cssi/SciSciGPT-SciSciNet huggingface dataset:
AV dissociation, an inevitable response.

Background: The independent activation of the atria and ventricles, AV dissociation, is a common phenomenon that occurs during a wide variety of electrophysiologic circumstances. The clinical significance of AV dissociation is often misunderstood. Methods: This article examines the basis and clinical implications of AV dissociation. Results: AV dissociation is often an obligatory, secondary phenomenon, and should not be construed as the primary disorder; it may be due to either the AV conduction system being completely blocked (3° AV block) or the P wave and the QRS complex being generated from separate sources (usually, the AV junction or ventricle) but occurring close together during the physiologic refractory period of each other. The latter may happen in junctional or ventricular arrhythmias including escape or accelerated rhythm, tachycardia, or premature beats. Conclusion: The crucial clinical point is not the AV dissociation itself, but that an underlying triggering primary disorder is present and should be identified. Ann Noninvasive Electrocardiol 2011;16(3):227–231
Color halftoning with M-lattice

This paper presents new results in the halftoning of color images. The first automatic generation of the Wall Street Journal type halftones of gray-scale images was done using the M-lattice system and reported in Sherstinsky and Picard [1994]. The M-lattice system was derived from the reaction-diffusion model, first proposed by Turing [1952] in order to explain mammal coat patterns. The M-lattice is a non-linear dynamical system that is well-suited for a variety of applications formulated as constrained non-linear optimization. In particular, it can perform image processing operations that emphasize oriented patterns. The present study uses this property to extend the special-effects halftoning of gray-scale images to that of color images. The duality metric comes from the directionality information extracted by steerable filters from the gray-scale version of the original color image. The binary requirement is stated as an explicit constraint, and all three (red, green, and blue) halftone components are synthesized simultaneously by the M-lattice.
Computer Adoption and Use in California Planning Agencies: Implications for Education

This paper presents the results of a mail survey of 501 California city and county planning directors and microcomputer managers on the number of computers local planning agencies have and the types of computers, software, and applications these agencies use or will use. Staff training and hardware and software funding are found to be common problems. Measures of effective utilization of computers are developed and associated factors that have contributed to successful implementation are explored. Based on these analyses, several changes in planning curricula are suggested. An outline for a specialization in planning information systems within the planning curriculum is presented.
Con: Antifibrinolytics are not safe and effective in patients undergoing liver transplantation.

s l t g ESPITE IMPROVEMENTS in the operative care of patients undergoing liver transplantation, significant blood oss requiring transfusion continues to be a common event.1,2 In 002, the United Network for Organ Sharing instituted the odel for End-Stage Liver Disease scoring system as the tratification method for the allocation of cadaveric donor livers n the United States.3 As intended, this has resulted in more ompromised patients (ie, patients with more severe coagulopahy, worse renal function, and more compromised liver funcion) presenting for transplant. Transplantation in this more ompromised patient population, as expected, has been shown o be associated with increased blood loss and the increased ransfusion of blood components.1,4 With the morbidity assoiated with the transfusion of blood components well estabished, any intervention that might significantly reduce blood oss would be expected to be beneficial.5-9 In addition, the eduction of transfusion rates could have significant impact on esource utilization and on both the direct and indirect costs elated to transfusion.10,11 The use of antifibrinolytic medications during liver translantation was popularized by Kang et al12 in the midto late 980s. The rationale for this use came not simply from the eneral desire to reduce blood loss but as a specific response to ntraoperative thromboelastographic monitoring, which howed that 40% of patients developed severe fibrinolysis on eperfusion of the newly grafted liver.13 This fibrinolysis is aused mainly by increased levels of tissue-type plasminogen ctivator.14 Since that time, antifibrinolytics have been used outinely by numerous centers throughout the world in the care f liver transplant patients. All of the clinically available antibrinolytics, aprotinin, epsilon aminocaproic acid (EACA), nd transexamic acid (TA), have been used in this role. The fficacy of these agents in reducing blood loss during liver
Effects of feature construction on classification performance: An empirical study in bank failure prediction

While extensive research in data mining has been devoted to developing better classification algorithms, relatively little research has been conducted to examine the effects of feature construction, guided by domain knowledge, on classification performance. However, in many application domains, domain knowledge can be used to construct higher-level features to potentially improve performance. For example, past research and regulatory practice in early warning of bank failures has resulted in various explanatory variables, in the form of financial ratios, that are constructed based on bank accounting variables and are believed to be more effective than the original variables in identifying potential problem banks. In this study, we empirically compare the performance of two sets of classifiers for bank failure prediction, one built using raw accounting variables and the other built using constructed financial ratios. Four popular data mining methods are used to learn the classifiers: logistic regression, decision tree, neural network, and k-nearest neighbor. We evaluate the classifiers on the basis of expected misclassification cost under a wide range of possible settings. The results of the study strongly indicate that feature construction, guided by domain knowledge, significantly improves classifier performance and that the degree of improvement varies significantly across the methods.
The Number of Evolutionary Steps on Random and Minimum Length Trees for Random Evolutionary Data

Abstract A model of evolutationarily uninformative data is derived and two separate character state distributions, one with two states (0, 1) and one with missing-value data (0, 1, {0, 1}), are obtained. The expectation of number of steps on random trees is derived for both types of data and the variance in number of steps is derived for missing-value data. It is conjectured that the number of steps on random trees for these data should be asymptotically normal. Computer simulation is used to find approximations for the expected number and variance in number of steps of minimum length trees for both types of random evolutionary data. In both cases, minimum length trees are shorter than random trees and, although the lengths diverge in number, they converge in proportion. The length of minimum length trees is frequently used to evaluate the goodness of the tree as a representation of the data and the goodness of the data for constructing a plausible hypothesis of evolutionary relationships. In turn, as the length of a minimum length tree increases, confidence in the resulting tree decreases. The distributions of lengths of minimum length trees are of interest to determine if any information on phylogenetic branching is present in the data. The expected length of random trees can be used as a measure to compare to the lengths of minimum length trees for real data sets.
Carbon monoxide attenuates bacteria-induced Endothelin-1 expression in second trimester placental explants.

Abstract Introduction The pro-inflammatory mediator and potent vasoconstrictor Endothelin-1 (ET-1) is known to be expressed in the placenta. We have recently demonstrated that very low, non-toxic doses of carbon monoxide (CO), prevented infection-induced preterm birth in mice. However the effect(s) of CO on human gestational tissues is yet to be fully explored. We hypothesize that CO will have a protective role against inflammation-induced E. coli by down-regulating the ET axis in placental explants. Methods Twenty placentas from elective termination of pregnancy in the second trimester were analyzed with or without exposure to heat killed E. coli over the course of 30 h. Placental ET-1, along with its biologically inactive precursor Big ET-1, and Endothelin Converting Enzyme-1 (ECE-1, responsible for the cleavage of Big ET-1 to ET-1), were analyzed by ELISA. Gene expression for ET-1 ( EDN1 ), ECE-1 and the ET A receptor ( EDNRA ) were analyzed using qPCR. Localization of ET-1 expression was also demonstrated using immunohistochemistry. Results E. coli significantly increased ET-1 transcription and secretion of BIG ET-1 and ET-1 in a time dependant manner which was ameliorated when exposed to CO at later time points. In the presence of CO, mRNA levels of ECE-1 were significantly reduced at 3 and 24 h, while EDNRA was significantly reduced at 6 and 18 h. Conclusions Up-regulation of ET-1 production in human placenta in the setting of infection can be attenuated by low doses of CO. Our results further explore the anti-inflammatory and regulatory mechanism(s) of CO on the ET axis components at the maternal fetal interface.
Effect of dietary vitamin E on the development of altered hepatic foci and hepatic tumors induced by the peroxisome proliferator ciprofibrate.

The purpose of this study was to determine the effect of the dietary antioxidant vitamin E on hepatocarcinogenesis by peroxisome proliferators which, it is hypothesized, induce tumors by increased production of hydrogen peroxide or other oxygen radicals. Rats were fed diets containing the peroxisome proliferator ciprofibrate and one of three concentrations (10, 50, or 500 ppm) ofα-tocopheryl acetate for 6 months or 21 months. The incidence of hepatic tumors and the number and volume ofγ-glutamyl-transpeptidase-positive, ATPase-negative, glucose-6-phosphatase-negative, and glucose-6-phosphatase-positive foci were quantified. No tumors or altered hepatic foci were seen at 6 months, but at 21 months the incidence of hepatic tumors and the number and volume of altered hepatic foci were increased in rats fed higher levels of vitamin E. Indices of oxidative damage — concentrations of malonaldehyde, conjugated dienes, and lipidsoluble fluorescence products — were not affected or were lower in rats fed higher amounts of vitamin E; the enhancing effect of vitamin E on the development of altered hepatic foci and hepatic tumors, therefore, was not related to the induction of cellular oxidative damage. Hepatic peroxisomal fatty acidΒ-oxidation and vitamin C concentrations were not affected by vitamin E, whereas the glutathione concentration was decreased in rats fed higher amounts of vitamin E. This study shows that increasing the vitamin E content of the diet enhances ciprofibrate-induced hepatocarcinogenesis, but the mechanism of this effect is unclear.
'Complementary' Signals and Orthogonalized Exponentials

When a signal is approximated by a finite set of component signals which span a subspace \Phi , the least-square approximation may be interpreted geometrically in signal space as the projection of the true signal vector upon this finite dimensional subspace. In case the component signals are one-sided exponentials, the projection operators may be realized by simple physical filters following Kautz' procedure for constructing orthogonalized exponentials. The purpose of this paper is to describe the 'present-instant' error, the 'complementary' signal and the 'complementary' filter which are useful concepts in approximating a signal by one-sided exponential components. An attempt is made to interpret directly in the time domain Kautz' procedure using the 'present-instant' error concept. Some important properties of the 'complementary' signals which prove to be of value in simplifying the process of error energy evaluation and synthesis of the approximating signal, are derived and discussed. In particular, it is found that the 'complementary' filter for a given finite exponential basis is simply an all-pass rational transmittance having zeros in the frequency domain which match the exponents of the basis. This familiar all-pass filter indeed represents an orthogonal transformation which preserves the energy of the signal under transformation. A signal to be approximated is transformed by this filter into the 'complementary' signal which can be separated in time domain into two parts, namely a 'complementary' approximating signal and a 'complementary' error signal. The actual approximating signal and error signal may be recovered independently from them by making certain physical filtering operations.
Stratigraphic constraints on the timing and emplacement of the Alika 2 giant Hawaiian submarine landslide

Abstract Previous work has found evidence for giant tsunami waves that impacted the coasts of Lanai, Molokai and other southern Hawaiian Islands, tentatively dated at 100+ and 200+ ka by U-series methods on uplifted coral clasts. Seafloor imaging and related work off Hawaii Island has suggested the Alika phase 2 debris avalanche as the source of the ∼100 ka “giant wave deposits”, although its precise age has been elusive. More recently, a basaltic sand bed in ODP site 842 (∼300 km west of Hawaii) estimated at 100±20 ka has been suggested to correlate with this or another large Hawaiian landslide. Our approach to the timing and linkage of giant submarine landslides and paleo-tsunami deposits is a detailed stratigraphic survey of pelagic deposits proximal to the landslide feature, beginning with a suite of seven piston, gravity and box cores collected in the vicinity of the Alika 2 slide. We used U-series dating techniques, including excess 230 Th and 210 Pb profiling, high-resolution paleomagnetic stratigraphy, including continuous, U-channel analysis, δ 18 O stratigraphy, visual and X-ray sediment lithology, and the petrology and geochemistry of the included turbidites and ash layers. Minimum ages for the Alika phase 2a slide from detailed investigation of two of the cores are 112±15 ka and 125±24 ka (2σ) based on excess 230 Th dating. A less precise age for the Alika phase 1 and/or South Kona slide is 242±80 ka (2σ), consistent with previous geological estimates. Oxygen isotope analyses of entrained planktonic foraminifera better constrain the Alika phase 2a maximum age at 127±5 ka, which corresponds to the beginning of the stage 5e interglacial period. It is proposed that triggering of these giant landslides may be related to climate change when wetter periods increase the possibility of groundwater intrusion and consequent phreatomagmatic eruptions of shallow magma chambers. Our study indicates the contemporaneity of the Alika giant submarine landslides and distal deposits from enormous turbidity currents as well as coral clasts reported to be tsunami deposits on Lanai and Molokai through direct dating and compositional analysis of the landslide deposits.
The uranium geochemistry of latten Volcanic National Park, California

Abstract The uranium contents and relative alpha-particle activities have been determined on thirty-nine samples from Lassen Volcanic National Park. Sodium and potassium were also determined on nineteen of the samples. Secular radioactive equilibrium to within sampling and analytical error was found between the uranium values and the radium values of other workers. The K 2 O U ratio was found to be constant over a fourfold variation in uranium. The relative alpha-particle activity to uranium ratio was also found to be constant in the main Lassen sequence. There is some evidence that zircon crystals contain a proportion of the uranium in the Lassen volcanic rocks.
281 ALANINE PRODUCTION FROM THE IN VITRO HUMAN PLACENTA

The ability of the human placenta to transport amino acids from the mother to fetus is well documented. Net synthesis of certain amino acids such as alanine (A) via transamination is known to occur in such tissues as muscle but it is unclear whether this capacity is shared by placental tissue. Five human placentas were obtained after elective caesarean section. Placental fragments were incubated in a bicarbonate-buffered Earle's solution enriched with oxygen. Placental A production was assessed during a 45 min incubation period by observing the net change in A in tissue and media before and after incubation. Placental glucose (G) consumption was measured utilizing a similar method. Net placental A production was 0.42±0.10 μmoles/gm wet weight/45 min (p<.01). When adjusted for total placental and fetal weights a net placental production of 1.56±0.34 μmoles/kg fetus/min is evident. This represents approximately 1/3 of the A uptake in the fetal sheep. Placental G consumption varied between placentas (mean 4.54±0.78 μmoles/gm/45 min) but was not related to A production. Neither the addition of pyruvate nor insulin altered A production or G consumption. Incubations of 15, 30 and 45 minutes revealed a linear relationship between incubation time and A production, evidence against a simple leaching phenomenon. These data suggest the possibility of intraplacental nitrogen transfer with net synthesis of alanine, a potential fetal fuel as well as protein constituent.
SU-D-218-01: Support Vector Machine Tissue Classification of Multiparametric MRI Tumor Data.

Purpose: To test the accuracy of Support Vector Machines in the classification of Glioblastoma Multiforme tumor voxels usingmultiparametric MRI data. Methods: Various MRI scans were collected from patients with recurrent GBM. Each scan session collected post‐contrastT1(+C T1), T2, diffusion, perfusion, and multi‐echo hypoxia images. Thediffusion‐weighted images were converted to Apparent Diffusion Coefficient (ADC) maps. The perfusion images were corrected for leakage and represented as corrected rCBV maps. All of these scans were co‐registered to each other, giving an input matrix to our support vector machine consisting of roughly 13,000 voxels, each with 5 feature values (+C T1, T2, ADC, rCBVcorrected, delta T2*). The SVM was then trained usingradiologist confirmed labels for ‘cyst’ , ‘tumor’, and ‘normal tissue’. These labels were obtained using longitudinal data as well as clinical scans, and tested on new data to determine the accuracy of classifying tumor and cyst voxels. Results: The tumor model resulted in a specificity of 0.9841 and a sensitivity of 0.7498. The cyst model resulted in a specificity of 0.9825 anda sensitivity of 0.9414. Both models showed improvement with increasing features. Conclusions: These results show that the SVM is capable of classifying tumor and cyst voxels in a single case study. Aside from optimizing the current tumor model, future work will focus on the potential for the SVM to help in early detection of recurrence. In order to achieve this,we will need to test SVMs across patients. If we truly aim for early detection, then we need to prove that the algorithm can be trained on a pool of subjects with recurrent disease, and then test that model on a new patient before recurrence is obvious.
Cost-benefit evaluation of on-farm milk progesterone testing to monitor return to cyclicity and to classify ovarian cysts.

Abstract The effect of using on-farm milk progesterone testing to monitor return to cyclicity after parturition and to classify correctly and to treat cystic cows was evaluated using modeling and simulation. The test was evaluated assuming low and high accuracies of progesterone measurement, first breeding policy of 40 d, average estrus detection rate of 55%, and an average fertility rate of 55%. Three testing schemes (starting milk progesterone testing on d 30, 40, or 50 after parturition) were compared against a control to evaluate the effect of monitoring return to cyclicity on cows' reproductive and economic performance. For this purpose, the use of the test was an economically justifiable management intervention. Starting to test on d 30 after parturition was the most effective scheme, reducing days open by 18 d, replacement rate by 2.4%, and increasing net return per cow per year by $11. Starting to test on d 50 postpartum was not economically justifiable. Accuracy of the test, within the range used in this study, was unimportant. Testing was most profitable in herds with low fertility and low efficiency of estrus detection. The use of the test to classify follicular and luteal cysts and to select the appropriate therapy was not economically justifiable because of the low proportion of cystic cows and the high variation in response to therapy.
The efficiency of binding spontaneous trait inferences to actors’ faces

Abstract Three experiments tested the hypothesis that the process of binding spontaneous trait inferences (STIs) to actors’ representations is relatively independent of attentional resources. Participants were presented with faces paired with single behaviors. Binding of STIs to actors was revealed by a higher false recognition of implied traits paired with actors’ faces than of implied traits randomly paired with other familiar faces. This effect replicated when each face–behavior pair was presented for 2 s (Experiment 1), when the processing of the information was shallow (Experiment 2), and when participants performed a secondary task during the presentation of behaviors (Experiment 3). Experiment 4 showed that explicit on-line trait judgments of the actor, but not explicit behavior judgments, predicted the false recognition of implied traits in the context of the actor. The possibility that the process of binding STIs to actors’ representations is automatic is discussed.
The physical environment affects quality of life based upon environmental sensitivity

Past research has found that architectural and interior features such as windows (Kaye & Murray, 1982; Ulrich, 1984), plants (Ulrich, 1984), comfortable furnishings (Cabral, 1988; Kaye & Murray, 1982), and/or color (Hamid & Newport, 1989; Kwallek, Lewis, & Robbins, 1988; Rosenstein, 1985; Wohlfarth & Gates, 1985) are connected to worker performance, mood and personality, and/or health status. Most strikingly, Ulrich (1984) documented that recovery time from surgery was speedier in a room with a view of a natural setting compared to a room viewing the adjacent building's wall. Furthermore, those people with a natural view took fewer potent analgesics and bothered the nurses less. Thus, a diversity of locales and features have demonstrated an impact upon mood, cognitive performance, and health for different populations, but how do these effects occur? Could mood and/or cognitive performance be affected? In this study, mood was assessed with the Profile of Mood States (McNair, Lorr, & Droppleman, 1971) and the Competency Mood Scale (McClelland & Meterko, 1983). Subscales that were used include Tension, Depression, Hostility, Vigor, Fatigue, Confusion, Relaxation, Anger, Resourcefulness, Friendliness, Negative Mood, and Positive Mood. Cognitive performance was assessed with the Digit Symbol subscale of the Wechsler Adult Intelligence Scale (Wechsler, 1955) and with performance on a tone discrimination task lasting 30 min. These mood and cognitive variables could be differentially affected by the two types of environments. Also, could the environmental sensitivity implied in this past research be mediated by individual differences such as seasonal affectivity and/or absorption ability? Rosenthal (1989) defined seasonal affectivity by the phenomena of sea-
Regulation of calcium currents by chemokines and their receptors

Abstract We investigated the modulation of voltage dependent Ca 2+ currents by chemokine receptors in heterologous expression systems and neurons. Fractalkine, SDF-1α , RANTES and MDC inhibited the I Ba in CX3CR1-, CXCR4-, CCR5- and CCR4-expressing G1A1 cells, respectively. The I Ba inhibition was voltage-dependent, exhibited prepulse facilitation, and was blocked by N -ethylmaleimide and pertussis toxin pretreatment, indicating that it was mediated by Gi/Go. Some chemokines also inhibited the I Ba in subpopulations of dorsal root ganglion neurons and area postrema/nucleus tractus solitarius neurons. These data provide evidence that chemokines can potentially modulate neuronal signaling through the inhibition of neuronal Ca 2+ currents.
Analysis of the relationship between pharmacological inhibition of cyclic nucleotide phosphodiesterase and relaxation of canine tracheal smooth muscle.

Abstract Dose-response curves for muscular relaxation produced by five phosphodiesterase inhibitors were compared to curves for inhibition of phosphodiesterase-catalyzed breakdown of cyclic AMP or cyclic GMP. The rank-order of potency of the agents as muscular relaxants was similar to their order of potency as phosphodiesterase inhibitors. When enzyme activity was measured with 1.5. 38 or 400 μM cyclic AMP or 1.5 μM cyclic GMP as substrate, it was found that two agents, caffeine and SQ 20,009 [1-ethyl-4-(isopropylidenehydrazino)-1H-pyrazolo-(3,4-b) -pyridine-5-car☐ylic acid, ethyl ester, HCl], inhibited activity in concentrations equal to or slightly less than were required for muscular relaxation. The remaining three agents, theophylline, MIX (1-methyl-3-isobutylxanthine), and ICI 58,301 (3-acetamido-6-methyl-8- n -propyl-s-triazolo[4,3-a]pyrazine), were required in 2.4 to 10.3-fold higher concentrations for enzyme inhibition than for muscular relaxation. It was concluded that, although these findings are generally consistent with the hypothesis that phosphodiesterase inhibition is important in the mechanism of action of the drugs tested, it may be necessary to take into account additional, presently unknown factors to explain fully the relaxant effects of these drugs on respiratory smooth muscle.
Theory of the Nucleation, Growth, and Structure of Hydrogen-Induced Extended Defects in Silicon

Implantation and plasma indiffusion of H in crystalline Si are known to induce planar defects (platelets) whose structure has remained elusive. We report extensive first-principles calculations that reveal mechanisms for the nucleation and growth of aggregates of second-neighbor hydrogenated vacancies. These defects exhibit the key features associated with platelets, including a preference for (111) and (100) planes, H release, and trapping of H{sub 2} molecules. {copyright} {ital 1999} {ital The American Physical Society }
Effect of Molecular Orientations on Vibrational‐Translational Energy Transfer

An evaluation of the steric factor 1/Z0 for molecule‐atom and molecule‐molecule collisions has been made for the orientation‐dependent Morse potential over the temperature range from 300° to 4000 °K. 1/Z0 is found to be of the order of 13 for H2‐Ar, 14 for N2‐Ar, 15 for O2‐Ar, 1/7 for Cl2‐Ar, and 19 for I2‐Ar at ordinary temperatures. 1/Z0 for molecule‐molecule collisions is very small compared to these values; it is of the order of 1/20 for H2‐H2, 1/25 for N2‐N2, 1/30 for O2‐O2, 1/50 for C12‐C12, and 1/55 for I2‐I2. A moderately important temperature dependence of 1/Z0 is found. In the calculation of 1/Z0 we explicitly considered the importance of attractive forces and used “realistic” exponential range parameters. The temperature dependence of the parameter is discussed, and it is shown that the serious errors might occur in calculating vibrational transition probabilities if the best‐fit parameter to experimental data at a particular temperature is used over a wide temperature range (>1000°).
Equivalence of the weak and strong axioms of revealed preference without demand continuity assumptions: A “regularity condition” approach

Abstract The main result of this paper is that, provided the range of the demand function is convex and the whole budget is spent, the strong axiom of revealed preference holds if and only if the weak axiom of revealed preference and a certain “regularity” condition both hold. The regularity condition is a relationship between two definitions of expenditure compensation function that must hold if the strong axiom holds. The paper distinguishes itself from previous work in that no continuity assumptions are made on the demand function. It also discusses the relationship of the regularity condition used in this paper to the one used by Uzawa and van Moeseke.
Action of inhibitory amino acids on acute epileptic foci: An electrographic study

Abstract Epileptiform activity was induced in adult cats anesthetized with Ketamine or Na-pentobarbital. Acute models of focal epilepsy were created by application of various epileptogenic agents to neocortical or limbic structures. Inhibitory amino acids were injected intravenously and their effects on epileptiform discharges monitored for 2 h after administration. Amino acid solutions were adjusted to pH between 5.5 and 8. Glycine (to 250 mg/kg) did not induce any change. Short-lasting inhibitory effects (5 s to 9 min) were noted with β-alanine, γ-aminobutyric acid (GABA) (>80 mg/kg), taurine (>50 mg/kg), and 3-aminopropane sulfonic acid (3-APS, >5 mg/kg). The action of 3-APS was particularly powerful in abolishing cortical spiking with only moderate depression of background EEG activity. GABA, taurine, and 3-APS also induced depression of respiration in animals under barbiturate anesthesia. In addition, 3-APS caused a 20% decrease in systolic blood pressure. Similar and even greater pressure decreases were observed after injection of control drugs which did not, however, affect the epileptic firing rate. 3-APS seems to deserve further investigation as a possible antiepileptic and GABA-mimetic agent.
Synthesis and Reactivity of a Coordinatively Unsaturated Ruthenium(II) Parent Amido Complex: Studies of X-H Activation (X = H or C)

Article discussing the synthesis and reactivity of a coordinatively unsaturated Ruthenium(II) parent amido complex and studies of X-H activation (X = H or C).
The Americans with Disabilities Act: II. Implications and Suggestions for Compliance for Medical Schools.

There is a need for more information about the Americans with Disabilities Act that is tailored to colleges of medicine so that faculty, staff, and administrators can understand and carry out their responsibilities under the Act. This report (Part II) and the previous one (Part I) in the same issue of Academic Medicine address this need. In Part I, key terms of the Act are defined; the present report focuses on the educational relationship between medical schools, applicants, and students in the context of the Act. A comprehensive array of the Act's implications are discussed in question-and-answer format. For example, what impact does the Act have on the application and admission process? Can a college of medicine ask students whether they have a disability? When does a school's duty to accommodate a disabled student begin? The report concludes with 15 recommended steps that colleges should take to comply with the Act, such as (1) colleges should develop policies and procedures for applicants and students who want to request accommodation for disabilities; (2) colleges should identify the essential abilities and skills required for admission and for participation in the degree program; and (3) colleges should consider instituting alternate dispute resolution procedures. Although following the recommended steps may seem overwhelming, medical schools are obligated by law to accommodate qualified disabled persons; failure to comply with the Act deprives academically qualified persons with disabilities of the opportunity to demonstrate their ability to fulfill degree requirements and become physicians. Medical educators must continue to adjust their understanding and knowledge of the Act's implications for medical schools, given that the interpretation of the Act will evolve as the courts amplify and implement it.
Solving Partially Hyper-Sensitive Optimal Control Problems Using Manifold Structure

Abstract Hyper-sensitivity to unknown boundary conditions plagues indirect methods of solving optimal control problems as a Hamiltonian boundary-value problem for both state and costate. Yet the hyper-sensitivity may imply manifold structure in the Hamiltonian flow, knowledge of which would yield insight regarding the optimal solutions and suggest a solution approximation strategy that circumvents the hyper-sensitivity. Finite-time Lyapunov exponents and vectors provide a means of diagnosing hypersensitivity and determining the associated manifold structure. A solution approximation approach is described that requires determining the unknown boundary conditions, such that the solution end points lie on certain invariant manifolds, and matching of forward and backward segments. The approach is applied to the optimal control of a nonlinear spring-mass-damper system. The approximate solution is shown to be accurate by comparison with a solution obtained by a collocation method.
Parent status and generativity within the context of race.

Generativity, or providing for the next generation (Erikson, 1950), is usually associated with midlife, and related to parenting. However, the extent to which grandparenting or non-parenting are as...
Nutritional supplementation of pregnant adolescents

Disadvantaged pregnant black teenagers have a higher proportion of low-birth-weight infants and their offspring have a lower mean birth weight. One hundred and fifty-seven pregnant adolescents enrolled in a Baltimore public school for pregnant teenagers were studied to determine the impact of a nutritional supplement on pregnancy outcome. Seventy-eight students voluntarily agreed to receive a nutritional supplement; 79 comparably matched students did not receive the supplement. The supplement Sustacal provided a mean intake of 8691 cal with 530 g of protein and additional vitamins and minerals over an average period of 15.1 weeks. This supplement was associated with a significant increase of 157 g in the mean infant birth weight ( P P P
Acute changes in sputum IL-10 following underground exposure to diesel exhaust

Introduction. Although exposure to diesel exhaust has been linked with adverse health effects, little is known about the acute effects of exposure in the underground workplace. Methods. Cross-shift...
Nonsingular Spherically Constrained Clemens Linkage Wrist

The parallel connection of a revolute-spherical-revolute Clemens linkage with a revolute-universal joint (RU) spherical linkage realizes a two-axis spherical pointing device suitable for use in a robot wrist. The design is derived from a Clemens linkage constant-velocity coupling having a spherical constraint. A novel transverse orientation of the RU linkage facilitates control of the pointing direction through actuation of a pair of revolute joints at the base of the device, a capability not otherwise required when this type of mechanism is employed as a constant-velocity coupling. As the mechanism is confined to spherical space, spherical trigonometry and related geometric reasoning may be employed in the analysis of mobility and actuation. The analysis derives the forward and inverse kinematic relations, showing that the mechanism allows a full 180 deg of deflection of the pointer from the center before encountering a singularity.
Feed-related anemia in cultured channel catfish (Ictalurus punctatus)

Abstract During 1983, 70 cases of severe anemia and death in cultured channel catfish occurred in Alabama and Georgia. These cases could not be associated consistently with pathogens or the pond environment. Diets fed to the affected fish contained no significant levels of pesticides, heavy metals, peroxides (oxidized lipids) or known mycotoxins that could cause the anemia. Experimental induction of severe anemia in cage-held channel catfish resulted in hematocrits as low as 1–9%. Average hematocrit of the affected population was 25.8% compared to an average of 37% for control fish. Hemoglobin concentration and erythrocyte counts were lower in affected fish than in controls, and clotting time of the blood was longer in test fish. The mortality during the study was 9% in the test fish compared to 0.05% in the controls.
A weighted mass explicit scheme for convection-diffusion equations

An explicit scheme based on a weighted mass matrix, for solving time-dependent convection-diffusion problems was recently proposed by the author and collaborators. Convenient bounds for the time step, in terms of both the method's weights and the mesh step size, ensure its stability in space and time, for piecewise linear finite element discretisations in any space dimension. In this work we study some techniques for choosing the weights that guarantee the convergence of the scheme with optimal order in the space-time maximum norm, as both discretisation parameters tend to zero. Mathematical subject classification: Primary: 65M60; Secondary: 76Rxx.
The Case of Pamela

The analysis of Pamela is described, followed by verbatim process of one session. An upbringing of emotional neglect, overstimulation, violent abuse, and lack of boundaries in a family with generations of trauma had left Pamel clinging to a rigid persona built around her abilities to drive herself, to offer herself to others, and to be everything that was required of her in work and social relations. The analysis revealed areas of profound dysregulation and the loss of the sense of herself as alive and inhabiting her own being and body. A consistent holding and containment of these disturbing states was central to the analysis, including, on occasion, the actual holding of Pamela when she was falling apart. A painful enactment of emotional murder in the treatment is described and the sincere and spontaneous response of the analyst that helped transform this potentially destructive moment into one of repair. The session reported occurs as Pamela struggles with the impending termination of this treatment. T...
Undergraduate Fisheries Education: Technical Specialization or Broad Foundation?

Abstract The fisheries profession continues to increase in complexity, and fisheries professionals are more frequently being called upon to function in new settings. Simultaneously, the general sphere of knowledge that surrounds fisheries science and management is expanding rapidly as we learn more about our world and how humans interact with it and each other. In this increasingly complex situation, universities have difficulty achieving their primary goal for undergraduate education—the inculcation of the fundamentals of knowledge combined with abilities to analyze and synthesize. Based on an analysis of a typical curriculum, we suggest that undergraduate training of fisheries professionals is no longer a valid proposition. The focus of undergraduate education should be to provide a broad foundation in the sciences and humanities with only an introduction to fisheries science and management. Undergraduate education of this nature will allow students to make informed decisions about whether they will pur...
In vitro synthesis of a functional avian sarcoma virus transforming-gene product.

A SINGLE avian sarcoma virus (ASV) gene (src) is responsible for the induction and maintenance of cell transformation in vitro and tumour production in infected animals1. The product of the ASV src gene is a phosphoprotein with an apparent molecular weight of 60,000 and has been designated p60src (refs 2–4). This src protein seems to act as a protein kinase when assayed by the transfer of 32P from γ-labelled ATP to IgG in specific immune complexes5. As this protein kinase activity is growth and temperature dependent in chick cells transformed with an ASV temperature-sensitive transformation mutant5, these results suggest that ASV may transform cells by aberrant phosphorylation of cellular proteins. Radiolabelled p60src is synthesised in cell-free extracts programmed by the 3′ third of the viral RNA, the region of the genome which contains the src gene, but not by similar RNA from a mutant which has a deletion of the src gene3,4. Because of the structural similarity between the in vitro and in vivo products4, we tested the in vitro translation product for phosphotransferase activity. We have found that it exhibits protein kinase activity, providing direct evidence that p60src is the functional product of the avian sarcoma virus transformation gene.
Retrieval performance in online search in thermal physiology

Documents on four topics in thermal physiology were searched for in both BIOSIS and MEDLINE using both natural language and standard index words. The search by natural language retrieved more relevant documents than the search by standard index words in both databases. Overall, more relevant documents were retrieved in MEDLINE than in BIOSIS. Even in MEDLINE, however, only about 40% of the total existing documents (as estimated by an expert in thermal physiology) were retrieved.
Postnatal development of the cerebellar cortex in the rat. II. Phases in the maturation of Purkinje cells and of the molecular layer

The growth and synaptic maturation of Purkinje cells and of the molecular layer were studied in the cerebellar cortex of rats aged 0, 3, 5, 7, 10, 12, 15, 21 and 30 days with histological (including Golgi), histochemical, autoradiographic and electron microscopic techniques. Five phases were distinguished in the maturation of Purkinje cells. During the first phase, Purkinje cells become dispersed and aligned in a monolayer but as yet few or no synapses are formed. Next, two transient structures appear: a hypertrophied apical cone composed of „reticular” cytoplasm, and lateral perisomatic processes which establish conspicuous asymmetrical synapses with climbing fibers. During the third phase the perisomatic processes disappear; the „reticular” cytoplasm streams upward into the growing dendrites; the soma is invaded by permanent inconspicuous, symmetrical synapses of basket cells; and, finally, it is surrounded by glial processes, which marks the end of the synaptic maturation of the soma. During the fourth phase parallel fibers form synapses with dendritritic spines in the lower half of the molecular layer. During the fifth phase, which occurs after the disappearance of the external germinal layer, parallel fibers establish synapses with dendritic spines in the upper molecular layer. The „march” of synaptogenesis in the molecular layer from the bottom upward is characterized by three successive events: an initial gradient in the appearance and disappearance of coated vesicles, heralding synaptogenesis; a similar subsequent trend in the formation of synapses; and finally, the interposition in the same sequence of glial processes between Purkinje cell dendrities and parallel fibers, marking the cessation of synaptogenesis.
Antithrombotic therapy in acute myocardial infarction: prevention of venous, left ventricular and coronary artery thromboembolism.

The antithrombotic approach to patients with acute myocardial infarction in the prevention of venous, left ventricular and coronary artery thromboembolic events should be based on an understanding of pathogenesis and risk. Coronary thrombotic events involve conditions of high shear rate present in areas of vessel stenosis or disrupted atherosclerotic plaque, which lead to activation of both platelets and the coagulation system, and are best prevented by platelet inhibitors alone or in combination with an anticoagulant. However, thromboembolism that originates in the venous system or cardiac chambers is related to situations of blood stasis and low shear rate, which predominantly result in clotting activation and fibrin-thrombus formation and are best approached with anticoagulant therapy. For prevention of venous thrombosis and pulmonary embolism, early mobilization is essential and should be supplemented by low-dose heparin in patients at high risk, including the elderly and those with large infarcts, heart failure or previous thromboembolic events. For prevention of left ventricular mural thrombosis and systemic embolism, high-dose heparinization is indicated in patients with large infarcts, particularly in the anterior location and in those with heart failure. Subsequently, warfarin therapy should be considered for patients at high embolic risk, including those with echocardiographic evidence of mobile and protruding thrombi, severe left ventricular dysfunction or prior emboli. In patients with acute infarction, aspirin is recommended for preventing coronary reocclusion and reinfarction. Although anticoagulants may also be of benefit for this purpose, their use is still controversial. In situations of high risk of reocclusion, such as after administration of a thrombolytic agent, a combination of aspirin and heparin seems most appropriate, pending the results from randomized trials that will address this issue. Finally, for secondary prevention of myocardial infarction and cardiac mortality, chronic aspirin therapy is indicated. Long-term anticoagulation may also be beneficial but is associated with significant cost, discomfort and adverse effects.
Compensation methods for buried defects in extreme ultraviolet lithography masks

Two methods will be presented to compensate for buried defects in patterned extreme ultraviolet (EUV) masks. The goal of the methods in this work is to prescribe modifications to the absorber pattern on an EUV mask with a buried defect so that the final image printed on the wafer matches the intended pattern through focus. The first method uses pre-calculated design curves to determine the required absorber modification for a given defect. This method is able to compensate for a defect in focus, but not through focus. A second method is presented, covering the defect with absorber, which reduces the effect of the defect through focus. Both of these methods work for pit and bump defects.
Isolation and structural studies of native RPE and BM fluorophores

Purpose To determine the chemical structure, fluorescence spectra and lifetimes and spatial distribution of the major retinal lipofuscin and Bruch’s membrane fluorophores and to correlate their relative amounts with disease. Methods Human RPE lipofuscin granules and Bruch’s membrane explants were isolated from donor globes (Midwest Eye Banks and Transplantation Centers). The organic soluble portion was obtained by extraction with equal amounts of CHCl3:CH3OH:H2O, and the extract was analyzed by LC-MS (Thermo Finnigan, LCQ Advantage, Surveyor; Surveyor LC with fluorescence and PDA detectors, quadrupole ion trap mass analyzer, electrospray ion source). Fluorescence lifetimes were measured with a PTI Timemaster Lifetime analyzer. MALDI spatial distribution maps were imaged with an Applied Biosystems Voyager-DE Biospectrometry workstation. Results Several derivatives, including higher molecular weight condensation products, of A2E have been isolated and structurally and spectroscopically characterized. A Bruch’s membrane specific biomarker, nitro-A2E, has also been characterized and found to increase in concentration with both age and progression of AMD. These materials have unique fluorescence emission maxima and lifetimes and can be used with non-invasive diagnostic methods. The spatial distribution of these molecules yields information as to their origin. Conclusion Knowledge of the fluorescence maxima and lifetimes of identified retinal fluorophores may allow for a more detailed interpretation of fundus autofluorescence. Of particular importance are the trends in concentration as a function of disease state.