cssi/SciSciGPT-SciSciNet huggingface dataset:
A non-additive interaction in a single locus causes a very short root phenotype in wheat

Non-additive allelic interactions underlie over dominant and under dominant inheritance, which explain positive and negative heterosis. These heteroses are often observed in the aboveground traits, but rarely reported in root. We identified a very short root (VSR) phenotype in the F1 hybrid between the common wheat (Triticum aestivum L.) landrace Chinese Spring and synthetic wheat accession TA4152-71. When germinated in tap water, primary roots of the parental lines reached ~15 cm 10 days after germination, but those of the F1 hybrid were ~3 cm long. Selfing populations segregated at a 1 (long-root) to 1 (short-root) ratio, indicating that VSR is controlled by a non-additive interaction between two alleles in a single gene locus, designated as Vsr1. Genome mapping localized the Vsr1 locus in a 3.8-cM interval delimited by markers XWL954 and XWL2506 on chromosome arm 5DL. When planted in vermiculite with supplemental fertilizer, the F1 hybrid had normal root growth, virtually identical to the parental lines, but the advanced backcrossing populations segregated for VSR, indicating that the F1 VSR expression was suppressed by interactions between other genes in the parental background and the vermiculite conditions. Preliminary physiological analyses showed that the VSR suppression is independent of light status but related to potassium homeostasis. Phenotyping additional hybrids between common wheat and synthetics revealed a high VSR frequency and their segregation data suggested more Vsr loci involved. Because the VSR plants can be regularly maintained and readily phenotyped at the early developmental stage, it provides a model for studies of non-additive interactions in wheat.
Transgenic DNA introgressed into traditional maize landraces in Oaxaca, Mexico

Concerns have been raised about the potential effects of transgenic introductions on the genetic diversity of crop landraces and wild relatives in areas of crop origin and diversification, as this diversity is considered essential for global food security. Direct effects on non-target species, and the possibility of unintentionally transferring traits of ecological relevance onto landraces and wild relatives have also been sources of concern. The degree of genetic connectivity between industrial crops and their progenitors in landraces and wild relatives is a principal determinant of the evolutionary history of crops and agroecosystems throughout the world. Recent introductions of transgenic DNA constructs into agricultural fields provide unique markers to measure such connectivity. For these reasons, the detection of transgenic DNA in crop landraces is of critical importance. Here we report the presence of introgressed transgenic DNA constructs in native maize landraces grown in remote mountains in Oaxaca, Mexico, part of the Mesoamerican centre of origin and diversification of this crop.
MIGUEL ÁNGEL ASTURIAS AND THE APORIA OF POSTCOLONIAL GEOGRAPHY

In this essay we examine the relation between race and space in the Americas. We do so by offering a broadly postcolonial reading of the Mayanist writings of Miguel Angel Asturias, the Guatemalan writer who won the 1967 Nobel Prize in literature. Specifically, we trace the ways in which his work problematizes the political relations between race and space and how, in turn, these relations problematize his own critical project. We argue that Asturias, in offering a trenchant critique of capitalist social relations and their articulation to practices of racism, fails to adequately address what we call the aporia of postcolonial geography. In so doing, he ends up reproducing the basic model of racialized territorialization that he attempts to attack. To analyse this problem we read the origins and transformations of his Mayanist work and its geographical tendencies over several decades. The major sources for our argument include the interdisciplinary field that we call ‘Mayanism’ and its relations to some of...
Foundations of quantum probability

This paper presents an overview of the foundations of quantum probability. The main concepts in this theory are measurements and generalized actions. These concepts correspond to the usual quantum observables and states. Probabilities are computed by means of a universal influence function. We first derive the form of the universal influence function and then construct the amplitude and probability of a measurement with respect to a given generalized action. It is shown that traditional quantum mechanics can be derived as a special case of this theory and moreover the theory gives a complete realistic interpretation of quantum mechanics. It is demonstrated that spins of any order can be described within this framework and a realistic solution to the EPR problem can be achieved.
Semiparametric regression for clustered data

We consider estimation in a semiparametric partially generalised linear model for clustered data using estimating equations. A marginal model is assumed where the mean of the outcome variable depends on some covariates parametrically and a cluster-level covariate nonparametrically. A profile-kernel method allowing for working correlation matrices is developed. We show that the nonparametric part of the model can be estimated using standard nonparametric methods, including smoothing-parameter estimation, and the parametric part of the model can be estimated in a profile fashion. The asymptotic distributions of the parameter estimators are derived, and the optimal estimators of both the nonparametric and parametric parts are shown to be obtained when the working correlation matrix equals the actual correlation matrix. The asymptotic covariance matrix of the parameter estimator is consistently estimated by the sandwich estimator. We show that the semiparametric efficient score takes on a simple form and our profile-kernel method is semiparametric efficient. The results for the case where the nonparametric part of the model is an observation-level covariate are noted to be dramatically different.
Markdown optimization for multiple products with a common markdown budget constraint

One of the biggest business problems faced by retailers of all kinds – apparel, mass, specialty, hard goods, food – is how to liquidate inventory at the end of the season as profitably as possible while following certain business rules and limitations. In retail practice, this problem is referred to as markdown optimization. The goal of markdown optimization is to determine which products in which stores to mark down, when to reduce the prices, and by how much. These decisions need to be made based on critical factors such as inventory levels, price elasticity, local preferences and demand. The markdown optimization problem is a complex mathematical problem due to the large number of product-location combinations and nonlinear objective and constraints. The problem is further complicated by a unique business rule called the markdown budget. Markdown budget is a virtual budget that puts a constraint on how deep the markdowns can go among a group of products. Product/location combinations can no longer be optimized independently in the presence of this constraint. In this article we propose an efficient two-step heuristic for solving the markdown problem with a common budget constraint.
Networks of accounting research: A citation-based structural and network analysis

Abstract This study measures journal influence using the principles of knowledge capital and social networks. The structural index measure is used to evaluate knowledge capital flows in a network of 22 accounting research journals over the years 2000–2006. The influence measure is a function of both the quantity and quality of citations resulting in journal influence rankings that reflect each journal's contribution to the broad context of accounting research. Findings show that although some journals are highly cited, they may be less influential in the accounting research community. Publishing research of high value is one key to increasing the influence of a journal in the network. Furthermore, the analysis of a well-defined journal network provides a view of the distinct contribution of individual journals. The network analysis diagram provides a visual perspective of journal relationships, emphasizes the strength of relational ties and suggests that influential journals may take on different roles. The contribution of other disciplines to the top-five influential accounting research journals is also presented.
Ultrastructural demonstration of acetylcholinesterase activity of motor endplates via osmiophilic diazothioethers.

The ultrastructural chemical localization of acetylcholinesterase of motor endplates of rat intercostal muscle has been studied with three new esterase substrates. These substrates, although not specific for acetylcholinesterase, have differential affinities for various types of esterases; two of them (NTA and TAB) are hydrolyzed preferentially by acetyl esterase enzymes, and the third (TPB) is a propionic acid ester and is hydrolyzed preferentially by pseudocholinesterase and other esterases. The end-product of the enzymatic reaction is converted to a diazothioether (droplet form) and upon osmication this is converted to a coordination polymer of osmium which has ideal properties for electron microscopy.
A study of steady-state steam-water counterflow in porous media

Vapor-liquid counterflow in porous media arises in processes such as heat pipes, oil recovery and geothermal systems. Previous studies analysed these phenomena in separate contexts. This paper presents a unified description from which previous models result as limiting cases. The analysis includes capillarity, heat conduction, and Kelvin effects. The importance of each term to various processes is examined. Significantly, it is found that the critical heat flux is not constant but increases with decreasing permeability. A threshold permeability is identified below which steady states may not exist. Analogous conclusions are reached regarding liquid-dominated geothermal systems. 24 refs., 15 figs.
Operation of SOI CMOS devices at liquid-nitrogen temperature

Liquid-nitrogen-temperature (LNT) operation of silicon-on-insulator (SOI) CMOS devices has been investigated experimentally. The maximum carrier mobilities in these devices increase by factors from 1.25 to 4.5 between room temperature and LNT. At LNT, the increase in depletion-layer width and the resulting threshold-voltage increase are limited by the silicon film thickness. For SOI devices with a body contact, the series resistance between channel and body contact increases at lower temperature, resulting in a current kink in saturation I-V characteristics. >
Symbiotic role of Glomus mosseae in phytoextraction of lead in vetiver grass [Chrysopogon zizanioides (L.)]

Abstract Lead (Pb) has limited solubility in the soil environment owing to complexation with various soil components. Although total soil Pb concentrations may be high at a given site, the fraction of soluble Pb that plants can extract is very small, which is the major limiting factor for Pb phytoremediation. The symbiotic effect of arbuscular mycorrhizal (AM) fungus, Glomus mosseae was examined on growth and phytoextraction of lead (Pb) by vetiver grass [Chrysopogon zizanioides (L.)]. A hydroponic study, Phase I (0, 1, 2, and 4 mM Pb) was conducted followed by an incubation pot study, Phase II (0, 400, 800, and 1200 mg kg−1 Pb) where vetiver plants were colonized with G. mosseae. The results obtained indicate that plants colonized by the AM fungi not only exhibit better growth (increase in plant biomass), but also significantly increase Pb uptake in root and higher translocation to the shoot at all given treatments. Moreover, plants colonized with AM fungi had higher chlorophyll content and reduced levels of low molecular weight thiols, indicating the ability to better tolerate metal-induced stress. Results from this study indicate that vetiver plants in association with AM fungi can be used for improved phytoextraction of Pb from contaminated soil.
MDR1 function is sensitive to the phosphorylation state of myosin regulatory light chain.

Abstract Multiple drug resistance protein 1 (MDR1) is composed of two homologous halves separated by an intracellular linker region. The linker has been reported to bind myosin regulatory light chain (RLC), but it is not clear how this can occur in the context of a myosin II complex. We characterized MDR1-RLC interactions and determined that binding occurs via the amino terminal of the RLC, a domain that typically binds myosin heavy chain. MDR1-RLC interactions were sensitive to the phosphorylation state of the light chain in that phosphorylation by myosin light chain kinase (MLCK) resulted in a loss of binding in vitro. We used ML-7, a specific inhibitor of MLCK, to study the functional consequences of disrupting RLC phosphorylation in intact cells. Pretreatment of polarized Madin–Darby canine kidney cells stably expressing MDR1 with ML-7 produced a significant increase in apical to basal permeability and a corresponding decrease in the efflux ratio (threefold; p
Comparisons between best polynomial approximations and interpolating polynomials

in H (A :H~H, f l : H ~ R +, 7:H--}R +) eine wesentliche Rolle spielen. Der allgemeine Satz wird auf das Newton-Verfahren und auf eine Reihe von Versch/irfungen des Newton-Verfahrens, auf die Regula falsi und auf inversionsfreie Verfahren (Kombinationen von Newton-Verfahren bzw. Regula falsi mit dem Inversionsverfahren von Schulz) angewendet. Als bekannte Spezialf/ille ergeben sich dabei u.a. ein allgemeiner Satz von Rheinboldt, der Fixpunktsatz von Banach, die S/itze von Kantorowitsch und Mysowskich ftir das Newton-Verfahren, S~itze von Collatz, D6ring, Shafiyev ffir Versch/irfungen des Newton-Verfahrens, ein Satz von Ulm fiir die Regula falsi, S~tze von Burmeister ffir inversionsfreie Verfahren. Die Gfite der Fehlerschranken wird an einigen numerischen Beispielen demonstriert.
Pulse propagation and windowed wave functions

AbstractWe apply quasi-distribution methods developed for quantum mechanics to the propagation of pulses in dispersive media with attenuation. We show that a Schrodinger type equation follows for propagation of the pulse for each mode. One then transforms the equation to obtain an equation of evolution in the phase space of position and wavenumber. In this paper we emphasize windowed wave functions and their corresponding phase space quasi-distributions. We obtain the time evolution equation, discuss possible approximations, and compare to the Wigner distribution approximation previously derived by Loughlin and Cohen by different methods.
Identification and Synthesis of a Unique Thiocarbazate Cathepsin L Inhibitor

Library samples containing 2,5-disubstituted oxadiazoles were identified as potent hits in a high throughput screen (HTS) of the NIH Molecular Libraries Small Molecule Repository (MLSMR) directed at discovering inhibitors of cathepsin L. However, when synthesized in pure form, the putative actives were found to be devoid of biological activity. Analyses by LC-MS of original library samples indicated the presence of a number of impurities, in addition to the oxadiazoles. Synthesis and bioassay of the probable impurities led to the identification of a thiocarbazate that likely originated via ring opening of the oxadiazole. Previously unknown, thiocarbazates (-)-11 and (-)-12 were independently synthesized as single enantiomers and found to inhibit cathepsin L in the low nanomolar range.
Enhancer Regions Responsible for Temporal and Cell-Type-Specific Expression of a Spore Coat Gene in Dictyostelium

The extracellular spore coat of Dictyostelium discoideum is composed of three major proteins, SP96, SP70, and SP60, encoded by the cotA, cotB, and cotC genes, respectively. The spore coat proteins are coordinately synthesized in prespore cells shortly after aggregation, stored in prespore vesicles during the slug stage, and secreted during encapsulation of spores. We have ligated various portions of the upstream region of cotB to lacZ such that a protein consisting of the first nine amino acids of SP70 fused to beta-galactosidase is synthesized in prespore cells. Individual cells that accumulate the enzyme can be observed in situ during early aggregation due to the sensitivity of the assay. We have found that prespore cells first appear in a random distribution throughout the aggregates with no indication of spatial localization. They subsequently sort out from prestalk cells that form a tip on the aggregates. The cotB regulatory region was subdivided into a proximal and a distal region, each of which could independently direct proper temporal and cell-type control. Transcriptional activity directed by these two regions appears to be additive in the full-length regulatory region. The proximal region was shown to be complex in that removal of certain portions partially reduced transcriptional activity while removal of other portions abolished all activity. Nevertheless, cells transformed with constructs showing attenuated activity expressed the fusion gene at the proper time in development and the activity was localized to prespore cells. The cis-acting regions responsible for all aspects of cotB regulation appear to be closely opposed within the minimal essential sequence of the proximal region.
The structure and conformation of HC-toxin.

Abstract Difference nuclear magnetic resonance studies and amino acid oxidase experiments establish the sequence and configuration of amino acids in HC-toxin as cyclo(L-Aoe-D-Pro-L-Ala-D-Ala). HC-toxin adopts the bis-γ-turn conformation in solution previously found for the cytostatic cyclic tetrapeptide chlamydocin.
Suspension and wheel evaluation and experimentation testbed for planetary rovers

This paper describes a robotic test bed that simulates a larger number of vehicle scenarios and enables better results from single wheel testing. The suspension and wheel evaluation and experimentation testbed (SWEET) is designed to evaluate and measure wheel to soil (or other media) interaction and performance. SWEET can measure wheels in true turns, on slopes, and also simulate dragging force and assisted force from other wheels. SWEET provides an efficient platform for a better understanding of wheel to soil interactions, without added expense of an extensive full rover testing programme.
Phase I/II study of docetaxel, ifosfamide, and doxorubicin in advanced, recurrent, or metastatic soft tissue sarcoma (STS)

Background: Based on reports of the efficacy of docetaxel (T) in STS, we undertook a phase I/II trial to determine the response rate (RR), dose-limiting toxicity (DLT), and maximum tolerated dose (MTD) of addition of T to doxorubicin (A) and ifosfamide (I) in advanced STS.
A Combination of Vocal f0 Dynamic and Summary Features Discriminates between Three Pragmatic Categories of Infant-Directed Speech

To assess the relative contribution of dynamic and summary features of vocal fundamental frequency (f0) to the statistical discrimination of pragmatic categories in infant-directed speech, 49 mothers were instructed to use their voice to get their 4-month-old baby's attention, show approval, and provide comfort. Vocal f0 from 621 tokens was extracted using a Computerized Speech Laboratory and custom software. Dynamic features were measured with convergent methods (visual judgment and quantitative modeling of f0 contour shape). Summary features were f0 mean, standard deviation, and duration. Dynamic and summary features both individually and in combination statistically discriminated between each of the pragmatic categories. Classification rates were 69% and 62% in initial and cross-validation DFAs, respectively.
Effect of actin filament length and filament number concentration on the actin-activated ATPase activity of Acanthamoeba myosin I

The actin-activated Mg2+-ATPase activities of phosphorylated Acanthamoeba myosins IA and IB were previously found to have a highly cooperative dependence on myosin concentration (Albanesi, J. P., Fujisaki, H., and Korn, E. D. (1985) J. Biol. Chem. 260, 11174-11179). This behavior is reflected in the requirement for a higher concentration of F-actin for half-maximal activation of the myosin Mg2+-ATPase at low ratios of myosin:actin (noncooperative phase) than at high ratios of myosin:actin (cooperative phase). These phenomena could be explained by a model in which each molecule of the nonfilamentous myosins IA and IB contains two F-actin-binding sites of different affinities with binding of the lower affinity site being required for expression of actin-activated ATPase activity. Thus, enzymatic activity would coincide with cross-linking of actin filaments by myosin. This theoretical model predicts that shortening the actin filaments and increasing their number concentration at constant total F-actin should increase the myosin concentration required to obtain the cooperative increase in activity and should decrease the F-actin concentration required to reach half-maximal activity at low myosin:actin ratios. These predictions have been experimentally confirmed by shortening actin filaments by addition of plasma gelsolin, an F-actin capping/severing protein. In addition, we have found that actin "filaments" as short as the 1:2 gelsolin-actin complex can significantly activate Acanthamoeba myosin I.
Circular Unidimensional Scaling: A New Look at Group Differences in Interest Structure

The fit of J. L. Holland’s (1959, 1997) RIASEC model to U.S. racial– ethnic groups was assessed using circular unidimensional scaling. Samples of African American, Asian American, Caucasian American, and Hispanic American high school students and employed adults who completed either the UNIACT Interest Inventory (K. B. Swaney, 1995) or the Strong Interest Inventory (L. W. Harmon, J. C. Hansen, F. H. Borgen, & A. L. Hammer, 1994) were obtained from published sources. Two circumplex models were evaluated: a quasi-circumplex model with unconstrained distances between adjacent types and a circulant model constrained to equal distances. Results indicate that a quasi-circumplex model was a good fit with all samples; however, the circulant model may be more appropriate for Asian Americans and Caucasian Americans than for other groups. Circulant model results suggest that distinctions made between Holland’s types may be less salient for some groups and that additional work is needed to produce interest measures with improved structural validity.
The Palaeomagnetism of the Great Dyke of Southern Rhodesia

i Oriented cores have been secured from fourteen sites in the Great Rhodesian Dyke, by means of a portable sampling drill. The natural remanent magnetizations showed high dispersion at all sites except one. After demagnetization in alternating magnetic fields, nine sites gave well grouped directions of primary magnetization. These sites include five rock types distributed among three Complexes of the Great Dyke and two satellite dykes, over 200 miles of the length of the Dyke and through several thousand feet in depth as the rocks were originally intruded. The nine site mean directions of primary magnetization are closely grouped and are believed to represent directions of thermo-remanent magnetization at the date of intrusion of the Great Dyke. It is suggested that the dates of magnetization at the sites must cover a sufficient time interval to give a mean pole position close to the axial geocentric dipole freed from secular variation. On the assumption of a geocentric dipole field, the position of the mean South magnetic pole is 211/2 °N, 611/2 °E, with radius of 95 per cent confidence 9°. This pole position is close to positions of North magnetic poles given by studies of the palaeo-magnetism of the Pilansberg Dykes and Bushveld gabbro.
Ribosome Development and the Methylation of Ribosomal Ribonucleic Acid

Immature ribonucleoprotein particles accumulate in amino acid-starved cells of a relaxed mutant of Escherichia coli. The ribonucleic acid (RNA) of these particles is nonmethylated in cells starved for methionine. However, in bacteria starved for arginine, lysine, or histidine, the RNA of these particles is one-half methylated. The relationship of submethylation to a structural alteration in the same RNA was studied. The results of kinetic studies showed that submethylation and the structural transition are not causally related, since they are described by different rate constants. Moreover, it was possible to accumulate fully methylated immature-particle RNA that possessed the sedimentation and chromatographic properties of nonmethylated RNA. It was concluded that, during the normal course of ribosome development, methylation of ribosomal RNA is completed prior to the final maturation steps.
The Relationship Between Black Racial Identity and Academic Achievement in Urban Settings

This article examines the relationship between Black racial identity and academic achievement in urban settings. Using Mary Shelley's Frankenstein (1918) as a comparative framework, the author describes current practices and suggests practical applications of empirical findings for practicing classroom teachers of African American students. Specifically, the article identifies an appreciation of the historical context for Black racial identity development and an acknowledgment of within-group diversity among African American adolescents as key in the development of a healthy racial identity.
Interactions between the immune and nervous systems in pain

Immune cells and glia interact with neurons to alter pain sensitivity and to mediate the transition from acute to chronic pain. In response to injury, resident immune cells are activated and blood-borne immune cells are recruited to the site of injury. Immune cells not only contribute to immune protection but also initiate the sensitization of peripheral nociceptors. Through the synthesis and release of inflammatory mediators and interactions with neurotransmitters and their receptors, the immune cells, glia and neurons form an integrated network that coordinates immune responses and modulates the excitability of pain pathways. The immune system also reduces sensitization by producing immune-derived analgesic and anti-inflammatory or proresolution agents. A greater understanding of the role of the immune system in pain processing and modulation reveals potential targets for analgesic drug development and new therapeutic opportunities for managing chronic pain.
Both Host and Pathogen Factors Predispose to Escherichia coli Urinary-Source Bacteremia in Hospitalized Patients

Background. The urinary tract is the most common source for Escherichia coli bacteremia. Mortality from E. coli urinary-source bacteremia is higher than that from urinary tract infection. Predisposing factors for urinary-source E. coli bacteremia are poorly characterized. Methods. In order to identify urinary-source bacteremia risk factors, we conducted a 12-month prospective cohort study of adult inpatients with E. coli bacteriuria that were tested for bacteremia within ±1 day of the bacteriuria. Patients with bacteremia were compared with those without bacteremia. Bacterial isolates from urine were screened for 16 putative virulence genes using high-throughput dot-blot hybridization. Results. Twenty-four of 156 subjects (15%) had E. coli bacteremia. Bacteremic patients were more likely to have benign prostatic hyperplasia (56% vs 19%; P = .04), a history of urogenital surgery (63% vs 28%; P = .001), and presentation with hesitancy/retention (21% vs 4%; P = .002), fever (63% vs 38%; P = .02), and pyelonephritis (67% vs 41%; P = .02). The genes kpsMT (group II capsule) (17 [71%] vs 62 [47%]; P = .03) and prf (P-fimbriae family) (13 [54%] vs 40 [30%]; P = .02) were more frequent in the urinary strains from bacteremic patients. Symptoms of hesitancy/retention (odds ratio [OR], 7.8; 95% confidence interval [CI], 1.6–37), history of a urogenital procedure (OR, 5.4; 95% CI, 2–14.7), and presence of kpsMT (OR, 2.9; 95% CI, 1–8.2) independently predicted bacteremia. Conclusions. Bacteremia secondary to E. coli bacteriuria was frequent (15%) in those tested for it. Urinary stasis, surgical disruption of urogenital tissues, and a bacterial capsule characteristic contribute to systemic invasion by uropathogenic E. coli.
Emotionally Focused Therapy as Treatment for Couples With Generalized Anxiety Disorder and Relationship Distress

Research has demonstrated a link between romantic relationship distress and generalized anxiety disorder (GAD); however, few have explored treating GAD with couple therapy. People with GAD often report insecure attachment and constantly search for safety. Emotionally focused therapy for couples (EFT), with its roots in attachment theory, may be an effective way to treat couples with relationship distress and where one partner has GAD. Overviews of GAD and EFT are provided, and then a case example is given demonstrating how the stages and steps of EFT can be adapted to alleviate the anxiety, constant worry, and relationship distress often associated with GAD.
Ultra low-loss waveguides of 0.12 dB/cm directly written in pure silica glass by femtosecond laser pulses

Ultra low-loss of 0.12 dB/cm at 1580 nm was achieved for directly written waveguides in pure silica glass using femto-second laser for the first time as far as we know. A three-dimensionally structured optical splitter was also demonstrated.
Reciprocity Applied to Volume Conductors and the ECG

The Helmholtz reciprocity theorem for currents in an inhomogeneous conducting media is put into a useful form for the solution of problems such as arise in electrocardiography. Several examples are considered which lead to known results and which illustrate the application of the method.
Adaptive path control of a manipulator with visual information

A picture of a scene is used to extract information for an adaptive control algorithm. The object of interest is first located by means of a classifier. The position and orientation of the object are determined from a binary picture. The desired path which the gripper of the manipulator is to follow is specified by discrete points, first is the Cartesian and then in the joint coordinate system. The adaptive self-tuning controller is outlined. The controller design is based on time series difference equation model, in which the parameters are estimated on-line. The gains of the controller are tuned so that a quadratic performance criteria is minimized. The performance of the system designed is then tested experimentally. Results of these experiments are presented.
The Status of Transistor Research in Compound Semiconductors

New semiconductors capable of competing with germanium and silicon in transistor applications must be looked for among the compound semiconductors, and more specifically among the III-V and IV-IV compounds. Gallium arsenide and indium phosphide are the most promising all-round materials for high-frequency as well as high-temperature performance. Indium antimonide and indium arsenide may be of interest for extremely high-frequency transistors operating at low temperatures The aluminum compounds, gallium phosphide and silicon carbide, are potentially useful for very high operating temperatures at the cost of high-frequency performance. Some of the unusual properties of the compound semiconductors have led to novel methods of junction preparation and new junction structures, such as the surface-diffusion and the widegap junction. Bipolar and unipolar surface-diffusion transistors have been demonstrated in indium phosphide, and the wide-gap emitter principle for high injection efficiency has been experimentally verified in gallium arsenide transistors. Electron lifetimes in these two compound semiconductors are estimated from the transistor results.
Continuous monitoring of crop reflectance, vegetation fraction, and identification of developmental stages using a four band radiometer

AbstrACt Real-time monitoring of crop vegetation fraction and identification of development stages provides useful information for crop management. Using sensors at close range makes it possible to collect data with very high temporal resolution. This study used four-band radiometers with green, red, red edge, and near infrared spectral bands for daily monitoring of maize ( Zea mays L.) and soybean [ Glycine max (L.) Merr.] reflectance during the growing season in three fields over 3 yr. Two fields were continuous irrigated maize and the third was managed under a maize/soybean rotation. The objectives were (i) determine diurnal and seasonal temporal behavior of reflectance in two contrasting crops, maize and soybean, (ii) remotely estimate the crop developmental stage using spectral spaces and vegetation indices, and (iii) estimate vegetation fraction using spectral spaces. Diurnal reflectance behavior indicated that the median reflectance measured within 2.5 h of solar noon was reliable for examining the daily behavior of reflectance and vegetation indices. Since the information content of reflectance in different spectral bands varies over the course of a season, spectral spaces (reflectance in one band vs. reflectance in another band) were constructed and shown to be a useful tool for identifying crop developmental stages. Five distinct stages of vegetation status (soil/residue, green-up, vegetative, senescence, and soil/stover/residue) were accurately identified using the red vs. green reflectance spectral space. Vegetation fraction was estimated using spectral spaces in maize with estimation error below 0.071 and in soybean below 0.064. Thus, high temporal resolution sensors can be a reliable tool for monitoring vegetation for a variety of applications.
Alteration of the C-terminal amino acid of tubulin specifically inhibits myogenic differentiation.

Detyrosination is an evolutionarily conserved post-translational modification of microtubule polymers that is known to be enhanced during early morphological differentiation of cultured myogenic cells (Gundersen, G. G., Khawaja, S., and Bulinski, J. C. (1989) J. Cell Biol. 109, 2275–2288). We proposed that altering the C terminus of α-tubulin by detyrosination plays a role in morphological differentiation. To test our hypothesis, we treated L6 myoblasts with 3-nitrotyrosine (Eiserich, J. P., Estevez, A. G., Bamberg, T. V., Ye, Y. Z., Chumley, P. H., Beckman, J. S., and Freeman, B. A. (1999)Proc. Natl. Acad. Sci. U. S. A. 96, 6365–6375), a nontoxic inhibitor that resulted in high level inhibition of microtubule detyrosination and low level incorporation of nitrotyrosine into microtubules. Even though microtubule stabilization or modification by acetylation still occurred normally, morphological differentiation was blocked; myoblasts neither elongated significantly nor fused. Nitrotyrosine treatment prevented synthesis or activation of markers of myogenic differentiation, including muscle-specific myosin, α-actin, integrin α7, and myogenin. Consistent with this, myoblast integrin β1A remained highly expressed. In contrast, the increase in β-catenin level characteristic of early myogenesis was unaffected by treatment. These results show that the identity of the C-terminal residue of α-tubulin modulates microtubule activity, possibly because binding to or signaling from modified microtubules is required for the myogenic program.
Knowledge-based indexing of the medical literature: the indexing aid project

This article describes the Indexing Aid Project for conducting research in the areas of knowledge representation and indexing for information retrieval in order to develop interactive knowledge-based systems for computer-assisted indexing of the periodical medical literature. The system uses an experimental frame-based knowledge representation language, FrameKit, implemented in Franz Lisp. The initial prototype is designed to interact with trained MEDLINE indexers who will be prompted to enter subject terms as slot values in filling in document-specific frame data structures that are derived from the knowledge-base frames. In addition, the automatic application of rules associated with the knowledge-base frames produces a set of Medical Subject Heading (MeSH) keyword indices to the document. Important features of the system are representation of explicit relationships through slots which express the relations; slot values, restrictions, and rules made available by inheritance through “is-a” hierarchies; slot values denoted by functions that retrieve values from other slots; and restrictions on slot values displayable during data entry.
A joint trajectory generator for motion recovery

This paper describes an adaptive S-curve used to recover a tool path upon a system crash in the Windows operating system (OS). For a mechanism such as a robot or machine tool, the joint values, being delivered as setpoints to the servo-controller, are dynamically recorded by the real-time operating system also residing on the computer. The real-time OS can control the abort and record pertinent motion data after Windows OS crash.Upon system recovery, the recovery trajectory generator examines the setpoints intervals to determine the current slow joint. At every trajectory step, and for the current slow joint, the S-curve velocity profile applies the joint entry state (position, speed, acceleration, and jerk) to interpolate the motion between the setpoints in a reverse direction. The other joints are proportionally interpolated (slowed) so that they pass through each setpoint simultaneously with the slow joint, but in a reverse direction.The trajectory algorithm is optimal since the slow joint always uses the maximum allowable jerk to change the profile speed and acceleration for each trajectory step.
Panniculus carnosus and formation of the pouch in Didelphids

Panniculus carnosus is well developed in the five Didelphids studied. It is described in three parts: pars dorsalis, pars thoracoabdominalis and pars pudenda, in Marmosa, Didelphis, Metachirops, Metachirus and Chironectes, and in Orolestes, a caenolestid marsupial. Pars dorsalis is well developed in all five genera, but not so well developed as in Orolestes; pars thoracoabdominalis is present in all five Didelphids, but not in Orolestes; and the degree of development of pars pudenda is correlated with the development of the pouch, being absent in Orolestes, weak in Marmosa and strong in both males and females of the other genera. In Chironectes, in which genus the male develops a pouch, pars pudenda is strikingly developed. The ‘sphincter marsupii’ of other writers is considered to be a portion of pars pudenda. In early development an epidermal ridge arises surrounding part of the mammary area. In Marmosa these ridges move laterally and posteriorly before the expanding mammary area. In Didelphis, Metachirops, Metachirus and Chironectes the ridges form the lips of the pouch. The pouch is formed when the ridges remain stationary and the expanding mammary area throws the skin into a double-walled fold.
The art of invective: Performing identity in cyberspace

This article examines the common computer-mediated communication (CMC) phenomenon of ‘flaming’ from a rhetorical perspective, situating the phenomenon diachronically in the histories of invective in art and society. An examination of the notorious alt.flame newsgroup draws connections between the political and sexual content of the flames and the rants and dozens genres of invective. The article concludes with an argument against the still prevalent media-determinant view that holds that flaming is somehow caused by the medium of CMC itself. Given the strategic nature of the different kinds of flames, it makes more sense to view them as performative enactments of identity which stress either group or individual identity depending on the genre of invective utilized by the flamer. This article demonstrates that the more historical approach offered by rhetorical criticism gives a vital perspective to an area of study from which rhetorical critics have for too long been absent.
Electrical Switching and Memory Phenomena in Semiconducting Organic Charge-Transfer Complexes

The observation of electrical switching and memory phenomena is known to exist in a wide variety of inorganic semiconducting thin films. These inorganic materials include the metal oxides of nickel, silicon, aluminum, titanium, zirconium, and tantalum, all of which exhibit a voltage controlled negative resistance when arranged in a metal-oxide-metal sandwich structure.1,2 The mechanism of switching is believed to be due to a forming process. The electrical behavior of these materials is not stable, reproducible, or independent of polarity. The amorphous alloys, including chalcogenide glasses, are inorganic semiconductors which also show switching behavior. These glasses contain up to four elements often including arsenic and/or tellurium and exhibit a current-controlled negative resistance. A typical example of an amorphous alloy which exhibits switching behavior is Te40As35Ge6Si18.3 These materials have been extensively investigated and the mechanism of conduction and switching is believed to be due to filaments which are described by both thermal and electronic models.
A fully digital, energy-efficient, adaptive power-supply regulator

A voltage scaling technique for energy-efficient operation requires an adaptive power-supply regulator to significantly reduce dynamic power consumption in synchronous digital circuits. A digitally controlled power converter that dynamically tracks circuit performance with a ring oscillator and regulates the supply voltage to the minimum required to operate at a desired frequency is presented. This paper investigates the issues involved in designing a fully digital power converter and describes a design fabricated in a MOSIS 0.8-/spl mu/m process. A variable-frequency digital controller design takes advantage of the power savings available through adaptive supply-voltage scaling and demonstrates converter efficiency greater than 90% over a dynamic range of regulated voltage levels.
Neural network interpretation of ultrasonic response for concrete condition assessment

Ultrasonic testing of concrete structures using the pitch-catch method is an effective technique for testing concrete structures that cannot be accessed on two opposing surfaces. However, the ultrasonic signals so measured are extremely noisy and contain a complicated pattern of multiple frequency-coupled reflections that makes interpretation a difficult task. In this investigation, a neural network modeling approach is used to classify ultrasonically tested concrete specimens into one of two classes: defective or nondefective. Different types of neural nets are used, and their performance is evaluated. It was found that correct classification of the individual ultrasonic signals could be achieved with an accuracy of 75 percent for the test set and 95 percent for the training set. These recognition rates lead to the correct classification of all the individual test specimens. The study shows that although some neural net architectures may show high performance using a particular training data set, their r...
A psychophysically justified bit allocation algorithm for subband image coding systems

The authors present a psychophysically justified bit allocation algorithm for use with subband image coding systems. This algorithm is also appropriate for DCT and DFT (discrete cosine and discrete Fourier transform)-based analysis-synthesis systems, as well as many others. The subjective performance of the algorithm was compared with the performance of a related algorithm that seeks to minimize the mean-square coding error. A two-dimensional analysis-synthesis system of J.P. Princen and A.B. Bradley (IEEE Trans. on Acoust. Speech, and Signal Proc., vol.ASSP-34, no.5, p.1153-1161, Oct. 1986) was used for the comparison. It is found that the psychophysically justified algorithm is superior to the minimum-mean-square-error algorithm at low bit rates. >
Development of environmentally superior treatment system to replace anaerobic swine lagoons in the USA

A full-scale treatment system for swine manure was developed to eliminate discharge to surface and ground waters and contamination of soil and groundwater by nutrients and heavy metals, along with related release of ammonia, odor, and pathogens. The system greatly increased the efficiency of liquid–solid separation by polymer injection to increase solids flocculation. Nitrogen management to reduce ammonia emissions was accomplished by passing the liquid through a module where bacteria transformed ammonia into harmless nitrogen gas. Subsequent alkaline treatment of the wastewater in a phosphorus module precipitated phosphorus and killed pathogens. Treated wastewater was recycled to clean swine houses and for crop irrigation. The system was tested during one year in a 4400-head finishing farm as part of the Agreement between the Attorney General of North Carolina and swine producers Smithfield Foods, Premium Standard Farms and Frontline Farmers to replace traditional waste treatment anaerobic lagoons with environmentally superior technology. The on-farm system removed 97.6% of the suspended solids, 99.7% of BOD, 98.5% of TKN, 98.7% of soluble ammonia ðNH þ –NÞ, 95.0% of total P, 98.7% of copper and 99.0% of zinc. It also removed 97.9% of odor compounds in the liquid and reduced pathogen indicators to non-detectable levels. Based on performance obtained, it was determined that the treatment system met the Agreement’s technical performance standards that define an environmentally superior technology. These findings overall showed that cleaner alternative technologies are technically and operationally feasible and that they can have significant positive impacts on the environment and the livestock industry. 2006 Elsevier Ltd. All rights reserved.
Estimating groundwater recharge in lowland watersheds

Little attention has been given to the role of groundwater in the hydrological cycle of lowland watersheds. Our objective in this study was to estimate total recharge to groundwater by analysing water table response to storm events and the rate at which water was transferred into the shallow aquifer. This was conducted at three sites in a rural watershed in the lower Atlantic coastal plain near Charleston, South Carolina, USA. A novel version of the water table fluctuation method was used to estimate total recharge to the shallow aquifer by comparing hourly data of water table position following storm events and measuring water table recession behavior, rather than subjective graphical analysis methods. Also, shallow aquifer recharge rates (vertical fluxes) were estimated using Darcy's Law by comparing static water levels in a water table well and in a shallow piezometer during dry periods. The total annual recharge estimated ranged from 107 ± 39 mm·yr–1 (5–10% of annual precipitation) at a poorly drained topographic low area to 1140 ± 230 mm·yr–1 (62–94% of annual precipitation) for a moderately well-drained upland site. The average aquifer recharge rate was 114 ± 60 mm·yr–1, which is similar to previous estimations of base flow for the ephemeral third-order streams in this watershed. The difference in the two methods may have been caused by processes not accounted for in the Darcy flux method, soil moisture deficits, and average evapotranspiration demand, which is about 1100 mm·yr–1 for this region. Although other factors also can affect partitioning of recharge, an integrated approach to inspecting easily gathered groundwater data can provide information on an often neglected aspect of water budget estimation. We also discuss the effects of land use change on recharge reduction, given a typical development scenario for the region. Copyright © 2011 John Wiley & Sons, Ltd.