellar Aggregates

States of the solubilized water in reverse micellar solution of aerosol-OT (AOT, bis(2-ethylhexyl) sodium sulfosuccinate) in isooctane were investigated by determining the apparent molar volume of water, Vw, through density measurements at different temperatures and water contents wo ([H2O]/[AOT]) of the solution. The low Vw values in the range up to wo = ∼ 2 are due to the strong interaction of H2O molecules with the ionic headgroup of AOT. Then, Vw exhibits a steep rise with water content in the range of wo = 2−6 owing to the swelling of the spherical reverse micelle, which is caused by the weaker binding of the additional water molecules to the ester group of AOT. In the range of wo = 6−12, Vw exhibits a complex behavior as a function of the water content with a distinct minimum in the vicinity of wo = 10. This nonmonotonic course of Vw as a function of water content in this range cannot be rationalized in terms of monotonic changes of the characteristics of the solubilized water in the micelle, or in ...
Geometric morphometrics reveals surprising diversity in the Lake Malawi cichlid genus Labeotropheus

The Lake Malawi cichlid genus Labeotropheus has been a source of confusion among biologists and taxonomists. Although unique populations of both L. fuelleborni and L. trewavasae exist throughout the lake, these populations have not been elevated to species, despite taxonomists doing so for populations within other Lake Malawi cichlids. One reason for this oversight is the supposed consistent differences in morphology between Labeotropheus species; since, where they co-occur, L. fuelleborni is always deeper-bodied than L. trewavasae, it is thought that all deep-bodied populations of Labeotropheus are L. fuelleborni, and the slender ones are L. trewavasae. Using geometric morphometrics, we analyze 18 populations of Labeotropheus and show that body shape varies among populations, and does not always fall into a deep-body/slender-body dichotomy. These differences in body shape are not related to geographical distance among populations, but are possibly related to the type of habitat in which the populations are found. Further, head shape is extremely variable among populations, and we find two locations where there is convergence in head shape between sympatric L. fuelleborni and L. trewavasae. Our results suggest that the morphological criteria applied to the Labeotropheus are not accurate, and hamper the recognition of Labeotropheus biodiversity.
Adenoid cystic carcinoma of the cervix: A report of 17 cases

Abstract Seventeen cases of adenoid cystic carcinoma of the cervix are presented. The long-term survival was in early stage IB–IIA. Patients with more than stage IIB had no survival rate over 5 years. One thing of interest was the fact that lung metastasis was 29.4%.
Plasmon-Enhanced Charge Carrier Generation in Organic Photovoltaic Films Using Silver Nanoprisms

We use photoinduced absorption spectroscopy to measure long-lived photogenerated charge carriers in optically thin donor/acceptor conjugated polymer blend films near plasmon-resonant silver nanoprisms. We measure up to 3 times more charge generation, as judged by the magnitude of the polaron absorption signal, in 35 nm thin blend films of poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester on top of films of silver nanoprisms (∼40−100 nm edge length). We find that the polaron yields increase linearly with the total sample extinction. These excitation enhancements could in principle be used to increase photocurrents in thin organic solar cells.
GameLog: fostering reflective gameplaying for learning

On the surface, it seems like teaching about games should be easy. After all, students are highly motivated, enjoy engaging with course content, and have extensive personal experience with videogames. Games education in reality is surprisingly complex. In game classes, students are often asked to reflect, generalize, and articulate their understanding of games as they play and analyze them. Educational research suggests that these tasks are particularly challenging for students. We report on the use of GameLog, an online blogging environment for supporting reflection on gameplaying experiences. GameLog differs from traditional blogging environments because each user maintains multiple parallel blogs, with each blog devoted to a single game. GameLog was used in two university level games-related classes. Our results indicate students perceived writing GameLogs as a positive learning experience for three reasons. First, it improved their relationship with videogames as a medium. Second, it helped them broaden and deepen their understanding of videogames. Third, it provided a vehicle for expression, communication, and collaboration. Students found that by reflecting on their experiences playing games they began to understand how game design elements helped shape that experience. Most importantly, they stepped back from their traditional role of "gamers" or "fans" and engaged in reasoning critically and analytically about the games they were studying. Our analysis of the students' GameLog entries supports the students' perceptions. We identified six common styles of entry: overview, narrative, comparative analysis, plan/hypothesis, experiment, and insight/analysis. These styles align with practices necessary for supporting learning and understanding. We propose that blogging about gameplay experience, as a reflective writing activity, can help lay the foundations on which further learning and understanding of games can happen.
Acetylcholine receptor channels in Xenopus myocyte culture; brief openings, brief closures and slow desensitization.

1. Single acetylcholine (ACh) receptor channel currents were analysed in Xenopus myocyte culture. Channel events activated by ACh were recorded using the cell-attached patch clamp technique at low temperatures (11.2-15.8 degrees C) and at 100 mV hyperpolarization over the average resting membrane potential of -75 mV. There were two types of channels, low- and high-conductance channels, as reported previously, with unitary current amplitudes 4.7 +/- 0.4 pA (mean +/- S.D., n = 17) and 6.6 +/- 1.2 pA (n = 14), respectively. 2. At low concentrations of ACh many brief openings (less than 1 ms in duration) were observed. Almost all of them occurred in isolation. The mean open time, which was not dependent on ACh concentration, was 63.1 +/- 18.1 microseconds (n = 15) for the low-conductance channel and 80.3 +/- 18.7 microseconds (n = 2) for the high-conductance channel. 3. Brief openings were frequently observed at 20 nM-ACh, at which concentration the frequency of longer openings (longer than 1 ms) was rare. The frequency of brief openings reached maximum at 50 nM-ACh and declined at high concentrations. The occurrence ratio between the long and brief openings increased linearly with ACh concentration. This finding suggests strongly that the brief openings are due to singly liganded receptor channels, since the long openings are most likely due to doubly liganded receptor channels. 4. A burst of openings was defined as a group of openings separated by brief closures (gaps) lasting less than 1 ms. The main component in the closed time histogram had a time constant of 25.0 +/- 5.1 microseconds (n = 16) for the low-conductance channel and 32.0 +/- 10.2 microseconds (n = 10) for the high-conductance channel. These values were not dependent on ACh concentration. The number of gaps per burst was 2.22 +/- 0.69 (n = 16) for the low-conductance channel and 0.85 +/- 0.23 (n = 9) for the high-conductance channel. The former is significantly greater than the latter. 5. During the recording from a single patch, the frequency of low-conductance channel events declined with time at all ACh concentrations, and the rate of decline was slower in the high-conductance channel in the same patch. The rate of decline was dependent linearly on the ACh concentration. It is most likely that this decline is due to desensitization of the receptors.(ABSTRACT TRUNCATED AT 400 WORDS)
A reliable method for measuring intensity fractions in two-phase NMR spectra

Abstract We describe a method of determining the fraction of intensity attributable to each constituent in an NMR spectrum consisting of two components having a common center and a width ratio of about 3 or greater. The method makes use of only two points in the integral of the absorption spectra for the unknown and both pure constituent components, and is free of systematic error. The method is tested and some applications are indicated.
Influenza Virus H1N1pdm09 Infections in the Young and Old: Evidence of Greater Antibody Diversity and Affinity for the Hemagglutinin Globular Head Domain (HA1 Domain) in the Elderly than in Young Adults and Children

The H1N1 2009 influenza virus (H1N1pdm09) pandemic had several unexpected features, including low morbidity and mortality in older populations. We performed in-depth evaluation of antibody responses generated following H1N1pdm09 infection of naive ferrets and of 130 humans ranging from the very young (0 to 9 years old) to the very old (70 to 89 years old). In addition to hemagglutination inhibition (HI) titers, we used H1N1pdm09 whole-genome-fragment phage display libraries (GFPDL) to evaluate the antibody repertoires against internal genes, hemagglutinin (HA), and neuraminidase (NA) and also measured antibody affinity for antigenic domains within HA. GFPDL analyses of H1N1pdm09-infected ferrets demonstrated gradual development of antibody repertoires with a focus on M1 and HA1 by day 21 postinfection. In humans, H1N1pdm09 infection in the elderly (>70 years old) induced antibodies with broader epitope recognition in both the internal genes and the HA1 receptor binding domain (RBD) than for the younger age groups (0 to 69 years). Importantly, post-H1N1 infection serum antibodies from the elderly demonstrated substantially higher avidity for recombinant HA1 (rHA1) (but not HA2) than those from younger subjects (50% versus <22% 7 M urea resistance, respectively) and lower antibody dissociation rates using surface plasmon resonance. This is the first study in humans that provides evidence for a qualitatively superior antibody response in the elderly following H1N1pdm09 infection, indicative of recall of long-term memory B cells or long-lived plasma cells. These findings may help explain the age-related morbidity and mortality pattern observed during the H1N1pdm09 pandemic.
Letter by Bachhuber and Lott Regarding Article, “Characteristics of Children Hospitalized With Infective Endocarditis”

To the Editor: A recent study by Day and colleagues1 describes the inpatient prevalence and associated characteristics of pediatric patients hospitalized for infective endocarditis using data extracted from the 2000 and 2003 Kids’ Inpatient Database (KID). As described by the authors, KID is a stratified survey sample …
Electric communication in the reproductive behavior of Sternopygus macrurus (Gymnotoidei).

Zusammenfassung Sternopygus macrurus, eine der dreizehn im Rupununi Distrikt von Guyana beheimateten Messeraal-Arten benutzt elektrische Signale im Fortpflanzungsverhalten. Sternopygus leben in steinigen und sandigen Bachen und kommen nachts aus ihren Verstecken. Ihre Laichzeit beginnt vor Eintritt der Regenzeit Ende April. Sternopygus hat langdauernde Entladungen mit kurzen Pausen, die im Lautsprecher einen summenden Ton ergeben (im Unterschied zu Arten mit kurzen Entladungen und langen Pausen, die “knattern”). Von den vier summenden Fischarten hat S. macrurus eine eigene Tonlage und Tonstarke. Ausgewachsene ♂♂ und ♀♀ erzeugen verschiedene Ruhe-Entladungen. In der Laichzeit reagieren ♂♂ auf Annaherung eines ♀ mit veranderten Entladungen. Diese scheinen ♀♀ anzulocken. Auch ♀♀ konnen ihre Entladungen variieren. Kunstlich uber Elektroden ins Wasser gespielte Sinus-Schwingungen mit ♀-Frequenz wurden von ♂♂ richtig beantwortet; auf ♂-Frequenz oder Frequenzen anderer Arten gab es keine Reaktion. Beobachtungen an zwei Sternopygus-Paaren ergaben, das die Individuen typische Entladungs-Frequenzen haben. Paarpartner konnen Frequenzen annehmen, die genau eine Oktave auseinander liegen.
Differential Activation by Restraint Stress of a Mechanism to conserve Brain Catecholamines and Serotonin in Mice differing in Excitability

THE relatively great reactivity of highly emotional animals must be correlated with neural function, but there seem to have been no previous reports of differential effects of stress on specific neurotransmitters in the brains of animals which differ in excitability. We have found that restraint stress can cause a greater elevation of brain catecholamines and serotonin in mice made hyperexcitable by 8–12 weeks of isolation than in their less excitable littermates housed in groups. This differential elevation of brain amines occurs in spite of the slower turnover of these neurotransmitters in isolated mice in normal non-stressed conditions1–3,6. Furthermore, after inhibition of catecholamine biosynthesis by α-methyltyrosine, stress facilitated the depletion of norepinephrine and dopamine in mice that had been kept isolated, but retarded their depletion in mice that had been housed in groups. It seems that restraint stress, which presumably imposes an increased demand for brain catecholamines and serotonin to maintain neurotransmission, rapidly activates a mechanism to conserve these amines and activates it to different degrees in mice which differ in emotional reactivity.
The location of olfactory receptors within olfactory epithelium is independent of odorant volatility and solubility

Our objective was to study the pattern of olfactory receptor expression within the dorsal and ventral regions of the mouse olfactory epithelium. We hypothesized that olfactory receptors were distributed based on the chemical properties of their ligands: e.g. receptors for polar, hydrophilic and weakly volatile odorants would be present in the dorsal region of olfactory epithelium; while receptors for non-polar, more volatile odorants would be distributed to the ventral region. To test our hypothesis, we used micro-transplantation of cilia-enriched plasma membranes derived from dorsal or ventral regions of the olfactory epithelium into Xenopus oocytes for electrophysiological characterization against a panel of 100 odorants. Odorants detected by ORs from the dorsal and ventral regions showed overlap in volatility and water solubility. We did not find evidence for a correlation between the solubility and volatility of odorants and the functional expression of olfactory receptors in the dorsal or ventral region of the olfactory epithelia. No simple clustering or relationship between chemical properties of odorants could be associated with the different regions of the olfactory epithelium. These results suggest that the location of ORs within the epithelium is not organized based on the physico-chemical properties of their ligands.
Effects of exciton-acoustic-phonon scattering on optical line shapes and exciton dephasing in semiconductors and semiconductor quantum wells

The interaction of excitons with acoustic phonons in direct band-gap semiconductors gives the dominant contribution to the temperature-dependent part of the exciton homogeneous linewidths and to dephasing rates at lower temperatures, e.g., below 150 K in bulk GaAs. Experimental results have shown that this contribution increases substantially in going from GaAs quantum wells to bulk GaAs. A perturbation treatment of acoustic phonon scattering in a simple band exciton model-i.e., neglecting valence-band coupling and anisotropy of exciton dispersion-agrees with experimental results in narrow quantum wells. On the other hand, it fails by an order of magnitude for bulk GaAs and by a large factor for other materials. Here we give a thorough theoretical discussion of this problem. The exciton linewidth is calculated to lowest order in the exciton-acoustic-phonon coupling including valence-band interactions and anisotropic exciton dispersion. The effects of multiple scatterings of phonons in higher orders of the exciton-phonon interactions are calculated and previous work on these effects are discussed. The effects of impurity motion from acoustic phonons on the exciton linewidths are evaluated. We conclude that the temperature-dependent exciton linewidth is given reasonably well by the lowest-order phonon scatterings provided that the full anisotropic exciton dispersion is included. Higher-order phonon scatterings give a small contribution to the linewidth and can affect the line shape. These results agree well with available experimental results for the low-temperature exciton linewidths in bulk GaAs and ZnSe and in quantum wells from these materials.
Polycyclic Aromatic Hydrocarbons and Digestive Tract Cancers: A Perspective

Cancers of the colon are most common in the Western world. In majority of these cases, there is no familial history and sporadic gene damage seems to play an important role in the development of tumors in the colon. Studies have shown that environmental factors, especially diet, play an important role in susceptibility to gastrointestinal (GI) tract cancers. Consequently, environmental chemicals that contaminate food or diet during preparation become important in the development of GI cancers. Polycyclic aromatic hydrocarbons (PAHs) are one such family of ubiquitous environmental toxicants. These pollutants enter the human body through consumption of contaminated food, drinking water, inhalation of cigarette smoke, automobile exhausts, and contaminated air from occupational settings. Among these pathways, dietary intake of PAHs constitutes a major source of exposure in humans. Although many reviews and books on PAHs and their ability to cause toxicity and breast or lung cancer have been published, aspects on contribution of diet, smoking and other factors toward development of digestive tract cancers, and strategies to assess risk from exposure to PAHs have received much less attention. This review, therefore, focuses on dietary intake of PAHs in humans, animal models, and cell cultures used for GI cancer studies along with epidemiological findings. Bioavailability and biotransformation processes, which influence the disposition of PAHs in body and the underlying causative mechanisms of GI cancers, are also discussed. The existing data gaps and scope for future studies is also emphasized. This information is expected to stimulate research on mechanisms of sporadic GI cancers caused by exposure to environmental carcinogens.
Materials chemistry and transport modeling for severe accident analyses in light-water reactors II: Gap processes and heat release

Several consequences of steam starvation of the gas filling the internals of the core of a light-water reactor in the fuel-uncovery phase of a severe accident up to cladding melting are analysed. Emphasis is placed on processes that occur in the H2-rich gas external to the fuel rod cladding; absorption of oxygen and hydrogen by the cladding; the composition and flow rates of gas in the fuel-cladding gap; and the response of the fuel to these conditions. The transport processes and chemical reactions in the cladding, and the fuel controlled by the behavior of the gas in the gap are modeled for a simple temperature transient characteristic of a severe fuel damage accident in a light-water reactor. Cladding burst is assumed to occur at 1273 K at the midplane elevation of the fuel rod, permitting the gas in the gap to come into contact with that external to the fuel rod. The results of the analysis include the following. Steam ingress is restricted to a few centimeters from the failure site by the gettering action of the metal-water reaction on the cladding inner wall. Hydrogen moves axially into the gap only a few times further than steam by diffusion in the Xe-He mixture. The chief process restricting H2 ingress is the backflow resulting from thermal expansion of the gas in the fuel rod as the temperature rises. When the protective ZrO2 scale on the outer surface of the cladding disappears by dissolution in the metal, hydrogen permeation through the cladding wall rapidly replaces the inert gas in the gap with H2. Hydrogen uptake by the cladding draws gas into the core region from the upper plenum and augments the heat release by the metal-water reaction. Exposure of the fuel to this H2-rich gas results in minor fuel reduction and accompanying cladding oxidation.
Mapping tRNA structure in solution using double-strand-specific ribonuclease V1 from cobra venom

A method for mapping all base-paired stems in both elongation and initiator tRNAs is described using double-stranded-specific ribonuclease V1 from the venom of the cobra Naja naja oxiana. 32p-end-labeled RNA is first partially digested with double-strand-specific V1 nuclease under near physiological conditions, and the resultant fragments are than electrophoretically fractionated by size in adjacent lanes of a polyacrylamide gel run in 90% formamide. After autoradiography, the base-paired nucleotides are definitively located by comparing V1 generated bands with fragments of known length produced by both Neurospora endonuclease and base-specific ribonucleases. Using the substrates yeast tRNAPhe an E, coli tRNAfMet of known three-dimensional structure, we find V1 nuclease to cleave entirely within every base-paired stem. Our studies also reveal that nuclease V1 will digest paired nucleotides not hydrogen-bonded by standard Watson-Crick base-pairing. In yeast tRNAPhe cleavage of both wobble base-pairs and nucleotides involved in tertiary base-base hydrogen bonding is demonstrated.
Bronchoselective actions of a new series of trimetoquinol analogues

In selected beta 1- (guinea pig atrial) and beta 2- (guinea pig trachea and lung parenchyma) adrenoceptor systems, we have examined the interaction of isoproterenol (ISO), trimetoquinol (TMQ), erythro- and threo-diastereoisomers of 1-(3,4,5-trimethoxy-alpha-methylbenzyl)-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (alpha-methylTMQ), alpha-dimethylTMQ, N-methylTMQ and N-[2-methyl-2-(3,4,5-trimethoxyphenyl)propyl]dopamine (open chain dimethylTMQ analogue). The rank order of potency for agonists in trachea was threo-alpha-methylTMQ greater than (+/-)-TMQ greater than ISO greater than erythro-alpha-methylTMQ greater than N-methylTMQ greater than alpha-dimethylTMQ. Only N-methylTMQ gave an intrinsic activity similar to ISO, whereas the alpha-methylated TMQ analogues were partial agonists in this beta 2-system. In atria, the rank order of beta 1-potency was ISO greater than (+/-)-TMQ greater than threo-alpha-methylTMQ greater than N-methylTMQ = erythro-alpha-methylTMQ. Maximal chronotropic effects of all compounds, with the exception of threo-alpha-methylTMQ, were similar to ISO in this preparation. Both alpha-dimethylTMQ and open chain dimethylTMQ analogues were inactive as agonists in this beta 1-system. The ratio of beta 2 : beta 1 selectivity (trachea vs. atria), relative to ISO for threo-alpha-methylTMQ, erythro-alpha-methylTMQ, TMQ and N-methylTMQ was 106.5, 27, 7 and 5.8, respectively. Whereas the rank order of potency for selected compounds in lung parenchyma was ISO greater than threo-alpha-methylTMQ = TMQ greater than erythro-alpha-methylTMQ, the comparative beta 2-selectivity (lung parenchyma vs. atria) relative to ISO, for erythro-alpha-methylTMQ, threo-alpha-methylTMQ and TMQ was 2.5, 1.9 and 0.24, respectively. It is concluded that lipophilic substitutions on the alpha-carbon of the 1-(3,4,5-trimethoxybenzyl)-substituent of TMQ can generate compounds which are potent bronchoselective adrenoceptor agonists. Threo-alpha-methylTMQ and erythro-alpha-methylTMQ were more beta 2-selective than (+/-)-TMQ.
Public/private-sector cooperation in urban transportation: Lessons from ridesharing experiences in Connecticut

An important characteristic of urban transportation policy and planning today is the increasing role that the private sector is playing in identifying and implementing transportation projects. For example, a recent examination of the possible forms of such involvement found that there were four major categories of action that could be used to classify recent private-sector efforts in urban transportation: (1) aid to and/or provision of transportation services; (2) formation of advocacy or advisory groups whose purpose is to influence public policy; (3) sponsorship of transportation studies; and (4) provision of management assistance to public agencies (Gordon, 1982). In many of these efforts, the successful implementation of a project or program required close cooperation between public and private-sector officials. The purpose of this paper is to examine the characteristics of this interaction and explore the implications for transportation planning and policy.
Lactoferrin and transferrin: a comparative study.

The optical and electron paramagnetic resonance (EPR) spectroscopic parameters which characterize the two metal-binding sites of lactoferrin are strikingly similar to those of transferrin. Ultraviolet difference spectra indicate the involvement of tyrosyl residues in iron binding, while EPR studies of the Cu(II)-lactoferrin-bicarbonate complex demonstrate the presence of at least one nitrogen ligand at each metal-binding site. However, the K1 for Fe(III) binding as obtained by equilibrium dialysis and corrected for H+ effects, is 300 times larger for human lactoferrin (measured near pH 6.4) than for human transferrin (measured near pH 6.7). Fe(III) binding to both proteins appears to involve equivalent and non-interacting sites. The disulfide structure of lactoferrin and transferrin also appear to be similar, as shown by gel-filtration studies. This, together with the nearly identical molecular weights of the proteins, their single-chain nature, metal-binding sites, corroborate the suggestion that the transferrins and lactoferrins constitute a single class of proteins evolving from a common ancestral protein.
Ferroelectrics and their Memory Applications

For information storage purposes, BaTiO 3 single crystals were grown, and typical data of the product are presented. Storage condensers using multidomain and c-domain crystals as a dielectric were produced. Memory as well as switching properties were studied with particular reference to their application in a multicondenser memory matrix. A method for testing bistable storage condensers was developed; typical data are presented. A gated, bidirectional pulse transformer circuit was developed, providing pulses of opposite polarity for writing and reading on the matrix leads. This circuit permits increase of the absolute ratio of matrix switching pulses from 2 to 1 to 3 to 1. Sequential, random or simultaneous sequential- and random-scanning of a multicondenser matrix are equally practical.
Theory of the broadening of vibrational spectra induced by lowered symmetry in yttria nanostructures

We calculate the vibrational spectra for typical nanostructures including thin films, nanowires, and quantum dots of yttria, an important laser host material. Lattice dynamics calculations show that the vibrational spectra of nanocrystals are distinct from that of the bulk phase in the enhanced tails at low and high frequencies. Some of the low-frequency and high-frequency modes only involve surface atoms. Molecular-dynamics simulations are used to further decompose the contributions of surface and internal atoms, and the results confirm the evident broadening of the surface spectra. The broadening in vibrational spectra is attributed to the broadened atomic spring constants, further to the lowered symmetry of nanostructures.
The Efficacy of Stuttering Measurement Training: Evaluating Two Training Programs.

Purpose Two stuttering measurement training programs currently used for training clinicians were evaluated for their efficacy in improving the accuracy of total stuttering event counting. Method Four groups, each with 12 randomly allocated participants, completed a pretest–posttest design training study. They were evaluated by their counts of stuttering events on eight 3-min audiovisual speech samples from adults and children who stutter. Stuttering judgment training involved use of either the Stuttering Measurement System (SMS), Stuttering Measurement Assessment and Training (SMAAT) programs, or no training. To test for the reliability of any training effect, SMS training was repeated with the 4th group. Results Both SMS-trained groups produced approximately 34% improvement, significantly better than no training or the SMAAT program. The SMAAT program produced a mixed result. Conclusions The SMS program was shown to produce a “medium” effect size improvement in the accuracy of stuttering event counts, an...
Elastic interactions of point defects in a semi-infinite medium

Abstract Two problems involving the elastic interactions of point defects in a semi-infinite, isotropic elastic medium, bounded by a planar, stress-free surface, have been solved. The first is the determination of the energy of interaction of a point defect with the surface. The point defect is represented by the superposition of three, mutually perpendicular, double forces without moment, of unequal strength, one of which is perpendicular to the plane of the surface. The interaction energy is negative and decreases as the inverse third power of the distance of the defect from the surface. The second problem solved is the determination of the energy of interaction of two such defects. In the case that both defects are isotropic (the three double forces without moments have equal strengths) there is no interaction at a distance between these two defects in an infinitely extended medium. In the presence of a surface, however, they interact with an energy that varies as the inverse cube of the function [(x ∥ (1) − x ∥ (2) ) 2 + (x 3 (1) + x 3 (2) ) 2 ] 1 2 , where (x ∥ (1) , x 3 (1) ) and (x ∥ (2) , x 3 (2) ) are the positions of the two defects, and which can be attractive or repulsive depending on the relative orientation of the two defects. In both cases the results are obtained analytically, in closed form, by a Green function approach.
Complex instructional analogies and theoretical concept acquisition in college genetics

This study investigated the role of complex instructional analogies on concept acquisition in an introductory college genetics course. The question of whether concept acquisition can be facilitated by use of complex instructional analogies was addressed using an experimental treatment and control group design. The experimental and control group students were administered a pretest of scientific reasoning and genetics knowledge to be used as covariates. The role of complex analogies on student attitude was also evaluated. Experimental treatment included complex instructional analogies. The control group received expository instruction alone. Achievement was assessed by use of eight weekly quizzes. Significant differences in student achievement were found in favor of the experimental group. However, the analogies did not appear to overcome the need for higher-order reasoning skills as the more skilled experimental group students performed significantly better than their less skilled peers. The attitude survey indicated that the majority of experimental group students believed that analogy-based instruction was beneficial. © 2001 John Wiley & Sons, Inc. Sci Ed85:665–683, 2001.
Computer expert systems for African-American smokers in physicians offices: a feasibility study.

Abstract Background. Stage-based computer expert systems (CES), delivered in physician offices, may offer unique opportunities to combine high participation and high efficacy, resulting in a high public health impact. Applying this technology in settings serving low-income African–American smokers, with the addition of practical tools for stress reduction, may help to reduce disparities in morbidity and mortality from smoking-related diseases. Methods. Ninety-eight African–American smokers were recruited from a publicly funded, continuity care clinic waiting room to a study of computer interactive feedback and stress reduction audiotapes. The study was designed to assess: participation and retention rates; acceptability of both the computer expert system and the audiotapes; the fit of the transtheoretical model for the target population; and the 6-month shift in stages of change. Results. Overall, 55.6% of invited smokers participated, 75.5% were seen at all three observation points. The CES and the audiotape were rated as highly interesting, relevant, and new, and most participants tried them. The predictable relationship between stage and decisional balance was reproduced in this low income African–American population. Significant stage progression occurred from baseline to 3 months (P = 0.011), from 3 to 6 months (P = 0.0001), and from baseline to 6 months (P = 0.0001). Conclusions. These data support the feasibility, acceptability and potential efficacy of stage-tailored computer interactive feedback plus stress reduction intervention delivered at the point of service to low-income African–Americans.
Effects of Chronic Lead Exposure on Cocaine-induced Disturbance of Fixed-interval Behavior

Abstract Chronic lead exposure has been shown to attenuate cocaine-induced increases in extracellular dopamine levels in the region of the nucleus accumbens, and antagonize the locomotor stimulating effects of the drug. The purpose of this study was to determine if similar lead-induced disturbances in the effects of cocaine include the impact of the drug on schedule-controlled responding. Adult male rats exposed ad libitum to water containing 500 ppm lead acetate (Group Lead), or a comparable concentration of sodium acetate (Group Control), were placed on a restricted diet (12–15 g food/day) prior to commencing fixed-interval (FI-5 min) schedule training on Day 33 of exposure. After 27 days of operant training, animals received a sequence of no injection, saline injection, and cocaine injection tests, repeating the sequence for 3, 10, 20 and 40 mg/kg cocaine HCl (ip). Local rates were determined for successive 30 s segments of the interval and the pattern of responding was compared under conditions of saline and cocaine injection. For both groups, cocaine increased responding, especially early in the interval. However, the rate enhancing effects of cocaine were less pronounced in lead-exposed animals than controls, at least at the 20 mg/kg dose. These data extend earlier findings and accent the need to examine further the interactive relations between the external chemical environment and drug sensitivity.
Creating new citizens: freed slaves, the state and citizenship in early Rome and under Augustus

In the first year of the Republic there was a conspiracy which failed because a slave reported it to the authorities. As a reward he received a sum of money and was granted his freedom as well as Roman citizenship. The historian Livy claims that this was the first time a slave was freed through the procedure of manumissio vindicta, and that the ceremony derived its name from the slave in question: Vindicius. Many scholars have pointed out that the story is unlikely to be historically accurate. Instead of demonstrating the accuracy or inaccuracy of Livy's story, however, the present study wants to suggest that in addition to providing an etymological explanation for a key procedure in the manumission of slaves Livy may have aimed to present the story as a specific deserving case of the granting of freedom and citizenship. This should be understood against the backdrop of the turbulent times that Livy's readers had recently experienced and the attempts by Augustus to re-energize Rome's destiny on the firm f...
Social Inequality and Art Institutions

Our objective is to examine how several aspects of the class structure influence the prevalence of artistic institutions. The analysis is based on quantitative comparisons of the 125 largest metropolitan areas in the United States. Most of the literature on the history of art concludes that artistic developments depend on the patronage of an elite—as noble patrons, as rich donors, or even as affluent bourgeois donors and audiences. Whereas these conclusions imply that class inequalities further the growth of the arts, our empirical findings indicate the opposite. Both lesser inequality and reductions of inequality in a metropolis increase a variety of artistic institutions, and these influences persist when other influences on these institutions are controlled.