cssi/SciSciGPT-SciSciNet huggingface dataset:
Glyphosate toxicity and the effects of long-term vegetation control on soil microbial communities.

Abstract We assessed the direct and indirect effect of the herbicide glyphosate on soil microbial communities from ponderosa pine ( Pinus ponderosa ) plantations of varying site quality. Direct, toxic effects were tested using culture media and soil bioassays at glyphosate concentrations up to 100-fold greater than expected following a single field application. Indirect effects on microbial biomass, respiration, and metabolic diversity (Biolog and catabolic response profile) were compared seasonally after 9–13 years of vegetation control using repeated glyphosate applications in a replicated field study. Three pine plantations were selected to provide a range of soil characteristics associated with glyphosate binding (clay, Fe and Al oxide content) and site growing potential from the lowest to the highest in northern California. Glyphosate was toxic to bacteria and fungi from each plantation when grown in soil-free media. Culturable populations were reduced, as was the growth rate and metabolic diversity of surviving bacteria, by increasing concentrations of glyphosate. This toxicity was not expressed when glyphosate was added directly to soil, however. Microbial respiration was unchanged at expected field concentrations (5–50 μg g −1 ), regardless of soil, and was stimulated by concentrations up to 100-fold greater. Increased microbial activity resulted from utilization of glyphosate as an available carbon substrate. Estimated N and P inputs from glyphosate were inconsequential to microbial activity. Long-term, repeated applications of glyphosate had minimal affect on seasonal microbial characteristics despite substantial changes in vegetation composition and growth. Instead, variation in microbial characteristics was a function of time of year and site quality. Community size, activity, and metabolic diversity generally were greatest in the spring and increased as site quality improved, regardless of herbicide treatment. Our findings suggest that artificial media assays are of limited relevance in predicting glyphosate toxicity to soil organisms and that field rate applications of glyphosate should have little or no affect on soil microbial communities in ponderosa pine plantations.
Antimicrobial Activity in the Pallial Cavity Fluids of the Oyster Crassostrea virginica (Gmelin) from a Highly Impacted Harbor in Western Long Island Sound

ABSTRACT Fluid and its associatedmucus from the pallial (mantle) cavity of eastern oysters Crassostrea virginica (Gmelin) from Black RockHarbor, Bridgeport, Connecticut, inhibited growth of both Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Serratia marcescens, and Vibrio parahaemolyticus) bacteria in antimicrobial assays. In the presence of oyster fluid, E. coli resulted in significant reduction in growth after 26 h. Soluble lysozyme activity in pallial cavity fluid of oysters collected in the fall was 3 times greater than that measured in combined winter—spring—summer samples (P = 0.0008). During the course of the study, copper concentrations in pallial cavity fluid ranged from 0.60–2.49 ppm and zinc concentrations ranged from 9.7–61.0 ppm. Copper concentrations remained relatively constant throughout the study; the highest zinc concentrations were recorded in the fall. Fall antimicrobial assays showed heightened antimicrobial activity compared with the sp...
Allergen-induced changes in airway responsiveness are not related to indices of airway edema

Abstract Background: The mechanisms behind airway hyperresponsiveness in asthma are unknown. Airway wall edema has been proposed as one possible culprit of this phenomenon. Objective: To test the hypothesis that airway edema may be the cause of allergen-induced increases in airway responsiveness in asthma, this trial aimed at determining the relationship between allergen-induced changes in airway responsiveness to inhaled methacholine and indirect indices of edema, namely peripheral airway resistance and the levels of the plasma protein fibrinogen in bronchoalveolar lavage (BAL) fluids. Methods: Twenty-six atopic individuals with mild asthma were subjected to bronchoscopy at baseline and 28 hours after allergen inhalation. Before each bronchoscopy, methacholine bronchoprovocation was performed. During bronchoscopy, peripheral airway resistance measurements were obtained by wedged bronchoscopy. BAL fluids were analyzed for fibrinogen, as well as for eosinophilic cationic protein. Cytology was performed, and cytokine gene expression was assessed with competitive reverse transcriptase PCR from cell pellets. Results: A significant increase in airway responsiveness to methacholine was recorded after allergen, but this did not correlate with changes in peripheral airway resistance (which was not affected) or with BAL fibrinogen (which decreased after allergen). Other BAL outcomes confirmed that airway inflammation was produced and was characterized by a T H 2 cytokine pattern. Conclusions: Airway responsiveness in asthma increases after exposure to allergen in the absence of increased indirect indices of edema. The role of edema in this phenomenon should therefore be tested more vigorously. (J Allergy Clin Immunol 2001;107:805-11.)
Conserved features of yeast and mammalian mitochondrial DNA replication

Mammalian mitochondrial DNA replication is initiated by the processing of RNA transcripts derived from an upstream promoter to create RNA primers for DNA replication. In the yeast Saccharomyces cerevisiae, mitochondrial ori/rep sequences contain a transcription promoter upstream of the site of transition from RNA to DNA synthesis, suggesting a common mode of replication initiation. Recent research has identified features in the mode and machinery of DNA replication conserved from yeast to mammals.
Linear functionals on nonlinear spaces and applications to problems from viscoplasticity theory

A classical result in the theory of monotone operators states that if C is a reflexive Banach space, and an operator A: CC* is monotone, semicontinuous and coercive, then A is surjective. In this paper, we define the ‘dual space’ C* of a convex, usually not linear, subset C of some Banach space X (in general, we will have C*⊃X*) and prove an analogous result. Then, we give an application to problems from viscoplasticity theory, where the natural space to look for solutions is not linear. Copyright © 2007 John Wiley & Sons, Ltd.
Dakota Diamond: An Exceptionally High Yielding, Cold Chipping Potato Cultivar with Long-Term Storage Potential

‘Dakota Diamond’, evaluated as ND5822C-7, is a medium to late-maturing cultivar with uniformly sized tubers and very high yield potential. It resulted from the cross of ND4103-2 and ‘Dakota Pearl’. Dakota Diamond is comprised of approximately 23.3% wild potato species germplasm. It combines the characteristics of several species, including Solanum tuberosum L. subsp. andigena Juz. and Bukasov, S. demissum Lindl., S. phureja Juz. and Bukasov, and purportedly, S. chacoense Bitter. Haulms are vigorous and large. Tubers are smooth and round, with bright white skin and white flesh. Dakota Diamond is suitable for the cold chip and fresh tablestock markets, both directly from the field and following storage at 7.2°C. Yield potential under both non-irrigated and irrigated conditions in North Dakota and Minnesota is very high, with total yield, US no. 1 yield, and percent US no. 1 tubers of Dakota Diamond superior to those of ‘Atlantic’ and Dakota Pearl, commercially acceptable chip cultivars. Mean yields for Dakota Diamond across these sites is 40.8 t ha−1. It is widely adapted based upon performance in the North Central Regional Potato Variety Trials and Snack Food Association/US Potato Board Trials. Dakota Diamond sets tubers slightly later than other commercially acceptable chip cultivars, but tubers size quickly. Dakota Diamond demonstrates resistance to common scab (Streptomyces scabies Thaxter) and to pink rot (Phytophthora erythroseptica Pethyb.), and preferential avoidance by Colorado potato beetle (Leptinotarsa decemlineata Say) in pest resistance screening evaluations. Dakota Diamond demonstrates resistance to most internal and external defects. It is susceptible to hollow heart, however, particularly in tubers over 283 g. Dakota Diamond expresses typical symptoms of PVYo. However, infection by PVYn and PVYn:o recombinant genotypes is difficult to detect visually. The specific gravity of Dakota Diamond is high, averaging 1.095 across irrigated and non-irrigated sites in North Dakota and Minnesota. Chip color reaches its optimal, and sugar levels reach their minimum in late January to early February when produced in northern locales, maintaining chip quality parameters throughout the late storage market window. Dakota Diamond is aptly named for its excellent attributes, including beautiful appearance, excellent chip quality particularly from late season storage, resistance to common scab, and exceptionally high yield potential, and in honor of the Diamond Jubilee, the 75th anniversary of the North Dakota State University potato breeding program as part of the North Dakota Agricultural Experiment Station. Dakota Diamond was released by the North Dakota Agricultural Experiment Station on 1 December 2005.
Probing the activation site of ribonuclease L with new N6-substituted 2',5'-adenylate trimers.

Abstract 2-5A trimer [5′-monophosphoryladenylyl(2′-5′)adenylyl(2′-5′)adenosine] activates RNase L. While the 5′-terminal and 2′-terminal adenosine N 6 -amino groups play a key role in binding to and activation of RNase L, the exocyclic amino function of the second adenylate (from the 5′-terminus) plays a relatively minor role in 2-5A's biological activity. To probe the available space proximal to the amino function of the central adenylate of 2-5A trimer during binding to RNase L, a variety of substituents were placed at that position. To accomplish this, the convertible building block 5′- O -dimethoxytrityl-3′- O -( tert -butyldimethylsilyl)-6-(2,4-dinitrophenyl)thioinosine 2′-(2-cyanoethyl N , N -diisopropylphosphoramidite) was prepared as a synthon to introduce 6-(2,4-dinitrophenyl)thioinosine into the middle position of the 2-5A trimer during automated synthesis. Post-synthetic treatment with aqueous amines transformed the (2,4-dinitrophenyl)thioinosine into N 6 -substituted adenosines. Assays of these modified trimers for their ability to bind and activate RNase L showed that activation activity could be retained, albeit with some sacrifice compared to unmodified p5′A2′p5′A2′p5′A. Thus, the spatial domain about this N 6 -amino function could be available for modifications to enhance the biological potency of 2-5A analogues and to ligate 2-5A to targeting vehicles such as antisense molecules.
TIME COURSE OF PULMONARY RESPONSE OF RATS TO INHALATION OF CRYSTALLINE SILICA: NF-kappa B ACTIVATION, INFLAMMATION, CYTOKINE PRODUCTION, AND DAMAGE

In vitro studies suggest that silica-induced lung disease may be linked to processes regulated by nuclear factor- κ B (NF- κ B) activation, but this has not been examined in vivo. Rats were exposed to a silica aerosol of 15 mg/m 3 (6 h/day, 5 days/wk) for 116 days, and bronchoalveolar lavage (BAL) was conducted at various times during the exposure. Silica-induced pulmonary inflammation and damage were determined by measuring BAL cell differentials and first BAL fluid lactate dehydrogenase (LDH) activity and serum albumin concentrations, respectively. NF- κ B activation and production of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) by BAL cells were also measured. The results demonstrate that NF- κ B activation occurred after 5 days exposure, and continued to increase thereafter. BAL cell production of IL-1 and TNF-α had increased incrementally by 10 and 30 days of exposure, respectively. This elevation continued through 79 days of exposure before further increasing at 116 days of exposure. Pul...
Evaluation of a zero intercept dual model by rational functions

A ghost-free zero-intercept dual model constructed by Gervais and Neveu is found to be Regge-behaved but not st symmetric in the four-point function. If the s-channel is taken to be tachyon-free, a tachyon appears in the t-channel.
Kinetics of the H + NCO reaction

Abstract Ab initio transition state theory (TST) based master equation simulations are used to predict the temperature and pressure dependence of the H + NCO reaction rate and product branching. The barrierless entrance channels to form singlet HNCO and NCOH are studied with variable reaction coordinate TST employing a potential energy surface obtained from multi-reference configuration interaction ab initio calculations. The remaining channels, including reactions on the triplet surface, are studied with standard TST methods employing high level electronic structure results. The energy transfer parameters for the master equation simulations arise from a fit to the experimentally observed HNCO dissociation rate. The lowest energy threshold to formation of bimolecular products, 3 NH + CO, lies well below the reactants. The bottleneck for intersystem crossing, which precedes the formation of 3 NH + CO from the singlet adducts, becomes the dominant bottleneck for that channel at quite low energies relative to reactants. The effect of this bottleneck is studied with model calculations designed to reproduce detailed experimental observations of photolysis branching ratios. This bottleneck greatly reduces the flux from H + NCO to 3 NH + CO via the singlet adducts. As a result, stabilization and reaction on solely the triplet surface are significant components of the overall rate. The present predictions for the high pressure and collisionless limit rate coefficients are accurately reproduced over the 200–2500 K range by the expressions, 1.53 × 10 −5 T −1.86 exp(−399/ T ) + 1.07 × 10 3 T −3.15 exp(−15219/ T ) and 5.62 × 10 −12 T 0.493 exp(148/T) cm 3 molecule −1 s −1 , respectively, where T is in K . These predictions are in reasonably satisfactory agreement with the somewhat discordant experimental rate measurements.
Clinical applicability of antifungal susceptibility testing on non-Candida albicans species in hospitalized patients

We assessed the distribution, antifungal susceptibility, and treatment associated with 161 non-Candida albicans isolates recovered from hospitalized patients over a 6-month period. The three most prevalent species were C. glabrata (100), C. tropicalis (28), and C. krusei (15). Resistance of C. glabrata to fluconazole and itraconazole were 6% and 17% respectively; 80% of the fluconazole-resistant isolates were cross-resistant to itraconazole. Prior azole exposure significantly reduced azole susceptibility in C. glabrata and also affected its subsequent selection among colonized patients. Only 21% of the patients had clinical infections. Patients with fungemia were more likely to be treated with amphotericin versus an azole. Overall treatment success was higher in patients treated with amphotericin versus an azole (56% vs 31%). Routine susceptibility testing on all Candida species does not appear necessary except where therapy with an azole is being considered to detect resistant isolates or for epidemiologic surveillance purposes. Further studies are needed to delineate the relationship between azole MICs and treatment outcomes of invasive candidiasis due to non-C. albicans species.
Regulation of rat pial arteriolar smooth muscle relaxation in vivo through multidrug resistance protein 5-mediated cGMP efflux.

Multidrug resistance protein 5 (MRP5) has been linked to cGMP cellular export in peripheral vascular smooth muscle cells (VSMCs) and is widely expressed in brain vascular tissue. In the present stu...
Mixing enhancement via nozzle trailing edge modifications in a high speed rectangular jet

An aspect ratio 3 rectangular nozzle with design Mach number 2 was used to investigate the effects of trailing edge modifications on mixing enhancement and to explore the sources of streamwise vorticity at the fully expanded jet Mach numbers 1.75, 2.0, and 2.5. The trailing edge modifications are simple cut-outs in the plane of the nozzle at the nozzle exit. The investigation of mixing and interaction between mixing layers and vortices was performed by the laser sheet illumination technique. Through surface flow visualizations and wall pressure measurements, the investigation of the major source of streamwise vorticity was carried out. In addition, the variation of thrust generated by the nozzle with modified trailing edges was investigated. In the underexpanded flow condition, the major source of streamwise vorticity was determined to be the spanwise surface pressure gradient on the modification. Substantial mixing enhancement was achieved in this flow regime. On the other hand, in the overexpanded flow regime, the role of streamwise vortices in mixing and the source of streamwise vorticity were unclear, and mixing enhancement was not substantial. No measurable thrust loss or gain was obtained for nozzles with trailing edge modifications, regardless of the type of modification.
A macroevolutionary study of historical contingency in the fanged frogs of Southeast Asia

The fanged frogs of South East Asia (50 species) show remarkable variation in body size, reproductive mode and sexual dimorphism. This study examines the importance of a specialized, primitive trait, relative fang size, in contributing to this diversity. Relatively small fang size is found to have a significant association with the evolution of small body size, terrestrial reproductive modes, and sexual dimorphism where females are larger than males. These results support the idea of historical contingency or that prior historical events can exert a significant influence on subsequent patterns of evolutionary change.
Reproductive versus therapeutic cloning: science, applications, and policies [Overview from the Guest Editor]

The articles presented herein will provide the scientist, the government, as well as the public with information, facts, and opinions on the current state of the art of a complex and very controversial technology— cloning. With these seven pieces, we hope to offer the reader an understanding of not only the scientific aspects of animal cloning but the legal and ethical debates concerning human reproductive versus therapeutic cloning as well. The fate of these technologies is coupled to the legal and ethical sanctions now being debated worldwide. The eventual outcome of these debates will dictate the potential applications of cloning and impact the future of human medicine. We have attempted to touch on a wide range of applications, present a concise description of cloning’s scientific aspects, and report diverse policy perspectives from around the world. Cloning Applications in Agriculture
Micromachined reference samples for particle counting

Three micromachined reference sample prototypes for particle counting have been fabricated by using dark ceramic spots in a transparent glass wafer to simulate particles on a surface. The direct write approach permits the spots to be positioned at random locations within an indicated area of the sample with sizes and numbers that are consistent with a distribution of particles. The goal of this work is to provide a path to creating a set of particle counting and sizing samples that can be used to establish the accuracy and precision of different measurements.
Fourier analysis of the complex envelope of the echos in an OFDR.

The Fourier transform of the complex envelope of the echos in an optical frequency domain reflectometer displays discrete lines in the spectrum. The location of each line in the spectrum corresponds to the location of a corresponding reflector along the fiber. For fibers with scattering loss, the determination of discrete lines depends on the value of the loss factor.
Effect on coronary artery anatomy of radiofrequency catheter ablation of atrial insertion sites of accessory pathways

Abstract Objectives. The purpose of this study was to analyze the effects of radiofrequency catheter ablation of the atrial insertion site of accessory pathways on the angiographie appearance of coronary arteries. Background. Radiofrequency catheter ablation of accessory pathways requires the application of energy to the endocardial surface of the atrioventricular groove adjacent to the major epicardial coronary arteries. A systematic analysis of the effect of radiofrequency ablation on coronary arteries has not previously been demonstrated. Methods. Seventy consecutive patients with 76 accessory pathways (7 right free wall, 44 left free wall, 12 posteroseptal, 8 anteroseptal and 5 midseptal) were studied. Quantitative coronary angiography was performed before, immediately after and a mean of 69 ± 42 days after radiofrequency catheter ablation. Results. Coronary artery diameter adjacent to the ablating electrode was 2.6 ± 0.9 mm before ablation, 2.7 ± 0.9 mm immediately after ablation and 2.7 ±1.0 mm at the time of follow-up study. Angiographie findings were unchanged from baseline in 69 of 70 patients immediately after ablation and in all 70 patients at the time of follow-up Study. Conclusions. Radiofrequency catheter ablation of the atrial insertion site of accessory pathways does not result in short-term angiographie changes in coronary artery anatomy.
Tube-dwelling coral symbionts induce significant morphological change in Montipora

Several groups of tube-dwelling coral symbionts induce the formation of long, finger-like branches (“fingers”) on Montipora corals in the lagoons of Moorea, French Polynesia. We surveyed the prevalence and taxonomic diversity of these symbionts across the northern lagoons of Moorea, and documented the length and density of the finger structures on coral colonies. We found that the symbionts, which include gammarid amphipods and chaetopterid polychaete worms that were not previously known to associate with scleractinian corals, dramatically alter coral skeletal morphology, and may alter coral biology and reef ecology.
The production of hemoglobin by small pond Daphnia pulex: intraspecific variation and its relation to habitat

SUMMARY. 1. Haemoglobin production was measured for two populations of Daphnia putex, one from a temporary pond (GR Pond) and one from a permanent pond (Rash Pond). Surface water in Rash Pond remains high in oxygen, while by late summer very Uttle oxygen remains in GR Pond. Haemoglobin synthesis was induced in the laboratory by artificial oxygen deficiency. 2. Reproductive state influenced the level of haemoglobin in Daphnia. Females with parthenogenetic eggs had higher total body haemoglobin than ephippial females. Clutches laid by pale Daphnia immediately before exposure to low oxygen conditions were aborted. Offspring produced by haemoglobin-rich females later in the treatment survived. 3. Haemoglobin production was higher for Rash Pond Daphnia. Visual predators exist in GR Pond, but are absent in Rash Pond. Also, Daphnia are smaller in GR Pond. Visual predation may have selected against high levels of haemoglobin in the temporary pond. Thus oxygen availability in nature is not necessarily a good predictor of haemoglobin production by Daphnia. 4. Feeding behaviour was altered in low oxygen conditions. Browsing was dominant in low oxygen treatments while Daphnia in control treatments filtered algae normally. Browsing may increase access to sedimented iron necessary for haemoglobin synthesis.
Needle tip visualization during ultrasound-guided vascular access: short-axis vs long-axis approach

Abstract Objectives Ultrasound guidance for central venous catheterization improves success rates and decreases complications when compared to the landmark technique. Prior research has demonstrated that arterial and/or posterior vein wall puncture still occurs despite real-time ultrasound guidance. The inability to maintain visualization of the needle tip may contribute to these complications. This study aims to identify whether long-axis or short-axis approaches to ultrasound-guided vascular access afford improved visibility of the needle tip. Methods A prospective trial was conducted at a level I trauma center with an emergency medicine residency. Medical students and residents placed needles into vascular access tissue phantoms using long-axis and short-axis approaches. Ultrasound images obtained at the time of vessel puncture were then reviewed. Primary outcome measures were visibility of the needle tip at the time of puncture and total time to successful puncture of the vessel. Results All subjects were able to successfully obtain simulated blood from the tissue phantom. Mean time to puncture was 14.8 seconds in the long-axis group and 12.4 seconds in the short-axis group ( P = .48). Needle tip visibility at the time of vessel puncture was higher in the long-axis group (24/39, 62%) as opposed to the short-axis group (9/39, 23%) ( P = .01). Conclusions In a simulated vascular access model, the long-axis approach to ultrasound-guided vascular access was associated with improved visibility of the needle tip during vessel puncture. This approach may help decrease complications associated with ultrasound-guided central venous catheterization and should be prospectively evaluated in future studies.
Weakened Links Between Mind and Body in Older Age: The Case for Maturational Dualism in the Experience of Emotion

As neuroscience methods begin to dominate emotion research it is critical for researchers to remember that peripheral embodiments are critical to understanding emotional experience and emotion–behavior links. Much of modern emotion research assumes reliable mind–body connections that suggest that changes in emotional states influence bodily responses and, vice versa, that somatovisceral information shapes emotional experiences. However, there may be important qualifications to the link between the mind and the (peripheral) body. For example, the ability to sense internal and external bodily states declines in older age as does activation of physiological systems, all of which may contribute to an impairment in emotional experiences and how emotions influence behavior. I describe this phenomenon as maturational dualism and suggest implications of this for emotion in older adults.
Molecular Basis for Evolving Modularity in the Yeast Protein Interaction Network

Scale-free networks are generically defined by a power-law distribution of node connectivities. Vastly different graph topologies fit this law, ranging from the assortative, with frequent similar-degree node connections, to a modular structure. Using a metric to determine the extent of modularity, we examined the yeast protein network and found it to be significantly self-dissimilar. By orthologous node categorization, we established the evolutionary trend in the network, from an "emerging" assortative network to a present-day modular topology. The evolving topology fits a generic connectivity distribution but with a progressive enrichment in intramodule hubs that avoid each other. Primeval tolerance to random node failure is shown to evolve toward resilience to hub failure, thus removing the fragility often ascribed to scale-free networks. This trend is algorithmically reproduced by adopting a connectivity accretion law that disfavors like-degree connections for large-degree nodes. The selective advantage of this trend relates to the need to prevent a failed hub from inducing failure in an adjacent hub. The molecular basis for the evolutionary trend is likely rooted in the high-entropy penalty entailed in the association of two intramodular hubs.
Sources and availability of raw materials for fluorine chemistry

Abstract The two most important sources of fluorine are the minerals fluorite, commercially known as fluorspar, and fluorapatite, commercially known as phosphate rock. The major consumers of fluorspar are the aluminum, chemical, and steel industries. Acid-grade fluorspar, one of three commercial grades, is used primarily to make hydrogen fluoride, which is then used to produce synthetic cryolite, aluminum fluoride, fluorocarbons, and other fluorochemicals. Elemental fluorine is prepared from anhydrous hydrogen fluoride by electrolysis. Fluosilicic acid is used primarily for water fluoridation but also to make aluminum fluoride and cryolite. Reported U.S. consumption of fluorspar was 753,000 tons in 1984. U.S. demand for fluorspar was projected to increase at an average annual rate of 2.7% between 1983 and 2000. U.S. production of finished fluorspar in 1984 was 72,000 tons. Fluosilicic acid production was 61,000 tons or 107,000 tons as equivalent fluorspar. More than 85% of domestic demand was imported, primarily from Mexico and the Republic of South Africa. A U.S. Bureau of Mines investigation of major fluorspar reserves and resources in market economy countries and China found approximately 900,000 tons of demonstrated and 1,200,000 tons of identified reserves in the United States. Total world demonstrated and identified reserves were 135 million tons and 262 million tons, respectively. The potential resources of fluosilicic acid were estimated at 12 million tons of equivalent fluorspar in the United States and 360 million tons for the total world. Fluorine reserves appear adequate through the year 2000 given current projections.
Children's shift performance in the absence of dimensionality and a learned representational response☆

Abstract The transfer performance of 6- and 8-year-old children on reversal (R) and half-reversal (HR) shifts was compared under treatments where the same or a new set of responses were used on the shift list. Performance on the reversal shift was superior to that on the half-reversal shift only for treatments where the responses were identical (I) on the two lists. Additional comparisons with performance under a control treatment (involving new stimuli and responses on List 1 and List 2) indicated strong positive transfer on the R-I treatment and negative transfer on the R-C treatment (where the responses were changed on List 1 and List 2). The pattern of results was functionally identical for both groups of children. The performance on the R-I treatment was attributable to the S s use of a nonmediational “response-switching” strategy.
On the branching factor of the alpha-beta pruning algorithm

An analysis of the alpha-beta pruning algorithm is presented which takes into account both shallow and deep cut-offs. A formula is first developed to measure the average number of terminal nodes examined by the algorithm in a uniform tree of degree n and depth d when ties are allowed among the bottom positions: specifically, all bottom values are assumed to be independent identically distributed random variables drawn from a discrete probability distribution. A worst case analysis over all possible probability distributions is then presented by considering the limiting case when the discrete probability distribution tends to a continuous probability distribution. The branching factor of the alpha-beta pruning algorithm is shown to grow with n as @Q(n/lnn), therefore confirming a claim by Knuth and Moore that deep cut-offs only have a second order effect on the behavior of the algorithm.
Design and Analysis of LTE Physical Downlink Control Channel

Long Term Evolution (LTE) of UMTS Terrestrial Radio Access and Radio Access Network is a Fourth Generation (4G) wireless broadband technology which is capable of delivering high data transmission rates and low latency with reduced costs, among other promises. A key research topic is to design efficient and reliable Physical Downlink Control Channels (PDCCHs) that carry the downlink scheduling assignments and uplink scheduling grants. A number of issues regarding the design and analysis of PDCCHs are discussed in this paper, such as the PDCCH interleaver, power boosting, power lending, receiver handling of power boosting with unknown boosting values, link level performance evaluation, and system level performance evaluation. Based on mathematical analysis and/or simulations, conclusions have been reached, including the adoption of the simple subblock interleaver to achieve desired interference randomization property; power boosting and power boosting limits; and a method of handling power boosting values unknown to the receiver in system simulations. These conclusions have been utilized to develop the LTE standards or adopted in LTE standards.
Coronary sinus catheterization made easy for port-access minimally invasive cardiac surgery

A MONG MANY evolving techniques for performing cardiac surgery through small incisions, the Port-Access system (Heartport Inc, Redwood City, CA) provides the convenience of cardiopulmonary bypass and hypothermic cardiac arrest without requiting sternotomy. The technique allows for administration of antegrade and, where indicated, retrograde cardioplegia, without the direct access to the heart that is conventionally enjoyed by the surgeon. For retrograde cardioplegia delivery, the anesthesiologist inserts a cardioplegia catheter into the CS from the internal jugular vein. Most anesthesiologists are unfamiliar with this new skill. A simple method for successful placement of a CS catheter using TEE and fluoroscopy is described in this article.
Controlled Size, Nanometer-Scale, Reaction Vessels in Two Dimensions

Islands of monolayer vacancies can be generated on transition metal surfaces by ion bombardment of samples held at elevated temperature. Our experiments show that the average size of the monolayer vacancy islands can be varied in a controlled manner from 3 to 30 nm by adjusting the sample temperature. We also demonstrate that monolayer vacancy islands can be used as two-dimensional nanometer-scale catalytic “reaction vessels.” The reactants are confined to the reaction vessels by energetic barriers to adsorbate diffusion across the atomic steps that form the walls of the vessels. Reaction vessels with diameters of ∼3 nm can accommodate only a small number of reactant molecules (e.g., a maximum of 28 ethylene molecules can be adsorbed in an area with a diameter of 3.3 nm on a Pt(111) surface). Reactions whose products or rates depend on the number of reactant molecules that are available can be controlled using these reaction vessels. This is demonstrated for the particular example of carbon particles that...
An introduction to the Internet. Part I: History, structure, and access.

Although the use of computers for word processing and spreadsheet analysis is widespread, other less well-known uses can also increase efficiency' and productivity. In this bimonthly column, Dr. Nicoll discusses a variety of computer applications to help the nurse executive catch up, keep up, and get ahead.
Connexin 35/36 is phosphorylated at regulatory sites in the retina

Connexin 35/36 is the most widespread neuronal gap junction protein in the retina and central nervous system. Electrical and/or tracer coupling in a number of neuronal circuits that express this connexin are regulated by light adaptation. In many cases, the regulation of coupling depends on signaling pathways that activate protein kinases such as PKA, and Cx35 has been shown to be regulated by PKA phosphorylation in cell culture systems. To examine whether phosphorylation might regulate Cx35/36 in the retina we developed phospho-specific polyclonal antibodies against the two regulatory phosphorylation sites of Cx35 and examined the phosphorylation state of this connexin in the retina. Western blot analysis with hybrid bass retinal membrane preparations showed Cx35 to be phosphorylated at both the Ser110 and Ser276 sites, and this labeling was eliminated by alkaline phosphatase digestion. The homologous sites of mouse and rabbit Cx36 were also phosphorylated in retinal membrane preparations. Quantitative confocal immunofluorescence analysis showed gap junctions identified with a monoclonal anti-Cx35 antibody to have variable levels of phosphorylation at both the Ser110 and Ser276 sites. Unusual gap junctions that could be identified by their large size (up to 32 μm2) and location in the IPL showed a prominent shift in phosphorylation state from heavily phosphorylated in nighttime, dark-adapted retina to weakly phosphorylated in daytime, light-adapted retina. Both Ser110 and Ser276 sites showed significant changes in this manner. Under both lighting conditions, other gap junctions varied from non-phosphorylated to heavily phosphorylated. We predict that changes in the phosphorylation states of these sites correlate with changes in the degree of coupling through Cx35/36 gap junctions. This leads to the conclusion that connexin phosphorylation mediates changes in coupling in some retinal networks. However, these changes are not global and likely occur in a cell type-specific or possibly a gap junction-specific manner.
Numerical Solution by the CESE Method of a First-Order Hyperbolic Form of the Equations of Dynamic Nonlinear Elasticity

This paper reports the application of the space-time conservation element and solution element (CESE) method to the numerical solution of nonlinear waves in elastic solids. The governing equations consist of a pair of coupled first-order nonlinear hyperbolic partial differential equations, formulated in the Eulerian frame. We report their derivations and present conservative, nonconservative, and diagonal forms. The conservative form is solved numerically by the CESE method; the other forms are used to study the eigenstructure of the hyperbolic system (which reveals the underlying wave physics) and deduce the Riemann invariants. The proposed theoretical/numerical approach is demonstrated by directly solving two benchmark elastic wave problems: one involving linear propagating extensional waves, the other involving nonlinear resonant standing waves. For the extensional wave problem, the CESE method accurately captures the sharp propagating wavefront without excessive numerical diffusion or spurious oscillations, and predicts correct reflection characteristics at the boundaries. For the resonant vibrations problem, the CESE method captures the linear-to-nonlinear evolution of the resonant waves and the distribution of wave energy among multiple modes in the nonlinear regime.
Statistical linear regression analysis of prediction models for creep and shrinkage

Abstract Several models for the prediction of creep and shrinkage of concrete are compared statistically with test data available in the literature. The models are algebraically transformed into a linearized form and statistical regression is then carried out. Although the BP model performs distinctly better than the ACI and CEB-FIP Models, the scatter is large for all models, due to the difficulty in predicting material parameter values without any tests of the given concrete.
RNA-Seq Transcriptome Profiling of Equine Inner Cell Mass and Trophectoderm

Formation of the inner cell mass (ICM) and trophectoderm (TE) marks the first differentiation event in mammalian development. These two cell types have completely divergent fates for the remainder of the developmental process. The molecular mechanisms that regulate ICM and TE formation are poorly characterized in horses. The objective of this study was to establish the transcriptome profiles of ICM and TE cells from horse blastocysts using RNA sequencing (RNA-seq). A total of 12 270 genes were found to be expressed in either lineage. Global analysis of the transcriptome profiles by unsupervised clustering indicated that ICM and TE samples presented different gene expression patterns. Statistical analysis indicated that 1662 genes were differentially expressed (adjusted P 2) between ICM and TE. Genes known to be specific to the ICM and TE were expressed primarily in their respective tissue. Transcript abundance for genes related to biological processes important for horse blastocyst formation and function is presented and discussed. Collectively, our data and analysis serve as a valuable resource for gene discovery and unraveling the fundamental mechanisms of early horse development.
Intense sub-kilometer-scale boundary layer rolls observed in hurricane Fran

High-resolution observations obtained with the Doppler On Wheels (DOW) mobile weather radar near the point of landfall of hurricane Fran (1996) revealed the existence of intense, sub-kilometer-scale, boundary layer rolls that strongly modulated the near-surface wind speed. It is proposed that these structures are one cause of geographically varying surface damage patterns that have been observed after some landfalling hurricanes and that they cause much of the observed gustiness, bringing high-velocity air from aloft to the lowest observable levels. High-resolution DOW radar observations are contrasted with lower-resolution observations obtained with an operational weather radar, which underestimated peak low-level wind speeds.
Biosynthesis of monoterpenes: preliminary characterization of i-endo-fenchol synthetase from fennel (Foeniculum vulgare) and evidence that no free intermediate is involved in the cyclization of geranyl pyrophosphate to the rearranged product.

Abstract A soluble enzyme preparation from the leaves of fennel (Foeniculum vulgare M.) has been shown to catalyze the cation-dependent cyclization of both geranyl pyrophosphate and neryl pyrophosphate to the bicyclic rearranged monoterpene l-endo-fenchol (R. Croteau, M. Felton, and R. Ronald, 1980 Arch. Biochem. Biophys.200, 524–533) . To examine the possible presence of free intermediates between the acyclic precursors and fenchol, and to remove competing cyclase and pyrophosphatase activities, the soluble preparation was partially purified by ammonium sulfate fractionation followed by gel filtration on Sephadex G-150 and ion exchange chromatography on O-diethylaminoethyl-cellulose. Activities for the cyclization of geranyl pyrophosphate and neryl pyrophosphate to fenchol were coincident on Chromatographic fractionation suggesting that the same enzyme was capable of cyclizing both acyclic substrates. No interconversion of the acyclic precursors was detected. Although bornyl pyrophosphate is a free intermediate in the biosynthesis of the related bicyclic monoterpenol borneol, both protein fractionation and isotopic dilution experiments ruled out endo-fenchyl pyrophosphate as a free intermediate in fenchol biosynthesis. Similarly, while construction of the fenchane skeleton was demonstrated to involve the rearrangement of an intermediate pinane skeleton, isotopic dilution experiments ruled out both optical antipodes of α-pinene, β-pinene, cis-2-pinanol, trans-2-pinanol, and the corresponding 2-pinyl pyrophosphates as free intermediates of the enzyme-catalyzed reaction. Furthermore, exhaustive search of the enzymatic reaction products provided no evidence to suggest the involvement of any free intermediate between the acyclic precursor and fenchol. The endo-fenchol synthetase has an apparent molecular weight of 60,000, shows a pH optimum near 7.0, and requires Mn2+ (1 m m ) for catalytic activity. Co2+ can partially substitute for Mn2+, but other divalent cations are ineffective. The partially purified synthetase is inhibited by p-hydroxymercuribenzoate and by phenylglyoxal, and it exhibits a preference for geranyl pyrophosphate over neryl pyrophosphate as substrate. An integrated scheme is proposed for the cyclization and rearrangement catalyzed by fenchol synthetase.
Multigrid algorithm for three-dimensional incompressible high-Reynolds number turbulent flows

A robust multigrid algorithm is presented for solving three-dimensional incompressible high-Reynolds number turbulent flows on high aspect ratio grids. The artificial compressibility form of the Navier-Stokes equations is discretized in a cell-centered finite volume form on a time-dependent curvilinear coordinate system, and the so-called discretized Newton-relaxation scheme is used as the iterative procedure for the solution of the system of equations. A nonlinear multigrid scheme (full approximation scheme [FAS]) is applied to accelerate the convergence of the time-dependent equations to a steady state. Two methods for constructing the coarse grid operator, the Galerkin coarse grid approximation and the discrete coarse grid approximation have also been investigated and incorporated into the FAS. A new procedure, called implicit correction smoothing that leads to high efficiency of the multigrid scheme by allowing large Courant-Friedrichs-Lewy numbers, is introduced in this work. Numerical solutions of high-Reynolds number turbulent flows for practical engineering problems are presented to illustrate the efficiency and accuracy of the current multigrid algorithm.
Implicit schemes for differential equations

Abstract Implicit high-order accurate temporal-integration schemes are developed to reduce partial differential equations of evolution type to a sequence of ordinary differential equations involving the spatial directions only. The ordinary differential equations are solved using various accurate integration methods. The schemes are free from extraneous boundary and/or initial conditions and are stable for large Courant number.
Photoelectron spectroscopy of the trimethylenemethane negative ion

The photoelectron spectrum of the trimethylenemethane (TMM) negative ion is described. The electron affinity of TMM is found from the spectrum to be 0. 431±0.006 eV, and the energy difference between the \(\tilde X^3 A'_2 \)3A′2 and \(\tilde b^1 A_1 \)1A1 states of TMM is determined to be 16.1±0.2 kcal/mol. The energy difference between the lowest energy triplet and singlet states is estimated to be 13–16 kcal/mol. The enthalpy of formation of TMM is measured to be 70±3 kcal/mol, and the C-H bond enthalpy in 2-methylallyl radical is 90±2 kcal/mol. Previously unobserved vibrational frequencies of 425, 915, and 1310 cm−1 are found for the triplet state of TMM, whereas a frequency of 325 cm−1 is found for the singlet state. In addition, an overtone peak is observed for the triplet state at 1455 cm−1, and both states contain peaks that are assigned to bands arising from excited vibrational levels of the ion.
Direct infrared imaging of VB 8

Near-infrared images of VB 8 taken at K (2.2 microns) and L-prime (3.75 microns) during a period of good seeing at the IRTF show no evidence of the brown dwarf companion reported by McCarthy et al. (1985). Any companion 1.0 arcsec away from the primary must be at least 4 mag fainter than the primary at K and 3 mag fainter at L-prime in order to escape detection. A faint nebula centered on the star with scattering properties similar to a nebula detected near another main-sequence M star, Lalande 21185 (reported by McCarthy in 1986), may account for the extended emission detected by speckle observations.
Community treatment for the seriously mentally ill: is this community psychology?

Community treatment for seriously mentally ill individuals fits well into the philosophy of community psychology. Community psychologists have skills and experiences with other populations that represent assets in improving the ACT service model and producing richer and more useful research results for the future. Maybe we should ask ourselves why community psychologists have obviously avoided this intervention area and the population of seriously mentally ill individuals. Does this represent an adolescent reaction to the parent discipline — clinical psychology? Is the label “mentally ill” as stigmatizing to community psychologists as it is to the general population? Are these individuals written off as not worthy of or capable of benefiting from preventive interventions? Advocates for the seriously mentally ill are mounting a backlash against prevention services. We would be well advised at this time to become involved in community treatment and demonstrate that community psychology is forall vulnerable and at-risk population groups. If the truth of the matter is that “community psychology is not doing much of a job of empowering people” (Berkowitz, 1990), maybe the truth of the matter is also that we need to reach out to more disenfranchised populations with research to show that community psychologycan do the job of empowering some.
Proof that static stellar models are spherical

We give a proof that static general-relativistic stellar models, in other words static perfect fluid stars in asymptotically-flat spacetimes, are spherically symmetric for physically reasonable equations of state. The analysis may also be of independent interest for differential geometric rigidity theorems.