cssi/SciSciGPT-SciSciNet huggingface dataset:
Simulation and modeling of intermodulation distortion in communication circuits

Distortion in circuits along the signal path of a transceiver plays a key role in determining the overall performance of digital communication systems. This paper describes how recent improvements in the mixed frequency/time algorithm (MFT) expand our ability to predict the distortion of these circuits. The MFT algorithm extends traditional shooting methods to directly compute the quasiperiodic steady-state response of circuits driven by two or more periodic signals, each at independent frequencies. With these improvements, MFT can be directly applied to accurately and efficiently compute the intermodulation distortion of large circuits driven by a small number of discrete tones. This is representative of the signals found in receivers. However in transmitters, concern focuses on the affect of intermodulation distortion from complex digitally modulated signals. Such signals cannot be handled directly by MFT, but we demonstrate how a macromodel can be constructed that is used to rapidly predict the spectral regrowth caused by the power amplifier and associated circuitry. This approach allows much more of the transmitter to be simulated than with envelope-transient methods.
Cricothyroidotomy for elective airway management in critically ill trauma patients with technically challenging neck anatomy.

Introduction To assess the value of elective cricothyroidotomy for airway management in critically ill trauma patients with technically challenging neck anatomy.
Different induction pathways for urokinase (u-PA) in A431 cells by EGF and by the phorbol ester, TPA

Abstract The signal transduction pathways of urokinase (u-PA) in the human epidermoid carcinoma cell line, A431, were studied using the inducers epidermal growth factor (EGF) and 12-tetradecanoyl phorbol acetate (TPA). Optimum concentrations were found to be approx. 100nM for both agents. Maximum induction of u-PA was achieved in 4–6 h, with mRNA levels rising within 1 h and peaking at 4 h following the addition of the inducers. These pathways appear to be different, based on the following observations: (1) the EGF and TPA effects are additive; (2) down-regulation of protein kinase C interferes with TPA-, but not with EGF-induction of u-PA; (3) the protein kinase C inhibitor, calphostin C, is much more effective in inhibiting u-PA induction by TPA than by EGF; (4) after EGF-induced tyrosine phosphorylations had been completed, addition of TPA still induces u-PA, an effect which can be blocked by the addition of genistein, a specific inhibitor of tyrosine phosphorylation, indicating that the two agents induce different tyrosine phosphorylations. The use of genistein also allowed the determination of the time needed for the completion of essential tyrosine phosphorylations following induction, 2 h for TPA and 3 h for EGF. 8-BR-cAMP has no effect by itself but it inhibits EGF-induction and doubles TPA-induction of u-PA. EGF induction is independent of extracellular Ca ++ levels, while full induction of u-PA by TPA can only be obtained in its presence. Some of the observations reported here, together with others in the literature, suggest the involvement of c-fos in the signal transduction pathway of u-PA.
An Examination of Teacher Trainees’ Knowledge of Attention-Deficit/Hyperactivity Disorder

Research has suggested that in-service teachers learn relatively little about attention-deficit/hyperactivity disorder (ADHD) during their education, but that on-the-job learning helps mitigate this deficiency. Current teacher trainees may receive more ADHD education than past cohorts, though it is unclear whether their ADHD knowledge is superior to that of peers and, more broadly, whether it is adequate for referral and other service provision in the classroom. This study compares the ADHD-related knowledge of teacher trainees to that of undergraduate peers of diverse majors. Trainees’ knowledge was more accurate than the peer comparison group, yet findings suggest that substantial room for improvement remains.
Salt preference in desalivate rats

Abstract Desalivate rats were tested in two-bottle preference tests for a 0.4% NaCl solution under different dietary conditions. Two effects were seen. A loss in preference may occur because of the prandial drinking pattern desalivates show. Elimination of prandial drinking abolished this effect. An enhancement in preference is seen with a diet that presumably initiates a prandial drinking pattern insufficient for taste masking, or when food is absent. Apparently desalivation has a direct enhancing effect on salt preference that may be exaggerated under appropriate dietary conditions.
Rydberg states in crossed fields: The gyropendulum

The spectrum of degenerate Rydberg states of an n-manifold of the hydrogen atom when placed in crossed (perpendicular) electric and magnetic fields (the diamagnetic term is disregarded) is shown to coincide with that of a charged-particle harmonic oscillator in a magnetic field. A mechanical counterpart is identified as the gyropendulum. These correspondences give further insight into the nature of Rydberg states in external fields.
Voltage programming in capillary zone electrophoresis

Abstract Temperature is an important factor in capillary zone electrophoresis since it affects the viscosity and the pH of the buffer solution. In this study, a capillary tube with a large radius (130 μm I.D.) and filled with buffer at a high ionic strength is used to generate substantial joule heat within the capillary tube to force a significant increase in temperature, in turn to decrease the viscosity and to change the pH of the bufrer solution. From a study of the degree of dissociation of analytes at different voltages, we show that voltage-induced pH change is significant in 0.1 M tris(hydroxyamino)methane (THAM) but not in 0.025 M hydrogencarbonate buffer system. A step change in voltage from 15 to 25 kV is implemented to generate a pH gradient in the THAM buffer solution. The results show that the method is useful for separating phenols which cannot be separated at a fixed voltage.
Interaction of embryonic corneal epithelium with exogenous collagen, laminin, and fibronectin: Role of endogenous protein synthesis

Abstract Previously, we have shown that the embryonic corneal epithelium is capable of interacting with exogenous collagen, laminin, and fibronectin in soluble form, each of which causes isolated epithelium cultured on Millipore filter to stop blebbing, reorganize the basal cytoskeleton, and flatten. Here we examine the involvement of endogenously derived extracellular matrix (ECM) molecules in the interaction of the basal epithelial cell surface with the added ECM molecules. We demonstrate here that the isolated avian corneal epithelium cultured on Millipore filter is capable of synthesizing collagens and laminin, but not fibronectin. To examine whether the epithelium is capable of interacting directly with exogenous ECM components or if there is the necessity for production of a linker molecule, epithelial protein synthesis was inhibited with cycloheximide (CHX). The blebbing epithelium in the presence of CHX was then confronted with soluble ECM molecules added to the medium under the filter; such epithelia are able to interact with, and flatten in response to, both collagen and laminin. However, such inhibited epithelia continue to bled in the presence of fibronectin. We next used l -azetidine-4-carboxylic acid (LACA) to interfere with collagen secretion. Epithelia exposed to LACA are still capable of interacting with collagen and laminin, but not fibronectin, indicating a dependence on collagen secretion. These results suggest that fibronectin requires a linker protein, probably collagen, to interact with the basal epithelial surface, whereas both collagen and laminin may interact directly with the cell surface to transform the basal cytoskeleton into the cortical mat typical of differentiating corneal epithelium in situ.
Anomalous Positive Point Prebreakdown Behavior in Dielectric Liquids

An experimental study was performed to determine the nature of events which lead to electrical breakdown in the normal alkanes from n-pentane to n-decane, and toluene. Disturbances prior to breakdown were rendered visibl by means of a shadowgraph optical system. Both electronically framed and high resolution single exposure photographs were taken during the prebreakdown period. Two distinct types of prebreakdown disturbance were observed whe using a point anode. In addition to the normally expected supersonic streamer, a new subsonic bush-like structure was recorded. Factors affecting the generation of the subsonic event were investigated, and are considered in terms of a gas phase process.
Strategy for interferometry with the Large Binocular Telescope

A summary of the scientific requirements and the optical design requirements for the Large Binocular Telescope (LBT, former Columbus Project) beam combining optics is presented. Our goal for LBT is to produce a phased focal plane combining the beams from two 8.408 m diameter primaries on a common mount (14.417 m center-center). This provides an interferometric baseline of 22.825 m (edge-edge). This combined focal plane should be phased, in-focus and unvignetted over a field covering most or all of the isoplanatic patch in the best seeing conditions. These field requirements should be met for wavelengths from 0.4 to 20 micrometers . This allows the observer to obtain the maximum amount of diffraction-limited imaging information around each reference source. The individual telescope images should be close to diffraction-limited over the isoplanatic patch in order to facilitate adaptive correction of the interferometric field. A minimum number of warm reflections and minimum obstruction of the beams should be used in order to reduce the emissivity. The two- shooter telescope will be uniquely powerful in the thermal infrared (based on the combination of interferometric baseline and single element diffraction limit). We will be discussing several related classes of beam combiners to evaluate design tradeoffs for LBT. An earlier design considered direct combination of the beams from two F/33 secondary mirrors with long back focal distance. We have also considered reimaging the F/15 Gregorian focal planes with a number of optical designs.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Influence of thyroxine on human granulosa cell steroidogenesis in vitro.

Purpose The objective of this study was to investigate the influence of thyroid hormone on estradiol and progesterone secretion of human granulosa cells maintained in vitro.
Molecular parameters of submaxillary mucins

Abstract Light scattering, refractive index increment, viscometric and apparent specific volume measurements were performed on bovine and porcine submaxillary mucins and on the mild acid hydrolysis products of the same. The molecular parameters thus obtained indicated that both mucins are highly anisotropic stiff rods. The stiffness of the bovine submaxillary mucin is derived mainly from the electrostatic repulsion of the frequent side chains ending in sialic acid moieties. The anisotropy of the porcine submaxillary mucin resides more in the intrinsic anisotropic structure of its protein core.
At the crossroads: Hazard assessment and reduction of health risks from arsenic in private well waters of the northeastern United States and Atlantic Canada

This special issue contains 12 papers that report on new understanding of arsenic (As) hydrogeochemistry, performance of household well water treatment systems, and testing and treatment behaviors of well users in several states of the northeastern region of the United States and Nova Scotia, Canada. The responsibility to ensure water safety of private wells falls on well owners. In the U.S., 43 million Americans, mostly from rural areas, use private wells. In order to reduce As exposure in rural populations that rely on private wells for drinking water, risk assessment, which includes estimation of population at risk of exposure to As above the EPA Maximum Contaminant Level, is helpful but insufficient because it does not identify individual households at risk. Persistent optimistic bias among well owners against testing and barriers such as cost of treatment mean that a large percentage of the population will not act to reduce their exposure to harmful substances such as As. If households are in areas with known As occurrence, a potentially large percentage of well owners will remain unaware of their exposure. To ensure that everyone, including vulnerable populations such as low income families with children and pregnant women, is not exposed to arsenic in their drinking water, alternative action will be required and warrants further research.
A parallel algorithm for estimating the secondary structure in ribonucleic acids

A parallel algorithm for estimating the secondary structure of an RNA molecule is presented in this paper. The mathematical problem to compute an optimal folding based on free-energy minimization is mapped onto a graph planarization problem. In the planarization problem we want to maximize the number of edges in a plane with no two edges crossing each other. To solve a sequence of n bases, n(n -- 1)/2 processing elements are used in our algorithm.
Toward understanding Machado-Joseph disease.

Machado-Joseph disease (MJD), also known as Spinocerebellar ataxia type 3 (SCA3), is the most common inherited spinocerebellar ataxia and one of many polyglutamine neurodegenerative diseases. In MJD, a CAG repeat expansion encodes an abnormally long polyglutamine (polyQ) tract in the disease protein, ATXN3. Here we review MJD, focusing primarily on the function and dysfunction of ATXN3 and on advances toward potential therapies. ATXN3 is a deubiquitinating enzyme (DUB) whose highly specialized properties suggest that it participates in ubiquitin-dependent proteostasis. By virtue of its interactions with VCP, various ubiquitin ligases and other ubiquitin-linked proteins, ATXN3 may help regulate the stability or activity of many proteins in diverse cellular pathways implicated in proteotoxic stress response, aging, and cell differentiation. Expansion of the polyQ tract in ATXN3 is thought to promote an altered conformation in the protein, leading to changes in interactions with native partners and to the formation of insoluble aggregates. The development of a wide range of cellular and animal models of MJD has been crucial to the emerging understanding of ATXN3 dysfunction upon polyQ expansion. Despite many advances, however, the principal molecular mechanisms by which mutant ATXN3 elicits neurotoxicity remain elusive. In a chronic degenerative disease like MJD, it is conceivable that mutant ATXN3 triggers multiple, interconnected pathogenic cascades that precipitate cellular dysfunction and eventual cell death. A better understanding of these complex molecular mechanisms will be important as scientists and clinicians begin to focus on developing effective therapies for this incurable, fatal disorder.
Hormonal Sex Reversal and Evidence of Female Homogamety in Black Crappie

Abstract This study reports the results on hormone-induced sex reversal in black crappie Pomoxis nigromaculatus and the sex ratios of progenies obtained from test crosses of androgen-treated males with normal females. The androgen 17α-methyltestosterone (MT) was orally administered to fish with an artificial diet (30 mg/kg) for 30 d beginning 37 d after hatching; mean fish lengths were 35 and 55 mm at the beginning and conclusion of the treatment, respectively. The MT-treated group consisted of 95% males and 5% intersex fish, while the sex ratio in the control group was not significantly different from 1:1. Four males from the androgen-treated group were individually test-crossed with normal females to identify sex-reversed males according to the sex ratios in progenies and to reveal the chromosomal mechanism of sex determination in black crappie. Two out of three analyzed progenies consisted of females only, while one progeny had a sex ratio not significantly different from 1:1. The appearance of all-fem...
Conception Rates and Calving Intervals After Prostaglandin F2α or Prebreeding Progesterone in Dairy Cows

Two experiments were performed in two different herds to determine if utilizing prostaglandin F 2 alpha to induce estrus for first services would be effective in reducing the duration and variability of calving intervals. In Experiment 1, cows were assigned randomly as controls (n = 217) to be inseminated as they were detected in estrus (beginning d 42 to 53 postpartum depending on replicate) or treated with prostaglandin F2 alpha (n = 185). In Experiment 2, the same treatments were utilized, except control cows (n = 124) were inseminated at their first detected estrus after d 40 postpartum, and treated cows received either one injection of prostaglandin F2 alpha between d 54 and 63 (n = 116) or were given progesterone (via a progesterone-releasing intravaginal device) for 7 d, with the device removed 24 h after prostaglandin F2 alpha (n = 116). More cows were inseminated and pregnancy rates were higher within 5 d after treatment with prostaglandin F2 alpha, and interval from prostaglandin F2 alpha to first service was reduced compared with that of control cows. Duration and variation of calving intervals were unaffected in either experiment, despite the fact the elective waiting period was 6 to 23 d longer for treated cows than for controls. Prebreeding treatment with progesterone failed to improve conception rates, but the efficiency of estrous expression increased from 54% in prostaglandin F2 alpha-treated cows to 71% in those cows also receiving prebreeding progesterone. We conclude that prostaglandin F2 alpha was ineffective in improving reproductive performance of these herds under good herd management. However, prostaglandin F2 alpha offers the convenience of inseminating small groups of cows, controlling when breedings occur during the work week, and prolonging the elective waiting period without extending the calving interval.
Cultivating inquiry about space in a middle school mathematics classroom

During 46 lessons in Euclidean geometry, sixth-grade students (ages 11, 12) were initiated in the mathematical practice of inquiry. Teachers supported inquiry by soliciting student questions and orienting students to related mathematical habits-of-mind such as generalizing, developing relations, and seeking invariants in light of change, to sustain investigations of their questions. When earlier and later phases of instruction were compared, student questions reflected an increasing disposition to seek generalization and to explore mathematical relations, forms of thinking valued by the discipline. Less prevalent were questions directed toward search for invariants in light of change. But when they were posed, questions about change tended to be oriented toward generalizing and establishing relations among mathematical objects and properties. As instruction proceeded, students developed an aesthetic that emphasized the value of questions oriented toward the collective pursuit of knowledge. Post-instructional interviews revealed that students experienced the forms of inquiry and investigation cultivated in the classroom as self-expressive.
Considerations of transient electromagnetic forces in structural behaviors for ITER shield blanket components

The structural designs of the ITER FW/shield blanket components take into account proper dissipation of the transient electromagnetic (EM) forces, and thus reduce the impact of those forces. In this paper we analyze how the blanket/electrical strap components react to EM forces and evaluate whether the design complies with the SDC-IC criteria under the envisioned fault conditions. Specifically, analyses were performed to evaluate the fatigue lifetime of the US proposed solid electric strap designs under a combined mechanical displacement and EM transient load. The stress analysis was performed using dynamic and time-independent static analysis. These results show that the EM forces tend to bend the strap away from its attachment points and lead to a large plastic strain, which results in a relatively short lifetime, and fails to meet ITER requirements. The study also shows that it is necessary for the analysis to take into account the time evolution of the EM force to correctly estimate the anticipated strain range. The views and opinions expressed herein do not necessarily reflect those of the ITER Organization.
Reason and Passion: Representation of Gender in Malay Society

Reason and Passion: Representation of Gender in Malay Society. MICHAEL PELETZ. Berkeley: University of California Press, 1996. xiii. 402 pp., illustrations, notes, bibliography, index.
Mental Health Problems and Behavioral Disruptions in Nursing Homes

This paper describes a study that examines knowledge of mental health problems and management of behavioral disruptions by social workers in nursing homes. Since a significant number of nursing home patients have mental health problems (estimates range from 50 to 80 percent) which present behavioral disruptions, this knowledge is critical. Results indicate that social workers are not prepared to provide needed services because they do not have adequate knowledge about the management of behavioral disruptions or the identification of mental health problems of nursing home patients. Recommendations are that social workers employed in nursing homes should have gerontological training and that national policy changes are needed to develop guidelines for qualifications of nursing home social workers. Nursing homes are not meeting the needs of older adults with mental health problems when social workers do not have the knowledge needed to provide nursing home services.
Partial biochemical characterization of venom from the ant, Pseudomyrmex triplarinus.

Abstract W. F. Hink , P. W. Pappas and D. C. Jaworski . Partial biochemical characterization of venom from the ant, Pseudomyrmex triplarinus . Toxicon 32, 763–772, 1994.—Venom from the ant, Pseudomyrmex triplarinus , contains 12 proteins with mol. wts of 100,000–4200, and they constitute 41.5% of the dry weight. In comparison with published data on ant, wasp, and bee venoms, whole venom has intense phospholipase activity and intermediate hemolytic activity. Four major proteins were isolated and purified by low pressure chromatography. The most abundant protein had a mol. wt of 4200 and weak hemolytic activity. The second most common protein was 20,400 and had phospholipase A 2 activity. The other two major proteins had mol. wts of 24,500 and 14,100 and both exhibited phospholipase and direct hemolytic activities. There are eight minor proteins (100,000−40,000), each present at about 1% or less of the total protein. Assayed as a mixture, they had hyaluronidase activity. Seventeen free amino acids were detected with aspartic acid, glutamic acid, and proline together making up 72% of the total mass of amino acids. Glycerol was present at a concentration of 3.1% of the dry weight and the venom was devoid of lipids.
Creating a political image: Shaping appearance and manipulating the vote

The key question addressed is whether political consultants can shape a candidate's appearance in such a way as to influence voters' preferences. To explore this question, an attempt was made to discover the components of a favorable political image and then use that information to manipulate voters' preferences. Photographs of over 200 women were analyzed and the features of the women's appearance which affected the quality of the image projected were isolated. Using this information, a make-up artist and photographer were employed to shape the appearance of six women. Photographs of the women were then placed on campaign flyers along with information on the women's political party affiliation and their position on several key issues. Pairs of flyers were used to create mock elections. The result of these elections suggest that it is possible to shape a political candidate's image in a way which may effect electoral outcomes. The implications of this for electoral politics are discussed.
Upwelling‐influence, macroalgal blooms, and seagrass production; temporal trends from latitudinal and local scales in northeast Pacific estuaries

In coastal marine systems worldwide, land-based nutrient inputs are often correlated with blooms of macroalgae, which can negatively affect seagrass habitats. We used spatiotemporal trends in production to identify the role of marine-derived nutrients in mediating these interactions. Among ocean upwelling-influenced estuaries along the northeastern Pacific, we documented a negative correlation between annual production of ulvoid macroalgae and the seagrass, Zostera marina L., at a regional scale that included four estuaries along a ∼ 400 km distance. While macroalgal biomass was ∼ 30 times greater in southern (Yaquina Bay and Coos Bay, Oregon) compared to northern (Willapa Bay, Washington, and Netarts Bay, Oregon) estuaries, no temporal patterns of eelgrass decline were observed within the estuaries over a 5 yr period. Latitudinally, 65% of the between-site ordination variance in interannual macrophyte production was associated with ocean upwelling; macroalgae was positively correlated, and eelgrass negatively correlated with more intense upwelling. Within one estuary, Coos Bay, we found that land-based nutrients had no effect on macrophyte productivity. Instead, a little more than a third of the variation was explained by upwelling (marine dissolved inorganic nitrogen and salinity) and climate (photosynthetically active radiation). Thus, contrary to the paradigm of negative effects of macroalgae on eelgrass, we found correlative evidence that ocean upwelling and local estuarine conditions could be responsible for these large biogeographic patterns.
Tumours with elevated levels of the Notch and Wnt pathways exhibit efficacy to PF-03084014, a γ-secretase inhibitor, in a preclinical colorectal explant model

Tumours with elevated levels of the Notch and Wnt pathways exhibit efficacy to PF-03084014, a γ -secretase inhibitor, in a preclinical colorectal explant model
Assessing the effects of selection bias on validity data for the general aptitude test battery

Previous analyses have suggested that the database of 755 studies of the validity of the General Aptitude Test Battery (GATB) demonstrates a small but consistent positive correlation with criteria relevant to job performance. Critics have noted that some of the validity studies conducted were not included in the database and have speculated that these studies may have found negligible or even negative validities, so that the extant database is subject to selection bias. The authors use a mathematical model to estimate the magnitude of possible selection and its effects on the mean and variance of GATB validities
Estimating Relative Standard of Living in the United States Using Cross-Migration Data

A new estimator links migration data to a random utility “voting with your feet” model to compare the relative living standards of pairs of regions. It is argued that this estimator has a firmer theoretical basis and uses migration information more efficiently than previous methods. An algorithm converts pairwise comparisons into rankings of the U.S. states for 1970, 1980, and 1990. The rankings indicate living standards were highest in the Northwest (1970, 1980) and the south Atlantic coast (1990). A nonparametric test suggests that the system was in disequilibrium in 1980 (probably due to energy price shocks), but near equilibrium in 1970 and 1990.
RAPESEED MEAL AND ITS USE IN POULTRY DIETS. A REVIEW

Abstract Rapeseed meal is a very important source of protein and its use for both ruminant and non-ruminant animals has increased over the last decade. Recent experiments, mainly within the last four years, on the use of rapeseed of different types for broilers, laying and breeding chickens, and turkeys are discussed. The chemical components of rapeseed which are responsible for its under-utilization in the poultry feed industry are described, together with an indication of the main areas of current research designed to improve the crop, increase its food value and remove the factors responsible for the problems associated with the use of rapeseed products by poultry. Emphasis is given to the two major problems currently limiting the use of rapeseed meal in poultry diets: the production of a fishy off-flavour in the eggs of certain birds from brown egg laying flocks; and the increased incidence of liver haemorrhage (and associated mortality) which results from high intake of certain varieties of rapeseed and its products. The consequences of adding rapeseed gums to poultry diets and of using full-fat rapeseed are also discussed.
Heading off with the herd: how cancer cells might maneuver supernumerary centrosomes for directional migration

The complicity of centrosomes in carcinogenesis is unmistakable. Mounting evidence clearly implicates a robust correlation between centrosome amplification (CA) and malignant transformation in diverse tissue types. Furthermore, CA has been suggested as a marker of cancer aggressiveness, in particular the invasive phenotype, in breast and prostate cancers. One means by which CA promotes malignancy is through induction of transient spindle multipolarity during mitosis, which predisposes the cell to karyotypic changes arising from low-grade chromosome mis-segregation. It is well recognized that during cell migration in interphase, centrosome-mediated nucleation of a radial microtubule array is crucial for establishing a polarized Golgi apparatus, without which directionality is precluded. The question of how cancer cells maneuver their supernumerary centrosomes to achieve directionality during cell migration is virtually uncharted territory. Given that CA is a hallmark of cancers and has been correlated with cancer aggressiveness, malignant cells are presumably competent in managing their centrosome surfeit during directional migration, although the cellular logistics of this process remain unexplored. Another key angle worth pondering is whether an overabundance of centrosomes confers some advantage on cancer cells in terms of their migratory and invasive capabilities. Recent studies have uncovered a remarkable strategy that cancer cells employ to deal with the problem of excess centrosomes and ensure bipolar mitoses, viz., centrosome clustering. This review aims to change the narrative by exploring how an increased centrosome complement may, via aneuploidy-independent modulation of the microtubule cytoskeleton, enhance directional migration and invasion of malignant cells. We postulate that CA imbues cancer cells with cytoskeletal advantages that enhance cell polarization, Golgi-dependent vesicular trafficking, stromal invasion, and other aspects of metastatic progression. We also propose that centrosome declustering may represent a novel, cancer cell-specific antimetastatic strategy, as cancer cells may rely on centrosome clustering during migration as they do in mitosis. Elucidation of these details offers an exciting avenue for future research, as does investigating how CA may promote metastasis through enhanced directional migration.
Risk assessment at hazardous waste-contaminated sites with variability of population characteristics.

Risk assessment is considered to be an effective scientific tool which enables decisionmakers to manage hazardous waste-contaminated sites in a cost-effective manner while preserving public health. However, the current risk assessment framework proposed by the US Environmental Protection Agency (US EPA) has limitations in addressing the true variability of population characteristics. This study proposed a methodology that is different from the existing framework by accounting for the true variability of population characteristics. The key differences of the proposed methodology and the existing framework are the (1) use of the transient exposure concentration; (2) use of the entire population rather than a representative ideal individual; (3) use of age- and gender-based population subgroups to represent population characteristics; (4) use of a population growth model to represent growth dynamics; and (5) presentation of risk through a risk profile with risk summarized through a single indicator, potential cancer incidences (PCI). The proposed methodology was applied in a ground water contamination scenario due to benzene to determine its applicability. The results of the study showed that age-based variability of population characteristics is important in predicting the population risk while gender played a small role. The existing US EPA methodology and its variation using age-independent variability of population characteristics overestimate the risk given by PCI substantially, and therefore, the decisions can lead to costly cleanup goals. Population risk is not a single value but a distribution due to the contribution from different individuals of the exposed population. Hence, the decision criterion proposed in this study, PCI, is found to be a useful indicator to describe population carcinogenic risk to the society under a variety of conditions and scenarios.
Pulmonary phospholipidosis in rats respiring air containing diesel particulates

Rats chronically exposed to diesel particulates (dp) or given intratracheally a single dose of dp show increased levels of phospholipids in the lungs and in pulmonary lavage fluid. Pulmonary phospholipidosis is accompanied by increase lecithin levels and by increased palmitate content in lecithin of both lungs and pulmonary lavage fluid. A de novo increase of pulmonary and hepatic phospholipid (PL) formation was detected 5 days after rats were treated with dp. The authors hypothesize that a dp-stressed lung releases a pulmonary lipogenic factor (PLF), which stimulates hepatic lipogenesis. This was further tested by an in vitro study in which primary cultures of free hepatocytes were incubated with (2-/sup 14/C)acetate and various molecular weight fractions of a pulmonary homogenate from rats. The results from these studies indicated that in rat lung homogenates a PLF exists of greater than 100,000 Da molecular mass. The results also indicate that respired air containing a dp concentration of greater than 750 ..mu..g dp/m/sup 3/ of air would result in a mild phospholipidosis in the lung, whereas a dp dose in respired air of 250 ..mu..g dp/m/sup 3/ of air for 2 years did not alter pulmonary PL content in rats.
The context-specific nature of competence and corporate development

Based on an analysis of knowledge-intensive innovations, this paper argues that much of the knowledge that provides distinctive competence for sustained competitive advantage is context specific. The development of this competence is a path-dependent process of numerous learning events in particular situations and practices. Because competence is embedded in the specific context in which it was created, it is very difficult to imitate and can become the basis for sustained competitive advantage. This represents an important opportunity for firms who have grown up in a developing country and learned how to compete successfully there. Firms from developing countries who run in packs to build and expand on their context-specific competencies can be more successful in expanding into other developing countries with similar national political institutional contexts than firms from developed countries who have not acquired this tacit knowledge of local practices.
Role of mesangial cells and gap junctions in tubuloglomerular feedback

Role of mesangial cells and gap junctions in tubuloglomerular feedback. Background Tubuloglomerular feedback (TGF) is a process whereby the resistance of the afferent arterioles delivering blood to the glomeruli is regulated by the NaCl concentration of the forming urine in the lumen of the macula densa. Intraglomerular mesangial cells are located between capillaries within the glomerulus, while extraglomerular mesangial cells are located between the macula densa and the afferent arteriole. They are electrically and chemically coupled via gap junctions. The purpose of this study was to investigate the role of mesangial cells and gap junctions in TGF using the isolated, perfused juxtaglomerular apparatus. Method Juxtaglomerular apparatuses were dissected from male New Zealand white rabbits and perfused in vitro. The NaCl concentration at the macula densa was changed from 17/2 to 65/50 Na/Cl to initiate a TGF response. Afferent arterioles were perfused at 60 mm Hg throughout the experiment. Changes in luminal diameter caused by increasing the NaCl concentration at the macula densa were taken as the TGF response. TGF was measured before and after disrupting the gap junctions or damaging the mesangial cells in paired experiments. Results During the control period, TGF decreased afferent arteriole diameter by 2.9 ± 0.2 μm. After mesangial cells were damaged by perfusing Thy 1-1 antibody and complement into the afferent arteriole, the TGF response was completely eliminated. Separate experiments showed no statistically significant change in TGF response with time, or when antibody and complement were perfused into the macula densa lumen. The presence of Thy 1-1 antibody and complement in the afferent arteriole perfusate did not alter the ability of norepinephrine to constrict or acetylcholine to dilate the afferent arteriole. To investigate the role of gap junctions in TGF, we used heptanol to disrupt them. During the control period, TGF decreased afferent arteriole diameter by 2.9 ± 0.4 μm. After perfusing heptanol into the lumen of the afferent arteriole, the TGF response was completely eliminated. When heptanol was added to the bath, it had no significant effect on TGF response. Discussion The data show that after mesangial cells were selectively damaged, the constriction of the afferent arteriole induced by increasing the NaCl concentration at the macula densa was eliminated. However, such treatment had no effect when Thy 1-1 was perfused into the macula densa lumen, and did not alter the response of the afferent arteriole to norepinephrine or acetylcholine. Disruption of the gap junctions also eliminated the TGF response. These data indicate that the mesangial cells play a key role in mediating the TGF response, and that gap junctions among mesangial cells and between mesangial cells and vascular smooth muscle cells communicate the TGF signal to the afferent arteriole.
Calcitriol Decreases Expression of Importin α3 and Attenuates RelA Translocation in Human Bronchial Smooth Muscle Cells

A potent immunomodulatory role of Vitamin D in both innate and adaptive immunity has recently been appreciated. In allergic asthma, activation of NF-кB induces transcription of various cytokines and chemokines involved in allergic airway inflammation. The nuclear import of activated NF-кB p50/RelA subunit is dependent on importin α3 (KPNA4) and importin α4 (KPNA3). In this study, we examined the role of importin α3 in immunomodulatory effect of calcitriol in human bronchial smooth muscle cells (HBSMCs). Cultured HBSMCs were stimulated with calcitriol in the presence and absence of cytokines, TNF-α, IL-1β, and IL-10. The mRNA transcripts of importin α3 and α4 were analyzed using qPCR while protein expression of importin α3, α4 and nuclear RelA was analyzed by immunoblotting. Calcitriol significantly decreased mRNA and protein expression of importin α3 as well as nuclear protein expression of NF-кB p65 (RelA). The decreased activation of RelA by calcitriol was confirmed by decreased release of RelA-inducible molecules, including IL-5, IL-6 and IL-8, by HBSMCs upon calcitriol treatment. Calcitriol attenuated the effect of TNF-α and IL-1β to upregulate mRNA and protein expression of importin α3. IL-10 significantly decreased the TNF-α induced expression of importin α3 and this effect was further potentiated by calcitriol. These data suggest that under inflammatory conditions, calcitriol decreases the expression of importin α3 resulting in decreased nuclear import of activated RelA. This could be a novel mechanism by which calcitriol could exert its immunomodulatory effects to reduce allergic airway inflammation and thus may alleviate the symptoms in allergic asthma.
Finite element analysis of carbon nanotube/cement composite with degraded bond strength

Abstract This paper utilizes finite element (FE) models to study the improvement in tensile strength and ductility of cement when using carbon nanotubes (CNTs) as reinforcement. Nanoscale and macroscale models are used to investigate the interfacial bond behavior of an individual CNT embedded in cement matrix and the flexural response of a CNT/cement composite beam, respectively. Experimental test results of CNT/cement composite beams are used to calibrate the numerical models. The results prove that the FE models are successful in capturing the degradation in the CNT/cement bond strength and its effect on the flexural strength, ductility, and toughness of the composite.
Implicit Identification of Non-Robustly Unsensitizable Paths using Bounded Delay Model

This paper presents a novel approach for identifying non-robustly unsensitizable paths using the bounded delay model for gate delays. A unique feature is that the unsensitizable paths are identified by working on a data structure that stores selected circuit paths instead of the netlist. It is shown that unless the delay of untestable paths are ignored, many non-robust paths will remain undetected. Experimental results show the approach implicitly identifies a large number of non-robustly unsensitizable paths, which were not identified with other existing techniques.
Party Politics, Governors, and Healthcare Expenditures

This study examines the impact of gubernatorial partisanship on the growth of healthcare expenditures (HCE) for a panel dataset of 50 U.S. states over the 1991–2009 period. Using the parametric regression discontinuity design, I find no partisan effect on the growth of state's per capita real total personal HCE. However, an analysis of the growth rates of the components of HCE suggests that there is a causal effect of party affiliation on the “prescription drugs” component. These findings are robust to the inclusion of additional covariates in the parametric approach as well to the use of the non-parametric regression discontinuity approach. The results further suggest that the impact of gubernatorial partisanship does not depend on the length of the governor's term in office.
George Grubler and Karl Hollborn: Two Founders of the Biological Stain Industry

AbstractThe aniline dye industry was created in 1856 when the Englishman William Perkin prepared the color mauve from aniline. Dye industries were then formed in several European countries, and each year thousands of new colors and shades were tested on fabrics. Scientists of that period used these new dyes to study the structures of plant and animal tissues. Starting in 1880 George Grubler, a German pharmacist, sold biological stains to scientists around the world. Grubler stains earned a reputation for reliability, and many of the staining methods developed at that time stipulated the use of Grubler's dyes, even after the firm was sold to Karl Hollborn who continued Grubler's work and devised new staining methods. The Grubler company continued to prosper until World War I. The Chroma Gesellschaft-Schmid GMBH Company in Germany is a successor of the Grubler company.The interrupted supply of Grubler stains during World War I prompted the start of the American biological stain industry and subsequently the...
Spatial scale of aggregation in three acarine predator species with different degrees of polyphagy.

Aggregative responses by the predatory mites, Phytoseiulus persimilis, Typhlodromus occidentalis, and Amblyseius andersoni (Acari: Phytoseiidae), to spatial variation in the density of mobile stages of Tetranychus urticae (Acari: Tetranychidae) were studied over different spatial scales on greenhouse roses. Significant spatial variations in prey numbers per leaflet, per leaf, per branch or per plant were present in all experimental plots. None of the predator species responded to prey numbers per plant, and all searched randomly among plants. Within a plant, the oligophagous P. persimilis searched randomly among branches, but aggregated strongly among leaves within a branch and among leaflets within a leaf. The narrowly polyphagous T. occidentalis searched randomly among leaflets within a leaf and amond leaves within a branch, but aggregated strongly among leaflets or leaves within a plant. The boradly polyphagous A. andersoni searched randomly among leaflets within a leaf, a branch or a plant, and among leaves within a branch or a plant, but distributed themselves more often on branches with lower prey densities. Thus, specialist predators aggregate strongly at lower spatial levels but show random search at higher spatial levels, whereas generalist predators show random search at lower spatial levels but aggregate at higher spatial levels. This is the first empirical evidence demonstrating the relation between the degree of polyphagy and the spatial scale of aggregation. It is also concluded that both the prey patch size (i.e. grain) and predator foraging range (i.e. extent) are important for analyzing spatial scales of predator aggregation. The importance of studying spatial scale of aggregation is also discussed in relation to predator-prey metapopulation dynamics.
Adrenergic control of somatostatin release.

The effects of adrenergic stimulation and suppression on somatostatin (SS), insulin, and glucagon release were studied in intact dogs. Isoproterenol, a β-adrenergic agonist, significantly increased portal venous and arterial levels of SS and arterial levels of insulin and glucagon. Propranolol, a β-adrenergic antagonist, significantly decreased portal venous SS and suppressed the isoproterenol-stimulated increases in the levels of SS, insulin, and glucagon. α-Adrenergic stimulation (propranolol plus epinephrine) decreased portal venous SS and arterial insulin. Phentolamine, an α-adrenergic antagonist, increased portal venous and arterial SS and arterial glucagon. These data suggest that in intact dogs, stimulation of β-adrenergic receptors enhances the release of SS, insulin, and glucagon, while stimulation of α-adrenergic receptors inhibits the release of SS and insulin without having a definitive effect on glucagon.
Ab initio quantum-chemical study of the unimolecular pyrolysis mechanisms of fluoroformic and chloroformic acid

Abstract Reaction pathways for the decomposition of fluoroformic and chloroformic acids, FC(O)OH and CIC(O)OH, have been studied using ab initio methods. Equilibrium geometries and transition state structures have been fully optimized at the Hartree-Fockand second-order Moller-Plesset levels of theory. The most favorable reaction pathway is molecular dissociation into CO 2 and hydrogen halide (HF or HCl). Dissociation into radical fragments are energetically non-favorable processes.