cssi/SciSciGPT-SciSciNet huggingface dataset:
Students' Intent to Persist in College: Moderating the Negative Effects of Receiver Apprehension with Instructor Credibility and Nonverbal Immediacy

In this study, we examined the extent to which perceptions of instructors' communication characteristics positively impacted students' intentions to persist in college until graduation. For the 621 participants currently enrolled in college, receiver apprehension (RA) was inversely associated with intent to persist, while perceptions of both instructor credibility and nonverbal immediacy were positively associated with intent to persist. Moreover, both credibility and immediacy interacted to moderate the negative effects of RA on attitudes about persistence. Hierarchical regression analysis produced three significant two-way interactions between RA and immediacy, RA and credibility, and immediacy and credibility. The model accounted for 30% of the total variance in students' intent to persist. Theoretical and pedagogical implications of these findings are discussed.
Intracavity and resonant external cavity laser frequency doubling using semiconductor heterostructures

Optical second-harmonic (SH) generation in nonlinear semiconductors can be used to convert infrared radiation from semiconductor laser sources to visible light. The high incident light intensities and spatial modulation of the linear and nonlinear optical properties occurring in AlxGa1-xAs vertical cavity heterostructures can lead to SH generation efficiencies many orders of magnitude larger than possible homogeneous GaAs. SH generation in vertical cavity heterostructures is analyzed using a model incorporating multilayer reflections and spatially varying nonlinear sources.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Evolving differential equations with developmental linear genetic programming and epigenetic hill climbing

This paper describes a method of solving the symbolic regression problem using developmental linear genetic programming (DLGP) with an epigenetic hill climber (EHC). We propose the EHC for optimizing the epigenetic properties of the genotype. The epigenetic characteristics are then inherited through coevolution with the population. Results reveal that the EHC improves performance through maintenance of smaller expressed program sizes. For some problems it produces more successful runs while remaining essentially cost-neutral with respect to number of fitness evaluations.
R&D Work Climate and Innovation in Semiconductors

The article discusses a research on research-and-development (R&D) work climate and innovation in the semiconductor industry. The perceptions of respondents with regard to work climate were compute...
Atrial pacing during selective aortocoronary saphenous vein bypass angiography.

Abstract Selective aortocoronary bypass graft angiography was performed in 30 postoperative subjects. Thirty-one of 39 patent graft injections resulted in cardiac arrhythmias including sinus bradycardia, premature ventricular depolarizations, sinoatrial arrest and atrioventricular (A-V) block. In contrast, only 2 of 39 graft angiograms performed during right atrial pacing produced arrhythmias. We conclude the following: (1) Routine prophylactic right atrial pacing is a valuable method for preventing certain cardiac arrhythmias during aortocoronary graft opacification; and (2) the potential for rapid institution of right ventricular pacing provides safety in the event that angiographically induced A-V block occurs.
Dating quartz near saturation – Simulations and application at archaeological sites in South Africa and South Carolina

Abstract Single-grain dating of quartz near saturation is shown to have the potential of under-estimating equivalent dose. Experimental work shows that dose recoveries can be under-estimated when the administered dose approaches saturation, an observation also seen by Duller (2012). Duller (2012) found that by calculating the ratio between the fast and medium bleaching components, the “fast ratio”, for each grain, the under-estimation can be corrected by removing those grains with low fast ratios. Similar results are shown for samples from archaeological sites in South Africa and South Carolina. To understand why grains with low fast ratios might lead to equivalent dose under-estimation, simulations using a comprehensive quartz model was employed. It was found that large grain-to-grain variation in the decay constants for the fast and medium components can cause this effect.
Unilateral uterine ischemia/reperfusion-induced bilateral fetal loss and fetal growth restriction in a murine model require intact complement component 5 ☆

The role of complement in ischemia/reperfusion-induced fetal growth restriction and fetal loss is unknown. C5-deficient or wild type timed-pregnant mice were subjected to unilateral uterine ischemia/reperfusion on gestation day 13, either by (1) partial flow restriction by right ovarian artery clamping for 30 min, or (2) total flow restriction by clamping both ovarian and uterine arteries for 5 min. Ischemia/reperfusion-challenged pregnancy outcomes were compared to sham-operated controls 5 days later. Ischemia/reperfusion-treated wild type mice exhibited significantly increased bilateral fetal loss, which was greater in total flow restriction than in partial flow restriction, and decreased fetal weights, which were the same in total flow restriction and partial flow restriction for the surviving fetuses. Placental weights were unchanged by treatments. Ischemia/reperfusion increased uterine, but not placental, myeloperoxidase activity, which correlated with fetal loss. In contrast, C5-deficient mice were protected from both fetal growth restriction and fetal loss, and exhibited no increase in myeloperoxidase activity. These results demonstrate that unilateral uterine ischemia/reperfusion results in bilateral fetal loss and fetal growth restriction, mediated by a systemic mechanism. In the current model, this pathological process is completely dependent on intact complement component 5.
Estimation by the nearest neighbor rule

Let R^{\ast} denote the Bayes risk (minimum expected loss) for the problem of estimating \theta \varepsilon \Theta , given an observed random variable x , joint probability distribution F(x,\theta) , and loss function L . Consider the problem in which the only knowledge of F is that which can be inferred from samples (x_{1},\theta_{1}),(x_{2},\theta_{2}), \cdots ,(x_{n}, \theta_{n}) , where the (x_{i}, \theta_{i})'s are independently identically distributed according to F . Let the nearest neighbor estimate of the parameter \theta associated with an observation x be defined to be the parameter \theta_{n}^{'} associated with the nearest neighbor x_{n}^{'} to x . Let R be the large sample risk of the nearest neighbor rule. It will be shown, for a wide range of probability distributions, that R \leq 2R^{\ast} for metric loss functions and R = 2R^{\ast} for squared-error loss functions. A simple estimator using the nearest k neighbors yields R = R^{\ast} (1 + 1/k) in the squared-error loss case. In this sense, it can be said that at least haft the information in the infinite training set is contained in the nearest neighbor. This paper is an extension of earlier work[q from the problem of classification by the nearest neighbor rule to that of estimation. However, the unbounded loss functions in the estimation problem introduce additional problems concerning the convergence of the unconditional risk. Thus some work is devoted to the investigation of natural conditions on the underlying distribution assuring the desired convergence.
Rethinking hyporheic flow and transient storage to advance understanding of stream‐catchment connections

[1] Although surface water and groundwater are increasingly referred to as one resource, there remain environmental and ecosystem needs to study the 10 m to 1 km reach scale as one hydrologic system. Streams gain and lose water over a range of spatial and temporal scales. Large spatial scales (kilometers) have traditionally been recognized and studied as river-aquifer connections. Over the last 25 years hyporheic exchange flows (1–10 m) have been studied extensively. Often a transient storage model has been used to quantify the physical solute transport setting in which biogeochemical processes occur. At the longer 10 m to 1 km scale of stream reaches it is now clear that streams which gain water overall can coincidentally lose water to the subsurface. At this scale, the amounts of water transferred are not necessarily significant but the exchanges can, however, influence solute transport. The interpretation of seemingly straightforward questions about water, contaminant, and nutrient fluxes into and along a stream can be confounded by flow losses which are too small to be apparent in stream gauging and along flow paths too long to be detected in tracer experiments. We suggest basic hydrologic approaches, e.g., measurement of flow along the channel, surface and subsurface solute sampling, and routine measurements of the water table that, in our opinion, can be used to extend simple exchange concepts from the hyporheic exchange scale to a scale of stream-catchment connection.
Gene amplification in yeast: CUP1 copy number regulates copper resistance

The CUP1 locus in yeast confers resistance to copper toxicity. We determined the molecular basis for copper resistance in three yeast strains, with differing degrees of resistance. Increased resistance to copper is associated with overproduction of a low molecular weight copper-binding protein, copper-chelatin. Increased chelatin synthesis results from amplification of the CUP1(r) gene and increased synthesis of the copper inducible mRNA. The copper resistance level of a given strain correlates directly with the gene copy number.Strains containing one copy and ten tandemly iterated copies of the CUP1 gene were studied. From the latter, a haploid strain with enhanced resistance was isolated following several selection cycles at elevated copper concentrations. This strain was disomic for chromosome VIII, the chromosome containing the CUP1 locus. The disomic chromosomes exhibit differential CUP1 gene amplification: 11 and 14 tandemly organized repeat units are found in the respective chromosome VIII homologues. We propose that the molecular mechanisms of gene amplification involve unequal sister chromatid exchange and intrachromosomal gene conversion, as well as disomy.
History, anthropology and the study of communities: Some problems in Macfarlane’s proposal

(1978). History, anthropology and the study of communities: Some problems in Macfarlane's proposal. Social History: Vol. 3, No. 3, pp. 363-373.
Sensory aspects and water quality impacts of chlorinated and chloraminated drinking water in contact with HDPE and cPVC pipe.

Abstract Pipes constructed with high-density polyethylene (HDPE) or chlorinated polyvinyl chloride (cPVC) are commonly used in drinking water distribution systems and premise plumbing. In this comprehensive investigation, the effects on odor, organic chemical release, trihalomethane (THM) formation, free chlorine demand and monochloramine demand were determined for water exposed to HDPE and cPVC pipes. The study was conducted in accordance with the Utility Quick Test (UQT), a migration/leaching protocol for analysis of materials in contact with drinking water. The sensory panel consistently attributed a weak to moderate intensity of a “waxy/plastic/citrus” odor to the water from the HDPE pipes but not the cPVC-contacted water samples. The odor intensity generated by the HDPE pipe remained relatively constant for multiple water flushes, and the odor descriptors were affected by disinfectant type. Water samples stored in both types of pipe showed a significant increase in the leaching of organic compounds when compared to glass controls, with HDPE producing 0.14 μg TOC/cm2 pipe surface, which was significantly greater than the TOC release from cPVC. Water stored in both types of pipe showed disinfectant demands of 0.1–0.9 μg disinfectant/cm2 pipe surface, with HDPE exerting more demand than cPVC. No THMs were detected in chlorinated water exposed to the pipes. The results demonstrate the impact that synthetic plumbing materials can have on sensory and chemical water quality, as well as the significant variations in drinking water quality generated from different materials.
Understanding the Effects of Stress on the Crystallization of Amorphous Silicon

This paper presents the results of a systematic study on the effects of stress on aluminum-induced crystallization (AIC) of plasma-enhanced chemical-vapor-deposited (PECVD) amorphous silicon (a-Si:H). To decouple the impact of stress on the AIC of a-Si:H from other factors that may affect crystallization, such as a-Si:H and aluminum deposition conditions, identical thin film structures [Al (200 nm)/a-Si:H (200 nm)] were deposited on the front surface of all samples. On the back surfaces, various amorphous silicon films were deposited to adjust the curvature of the samples and, therefore, the stress in the a-Si:H film on the front surface. It was found that tensile stress in a-Si:H can retard the AIC of a-Si:H.
The α1-Subunit of Skeletal Muscle L-Type Ca Channels Is the Key Target for Regulation by A-Kinase and Protein Phosphatase-1C

Despite the fact that the phosphorylation-mediated regulation of L-type Ca channels is viewed as a model of ion channel regulation, much remains to be learned about the protein phosphorylation and dephosphorylation reactions that underlie the regulation of the channels. The channel isoform most well studied biochemically is that expressed in skeletal muscle. The alpha 1- and beta-subunits of this channel isoform are substrates for protein kinase A, but it is unknown if phosphorylation or dephosphorylation of both subunits contributes to altered channel properties. Here, we report experiments in which the alpha 1- and beta-subunits were differentially phosphorylated by protein kinase A and dephosphorylated by protein phosphatase 1c under conditions that led to channel regulation. The results suggest that the alpha 1-subunit plays a key role in the phosphorylation and dephosphorylation-dependent regulation of the L-type Ca channels from skeletal muscle.
Estimating LTL rates using publicly available empirical data

We develop a shipper-oriented model to estimate less-than-truckload (LTL) truck rates for transporting goods between origin–destination (O–D) pairs located anywhere in the continental United States. The rate estimate is developed from internet-accessible tariff tables and allows straightforward computation of optimal shipment sizes (minimising total logistics costs) and comparison with the total cost of other modes. The model uses publicly available nominal rates along with a characterisation of the distribution of LTL shipments, based on other publicly available data, to determine a rate that also accounts for the estimated industry average discount from the nominal rate. We use nonlinear regression to build the estimate, with tariff-based rates serving as the dependent variable and load density, shipment weight, and O–D pair distance as the explanatory variables. The model is normalised to reflect average industry rates and current economic conditions using the Producer Price Index for LTL service. Alth...
Postprandial limb-shaking: an unusual presentation of transient cerebral ischemia

We describe a 61-year-old woman with complete occlusion of the left carotid artery who presented with shaking of the right limbs after eating. She was found to have profound postprandial hypotension, and the episodes were interpreted as an unusual transient ischemic attack.
Experimental maternal hyperpipecolatemia decreases DNA in the mouse brain

Abstract Pipecolic acid represents the major metabolite of lysine in the CNS. This study aimed to mimic the known pathological condition of hyperpipecolatemia in human neonates by maintaining high and steady concentrations in the mouse brain both pre- and postnatally. Although histological observations did not reveal any abnormal findings in the brain, liver and kidney, the offsprings of mothers which were injected during pregnancy with 250 mg/kg PA presented a significant decrease in both cortical and whole brain DNA content. Protein, RNA and CNPase activity were not altered. The changes in DNA content are of particular interest since they demonstrate that a high and steady level of pipecolic acid, which is comparable to the level seen in human hyperpipecolatemic brain, can induce a neurotoxic effect in the fetal mouse brain. Mice injected with the same dose from day 1 to day 29 after birth did not show any change in DNA content in the cortex. These results suggest that the critical period from pipecolic acid neurotoxic effect is prenatal, probably due to a selective vulnerability of developing neurons to high levels of pipecolic acid. The decrease in DNA concentration induced by maternal hyperpipecolatemia suggests a neurotoxic effect of pipecolic acid on cell proliferation during fetal development which could be related to the neuronal damage observed in the brain of hyperpipecolatemic neonates.
The production of molybdenum targets for heavy-ion experiments by electron beam evaporation☆

Self-supporting targets of 92,98Mo, with thicknesses of 100 and 200 μg/cm2, were prepared by electron beam gun evaporation. Substrate heating proved crucial for the production of these foils. The numerous parting agents explored will be discussed. Targets of 92,98Mo were also prepared on carbon backings of various thicknesses. Problems encountered in the production of 100–200 μg/cm2 thick self-supporting and carbon-backed Mo targets for reactions with heavy ions are discussed.
On the dynamics and recursive properties of multidimensional symbolic systems

We study the (sub)dynamics of multidimensional shifts of finite type and sofic shifts, and the action of cellular automata on their limit sets. Such a subaction is always an effective dynamical system: i.e. it is isomorphic to a subshift over the Cantor set the complement of which can be written as the union of a recursive sequence of basic sets. Our main result is that, to varying degrees, this recursive-theoretic condition is also sufficient. We show that the class of expansive subactions of multidimensional sofic shifts is the same as the class of expansive effective systems, and that a general effective system can be realized, modulo a small extension, as the subaction of a shift of finite type or as the action of a cellular automaton on its limit set (after removing a dynamically trivial set). As applications, we characterize, in terms of their computational properties, the numbers which can occur as the entropy of cellular automata, and construct SFTs and CAs with various interesting properties.
Phosphate interaction with uptake and leaf concentration of magnesium, calcium, and potassium in winter wheat seedlings

Low concentrations of Mg and Ca in cool-season grasses in late fall and early spring are a primary cause of grass tetany and wheat pasture poisoning in grazing cattle. Our objective was to investigate phosphate interaction with the uptake and leaf concentration of Mg, Ca, and K in winter wheat (Triticum aestivum L., cv. Larned) seedlings. Seedlings were grown hydroponically or in pots containing perlite with a solution containing nutrient element concentrations that mimicked the soil solution of a typical midwestern alfisol. Phosphate concentration of this solution was low so that wheat seedlings depleted solution p within a few hours (...)
Cost-effectiveness of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor therapy in older patients with myocardial infarction.

The cost-effectiveness ratios of statin therapy in older patients who have previously had myocardial infarction are reasonable under a variety of assumptions about drug efficacy, drug cost, and rat...
Average Ambiguity Function for a Randomly Staggered Pulse Sequence

An average ambiguity function for the envel?pe of a randomly stagger-pulsed radar is defined. This function is related to the characteristic function of the pulse occurrence time statistics, and is numerically evaluated for some special cases.
Dark-dark solitons and modulational instability in miscible two-component Bose-Einstein condensates

We investigate the dynamics of two miscible superfluids experiencing fast counterflow in a narrow channel. The superfluids are formed by two distinguishable components of a trapped dilute-gas Bose-Einstein condensate (BEC). The onset of counterflow-induced modulational instability throughout the cloud is observed and shown to lead to the proliferation of dark-dark vector solitons. These solitons do not exist in single-component systems, exhibit intriguing beating dynamics, and can experience a transverse instability leading to vortex line structures. Experimental results and multidimensional numerical simulations are presented.
Effects of extracellular matrix components on the growth and differentiation of cultured rat hepatocytes.

Some effects of culturing adult rat hepatocytes on each of four different substrates—laminin (LN), collagen type I (C-I), collagen type IV (C-IV), and fibronectin (FN)—have been investigated under defined conditions. No differential effect on the attachment of the cells to the various substrates was noted; however, the spreading of hepatocytes shortly after initial plating was most strikingly enhanced by FN, whereas LN exhibited little or no such enhancement. The two collagen substrates enhanced the spreading of hepatocytes more than did LN, but less than FN. The different substrates had no differential effect on the induction of tyrosine aminotransferase by dexamethasone and glucagon for at least the first 10 d in culture. The longevity of the hepatocytes was not changed significantly by any of the substrates, at least through the 14th d of culture. During the culture periods the hepatocytes at high cell density were maintained as confluent monolayers, regardless of the substrate on which they had been cultured. After 14 d of culture, γ-glutamyltranspeptidase activity was highest in cells cultured on C-IV, and lowest in those on FN. DNA synthesis in cultured hepatocytes at a low cell density was highest in cells cultured on FN, with decreasing levels of this parameter in cells cultured on C-IV, C-I, and LN, respectively. These results demonstrate that specific components of the extracellular matrix modulate both differentiated functions and the replication of hepatocytes cultured in serum-free medium.
Performance of Stocks Recommended by Brokerages

Examination of performance over 1993–2002 indicates that average quarterly and cumulative returns of stocks recommended by brokerage firms are slightly below the returns of the S&P 500. And recommended stock returns are more volatile. Stocks recommended by top-tier brokerage firms perform more poorly than those recommended by mid-tier or regional firms. There is considerable variability across recommendations of individual brokerage firms. The stock recommendations of Merrill Lynch and Raymond James show the best results among top-tier and mid-tier or regional brokerage firms. On a risk-adjusted basis, only stocks recommended by three of the ten brokerage firms with a full ten years of data outperformed the S&P 500.
On Bounding the Number of Generators for Fat Point Ideals on the Projective Plane

Abstract Let X be the surface obtained by blowing up general points p1, …,pn of the projective plane over an algebraically closed ground field k, and let L be the pullback to X of a line on the plane. If C is a rational curve on X with C · L = d, then for every t there is a natural map Γ(C, O C(t)) ⊗ Γ(X, O X(L)) → Γ(C, O C(t + d)) given by multiplication on simple tensors. The ranks of such maps are determined as a function of t, d, and m, where m is the largest multiplicity of C at any of the points pi. If I is the ideal defining the fat point subscheme Z = m1p1 + ··· + mnpn ⊂ P2, and α is the least degree in which I has generators, then the ranks of the maps Γ(C, O C(t)) ⊗ Γ(X, O X(L)) → Γ(C, O C(t + d)) can be used for bounding the number of generators of I in degrees t > α + 1.
Sentinel Lymph Node Biopsy for Cutaneous Head and Neck Melanoma: Mapping the Parotid Gland

Background Sentinel lymph node biopsy (SLNB) for primary cutaneous head and neck melanoma (CHNM) has been shown to be successful and is the current standard of care for intermediate-thickness melanoma. We evaluated our experience with CHNM associated with SLNB mapping to the region of the parotid gland.
A new proposal for the mechanism of glycine hydroxylation as catalyzed by peptidylglycine α-hydroxylating monooxygenase (PHM)

The title enzyme, peptidylglycine alpha-hydroxylating monooxygenase (PHM), is essential to the in vivo generation of a wide variety of physiologically significant alpha-amidated peptide hormones from the corresponding C-terminal glycine-extended prohormones. Over a 20-year period of time a massive amount of experimental information about the enzyme has accumulated, but its mechanism of action has remained obscure. A major stumbling block to proposed mechanisms is the fact that the two copper atoms found in the active site are fixed 11 A apart. A novel mechanism is now proposed which accommodates and, indeed, requires this separation and proceeds through energetically accessible steps. It is proposed that hydroxylation at the terminal glycine residue of the C-terminal glycine-extended prohormone proceeds first by a concerted sequence of single-electron electromeric shifts, whereby both copper atoms are oxidized to Cu(II), oxygen is reduced to peroxide coordinated to Cu(M), and the glycyl group is tautomerized to its enolate coordinately bound to Cu(H). Upon subsequent reversion to the carbonyl tautomer, by a sequence of two-electron shifts, the enolate as nucleophile reacts with peroxide as electrophile, generating product alpha-hydroxyglycine, decoordinated from Cu(H), reopening the mouth of the active-site pocket to egress of product and ingress of substrates.
Formation of Positronium in an Electron Gas

It is shown that for a positron in a free electron gas, radiationless captures to form positronium, is very likely prior to annihilation. (auth)
On the Active-Passive Hybrid Control Actions of Structures With Active Constrained Layer Treatments

This paper is concerned with the analysis of active and passive hybrid actions in structures with active constrained damping layers (ACL). A system model is derived via Hamilton's Principle, based on the constitutive equations of the elastic, viscoelastic, and piezoelectric materials. The model converges to a purely active piezotronic system as the thickness of the viscoelastic material (VEM) layer approaches zero. A mixed Galerkin-GHM (Golla-Hughes-McTavish) method is employed to discretize and analyze the model in time domain. With an LQR (linear quadratic regulator) optimal control, the effects of the active constrained layer configuration on the system vibration suppression performance and control effort requirements are investigated. Analysis illustrates that the active piezoelectric action with proper feedback control will always enhance the damping ability of the passive constrained layer. When compared to a purely active configuration, while the viscoelastic layer of the ACL treatment will enhance damping, it will also reduce the direct control authorities (active action transmissibility) from the active source to the host structure. Therefore, whether the ACL treatment is better than a purely active configuration depends on whether the effect of damping enhancement is greater than that of transmissibility reduction caused by the VEM layer. The significance of these effects depends very much on the viscoelastic layer thickness and material properties. With some parameter combinations, the ACL configuration could require more control effort while achieving less vibration reductions compared to a purely active system. Through analyzing the performance and control effort indices, the conditions where this active-passive hybrid approach can outperform both the passive and active configurations are quantified. Based on this study, design guidelines can be set up to effectively integrate the host structure with the piezoelectric and viscoelastic materials, such that a truly beneficial active-passive hybrid control system could be achieved.
Large second-order nonlinear optical properties of novel organometallic (sigma-aryl-enynyl)ruthenium complexes

Novel homo- and heterobimetallic complexes have been synthesized, and their nonlinear optical properties were evaluated. The effects upon the hyperpolarizability of chain length, configuration of the metal donor group, and kind of metal acceptor group are reported.
Soil Water Use and Growth of Russian Thistle after Wheat Harvest

crop cycle (Ramig and Ekin, 1991). Consequently, many growers in this dryland region are increasing the intenRussian thistle (Salsola iberica Sennen and Pau) is a major broadsity of spring cereal cropping (i.e., decreasing the freleaf weed in dryland crops (,300 mm annual precipitation) in the Pacific Northwest of the USA. Russian thistle frequently infests wheat quency of fallow) and reducing or eliminating tillage. (Triticum aestivum L.) and other spring-sown crops, especially during Russian thistle presents a formidable obstacle to sucdrought. Quantitative information on water use, biomass accumula- cessful dryland spring cropping. Spring wheat and spring tion, and seed production of Russian thistle after wheat harvest is barley (Hordeum vulgare L.) have less early growth lacking. In a 2-yr field study at Lind, Washington, Russian thistle and slower canopy closure compared with winter wheat, plants were allowed to grow yearly in spring wheat in a grid pattern which grows vigorously in early spring. Infestation is without competition from other weeds. Individual Russian thistle most severe when crop competition is reduced by poor plants used 70 L of soil water while growing with the crop. From stands, drought, inadequate fertility, and late growth. wheat harvest in early August until killing frost in late October, each Russian thistle seedlings first emerge in March or April, Russian thistle used an additional 100 L of soil water. Water use flower in June, and produce seed beginning in August. occurred within a 1.5-m radius of the Russian thistle. Spring wheat competed with Russian thistle for water at shallow soil depths; most Grain yield of spring cereals may be reduced by 50% water use by Russian thistle was from deeper than 1.0 m. Russian or more in severe infestations (Young, 1988). Grain thistle dry weight increased from 170 to 1280 g per plant between quality also is diminished when green Russian thistle grain harvest and killing frost. Russian thistle seeds were either not biomass and seed contaminate the grain and increase produced or germinable until mid-September. By late October, indi- moisture (Holm et al., 1997). Russian thistle also infests vidual plants had produced 67 000 and 25 000 seeds in 1996 and 1997, broadleaf crops that are needed to diversify the present respectively. In low crop residue situations, rapid post-harvest growth cereal-only cropping system. Herbicides for Russian by Russian thistle (before seed production) provides valuable surface thistle control in broadleaf crops are either not labeled, cover for erosion control, but with the prospect that soil water may have rotational restrictions, or require incorporation
Determination of the Concentrations of CF2 and CF3 Radicals in an Argon Matrix: An Illustration Using Predicted Infrared Intensities

A novel procedure is described for the determination of concentrations of CF2 and CF3 radicals from the infrared spectrum using predicted values for the absolute integrated molar absorption coefficients. The predictions were made using an F-atom polar tensor transferred from CH3F according to procedures described earlier. These predicted intensities are used to calculate a simulated spectrum, adjusting the values assumed for the concentrations of CF4, CF3, and CF2 until agreement is obtained with the experimental spectrum obtained by Milligan and Jacox from a sample of CF2N2 photolyzed in an argon matrix in the presence of an added F-atom source. This procedure illustrates an analytical application of predicted infrared intensities that may also be important for other unstable species.
Effect of feed rate, workpiece hardness and cutting edge on subsurface residual stress in the hard turning of bearing steel using chamfer + hone cutting edge geometry

Abstract Residual stress on the machined surface and the subsurface is known to influence the service quality of a component, such as fatigue life, tribological properties, and distortion. Therefore, it is essential to predict and control it for enhanced performance. In this paper, a newly proposed hardness based flow stress model is incorporated into an elastic–viscoplastic finite element model of hard turning to analyze process variables that affect the residual stress profile of the machined surface. The effects of cutting edge geometry and workpiece hardness as well as cutting conditions, such as feed rate and cutting speed, are investigated. Numerical analysis shows that hone edge plus chamfer cutting edge and aggressive feed rate help to increase both compressive residual stress and penetration depth. These predictions are validated by face turning experiments which were conducted using a chamfer with hone cutting edge for different material hardness and cutting parameters. The residual stresses under the machined surface are measured by X-ray diffraction/electropolishing method. A maximum circumferential residual stress of about 1700 MPa at a depth of 40 μm is reached for hardness of 62 HRc and feed rate of 0.56 mm/rev. This represents a significant increase from previously reported results in literatures. It is found from this analysis that using medium hone radius (0.02–0.05 mm) plus chamfer is good for keeping tool temperature and cutting force low, while obtaining desired residual stress profile.
Vitamin E in foods: determination of tocols and tocotrienols.

A method is described for the analysis of foods for the forms of vitamin E. Detailed procedures are given for extraction, saponification and partial purification by thin layer chromatography. The individual tocopherols (both tocols and tocotrienols) are identified and estimated as their trimethylsilyl ethers by gas liquid chromatography on SE-30 or Apiezon L at 235 C. Retention ratios are also given for separations on OV-17. Response factors relative to didecyl pimelate as an internal standard and overall recoveries were determined for α-tocopherol, β-tocopherol, γ-tocopherol, δ-tocopherol, β-tocotrienol and α-tocotrienol. Sample sizes depended on tocopherol content and were usually chosen to contain 3–50 µg of the individual tocopherols. Data for a number of seeds and oils are given. The greatest variety of forms was found in barley, which contains all the forms listed above, plus γ-tocotrienol.
Effects of multiple courses of antenatal corticosteroids on blood-brain barrier permeability in the ovine fetus.

To test the hypothesis that multiple courses of antenatal corticosteroids accentuate the decreases in blood-brain barrier permeability observed after a single course of corticosteroids in preterm ovine fetuses. Chronically instrumented 106-day gestation ovine fetuses were studied after single and multiple courses of dexamethasone or placebo were given to ewes beginning at 104 to 106 or 76 to 78 days of gestation, respectively. In the single-course groups, the ewes received dexamethasone (6 mg, n = 6) or placebo (n = 6) as four intramuscular injections every 12 hours over 48 hours. In the multiple course groups, the ewes received the same treatment (dexamethasone, n = 9, or placebo, n = 8), once per week for 5 weeks starting at 76 to 78 days of gestation. Blood-brain barrier permeability was quantified with the blood-to-brain transfer constant (Ki) for α-aminoisobutyric acid (AIB) in the brain regions of the fetuses 12 hours after the last injection of dexamethasone was given to the ewes at 106 to 107 days of gestation. Both single (analysis of variance [ANOVA]; main effects for dexamethasone treatment, F = 5.92, P <.04) and multiple (ANOVA; main effects for dexamethasone treatment, F = 4.74, P <.04) courses of antenatal corticosteroids were associated with decreases in blood-brain barrier permeability in the brain regions of the ovine fetus. However, the multiple courses did not accentuate (ANOVA; main effects for single versus multiple courses, F = 1.06, P =.32) the decreases in permeability observed after a single course. Contrary to our hypothesis, antenatal treatment with a 5-week course of corticosteroids did not accentuate the reductions in blood-brain barrier permeability that we observed after a single course of corticosteroids in the fetus.
Blastocoel expansion in the preimplantation mouse embryo: stimulation of sodium uptake by cAMP and possible involvement of cAMP-dependent protein kinase.

Abstract Elevating cAMP levels in mouse blastocysts increases the rate of blastocoel expansion ( F. Manejwala, E. Kaji, and R. M. Schultz, 1986 , Cell , 46, 95–103), which requires extracellular sodium ( F. Manejwala, E. J. Crago, Jr., and R. M. Schultz, 1989 , Dev. Biol. 133, 210–220). We report that cAMP analogs that can activate the cAMP-dependent protein kinase stimulate 22 Na + uptake by cavitating mouse blastocysts and that inhibitors of cAMP-dependent protein kinase activity inhibit the cAMP-stimulated increase in both the rate of blastocoel expansion and 22 Na + uptake.
Spinal Accessory Neuropathy Associated With Deep Tissue Massage: A Case Report

Spinal accessory neuropathy (SAN) causes impaired arm mobility and pain. The spinal accessory nerve is often injured during surgical procedures such as neck dissection for tumor resection or cervical lymph node biopsy. Other traumatic injuries may also occur. SAN causes weakness of the trapezius muscle and, less frequently, of the sternocleidomastoid muscle. The clinical consequence of trapezius muscle weakness includes impaired stability of the scapula leading to upper limb dysfunction and pain. We present a rare and illustrative case of SAN associated with deep tissue massage leading to scapular winging and droopy shoulder as a result of weakness of the trapezius muscle.
Infectivity of nucleic acid and adsorptive properties of Venezuelan encephalitis virions inactivated by lipid solvents.

SummaryVenezuelan encephalitis (VE) virions, inactivated by 0.1% sodium deoxycholate (SDC), 50% diethyl ether, or 50% chloroform yielded infectious ribonucleic acid (IRNA) upon hot or cold phenol treatment, but they could not be shown to adsorb to cultured chicken embryonic cells as measured by hemagglutinin in cultural fluid or by interference with homologous virus. These lipid solvents in the above concentrations did not inactivate phenol-extracted IRNA nor did they release IRNA from purified VE virions, although it was found after treatment of crude suspensions of virus which apparently contained incomplete, unstable virions. Therefore, it is postulated that SDC, diethyl ether, or chloroform inactivate VE virus by altering viral surface properties related to adsorption to susceptible cells rather than by disruption of the capsid with release of IRNA or by destruction of IRNA within the virus.
Interfacial reactions in titanium-matrix composites

A study of the interfacial reaction characteristics of SiC fiber-reinforced titanium aluminide and disordered titanium alloy composites has determined that the matrix alloy compositions affect the microstructure and the distribution of the reaction products, as well as the growth kinetics of the reaction zones. The interfacial reaction products in the ordered titanium aluminide composite are more complicated than those in the disordered titanium-alloy composite. The activation energy of the interfacial reaction in the ordered titanium aluminide composite is also higher than that in the disordered titanium alloy composite. Designing an optimum interface is necessary to enhance the reliability and service life at elevated temperatures.
Genetic explorations of recent human metabolic adaptations: hypotheses and evidence

Since humans and chimpanzees split from a common ancestor over 6 million years ago, human metabolism has changed dramatically. This change includes adaptations to a high-quality diet, the evolution of an energetically expensive brain, dramatic increases in endurance abilities, and capacity for energy storage in white adipose tissue. Human metabolism continues to evolve in modern human populations in response to local environmental and cultural selective forces. Understanding the nature of these selective forces and the physiological responses during human evolution is a compelling challenge for evolutionary biologists. The complex genetic architecture surrounding metabolic phenotypes indicates that selection probably altered allelic frequencies across many loci in populations experiencing adaptive metabolic change to fit their environment. A recent analysis supports this hypothesis, finding that classic selective sweeps at single loci were rare during the past 250,000 years of human evolution. Detection of selective signatures at multiple loci, as well as exploration of physiological adaptation to environment in humans, will require cross-disciplinary collaboration, including the incorporation of biological pathway analysis. This review explores the Thrifty Genotype Hypothesis, high-altitude adaptation, cold-resistance adaptation, and genetic evidence surrounding these proposed metabolic adaptations in an attempt to clarify current challenges and avenues for future progress.
Highly directed transmission of multipole radiation by an interface

Electromagnetic multipole radiation can have a highly directed peak in its angular intensity distribution when transmitted through an interface (xy-plane) with a medium that has a higher index of refraction. We show that the possible occurrence of such a peak depends on the order of the multipole. It is also shown that the peak intensity is determined uniquely by the intensity of the multipole radiation in the xy-plane in the absence of the interface. This peak occurs at the slightest difference in index of refraction of the two media, and when the indices of refraction are almost equal, the peak appears just below the interface in the denser medium, and it has an intensity of four times the intensity in the xy-plane of the unbounded multipole.
The Relative Effects of Classwide Peer Tutoring and Peer Coaching on the Positive Social Behaviors of Children With ADHD

This study investigates the effects of Classwide Peer Tutoring (CWPT) and peer coaching on the peer social behaviors of children with ADHD. A single-subject, multiple-baseline design is used with three elementary-school students in Grades 3 and 4. Following a baseline period, CWPT is implemented in each student’s classroom. During the second intervention phase, CWPT is continued and peer coaching is added. Peer social behaviors are observed in both academic and social settings, with a primary focus on intervention effects on the latter setting. Results suggest that students participating in CWPT are actively and positively engaged with their peers while carrying out the CWPT program in the academic setting. However, when only CWPT is implemented, increases in positive peer social behaviors are not observed in social settings. The addition of peer coaching results in enhanced social behaviors during recess and lunch.
CHARACTERIZATION OF THE CARBOHYDRATE DEGRADING ENZYMES IN THE SURF CLAM CRYSTALLINE STYLE

The digestive enzymes within the crystalline style of the surf clam, Spisula solidissima, were examined for possible future use in algal carbohydrate degradation. Measurement and characterization of enzymatic activities, contained in a simple homogenate and useful in polysaccharide breakdown has been accomplished. The activities of amylase, cellulase, and the major enzyme, laminarinase, were evaluated by determining the amount of glucose which was released from the appropriate substrates. The activity of a fourth enzyme, alginase, was detected by a modified thiobarbituric acid test which measured the mannuronic and guluronic acids produced from an algin substrate. Conditions for the best combination of coordinated enzymatic activity were evaluated, and the majority of the crystalline style enzymes could function to a satisfactory level at 37°C when the pH was maintained at 6.0.
Are in vivo and in situ brain tissues mechanically similar

Brain tissue mechanical properties have been well-characterized in vitro, and were found to be inhomogeneous, nonlinear anisotropic and influenced by neurological development and postmortem time interval prior to testing. However, brain in vivo is a vascularized tissue, and there is a paucity of information regarding the effect of perfusion on brain mechanical properties. Furthermore, mechanical properties are often extracted from preconditioned tissue, and it remains unclear if these properties are representative of non-preconditioned tissue. We present non-preconditioned (NPC) and preconditioned (PC) relaxation responses of porcine brain (N = 10) obtained in vivo, in situ and in vitro, at anterior, mid and posterior regions of the cerebral cortex during 4mm indentations at either 3 or 1 mm/s. Material property characteristics showed no dependency on the site tested, thus revealing that cortical gray matter on the parietal and frontal lobes can be considered homogenous. In most cases, preconditioning decreased the shear moduli, with a more pronounced effect in the dead (in situ and in vitro) brain. For most conditions, it was found that only the long-term time constant of relaxation (tau > 20 s) significantly decreased from in vivo to in situ modes (p < 0.02), and perfusion had no effect on any other property. These findings support the concept that perfusion does not affect the stiffness of living cortical tissue.
Open-ended metallized ceramic coaxial probe for high-temperature dielectric properties measurements

A metallized ceramic coaxial probe has been developed for high temperature complex permittivity measurements. The probe is made of alumina and metallized with a 3.0-mil-thick layer of moly-manganese, and a 0.5-mil-thick protective coating of nickel plating. It is shown that based on carrying out the network analysis calibration procedure up to 1000/spl deg/C, and on actual dielectric properties measurements, the probe provides accurate dielectric measurements over a broad frequency range (500 MHz to 3 GHz) and for temperatures up to 1000/spl deg/C. An uncertainty analysis based on two different calibration techniques was also given to help quantify possible measurement errors.
Zinc turnover in mice during pregnancy, lactation, and growth.

The turnover of '5Zn was examined in mice. During pregnancy, lactation, and growth, the loss of "Zn from the body was twice as great as that observed in mature, nonpregnant animals. The results of this study emphasize the need for consideration of zinc losses in the formulation of the minimum daily requirement for zinc in humans and other mammalian species Am.J. C/in. Nutr. 29: 814-816, 1976. The essentiality of zinc in human and animal nutrition is well established (1-3). The biochemical functions that require zinc include: I) enzyme structure and function; 2) protein metabolism; 3) nucleic acid metabo- lism; and 4) carbohydrate metabolism. Be- cause of the critical role of zinc in mamma- lian metabolism, an adequate dietary supply of this element is essential during growth and development. Hambidge (4) has demon- strated the importance of optimal zinc nutri- tion in growing children, and Sandstead (3) has described the need for increased zinc intake in women during pregnancy and lacta- tion. During the course of our investigations into zinc metabolism, we examined the turnover of zinc in mice during pregnancy, lactation, and growth. The results of our experiments indicate that the zinc turnover rate is twice as great in pregnant, lactating, or growing mice as in mature, nonpregnant mice, thus empha- sizing the need in mice for adequate zinc nutrition during pregnancy, lactation, and growth.