cssi/SciSciGPT-SciSciNet huggingface dataset:
Equilibrium constants in reactions of 2-aminoethanol and ammonia with isophthalaldehyde and terephthalaldehyde.

Equilibria established in reactions between isophthalaldehyde (IPA) and terephthalaldehyde (TPA) on one side and 2-aminoethanol and NH3 on the other side were followed in solutions, where these amines acted both as reagents and as buffers. The equilibrium between TPA and 2-aminoethanol was followed spectrophotometrically; all others, of reactions of TPA with NH3 and of IPA with both NH3 and H2N−CH2CH2−OH, were followed by using polarography. Separate limiting reduction currents of the dialdehyde and its imine enable simultaneous determination of the starting material and the product. The equilibria are shifted more in favor of the imine in reactions of TPA than those of IPA. Equilibrium constants for reactions of both TPA and IPA with 2-aminoethanol are 3 orders of magnitude higher than those observed for the reactions of dialdehydes with NH3, even when the pKa values of these two reagents differ only slightly.
Quantitating silver-stained neurodegeneration: the neurotoxicity of trimethlytin (TMT) in aged rats.

This report describes the development of a histoanalytical procedure to measure the degree of neurodegeneration produced by the organometal toxicant trimethyltin (TMT). Based on a previous, non-quantitated experiment we hypothesized that the same dose of TMT would produce greater damage in animals of increasing age. Male rats aged 6, 12, 18, or 24 months at the time of dosing were given either 4.5 mg/kg TMT or saline (i.p.). One month after dosing, rats were perfused and their brains removed and processed to selectively silver-impregnate degenerating cell bodies as well as axon terminals and dendrites. Neurodegeneration was most prominent in the hippocampi (especially CA1 stratum radiatum) of TMT-treated rats, but not in the controls. Computer-assisted counting of the silver grains marking damage indicated greater neurotoxicity from the same dose of TMT when given to the older animals. Thus the grain density in the 6-month-old TMT-treated rats was not significantly elevated from the 6-month-old controls (P>0.10). The 12-month-old TMT-treated rats had significantly increased grain densities compared to their controls (P<0.05), but still larger increases of grain counts were observed in the 18- and 24-month-old rats (both P-values<0.01). Our findings with TMT are similar to previous, but nonquantitative, reports that the neurotoxic effects of kainic acid and methionine sulfoximine were also greater in older rats. An increased sensitivity to neurotoxicants might help explain the apparently spontaneous degeneration of cortical neurons in aging and in the neurological diseases of old age. The method we report here for quantitation of silver grains marking neurodegeneration should be adaptable to a wide range of histologically-based neurotoxicology investigations.
Elucidation of the Cross-Link Structure of Nadic-End-Capped Polyimides Using NMR of 13C-Labeled Polymers

Solid NMR of 13C isotope-labeled samples of PMR-15 was used to follow the cross-linking reaction of the nadic end cap. Some samples were labeled on one of the carbon atoms of the nadic end cap, and others on the methylene carbon atom of the methylenedianiline portion of the polymer. NMR spectra were run on these samples both before and after cross-linking. In this way, direct evidence of the major products of cross-linking under normal cure conditions is provided. The majority (∼85%) of the cross-linking derives from olefin polymerization through the double bond of the end cap. Approximately 15% of the products could come from a pathway involving a retro-Diels−Alder reaction. However, all of the products could be explained by a biradical intermediate without a retro-Diels−Alder reaction. Evidence is also presented that the methylene moiety in the methylenedianiline part of the polymer chain also participates in the cross-linking, albeit to a small extent, by a radical transfer reaction. Different cure con...
Number Systems with Simplicity Hierarchies: A Generalization of Conway's Theory of Surreal Numbers

In [16], the algebraico-tree-theoretic simplicity hierarchical structure of J. H. Conway’s ordered field .
Observations of storm and river flood-driven sediment transport on the northern California continental shelf

Abstract In the winter of 1996–1997, three bottom-boundary layer tripods were placed in an alongshelf array on the northern California continental shelf off Eureka, CA in 60–65-m water depth. During the observation period, multiple storms and river discharge events occurred, as well as the largest flood on record since 1964. Suspended-sediment concentration at all three sites fluctuated in response to both wave resuspension and advection of river-derived sediments. However, considerable spatial differences in low-frequency currents and suspended-sediment concentration were observed at the three sites. Sediment flux vectors calculated during periods of high suspended-sediment concentration suggest a convergence of sediment flux coincident with the center of recent flood deposits. Suspended-sediment concentrations observed at the two northern tripod sites following the large flood reached magnitudes typical of fluid mud (>10 g/l) in a thin near-bed layer. The net sediment flux during the single three-day event was two orders of magnitude larger than any other event during the winter, and accounted for seven times the flux observed over an entire year (1995–1996). A conceptual model for the advection of sediment to the mid shelf is proposed in which river plume sediments are trapped on the inner shelf either due to a weak front or the rapid input of sediment from a confined plume, and form a thin layer of fluid mud. The fluid mud subsequently is transported seaward due to gravitational forcing. The measured sediment concentration and velocity profiles on the shelf provide strong evidence to support this conclusion.
Low-infiltration housing in Rochester, New York: A study of air-exchange rates and indoor air quality

Abstract A sample of 58 occupied homes in Rochester, NY, most of which incorporated special builder-designed weatherization components, were studied to assess (1) the effectiveness of construction techniques designed to reduce air leakage; (2) the indoor air quality and air-exchange rates in selected airtight houses, and (3) the impact on indoor air quality of mechanical ventilation systems employing air-to-air heat exchangers. The “specific leakage area” was measured in each house using the fan pressurization technique. Houses built with polyethylene vapor barriers and joint-sealing were as a group 50% tighter than a similar group of houses without such components. Mechanical ventilation systems with air-to-air heat exchangers were installed in nine relatively airtight houses, some of which had gas stoves and/or tobacco smoking occupants. Air-exchange rates and indoor concentrations of radon (Rn), formaldehyde (HCHO), nitrogen dioxide (NO 2 ), and humidity were measured in each house for 1-week periods with and without mechanical ventilation. More detailed measurements, including concentrations of carbon monoxide and inhalable particulates, were made in two of these houses by a mobile laboratory. In all nine houses, air-exchange rates were relatively low (0.2–0.5 ach) without mechanical ventilation, and yet indoor concentrations of Rn, HCHO, and NO 2 were below existing guidelines. Mechanical ventilation systems were effective in further reducing indoor contaminant concentrations. We conclude that when contaminant source strengths are low, acceptable indoor air quality can be compatible with low air-exchange rates.
Preventing premature deaths from breast and cervical cancer among underserved women in the United States: insights gained from a national cancer screening program

This commentary highlights some of the valuable insights gained from a special collection of papers that utilized data from the National Breast and Cervical Cancer Early Detection Program (NBCCEDP) and appear in this special issue. The data and experiences of the NBCCEDP can inform the identification of new opportunities and directions for meeting the cancer screening needs of underserved women in a complex and changing health care environment.
Effect of phase noise on the evaluation of coherence of laser beam propagating through turbid medium

The spectral broadening or the coherence time of a laser beam travelling through a turbid dense medium can be measured with high accuracy using heterodyne techniques. However, the random amplitude and phase fluctuations in the laser source can limit the accuracy of these measurements. In this paper, the limitations due to the phase noise are investigated.
A novel model of ischemia in renal tubular cells which closely parallels in vivo injury.

Abstract Purpose. Renal ischemia-reperfusion (IR) injury is a devastating clinical problem. While effective animal models have been developed to investigate this condition, they are limited by differential renal cell inflammatory mediator production and heterogeneous cell sensitivity to ischemia. We therefore developed an in vitro model of renal tubular cell ischemia that simulates the cellular injury observed in animal models of renal IR injury. Materials and methods. Using the established renal tubular cell line, LLC-PK1, simulated ischemia was induced by immersing the cellular monolayer in mineral oil. The effect of simulated ischemia on renal tubular cells was then determined by measuring the time course of TNF-α protein expression (ELISA), TNF-α mRNA induction (RT-PCR), and renal tubular cell apoptosis (TUNEL). Results. Maximal TNF-α protein expression occurs following 60 min of simulated ischemia and 2 h of substrate replacement (reimmersion in media), and maximal TNF-α mRNA induction occurs following 60 min of simulated ischemia. Cellular apoptosis peaks following 60 min of simulated ischemia and 24 h of reperfusion. Conclusion. The time course of TNF-α production and apoptosis induction in this model closely parallels the time course for these markers in vivo. This study constitutes the initial demonstration that an in vitro oil immersion model of ischemia simulates the cellular injury (TNF-α production and apoptosis) observed in animal models of renal ischemia-reperfusion. This model may be used to study cellular mechanisms of IR in the absence of the systemic confounding variables.
“All My Hopes and Dreams” Families, Schools, and Subjectivities in Collegiate Softball

The title quote indicates that despite the success of the women who were interviewed for this research, many of them felt ill prepared to access the system of collegiate softball. Yet the women int...
Assessment of Western North Pacific 96- and 120-h Track Guidance and Present Forecastability

Abstract Because the Joint Typhoon Warning Center (JTWC) has only four dynamical models for guidance in making 96- and 120-h track forecasts, an opportunity exists for improving the consensus forecast by the proper removal of a likely erroneous forecast to form a selective consensus (SCON). Forecast fields from all four models [the U.S. Navy Operational Global Atmospheric Prediction System (NOGAPS), the U.S. Navy version of the Geophysical Fluid Dynamics Laboratory model (GFDN), the Met Office (UKMO) model, and the Global Forecast System (GFS)] were available during the 2005 western North Pacific season to evaluate for the first time the error mechanisms leading to large track errors. As shown previously for the NOGAPS and GFDN models during the 2004 season, error sources related to the midlatitude circulations accounted for about 90% of all large 120-h track errors by all four models during the 2005 season. This dominance of midlatitude-related error source is a major shift from the 72-h errors, which in...
SOILBORNE PLANT DISEASES CAUSED BY PYTHIUM SPP: ECOLOGY, EPIDEMIOLOGY, AND PROSPECTS FOR BIOLOGICAL CONTROL

Soilborne root diseases caused by plant pathogenic Pythium species cause serious losses in a number of agricultural production systems, which has led to a considerable effort devoted to the development of biological agents for disease control. In this article we review information on the ecology and biological control of these pathogens with the premise that a clear understanding of the ecology of the pathogen will assist in the development of efficacious biocontrol agents. The lifecycles of the pathogens and etiology of host infection also are reviewed, as are epidemiological concepts of inoculum-disease relationships and the influence of environmental factors on pathogen aggressiveness and host susceptibility. A number of fungal and bacterial biocontrol agents are discussed and parallels between their ecology and that of the target pathogens highlighted. The mechanisms by which these microbial agents suppress diseases caused by Pythium spp., such as interference with pathogen survival, disruption of the...
Computational Modeling of Ducted Wind Turbines for Residential Applications

As wind turbines are increasingly being adopted for meeting growing energy needs, their implementation for personal home use in the near future is imminent. There are very few studies conducted on these small-scale turbines in the one to two meter diameter range because the power generated at this scale is not sufficient to justify the cost of installation and maintenance. The problem is further complicated by the fact that these turbines are normally mounted at low altitudes and thus there is necessity to have the optimum operating regime in the wind speed range of 3–10 mph (1.34–4.47 m/s). This study analyzes the turbine performance with a diffuser at these dimensions and demonstrates the pathway that can meet these challenges. The design was modeled using commercial computational fluid dynamics code. Two-dimensional modeling using actuator disk theory was used to optimize the diffuser design. A statistical study was then conducted to reduce the computational time by selecting a descriptive set of models to test and characterize the effect of prominent parameters rather than evaluating all the possible combinations of input parameters. Individual dimensions were incorporated into JMP software and randomized to design the experiment. The results of the JMP analysis are discussed in this paper. Consistent with the literature, a long outlet section (one to three times the length of the diameter) coupled with a sharp angled inlet was found to provide the highest amplification for a wind turbine diffuser.Copyright © 2013 by ASME
Effects of cycloheximide and of chloramphenicol on DNA synthesis in Euglena gracilis.

Abstract 1. The independence of chloroplasts in synthesis of their DNA has been examined in Euglena gracilis by 32 Plabeling of the DNA and with the aid of the inhibitors, chloramphenicol and cycloheximide. Strain Z, containing chloroplast and mitochondrial DNA, and strain W3 BUL, containing mitochondrial DNA, were used. 2. Chloramphenicol has no effect on the labeling or on the distribution of chloroplast and mitochondrial DNA relative to nuclear DNA for at least 5.5 generations. Cell division is slowed in strain Z but is unaffected in strain W3 BUL. Since chloramphenicol inhibits protein synthesis on Euglena chloroplast ribosomes, continued synthesis of chloroplast DNA and continued cell division suggest that all unstable proteins essential for synthesis of chloroplast DNA are made on cytoplasmic ribosomes, or all proteins required for this synthesis turn over slowly. 3. After growth in the presence of cycloheximide, the specific activity of the nuclear DNA is 35 to 40 % of that of the mitochondrial DNA and 50 % of that of the chloroplast DNA. Under these conditions cell division is halted. Since control cultures did not show increased turnover of extranuclear DNA, synthesis of chloroplast and mitochondrial DNA must continue after synthesis of nuclear DNA has been virtually stopped by cycloheximide.
A parametric study of isothermal fixed bed catalytic reactors undergoing concentration-dependent deactivation

Abstract A parametric study is conducted for deactivating packed bed reactors under two common policies of operation — constant conversion and constant temperature. The parallel deactivation kinetics are described by a power law model. Analytic solutions are available for some special cases, but the general problem requires a numerical approach. A computational algorithm based on centered finite differences is presented. Contrary to predictions of the concentration-independent model which is often employed, it is found that the deactivation curves are strongly influenced by space time and kinetics of the main reaction. In addition, deactivation is most rapid for the concentration-independent case.
Teaching Students How to Avoid Errors in Theory Application

This article identifies six major misperceptions and errors in the application of theory in direct practice to establish the need for a conceptual tool capable of teaching direct practice and managing the practice environment. Such a tool is introduced as part of the previous article: ‘‘Decision Tree: A Conceptual Tool for Best Practices’’ (p. 37). The six errors and misperceptions are as follows: (1) one theory is as good as another theory, (2) nomothetic theory is interchangeable with practice theory, (3) a single theory can accommodate complex case data, (4) any theory can explain everything and anything, (5) eclecticism does no harm, (6) theory does not matter anyway. Case examples illustrating these errors are provided. [Brief Treatment and Crisis Intervention 4:49‐56 (2004)]
Retinoic acid: a binding protein in chick embryo metatarsal skin.

Summary A protein which binds retinoic acid and which sediments with an S 20,w value of 2.2 is present in extracts of metatarsal skin from 12- to 13-day-old chick embryos. Competition experiments with unlabeled retinoic acid, retinol, retinal, and a cyclopentene analog of retinoic acid demonstrate that a terminal carboxyl group is required for binding. Since retinoic acid and the cyclopentene analog have potent biological action in preventing squamous metaplasia of chick skin explants, this binding protein may be involved in their effect.
Review op X-ray lithography technology

X-ray lithography using an Al k source (8.34 A) and masks consisting of gold absorber patterns on single-crystal silicon membranes has been successfully applied to the fabrication of surface wave delay lines, and silicon diodes and transistors. The status of this work and the advantages of using silicon masks will be reviewed.
Biochemical and functional characterization of CpMuc4, a Cryptosporidium surface antigen that binds to host epithelial cells.

Abstract Cryptosporidium spp. are intracellular apicomplexan parasites that cause outbreaks of waterborne diarrheal disease worldwide. Previous studies had identified a Cryptosporidium parvum sporozoite antigen, CpMuc4, that appeared to be involved in attachment and invasion of the parasite into intestinal epithelial cells. CpMuc4 is predicted to be O- and N-glycosylated and the antigen exhibits an apparent molecular weight 10 kDa larger than the antigen expressed in Escherichia coli , indicative of post-translational modifications. However, lectin blotting and enzymatic and chemical deglycosylation did not identify any glycans on the native antigen. Expression of CpMuc4 in Toxoplasma gondii produced a recombinant protein of a similar molecular weight to the native antigen. Both purified native CpMuc4 and T. gondii recombinant CpMuc4, but not CpMuc4 expressed in E. coli , bind to fixed Caco-2A cells in a dose dependent and saturable manner, suggesting that this antigen bears epitopes that bind to a host cell receptor, and that the T. gondii recombinant CpMuc4 functionally mimics the native antigen. Binding of native CpMuc4 to Caco2A cells could not be inhibited with excess CpMuc4 peptide, or an excess of E. coli recombinant CpMuc4. These data suggest that CpMuc4 interacts directly with a host cell receptor and that post-translational modifications are necessary for the antigen to bind to the host cell receptor. T. gondii recombinant CpMuc4 may mimic the native antigen well enough to serve as a useful tool for identifying the host cell receptor and determining the role of native CpMuc4 in host cell invasion.
Biosynthetische anorganische Chemie

Anorganische Chemie und Biologie konnen sehr voneinander profitieren. Nachdem anorganische Synthese und physikalische Chemie zu den grosen Erfolgen bei der Aufklarung der Rolle von Metallionen in biologischen Systemen beigetragen haben, sollen nun biologische Systeme bei der Weiterentwicklung der Koordinationschemie helfen. Ein Beispiel dafur sind kleine, stabile, leicht herstellbare und gut charakterisierte Proteinliganden fur die Synthese neuer anorganischer Verbindungen. Diese “biosynthetische anorganische Chemie” wird erst dank einiger Entwicklungen in der Biologie moglich. Der Aufsatz beginnt mit Fortschritten bei der Synthese genauer Modelle von komplexen Metalloproteinen. Anschliesend wird gezeigt, wie das Konzept fur anorganische Chemie ebenso wie Biologie neuartige Verbindungen hervorbringen kann. Im Vordergrund stehen “Synthesetricks”, die von biologischen Systemen erlernt wurden, sowie neue Strukturen.
Verbal Logic and Ear-Asymmetry in Third and Fifth Grade Males and Females

Summary The overall objective of the study was to determine if there are differences between left and right ears in the performance of transitive inference, verbal logic problems in third and fifth grade males and females. The sample consisted of 24 males and 24 females at the third and fifth grade level. Each child was tested individually. A total of twelve two and three term transitive inference problems were presented monaurally. The transitive inference problems were of the type “Tom is taller than Jim. Who is the shortest?”, and “John is stronger than Alfred and Alfred is stronger than Peter. Who is the weakest?” A three-way analysis of repeated measures (Sex × Grade × Ear) was performed on number correct and on reaction times for left and right ears. The results based on number correct indicated a right ear superiority in performance, Ear × Sex interaction and a Ear × Grade interaction. Females performed better using their right ear while males had no difference in performance between left and right ears. Fifth graders performed better using their right ear while third graders exhibited no difference in performance between left and right ears. The data from reaction times indicated a faster reaction time for right ear than the left ear. These results were discussed in terms of the progressive lateralization hypothesis and gender differences in the development of left hemisphere dominance for language functions.
Effect of Hexaflumuron on Gustation and Reproduction of Adult Boll Weevil

Abstract. Hexaflumuron was evaluated for effects on gustatory response and reproduction of boll weevil, Anthonomus grandis grandis Boheman, captured in pheromone-baited traps. Hexaflumuron is an insect-growth regulator that inhibits chitin synthesis and disrupts insect cuticle formation during molting. The intent was to determine the effect of hexaflumuron mixed in ppm active ingredient (weight:volume) with 10% sucrose as a feeding stimulant on gustation and reproduction of boll weevil. Regardless of concentrations, weevils captured in pheromone-baited traps in the fall ingested significantly more hexaflumuron than those captured in the spring. Seasonal mean amount of hexaflumuron ingested by the weevil decreased significantly with greater concentrations (adjusted R2 = 0.82). At 5 and 25 ppm, hexaflumuron significantly depressed gustatory response for falland spring-captured boll weevils, respectively. Hexaflumuron at 5 and 25 ppm significantly depressed oviposition and larval hatch, respectively, for bot...
Indo‐Pakistani Nuclear issues and the stability/instability paradox

The incipient nuclearization of South Asia appears to have reproduced a variant of Glenn Snyder's “stability/instability paradox” in the region. The danger of escalation to the nuclear level has significantly limited the prospects of direct interstate conflict. Simultaneously, both India and Pakistan are involved in supporting indigenous insurgencies in their respective states. Decision makers in both capitals see the risks of these ventures as controllable and calculable. A combination of mutual restraint and timely U.S. intercession has prevented two recent crises, in 1987 and 1990, from escalating. Despite the successful defusing of these two crises, a combination of inadvertence and misperception may still lead to conflict escalation in the region.
Quantitative calculation of dislocation mobility

The authors present a new method to calculate the response of dislocations to applied stress. This new method, called the dislocation treadmill, can be used to study the effect of vacancies, interstitials, stresses, strain rate, temperature, etc., on the steady state velocity of the dislocation. The authors demonstrate the use of the method by calculating the response of a dislocation to a constant applied shear stress.
Surgical complications requiring early relaparotomy after pancreas transplantation: a multivariate risk factor and economic impact analysis of the cyclosporine era.

OBJECTIVES: To study significant surgical complications requiring early (< or = 3 months posttransplant) relaparotomy (relap) after pancreas transplants, and to develop clinically relevant surgical and peritransplant decision-making guidelines for preventing and managing such complications. SUMMARY BACKGROUND DATA: Pancreas grafts are still associated with the highest surgical complication rate of all routinely transplanted solid organs. However, the impact of surgical complications on morbidity, hospital costs, and graft and patient survival rates has not been analyzed in detail to date. METHODS: We retrospectively studied surgical complications requiring relap in 441 consecutive cadaver, bladder-drained pancreas transplants (54% simultaneous pancreas and kidney [SPK]; 22% pancreas after kidney [PAK]; 24% pancreas transplant alone [PTA]; 37% retransplant). Outcome and hospital charges were analyzed separately for recipients with versus without reoperation. RESULTS: The overall relap rate was 32% (SPK, 36%; PAK, 25%; PTA, 16%; p = 0.04). The most common causes were intraabdominal infection and graft pancreatitis (38%), pancreas graft thrombosis (27%), and anastomotic leak (15%). Perioperative relap mortality was 9%; transplant pancreatectomy was necessary in 57% of all recipients with one or more relaps. The pancreas graft was lost in 80% of recipients with versus 41% without relap (p < 0.0001). Patient survival rates were significantly lower (p < 0.05) for recipients with versus without relap. By multivariate analysis, significant risk factors for graft loss included older donor age (SPK, PAK), retransplant (PAK), relap for infection (SPK, PAK), and relap for leak or bleeding (PAK). For death, risk factors included older recipient age (SPK, PAK),retransplant (SPK, PAK), relap for thrombosis (PAK), relap for infection or leak (SPK), and relap for bleeding (PTA). CONCLUSIONS: Posttransplant surgical complications requiring relap were frequent, resulted in a high rate of pancreas (SPK, PAK, PTA) and kidney (SPK, PAK) graft loss, and had a major economic impact (p = 0.0001). Complications were associated with substantial perioperative mortality and decreased patient survival rates. The focus must therefore shift from graft salvage to preservation of the recipient's life once a pancreas graft-related complication requiring relap occurs. Thus, the threshold for pancreatectomy should be low. In this context, acceptance of older donors and recipients must be reconsidered.
Therapeutic index of epinephrine and dipivefrin with nasolacrimal occlusion.

We assessed the effect of nasolacrimal occlusion on the therapeutic index of the adrenoreceptor agonists in healthy volunteers and patients with glaucoma. Nasolacrimal occlusion did not significantly alter the response to 2% epinephrine or to 0.1% dipivefrin in healthy subjects, suggesting that both 2% epinephrine and 0.1% dipivefrin are at the top of the dose-response curve. When 0.5% epinephrine with nasolacrimal occlusion was tested in patients with glaucoma, effects were noticeable at four and eight hours (P
Assessing community informatics: a review of methodological approaches for evaluating community networks and community technology centers

Community informatics can be defined as a strategy or discipline that focuses on the use of information and communication technologies by territorial communities. This paper analyzes the emerging community informatics evaluation literature to develop an understanding of the indicators used to gauge project impacts in community networks and community technology centers. This study finds that community networks and community technology center assessments fall into five key areas: strong democracy; social capital; individual empowerment; sense of community; and economic development opportunities. The paper concludes by making recommendations for future community informatics evaluations.
Wrinkle formation on a biocompatible shape memory polymer

Ordered wrinkles have been used for a variety of applications and have found much interest in the field of mechanobiology, as topography has been shown to influence cell behavior. In this study we aimed to synthesize a biocompatible material that could be triggered to form wrinkles under physiological conditions. To achieve this aim, we used a shape memory polymer (SMP) substrate to induce surface buckling of a thin gold film resting atop the SMP. The SMP composition was tuned to allow for surface buckling to occur under cell culture compatible conditions. The SMP was strained to different values prior to buckling and the resulting wavelength and amplitude for each strain was characterized. Increasing the strain allowed for smaller wavelengths and larger wrinkle amplitudes. Preliminary cell culture experiments showed high cell viability and cell alignment atop the wrinkled topography.
Polymerases Leave Fingerprints: Analysis of the Mutational Spectrum in Escherichia coli rpoB To Assess the Role of Polymerase IV in Spontaneous Mutation

ABSTRACT We compared the distribution of mutations in rpoB that lead to rifampin resistance in strains with differing levels of polymerase IV (Pol IV), including strains with deletions of the Pol IV-encoding dinB gene, strains with a chromosomal copy of dinB, strains with the F′128 plasmid, and strains with plasmid amplification of either the dinB operon (dinB-yafNOP) or the dinB gene alone. This analysis identifies several hot spots specific to Pol IV which are virtually absent from the normal spontaneous spectrum, indicating that Pol IV does not contribute significantly to mutations occurring during exponential growth in liquid culture.
Analog-Based Free Testosterone Test Results Linked to Total Testosterone Concentrations, Not Free Testosterone Concentrations

Background: Analog-based free testosterone test results, sex hormone binding globulin (SHBG) concentrations, and total testosterone concentrations are somehow related. This study used new experiments to clarify these relationships. Methods: An analog-based free testosterone immunoassay and a total testosterone immunoassay were applied to well-defined fractions of serum testosterone. First, they were applied to the 2 fractions (retentate and dialysate) of normal male serum obtained by equilibrium dialysis. Second, they were applied to covaried concentrations of SHBG and total testosterone. Third, they were applied to decreasing concentrations of SHBG and protein-bound testosterone, offset by increasing concentrations of protein-free testosterone, while total testosterone was held constant. Results: The analog-based free testosterone assay and the total testosterone assay detected and reported serum testosterone test results from serum retentate, whereas neither assay detected the free testosterone in serum dialysate. Test results reported by the analog-based free testosterone assay followed varied concentrations of SHBG and total testosterone. When total testosterone was held constant, however, analog-based free testosterone test results did not follow varied concentrations of serum proteins or of free testosterone. Conclusion: An analog-based free testosterone immunoassay reported free testosterone test results that were related to total testosterone concentrations under varied experimental conditions. This alleged free testosterone assay did not detect serum free testosterone (the test results it reported were nonspecific) and should not be used for this purpose.
Free-space-optical networks: some capacity considerations

Free space-optical networks deployed as a mesh topology are well suited for ultra broadband last mile business and residential services. Considered are several capacity and mobility management aspects of such networks.
Molecular basis for antagonism between PDGF and the TGFβ family of signalling pathways by control of miR-24 expression

Modulation of the vascular smooth‐muscle‐cell (vSMC) phenotype from a quiescent ‘contractile’ phenotype to a proliferative ‘synthetic’ phenotype has been implicated in vascular injury repair, as well as pathogenesis of vascular proliferative diseases. Both bone morphogenetic protein (BMP) and transforming growth factor‐β (TGFβ)‐signalling pathways promote a contractile phenotype, while the platelet‐derived growth factor‐BB (PDGF‐BB)‐signalling pathway promotes a switch to the synthetic phenotype. Here we show that PDGF‐BB induces microRNA‐24 (miR‐24), which in turn leads to downregulation of Tribbles‐like protein‐3 (Trb3). Repression of Trb3 coincides with reduced expression of Smad proteins and decrease in BMP and TGFβ signalling, promoting a synthetic phenotype in vSMCs. Inhibition of miR‐24 by antisense oligonuclotides abrogates the downregulation of Trb3 as well as pro‐synthetic activity of the PDGF‐signalling pathway. Thus, this study provides a molecular basis for the antagonism between the PDGF and TGFβ pathways, and its effect on the control of the vSMC phenotype.
Developing versus Nondeveloping Disturbances for Tropical Cyclone Formation. Part II: Western North Pacific

GlobaldailyreanalysisfieldsfromtheNavyOperationalGlobalAtmosphericPredictionSystem(NOGAPS) are used to analyze Northern Hemisphere summertime (June‐September) developing and nondeveloping disturbances for tropical cyclone (TC) formation from 2003 to 2008. This is Part II of the study focusing on the westernNorthPacific(WNP),followingPartIfortheNorthAtlantic(NATL)basin.Tropicalcyclonegenesisin the WNP shows different characteristics from that in the NATL in both large-scale environmental conditions and prestorm disturbances. A box difference index (BDI) is used to identify parameters in differentiating between the developing and nondeveloping disturbances. In order of importance, they are 1) 800-hPa maximum relative vorticity, 2) rain rate, 3) vertically averaged horizontal shear, 4) vertically averaged divergence, 5) 925‐400-hPa water vapor content, 6) SST, and 7) translational speed. The study indicates that dynamic variables are more important in TC genesis in the WNP, while in Part I of the study the thermodynamic variables are identified as more important in the NATL. The characteristic differences between the WNP and the NATL are compared.
SIRT6 in DNA repair, metabolism and ageing

Ageing, or increased mortality with time, coupled with physiologic decline, is a nearly universal yet poorly understood biological phenomenon. Studies in model organisms suggest that two conserved pathways modulate longevity: DNA damage repair and Insulin/Igf1-like signalling. In addition, homologs of yeast Sir2 - the sirtuins - regulate lifespan in diverse organisms. Here, we focus on one particular sirtuin, SIRT6. Mice lacking SIRT6 develop a degenerative disorder that in some respects mimics models of accelerated ageing [Cell (2006) 124:315]. We discuss how sirtuins in general and SIRT6 specifically relate to other evolutionarily conserved pathways affecting ageing, and how SIRT6 might function to ensure organismal homeostasis and normal lifespan.
Physician Dismissal of Families Who Refuse Vaccination: An Ethical Assessment

Thousands of U.S. parents choose to refuse or delay the administration of selected vaccines to their children each year, and some choose not to vaccinate their children at all. While most physicians continue to provide care to these families over time, using each visit as an opportunity to educate and encourage vaccination, an increasing number of physicians are choosing to dismiss these families from their practice unless they agree to vaccinate their children. This paper will examine this emerging trend along with the reasons given by those who advocate such an approach. I will argue that the strategy of refusing to allow families into a clinic unless they agree to vaccinate their children is misguided, and the arguments for doing so fail to stand up to close scrutiny. Such a strategy does not benefit the child or the health of the community, and may have a negative impact on both. Furthermore, some of the arguments in support of dismissal policies ignore the importance of professional obligation and appear to favor self-interest over the interest of the patient.
Aircraft measurement of HONO vertical profiles over a forested region

[1] Here we present the first HONO vertical profiles in the atmospheric boundary layer (BL) and the lower free troposphere (FT) over a forested region in northern Michigan and the neighboring Great Lakes, measured from a small aircraft in summer of 2007. The HONO mixing ratios ranged from 4 to 17 pptv in the FT and from 8 to 74 pptv in the BL. The HONO distribution pattern was strongly influenced by the air column stability, i.e., strong negative HONO gradients existed in stable BL in the morning hours, whereas the HONO distribution was relatively uniform in the unstable and well-mixed BL in the afternoons. The ground surface was a major source of HONO in the lower BL. The presence of substantial daytime HONO in the FT (∼8 pptv) and in the upper BL (25 pptv) suggests that a significant in situ source of HONO exists in the air column.
Motion learning in variable environments using probabilistic flow tubes

Commanding an autonomous system through complex motions at a low level can be tedious or impractical for systems with many degrees of freedom. Allowing an operator to demonstrate the desired motions directly can often enable more intuitive and efficient interaction. Two challenges in the field of learning from demonstration include (1) how to best represent learned motions to accurately reflect a human's intentions, and (2) how to enable learned motions to be easily applicable in new situations. This paper introduces a novel representation of continuous actions called probabilistic flow tubes that can provide flexibility during execution while robustly encoding a human's intended motions. Our approach also automatically determines certain qualitative characteristics of a motion so that these characteristics can be preserved when autonomously executing the motion in a new situation. We demonstrate the effectiveness of our motion learning approach both in a simulated two-dimensional environment and on the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) robot performing object manipulation tasks.
A micromachined membrane-based active probe for biomolecular mechanics measurement

A novel micromachined, membrane-based probe has been developed and fabricated as assays to enable parallel measurements. Each probe in the array can be individually actuated, and the membrane displacement can be measured with high resolution using an integrated diffraction-based optical interferometer. To illustrate its application in single-molecule mechanics experiments, this membrane probe was used to measure unbinding forces between L-selectin reconstituted in a polymer-cushioned lipid bilayer on the probe membrane and an antibody adsorbed on an atomic force microscope cantilever. Piconewton range forces between single pairs of interacting molecules were measured from the cantilever bending while using the membrane probe as an actuator. The integrated diffraction-based optical interferometer of the probe was demonstrated to have <10 fm Hz−1/2 noise floor for frequencies as low as 3 Hz with a differential readout scheme. With soft probe membranes, this low noise level would be suitable for direct force measurements without the need for a cantilever. Furthermore, the probe membranes were shown to have 0.5 µm actuation range with a flat response up to 100 kHz, enabling measurements at fast speeds.
Optical spectroscopy of InGaN epilayers in the low indium composition regime

Photoluminescence (PL) spectroscopy was carried out on a series of Si-doped bulk InGaN films in the low indium (In) composition regime. Room temperature PL showed a factor of 25 increase in integrated intensity as the In composition was increased from 0 to 0.07. Temperature dependent PL data was fit to an Arrhenius equation to reveal an increasing activation energy for thermal quenching of the PL intensity as the In composition is increased. Time resolved PL measurements revealed that only the sample with highest In (x = 0.07) showed a strong spectral variation in decay time across the T=4K PL resonance, indicative of recombination from localized states at low temperatures. The decay times at room temperature were non-radiatively dominated for all films, and the room temperature (non-radiative) decay times increased with increasing In, from 50--230 psec for x = 0--0.07. The data demonstrate that non-radiative recombination is less effective with increasing In composition.
Large-signal analysis and control of buck converters loaded by DC-DC converters

The dynamic behavior of the buck converter feeding downstream DC-DC converters is studied in this paper. DC-DC converters acting as a load are modeled as constant power loads except at low voltage, where the behavior of the start-up circuitry is included. A comprehensive large-signal analysis of a buck converter including over-current protection and feeding the described load is performed. This paper addresses the transient process of the converter's start-up and turn on/off of loads consisting of DC-DC converters and gives design considerations to assess performance and stability robustness of a simple proportional-derivative controller.
High-Voltage Corona in Air

In the last few years contributions to corona literature by Holm, Ryan, Willis, and others have shown that the space charge liberated by alternating corona reacts on the corona to a high degree in determining its characteristics. This investigation studies the nature of these effects as influenced by variation in the limits of travel of the space charge. The three properties of corona readily lending themselves to experimental observation, the wave form and the value of the corona current, and the corona loss, have been observed when high alternating voltages are applied to a small smooth cylindrical conductor placed successively along the axes of four sizes of metal cylinders. In addition four frequencies of the alternating voltages were used. All the work has been done under atmospheric conditions. The theory of the influence of space charge as developed by Holm has been tested by experiment and a marked discrepancy is indicated. Values of power loss due to corona, as measured, differ appreciably from those predicted by Holm, but in general follow the quadratic relation suggested by Peek. Unusually large and clear oscillograms afford much interesting qualitative information as to the influence of space charge travel on corona.
Bubble nucleation in superheated liquid—liquid emulsions

Abstract An investigation of the process by which bubbles form in superheated liquid-liquid emulsions is reported. A theoretical model for the rate of bubble nucleation is developed that is valid for any binary liquid system. Because of the interesting “microexplosion” phenomenon postulated to occur during combustion of fuel/water emulsions, special attention is focused on hydrocarbon/water/surfactant mixtures. The model predicts that in these systems nucleation takes place at the interface between the two liquids but that the vapor bubbles rest entirely within the hydrocarbon phase. The maximum superheat limits of emulsions containing 83% by volume hydrocarbon (benzene, n-decane, n-dodecane, n-tetradecane, and n-hexadecane), 15% water and 2% surfactant were measured experimentally at 1 atm and found to be in good agreement with the predictions of the theoretical model. The superheat limits of these emulsions are lower than those of either pure liquid. However, for microexplosion of an emulsified fuel droplet, the superheat limit of the fuel/water emulsion must be less than the boiling point of the fuel. Only the n-hexadecane/water emulsion satisfies this criterion at atmospheric pressure.
Diversity of thymidine analogue resistance genotypes among newly diagnosed HIV-1-infected persons

The introduction of highly active antiretroviral therapy (HAART) has resulted in a significant decrease in HIV and AIDS-related mortality and morbidity. However, these treatments can select for drug-resistant viruses which are associated with poor virological responses to the antiretroviral therapy and possible loss of clinical benefit. Drug-resistant viruses can also be transmitted between individuals. In the absence of drug pressure, transmitted drug-resistant viruses gradually lose resistance mutations that confer a selective disadvantage as they evolve to more fit viruses. As a result, unusual resistance-related genotypes not commonly seen in treated patients may arise in the population. Viruses with unique patterns of thymidine analogue-associated mutations (TAMs) have now been identified in a substantial proportion of treatment-naive recently diagnosed persons. In this leading article, I discuss these findings and the potential impact of these unique reverse transcriptase (RT) genotypes on evolution of resistance and treatment responses.
Protease Probes Built from DNA: Multispectral Fluorescent DNA–Peptide Conjugates as Caspase Chemosensors

The direct monitoring of enzyme activities is broadly useful in many fields, ranging from biochemistry to medicinal chemistry and biology.[1] A biological process often involves multiple enzymes, which can work independently or cooperatively to control a specific biological event. Monitoring their activities can provide markers of the progress of such a process (such as the cascade of caspase activity that occurs in apoptosis), and yield information about the mechanism and timing of the interacting species. The ability to track multiple targets in a single event or different processes simultaneously could greatly improve our basic understanding, and facilitate biological and clinical studies as well.