cssi/SciSciGPT-SciSciNet huggingface dataset:
Differential induction of DNA strand breaks by nitrosamines in the rat liver and esophagus.

Abstract Hepatic and esophageal nuclei were isolated from Sprague-Dawley rats treated with 5 mg/kg dimethylnitrosamine (DMN), 100 mg/kg diethylnitrosamine (DEN) and 2.5 mg and 10 mg/kg methylbenzylnitrosamine (MBN) and subjected to alkaline elution to determine DNA strand breaks and their subsequent repair. Results obtained showed that hepatic nuclei isolated from rats 4 h after treatment by either DMN or DEN had about 60% of the DNA eluting through the filter. However, at 12 h post treatment, while about 50% of the single-strand breaks in dimethylnitrosamine treated rats were repaired, only about 10–15% of such breaks induced by DEN were repaired in the liver. That DEN is a more effective inducer of hepatic preneoplastic lesions could thus be attributed to this slow repair of the DEN induced lesions. Strand breaks were neither induced by DMN in the esophagus nor by MBN in the liver, the nontarget tissues. More surprising, however, was the finding that MBN induced little or no single-strand breaks in its target tissue, the esophagus. Furthermore, there was no evidence for DNA-protein cross-linking or alkali labile sites in the esophageal DNA. The results indicate that DNA damage induced by the initiating carcinogen in the target tissue may not necessarily involve strand breaks.
Adaptive control of flexible joint robots using position and velocity feedback

An adaptive control law is described for a flexible joint robot which utilizes position and velocity feedback of the actuator and the joint. Energy motivated Lyapunov functions are used to derive the control law. Extensive simulations are given to show the effectiveness of this control law when applied to flexible joint robots with extremely compliant joints
High Resolution and High Order Schemes for Two-Fluid Plasma Equation

Summary form only given. Two algorithms for the simulation of an ideal two-fluid plasma are presented. The two-fluid model is more general than the often used magnetohydrodynamic (MHD) model. The model takes into account electron inertia effects, charge separation and the full electromagnetic field equations and allows for electron and ion demagnetization. The algorithms used are the wave propagation method and the weighted essentially non oscillatory (WENO) method. The wave propagation method is based on solutions to the Riemann problem at cell interfaces. A semi-implicit method is used to incorporate the Lorentz and electromagnetic source terms. The WENO method is based on a high order (up to 13th order) reconstruction of solution variables at cell interfaces. The solution is then advanced using a 3rd order Runge-Kutta time stepping scheme. To preserve the divergence constraints on the electric and magnetic fields the so called perfectly-hyperbolic form of Maxwell's equations are used which explicitly incorporate the divergence equations into the time stepping scheme. The algorithm is validated with the one dimensional MHD shock problem and a Z-pinch and theta-pinch equilibrium. It is shown that complex flows exhibiting turbulence and instabilities, not hitherto observed using MHD, can be simulated. A two dimensional shock problem is simulated which shows a Weibel instability leading to turbulence. Results of a magnetic reconnection problem and theta-pinch instabilities are presented
Two Large Open-Access Datasets for Fitts’ Law of Human Motion and a Succinct Derivation of the Square-Root Variant

Fitts’ law specifies a logarithmic relationship between motion duration and the ratio of target distance over target size. This paper introduces two large open-access datasets from experimental user studies: first a controlled (in-lab) study with 46 participants, and second an uncontrolled online study using a Java applet. We present a succinct derivation of the square-root variant of Fitts’ law using optimal control theory and compare three models that relate motion duration to the ratio of target distance over target size: LOG (Fitts’ original logarithmic function), SQR (square-root), and LOG’ (McKenzie's logarithmic plus 1.0). We find that: 1) the data from the controlled and uncontrolled studies are consistent; 2) for homogeneous targets (with fixed size and distance), the SQR model yields a significantly better fit than LOG or LOG', except with the most difficult targets (where the ratio of target distance over target size is large) where the models are not significantly different; and 3) for heterogeneous targets (with varying size and distance), SQR yields a significantly better fit than LOG for easy targets and LOG yields a significantly better fit for targets of medium difficulty, while the LOG' model yields a significantly better fit than both LOG and SQR on very difficult targets. The anonymized datasets including 94 580 human reaching motion timing measurements are, to our knowledge, the largest collected to date.
Diffusion Behavior and Interfacial Reaction of Heterogeneous Metal Systems Controlled by High Magnetic Fields

The interdiffusion behaviors and interfacial reaction in solid Cu/solid Ni, liquid Bi/solid Bi0.4Sb0.6, liquid Al/solid Cu, and gas Al/solid Cu diffusion couples have been experimentally studied under a high magnetic field of up to 12T. The effects of magnetic flux density and the direction of magnetic field (B) on the evolution of interfacial microstructure (including interfacial migration, phase composition and thickness of diffusion layers) have been examined systematically. We found that (1) The shift distance of Kirkendall marker and the inter-diffusion coefficient in solid Cu/solid Ni diffusion couples increased with increasing magnetic flux density in case of the direction of diffusion parallel to B; (2) The migration of the Bi/Bi0.4Sb0.6 interface due to the self-diffusion of the liquid metal into the solid alloy decreased markedly with the increase of magnetic flux density; (3) High magnetic fields exerted a non-monotonic influence on the thickness of diffusion layers during the reactive diffusion process between liquid Al and solid Cu; (4) The application of a high magnetic field during chemical reactive-diffusion process of gas Al/solid Cu system induced a significant change in the final products.
Kinetic and morphologic alterations in the colon of a patient with multiple polyposis.

The histologic and proliferative characteristics of 16 colonic biopsies taken from an operative specimen of a 38-year-old female patient with multiple polyposis are presented. Kinetic measurements are based on 3HTdR incorporation accomplished in vitro, using both single and double labelling techniques. Epithelial cells in adenomatous tissue were more actively engaged in DNA synthesis than those normal-appearing mucosa (L.I.13.0 +/- 6.9 versus 9.3 +/- 1.6); however, because of extreme variability between biopsies, the difference was not significant. No difference in S phase duration was found, but a faster turnover time (Tg) than that in the normal appearing colonic mucosa was estimated (Tg 52.6 hours versus 74.2 hours). Only two of ten biopsies containing normal-appearing mucosa had a completely normal incorporation pattern with proliferative cells located only in the lower two thirds of crypts. Eight biopsies showed extension of the proliferative compartment to the luminal surface. One of these eight also expressed an additional proliferative defect, namely, a shift of the major zone of DNA synthesis to the middle and upper regions of the crypts. This specimen had been located adjacent to an area of microscopic adenoma. Subpopulations of labelled epithelial cells showing transition from normal to hyperplastic or to adenomatous appearance were in the otherwise normal-appearing crypts. The majority of labelled hyperplastic-appearing cells occupied the lower thirds of the crypts, whereas 68% of labelled adenomatous-appearing cells were located in the middle and upper zones of the glands. Based on these observations, the development of an adenoma is believed forecast by the redistribution of the proliferative compartment toward the surface. A further stage in tumorogenesis before the appearance of a focus of neoplasia is the emergence of actively proliferating cells transforming to a more adenomatous appearance primarily in that same location, that is, the middle and upper third of the colonic crypts.
An analytical all-injection charge-based model for graded-base HBTs

Abstract Current transpsort and charge concentration in graded base heterojunction bipolar transistors (HBTs) have been investigated, and an all injection charge-based model suitable for implementation in computer aided design tools has been developed. In this model, injected current, charge and recombination current components are formulated for all levels of injection. Base grading effect on current components, current gain and cutoff frequency in the high current regions are studied. This model is a general model which is also valid for modeling ungraded base HBTs. The model is found to be in good agreement with the experimental and numerical results.
Combination of intrauterine growth restriction and a high-fat diet impairs cholesterol elimination in rats

Combination of intrauterine growth restriction and a high-fat diet impairs cholesterol elimination in rats
Model rock blasting—effect of explosives properties and other variables on blasting results

Abstract Results of instrumented model blasting experiments in homogeneous granite and limestone showed that rock fragmentation is not controlled by a single explosive property but by a combination of several properties. Empirical fragmentation equations were developed for granite, limestone and sandstone. From these relationships an expression was developed that may be used to rate fragmentation performance of different explosives. The results also indicate that gage hole pressure can be related to fragmentation for PETN based explosives provided the proper corrections are applied to the measured pressure values.
The Microcellular Injection Molding of Low-Density Polyethylene (LDPE) Composites

This paper reports the study of microcellular injection molding of low-density polyethylene- (LDPE) based composites. The effects of adding nanoclays and polymer additives in LDPE as well as rheological property of materials on the cell morphology, mechanical properties and surface properties of microcellular injection molded LDPE based composites are presented. For the microcellular injection molding process, when 3 wt% of nanoclays are added into LDPE-based polymers, the cell morphology can be significantly improved due to the nucleating effects resulting from the broad interface areas between polymer and nanoclays. Also, the addition of low melt flow LDPE into high melt flow LDPE could achieve smaller and denser bubbles in the polymer matrix than neat high melt flow LDPE.
Crack length calculation for bend specimens under static and dynamic loading

Crack length calculations in bend specimens have been derived by analyzing the sample's load-line compliance. This compliance equation is based upon calculating stiffness that incorporates the effects of shear deformation, rotary inertia and crack length in a dynamic test. Three-point bend tests for a high-strength steel and an aluminum alloy were conducted under static and dynamic loading to investigate the validity of the equation derived. The present static test results show good agreement with those predicted from ASTM E399. Dynamic crack lengths determined by the formula proposed in this work are also in good agreement with other models in the literature, and with the experimental results presented here. The applicability of the present approach to effective crack length determination under small-scale yielding conditions is discussed.
Nonhuman primate infants have an impaired respiratory but not systemic IgG antibody response following influenza virus infection

Respiratory infection of young infants results in increased morbidity and mortality compared to infection of adults. In spite of the significance of this health issue, our understanding of the immune response elicited in infants especially in the respiratory tract is highly limited. We developed a nonhuman primate model to probe the virus-specific antibody response in infants following infection with influenza virus. Infection of infants resulted in more pulmonary damage and higher viral loads compared to adults. While the systemic IgG antibody response was similar in infant and adult animals, the response in the upper respiratory tract of the infant was compromised. This lower response was associated with an increased prevalence of Treg cells and low levels of BALT. These data suggest a defect in the ability to produce effective virus-specific antibody responses at the local infection site is a contributor to increased pulmonary damage in the at-risk infant population.
Mean stresses in microstructures due to interface stresses: A generalization of a capillary equation for solids

Abstract We derive a general expression for the mean stress in a solid induced by the stresses of areal and linear defects such as grain boundaries and triple junction lines. The mean stress is a function of measurable stereological quantities, weighted areas of interfaces and lengths of the linear defects, not their curvatures. Generally the stress is non-hydrostatic. For anisotropic and textured microstructures, the mean stress depends on stereological moments of the interface orientation distribution function, but otherwise it is independent of the geometry of the microstructure. In two limiting cases, isolated spherical particles (in a matrix or not) and layer structures, the solution for the stress reduces to results which have been derived previously. These solutions can be used to determine average interface stresses from experimental lattice constant data. Although the specific interface area is always the important quantity in this relation, for the spheres this area/volume reduces to the particle curvatures commonly used in the literature for many microstructures.
Seismic evidence for catastrophic slab loss beneath Kamchatka

In the northwest Pacific Ocean, a sharp corner in the boundary between the Pacific plate and the North American plate joins a subduction zone running along the southern half of the Kamchatka peninsula1 with a region of transcurrent motion along the western Aleutian arc1,2. Here we present images of the seismic structure beneath the Aleutian–Kamchatka junction and the surrounding region, indicating that: the subducting Pacific lithosphere terminates at the Aleutian–Kamchatka junction; no relict slab underlies the extinct northern Kamchatka volcanic arc; and the upper mantle beneath northern Kamchatka has unusually slow shear wavespeeds. From the tectonic and volcanic evolution of Kamchatka over the past 10 Myr (refs 3, 4–5) we infer that at least two episodes of catastrophic slab loss have occurred. About 5 to 10 Myr ago, catastrophic slab loss shut down island-arc volcanic activity north of the Aleutian–Kamchatka junction. A later episode of slab loss, since about 2 Myr ago, seems to be related to the activity of the world's most productive island-arc volcano, Klyuchevskoy6. Removal of lithospheric mantle is commonly discussed in the context of a continental collision, but our findings imply that episodes of slab detachment and loss are also important agents in the evolution of oceanic convergent margins.
Exploring and developing reciprocity in research design

The researcher–participant relationship has the potential to be reciprocal, a relationship in which each contributes something the other needs or desires. Participants devote their time, effort, experiences, and wisdom to inform and shape the researcher’s study. The researcher’s scope, depth, and nature of inquiry introduce vulnerability to participants’ lives. In turn, researchers are susceptible to variable involvement and apathy from participants. While neither the relational aspect of research nor its potential for reciprocity is new, we are concerned that the concept is overshadowed in the current, positivistic culture of evidence in education research. Using vignettes from our special education research, we describe the affordances of a stance of reciprocity, illustrating the contours of the component in recruitment, participation, analysis, and presentation. We ask: How do truth traditions support reciprocity? How do we authentically reciprocate participants’ efforts throughout the research process...
An Ant Nest That Facilitates Removing Individuals at All Stages of Development

My studies of behavioral development in the harvester ant, Pogonomyrmex occidentalis Cresson, require that individuals at all stages of development be removed from their nest during periods of testing, and placed back in the nest afterwards. Most nests make this procedure difficult, because lifting the cover of the nest for even a brief moment creates enough disturbance that many ants run out of the nest. Since harvester ants cannot climb up smooth plastic, I was able to design a more versatile nest enabling me to routinely remove individual brood and adult ants without other ants escaping.
Plio-Pleistocene climate evolution: trends and transitions in glacial cycle dynamics

Abstract We describe the evolution of climate system dynamics by examining the climate response to changes in obliquity and precession over the last 5.3 Myr. In particular, we examine changes in the shape of glacial cycles and the power of obliquity and precession response in benthic δ 18 O. When the exponential trend in δ 18 O variance is removed, its spectral power exhibits strong, proportional responses to amplitude modulations in orbital forcing over most of the Plio–Pleistocene. Precession responses correlate with modulations in forcing for the last 5 Myr, but 41-kyr response is sensitive to obliquity modulation only before 1.4 Myr. Where responses are sensitive to modulations in forcing, we demonstrate that glacial cycles are orbitally forced rather than being self-sustained or paced by orbital changes. The shapes of glacial cycles have several nonlinear properties, which may be indicative of glacial–interglacial differences in climate sensitivity or response time. The “saw-tooth” asymmetry of glacial cycles first appears shortly after the onset of major northern hemisphere glaciation, and the relative duration of interglacial stages decreases at 1.4 Myr. Collectively, trends in the shape of glacial cycles and the sensitivity of δ 18 O to obliquity and precession are suggestive of major transitions in climate dynamics at approximately 2.5 and 1.4 Myr but show no significant change associated with the appearance of strong 100-kyr cycles during the mid-Pleistocene transition.
JOHN LOCKE AND THE PROBLEMS OF MORAL KNOWLEDGE

Abstract: In this paper, I argue that John Locke's account of knowledge coupled with his commitments to moral ideas being voluntary constructions of our own minds and to divine voluntarism (moral rules are given by God according to his will) leads to a seriously flawed view of moral knowledge. After explicating Locke's view of moral knowledge, highlighting the specific problems that seem to arise from it, and suggesting some possible Lockean responses, I conclude that the best Locke can do is give us a trivial account of moral knowledge which cannot avoid problems with subjectivity and relativism.
Role of β2-containing nicotinic acetylcholine receptors in auditory event-related potentials

Nicotine improves sensory processing in schizophrenic individuals, as measured by changes in auditory event-related potentials (ERPs). Nicotine administration also alters ERPs in mice by increasing the amplitude and gating of the P20 ERP component while decreasing the amplitude of the N40 ERP component. Less is known about the role of specific nicotinic acetylcholine receptor (nAChR) subtypes. In this study, we examined whether nAChRs containing the β2 subunit contribute to nicotine’s effects on auditory ERPs. We tested the effect of nicotine in wild-type mice and mice lacking the β2 nAChR subunit. Mice underwent stereotaxic implantation of stainless steel electrodes located in the CA3 region of the hippocampus, and 50 paired click stimuli were delivered during each drug condition. There was no significant difference in P20 or N40 amplitude or gating between genotypes during the control condition, suggesting that β2-containing receptors are not essential for the baseline auditory ERP response. Nicotine increased P20 amplitude and enhanced gating in wild-type and β2 knockout mice, but only decreased N40 amplitude in wild-type mice. There was no effect of nicotine on N40 gating in either genotype. β2-containing receptors are necessary for nicotine’s effects on the N40 component of the mouse auditory ERP. These results suggest that β2-containing nAChRs modulate sensory processing and may serve as a therapeutic target in schizophrenic individuals.
Genetic discovery: the prescription for chronic pain

A recent publication that combined rat gene expression data and a human genetic association study has identified the first genetic risk factor for chronic pain in humans. In four of the five cohorts studied, there was a significant association of an allele within a gene (KCNS1) encoding a potassium channel (Kv9.1) with an increased risk for chronic pain. Identification of genetic risk factors for chronic pain could catalyze new advances in this difficult clinical area that has become a major public health problem. Genomic-medicine-based advances for chronic pain could include the development of a mechanism-based classification system for chronic pain, new treatment options, improved methods for treatment selection and targeted prevention strategies for high-risk individuals.
The effect of added vitamin A alcohol on the metabolism of progesterone in the placenta of the guinea pig, Cavia porcellus.

1. 1. 20α-Hydroxy-4-pregnen-3-one is isolated and characterized as the major metabolite of progesterone-4-14C in the placenta of the guinea pig. 2. 2. The tenfold increase in progesterone-4-14C metabolism in the presence of added vitamin A alcohol is discussed.
Emotional Connections and Dyadic Consciousness in Infant-Mother and Patient-Therapist Interactions: Commentary on Paper by Frank M. Lachmann

The emotional connection between patients and therapists and between developmental infants and researchers is argued to be a uniting basis for discussion of differences between therapists and researchers. Infant-mother research is seen as providing an understanding of the specificity of relationships and of the dyadic expansion of consciousness (DEC). DEC is hypothesized to be a mechanism of developmental change as well as a change process of therapy.
Pigment epithelium derived factor (PEDF) is neuroprotective in two in vitro models of Parkinson's disease.

Abstract Transplantation of retinal pigment epithelial (RPE) cells in the basal ganglia has been proposed as a novel cell-based therapy for Parkinson's disease (PD), by providing a constant source of dopamine replacement via the melanin synthetic pathway enzyme tyrosinase. We have demonstrated previously that human RPE cells also produce a neurotrophic effect on primary cultures of rat striata mesencephalic (dopaminergic) neurons and showed that pigment epithelium derived factor (PEDF) accounted for a major portion of the neurotrophic effect. We now have also begun studies that demonstrate that the neurotrophic effect of PEDF corresponds to neuroprotection against toxins used to produce experimental PD. This was shown in (1) rotenone and (2) 6-hydroxydopamine (6-OHDA) in vitro models. The toxins were added at day 10 in culture, PEDF was added 1 h prior. The cultures were fixed and analyzed after tyrosine hydroxylase (TH) immunocytochemical staining. Cell count of TH+ neurons clearly shows the neuroprotective potential of PEDF in both neurotoxin models. The neurotoxic effect of rotenone (25 nM) on dopaminergic neurons is reversed by addition of PEDF. At a concentration of 1 ng/ml PEDF the neurotoxic effect of rotenone is completely counteracted. PEDF (1 ng/ml) has also a neuroprotective effect in the 6-OHDA midbrain in vitro model. The effect is most pronounced at concentrations of 25 μM and 50 μM 6-OHDA. We conclude that the neurotrophic factor PEDF, produced from RPE cells, can improve neuronal survival in models of PD, and plan to test if this effect can be observed using in vivo models of PD following RPE transplantation.
Breaking the Diffraction Barrier: Super-Resolution Imaging of Cells

Anyone who has used a light microscope has wished that its resolution could be a little better. Now, after centuries of gradual improvements, fluorescence microscopy has made a quantum leap in its resolving power due, in large part, to advancements over the past several years in a new area of research called super-resolution fluorescence microscopy. In this Primer, we explain the principles of various super-resolution approaches, such as STED, (S)SIM, and STORM/(F)PALM. Then, we describe recent applications of super-resolution microscopy in cells, which demonstrate how these approaches are beginning to provide new insights into cell biology, microbiology, and neurobiology.
Hot tearing of ternary Mg−Al−Ca alloy castings

Ternary Mg−Al−Ca alloys are the base of a few new creep-resistant, lightweight Mg alloys for automobiles. Hot tearing in Mg−xAl−yCa alloys was studied, including Mg−4Al−0.5Ca, Mg−4Al−1.5Ca. Mg−4Al−2.5Ca, Mg−4Al−3.5Ca, Mg−5Al−2.5Ca, and Mg−6Al−2.5Ca, by constrained rod casting (CRC) in a steel mold—with a movable pouring cup to keep solidification therein from interfering with the rising tension in the rods. The hot tearing susceptibility, based on measured crack widths and crack locations, decreased significantly with increasing Ca content (y) but did not change much with the Al content (x). An instrumented CRC with a steel mold was developed to detect the onset of hot tearing by monitoring the tension in the rod during casting and the temperature near the cracking site. It was further improved by reducing the rod diameter to detect hot tearing earlier, at a higher temperature, and with a clear peak in the load curve. To further understand the hot tearing susceptibility of these alloys, the secondary phases, eutectic content, solidification path, and freezing range were examined. Alloy Mg−4Al−0.5Ca had the widest freezing range and the lowest eutectic content and was most susceptible to hot tearing, while alloys Mg−4Al−3.5Ca and Mg−6Al−2.5Ca were the opposite. Mg−4Al−0.5Ca had the widest freezing range (183 °C) because its solidification path led to the formation of Mg17Al12 from the liquid at a very low temperature (440°C). The application of the results to die casting was discussed.
The computer-aided engineer: Prospects and risks

Within the last 20 years, much research and development has been conducted to deliver computer tools to assist engineers in performing their tasks. We are now experiencing the power of worldwide networked computing environments and the ability to easily share large quantities of information over geographically dispersed environments. However, are the computing environments available today supporting engineers in doing their job or defining how they must do their job? We need to develop systems that are more transparent and understandable to the users and that are more responsive to the individual needs and idiosyncrasies of the persons using these assistants.
Air stability of supported lipid membrane spots

Abstract Air-stability of supported lipid membranes is crucial to large scale applications of lipid membrane based biosensors and microarrays. Here we examined the air-stability of supported lipid membrane spots, and found that it was dependent on spot size. The smaller the lipid spot is, the more resistant to deterioration caused by air exposure it is, probably due to increased stable edge of small bilayer spots. This study suggests a strategy to design air-stable biomembrane based biosensors for biosensing applications.
Effects of crosslinking in demulsifiers on their performance

Chemical demulsification is the most widely used method for breaking water-in-diluted bitumen emulsions in oil sands processing. In this work, the properties and performance of six ethylene oxide (EO)–propylene oxide (PO) demulsifiers from three families were investigated. The demulsifiers were characterised by their relative solubility number (RSN) and number of EO–PO branches. The results showed that the performance of the demulsifiers is correlated to the starting base compound, number of EO–PO branches, RSN, oil/water interfacial tension (IFT), increase of molecular weight (MW) by incorporation of crosslinks in EO–PO branches and yield stress of underflow. An increase in MW by the incorporation of crosslinks in EO–PO block copolymers decreased the RSN value while improved the dehydration efficiency. Dynamic IFT measurements revealed that the higher adsorption of EO–PO block copolymers at the oil/water interface on crosslinking, which resulted in higher dehydration efficiencies. The yield stress of the underflow increased on crosslinking the EO–PO block copolymers due to the release of more water and solids to the underflow, which increased the number of aggregates present in the underflow, resulting in increased immobility and constriction and higher yield stress.
Design, fabrication and experimental results of a multi-purpose Panofsky magnet

Abstract A fast, flexible magnet system, consisting of Panofsky style ferrite picture frame magnet and pulsed power supply has been developed. The magnet specifications are 8 cm × 8 cm aperture, 23 cm length, 500 A pulsed/160 A DC, and a 1 μs rise time. Designed for general accelerator physics studies, the magnet may be quickly converted from dipole to quadrupole by change the winding end terminations. In the quadrupole configuration, a field gradient of 0.5 T/m has been achieved at 500 A.
Mapping Cyberspace: The Image of the Internet

Why would anyone try to map the Internet in the first place? What purpose do speculations on the unrealized physical form of amorphous electronic data serve? The straightforward answer is that maps are a handy tool for organizing and communicating large amounts of information. To say one is "on the Internet" today means something much different than it meant 15 years ago, and the rapid pace of change is a staggeringly difficult concept to tackle and absorb, much less to catalogue. A Web surfer looking at the Internet is like an astronomer looking at space: narrow slivers can be observed, but to see the whole requires a much more powerful instrument. Using the Internet is easy (for most of us), but to actually step back and stare at the whole Internet is nearly impossible. Maps of the Internet are an attempt to overcome this difficulty. Moreover, there is a desire among many to document the progression of these changes before it is too late; these snapshots of our Internet through time may serve as a valuable record for future analysis and historic understanding.
Head and neck manifestations of gastroesophageal reflux

Gastroesophageal reflux (GER) is a common condition with many manifestations which are of interest to the otolaryngologist. Factors predisposing to GER include anatomic abnormalities of the esophagus and pharynx, neurogenic disease and diet induced decreased lower esophageal sphincter pressure. Three interesting cases are reported, including subglottic stenosis which has not previously been thought to be a complication of GER. A literature review of otolaryngologic symptoms, the problems of diagnosis, and a suggested treatment plan are presented.
Elective Percutaneous Dilatational Tracheostomy: A New Simple Bedside Procedure; Preliminary Report

The development by the senior author (P. C.) of percutaneous tracheostomy from cricothyroidostomy and subcricoid fingertip tracheostomy is traced, and the technique and patient material of percutaneous subcricoid tracheostomy is presented. This new technique consists of inserting a tracheostomy tube by the use of a J guide wire inserted through a cannula into the tracheal lumen. Tapered dilators follow the guide wire and dilate the opening in the tracheal walls. A tracheostomy tube snugly fitted over a dilator is then passed into the trachea between the cricoid cartilage and the first tracheal ring. This procedure avoids the immediate and postoperative complications of “standard” tracheostomy. An experience of 134 tracheostomies of various types culminated in the development of the percutaneous technique. To date 26 such operations on 24 patients have been done with no significant complications due to the operation. The percutaneous technique should reduce the severity and incidence of intraoperative complications. Late complications, which have been no problem to date, are being evaluated with longer follow-up and with a greater patient population.
Age-related variability in body composition methods for assessment of percent fat and fat-free mass in men aged 20–74 years

Introduction: assessing body composition is important because of the association between excess body fat or obesity and the increased risk for coronary artery disease, diabetes, hyperlipidaemia and hypertension. Methodological differences among indirect body composition techniques are a source of variability that can affect estimations of fat-free mass (FFM) or percent fat, especially for different age groups. Purpose: this study examined the effect of age on the estimation of body composition by three methods based on the two-component model. One hundred and fifty-three men were placed into 5-year age groups from 20-24 to 7074 years. Body composition was assessed by hydrodensitometry (underwater weighing; UWW), 40K spectroscopy (K40) and anthropometry. Results: day-to-day reliability was excellent for each method. Correlation coefficients between methods, independent of age, ranged from r = 0.71 (K40 and UWW) to r = 0.83 (UWW and anthropometry) for % fat and from r = 0.76 (K40 and anthropometry) to r = 0.90 (UWW and anthropometry) for FFM. Correlations between techniques weakened and showed greater variability as age increased. UWW produced the highest % fat and lowest FFM for the different age groups, while K40 and anthropometry yielded similar body composition values. All three methods detected age-related differences in % fat; however, only UWW determined a significant age effect in FFM. The greatest discrepancies between the methods occurred for the oldest age groups (60-74 years), but noticeable differences began occurring after the age of 40. Conclusions: each method produced reliable data. Care should be taken when choosing any method based on the two-component model, especially when different age groups are being examined, since estimating % fat and FFM is dependent on the age-related chemical composition of an individual and the limitations of each method.
Algorithms for identifying local molecular sequence features

Efficient algorithms are described for identifying local molecular sequence features including repeats, dyad symmetry pairings and aligned matches between sequences, while allowing for errors. Specific applications are given to the genomic sequences of the Epstein-Barr virus, Varicella-Zoster virus and the bacteriophages lambda and T7.
Epithelial Ca2+ entry channels: transcellular Ca2+ transport and beyond

The recently discovered apical calcium channels CaT1 (TRPV6) and ECaC (TRPV5) belong to a family of six members called the ‘TRPV family’. Unlike the other four members which are nonselective cation channels functioning as heat or osmolarity sensors in the body, CaT1 and ECaC are remarkably calcium-selective channels which serve as apical calcium entry mechanisms in absorptive and secretory tissues. CaT1 is highly expressed in the proximal intestine, placenta and exocrine tissues, whereas ECaC expression is most prominent in the distal convoluted and connecting tubules of the kidney. CaT1 in the intestine is highly responsive to 1,25-dihydroxyvitamin D3 and shows both fast and slow calcium-dependent feedback inhibition to prevent calcium overload. In contrast, ECaC only shows slow inactivation kinetics and appears to be mostly regulated by the calcium load in the kidney. Outside the calcium-transporting epithelia, CaT1 is highly expressed in exocrine tissues such as pancreas, prostate and salivary gland. In these tissues it probably mediates re-uptake of calcium following its release by secretory vesicles. CaT1 also contributes to store-operated calcium entry in Jurkat T-lymphocytes and prostate cancer LNCaP cells, possibly in conjunction with other cellular components which link CaT1 activity to the filling state of the calcium stores. Finally, CaT1 expression is upregulated in prostate cancer and other cancers of epithelial origin, highlighting its potential as a target for cancer therapy.
Beauty-ful Inferiority: Female Subservience in Disney's Beauty and the Beast

The ubiquity of Disney movies has certainly transformed the American cultural landscape. The Disney zeitgeist manifests itself as generations of children actively seek Prince Charmings, unrealistic fairy tale relationships and the omnipotent, happily-ever-after. One such Disney favorite, Beauty and the Beast (1991), reveals typical Disney themes such as the power of altruism, the transformation of the anthropomorphic, and the catharsis of true love. Yet, under these benevolent-seeming Disney themes lurk more sinister, subliminal messages. Beauty and the Beast promotes female subservience and subjugation in addition to the glorification of abusive relationships. Belle, the female protagonist, embodies these gendered disparities and remains objectified by the film’s masculine characters. At first glance, Belle seems as if an assertive, valiant heroine; however, a closer examination belies this understanding of Belle. Thus, my analysis intends to unearth these unexamined messages and also reveals the effect of these messages as consumed by Disney’s target audience: children. Ultimately, the animated Disney cartoon landscape conceals its more sobering, implicit messages. Unveiling these messages reveals the true nature of Disney films, and acknowledges the troubling damage inflicted by the pervasiveness of Disney and its ability to mold American culture.
Determining the Optimal Dose of Intravenous Fat Emulsion for the Treatment of Severe Verapamil Toxicity in a Rodent Model

Objectives: Recent animal studies have shown that intravenous fat emulsion (IFE) increases survival and hemodynamics in severe verapamil toxicity. However, the optimal dose of IFE is unknown. The primary objective was to determine the optimal dose of IFE based on survival in severe verapamil toxicity. Secondary objectives were to determine the effects on hemodynamic and metabolic parameters. The hypothesis was that there is a dose-dependent effect of IFE on survival until a maximum dose is reached. Methods: This was a controlled dose-escalation study. Thirty male rats were anesthetized, ventilated, and instrumented to record mean arterial pressure (MAP) and heart rate (HR). Verapamil toxicity was achieved by a constant infusion of 15 mg ⁄kg ⁄hr. After 5 minutes, a bolus of 20% IFE was given. Animals were divided into six groups based on differing doses of IFE. Arterial base excess (ABE) was measured every 30 minutes. Data were analyzed with analysis of variance. Results: The mean survival time for each dose of IFE was 0 mL ⁄kg = 34 minutes, 6.2 mL ⁄kg = 58 minutes, 12.4 mL ⁄kg = 63 minutes, 18.6 mL ⁄kg = 143.8 minutes, 24.8 mL ⁄kg = 125.6 minutes, and 37.6 mL ⁄kg = 130 minutes. Post hoc testing determined that the 18.6 mL ⁄kg dose resulted in the greatest survival when compared to other doses. It increased survival 107.2 minutes (p = 0.004), 91.2 minutes (p = 0.001), and 80.8 minutes (p = 0.023) when compared to the lower doses of 0, 6.2, and 12.4 mL ⁄kg, respectively. There was no added benefit to survival for doses greater than 18.6 mL ⁄kg. The secondary outcomes of HR, MAP, and ABE showed the most benefit with 24.8 mL ⁄kg of IFE at both 30 and 60 minutes. Conclusions: The greatest benefit to survival occurs with 18.6 mL ⁄kg IFE, while the greatest benefit to HR, MAP, and BE occurs at 24.8 mL ⁄kg IFE. The optimal dose for the treatment of severe verapamil toxicity in this murine model was 18.6 mL ⁄kg. ACADEMIC EMERGENCY MEDICINE 2008; 15:1284‐1289 a 2008 by the Society for Academic Emergency Medicine
Using Issue Tracking Tools to Facilitate Student Learning of Communication Skills in Software Engineering Courses

When teaching communication and teamwork skills in software engineering courses, it is often difficult to relate the theories of communication as presented in communication textbooks to actual student interactions and team activities because the majority of student interactions and team activities take place outside the classroom. Through our experience in teaching communication theories in CS456/556, a software engineering course at Ohio University, we observed that when communication theories are delivered in traditional methods such as lectures without additional exercises designed for students to apply the theories, many students tend to treat them as an independent part of the course and continue to guide their behaviors in team activities with their old habits and preexisting intuitions. We found that issue tracking tools can help facilitate student learning of communication skills by forcing students to explicitly carry out effective steps recommended by communication theories and thus improve communications among students. Moreover, issue tracking tools also improve communications between the students and the instructor, and enable the instructor to be more aware of team status, detect team problems early on, and reply less on time-consuming and often inaccurate in-class team status reports
Central U.S. Atmospheric Water and Energy Budgets Adjusted for Diurnal Sampling Biases Using Top-of-Atmosphere Radiation

The water and energy budgets of the atmospheric column over the Mississippi River basin are estimated using 18 yr (1976‐93) of twice-daily radiosonde observations, top-of-atmosphere net radiation estimates from the Earth Radiation Budget Experiment (ERBE), streamflow measurements, and reanalysis-based estimates of ground heat storage. The seasonal cycle of the divergence of moisture, moist static energy, and dry static energy are decomposed into three terms, the mean divergence, mean advection, and eddy source, each of which are seen to have similar magnitudes and, in many cases, opposite signs. Because of this, the residuals found when comparing atmospheric energy divergence to top-of-atmosphere net radiation or when comparing moisture divergence with land surface streamflow, are highly sensitive to propagating errors. Further analysis of four times per day radiosonde observations from an earlier 18-yr period (1948‐65) indicate that the divergence profile of the wind field oscillates equally strongly at seasonal, diurnal, and semidiurnal time scales. The implication of these variations is that climatological means formed by twice-daily sampling (0000 and 1200 UTC) will produce a systematic, seasonally varying bias in the water and energy budgets. To estimate this bias, the monthly mean wind divergence profile is adjusted from a prior estimate until the atmospheric energy budget is closed. The divergence of the eddy and mean-advection terms, which showed significantly less diurnal variability, are unaltered. As an independent check on the procedure, the moisture budget calculated using the adjusted wind divergence profiles are compared with streamflow-based estimates of terrestrial runoff. The adjustment procedure increases the moisture convergence from 0.2 to 0.5 mm day21, bringing it closer to the terrestrial estimate (0.6 mm day21), and induces a qualitatively more reasonable looking seasonal cycle in the mean-divergence term.
Nadaraya-Watson estimator for sensor fusion problems

In a system of N sensors, the sensor S/sub j/, j=1,2...,N, outputs Y/sup j/spl isin//[0, 1], according to an unknown probability density p/sub j/(Y/sup j|/X), corresponding to input X/spl isin/[0, 1]. A training n-sample (X/sub 1/,Y/sub 1/), (X/sub 2/,Y/sub 2/), ..., (X/sub n/,Y/sub n/) is given where Y/sub i/=(Y/sub i//sup 1,/Y/sub i//sup 2,/...,Y/sub i//sup N/) such that Y/sub i//sup j /is the output of S/sub j/ in response to input X/sub i/. The problem is to estimate a fusion rule f:[0,1]/sup N//spl rarr/[0,1], based on the sample, such that the expected square error, I(f), is minimized over a family of functions /spl Fscr/ with uniformly bounded modulus of smoothness. Let f* minimize I(.) over /spl Fscr/; f* cannot be computed since the underlying densities are unknown. We estimate the sample size sufficient to ensure that Nadaraya-Watson estimator f/spl circ/ satisfies P[I(f/spl circ/)-I(f*)>/spl epsiv/] 0 and /spl delta/, 0</spl delta/<1. We apply this method to the problem of detecting a door by a mobile robot equipped with arrays of ultrasonic and infrared sensors.
Comparison of Methods for Combining the Minimum Passing Levels for Individual Items into a Passing Score for a Test

The purpose of this study was to compare several methods for determining a passing score on an examination from the individual raters' estimates of minimal pass levels for the items. The methods investigated differ in the weighting that the estimates for each item receive in the aggregation process. An IRT-based simulation method was used to model a variety of error components of minimum pass levels. The results indicate little difference in estimated passing scores across the three methods. Less error was present when the ability level of the minimally competent candidates matched the expected difficulty level of the test. No meaningful improvement in passing score estimation was achieved for a 50-item test as opposed to a 25-item test; however, the RMSE values for estimates with 10 raters were smaller than those for 5 raters. The results suggest that the simplest method for aggregating minimum pass levels across the items in a test-adding them up-is the preferred method. In common use are standard setting methods in which expert raters' estimates of minimum passing levels (MPLs) for individual test items are aggregated into an overall passing score for a test. Traditionally, this aggregation is accomplished by first having the raters conceptualize a hypothetical minimally competent candidate. Then, depending on the specific standard setting methods utilized (e.g., Angoff, 1971; Nedelsky, 1954), each rater is asked to assign independently a MPL to each item reflecting the probability that a minimally competent candidate would answer the item correctly. Finally, these individual raters' estimates are incorporated into an algorithm to determine the passing score for the test.
Does situation awareness add to the validity of cognitive tests

OBJECTIVE: Does adding situation awareness (SA) to a battery of cognitive tests improve prediction? BACKGROUND: Identifying variables that predict skilled performance in a complex task aids in understanding the nature of skill and also aids in the selection of operators to perform that task. SA is thought to be an important predictor of performance. SA is often thought to be based on underlying cognitive mechanisms. METHOD: Three performance measures taken from the Federal Aviation Administration's (FAA's) Air Traffic Scenarios Test, the low-fidelity simulation component of the FAA's controller selection battery, were used as criterion variables in a hierarchical regression. After predicting performance based on a battery of cognitive (e.g., intelligence, working memory, spatial memory) and noncognitive tests (e.g., cognitive style, personality, demographics), we added measures of SA. RESULTS: SA did provide increases in prediction, but only when measured with the Situation Present Assessment Method, an on-line query method. When the same questions were asked off line, SA did not enter the model in two cases and improved prediction by only 2% in the third. CONCLUSION: Thus, some measures of SA do show incremental validity, even against a backdrop of a large number of cognitive variables. APPLICATION: On-line measures of SA can be a worthwhile addition to standard batteries of tests used to predict performance in cognitively oriented industrial tasks. Language: en