cssi/SciSciGPT-SciSciNet huggingface dataset:
Surgical approaches to the management of epithelial cysts.

PURPOSE: The purpose of this study was to review management strategies for treatment of epithelial cysts. STUDY DESIGN: Retrospective consecutive interventional case series. METHODS: Charts of patients treated for epithelial ingrowth over a 10-year period by a single surgeon (J.A.H.) were reviewed. Cases of epithelial cysts were identified and the following data were recorded: details of ocular history, preoperative and postoperative visual acuity, intraocular pressure (IOP), ocular examination findings, type of surgical intervention, and details of subsequent procedures performed. RESULTS: Seven eyes with epithelial cysts were identified. Patients ranged in age from 1 1/2 years to 53 years at presentation. Three patients were children. Four cysts were due to trauma, one was presumably congenital, one developed after corneal perforation in an eye with Terrien's marginal degeneration, and one developed after penetrating keratoplasty. Three patients were treated with vitrectomy, en bloc resection of the cyst and associated tissue, fluid-air exchange, and cryotherapy. Four patients were treated with conservative strategy consisting of cyst aspiration (three cases) or local excision (one "keratin pearl" cyst) and endolaser photocoagulation of the collapsed cyst wall or base. In all cases, the epithelial tissue was successfully eradicated; one case required a second excision (follow-up, 9 months to 78 months; mean, 45 months). Two eyes required subsequent surgery for elevated IOP, two for cataract extraction, and one for a second penetrating keratoplasty. Final visual acuity ranged from 20/20 to hand motions, depending on associated ocular damage. Best visual results were obtained in the more conservatively managed eyes. CONCLUSION: Epithelial cysts can be managed conservatively in selected patients with good results. This strategy may be particularly useful in children, in whom preservation of the lens, iris, and other structures may facilitate amblyopia management.
Updating the SAPRC Maximum Incremental Reactivity (MIR) scale for the United States from 1988 to 2010.

Ozone reactivity scales play an important role in selecting which chemical compounds are used in products ranging from gasoline to pesticides to hairspray in California, across the United States an...
Cholestatic Variants of Viral Disease and Alcohol

Hepatitis of any etiology routinely presents with elevated transaminases. However, the presence of cholestasis should not necessarily rule out the presence of viral or alcoholic hepatitis. Hepatotropic viruses, such as hepatitis A, B, C, and E, can present with an elevated alkaline phosphatase and hyperbilirubinemia. Cytomegalovirus and Epstein-Barr virus infections may also present in this manner. Alcoholic hepatitis, often defined by an AST/ALT ratio of 2–3:1, can have cholestatic characteristics, as well. A careful clinical history, viral serologies, and, in some cases, a liver biopsy can clarify these disease states.
Conflicts and Facework in Online Discussions

The purpose of this study is to explore the relation between conflict and the outcomes of online discussions, the moderating effect of facework behaviors on the relation between conflict and online discussion outcomes, the effect of gender in this relation, and in the moderating effect of facework behaviors. During a two-week period, participants (149) in groups of three to four members used an online discussion board to discuss topics commonly controversial. The results indicate that conflict influenced the outcomes of online discussions; facework behaviors moderated the relation between conflict and outcomes; and gender influenced the choice of facework behaviors each member adopted during discussions.
Soil Washing and in Situ Stabilization Methods

The contamination of soils by chemically toxic or radioactive metals presents a major environmental problem. This problem is a combination of several factors. One problem is that metals in an aqueous environment are usually in a cationic form. Since soils are generally zeolites, which are negatively charged structures, metals are strongly bound to them. This charge association between metals and soils is especially problematic when the metal ion has a high positive charge such as +3 and +4. In these cases the charge pairing interaction is high, and the metal ion cannot be easily extracted by ion exchange with singly charged cations such as protons or sodium(I). Solvent washing is also inefficient in such cases because the solvation energies are usually not sufficiently strong for the metals to be eluted with small volumes of fluid extractants. Another problem with contaminated soils is that they are fixed in place, which contrasts with waters that can often be transported to another more convenient site for subsequent cleansing. With soils, however, excavation and transportation to an alternative location is at best very expensive. In many cases of soil remediation, numerous other problems must also be addressed. One problem is that excavation and removal may not be viable because of the presence of buildings or trees on the site that are not scheduled for removal. In these cases, electrokinetic extraction (Chapter 4) of metals is a viable alternative, especially for the areas around and beneath these immovable objects. Another problem with the removal of metals by soil washing is that it is usually desirable for the soil to be reclaimed to its original state before the contamination occurred. Since natural soils contain a range of desirable cationic components, these ions must be subsequently replaced if a consequence of soil washing is that they are removed along with the toxic and/or radioactive metals. Soils also have particular properties that result from the particle size distribution within them, and the cleansing process must not destroy these individual characteristics that makes the soils useful for cultivation applications. In addition to soils, another fixed environment that presents particular problems for the cleansing of metal contaminants is contaminated buildings. In some cases the building can be demolished with the materials transported for off-site remediation, but in other cases it is only a portion of the building that is contaminated, and it is desirable to retain the entire structure.
Early therapy for the incompetent cervix in patients with habitual abortion

From a thorough evaluation of 66 couples with habitual abortion (HA), 42 were found to have a widened uterine isthmus at hysterosalpingography (HSG) as their only abnormality. First trimester cervical effacement occurred in 90% of these patients. A combination of medical (progesterone [P]), and surgical (McDonald cerclage) begun during the first trimester resulted in successful term pregnancy in 35 of the 36HA patients (97%) who were treated. The results of this study suggest that (1) functional cervical incompetence may play a major role in HA; (2) a widened uterine isthmus at HSG and first trimester cervical effacement are clinical signs that may define this group of HA; (3) early recognition and therapy for the incompetent cervix can interrupt the progression of events leading to the loss of an otherwise normally developing fetus; and (4) increased perinatal morbidity demands continuous antepartum assessment of fetoplacental integrity in these patients.
Computational influence for training and entertainment

An interactive narrative is an education, training, or entertainment experience. There are two qualities that make an experience an interactive narrative. To understand those, let us clarify the meanings of interactive and narrative. Interactive: capable of acting on or influencing each other; and Narrative: presentation of events in a purposeful sequence. Thus, the qualities that define an interactive narrative are autonomy for players to act and intent of the system for the player to experience a narrative prescribed by an author. This conception of interactive narrative is broad and encompasses many types of entertainment and training experiences. One characteristic that sets it apart from other experiences and common games like Chess is that authorial intent often requires the player’s experience to be dramatic or adhere to some aesthetic. There is a tension between the systematic control required to ensure the intent of the narrative and the player autonomy required for interactivity— the player-driven exploration that results in an interactive quality is a potential threat to the narrative. Therefore, AI researchers in the field of interactive narrative are interested in balancing the conflicting requirements of autonomy and authorial intent. It is in this area that both I and many interactive narrative researchers have focused their efforts (Roberts and Isbell 2008). While many of the existing research projects have met with success in their own right, they have also uncovered limitations in the state of the art. I plan to complete my dissertation by addressing some of these limitations. The tools of artificial intelligence and machine learning have often been applied in domains where the limits of human ability are stretched. For example, sophisticated AI algorithms retrieve information from the internet, filter spam from email inboxes, and aid doctors in diagnosing illnesses. In each of these cases, a technically-minded AI expert has created a technique to solve a class of problems and has put the power of that technology in the hands of a practitioner. Similarly, I plan to develop AI technologies for computerbased gaming and simulation that when given to game designers will ease their authorial burden and increase their expressive power. The fundamental question I plan to an-
Neurocognitive function of 10-year-old multiples born less than 28 weeks of gestational age.

Few studies have examined the relationship between birth plurality and neurocognitive function among children born extremely preterm. We compared rates of Z-scores ≤−2 on 18 tests of neurocognitive function and academic achievement at age 10 years in 245 children arising from twin pregnancies, 55 from triplet pregnancies, and 6 from a septuplet pregnancy to that of 568 singletons, all of whom were born before the 28th week of gestation. In total, 874 children were evaluated at the age of 10 years. After adjusting for confounders, children of multifetal pregnancies performed significantly better on one of six subtests of executive function than their singleton peers. Performance was similar on all other assessments of intelligence, language, academic achievement, processing speed, visual perception, and fine motor skills. We found no evidence that children born of multifetal pregnancies had worse scores than their singleton peers on assessments of neurocognitive and academic function.
Preclinical Characterization of 86/90Y-NM600 in a Variety of Murine and Human Cancer Tumor Models.

We characterize the in vivo biodistribution and tumor selectivity of 86Y-NM600, a theranostic alkylphosphocholine radiometal chelate with broad tumor selectivity, in a variety of preclinical cancer models. Methods: Mice bearing flank tumors (representative of lung, pancreatic, prostate, liver, skin, and lymphoid cancers) were injected intravenously (IV) with 9.25 MBq of 86Y-NM600 and imaged longitudinally over 4-5 days using microPET/CT. Percent injected activity per gram (%IA/g) for each volume-of-interest (VOI) was measured at each time point for the organs of interest. Mice were euthanized after the final time point and the tumor and organs of interest were counted with an automatic gamma counter. Absorbed doses delivered by 90Y-NM600 per injected activity (Gy/MBq) were estimated. Mice bearing B78 flank tumors were injected with a prescription of 90Y-NM600 that delivered 2.5 Gy of absorbed tumor dose and was compared to an equivalent absorbed dose delivered via external beam radiotherapy (XRT) using tumor volume as a measure of response. Histology and complete blood counts (CBC) were analyzed in naive C57BL/6 mice who were injected with 9.25 MBq of 90Y-NM600 at 5, 10, and 28 days post injection (p.i.). Results: PET imaging showed consistent tumor accumulation and retention across all tumor models investigated with little off-target retention of NM600 except for in the liver, which is characteristic of hepatobiliary metabolism. The tumor uptake was highest in the pancreatic and lymphoid cancer models, reaching peak concentrations of 9.34 ± 2.66%IA/g (n = 3) and 9.10 ± 0.13 %IA/g (n = 3), respectively, at approximately 40-48 hr post injection. These corresponded to tumor dose estimates of 2.72 ± 0.33 Gy/MBq and 2.67 ± 0.32 Gy/MBq, respectively. In the toxicity study, there were no visible signs of acute toxicity by histology, and perturbation of hematological parameters was transient when observed, returning to pre-therapy levels after 28 days. Conclusion: NM600 is a theranostic agent with a unique ability to selectively target a variety of cancer types, presenting a unique opportunity for PET image guided TRT and combination with immunotherapies.
Downhole thermoelectric generation in unconventional horizontal wells

Abstract Excessive water production from hydraulically fractured unconventional reservoirs is historically considered as burdensome liability in terms of costly treatment and disposal. However, this paper demonstrated produced water as a valuable asset, which is capable of producing geothermal energy, and it can actually help offset the operation costs for unconventional oil and gas producers. Harnessing geothermal energy of produced water for power generation from unconventional horizontal wells features significant advantages over traditional geothermal wells, especially in reducing capital expenditure and operational risks. This paper proposed a novel design of downhole power generation in horizontal wells by integration of thermoelectric technology with hydrocarbon production. In the design, we retrofit the horizontal wellbore to circulate cold water inside the tubing so that a cold temperature interface can be created. The produced fluids flow through the annulus of the tubing and casing to maintain hot temperature on the side of tubing. By attaching thermoelectric generators (TEG) on the outer surface of tubing, this retrofit will make it possible to capture subsurface in-situ geothermal energy of the produced fluid and directly transfer heat to electricity inside the horizontal wellbore. Furthermore, we also built the mathematical model to account for the heat conduction and convention in the wellbore and surrounding formation, which could accurately simulate the temperature distribution and power generation under variable operational conditions. Based on the model, we identified the key parameters with significant impact on power generation and established the well section criteria for best power generation performance. To discover the potential of power generation in horizontal wells, we conducted a case study in Daqing Oilfield in northeast China and compared the power generation performance with vertical well with same TVD and same power generation device installation. The results of case study indicated that horizontal well displayed exceeding power generation performance over vertical wells. In practice, this paper could contribute to enrich geothermal development methods and provide the guidelines for oil and gas producer to evaluate their horizontal assets and identify the opportunity to capitalize on geothermal power generation from horizontal wells.
Divergence in foraging and predator avoidance behavior across the geographic range of native and non-native crayfish

There is growing evidence that species’ traits may diverge during biological invasions; however, we still lack a general understanding of how the invasion process affects behavior. We used a biogeographic approach to compare foraging and antipredator behavior across a reciprocal invasion (in which each species invaded the native range of the other) of virile (Faxonius virilis) and rusty crayfish (F. rusticus). We hypothesized that the invasion process would select for individuals that invest more in foraging and less in defense than their native counterparts. We used laboratory experiments to examine crayfish boldness, activity, and foraging voracity and mesocosm experiments to examine antipredator behavior in response to fish. Non-native virile crayfish (Indiana, USA) were less bold, active and voracious than native virile crayfish (Wisconsin, USA), and they exhibited more antipredator behavior. Non-native rusty crayfish (Wisconsin) were more active in mesocosms and exhibited less antipredator behavior than native rusty crayfish (Indiana). Combined, these findings suggest a growth/mortality trade-off. Counter to our hypothesis, relative investment in foraging versus predator avoidance differed across regions and was not consistently associated with native or invasive populations. Thus, the substantial divergence in behavior we observed may by driven by local adaptation.
Optimal Power Adaptation in Covert Communication With an Uninformed Jammer

Covert communication is achieved if a transmitter (Alice) sends a message to a legitimate receiver (Bob) without being detected by an attentive warden (Willie). Recent work has taken an outage approach that considers an infinite blocklength and analyzes the probability that channel conditions are such that communication is reliable and/or covert. Power adaptation via truncated channel inversion (TCI) has been examined in previous work in an attempt to minimize outage under the covertness constraint. However, the optimality of TCI was not established, and the associated parameters in the TCI scheme were only found numerically. We provide the exact optimal power adaptation schemes under different covertness constraints and with different channel models: 1) when the channel between Willie and an uninformed jammer is AWGN; and 2) when the channel is a Rayleigh fading channel. We also examine the performance improvement of these schemes over standard approaches. This establishes that TCI is optimal in some, but not all, scenarios of interest.
23 Structural Equation Modeling

The first half of this chapter presents an overview of the type hypotheses, statistical theory, and major issues relevant to specifying, estimating, evaluating, and interpreting structural equation models. Following this brief SEM overview, a complete example of a simple SEM model of risky behavior using a large dataset of responses from preteen children is presented. This presentation includes examples of output from EQS 6.1. The second half of chapter is devoted to a detailed presentation of the current issues and important future research directions in structural equation modeling. Keywords: data analysis; statistics; structural equation model
Skeptical Theism Proved

Skeptical theism is a popular response to arguments from evil. Many hold that it undermines a key inference often used by such arguments. However, the case for skeptical theism is often kept at an intuitive level: no one has offered an explicit argument for the truth of skeptical theism. In this article, I aim to remedy this situation: I construct an explicit, rigorous argument for the truth of skeptical theism.
Single Electron Tunneling

This is a brief review of some recent developments inexperiments and theory of the Coulomb blockade phenomenon. Weconcentrate on electron tunneling through semiconductorquantum dots and normal-metal nanoparticles. The linearconductance and non-linear I–V characteristics are sensitivenot only to the charging energy, but also to smaller energyscales. These are the spacing between discrete energy levelsof intra-dot electron excitations, and the width these levelsacquire due to the electron escape to leads through thejunctions. At sufficiently low temperatures, or at not-so-small junction conductances, the many-body phenomena, such asKondo effect, become observable in the dot-lead system. Kondoeffect yields an additional fine energy scale to the problem.We discuss a simple theoretical model incorporating theseenergy scales, and its relation to the experimentalobservations.
Remarks on The Virtue of Nationalism

These remarks restate Hazony's distinction between nation and empire and the characteristics uses to typify them. In both cases, I argue, the ideal types do not account for the range of historical ...
‘Los esqueletos oxidados de los buques hundidos en la guerra’: Tracing the Spanish Civil War and Barcelona’s Expansion in Carmen Laforet’s Nada

The present article argues that the presence of the Spanish Civil War in Carmen Laforet’s Nada (1945) is much more pervasive than previously asserted in criticism on the novel. I maintain that when...
Variational Transport: A Convergent Particle-BasedAlgorithm for Distributional Optimization.

We consider the optimization problem of minimizing a functional defined over a family of probability distributions, where the objective functional is assumed to possess a variational form. Such a distributional optimization problem arises widely in machine learning and statistics, with Monte-Carlo sampling, variational inference, policy optimization, and generative adversarial network as examples. For this problem, we propose a novel particle-based algorithm, dubbed as variational transport, which approximately performs Wasserstein gradient descent over the manifold of probability distributions via iteratively pushing a set of particles. Specifically, we prove that moving along the geodesic in the direction of functional gradient with respect to the second-order Wasserstein distance is equivalent to applying a pushforward mapping to a probability distribution, which can be approximated accurately by pushing a set of particles. Specifically, in each iteration of variational transport, we first solve the variational problem associated with the objective functional using the particles, whose solution yields the Wasserstein gradient direction. Then we update the current distribution by pushing each particle along the direction specified by such a solution. By characterizing both the statistical error incurred in estimating the Wasserstein gradient and the progress of the optimization algorithm, we prove that when the objective function satisfies a functional version of the Polyak-Łojasiewicz (PL) (Polyak, 1963) and smoothness conditions, variational transport converges linearly to the global minimum of the objective functional up to a certain statistical error, which decays to zero sublinearly as the number of particles goes to infinity.
Debt Financing and Financial Flexibility Evidence from Proactive Leverage Increases

Firms that intentionally increase leverage through substantial debt issuances do so primarily as a response to operating needs rather than a desire to make a large equity payout. Subsequent debt reductions are neither rapid, nor the result of pro-active attempts to rebalance the firms capital structure towards a long-run target. Instead, the evolution of the firms leverage ratio depends primarily on whether or not the firm produces a financial surplus. In fact, firms that generate subsequent deficits tend to cover these deficits predominantly with more debt even though they exhibit leverage ratios that are well above estimated target levels. While many of our findings are difficult to reconcile with traditional capital structure models, they are broadly consistent with a capital structure theory in which financial flexibility, in the form of unused debt capacity, plays an important role in capital structure choices.
A computational study of the hemodynamics of bioprosthetic aortic valves with reduced leaflet motion.

Abstract We employ a reduced degree-of-freedom aortic valve model to investigate the flow physics associated with early-stage reduced leaflet motion in bioprosthetic aortic valves. The model is coupled with a sharp-interface immersed boundary based incompressible flow solver to efficiently simulate the fluid–structure interaction. A total of 19 cases of flow through aortic valves with varying degrees of reduced leaflet motion (RLM) are considered. The characteristics of the aortic jet and the consequent aorta wall loading patterns are analyzed. Our results show that asymmetric RLM tilts the aortic jet and leads to large reverse and recirculating flow regions downstream from leaflets with restricted mobility. The changes in flow patterns increase wall pressure and shear stress fluctuations, and result in asymmetric oscillating shear on the aorta wall. These findings have implications for auscultation based diagnosis of this condition as well as the health of the aorta.
Hyperemesis gravidarum and neonatal outcomes: A systematic review of observational studies.

Abstract Hyperemesis gravidarum (HG) is associated with adverse somatic and psychological effects. The impact of HG on neonatal outcomes is debatable given that disagreeing research results have appeared. The objective of this study was to systematically review, according to the PRISMA guidelines, and synthesize the available evidence from observational studies on the relationship between HG and neonatal outcomes. The PubMed, Scopus, and Science Direct databases were systematically reviewed, with the last search carried out in April 2020. The quality of the studies was estimated using the Newcastle–Ottawa Scale (NOS) for non-randomized studies. The databases search yielded 516 studies 15 of which (n = 112.372 HG cases) matched eligibility criteria while the majority of the studies were of moderate quality (n = 12). We observed heterogeneity among the studies regarding the definition of HG and characteristics of the samples. The results of this systematic review suggest that it is still uncertain whether HG has an adverse impact on neonatal outcomes, fact that requires more studies to be conducted.
Ergonomic Control Panel (ECP): A Proposed Comprehensive Ergonomics Evaluation Tool Using Multi-task Evaluation Models

The authors propose a dynamic simulation model useful for determining the degree to which ergonomic exposure metrics are impacted by changes in various operational decisions such as scheduled overtime, cycle time, and make/model mix. Conventional ergonomics analyses and risk assessment approaches are incapable of rapidly assessing the impact of these types of operational decisions on resultant ergonomic exposure metrics. It is common practice to treat ergonomic exposure metrics as static/constant, when in actuality they change in response to variations in a multitude of operational parameters. The proposed simulation model extends the capabilities of current multi-task ergonomics assessment tools to account for this variation. State-of-the-art multi-task evaluation models such as RCRA (Recommended Cumulative Recovery Allowance) and Fatigue Failure theory-based models can be utilized to recommend appropriate job rotation schedules and modifications in shift duration to limit exposure duration, increase recovery time, and protect employees.
Evaluation of Inappropriate COVID-19 RT-PCR Test Utilization at an academic medical center.

BACKGROUND An evolving COVID-19 testing landscape and issues with test supply allocation, especially in the current pandemic, has made it challenging for ordering providers. We audited orders of the Xpert® Xpress SARS-CoV-2 PCR with reverse transcription (RT-PCR) platform-the fastest of several other testing modalities available-to illuminate these challenges utilizing a multidisciplinary laboratory professional team consisting of a pathology resident and microbiology laboratory director. METHODS Retrospective review of the first 5 hundred Xpert Xpress SARS-CoV-2 RT-PCR test orders from a 2-week period to determine test appropriateness based on the following indications: emergency surgery, emergent obstetric procedures, initial behavioral health admission, and later including discharge to skilled care facilities and pediatric admissions. Our hypothesis was that a significant proportion of orders for this testing platform were inappropriate. RESULTS On review, a significant proportion of orders were incorrect, with 69.8% (n = 349, P < 0.0001) not meeting indications for rapid testing. Of all orders, 249 designated as emergency surgery were inappropriate, with 49.0% of those orders never proceeding with any surgical intervention; most of these were trauma related (64.6% were orders associated with a trauma unit). CONCLUSIONS Significant, pervasive inappropriate ordering practices were identified at this center. A laboratory professional team can be key to identifying problems in testing and play a significant role in combating inappropriate test utilization.
Reaction-diffusion informed approach to determine myocardial ischemia using stochastic in-silico ECGs and CNNs.

Abstract Every year, nine million people die globally from ischemic heart disease (IHD). There are many methods of early detection of IHD which can help prevent death, but few are able to determine the configuration and severity of this disease. Our study aims to determine the severity and configuration of ischemic zones by implementing the reaction-diffusion analysis of cardiac excitation in a model of the left ventricle of the human heart. Initially, this model is applied to compute twenty thousand in-silico ECG signals with stochastic distribution of ischemic parameters. Furthermore, generated data is effectively ( r 2 = 0.85 ) implemented for training a one-dimensional convolutional neural network to determine the severity and configuration of ischemia using only two lead surface ECG. Our results readily demonstrate that using a minimally configured portable ECG system can be instrumental for monitoring IHD and allowing early tracking of acute ischemic events.
A global radio frequency noise survey as observed by the FORTE satellite at 800 km altitude

We present a dynamic global radio-frequency survey of noise observed from the FORTE satellite at 800 km altitude.This is a survey of squared amplitudes in 44 sub-bands each spaced by 0.5 MHz centered at 38 MHz (``lo-band'') and 44 sub-bands spaced by 0.5 MHz centered at 130 MHz (``hi-band''). More specifically, we survey the distribution of , where R 2 is the squared amplitude at a given frequency and is the most recent mean squared amplitude. The definition of ``most recent'' ranges from 10 microseconds to 10 s. We also vary the fraction of the update period used to compute the mean from 0.1% to 100% of the period. We define 13 geographic regions and analyze signal-free regions of event data generated from 1997 to 1999. We use cross validation to adequately sample the distribution of across time. Summary statistics presented include percentiles of the distribution and fractions exceeding thresholds in each of 44 frequency bands spaced by 0.5 MHz for the lo and hi frequency bands in each of the geographic regions.
Transport performance of a transparent WDM regional area ring network utilizing optimized components/fiber

We present excellent performance results (Q-factor>10) for a transparent regional-size ring network based on application-optimized optical layer components and fiber. The network consists of 6 nodes interconnected with 86.5 km-spans of uncompensated negative dispersion fiber (520 km-ring circumference n no dispersion compensation) and supports 32 directly modulated channels operating at 2.5 Gb/s (80 Gb/s capacity).
Anomalies in sedimentation: IV. Decrease in sedimentation coefficients of chains at high fields

Abstract A theory is presented for the decrease of sedimentation coefficient at high centrifugal fields recently reported for samples of DNA by Rubenstein and Leighton and others. The theory uses the model of a chain of beads and springs to represent the molecule. Kirkwood's approximation is used for the sedimentation coefficient. The decrease in sedimentation coefficient with field comes about as a result of the uneven frictional forces in the chain, which on the average are less on segments near the center of the chain than on those near the ends. As a result the ends of the chain tend to drag behind the center, and the average intersegment distances are increased; consequently the hydrodynamic shielding of one segment by another is reduced, and the average friction is increased. The effect is thus characteristic of single molecules; intermolecular interaction is not involved. The sedimentation coefficient, S, varies as a power series in a parameter y that measures the distortion produced by the uneven friction: S = S0(1−D2y2 + D4y4 − ·). where S0 is the limiting value of S at zero centrifugal field and D2 and D4 are constants; y is proportional to the cen speed squared tunes the molecular weight squared divided by S0. It has been observed that the effects of centrifuge speed on S are negligible below certain critical values of the speed and molecular weight, but increase dramatically immediately above these values; this follows naturally from the high powers of the speed and molecular weight that appear in the above equation.
Experience, Lessons Learned and Methodology in the Design of Space Systems to Accommodate Total Dose and Seu Effects

We now have considerable experience with successfully designing science systems to function properly, even during and after exposure to ionizing radiation approaching one Megarad, and during large solar particle events with substantial high Z fluxes such as the events that happened in August, 1972 and in the fall of 1989. Nevertheless, with changing device dimensions and properties, newer technologies and new applications, new problems arise. Some recent basic research has shed light on these problems and pointed the way to better diagnostic tests. In the case of single event upsets, clearly one cannot always accurately predict upset probabilities simply by knowing the quiescent LET threshold and the asymptotic cross-section of the device.
Issues in second language teaching, by Alessandro G. Benati

Issues in Second Language Teaching approaches a range of typical L2 pedagogical concerns from a research and theoretical perspective. Teachers with little training may find it a beneficial starting...
Diet, Anthropometry and Breast Cancer: Integration of Experimental and Epidemiologic Approaches

The interrelation ships of dietary fat and energy, growth rates and anthropometry, and breast carcinogenesis have been examined by a diverse array of approaches throughout the last 50 y as new investigative tools have been developed by laboratory scientists and epidemiologists. A consensus among investigators has not emerged, however, and dietary recommendations for breast cancer prevention have not been clearly formulated or effectively communicated to the public. Indeed, the gap between those investigators utilizing laboratory-based approaches and those using epidemiologic models has expanded in recent years. Cancer epidemiologists have become increasingly skeptical that results derived form laboratory animal models of breast carcinogenesis and in vitro systems are directly applicable to human breast cancer risk. Concurrently, laboratory scientists have questioned the ability of epidemiological tools to accurately measure dietary intake and relevant biomarkers and to account for a diverse array of potentially confounding environmental and genetic factors characteristic of human populations under study. These polarized views are reinforced by a failure of investigators using diverse approaches to interact, integrate their skills and resources, develop novel hypotheses, and propose solutions using both laboratory and epidemiologic techniques. Therefore, the objectives of this symposium are to summarize experimental and epidemiologic knowledge, foster communication and collaboration, and attempt to identify appropriate studies to bridge the gaps in our knowledge concerning dietary lipid and energy, anthropometrics, and breast cancer risk.
Age-dependent electroencephalogram (EEG) patterns during sevoflurane general anesthesia in infants

Every year about 200,000 infants in the United States are given general anesthesia during their first year of life. Though anesthesia is essential to control pain during surgery and other medical procedures on infants, it involves some risks. There are some controversial studies suggesting that repeated anesthetics early in life may impact how the brain develops, but other studies have been reassuring and found no such effects. To reduce the risks, doctors carefully monitor infants' blood pressure, heart rate, body temperature, and oxygen levels while they are receiving anesthesia. Electroencephalograms (EEGs) have proven to be a useful tool for monitoring the brain activity of adults undergoing anesthesia, but studies have found EEG-based monitoring to be unreliable in infants under anesthesia. A more reliable method of monitoring the brains of infants during anesthesia is needed. Anesthesiologists nevertheless need to better understand how the infant's brain works under general anesthesia, and novel EEG techniques hold promise for monitoring brain well-being and for adjusting anesthetic dosing in infants of different ages. Differences in the way infants' brains respond to anesthesia may explain why current EEG-based monitoring methods developed for adults don't work as well in infants as in adults. Now, Cornelissen, Kim et al. have used a new EEG-based approach to demonstrate that as infants' brains develop, their responses to anesthesia change. The experiments involved 36 infants aged up to six months old who were going through routine surgical procedures. The brain activity of the infants was recorded using EEG—via electrodes placed on their scalps—when they were awake, during anesthesia, and as they recovered afterwards. The infants were videoed at the same time. Comparing the video with the EEG recordings allowed the brain activity of the infants to be matched up with their state of consciousness. Cornelissen, Kim et al. detected slow waves of brain activity across the entire scalp of infants who are under six months old and under anesthesia. Infants who are older than about four months old also display some faster brain waves, which decreased in power as the infants emerged from anesthesia. However, none of the infants has the same pattern seen in adults—where faster waves appear near the front of the brain. These findings may help scientists develop more reliable ways to monitor infants' brains during anesthesia.
Alignment of multi-segmented anatomical features from radiation therapy images by using least square fitting.

A least square fitting algorithm for alignment of multi‐open‐curved segments and point pairs of anatomical features obtained from both portal images and simulation radiographs has been developed for patient position verification in radiation therapy. A coordinate system associated with each curved segment pair is constructed so that the discrepancies of each segment pair can be obtained easily. The algorithm allows users to select not only multiple curve pairs but also individual point pairs on the important anatomic landmarks. The misregistration is measured by the sum of the position deviation of individual point pairs and ordinate discrepancies of all segment pairs from their corresponding coordinate systems. A mathematical minimization method is applied to seek an optimal transformation for matching of all segment and/or point pairs involved. The reliability of the algorithm has been tested with both phantom and clinical images. The test results indicate that the typical errors are less than 1 mm and 1° in translation and rotation, respectively.
Cyclized Substituted Thioureas III: l-Substituted-tetrazolines-5-thiones

A convenient synthesis and purification of some 1-substituted-tetrazoline-5-thiones is accomplished. Decreased per cent yields with increased chain length lends some credence to the probability that steric hindrance occurs in the ring closing step. The infrared studies show identifying bands for —N = C = S, C = S, cyclic —N—N = N—, and the tetrazole ring. Low toxicity for these compounds is indicated.
Electrogenic properties of acetylcholine.

FOLLOWING the classical work of Dale on acetylcholine, numerous investigators have demonstrated the important part played by this quaternary amine in the nervous system1. A neglected property of acetylcholine is its extraordinary electrogenic action at the phase boundary between oils and aqueous solutions2. This negative phase boundary potential provides a possible explanation of the electrical component of the nerve impulse in cholinergic nerves3. It seems reasonable to suppose that the action potential4 might arise from the contact of acetylcholine with the lipoid layer of the nerve fibre according to the theory of phase-boundary potentials5. Moreover, it has been shown that acetylcholine produces a negative electrical potential on living frog skin6.
A General covariant jump condition across a bubble wall and the QCD phase transition

Abstract Covariant jump conditions across a bubble wall, including surface tension and dissipation, for a nongravitational moving surface have been derived. Special situations, such as those associated with a domain wall, a dust shell, and a spherical boundary, are discussed. In particular, the cosmological QCD phase transition has been examined as a specific application of the general formalism. The possible mechanism of energy transport during the phase transition is studied, and a critical condition for neutrino conduction to dominate over the hydrodynamic flow has been obtained.
Dairy Herd Improvement Associations

Abstract A 75-yr history of the development of Dairy Herd Improvement Associations in the United States includes early cow testing efforts, involvement of the American Dairy Science Association, and activities of Cooperative Extension Service and United States Department of Agriculture personnel. Changes in organizational structure, improvement in methods and equipment, and expanding uses of data are documented. Enrollment and production improvement data are summarized.
How “Proficient” Is Proficient? Subjective Proficiency as a Predictor of Bilingual Listeners’ Recognition of English Words

Purpose English proficiency must be considered when a bilingual individual is to be evaluated clinically with English speech material. This study describes the minimum level of self-reported Englis...
Determination of anisotropy fields in particulate recording media by Mossbauer spectroscopy

Anisotropy fields in some randomly oriented uniaxial magnetic recording materials were determined by magnetometry and the Mossbauer effect. The Mossbauer determination used the polarization parameter. Calculated values of polarization were obtained using the Stoner-Wohlfarth theory. Agreement between the two techniques was good for simpler particles. It was found that resolved Mossbauer subspectra can be used for the determination of separate site anisotropy energies if exchange coupling is sufficiently weak. >
Using knowledge to drive improvements

Offers a case study describing how the Fossil and Hydro Power (F&HP) Organization of the Tennessee Valley Authority ‐ a finalist for the 1995 Presidential Award for Quality ‐ has taken information from feedback reports and other sources, and developed a strategy for implementing areas of opportunity into its core business. The strategy expands the plan‐do‐check‐act logic into a plan‐do‐knowledge‐act model which couples assessment information with theory ‐ in the form of the conceptual guidelines of the Baldrige criteria ‐ to create knowledge. Details how the model has been implemented at F&HP over the past three years, and describes the resulting accomplishments.
Restriction enzyme banding of mouse metaphase chromosomes.

Fixed metaphase chromosomes from mouse strain RIII embryos or A9 cells were treated with a restriction endonuclease, followed by Giemsa staining. Aha I, Hinf I, or Mbo I treatment produced a C-band pattern, and Eco RII or Hae III produced a G-band plus C-band pattern. Ava II and Bst NI each produced a G-band pattern, but on most chromosomes only a small segment of each C-band, adjacent to the centromere, was stained. These tiny residual C-bands may contain a minor satellite located adjacent to the major satellite clusters.
Guiding navigation in colonoscopy

Nonrigid environments such as the human colon present unique challenges for the navigator in maintaining spatial orientation. Conventional wisdom suggests that a navigational aid, similar to a map, that provides critical shape information would be useful. This article presents a design concept for a colonoscopy navigational aid and the results of an experiment conducted to evaluate the display for supporting navigation and spatial orientation in simulated colonoscopy. A navigational aid was designed to present shape information in an augmented reality display. A total of 14 untrained subjects performed a colonoscopy procedure in rigid and nonrigid colon models, with and without the navigational aid display, in a Latin square design. Performance measures such as time, distance or efficiency of travel, and location and direction error were recorded, together with subjective measures of confidence and workload. The results showed that, unlike navigating in rigid environments, the subjects spent more time navigating in the nonrigid environment (p < 0.01) and traveled a longer total distance (p = 0.01). The navigational aid had no effect on performance, as compared with the no aid condition. However, subjective measures showed that the subjects were more confident about their determination of location and direction (p < 0.01). They also preferred having the aid during navigation. A navigational aid or map that provides shape information does not seem to improve performance in colonoscopy. In fact, it may lead to a false sense of security about location and orientation in the colon. The value of a map for training purposes remains to be examined.
A single spiral artefact in Arthropod cuticle

Spirals are often seen in sections transverse to the axes of bumped structures in arthropod cuticle. (Sections through arthropod cornea or exocones yield excellent examples.) As arthropod cuticle has a helicoidal architecture (Bouligand, 1965), it might be expected that the spirals are a simple consequence of that structure. According to a symmetry argument, the spirals thus predicted must be double spirals. In contrast, the observed spirals are usually single. We propose that the single spirals result from an interaction between the microtome knife and the cuticle architecture. The direction of knife travel defines an orientation within the cuticle, subverting the symmetry arguments that require double spirals. Bouligand (1972) presented a model for the interaction of the knife with the cuticle. However, we offer arguments and observations show that Bouligand's model is incorrect. We argue from detailed observations of the single spiral that it is indeed a knifing artifact and that its explanation probably lies within a certain class of models. Two related models based on relative movements of cuticle components are examined via computer techniques.