cssi/SciSciGPT-SciSciNet huggingface dataset:
Ablative Therapies in Barrett’s Esophagus

Barrett’s esophagus (BE) is a condition in which the stratified squamous epithelium that normally lines the distal esophagus lumen is replaced by metaplastic columnar epithelium that has both gastric and intestinal features. It is usually caused by persistent damage to the esophageal mucosa due to long-standing gastroesophageal reflux disease (GERD) and predisposes patients to esophageal adenocarcinoma (EAC), a cancer with a significantly increasing incidence over the past 40 years. While there are several risk factors for EAC, including smoking and obesity, GERD is the most significant one. Patients with BE have an estimated 30–125-fold greater chance of developing EAC compared to the general population.
Validated Models to Estimate Probability of Dialysis After Nephrectomy and Partial Nephrectomy.

This cross-sectional study aims to develop validated models to estimate the probability of dialysis after nephrectomy and partial nephrectomy.
Eye Morphogenesis and Patterning of the Optic Vesicle

Organogenesis of the eye is a multistep process that starts with the formation of optic vesicles followed by invagination of the distal domain of the vesicles and the overlying lens placode resulting in morphogenesis of the optic cup. The late optic vesicle becomes patterned into distinct ocular tissues: the neural retina, retinal pigment epithelium (RPE), and optic stalk. Multiple congenital eye disorders, including anophthalmia or microphthalmia, aniridia, coloboma, and retinal dysplasia, stem from disruptions in embryonic eye development. Thus, it is critical to understand the mechanisms that lead to initial specification and differentiation of ocular tissues. An accumulating number of studies demonstrate that a complex interplay between inductive signals provided by tissue-tissue interactions and cell-intrinsic factors is critical to ensuring proper specification of ocular tissues as well as maintenance of RPE cell fate. While several of the extrinsic and intrinsic determinants have been identified, we are just at the beginning in understanding how these signals are integrated. In addition, we know very little about the actual output of these interactions. In this chapter, we provide an update of the mechanisms controlling the early steps of eye development in vertebrates, with emphasis on optic vesicle evagination, specification of neural retina and RPE at the optic vesicle stage, the process of invagination during morphogenesis of the optic cup, and maintenance of the RPE cell fate.
U.S. ARMY PROCUREMENT OF DRAFT AND PACK ANIMALS IN THE CIVIL WAR ERA

The old adage attributed to Napoleon that an army marches on its belly reminds us of the importance of supplying an army in the field. Logistical supremacy cannot win a battle by itself, but adequate supply is necessary to the ultimate success of any military campaign. The North’s naval blockade of the South and its overwhelming dominance of rail transport proved decisive in the outcome of the Civil War. Soldiers must be fed, clothed, and provided weapons, and these supplies must be carried from dock or depot to camp. During the Civil War, mules and horses transported most of the supplies that provisioned the combatants. The economics of the army’s procurement of draft and pack animals is thus a crucial, though little studied, aspect of the Union’s victory. Kyle Kauffman’s 1996 article in this journal, “The U.S. Army as a Rational Economic Agent: The Choice of Draft Animals during the Civil War,” returns to a theme that he has developed in several publications: the role of agency in the choice between the mule and the draft horse [Kauffman 1992; 1993a; 1993b; 1996a; 1996b; 2000; Kauffman and Liebowitz, forthcoming; Galassi and Kauffman, undated]. He argues that the army chose the abuse-resistant mule instead of the horse—despite the mule’s higher price—where soldiers using the animals were not closely monitored by officers and thus were more likely to abuse the animals in their charge. He finds a statistically significant and positive correlation between the ratio of enlisted men to all soldiers (enlisted men plus officers) and the ratio of mules to all draft equines (mules plus horses) in 486 U.S. army installations between 1863 and 1866, and argues that this correlation corroborates his hypothesis that monitoring costs determined the choice of military draft animal. Kauffman describes two differences between horses and mules that are widely noted in the literature on equines. While the horse can be driven to the point of exhaustion or even death, the mule will stubbornly resist its handler’s demands when it becomes fatigued or overheated. Additionally, the horse can make itself sick by eating and drinking too much, but the more sensible mule generally will not. For both these reasons, inattentive or incompetent animal handlers can injure or kill a horse more easily than a mule. Kauffman concludes that a rational army procurement strategy would have selected mules rather than horses in situations where the animal handlers could not be carefully supervised. Conversely, units in which soldiers were better monitored (that is, units with a higher ratio of officers to soldiers) would have preferred horses since they were everywhere about 10 percent cheaper than mules
On the birth and growth of cities

Abstract In a growing laissez-faire economy, the optimal time when the large cities should be decentralized into new settlements is missed because such timing requires collective migration to the same place by many self-interested agents. New cities are born at stochastically determined times when existing cities are larger than their optimal sizes and unstable. With negligible migration costs, such city births are associated with panic-migrations and related economic shocks. Thus, laissez-faire city systems develop in cycles of booms and busts. The planned timing of settlements smooths these cycles by rounding the tops and raising the troughs in the per capita utility profile over time.Efficient growth requires alternating cycles of laissez-faire and planning. Planning establishes each new city at the optimal time and nurses it through an initial period of instability. As the economy grows large, the duration of the necessary planning periods vanishes asymptotically. In a declining laissez-faire economy, cities are abandoned at deterministic times and at smaller sizes than the sizes at which they would be born during growth. The decline path cannot be obtained by reversing the growth path, and a hysteresis effect is present.
Creativity Revisited: Narration and Embodiment in African Art

After half a century at the forefront of scholarship, the topic of artistic creativity in sub-Saharan Africa has lost much of its glamour. In light of her apprenticeship to a basket maker in northwest Zambia the author revisits the work of several scholars who have written on the topic, arguing that visualism and logocentrism are ultimately detrimental to the understanding of the creative process. Creativity, she argues, blossoms in art making when the artist’s mind and skillful body coalesce in engagement with materials. Consequently, a theoretical and methodological reorientation to the study of creativity is in order, one in which, together with observation and interviewing, the experiential methodology of apprenticeship is uniquely promising.
The large‐scale frozen‐in anticyclone in the 2011 Arctic summer stratosphere

[1] The 2011 Arctic stratospheric final warming was characterized by a large-scale frozen-in anticyclone (FrIAC) that rapidly displaced the winter polar vortex, establishing unusually strong polar easterlies. A comprehensive overview of the 2011 FrIAC is provided using meteorological analyses, Microwave Limb Sounder (MLS) N2O observations, and N2O simulations from the Global Modeling Initiative (GMI) 3-D chemistry and transport model and the Van Leer Icosahedral Triangular Advection (VITA) 2-D (latitude × longitude) isentropic transport model. A vortex edge diagnostic is used to determine the FrIAC boundary, allowing quantification of several FrIAC properties. The 2011 FrIAC originated over North Africa in late March and traveled eastward and poleward over 2 weeks, forming a strong anticyclone that extended from ~580–2100 K potential temperature (~25–50 km). Low potential vorticity (PV) was transported to the pole with the FrIAC in early April; during May, most of the PV signature decayed due to diabatic processes. A small remnant negative PV anomaly persisted near the pole until mid-June. Tracer equivalent latitude was low initially and remained low throughout the summer. GMI, VITA, and MLS showed elevated N2O in the FrIAC, although the peak value was smaller in GMI due to a subtropical low bias. The high-resolution (~20 km) VITA filamentary structure quantitatively matched most of the features observed by MLS when smoothed to match the MLS resolution. The high-N2O anomaly persisted in the middle stratosphere over 4 months until late August, when it was destroyed by horizontal and vertical shearing, combined with photochemical processes.
The problem of postoperative recurrence of Crohn's disease.

The single most frustrating problem in the management of Crohn’s disease is the stubborn incurability of the condition. Nobody expects medical therapy to effect a permanent cure of Crohn’s disease, but even among the 70% of all patients who ultimately come to surgery, the overwhelming majority will ultimately experience a recurrence of their disease. For those whose original disease was ileitis, recurrent disease almost invariably appears just proximal to the ileocolonic anastomosis; for those with initial colitis or ileocolitis, recurrence develops on either or both sides of the anastomosis (15). Although this tendency to postoperative recurrence has been recognized for more than half a century since the early description of the disease by Crohn, Ginzburg, and Oppenheimer (3), confusion and controversy persist regarding the frequencies and risk factors for this unwelcome phenomenon (9,12,26,29).
FREEDOM AND RESPONSIBILITY IN THE MYTH OF ER

Plato uses the myth of Er in the Republic in order to carve out space for political freedom and responsibility for human freedom in the ordinary polis. While much of the Republic concentrates on the development of an ideal city in speech, that city is fundamentally a mythos presented in order for Socrates and his friends to learn something about political and individual virtue. The city in which Socrates and his friends exist is an imperfect city and myth of Er is intended for those audience members. Its emphasis on the necessity for personal responsibility in the midst of freedom can be understood as a political claim about the place of individual choice in a world that is constrained by both political and cosmic “necessity”.
Individualism, Family Values, and the Professional Middle Class: In-Depth Interviews with Advanced Law and MBA Students

This study examines in-depth interview data on how advanced law and MBA students defined long-term meaning in life in the context of their life plans for work, family, leisure, and community. Findi...
Teaching and Learning Guide for: Substantivalism vs Relationalism about Space in Classical Physics

This article is about the nature of space, focusing on the question of whether it exists independently of matter and related questions about its geometric structure. One fascinating aspect of this debate is how it straddles the border between empirical science and philosophy. Since at least the time of Newton, it has been thought that various physical phenomena demonstrate some conclusion about the nature of space, but as I try to emphasize, the arguments are invariably suffused with philosophical presuppositions. This article examines these arguments in the context of classical physics. The article is designed to be used in a range of teaching settings. In an intro-level class, one could use just sections 1–3. They introduce the debate as it played out betweenNewton and Leibniz, and should be accessible to students with little or no previous exposure to the topic or to philosophy. In an upper-level undergraduate class, one could add sections 4–6, which describe how the debate has developed in the contemporary era. And in a research seminar, one could then add sections 7–9, which offer a critical analysis of the contemporary debate.
PICK-UP IONS IN THE OUTER HELIOSHEATH: A POSSIBLE MECHANISM FOR THE INTERSTELLAR BOUNDARY EXplorer RIBBON

First data from NASA's Interstellar Boundary EXplorer (IBEX) mission show a striking ribbon feature of enhanced energetic neutral atom (ENA) emission. The enhancement in flux is between 2 and 3 times greater than adjacent regions of the sky. Yet the spectral index of ENAs appears to be the same both inside and outside the ribbon. While the ribbon itself was not predicted by any models of the heliospheric interface, its geometry appears to be related to the predicted interstellar magnetic field (ISMF) outside the heliopause (HP). In this Letter, we examine a process of ENA emission from the outer heliosheath, based on a source population of non-isotropic pick-up ions that themselves originate as ENAs from inside the HP. We find that our simplistic approach yields a ribbon of enhanced ENA fluxes as viewed from the inner heliosphere with a spatial location and ENA flux similar to the IBEX measurements, with the provision that the ions retain a partial shell distribution long enough for the ions to be neutralized. As a corollary, our idealized simulation of this mechanism suggests that ISMF is likely oriented close to the center of the observed ribbon.
Involvement of the pontine reticular formation in head movements and labyrinthine righting in the rat.

Abstract Compensatory head movements as responses to passive angular acceleration are obvious in lower vertebrates, but they are usually small and difficult to observe in mammals. The may simply be cut short very early by an inhibitory mechanism linked to the initiation of anticompensatory head movements (quick phases of head nystagmus). After electrolytic lesions of the pontine reticular formation (PRF), rats made no spontaneous lateral head movements, but exhibited large compensatory lateral head movements and abnormal postrotatory circus movements, both of which can be regarded as consequences of a loss of the quick phase of head nystagmus. The quick phase of ocular nystagmus was also lost, corroborating earlier findings of others in primates, cats, and rabbits, and supporting the view that saccadic movements of the head and eyes are generated by closely related neural substrates. Rats with bilateral PRF lesions were unable to right themselves in the air. Together with additional observations, this indicates involvement of the PRF in some functions of the otolith organ.
Waterproof cockroaches: the early work of J. A. Ramsay.

![Graphic][1] Allen Gibbs writes about J. Arthur Ramsay's 1935 classic paper on insect water balance entitled `The evaporation of water from the cockroach'. A copy of the paper can be obtained at The relatively small size of insects, and
A time-series forecast of average daily traffic volume

Abstract This paper presents a procedure for forecasting average daily traffic using a time-series analysis. The procedure assumes a logistic function to model traffic volume over a period of years. Model parameters are estimated using ordinary least-squares regression. The method was tested empirically. Model parameters were found to be significant for each of the three different thoroughfares. Further, time-series forecasts compared favorably to observed traffic and to interpolated forecasts for the same period. The method is simpler to and more economical than the standard demand forecasting procedure and is recommended where land-use patterns are stable and only small modifications to the thoroughfare network are planned.
Commentary to 'Long-term fate of the bladder after isolated bladder neck procedure'.

sphincter in children and young adults. J Urol 2003;169: 650e4. [11] Hidas G, Ortiz-Vanderdys G, Braga LH, Khoury AE. Are bladder and renal function at risk after a procedure to increase bladder outlet resistance? A systematic review and metaanalysis. In: European Society for Pediatric Urology meeting; 2013. Genoa, Italy. [12] Kryger JV, Gonzalez R, Barthold JS. Surgical management of urinary incontinence in children with neurogenic sphincteric incompetence. J Urol 2000;163:256e63.
Efficient venture capital financing combining debt and equity

I present a model of venture capital contracting in which contracts that involve a mixture of both debt and equity are efficient and dominate pure-equity and pure-debt financing. The optimal contract balances the venture capitalist's incentive to intervene in the project and the entrepreneur's desire for control.
TEACHING SCIENCE AND TECHNOLOGY PRINCIPLES TO NON-TECHNOLOGISTS — LESSONS LEARNED

ABSTRACT Much has been written over the past several decades on the “inevitability” that the technological revolution will transform international, interpersonal, and business relations. But are the effects of technological change as far reaching as the literature suggests and where it does reach does it penetrate very deeply into the general culture, its organizations, or into the psyche of its citizens? The linkage of science and technology education to industrial trends, and its prominence in pubic policy debates makes it all the more important to ensure that the educated public have as complete a grounding in S&T issues as possible. Perhaps it is a unique twenty-first century paradox that it is more important for “progress” and public policy formulation to focus the attention of our educational system upon the inter-relationships, consequences, and implications of current and previous technological developments rather than mindlessly joining the “bandwagon of progress.” Students must be exposed to the...
Authorship and publication practices in the social sciences: historical reflections on current practices.

An historical review of authorship definitions and publication practices that are embedded in directions to authors and in the codes of ethics in the fields of psychology, sociology, and education illuminates reasonable agreement and consistency across the fields with regard to (a) originality of the work submitted, (b) data sharing, (c) human participants’ protection, and (d) conflict of interest disclosure. However, the role of the professional association in addressing violations of research or publication practices varies among these fields. Psychology and sociology provide active oversight with sanction authority. In education, the association assumes a more limited role: to develop and communicate standards to evoke voluntary compliance. With respect to authorship credit, each association’s standards focus on criteria for inclusion as an author, other than on the author’s ability to defend and willingness to take responsibility for the entire work. Discussions across a broad range of research disciplines beyond the social sciences would likely be beneficial. Whether improved standards will reduce either misattribution or perceptions of inappropriate attribution of credit within social science disciplines will likely depend on how well authorship issues are addressed in responsible conduct of research education (RCR), in research practice, and in each association’s ongoing efforts to influence normative practice by specifying and clarifying best practices.
Spontaneous reactions of xenon, flourine and antimony pentaflouride

Abstract Mixtures of xenon and fluorine gases react spontaneously with liquid antimony pentafluoride in the dark to form solutions of XeF+Sb2F−11. Dixenon cation, Xe+2, is formed as a labile intermediate product and is oxidized by the fluorine to XeF+ cation. The rate of the overall reaction is proportional to the partial pressure of xenon and the partial pressure of fluorine. This direct combination of reagents provides a simple method for the preparation of XeF+Sb2F−11.
Phosphate and mannose transfer from guanosine diphosphate mannose to yeast mannan acceptors

Abstract A particulate enzyme isolated from Hansenula holstii catalyzes the transfer of 14C-mannose from guanosine diphosphate 14C-mannose and of 32P-phosphate from β-32P-guanosine diphosphate mannose to endogenous acceptor molecules. The 32P-product is solubilized with Tris buffer, excluded from Sephadex G-50 and precipitated with Fehling's reagent.32P-Mannose 6-phosphate is recovered from acid hydrolyzates. Mild acid hydrolysis liberates newly incorporated mannose residues and allows the 32P-phosphate to be released as inorganic phosphate by phoshomonoesterase. The synthesis of a 1, 6′-phosphodiester linkage between 2 mannose residues is proposed.
Time-Dependent Pressure and Flow Behavior of a Self-oscillating Laryngeal Model With Ventricular Folds.

Summary Objective The purpose of the study was to better understand the pressure-flow behavior of a self-oscillating vocal fold model at various stages of the glottal cycle. Methods An established self-oscillating vocal fold model was extended to include the false vocal folds (FVFs) and was used to study time-dependent pressure and velocity distributions through the larynx (including the true vocal folds [TVFs] and FVFs). Vocal fold vibration was modeled with a finite element method, laryngeal flow was simulated with the solution of unsteady Navier-Stokes equations, and the acoustics of the vocal tract was modeled with a wave reflection method. Results The results demonstrate realistic phonatory behaviors and therefore may be considered as a pedagogical tool for showing detailed aerodynamic, kinematic, and acoustic characteristics. The TVFs self-oscillated regularly with reasonable amplitude and mucosal waves. There were large pressure gradients in the glottal region. The centerline velocity was highest during glottal closing and sharply dropped near the center of the flow vortex. The average centerline velocity was about 25 m/second in the glottal region. The transglottal pressure was higher during glottal closing when the glottal shape was divergent and pressure recovery was present within the glottis. The centerline velocity increased as expected throughout the convergent glottis, tended to decrease throughout the divergent glottis, and decreased past the TVFs within the ventricle-FVF region. Conclusions This model produces realistic results and demonstrates interactions among phonation variables of a highly instructive nature, including the influence of the FVFs.
Early postnatal weight gain, intellectual performance, and body mass index at 7 years of age in term infants with intrauterine growth restriction.

Objective To determine whether the postnatal growth rate of infants with intrauterine growth restriction (IUGR) is associated with later cognitive function and body mass index (BMI). Study design Infants with IUGR ( Results Weight gain at 16 postnatal weeks ranged from 1059 to 5119 g in the infants with IUGR, with lower achieved cognitive testing scores apparent at both extremes (ie, an inverted J-shape; P P Conclusions Growth in the first 4 postnatal months is an independent risk factor for cognitive outcome at age 7 years, with both extremes associated with negative effects.
Epizootic and Enzootic Aspects of Minchinia nelsoni (Haplosporida) Disease in Maryland Oysters

SYNOPSIS. Minchinia nelsoni disease in oysters (Crassostrea virginica) from Marumsco Bar, Pocomoke Sound, Maryland (an estuarine tributary of Chesapeake Bay) was studied for 8 years (1961–68) to determine epizootiologic relationships concerning life cycle of the parasite, pathologic effects on the host, and effects of physical factors on population density and recruitment of the host and parasite. The study period covered pre-epizootic, epizootic, and post-epizootic disease conditions. Data on the native oyster population as well as annual introductions of previously unexposed, susceptible populations of juvenile oysters from 1965–68 were included. Salinity, water temperature, mortality, prevalence, incidence, life cycle stages, gross pathology, and histopathologic relationships were observed. Mortality was high (45–55% per year) during the first 3 years of the study; however, M. nelsoni prevalences were low (> 25%) and did not clearly imply a cause and effect relationship. Drought conditions that began in the summer of 1963 and continued through 1967 caused higher salinities, and apparently initiated epizootic disease in the native oyster population. The epizootic peaked in May 1965 with a diagnosed prevalence in native oysters of 70%. Enzootic levels of annual mortality (40% in 1966, 30% in 1967, and 2% in 1968) and fall prevalence (16%, 24%, and 4%) developed after that time. Introduced populations had a typical epizootiologic pattern in 1965 (55% annual mortality, 82% incidence) and 1966 (55% annual mortality, 66% incidence) which declined in 1967 (30% annual mortality, 44% incidence) followed by a disappearance of the disease in 1968. Epizootiologic differences noted between native oysters (adult and juvenile) and the introduced juvenile populations were also evident from the stages of the disease. Infections in native animals tended to be less serious, and in many cases were delayed or attenuated, while infections in introduced oysters progressed to advanced or terminal phases. Occult manifestations (mantle recession thought to be due to M. nelsoni in oysters not showing histologic evidence of infection) were absent in introduced populations and common in the native population. These differences are interpreted as evidence of resistance in surviving native oysters and their progeny, and may indicate genetic resistance developed by natural selection and manifested by an increased ability to survive and overcome infection.
Ichthyoplankton samplers for simultaneous replicate samples at surface and bottom

Descriptions and illustrations of ichthyoplankton sampling gear which utilize onemeter diameter nets on square and rectangular frames and provide simultaneous surface and bottom samples are presented. Designed for use on boats as small as five meters in length, the gear was developed to provide quantitative and qualitative ichthyoplankton samples from shallow estuarine waters (1–12 m). Data are presented which indicate that filtration performance (in relation to clogging of 505 micron mesh nets), averaged 97% and 103% for the surface and bottom nets respectively. These high filtration rates were attributed to the design of the net frames which apparently act as mouth reducing cones. Catch data for several species from the side-by-side and separated rigs were analyzed with a nested model of analysis of variance. Neither the main effects nor their interactions showed any significant effects. We concluded, therefore, that there is no systematic error inherent in the design of the two samplers which precludes direct comparison of surface and bottom samples taken with them.
Role of ampa receptor endocytosis in synaptic plasticity

Activity-mediated changes in the strength of synaptic communication are important for the establishment of proper neuronal connections during development and for the experience-dependent modification of neural circuitry that is believed to underlie all forms of behavioural plasticity. Owing to the wide-ranging significance of synaptic plasticity, considerable efforts have been made to identify the mechanisms by which synaptic changes are triggered and expressed. New evidence indicates that one important expression mechanism of several long-lasting forms of synaptic plasticity might involve the physical transport of AMPA-type glutamate receptors in and out of the synaptic membrane. Here, we focus on the rapidly accumulating evidence that AMPA receptors undergo regulated endocytosis, which is important for long-term depression.
At-Speed Structural Test For High-Performance ASICs

At-speed test of integrated circuits is becoming critical to detect subtle delay defects. Existing structural at-speed test methods are inadequate because they are unable to supply sufficiently-varied functional clock sequences to test complex sequential logic. Moreover, they require tight restrictions on the circuit design. In this paper, we present a new method for at-speed structural test of ASICs, having no tight restrictions on the circuit design. In the present implementation, any complex at-speed functional clock waveform for 16 cycles can be applied. We present DFT structures that can generate high-speed launch-off-capture as well as launch-off-scan clocking without the need to switch a scan enable at-speed. We also describe a method to test asynchronous clock domains simultaneously. Experimental results on fault coverage and hardware measurements for three multi-million gate ASICs demonstrate the feasibility of the proposed approach.
OPTIMIZATION THROUGH EXPERIMENTATION: APPLYING RESPONSE SURFACE METHODOLOGY

The crucial steps in a quantitative analysis of a decision problem are problem formulation, model building, analysis, and implementation. Given an initial model specification, the goal of analysis is to determine the values of the controllable or decision variables that optimize the objective function. Frequently the initial model is inadequate and must be reformulated. While modeling is an evolutionary process involving art and science, under certain conditions Response Surface Methodology (RSM) is an effective vehicle for constructing and parameterizing optimization models. RSM, which draws upon the areas of experimental design, modeling, inference, and optimization, utilizes different opening and ending strategies. Through simultaneous and sequential experimentation, the approximate region of the model's maximum response is found by employing the steepest ascent method. Subsequently, the exact values of the controllable variables that maximize the model's response are determined by canonical analysis. The RSM concepts are first developed within the context of a manufacturing problem. A potential application to simulation studies is then presented.
Cloning and characterization of microsatellite loci in channel catfish, Ictalurus punctatus

Short tandem repeat (microsatellite) loci were cloned from the channel catfish, Ictalurus punctatus, genome for use as molecular markers for genetic improvement of this important agricultural species. Plasmid clones containing catfish genomic DNA inserts were identified, by hybridization with tandem repeat DNA probes, and sequenced using automated laser fluorescence. A feral population of catfish displayed levels of heterozygosity greater than 0.7 for 13 of 22 loci and heterozygosity greater than 0.5 for 20 of 22 loci. Allelic polymorphism ranged from three to 17 alleles per locus in the feral population. Populations of domestic, farm-raised catfish and a research strain displayed levels of heterozygosity similar to the feral population. Non-invasive tissue sampling provided abundant material for the polymerase chain reaction-based genotype assay. The microsatellite loci will be useful in the molecular characterization and genetic improvement of channel catfish populations.
From Serendipity to Therapy

My postdoctoral training in the biosynthesis of plant polysaccharides at the University of California, Berkeley, led me, rather improbably, to study mucopolysaccharide storage disorders in the intramural program of the National Institutes of Health (NIH). I have traced the path from studies of mucopolysaccharide turnover in cultured cells to the development of therapy for patients. The key experiment started as an accident, i.e., the mixing of cells of different genotypes, resulting in correction of their biochemical defect. This serendipitous experiment led to identification of the enzyme deficiencies in the Hurler and Hunter syndromes, to an understanding of the biochemistry of lysosomal enzymes in general, and to the cell biology of receptor-mediated endocytosis and targeting to lysosomes. It paved the way for the development of enzyme replacement therapy with recombinant enzymes. I have also included studies performed after I moved to the University of California, Los Angeles (UCLA), including a recen...
The cytoplasmic domain of the Drosophila cell adhesion molecule neuroglian is not essential for its homophilic adhesive properties in S2 cells.

Drosophila neuroglian is a transmembrane glycoprotein that has strong structural and sequence homology to the vertebrate L1 gene family of cell adhesion molecules (Bieber, A. J., Snow, P. M., Hortsch, M., Patel, N. H., Jacobs, J. R., Traquina, Z. R., Schilling, J., and Goodman, C. S.(1989) Cell 59, 447-460). Two different neuroglian protein forms that are generated by a differential splicing process are expressed in a tissue-specific fashion by embryonic and larval cells (Hortsch, M., Bieber, A. J., Patel, N. H., and Goodman, C. S. (1990) Neuron 4, 697-709). The two neuroglian polypeptides differ only in their cytoplasmic domains. Both of these neuroglian species, when transfected into and expressed in Drosophila S2 cells, induce the calcium-independent, homophilic aggregation of transformed cells. A third artificial neuroglian protein form was constructed by substituting the neuroglian transmembrane segment and cytoplasmic domains with the glycosyl phosphatidylinositol attachment signal of the Drosophila fasciclin I protein. This cDNA construct generates a glycosyl phosphatidylinositol-anchored form of neuroglian, which retains the ability to induce homophilic cell aggregation when expressed in S2 cells, and was able to interact with both of the two naturally occurring neuroglian polypeptides. These results demonstrate that neuroglian mediates a calcium-independent, homophilic cell adhesion activity and that neither cytoplasmic neuroglian domains nor a direct interaction with cytoskeletal elements is essential for this property.
Computed tomography with energy-resolved detection: a feasibility study.

The feasibility of computed tomography (CT) with energy-resolved x-ray detection has been investigated. A breast CT design with multi slit multi slice (MSMS) data acquisition was used for this study. The MSMS CT includes linear arrays of photon counting detectors separated by gaps. This CT configuration allows for efficient scatter rejection and 3D data acquisition. The energy-resolved CT images were simulated using a digital breast phantom and the design parameters of the proposed MSMS CT. The phantom had 14 cm diameter and 50/50 adipose/glandular composition, and included carcinoma, adipose, blood, iodine and CaCO3 as contrast elements. The x-ray technique was 90 kVp tube voltage with 660 mR skin exposure. Photon counting, charge (energy) integrating and photon energy weighting CT images were generated. The contrast-to-noise (CNR) improvement with photon energy weighting was quantified. The dual energy subtracted images of CaCO3 and iodine were generated using a single CT scan at a fixed x-ray tube voltage. The x-ray spectrum was electronically split into low- and high-energy parts by a photon counting detector. The CNR of the energy weighting CT images of carcinoma, blood, adipose, iodine, and CaCO3 was higher by a factor of 1.16, 1.20, 1.21, 1.36 and 1.35, respectively, as compared to CT with a conventional charge (energy) integrating detector. Photon energy weighting was applied to CT projections prior to dual energy subtraction and reconstruction. Photon energy weighting improved the CNR in dual energy subtracted CT images of CaCO3 and iodine by a factor of 1.35 and 1.33, respectively. The combination of CNR improvements due to scatter rejection and energy weighting was in the range of 1.71–2 depending on the type of the contrast element. The tilted angle CZT detector was considered as the detector of choice. Experiments were performed to test the effect of the tilting angle on the energy spectrum. Using the CZT detector with 20° tilting angle decreased the tailing of the measured x-ray spectrum as compared to a conventional CZT detector. It was concluded that the energy-resolved MSMS CT with tilted angle CZT detector is potentially feasible and could provide a unique combination of photon counting, energy weighting, scatter rejection and single kVp dual energy subtraction CT imaging.
Surrounded by quality metrics: what do surgeons think of ACS-NSQIP?

Background In an era of proliferating systems of quality assessment, surgeon confidence in metric tools is essential for successful initiatives in quality improvement. We evaluated surgeons' awareness and attitudes about ACS-NSQIP, which is the only national, surgeon-developed, risk-adjusted, system of surgical outcome assessment. Methods A 33-item survey instrument was constructed and content validity established through content expert review; test-retest reliability was assessed (weighted-kappa = 0.72). Survey administration occurred in three institutions with varying ACS-NSQIP experience. Summary statistics were generated and subgroup analyses performed (Fisher's exact test). Results One-hundred and eight surgeons participated. Practice experience varied (27% residents, 33% 20 years). Seventy-two percent had fellowship training. Surgeons were familiar with ACS-NSQIP structure, including prospective datacollection (70%), case-sampling (63%), and reporting as observed/expected ratios (83%). Surgeons knew some collected data-points but misidentified EKG-findings of MI (67%), surgeon case-experience (41%), and anastomotic dehiscence (79%). Most felt ACS-NSQIP would improve quality of care (79%) and identify areas for improvement (92%). Surgeons were less confident regarding utility at an individual level, with only 46% believing surgeon-specific outcomes should be reported. Few thought ACS-NSQIP data should be available publicly (45%), used for marketing (26%), or direct pay-for-performance (24%). Reservations were most pronounced among surgeons with institutional ACS-NSQIP experience. Conclusion While surgeons accept ACS-NSQIP at an institutional level, skepticism remains surrounding measurement of individual outcomes and public reporting. Surgeons at institutions with a longer duration of experience with ACS-NSQIP tended to be more cynical about potential data applications. Ongoing education and assessment of surgeons' perceptions of quality improvement initiatives is necessary to ensure surgeons remain engaged actively in determining how quality of care data is measured and utilized.
Crystal structure of 4,5-dinitronaphthalic anhydride

The structure of 4,5-dinitronaphthalic anhydride was determined in three dimensions. The molecule is not planar, the carbonyl oxygens being out of the plane of the naphthalene ring system by -0·29 and 0·26 A. Electronic and infrared spectra seem to indicate that this deviation is not peculiar to the crystalline state. The compound crystallizes in space groupP21/c with unit cell dimensions ofa = 8·096,b = 8·813,c = 15·11 A, and β = 92·47 °. The finalR index was 5·4%.
Retention of visually presented information in children’s spelling

One hundred and thirty-six 8-year-old children participated in two studies of their ability to spell familiar or nonsense words which they had seen or heard for 2–5 sec. A visual or auditory task was interpolated for 12–15 sec before spelling began. Spelling of meaningful words was most accurate when words were presented visually, except when the interpolated task was watching random letters of the alphabet. Nonsense spelling did not show a similar pattern. The theoretical implication of this difference is that, under certain conditions, visual word presentation provides more efficient pointers to long-term memory information than auditory presentation does. A model of the facilitation process is offered.
Bilateral thoraco-abdominal skin defects in the newborn

Abstract Two neonates with bilateral thoraco-abdominal skin defects had successful management by conservative means.
Selective changes in sensitivity to benzodiazepines, and not other positive GABAA modulators, in rats receiving flunitrazepam chronically

Tolerance and dependence can develop during chronic benzodiazepine treatment; however, cross tolerance and cross dependence to positive modulators acting at other sites on GABAA receptors might not occur. The current study evaluated changes in sensitivity to positive GABAA modulators during chronic treatment with the benzodiazepine flunitrazepam to determine whether cross tolerance and cross dependence varied as a function of site of action. Eight rats responded under a fixed ratio 20 schedule of food presentation. Dose–effect curves were determined before, during and after chronic treatment with one or two daily injections of 1 mg/kg of flunitrazepam. Prior to chronic treatment, benzodiazepines (flunitrazepam, midazolam), a barbiturate (pentobarbital), a neuroactive steroid (pregnanolone), and drugs with primary mechanisms of action at receptors other than GABAA receptors (morphine, ketamine) dose-dependently decreased responding. Twice daily treatment with flunitrazepam produced 9.5- and 23-fold shifts to the right in the flunitrazepam and midazolam dose–effect curves, respectively. In contrast, dose–effect curves for other drugs either were not changed or were shifted less than or equal to fourfold to the right. Decreased sensitivity to benzodiazepines and not to a barbiturate or a neuroactive steroid during chronic flunitrazepam treatment indicates that tolerance and cross tolerance developed only to benzodiazepines. Despite similar acute behavioral effects among positive GABAA modulators, the differential development of cross tolerance suggests that adaptations at GABAA receptors produced by chronic benzodiazepine treatment differentially affect positive modulators depending on their site of action; such differences might be exploited to benefit patients treated daily with positive GABAA modulators.
Endovascular treatment of basilar tip aneurysms using Guglielmi detachable coils: anatomic and clinical outcomes in 73 patients from a single institution.

Objective Seventy-three consecutive patients with 75 basilar tip aneurysms were treated with Guglielmi detachable coil (GDC) technology. Their anatomic and clinical outcomes are discussed. Methods Seventy-five basilar tip aneurysms were treated with the GDC system at the University of California, Los Angeles Medical Center from 1990 to 1999. The average age of the population was 48.3 years (range, 28-82 yr). Forty-two patients (57.5%) presented with acute subarachnoid hemorrhage, 8 patients (10.9%) had unruptured aneurysms with mass effect, and 23 patients (31.5%) had incidental aneurysms. Thirty-one aneurysms (41.3%) were small with a small neck, 18 (24%) were small with a wide neck, 16 (21.3%) were large, and 10 (13.3%) were giant aneurysms. Results Immediate anatomic outcomes demonstrated complete or near-complete occlusion in 64 aneurysms (85.3%) and incomplete occlusion in 7 aneurysms (9.3%). Four aneurysms (5.3%) could not be embolized because of anatomic difficulties. Of the 69 patients treated with GDCs, 63 patients (91.3%) remained neurologically intact or unchanged from their initial clinical status. Procedure-related morbidity and mortality were 4.1% and 1.4%, respectively. Long-term follow-up angiograms were obtained in 41 patients with 42 aneurysms. Thirty aneurysms (71.4%) demonstrated complete or near-complete occlusion. One incompletely embolized giant aneurysm ruptured during the follow-up period. Conclusion In contrast to surgical clipping of basilar tip aneurysms, the main technical challenge of the Guglielmi detachable coiling procedure depends on the shape of the aneurysm, not its location. The results of this study indicate that endovascular GDC technology is an appropriate therapeutic alternative in ruptured or unruptured basilar tip aneurysms regardless of patient age, clinical presentation, clinical status, or timing of treatment.
Analysis of a PWR vessel rupture using computer programs RELAP-3 and RELAP- 4

Although the probability of a PWR vessel rupture is extremely small, it is important to be aware of the consequences of this unlikely event. Thus, Doan, Lanning and Rasmussen carried out a sensitivity study of a vessel rupture for the Indian Point-2 reactor by using the computer program RELAP-3 and WHAM. Since RELAP-3 has been superseded by the computer program RELAP-4, and since Doan et al. had observed several anomalous results with RELAP-3, the present study has been devoted to an analysis of the consequences of a vessel rupture with the computer program RELAP-4. Specifically, an attempt has been made to determine if RELAP-4 provides results that are more conservative (safer) than those reported by Doan et al. and if the anomalies obtained by the use of RELAP-3 are adequately removed. The present study has been based on a fourteen volume, sixteen junction system representing the Indian Point-2 reactor. Several hypothetical accident situations including bottom breaks, side breaks, top breaks of different sizes in the pressure vessel have been studied. Both the RELAP-3 and the RELAP-4 programs have been used to evaluate the same accident situations and a comparison of the results is presented. Detailed sensitivity studies have been carried out by using different values of gap thermal conductivity, break opening times, break sizes, location of breaks, cavitation coefficients, etc. Since RELAP-4 permits the use of several different finite differencing schemes and compressible or incompressible flow options, the effects of the use of these options on the results has also been examined. Based on the present results, it is concluded that generally RELAP-4 gives more conservative results than those obtained with RELAP-3 and that several of the anomalies observed with the use of RELAP-3 are effectively removed.
A discipline-specific determination of high quality nursing care.

A discipline-specific determination of high quality nursing care Aim. The purpose of this study is to establish a framework for defining quality of care based in nursing's unique body of knowledge through identification of nursing actions associated with high quality care. Rationale. Nurses are legally liable and morally responsible for the quality of the care they provide to patients. Yet the meaning of `high quality nursing care' remains ambiguous mainly because models used to define it are borrowed from other disciplines. Design. Two frameworks, quality and nursing knowledge, guided the selection and review of this literature review. The third framework of learning domains, an educational theory, assisted in organizing the data gathered from the literature. Findings. Attributes of high quality nursing care as perceived by both patients and nurses are described. Despite a professed philosophy of holism and humanism, nursing relies heavily on the industrially derived structure-process-outcome model with current emphasis on outcomes. Conclusions. Patient outcomes are the product of the service nurses deliver and are appropriate as defining criteria only when care is being evaluated from the patient's perspective. Defining quality from the nursing profession's frame of reference focuses on evaluating the services provided; that is, nursing actions and behaviours, linked to the use of nursing knowledge. High quality nursing equates with competence in the cognitive, affective, and psychomotor domains.
Recent advancements in high intensity heavy negative ion sources based on the sputter principle

Abstract Significant advancements have been recently made in the technology of forming high intensity heavy negative ion beams. Due to their ease of operation, simplicity, long lifetime, and wide range of species capabilities, negative ion sources predicated on the sputter principle are being used for an increasing number of diverse applications, including standard tandem accelerator-based research, high-energy ion implantation, tandem accelerator mass spectrometry, and low-energy atomic physics research. Sources have been developed which utilize either (1) direct surface ionization, or (2) a plasma to form the positive ion beam used to effect sputtering of samples containing the material of interest. This article will include a brief review of the fundamental processes underlying negative ion formation in these source. Emphasis will be placed on the descriptions and performance characteristics of specific sources based on each of the positive ion formation techniques.