cssi/SciSciGPT-SciSciNet huggingface dataset:
Fabrication and Characterization of a Solid State Reference Electrode for Electroanalysis of Natural Waters with Ultramicroelectrodes

As an alternative to standard commercial reference electrodes, a solid state reference electrode is fabricated for in situ voltammetric analysis in solutions containing little or no added supporting electrolyte. In the fabrication process, a Ag/AgCl wire is coated with an electrolyte immobilized and protected with Nafion or polyurethane. The electrode potential is measured as a function of time, ionic strength, and pH. A stable potential is obtained for Nafion and polyurethane within 30−35 min in water. Both the polyurethane and Nafion solid state reference electrodes are stable for at least 90 days, but the Nafion electrode fluctuates more than the polyurethane electrode. The electrode is demonstrated using square wave anodic stripping voltammetry at a large electrode (3 mm), an ultramicroelectrode (10 μm), and an array of ultramicroelectrodes.
The isoperimetric inequality and rational approximation

Etude d'une nouvelle approche de l'inegalite isoperimetrique par la formule de Stokes complexe et la theorie de l'approximation rationnelle
Short-time behavior of mixed diffusion-barrier controlled adsorption

This paper focuses on the short-time adsorption kinetics of nonionic surfactants onto water/air surfaces, analyzed in the context of the mixed diffusion-barrier controlled adsorption modeling framework. Specifically, we reconcile the apparent contradiction between theoretical prediction and experimental observations on the adsorption kinetics mechanism at short times: while the mixed diffusion-barrier controlled model predicts a barrier-controlled adsorption, as well as the impossibility of a diffusion-controlled adsorption at asymptotic short times, the short-time experimental dynamic surface tension (DST) behavior of many nonionic surfactants has been interpreted to result from diffusion-controlled adsorption at asymptotic short times. This is because the short-time experimental DST of these surfactants displays a t variation, which is considered as a fingerprint for the existence of diffusion-controlled adsorption, based on the short-time asymptotic behavior of the diffusion-controlled adsorption model. As a result of this interpretation, the fundamental physical nature of the energy barrier has been proposed to be associated with high surfactant surface concentrations. In this paper, we derive a new nonasymptotic short-time formalism of the mixed diffusion-barrier controlled model to describe surfactant adsorption onto a spherical pendant-bubble surface, including determining the ranges of time and surfactant surface concentration values where the short-time formalism is applicable. Based on this formalism, we find that one can expect to observe an apparent t variation of the DST at short times even for the mixed diffusion-barrier controlled adsorption model. We analyze the consequence of this finding by re-evaluating the existing notions of the energy barrier. We conclude that the energy barrier is associated with the adsorption of a single surfactant molecule onto a clean surface.
Learning Bridge Tool to Improve Student Learning, Preceptor Training, and Faculty Teamwork

Objectives. To implement a Learning Bridge tool to improve educational outcomes for pharmacy students as well as for preceptors and faculty members.Design. Pharmacy faculty members collaborated to write 9 case-based assignments that first-year pharmacy (P1) students worked with preceptors to complete while at experiential sites.Assessment. Students, faculty members, and preceptors were surveyed about their perceptions of the Learning Bridge process. As in our pilot study,1 the Learning Bridge process promoted student learning. Additionally, the Learning Bridge assignments familiarized preceptors with the school's P1 curriculum and its content. Faculty teamwork also was increased through collaborating on the assignments.Conclusions. The Learning Bridge assignments provided a compelling learning environment and benefited students, preceptors, and faculty members.
Effects of forced oscillations on spectral-based mode-shape estimation

The impact of forced oscillations on estimating electromechanical mode-shape from time-synchronized phasor measurements is assessed. The mode-shape algorithm is mathematically derived while including a forced-oscillation component. This provides a basis of a hypothesis of how the forced oscillation impacts the algorithm. The hypothesis is tested via a four-machine simulation.
Home cage behavior and lead treatment in rhesus monkeys : a comparison with open-field behavior

Nursery-reared rhesus monkeys were treated with no (n = 4) or moderate levels of lead (n = 4) during the first postnatal year. Mean blood lead levels peaked at 55 micrograms/dl at 5 weeks of age, averaged 36 micrograms/dl for the remainder of the first year postpartum, and declined to < or = 5 micrograms/dl for the 4 monkeys by 2.3 years of age. Previously, the lead-treated monkeys exhibited increased environmental exploration and decreased inactivity in a nonhuman primate version of the open field when tested at 4, 5, and 6 years of age (5,6). The current study was designed to assess behavior in the home cage of these monkeys at 6 years of age to determine: (a) whether the increased exploration was specific to the open field, and (b) any lead-related behavioral alterations specific to the home cage. Each monkey was observed twice weekly for 10 weeks and the duration and frequency of 17 behaviors were recorded. Lead treatment did not result in significant alterations in any of the six behaviors which occurred with enough frequency to warrant analysis. As a whole, all monkeys were either inactive or engaged in self-grooming for a large proportion of the test session. Less frequent were behaviors such as locomotion, environmental exploration, and self-directed behaviors. The distribution of behavioral activities in the home cage differed from that in the open field. Potential reasons for the expression of significant lead-related effects in the open field and not in the home cage are discussed as well as the differences in distribution of behavioral activities.
Endothelins and their role in hypertension

Endothelin is a naturally occurring polypeptide substance with potent vasoconstrictive actions. It is produced from endothelial as well as non-endothelial cells. There are three closely related isoforms: endothelin-1, −2 and −3 (ET1, ET2 and ET3). The receptors for endothelin have been isolated and their genes cloned. Two receptors, called ET A and ET B , and having different affinities for the different endothelin isoforms, are well characterized. The different distribution of endothelin receptors in various tissues is responsible for the multiplicity of actions attributed to endothelin. Endothelin released from endothelial cells has local paracrine and autocrine effects on smooth muscle cells. It appears to be contributory to the pathophysiology of systemic hypertension, atherosclerosis, myocardial ischaemia, left ventricular dysfunction and congestive heart failure, ventricular hypertrophy, renal failure and pulmonary hypertension. Elevations of endothelin in the blod may also be markers of disease. Active research and drug development programmes are evaluating endothelin receptor inhibitors and endothelin-converting enzyme inhibitors for the treatment of patients with various cardiovascular, cerebrovascular, pulmonary vascular and renal diseases. Available agents such as potassium ion channel openers, calcium entry blockers and angiotensin-converting enzyme inhibitors also interfere with endothelin activity.
Augmenting major histocompatibility complex class I expression by murine tumors in vivo enhances antitumor immunity induced by an active immunotherapy strategy.

Abstract Objective Tumors down-regulate major histocompatibility complex class I expression, escaping recognition by the cellular immune response. We hypothesized that augmentation of tumor cell class I expression by interferon-gamma would enhance the cellular antitumor immune response and cure rate of an active immunotherapy strategy. Methods B16.F10 tumor cells were exposed to interferon-gamma in culture, and class I expression was quantified using flow cytometry. Syngeneic mice bearing established tumors were injected with interferon-gamma (5000 U, intraperitoneal), and class I expression was assessed using immunohistochemistry. Tumor-specific cytotoxic T lymphocytes were induced in mice by an intratumoral injection of AdCD40L (5 × 10 10 particles), an adenovirus gene transfer vector-based immunotherapy strategy previously demonstrated to augment cellular antitumor immunity. A conjugate-formation assay and the enzyme-linked immunospot assay were used to evaluate the binding and activation of cytotoxic T lymphocytes, respectively. Interferon-gamma was administered to tumor-bearing mice concomitantly with intratumoral AdCD40L. End points measured included the frequencies of cytotoxic T lymphocytes using the enzyme-linked immunospot assay, tumor size, and mouse survival. The role of class I expression was further evaluated by monoclonal antibody blockade in both in vitro and in vivo experiments. Results B16.F10 cells exposed to interferon-gamma expressed significantly more class I, both in vitro and in vivo, and were able to bind to and activate cytotoxic T lymphocytes more efficiently than untreated cells. Cytotoxic T-lymphocyte frequencies, tumor regression, and the cure rate induced by AdCD40L were augmented by the addition of a single dose of interferon-gamma in tumor-bearing mice. These in vitro and in vivo effects of interferon-gamma were attenuated by class I monoclonal antibody blockade. Conclusions Up-regulation of class I expression using interferon-gamma enhances the cellular antitumor immune response and cure rate of AdCD40L, an active immunotherapy strategy. This approach may be useful for human tumors that lack class I expression.
Adolescent Self-Reports and Religiosity

The Brownfain Self-rating Inventory and Religiosity Index were administered to high school juniors, 46 males and 66 females. Correlations between scores on the two inventories were significant for males (.41, p < .01) but not for females (r = .22). Subjects were divided into high and low groups on the Self-rating Inventory (self-concept). The high group scores were .5 SD above the mean and low group .5 SD below. Mean differences on the Religiosity Index for two groups were significant for males (p < .01) but not females. Results suggest that male adolescents with positive self-reports score higher on religiosity than those with low self-reports but not female adolescents.
Note on Quenching of Photoconductivity in Cadmium Sulfide

The spectral distribution of quenching of the photoconductivity in cadmium sulfide crystals has been investigated. The process is interpreted as excitation of trapped holes by the quenching radiation, followed by thermal ionization to the filled band. Freeing of trapped electrons does not appear important. Two peaks in the quenching spectrum occur at hν=1.5 and 0.9 ev and are attributed to different hole traps. Transient changes in photoconductivity on application or removal of radiation in the red are shown to arise from simultaneous excitation and quenching processes with different time dependences. As a consequence, the quenching spectrum can be followed for some distance into the excitation region and vice versa.
Genome-assisted analysis of dissimilatory metal-reducing bacteria

The availability of whole genome sequences for Shewanella oneidensis and Geobacter sulfurreducens has provided numerous new biological insights into the function of these model dissimilatory metal-reducing bacteria. Many of these findings, including the identification of a high number of c-type cytochromes in both organisms, have resulted from comparative genomic analyses, and several have been experimentally confirmed. These genome sequences have also aided the identification of genes important for the reduction of metal ions and other electron acceptors utilized during anaerobic growth, by facilitating the identification of genes disrupted by random insertions. Technologies for assaying global expression patterns for genes and proteins have also been employed, but their application has been limited mainly to the analysis of the role of global regulatory genes and to identifying genes expressed or repressed in response to specific electron acceptors. It is anticipated that details of the mechanisms of metal ion respiration, and metabolism in general, will eventually be revealed by comprehensive, systems-level analyses enabled by functional genomics data.
Concentration and timing dependence of lethality enhancement between topotecan, a topoisomerase I inhibitor, and ionizing radiation.

Purpose : Topotecan (TPT) is a water-soluble Topoisomerase I (Topo I) inhibitor with reported antineoplastic activity against a variety of solid tumors (including nonsmall cell lung, small cell lung, ovarian, breast, esophageal, and head and neck primaries) and leukemias. We sought to determine : (a) if TPT enhanced the lethal effects of ionizing radiation ; and (b) the biological and biochemical characteristics of the enhancement. Methods and Materials : Quiescent human radioresistant melanoma (Ul-Mel) cells were x-irradiated (1-12 Gy) and exposed to various TPT concentrations (0.1-300 μM) either before (for 4 h), during, or after (for 4 h) radiation. Survival was determined via colony forming assays and normalized to correct for drug cytotoxicity. The effects of TPT on radiation-related potential lethal damage repair (PLDR) and sublethal damage repair (SLDR) were measured. A modification of the SDS-KCI assay was used to quantify DNA-Topo I complexes. Results : Enhanced radiation lethality by TPT was observed using quiescent U1-Mel cells. The sensitizer enhancement ratio (SER) after a 4 h postirradiation exposure of 4 μM TPT was 1.6 at 10% survival. The effect was : (a) dependent on drug concentration, with lethality enhancement and minimal drug lethality alone in the 2-10 μM range for a 4 h posttreatment ; (b) dependent on timing, with enhancement observed only when drug was present at the time of, or shortly after, radiation ; and (c) irreversible, with inhibition of PLDR and SLDR. Exposure to TPT during or after radiation substantially elevated DNA-Topo I complexes (four- to tenfold) over control levels and complex formation correlated to some degree with loss of survival. Conclusions : TPT enhanced radiation lethality in vitro at low drug concentrations that are clinically feasible. The rationale and design of an ongoing Phase I trial which utilizes concurrent TPT and radiation is discussed.
Microspore embryogenesis and the development of a double haploidy protocol for cow cockle (Saponaria vaccaria).

Factors affecting microspore embryogenesis of cow cockle (Saponaria vaccaria) were evaluated including donor plant growing conditions, genotype, bud size, density, medium composition, and culture conditions. Of the two donor plant (day/night) temperature regimes evaluated (10/5°C and 20/15°C), plants grown at 20/15°C were the most embryogenic. An embryogenic frequency of greater than 350 embryos/100 buds was observed in the most embryogenic genotype, cv. ‘White Beauty’. Buds from 3–9 mm in length were evaluated for their embryogenic potential; buds that were 4–7.9 mm produced the most embryos/100 buds. Of all the media compositions evaluated, NLN medium with 15% sucrose resulted in the most embryos. Cow cockle microspores required an initial period of 32°C for 3 days for production of microspore-derived embryos (MDEs).
Dual diffusions, killed diffusions, and the age distribution problem in population genetics

Abstract A method is given for justifying some recent approaches to the definition of the age of an allele in two-allele diffusion-type population genetic models. The method uses the notion of the dual of a diffusion, and introduces naturally an interesting application of killed diffusions. Many results in the literature are shown to be special cases of this approach.
Exploiting partial operand knowledge

Conventional microprocessor designs treat register operands as atomic units. In such designs, no portion of an operand may be consumed until the entire operand has been produced. In practice, logic circuits and arithmetic units that generate some portion of an operand in advance of the remaining portions are both feasible and desirable, and have been employed in several existing designs. We examine existing and new approaches for exploiting early partial knowledge of an instruction's input operands for overlapping the execution of dependent instructions and resolving unknown dependences. In particular, we study three applications of partial operand knowledge: disambiguating loads from earlier stores, performing partial tag matching in set-associative caches, and resolving mispredicted conditional branches. We find that each of these is feasible with partial input operands. With the goal of fully exploiting this characteristic, we propose and evaluate a bit-sliced microarchitecture that decomposes a processor's datapath into 16- and 8-bit slices. We find that a bit-slice design using two 16-bit slices achieves IPC within 1% of an ideal design and attains a 16% speed-up over a conventional pipelined design not using partial operands
Induction of murine immune responses by DNA encoding a 23-kDa antigen of Cryptosporidium parvum

Cp23 has been identified as one of the immunodominant antigens involved in the immune response to Cryptosporidium parvum infection. Thus, in this study, Cp23 antigen was investigated as a vaccine candidate using the DNA vaccine model in adult interleukin-12 (IL-12) knockout (KO) mice, which are susceptible to C. parvum infection. Our data show that subcutaneous immunization in the ear with DNA encoding Cp23 (Cp23-DNA) cloned into the pUMVCb4 vector induced a significant anti-Cp23 immunoglobulin G1 (IgG1) and IgG2a antibody response and specific in vitro spleen cell proliferation to recombinant Cp23 as compared to control mice. Long-term memory responses were also detected after administration of the Cp23-DNA vaccine. Furthermore, Cp23-DNA vaccination induced a 50–60% reduction in oocysts shedding, indicating a partial protection against C. parvum infection in IL-12 KO mice. However, it is possible that this protective response was nonspecific because mice immunized with vector only also exhibited lower oocyst shedding than the naive controls. These results suggest that DNA encoding for immunodominant C. parvum antigens may provide an effective means of eliciting humoral and cellular responses and possibly in generating protective immunity against C. parvum infections in mammals.
Interparticle forces and lift on a particle attached to a solid boundary in suspension flow

The lattice Boltzmann method is used to simulate the shear flow field around a stationary particle attached to a solid boundary. One or more freely flowing (suspended) particles are introduced in the flow and are allowed to move, subject to the gravity force and the induced hydrodynamic force. Periodic conditions on the side boundaries assure that the same number of particles always remains in the computational domain. The total force exerted on the stationary particle is computed during the whole simulation process and resolved as the drag and lift components. By comparing these components of the hydrodynamic force before and after the freely flowing particles are introduced in the flow field, we determine the effect of suspended particles on a stationary particle. The results show that, even in the absence of particle collisions, the hydrodynamic force developed on the stationary particle is significant enough to induce the resuspension process if this particle were free to move.
SR-Mitochondrial Ultrastructure in the Heart of Normal and Ethanol-Fed Rats

Chronic alcoholism causes various forms of stress in the heart, and this is often accompanied by mitochondrial dysfunction. A putative source of mitochondrial dysfunction is SR-mitochondrial stress and the ensuing mitochondrial Ca2+ overload. To test this possibility, first we isolated mitochondria from chronic ethanol-fed (6 months) and paired control rats, and documented ethanol-dependent sensitization to Ca2+ and ROS-induced permeabilization. To evaluate the ultrastructural basis of the mitochondrial impairments, we performed transmission electron microscopy (TEM) and electron tomography studies of left ventricular muscle. The overall ultrastructure of the myocytes became less organized in the ethanol-fed condition. Also, a considerable fraction of the mitochondria lost the highly ordered structure of the cristae and showed an increase in the cross-sectional area. However, the size of the SR-mitochondrial associations and the gap-width at the interface was unchanged. Evaluation of the SR-mitochondrial tethers by electron tomography indicates that they occur in clusters and display heterogeneity in length, as previously reported for ER-mitochondrial tethers in normal rat liver (Csordas et al, 2006, J Cell Biol, 174:915). Overall tether length distribution appears to be unaltered by alcohol ingestion. Analyses of effects of alcohol ingestion on tether membrane-surface density and structural classes (linear, V, Y and more complex shapes) is in progress, as is 3D analysis of SER and mitochondrial inner- and outer-membrane topologies. (Supported by NIH grant 1RC2AA019416.)
H2SO4/(NH4)2SO4 background aerosol: optical detection in St. Louis region.

Abstract Atmospheric H 2 SO 4 present as droplets of the free acid and the half neutralized acid, NH 4 HSO 4 mixed with other substances have proved difficult to identify by traditional air sampling methods and ionic analyses. Knowledge of their existence as a major or minor fraction of atmospheric aerosol is important to studies of health effects of air pollution, atmospheric optics, acid rain and to understanding the global sulfur cycle. The in situ method reported here utilizes a light scattering/humidity relation to detect reaction of the aerosol with NH 3 to form the deliquescent salt (NH 4 ) 2 SO 4 . Field measurements in and near Saint Louis, Missouri, confirm that H 2 SO 4 and/or NH 4 HSO 4 are frequently present as a major fraction ( ca. 1/2 or more) of the submicrometer particles, and that (NH 4 ) 2 SO 4 also is frequently found. At one site 35 km W.S.W. of the Arch, over 98 per cent of the measurements were dominated by H 2 SO 4 or its neutralization products and showed no dependence on wind direction or synoptic condition, thus indicating a regional as opposed to urban behavior. While the results to date are qualitative and semi-quantitative in nature, it appears possible to utilize gas phase titration with NH 3 to quantify the method.
Between Authors and Agents: Gender and Affirmative Culture in Das Leben der Anderen

Criticisms of Donnersmarck's highly successful film Das Leben der Anderen (2006) have focused primarily on historical inaccuracies, but the issues at stake in the film have little to do with the reality of life in the GDR and far more with the film's self-legitimation within a humanist aesthetic tradition. I argue that the film's semiotics of gender—which ascribe to the masculine the qualities of spirit, intellect, and reason, and to the feminine the qualities associated with materiality and corporeality—form the cornerstone of a manifesto for affirmative culture that, surprisingly, even enlists Brecht in order to create a consensus on the apolitical timelessness of art. The vanishing of the feminine at the end of the film coincides with play wright Dreyman's turn to the novelistic form, which eschews the problematic feminine vehicle (Sieland as actress) and allows direct communication between the minds of agent Wiesler and author Dreyman.
Cocaine Cues Drive Opposing Context-Dependent Shifts in Reward Processing and Emotional State

Background Prominent neurobiological theories of addiction posit a central role for aberrant mesolimbic dopamine release but disagree as to whether repeated drug experience blunts or enhances this system. Although drug withdrawal diminishes dopamine release, drug sensitization augments mesolimbic function, and both processes have been linked to drug seeking. One possibility is that the dopamine system can rapidly switch from dampened to enhanced release depending on the specific drug-predictive environment. To test this, we examined dopamine release when cues signaled delayed cocaine delivery versus imminent cocaine self-administration. Methods Fast-scan cyclic voltammetry was used to examine real-time dopamine release while simultaneously monitoring behavioral indexes of aversion as rats experienced a sweet taste cue that predicted delayed cocaine availability and during self-administration. Furthermore, the impact of cues signaling delayed drug availability on intracranial self-stimulation, a broad measure of reward function, was assessed. Results We observed decreased mesolimbic dopamine concentrations, decreased reward sensitivity, and negative affect in response to the cocaine-predictive taste cue that signaled delayed cocaine availability. Importantly, dopamine concentration rapidly switched to elevated levels to cues signaling imminent cocaine delivery in the subsequent self-administration session. Conclusions These findings show rapid, bivalent contextual control over brain reward processing, affect, and motivated behavior and have implications for mechanisms mediating substance abuse.
Distribution of type VI collagen in human gliomas: comparison with fibronectin and glioma-mesenchymal matrix glycoprotein.

The distribution of type VI collagen was examined immunohistochemically in normal tissues and in 24 human gliomas and six medulloblastomas. Its localization in the neoplasms was compared with that of fibronectin and gliomamesenchymal extracellular matrix (GMEM) glycoprotein. In normal non-neural tissues type VI collagen was demonstrated in the interstitial connective tissue and in some basement membranes. In normal brain it was localized to the vasculature, leptomeninges, and pial-glial membrane. In neoplasms type VI collagen and fibronectin codistributed in the vasculature and stromal connective tissue. The GMEM glycoprotein, as identified by monoclonal antibody (MAb) 81C6, and a related gliomamesenchymal matrix antigen identified by MAb 2A6 , were expressed not only in the tumor vasculature and connective tissue, but also within the tumor parenchyma in association with glioma cells. The staining intensity was variable in 20 malignant gliomas and weak to absent in two pilocytic astrocytomas and six medulloblastomas. An oligodendroglioma and ependymoma both expressed the 2A6 epitope, but staining with MAb 81C6 was weak to absent. The antigens identified by MAb 81C6 and MAb 2A6 represent the only recognized extracellular matrix components, other than proteoglycans, that are associated with glioma cells in vivo. As prominent constituents of the pericellular matrix, they may be involved in recognized matrix functions such as the modulation of cell adhesion and migration.
AN ASYMPTOCALLY UNBIASED TWO‐STAGE LEAST SQUARES ESTIMATOR OF THE STRUCTURAL DISTURBANCE VARIANCES AND THE BIAS

Let Σ represent the covariance matrix of the structural disturbances of a simultaneous equations model. The conventional consistent estimator of the elements of Σ is usually given as the mean 2SLS residuals. However, neither the bais nor the asymptotic bias of the estimator of Σ by 2SLS have been found. This paper analytically derives an asymptotically unbiased estimator of Σ by 2SLS and determines the bias for finite samples. It is shown that the bias vanishes asymptotically. Then the paper suggests that the derived estimator may be applied in the second stage as well as in the third stage of 3SLS estimation. Other possible applications are indicated.
Relationship of Parental Attachment and Gender to Beliefs About Mood

ABSTRACT The relationship of parental attachment and gender to generalized expectancies about negative mood regulation and individual differences in the ability to reflect upon and manage one's emotions was examined in this study. The sample of 254 traditional age college students completed a measure of parental attachment and two questionnaires which measured their beliefs about mood evaluation and regulation functions. MANOVAs using level of attachment and gender as independent variables and beliefs about mood as dependent variables were significant, indicating that current beliefs about mood were related to level of attachment and gender. Implications for psychotherapy with college students are discussed.
Data-Driven Efficient Estimation of the Spectral Density

Abstract A nonparametric data-driven spectral density estimator is suggested for a class of processes with the exponentially decaying autocovariance function. This particular class is motivated by causal ARMA processes. The estimator is asymptotically efficient; that is, its mean integrated squared error converges with optimal minimax constant and rate as the sample size increases. The article also presents a Monte Carlo study of the estimator for the case of small sample sizes and an illustrative example of its application in the spectral domain analysis of insulin secretion data. The estimator is both simple and reliable, and does not require human supervision; thus it can be recommended to a practitioner with little or even no experience in spectral analysis of time series.
Cenozoic Migration of the Pacific Plate, Northward Shift of the Axis of Deposition, and Paleobathymetry of the Central Equatorial Pacific

Cenozoic northward migration of the Pacific plate is documented by magnetization vectors of seamounts and by volcanic lineations resulting from drift over fixed melting spots in the mantle. The rotation with respect to the spin axis of the Earth can also be established from the northward shift with time of the equatorial axis of maximum deposition. Data from Deep Sea Drilling Project sites in the equatorial Pacific indicate a pole of rotation for the past 45 m.y. at lat 67° N., long 59° W., in satisfactory agreement with locations derived from other evidence. The best fit is obtained for an initial rate of 0.25°/m.y., which accelerated to 0.8°/m.y. about 25 m.y. B.P. With this rotation scheme and the subsidence history of the individual drill sites, the paleobathymetric evolution of the central equatorial Pacific during Cenozoic time and the position of the ancestral East Pacific Rise can be established.
Carcinogen-induced immunoreactivity to antinucleoside antibodies in HeLa cells.

Abstract Immunoreactivity to fluorescein-labelled antinucleoside antibodies was induced in HeLa cell nuclei by the carcinogen N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). DNA strand breaks induced by MNNG were detected by measuring the influence of MNNG on the sedimentation in alkaline sucrose gradients of a fast sedimenting DNA-Containing complex. Dissociation of the complex and induction of immunoreactivity both proved to be sensitive, dose-dependent indicators of MNNG action in HeLa cells. Since antibodies directed against nucleosides react only with denatured or single-stranded DNA, it appears likely that MNNG-induced immunoreactivity results from exposure of single-stranded regions of DNA, providing a means for the rapid identification of carcinogen action by immunofluorescent techniques. N-Acetoxy-2-acetylaminofluorene also induced immunoreactivity and led to the dissociation of the DNA complex in HeLa cells. Seven other chemicals with known carcinogenic properties also induced immunoreactivity in this test. Immunoreactivity and dissociation of the complex were not induced by inhibitors of DNA synthesis such as hydroxyurea and cytosine arabinoside. Protein synthesis inhibitors such as cycloheximide induced immunoreactivity but did not dissociate the complex. Cycloheximide-induced immunoreactivity was rapidly and completely reversible following removal of the drug; the effects of MNNG were not reversible in our experiments. This novel application of immunofluorescent techniques provides a rapid quantitative means for detecting and studying the action of carcinogens in animal cells.
Beam orientation selection for intensity-modulated radiation therapy based on target equivalent uniform dose maximization.

Abstract Purpose: To develop an automated beam-orientation selection procedure for intensity-modulated radiotherapy (IMRT), and to determine if a small number of beams picked by this automated procedure can yield results comparable to a large number of manually placed orientations. Methods and Materials: The automated beam selection procedure maximizes an unconstrained objective function composed of target equivalent uniform dose (EUD) and critical structure dose-volume histogram (DVH) constraints. Beam orientations are selected from a large feasible set of directions through a series of alternating fluence optimization and orientation alteration steps, until convergence to a stable orientation set. The fluence optimization step adjusts fluences to maximize the objective function. The orientation alteration step substitutes beams in the orientation set currently under consideration with beams of the parent set in the immediate angular vicinity; the altered orientation set is deemed current if it produces a higher objective function value in the fluence optimization step. Results and Conclusions: It is demonstrated, for prostate IMRT planning, that a modest number of appropriately selected beam orientations (3 or 5) can provide dose distributions as satisfactory as those produced by a large number of unselected equispaced orientations. Such selected beam orientations can reduce overall treatment time, thus making IMRT more clinically practical.
Rate of sister chromatid exchanges in mammalian cells differing in diploid numbers.

The rate of sister chromatid exchanges (SCE) under identical experimental conditions is the same in various mammalian species irrespective of their diploid chromosome numbers.
ELECTRICAL ACTIVITY IN SHOCK-LOADED POLYMERS

ABSTRACT Studies concerning shock-induced conduction and shock-induced polarization phenomena in polymers are summarized and recent results presented.
Diffusive-thermal instability and flame extinction in nonpremixed combustion

A systematic study of cellular instabilities in nonpremixed flames is performed by examining shapes, heights, and extinction conditions of over- and under-ventilated slot-jet flames. A variety of fuels and diluents are used to vary Lewis numbers of fuel and oxidizer. Only nonpremixed flames near extinction having sufficiently low effective Le were found to exhibit cellular instability. It is proposed that near-extinction conditions are required so that reactant intermixing occurs before combustion takes place and that the effective Le is that of the more completely consumed reactant according to Linan's criterion for fuel or oxidizer leakage in diffusion flames, which msut be 0.8 for cellular instability. It is shown that all known observations of cellular nonpremixed flames can be described this way. Mechanisms proposed in previous work, such as preferential diffusion of light reactants and stoichiometric considerations, are disputed. Flame-height and extinction limit scalings suggest that flame height may be controlled by either buoyancy or jet momentum and extinction by blowoff or heatloss mechanisms. The characteristics of the observed cellular structures are consistent with the proposed mechanisms. Temperatures at cellular fronts are found to be higher than the calculated equilibrium values, but extinction limits appear not to be extended by diffusivethermal effects as much as in premixed flames. It is concluded that diffusive-thermal instability of nonpremixed flames occurs in a manner simililar to that of premixed flames, regardless of the mechanism leading to reactant intermixing.
Risk-based method for development and management of a traffic sign inventory for local agencies

A risk-based approach to manage traffic sign inventories was developed for application in local public agencies (LPAs). The method incorporates key aspects of safety such as accident history and hot spot ranking and allows agencies to develop sign inventories strategically for a variety of staffing resources and budget levels. This method would enable LPAs to more easily comply with Federal Highway Administration Manual on Uniform Traffic Control Devices (MUTCD) retroreflectivity guidelines and to prioritize the signs to be included in the inventory. A procedure has been developed that puts priority on reducing the risk of liability for sign-related accidents. The inventory developed as part of this research also supports the broader focus of better management of LPA roadway assets. Consistent and strategic updates of the inventory would provide the LPAs with a sustainable asset management system to utilize in the future. Language: en
Experimental Verification of the Van Vleck Nature of Long-Range Ferromagnetic Order in the Vanadium-Doped Three-Dimensional Topological Insulator Sb 2 Te 3

We demonstrate by high resolution low temperature electron energy loss spectroscopy (EELS) measurements that the long range ferromagnetic (FM) order in the vanadium- (V-)doped topological insulator ${\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$ has the nature of van Vleck--type ferromagnetism. The positions and the relative amplitudes of two core-level peaks (${L}_{3}$ and ${L}_{2}$) of the V EELS spectrum show unambiguous change when the sample is cooled from room temperature to $T=10\text{ }\text{ }\mathrm{K}$. Magnetotransport and comparison of the measured and simulated EELS spectra confirm that these changes originate from the onset of FM order. Crystal field analysis indicates that in V-doped ${\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$, partially filled core states contribute to the FM order. Since van Vleck magnetism is a result of summing over all states, this magnetization of core level verifies the van Vleck--type ferromagnetism in a direct manner.
Lift, drag and flow-field measurements around a small ornithopter

The aerodynamics of a flight-worthy, radio controlled ornithopter is investigated using a combination of Particle-Image Velocimetry (PIV), load cell measurements, and high-speed photography of smoke visualizations. The lift and thrust forces of the ornithopter are measured at various flow speeds, flapping frequencies and angles of attack to characterize the flight performance. These direct force measurements are then compared with forces estimated using control volume analysis on PIV data. High-speed photography of smoke streaks is used to visualize the evolution of leading edge vortices, and to qualitatively infer the effect of wing deformation on the net downwash. Vortical structures in the wake are compared to previous studies on root flapping, and direct measurements of flapping efficiency are used to argue that the current ornithopter operates sub-optimally in converting the input energy into propulsive work.
Possible worlds of doubt

A prominent contemporary anti-skeptical strategy, most famously articulated by Keith DeRose, aims to cage the skeptic′s doubts by contextualizing subjunctive conditional accounts of knowledge through a conversational rule of sensitivity. This strategy, I argue, courts charges of circularity by selectively invoking heavy counterfactual machinery. The reason: such invocation threatens to utilize a metric for modal comparison that is implicitly informed by judgments of epistemic sameness. This gives us reason to fear that said modal metric is selectively cherry-picked in advance to support the very anti-skeptical conclusion for which the contextualist longs.
Slow crack growth of blends of high density and linear low density polyethylenes as influenced by morphology

Abstract A high density polyethylene homopolymer was blended with a linear low density ethylene hexene copolymer over the composition range of 0–100%. The resistance to slow crack growth was measured by a notched tensile test under constant load at 42, 60 and 80°C. The morphology was varied by slow cooling, quenching and annealing at 129°C for 24 h. Whereas the resistance to slow crack growth increased by a factor of 10 6 over the composition range, the differences in morphology could only change the resistance to slow crack growth at the most by a factor of ∼3. The effect of temperature was independent of the effect of composition on slow crack growth. The effects of molecular and morphological structure are discussed.
Multiple Elimination By Reverse-time Datuming And Primary-only Imaging Condition

I present a two-step approach for multiple suppression below salt: redatuming data below salt by waveequation extrapolation followed by multiple suppression using the primary-only imaging condition (POIC). Full wave-equation based reverse-time datuming (RTD) can extrapolate the wavefields accurately to any artificial datum in complex models, and POIC can be effective with the redatumed data because of the relatively simple velocity model below salt. Synthetic tests on the SMAART model indicate that the RTD helps to reveal the deep structure below the datum and RTD + POIC hybrid method can distinguish and eliminate multiples in the datum below, e.g., a salt dome and thus provide a good sub-salt image.
Mapping off-shore coastal areas: ‘The submerged lands of Texas Atlas’—A review☆

Abstract Texas has a quarter of its population living within 60 km of its low-relief, barrier island/lagoonal coastline. By 1980, the State had available an atlas of environmental geologic and derivative maps for decision-making. As the State owns the submerged bays and continental shelf out to 16 km offshore, an atlas of the submerged lands was needed to provide required information for permitting and regulating State properties. The atlas includes maps, graphs, and tables of the bathymetry, bottom sediments, geochemistry, benthic communities and wetlands. Federal and Texas agencies are presently using the atlas in regulating and issuing permits for offshore activities.
Adolescent and young adult mortality by cause: age, gender, and country, 1955 to 1994.

Abstract Purpose: To compare mortality rates from motor vehicle accidents (MVA), homicide, and suicide across countries, age groups, and time. Methods: The World Health Organization Mortality Database was used to construct age- and gender-specific rates in 26 countries for individuals aged 15 to 34 years during the period 1955 to 1994. The rates were adjusted for differences among countries in the age-and-gender distributions of their populations. Cause-specific rates were compared by country, 4-year age groups, 8-year time blocks, and male/female ratios. Results: The proportion of deaths in 15–34-year-olds owing to MVA, homicide, and suicide increased from 26% to 43% over the 40-year study period. Mortality rates differ by country more than time block, peak at ages 15–29 years, and are higher in males than females. Compared to the United States, 24 countries had lower homicide rates and 23 had lower MVA-death rates. Conclusions: Despite declining rates of death from other causes, the rates of adolescent and young adult death from MVA, homicide, and suicide remain high in countries throughout the world. The proportion of deaths attributable to these causes increased steadily during the latter half of the 20th century. Fatal risk behaviors begin to increase during adolescence but do not peak until age 30 years, suggesting that the target population for prevention extends well beyond the teenage years.
On the formation of the 1,2-acetonide of (+), (−), and (±) 1,2,4-butanetriol and its corresponding aldehyde

Abstract The acetonides 1 and 3 are components of a 9:1 equilibrium established during their formation.
Comparative study of rate of weight loss among premorbid and healthy restrictive eaters.

Initial body mass index (BMI) and rate of weight loss are compared between cohorts of pathological and healthy dieters. The eating disordered sample consists of young adults reported in case studies in the past ten years with a primary diagnosis of anorexia nervosa (AN). The healthy dieters were adolescents who participated in the National Longitudinal Survey of Adolescent Health and indicated at the time of study enrollment that they were trying to lose weight. At diet initiation, the anorexic sample had a mean BMI (kg/m2) of 20.5 while the healthy dieters had a mean of 24.8._The median rate of weight loss was −1.87 kg per month (1 pound per week) for individuals later diagnosed with AN, while the median weight change was 0.24 kg per month for the Add Health dieters, reflecting an actual gain of 0.13 pounds per week. These findings suggest that measurable physiological characteristics during the early phase of a diet could be predictive of pathological food restriction.
Gameplaying for maths learning: cooperative or not?

This study investigated the effects of gameplaying on fifth-graders’ maths performance and attitudes. One hundred twenty five fifth graders were recruited and assigned to a cooperative Teams-Games-Tournament (TGT), interpersonal competitive or no gameplaying condition. A state standards-based maths exam and an inventory on attitudes towards maths were used for the pretest and posttest. The students’ gender, socio-economic status and prior maths ability were examined as the moderating variables and covariate. Multivariate analysis of covariance (MANCOVA) indicated that gameplaying was more effective than drills in promoting maths performance, and cooperative gameplaying was most effective for promoting positive maths attitudes regardless of students’ individual differences.
Characterization of nonspecific crossover in split-flow thin channel fractionation.

Split-flow thin channel (SPLITT) fractionation is a technique for continuous separation of particles or macromolecules in a fluid stream into fractions according to the lateral migration induced by application of a field perpendicular to the direction of flow. Typical applications have involved isolation of different fractions from a polydisperse sample. Some specialized applications involve the separation of the fraction influenced by the transverse field from the fraction that is not. For example, immuno-magnetically labeled biological cells may be separated from non-labeled cells with the application of a transverse magnetic field gradient. In such cases, it may be critically important to minimize contamination of the labeled cells with non-labeled cells while at the same time maximizing the throughput. Such contamination is known as non-specific crossover (NSC) and refers to the real or apparent migration of non-mobile particles or cells across streamlines with the mobile material. The possible mechanisms for NSC are discussed, and experimental results interpreted in terms of shear-induced diffusion (SID) caused by viscous interactions between particles in a sheared flow. It is concluded that SID may contribute to NSC, but that further experiments and mathematical modeling are necessary to more fully explore the phenomenon.
Critical thinking about fables: examining language production and comprehension in adolescents.

Purpose This study was designed primarily to determine if a critical-thinking task involving fables would elicit greater syntactic complexity than a conversational task in adolescents. Another purpose was to determine how well adolescents understand critical-thinking questions about fables. Method Forty adolescents (N = 20 boys and 20 girls; mean age = 14 years) with typical language development answered critical-thinking questions about the deeper meanings of fables. They also participated in a standard conversational task. The syntactic complexity of their responses during the speaking tasks was analyzed for mean length of communication unit (MLCU) and clausal density (CD). Results Both measures of syntactic complexity, MLCU and CD, were substantially greater during the critical-thinking task compared with the conversational task. It was also found that the adolescents understood the questions quite well, earning a mean accuracy score of 80%. Conclusions The critical-thinking task has potential for use ...