cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of soil heterogeneity and endogenous processes on plant spatial structure.

Within communities, organisms potentially self-organize through endogenous processes that create nonrandom spatial structure as they interact with one another or modify the abiotic environment. In contrast, exogenous processes such as environmental heterogeneity or variable immigration are thought to be dominant processes controlling these spatial patterns. Although both endogenous and exogenous processes likely occur, their relative importance is still largely unknown because of limited analytical tools and the lack of experimental evidence, particularly those that address exogenous sources of environmental heterogeneity. Here, we used a soil heterogeneity experiment to examine the relative effect of endogenous and exogenous processes on plant spatial structure after five years of community assembly. Soil heterogeneity was manipulated by splitting the vertical soil profile into three soil-types that were randomly assigned to 40 × 40 cm patches within 2.4 × 2.4 m plots. Homogeneous plots were created by mixing all soils before filling each patch. Thirty-four grassland species were then sown into all plots and allowed to grow for five years after which the location of all plants was mapped using a 5 × 5 cm grid. Results from point-pattern spatial analysis indicated that, even in the absence of soil heterogeneity and with initial seed arrival, spatial structure was primarily generated by endogenous processes. Although soil heterogeneity increased species aggregation at certain scales, most of the spatial structure was created by endogenous processes. These results suggest that endogenous processes may be more important than expected for generating spatial structure and can develop much faster than anticipated.
System Reliability Analysis

Component reliability was covered in Chap. 6, but we may often have a system made of many components.
Leave the Dead Some Room to Dance: Postcolonial Founding and the Problem of Inheritance in Wole Soyinka’s A Dance of the Forests

In this essay, I examine Nigerian playwright Wole Soyinka’s A Dance of the Forests in order to think through political founding. Viewing founding from the postcolonial context, I explore how member...
Behavior, size, and body condition predict susceptibility to management and reflect post-treatment frequency shifts in an invasive snake

Abstract Foraging behavior can have population-level effects that are of interest for wildlife management. For invasive species, foraging behavior has been tied to establishment ability and rate of spread and is generally of import in understanding invasion biology. A major method for controlling invasive vertebrates is using food-based baits as attractants. Tool efficacy is therefore partially driven by individual decision-making during foraging, which may also affect population response to control. We used three studies on the invasive, arboreal brown treesnake (Boiga irregularis) on Guam to measure 1) size, body condition, and behavioral correlates with mortality in response to control using toxic baits, 2) shifts in prevalence of those traits after control treatments occurred and, based on the prior two findings, 3) interactive relationships between size, body condition, and behavioral traits at the landscape scale for untreated populations. Each trait was selected due to a potential relationship with foraging behavior or energetic state of an arboreal snake, as a method to estimate how foraging behavior can inform control tool efficacy. We found that snakes were more likely to be killed by toxiic baits if they had a lower body weight, were more active leading up to a bait application, and encountered on the ground more frequently. Across two treated populations, both body size and condition of sampled snakes increased after treatment, while the incidence of ground encounters decreased. Throughout forested habitat on Guam, ground encounter probability was positively correlated with snake size and inversely correlated to body condition. Additionally, size and condition had interactive effects such that snakes in good condition were more arboreal. Thus, body size and behavior (ground encounters) correlated with control-tool susceptibility and frequency shifts occurred in those traits within sampled post-treatment populations. Individual decision-making during foraging may thus inform population responses to bait-based control tools. Management decisions such as prey suppression are likely to directly influence removal efficacy through altered foraging behavior in snakes.
Afectación del aparato digestivo en la covid-19. Una revisión sobre el tema

Resumen La pandemia por el SARS-CoV-2 esta conllevando una elevada mortalidad y suponiendo una crisis sanitaria a nivel mundial. La afectacion fundamental es respiratoria; sin embargo, el virus tambien puede afectar a otros organos, como el tracto gastrointestinal y el higado. Los sintomas mas habituales son anorexia y diarrea. Aproximadamente, en la mitad de los casos se podria detectar ARN viral en heces, lo que constituye otra linea de transmision y diagnostico. La covid-19 tiene peor pronostico en pacientes con comorbilidades, aunque no existe evidencia suficiente en caso de enfermedades digestivas previas. Las endoscopias digestivas pueden originar aerosoles, lo que que las convierte en tecnicas con elevado riesgo de infeccion. Expertos y organizaciones cientificas a nivel mundial han elaborado guias de funcionamiento para adoptar medidas de prevencion. Se revisan las evidencias disponibles sobre la afectacion gastrointestinal y hepatica, la repercusion en pacientes con enfermedades digestivas previas y las guias de funcionamiento para las unidades de endoscopia durante la pandemia.
Simulation Models in Climatology

During the last two decades there has been an explosion of research and publications dealing with simulation of atmospheric processes. Just a listing of those works would fill the space allotted to this paper. Consequently, the following is a highly selective review of the topic and the reader should refer to the references cited for more details and a more extensive literature list. On the other hand, the coverage is broad and, following the philosophy of the author, encompasses much which would be classified by some as meteorology. That is, he makes no clear distinction between meteorology and climatology and considers these subjects to be part of an integrated continuum. Durst (1951) recognized this in his definition, “The physical problem of synoptic forecasting and climatology is the same, for climate is but the synthesis of weather.” Synthesis of weather in Landsberg’s (1960) definition is “... the collective state of the earth’s atmosphere for a given place within a specified interval of time.” For Lorenz (1975), “Climate may be identified with a set of statistics of an ensemble of many states of the atmosphere.” If we accept these descriptions, a true understanding of climate must of necessity involve the instantaneous states, so frequently we find climatologists involved in studies which are normally classified as meteorology. Geographers, whose interests lie in climatology, are part of the same current research milieu and many are engaged in simulating aspects of the atmosphere. The number has grown substantially since the author’s short survey in 1974 (Rayner, 1974) and currently a non-exhaustive list would include: Arnfield, Bach, Barry, Brazel, Davies, Dozier, Hay, Henderson-Sellers, Hobgood, Lockwood, Outcalt, Parkinson, P. J. Sellers, Suckling, Terjung, Tyson and Williams.
Dipole-coupled emitters as deterministic entangled photon-pair sources

The authors show that electric dipole-coupled emitters can deterministically emit entangled photon pairs. They estimate electric dipole coupling energies and characterize the generated entanglement.
Oral Microbiota Composition Predicts Early Childhood Caries Onset.

As the most common chronic disease in preschool children in the United States, early childhood caries (ECC) has a profound impact on a child’s quality of life, represents a tremendous human and eco...
Agency theory utility and social entrepreneurship: issues of identity and role conflict

Social entrepreneurs are often at the forefront of remedying complex societal issues by linking the entrepreneurial mindset with approaches to solving these systemic societal issues. We build upon existing notions regarding the field of social entrepreneurship and existing forms of social entrepreneurship while deepening the understanding of the different roles that social entrepreneurs must embody on a daily basis. Agency theory is used by identifying principal and agent factors underlying social entrepreneurship in terms of role stressors and role conflict. We outline varying types of social entrepreneurs and discuss role duality, an area with room for much exploration. We also identify and discuss problems for principals and agents within these types of social entrepreneurship. Thus we contribute to the literature (1) by extending on the types of social entrepreneurs, (2) by identifying the threats that social entrepreneurs face through an agency lens; namely the dual role that social entrepreneurs must embark upon, and (3) by describing the boundary conditions of the different social entrepreneur types, we link the potential challenges of social entrepreneurship with a deeper look into the growing domain that is social entrepreneurship.
Factors Affecting Hydroxide Ion Concentrations in Bipolar Membranes

The useful lifetime of bipolar ion exchange membranes is often limited by nucleophilic attack by hydroxide ions on the ionic groups and polymer backbone in the anion exchange layers (AELs). This is especially problematic in water treatment applications for making acid and base from salt solutions. This research investigated the effect of bulk electrolyte composition, current density, membrane thickness, ion exchange capacity, and bulk solution pH value on hydroxide ion concentrations inside the AELs of a bipolar membrane. Onedimensional Nernst-Plank equations were solved for the species Na+, Cl-, OH- and H+ within 20-100 μm thick anion and cation exchange layers with fixed charged densities ranging from 0.5-2.0 eq/L. In 1 M NaCl solutions at neutral pH values, hydroxide concentrations in the AEL reached as high as 2.2 M at a current density of 100 mA/cm2. In 1 M NaOH solutions, hydroxide ion concentrations reached as high as 3.77 M. Hydroxide concentrations in the AEL were significantly affected by the ratio of Cl- to hydroxide ions in the bulk electrolyte. Where hydroxide concentrations in the bulk electrolyte were an order of magnitude lower than chloride concentrations, membrane hydroxide concentrations were nearly proportional to the current density. Increases in ion exchange capacity and AEL thickness resulted in increased membrane hydroxide ion concentrations. Membrane concentrations of hydroxide ions can be minimized by operation at low current densities, with high background electrolyte concentrations using thin membranes with low ion exchange capacities and producing base concentrations less than 0.1 M.
A Sea of Whiteness: Teaching Sexuality through a New Sociology at a U.S. American University:

This article connects sociological analyses of race to sexuality to rethink the teaching of the sociology of sexualities. Through the use of the image of the sea, I locate whiteness as a root for t...
Psychoanalysis at the End of the World

This chapter argues that the end of the world is not a storm upon a menacing horizon but an irreversible fact of the present. The general refusal to acknowledge this fact is most evident in Hollywood visions of global cataclysm, the endless repetition of which is the symptom of a melancholic attachment to the world whose end we are already living. Reading these films symptomatically further reveals the unconscious logic of the apparent contradiction between widespread anxiety and general inaction in the face of accelerating environmental collapse. Combining Freud’s insights into the libidinal foundations of messianic religion with Lacan’s study of the psychoses, the chapter wagers that psychoanalysis can disrupt environmental melancholia by motivating a painful but necessary work of mourning on the way to another future.
Kernel methods for classification with irregularly sampled and contaminated data

Design of a classifier consists of two stages: feature extraction and classifier learning. For a better performance, the nature, characteristics, or underlying structure of data should be taken into account in either of the stages when we design a classifier. In this thesis, we present kernel methods for classification with irregularly sampled and contaminated data. First, we propose a feature extraction method for irregularly sampled data. Irregularly sampled data often arises in medical applications where the vital signs of patients are monitored based on the severity of their condition and the availability of nursing staff. In particular, we consider an ICU (intensive care unit) admission prediction problem for a post-operative patient with possible sepsis. The experimental results show that the proposed features, when paired with kernel methods, have more discriminating power than those used by clinicians. Second, we consider one-class classification problem with contaminated data, where the majority of the data comes from a “nominal” distribution with a small fraction of the data coming from an outlying distribution. We deal with this problem by robustly estimating the nominal density (or a level set thereof) from the contaminated data. Our proposed density estimation achieves robustness by combinining a traditional kernel density estimator (KDE) with ideas from classical M-estimation. The robustness of the density estimator is demonstrated with a representer theorem, the influence function, and experimental results. Third, we propose a kernel classifier that optimizes the L 2 distances between “difference of densities”. Like a support vector machine (SVM), the classifier is sparse and results from solving a quadratic program. We also provide statistical performance guarantees for the proposed L2 kernel classifier in the form of a finite sample oracle inequality, and strong consistency in the sense of both ISE and probability of error.
Automated Construction of Relational Attributes ACORA: A Progress Report

Data mining research has not only development a large number of algorithms, but alsoenhanced our knowledge and understanding of their applicability and performance.However, the application of data mining technology in business environments is still novery common, despite the fact that organizations have access to large amounts of dataand make decisions that could profit from data mining on a daily basis. One of thereasons is the mismatch between data representation for data storage and data analysis.Data are most commonly stored in multi-table relational databases whereas data miningmethods require that the data be represented as a simple feature vector. This workpresents a general framework for feature construction from multiple relational tables fordata mining applications. The second part describes our prototype implementationACORA (Automated Construction of Relational Features).
EXPERIMENTAL AORTIC REGURGITATION. THE MAGNITUDE AND ACUTE HEMODYNAMIC EFFECTS OF REGURGITANT FLOWS ASSOCIATED WITH VALVULAR DEFECTS OF VARIOUS SIZES.

Summary Aortic regurgitation was induced acutely in 24 normal dogs by means of special cannulas which permitted the establishment of fixed regurgitant orifices of predetermined sizes. By means of electromagnetic flowmeters, the retrograde flow, as well as the net and total forward flows, were measured in the ascending aorta and femoral artery. With regurgitant orifices ranging between 3.0 and 10 mm. in diameter, retrograde flow was found to constitute 27 to 71 per cent of total forward flow in the aorta and between 32 and 80 per cent of total forward flow in the femoral artery. These changes in flow were accompanied by an increased pulse pressure and systolic pressure in the aorta and decreases in the diastolic and mean pressures. The measured aortic regurgitant flow bore an almost linear relationship to the area of the valvular defect. This relationship was less well marked in the femoral artery, but the ratio between forward and retrograde flow in the femoral artery exhibited a general correlation with the regurgitant orifice. The physiologic significance of these observations in aortic regurgitation is discussed.
Estimation of human corneal oxygen consumption by noninvasive measurement of tear oxygen tension while wearing hydrogel lenses.

PURPOSE. To devise a procedure for direct estimation of corneal oxygen consumption in human subjects. METHODS. Tear oxygen tension (PO 2 ) was measured at the posterior surface of two standard hydrogel contact lenses (38% water, 0.2 and 0.06 mm thick, oxygen transmissibility [Dk/t] = 4.2 and 14 × 10 -9 cm.mL O 2 /mL.sec.torr) and one newly available hydrogel-silicone polymer lens (Dk/t = 99 X 10 -9 ). The oxygen-sensitive dye, Pd-meso-tetra (4-carboxyphenyl) porphine, bound to bovine serum albumin, was incubated with the lenses overnight. The lenses, coated with the protein-dye complex, were placed on four subjects' eyes, and tear PO 2 was measured in the open eye and after 5 minutes of eye closure, using a time-domain phosphorescence measurement system. Given the tear PO 2 , lens Dk/t, and corneal thickness, oxygen consumption (Q C , in mL O 2 /cm 3 sec) could be calculated from established oxygen diffusion models. RESULTS. Protein-dye complex bound to the lens surface enabled reporting of tear PO 2 for long periods. As expected, estimated tear Po2 was higher in subjects wearing lenses with higher Dk/t: mean open-eye PO 2 = 30.6 ± 3.1 and 8.1 ± 1.3 torr for the thin and thick hydrogel lenses, respectively, and 97.6 ± 22.9 torr for the hydrogel-silicone lens. After 5 minutes of eye closure, tear PO 2 was significantly reduced and reached a new steady state in approximately 20 seconds after eye opening. Fitting a single exponential model to the data and extrapolating to t = 0 provided an estimate of PO 2 under the closed lid for the thin hydrogel (PO 2 = 7 ± 2.3 torr) and the hydrogel-silicone lens (PO 2 = 22.6 ± 4 torr). After 5 minutes of eye closure with the thick hydrogel lens, tear PO 2 remained constant for ∼10 seconds after eye opening (mean PO 2 = 3.9 ± 0.7) before increasing to a new steady state. This delay could be accounted for by the time needed for oxygen to diffuse to the posterior surface of the lens. Calculated Q C ranged from 2.2 × 10 -4 to 3.7 × 10 -6 mL O 2 /cm 3 .sec) at the highest and lowest PO 2 s, respectively, and is comparable to previous in vitro and in vivo estimates. CONCLUSIONS. Tear PO 2 behind hydrogel lenses can be measured in human subjects using the phosphorescence of the porphyrin-protein complex bound to the lens surface. The method is simple, fast, reliable, and noninvasive, allowing quick and direct estimates of Q C . In addition to contact lens wear, this method should be useful for examining the effects of disease, surgery, or topical drugs on the corneal oxygen consumption rate.
America's Other Immigration Crisis

The United States is bringing the world's smartest people to its shores, training them, and then making them leave.
A Perspective on Pharmaceutical Marketing Practices: Message Development, Media Selection, Medication Adherence and Health Literacy

According to the National Action Plan to Improve Health Literacy issued in 2010 by the U.S. Department of Health and Human Services, health literacy is a multi-faceted concept and has importance for multiple sectors. Stakeholders typically involved in the health literacy discussion include government, public health officials, practitioners and those concerned with health promotion (U.S. Department of Health and Human Services 2010). In addition to these stakeholders, there is the opportunity for the pharmaceutical industry to be an active participant in the health literacy discussion.
Trade liberalization and employment in developing economies of the Americas

A l’aide d’un modele d’equilibre general calculable, cet article analyse les effets d’une liberalisation commerciale complete appliquee par certaines economies en developpement de l’Amerique latine. Au cours de la decennie ecoulee, nombre de ces economies ont connu un taux de chomage eleve, et les consequences des reformes sur le chomage, tout comme celles du chomage sur les repercusions des reformes, sont sensibles. L’approche presentee ici recourt a differents bouclages du marche du travail. L’utilisation alternative d’un modele neo-classique, qui fait abstraction du chomage, et d’un bouclage tenant compte du chomage permet d’etablir des bornes a l’effet statique d’une reforme commerciale. Nous utilisons aussi une specification plus inhabituelle fondee sur l’approche neo-classique a la Harris-Todaro de l’economie duale. Les resultats montrent que le sous-emploi peut accroitre sensiblement le gain potentiel en bien-etre tire d’une reforme commerciale en Amerique.Classification JEL : C68 ; F13 ; J60 ; O54.
Correlation of pattern electroretinogram with optic disc cup shape in ocular hypertension.

PURPOSE. To evaluate the correlation of pattern electroretinogram (PERG), an index of inner retinal function, with confocal scanning laser (CSLO) optic disc structural parameters in ocular hypertension (OHT). METHODS. Thirty-four patients with OHT, normal white-on-white (Humphrey 30-2) perimetry, and normal clinical optic discs were examined with PERG and CSLO disc analysis. Two groups of normal subjects (n = 38 and 18, for PERG and CSLO, respectively) and a group of 12 patients with early open-angle glaucoma (EOAG) were also tested. Pattern electroretinogram amplitudes were measured in response to sinusoidal gratings of variable spatial frequency (0.58-5.8 cycles/degree), modulated in counter-phase at 7.5 Hz. Morphometric optic disc parameters were obtained by the Heidelberg Retina Tomograph (HRT), either globally or from predefined disc sectors. In addition to standard parameters, the cup shape measure, an index of depth variation and steepness of the cup walls, was determined. RESULTS. In individual OHT patients, PERG amplitudes at 2.6 cycles/degree were negatively correlated with cup shape measures (r = -0.43, P < 0.01) obtained from analysis of the inferotemporal (IT) sector. No significant correlations were found for the other parameters. On average, the cup shape measures derived from IT sector or global analysis were significantly (P < 0.01) worse, and closer to the measures of EOAG patients, in OHT patients with abnormal PERG compared with those with normal PERGs. The cup shape measure displayed a low sensitivity (20%) and a high specificity (100%) in predicting PERG abnormalities in individual OHT patients. CONCLUSIONS. The results indicate that in OHT there is a significant although weak correlation between PERG amplitude and the shape of the optic disc cup, suggesting a parallel involvement of both function and morphology. Combined PERG and optic disc cup structural analysis is of potential diagnostic value to detect early damage to optic nerve head in individual OHT patients.
Measuring environmental effects on property values without hedonic regressions

Abstract The effect of environmental nuisances on property values has been frequently studied using hedonic regressions, yet that method has extensive data and estimation requirements. The technique developed in this paper uses repeat sales on houses to substantially reduce these requirements. The technique adjusts for depreciation between sales and allows for nonzero error covariance terms when a house has been sold more than twice. The effect of highway noise on property values is studied using this method, and the results are statistically equivalent to the results of an extensive hedonic study for the same area.
A camphor-derived chiral auxiliary for hydroxyalkyl radicals

Abstract A new camphor-derived chiral auxiliary for hydroxyalkyl radicals is described. The auxiliary is prepared by the Baeyer–Villiger oxidation of 3-fluorocamphor 12 to give lactone 14 , followed by its reduction to the lactol 16 . Compound 16 is converted to the acetal–ester 17 and then on to radical precursor 18 . A key feature of this auxiliary is the incorporation of a fluorine atom at C-3 (pyranoside numbering), which accelerates the Baeyer–Villiger reaction, results in complete anomeric control during auxiliary attachment, and stabilizes the resulting acetal center. The chiral radical derived from carboxylic acid 18 adds to methyl 2-trifluoroacetoxyacrylate to give adducts 22 and 23 with good diastereocontrol (ds from 3:1 at 0°C up to 4.5:1 at −78°C).
Instantons and the topology of 4-manifolds

Geometric topology is the study of metric spaces which are locally homeomorphic to Euclidean n-space R n ; that is, it studies topological (TOP) n-manifolds. The customary goal is to discover invariants, usually algebraic invariants, which classify all manifolds of a given dimension. This is separated into an existence question—finding an n-manifold with the given invariants—and a uniqueness question—determining how many n-manifolds have the given invariant. As is (and was) quickly discovered, TOP manifolds are too amorphous to study initially, so one adds structure which is compatible with the available topology and which broadens the available tools. Presumably, the richer the structure imposed on a manifold, the fewer objects one is forced to study.
An algorithm for uniform vector quantizer design

A vector quantizer maps a k -dimensional vector into one of a finite set of output vectors or "points". Although certain lattices have been shown to have desirable properties for vector quantization applications, there are as yet no algorithms available in the quantization literature for building quantizers based on these lattices. An algorithm for designing vector quantizers based on the root lattices A_{n}, D_{n} , and E_{n} and their duals is presented. Also, a coding scheme that has general applicability to all vector quantizers is presented. A four-dimensional uniform vector quantizer is used to encode Laplacian and gamma-distributed sources at entropy rates of one and two bits/sample and is demonstrated to achieve performance that compares favorably with the rate distortion bound and other scalar and vector quantizers. Finally, an application using uniform four- and eight-dimensional vector quantizers for encoding the discrete cosine transform coefficients of an image at 0.5 bit/pel is presented, which visibly illustrates the performance advantage of vector quantization over scalar quantization.
The Radovich Cycle: A Novel MSW-Fired Heat Cycle

A conceptual study was performed for a novel heat cycle designed to utilize fuel gases produced by a Taylor Biomass Energy (TBE) Gasification System. The system is sized to consume 500 dry tons per day Municipal Solid Waste (MSW). The heat cycle utilizes a Solid Oxide Fuel Cell (SOFC) feeding directly to a Twin-Fluidized Bed Steam Gasification Unit (TFBSGU). MSW fed into the TFBSGU is partially gasified by exhaust from the anode space of the fuel cell. The resulting gas is cooled, sour-shifted, dehydrated and compressed. The compressed gas passes through an acid-gas removal (AGR) system and then is returned to the anode space of the fuel cell. Combustion air is compressed and passes through the cathode space of the fuel cell before entering the TFBSGU in a separate stream from the fuel gas. The resulting flue gas leaves the TFBSGU and is cooled and expanded before exhausting to atmosphere. The design also features sour shift and acid gas removal from the fuel stream. The plant produces 44 net MW, converting approximately 43% of the energy in the MSW into electricity and 23% of the energy into usable thermal energy. Overnight 2009 EPC costs are estimated at $6000/net kw. Electrical production costs are estimated at 126$/MWhr. Because the plant burns MSW, it provides carbon offsets. In addition, approximately 60% of the carbon dioxide produced by the plant can be readily sequestered. The conceptual design included a heat balance, water balance, auxiliary load list, capital cost estimate, and cost of electricity estimate.Copyright © 2009 by ASME
RunBuddy: a smartphone system for running rhythm monitoring

As one of the most popular exercises, running is accomplished through a tight cooperation between the respiratory and locomotor systems. Research has suggested that a proper running rhythm -- the coordination between breathing and strides -- helps improve exercise efficiency and postpone fatigue. This paper presents RunBuddy -- the first smartphone-based system for continuous running rhythm monitoring. RunBuddy is designed to be a convenient and unobtrusive exercise feedback system, and only utilizes commodity devices including smartphone and Bluetooth headset. A key challenge in designing RunBuddy is that the sound of breathing typically has very low intensity and is susceptible to interference. To reliably measure running rhythm, we propose a novel approach that integrates ambient sensing based on accelerometer and microphone, and a physiological model called Locomotor Respiratory Coupling (LRC), which indicates possible ratios between the stride and breathing frequencies. We evaluate RunBuddy through experiments involving 13 subjects and 39 runs. Our results show that, by leveraging the LRC model, RunBuddy correctly measures the running rhythm for indoor/outdoor running 92:7% of the time. Moreover, RunBuddy also provides detailed physiological profile of running that can help users better understand their running process and improve exercise self-efficacy.
Accurate finite element simulation and experimental study of elastic wave propagation in a long cylinder under impact loading

Abstract For the first time, detailed accurate numerical solutions for elastic wave propagation in a long axisymmetric elastic bar under impact loading are obtained using the new finite element technique proposed in our recent papers. In contrast to known numerical techniques, the new numerical approach quantifies and removes spurious high-frequency oscillations which may invalidate numerical results in impact loading simulations. The comparison of the accurate experimental results for the impact of striker and incident bars with the corresponding accurate numerical results allows us to explain some details of elastic wave propagation in long bars. For example, due to the absence of very high frequencies in the obtained experimental results, the mathematical formulation of the problem should include physical damping for the corresponding range of high frequencies. This range can be defined by the filtering stage of the new approach in terms of the number of finite elements along the radial direction of the bar. By the variation of this number we can fit the experimental curves with the numerical results obtained by the new numerical technique. However, for the accurate numerical solution of the impact problem with zero physical damping, the number of elements in the radial direction should be large. By the comparison of the numerical and experimental data, we can accurately determine the longitudinal wave velocity from experiments. The accurate numerical solutions also allow the analysis of the uniformity of the different strain and velocity components across the radius at different distances from the impact face. The validity of some assumptions used in the 1-D theory for wave propagation in long bars is also checked by the use of the accurate numerical solution. We have also shown that at the elastic impact the known dispersion-correction technique used for the description of the shape of the wave pulse at different locations along the axisymmetric bar is inaccurate for the prediction of pulses close to the impact face.
Probability of vibrational excitations in high energy collisions

Abstract Vibrational transition probability Pnm for n → m is formulated from the solution of the time-independent Schrodinger equation for colinear collision between an oscillator and a particle (an atom or a molecule). The resulting expression can be used for calculating Pnm in high energy collisions.
Is insulin a factor in the genesis of the vascular complications of diabetes

Several recent studies report that insulin may be a pathogenic factor in cardiovascular disease and the vascular complications of diabetes. The route of administration of insulin may be partially responsible for vascular side effects that occur in the management of diabetes. These side effects may be overcome by the development of a more physiologic route of administration than by subcutaneous injection.
Right Atrial Myxoma

A case of myxoma of the right atrium with physiologic, surgical, and angiocardiographic findings has been presented together with a review of 6 other published cases. Several findings have been emphasized that may call attention to the possible diagnosis of right atrial myxoma: right-sided heart failure; intracardiac calcification of the right heart; enlargement of the right ventricle and right atrium; electrocardiographic findings of a prominent P wave and low voltage over right precordium simulating that found in Ebstein's anomaly and marked variation in heart rate not related to any physiologic event or change in rhythm; use of intracavitary electrode catheter to rule out Ebstein's anomaly; and finally, analysis of the right atrial curve may lead one to suspect that other than valvular stenosis is present. Angiocardiography gives a definitive diagnosis. Cure may now be obtained with surgical removal of myxomas; therefore, it is important that they be detected during life.
Introduction of the α-P-Borano-Group into Deoxynucleoside Triphosphates Increases Their Selectivity to HIV-1 Reverse Transcriptase Relative to DNA Polymerases

Abstract A series of 2′-deoxynucleoside 5′-triphosphates (dNTPs) and their α-P-thio or α-P-borano analogues, i.e., (Sp-dNTPαS), (Rp-dNTPαB) and (Sp-dNTPαB) were studied as substrates for DNA dependent DNA polymerases and HIV-1 reverse transcriptase (RT). For HIV-1 RT the Rp-dNTPαB isomers are 1.2-fold better substrates than natural dNTPs. For DNA polymerases their efficiencies of incorporation are 3-fold (Klenow, Sequenase) and 5-fold (Taq) lower than for dNTPs. Thus, introduction of the α-boranophosphate group into dNTPs increases their selectivity to HIV-1 RT relative to bacterial DNA polymerases.
Point-Counterpoint: Can Special Education and General Education Get Along?.

Abstract This essay grew out of a mutual frustration over differences between two fields within education. In the following discussion, special education professor, Leah Wasburn-Moses, argues that special and general education can resolve their differences. Her colleague, teacher education professor, Alan M. Frager, argues that the differences have become too great to bridge. They consider three topics: learning theories, views of justice, and assessment. Arguments are sequentially presented under each subheading.
Electromigration Failure in Thin Film Silicides and Polysilicon/Silicide (Polycide) Structures

Thin film conductor stripes (150 nm thick), of silicides of tantalum and tungsten deposited on to thermal oxide as well as silicides deposited on to 150 nm of n-type polycrystalline silicon were stressed at high DC current densities (<106 A/cm2) untill open-circuit failure. All of the stripes failed by electromigration. The sign of the charge carrier in silicides of Ta and W, determined by failure location, was opposite to the published data determined from the Hall effect.
Protein disulfide isomerase is a multifunctional regulator of estrogenic status in target cells

Abstract Earlier studies showed that protein disulfide isomerase (PDI), a well-known protein folding catalyst and a molecular chaperone, can bind estrogens and may also directly interact with the estrogen receptor (ER). In this study, we sought to determine the biological functions of these intriguing properties of PDI. We showed that PDI can function as a high-capacity intracellular 17β-estradiol (E 2 )-binding protein that increases the concentration and accumulation of E 2 in live cells. The intracellular PDI-bound E 2 can be released from PDI upon a drop in E 2 levels and the released E 2 can augment estrogen receptor-mediated transcriptional activity and mitogenic actions in cultured cells. In addition, the binding of E 2 by PDI also reduces the rate of metabolic disposition of this hormone. We showed, for the first time, that knockdown of PDI in MCF-7 human breast cancer cells with RNA interference down-regulates ERα protein but up-regulates ERβ protein, resulting in a drastic increase in ERβ/ERα ratio, which is a crucial determinant of different cellular responses to estrogens. To explain the mechanism of this differential regulation, we also studied the interactions of PDI with ERα and ERβ. We found that PDI can directly interact with ERα, but it does not interact with ERβ. Altogether, these data showed that PDI is a multifunctional regulator of intracellular estrogenic status. It not only regulates the intracellular concentrations of E 2 and the magnitude of estrogen action, but it also modulates the ERβ/ERα ratio.
A database of computational models of a half-center oscillator for analyzing how neuronal parameters influence network activity

A half-center oscillator (HCO) is a common circuit building block of central pattern generator networks that produce rhythmic motor patterns in animals. Here we constructed an efficient relational database table with the resulting characteristics of the Hill et al.’s (J Comput Neurosci 10:281–302, 2001) HCO simple conductance-based model. The model consists of two reciprocally inhibitory neurons and replicates the electrical activity of the oscillator interneurons of the leech heartbeat central pattern generator under a variety of experimental conditions. Our long-range goal is to understand how this basic circuit building block produces functional activity under a variety of parameter regimes and how different parameter regimes influence stability and modulatability. By using the latest developments in computer technology, we simulated and stored large amounts of data (on the order of terabytes). We systematically explored the parameter space of the HCO and corresponding isolated neuron models using a brute-force approach. We varied a set of selected parameters (maximal conductance of intrinsic and synaptic currents) in all combinations, resulting in about 10 million simulations. We classified these HCO and isolated neuron model simulations by their activity characteristics into identifiable groups and quantified their prevalence. By querying the database, we compared the activity characteristics of the identified groups of our simulated HCO models with those of our simulated isolated neuron models and found that regularly bursting neurons compose only a small minority of functional HCO models; the vast majority was composed of spiking neurons.
The Effects of Unstructured Group Discussion on Ethical Judgment.

The authors examine the effects of shared information and group discussion on ethical judgment when no structure is imposed on the discussion to encourage ethical considerations. Discussants were asked to identify arguments for and against a variety of business behaviors with ethical implications. A group moderator solicited and recorded arguments for and against the behaviors but provided no evaluation of the arguments presented or the behaviors described. Discussion group subjects were significantly less critical of profit-driven business behaviors than a control group, and were also less critical of self-interest-driven behaviors when those behaviors did not appear to adversely affect profits.
Effect of buffer size on productivity of work stations that are subject to breakdown

A production line consisting of two work stations in series, and intermediate buffer of size m is modeled as a discrete-parameter Markov process with 4m + 8 states. Owing to the block structure of the transition probability matrix, the steady-state probabilities are obtained by the successive solution of systems of 4 simultaneous equations. Moreover, the probabilities of the interior states are shown to follow a scalar geometric relation Hence numerical solutions are very easily obtained even for large buffer sizes. An empirical formula for the production rate is presented. This formula is remarkably accurate over a wide range of parameters.
Comparative study of notoungulate (Placentalia, Mammalia) bony labyrinths and new phylogenetically informative inner ear characters.

The phylogenetic relationships of notoungulates, an extinct group of predominantly South American herbivores, remain poorly resolved with respect to both other placental mammals and among one another. Most previous phylogenetic analyses of notoungulates have not included characters of the internal cranium, not least because few such features, including the bony labyrinth, have been described for members of the group. Here we describe the inner ears of the notoungulates Altitypotherium chucalensis (Mesotheriidae), Pachyrukhos moyani (Hegetotheriidae) and Cochilius sp. (Interatheriidae) based on reconstructions of bony labyrinths obtained from computed tomography imagery. Comparisons of the bony labyrinths of these taxa with the basally diverging notoungulate Notostylops murinus (Notostylopidae), an isolated petrosal from Itaborai, Brazil, referred to Notoungulata, and six therian outgroups, yielded an inner ear character matrix of 25 potentially phylogenetically informative characters, 14 of them novel to this study. Two equivocally optimized character states potentially support a pairing of Mesotheriidae and Hegetotheriidae, whereas four others may be diagnostic of Notoungulata. Three additional characters are potentially informative for diagnosing more inclusive clades: one for crown Placentalia; another for a clade containing Kulbeckia, Zalambdalestes, and Placentalia; and a third for Eutheria (crown Placentalia plus stem taxa). Several other characters are apomorphic for at least one notoungulate in our study and are of potential interest for broader taxonomic sampling within Notoungulata to clarify currently enigmatic interrelationships. Measures of the semicircular canals were used to infer agility (e.g. capable of quick movements vs. lethargic movements) of these taxa. Agility scores calculated from these data generally corroborate interpretations based on postcranial remains of these or closely related species. We provide estimates of the low-frequency hearing limits in notoungulates based on the ratio of radii of the apical and basal turns of the cochlea. These limits range from 15 Hz in Notostylops to 149 Hz in Pachyrukhos, values comparable to the Asian elephant (Elephas maximus) and the California sea lion (Zalophus californianus) when hearing in air, respectively.
Daytime naps in night-migrating birds: behavioural adaptation to seasonal sleep deprivation in the Swainson's thrush, Catharus ustulatus

Many typically diurnal songbird species are routinely subjected to severe sleep deprivation during their seasonal, nocturnal migrations, yet they seem to suffer few of the negative consequences so obvious in sleep-deprived mammals. Studying the Swainson's thrush, a Nearctic–Neotropical long-distance migrant, we investigated seasonal changes in behaviour as possible adaptations to naturally occurring sleep loss during the migratory season. We found that captive Swainson's thrushes substantially change their daytime behaviour in response to significant loss of night-time sleep during migration, engaging in numerous episodes of daytime sleep, unilateral eye closure and drowsiness. Our observations suggest that brief episodes of sleep and sleep-like behaviour during the day, including lateralized naps in the form of unihemispheric sleep, enable migratory birds to compensate for extended periods of nocturnal sleep loss. Although episodes of daytime sleep and unilateral eye closure rarely exceed 30 s, these brief episodes, considering the short sleep cycle of birds, appear sufficiently long to provide recuperative opportunities without stretching a migrant's time budget. Importantly, the temporal structure of the daytime rest and sleep behaviour would not preclude migrants from foraging and replenishing fat deposits during a large portion of the day.
A numerical study of the use of pilot or split rate injection to reduce diesel engine noise

AbstractThis paper investigates the effects of the various factors on combustion noise without increasing nitrogen oxides (NOx) in different operating conditions, especially at idle by using a combustion-simulation computer program (KIVA) and orthogonal array. Results indicated that the effects of pilot or split injection, compression ratio, and dynamic injection timing on combustion noise were strong at idle, while the effects of induction swirl ratio and number of injector holes were weak. Injection rate shaping, pilot or split injection, and double injections showed promising reduction in combustion noise and NOx simultaneously at the idle condition. The selected optimized injector (a split injection) for combustion noise reduction at the idle engine operating condition created different rate shapings from the baseline engine at medium speed and full load. This injector lowered combustion noise and NOx at medium speed and full load in comparison with the baseline injector. Generally, the pilot or split...
Dopamine constricts porcine pial veins.

Abstract Dopamine has been shown to induce pial arterial relaxation and constriction in several species. Its mode of action on pial veins, however, remains unclarified. The vasomotor effect of dopamine on porcine pial veins was, therefore, examined using an in vitro tissue bath technique. The results indicated that dopamine constricted exclusively isolated ring segments of pial veins in the presence or absence of active muscle tone. The constriction induced by dopamine was not affected by Nω-nitro- l -arginine ( l -NNA, 2×10−5 M) or indomethacin (10−5 M). Only in few preparations was the constriction induced by maximum concentration of dopamine potentiated by l -NNA, suggesting that dopamine at high concentrations may release NO or a NO-related substance. In the presence of l -NNA (2×10−5 M), dopamine-induced constriction was inhibited by phentolamine and yohimbine (but not prazosin) in a concentration-dependent manner with maximum inhibition at 10−6 M. SKF38393 and 6-bromo-APB (selective dopamine D1 receptor agonists) and LY171555 (a selective dopamine D2 receptor agonist) also induced pial venous constriction exclusively in the presence of l -NNA. The constriction was not affected by phentolamine (10−6 M). The order of potency for these agonists in the presence of phentolamine, propranolol, guanethidine and l -NNA was: 6-bromo-APB>SKF38393>dopamine>LY171555. The dopamine-induced constriction in the presence of phentolamine was further inhibited by both SCH23390 (a selective dopamine D1 receptor antagonist) and sulpiride (a selective dopamine D2 receptor antagonist), but was not affected by dopamine D3 or D4 receptor antagonists. These results indicate that dopamine at low and high concentrations induces exclusively constriction of isolated porcine pial veins. The constriction is mediated by postsynaptic α2-adrenoceptors, and dopamine D1 and D2 receptors.
A comparison of pulsed amperometric detection and conductivity detection of underivatized amino-acids in liquid chromatography

Pulsed amperometric detection (PAD) in tandem with conductivity detection (CD) has been applied to the direct detection of amino-acids by liquid chromatography. Although sensitive, PAD has a limited linear range of response. Sequential use of conductimetric detection and then PAD extends the dynamic range of amino-acid determination.