cssi/SciSciGPT-SciSciNet huggingface dataset:
Aging and the discrimination of 3-D shape from motion and binocular disparity

Two experiments evaluated the ability of younger and older adults to visually discriminate 3-D shape as a function of surface coherence. The coherence was manipulated by embedding the 3-D surfaces in volumetric noise (e.g., for a 55 % coherent surface, 55 % of the stimulus points fell on a 3-D surface, while 45 % of the points occupied random locations within the same volume of space). The 3-D surfaces were defined by static binocular disparity, dynamic binocular disparity, and motion. The results of both experiments demonstrated significant effects of age: Older adults required more coherence (tolerated volumetric noise less) for reliable shape discrimination than did younger adults. Motion-defined and static-binocular-disparity-defined surfaces resulted in similar coherence thresholds. However, performance for dynamic-binocular-disparity-defined surfaces was superior (i.e., the observers’ surface coherence thresholds were lowest for these stimuli). The results of both experiments showed that younger and older adults possess considerable tolerance to the disrupting effects of volumetric noise; the observers could reliably discriminate 3-D surface shape even when 45 % of the stimulus points (or more) constituted noise.
Functional heterogeneity of mesenchymal stem cells: Implications for cell therapy

The term mesenchymal stem cell (MSCs) was adopted in the 1990s to describe a population of bone-marrow-derived cells that demonstrated the capacity for tri-lineage differentiation at a clonal level. Research conducted during the ensuing decades has demonstrated that MSCs fulfill many functions in addition to connective tissue progenitors including contributing to the HSC niche and regulating the function of immune effector cells of both the innate and adaptive immune system. Despite these advances, fundamental aspects of MSC biology remain indeterminate. For example, the embryonic origin of MSCs and their niche in vivo remains a highly debated topic. More importantly, the mechanisms that regulate self-renewal and lineage specification have also been largely unexplored. The later is significant in that MSC population's exhibit considerable donor-to-donor and intra-population heterogeneity but knowledge regarding how different functional attributes of MSCs are specified at the population level is unknown. This poses significant obstacles in research and in efforts to develop clinical manufacturing protocols that reproducibly generate functionally equivalent MSC populations. Herein, I discuss data demonstrating that MSC populations are intrinsically heterogeneous, elaborate on the molecular basis for this heterogeneity, and discuss how heterogeneity impacts clinical manufacturing and the therapeutic potency of MSCs.
The consumer retail search process: A conceptual model and research agenda

Consumers are continually faced with the task of finding their way through a wide variety of retail environments. Surprisingly, very little research has addressed questions about how consumers physically search through retail settings. This article explores this important, yet little researched behavior. A conceptual model of the consumer’s retail search process (CRSP) and several research propositions are advanced. The CRSP model integrates research findings relevant to an understanding of consumer retail search behavior. Literature from such diverse fields of scientific inquiry as environmental psychology, human factors, architecture, and marketing are reviewed and serve as the theoretical basis of the CRSP model.
Ten new species of chiggers (Acari: Trombiculidae) from bat hosts from the Philippines

Abstact Ten new species of chiggers are described from specimens collected from bat hosts on Leyte and Negros Islands., Philippines. Comments on the genera are provided. The new species are: Cheladonta (Susa) chiropteraphilus n.sp., Chiroptella (Neosomia) heidemani n.sp., Diplectria manjuyodensis n.sp., Microtrombicula (Microtrombicula) megaderma n.sp., Microtrombicula (M.) octaintercoxalaea n.sp., Myotrombicula (Myotrombicula) armigera n.sp., Myotrombicula (Myo.) oconnori n.sp., Rudnicula hex-asternalaea n.sp., Sasatrombicula leegoffi n.sp. and Trombigastia tehminae n.sp
Reductive dehalogenation of trichloroethylene: kinetic models and experimental verification

Abstract This paper develops a generalized kinetic model for two-phase systems involving reactions in one phase with product partitioning into a second phase, and applies it to the reductive dehalogenation of trichloroethylene using two systems. The generalized approach can be used for a variety of catalyst choices, including zero-valent metals. With vitamin B 12 , the model includes specific reaction pathways for the reductive dehalogenation of TCE combined with the partitioning of reactants, intermediates, and products between the gas and liquid phases. The model has been used to study the effect of various parameters on the process effectiveness, which otherwise are very difficult to conceive through experimental analysis. In the case of zero-headspace system with zero-valent iron, sorption effects are included to incorporate the partitioning onto the solid surface. A new parameter, `fractional active site concentration' is introduced to incorporate the differences in reactive and nonreactive sites on the iron surface, which affects the degradation performance. The generalized model has important implications for kinetic modeling, monitoring of VOCs and their degradation products, and design and selection of remediation technologies for such materials. The model predictions have been verified with our experimental data and the results from the literature.
Contractual issues for faculty practice.

Abstract Contracts are a common foundation for faculty practice relationships between a college of nursing and other agencies. Although the legal format of a contract is relatively standardized, the process of contracting entails decisions and issues that increase its complexity. Little is available in the faculty practice literature that addresses contracts and contractual issues as a comprehensive whole. This article contains discussions of nursing faculty practice contractual issues such as the elements of a contract as a framework, including competent parties, offer, consideration, and acceptance. Evaluation of contract performance is addressed and alternatives for decision making and problem resolutions are suggested throughout. J Prof Nurs 17:173-179, 2001. Copyright © 2001 by W.B. Saunders Company
Multi-state initiative to enhance pollution prevention technology diffusion using the ADOP2T model

Abstract Accelerated Diffusion of Pollution Prevention Technologies (ADOP2T) is a stepwise model designed to improve the implementation rate of pollution prevention technologies. It focuses on reducing the uncertainty associated with new technologies by providing demonstrations and “how-to” knowledge through pilot testing. Three university-based technical assistance programs collaborated to promote implementation of pollution prevention technologies using the ADOP2T model. This paper briefly describes the model, and discusses the experiences, observations, and results obtained by the technical assistance programs that used the model.
Electrical Spiking in Escherichia coli Probed with a Fluorescent Voltage-Indicating Protein

Bacteria have many voltage- and ligand-gated ion channels, and population-level measurements indicate that membrane potential is important for bacterial survival. However, it has not been possible to probe voltage dynamics in an intact bacterium. Here we developed a method to reveal electrical spiking in Escherichia coli. To probe bacterial membrane potential, we engineered a voltage-sensitive fluorescent protein based on green-absorbing proteorhodopsin. Expression of the proteorhodopsin optical proton sensor (PROPS) in E. coli revealed electrical spiking at up to 1 hertz. Spiking was sensitive to chemical and physical perturbations and coincided with rapid efflux of a small-molecule fluorophore, suggesting that bacterial efflux machinery may be electrically regulated.
Identifying and Nurturing Future Innovators in Science, Technology, Engineering, and Mathematics: A Review of Findings From the Study of Mathematically Precocious Youth

Calls to strengthen education in science, technology, engineering, and mathematics (STEM) are underscored by employment trends and the importance of STEM innovation for the economy. The Study of Mathematically Precocious Youth (SMPY) has been tracking over 5,000 talented individuals longitudinally for 40 years, throwing light on critical questions in talent identification and development in STEM. SMPY includes individuals identified in 7th/8th grade as in the top 1% or higher in mathematical or verbal ability, and a comparison group identified as top STEM graduate students. SMPY findings cover the educational and occupational attainments of participants, including a large percentage earning a degree or pursuing high powered careers in STEM; gender differences; the extent to which high school experiences, abilities, and interests predict later outcomes; and subsequent creative production. Mathematical reasoning ability as measured by standardized tests is a reliable predictor for later math/science engagem...
EVIDENCE OF ANOMALOUS THERMAL EXPANSION OF WATER IN CEMENT PASTE

A comparative study of permeability measurement by thermopermeametry (TPA) and beam bending was performed on cement paste. To bring the two measurements into agreement, it is necessary to recognize that the pore solution has a thermal expansion coefficient about one and a half times that of bulk liquid and to account for viscoelastic stress relaxation during TPA experiments. The anomalous thermal expansion is not accounted for by the presence of ions in the cement paste pore solution.
Characteristics of Vomiting Associated with Acute Sustained Release Theophylline Poisoning: Implications for Management with Oral Activated Charcoal

Vomiting in acute theophylline toxicity has assumed increased clinical importance since the introduction of multiple dose activated charcoal therapy. We performed a prospective study of 26 patients with acute overdose of sustained release theophylline to characterize vomiting, and its possible interference with the acceptance of activated charcoal. Twenty five of 26 patients vomited. The duration of vomiting correlated with both peak serum theophylline concentrations (p less than 0.001) and the duration of theophylline toxicity (p less than 0.001). Vomiting extended over 63% of the drug's absorptive phase (the time interval between ingestion and the peak level) and 49% of the elimination phase (the time interval between the peak level and decrease of theophylline level to less than 20 mcg/ml). Patients with peak serum theophylline concentrations less than 70 mcg/ml were able to accept larger amounts of activated charcoal than patients with serum theophylline concentrations greater than 70 mcg/ml (113 +/- 15 gms vs. 57 +/- 24 gms, p less than 0.05). Vomiting in acute sustained release theophylline toxicity is protracted, and limits the use of activated charcoal especially in patients with severe acute theophylline poisoning.
Type I Interferon Induction during Influenza Virus Infection Increases Susceptibility to Secondary Streptococcus pneumoniae Infection by Negative Regulation of γδ T Cells

The majority of deaths following influenza virus infection result from secondary bacterial superinfection, most commonly caused by Streptococcus pneumoniae. Several models have been proposed to explain how primary respiratory viral infections exacerbate secondary bacterial disease, but the mechanistic explanations have been contradictory. In this study, mice were infected with S. pneumoniae at different days after primary influenza A (X31) virus infection. Our findings show that the induction of type I interferons (IFNs) during a primary nonlethal influenza virus infection is sufficient to promote a deadly S. pneumoniae secondary infection. Moreover, mice deficient in type I interferon receptor (IFNAR knockout [KO] mice) effectively cleared the secondary bacterial infection from their lungs, increased the recruitment of neutrophils, and demonstrated an enhanced innate expression of interleukin-17 (IL-17) relative to wild-type (WT) mice. Lung γδ T cells were responsible for almost all IL-17 production, and their function is compromised during secondary S. pneumoniae infection of WT but not IFNAR KO mice. Adoptive transfer of γδ T cells from IFNAR KO mice reduced the susceptibility to secondary S. pneumoniae infection in the lung of WT mice. Altogether, our study highlights the importance of type I interferon as a key master regulator that is exploited by opportunistic pathogens such as S. pneumoniae. Our findings may be utilized to design effective preventive and therapeutic strategies that may be beneficial for coinfected patients during influenza epidemics.
Dating jealousy among college students

In a study of dating jealousy, questionnaires were administered to 147 male and 189 female college students. Subjects were asked to rate how they would feel about their dating partner's behavior in five hypothetical situations designed to measure jealousy. Results indicate that females are more jealous than males over situations involving the partner spending time on a hobby or with family members, but other situations evoke no sex differences. Sex-role orientation is the variable most consistently related to dating jealousy, with sex-role traditional subjects being the most jealous. A significant proportion of subjects expect dating partners to give up close personal friendships with others of the opposite sex, and most subjects begin to expect sexual exclusiveness from the earliest stages of their relationships.
Enhancing the sensitivity of ionic liquid sensors for methane detection with polyaniline template

Abstract Flammable gas sensors are essential in occupational health and safety to prevent fire or explosion in gas facilities and underground mining. Our early study demonstrated that ionic liquid (IL)/quartz crystal microbalance (QCM) gas sensors and sensor arrays were excellent for the detection of various organic vapors at both room temperature and elevated temperatures. In this paper, we developed a general method that significantly enhanced the sensitivity of the IL/QCM sensors for flammable gases detection by immobilizing IL on a conductive polymer polyaniline (PAn) template. Studies were performed to optimize the PAn oxidation states, thickness, and IL concentrations. Results showed that the sensitivity increased with increasing the PAn film thickness and the amount of IL immobilized within the PAn film. The sensitivity depended also on the oxidation state and doping state of PAn. With doped and partially oxidized PAn (emeraldine salt) the IL/QCM sensor showed the best performance. The current detection limit for methane was as low as about 115 ppm at room temperature. The sensitivity also depended on the structure of the IL used. Among the four ILs tested, two of them showed excellent sensitivities after being immobilized in the PAn film.
Early transition metal complexes containing 1,2,4-triazolato and tetrazolato ligands: synthesis, structure, and molecular orbital studies.

Several early transition metal complexes bearing 1,2,4-triazolato and tetrazolato ligands have been prepared by reaction of the pyrazolato complexes Ti(tBu2pz)4-xClx (tBu2pz = 3,5-di-tert-butylpyrazolato; x = 1, 2) and M(tBu2pz)5-xClx (M = Nb, Ta: x = 2, 3) with the sodium or potassium salts derived from 1,2,4-triazoles and tetrazoles. The X-ray structure analysis of Ti(tBu2pz)2(Me2C2N3)2 shows η2-coordination of the 1,2,4-triazolato ligands, while in Ti(tBu2pz)3(C2H2N3) and Nb(tBu2pz)3(Me2C2N3)2 the analogous groups are joined in a η1-fashion in the solid-state structure. Solution NMR studies at different temperatures suggest transition states involving η2-1,2,4-triazolato ligands for the complexes containing η1-1,2,4-triazolato ligands in the solid state. X-ray crystal structures of analogous tetrazolato complexes Ti(tBu2pz)3(PhCN4) and Nb(tBu2pz)3(PhCN4)2 show η1-coordination of the 2-nitrogen atoms of the tetrazolato ligands. Molecular orbital calculations have been carried out on several model titan...
Viability of Escherichia coli K-12 DNA adenine methylase (dam) mutants requires increased expression of specific genes in the SOS regulon.

We have examined the level of expression of the SOS regulon in cells lacking DNA adenine methylase activity (dam-). Mud (Ap, lac) fusions to several SOS operons (recA, lexA, uvrA, uvrB, uvrD, sulA, dinD and dinF) were found to express higher levels of β-galactosidase in dam- strains than in isogenic dam+ strains. The attempted construction of dam- strains that were also mutant in one of several SOS genes indicated that the viability of methylase-deficient strains correlates with the inactivation of the SOS repressor (LexA protein). Consistent with this, the wild-type functions of two LexA-repressed genes (recA and ruv) appear to be required for dam- strain viability.
Hydrogen production from methane using an RF plasma source in total nonambipolar flow

A radio-frequency (RF) helicon plasma reaction chamber (HPRC) is developed and used to decompose methane gas into high-purity hydrogen gas and solid carbon in the form of graphite. A single-turn (m = 0) helicon antenna, operated at 13.56 MHz, and a 100 G dipole magnetic field are used to excite a helicon mode in a nonthermal plasma, creating plasma densities exceeding 1013 cm−3 using 8–20 SCCM methane gas at up to 1300 W of RF power. The HPRC device takes advantage of a uniform large amplitude electron sheath across the exit aperture. At this aperture, all of the incident electron flux from the plasma is extracted and all ions are reflected back into the source. In this way, only neutrals and electrons are allowed out of the reaction chamber, enhancing the breakdown of methane into deposited carbon and hydrogen gas that escapes. A methane decomposition percentage of 99.99 ± 0.06% is demonstrated using 1300 W of RF power and a methane gas flow rate of 8 SCCM. A total nonambipolar flow of particles maximizes the recirculation of ions, and leads to the very high degree of molecular decomposition achieved in this proof-of-concept device. The HPRC in its present proof-of-concept form requires 37× more energy per kg of H2 produced, compared with steam-methane reformation, though this energy comparison does not include the energy required to sequester the emitted CO2 during the steam–methane reformation cycle.
Experimental demonstration of a Rayleigh-scattered laser guide star at 351 nm.

A commercially manufactured excimer laser was used to project a focused laser beam into the atmosphere to altitudes in the range of 10 to 30 km. Rayleigh-backscattered light from a slice of the illuminated column, when imaged in a ground-based telescope, produced an image that is essentially identical to that of a natural star. This experiment demonstrates the ease of producing bright and sharply focused laser guide stars at 351 nm. Such laser guide stars are ideal for guiding astronomical telescopes equipped with adaptive optics.
Comparative study of the vapor analytes of trinitrotoluene (TNT)

Trinitrotoluene (TNT) is a high explosive used in most antipersonnel and antitank landmines. The Institute for Biological Detection Systems (IBDS) has developed a quantitative vapor delivery system, termed olfactometer, for conducting canine olfactory research. The research is conducted utilizing dynamic conditions, therefore, it is imperative to evaluate the headspace of TNT to ensure consistency with the dynamic generation of vapor. This study quantified the vapor headspace of military- grade TNT utilizing two different vapor generated methodologies, static and dynamic, reflecting differences between field and laboratory environments. Static vapor collection, which closely mimics conditions found during field detection, is defined as vapor collected in an open-air environment at ambient temperature. Dynamic vapor collection incorporates trapping of gases from a high flow vapor generation cell used during olfactometer operation. Analysis of samples collected by the two methodologies was performed by gas chromatography/mass spectrometry and the results provided information with regard to the constituents detected. However, constituent concentration did vary between the sampling methods. This study provides essential information regarding the vapor constituents associated with the TNT sampled using different sampling methods. These differences may be important in determining the detection signature dogs use to recognize TNT.
Adolescent Same-Sex Attraction and Mental Health: The Role of Stress and Support

This study draws on the social stress model from the sociology of mental health to examine the impact of same-sex attraction on depressed mood and suicidal tendencies. Specifically, we hypothesize that across multiple contexts, adolescents with same-sex attractions are likely to experience more social stress and less social support than heterosexual adolescents. In turn, these experiences increase the likelihood of negative mental health outcomes. Using data from the National Longitudinal Study of Adolescent Health (n = 11,911), we find that adolescents with same-sex attraction are more likely than their heterosexual counterparts to report depressed mood and suicidal tendencies. Moreover, stress and social support were found to mediate a substantial part of the relationship between same-sex attraction and depressed mood. In addition, stress and social support mediated about one third of the relationship between same-sex attraction and suicidal tendencies. These findings give strong support for the social ...
Lack of specificity in the interactions of cranial sensory and motoneuron axons in vitro

During embryogenesis sensory innervation is established quite precisely, but the mechanisms responsible are poorly understood. Whereas sensory neurons that supply muscle appear to require nearby motor axons to reach their target muscles, sensory neurons that supply skin do not. We have investigated the specificity with which sensory axons interact with motor axons, using the avian trigeminal sensory system, where prospective cutaneous and muscle afferents are anatomically separate. To test whether muscle afferents selectively associate with the appropriate motor axons, we co-cultured muscle afferents from the trigeminal mesencephalic nucleus with appropriate trigeminal motoneurons from rhombomeres 2/3 and with inappropriate facial motoneurons from rhombomeres 4/5. To test whether prospective cutaneous and muscle afferents can be distinguished by their interactions with motor axons, we cocultured cutaneous neurons from trigeminal ganglia with trigeminal motoneurons. Dye labeling and time-lapse videomicroscopy revealed no obvious differences between the interactions of muscle afferents with appropriate and inappropriate motor axons or between the interactions of cutaneous and muscle afferents with motor axons. Sensory axons intermixed freely with and crossed over motor axons without fasciculating, regardless of the combination of sensory and motor axons examined. These results suggest that outgrowing sensory neurons may not yet have distinct identities, raising the possibility that sensory innervation patterns are determined more by spatial or temporal constraints on axon growth than by active pathway or target selection. In contrast, motor axons often retracted upon contacting sensory afferents, indicating that there are marked differences between sensory and motor growth cones at the stages studied.
Finite deformation analysis of liquefaction-induced flow failure in soil embankments

A finite element formulation is proposed for finite deformation dynamic analysis of saturated soil systems. The formulation is based on an updated Lagrangian approach and specifically considers the finite deformation effects on the flow of water through a soil element which undergoes a large deformation or rotation. A two-surface plasticity model is used to model the stress-strain behaviour of the soil skeleton. The proposed formulation has been implemented and is applied to simulate the response of a centrifuge model embankment. The calculated response is in good agreement with the observed behaviour of the soil embankment in the centrifuge test.
Stimulus control in pigeons after extended discriminative training.

The effects of amount of training on conditioned inhibition and on the degree of stimulus control were studied using pigeons. The ability of an S- associated with non-reinforcement of suppress positive reinforced behavior was acquired very rapidly during discriminative training. Increased S+, S- training appeared to weaken this conditioned inhibitory effect while at the same time more S+ training apparently increased the amount of external inhibition (non-conditioned inhibition) of positively reinforced behavior by a novel stimulus. Behavioral contrast and incremental generalization gradients along the S- dimension (inhibitory dimensional control) were absent at all stages of training. Behavioral contrast and inhibitory dimensional control are therefore not necessary concomitants of conditioned inhibition by an S-. A new method of assessing the suppressive effects of stimuli during generalization tests was described.
One- and two-photon dissociation of acetyl chloride at 193 nm

Abstract The photolysis of CH 3 COCl by 193 nm radiation yields Cl, CH 3 , CO, and CH amongst its photodissociation products. The Cl and CH 3 fragments are formed in equal amounts with a quantum yield of 0.90±0.07 relative to the photodissociation of methyl chloride at 193 nm. The CO is born with a vibrational temperature of 2600 +400 −300 K. The concentrations of Cl, CH 3 , and CO are first order in laser power indicating that they arise from a one-photon process. The CH fragment is formed in the B 2 Σ − and A 2 Δ states. Its formation varies quadratically with laser power and is attributed to resonance-enhanced two-photon dissociation of acetyl chloride.
In vitro metabolism of the nephrotoxicant N-(3,5-dichlorophenyl)succinimide in the Fischer 344 rat and New Zealand white rabbit

1. The nephrotoxicant N-(3,5-dichlorophenyl)succinimide (NDPS) underwent nonenzymatic hydrolysis to N-(3,5-dichlorophenyl)succinamic acid (NDPSA) in buffer, rat liver and kidney homogenates, and rabbit liver homogenates. 2. In the presence of NADPH, rat liver homogenates converted NDPS to NDPSA and N-(3,5-dichlorophenyl)-2-hydroxysuccinamic acid (2-NDHSA). 3. Using liver homogenates from the phenobarbital (PB)-pretreated rat, 2-NDHSA production was increased 5-fold, and the metabolites N-(3,5-dichlorophenyl)-2-hydroxysuccinimide (NDHS) and N-(3,5-dichlorophenyl)-3-hydroxysuccinamic acid (3NDHSA) were also detected. Formation of these latter metabolites was suppressed by CO or omission of NADPH. No hydroxylated metabolites were detected when NDPSA was incubated with PB-induced rat liver homogenates. 4. Oxidative metabolites were not produced when NDPS was incubated with kidney homogenates from the control or PB-pretreated rat. 5. NDHS underwent rapid hydrolysis in buffer to yield 2-NDHSA and 3-NDHSA. 6. Rabbit liver homogenates converted NDPS to NDPSA, 3,5-dichloroaniline (DCA), and succinic acid (SA). Production of DCA and SA was inhibited by the amidase inhibitor bis-p-nitrophenyl phosphate. Oxidative metabolism did not occur in rabbit tissue. 7. These experiments demonstrate that a PB-inducible form of rat liver P450 converts NDPS to NDHS, which then undergoes hydrolysis to 2-NDHSA and 3-NDHSA. An alternative route of production for 2-NDHSA and 3-NDHSA, via hydroxylation of NDPSA, does not occur. In rabbit liver NDPS metabolism was primarily amidase-mediated.
Magnetic resonance, non-Fermi-liquid behavior, and disorder in f-electron materials

Abstract Magnetic resonance techniques are local probes of real-space magnetism. As a result NMR and μ SR spectra are sensitive to disorder, and thus are suited to investigations of disorder-driven effects. Three such studies in non-Fermi liquid (NFL) f -electron metals are reviewed: (1) Cu NMR and μ SR linewidths in NFL UCu 5 - x Pd x reveal that uncompensated spins at low energies due to atomic-scale disorder are a major factor in these alloys. (2) 29 Si NMR in CePtSi 1 - x Ge x shows that disorder influences the NFL behavior for x = 0.1 but not for x = 0 . (3) 27 Al NMR impurity satellite linewidths in f -site diluted NFL alloys U 1 - x La x Pd 2 Al 3 , x ≲ 1 , give evidence for a modest degree of disorder which, however, does not appreciably affect the NFL behavior of this system.
A two dimensional asymmetrical crack problem

The distribution of stress in the neighborhood of a Griffith crack located asymmetrically in an infinitely long elastic strip is considered. It is assumed that the edges of the strip are stress free and that the crack is opened by an internal pressure varying along its length. Expressions are derived up to the order of δ−8, where 2δ denotes the thickness of the strip, for the stress intensity factor, the shape of the deformed crack, and the crack energy.
Binding of soybean agglutinin to glycolipid components of porcine lymphocyte plasma membranes

Abstract 125I-Labeled soybean agglutinin binds primarily to glycolipids contained in pig lymphocyte plasma membranes as measured by in situ “staining” of membranes subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Separation of these glycolipids by differential extraction, silicic acid chromatography, and high-performance thin-layer chromatography showed that three different species of plasma membrane glycolipid bind this lectin; trihexosyl ceramide, globoside, and ganglioside GM2 in order of increasing affinity (over a range of 10- to 20-fold). Trihexosyl ceramide and globoside, major neutral membrane glycolipids, are the major binders; while GM2, a minor acidic glycolipid, is a quantitatively smaller lectin-binding component.
Prostate cancer chemoprevention: update of the prostate cancer prevention trial findings and implications for clinical practice.

This article updates the findings of the Prostate Cancer Prevention Trial (PCPT) based on recent publications and reviews of the PCPT. New evidence shows that finasteride reduces the overall risk of prostate cancer by 30% and reduces the risk of clinically significant prostate cancer, including high-grade tumors. For tumors with Gleason scores of ≤ 6, men in the finasteride arm had a relative risk reduction (RRR) of 34% (RR, 0.66; 95% CI, 0.55–0.80; P ≤ 0.0001); tumors with Gleason scores of ≥ 7 had an RRR of 27% (RR, 0.73; 95% CI, 0.56-0.96; P = 0.02). The effect of finasteride on sexual function appears to be minimal as men on finasteride had an average 3.21 point increase on the 100 point Sexual Activity Scale compared with men on placebo. With an excellent safety profile and minimal side effects, men aged 55 years or older should be informed of the opportunity to reduce their risk of prostate cancer with finasteride.
Physics of laser-driven plasma-based electron accelerators

Laser-driven plasma-based accelerators, which are capable of supporting fields in excess of 100 GV/m, are reviewed. This includes the laser wakefield accelerator, the plasma beat wave accelerator, the self-modulated laser wakefield accelerator, plasma waves driven by multiple laser pulses, and highly nonlinear regimes. The properties of linear and nonlinear plasma waves are discussed, as well as electron acceleration in plasma waves. Methods for injecting and trapping plasma electrons in plasma waves are also discussed. Limits to the electron energy gain are summarized, including laser pulse diffraction, electron dephasing, laser pulse energy depletion, and beam loading limitations. The basic physics of laser pulse evolution in underdense plasmas is also reviewed. This includes the propagation, self-focusing, and guiding of laser pulses in uniform plasmas and with preformed density channels. Instabilities relevant to intense short-pulse laser-plasma interactions, such as Raman, self-modulation, and hose instabilities, are discussed. Experiments demonstrating key physics, such as the production of high-quality electron bunches at energies of 0.1-1 GeV, are summarized.
STRUCTURE OF CONIFEROUS FOREST COMMUNITIES IN WESTERN WASHINGTON: DIVERSITY AND ECOTOPE PROPERTIES*

Vegetation patterns were examined in three regions of coniferous forest, arrayed along a gradient of decreasing maritime influence. The following responses to decreasing maritime influence were noted: all aspects of species diversity increase; growth-form complexity increases; habitat heterogeneity increases; species habitat breadths decrease; and habitat overlaps decrease. These observations result from studies of both individual plots and data aggregated into community types. The contrasts between the maritime western study region and the more continental eastern study region imply that ecotope differentiation increases from west to east. The enhanced structural complexity of the eastern region results from climatical limitation of the dominant tree species. Reduced canopy dominance produces greater within-habitat heterogeneity with respect to moisture, light, and soil properties. Furthermore, contrasts between the extremes of the topographic-moisture gradient increase toward the east. These factors combine to increase alpha, beta, and gamma diversities in the eastern study region above those of the western study region. Corresponding to these diversity trends are decreasing mean relative niche, habitat, and ecotope breadths of species toward the east
Synthesis and spectra of some 2H-, 13C-, and 15N-labeled isomers of 1,3,3-trinitroazetidine and 3,3-dinitroazetidinium nitrate

Abstract The title compounds were synthesized by utilizing appropriately labeled starting materials and reagents according to literature procedures.1,2 The products were characterized by NMR and mass spectral analysis. Unequivocal assignments of all NMR chemical shifts of the unlabeled title compounds and their intermediate precursors were facilitated by the NMR spectra of the labeled compounds along with carbon-hydrogen correlation experiments.
Cancer mortality among Mormons

Preliminary results show that the 1970-72 cancer mortality rate among California Mormon adults is about one-half to three-fourths that of the general California population for most cancer sites, including many sites with an unclear etiology. Furthermore, the cancer death rate in the predominately Mormon state of Utah is about two-thirds to three-fourths of the United States rate, and the lowest in the entire country. Mormons are a large, health-conscious religious group whose Church doctrine forbids the use of tobacco, alcohol, coffee, and tea, and recommends a nutritious diet. Initial indications are that Mormons as a whole smoke and drink about half as much as the general population, and that active Mormons abstain almost completely from tobacco and alcohol. However, they appear to be fairly similar to the general white population in other respects, such as socioeconomic status and urbanization. The significance of these findings is discussed.
186Re/188Re labeled polypeptide microspheres as a potential radiation synovectomy agent

Polypeptide microspheres containing polycysteine crosslinked with polylysine were prepared and radiolabeled with186Re and188Re. High labeling yields with the microspheres with both186Re and188Re (97%) were obtained, and above 99% retention of radiolabels in water in 24 hours was obtained. Rhenum-186 labeled polycysteine and polylysine microspheres (1∶1 ratio, 20 μm as mean diameter) were injected intra-articularly into the rear stifes (knee joints) of normal New Zealand white rabbits. About 87% of injected dose was retained in rabbit stifles and adjacent tissues in 96 hours after injection, while most of the activity lost from the joints was excreted in the urine. Due to its simplicity of preparation and radiolabeling, versatility, and biodegradability, this type of conjugate system may become the therapeutics of choice for radiation synovectomy.
Paracelsus, religion, and dissent: the case of Philipp Homagius and Georg Zimmermann.

Les livres de Paracelse traitant de discussions abusives sur la divinite et la trinite sacree sont critiques et detruits par Zimmermann (G.) et Homagius (P.H.)
Contribution of tactile afferent information to the control of isometric finger forces

The ability to match the voluntary isometric force output of the right and left index fingers when the contact surfaces differ in shape was examined. Before the experiment, subjects were trained to produce both a “low” force level (50±25 g) and a “high” force level (200±50 g) with the right and left index finger, separately. Following the training session, subjects were instructed to match the forces of both fingers simultaneously within the required range (either low or high) so that the forces were perceived to be identical. One of the index fingers pushed against a conical contact pad, while the other pushed against a flat contact pad. Midway through the experiment, the two contact pads were reversed. Subjects consistently produced less force with the finger pressing against the conical pad. This asymmetry could already be seen during the beginning of the ramp increase in force and continued throughout the trial, independent of the target force levels (low or high). These findings suggest tactile afferent information at the fingertip is important for determining the voluntary force exerted by the finger. It must be properly integrated with other peripheral information as well as with the central motor command, otherwise the perception of force is distorted. Furthermore, the perception of the force produced seemingly is dependent on the extent to which the skin of the fingertip is indented rather than the local pressure exerted at the skin.
Frequency/Wavelength Calibration of Multipurpose Multichannel Raman Spectrometers. Part II: Calibration Fit Considerations and Calibration Standards

Approaches for frequency/wavelength calibration of multichannel Raman spectrometers are presented. These approaches are directed towards practical use in laboratories in which multipurpose or specialized applications result in the need for frequent spectrometer calibration. These approaches are also useful when the sample type or configuration does not permit calibration by more routine methods. Guidelines are presented for effective use of polynomials commonly found in spectrometer calibration software for conversion of pixel number to either wavenumber or wavelength. Guidelines for the selection and use of Raman calibration standards are also presented. Standards currently used for calibration of Raman spectrometers are reviewed. Improved frequency data for indene and the Ar+ plasma lines are presented, along with frequency data for two materials (imidazole and α-cyclodextrin) which are recommended for use as solid Raman standards.
Arsenic alters cytosine methylation patterns of the promoter of the tumor suppressor gene p53 in human lung cells: a model for a mechanism of carcinogenesis

Arsenic is a potent human carcinogen to which there is significant worldwide exposure through natural contamination of food and drinking water sources. Because arsenic is detoxified via methylation using a methyltransferase (MTase) and S-adenosylmethionine (SAM) as the methyl donor, we hypothesized that a mechanism of carcinogenesis of arsenic could involve alterations of MTase/SAM-dependent DNA methylation of a tumor suppressor gene. We found that exposure of human lung adenocarcinoma A549 cells to sodium arsenite (0.08-2 microM) or sodium arsenate (30-300 microM), but not dimethylarsenic acid (2-2000 microM), produced significant dose-responsive hypermethylation within a 341-base pair fragment of the promoter of p53. This was determined by quantitative PCR/HpaII restriction site analysis to analyze methylation status of two CCGG sites. In experiments with arsenite, DNA sequencing using bisulfite to visualize 5-methylcytosine (5-MeC) over the entire promoter region confirmed data obtained by restriction analysis. Limited data using SssI methylase also suggested that over-methylation of CpG sequences may exist over the entire genome in response to arsenite exposure. We propose that alteration of DNA methylation by arsenic offers a plausible, unified hypothesis for the carcinogenic mechanism of action of arsenic, and we present a model for arsenic carcinogenesis that utilizes perturbations of DNA methylation as the basis for the carcinogenic effects of arsenic.
Fatty acid carbon isotope signatures in chemosynthetic mussels and tube worms from gulf of Mexico hydrocarbon seep communities

Abstract The δ 13 C values of specific fatty acids isolated from mussels and two species of tube worm from Gulf of Mexico hydrocarbon seep communities show 13 C depletion characteristic of a chemosynthetic food source. The carbon isotopic composition of fatty acids in Lamellibrachia and Escarpia -like tube worms ranged from −29.3‰ to −18.0‰ while the fatty acid C-isotopic composition in the methanotrophic mussel Bathymodiolus childressi ranged from −45.4‰ to−39.6‰ or from −78.8‰ to −68.4‰, depending upon whether thermogenic or biogenic methane was utilized by the methanotrophic symbionts. In most cases, unsaturated fatty acids were depleted relative to saturated fatty acids, indicating de novo transformations.Exceptions some unsaturated 18 carbon fatty acids, which were enriched relative to saturated acids of the same length indicating direct incorporation of the bacterial fatty acids by the host.
Tis the gift to be simple

IC engineers rarely get to crash test their designs. Instead, they take pride in getting the design right the first time&#x2014;no room for iterations and redesign. This is done by performing extensive computer simulations of designs. These simulations let engineers accurately predict the behavior of the design while it is still represented by computer data, before it ever becomes a real physical object.
Sexual activity in middle to later life

Better health leads to frequent, good quality sex in older adults A cursory search of the BMJ ’s archives using the terms “sexuality” and “older adults” yields one study report and one editorial, both published in the past decade.1 2 Using the terms “sexual activity” and “elderly” yields only two additional citations, which focus on gynaecological and epidemiological topics.3 4 If for no other reason than that of filling a glaring void, the linked study by Lindau and Gavrilova (doi:10.1136/bmj.c810) represents a refreshing addition to the BMJ ’s sexuality and ageing repertoire.5 The study is equally refreshing because it offers a health enhancing, health promoting perspective: most human sexuality studies—especially those informing healthcare professionals—centre on outlining problems, diagnosing illnesses, and managing treatments. To unearth positive news amid the rubble of a trouble focused literature is just as refreshing, stimulating, and invigorating as good healthy sex. Lindau and Gavrilova examined data from two cross sectional surveys of ageing populations in the United States (national survey of midlife development in the United States (MIDUS) and national social life, health and aging project (NSHAP)). …
A comparison of direct and indirect methods for estimating forest canopy leaf area

Abstract Two indirect gap fraction methods for estimating leaf area index (LAI) are compared with estimates from litterfall collections in a mixed-age oak-hickory forest. One indirect method uses averaged, direct beam penetration data obtained with a moving tram. The second uses a portable light sensor system that measures diffuse light penetration for five sky sectors between zenith angles 0 and 75°. Data were collected from September 1989 to January 1990. The Poisson model and the negative binomial model of gap frequency were applied to estimate LAI from observed transmittances. With the Poisson model, an assumption of a random leaf spatial distribution contributes to an underestimation of LAI by as much as 45%; this is because leaves at this site are actually clumped at both large and small scales. The negative binomial, which requires determination of a clumping parameter, produces estimates comparable with those of the litterfall method. Both indirect techniques accurately describe temporal changes in leaf area using either the Poisson or negative binomial model. The portable system also allows easy estimation of the spatial variation in leaf area within the site or between sites, and it can be used to obtain a vertical profile of leaf area.
Natural convection flow structures and heat transfer in a model hydrothermal growth reactor

Due to the experimental difficulties brought about by high pressure and temperature growth conditions, flow and heat transfer in industrial hydrothermal autoclaves for the growth of single quartz crystals have been studied mostly numerically. To date, most of the numerical models and associated results are not experimentally validated; only qualitative validation data from experiments done during actual crystal growth production is partly available. In this study, the authors used a model simulated reactor represented by an enclosure with two lower half sidewalls uniformly heated while the upper half sidewalls are uniformly cooled. Flow structures in the reactor are qualitatively visualized using full field flow tracking; particle image velocimetry (PIV) is used for quantitative velocity pattern evaluation. Based on the physical setup and experimentally determined boundary conditions, flow is numerically simulated and the corresponding model is validated through comparison to the experimental results. The ensuing parametric studies show the changing of flow patterns and velocity magnitudes for a variety of enclosure aspect ratios.
Associative symmetry: II. Further studies of position learning in the gerbil

In a series of studies, gerbils were trained to make a turn in a Y maze to escape from punishing heat. On every sixth trial there was an interpolated back run, with four groups being tested. The back run originated in the positive goal for two groups, with one group reinforced for returning to the startbox and the other group to the negative goal. The remaining groups ran back from the negative goal, one going to the start and the other to the positive goal. Symmetrical connections were found to occur during frontward training. As to the back runs, the animals having to return to the start demonstrated significantly better performance than the other groups, which in turn did not differ from each other. Thus, during forward learning the maze was cognitively structured, with the startbox established as the most highly preferred place of all. A second study indicated that the animals were attracted back to the start on the basis of a visual map, rather than by sebaceous odors deposited during forward training. The final study showed the appeal of the start to be so great that the animals departed from a cool goalbox, on the back runs, to return to a heated startbox.