cssi/SciSciGPT-SciSciNet huggingface dataset:
The 31P NMR spectra of partially oriented cyclic halogenophosphazenes

31P chemical shift anisotropies for P3N3F6 and P3N3Cl6 from NMR spectra in the nematic phase are reported. Molecular symmetries for P3N3F6, P3N3Cl6, and P4N4Cl8 are also determined from the splitting pattern. Decoupling through double irradiation is employed to achieve simplification of the P3N3F6 spectra. The results are correlated with other experimental evidence and discussed in terms of a bonding model by Paddock.
The specific impedance of the dorsal columns of cat: An anisotropic medium

Abstract Low frequency, nonstimulating current was passed from a small electrode on the surface of the dorsal columns in the cervical cord of cats. A glass microelectrode was used to record the voltage at distances of 0.5 to 3 mm from the current electrode. The voltage fell off more rapidly in depth and across the dorsal columns than it did longitudinally—the resistance was lower in the longitudinal direction. Accordingly, the dorsal columns are anisotropic. An approximate equation is presented which describes the data fairly well and which is consistent with the anatomy. From this equation, the resistivity in the longitudinal direction was 138 to 212 ohm-cm and in the transverse direction, 1,211 ohm-cm. These values are shown to be consistent with the view that the anisotropy is primarily due to current flowing longitudinally in axons. The frequency dependence of the specific impedance was also measured. Some features of this frequency dependence have no clear explanation, but some of them are consistent with a nodal membrane having a time constant of roughly 50 μsec.
Inhibition of Ebola Virus Entry through Biophysical Identification of Functionally Important Residues in the GP2 Fusion Loop

Ebola virus (Ebov), is an enveloped filovirus capable of causing severe hemorrhagic fever in humans. Viral entry and membrane fusion is accomplished through rearrangement of the glycoproteins (GP) that stud the outside of the virus particle. Here we have focused our attention on the section of amino acids found in GP called the internal fusion loop (FL). The FL is thought to interact directly with the host membrane allowing for the fusion process to begin. We performed site-directed mutagenesis on the FL to identify key residues required for activity in liposome mixing and pseudo-virus entry. A completely inhibited mutant was identified and a structure in DPC micelles at pH 5.5 was determined using solution NMR spectroscopy.From our previous Ebov FL structures, we hypothesized that the arrangement of hydrophobic residues was key for membrane interaction (1). This was further confirmed through the NMR structure presented here of the inhibited double mutant L529A/I544A FL where the arrangement of hydrophobic residues at the tip of the molecule was significantly disrupted compared to WT. This study shows the importance of the structural arrangement of residues in the FL and their impact on Ebola virus entry.1. Gregory, S. M., Harada, E., Liang, B., Delos, S. E., White, J. M., and Tamm, L. K. (2011). Structure and function of the complete internal fusion loop from Ebolavirus glycoprotein 2. Proc Natl Acad Sci USA 108(27), 11211-6.
Antigenic relationships of the venom of Atractaspis microlepidota to that of other snakes.

Abstract Venoms of Atractaspis microlepidota and Causes rhombeatus were used in gel diffusion reactions against 31 antisera. Atractaspis venom reacted with 10 of 16 elapid sera giving 1 to 3 bands of precipitate, with 1 of 6 viperid antisera and with 2 of 7 crotalid antisera. Causus venom reacted with all viperid antisera giving 2 to 4 bands of precipitate, with 6 crotalid antisera and with 8 elapid antisera. Atractaspis venom gave no reaction with boomslang (Dispholidus) or sea snake (Enhydrina) antiserum; Causus venom gave a weak reaction with boomslang. Atractaspis venom was not neutralized by cobra, tiger snake or habu antivenins, although it gave strong precipitin reactions with them. No definite evidence for neurotoxic action of Atractaspis venom was obtained.
Development and Characterization of Stable Sediment-Free Anaerobic Bacterial Enrichment Cultures That Dechlorinate Aroclor 1260

We have developed sediment-free anaerobic enrichment cultures that dechlorinate a broad spectrum of highly chlorinated polychlorinated biphenyls (PCBs). The cultures were developed from Aroclor 1260-contaminated sediment from the Housatonic River in Lenox, MA. Sediment slurries were primed with 2,6-dibromobiphenyl to stimulate Process N dechlorination (primarily meta dechlorination), and sediment was gradually removed by successive transfers (10%) to minimal medium. The cultures grow on pyruvate, butyrate, or acetate plus H(2). Gas chromatography-electron capture detector analysis demonstrated that the cultures extensively dechlorinate 50 to 500 mug/ml of Aroclor 1260 at 22 to 24 degrees C by Dechlorination Process N. Triplicate cultures of the eighth transfer without sediment dechlorinated 76% of the hexa- through nonachlorobiphenyls in Aroclor 1260 (250 mug/ml) to tri- through pentachlorobiphenyls in 110 days. At least 64 PCB congeners, all of which are chlorinated on both rings and 47 of which have six or more chlorines, were substrates for this dechlorination. To characterize the bacterial diversity in the enrichments, we used eubacterial primers to amplify and clone 16S rRNA genes from DNA extracted from cultures grown on acetate plus H(2). Restriction fragment length polymorphism analysis of 107 clones demonstrated the presence of Thauera-like Betaproteobacteria, Geobacter-like Deltaproteobacteria, Pseudomonas species, various Clostridiales, Bacteroidetes, Dehalococcoides of the Chloroflexi group, and unclassified Eubacteria. Our development of highly enriched, robust, stable, sediment-free cultures that extensively dechlorinate a highly chlorinated commercial PCB mixture is a major and unprecedented breakthrough in the field. It will enable intensive study of the organisms and genes responsible for a major PCB dechlorination process that occurs in the environment and could also lead to effective remediation applications.
Melatonin stimulates brain glutathione peroxidase activity

Exogenously administered melatonin causes a 2-fold rise in glutathione peroxidase activity within 30 min in the brain of the rat. Furthermore, brain glutathione peroxidase activity is higher at night than during the day and is correlated with high night-time tissue melatonin levels. Glutathione peroxidase is thought to be the principal enzyme eliminating peroxides in the brain. This antioxidative enzyme reduces the formation of hydroxyl radicals formed via iron-catalyzed Fenton-type reactions from hydrogen peroxide by reducing this oxidant to water. Since the hydroxyl radical is the most noxious oxygen radical known, induction of brain glutathione peroxidase might be an important mechanism by which melatonin exerts its potent neuroprotective effects.
Levels of 19F from the 15N(α, γ)19F reaction for Eα = 2.8–4.0 MeV

Abstract Resonances in the 15N(α, γ)19F reaction for Eα = 2.8–4.0 MeV have been studied. Resonance strengths and angular distributions have been measured, leading to branching ratios, mixing ratios, γ-decay strengths and spin-parity assignments for the following levels (energies in keV) in 19 F : 6281 ( 5 2 + ), 6330 ( 7 2 + ), 6498 ( 3 2 + ), 6526 ( 3 2 + ), 6553 ( 7 2 ), 6592 ( 9 2 + ), 6785 ( 3 2 − ), 6836 ( 5 2 ), 6891 ( 3 2 − ) and 6925 ( 7 2 − ) .
Unexpected symmetries in unstable graphs

This paper considers instability of graphs in all of its possible forms. First, four theorems (one with two interesting special cases) are presented, each of which shows that graphs satisfying certain conditions are unstable. Several infinite families of graphs are investigated. For each family, the four general theorems are used to find and prove enough theorems particular for the family to explain the instability of all graphs in the family up to a certain point. A very dense family of edge-transitive unstable graphs is constructed and, at the other extreme, an unstable graph is constructed whose only symmetry is trivial. Finally, the four theorems are shown to be able to explain all instability.
ESR of pernigraniline base solutions revisited

Abstract A new electron spin resonance solution spectrum for intrinsic paramagnetic defects in pernigraniline base (PNB) is reported. Our previously reported ( Synth. Met. , 55–57 (1993) 648) solution spectra for PNB were found to correspond to a nitroxyl radical contaminant. The correct isotropic splitting constant for the nitrogen hyperfine interaction in PNB is measured to be 9.8 ± 0.4 G. The π-electron spin density on the central nitrogen atom for intrinsic defects in PNB is estimated to be 0.36. This experimentally determined density is in good agreement with calculated densities for the neutral soliton in PNB.
Mouse limb bud development in submerged culture: Quantitative assessment of the effects of in vivo exposure to retinoic acid

Retinoic acid, suspended in cottonseed oil, was administered via gavage to pregnant mice (ICR strain) on day 11 (E 11) of gestation at doses of either 20, 40, or 80 mg/kg. Fetuses were examined for external malformations on day 17 (E 17). Retinoic acid treatment induced micromelia (with the elimination of several long bones at higher doses) and digital defects (ectrodactyly and syndactyly) in a dose-dependent manner in fetuses examined on day 17. Hindlimbs were affected more than forelimbs. In another group of experiments, limbs exposed to retinoic acid treatment in utero on E 11 were cultured on E 12 and maintained for 3 days in submerged culture. Cultured limbs were examined qualitatively for digital and long bone defects, and image analysis of the area and form of bone anlagen of cultured limbs was used to quantitatively evaluate the teratogenic potential of retinoic acid. The qualitative evaluation indicated that the retinoic acid-induced effects obtained in vivo and with pretreated, cultured limbs were essentially the same, except that the severity of regional effects changed as a result of culture. The incidence of ectrodactyly was higher with cultured limbs than with E 17 fetal limbs, but fewer cultured limbs were missing long bones. These results suggest that culturing limbs, after they have been pretreated in utero, modifies their response to a teratogen and demonstrates that the paw skeleton is extremely sensitive to teratogen treatment under these experimental conditions. Therefore, care must be exercised when attempting to compare in vivo and in vitro teratogenic data. This study also clearly demonstrates the power and usefulness of image analysis for quantitative evaluation of both the area and form of a cultured specimen such as the developing limb bud. Quantitative, image analysis of cultured limbs showed a dose-dependent decrease in area of both fore- and hindlimbs. The effect was most severe in hindlimbs. In the forelimb, the paw was affected more than the long bones; as the dose increased, this disparity of effect also increased. With the hindlimb, a greater effect on the paw occurred only at 80 mg/kg. Computing the soft tissue/bone ratio illustrated that retinoic acid had a greater effect on chondrogenic tissue than on soft tissue.
RCS: A cognitive architecture for intelligent multi-agent systems☆

Abstract Real-time control system (RCS) is a cognitive architecture designed to enable any level of intelligent behavior, up to and including human levels of performance. RCS consists of a multi-layered multi-resolutional hierarchy of computational agents each containing elements of sensory processing (SP), world modeling (WM), value judgment (VJ), behavior generation (BG), and a knowledge database (KD). At the lower levels, these agents generate goal-seeking reactive behavior. At higher levels, they enable decision-making, planning, and deliberative behavior. At all levels, the architecture supports signal grounding and abductive inference. A methodology is described for designing RCS systems, and experimental results are presented from a series of performance tests designed to measure technology readiness.
Cardiovascular effects of estrogen

There is a strong link between menopause and increased cardiovascular disease incidence in women, and observational studies suggest that postmenopausal hormone replacement therapy (HRT) reduces cardiovascular disease risk. However, the only published prospective controlled trial of the effects of HRT on cardiovascular outcomes (Heart and Estrogen-Progestin Replacement Study, HERS) showed no net benefit of conventional HRT in women with established coronary disease. An angiograpic study of HRT in a similar patient population showed no regression of established coronary lesions in the active treatment group. Fundamental mechanistic studies of the cellular and molecular events by which hormones protect (or fail to protect) blood vessels are needed to define the role of postmenopausal HRT in cardiovascular disease. Herein, we review studies from our laboratory using the rat carotid injury model showing that estrogen inhibits neointima formation through an estrogen receptor (ER)-dependent mechanism operative in the early period after vascular injury. We have demonstrated that activation of vascular smooth muscle cells and subsequent release of soluble factors including osteopontin stimulate the migration of adventitial fibroblasts in a luminal direction to eventually take up residence in the neointima, and furthermore, that production, release, or posttranslational processing of these factors are inhibited by estrogen through an ER-dependent mechanism. The relevant observational and prospective data on HRT in cardiovascular disease prevention are reviewed, and the cardiovascular effects of estrogen are discussed.
13C NMR studies of poly(propylene oxide) complexed with alkali iodes

Abstract 13 C NMR spectra of poly(propylene oxide) (PPO) and PPO complexed with LiI or NaI, obtained in the solid state using CPMAS techniques, are reported. The methyl carbon exhibits a surprisingly large upfield shift (∼2 ppm in PPO 8 LiI) due to complexation, which may reflect the negative role played by the methyl group in cation solvation. Line broadening in the complexes is entirely consistent with the increase in the glass transition temperature associated with the formation of the complex. Measurements on PPO 8 NaI obtained under a variety of conditions indicate the presence of limited segmental motions on several timescales.
Optical wave group velocity reduction in sodium without on-resonance electromagnetically induced transparency

A Raman scheme for optical-pulse group velocity reduction is applied to a pure lifetime broadened sodium atomic system. In addition to the significant reduction of group velocity, probe field loss and smaller pulse distortion, as expected for such a scheme, we also investigate possible dipole moment combinations for the optimum probe pulse propagation. We show that the nuclear spin of sodium atomic system and proper laser coupling scheme can conspire to dramatically reduce the influence of any nearby state in a multi-level system, making it a nearly perfect 3-level system.
Undergraduate fluency with information and communication technology: perceptions and reality

Students must be fluent with information and communication technology (ICT) to participate fully and confidently in the 21st century. However, there is growing concern that despite having grown up with computers and the Internet, today's undergraduates may not be sufficiently fluent with ICT. There is also evidence that suggests a discrepancy between perceptions and reality regarding students' ICT fluency.This paper reports student's perceptions regarding their own ICT fluency and compares their perceptions with actual ICT assessment results. Approximately 200 undergraduate students enrolled in a computer information science (CIS) general education course were surveyed and asked to rate their proficiency performing tasks requiring the use of ICT. These students also completed an online scenario based ICT assessment in which they were required to actually perform tasks associated with accessing, evaluating, integrating and communicating information. The majority of students did not perform at their own perceived level. Results of the study have implications for information literacy, ICT education and assessment.
The Programmer's Apprentice: Knowledge Based Program Editing

An initial implementation of an interactive programming assistant system called the programmer's apprentice (PA) is described. The PA is designed to be midway between an improved programming methodology and an automatic programming system. The intention is that the programmer will do the hard parts of design and implementation while the PA will assist him wherever possible. One of the major underpinnings of the PA is a representation (called a plan) for programs which abstracts away from the inessential features of a program, and represents the basic logical properties of the algorithm explicitly.
Shell model level densities for light nuclei

Abstract Shell model level densities are calculated for many light nuclei assuming the valence nucleons move in the ( ls , 0 d , 0 f case7 2 ) orbits about an inert 16O core and interact via realistic effective two-nucleon interactions. These level densities are compared, near the proton threshold, to those of the Fermi level densities used in the compound heavy ion reactions. The general conclusion is that the Fermi level densities underestimate the level densities of higher angular momentum states. The shell model level densities are used to extract ground-state energies and low excitation spectra for light nuclei and these are compared to empirical values. Predicted yrast lines agree quite well with recent experimental data on high angular momenta states in 23Na and 23Mg.
Comparative metabolism of 7,12-dimethylbenz[a]-anthracene and its non-carcinogenic 2-fluoro analogue by Syrian hamster embryo cells.

Abstract The metabolism of 7,12-dimethylbenz[ a ]anthracene (DMBA) and its non-carcinogenic 2-fluoro analogue (2F-DMBA) by Syrian hamster embyro (SHE) cells has been studied using high pressure liquid chromatography (HPLC) and fluorescence spectroscopy. Metabolites produced by SHE cells were compared chromatographically to those produced on a larger scale by liver microsomal preparations and previously identified by gas chromatography and mass spectrometry. At least 2 (possibly 3) phenol metabolites, none of which appear to be in the A-ring, were formed from [ 3 H] 2F-DMBA and totalled only 3% of the organic extractable activity present in the media at 24 h. On the other hand, 3 A-ring phenols (DMBA-2-ol, DMBA-3-ol and DMBA-4-ol) comprising almost 12% of the total organic extractable radioactivity at 24 h were identified as metabolites in SHE cell culture media. For both hydrocarbons the major organic extractable metabolite present at 24 h was the respective 8,9-dihydro-dihydroxydiol (DMBA 45%, 2F-DMBA 39%). Thus, substitution of fluorine for hydrogen at the 2-carbon of DMBA appears to block or greatly reduce the A-ring metabolism of this compound but has relatively little effect on D-ring oxidation. Therefore loss of the carcinogenic/mutagenic activity of DMBA correlates with the extent of A-ring metabolism including, possibly, the bay region diol epoxide.
The formation of atmospheric fronts downstream in a deformation field

An analytical study is made of simple models of steady fronts in the atmosphere in which the temperature field is subjected to deformation as the fluid moves downstream in a large-scale horizontal flow. One fundamental approximation is made and then a Lagrangian method, in which fluid particles are identified by conservation of entropy and potential vorticity, and by Bernoulli's theorem, enables the steady problem to be solved. Solutions for models of surface fronts and upper tropospheric fronts are compared with those obtained from a model in which there is no variation along the front and the frontogenesis proceeds in time. If the thermal wind is comparable with the basic wind, and the potential vorticity is not negligible in some sense, the frontogenesis is increased where the thermal wind opposes the basic flow but, decreased where it reinforces the flow.
Design and applications of a CMOS analog multiplier cell using the differential difference amplifier

This paper presents design techniques for a wide input range CMOS differential difference amplifier (DDA) and discusses its application as a basic block in the implementation of a simple four-quadrant multiplier cell. The cell can be configured as an amplitude modulator or a one-over circuit, which are widely used in many analog signal processing applications. The DDA can also be reconfigured as an opamp, and hence can be used to design many of the opamp-based multiplier circuits. The DDA amplitude modulator (AM) uses a transistor and a resistor as the only components external to the DDA. A DDA one-over circuit, which provides an output proportional to the inverse of the input, is also achieved with the same level of simplicity. High-frequency effects due to the DDA's finite gain-bandwidth (GB) and MOS parasitic capacitances are investigated. Experimental results obtained from a 2µm CMOS MOSIS chip are given.
Developmental Models of Adult Life: Myth or Reality.

This study investigates the existence of age related life stages and the presumed evolution of attitudes and perceptions in accordance with passages through these successive developmental plateaus. The research utilizes data from six national samples gathered as part of the General Social Survey between 1972 and 1977 by the National Opinion Research Center (N=9120). Criteria suggested by developmental theorists and other social scientists are employed to examine respondents' life orientation and satisfaction. In most Instances age is minimally related to attitudes in these areas while social class and to a lesser extent race and sex emerge as statistically significant and substantively important predictors of these dimensions. The results suggest the difficulties in identifying age related adult life phases through national surveys of attitudes and challenges the underlying assumptions for the existence of uniform age related stages.
Mobility of the early equine conceptus

Movement of the conceptus within the uterine lumen of barren mares was studied by daily ultrasound examinations on days 11-20 and by rectal palpation on days 15-48 (Experiment 1) and by ultrasound examinations 3 or 4 times per day at 2-4 hour intervals on days 11-16 (Experiment 2). In addition, broodfarm records were analyzed to compare side of ovulation with side of embryo attachment (Experiment 3). The vesicle was found in opposite uterine horns for 43% of the successive, daily, ultrasound examinations on days 11 and 12, 12 and 13, 13 and 14, and 14 and 15; 24% of the successive examinations on days 15 and 16; and 8% on days 16 and 17. No movement was detected after day 17. The vesicle was found in opposite horns during 41% of the successive examinations at 2-4 hour intervals on days 11, 12, 13, 14, and 15, but no movement was detected on day 16. In addition, no transuterine migration was found by rectal palpation between the day of first detection of an embryonal enlargement (mean, day 17) and day 48. During ultrasound examination on days 11-15, the vesicle was found significantly more frequently in the left horn (66% of the observations) than in the right horn (34%); however, final attachment occurred more frequently in the right horn (63% of the mares). In analyses of brood-farm records, ovulation occurred with equal frequency in left and right ovaries in barren and lactating mares, but with significantly greater frequency in the left ovary (63%) in maiden mares. Regardless of the side of ovulation, final attachment of the conceptus occurred significantly more frequently in the right horn (66%) in barren and maiden mares, but not in lactating mares.
Integral equation approach to multiphoton ionization by intense fields

We discuss the integral equation for an electron bound by a potential in a monochromatic, spatially homogeneous laser field which is turned on adiabatically. We outline a method for the solution of this equation, and, as a numerical example, present results for the photoionization of hydrogen in the weak field limit.
Mean and variance of FST in a finite number of incompletely isolated populations.

Abstract In the presence of migration F ST in a finite number of incompletely isolated populations first increases, but after reaching a certain maximum value, it starts to decline and eventually becomes 0. The mean and variance of F ST in this process are studied by using the recurrence formulas for the moments of gene frequencies in the island model of finite size as well as by using Monte Carlo simulation. The mean and variance in the early generations can be predicted by the approximate formulas developed. On the other hand, if we exclude the cases of an allele being fixed in all subpopulations, the mean of F ST eventually reaches a steady-state value. This value is given by 1 − 2 N T (1 − λ ) approximately, where N T is the total population size and λ is the rate of decay of heterozygosity at steady state. It is shown that the mean and variance of F ST depend on the initial gene frequency and when this is close to 0 or 1, Lewontin and Krakauer's test of the neutrality of polymorphic genes is not valid.
Measurement of interface strength by a laser spallation technique

Abstract A laser spallation experiment has been developed to measure the strength of planar interfaces between a substrate and a thin coating (in the thickness range of 0.3–3 μm). In this technique a laser pulse of a high enough energy and a pre-determined duration is converted into a pressure pulse of a critical amplitude and width that is sent through the substrate toward the free surface with the coating. The reflected tensile wave from the free surface of the coating pries-off the coating. The critical stress amplitude that accomplishes the removal of the coating is determined from a computer simulation of the process. The simulation itself is verified by means of a piezo-electric crystal probe that is capable of mapping out the profile of the stress pulse generated by the laser pulse. Interface strength values ranging from 3.7 to 10.5 GPa were determined for the Si/SiC system. For the interfaces between pyrolytic graphite and SiC coatings an average strength of 7.2 GPA was measured, while the corresponding interface strength between a Pitch-55 type ribbon with a fiber-like morphology and SiC coatings was found to be 0.23 GPa. Intrinsic strengths of SiC coatings and Si crystal were also determined using this technique. These were, on the average, 8.6 GPa for Si crystals and 11.9 GPa for a SiC coating. Furthermore, the potential of the laser technique to determine the interface toughness was also demonstrated, provided well-characterizable flaws can be planted on the interface.
Modulated lapped transforms in image coding

The class of modulated lapped transforms (MLT) with extended overlap is investigated in image coding. The finite-length-signals implementation using symmetric extensions is introduced and human visual sensitivity arrays are computed. Theoretical comparisons with other popular transforms are carried and simulations are made using intraframe coders. Emphasis is given in transmission over packet networks assuming high rate of data losses. The MLT with overlap factor 2 is shown to be superior in all our tests with bonus features such as greater robustness against block losses.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Flow Behavior of Mixed-Protein Incipient Gels

Strong protein gel networks may result from synergistic interactions with other proteins or food materials above that are not achievable with a single protein alone. The varying flow and viscoelastic behavior of calcium caseinate or whey protein isolate mixed with egg albumin, fish protein isolate, soy protein isolate, or wheat gluten in a model system with wheat flour and glycerol as starch and oil surrogates was determined. Temperature sweeps revealed peak tan δ values as the proteins aggregated. Single protein gels of calcium caseinate, soy protein isolate, and wheat gluten were predominantly elastic, while egg albumin and whey protein isolate gels were mostly viscous. For example, egg albumin steady shear viscosities were: 0.0145 Pa s (0.5 min) and 0.1331 Pa s (45 min), and whey protein isolate 0.0003 Pa s (0.5 min) and 0.0024 Pa s (45 min); but combined with whey protein isolate (whey protein isolate/egg albumin: 10/5 wt%), the apparent viscosity values dropped to 0.0053 Pa.s (0.5 min) and 0.0221 Pa ...
Postictal pulmonary edema.

IN 1908 Shanahan 1 described acute pulmonary edema as a complication of convulsions in 11 epileptics. Two years later Ohlmacher 2 presented five similar cases. Since that time few reports on postictal pulmonary edema (PIPE) have appeared, 3-6 only one 6 being in the English language. The purpose of this communication is to review the subject of PIPE and to present two illustrative cases. Report of Cases Case 1. —A 69-year-old Negro man was brought to the hospital on Sept 23, 1965, after having been found unconscious in a local bus depot. According to a friend the patient had experienced about one generalized epileptic seizure per month during the previous four years. Upon his arrival in the emergency room, the patient was oriented but lethargic. Minutes later he had a typical grand mal seizure which was witnessed by a physician. When the convulsion ended the patient was not in distress.
Bullae in the Donor Site of a Split‐Thickness Skin Graft

A patient developed bullae in a donor site 3 weeks after a split-thickness skin graft was taken. No reference to blistering in the donor site of a recently taken split-thickness skin graft could be found in the surgical literature, and a computerized search of the world's medical literature revealed only a single report of a similar case. The mechanism of bulla formation has not been elucidated. We alert physicians to this phenomenon and urge that each case that is seen be studied in an orderly manner by histologic, electron microscopic, and immunofluorescent techniques.
Théorie de la diffraction de photoélectrons appliquée au dichroïsme circulaire et à l'émission de photoélectrons polarisés en spin

Nous esquissons des methodes theoriques pour calculer le dichroisme circulaire (DC), la polarisation en spin (PS), le dichroisme magnetique circulaire (DMC), et le dichroisme magnetique lineaire (DML), phenomenes qui existent en photoemission de niveaux de coeur excitee par de la lumiere polarisee circulairement et lineairement. Le present formalisme generalise nos logiciels anterieurs qui calculent la multidiffracticn des photoelectrons jusqu'a convergence complete. Les resultats de ces nouveaux calculs sont compares a des donnees experimentales obtenues par plusieurs groupes pour plusieurs cas illustratifs: le DC en photoemission de surfaces non-chirales [CO sur Pd(111); Si(001)]; la PS en photoemission d'atomes non-magnetiques et magnetiques, et de surfaces [Xe; W(110); Fe(110)]; et le DMC en photoemission de Fe(110). Nous discutons les conditions qui engendrent le dichroisme circulaire en l'absence de chiralite structurelle ou de magnetisme. Nous mettons egalement l'accent sur le rapport etroit entre le DC non-magnetique et le DC magnetique, ainsi que sur le comportement tres anisotrope de la PS et son importance dans les etudes de l'ordre magnetique par diffraction de photoelectrons polarises en spin.
Experience with directional coronary atherectomy since pre-market approval.

Abstract Directional coronary atherectomy (DCA) received Food and Drug Administration (FDA) Pre-Market Approval in September 1990 and was then released through formal training certification of physicians at each new site. Procedure volume has increased dramatically since approval, with >17,000 DCA procedures performed in 1991 and a cumulative total of >33,000 procedures by mid-1992, at >670 centers in the United States. Clinical application and results since approval have generally been similar to preapproval multicenter investigational results. Comparison of pre- and postapproval usage at the Medical College of Virginia shows similar baseline characteristics and indications, although recent patients show a higher proportion of “salvage” DCA for failed or suboptimal angioplasty (60% vs 14%) or DCA in combination with multidevice multiple vessel intervention (30% vs 38%). Overall results in 300 patients and 345 procedures included procedural success in 95%, clinical success In 94%, with major complications in 4.6% (including urgent bypass surgery in 3.8%, Q wave myocardial infarction in 1.7%, and hospital mortality in 0.3%). Results before and after FDA approval were similar for procedural success (94% vs 96%), clinical success rate (94% vs 94%), and major complications (5.5% vs 4.4%). There was a trend toward lower urgent surgery rate (5.4% vs 3.3%) in the more recent experience. In addition to its established efficacy for highly eccentric lesions, newer applications for which DCA is being used following FDA approval include treatment of saphenous vein grafts, thrombus-associated lesions, aorto-ostial lesions, failed or suboptimal percutaneous transluminal coronary angioplasty result, bifurcation lesions, and use as part of multivessel intervention. Although comparative studies of DCA versus balloon angioplasty or other technologies will help clarify the optimal interventional approach for these indications, the post-FDA approval experience with DCA shows that a new technology can be introduced and disseminated effectively by transmitting the lessons learned during preapproval investigation to newer operators attending organized training programs.
Mapping a 3‐D conductivity anomaly using a vertical electric source: Field results

A method for monitoring an enhanced oil recovery (EOR) process is the mapping of electrical conductivity changes due to injection of steam or other fluids. Since the conductivity change will be three-dimensional (3-D) in character, it is necessary to develop techniques to map 3-D conductivity distributions. At the Richmond test site, near Berkeley California, we conducted a field experiment to map a 3-D salt water plume using a vertical electric source (VES) emplaced in the earth. We selected this source because when emplaced in a horizontally layered host it produces no vertical magnetic field nor horizontal magnetic field at or above the earth's surface. Because there is no layered host response in these instances, the detectability of 3-D electrical structures is greatly increased since only secondary magnetic fields are measured for this case. Data consisting of the horizontal magnetic field were collected at the surface before and after injection of the salt water to create a plume. These data were spatially filtered to eliminate near surface geologic variations. The post-injection data were then normalized with respect to the pre-injection data and interpreted. Our preliminary interpretation of the data is based on 3-D forward modeling. We interpret a 3-D conducting, elongatedmore » target centered approximately 10 m away from the injection well. At the present time our analysis has not provided depth information; however, we expect the target to be contained within the aquifer at a depth of 30 m. The results of this field test illustrate the utility of this technique. 10 refs., 6 figs.« less
Epicenter Location by Analysis of Interictal Spikes

: Artificial neural network (ANN) technology is finding increasing application in medicine and biomedical engineering. This paper supplies necessary background in ANN technology for researchers unfamiliar with this rapidly emerging discipline. This introduction to ANN application is cast in the context of epileptic seizure epicenter location. This is a very real problem faced by neurosurgeons every day. Precise location of the area of excision is currently determined with a network of surgically implanted subdural electrodes. This means that the cure entails two surgical procedures: one to implant the electrode array that precisely locates the epicenter, and another to remove the epicenter. This paper outlines an experimental diagnostic software system (DSS) that uses artificial neural network (ANN) analysis of magnetoencephalographic (MEG) data to eliminate the first of these surgical procedures. The MEG recording is a quick and painless process that requires no surgery. This approach has the potential to save time, reduce patient discomfort, and eliminate a painful and potentially dangerous surgical step in the treatment procedure.
The relationship between ADHD theory and practice: A preliminary investigation

In a study of the degree to which theoretical understanding of ADHD as a disorder of executive function influences school-based intervention, the most commonly used curricular materials produced and distributed for use with ADHD students were reviewed. In addition, school psychologists were surveyed regarding typical intervention practices. School psychologists reported infrequent use of general practices designed to systematically improve executive functions in contextually relevant ways. Similarly, commonly used curricular materials for students with ADHD include rare references to general executive function interventions through everyday routines. Although school psychologists reported use of both contingency and antecedent management approaches, the curricular materials reviewed reveal considerably greater emphasis on contingency management procedures, which are generally not consistent with an executive function orientation and are contrary to the growing body of literature suggesting that individual...
Disability Simulations: Logical, Methodological and Ethical Issues

ABSTRACT This paper examines issues of theory, methods and ethics in the use of disability simulations. Much of the educational, rehabilitation and counseling literature encourages teachers and counselors to use simulations to reduce prejudice toward persons with disabilities. However, the disability simulation literature reveals that: (a) there is typically a failure to consider the relationship between social/behavioral science theory and simulation design; (b) there are methodological weaknesses in most of the studies that render them virtually worthless to evaluate attitude change; and (c) there is little discussion of ethical concerns in disability simulations. A research agenda is proposed that focuses on logical, methodological and ethical issues in disability simulations. It is argued that simulations can be effective if: (a) certain ethical precautions are taken; (b) activities are well designed and evaluated; and (c) the simulation exercises are closely linked to social/behavioral science theory.
On UMVU estimators and Bhattacharya bounds in exponential distributions

Abstract A subfamily of exponential distributions is considered and it is shown that the variance of the UMVU estimator of an estimable function g (θ) having power series expansion is the limit of Bhattacharya bounds.
UMBILICAL VEIN TO UMBILICAL ARTERY GRADIENT FOR α AND γ TOCOPHEROL AT TERM. † 1858

Postnatal tocopherol requirements have remained controversial. To study tissue uptake of α and γ tocopherol we have measured the concentration difference between paired samples of umbilical vein and artery blood (confirmed by blood gas analysis) obtained from the placenta immediately after uncomplicated term delivery (n=8). Measurements were made by HPLC techniques in light protected and deep frozen samples of plasma. Concentration of both α and γ tocopherol was higher in the umbilical vein than in the umbilical artery except for one instance for γ tocopheral in which vein and artery concentrations were identical. As shown in thefigure, the magnitude of the UV/UA difference was significantly correlated with concentration in the umbilical vein but varied widely between babies. Assuming an umbilical blood flow of 100 ml/kg/minute, a HCT of 50% and nonparticipation of the RBC in tissue uptake, estimated mean delivery to the tissues of total tocopherol was 66 mg/kg/day (Range 14 to 140). This represents a higher availability of tocopherol during the time of rapid intrauterine growth than is provided by routine oral or paren-teral feedings after delivery. Effects of stress of labor on measured UV/UA gradients are not known. Conclusions: On the basis of this data, optimal tocopherol intake after birth for growing preterm and term infants has probably been underestimated. A larger mother/infant population needs to be studied.
Rehybridization and pairing in the cuprates

The correlation effects associated with the formation of the local Zhang-Rice singlet are shown to lead to a bound pair of holes in a simple three-band cluster model of the cuprates. The symmetry of the pair function is {ital d}{sub {ital x}{sup 2}{minus}{ital y}{sup 2}}. The attractive interaction is generated by an occupation-dependent hopping integral deriving from the large {ital U}{sub {ital d}} characteristic of these materials. Upon doping away from the antiferromagnet, this term drives strong Cu 3{ital d}{endash}O 2{ital p} charge-transfer excitations, which lead to a dramatic rehybridization and resultant reduction in the local kinetic and Coulomb energy. {copyright} {ital 1996 The American Physical Society.}
Responsiveness of genetically epilepsy-prone rats to intracerebroventricular morphine-induced convulsions

Abstract The sensitivity of intracerebroventricular morphine-induced convulsions was determined in members of the severe seizure (GEPR-9) and moderate seizure (GEPR-3) colonies of genetically epilepsy-prone rats as well as in non-epileptic control rats. GEPR-9s were more sensitive to morphine-induced wet-dog shakes, rearing with bilateral forelimb clonus and generalized clonus than controls or GEPR-3s. GEPR-3s were less sensitive to morphine-induced wet-dog shakes and rearing with bilateral forelimb clonus than controls. Both high and extremely low doses of morphine in GEPR-9s elicited tonic extensor convulsions resembling the characteristic sound-induced convulsion of GEPR-9s. The results suggest that opiotergic systems may contribute to the pathophysiology of the seizure-prone condition in GEPR-9s. Further, differences in responsiveness of opiotergic systems in GEPR-3s and GEPR-9s may partially account for differences in seizure severity in the characteristic sound-induced seizures of these two types of GEPRs.
Earwax and level of paralysis

Study design: Inception cohort. Objectives: The clinical impression that earwax is uncommonly frequent among spinal cord injury patients with high levels of paralysis was tested. Setting: Veterans Administration Hospital, USA. Methods: A cohort of 15 chronically paralyzed patients, motor complete, living as residents in a long-term care facility was offered monthly irrigations of the ears for removal of wax over a 6-month period. The number of requests was tabulated. All ears were examined once on a single day to determine point prevalence. The accumulated wax graded as absent or small, moderate or large. Results: Two patients with C2 lesions, aged 37 and 52 years and paralyzed 15 and 16 years, were compared with 13 patients at C4–T6 aged 44–78 years, median 62 years, and paralyzed 2–33 years, median 24 years. Over a 6-month observation period, 10 irrigations were requested by the C2 patients and three by the C4–T6 patients. The reasons were hearing loss. Wax was found and removed, and symptoms were relieved in all instances, P<0.001. The spot survey revealed earwax of moderate or large amounts in four of four C2 patient ears and in two of 24 C4–T6 patient ears, P=0.001. Conclusion: Patients with C2 tetraplegia accumulate more earwax and request its removal more often than patients with lower levels of paralysis.
Engineering DNA scaffolds for delivery of anticancer therapeutics

Engineering DNA nanostructures with programmability in size, shape and surface chemistry holds tremendous promise in biomedical applications. As an emerging platform for drug delivery, DNA nanostructures have been extensively studied for delivering anticancer therapeutics, including small-molecule drug, nucleic acids and proteins. In this mini-review, current advances in utilizing DNA scaffolds as drug carriers for cancer treatment were summarized and future challenges were also discussed.
High capacity blind information hiding schemes using Tchebichef moments

In this paper, we present two high capacity information hiding schemes in which large amount of information can be hidden in gray level images with high transparency using Tchebichef moments. In particular, the hidden information is a gray level image of the same size as the original image. A watermark image is also hidden in the original image for hidden data authentication and tampering localization purposes. The novelty of our work comes from combining both steganography and digital watermarking in one scheme. The first scheme is a secure fragile information hiding scheme with tampering localization capability. By fragile we mean that the watermark will be distorted under any kind of attack applied on the watermarked images including geometric attacks. The second scheme is a semifragile scheme. It is based on the first scheme with some modifications to make it withstand geometric attacks, but with some compromise in security. Both proposed schemes are moment-based, in which the hidden information and the watermark are embedded in the Tchebichef moments of the original image. Transparent watermarked images with PSNR (Peak Signal to Noise Ratio) of 40 and above are obtained. Watermark and hidden images are extracted successfully at the receiver side with high accuracy.
Are minimization of delay and minimization of freeway congestion compatible ramp metering objectives

Analysis of mechanisms by which ramp metering can reduce traffic delay, such as increasing bottleneck flow, expediting flow to exits upstream of the bottleneck, and diverting traffic around the bottleneck, suggests that minimization of delay and minimization of congestion on the freeway main line are not always compatible objectives. Simulations were performed to tentatively resolve this question. These simulations used a flow model based on Newell's simplified kinematic wave theory and a control strategy that was a modification of that of Wattleworth and Berry. Simulation scenarios defined physical characteristics, demand patterns, and flow characteristics for hypothetical freeway sections on the basis of data from Blumentritt et al. and the San Diego area. Results of the simulations show that there are circumstances under which minimization of delay does not coincide with minimization of congestion on the main line and that relationships between delay and main-line congestion depend on the combination of the metering mechanisms in effect.
Novel approach to the analysis and use of fullerenes in capillary electrophoresis

The analysis and use of fullerenes in capillary electrophoresis (CE) was investigated. Sodium dodecyl sulfate (SDS) was used to solubilize fullerenes C60, C70, and a mixture of C60 and C70 in water. The behavior of the solutions of the C60- and C70-SDS complexes was examined by CE with on-line UV-Vis diode array detection. This study included the use of a C60-SDS complex as a new method of micellar electrokinetic chromatography (MEKC) for the separation of polycyclic aromatic hydrocarbons (PAHs) using CE with uniwavelength detection. Since SDS micelles act as a pseudostationary phase in which the PAH compounds partition with their hydrophobic interior, the addition of C60 within the micelles enhanced separation of the PAHs. The preliminary results using C60-MEKC with SDS were compared to those obtained with MEKC with SDS. The capillary electrophoretic separations were performed in 10 mM borate-phosphate buffer with 100 mM SDS at pH 9.5.