cssi/SciSciGPT-SciSciNet huggingface dataset:
Photosynthetic Characteristics of CAM Succulents with High Productivity

Responses of net CO2 uptake over 24-h periods to total daily photosynthetic photon flux (PPF), day/night air temperatures, and soil water status under controlled conditions in environmental chambers have been determined for 9 species exhibiting Crassulacean Acid Metabolism (CAM) as well as one C3 and one C4 species. For the CAM species, this has enabled accurate predictions of net CO2 uptake under field conditions and the PPF responses have led to the design of field plant spacings that maximize annual net CO2 uptake per unit ground area. Two Agave species and two Opuntia species have an average measured dry weight productivity of 43 metric tons hectare−1 year−1, which exceeds that of all C3 agronomic species and C3 trees and is only slightly less than the most highly productive C4 species. The high productivity of these CAM species can be explained based on daily net CO2 exchange and cellular photosynthetic properties. However, highly productive agaves and cacti are not tolerant of low temperatures, a problem for their cultivation in regions of the United States and other countries where air temperatures annually fall below about −5°C.
Neonatal epileptic encephalopathy caused by de novo GNAO1 mutation misdiagnosed as atypical Rett syndrome: Cautions in interpretation of genomic test results

Epileptic encephalopathies are childhood brain disorders characterized by a variety of severe epilepsy syndromes that differ by the age of onset and seizure type. Until recently, the cause of many epileptic encephalopathies was unknown. Whole exome or whole genome sequencing has led to the identification of several causal genes in individuals with epileptic encephalopathy, and the list of genes has now expanded greatly. Genetic testing with epilepsy gene panels is now done quite early in the evaluation of children with epilepsy, following brain imaging, electroencephalogram, and metabolic profile. Early infantile epileptic encephalopathy (EIEE1; OMIM #308350) is the earliest of these age-dependent encephalopathies, manifesting as tonic spasms, myoclonic seizures, or partial seizures, with severely abnormal electroencephalogram, often showing a suppression-burst pattern. In this case study, we describe a 33-month-old female child with severe, neonatal onset epileptic encephalopathy. An infantile epilepsy gene panel test revealed 2 novel heterozygous variants in the MECP2 gene; a 70-bp deletion resulting in a frameshift and truncation (p.Lys377ProfsX9) thought to be pathogenic, and a 6-bp in-frame deletion (p.His371_372del), designated as a variant of unknown significance. Based on this test result, the diagnosis of atypical Rett syndrome (RTT) was made. Family-based targeted testing and segregation analysis, however, raised questions about the pathogenicity of these specific MECP2 variants. Whole exome sequencing was performed in this family trio, leading to the discovery of a rare, de novo, missense mutation in GNAO1 (p. Leu284Ser). De novo, heterozygous mutations in GNAO1 have been reported to cause early infantile epileptic encephalopathy-17 (EIEE17; OMIM 615473). The child's severe phenotype, the family history and segregation analysis of variants and prior reports of GNAO1-linked disease allowed us to conclude that the GNAO1 mutation, and not the MECP2 variants, was the cause of this child's neurological disease. With the increased use of genetic panels and whole exome sequencing, we will be confronted with lists of gene variants suspected to be pathogenic or of unknown significance. It is important to integrate clinical information, genetic testing that includes family members and correlates this with the published clinical and scientific literature, to help one arrive at the correct genetic diagnosis.
The War Worth Fighting: Abraham Lincoln's Presidency and Civil War America. Edited by Stephen D. Engle. (Gainesville, FL: University Press of Florida, 2015. Pp. 268. $31.95.)

This edited collection of essays gathers contributions from a number of the most distinguished current historians of Abraham Lincoln and the Civil War North. The essays are grouped into three thema...
Brain-Inspired Wireless Communications: Where Reservoir Computing Meets MIMO-OFDM

Reservoir computing (RC) is a class of neuromorphic computing approaches that deals particularly well with time-series prediction tasks. It significantly reduces the training complexity of recurrent neural networks and is also suitable for hardware implementation whereby device physics are utilized in performing data processing. In this paper, the RC concept is applied to detecting a transmitted symbol in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems. Due to wireless propagation, the transmitted signal may undergo severe distortion before reaching the receiver. The nonlinear distortion introduced by the power amplifier at the transmitter may further complicate this process. Therefore, an efficient symbol detection strategy becomes critical. The conventional approach for symbol detection at the receiver requires accurate channel estimation of the underlying MIMO-OFDM system. However, in this paper, we introduce a novel symbol detection scheme where the estimation of the MIMO-OFDM channel becomes unnecessary. The introduced scheme utilizes an echo state network (ESN), which is a special class of RC. The ESN acts as a black box for system modeling purposes and can predict nonlinear dynamic systems in an efficient way. Simulation results for the uncoded bit error rate of nonlinear MIMO-OFDM systems show that the introduced scheme outperforms conventional symbol detection methods.
Liver-directed therapy (LDT) for metastatic renal cell carcinoma (mRCC): Single center experience.

681Background: Liver metastases arising from RCC are common and signify a poor prognosis. Given the negative impact of liver metastases on overall survival (OS) and quality of life, it is reasonabl...
The discovery of mitochondrial ribosomes

Observations leading to the discovery of mitochondrial ribosomes are recounted. Mammalian mitochondrial ribosomes, the first to be discovered (O’Brien and Kalf, 1967 a,b), are 55S ribosomes, with a sedimentation rate much slower than that of 70S bacterial or 80S eukaryotic cytoplasmic ribosomes. This result was not widely received because of the prevailing notion that mitochondrial ribosomes would resemble bacterial 70S ribosomes, reminiscent of their ancestral prokaryotic origins. After rigorous purification procedures to eliminate contaminating microsomal ribosomes (O’Brien and Kalf, 1967a) and further studies to confirm this finding (O’Brien, 1971) the 55S mitochondrial ribosome emerges as a ribosome with properties remarkably different from bacterial and eukaryotic, cytoplasmic ribosomes (O’Brien, 2003). Despite their lower sedimentation coefficient, the 55S mitoribosomes are physically larger than bacterial 70S ribosomes. Their mass is greater and so also are their physical dimensions (Hamilton and O’Brien (1974). While larger than bacterial ribosomes, they actually contain smaller RNAs (Andersen, et al., 1981). Their increased size is due to the presence of several extra proteins which are unique to mitochondrial ribosomes (O’Brien, 2003). All of the MRPs are candidates for mitochondrial disease (Sylvester, et al., 2004).
Axon Collaterals and Brain States.

Multiple mechanisms have been identified as relevant to plasticity, functional stability, and reliable processing across brain states. In the context of stability under “ever-changing conditions” (this Topic), the role of axons has been relatively under-investigated. The highly branched topologies of many axons, however, seem well designed to differentially recruit and regulate distributed postsynaptic groups, possibly in a state-dependent fashion. In this Perspective, I briefly discuss several examples of axon collateralization, and then some of the branch-specific features that might subserve differential recruitment and whole brain activation. An emerging principle is that the number of collaterals and number of target structures are not stereotyped. Rather, axons originating from one defined source typically send branches to diversified subsets of target areas. This could achieve heterogeneous inputs, with different degrees of synchronicity. Variability of neuronal responses has been suggested as inversely proportional to the degree of temporally correlated input. Increased input homogeneity, driven by sensory stimulation or behavioral conditions, is reported to reduce neuronal variability, with axon collateralization potentially having an important role.
A Linear Approach for Experimental Dynamic Parameter Estimation of Planar Mechanisms

Because of joint constraints, not all standard dynamic parameters of amechanism affect its dynamic response. The set with the minimum numberof standard dynamic parameters or linear combinations of standarddynamic parameters that is sufficient to uniquely determine the dynamicresponse of the mechanism is defined as a set of base dynamicparameters. Accurate knowledge of base dynamic parameters is crucial foraccurate dynamic analysis. This paper presents a new experimental methodto estimate base dynamic parameters based on linearized dynamic modelsand frequency analysis techniques. Rather than using traditionaltrajectories, the system to be estimated is excited with a hammer forcecausing oscillation in several small neighborhoods that are optimized.It is locally treated as a linear system. Base dynamic parameters areextracted from the frequency response function (accelerance). It isshown that all base dynamic parameters of nonlinear systems can beestimated with this new method. This is a general method that can beused in the estimation of general mechanisms. The method is successfullytested on a computer simulated response of a planar four-bar mechanismin four optimal spring-loaded static equilibrium positions with 10 dB ofsuperimposed noise.
An incremental conceptual clustering algorithm that reduces input-ordering bias

Cluster analysis has been of long-standing interest in statistics. It can be traced to the work of Adanson in 1757 [Adanson 1757] who used numerical clustering for classifying botanic species. Statisticians and more particularly taxonomists have widely developed the field since then. Cluster analysis offers now a large range of techniques for identifying underlying structures in large sets of objects.
Exploring the Time Dimension in the Technology Acceptance Model with Latent Growth Curve Modeling

This paper investigates the dynamics of users’ beliefs and intention to adopt a new technology during the course of its training. It also identifies the relationships among the dynamic elements over a time continuum. As a research method, we introduce latent growth curve modeling to better analyze the dynamics over a longitudinal time horizon. We provide an outline of the method for a research in progress. In addition, we demonstrate the application of latent growth curve modeling to a secondary data set obtained from Venkatesh et al. (2006). The results indicate that those with a higher level of initial behavioral intention to use are likely to have a higher level of initial use of a technology. In addition, those who have a steeper rate of increase in behavioral intention during the implementation are likely to have a steeper increase in their use of the technology.
The Battle of the Intellectually Disabled for Jobs, Not Drugs: A Socialist versus Medicaid History

This article is about the economic rights of Washington, DC’s so-called “intellectually disabled.” They have a history of resisting being drugged up, unemployed and impoverished, in short of being ...
An engineering approach for rapid evaluation of traction coefficient and wear in mixed EHL

An engineering approach is introduced for estimating the traction coefficient and the wear rate in elastohydrodynamic lubrication of rough surfaces without the need of extensive numerical simulations. The method suggested by Tian and Kennedy is extended to the mixed EHL to estimate the temperature rise. This temperature rise is then used together with the formulas for the film thickness and asperity load to evaluate the traction coefficient and the wear rate for different input conditions. The results from this method are compared to those from numerical simulations.
Harm Perceptions of Alternative Tobacco Products among US Adolescents.

Objectives In this study, we identified groups of adolescents who share similar awareness and perceptions of harm regarding e-cigarettes, cigars, hookah, and smokeless tobacco. Methods We used latent class analyses (LCA) with the data from Wave 1 (2013-14) of the Population Assessment of Tobacco and Health youth and parent survey (PATH; N = 13,650) to address the research goal. Multinomial logistic regression analysis assessed the associations between identified classes with demographic characteristics and tobacco use. Results LCA identified 5 classes: (1) perceived harm across all alternative tobacco products (36.6%); (2) perceived harm for e-cigarettes and smokeless tobacco but never heard of cigars and hookah (48.2%); (3) never heard of alternative tobacco products (8.6%); (4) mix of no harm and harm across alternative tobacco products (5.2%); and (5) "don't know" the harm across alternative tobacco products (1.4%). Relative to the class who perceived harm across all alternative tobacco products, classes of adolescents who were unaware of the products or did not know the harms were more likely to be non-white, younger, have lower parental education, and less likely to have tried an alternative tobacco product. Conclusions Tobacco prevention should target vulnerable youth, such as adolescents who are non-white, young, and have low parental education.
Racial and Ethnic Disparities in Homeownership

There are persistent differences in homeownership rates across racial and ethnic groups. Homeownership rates for whites are over 20 percentage points higher than for blacks or Hispanics. This paper uses a model of the housing tenure decision to gain a better understanding of these racial and ethnic differentials in homeownership and employs a decomposition technique that has been applied to labor market discrimination to report the results of the empirical testing of two hypotheses; (1) race (ethnicity) influences the probability of ownership through differences in household endowments (income, education, age, gender, and family type) and market endowments (price and location); and (2) race (ethnicity) directly influences the probability of ownership through racial or ethnic discrimination and other factors that may be correlated with race or ethnicity. We find endowment effects important in explaining the persistent racial and ethnic disparities in homeownership. In brief, logit analysis of 1989 American Housing Survey (AHS) national sample data reveals that 81 percent (78 percent) of the differences between the predicted probability of ownership between black and white households (Hispanic/non-Hispanic) are due to differences in group endowments. Direct effects explain 19 percent of the black-white differentials and 22 percent of the Hispanic/non-Hispanic differentials. Because the direct effects are modeled as residual differences, it must be realized that the residual components could also be capturing the influence of important omitted or harder to measure variables internal to the market process and correlated with race or ethnicity. These include wealth, household location, employment history, credit history, and cultural predisposition toward homeownership.
Histological and developmental insights into the herbivorous dentition of tapinocephalid therapsids

Tapinocephalids were one of the earliest therapsid clades to evolve herbivory. In acquiring derived tooth-to-tooth occlusion by means of an exaggerated heel and talon crown morphology, members of this family have long been considered herbivorous, yet little work has been done to describe their dentition. Given the early occurrence of this clade and their acquisition of a dentition with several derived features, tapinocephalids serve as an important clade in understanding adaptations to herbivory as well as macroevolutionary patterns of dental trait acquisition. Here we describe the histology of tapinocephalid jaws and incisors to assess adaptations to herbivory. Our results yield new dental characters for tapinocephalids including a peculiar enamel structure and reduced enamel deposition on the occlusal surface. These traits are convergent with other specialized herbivorous dentitions like those found in ornithischian dinosaurs and ungulates. Furthermore, these results demonstrate that while acquiring some specializations, tapinocephalids also retained plesiomorphic traits like alternate, continuous replacement. We interpret these findings as an example of how different combinations of traits can facilitate a derived and specialized dentition and then discuss their implications in the acquisition of a mammal-like dentition.
Imaging intercellular interaction and extracellular vesicle exchange in a co-culture model of chronic lymphocytic leukemia and stromal cells by lattice light-sheet fluorescence microscopy.

Abstract Recent advances in live cell imaging allow investigating processes that take place over the entire cell volume with unprecedented time and spatial resolution. Here we describe a protocol to study intercellular communication, including extracellular vesicle exchange, between cancer cells and their microenvironment, using lattice light sheet fluorescence microscopy. While the described protocol is intended to study the interactions between chronic lymphocytic leukemia cells and bone marrow stromal cells, many components of it can be applied to study other cancers of hematopoietic or solid tumor origin, as well as to characterize other modalities of intercellular communication.
Abstract D044: Age and sex effects on quantitative sensory testing values in healthy African American adults

Introduction: Only a few studies have reported quantitative sensory testing (QST) reference values for healthy African Americans, and those studies are limited in sample size and range of age of participants. The intent of our study was to fill a gap in the understanding of pain and somatosensory function in African Americans by generating QST values for healthy African American adults. In a large cohort of pain-free, healthy African American adults whose past pain experiences and current psychological status were known, our study aim was to determine thermal and mechanical QST values and compare those values at the anterior forearm by age and sex. We also determined the values for 5 other body sites and compared the values for differences by testing site location (upper body versus lower body). Methodology: In this cross-sectional study, 124 pain-free African American adults (age 18 to 69 years, 49% female) completed demographic and self-reported pain, fatigue and psychosocial measures. QST included obtaining thermal and mechanical responses and associated pain intensity levels. We applied the Benjamini-Hochberg procedure to adjust the p values to account for the multiple t tests. Results: We found thermal detection values at the anterior forearm were (29.2°C±1.6) for cool detection (CD) and (34.5°C±1.2) for warm detection (WD). At that site, pain thresholds were: cold pain threshold (CPTh) (26.3°C±5.0), heat pain threshold (HPTh) (37.8°C±3.6), and mechanical pain thresholds (MPTH) (16.7±22.2 grams of force, gF). There was a significant between sex difference for WD, with women being more sensitive (q=0.027). Lower body sites were less sensitive than upper body sites across all thermal modalities (q Citation Format: Keesha L. Powell-Roach, Starja Q. Booker, Yingwei Yao, Marie L. Suarez, Miriam O. Ezenwa, Roger B. Fillingim, Zaijie J. Wang, Robert E. Molokie, Diana J. Wilkie. Age and sex effects on quantitative sensory testing values in healthy African American adults [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D044.
Risk management for cyber-infrastructure protection: A bi-objective integer programming approach

Abstract Information and communication technology supply chains present risks that are complex and difficult for organizations to manage. The cost and benefit of proposed security controls must be assessed to best match an organizational risk tolerance and direct the use of security resources. In this paper, we present integer and stochastic optimization models for selecting a portfolio of security controls within an organizational budget. We consider two objectives: to maximize the risk reduction across all potential attacks and to maximize the number of attacks whose risk levels are lower than a risk threshold after security controls are applied. Deterministic and stochastic bi-objective budgeted difficulty-threshold control selection problems are formulated for selecting mitigating controls to reflect an organization’s risk preference. In the stochastic problem, we consider uncertainty as to whether the selected controls can reduce the risks associated with attacks. We demonstrate through a computational study that the trade-off between the two objectives is important to consider for certain risk preferences and budgets. We demonstrate the value of the stochastic model when a relatively high number of attacks are desired to be secured past a risk threshold and show the deterministic solution provides near optimal solutions otherwise. We provide an analysis of model solutions.
Legal Issues and the Professorate

A hard truth about contemporary higher education is that colleges and universities (and those who work within them) are increasingly finding themselves embroiled in legal disputes of various types. A 1997 poll conducted by Tillinghast-Towers Perrin, to cite just one example, found that the frequency of legal claims involving academic institutions had more than tripled in the five-year period since 1992. Claims against public postsecondary institutions during that same time span had at least quadrupled.1 College or university employees accounted for 67 percent of all claims initiated. Meanwhile, it was found that suits brought by students against institutions or their employees had more than doubled and were projected to increase at an even faster pace in future.2
Innovative Team-Learning Project for Undergraduate Pathology Education.

At the University of Minnesota, Twin Cities Campus, we have completed our seventh year of an innovative small group learning activity in an undergraduate medical school course. The purpose of the I...
Translation affects literary and cultural systems: how to observe the features of translation?

In the field of translation studies, it has been researched how good translation should be done, how translation affects other literary and cultural systems, how translation is carried out to produce the desired response, who influences translation, how translation can be said to be a tool for mastering marginalized groups, and Finally, how to observe the translation features of the translated text database. The flow of this development leads to a conclusion that research in the early days started from the essence of translation and shifted and branched to things that were not closely related to the essence of translation, e.g. postcolonial studies in the field of translation. However, some try to come back with a new tool (corpus study). From the point of view of the language industry, there is an irresistible trend. The first trend is that the industry now views translation as a means to achieve communication goals (business, politics, culture, etc.). The second trend is better computer technology and the increasingly widespread use of cloud computing. As a result, this development, supported by economic globalization, has forced many changes in professions related to the language industry.
The influence of violent video game enjoyment on hostile attributions

Violent video games did not lessen aggressive cognition among frustrated players.Playing a video game helped frustrated participants purge negative emotions.Frustrated participants rated gameplay as more enjoyable, regardless of content.Enjoyment of violent games moderated the effect of game on hostile attributions.High enjoyment increased hostile attributions; low enjoyment decreased them. Although catharsis theory as applied to violent media has been repeatedly refuted in the literature, scholars have recently proposed methods by which a cognitive form of catharsis might occur for people who utilize games to manage negative affect. Drawing on these ideas, the current study tests how video games are used to manage feelings of frustration and boost one's sense of competency. It also explores how these emotional processes influence game enjoyment and hostile attribution bias (HAB). We frustrated half of 82 participants prior to randomizing them to play a violent or nonviolent game. Our results showed that frustrated participants were motivated to progress farther in a video game. This in-game performance decreased their feelings of frustration, boosted their sense of competency, and increased their enjoyment of the game. However, for those who played a violent game, this enjoyment predicted hostile attributions: high enjoyment of violence increased HAB, while low enjoyment of violence decreased HAB. These findings have implications for how video games are used to manage negative feelings.
Architecture Meets Gaming and Robotics: Creating Interactive Prototypes and Digital Simulations for Architects

This paper presents an approach to producing an interactive physical kinetic prototype and its digital simulation for architects using a series of proposed methods. Conventional architectural CAD applications alone are not always sufficient for illustrating ideas for adaptable and responsive architecture that can conditionally change its states over time. The use of technologies from game design and robotics has a potential to extend the role of architects beyond merely providing static formal design solutions to various spatial problems. The paper introduces methods for rapid prototyping and real-time interaction between physical kinetic prototypes and a digital application environment for simulation using readily available commodity hardware, such as Arduino microcontrollers, 9 g servo motors, Kinect sensors, and Unity 3D game engine software with its computational physics. The paper also presents case studies using the approach and discusses possible applications and assessment of this approach.
Evaluating the Political Impact of Microfinance: Evidence from Senegal

This paper examines the political impact of microfinance programs. Current research suggests that microfinance programs increase individual political participation through deepening and increasing social networks. Studies on this topic are based on the Bangladesh model of group and gender-based borrowing structures with embedded social capital. This paper explores the microfinance industry in Senegal and constructs a generalizeable theory that considers the diversity within the microfinance industry. The paper argues that microfinance engenders an increase in individual political participation not because of its creation of, or impact on, social networks but through its impact on an individual’s perception of their political efficacy. These feelings of efficacy are based on individual socioeconomic status (SES), improved by participation in a microfinance program.. The data collection for this project involved 12 months of field research during which an original survey was administered to 703 Senegalese citizens, and interviews were conducted with more than 25 officials of microfinance organizations and dozens of microfinance borrowers. Findings show that participation in a microfinance program has a strong and positive impact on individual voting behavior and other forms of political participation but determining a direct causal effect of microfinance is problematic.
All optical switching via XPM in silicon waveguides

We demonstrate all-optical switching based on cross phase modulation in silicon waveguides. Switching of a 1537 nm CW signal by a pulsed pump at 1560 nm and with extinction of 13 dB is demonstrated.
Flecainide and the electrophysiologic matrix: the effects of flecainide acetate on the determinants of cardiac excitability in sheep Purkinje fibers.

Flecainide and Excitability. Flecainide was associated with excess mortality distributed virtually equally throughout the period of the Cardiac Arrhythmia Suppression Trial, suggesting the intersection of two events, drug effect and perhaps ischemia. Flecainide's effect on active properties has been studied extensively, but nothing is known of its effects on passive properties or on the balance among active and passive cellular properties that determines cardiac excitability. The multiple microelectrode method of intracellular current application and transmembrane voltage recording was used in sheep Purkinje fibers to determine strength-and charge-duration as well as constant current-voltage relationships and to estimate active properties, liminal length, and cable properties at a normal [K+]o and in a setting of hyper-kalemia analogous to that of ischemia. A computer tracked in time the alterations in the active and passive properties relevant to excitability. Flecainide slightly decreased excitability at a normal [K+]o, primarily by depressing the sodium system with some contributory effect of passive properties. At high [K+]o, flecainide caused a frequency-dependent decrease in excitability and conduction, the latter hest interpreted as a failure of the fiber to attain the liminal length requirements to produce a local action potential due primarily to an effect on sodium conductance. Together, the observations suggest that the action potential is the local phenomenon and that the propagated event is the sequential fulfillment of liminal length requirements. The data were interpreted in terms of the electrophysiologic matrix first proposed in detail in this Journal, which indicated that the electrophysiologic universe moved as a system in response to t he drug and a change in [K+]o, the presumed antiarrhythmic and proarrhythmic electrophysiologic matrices for flecainide were quite similar, and the matrical coufiguration shared characteristics with the matrices of other drugs with know proarrhythmic potential.
Nonsteady crack and craze behavior in PMMA under cyclical loading: I. Experimental preliminaries

This is the first of three papers devoted to the study of nonsteady crack propagation under cyclic loading in polymers, specifically PMMA. Drawing on experimental tools and measurement methods offering high spatial and real-time resolution at the subcycle level, we find that the change in craze behavior with load history is more complex than believed to date. At room temperature the change in fatigue cycle frequency on the order of slightly more than a decade gives rise to considerably different fracture surface morphologies, which are load history dependent. These observations are categorized and deductions for the variable cohesive force transmission by the craze are considered. In this first paper we outline the design of a special loading device which allows ultra-precise load or displacement control commensurate with the high resolution measurements of the crack tip material response. This development illustrates the precision of control for the experiments described in the subsequent papers. In addition, we delineate the software control and data acquisition methods to highlight the spatial resolution which provides the micron accuracy for measuring sub-cyclical crack propagation necessary for the later accounts.
Transparency: Two years of blogging the NIH

Sally Rockey, deputy director for extramural research at the US National Institutes of Health, reflects on the second anniversary of her precedent-setting blog.
On tympanostomy tubes: rationale, results, reservations, and recommendations.

The eardrums of millions of infants and children throughout the world contain foreign bodies, surgically implanted as prostheses. Myringotomy combined with placement of an indwelling tympanostomy tube (or grommet) has gained widespread acceptance among otolaryngologists as the treatment of choice for persistent middle ear effusion1 and for certain related otologic conditions. But otolaryngologists by no means stand alone: many if not most of the operations currently performed were initially recommended by pediatricians. It is difficult to determine how many such operations are currently performed on pediatric patients in this country, since most operations take place in outpatient settings and therefore escape systematic reportage. A reasonable estimate, however, would be 1 million procedures per year or, because most of them are bilateral, two million tubes inserted. Among the conditions for which the operation is performed, undoubtedly the most common is chronic secretory otitis media. Here there are three interrelated objectives: to remove the effusion, to relieve any associated hearing loss, and to institute and maintain middle ear ventilation. Less commonly the operation may be undertaken for one of various other reasons: to try to reduce the frequency of episodes of acute otitis media2,3; to relieve persistent underaeration of the middle ear when associated with conductive hearing loss or other symptoms2; or to prevent the development of adhesive otitis media or cholesteatoma when atelectasis or, especially, retraction pockets of the eardrum are present.2,4-6 The idea of using an indwelling tube to artificially ventilate the middle ear dates from 1868, when the great Viennese otologist, Politzer, introduced a ventilating eyelet made of hard rubber.7
Environmental Issues and Policies in Costa Rica

Despite its widely publicized efforts in environmental conservation, Costa Rica continues to experience severe deforestation due to entrenched deforestation interests in the country. These interests are created by existing legislation which unintentionally favors deforestation, and by the longstanding nonapplication of positive legislation. Costa Rica's newest strategy involves the mobilization of a broad-bayed conservation constituency through environmental education and the development of a “conservation area” strategy which helps distribute responsibilities and benefits of conservation among populations adjacent to protected areas.
Quantum Combustion Chamber for the Digital Engine

For increasing fuel economy and reducing hydrocarbon emissions, a two-stoke-cycle, loop-scavenged single cylinder engine was modified by replacing the head with a head having three subchambers and incorporating a distributing pump fuel injection system. The fuel injection system allowed one subchamber to be operated at a time. The quantum combustion system demonstrated both lower fuel consumption and lower hydrocarbon emissions than a conventional homogeneous charge engine. The experimental evidence also indicates that the combustion essentially occurred in the one chamber into which fuel was injected. Establishing stratified charge combustion by mechanically separating the regions of air from the regions of air/fuel mixtures by means of subchambers is feasible.
Prep benchmarks reveal performance and capacity tradeoffs of programmable logic devices

The process of choosing a programmable logic device (PLD) involves reviewing marketing material, studying specifications and learning PLD development tools. Until benchmark circuits were developed by the Programmable Electronics Performance Corporation (PREP), this was a costly and timely undertaking because no standard existed to compare PLDs against one another. This paper analyzes the PREP benchmark results and shows the capacity and performance tradeoffs associated with different programmable logic devices. >
Covalent Polymers Containing Discrete Heterocyclic Anion Receptors.

This chapter covers recent advances in the development of polymeric materials containing discrete heterocyclic anion receptors, and focuses on advances in anion binding and chemosensor chemistry. The development of polymers specific for anionic species is a relatively new and flourishing area of materials chemistry. The incorporation of heterocyclic receptors capable of complexing anions through noncovalent interactions (e.g., hydrogen bonding and electrostatic interactions) provides a route to not only sensitive but also selective polymeric materials. Furthermore, these systems have been utilized in the development of polymers capable of extracting anionic species from aqueous media. These latter materials may lead to advances in water purification and treatment of diseases resulting from surplus ions.
Scanning tunneling spectroscopy examination of surface electronic structures of surface

Abstract Scanning tunneling spectroscopy (STS) measurements have been performed on Si (111)(2 3 ×2 3 )30°- Sn surface. Tunneling spectral analysis of the energy of the surface states around the Fermi-level (Ef) indicates two filled and two empty states straddling Ef, showing a ∼ 1.6 eV surface bandgap. As part of the identification of these surface states, STS spectra were also taken on a coexisting well-known 3 × 3 surface, and the intrisic nature of these surface states is discussed.
NRF2-regulated genes SLC7A11 and NQO1 confer chemoresistance in mesotheliomas

3250 Mesothelioma is an aggressive and treatment-resistant tumor with increasing prevalence throughout the world. Expression of genes encoding antioxidants ( e.g ., glutathione) and xenobiotic detoxification enzymes has been shown to increase in mesothelioma cells, which may play an important role in anticancer drug resistance. SLC7A11 (xCT) is an amino acid transporter designated as system x c - , responsible for the cystine entry in exchange for intracellular glutamate. Once inside the cell, cystine is rapidly reduced to cysteine, the rate limiting amino acid for glutathione biosynthesis. Our previous studies showed that SLC7A11 overexpression in lung and ovarian cancers maintained a high intracellular glutathione level and conferred chemoresistance to multiple anticancer agents. The present study investigated the expression and activity of SLC7A11 and related gene NADP[H] quinine oxidoreductase 1 (NQO1), both of which are positively regulated by the transcriptional factor NRF2 and negatively regulated by the NRF2 suppressor gene KEAP1. We examined the mRNA and protein levels of SLC7A11, NQO1, NRF2 and KEAP1 in eight mesothelioma cell lines using real-time RT-PCR, dot blot, Western blot and immunocytochemistry techniques. We also inhibited the transport activity of SLC7A11 using glutamate or (S)-4-carboxyphenylglycine and examined the effects of SLC7A11 inhibition on the sensitivity of tumor cells to anticancer drugs geldanamycin and L-alanosine. Our results indicated that SLC7A11 and NQO1 are expressed at different levels in mesothelioma cell lines and their expression levels correlated with the degree of drug resistance in these cells. In cell lines with high levels of SLC7A11 expression (e.g., H2461), SLC7A11 inhibition significantly increased the growth inhibitory potency of geldanamycin, while the potency of L-alanosine, an amino acid analog and potential substrate of SLC7A11, was reduced. Although we hypothesized that constitutive activation of NRF2-regulated SLC7A11 and NQO1 may be due to the loss of function of KEAP1, no somatic mutation(s) in exon-coding regions of the KEAP1 gene have been detected in the eight cell lines by sequencing analysis of the tumor genomic DNA. These findings suggest a potential role of NRF2-regulated genes such as SLC7A11 and NQO1 in chemoresistance of mesothelioma. The mechanisms for overexpression of SLC7A11 and NQO1 in the subset of mesotheliomas need further investigation. Understanding the function of these genes and their regulatory pathways may lead to effective pharmacological treatment for this malignancy.
CURVE SINGULARITIES AND MONSTER / SEMPLE TOWERS

In earlier work, we introduced the 'Monster tower', a tower of fibrations associated to planar curves. We constructed an algorithm for classi- fying its points with respect to the equivalence relation generated by the action of the contact pseudogroup on the tower. Here, we construct the analogous tower for curves in n-space. (This tower is known as the Semple Bundle in Algebraic Geometry.) The pseudo-group of diffeomorphisms of n-space acts on each level of the extended tower. We take initial steps toward classifying points of this extended Monster tower under this pseudogroup action. Arnol'd's list of stable simple curve singularities plays a central role in these initial steps. We end with a list of open problems.
Calibration of detector sensitivities in a cylindrical PET camera

A method for calibrating the detectors in a cylindrical positron camera that uses cross-plane data is presented, and its performance is described. The method is based on the assumption that the sensitivity of a pair of detectors is the product of the individual sensitivity of the two detectors and a geometric factor. The calibration source is an annulus or rotating line of activity close to the detectors. The method uses measurements of the sum of all the coincidences from a detector, solves for geometric factors and sensitivities simultaneously, and is iterative. A key part of the method is a technique for forcing the iteration to converge quickly, usually within two or three iterations. The precision of the estimate of a detector's sensitivity approaches the theoretical lower bound determined by the sum of all the counts in the fan of coincidences from that detector. >
Use of neural networks in detection of structural damage

Abstract Damage to structures may be caused as a result of normal operations, accidents, deterioration or severe natural events such as earthquakes and storms. Most often the extent and the location of the damage can be determined through visual inspection. However, in some cases visual inspection may not be feasible. The study reported in this paper is the first stage of a research aimed at developing automatic monitoring methods for detection of structural damage. In this feasibility study we have explored the use of the self-organization and learning capabilities of neural networks in structural damage assessment. The basic strategy is to train a neural network to recognize the behavior of the undamaged structure as well as the behavior of the structure with various possible damage states. When the trained network is subjected to the measurements of the structural response, it should be able to detect any existing damage. We have tried this basic idea on a simple structure and the results are promising.
Coupled thermomechanical high cycle fatigue in a single crystal Ni-base superalloy

Abstract Thermomechanical fatigue (TMF) is the life-limiting damage phenomenon occurring in gas turbine components. Laboratory TMF tests are traditionally used to simulate the operating conditions inside of the turbine. However, typical LCF laboratory TMF test conditions do not account for the superposition of a HCF waveform which occurs during operation. This work studies the effects of the superposition of a HCF waveform during a high temperature hold occurring in both in-phase and out-of-phase bithermal fatigue TMF tests performed on a single crystal Ni-base superalloy. Results indicate that an atypical inelastic deformation–environmental degradation interaction is caused by the modification of the waveform due primarily to the change in the mean strain during HCF loading. The effect on life was found to be severe under certain conditions. Analysis of the deformation response and the extent of environmental degradation, in the form of γ′ depletion, are presented. An existing physics-based life model (Amaro, R.L., Antolovich, S.D., Neu, R.W. Mechanism-based life model for out-of-phase thermomechanical fatigue in single crystal Ni-base superalloys. Fatigue Fracture Eng Mater Struct; 2012) [1] , which explicitly accounts for inelastic–environmental interactions, is used to provide insight to the likely dominant deformation modes.
Prevalence of mercury hypersensitivity in dental students.

F or approximately 150 years, mercury in amalgam has been used as a dental restorative material. Throughout this time the potential toxicity of this metal to patients’” and dental professionals4-9 has been studied and debated. In these reports and many others, problems with mercury contamination and toxicity were uncovered. Although the extent of the problems may be controversial, the overall impact has led to increased emphasis on mercury hygiene in dental schools and in private practice.‘0,1’ Most studies on mercury contamination have concentrated on patients and dentists, with considerably less attention to dental students. This is unfortunate because students, in a sense, serve as a bridge between the two major groups, practicing dentists and their patients. Certainly, problems with mercruy contamination in first-year dental students should be similar to problems in patients. Conversely, problems with mercury contamination or toxicity in fourth-year dental students should reflect problems in practicing dentists. Some attempts have been made to study this unique group. In most of these experiments, however, the number of students screened for different forms of mercury contamination or toxicity has been small, with numbers ranging from 8 to 29 students.‘2-‘6 For this reason, there is little agreement between the results of these pilot studies. In a study by White and Brandt,” however, 298 dental students were screened for allergic responses to mercury. Through the use of epicutaneous patch-test procedures, they showed that the rate of hypersensitivity to mercuric chloride increased as students progressed through the dental curriculum. This observation linking hypersensitivity to mercury to the preparation of alloy restorations suggested that mercury as an allergen was an additional occupational hazard for the dental profession. With increased emphasis on mercury hygiene and the development of improved techniques for preparing amalgam, a second study of this phenomenom was
A multi-coil Magneto-Inductive transceiver for low-cost wireless sensor networks

A short-range low-cost Magneto-Inductive (MI) communication system is presented for wireless sensor network applications. The advantages of MI communications include the capability of communication in all conditions such as in air, underwater, and through solids. The hardware implementation and software design incorporate three coils for multi-channel receiving and transmission. Field tests have been conducted that demonstrate promising performance in terms of communication range and robustness against coil orientation mismatch.
Toward effective hospital utilization management. Ten lessons from case studies.

The challenges presented by managed care ar rangements and third-party utilization controls have led hospitals to strengthen internal utilization man agement programs. This article reports findings from a set of case studies on how hospitals have adapted their utilization management programs to their en vironments. While knowledge acquired from case studies should not be overgeneralized, the findings of these studies suggest some lessons that merit consid eration by hospitals advancing their own programs in utilization management.