cssi/SciSciGPT-SciSciNet huggingface dataset:
The incorporation of radioactive phosphate into the ribonucleic acid of cell-free preparations of Azotobacter vinelandii

Abstract 1. 1. A cell-free preparation from Azotobacter vinelandii is capable of incorporating [ 32 P]P i into RNA in the presence of Mg 2+ ions and 3-phosphoglyceric acid (or phosphoenol pyruvate). 2. 2. The 105 000 × g particulate fraction as well as the 105 000 × g supernatant fraction are essential for the incorporation. 3. 3. The incorporation is considerably stimulated by the addition of AMP, ADP, ATP or Poly-A at a concentration of 1·10 −3 M. Higher concentrations usually lead to inhibition. 4. 4. The possibility of the labelling of RNA by the freely reversible reaction catalysed by polynucleotide phosphorylase has been ruled out. 5. 5. The radioactive RNA isolated from the incubation mixture behaves as s-RNA and all of its four nucleotidic components are radioactive.
A Nonlinear Transformation Method for Obtaining Approximate Analytic Steady-State Solutions of Nonlinear Stochastic Differential Equations

We exemplify the method of nonlinear transformation (NTR) as a powerful tool for obtaining approximate analytic steady-state solutions of nonlinear stochastic differential equations (SDEs). A number of nonlinear SDEs classified into two-components Haken-Zwanzing model are used to demonstrate its suitability and usefulness.
Structural insights into selective agonist actions of tamoxifen on human estrogen receptor alpha

Tamoxifen—an anti-estrogenic ligand in breast tissues used as a first-line treatment in estrogen receptor (ER)-positive breast cancers—is associated with the development of resistance followed by resumption of tumor growth in about 30 % of cases. Whether tamoxifen assists in proliferation in such cases or whether any ligand-independent pathway to transcription exists is not fully understood; also, no ERα mutants have been detected so far that could lead to tamoxifen resistance. Using in silico conformational analysis of the ERα ligand binding domain (LBD), in the absence and presence of selective agonist (diethylstilbestrol; DES), antagonist (Faslodex; ICI), and selective estrogen receptor modulator (SERM; 4-hydroxy tamoxifen; 4-OHT) ligands, we have elucidated ligand-responsive structural modulations of the ERα-LBD dimer in its agonist and antagonist complexes to address the issue of “tamoxifen resistance”. DES and ICI were found to stabilize the dimer in their agonist and antagonist conformations, respectively. The ERα-LBD dimer without the presence of any bound ligand also led to a stable structure in agonist conformation. However, binding of 4-OHT to the antagonist structure led to a flexible conformation allowing the protein to visit conformations populated by agonists as was evident from principal component analysis and radius of gyration plots. Further, the relaxed conformations of the 4-OHT bound protein exhibited a diminished size of the co-repressor binding pocket in the LBD, thus signaling a partial blockage of the co-repressor binding motif. Thus, the ability of 4-OHT-bound ERα-LBD to assume flexible conformations visited by agonists and reduced co-repressor binding surface at the LBD provide crucial structural insights into tamoxifen-resistance that complement our existing understanding.
Optimal trade-off and distance-classifier circular filters for rotation invariance

We showed that advanced distortion-invariant filters such as OTSDF and DCCF filters can be used in conjunction with circular filters to obtain rotation-invariant correlation filters. The combination allows the calculation of OTSDF and DCCF filters to be greatly simplified when compared to using rotated views of an object to create a filter. The performance of the filters were different yet overall comparable indicating that perhaps different training data could have altered the results. In addition, the filters generated were real-valued so they may be implemented on a wider variety of SLMs usually associated with general distortion-invariant filters.
Innovation attributes and category membership: Explaining intention to adopt technological innovations in strategic decision making contexts

Abstract This study explores the cognitive categories and category attributes that top managers are likely to use in strategic decisions regarding organizational innovation adoptions. Data were collected from 1096 hospital executives nationwide. The findings indicated that (1) innovation attributes of “controllable,” “high relative advantage.” “compatible,” “uncomplicated,” and “low risk” have high cue validity for imaging innovations categorized as “functional” by the top managers; and that (2) innovation category membership determines top managers' intentions to adopt. Future research directions are discussed.
Investigations on the anther culturability of four German spring wheat cultivars and the influence of light on regeneration of green vs. albino plants.

In anther culture experiments with four German spring wheat cultivars (‘Turbo’, ‘Kadett’, ‘Planet’ and ‘Nandu’), ‘Nandu’ showed the best results. The rate of responding anthers with ‘Nandu’ was 0.8 % on medium N6 and 3.7% on potato-2. This was similar to the Chinese cultivar ‘Orofen’. Higher yields of embryoids could be obtained with medium potato-2 than with N6. Experiments with medium potato-2 showed that anther response, production of embryos and regeneration increased with decreasing agarose concentration. Regeneration of green plantlets was improved by differentiation in the dark whereas differentiation under light yielded more than 90 % albino plants.
Advanced thermal management technologies for defense electronics

Thermal management technology plays a key role in the continuing miniaturization, performance improvements, and higher reliability of electronic systems. For the past decade, and particularly, the past 4 years, the Defense Advanced Research Projects Agency (DARPA) has aggressively pursued the application of micro- and nano-technology to reduce or remove thermal constraints on the performance of defense electronic systems. The DARPA Thermal Management Technologies (TMT) portfolio is comprised of five technical thrust areas: Thermal Ground Plane (TGP), Microtechnologies for Air-Cooled Exchangers (MACE), NanoThermal Interfaces (NTI), Active Cooling Modules (ACM), and Near Junction Thermal Transport (NJTT). An overview of the TMT program will be presented with emphasis on the goals and status of these efforts relative to the current State-of-the-Art. The presentation will close with future challenges and opportunities in the thermal management of defense electronics.
Children's Symbolic Representation of Addition and Subtraction Word Problems.

Forty-five first graders were categorized into three levels according to their informal strategies for solving addition and subtraction word problems. They were taught to write canonical and noncanonical open number sentences to symbolically represent the structure of eight types of Change and Combine word problems. Their performances on the posttest indicated that children at each level were successful in learning to symbolically represent and solve the instructed problem types.
Salt-finger convection generated by thermal and solutal capillary motion in a stratified fluid

Abstract Experiments and numerical simulations were performed to study the onset of finger convection in a stratified fluid layer caused by thermal and solutal capillary motion. Experiments were performed in a stratified ethanol–water solution contained in a shallow tank. Capillary motion was generated by a 2°C temperature difference maintained between the sidewalls. It caused the onset of finger convection by bringing relatively warm and solute-rich fluid on top of relatively cooler solute-poor fluid. A two-dimensional numerical simulation at early times prior to the onset of finger convection was carried out. The results clearly show the interactive effects of thermal and solutal capillary motion.
Innovation and efficiency in health care: does anyone really know what they mean?

This paper challenges common perceptions and definitions of innovation and efficiency in health care. Once one accepts that optimum levels of innovation and efficiency will not be driven purely by market forces, as all countries in the world except the United States clearly have, then this is a serious problem. Moreover, even in the United States, this paper documents numerous circular or flawed definitions that are commonly employed for efficiency, and presents opportunities for directions to improve or develop new ways of defining efficiency in health care in ways that may promote innovation more effectively. Establishing more shared understanding of these important concepts in an interdisciplinary systems framework is crucial for making progress in achieving better outcomes for patients with better allocations of scarce resources.
States in 15 O Between 8.8 and 9.0 MeV Excitation

The reaction $^{14}\mathrm{N}(p, \ensuremath{\gamma})^{15}\mathrm{O}$ was used to examine the resonance structure in $^{15}\mathrm{O}$ between 8.8 and 9.0 MeV. The resonance previously reported at ${E}_{p}=1.742$ MeV was found to have two components corresponding to excitations in $^{15}\mathrm{O}$ of 8.920 and 8.925 MeV, respectively. The decay properties of these two levels were studied with high-resolution Ge(Li) detectors, showing that they closely resemble the properties of probable mirror levels at 9.23 and 9.155 MeV in $^{15}\mathrm{N}$.
Point of zero charge of weathered forsterite

Abstract The point of zero charge of forsterite shifts from an estimated 8.9 for the unaltered mineral to 8.4 and 8.0, respectively, after being weathered artificially for 1 h and 4 h. These results corroborate the presence of magnesium-deficient surfaces on the weathered minerals, also indicated by chemical analyses of the solutions. H + and OH − are shown to be potential-determining ions in this system
Dr. Wallace and Dr. Stone reply.

To the Editor: We appreciate the experience that Wendling and colleagues have shared1. Relapsing polychondritis (RP) is a difficult condition to manage and its rarity limits our ability to study the disease and to optimize treatment strategies. Numerous reviews and case reports have cited varying success with a number of treatment strategies, but predicting which patients will respond to … Address correspondence to Dr. Stone; E-mail: jhstone{at}partners.org
Gating Modulation of Connexin45 Gap Junction Channels By Intracellular pH

Intracellular pH (pHi) changes considerably during pathological conditions such as ischemia or epilepsy. Changes of pHi affect the way cells communicate through gap junction (GJ) channels, and therefore disturb normal tissue function. To study pHi-dependent modulation of GJ channels, we used HeLa cells expressing connexin45 (Cx45) or its fusion form with EGFP. The latter along with electrophysiological data allowed us to estimate the proportion of functional channels (NF) within a junctional plaque (JP). We examined how junctional conductance (gj) depends on pHi and how pHi affects voltage-gating properties of Cx45 homotypic and Cx45/Cx43-EGFP heterotypic GJs. Even at pHi= ∼8, where the probability of the channels being fully open approximates 1, gj was maximal but only 5 % of the channels were functional. Changes in pHi from ∼7.2 to ∼8 increased gj ∼1.8-fold in homotypic Cx45 GJs; gj-pHi dependence was sigmoidal with pKa = ∼7. We used a stochastic four-state model of contingent gating to fit experimental gj-Vj dependence, which allowed us to define parameters characterizing voltage-gating sensitivity (V0and A) and NF. We found that alkalization increases gj mainly by increasing V0, i.e., voltage at which open and closed states of hemichannel are at equilibrium. On the other hand, uncoupling by acidification was due to a decrease of both V0 and NF. In both cases, the constant A, characterizing the steepness of gj changes over Vj remained stable. These results agree with data obtained from heterotypic Cx45/Cx43-EGFP GJs in which pKa= ∼6.7, i.e., in between pKas of Cx43-EGFP and Cx45 homotypic GJs. In summary, pHi modulates Vj-gating that largely explains observed pH-dependent changes of cell-cell coupling.
Synthesis and Reactivity of Group 4 Homoleptic Selenolates and Tellurolates: Lewis Base Induced Conversion to Terminal and Bridging Chalcogenides

A combination of either salt metathesis reactions between MCl4 (M = Zr, Hf) and (THF)2LiSeSi(SiMe3)3 (THF = tetrahydrofuran) or between TiCl3(THF)3 and (THF)2LiESi(SiME3)3 (E = Se, Te), or chalcogenolysis reactions between M(CH2Ph)4 (M = Zr, Hf) and HESi(SiMe3)3 (E = Se, Te) afforded the series of compounds M[ESi(SiMe3)3]4 (M = Ti, Zr, Hf; E = Se, Te). The X-ray structures of M[TeSi(SiMe3)3]4 (M = Zr, Hf) and Zr[SeSi(SiMe3)3]4 have been determined and are presented for comparison. Reaction of group 4 tetrabenzyls with 3 equiv of HSeSi(SiMe3)3 gave the complexes M[SeSi(SiMe3)3]3(CH2Ph) (M = Ti, Zr, Hf) in high yields. Treatment of the zirconium and hafnium homoleptic tellurolates with 2 equiv of xylyl isocyanide produced the bis-L trans adducts M[TeSi(SiMe3)3]4[CN(xylyl)]2 (M = Zr, Hf) in moderate yields. The related six-coordinate DMPE adducts M[TeSi(SiMe3)3]4(DMPE) (M = Zr, Hf; DMPE = 1,2-bis(dimethylphosphino)ethane) were similarly prepared. Reaction of the mono-DMPE complexes with a second equilvalent ...
Expression of MHC class II in T cells is associated with increased HIV-1 expression.

HIV-1 replicates in activated T cells at significantly higher levels than in resting cells. Thus, certain molecules up-regulated during T cell activation appear to be important for HIV-1 replication. In this study, we present evidence suggesting that expression of MHC class II (class II) molecules on CD4+ T cells facilitate HIV-1 replication. T cells that expressed class II supported greater virus replication than T cells lacking class II. The class II+ cells, when either infected with HIV-1 or transfected with an env-minus HIV-1 provirus plasmid, produced 10–20-fold greater virus expression than class II− cells. Anti-class II antibody markedly inhibited virus expression in class II+ cells (but not class II− cells) and also decreased the nuclear binding activity of AP-1, an inducible transcription factor important in T cell activation and HIV-1 expression. Most importantly, the induction of class II expression by transfection of the MHC class II transactivator (CIITA) stimulated HIV-1 replication in Jurkat T cells. Taken together, these data suggest that expression of MHC class II molecules and/or CIITA in T cells enhances HIV-1 transcription.
Deletion of the major peroxiredoxin Tsa1 alters telomere length homeostasis

Reactive oxygen species (ROS) are proposed to play a major role in telomere length alterations during aging. The mechanisms by which ROS disrupt telomeres remain unclear. In Saccharomyces cerevisiae, telomere DNA consists of TG(1-3) repeats, which are maintained primarily by telomerase. Telomere length maintenance can be modulated by the expression level of telomerase subunits and telomerase activity. Additionally, telomerase-mediated telomere repeat addition is negatively modulated by the levels of telomere-bound Rap1-Rif1-Rif2 protein complex. Using a yeast strain defective in the major peroxiredoxin Tsa1 that is involved in ROS neutralization, we have investigated the effect of defective ROS detoxification on telomere DNA, telomerase, telomere-binding proteins, and telomere length. Surprisingly, the tsa1 mutant does not show significant increase in steady-state levels of oxidative DNA lesions at telomeres. The tsa1 mutant displays abnormal telomere lengthening, and reduction in oxidative exposure alleviates this phenotype. The telomere lengthening in the tsa1 cells was abolished by disruption of Est2, subtelomeric DNA, Rap1 C-terminus, or Rif2, but not by Rif1 deletion. Although telomerase expression and activity are not altered, telomere-bound Est2 is increased, while telomere-bound Rap1 is reduced in the tsa1 mutant. We propose that defective ROS scavenging can interfere with pathways that are critical in controlling telomere length homeostasis.
6.2.1 Toward Efficient and Effective Contracting Structures and Processes for Systems-of-Systems Acquisition

Acquisition of a system of systems can be an all new acquisition of multiple systems that are intended to operate together as a system-of-systems. Much more common in the DoD is acquisition of one or more new systems that are intended to interoperate with existing systems as a system of systems with new capabilities. In either case, successful acquisition of systems-of-systems (SoS) necessarily depends on effective contracting structures and processes for systems-of-systems acquisition. In this paper, a set of system-of-systems issues that need to be addressed in SoS acquisition are identified and the current findings in this on-going research are discussed. The findings suggest sustainment of extensive systems engineering effort within the SoS acquisition and change to the existing contracting structures and process and organizational structures to maximize the probability of SoS acquisition success. The resulting changes will be applied to current and future DoD SoS acquisitions.
Raman spectroscopy of charge transfer interactions between single wall carbon nanotubes and [FeFe] hydrogenase

We report a Raman spectroscopy study of charge transfer interactions in complexes formed by single-walled carbon nanotubes (SWNTs) and [FeFe] hydrogenase I (CaHydI) from Clostridium acetobutylicum. The choice of Raman excitation wavelength and sample preparation conditions allows differences to be observed for complexes involving metallic (m) and semiconducting (s) species. Adsorbed CaHydI can reversibly inject electronic charge into the LUMOs of s-SWNTs, while charge can be injected and removed from m-SWNTs at lower potentials just above the Fermi energy. Time-dependent enzymatic assays demonstrated that the reduced and oxidized forms of CaHydI are deactivated by oxygen, but at rates that varied by an order of magnitude. The time evolution of the oxidative decay of the CaHydI activity reveals different time constants when complexed with m-SWNTs and s-SWNTs. The correlation of enzymatic assays with time-dependent Raman spectroscopy provides a novel method by which the charge transfer interactions may be investigated in the various SWNT-CaHydI complexes. Surprisingly, an oxidized form of CaHydI is apparently more resistant to oxygen deactivation when complexed to m-SWNTs rather than s-SWNTs.
Trace elements in fines from the Apollo 15 deep drill

Samples of fines from the bottom of the Apollo 15 deep drill core and from each junction between the six 42.5-cm long segments of the drill stem were analyzed for Ag, Co, Cr, Cs, Cu, Ga, Hf, Rb, Sc, and Zn by neutron activation. The most striking feature of the results is the absence of significant variations in concentration for any element throughout the depth of the drill sample and despite the considerable stratigraphy of the cored material. The presence of a significant amount of KREEP material is indicated.
aPKC Phosphorylation of HDAC6 Results in Increased Deacetylation Activity

The Class II histone deacetylase, HDAC6, has been shown to be involved in cell motility, aggresome formation and mitochondria transport. HDAC6 deacetylase activity regulates α-tubulin acetylation levels and thus plays a critical role in these processes. In turn, HDAC6 activity can be regulated by interaction with various proteins including multiple kinases. Kinase mediated phosphorylation of HDAC6 can lead to either increased or reduced activity. Our previous research has shown that sequestosome1/p62 (SQSTM1/p62) interacts with HDAC6 and regulates its activity. As SQSTM1/p62 is a scaffolding protein known to interact directly with the zeta isoform of Protein Kinase C (PKCζ), we sought to examine if HDAC6 could be a substrate for PKCζ phosphorylation and if so, how its activity might be regulated. Our data demonstrate that HDAC6 is not only present in a protein complex with PKCζ but can also be phosphorylated by PKCζ. We also show that specific phosphorylation of HDAC6 by PKCζ increases HDAC6 deacetylase activity resulting in reduced acetylated tubulin levels. Our findings provide novel insight into the molecular mechanism by which HDAC6, PKCζ and SQSTM1/p62 function together in protein aggregate clearance. These results also highlight a new research direction which may prove fruitful for understanding the underlying cause of several neurodegenerative diseases.
Adolescent pregnancy and gestational weight gain: do the Institute of Medicine recommendations apply?

STUDY DESIGN: We studied a retrospective cohort using the Missouri Birth Certificate Registry and included subjects who were primiparous, who had singleton gestations, who were 20 years old, and who delivered at 24-44 weeks gestation. The exposure was defined as weight gain less than, within, or greater than IOM recommendations. Outcomes that were examined were small-for-gestational-age (SGA) infants, large-for-gestational age (LGA) infants, preterm delivery, infant death, preeclampsia, cesarean delivery, and operative vaginal delivery. The analysis was stratified by body mass index category. RESULTS: In any body mass index category, inadequate weight gain was associated with increased odds of SGA infants, preterm delivery, and infant death. When subjects gained more than the IOM recommendations, the number of SGA infants decreased, with slight increases in the number of LGA infants, preeclampsia, and cesarean delivery. CONCLUSION: Adolescents should be counseled regarding adequate weight gain in pregnancy. Further research is necessary to determine whether the IOM recommendations recommend enough weight gain in adolescents to optimize pregnancy outcomes.
Social support, social selection and self-assessed health status: results from the veterans health study in the United States

This study provided a comprehensive assessment of the association between social support and health using longitudinal data from the Veterans Health Study. Unlike previous studies which examined the relationship between one single domain of social support with either mental or physical health, the present study assessed the effects of three different domains of social support on multiple measures of health. The findings of the study indicated that social support tended to mediate the deleterious effects of non-military traumatic events; whereas the adverse consequences of traumatic events experienced in the military were not affected by social support, suggesting that stressors associated with combat had a long lasting effect on the health status of veterans. The study results revealed that compared with those with better health, respondents with poor health were more likely to have lower levels of social support, suggesting that poor health might be a barrier to a person's ability to participate and/or maintain social relationships. The study also showed that different types of social support had varying beneficial effects on different measures of health. While perceived support had a strong effect on all the measures of health (except alcoholism) included in the study, living arrangement had a significant effect on post-traumatic stress disorder or physical health and participation in group activities had a strong effect only on physical functioning. The results of the study highlight the need for future research to determine whether particular types of social support affect various aspects of health differently. This simultaneous focus on multiple support functions and health outcomes is important because it provides insight into the mechanisms linking social support to health.
What Makes a Feminist? Predictors and Correlates of Feminist Social Identity in College Women

What factors predict self-identification as a feminist? College women (N = 233) were given measures of feminist ideology; feminist identity development; evaluation of feminists, collectivism, and individualism. Feminist identification was measured both as a dichotomous and a continuous variable. Measured dichotomously, feminist self-identification was predicted by not having conservative beliefs and having a positive general evaluation of feminists. In addition, self-identified feminists were more likely to believe in collective action; to hold liberal, radical, and womanist ideologies; and to endorse items in the Synthesis stage of identity development. They were less likely to believe a feminist is a lesbian, to endorse items in the Passive Acceptance stage, and to believe in the existence of a meritocracy. Measured continuously degree of feminist identity was predicted by having a positive general evaluation of feminists, not having conservative beliefs, and endorsing items in the Revelation and Embedd...
Effects of cytoskeletal disrupting agents on mouse mammary tumor virus replication.

Abstract Alterations in mouse mammary tumor virus (MMTV) production and composition were induced by exposure of mammary tumor cells to cytodisruptive agents. Treatment with 2.1 × μM cytochalasin D (CD) for 24 h reduced MMTV yield by 80% and electron microscopic examination of these cells did not reveal budding virions. Immune precipitation and quantitative immunofluorescence studies demonstrated that CD had no significant effect on MMTV polypeptide synthesis or surface expression suggesting that CD inhibited late steps in MMTV maturation. Decreases in MMTV production were also observed as a result of 24 h exposure of the cells to 2.1 μM cytochalasin B (CB). However, an initial 70% increase in the levels of extracellular virions within the first 18 h of treatment preceded diminution of virus production. In addition, CB was unable to abrogate maturation and release of MMTV particles as revealed by electron microscopic evaluation of thin sections of treated cells. Colcemid at 0.28 μM had no effect on virus production during the first 24 h of exposure although MMTV yield was reduced by 60–70% after 36 h of treatment. Polypeptide profiles of MMTV purified from cell cultures treated with any of the three cytodisruptive agents were altered and included 5–7 polypeptides not typically present in MMTV from untreated cells. These cytodisruptive agents did not significantly affect viability and protein metabolism of MJY-alpha cells; the data suggest that alterations in MMTV replication were due to disruption of the cellular cytoskeleton.
Side population keratinocytes resembling bone marrow side population stem cells are distinct from label-retaining keratinocyte stem cells.

Very primitive hematopoietic stem cells have been identified as side population cells based on their ability to efflux a fluorescent vital dye, Hoechst 33342. In this study we show that keratinocytes with the same side population phenotype are also present in the human epidermis. Although side population keratinocytes have the same dye-effluxing phenotype as bone marrow side population cells and can be blocked by verapamil, they do not express increased levels of the ABCG2 transporter that is believed to be responsible for the bone marrow side population phenotype. Because bone marrow side population cells have stem cell characteristics, we sought to determine if side population keratinocytes represent a keratinocyte stem cell population by comparing side population keratinocytes with a traditional keratinocyte stem cell candidate, label-retaining keratinocytes. Flow cytometric analyses demonstrated that side population keratinocytes have a different cell surface phenotype (low β1 integrin and low α6 integrin expression) than label-retaining keratinocytes and represent a unique population of keratinocytes distinctly different from the traditional keratinocyte stem cell candidate. Future in vivo studies will be required to analyze the function of side population keratinocytes in epidermal homeostasis and to determine if side population keratinocytes have characteristics of keratinocyte stem cells.
Occurrence of d-amino acids in higher organisms: A survey of the distribution of d-amino acids in marine invertebrates

Abstract 1. 1. d -amino acids assayed using a d -amino acid oxidase (DAO) technique have been found in 18 species of marine invertebrates in six phyla out of a total of 43 species in eight phyla that were analyzed (42%). 2. 2. The apparent tissue concentrations ranged from 44 mM in the polychaete, Glycera dibranchiata to 0.04 mM in the nemertine, Parborlasia corrugatus . 3. 3. Endogenous inhibitors (mol. wt 1000–2000 as determined by gel filtration) were discovered which drastically decrease the sensitivity of the DAO assay technique. It is therefore possible that the reported concentrations are underestimates of the true tissue concentrations. 4. 4. Their wide distribution in marine invertebrates suggests there may be undiscovered physiological and nutritional roles for d -amino acids.
An Investigation of Three Dimensional Elastic-Plastic Hemispherical Sliding Contact, Part II: Results

This work presents the results from a three dimensional (3D) finite element analysis (FEA) of an elastic-plastic asperity contact model for two spherical bodies sliding across each other with various preset vertical interferences. Stresses, forces, contact areas, deformations, and net energy loss are presented for steel-on-steel and aluminum-on-copper contact.Copyright © 2007 by ASME
Analysis and Realization of an Active Noise Control System on DSP Hardware using an fMRI bore model

The performance of Active Noise Control (ANC) Algorithms (epsiv-nLMS and APA) are tested on floating point DSP hardware with high sampling rates to reveal their effectiveness in cancelling noise at high sound pressure levels. The results presented use a realistic primary path of an fMRI bore simulated by a half cylindrical acrylic bore of 0.76 m (D) x 1.52 m (L). Detailed results of the performance of the ANC system are presented in the paper. The results were obtained by using an automated system, designed to systematically test any frequency range with high precision. Our experiments show that the LMS algorithm gives the best performance over all frequencies with cancellation of over 50 dB(A) over a 5 kHz frequency band.
Thermal Conductivity Measurements of Porous Materials in Several Gaseous Environments

6 tonusing the line-source technique. Gases and gas mixtures employed were N2, CO2, 50% CO2 and 50% N2, 50% Ar and 50% CO2, and 11.6% Ar and 88.4% CO2, the last combination representing a simulated Martian atmosphere. Data obtained were analyzed extensively to determine causes for the unusual behavior of some of the data sets. The most plausible explanation of the anomalous behavior appeared to be sorption and/or desorption of water vapor. In addition error analyses of the line-source technique of obtaining thermal conductivity and thermal-difiusivity measurements were made which indicated the importance of obtaining accurate measurements of both temperature and heater-wire current, as the errors are of comparable magnitude. Thermal diffusivity measurements using the line-source technique are shown to have inherently greater scatter than thermal conductivity measurements.
Some unusual case histories from personal experience

Abstract Is protection of equipment the only consideration when setting the relieving pressures of safety relief valves? I will show you a case where other factors should have been considered and suggest that you might give your safety valve set pressures a second thought. Do you have side-by-side pieces of identical equipment? If so, you must consider that operating or maintenance personnel may become confused, and the results maybe catastrophic. A PVC reactor incident will demonstrate this point. Does your process contain materials that could decompose? After thirty years of safe operation in butadiene units, there was a vinyl acetylene decomposition. Could it happen to you? It is my hope that these three unique and unusual cases will provide valuable information for operations and maintenance personnel, managers, safety professionals, and engineers.
Selective influence through conditional independence

Let each of several (generally interdependent) random vectors, taken separately, be influenced by a particular set of external factors. Under what kind of the joint dependence of these vectors on the union of these factor sets can one say that each vector is selectively influenced by “its own” factor set? The answer proposed and elaborated in this paper is: One can say this if and only if one can find a factor-independent random vector given whose value the vectors in question are conditionally independent, with their conditional distributions selectively influenced by the corresponding factor sets. Equivalently, the random vectors should be representable as deterministic functions of “their” factor sets and of some mutually independent and factor-independent random variables, some of which may be shared by several of the functions.
Effect of placebo on ambulatory blood pressure monitoring in children.

Ambulatory blood pressure monitoring (ABPM) has been proposed as a useful tool for more accurately diagnosing hypertension (HTN) and evaluating blood pressure (BP) response in pediatric anti-hypertensive trials. ABPM captures multiple BP measurements during routine daily activities and is thus an excellent method for identifying white-coat HTN. Additionally, ABPM measurements in adults do not demonstrate the placebo effect commonly seen with casual BP measurements, although this has yet to be evaluated in children. Therefore,, the aim of this study was to assess the effect of placebo on ABPM measurements in children. A total of 141 children aged 5–16 years with elevated BP were randomized into a multi-center, single-blind, cross-over trial. Subjects received a placebo pill prior to wearing a 24-h ABPM device at one of two visits separated by 1–2 weeks. Study procedures were otherwise identical at both visits. Mean systolic and diastolic BP for all measured time periods were similar between visits, as was the number of children diagnosed with HTN at each visit. Having confirmed HTN at baseline did not affect the impact of placebo on mean BP. If confirmed, this lack of placebo effect on ABPM measurements may allow for the design of direct comparison pediatric anti-hypertensive trials without a placebo arm.
Coastal phytoplankton blooms in the Southern California Bight

Abstract Surface chlorophyll (CHL) measured at the Scripps Pier in the Southern California Bight (SCB) for 18 years (1983–2000) reveals that the spring bloom occurs with irregular timing and intensity each year, unlike sea-surface temperature (SST), which is dominated by a regular seasonal cycle. In the 1990s, the spring bloom occurred earlier in the year and with larger amplitudes compared to those of the 1980s. Seasonal anomalies of the Pier CHL have no significant correlation with local winds, local SST, or upwelling index, which implies that classical coastal upwelling is not directly responsible for driving chlorophyll variations in nearshore SCB. The annual mean Pier CHL exhibits an increasing trend, whereas the Pier SST has no evident concomitant trend during the CHL observation period. The interannual variation of the Pier CHL is not correlated with tropical El Nino or La Nina conditions over the entire observing period. However, the Pier CHL was significantly influenced by El Nino/Southern Oscillation during the 1997/1998 El Nino and 1998/1999 La Nina transition period. The Pier CHL is highly coherent at long periods (3–7 years) with nearby offshore in situ surface CHL at the CalCOFI (California Cooperative Fisheries Investigations) station 93.27.
Differentiation of underivatized monosaccharides by atmospheric pressure chemical ionization quadrupole time‐of‐flight mass spectrometry

Rationale Differentiation of underivatized monosaccharides is essential in the structural elucidation of oligosaccharides which are closely involved in many life processes. So far, such differentiation has been usually achieved by electrospray ionization mass spectrometry (ESI-MS). As an alternative to ESI-MS, atmospheric pressure chemical ionization mass spectrometry (APCI-MS) should provide complementary results. Methods A quadrupole time-of-flight (QTOF) mass spectrometer with accurate mass measurement ability was used with an APCI heated nebulizer ion source because we believe that a recently published article using a single quadrupole mass spectrometer assigned incorrect identities for APCI ions from hexoses. Using APCI-QTOF, the MS(2) and pseudo-MS(3) mass spectra of 11 underivatized monosaccharides were obtained under various collision voltages. The mass spectra were carefully interpreted after accurate mass measurement. Results Differentiation of three hexoses was achieved by different MS(2) spectra of their [M + NH(4)](+) and [M - H](-) ions. The MS(2) spectra of the [M + NH(4)](+) ions were also used to distinguish methyl α-D-glucose and methyl β-D-glucose, while the pseudo-MS(3) spectra of the [M + H](+) ions were utilized to differentiate the three hexosamine and N-acetylhexosamine stereoisomers. Unique [M + O(2)](-) ions were observed and their distinctive fragmentation patterns were utilized to differentiate the three hexosamine stereoisomers. Conclusions Although ESI coupled with single or triple quadrupole and ion trap mass spectrometers has been widely utilized in the differentiation of monosaccharides, this report demonstrated that APCI-QTOF-MS had its own advantages in achieving the same goal.
Generic Statements Require Little Evidence for Acceptance but Have Powerful Implications

Generic statements (e.g., “Birds lay eggs”) express generalizations about categories. In this paper, we hypothesized that there is a paradoxical asymmetry at the core of generic meaning, such that these sentences have extremely strong implications but require little evidence to be judged true. Four experiments confirmed the hypothesized asymmetry: Participants interpreted novel generics such as “Lorches have purple feathers” as referring to nearly all lorches, but they judged the same novel generics to be true given a wide range of prevalence levels (e.g., even when only 10% or 30% of lorches had purple feathers). A second hypothesis, also confirmed by the results, was that novel generic sentences about dangerous or distinctive properties would be more acceptable than generic sentences that were similar but did not have these connotations. In addition to clarifying important aspects of generics’ meaning, these findings are applicable to a range of real-world processes such as stereotyping and political discourse.
Ultrasensitive p24 Antigen Assay for Diagnosis of Perinatal Human Immunodeficiency Virus Type 1 Infection

We evaluated an ultrasensitive p24 antigen enzyme immunosorbent assay on 802 plasma specimens from 582 infants and children of 0 to 180 days of age. Overall sensitivity and specificity were 91.7% and 98.5%, respectively. After exclusion of infants of less than 7 days of age, the sensitivity and specificity were 93.7% and 98.3%, respectively.
Oil and Water Do Mix

In the 20 November 2009 section of This Week in Science (p. [1040][1]), the piece “Methane's path to captivity” invoked a widespread scientific misconception: the idea that oil and water repel each other. In fact, water molecules and hydrophobic substances—including oil—attract one another,
Two-Color Charge Transfer Transitions as a Probe of Electronic Relaxation and Photodissociation Dynamics at High Densities: Molecular Halogens in Xenon

Two-color charge transfer transitions are developed as a probe of intermolecular potentials, electronic relaxation, and photodissociation dynamics of halogens in condensed rare gases. Two illustrative examples are given: electronic relaxation of Br2 in liquid Xe and recombination dynamics of Cl atoms in high pressures of Xe. The Br2 A(3π1+u) and A'(3π2+u) states, which are in fast equilibrium, are not quenched by the solvent in liquid Xe. In dilute solutions, they relax radiatively via the A' state with a lifetime of ∼ 100 μs. In concentrated solutions, diffusion-controlled self-quenching of Br2(A/A') proceeds with a probability of 0.07 per encounter. An encounter is found to be equivalent to four gas kinetic collisions. The photodissociation of Cl2 and recombination of Cl atoms in gaseous Xe, 1–55 atm, are studied. The recombination kinetics is well reproduced by incorporation of diffusion-controlled encounter frequencies in the rate constants. An equilibrium constant for formation of XeCl(X) of 2.3 × 10−22 cm3 is derived from the kinetic analysis.
Changes in contraceptive use and method mix in Pakistan: 1990-91 to 2006-07

OBJECTIVES To determine (a) whether the influence of the determinants of family planning use in Pakistan changed between 1990-91 and 2006-07 and (b) if these changes were associated with changes in the method mix. METHODS Data from the Pakistan Demographic and Health Surveys (PDHS) of 1990-91 and 2006-07 were used in the analyses. Data on 5184 married non-pregnant fecund women in 1990-91 and 8041 married non-pregnant fecund women in 2006-07 were used. Logistic regression analysis was used to identify factors associated with the use of any contraceptive method and whether the influence of these factors changed between the survey years. Changes in the method mix were examined. RESULTS The effects of urban/rural residence wealth and education on contraceptive use changed between 1990-91 and 2006-07. Differentials in contraceptive use by residence wealth and education declined and were accompanied by changes in the method mix. In rural areas and among less-educated women the contribution of traditional methods to the method mix increased. Among the poorest women the method mix shifted towards traditional methods and condoms. CONCLUSIONS Less-educated rural Pakistani women increased the use of family planning at a faster rate than more-educated urban women by adopting the use of traditional family planning methods. Poor women also increased family planning use more quickly than non-poor women by adopting condoms and traditional methods. The more rapid increase in the demand for family planning among poorer less-educated rural women is a positive trend. In order to convert this demand into the use of longer-term modern methods however access to high quality services must be improved in rural and low-income urban areas.
Distance and Scenic Beauty: A Nonmonotonic Relationship

Distance to major topographic features was found to be highly predictive of perceived scenic beauty of natural scenes. In addition, the hypothesis of a nonmonotonic functional relationship was supp...
Issues in scaling tree size and age responses to ozone: a review

Abstract Ozone is probably the most important regional air pollutant currently affecting forest trees. The vast majority of information regarding ozone effects on trees has come from experiments with seedlings, where controlled concentrations of ozone were administered in indoor or outdoor chambers for periods lasting from several days to one or more growing seasons. However, it is difficult to extrapolate, or scale, results from experiments on seedlings to larger forest trees. Mature trees typically differ from seedlings in morphological, phenological, and physiological characteristics that may profoundly influence response to ozone exposure. Also, it is possible that ozone exposure dynamics may differ for seedlings growing near the ground compared to exposure within the forest canopy. Complicating the ability to scale ozone responses from seedlings to canopy trees are differing interpretations of what is meant by ozone sensitivity. Differences in ozone sensitivity between mature trees and seedlings may occur because of differences in: ozone uptake (avoidance), compensation for injured tissues, internal properties that oppose the production of tissue injury (defense), and repair of tissue injury. Of these mechanisms, avoidance is commonly measured in scaling studies whereas compensation, defense, and repair are not. A review of studies that have compared stomatal conductance between trees of different size and age showed that large trees typically have lower stomatal conductance than seedlings, suggesting greater avoidance of ozone uptake by large trees, but there are notable exceptions to this apparent trend. For tree species where response to ozone and stomatal conductance has been compared between large and small trees, the tree size class with the greatest stomatal conductance showed the greatest detrimental leaf physiological response to ozone. This finding supports the hypothesis that differences in ozone response between different-sized trees of the same species occurs, at least in part, because of differences in ozone uptake. For most of these species (Picea rubens, Pinus ponderosa, Prunus serotina, Sequoiadendron giganteum), large or old trees had lower stomatal conductance and lower ozone foliar injury than small or young trees, whereas for Quercus rubra, large trees had greater stomatal conductance and greater ozone foliar injury than small trees. Drawing firm conclusions from published scaling studies is complicated by wide variation in study methodology and how ‘seedling’ and ‘mature tree’ are defined. To facilitate synthesis and improve prediction of ozone impacts on trees, we recommend that future ozone scaling research examine the occurrence and effectiveness of avoidance, compensation, defense, and repair in trees of different sizes with consistent methodology on a suite of species that vary in ecological and physiological characteristics. We also recommend that future research examine the possible consequences of these mechanisms to long-term ecological success for trees of different sizes in the presence of other biotic and abiotic stresses.
Characteristics of acoustic streaming created and measured by pulsed Doppler ultrasound

Self measurement of acoustic streaming by Doppler ultrasound could be used to evaluate properties of fluids such as viscosity or the coagulation of blood. To characterize acoustic streaming caused by pulsed ultrasonic beams, Doppler signal processing was used to measure streaming velocity under a variety of conditions in vitro using blood and water. Velocities as high as 5 mm/s were measured in blood at the diagnostic power levels (3.5 mW) used in 20 MHz catheter velocimetry. It was found that streaming decreases with distance due to absorption and beam spreading, increases with applied acoustic power, and decreases with increased viscosity during blood coagulation. However, the increase in velocity with acoustic power is nonlinear with an exponent of 0.67 for water and 1.42 for blood even though the radiation force as measured by deflection of a suspended transducer is linear with power. The time constant of streaming to a step change in acoustic power is 80 ms in blood and 200 ms in water. It is concluded that streaming is measurable in pulsed Doppler beams, that it could produce artifacts or unintended effects, and that it could be used to characterize fluid properties and to detect coagulation of whole blood.
Stable competitive coexistence in a continuous fermentor with size-selective properties.

A reactor with size-selective properties was found to allow a mixed culture of Escherichia coli and Saccharomyces cerevisiae to coexist under continuous culture conditions. The reactor consisted of a fermentor with an attached inclined side-arm to recycle the cells by enhanced sedimentation. The larger size yeast population was retained preferentially and recycled at high efficiencies while the smaller yet faster growing bacteria were removed through the side-arm. Stability analysis indicated that the coexistence of this system could be stable only if the net yeast removal rate through the side-arm as a function of the reactor yeast concentration was concave up. This would occur if growth continued in the side-arm or if settling efficiency decreased at higher cell densities. Another experimental system was devised to measure this net removal rate function. A negative removal rate (i.e., a net addition of yeast to the fermentor) was observed at low biomass indicating growth in the settler and explaining the stability of the coexistence steady state.