cssi/SciSciGPT-SciSciNet huggingface dataset:
Non-Riemannian metric emergent from scalar quantum field theory

We show that the two-point function $\ensuremath{\sigma}(x,{x}^{\ensuremath{'}})=\sqrt{⟨[\ensuremath{\phi}(x)\ensuremath{-}\ensuremath{\phi}({x}^{\ensuremath{'}}){]}^{2}⟩}$ of a scalar quantum field theory is a metric (i.e., a symmetric positive function satisfying the triangle inequality) on space-time (with imaginary time). It is very different from the Euclidean metric $|x\ensuremath{-}{x}^{\ensuremath{'}}|$ at large distances, yet agrees with it at short distances. For example, space-time has a finite diameter that is not universal. The Lipschitz equivalence class of the metric is independent of the cutoff. $\ensuremath{\sigma}(x,{x}^{\ensuremath{'}})$ is not the length of the geodesic in any Riemannian metric. Nevertheless, it is possible to embed space-time in a higher dimensional space so that $\ensuremath{\sigma}(x,{x}^{\ensuremath{'}})$ is the length of the geodesic in the ambient space. $\ensuremath{\sigma}(x,{x}^{\ensuremath{'}})$ should be useful in constructing the continuum limit of quantum field theory with fundamental scalar particles.
Air-ground channel characterization for unmanned aircraft systems: The mountainous environment

Unmanned aircraft systems (UAS) technology has advanced quickly, and the civil use of UAS is expected to expand greatly in the near future. Government, industry, academia, and standards bodies are all doing research for the safe integration of UAS into the worldwide airspace (in the USA, this is designated the National Airspace System (NAS)). For safe operation, requirements for control and non-payload communication (CNPC) systems for UAS are being developed for two frequency bands (960–977 MHz and 5030–5091 MHz) that have been recently allocated by the ITU. Since the air-ground (AG) channel can have a significant effect upon signal reliability, the comprehensive characterization of the AG radio propagation channel plays an essential role in the reliability and safety of CNPC links. Based upon a customized dual-band SIMO wideband channel sounder, NASA Glenn Research Center has conducted an AG channel measurement campaign for various ground site local environments, e.g., over sea, over freshwater, suburban, near-urban, desert, hilly and mountainous terrain. This paper addresses the quantitative models for one of these AG channels: the mountainous terrain. We briefly introduce the current status of our AG channel study and the NASA project, then describe our testing system and the measurement site in the Rocky Mountains. This paper provides example results for propagation path loss, dispersion as quantified by the root-mean square delay spread, and small scale fading Ricean K-factors. We also describe correlations among channels seen by multiple antennas, useful in assessing aircraft antenna diversity.
Heterogenous azeotropic distillaion-homotopy-continuation methods

Abstract An algorithm for the simulation of three-phase distillation towers and associated phase separators is presented. The algorithm utilizes the homotopy-continuation method of Allgower and Georg[1] to accurately track the homotopy path, with extensions to avoid limit points when multiple solutions are encountered and when liquid phases are introduced on the trays. The Allgower and Georg algorithm is also extended to track solution paths in parametric studies. Emphasis is placed on the calculation of liquid—liquid equilibria, with a reliable, yet efficient, homotopy-continuation algorithm introduced. An effective method for incorporating the LLE algorithm in the homotopy-continuation algorithm for heterogenous distillation is also introduced. The combined algorithms have located two steady-state solutions for an industrial azeotropic distillation tower a very narrow range of the reflux ratios, one with a single liquid phase on the trays, the other with two liquid phases on 70% of the trays. In addition, for the dehydration of ethanol with benzene, it has detected a region in which five steady-state solutions exist for the same specifications. Three of these solutions were reported by Magnussen .[2] and observed in dynamic simulations by Prokopakis and Seider[3].
A Simple Spectrophotometric Assay for Arogenate Dehydratase

Abstract A simple spectrophotometric assay for arogenate dehydratase, the enzyme that catalyzes the formation of l -phenylalanine from l -arogenate, is presented. The method couples the arogenate dehydratase reaction with that of an aromatic aminotransferase partially purified from Acinetobacter calcoaceticus . In the presence of 2-ketoglutarate, phenylpyruvate formation is measured at 320 nm at basic pH. The method was compared with two other methods already in use in our laboratory for arogenate dehydratase. The new method is simple, quick, fairly sensitive, and especially suitable for the screening of a large number of samples.
Student response to a new electronic reserves system

Abstract This survey investigated students’ experience with and reactions to a college library’s new electronic reserve system (ERS). Results document active use, a preference for ERS over traditional reserves, and enthusiasm with enhanced access. Somewhat greater satisfaction was found among off-campus students and those who had previously used traditional reserves.
PLDS: Partitioning linked data structures for parallelism

Recently, parallelization of computations in the presence of dynamic data structures has shown promising potential. In this paper, we present PLDS, a system for easily expressing and efficiently exploiting parallelism in computations that are based on dynamic linked data structures. PLDS improves the execution efficiency by providing support for data partitioning and then distributing computation across threads based on the partitioning. Such computations often require the use of speculation to exploit dynamic parallelism. PLDS supports a conditional speculation mechanism that reduces the cost of speculation. PLDS can be employed in the context of different forms of parallelism, which to cover a wide range of parallel applications. PLDS provides easy-to-use compiler directives, using enabling programmers to choose from among a variety of data partitionings to distribute computation across threads in a partitioning-sensitive fashion, and to use conditional speculation when required. We evaluate our implementation of PLDS using ten benchmarks, of which six are parallelized using speculation. PLDS achieves 1.3x--6.9x speedups on an 8-core machine.
Electrostrictive Constants of Insulating Crystals

The electrostrictive constants of insulating crystals have been related to the microscopic coupling parameters of lattice theory. This is done within the framework of the Born-Huang method of long waves. It is shown that the electrostrictive constants, as commonly defined, include the effects of Maxwell stresses and local stresses in the crystal. The connection between the theory and the properties of displacive ferroelectrics in the unpolarized phase is discussed. The relation between the observed temperature dependence of the electrostrictive coefficients and the temperature dependent "ferroelectric mode" is exhibited. Order-of-magnitude agreement is obtained between the theory and experiment for SrTi${\mathrm{O}}_{3}$.
A different kind of revolutionary change: transformation from object to process concepts

I propose a new perspective with which to understand scientific revolutions. This is a conversion from an object-only perspective to one that properly treats object and process concepts as distinct kinds. I begin with a re-examination of the Copernican revolution. Recent findings from the history of astronomy suggest that the Copernican revolution was a move from a conceptual framework built around an object concept to one built around a process concept. Drawing from studies in the cognitive sciences, I then show that process concepts are independent of object concepts, grounded in specific regions of the brain and involving unique representational mechanisms. There are cognitive obstacles to the transformation from object to process concepts, and an object bias—a tendency to treat processes as objects—makes this kind of conceptual change difficult. Consequently, transformation from object to process concepts is disruptive and revolutionary. Finally, I explore the implications of this new perspective on scientific revolutions for both the history and philosophy of science.
Regulation of the actin cytoskeleton in living cells

The dynamic behavior of pure actin in vitro is more complex than that of most simple polymers, due to the energy input from the irreversible nucleotide hydrolysis associated with polymerization. However, the dynamic behavior of actin is vastly more complicated inside cells, where dozens of different types of actin-binding proteins alter every rate constant for actin polymerization and the chemical environment is inhomogeneous both temporally and spatially. Actin dynamics in cells are tightly regulated, so that rapid filament polymerization can occur in response to external signals or at the front of an active lamellipodium, while rapid depolymerization occurs simultaneously elsewhere in the cell. Although more direct observations of actin dynamics in vivo are accumulating, it is not yet clear how to reconcile the behavior of actin in cells with its well-documented in vitro properties.
Putative nociceptive modulatory neurons in the dorsolateral pontomesencephalic reticular formation

Abstract The present study was undertaken to confirm the dorsolateral pontomesencephalic reticular formation (an area that includes the nucleus cuneiformis (NCF) and nucleus parabrachialis (NPB)) as a sensitive site for stimulation-produced antinociception and to investigate the possibility that there are cells in this region that show a change in activity that can be correlated with the occurrence of a nocifensive reflex (the tail-flick withdrawal response from noxious heat (TF)). Such cells have been previously demonstrated in the rostral ventromedial medulla (RVM). Extracellular single unit recording studies were made at sites from which it was possible to inhibit the TF with currents of 10 μA or less. Cellular response to 3 TF trials at 5 min intervals, and spontaneous activity over a 10 min period, were monitored for each unit. Of the cells encountered, 17% displayed an increase (on-cells) and 4% a decrease (off-cells) in activity that preceded the TF. The remaining cells were unaffected by the TF (neutral cells). On- and off-cells were found throughout the region from which TF suppression was observed but were most concentrated in the areas of the NCF and NPB. The presence of on- and off-cells in the NCF/NPB region as well as the RVM suggests that the input to RVM from NCF/NPB may be important in descending nociceptive modulation.
Performance of the experimental HWRF in the 2008 Hurricane Season

In response to the needs of improving hurricane forecasts, we have built an experimental version of the operational Hurricane Weather Research and Forecasting Model (HWRF), which is based on the Weather Research and Forecasting Nonhydrostatic Mesoscale Model of the National Oceanic and Atmospheric Administration (NOAA). The experimental HWRF (HWRFx) is adopted to study the intensity change problem at the highest possible resolutions with the existing computing facility, using moving nests to focus the model resolution in the vicinity of the storms. Although this is at an early stage of development, results from real-time experiments in the 2008 hurricane season show that the HWRFx is generally comparable to the NOAA operational models, in terms of the accuracy of both track and intensity forecasts. The HWRFx, however, has a negative bias in the intensity forecasts as opposed to the positive biases of the NOAA operational models. We present in this article a brief description of the HWRFx and its performance during the 2008 hurricane season in comparison with the NOAA operational models.
Determination of rock mass modulus nonlinear variation with loading and depth

Abstract Analytical solutions and plate load tests conducted on mine floors have shown nonlinear variation of the in situ rock mass modulus. This nonlinear variation extends down to a critical depth, below which the rock mass modulus remains relatively constant. Theoretical and empirical expressions are given, and the parameters involved are evaluated in an attempt to quantify the above-noted phenomena.
Nucleic acid aptamers for biosensors and bio-analytical applications

Oligonucleotides were once considered only functional as molecules for the storage of genetic information. However, the discovery of RNAzymes, and later, DNAzymes, unravelled the innate potential of oligonucleotides in many other biological applications. In the last two decades, these applications have been further expanded through the introduction of Systematic Evolution of Ligands by EXponential enrichment (SELEX) which has generated, by repeated rounds of in vitro selection, a type of molecular probe termed aptamers. Aptamers are oligonucleic acid (or peptide) molecules that can bind to various molecular targets and are viewed as complements to antibodies. Aptamers have found applications in many areas, such as bio-technology, medicine, pharmacology, microbiology, and analytical chemistry, including chromatographic separation and biosensors. In this review, we focus on the use of aptamers in the development of biosensors. Coupled with their ability to bind a variety of targets, the robust nature of oligonucleotides, in terms of synthesis, storage, and wide range of temperature stability and chemical manipulation, makes them highly suitable for biosensor design and engineering. Among the many design strategies, we discuss three general paradigms that have appeared most frequently in the literature: structure-switching, enzyme-based, and aptazyme-based designs.
Scalp hibernoma: Case report and literature review

Hibernomas are uncommon, benign neoplasms derived from the remnants of fetal brown adipose tissue. A review of the world literature revealed 105 cases, with the interscapular location the most common. Typically, hibernomas are asymptomatic and slow-growing. Adequate treatment usually consists of simple excision. We describe the second documented case of a scalp hibernoma.
Hierarchy and Legitimacy in International Systems: The Tribute System in Early Modern East Asia

The East Asian “tribute system” from 1368 to 1841 comprised an enduring, stable, and hierarchic system, with China clearly the hegemon, in which cultural achievement was as important as economic or military prowess. Most significant is the recognition that the Chinese tributary order was in fact a viable and recognized international system with military, cultural, and economic dimensions that all intersected to create a very interesting and stable security system. Recently it has become fashionable in historical circles to question the viability of the tributary system in part because scholars have become increasingly aware of the realties behind Chinese rhetoric. However, more nuanced studies and new interpretations only serve to underscore the centrality of the system for its participants. This paper demonstrates that there is a hierarchical relationship—generated by a common culture defined by a Confucian worldview—in place in the context of China and the East Asian states and helps clarify the distinc...
Loose-patch clamp currents from the hypothalamo-neurohypophysial system of the rat

The loose-patch clamp technique was used to study voltage-activated currents from the surface of rat neurohypophysial and hypothalamic regions in situ. In the neurohypophysis, depolarizing pulses of 4-8 ms duration yielded tetrodotoxin (TTX)-sensitive sodium currents, a 4-AP-sensitive "A"-type potassium current, and a long-lasting outward TEA- and tetrandrine-sensitive Ca(2+)-activated potassium current. All of these currents were elicited during the application of the pulse. With high external calcium there were long-lasting inward currents blocked by Ni(2+) and Cd(2+), identifying them as voltage-gated calcium currents. Depolarizing pulses of 0.3-0.7 ms duration yielded fast biphasic responses, of 1-3 ms duration, composed of mostly sodium and "A"-type potassium currents. With high external calcium there were fast inward currents blocked by Ni(2+) and Cd(2+), indicating that these were voltage-gated calcium currents. These responses have the characteristics of action potential currents: they were elicited after the cessation of the applied pulse and the "A" component is eliminated together with the sodium component upon application of TTX. Similar responses to long and short pulses were obtained from the surface of the associated magnocellular somata in the supraoptic nucleus, and their projections. The explant currents are similar to those previously characterized using conventional methods from somata and terminals.
Extending the range and performance of non-line-of-sight ultraviolet communication links

This paper describes recent advances in the technology for, and implementation of, short-range non-line-of-sight (NLOS) optical communication links. The approach relies on molecular scattering of ultraviolet wavelengths by the atmosphere to achieve NLOS, omni-directional communication Links. The implementation employs commercially produced semiconductor sources emitting in the solar-blind region of the UV spectrum, around 275nm. This paper extends previously reported field measurements to longer ranges (100+m) and to a wider variety of application scenarios, including an outdoor demonstration of real-time speech at 2.4kbps in full sunlight. The paper also addresses the design trades associated with replacing photomultiplier detectors with semiconductor detectors for reasons of cost and ruggedness. Even with improvements in semiconductor materials and commensurate reduction in dark currents, the use of semiconductor detectors will require the introduction of imaging arrays. Incorporation of imaging arrays opens the possibility of adaptive links in which bandwidth and transmit power are adapted to best exploit the channel constraints.
Research priorities in geriatric palliative care: informal caregiving.

Abstract Background: Informal care provided by family members is an essential feature of health care systems worldwide. Although caregiving often begins early in the disease process, over time informal caregivers must deal with chronic, debilitating, and life-threatening illnesses. Despite thousands of published studies on informal care, little is known about the intersection of informal caregiving and formal palliative care. Objective: The goal of this review is to identify research priorities that would enhance our understanding of the relationship between informal caregiving and palliative care. Design: To better understand palliative care in the context of caregiving, we provide an overview of the nature of a caregiving career from inception to care recipient placement and death and the associated tasks, challenges, and health effects at each stage of a caregiving career. This in turn leads to key unanswered questions designed to advance research in caregiving and palliative care. Results: Little is k...
Production and Stabilization of Real-Time Task Schedules

A model for multiprocessor control is considered in which jobs are broken into various pieces, called tasks. Tasks are executed by single processing units. In this paper the structure controlling the assignment of tasks to processors is the task list, which orders all tasks according to servicing priority. When a processors becomes free, it simply picks up the highest priority task that is executable at that moment.The job and its component tasks are imagined to be interacting with an environment consisting of a set of rigid timing constraints. Such constraints are of two types, called start-times and deadlines. The interaction is specified by requiring that certain distinguished tasks conform directly to one or more of these constraints. Tasks conforming to a start-time cannot begin until the start-time has passed, and tasks conforming to a deadline cannot proceed beyond the deadline. In our model, all tasks have known maximum run-times, but in any particular job execution, task run-times are unknown.It is shown that despite the simplicity of this control scheme some peculiar phenomena result. Most of these phenomena were first noticed by P. Richards in 1960. A simulation study (Appendix I) reveals that they may be very common in practice. In the present paper and a companion paper by R. L. Graham [Bell Syst. Tech. J. 45 (1966), 1563-1581] a coherent theory of task-list control is developed, in which the nature of these peculiarities is brought under systematic study. A number of potentially useful results are derived.
A neural network model of multistable perception.

Abstract The major properties of multistable perception are reviewed and previous models to explain it are described. We then suggest a neural network model based on state vectors, feedback and Hebbian synaptic modification which can be made to account for a number of the experimental findings. Some simple extensions are made to previous versions of the neural model to allow the dynamic modification of synaptic connectivities during the course of the stimulus presentation. This enables such properties as the time course of reversals, adaptation, and hysteresis to be simulated. In addition, we present evidence demonstrating the importance of both the stimulus and the recent and distant history of the system to disambiguate ambiguous stimuli.
The use of a charge-coupled device for quantitative optical microscopy of biological structures

The properties of a charge-coupled device (CCD) and its application to the high-resolution analysis of biological structures by optical microscopy are described. The CCD, with its high resolution, high sensitivity, wide dynamic range, photometric accuracy, and geometric stability, can provide data of such high quality that quantitative analysis on two- and three-dimensional microscopic images is possible. For example, the three-dimensional imaging properties of an epifluorescence microscope have been quantitatively determined with the CCD. This description of the imaging properties of the microscope, and the high-quality image data provided by the CCD, allow sophisticated computational image processing methods to be used that greatly improve the effective resolution obtainable for biological structures. Image processing techniques revealed fine substructures in Drosophila embryonic diploid chromosomes in two and three dimensions. The same approach can be extended to structures as small as yeast chromosomes or to other problems in structural cell biology.
SUPPORT VARIETIES FOR MODULES OVER CHEVALLEY GROUPS AND CLASSICAL LIE ALGEBRAS

Let G be a connected reductive algebraic group over an algebraically closed field of characteristic p > 0, G 1 be the first Frobenius kernel, and G(F p ) be the corresponding finite Chevalley group. Let M be a rational G-module. In this paper we relate the support variety of M over the first Frobenius kernel with the support variety of M over the group algebra kG(F p ). This provides an answer to a question of Parshall. Applications of our new techniques are presented, which allow us to extend results of Alperin-Mason and Janiszczak-Jantzen, and to calculate the dimensions of support varieties for finite Chevalley groups.
A Direct Convertor Based upon Space Charge Effects

A device capable of converting directly the kinetic energy of charged particles into electrical energy is considered. The device differs from earlier ones (such as Post's periodic focus electrostatic direct convertor) in that it makes use of the space charge repulsion in a high density charged particle beam. The beam is directed into a monotonic decelerating electrostatic field of a several stage planar finned structure. The collector fins coincide with vacuum equipotential surfaces. Space charge blowup of the beam directs particles onto various collector fins. The energy efficiency of a 4-stage device has been determined using a numerical simulation approach. We find that efficiencies approaching 75 percent are possible. An approximate scaling law is derived for the space charge based direct convertor and a comparison is made to the periodic focus direct convertor. We find the space charge based direct convertor to be superior in a number of ways.
Social Linguistics And Literacies: Ideology in Discourse

Part 1 Background: ideology and theory - the moral basis of discourse analysis literacy - from Plato to Freire background to the "new literacy studies". Part 2 Introduction to sociolinguistics: language and meaning - humans as choosers and guessers discourses and society - language caught up in the social world. Part 3 A theory of discourses: discourses and literacies - two theorems individuals, acts and discourses - humans in the act of making and being made by their discourses.
Increased hemagglutinins after intraperitoneal immunization in postinflammatory state

Hemagglutinins to xenogeneic erythrocytes were increased in rats if intraperitoneal immunization was performed during the healing phase of a chemical peritonitis. Increased absorption of the antigen into lymph nodes draining the peritoneal cavity was probably responsible for the enhanced immune response.
Bivalent behavior in Drosophila melanogaster males containing the In (1) sc4Lsc8RX chromosome

The sex chromosome bivalent was examined in Drosophila melanogaster males possessing the In(1)sc4Lsc8R X chromosome. Three-dimensional reconstructions from electron micrographs of serially cut thin sections were made. A large proportion of the kinetochores of In(1)sc4Lsc8R/Y bivalents did not face opposite poles during metaphase I and anaphase I. This suggests that In(1)sc4Lsc8R/Y bivalents may have difficulty achieving bipolar stability. Delay in achieving bipolar stability could contribute to the nondisjunctional behavior found in In(1)sc4Lsc8R/Y males.
Decreased winter severity increases viability of a montane frog population

Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range.
In response to Isbister et al.: Application of pharmacokinetic–pharmacodynamic modeling in management of QT abnormalities after citalopram overdose

Sir: We read with interest the recent article [1] regarding derivation of a clinical algorithm for citalopram overdose and applaud the use of serum citalopram concentrations from the derivation cohort. While the performance of computer simulations to derive “at risk” clinical parameters is a potentially powerful approach, we have some hesitation about applying this particular algorithm to actual patients. The algorithm uses “ingested dose” as a critical decision point to guide management. In practice, reliable information about the ingested dose for a suicidal patient is rarely available. There are already three published case studies [2, 3, 4] that challenge the safety of using a 600 mg ingested dose cutoff for cardiac monitoring. Although the authors’ model is derived from serum citalopram concentrations, subsequently equating serum citalopram concentrations to self-reported citalopram ingested dose may not be a valid assumption. This is because citalopram steady-state plasma concentrations vary 7to 24-fold, and intra-individual variation averages 15% [5]. Furthermore, the model was derived from only 62 patients, one-third of whom ingested other substances with possible QT effects. Use of a small, heterogeneous cohort in the derivation set limits the external validity. The authors used a QT interval nomogram derived by Fossa et al. [6] to determine “at risk” QT intervals instead of the QTc. However, this nomogram was originally derived from a canine model. Therefore, Fossa’s nomogram may not be applicable until validated in humans prospectively. The original model used to derive the algorithm does not take into account the factors affecting metabolism of citalopram to didemethylcitalopram (DDCT), a metabolite responsible for QTc effects. The reported DDCT maximum plasma levels at 6.6–7.3 h [7] is similar to the authors’ stated maximum QTc prolongation at 7.8 h. Substances that interact with P450 isoenzymes alter citalopram levels and vice versa, and poor metabolizers of CYP2C19 have significantly higher citalopram steady-state plasma concentrations [5]. We urge that the above factors be examined in any effort to model citalopram overdose and we look forward to seeing future work. References
Drug use and weight loss in HIV-infected Hispanic men.

Abstract Weight loss is an independent risk factor for mortality in HIV but the role of drug use in HIV-related weight loss is not well described. We conducted this study to determine the role of drug use in HIV-related weight loss. Men (n=304), all of whom were Hispanic, were recruited into one of three groups: HIV-infected drug users; HIV-non-infected drug users; and HIV-infected non-drug users. Body mass index (BMI) was measured at successive visits. The groups were re-categorized based on self-reported drug use at the current visit into: (1) users of cocaine alone; (2) users of cocaine and opiates; (3) users of opiates alone; (4) former drug users; and (5) those who denied ever using drugs (all HIV-infected). The effect on BMI of the duration of use of the specific drug types was evaluated using repeated-measures analyses. Longer duration of exclusive opiate use or mixed cocaine and opiate use did not affect BMI in the men, regardless of HIV status. Exclusive cocaine use was associated with a decline ...
Prenatal and early postnatal β-adrenergic receptor-mediated increase of cyclic AMP in slices of rat brain

Summary The levels of cyclic AMP in slices of cerebral cortex and cerebellum from newborn rats were significantly, but transiently, increased by exposure to the β-adrenergic agonist, isoproterenol. Isobutylmethyxanthine, an inhibitor of phosphodiesterase, enhanced this effect and permitted its detection in cerebral cortex obtained from the prenatal rat. These results are consistent with the possibilities that functional noradrenergic synapses are formed early in the ontogeny of the CNS, and that norepinephrine may exert cyclic AMP-mediated influences on brain development.
Examining the competitive advantage of Diuraphis noxia (Hemiptera: Aphididae) biotype 2 over biotype 1.

ABSTRACT The Russian wheat aphid, Diuraphis noxia (Kurdjumov) is a serious pest of small grains, such as wheat and barley. High population growth rates and a broad gramineae host range have allowed this aphid to successfully establish and become pestiferous across much of North America since its invasion in the mid-1980s. Resistant wheat cultivars were developed and provided control of D. noxia until 2003, when a new biotype (designated RWA2, as contrasted with the original biotype’s designation, RWA1) emerged and rapidly spread through dryland winter wheat-growing regions. RWA2 displaced RWA1 more quickly than expected, based on RWA2’s advantage in RWA1-resistant wheat cultivars. Previous research suggested that RWA2 may out-compete RWA1 in cooler temperatures. Thus, we sought to determine if RWA2 had a competitive advantage over RWA1 during the overwintering period. We placed a known distribution of RWA1 and RWA2 aphids in the field for the winter at three sites across a latitudinal gradient (from north...
Gaining perspective for the future of distance education from early leaders

Abstract Studying examples of early, important leaders in the field of distance education enriches the professional knowledge of distance educators today. The International Council for Distance Education (ICDE), organized in 1938, offers examples of early leaders who provided vital guidance for the field. These leaders had a clear vision of the value of distance education and articulated this vision in such a way that others could understand and achieve it. Based on an analysis of the ICDE conference proceedings from 1938 to 1995, this paper highlights the work of a few early distance educators who served as leaders of ICDE (then called the International Council on Correspondence Education) in the first half of this century.
Incidental Focus on Form in University Spanish Literature Courses.

Incidental focus on form is one of several ways to direct language learners' attention to formal aspects of language within meaningful communicative contexts. Learners can benefit from focus on form, but the extent to which incidental focus on form, or any other type, is available to learners in advanced foreign language literature classes has not been widely researched. In a multiple case study approach, three university Spanish literature classes were studied over the course of a 15-week semester. Data were collected through class observations, instructor interviews, and instructor stimulated recalls. Using a modified version of Ellis's (2001) taxonomy of form-focused instruction, we found that recasts were the instructors' preferred form of feedback, with negotiation and explicit correction being extremely rare. Furthermore, preemptive focus on form was common, but almost exclusively limited to vocabulary. We discuss these findings with regard to two different points of view, the literature instructors' and the research on form-focused instruction. We then provide suggestions for increasing learners' opportunities for attention to form in literature courses while acknowledging the reality of the context.
The Polyphase Commutator Machine As A Wind Generator

The polyphase commutator machine is recognized as a candiate for wind generation systems. This paper discusses the generating mode of this type of machine, in an attempt to define the practically feasible operating regions from the viewpoint of utilities anticipating an increase in the application of small wind generation.
Steroidogenic changes and steady state amount of messenger RNA encoding steroidogenic enzymes, gonadotropin receptors and cell-death signalling in the dominant ovarian follicle during estradiol-induced atresia in cattle

Abstract Changes in steroidogenic function and associated gene expression were characterized in dominant ovarian follicles (DF) of cattle where follicles were induced to become atretic by systemic administration of estradiol benzoate (EB). In experiment 1, follicular fluid (FF) steroid concentrations in the DF were measured at 12-hourly time points for 48h in heifers treated with 1mg EB i.m./500kg body weight (EB; n =20) as compared with untreated controls (C; n =19). Treatment with EB promoted a transient reduction in circulating FSH, a rapid (12h) and sustained reduction in FF estradiol, a rapid (12h) but transient reduction in FF progesterone and a delayed (36h) increase in FF testosterone concentrations. In experiment 2, whole follicular wall tissue was collected from DF of mature non-lactating cows allocated to a 0h control group (0HC: n =7), a 24h control group (24HC; n =7) or an EB-treated group where tissue was collected 24h after administration of 1mg EB i.m./500kg body weight (EB; n =8). As for experiment 1, EB promoted a transient reduction in circulating FSH, a pronounced reduction in FF estradiol and a smaller but significant reduction in FF progesterone concentrations. Semi-quantitative RT-PCR on follicular wall tissue revealed that the loss in estrogen activity at 24h after EB was associated with two-fold reduction in aromatase mRNA, with an apparent acceleration in loss of 17α-hydroxylase mRNA. Expression of genes for gonadotropin receptors (LHR and FSHR) and a cell-death signalling pathway (Fas antigen and Fas ligand) were unchanged during the initial 24h of EB-induced atresia. These results suggest that EB initiates atresia in dominant ovarian follicles through a rapid suppression of follicular estradiol synthesis, an effect associated with down-regulation of the aromatase gene. A transient suppression in circulating FSH following administration of EB appears to have initiated these events, and it is suggested that subsequent processes involved in atresia follow this loss in estrogenic function.
Detailed chemical kinetic modeling of the pyrolysis and oxidative pyrolysis of C2H5Cl

A detailed chemical kinetic mechanism describing the pyrolysis and oxidative pyrolysis of C2H5Cl has been developed and tested using experimental data acquired in an atmospheric pressure, one dimensional flow reactor operating at 600–630°C and 0.7–1.17 s residence time. The mechanism involves the participation of 31 species in 73 reversible elementary reactions, and accounts for all the experimental data measured in a one-dimensional flow reactor. The mechanism predicts the increased production of C2H3Cl in the presence of O2, which is caused by the preferential removal of α-H from C2H5Cl by radical attack followed by the abstraction of β-H from CH3CHCl by O2. The major reaction pathways responsible for the formation and destruction of species have been identified via the calculation of reaction rates.
Reading problems, psychiatric disorders, and functional impairment from mid- to late adolescence.

ABSTRACT Objective To examine psychiatric morbidity and functional impairment of adolescents with and without poor reading skills during mid- to late adolescence. Method The sample consisted of 188 adolescents, 94 with poor reading skills and 94 with typical reading skills, screened from a larger sample in the public schools at age 15. To assess psychiatric disorders, participants were assessed annually with the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Epidemiologic Version (up to 4.5 years; maximum age, 20 years). Functional impairment was assessed with the Child and Adolescent Functional Assessment Scale. Results Adolescents with poor reading skills evidenced higher rates of current attention-deficit/hyperactivity, affective, and anxiety disorders, particularly social phobia and generalized anxiety disorder. Anxiety disorders but not affective disorders were related to reading status after controlling for attention-deficit/hyperactivity disorder. Adolescents with poor reading evidenced more functional impairment across multiple areas than youths with typical reading skills, even after considering the presence of comorbid attention-deficit/hyperactivity disorder. Conclusions The increased psychiatric morbidity and functional impairment of adolescents with reading problems highlight the importance of developing interventions that help these youths address reading deficits and associated vulnerabilities during the last years of secondary school.
Flexible intraoral stents.

n tiring and following head and neck surgery, surgeons may require intraand/or extraoral stents and obturators that are used (1) for grafts, (2) for repositioning tissues, (3) as medication carriers, (4) as dressings, and (5) for immediate obturation of defects created by the surgical eradication of malignancies.i-5 The proper fabrication of such prostheses is usually done from presurgical casts with the assistance of the surgeon. The design is made from a drawing on the cast and is an approximation of the anticipated extent, amount, and area of structure to be removed and/or the region requiring coverage. Often during surgery the prefabricated prostheses may require modifications to correct underor overextensions of the borders. Most surgeons are not trained to modify prostheses in the operating room and usually require the assistance of a maxillofacial prosthodontist and/or technician as well as special laboratory equipment. These added personnel increase the costs of the surgical procedure (personnel and operating room time). The proposed surgical stent and/or obturator can be modified easily and quickly by the surgeon with standard operating room equipment such as a scalpel, scissors, rasp, and marking pencil. The requirements of the prosthesis are that (1) it should be constructed of materials that are tissue tolerated, nonporous, easily sterilized, and easily relined postsurgically; (2) it must be easy, not time consuming, and inexpensive to make; (3) it should not distort easily and should be relatively flexible; (4) it should be overextended beyond the anticipated borders, and the overextensions should be readily adjusted; and (5) the corrected borders must be smooth and not cause pressure irritation. This article describes an alternative approach to the intraoral surgical maxillary obturator prosthesis by means of various designs and materials.
Genome-wide functional annotation by integrating multiple microarray datasets using meta-analysis

Tremendous amounts of microarray data for various organisms have provided a rich opportunity for computational analyses of gene products. Integrating these data can help inferring biological knowledge effectively. We present a new statistical method of integrating multiple microarray datasets for gene function prediction. We tested the performance of our model using yeast and human datasets. Our results show that combining multiple datasets improves the accuracy over the best function prediction of any single dataset significantly. We also compared performance of the meta p-value and meta correlation methods for function prediction. Supplementary results and code are available at http://digbio.missouri.edu/meta_analyses.
An efficient blind modulation detection for adaptive OFDM systems

Adaptive modulation is a method to increase the data capacity, throughput and efficiency of time division duplexed wireless communication systems. In adaptive modulation, the transmitter continually monitors the dynamic channel and adjusts the transmission parameters such as modulation order, coding rate etc. accordingly. Blind modulation detection schemes play an important role in adaptive systems to eliminate the need for transmitting modulation information, thereby increasing spectral efficiency. In this paper, an improved statistical blind modulation detection method based on the Kullback-Leibler distance is proposed for OFDM based wireless communication systems. Simulation results show that this blind modulation detection algorithm outperforms similar previously proposed algorithms.
THE FINE STRUCTURE OF THE DIGESTIVE GLAND OF VENUS'S FLYTRAP

A B S T R A C T The digestive gland of Venus's flytrap has been studied by light and electron microscopy. Cells of the gland contain dense protoplasm comprised of relatively large nuclei, granular endoplasmic reticulum, osmiophilic vacuolar inclusions and numerous mitochondria, Golgi bodies and plastids. The vacuolar inclusions are predominantly protein but are also sudanophilic, therefore containing some lipid material. They are similar in appearance to aleurone grains. The nuclear envelope is a porous, double-membrane structure, the pores of which are approximately 900 A and have a dense granular appearance. Plastids contain dense fine-grained stroma, several thylakoids, osmiophilic globules and a tubular complex. Gland cell walls have many complex-shaped protuberances extending into the cytoplasm providing a very large internal surface area. The stalk and basal cells contain numerous lipid globules and the common wall between the two cells is traversed by numerous plasmodesmata. In general the digestive gland fine structure is discussed in relation to its function. VENUS'S FLYTRAP (Dionaea muscipula), originally described by Ellis in 1700, attracted the attention of most botanists and naturalists at one time or another during the 19th and early 20th centuries. Their investigations concerned the functions which the plant performed and its structural features. Lloyd (1942) has summarized their work in an extensive monograph. Recent investigations have, in the main, been concerned with the response to stimuli by this plant. Stuhlman (1951) showed that, after touching a sensitive hair, a biphasic electrical impulse moved across the lobe at 3.0 cm/sec. He also observed that the impulse is proportional to the age of the plant and the environmental temperature. DiPalma, McMichael, and DiPalma (1966) have implicated the "stellate trichomes" in the response to stimuli resulting from touch by a sufficiently large insect. These trichomes are located on the leaf and the peripheral spines and underside of the lobes. The data of DiPalma et al. (1966) show that the trigger hairs are probably sensitized by subthreshold stimulation of the trichomes. The function of the digestive gland was comprehensively described by Darwin (1875). He conducted a series of experiments in which he showed that proteinases and formic acid were secreted by these glands, which constituted the proteolytic solution in the closed trap. Darwin also suggested that the digestive gland provides the pathway for absorption of the digested material into the plant. Lloyd (1942) has extensively summarized Darwin's investigations and discusses the properties of the digestive glands.
Genetic analysis of ion channels of prokaryotes and lower eukaryotes.

Electrophysiological studies of membrane excitability in microorganisms have significantly advanced our understanding of the roles of certain classes of ion channel, their relationship to the lipid bilayer, and about how channels respond to a changing intracellular milieu.
Tendency to irritation: Sensitive skin

The plausibility of the concept of "sensitive skin" evokes discussion and often amusement, because of the variance of the number of opinions compared with the amount of data, at least until recently. This report presents recent biologically oriented data that suggest that sensitive skin is a reality and is assessable with the use of contemporary methods.
Forecasting broadband provision

Abstract The provision of broadband telecommunication services in the United States is spatially heterogeneous. Previous studies find that urban locales typically have a larger selection of access platforms and providers when compared to rural or remote areas. Therefore, the ability to forecast broadband provision is important to understanding regional trends in telecommunications competition and availability. This paper provides a comparative analysis of cross-sectional and spatial econometric forecasts of broadband provision, with results suggesting that the integration of spatially referenced demand-side variables significantly improve the accuracy of short and mid-range forecasts.