cssi/SciSciGPT-SciSciNet huggingface dataset:
Effects of constant-voltage stress on the stability of Parylene-C columnar microfibrous thin films

A systematic study of the degradation caused by electrical stress in Parylene-C columnar microfibrous thin films (μFTFs) was carried out to explore their suitability for applications in flexible electronics. The columnar μFTFs were fabricated by directing a collimated flux of Parylene-C monomers normally toward a planar substrate in a low-vacuum chamber. Metal-insulator-metal (MIM) capacitors incorporating Parylene-C columnar μFTFs were fabricated and electrically characterized to examine reliability and electrical-stress resistance. The measured leakage current in and capacitance of MIMs were studied as functions of constant-voltage stress (CVS) applied to the MIMs. Room-temperature leakage current in the MIMs before and after CVS was found to be space-charge limited. The space charge comprises defects introduced during fabrication, no new defects being induced by the CVS. Kohlrausch-Williams-Watts relaxation was exploited to understand transient leakage-current behavior, and characteristic times in the 3.5–3.9 s range and stretch factors in the 4.2–5.2 range were determined. These parameters suggest that carrier trapping at defects and their polarization orientation are related to space-charge formation. Furthermore, capacitance dependences on time and frequency were found to be good indicators of the CVS-induced degradation and stability. Charge buildup in the Parylene-C columnar μ-FTFs is accompanied by capacitance decrease with CVS duration. Extrapolation of the capacitance-decrease dependence on CVS duration enables predictions of reliability over extended periods.
Sparse Additive Gaussian Process Regression

In this paper we introduce a novel model for Gaussian process (GP) regression in the fully Bayesian setting. Motivated by the ideas of sparsification, localization and Bayesian additive modeling, our model is built around a recursive partitioning (RP) scheme. Within each RP partition, a sparse GP (SGP) regression model is fitted. A Bayesian additive framework then combines multiple layers of partitioned SGPs, capturing both global trends and local refinements with efficient computations. The model addresses both the problem of efficiency in fitting a full Gaussian process regression model and the problem of prediction performance associated with a single SGP. Our approach mitigates the issue of pseudo-input selection and avoids the need for complex inter-block correlations in existing methods. The crucial trade-off becomes choosing between many simpler local model components or fewer complex global model components, which the practitioner can sensibly tune. Implementation is via a Metropolis-Hasting Markov chain Monte-Carlo algorithm with Bayesian back-fitting. We compare our model against popular alternatives on simulated and real datasets, and find the performance is competitive, while the fully Bayesian procedure enables the quantification of model uncertainties.
Characterization of 3D printed computational imaging element for use in task-specific compressive classification

We investigate the feasibility of additively manufacturing optical components to accomplish task-specific classification in a computational imaging device. We report on the design, fabrication, and characterization of a non-traditional optical element that physically realizes an extremely compressed, optimized sensing matrix. The compression is achieved by designing an optical element that only samples the regions of object space most relevant to the classification algorithms, as determined by machine learning algorithms. The design process for the proposed optical element converts the optimal sensing matrix to a refractive surface composed of a minimized set of non-repeating, unique prisms. The optical elements are 3D printed using a Nanoscribe, which uses two-photon polymerization for high-precision printing. We describe the design of several computational imaging prototype elements. We characterize these components, including surface topography, surface roughness, and angle of prism facets of the as-fabricated elements.
Effects of oats on gastrointestinal health as assessed by in vitro, animal, and human studies

Oats are uniquely nutritious, owing to their composition of bioactive compounds, lipids, and β-glucan. Scientific research has established that oats can improve diet quality, reduce cholesterol, regulate satiety, and protect against carcinogenesis in the colon; however, determining the effects of oats on gastrointestinal health and the gut microbiome is a newer, evolving area of research. To better understand the effects of oats on gastrointestinal health in humans, a literature review with predefined search criteria was conducted using the PubMed database and keywords for common gastrointestinal health outcomes. Moreover, to examine the gastrointestinal effects of oats across the scientific spectrum, a similar search strategy was executed to identify animal studies. In vitro studies were identified from the reference lists of human and animal studies. A total of 8 human studies, 19 animal studies, and 5 in vitro studies met the inclusion criteria for this review. The evidence in humans shows beneficial effects of oats on gastrointestinal health, with supportive evidence provided by in vitro and animal studies. The effective dose of oats varies by type, although an amount providing 2.5 to 2.9 g of β-glucan per day was shown to decrease fecal pH and alter fecal bacteria. For oat bran, 40 to 100 g/d was shown to increase fecal bacterial mass and short-chain fatty acids in humans. Differences in study design, methodology, and type of oats tested make valid comparisons difficult. The identification of best practices for the design of oat studies should be a priority in future research, as the findings will be useful for determining how oats influence specific indices of gastrointestinal health, including the composition of the human gut microbiome.
Redox-mediated regulation of a labile, evolutionarily conserved cross-β structure formed by the TDP43 low complexity domain

An evolutionarily conserved low complexity (LC) domain is found within a 152 residue segment localized to the carboxyl-terminal region of the TDP43 RNA-binding protein. This TDP43 LC domain contains ten conserved methionine residues. Self-association of this domain leads to the formation of liquid-like droplets composed of labile, cross-β polymers. Exposure of polymers to low concentrations of H2O2 leads to a phenomenon of droplet melting that can be reversed upon exposure of the oxidized protein to the MsrA and MsrB methionine sulfoxide reductase enzymes, thioredoxin, thioredoxin reductase and NADPH. Morphological features of the cross-β polymers were revealed by a method of H2O2-mediated footprinting. Similar TDP43 LC domain footprints were observed in highly polymerized, hydrogel samples, liquid-like droplet samples, and living cells. The ability of H2O2 to impede cross-β polymerization was abrogated by a prominent ALS-causing mutation that changes methionine residue 337 to valine. These observations offer potentially useful insight into the biological role of TDP43 in facilitating synapse-localized translation, as well as aberrant aggregation of the protein in neurodegenerative disease.
Translational Control of Secretory Proteins in Health and Disease

Secretory proteins are synthesized in a form of precursors with additional sequences at their N-terminal ends called signal peptides. The signal peptides are recognized co-translationally by signal recognition particle (SRP). This interaction leads to targeting to the endoplasmic reticulum (ER) membrane and translocation of the nascent chains into the ER lumen. It was demonstrated recently that in addition to a targeting function, SRP has a novel role in protection of secretory protein mRNAs from degradation. It was also found that the quality of secretory proteins is controlled by the recently discovered Regulation of Aberrant Protein Production (RAPP) pathway. RAPP monitors interactions of polypeptide nascent chains during their synthesis on the ribosomes and specifically degrades their mRNAs if these interactions are abolished due to mutations in the nascent chains or defects in the targeting factor. It was demonstrated that pathological RAPP activation is one of the molecular mechanisms of human diseases associated with defects in the secretory proteins. In this review, we discuss recent progress in understanding of translational control of secretory protein biogenesis on the ribosome and pathological consequences of its dysregulation in human diseases.
Asymmetries in Dynamic CEO Compensation

In this study we test the null hypothesis of symmetry in contemporaneous and long-run responses of CEO cash and total compensation to stock and accounting returns. Over the long run, we find that cumulative cash and total compensation responses are concave in stock returns (i.e., are more sensitive to stock returns when company performance is poor). Although prior research has documented concavity in contemporaneous cash compensation (Leone et al. 2006), we find that the majority of the asymmetry for cash compensation, and virtually all of the asymmetry for total compensation, occur after the contemporaneous period. Prior research (e.g., Shaw and Zhang 2010) has also documented that contemporaneous cash compensation is convex in accounting returns (i.e., less sensitive to accounting returns when company performance is poor). We also find contemporaneous convexity for cash (and for total) compensation, but this convexity reverses over time, such that the long-run cumulative cash and total compensation responses are directionally, but not significantly, concave in accounting returns. Our findings of concavity are consistent with “prudent” boards of directors steering CEOs away from downside risk via their long-run compensation contracts. Our weaker results for accounting returns are consistent with a substitution of accounting conservatism for concavity in pay arrangements. However, our long-run results are not consistent with CEO cash or total pay being shielded from the effects of poor outcomes in either stock or accounting performance.
Las leyes del patrimonio arquitectónico: gravedad, suelo y ruina

espanolLa declaratoria patrimonial implica que una ley proteja a ciertos ediﬁcios de los embates de otras leyes como las de la fisica o del mercado. En otras palabras, lo que la declaratoria combate es la obsolescencia - fisica o funcional - por medio de un escudo legal que obliga a conservar un ediﬁcio en un estado en particular. Analizando los debates en torno a la conservacion de la Casa Colorada en Santiago, este articulo profundiza en las contradicciones inherentes entre las distintas leyes que afectan a un ediﬁcio. EnglishHeritage declaration implies a law protecting buildings from the onslaught of other laws such as those of physics or the market. In other words, what the declaration ﬁghts oﬀ is obsolescence - physical or functional - by means of a legal shield that compels to preserve a building in a particular state. Analyzing the debates around the conservation of the Casa Colorada in Santiago, this article delves into the inherent contradictions between the diﬀerent laws that aﬀect a building.
A novel use of contrast-enhanced ultrasound in uterine artery embolization

Contrast-enhanced ultrasound (CEUS) is a cost-effective, quick, and non-invasive imaging modality that has yet to be incorporated in uterine artery embolization (UAE). We present two cases that demonstrate the utility of CEUS in UAE for the identification of uterine-ovarian collaterals which otherwise can result in ineffective fibroid treatment and non-target embolization.
Compliance-Tuning Soft Inflatable Wheels for Robot Mobility on Various Terrains

Performance of a rigid wheel on deformable soils has been studied extensively, however little research had focused on inflatable soft wheels. In this project, we have designed and constructed a pneumatic actuated compliance tuning wheel. Unlike traditional rigid rim wheels, the proposed design embeds air bladders between the wheel grousers. Inflated air bladders provide additional traction by increasing the wheel’s contact area with the ground. The wheel was tested for slippage on deformable sandy terrain, rough obstacles and smooth metal surfaces. Reduced slippage was observed with bladder inflation in both a sandy terrain test and obstacle test. A smoother forward motion was observed in all test conditions with inflated bladders. The wheel’s capability of climbing was also evaluated qualitatively on a smooth metal-surface slope. As the slope angle increased, the bladder inflation proved to be necessary in order to successfully climb. Overall, the mobility of the wheel was improved on various terrains by the addition of inflatable soft air bladders.
Development of in-use engine speed/torque heat maps across multiple heavy-duty commercial vehicle vocations:

The U.S. Department of Energy (DOE) established the SuperTruck program with the goal of achieving brake thermal efficiency (BTE) greater than or equal to 55% as demonstrated in an operational heavy...
Advance Care Planning and Goals of Care Discussions in Advanced Liver Disease

Advance care planning (ACP) has been shown to improve multiple outcomes in patients with serious illnesses; however, patients with advanced liver disease, or cirrhosis, rarely receive timely ACP. The purpose of this review is to evaluate the current state of ACP for patients with advanced liver disease and to provide practical guidance for integrating early ACP into routine outpatient hepatology care. Due to multiple patient-, physician-, and systems-level barriers, patients with advanced liver disease have low rates of timely ACP engagement. Early identification and preparation of a surrogate decision-maker, enhancing clinician ACP communication skills, use of patient-centered educational tools, optimizing outpatient processes for ACP documentation, and early referral to specialty palliative care may help to improve current deficits in ACP for this population. Provision of early ACP to patients with advanced liver disease may better ensure that patients receive medical care that is consistent with their goals and values.
The Contribution of Morphological Awareness and Vocabulary Knowledge to Chinese as a Second Language Reading Comprehension: A Path Analysis

This study explored the role of morphological awareness and vocabulary knowledge in reading comprehension ability of Chinese as a second language (CSL) learners. Two-hundred and nine CSL students participated in this study and completed a series of measures including two tests of morphological awareness (morpheme discrimination test and compound structure test), a vocabulary knowledge test and a reading comprehension test. Drawing upon path analysis, this study found that morphological awareness contributed to vocabulary knowledge, and vocabulary knowledge is predictive to L2 Chinese reading comprehension. The results also indicated that morphological awareness significantly indirectly contributed to L2 Chinese reading comprehension through the mediation of vocabulary knowledge. Hierarchical regression analysis revealed that although both morpheme awareness and compound structure awareness contributed to vocabulary knowledge and L2 Chinese reading, morpheme awareness made more contribution compared to compound structure awareness.
Organizational Means to Increase Software Quality

An organizational model for software implementation is described based on actual experience. Emphasis is on aspects of product quality. Necessary organizational separations and combinations are discussed.
Degradation of basement membranes by human matrix metalloproteinase 3 (stromelysin).

Connective tissue cells synthesize and secrete a group of matrix metalloproteinases (MMPs), all of which are capable of degrading the extracellular-matrix components. One of them, MMP-3 (stromelysin) has been shown to degrade purified basement-membrane components, collagen IV and laminin [Okada, Y., Nagase, H. & Harris, E. D., Jr. (1986) J. Biol. Chem. 261, 14245-14255]. Here we report that MMP-3 degrades collagen IV and laminin in intact basement membranes from bovine glomeruli (GBM) and bovine anterior-lens capsules (LBM). Degradation products were analysed by SDS/polyacrylamide-gel electrophoresis to determine the number and sizes of polypeptide fragments. Immunoblotting techniques were used to identify the origins of the fragments, i.e. collagen IV or laminin. The fragments of collagen IV were further mapped using specific antibodies that recognize the N-terminal (7 S) domain, the C-terminal (NC-1) domain, or the major triple-helical region between the terminal domains. Degradation of collagen IV was extensive; many fragments were found, from both GBM and LBM, in the Mr range 25,000-380,000. A large fragment of laminin (Mr greater than 380,000) was found in the GBM digests without reduction, but it dissociated into 220,000-Mr chains upon reduction. The results suggest that MMP-3 plays an important role in the catabolism of basement membranes.
How Critical is Critical Thinking

T he improvement of thinking skills in students is considered a top priority by a growing number of American educators (Gallup 1985). This sensibility is reflected in the curriculum by a dramatic increase in courses that teach critical thinking at college as well as precollege levels. Although there is much debate as to how critical thinking is best taught (whether, for instance, it should be approached as an isolated subject or integrated into domain-specific courses), the educational establishment is in almost unanimous agreement that it should be taught. Some (Barry 1984; Blair and Johnson 1980; National Assessment of Educational Progress 1981; Nosich 1982) defend this contention by claiming that critical thinking is a pragmatic imperative in an age of information overload, deceptive advertising, and political ideology. Others (McPeck 1981; Postman 1985; Siegel 1988) argue that training in critical thinking is a necessary condition for the very possibility of effective learning in general. Still others (Paul 1982, 184, 1987; Scriven 1980) hold that instruction in critical thinking fosters an open-minded tolerance of alternative perspectives and worldviews.
The security and prosperity partnership in North America challenges for a successful agenda

The economic integration of North America has deepened in the last 25 years as never before. NAFTA, despite its inadequacies, cemented a pro cess that goes beyond traditional economic trade models by including other social, political, environmental and cultural elements. Now, after 9/11, the emerging policies of U.S. homeland security will require important adjustments in the interaction of the United States with Mex ico and Canada. Security policies have shifted a paradigm on the format of interaction among the three countries including logistics, transportation, persons crossing borders, biohazard threats, food safety and the synchronization of industries in more integrated ways. The challenges, especially along the border, illustrate that the relationship between the U.S. and Mexico and Canada is entering a new stage of complex interdependence. To ensure proper implemen tation, the three countries will need to make sig ni ficant structural adjustments focusing on a) col lective prosperity, b) the inclusion of actors at the local level, and c) strengthening public opinion.
Sleep and Sleeplessness in the Victorian Novel, Jane Eyre to Dracula

Sleep and Sleeplessness in the Victorian Novel, Jane Eyre to Dracula by Karen Beth Strovas Claremont Graduate University: 2011 Victorian inquisitiveness about sleep and dysfunctions of sleep is exemplified in novels published during the fifty-year period from Jane Eyre (1847) to Dracula (1897). This inquisitiveness foreshadows modern medical sleep science and immerses the reading public in a body of popular literature that subverts the concept of “normal” sleep. My dissertation explores the ways in which Victorian fiction brings physiological and psychological female concerns to the fore through the plot devices of sleep and sleeplessness. I examine the Victorians’ diverse interpretations of illness, physical and sexual vulnerability, moral insanity, criminality, and anxiety to determine the thematic and narratological ways in which these issues are linked to sleeping and waking states. Drawing on feminist literary criticism, cultural historicism, and medical insight from the early nineteenth-century to the present, I argue that Charlotte Bronte, Wilkie Collins, and Bram Stoker use sleep and wakefulness as vehicles to navigate gendered fluctuations of power and loss. Jane Eyre, The Woman in White, and Dracula each present sleep as a gendered space in which power is contested. I argue that sleeplessness and restlessness are the methods women adopt, either on purpose or unintentionally, to realize self-sufficiency and protect themselves from patriarchal jurisdiction and other social restrictions on women. Women must reject their instinctual desires for a certain amount of sleep so that they can maintain agency and authority over their bodies and narratives. Implicit in the novels is the idea that deep sleep is a mechanism for achieving health and moral strength of character. However, explicitly and without apology, the novels use the trope of sleep for women as a violent instrument of loss, infection, powerlessness, and weakness. The cultural and medical artifacts of the time suggest that deep, indulgent sleep is the only way to achieve or maintain health. Yet Victorian authors write sleep as a sure road to incapacitation and subjugation. Bronte, Collins, and Stoker demonstrate that a woman’s mind is only as healthy as her sleep, while her body is always safer awake.
Peak pulse power enhancement via substrate integrated waveguides filled with non-linear dielectrics

Peak pulse power enhancement occurring in substrate integrated waveguides loaded with a nonlinear dielectric material was investigated via a series of finite difference, time domain simulations. The code was developed to run efficiently on GPU platforms thereby radically reducing solution runtimes and allowing a significant number of dielectric-waveguide models to be characterized. The low-loss ferroelectric dielectric Barium Strontium Titanate (BST) was selected as the fill dielectric due to its availability and current utilization by industry. A single probe feed was assumed with a single pulse, cosine modulated Gaussian voltage waveform. This research is an extension of the earlier work of Caudle et. al., and focuses on the effects of the waveguide's dimensions and density of the fill dielectric. The results of the simulations indicate that a maximum peak pulse power enhancement of 11.25% and suggests the possibility of even greater power enhancement if global optimization is used.
Comparing effective population sizes of dominant marine alphaproteobacteria lineages.

Summary A fundamental question in marine microbial ecology is how microbes adapt to ocean environments. Although numerically dominant populations are typically considered more successful, higher census population sizes (Nc) do not equate directly to a greater capability for adaptation. Instead, effective population size (Ne) determines the fate of deleterious and favourable mutations, and thus is a key parameter for determining the adaptive potential of a population. In the case of the SAR11 and Roseobacter lineages, two abundant heterotrophic bacteria in ocean surface waters with contrasting life history strategies, culture-independent population surveys suggest that SAR11s have greater Nc than Roseobacters. To determine relative Ne, we compared the ratio of nonsynonymous to synonymous substitution rates (ω) of recently diverged lineages of these taxa. Values of ω associated with several of the Roseobacter subclades were lower than for SAR11 subclades, suggesting greater Ne in these cases. Most Roseobacter lineages also had smaller ω values compared with an atypical basal Roseobacter lineage with a large Nc. This finding provides insight into variability in Ne across two important marine bacterial lineages, and provides an evolutionary context for considering how heterotrophic marine bacteria may differ in their ability to adapt to changing ocean habitats.
Ultrasound of the Groin: Techniques, Pathology, and Pitfalls.

OBJECTIVE. In a patient with symptoms referable to the groin, there can be a number of causes to consider and at times the cause of the symptoms is multifactorial. Although ultrasound can be effective in the evaluation of the groin, the depth and complexity of the anatomy can be problematic. A protocol-driven approach for ultrasound evaluation of the groin will help to ensure an accurate and comprehensive evaluation. This article summarizes the ultrasound technique and protocol for evaluation of the groin to include evaluation of the hip joint, anterior hip musculature, the iliopsoas bursa, the inguinal lymph nodes, the pubic symphyseal region, and the inguinal region for hernias. Common pathologic conditions and pitfalls related to ultrasound evaluation of the groin will be reviewed. CONCLUSION. There are many potential pathologic conditions in a patient with groin symptoms. Because symptoms may be multifactorial and history may be ambiguous or misleading, a protocol-driven evaluation with ultrasound is ...
Evidence for a scalar {kappa}(900) resonance in {pi}K scattering

Motivated by the 1/N{sub c} expansion, we study a simple model in which the {pi}K scattering amplitude is the sum of a {ital current-algebra} contact term and resonance pole exchange. This phenomenological model is crossing symmetric and, when a putative light strange scalar meson {kappa} is included, satisfies the unitarity bounds to well above 1 GeV. The model also features chiral dynamics, vector meson dominance and appropriate interference between the established K{sub 0}{sup {asterisk}}(1430) resonance and its predicted background. {copyright} {ital 1998 American Institute of Physics.}
Evidence for different replicative strategies in the plant tombusviruses.

Abstract Analysis of the replicative form (RF) RNAs of three viruses assigned to the Tombusvirus group—tomato bushy stunt virus (TBSV), carnation ringspot (CRSV), and turnip crinkle (TCV) viruses-indicated that all three have different replicative strategies. Viral specific double-stranded (ds)RNAs were isolated from infected plant tissues by phenol extraction and cellulose chromatography and analyzed by polyacrylamide gel electrophoresis. A single RF species with a molecular weight of 3.0 x 106 daltons, twofold that of the viral single-stranded RNA, was isolated from TCV-infected plants. Two major RF species of 3.0 and 1.0 × 106 daltons and a minor one with 1.2 x 106 daltons were isolated from CRSV-infected tissues corresponding to the three genomic RNAs of this multicomponent virus. TBSV-infected tissues yielded two replicative intermediate RNA species in addition to two dsRNAs with molecular weights of 3.2 and 1.5 x 106 daltons. Hybridization experiments indicated that both dsRNAs were TBSV-specific. It is proposed that the 1.5 × 106 dalton dsRNA represents the replicative form of a subgenomic fragment of the TBSV RNA with a postulated MW of 0.75 × 106 daltons. A model for the replication of TBSV is suggested and its possible significance discussed.
A Foreigner in My Own Country: Forgetting the Heterogeneity of Our National Community

I would like to thank Nelson, Lushkov, Pomerantz, and Weeks (2006) for identifying the significant lack of scholarly research focusing on rural ethics and for suggesting that we rigorously address ...
Tafamidis in Transthyretin Amyloid Cardiomyopathy: Effects on Transthyretin Stabilization and Clinical Outcomes

Background—Transthyretin (TTR) amyloidosis is a progressive systemic disorder caused by misfolded TTR monomers that cumulatively deposit in the heart and systemically as amyloid. Methods and Results—This phase 2 open-label trial evaluated the stabilization of TTR tetramers using 20 mg of tafamidis daily at week 6 (primary end point), month 6, and month 12, as well as safety of tafamidis treatment and efficacy with respect to progression of TTR amyloid cardiomyopathy. Thirty-one wild-type patients (median age, 76.7 years; 93.5% men) with a median disease duration of 55.6 months and mild to moderate heart failure (96.8%; New York Heart Association, classes I–II) were enrolled. Thirty of 31 patients (96.8%) achieved TTR stabilization after 6 weeks and 25 of 28 patients (89.3%) after 12 months. After 12 months of treatment, 3 patients discontinued prematurely, 2 patients died, 7 patients were hospitalized because of cardiovascular events, 20 of 28 patients demonstrated preserved New York Heart Association cla...
Hepatic clotrimazole concentrations and hepatic drug metabolizing enzyme activities in adult male Sprague-Dawley rats.

Abstract A single high dose, 75 mg/kg, of clotrimazole (CloTZ) was administered intragastrically (i.g.) to adult male Sprague-Dawley rats. Hepatic CloTZ concentrations were determined in organic extracts of whole liver homogenate, by high-performance liquid chromatography (HPLC). The peak liver CloTZ concentration was found at 2.5 h post dose, and the liver t 1 2 was 11 h. With the present procedure CloTZ was detectable in the liver for up to 40 h and during this period, the hexobarbital sleep-time in these treated rats was prolonged. Between 40 and 120 h following a single dose of CloTZ, hexobarbital sleep-times were less than in untreated rats. The shortened sleep-time coincided with cytochrome P-450 induction which could be demonstrated in microsamal fractions obtained from the livers. Cytochrome P-450 catalyzed p-nitroanisole-demethylase a activity in the microsamal fractions in vitro was inhibited in the first 24 h and induced in microsomes prepared after that time.
The farm tractor and the nature of technological innovation

Abstract While the of diffusion of technology has been extensively studied, a sysetematic treatment of origin of innovations is generally lacking. This has important implications for studies not only of the phenomenon of diffusion itself, but also for studies of long-term growth of productivity. This paper presents an investigation of technological; innovations in the farm tractor during a time period of nearly five decades from its genesis. It is concluded that the observed advances in technology are attributable to variations in farm size and experience acquired in the production and utilization of the tractor over the course of time. More generally, two main hypotheses of technological change emerge from the results of thus study. One is the hypothesis of learning i.e. that technological innovation originates in the accumulated experience of a practical nature. The other is the hypothesis of scaling, i.e. that the process of innovation is further governed by changes in the size of the larger system, within which the technology is embedded. However, certain widely believed alternative hypotheses of technological change do not seem to generally hold. It is concluded that technological development is an evolutionary process which is best understood in terms of an internal logic of its own.
Non‐linear analysis of plane elastic bodies with inclusions by a BEM‐FEM approach

In the present study a hybrid boundary-element and finite-element method is developed for the non-linear analysis of two-dimensional elastic media with inclusions, and it is utilized in defining the micro-mechanical stress field in composite materials. The linear elastic, isotropic and homogeneous matrix is treated with the BEM, while the non-linear elastic and orthotropic inclusions (fibres) are treated with the FEM.
Designing drugs for parasitic diseases of the developing world.

McKerrow outlines three new strategies, all originating within academic centers, that provide a new drug pipeline for treating parasitic diseases.
Long-Term Prairie Falcon Population Changes in Relation to Prey Abundance, Weather, Land Uses, and Habitat Conditions

We studied a nesting population of Prairie Falcons (Falco mexicanus) in the Snake River Birds of Prey National Conservation Area (NCA) from 1974-1997 to identify factors that influence abundance and reproduction. Our sampling period included two major droughts and associated crashes in Townsend's ground squirrel (Spermophilus townsendii) populations. The number of Prairie Falcon pairs found on long-term survey segments de- clined significantly from 1976-1997. Early declines were most severe at the eastern end of the NCA, where fires and agriculture have changed native shrubsteppe habitat. More recent declines occurred in the portion of canyon near the Orchard Training Area (OTA), where the Idaho Army National Guard conducts artillery firing and tank maneuvers. Overall Prairie Falcon reproductive rates were tied closely to annual indexes of ground squirrel abundance, but precipitation before and during the breeding season was related inversely to some mea- sures of reproduction. Most reproductive parameters showed no significant trends over time, but during the 1990s, nesting success and productivity were lower in the stretch of canyon near the OTA than in adjacent areas. Extensive shrub loss, by itself, did not explain the pattern of declines in abundance and reproduction that we observed. Recent military training activities likely have interacted with fire and livestock grazing to create less than favorable foraging opportunities for Prairie Falcons in a large part of the NCA. To maintain Prairie Falcon populations in the NCA, managers should suppress wildfires, restore native plant communities, and regulate potentially incompatible land uses.
A cis-acting element within the 5′ leader of a cytomegalovirus β transcript determines kinetic class

Abstract During cytomegalovirus (CMV) infection, gene expression is regulated by transcriptional and posttranscriptional events. Although recent studies have established that posttranscriptional controls are important determinants of gene expression in several eukaryotic systems, the precise signals and mechanisms have not been clearly identified. We present evidence for a cis -acting signal, contained within the 5′ leader region of a CMV β (or early) gene, that acts posttranscriptionally in the regulation of gene expression. Addition of this signal to an α (or immediate early) gene construct converted expression of the indicator protein to the β class, even though the gene remained under α transcriptional control. Deletion of a portion of the β gene leader sequence (nucleotides +62 to +142) reverted expression to the α class. This cis -dominant signal appers to act by blocking expression posttranscriptionally until a viral function activates full gene expression at the appropriate time in infection.
Highly Emissive Iptycene-Fluorene Conjugated Copolymers: Synthesis and Photophysical Properties

Iptycene-type quinoxaline and thienopyrazine monomers were successfully synthesized via a condensation between 10-dihydro-9,10-ethanoanthracene-11,12-dione and the corresponding diamines. Copolymers based on fluorene and three iptycene monomers were prepared via Suzuki coupling reaction, and they exhibited good solubility in appropriate organic solvents. These copolymers are fluorescent in both solution and the solid state, emitting blue, greenish-blue, and red color due to the different electronic properties of the iptycene comonomers. The difference in their absorption and emission spectra was attributed to the donor−acceptor charge transfer interactions and/or polymer backbone conformational changes induced by steric effects. Moreover, the spectroscopic data clearly demonstrated the insulating effect of iptycene units, which prevented the aggregation of the polymer chains and the formation of excimers in the solid state.
Cumulative Risk of Second Primary Cancers in Women with Index Primary Cancers of Uterine Cervix and Incidence of Lower Anogenital Tract Cancers, Michigan, 1985–1992

Abstract A retrospective cohort study of women with cancers of the lower anogenital tract was derived from the Michigan Tumor Registry records for the years 1985–1992. Incidence rates of invasive cervical, vulvar, vaginal, and anal cancers were analyzed with respect to age, race, year of diagnosis, stage at diagnosis, and histopathology. The incidence of metachronous primary cancers following initial primaries of the cervix was also investigated. Anogenital cancers constituted about 4% of all cancers in Michigan women between 1985 and 1992. Age-adjusted incidence rates per 100,000 women per year for each site were found to be as follows: 10.1 (cervix), 1.9 (vulva), 1.0 (vagina), and 0.6 (anus). The incidence rates of women in the United States for cancers in the anogenital region were higher in blacks than in whites, with the exception of vulvar cancer. U.S. blacks were more likely to develop squamous cell carcinomas, but less likely to develop adenocarcinomas of the cervix and vagina when compared to whites. Over the 5- to 8-year follow-up period, 6.5% of the women with index cases of cervical cancer developed second primary cancers. This represented a 40% increase in the risk of incident primary cancers compared to the risk in the general population of Michigan women. The significant occurrence of second primaries of the vagina following index primaries of the cervix suggests a shared etiology, such as infection with human papillomavirus. The incidences of cancers related to smoking, including cancers of the urinary bladder, lung/bronchus, and lower anogenital tract were also increased.
David F. Treagust: Congenial soul, science educator, and international research leader

For almost a half century David F. Treagust has been an exemplary science educator who has contributed through his dedication and commitments to students, curriculum development and collaboration with teachers, and cutting edge research in science education that has impacted the field globally, nationally and locally. A hallmark of his outstanding career is his collaborative style that inspires others to produce their best work.
On minimum step response rise time of linear low-pass systems under the constraint of a given noise bandwidth

If the step-response rise time of a linear low-pass system is to be a minimum under the constraint of a given noise bandwidth, the systems parameters should be so tuned that the step response is strictly free from overshoot. This conclusion is also true when the system bandwidth is defined as its 3-dB bandwidth.
Magnetizing End-Effects in Salient Pole Machines

Analytical models of electric machinery often utilize a two-axis lumped-circuit approach, wherein the inductance parameters are obtained by applications of Ampere's law in a two-dimensional (2-D) cross section of the machine. A method of incorporating end-effects in the magnetizing inductance calculations of wound rotor synchronous machines is presented, allowing machines with high diameter-to-length ratios to be modeled more accurately. The method is verified using three-dimensional (3-D) finite element analysis.
Diagnostic imaging evaluation of renovascular hypertension

Over 50 million people in the United States are hypertensive. Renovascular disease accounts for 3-5% of these hypertensive patients. Because renovascular hypertension is potentially curable, much effort has been devoted to detecting and treating renal artery stenosis. Conventional angiography has been traditionally used to diagnose renal artery stenosis. However, because of its invasiveness and cost, conventional angiography cannot be utilized as a screening test in all patients who may have renal artery stenosis. Several noninvasive studies have been advocated for screening in hypertensive patients who may have renovascular disease. However, the accuracy of these noninvasive studies is widely variable, and appropriate use of these noninvasive studies needs to be better defined. Appropriate use of diagnostic imaging examinations for hypertensive patients depends on the index of suspicion for renovascular disease and on the patient's renal function. If certain clinical findings suggest the possibility of renovascular disease, then conventional angiography/intraarterial digital subtraction angiography should be performed. Captopril renography or duplex Doppler sonography could also be utilized if angiography is not desired or is contraindicated because of impaired renal function or a contrast allergy. Magnetic resonance angiography appears to be most helpful in a small, select group of patients who are likely to have proximal renal artery stenosis.
Transient analysis of electromagnetic scattering from wire structures utilizing an implicit time‐domain integral‐equation technique

An implicit version of the time-domain integral equation is presented for the analysis of electromagnetic scattering from wire structures. The advantage of the implicit form is that for large values of the time step, the method is unconditionally stable over the explicit version. Numerical results are presented to illustrate the efficacy of this approach. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 17: 66–69, 1998.
CARDIAC POWER OUTPUT IN CRITICALLY ILL SURGICAL PATIENTS: A SIMULTANEOUS PULMONARY ARTERY CATHETERIZATION AND TRANSTHORACIC ECHOCARDIOGRAPHY STUDY

Cardiac power output (CPO) (W) is a novel hemodynamic endpoint of resuscitation. A paucity of data exists as to the non-invasive estimation of CPO in surgical intensive care unit (ICU) patients. This 48 hours study enrolled 32 critically ill and/or injured adult surgical patients within 6 hours of
Energy transfer between UV generated color centers and the CN- ion in alkali halides

Abstract In alkali halide crystals containing CN - ions, pulsed UV radiation below the band gap is observed to produce F centers and then IR vibrational fluorescence, in that order. The stretch mode excitations are driven by inelastic collisions from conduction band electrons produced by the UV ionized F centers.
Id1 represses osteoclast-dependent transcription and affects bone formation and hematopoiesis.

Background The bone-bone marrow interface is an area of the bone marrow microenvironment in which both bone remodeling cells, osteoblasts and osteoclasts, and hematopoietic cells are anatomically juxtaposed. The close proximity of these cells naturally suggests that they interact with one another, but these interactions are just beginning to be characterized.
Relationship between cardiac hypertrophy and idioventricular rate in dogs with chronic A–V block

Abstract Resting idioventricular rates were determined in dogs with chronic A–V block (n=6) starting from 10–14 days after production of heart block and continuing until 18–88 days had elapsed. The ratio of heart weight to body weight was significantly greater (P
Detector inefficiencies in the Einstein-Podolsky-Rosen experiment

The question of how to deal with inefficient detectors in actual experiments of the Einstein-Podolsky-Rosen type is studied. We derive the necessary and sufficient condition for compatibility with local realism of data collected in experiments with two settings of each detector, without making auxiliary assumptions about undetected events. For the conventional experiment with particles in the singlet state (or its photon analogue), the data predicted by the quantum theory do not violate this condition unless the quantum efficiency of the detectors exceeds 83%.
Voices in the park, voices in the classroom: Readers responding to postmodern picture books

Abstract As the publication of picture books that contain meta‐fictive or postmodern elements increases, research concerning how intermediate grade readers respond and construct meaning in transaction with these texts is important. This study explores readers’ responses and discussions focusing on the picture book Voices in the Park by Anthony Browne. Utilizing discussion transcripts and response journal entries, this article focuses on how readers deal with the non‐linear aspects of the picture book, the interplay between written text and illustrations, and how these readers construct symbolic connections to their own world and experiences.
A meta-analysis of occupational trichloroethylene exposure and liver cancer

Findings from epidemiologic studies of trichloroethylene (TCE) exposure and liver cancer have been inconsistent. To quantitatively evaluate this association and to examine sources of heterogeneity, we conducted a meta-analysis of occupational studies of TCE exposure and liver/biliary tract cancer. We identified 14 occupational cohort studies of TCE exposed workers and one case-control study that met our inclusion criteria. Nine studies specifically identified TCE as a workplace exposure, and were classified as Group I cohort studies. Subcohorts of workers, identified within eight of these studies as more likely exposed to TCE than the total cohort, were analyzed separately. The combined liver/biliary cancer summary relative risk estimate (SRRE) for all studies was 1.08 (95% CI 0.91–1.29; heterogeneity (H)-P-value = 0.12). For the total study populations in the Group I cohorts, the SRRE was 1.14 (95% CI 0.93–1.39; H-P-value = 0.05) and for the subcohorts, the SRRE was 1.30 (95% CI 1.09–1.55). Within this subcohort analysis, the association for the European studies of workers from various industries (SRRE = 1.38; based on four studies) was higher than the association for the US studies of aerospace and aircraft workers (SRRE = 0.97, based on four studies). Although positive associations were observed for some analyses, results were inconsistent across occupational groups (aerospace/aircraft vs. other industries combined), study location, and incidence versus mortality endpoints. In addition, exposure-response trends were not observed consistently across studies. Interpretation is also limited by the potential impact of uncontrolled confounding by other occupational or lifestyle exposures such as smoking or alcohol consumption. Given these limitations, the currently available epidemiologic data are not sufficient to support a causal relation between occupational TCE exposure and liver/biliary cancer.