cssi/SciSciGPT-SciSciNet huggingface dataset:
A Microscale GC-MS Experiment: Identification of an Acyclic Saturated Ketone

The identification of an unknown acyclic, saturated ketone containing up to nine carbons is accomplished by analysis of its mass spectrum and the mass spectrum of the derivative formed by exchange ...
Tandem [4 + 2]/[3 + 2] Cycloadditions of Nitroalkenes. 11. The Synthesis of (+)-Crotanecine

(+)-Crotanecine (1) is the necine base component of a number of pyrrolizidine alkaloids. This necine subunit is an amino triol bearing a primary allylic alcohol characterized by an all-cis relationship of its stereocenters. The synthesis of (+)-crotanecine has been accomplished in 10 steps and 10.2% overall yield. The key step in the asymmetric synthesis is a Lewis acid-promoted, tandem inter[4 + 2]/intra[3 + 2] cycloaddition between a (fumaroyloxy)nitroalkene 14 and chiral β-silylvinyl ether (−)-26. This synthesis serves to illustrate the synthetic versatility of the tandem cycloaddition to incorporate additional functionality.
Inhibition of Neisseria catarrhalis NE-11 transformation.

Nachweis, dass die Transformation vonNeisseria catarrhalis sich mit Antibiotika und Chemikalien hemmen lasst, die ihrerseits die Eiweiss-und Zellwandsynthese hemmen. Daraus wird geschlossen, dass Eiweiss- und Zellwandsynthese zur Transformation notig sind.
A New Frontier: Integrating Behavioral and Digital Technology to Promote Health Behavior

Modifiable behavioral risk factors such as cigarette smoking, physical inactivity, and obesity contribute to over 40 % of premature deaths in the USA. Advances in digital and information technology are creating unprecedented opportunities for behavior analysts to assess and modify these risk factors. Technological advances include mobile devices, wearable sensors, biomarker detectors, and real-time access to therapeutic support via information technology. Integrating these advances with behavioral technology in the form of conceptually systematic principles and procedures could usher in a new generation of effective and scalable behavioral interventions targeting health behavior. In this selective review of the literature, we discuss how technological tools can assess and modify a range of antecedents and consequences of healthy and unhealthy behavior. We also describe practical, methodological, and conceptual advantages for behavior analysts that stem from the use of technology to assess and treat health behavior.
Thomson scattering for determining electron concentrations and temperatures in an inductively coupled plasma-II. Description and evaluation of a multichannel instrument

Abstract A new instrument has been assembled to measure Thomson scattering from an inductively coupled plasma. Unlike previous designs, the new system employs a fiber-optic array to measure simultaneously up to 12 channels on a Thomson-scattering spectrum. Shutters enable either side of the nominally symmetrical Thomson spectrum to be examined, or permit summing equally spaced channels on opposite sides of the spectrum from the incident laser wavelength. A central channel, used to monitor Rayleigh scattering, enables a simultaneous determination of true gas-kinetic temperatures. Photodetector fatigue is avoided through a rotating mirror that serves as an optical shutter while individual gated integrators attached to each detector minimize the detection of background radiation from the plasma. The new instrument offers high stray-light rejection capability and provides measurements whose precision is photon-limited. Results obtained with the new instrument are presented in a companion paper.
Soup preloads in a variety of forms reduce meal energy intake

Consuming soup can enhance satiety and reduce energy intake. Little is known about the influence on energy intake and satiety of varying the form of soup by altering the blending of ingredients. We tested the effects on meal intake of consuming different forms of soup as a preload: broth and vegetables served separately, chunky vegetable soup, chunky-pureed vegetable soup, or pureed vegetable soup. Normal-weight men and women (n=60) came to the laboratory for lunch once a week for 5 weeks. Each week, one of four compulsory preloads, or no preload, was consumed prior to lunch. A test meal was consumed ad libitum 15 min after the soup was served. Results showed that consuming soup significantly reduced test meal intake and total meal energy intake (preload + test meal) compared to having no soup. When soup was consumed, subjects reduced meal energy intake by 20% (134±25 kcal; 561±105 kJ). The type of soup had no significant effect on test meal intake or total meal energy intake. Consuming a preload of low-energy-dense soup, in a variety of forms, is one strategy for moderating energy intake in adults.
The Effects of Mountain Lee Waves on the Transport of Liquid Propane-Generated Ice Crystals

Abstract A combination of rawinsonde balloon ascent rates, low-elevation aircraft, and ground-based tracer sampling measurements are presented. These data indicate that mountain-induced gravity waves have a significant impact on the transport of ice crystals produced by the release of liquid propane from high-altitude dispensers along the crest of the northern Sierra Nevada in California. Special rawinsonde launches were made just downwind of the main Sierra Nevada crest. Balloon ascent rates show a very well defined mountain lee wave present during most precipitation events. Strong descent to the lee of the Sierra will thus have a detrimental effect on the growth of particles generated on the crest. The tracer SF6 (sulfur hexaflouride) is used to simulate the transport and dispersion of propane-generated ice crystals. Sulfur hexaflouride was released from two propane dispenser sites as a proxy for seeded ice crystals. Aircraft measurements of SF6 indicated that at the normal flight altitudes of 2500 m ov...
Sedimentation rates in Baffin Island fiord cores from comparative radiocarbon dates

Five accelerator (TAMS system, University of Arizona) radiocarbon dates on small (30–50 mg) paired bivalves or shell fragments have been obtained on two piston cores. These dates are compared with ...
A radial velocity spectrometer for the Automated Planet Finder Telescope at Lick Observatory

The Ken and Gloria Levy Spectrometer is being constructed at the Instrument Development Laboratory (Technical Facilities) of UCO/ Lick Observatory for use on the 2.4 meter Automated Planet Finder Telescope at Mt. Hamilton. The mechanical design of the instrument has been optimized for precision Doppler measurements. A key component of the design is the space-frame structure that contains passive thermal compensation. Determinate hexapod structures are used to mount the collimator, prism, and echelle grating. In this paper we describe the instrument mechanical design and some features that will help it detect rocky planets in the habitable zone.
Influence of Urban Residence on Use of Psychotropic Medications in Pennsylvania, USA: Cross-sectional Comparison of Older Adults Attending Senior Centers

Background Differences in medication use by geographic region may indicate differences in access to specialist medical care, especially in the case of prescriptions for psychotropic medications. We assessed the effect of more or less urbanized residence on likelihood of psychotropic medication use in a large cohort of older adults in Pennsylvania, USA.
Detection of hydrogen-bonded adenine-thymine base-pair complexes by electrospray mass spectrometry

Abstract Bibracchial lariat ether compounds having three-carbon sidearms terminated in either adenine or thymine have the potential to form a molecular box in which the “ends” are crown ethers and the “sides” are hydrogen-bonded base pairs. Previous solution studies relying upon NMR and vapor pressure osmometry confirmed the formation of complexes. In the present study, four diaza-18-crown-6 derivatives having either one or two sidearms each terminated in either adenine or thymine have been studied in a mixture of CHCl3 and CH3OH. Either acetic acid or sodium chloride was added to the solutions. For the two-armed systems, the preferred complex was the dimer involving adenines on one monomer and thymines on the other. Homodimers and other complexes were detected as well. The preferred single-armed complex was that occurring between the monomer whose sidearm was terminated in thymine and either H+ or Na+.
Intracerebral administration of naloxone and drinking in water-deprived rats

Abstract In 24-hr water-deprived rats, naloxone, at various doses (0, 12.5, 25, 50 μg/rat), was administered prior to a 15-min drinking period. Infusions were made bilaterally into each lateral ventricle, frontal cortex, lateral preoptic area, lateral hypothalamus, and caudate nucleus. Naloxone reliably reduced water consumption at 50 μg/rat when infused into the lateral ventricles and lateral hypothalamic areas. When comparable doses of naloxone were given by peripheral injection, no effect on drinking was observed. There appeared to be a trend developing for greater sensitivity to naloxone when infusions were made into a particular part of the hypothalamus. These data support the idea that naloxone reduces drinking by acting at central opiate receptors.
High Resolution Electronic Spectroscopy of Molecular Conformers. Methyl-3-methoxybenzoic Acid Ester

By combining the techniques of rotationally resolved fluorescence excitation spectroscopy in molecular beams and ab initio quantum mechanics, we have determined the identity of the four conformers that contribute to the S1S0 electronic spectrum of methyl-3-methoxybenzoic acid ester in the gas phase. Each conformer exhibits a unique spectrum. Each conformer also exhibits a differently oriented electronic transition moment (TM) in the molecular frame, for which the distinguishable inertial and electronic contributions also have been determined. The results suggest that the S1S0 TM vectors of all conformers are rotated by relatively large (counterclockwise) angles with respect to the a inertial axes, placing them close to the b axis of a —OCH3 substituted benzene, and that the exact values of these angles depend upon the mutual conformations of both attached groups with respect to each other.
The acquisition of a caulimovirus by different aphid species: comparison with a potyvirus

SUMMARY The acquisition and transmission of cauliflower mosaic virus (CaMV) by six aphid species and three clones of aphids was studied and compared with that of turnip mosaic virus (TuMV) with Myzus persicae. Two clones of Aphis fabae were unable to transmit CaMV, but the other species, Acyrthosiphon pisum, Brevicoryne brassicae, Megoura viciae, M. persicae and Rhopalosiphum padi transmitted in a bior multi-phasic manner. There was no statistical evidence of a bimodal transmission pattern. R. padi is recorded as a vector of CaMV for the first time. The transmission efficiency of CaMV varied with time of acquisition and suggested that accumulation of the virus occurred with two peaks of efficiency within the anterior region of the insect gut. The time at which these two peaks occurred varied between the species, but the basic pattern was common to all transmitting aphid species in this study. This pattern contrasted with that of TuMV. The transmission data are discussed in terms of bimodal transmission, the influence of feeding behaviour, the role of a helper protein associated with both TuMV and CaMV and the evidence for site specific attachment of CaMV.
Coincidence and covariance data acquisition in photoelectron and -ion spectroscopy. I. Formal theory

AbstractWe derive a formal theory of noisy Poisson processes with multiple outcomes. We obtain simple, compact expressions for the probability distribution function of arbitrarily complex composite events and its moments. We illustrate the utility of the theory by analyzing properties of coincidence and covariance photoelectron–photoion detection involving single-ionization events. The results and techniques introduced in this work are directly applicable to more general coincidence and covariance experiments, including multiple ionization and multiple-ion fragmentation pathways.
Security Refresh: Protecting Phase-Change Memory against Malicious Wear Out

As dynamic RAM scaling approaches its physical limit, phase-change memory is the most mature and well-studied option for potential DRAM replacement. However, malicious wear-out attacks can exploit PCM's limited write endurance. To address this, a low-cost wear-leveling scheme can dynamically randomize the data addresses across the entire address space and obfuscate their actual locations from users and system software.
Role of adjunct questions and reading ability levels on rote and conceptual learning from prose

This research evaluated the effect of question type (rote, conceptual) and adjunct question response mode (multiple choice, short answer) on rote and conceptual learning outcomes of high and low ability readers. Subjects were 98 freshman students of a small, historically black, undergraduate institution. Students studied a passage containing either rote- or conceptual-level adjunct questions or no questions. They were then administered a rote and a conceptual post-test over the presented concepts. A 2 × 2 × 2 factorial design was used. The results indicated, contrary to most other research, that rote adjunct questions were more helpful to readers than conceptual adjunct questions on both rote and conceptual post-tests. As expected, high reading ability students performed better than low reading ability students within treatments. There were no significant aptitude-treatment interactions.
Form and patterning of anterior tooth wear among aboriginal human groups.

Form and severity of dental attrition was assessed in aboriginal human groups including hunter-gatherers (Eskimos, Australians) and those with dependence to a varying degree on food production (Southwest U.S. and Ohio American Indians). Wear on anterior teeth was both relatively and absolutely greater in the hunter-gatherers, as indicated by comparisons of wear on anterior and posterior teeth which come into occlusion at roughly the same time. Distinct differences in form of anterior wear were also apparent: The hunter-gatherers exhibited steadily increasing incidences of labially rounded wear with greater functional age, while the food-producing groups showed little or no rounding but instead high frequencies of heavily cupped wear (especially in those with premature loss of posterior teeth). These differences were attributed to nonmasticatory utilization of the front teeth in hunter-gatherers and to employment of the anterior teeth in masticatory (grinding) activities necessitated by large-scale molar loss in food producers.
Use of fungicide-resistant rhizobia for legume inoculation

Abstract Isolates of Rhizobium phaseoli resistant to spergon (2,3,5,6-tetrachloro-l,4-benzoquinone), Rhizobium meliloti resistant to thiram (tetramethylthiuram disulfide) and of a cowpea Rhizobium resistant to phygon (2,3-dichloro-l,4-naphthoquinone) were obtained by culturing the bacteria in media with increasing concentrations of these fungicides. The cultures grew in media with 200 μg thiram ml −1 , 150 μg spergon ml −1 or 400 μg phygon ml −1 . Spergon-tolerant R . phaseoli was sensitive to thiram, and thiram-tolerant R . meliloti was sensitive to spergon. The dry weights of beans, alfalfa and cowpeas and the amount of N 2 fixed were the same for plants inoculated with the fungicide-resistant or the sensitive parent rhizobia. However, when the three parent Rhizobium strains were applied to seeds treated with the three fungicides, the plants that developed were stunted, chlorotic, grew poorly and fixed little or no N 2 . By contrast, beans, alfalfa or cowpea plants derived from seeds coated with spergon, thiram or phygon and inoculated with the resistant rhizobia grew as well and fixed as much N 2 as legumes derived from seeds not treated with the pesticides. These findings provide the basis for a simple method for simultaneously allowing for N 2 fixation and seed protection of legumes.
Importance of internal regions and the overall length of tropomyosin for actin binding and regulatory function.

Tropomyosin (Tm) binds along actin filaments, one molecule spanning four to seven actin monomers, depending on the isoform. Periodic repeats in the sequence have been proposed to correspond to actin binding sites. To learn the functional importance of length and the internal periods we made a series of progressively shorter Tms, deleting from two up to six of the internal periods from rat striated α-TM (dAc2−3, dAc2−4, dAc3−5, dAc2−5, dAc2−6, dAc1.5−6.5). Recombinant Tms (unacetylated) were expressed in Escherichia coli. Tropomyosins that are four or more periods long (dAc2−3, dAc2−4, and dAc3−5) bound well to F-actin with troponin (Tn). dAc2−5 bound weakly (with EGTA) and binding of shorter mutants was undetectable in any condition. Myosin S1-induced binding of Tm to actin in the tight Tm-binding “open” state did not correlate with actin binding. dAc3−5 and dAc2−5 did not bind to actin even when the filament was saturated with S1. In contrast, dAc2−3 and dAc2−4 did, like wild-type-Tm, requiring about 3 m...
Empathy as Intersubjectivity: Resolving Hume and Smith's Divide.

Although empathy is arguably an important factor to consider in moral education, the concept itself has consistently stood on tenuous ground. In this essay, I claim that our adherence to ontological dualism and discrete subjectivity have problematized our comprehension of empathy. I propose that our understanding is limited by our understanding of selfhood. If the self were defined as intersubjective, along the lines of Merleau-Ponty, then empathy’s ambiguities would dissipate. After reconceptualizing empathy in light of intersubjectivity, I call for pedagogical relations that are aligned with developmental research, which provides further support for adhering to an alternative conception of the phenomenon.
Decarbonizing the electric sector: Combining renewable and nuclear energy using thermal storage

Abstract Both renewable and nuclear energy can provide significant contributions to decarbonizing the electric sector. However, a grid employing large amounts of wind and solar energy requires the balance of the system to be highly flexible to respond to the increased variability of the net load. This makes deployment of conventional nuclear power challenging both due to the technical challenges of plant cycling and economic limits of reduced capacity factor. In the United States nuclear power plants generally provide constant, base load power and are most economic when operated at constant power levels. Operating nuclear power plants in load-following modes decreases the plants' annual energy output and increases the levelized cost of energy, decreasing economic competitiveness. One possible solution is to couple thermal energy storage to nuclear power plants. This would enable the reactor to remain at nearly constant output, while cycling the electrical generator in response to the variability of the net load. This paper conceptually explores combinations of wind, solar, and nuclear that can provide a large fraction of a system's electricity, assuming the use of thermal energy storage that would allow nuclear power to provide load following and cycling duty while operating at a constant reactor power output.
A Low-Order Dynamic Model for Planar Solid Oxide Fuel Cells Using Online Iterative Computation

High-fidelity dynamic models of solid oxide fuel cells (SOFCs) capture the spatial distribution of key performance variables by considering the cells as distributed parameter systems. As such, they are often complex and require extensive computational resources. In this paper, driven by the need to support the control strategy development and system optimization, we develop a low-order SOFC model by approximating the mass and energy balance dynamics in the fuel and air bulk flows using quasi-static relations. However, due to the coupling between the quasi-static mass balance and current distribution, this approximation leads to a large set of coupled nonlinear algebraic equations that have to be solved online using iterative computation. In order to mitigate the computational cost involved, an efficient iterative algorithm is proposed to solve these equations. The new algorithm requires to iterate on only one variable-the cell voltage-to determine the current and flow compositions and their distributions. The low-order model with 16 states is compared to the baseline model, which has 160 states that incorporates fully the mass and energy balance dynamics. Simulations are performed to evaluate the model performance for both steady-state and transient operations, and to assess the computational cost associated with the low-order and full order models. It is shown that the low-order model closely matches the original baseline model, while the computation time is reduced by more than 50% compared to the baseline model.
COMPLICATIONS ASSOCIATED WITH THIOUREA THERAPY

We reviewed the clinical courses of 105 children with hyperthyroidism: 69 received propylthiouracil (PTU), 29 received Tapazole (TAP) and 7 were begun on one drug and later switched to the other (for purposes of analysis, these 7 were included in both groups). Choice of drug depended on the individual physician's preference. The mean ± 1 SD duration of therapy for PTU was 20± 16 months, and for TAP 16± 12 mos. Prior to therapy, there were no significant differences in the two treatment groups with respect to age, gender, family history of thyroid disease, mean T4 concentration,or mean goiter size. There were no significant differences in the clinical remission rates in the two groups (45.7% for PTU and 29.4% for TAP, p=0.11). However, hepatitis or collagen-like diseases occurred more frequently in children treated with PTU (14/76, 18%) than in children treated with TAP (0/36, p<0.006 by chi square). In contrast, there were no significant differences in the frequency of leukopenia (4.3 v. 2.9%) or rash (2.9 v. 8.9%, respectively, p=NS). The occurrence of hepatitis or collagen-like illness did not appear to be related to dosage or duration of therapy. In conclusion, the efficacy of the two drugs appears to be similar but serious complications occur more frequently with PTU. Therefore, TAP would appear to be the drug of choice in initial therapy of hyperthyroidism in children.
The effects of GABA(A) receptor blockade in the dorsomedial hypothalamic nucleus on corticotrophin (ACTH) and corticosterone secretion in male rats

Experiments were conducted to test if blockade of GABAA receptors in the dorsomedial hypothalamic nucleus (DMH) of rats, which is known to elicit cardiovascular and anxiety responses, would also elicit changes in the plasma levels of adrenocorticotrophic hormone (ACTH) and corticosterone. Male Sprague-Dawley rats were anesthetized with pentobarbital, fitted with femoral arterial catheters and implanted with microinjection cannulae into the DMH or the sites anterior to the DMH (i.e., closer to the paraventricular nucleus (PVN) of the hypothalamus). The rats were then injected with either artificial cerebrospinal fluid (aCSF; 100 nl) or the GABAA antagonist, bicuculline methiodide (BMI; 50 pmol in 100 nl) and their plasma samples obtained at 5, 30, 60, and 120 min after microinjection. Plasma ACTH and corticosterone were measured by using a radioimmunoassay. Rats injected with BMI, but not aCSF, into the DMH showed significant increases in heart rate (HR, 110 ± 16 beats/min), blood pressure (BP; 30 ± 4 mmHg), and plasma levels of both ACTH (64 ± 10 pg/ml) and corticosterone (170 ± 25 ng/ml) from baseline. BMI injections into the anterior sites closer to the PVN did not elicit significant increases in HR, BP, or plasma levels of ACTH and corticosterone. These results suggest that a tonic GABAA receptor-mediated inhibition system regulates a coordinated physiological and neuroendocrine response in the DMH and that this neuroendocrine response is not due to diffusion of BMI to the PVN of rats.
Question 5: Does the RNA-World Still Retain its Appeal After 40 Years of Research?

Forty years after its formulation, the hypothesis of the RNA-World remains rather controversial even though studies of RNA catalysis in cellular processes (for example, in the ubiquitous ribosomal peptide-bond formation) have clearly lent increased plausibility to the idea that an RNA-World existed at some point in the evolution leading to the emergence of cellular life. Indeed, several issues remain that weaken the concept: the synthesis of the RNA monomers under prebiotic conditions, their subsequent, efficient polymerization to yield ribozymes that specifically catalyze their own replication. This communication summarizes existing studies of the RNA polymerization from monomers. In our opinion, the recent developments show that given time plausible answers to some of the issues facing the RNA-World hypothesis will be found.
Race, Research, and Tenure: Institutional Credibility and the Incorporation of African, Latino, and American Indian Faculty

Conventional wisdom suggests that colleges and universities act in objective ways that are guided, in large measure, by an unrelenting quest for the truth. This article, however, draws on the literature on the power of race to demonstrate how some universities use tenure and promotion committees, as well as other resources, to show that private universities are more susceptible to the interests of alumni and, as a result, are sometimes less interested in safeguarding the interests of faculty of color, who are involved in controversial research on racial issues. This suggests that institutions vary in their willingness or ability to facilitate incorporation among faculty of color in academia.
CHARACTERIZATION OF PROTEINS DURING AGGREGATION II: USE OF MODEL MOLECULES FOR SPECTROSCOPY ANALYSIS

Abstract This study describes the progress made in the use of combined light scattering-spectral deconvolution techniques for the quantitative characterization of proteins in particular, pituitary and recombinant porcine somatotropin. Model molecules for the main ultraviolet chromophores contained in proteins (i.e., tyrosine, tryptophan, phenylalanine and cysteine) have been investigated as functions of ionic strength and denaturant concentration. The objective, in the use of model molecules for the representation of the spectra, is the identification and quantification of the spectral changes undergone by proteins during denaturation and renaturation reactions. Since the denaturation-renaturation reactions of porcine somatotropin involve aggregation processes, the effects of the combined absorption and scattering have been accounted for through the use of Mie and Rayleigh-Gans theories. It is demonstrated that quantitative information on the functional groups participating in the denaturation-renaturatio...
Correlating the Plastic Strain With the Properties of the Low Density Polyethylene Blown Film

Experiments were carried out to verify a theory developed to cor relate the plastic strain history in the film blowing to the ultimate physical properties of the blown film. The theory predicts that the amount of strain put in the blown film once it starts to freeze, defined as plastic strain here, has the prominent effect on the film's ultimate physical properties. A grade of low den sity polyethylene was used to produce the blown film runs yielding a 1.25 mil thin film at the outlet. Film surface and bulk temperatures, along the machine direction, were measured using the infra-red techniques to identify the points where film starts to crystallize. A video digitization technique was used to measure the bubble kinematics. Film's physical properties were measured us ing standard ASTM methods. The results indicate a correlation between the amount of plastic strain, or its derivatives, and the ultimate physical properties of the blown film. This principal applies equally well to the film properties in the cr...
Organic agriculture promotes evenness and natural pest control

Declining species number (richness) harms ecosystems, and conservation efforts have largely focused on conserving or restoring particular rare species. However, greater disparity in species relative abundances (evenness) might also do ecological harm, which could only be reversed by altering the densities of many species at once. A new survey of organic and conventionally managed potato fields shows that species evenness is greater under organic management. Replicating these levels of evenness in a field trial shows that the evenness of natural enemies found in organic fields promotes pest control and increases crop biomass. In organic crops many beneficial species (that eat pest insects) are equally common, which in potatoes leads to fewer pests and larger plants. A survey of organic and conventional potato fields shows that species evenness is greater under organic management. Replicating these levels of evenness in a field trial shows that the evenness of natural enemies found in organic fields promotes pest control and increases crop biomass. This is independent of the identity of the dominant enemy species, so is a result of evenness itself. Human activity can degrade ecosystem function by reducing species number (richness)1,2,3,4 and by skewing the relative abundance of species (evenness)5,6,7. Conservation efforts often focus on restoring or maintaining species number8,9, reflecting the well-known impacts of richness on many ecological processes1,2,3,4. In contrast, the ecological effects of disrupted evenness have received far less attention7, and developing strategies for restoring evenness remains a conceptual challenge7. In farmlands, agricultural pest-management practices often lead to altered food web structure and communities dominated by a few common species, which together contribute to pest outbreaks6,7,10,11. Here we show that organic farming methods mitigate this ecological damage by promoting evenness among natural enemies. In field enclosures, very even communities of predator and pathogen biological control agents, typical of organic farms, exerted the strongest pest control and yielded the largest plants. In contrast, pest densities were high and plant biomass was low when enemy evenness was disrupted, as is typical under conventional management. Our results were independent of the numerically dominant predator or pathogen species, and so resulted from evenness itself. Moreover, evenness effects among natural enemy groups were independent and complementary. Our results strengthen the argument that rejuvenation of ecosystem function requires restoration of species evenness, rather than just richness. Organic farming potentially offers a means of returning functional evenness to ecosystems.
Free U.S. Government Databases for Non-Depository Libraries

Free federal government databases are an untapped resource of which many libraries do not take advantage. Many of the databases are cataloged and can be added to a library Online Public Access Catalog; other databases have persistent URLs that can be linked from LibGuides or other online subject finding aids. The desirability and potential drawbacks of adding these resources to the catalog are discussed. Before referring library users to the databases, evaluative criteria must be applied to ensure stability, authority, currency, and ease of search. A select list of federal agency databases that meet the criteria is offered.
Structural insights into amino acid binding and gene control by a lysine riboswitch

In bacteria, the intracellular concentration of several amino acids is controlled by riboswitches. One of the important regulatory circuits involves lysine-specific riboswitches, which direct the biosynthesis and transport of lysine and precursors common for lysine and other amino acids. To understand the molecular basis of amino acid recognition by riboswitches, here we present the crystal structure of the 174-nucleotide sensing domain of the Thermotoga maritima lysine riboswitch in the lysine-bound (1.9 angstrom (A)) and free (3.1 A) states. The riboswitch features an unusual and intricate architecture, involving three-helical and two-helical bundles connected by a compact five-helical junction and stabilized by various long-range tertiary interactions. Lysine interacts with the junctional core of the riboswitch and is specifically recognized through shape-complementarity within the elongated binding pocket and through several direct and K(+)-mediated hydrogen bonds to its charged ends. Our structural and biochemical studies indicate preformation of the riboswitch scaffold and identify conformational changes associated with the formation of a stable lysine-bound state, which prevents alternative folding of the riboswitch and facilitates formation of downstream regulatory elements. We have also determined several structures of the riboswitch bound to different lysine analogues, including antibiotics, in an effort to understand the ligand-binding capabilities of the lysine riboswitch and understand the nature of antibiotic resistance. Our results provide insights into a mechanism of lysine-riboswitch-dependent gene control at the molecular level, thereby contributing to continuing efforts at exploration of the pharmaceutical and biotechnological potential of riboswitches.
Amplitude response of coupled oscillators

Abstract We investigate the interaction of a pair of weakly nonlinear oscillators (eg. each near a Hopf bifurcation) when the coupling strength is comparable to the attraction of the limit cycles. Changes in amplitude cannot then be ignored, and there are new phenomena. We show that even for simple forms of these equations, there are parameter regimes in which the interaction causes the system to stop oscillating, and the rest state at zero, stabilized by the interaction, is the only stable solution. When the uncoupled oscillators have a local frequency that is independent of amplitude (zero shear), and the coupling is scalar, we give a complete description of the behavior. We then analyze more complicated equations to show the effects of amplitude-dependent frequency in the uncoupled equations (nonzero shear) and nonscalar coupling. For example, when there is shear, there can be bistability between a phase-locked solution and an unlocked “drift” solution, in which the oscillators go at different average frequencies. There can also be bistability between a phase locked solution and an equilibrium, nonoscillatory, solution. The equations for the zero shear case have a pair of degenerate bifurcation points, and the new phenomena in the nonzero shear case arise from a partial unfolding of these singularities. When the coupling is nonscalar, there are a variety of new behaviors, including bistability of an in-phase and an anti-phase solution for two identical oscillators, parameters for which only the anti-phase solution is stable, and “phase-trapping,” i.e. nonlocked solutions in which the oscillators still have the same average frequency. It is shown that whether the coupling is diffusive or direct has many effects on the behavior of the system.
On the efficient computation of the nonlinear full-information maximum-likelihood estimator

Abstract This paper examines important elements in calculating the nonlinear full-information maximum-likelihood (NLFIML) estimator which produce substantial reductions (80 percent or more) in computational cost. It examines the (i) choice of optimization algorithm, (ii) method of Hessian approximation, (iii) choice of stopping criterion, and (iv) exploitation of sparsity. We find that the Newton-Raphson algorithm employing an analytically-computed Hessian is computationally much more efficient (up to 75 percent) in this context than its oft-employed competitors, such as DFP. Additional gains (up to 30 percent) result from using a weighted-gradient stopping criterion. Exploitation of matrix sparsity adds further gains.
Measurement of renal medullary blood flow.

Toutes les methodes de determination du flux sanguin dans la medullaire renale sont basees, jusqu'a present, sur lemploi de substances traceuses. Les differentes techniques sont passees en revue dans le present artical. Quelques-unes manquent de fondation theoriques rigoureuse; cependant, les valeurs moyennes obtenues pour le temps de passage a travers les zones corticales er medullaires be varient que tres peu.
The cathodal OFF response of electric taste in rats

The cathodal OFF response in electric taste, the production of a taste sensation at the break of a microampere cathodal current passed through the tongue, was studied electrophysiologically in the rat chorda tympani nerve. Previous work in electric taste has centered on ON responses to both anodal and cathodal currents. The cathodal OFF response, like ON responses, increased with increasing current intensity until a saturated response level was achieved. Unlike previously reported ON responses, the OFF response did not show a sensitivity to the ionic composition of the fluid bathing the tongue making this the first electrophysiological report of ion insensitivity in electric taste. The cathodal OFF response was sensitive to the duration of the current pulse preceding it. Longer pulses produced larger OFF responses, until with very long pulses (seconds) a saturated response level was achieved. The half maximal response occurred at 12.5 ms. These results have been interpreted to mean that the cathodal OFF response has an origin other than the microvillus membrane, the site most often implied for ON responses, due largely to its ion insensitivity. A probable location may reside with ion channels transversing the basal membrane which are transiently excited at the break of the current resulting in excitation at the receptor-afferent synapse.
Study of air-bubble-induced light scattering effect on image quality in 193-nm immersion lithography

As an emerging technique, immersion lithography offers the capability of reducing critical dimensions by increasing numerical aperture (NA) due to the higher refractive indices of immersion liquids than that of air. Among the candidates for immersion liquids, water appears to be an excellent choice due to its high transparency at a wavelength of 193 nm, as well as its immediate availability and low processing cost. However, in the process of forming a water fluid layer between the resist and lens surfaces, air bubbles are often created due to the high surface tension of water. The presence of air bubbles in the immersion layer will degrade the image quality because of the inhomogeneity induced light scattering in the optical path. Therefore, it is essential to understand the air bubble induced light scattering effect on image quality. Analysis by geometrical optics indicates that the total reflection of light causes the enhancement of scattering in the region where the scattering angle is less than the critical scattering angle, which is 92 degrees at 193 nm. Based on Mie theory, numerical evaluation of scattering due to air bubbles, polystyrene spheres and PMMA spheres was conducted for TE, TM or unpolarized incident light. Comparison of the scattering patterns shows that the polystyrene spheres and air bubbles resemble each other with respect to scattering properties. Hence polystyrene spheres are used to mimic air bubbles in studies of lithographic imaging of “bubbles” in immersion water. In direct interference lithography, it is found that polystyrene spheres (2 μm in diameter) 0.3 mm away from the resist surface would not image, while for interferometric lithography at 0.5NA, this distance is estimated to be 1.3 mm. Surprisingly, polystyrene spheres in diameter of 0.5 μm (which is 5 times larger than the interferometric line-width) will not image. It is proposed that “bubbles” are repelled from contact with the resist film by surface tension. The scatter of exposure light can be characterized as “flare”. This work shows that microbubbles are not a technical barrier to immersion lithography.
Stochastic sequential assignment problem with threshold criteria

The stochastic sequential assignment problem (SSAP) allocates distinct workers to sequentially arriving tasks with stochastic parameters to maximize the expected total reward. In this paper, the assignment of tasks is performed under the threshold criterion, which seeks a policy that minimizes the probability of the total reward failing to achieve a target value. A Markov-decision-process approach is employed to model the problem, and sufficient conditions for the existence of a deterministic Markov optimal policy are derived, along with fundamental properties of the optimal value function. An algorithm to approximate the optimal value function is presented, and convergence results are established.
Interfacial shear strengths of dental resin-glass fibers by the microbond test.

Abstract Objective: The aim of this study was to investigate the feasibility of using the microbond test (MBT) to probe the durability of the bond between a polymerized dental resin with differently silanized E-glass fibers. Methods: The E-glass fibers were silanized with equivalent amounts of two types of acrylic-silane coupling agents: 3-methacryloxypropyltrimethoxysilane (MPTMS) and 10-methacryloxydecyltrimethoxysilane (MDTMS), a more hydrophobic silane coupling agent than MPTMS. Unsilanized E-glass fibers were used as the control. Microdroplets of a photo-activated dental resin were applied on the fiber and photocured with visible light irradiation (470 nm). Subsequently, the specimens were tested in shear after 24 h storage in air at 23°C or water at 60°C. Results: The mean interfacial shear strength (τ) and the standard deviation in MPa for the three systems in 23°C in air ( n >7) were: 33.8(10.1), 33.7(8.9) and 15.3(4.2) for the MPTMS silanized, MDTMS silanized, and unsilanized fibers, respectively. When the three types of fibers were first exposed to 60°C water for 24 h prior to having the microdroplets of the resin bonded to them, the strength values of the MDTMS silanized fibers and the control fibers remained essentially unchanged at ( n ≥7) 31.8(7.7) and 17.5(4.9) MPa respectively; the MPTMS specimens showed a significant decrease to 15.8(4.8) MPa. Similar trends were observed when the fibers had microdroplets of the resin bonded to them prior to aqueous exposure. Significance: These results indicate that the microbond test has the sensitivity to measure changes at the interface between polymerized dental resins and variously silanized E-glass fibers. It appears that surface modification of the fibers with the more hydrophobic silane coupling agent MDTMS promotes enhanced resistance to degradation from exposure to water. The microbond test has the potential for studying dental adhesion involving small bonded areas under a variety of conditions with different adhesive systems and substrates.
Special Issue: Crosslinguistic Perspectives on the Development of Prosodic Words

Researchers have long known that children’s early word productions differ from those of adults, both in the segments and syllables produced (e.g., dog > [dɑ]; banana > [ n nə). Some have proposed that these early segmental /syllabic truncations are due to early perceptual or articulatory limitations (e.g., Echols, 1992; MacNeilage, 1980). Others have proposed that children’s early words are phonologically “unmarked,” becoming more marked over time (Demuth, 1995; Gnanadesikan, 2004). However, results from recent crosslinguistic research suggest that children’s early word productions are sensitive to language-specific phonologies, showing earlier acquisition of high frequency syllable and prosodic word structures (e.g., Levelt, Schiller, & Levelt, 2000; Roark & Demuth, 2000). This indicates that children’s early prosodic words show more systematic language-specific differences in shape than perceptual, articulatory and markedness proposals would predict. To the extent that these findings are robust, we should then be able to make predictions regarding the timing and course of prosodic word development across languages. The first goal of this special volume is to explore these issues more fully by bringing together recent research on the acquisition of prosodic words (PWs) from a number of languages with different distributions of prosodic structures. The papers in this volume therefore include contributions from the less studied Catalan (Prieto), European Portuguese (Vigario, Freitas & Frota) and Japanese (Ota), as well as the better-known Spanish (Lleo) and English (Demuth, Culbertson & Alter). In most cases newly collected longitudinal corpora, including data from several children between the ages of 1 – 2 years, now makes it possible to provide a more systematic, quantitative study of PW development. A second goal of this volume was to test some of the frequency-based predictions, providing a theoretical framework for further investigation of children’s developing phonologies. For example, frequency and markedness constraints often co-occur, facilitating the early acquisition of high-frequency, unmarked structures (e.g., core CV syllables, trochaic feet). Occasionally, however, the “unmarked” structure is not the most frequent, raising questions regarding the course of acquisition under such conditions (e.g., Stites, Demuth, & Kirk, 2004; Zamuner, Gerken, & Hammond, 2005). The existence of these new longitudinal acquisition corpora, many of which include extensive samples of early child-directed speech, now make it possible to LANGUAGE AND SPEECH, 2006, 49 (2), 129 –135
A limited role of p53 on the ability of a hexane fraction of American ginseng to suppress mouse colitis

Ulcerative colitis (UC) is debilitating and carries a high colon cancer risk. Apoptosis of inflammatory cells is a key mechanism regulating UC. We have recently shown that American ginseng (AG), and to a greater extent, a Hexane fraction of AG (HAG) can cause apoptosis and suppress mouse colitis through a p53-mediated mechanism. Here, we tested the hypothesis that HAG suppresses colitis through a p53 mechanism. We found only a limited impact of p53 in the ability of HAG to induce inflammatory cell apoptosis and suppress mouse colitis in vitro and in vivo. Finally, we asked whether HAG could cause cell cycle arrest of HCT116 colon cancer cells in vitro. Interestingly, HAG caused a G1 arrest of such cells independent of p53 status. Findings are significant because HAG suppresses colitis and associated colon cancer, and mutation in p53 is observed in most colitis-driven colon cancers. Therefore, HAG might be very effective in targeting the inflammatory cells and cancer cells since it induces apoptosis of inflammatory cells and cell cycle arrest in both p53−/− and WT p53 colon cancer cells.
Estimation of motion and structure of planar surfaces from a sequence of monocular images

An algorithm is presented which estimates 10 parameters for motion and structure of a rigid planar patch given point correspondences in a monocular image sequence under perspective projection. The rotational velocity is assumed constant and the rotation center arbitrary. The algorithm mainly consists of two steps. First, the 3-D space of ( omega /sub x/, omega /sub y/, omega /sub z/) is searched exhaustively and for each ( omega /sub x/, omega /sub y/, omega /sub z/) all the other parameters with the value of an objective function are computed linearly. some of the ( omega /sub x/, omega /sub y/, omega /sub z/) and the corresponding structure values are used as the initial guesses in the second step. The objective function is iteratively minimized with respect to five variables for rotation and structure. The solution corresponding to the global minimum is used to obtain least squares estimates of the remaining unknowns, for translation and rotation center. It was experimentally found that the objective function converges well so that the 3-D space need not be densely searched. Results are presented for three image sequences, two simulated and one real. >