cssi/SciSciGPT-SciSciNet huggingface dataset:
Proton-nitrogen-15 NMR studies of Escherichia coli tRNAPhe from HisT mutants: a structural role for pseudouridine

Escherichia coli tRNA(Phe)U39 was isolated from a specially constructed bacterial strain (DD1003/pRK3) carrying mutations in the hisT gene (the structural gene for tRNA pseudouridine synthase I) and in the pyrB gene (uracil auxotrophy). The pheU gene for tRNA(Phe) under control of the native tRNA promoter was on a multicopy plasmid and gave up to 40-fold overproduction of tRNA(Phe)U39. The double mutant permitted efficient incorporation of [3-15N]uracil, resulting in greater than 95% 15N enrichment of uracil-derived bases. 1H and 1H-15N NMR experiments were used to assign the low-field proton resonances to specific hydrogen-bonding interactions. 1H NMR assignments indicate that tRNA(Phe)U39 has a structure similar to that of native tRNA(Phe) except in the anticodon region where replacement of pseudouridine (psi) at position 39 with uridine (U) destabilizes hydrogen-bonding interactions at the base of the anticodon stem. We propose that U----psi modifications further stabilize interactions normally available to U by providing an additional locus for hydrogen bonding to the pyrimidine ring.
Risks from Ambient Chemicals and Radiations

This morning we heard three very excellent, and yet distinctly different, presentations. With the permission of Drs Saffiotti, Legator and Arlett, I would like to reiterate several of the major points of their presentations and to raise a question to each of them. Then perhaps we can hear from each of them to offer them an opportunity to clarify or expand on any of the points that they rade in their presentations. I’d like to suggest that we then open the floor to general discussion following each of their brief presentations regarding this morning’s discussion.
Social media and E-cigarette use among US youth: Longitudinal evidence on the role of online advertisement exposure and risk perception

Abstract Objectives Previous studies revealed a link between social media use and e-cigarette use among U.S. youth, but less is known about the mechanisms through which they interconnect. This study examined how social media and e-cigarette use are connected through online advertisement exposure and risk perception of e-cigarettes among U.S. youth. Methods Youth aged 12–17 from the Public Assessment of Tobacco and Health (PATH) Study Waves 2–4 (2014–2018) were included (N = 6,208). This study integrated the incidental exposure framework and the risk perception framework to guide study conceptualization and variable selection. Generalized structural equation modeling was performed to investigate the sequential mediation relationship between social media and e-cigarette use through online e-cigarette advertisement exposure and risk perception of e-cigarette use. Results Youth respondents with more social media use were more likely to be exposed to e-cigarette advertisement at Wave 2 (OR = 1.13, p Conclusions The results indicate that social media use is associated with increased e-cigarette use through online e-cigarette advertisement exposure and subsequently decreased e-cigarette risk perception among U.S. youth. Our findings underscore the importance of regulating online e-cigarette advertisement, with the emphasis of avoiding information that could twist youth’s risk perception of e-cigarettes, which may in turn curtail youth e-cigarette use.
“There’s a stopgap in the conversation”: LGBTQ + mental health care and community connection in a semi-rural county

LGBTQ + people face barriers accessing affirming mental health care in semi-rural communities. Little research has addressed the unique barriers, needs, and experiences of LGBTQ + communities, incl...
Genomics-driven discovery of chiral triscatechol siderophores with enantiomeric Fe(III) coordination

Ferric complexes of triscatechol siderophores may assume one of two enantiomeric configurations at the iron site. Chirality is known to be important in the iron uptake process, however an understanding of the molecular features directing stereospecific coordination remains ambiguous. Synthesis of the full suite of (DHBL/DLysL/DSer)3 macrolactone diastereomers, which includes the siderophore cyclic trichrysobactin (CTC), enables the effects that the chirality of Lys and Ser residues exert on the configuration of the Fe(iii) complex to be defined. Computationally optimized geometries indicate that the Λ/Δ configurational preferences are set by steric interactions between the Lys sidechains and the peptide backbone. The ability of each (DHBL/DLysL/DSer)3 diastereomer to form a stable Fe(iii) complex prompted a genomic search for biosynthetic gene clusters (BGCs) encoding the synthesis of these diastereomers in microbes. The genome of the plant pathogen Dickeya chrysanthemi EC16 was sequenced and the genes responsible for the biosynthesis of CTC were identified. A related but distinct BGC was identified in the genome of the opportunistic pathogen Yersinia frederiksenii ATCC 33641; isolation of the siderophore from Y. frederiksenii ATCC 33641, named frederiksenibactin (FSB), revealed the triscatechol oligoester, linear-(DHBLLysLSer)3. Circular dichroism (CD) spectroscopy establishes that Fe(iii)-CTC and Fe(iii)-FSB are formed in opposite enantiomeric configuration, consistent with the results of the ferric complexes of the cyclic (DHBL/DLysL/DSer)3 diastereomers.
Experimental and theoretical investigation of the formation of two-dimensional Fe silicate on Pd(111)

A single layer of Fe silicate was grown on Pd(111) and analyzed experimentally and theoretically. Following sequential deposition of SiO and Fe and annealing above 900 K in O2, an incommensurate but well-ordered, low-defect density layer was observed with low-energy electron diffraction and scanning tunneling microscopy (STM). The STM images revealed a moire pattern due to the lattice mismatch between the relaxed oxide layer and the substrate, while high-resolution images showed a honeycomb structure consistent with a silicate layer with six-membered rings of corner-sharing SiO4 tetrahedra at its surface. Reflection-absorption infrared spectroscopy revealed a single peak at 1050 cm−1 due to Si–O–Fe linkages, while x-ray photoelectron spectroscopy data indicated a Si/Fe ratio of one, that the Fe were all 3+, and that the Si atoms were closest to the surface. Consistent with these experimental observations, first principles theory identified a layer with an overall stoichiometry of Fe2Si2O9 with the six-membered rings of SiO4 tetrahedra at the surface. One of the oxygen atoms appears as a chemisorbed atom on the Pd surface, and, thus, the layer is better described as Fe2Si2O8 atop an oxygen-covered Pd surface. The Fe2Si2O8 is chemically bound to the Pd surface through its oxygen atoms; and the passivation of these bonds by hydrogen was investigated theoretically. Upon hydrogenation, the adsorbed O atom joins the Fe silicate layer and thermodynamic analysis indicates that, at room temperature and H2 pressures below 1 atm, Fe2Si2O9H4 becomes favored. The hydrogenation is accompanied by a substantial increase in the equilibrium distance between the oxide layer and the Pd surface and a drop in the adhesion energy to the surface. Together the results indicate that a highly ordered 2D Fe silicate can be grown on Pd(111) and that subsequent hydrogenation of this layer offers potential to release the 2D material from the growth substrate.
Student Versus Scholar: A Review of Carol Grbich's Qualitative Data Analysis: An Introduction (2nd ed.)

Grbich’s analysis text is marketed for beginners although it contains some content that may be more meaningful for those with prior exposure to qualitative inquiry. The content of the book might be viewed as a series of contrasts: serious versus humorous; decisive versus flexible; didactic versus experiential. While some content areas are covered in great detail, the role of transcription in analysis is minimized. Recommended use of this text is as a supplemental book in a first qualitative course or as a primary text in a subsequent course. Keywords: Qualitative Analysis, Contrasts, Qualitative
A semiparametric scale-mixture regression model and predictive recursion maximum likelihood

To avoid specification of a particular distribution for the error in a regression model, we propose a flexible scale mixture model with a nonparametric mixing distribution. This model contains, among other things, the familiar normal and Student-t models as special cases. For fitting such mixtures, the predictive recursion method is a simple and computationally efficient alternative to existing methods. We define a predictive recursion-based marginal likelihood function, and estimation of the regression parameters proceeds by maximizing this function. A hybrid predictive recursion-EM algorithm is proposed for this purpose. The method's performance is compared with that of existing methods in simulations and real data analyses.
Properties of the cell surfaces of pathogenic bacteria.

Publisher Summary This chapter reviews the aspects of bacterial-cell surfaces, with an emphasis on the role of surface structures in pathogenesis and in biological responses. The bacterial-cell surface possesses many properties that are important in pathogenesis and immunity. The surface may contain components that stimulate or depress the immune response, depending on concentrations of the components. The surface serves as a site of antigenic recognition. Many bacterial vaccines are composed of surface structure materials. Vaccines against the pneumococcus or Haemophilus influenza utilize surface-associated polysaccharides. The surface structures tend to inhibit phagocytosis of an invading bacterium. Any encapsulated bacterium is more resistant to phagocytosis and subsequent intracellular digestion than a nonencapsulated mutant of the same species. The surface also may serve as an anchoring point for a bacterium. Lipopolysaccharides (LPS), surface constituents of many gram-negative pathogens, exhibit several manifestations of toxicity in infected hosts. Lipoteichoic acids (LTA) from gram-positive bacteria also possess toxic and immunomodulating activities. The surface may serve as a target for antibiotic action. Penicillin and penicillin-like antibiotics and drugs prevent the synthesis of peptidoglycan (PG), resulting in cell death.
Developing an object-oriented view management system

This paper discusses our experiences regarding the design and implementation of the Multi View system - a framework for the specification, creation, and management of updatable views in object-oriented databases (OODBs) - using commercially available OODB technology. Multi View, which simplifies view schema design and maintenance by breaking view specification into the tasks of class derivation, global schema integration, view class selection, and view hierarchy generation, has been implemented on top of the GemStone OODB. The current implementation employs a three-layered architecture (composed of meta-objects, schema-objects, and data-objects) to extend the GemStone object model. It results in a view tool that extends the GemStone data model by supporting view specification, maintenance, and access. In this paper, we describe the system classes and methods as well as necessary algorithms. The first prototype of Multi View has been built, and we describe a sample application example.
Introduction to Theoretical Kinematics

"Introduction to Theoretical Kinematics" provides a uniform presentation of the mathematical foundations required for studying the movement of a kinematic chain that makes up robot arms, mechanical hands, walking machines, and similar mechanisms. It is a concise and readable introduction that takes a more modern approach than other kinematics texts and introduces several useful derivations that are new to the literature. The author employees a unique format, highlighting the similarity of the mathematical results for planar, spherical, and spatial cases by studying them all in each chapter rather than as separate topics. For the first time, he applies to kinematic theory two tools of modern mathematics--the theory of multivectors and the theory of Clifford algebras--that serve to clarify the seemingly arbitrary nature of the construction of screws and dual quaternions. The first two chapters formulate the matrices that represent planar, spherical, and spatial displacements and examine a continuous set of displacements which define a continuous movement of a body, introducing the "tangent operator." Chapter 3 focuses on the tangent operators of spatial motion as they are reassembled into six-dimensional vectors or screws, placing these in the modern setting of multivector algebra. Clifford algebras are used in chapter 4 to unify the construction of various hypercomplex "quaternion" numbers. Chapter 5 presents the elementary formulas that compute the degrees of freedom, or mobility, of kinematic chains, and chapter 6 defines the structure equations of these chains in terms of matrix transformations. The last chapter computes the quaternion form ofthe structure equations for ten specific mechanisms. These equations define parameterized manifolds in the Clifford algebras, or "image spaces," associated with planar, spherical, and spatial displacements. McCarthy reveals a particularly interesting result by showing that these parameters can be mathematically manipulated to yield hyperboloids or intersections of hyperboloids.
QR codes and authentication protection

The development of the Internet and telecommunication urges researchers to look for a better way to secure online users' private information. This study is rooted in online user account protection, measuring the effect of QR codes on fear appeals and authentication protection. This study contributes to the extant literature by integrating two theories — protection motivation theory and the theory of planned behavior. The main goal of this study is to investigate how the co-use of computers and mobile devices protect online users' online credentials. The results of the study also provide guidelines to IT developers for future directions in authentication protection.
E-GOVERNMENT: TRENDS AT THE GRASS ROOTS

Electronic-government, or e-government, of offers all levels of government the ability to communicate information, deliver services, and provide additional avenues designed to interact with and participate in government. Based on a Detailed content analysis of government websites in conjunction with descriptive and multiple regression approaches, thus study assesses and explains the level of e-government sophi&1ication at the local level of government in the state of Oklahoma. The study hypothesizes that the council-manager form of govemmen1and increasing levels of organizational resources and socioeconomic wealth enhance c-government sophistication at the local level of government. While the findings mostly support the hypothesis, local governments in Oklahoma, like many municipalities across the country, have not fully embraced the potentials of e-government.
Jerry Springer and the Marlboro man in Africa: Globalisation and cultural eclecticism

Abstract Despite its relative isolation from the global culture industry, telecommunications and mass communication centres and markets, Africa is buffeted by the winds of globalisation. Under World Bank and the IMF structural adjustment programs virtually all African countries privatised their telecommunications and mass media sectors, thus opening them up to Western multi‐national corporate investors. Though there might be an impression that African culture is being inundated and destroyed by American mass mediated culture, it is argued that Africans tend to select only certain aspects of Western cultural idioms, Africanise them and use them to promote African cultural values. Thus, it is argued, globalisation has had positive effects on certain aspects of African culture.
Visible Light‐Curing

Visible light-curing of resin-based materials is a routine but very important process in restorative dentistry. New light-curing technologies have emerged in recent years, particularly the development of light-emitting diode (LED)-based devices. In addition, our understanding of light-curing has improved greatly, as research has revealed aspects of the process that were unknown or poorly understood in the past. This Critical Appraisal presents some of the better research on the subject that has appeared in the recent literature.
Precisión de la aproximación geoide y geoestadística: cómo encontrar un mapa contínuo de datos de gravedad absoluta

An accurate geoid model is needed for surveyors and engineers who require orthometric heights on a common datum, and environment scientists who require elevations relative to present sea level. Airborne gravity data has been collected by the National Geodetic Survey (NGS) under the Gravity for the Redefinition of the Amer- ican Vertical Datum (GRAV-D) project and is available along the coasts of the Gulf of Mexico. For this study we obtained a set of absolute gravity data derived from full-field gravity at altitude/elevation. We used the data to derive free-air gravity anomalies to establish gravity on the geoid. For spatial interpolation we used the kriging method to estimate gravity on the geoid in any location and kriging of the difference between gravity on the ellipsoid of reference and the geoid. Various kriging methods were used for evaluation of errors calculated in this study. The mean precision of the predicted values is around 1.23 cm, a very good result for coastal regions, which traditionally have sparse gravity data sets.
The local pathology of interstitial edema : Surface tension increases hydration potential in heat-damaged skin

The local pathogenesis of interstitial edema in burns is incompletely understood. This ex vivo study investigates the forces mediating water-transfer in and out of heat-denatured interstitial matrix. Experimentally, full-thickness dermal samples are heated progressively to disrupt glycosaminoglycans, kill cells, and denature collagen under conditions that prevent water loss/gain; subsequently, a battery of complementary techniques including among others, high-resolution magnetic resonance imaging, equilibrium vapor pressure and osmotic stress are used to compare water-potential parameters of nonheated and heated dermis. The hydration potential (HP) determined by osmotic stress is a measure of the total water-potential defined empirically as the pressure at which no net water influx/efflux into/from the dermis is detected. Results show that after heat denaturation, the HP, the intensity of T2-weighed magnetic resonance images, and the vapor pressure increase indicating higher water activity and necessarily, smaller contributions from colloidosmotic forces to fluid influx in burned relative to healthy dermis. Concomitant increases in HP and in water activity implicate local changes in interfacial and metabolic energy as the source of excess fluid-transfer potential. These ex vivo findings also show that these additional forces contributing to abnormal fluid-transfer in burned skin develop independently of inflammatory and systemic hydrodynamic responses.
ALLIANCE: an architecture for fault tolerant, cooperative control of heterogeneous mobile robots

This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. We describe a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. The software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, we describe in detail our experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. >
A possible role for angiotensin II in the regulation of male sexual behavior in rats.

Abstract To investigate the possibility that angiotensin II (AII) is involved in the regulation of male sexual behavior, AII was injected intraventricularly into sexually experienced male rats immediately prior to mating tests. Third ventricular administration of 0.48 nmol AII resulted in an increased latency to the initiation of copulatory behavior (625% of control values), and administration of 4.8 nmol had a similar effect on initiation latencies (650% of control values) and, additionally, significantly increased the number of intromissions preceding ejaculation (the ejaculatory threshold, to 130% of control values) and the interval to reinitiate copulatory behavior after ejaculation (the postejaculatory interval, to 125% of control values). Water intake was affected only by the higher dose of AII, with no animals drinking in the 15 minutes following saline or 0.48 nmol AII and 69% of the rats treated with 4.8 nmol AII drinking (mean intake 1.5±0.26 ml for those rats drinking). These data demonstrate that AII can suppress male sexual behavior, and that this suppression is not due simply to a stimulation of drinking.
Effect of pH and Brine Concentration on Gas Production by a Putrefactive Anaerobe (PA) 3679 in a Processed Cheese Spread

Summary Gas production by PA (putrefactive anaerobe) 3679 in a processed cheese spread containing 8.5% skimmilk powder and packaged in TDT (thermal death time) cans incubated at 37° C. was studied at pH levels of 5.2 to 7.0 and brine concentrations of 2.0 to 8.4%. Most of the expansion attributable to gas production in the TDT cans occurred during the first 20 days and no measurable gas production developed after 60 days. As the pH decreased from 7.0 to 6.0, the lag time for gas production increased and gas production was completely inhibited at pH 5.6 and below. As the brine concentration increased, the lag time for gas production increased, and there was a decrease in the rate, total amount, and duration of gas production. Gas production was completely inhibited at a brine concentration of 7.6% or more. A technique using a dial-micrometer was developed for detecting small amounts of gas production in TDT cans.
Simulation model for guiding Lebanon's post-war reconstruction

This paper describes a pilot model, NRDM-2 for National Reconstruction and Development Model Version Two, the harbinger of a package of interactive national, regional, and sectoral computer models to be used to guide reconstruction and development in Lebanon. NRDM-2 is displayed in the form of a causal diagram in Fig. 3.1. The model is comprised of 12 sectors: Manufacturing, Business, Infrastructure, Manpower, Government Services, Agriculture, Population, Utilities, Highways, Housing, Trade-Energy, and Socio-Economic Indicators. There are 435 equations expressed in the DYNAMO simulation language. The objective aspects of Lebanon's development are contained in the relationships between the variables. Knowing the values of the 435 parameters at the initial year 1980 permits their calculation at consecutive years for the next 50 years. The subjective aspects of Lebanon's development are dealt with in the way the model is used to analyze possible future development alternatives using scenario analysis. Three basic scenarios identified for investigation are: (1) Base (No-War) Scenario, (2) No Reconciliation or Reconstruction Scenario, and (3) Reconstruction and Reconciliation Scenario.
Three-Dimensional Terrestrial LIDAR for Operational Bridge Clearance Measurements

AbstractThis paper reports the outcomes of a study of the vehicle crossing effects on a terrestrial light detection and ranging (LIDAR) scan on highway bridges for underclearance measurements. Ground-based or vehicle-mount terrestrial LIDAR scanners, which recreate the bridge structure as a three-dimensional point cloud of thousands of position data points, have been found to be ideal for bridge clearance measurements. To determine the effects of ambient overhead vehicle crossing and seasonal temperature variation on clearance measurements, periodic monitoring of the Harris Road Bridge has been conducted. A simplistic but practical correlation analysis is performed, which shows that operational LIDAR scanning is a viable technique for bridge clearance measurements.
The implications of multiple forms of phenylalanine hydroxylase in phenylketonuria and related diseases of phenylalanine metabolism.

Abstract Phenylalanine hydroxylase prepared from rat and human liver occurs in three unique isozymal forms. The enzyme was separated into three fractions on neutral calcium phosphate gel columns. Authenticity of the enzyme activities was confirmed by substrate specificity, Michaelis constants for substrate and cofactor, and pH optima. Differentiation of three forms as suggested by column chromatography was confirmed by rechromatography, gel filtration, density gradient centrifugation, and dissimilar responses to temperature, para -chlorophenylalanine, and pretreatment with lecithin. We have demonstrated that the isozymes mature at different times during intrauterine and extrauterine development and that the enzyme is not mature at birth in the rat. We offer various proposals of the significance of isozymes of this enzyme, particularly with regard to the various states of hyperphenylalaninemia and particularly phenylketonuria.
Conformal mapping of gauge fields

A conformal mapping of gauge fields is defined. It preserves sourcelessness for four dimensions for any signatures of the metric. It also preserves orthogonality.
An Investigation of the ECST-R as a Measure of Competence and Feigning

Competency to stand trial is the most commonly raised psycholegal issue. Evaluations of a defendant's competency must be as accurate and complete as possible, and clinicians must be careful to screen for feigned incompetence. The Evaluation of Competency to Stand Trial-Revised (ECST-R), a recently developed co-mpetency assessment instrument, assesses the constructs of both competence and feigning. The present study provides further validation research on the ECST-R by comparing the performance of honest responders and coached feigners. Results support the discriminant validity of the ESCT-R and homogeneity of individual scales. This study supports use of the competency scales and provides some support for the use of the feigning scales, although some caution is advised.
An identity-based security framework For VANETs

We present a security framework for Vehicular Ad hoc Networks (VANETs), using identity-based cryptography, to provide authentication, confidentiality, non-repudiation and message integrity. Additionally it provides scalable security and privacy using short-lived, authenticated and unforgeable, pseudonyms. This feature can be used by VANET applications that require quantifiable trust and privacy to provide differentiated service based on various levels of trust and privacy thresholds.
Computational Ghost Imaging for Remote Sensing

Computational ghost imaging is a structured-illumination active imager coupled with a single-pixel detector that has potential applications in remote sensing. Here we report on an architecture that acquires the two-dimensional spatial Fourier transform of the target object (which can be inverted to obtain a conventional image). We determine its image signature, resolution, and signal-to-noise ratio in the presence of practical constraints such as atmospheric turbulence, background radiation, and photodetector noise. We consider a bistatic imaging geometry and quantify the resolution impact of nonuniform Kolmogorov-spectrum turbulence along the propagation paths. We show that, in some cases, short-exposure intensity averaging can mitigate atmospheric-turbulence-induced resolution loss. Our analysis reveals some key performance differences between computational ghost imaging and conventional active imaging, and identifies scenarios in which theory predicts that the former will perform better than the latter.
Sources of support for skin research in departments and divisions of dermatology in the United States

This is a report on a survey by the Society for Investigative Dermatology concerning the scope of skin research and the amount and sources of funding for skin research in the United States during 1980–1981.
Enumeration of Fanout-Free Boolean Functions

A solution to the problem of counting the number of fanout-free Boolean functions of n variables is presented. The relevant properties of fanout-free functions and circuits are summarized. The AND and OR ranks of a fanout-free function are defined. Recursive formulas for determining the number of distinct functions of specified rank are derived. Based on these, expressions are obtained for
Developmental regulation of the a-type potassium-channel current in hippocampal neurons: role of the kvβ1.1 subunit

The rapidly inactivating A-type K+ current (IA) is prominent in hippocampal neurons; and the speed of its inactivation may regulate electrical excitability. The auxiliary K+ channel subunit Kvbeta 1.1 confers fast inactivation to Shaker-related channels and is postulated to affect IA. Whole-cell patch clamp recordings of rat hippocampal pyramidal neurons in primary culture showed a developmental decrease in the time constant of inactivation (tau(in)) of voltage-gated K+ currents: 17.9+/-1.5 ms in young neurons (5-7 days in vitro; n=53, mean+/-S.E.M.); 9.9+/-1.0 ms in mature neurons (12-15 days in vitro; n=72, mean+/-S.E.M., P<0.01). During the same developmental time, the level of Kvbeta 1.1 transcript increased more than two-fold in vitro and in vivo, determined by semi-quantitative reverse transcriptase-polymerase chain reaction for hippocampus. The hypothesis that up-regulation of Kvbeta 1.1 led to the changes in tau(in) was tested in vitro, using antisense knockdown. Kvbeta 1.1-specific antisense DNA was introduced with a modified herpes virus co-expressing enhanced green fluorescent protein and knockdown of Kvbeta 1.1 was verified by immunocytochemistry. Following transduction with the antisense virus, mature neurons reverted to tau(in) values characteristic of young neurons: 18.3+/-2.4 ms (n=20). The effect of antisense knockdown on electrical excitability was tested using current-clamp protocols to induce repetitive firing. Treatment with the antisense virus increased the interspike interval over a range of membrane depolarization (baseline membrane potential=-40 to +20 mV). This effect was most pronounced at -40 mV, where the ISI of the first pair of action potentials was nearly doubled. These data indicate that Kvbeta 1.1 contributes to the developmental control of IA in hippocampal neurons and that the magnitude of effect is sufficient to regulate electrical excitability. Viral-mediated antisense knockdown of Kvbeta 1.1 is capable of decreasing the electrical excitability of post-mitotic hippocampal neurons, suggesting this approach has applicability to gene therapy of neurological diseases associated with hyperexcitability.
Effect of maximal coronary vasodilation on transmural myocardial perfusion during tachycardia in dogs with left ventricular hypertrophy.

We tested the hypothesis that a functional abnormality may contribute to impaired myocardial perfusion during tachycardia in the chronically pressure-overloaded hypertrophied left ventricle. Left ventricular hypertrophy (LVH) was produced by banding the ascending aorta of seven young dogs, 5-6 weeks of age, and studies were carried out after the animals reached adulthood when the mean left ventricular: body weight ratio was 91% greater than in seven control dogs. Myocardial blood flow was measured with radioactive microspheres during ventricular pacing at 100, 200, and 250 beats/min in the presence of normal coronary vasomotor activity and during maximum coronary vasodilation (adenosine, iv). At a heart rate of 100 beat«/min, there was no difference in myocardial blood flow between control and LVH dogs either during normal conditions or during adenosine infusion. However, since mean coronary perfusion pressure was higher in the dogs with aortic banding, minimum coronary resistance was greater in the dogs with LVH [22.7 ± 2.5 (mean ± BE)] than in the control dogs (14.5 ± 1.4 mm Hg/min per g per ml; P < 0.05). In the presence of intact coronary vasomotor tone, pacing at 2S0 beats/min resulted in transmural redistribution of perfusion away from the subendocardium in the dogs with LVH [subendocardial: subepicardial blood flow ratio (endoiepi) 0.68 ± 0.09], but not in the control dogs (endo: epi = 1.05 ± 0.03; P < 0.02). This relative reduction of subendocardial flow In the dogs with LVH resulted from extravascular factors since blood flow to the inner half of the left ventricular wall failed to increase in response to adenosine infusion during pacing at 250 beats/min. Thus, both an anatomic abnormality of coronary perfusion, marked by impaired minimum coronary resistance at a heart rate of 100 beats/min, and a functional abnormality of perfusion resulting in redistribution of blood flow away from the subendocardium at a heart rate of 250 beats/min were demonstrated in this model of LVH. Ore Res 49: 742750, 1981
A cog in cognition: How the α7 nicotinic acetylcholine receptor is geared towards improving cognitive deficits

Cognition, memory, and attention and arousal have been linked to nicotinic acetylcholine receptors (nAChRs). Thus it is not surprising that nAChRs have been strongly implicated as therapeutic targets for treating cognitive deficits in disorders such as schizophrenia and Alzheimer's disease (AD). In particular the alpha7 (α7) nAChR has been closely linked with normalization of P50 auditory evoked potential (AEP) gating deficits, and to a lesser extent improvements in pre-pulse inhibition (PPI) of the acoustic startle response. These two brain phenomena can be considered as pre-attentive, occurring while sensory information is being processed, and are important endophenotypes in schizophrenia with deficits likely contributing to the cognitive fragmentation associated with the disease. In addition α7 nAChRs have been implicated in attention, in particular under high attentional demand, and in more demanding working memory tasks such as long delays in delayed matching tasks. Efficacy of α7 nAChR agonists across a range of cognitive processes ranging from pre-attentive to attentive states and working and recognition memory provides a solid basis for their pro-cognitive effects. This review will focus on the recent work highlighting the role of α7 in cognition and cognitive processes.
The nature of immune complexes initiating allergic wheal-and-flare reactions: A comparative study of the abilities of various divalent and multivalent benzylpencilloyl-polylysine haptens to elicit wheal-and-flare reactions in penicillin-sensitive human beings☆

Abstract A bivalent benzylpenicilloyl (BPO) hapten, multivalent BPO-poly-D-lysine (PDL) conjugates, and a homologous series of succinylated multivalent BPO-poly-L-lysine (PLL) haptens of widely differing extents of conjugation and molecular sizes were compared with regard to their abilities to evoke specific wheal-and-flare reactions in BPO-hypersensitive patients. It was found that BPO-polylysine conjugates (of 402 lysine groups per molecule) containing 38 to 148 BPO groups per mole were equally effective, whereas conjugates containing 11 or 230 BPO groups per mole were slightly less effective. In end-point dilution titrations, BPO-polylysine conjugates (of PLL or PDL) of widely differing molecular sizes were equally effective when compared at equimolar concentrations, but not when compared at equal weight concentrations. These results indicate that wheal-and-flare reactions are initiated by simple bridging of two (or a small integer, n) "tissue fixed" skin-sensitizing antibody molecules by multivalent haptens to form simple complexes of the composition H 1 Ab n . Succinylated, optimally coupled penicilloyl-poly-D-lysine conjugates of molecular sizes in the range of 20 to 100 lysine residues per molecule appear at present to be the optimal clinical reagents to detect penicilloyl-specific wheal-and-flare reactions. In order to standardize their clinical usage, concentrations of penicilloyl-polylysine solutions should be expressed as moles per liter of the entire conjugate molecule.
Clinically resectable adenocarcinoma of the rectum treated with preoperative irradiation and surgery.

Seventy-four patients with clinically resectable adenocarcinoma of the rectum were treated with preoperative irradiation and surgery at the University of Florida between August 1975 and February 1982. All patients have been followed for at least five years. Between 1975 and 1978, 29 patients received 3500 cGy; thereafter the dose was increased to 4000 to 5000 cGy for the remaining 45 patients. All patients were treated at 180 cGy per fraction. Following preoperative irradiation, 65 of 74 patients (88 percent) underwent complete resection of their lesions. Compared with a series of historical controls treated with surgery alone, the local recurrence rate at five years was 5 of 65 (7.7 percent) vs. 39 of 135 (29 percent) (P = .001), and the five-year absolute survival was 43 of 65 (66 percent) vs. 51 of 135 (38 percent) (P less than .001). The local recurrence rate was 13 percent for patients receiving 3500 cGy and 5 percent for doses of 4000 to 5000 cGy. There was no apparent increased incidence in postoperative complications in the preoperatively irradiated patients.
Pollen Morphology of the Oklahoma Endemic Plants Leavenworthia aurea (Brassicaceae/Cruciferae) and Phlox pilosa Subsp. Longipilosa (Polemoniaceae), With Special Reference To Their Natural History

Abstract The morphology, taxonomy, ecology, distribution, and conservation status of the Oklahoma endemics, Leavenworthia aurea (Brassicaceae/Crucifereae) and Phlox pilosa subsp. longipilosa (Polemoniaceae) Pennell, are reviewed and supplemented with original pollen morphological descriptions that include comparisons to related taxa. These descriptions are considered extensions of the original taxonomic descriptions. Leavenworthia aurea is a glabrous winter annual found on limestone glades in Choctaw and McCurtain counties. The taxon is considered imperiled, with Natural Heritage rankings of G2S2. The pollen has three colpi with a reticulate surface enclosing polygonal lumina (openings within reticulations on the pollen surface) with lengths varying from 0.5–2.5 µm, that are either empty or contain inclined free standing columellae approximately 0.5–0.8 µm in height. Granules less than 0.5 µm in diameter also occur in some lumina, but are most common in the colpus. The reticulate surface of Leavenworthia ...
Pulmonary artery size and clinical outcome after the modified Fontan operation

The maximum cross-sectional area of the central pulmonary arteries indexed to the body surface area (pulmonary artery index [PAI]) was measured preoperatively from angiograms in 173 patients evaluated for a Fontan-type operation between 1981 and June 1989. Of these, 34 patients underwent another palliative procedure, 8 primarily on the basis of small pulmonary arteries (PAI, 106 to 167 mm2/m2). The mean PAI of this group was significantly smaller than the mean PAI of the remaining 139 patients who underwent a Fontan operation (136 +/- 20 versus 310 +/- 113 mm2/m2) (p < 0.001). The patients who underwent a Fontan operation were evaluated according to three overlapping end points: (1) hospital death or takedown of repair (12.2%), (2) early failure (cumulative death or takedown of repair within 6 months of operation) (16.5%), and (3) early failure or persistent effusions (33.8%). With regard to these end points, no significant difference in pulmonary artery size could be found between patients having a favorable or unfavorable outcome. However, among a low-risk subset of 30 patients with tricuspid atresia, those with "early failure or persistent effusions" had significantly smaller pulmonary arteries than those with a good outcome (PAI, 185 +/- 47 versus 276 +/- 83 mm2/m2) (p < 0.01). The postoperative transpulmonary gradient of the 8 patients with the smallest pulmonary arteries who underwent a Fontan operation (all PAIs < 170 mm2/m2) was significantly greater than that of the rest of the study group (9.88 +/- 2.3 versus 8.13 +/- 2.3 mm Hg) (p < 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)
Slater transform functions. Application to the helium atom ground state

Abstract Slater transform functions have been used variationally to approximate the helium atom ground state. The results are significantly better than either a scaled gaussian or a scaled exponential and the energy is very close to the Hartree-Fock value.
Classical conditioning of the Aplysia siphon-withdrawal reflex exhibits response specificity

The gill- and siphon-withdrawal reflex of Aplysia undergoes classical conditioning of its amplitude and duration when siphon stimulation (the conditioned stimulus, CS) is paired with tail or mantle shock (the unconditioned stimulus, US). This conditioning of a preexisting response exhibits both temporal and stimulus specificities, which can be accounted for by activity-dependent enhancement of presynaptic facilitation of the siphon sensory neurons. To test whether conditioning of the reflex also exhibits response specificity (development of a new type of response to the CS that often resembles the response to the US), we measured the direction of siphon withdrawal in response to siphon stimulation (the CS) with tail or mantle shock as the US. The unlearned response to siphon stimulation is straight contraction, the response to tail shock is backward bending, and the response to mantle shock is forward bending. In the first experiment, we trained different animals with the tail or mantle US paired or unpaired with the CS; in a second experiment, we trained each animal with two CSs, one of which was paired with the US; in a third experiment, we varied US intensity; and in a fourth experiment, we trained each animal with two USs, one of which was paired with the CS. There was a significant, pairing-specific tendency for the direction of the response to the CS to resemble the response to the US after training in each experiment, demonstrating response specificity in conditioning of the withdrawal reflex. This feature of conditioning could in principle be accounted for by an elaboration of activity-dependent facilitation.
Invasive pneumococcal infections among vaccinated children in the United States.

Objective Because 7-valent pneumococcal conjugate vaccine (PCV7) is highly efficacious, pneumococcal infections in vaccinated children raise concerns about immunologic disorders. We characterized a case series of US children in whom invasive pneumococcal infections developed despite vaccination. Study design We reviewed invasive (sterile site) pneumococcal infections in children aged Results We identified 753 invasive infections; 155 infections (21%) were breakthrough cases, predominantly caused by serotypes 6B (n = 50, 32%) and 19F (n = 45, 29%). The proportion of breakthrough cases decreased with the increasing number of PCV7 doses received ( P 2 for linear trend). Children with co-morbid conditions accounted for 31% of breakthrough infections. Twenty-seven cases (4%) were classified as vaccine failures. Most failures (71%) occurred in children who were vaccinated according to catch-up schedules; 37% had co-morbid conditions. Conclusion Invasive pneumococcal infections identified in vaccinated U.S. children were primarily caused by disease resulting from serotypes not covered with PCV7, rather than failure of the vaccine. Incomplete vaccination and co-morbid conditions likely contribute to breakthrough vaccine-type pneumococcal infections.
Localization of the inositol 1,4,5-trisphosphate receptor in synaptic terminals in the vertebrate retina

Abstract Inositol 1,4,5-trisphosphate (InsP 3 ) mobilizes internal Ca 2+ in cells by binding to a receptor protein, which has recently been purified and molecularly cloned. To clarify those neuronal functions that are regulated by InsP 3 , we have localized this (InsP 3 ) receptor protein immunocytochemically in the retina, a neural tissue of well-defined structure and function. Positive staining in neurons is confined almost exclusively to the synaptic layers. Using dissociated retinal neurons, we have further localized the receptor to presynaptic terminals of photoreceptors and bipolar cells, as well as the synaptic processes of amacrine cells. The specific association of InsP 3 receptors with synaptic terminals suggests a role for InsP 3 in synaptic modulation, especially with respect to transmitter release.
High frequency excitation and vibration studies on hyperfiltration membranes

Abstract In an effort to increase the freshwater production rate, possible effects of high-frequency vibrations (both acoustically and electrically induced) on the hyperfiltration (reverse osmosis) process have been reexamined comprehensively. Cellulose-acetate membranes were used, both as customarily prepared by the Loeb-Sourirajan process, and with added magnetic and non-magnetic iron oxide powders. Flow and salt rejection were measured with sodium chloride feeds, without and with iron hydroxide or calcium sulfate membrane fouling. Flow and rejection were found substantially independent of the applied vibrations over the frequency and power ranges applied. The one exception was ultrasonic vibration on a depressurized, fouled membrane, which showed an advantageous cleaning effect (hyperfiltrate flux increased after the treatment), confirming previous observations.
On future traffic control: Advanced systems hardware

Four advanced system concepts are critiqued: automatic vehicle identification, automatic vehicle monitoring, automatic route guidance, and the automatic highway. Each concept is defined, its potential applications are delineated, an overview of the state of the relevant technology given (and shortcomings noted), and the prospects for future deployments are considered. In addition, an extensive reference list is included.
SuperLab LT: Evaluation and Uses in Teaching Experimental Psychology.

I describe and evaluate SuperLab LT (Chase & Abboud, 1990), a software package that enables students to replicate classic experiments in cognitive psychology. I also discuss the package with respect to its uses in teaching an undergraduate course in Experimental Psychology. Although the package has minor flaws, SuperLab LT provides numerous pedagogical benefits.
Incidence of Delayed Gastric Emptying Associated with Revisional Laparoscopic Paraesophageal Hernia Repair

Background Over the past 15 years, laparoscopic repair of primary paraesophageal hernias (PEH) has become the preferred operative approach. Today, more surgeons are approaching recurrent PEHs laparoscopically, though few studies exist on the long-term results of these revisional operations, particularly regarding the incidence of postoperative delayed gastric emptying (DGE).