cssi/SciSciGPT-SciSciNet huggingface dataset:
Does traffic metering improve network performance efficiency

Traffic metering at on-ramps in interstate highways has been widely used and led to desirable results. In urban transportation networks when demand reaches network capacity level, traffic metering may also increase network performance efficiency. In this paper, we apply different metering strategies to a case study network to see if they result in a different network operation and potentially a more efficient performance. To make sure if any observed differences in network performance efficiency is due to metering strategies and not due to an inappropriate signal timing, we determine near optimal signal timing of the network by using our Intelligent Dynamic Signal Timing Optimization Program (IDSTOP). IDSTOP incorporates Genetic Algorithms (GAs) with microscopic traffic simulation to find near-optimal signal timing parameters of the network. Our results showed that letting all traffic enter the network or metering a large portion of the traffic are not the best options. Instead metering around 20% of the traffic resulted in the best network performance in terms of average delay (16% reduction compared to no metering and 17% reduction compared to extremely heavy metering strategies), network throughput (18% increase compared to heavy metering), and average travel time (14% reduction compared to no metering and 10% reduction compared to heavy metering). Our findings suggested that in an urban network, there is an optimal point that sending more vehicles into the network than that deteriorates network performance efficiency.
Pancreatic polypeptide and intestinal motility in dogs.

This study was designed to determine the potential role of endogenous PP in the control of intestinal motility by correlating plasma PP levels with motility patterns in fasted and fed dogs without and with administration of exogenous PP and rabbit PP antiserum. After an overnight fast, when the interdigestive myoelectric activity was recorded in each dog, mean basal PP at phase I averaged 35±7 pM with peaks of 52±5 pM coinciding with phase III (MMC) in duodenum. Postprandial rise in PP reached the peak level of 280±70 pM at the end of 1 hr after a meal when MMC was interrupted and replaced by fed-type motility pattern. Exogenous PP in a dose of 100 pmol/kg/hr infused when the phase III of the MMC passed mid-jejunum raised plasma PP to the level of 130±27 pM but failed to affect the spike activity or MMC periodicity. PP given in doses of 200 and 400 pmol/kg/hr, which raised plasma PP to 298±25 and 453±24 pM, respectively, increased dose dependently (but did not abolish) the MMC intervals and an overall spike activity due to the prolongation of phase II of the MMC. After termination of PP infusion, phase III-like activity appeared within 7–10 min. Injection of highly specific PP antiserum, which caused almost complete disappearance of plasma PP both in fasted and fed dogs, did not affect the MMC interval but increased spike activity in fasted animals and failed to affect significantly spike activity in fed animals. We conclude that PP does not play any role in fasted intestinal motility but may contribute, at least in part, to the postprandial suppression of MMC.
Oxygen sensing in neuroendocrine cells and other cell types: pheochromocytoma (PC12) cells as an experimental model.

A steady supply of oxygen is an absolute requirement for mammalian cells to maintain normal cellular functions. To answer the challenge that oxygen deprivation represents, mammals have evolved specialized cell types that can sense changes in oxygen tension and alter gene expression to enhance oxygen delivery to hypoxic areas. These oxygen-sensing cells are rare and difficult to study in vivo. As a result, pheochromocytoma (PC12) cells have become a vital in vitro model system for deciphering the molecular events that confer the hypoxia-resistant and oxygen-sensing phenotypes. Research over the last few years has revealed that the hypoxia response in PC12 cells involves the interactions of several signal transduction pathways (Ca2+/calmodulin-dependent kinases, Akt, SAPKs, and MAPKs) and transcription factors (HIFs, CREB, and c-fos/junB). This review summarizes the current understanding of the role these signal transduction pathways and transcription factors play in determining the hypoxic response.
Arterial Wall Adaptation under Elevated Longitudinal Stretch in Organ Culture

Arteries in vivo are subjected to large longitudinal stretch which may change significantly due to vascular disease and surgery. However, little is known about the effect of longitudinal stretch on vascular function and wall remodeling, although the effects of tensile and shear stress from blood pressure and flow have been well documented. To study the effect of longitudinal stretch on vascular function and wall remodeling, porcine carotid arteries were longitudinally stretched 20% more than in vivo for 5 days while being maintained in an ex vivo organ culture system under conditions of pulsatile flow at physiologic pressure. Vessel viability was demonstrated by strong vasomotor responses to norepinephrine (NE, 10(-6) M), carbachol (10(-6) M), and sodium nitroprusside (10(-5) M), as well as by dense staining for mitochondrial activity and a low occurrence of cell necrosis. Cell proliferation was examined by incorporation of bromodeoxyuridine (BrdU). Results showed that arteries maintain normal structure and viability after 5 days in organ culture. Both the stretched and control arteries demonstrated significant contractile responses. For example, both stretched and control arteries showed approximately 10% diameter contraction in response to NE. Stretched arteries contained 8% BrdU-positive cells compared to 5% in controls (p<0.05). These results indicate that longitudinal stretch promotes cell proliferation in arteries while maintaining arterial function.
Corruption in the Gulag: Dilemmas of Officials and Prisoners

Based on research in the archives of the Soviet penal camp system, this article addresses the phenomenon of corruption among officials of the Gulag in the period between 1945 and 1953. The Ministry of Internal Affairs, which oversaw the camp system, treated corruption as a harmful and dangerous phenomenon that was unacceptably pervasive. The article investigates the varieties and frequency of corrupt activities among camp officials, including bribery, theft of state property, participation in illegal markets and speculation, and embezzlement Gulag authorities' anti-corruption efforts included inspections, audits, and a large network of prisoner–informants. These anti-corruption campaigns were largely ineffective. The article concludes that corruption existed in significant quantities inside the camp system, and that the forms it took were largely the same as in the wider Soviet society.
Effect of chronic administration of ethanol on the regulation of the δ-subunit of GABAA receptors in the rat brain

In the present study, we investigated the effect of chronic ethanol (CE) administration on the polypeptide levels of the delta-subunit of GABA(A) receptors and [(3)H]muscimol binding to the immunoprecipitated delta-subunit-containing GABA(A) receptor assemblies in the rat brain. CE administration resulted a down-regulation of polypeptide levels of the delta-subunit of GABA(A) receptors in the rat cerebellum and hippocampus, whereas there were no changes in the delta-subunit polypeptide levels in the rat cerebral cortex. Further, CE administration caused a down-regulation of native delta-subunit-containing GABA(A) receptor assemblies in the rat cerebellum as determined by [(3)H]muscimol binding to the immunoprecipitated receptor assemblies. These results indicate that the delta-subunit-containing GABA(A) receptors may play a role in chronic ethanol-induced tolerance and dependence.
Downregulation of miR‐122 in the rodent and human hepatocellular carcinomas

MicroRNAs (miRs) are conserved small non-coding RNAs that negatively regulate gene expression. The miR profiles are markedly altered in cancers and some of them have a causal role in tumorigenesis. Here, we report changes in miR expression profile in hepatocellular carcinomas (HCCs) developed in male Fisher rats-fed folic acid, methionine, and choline-deficient (FMD) diet. Comparison of the miR profile by microarray analysis showed altered expression of some miRs in hepatomas compared to the livers from age-matched rats on the normal diet. While let-7a, miR-21, miR-23, miR-130, miR-190, and miR-17-92 family of genes was upregulated, miR-122, an abundant liver-specific miR, was downregulated in the tumors. The decrease in hepatic miR-122 was a tumor-specific event because it did not occur in the rats switched to the folate and methyl-adequate diet after 36 weeks on deficient diet, which did not lead to hepatocarcinogenesis. miR-122 was also silent in a transplanted rat hepatoma. Extrapolation of this study to human primary HCCs revealed that miR-122 expression was significantly (P = 0.013) reduced in 10 out of 20 tumors compared to the pair-matched control tissues. These findings suggest that the downregulation of miR-122 is associated with hepatocarcinogenesis and could be a potential biomarker for liver cancers.
The ascent of Babel: An exploration of language, mind, and understanding . Gerry T. M. Altmann. Oxford University Press, 1997. Pp. 304.

Given the small number of introductory psycholinguistics books currently available, it is not only refreshing to find a new one but also delightful to find one as accessible to general audiences as Altmann's The Ascent of Babel. Altmann, a professor at the University of York and an established psycholinguistics researcher, aimed to write a book that anyone could understand and enjoy. Indeed, he has succeeded. The result is not just another run-of-the-mill textbook. The prose reads like the transcription from a semester of lectures or from a very long conversation carried out between mentor and student. The prose reads as smoothly as it does, in part, because there are no references cited within the text. They have been included at the end of the book in a chapter-by-chapter format. In addition, very few researchers are mentioned by name, which serves to speed readers along, allowing them to focus on findings rather than individuals. The names that are mentioned are of those at the top of the field who should become known to every student of psycholinguistics.
Detecting Topological Order through a Continuous Quantum Phase Transition

We study a continuous quantum phase transition that breaks a Z2 symmetry. We show that the transition is described by a new critical point which does not belong to the Ising universality class, despite the presence of well-defined symmetry-breaking order parameter. The new critical point arises since the transition not only breaks the Z2 symmetry, it also changes the topological or quantum order in the two phases across the transition. We show that the new critical point can be identified in experiments by measuring critical exponents. So measuring critical exponents and identifying new critical points is a way to detect new topological phases and a way to measure topological or quantum orders in those phases.
Comparison of model independent control and tracking with standard control techniques

This paper highlights some of the new contributions nonlinear dynamics has made in the areas of control and tracking. In particular, emphasis is placed on the model independent approach to control and tracking: The connections between the classical control and the control based on time series embedding methods are made. In experiments of control, our approach does not necessarily imply new equipment is needed in the loop. Rather, it is the control settings which are constructed off-line so that location of the control point and gain are determined without trial and error. Using the model independent approach also allows one to locate and control many other accessible unstable phenomena without having to construct a global nonlinear model. Tracking gives a constructive approach to control inaccessible states, as well as maps out the global regions of phase space.
Synergy between Conserved ABC Signature Ser Residues in P-glycoprotein Catalysis *

Functional roles of the two ABC signature sequences ("LSGGQ") in the N- and C-terminal nucleotide binding domains of P-glycoprotein were studied by mutating the conserved Ser residues to Ala. The two single mutants (S528A; S1173A) each impaired ATPase activity mildly, and showed generally symmetrical effects on function, consistent with equivalent mechanistic roles of the two nucleotide sites. Synergy between the two mutations when combined was remarkable and resulted in strong catalytic impairment. The Ser residues are not involved significantly in MgATP- or MgADP-binding or in interdomain communication between catalytic sites and drug binding sites. Retention of product MgADP is not the cause of reduced turnover. Mutation of Ser to Ala reduced the strength of interaction with the chemical transition state specifically, as shown by vanadate-ADP and beryllium fluoride-ADP trapping experiments. Therefore, the two conserved ABC signature motif Ser residues of P-glycoprotein cooperatively accelerate ATP hydrolysis via chemical transition state interaction. Because the transition state complex is currently believed to form in the dimerized state of the nucleotide binding domains, one may also conclude that both Ser-OH are necessary for correct formation of the dimer state.
Potential mechanisms of low-temperature tolerance of C4 photosynthesis in Miscanthus x giganteus: an in vivo analysis.

Miscanthus × giganteus (Greef & Deuter ex Hodkinson & Renvoize) is unique among C4 species in its remarkable ability to maintain high photosynthetic productivity at low temperature, by contrast to the related C4 NADP-malic enzyme-type species Zea mays L. In order to determine the in vivo physiological basis of this difference in photosynthesis, water vapor and CO2 exchange and modulated chlorophyll fluorescence were simultaneously monitored on attached leaf segments from plants grown and measured at 25/20°C or 14/11°C (day/night temperature). Analysis of the response of photosynthesis to internal CO2 concentration suggested that ribulose bisphosphate carboxylase/oxygenase (Rubisco) and/or pyruvate orthophosphate dikinase (PPDK) play a more important role in determining the response to low temperature than does phosphoenolpyruvate carboxylase (PEPc). For both species at both temperatures, the linear relationship between operating efficiency of whole-chain electron transport through photosystem II (ΦPSII) and the efficiency of CO2 assimilation (ΦCO2) was unchanged and had a zero intercept, suggesting the absence of non-photosynthetic electron sinks. The major limitation at low temperature could not be solely at Rubisco or at any other point in the Calvin cycle, since this would have increased leakage of CO2 to the mesophyll and increased ΦPSII/ΦCO2. This in vivo analysis suggested that maintenance of high photosynthetic rates in M. × giganteus at low temperature, in contrast to Z. mays, is most likely the result of different properties of Rubisco and/or PPDK, reduced susceptibility to photoinhibition, and the ability to maintain high levels of leaf absorptance during growth at low temperature.
An EM Algorithm for Smoothing the Self‐consistent Estimator of Survival Functions with Interval‐censored Data

Interval-censored data arise in a wide variety of application and research areas such as, for example, AIDS studies (Kim et al., 1993) and cancer research (Finkelstein, 1986; Becker & Melbye, 1991). Peto (1973) proposed a Newton-Raphson algorithm for obtaining a generalized maximum likelihood estimate (GMLE) of the survival function with interval- censored observations. Turnbull (1976) proposed a self-consistent algorithm for interval- censored data and obtained the same GMLE. Groeneboom & Wellner (1992) used the convex minorant algorithm for constructing an estimator of the survival function with "case 2" interval-censored data. However, as is known, the GMLE is not uniquely defined on the interval 10, oo). In addition, Turnbull's algorithm leads to a self-consistent equation which is not in the form of an integral equation. Large sample properties of the GMLE have not been previously examined because of, we believe, among other things, the lack of such an integral equation. In this paper, we present an EM algorithm for constructing a GMLE on (0, oo). The GMLE is expressed as a solution of an integral equation. More recently, with the help of this integral equation, Yu et al. (1997a, b) have shown that the GMLE is consistent and asymptotically normally distributed. An application of the proposed GMLE is presented.
Automation of the microscope-a scheme for improving the microscope

A conventional optical microscope has been improved to obtain faster, continuous measurement automatically. A digitized microscope system has been developed by adding an image acquisition subsystem, an (x, y)-axes controller for the stage, and a z-axis controller for focusing. The system is supervised by a microcomputer. A simple automatic focusing algorithm is discussed. >
Mapping sleep using coupled biological oscillations

Sleep and wake state have different influences on a variety of recordable signals that make up the polysomnogram. Conventional sleep stages are dependent on analysis of electroencephalogram (EEG) waveforms. Non-EEG approaches can provide a different view of sleep. One such example is the electrocardiogram (ECG) derived sleep spectrogram, which computes the coupling and coherence of heart rate variability and respiratory tidal volume influences on the ECG R wave. Novel insights into sleep physiology and pathology are available through this technique.
The Normal Human Intra-Aural Muscle Reflex in Response to Sound

1. The particular modification of the method of tympanomanometry as it is employed in our laboratory has proven to be a useful tool in the investigation of the normal human intra-aural muscle reflex.2. Some of the signal-response relationships of this reflex have been investigated and discussed.3. Evidence was presented which supports the thesis that both the stapedius and tensor tympany muscles in the human respond to sound stimuli.4. The suggestion is made that this technique lends itself to increasing the accuracy of pre-operative diagnosis of some forms of conductive hearing loss.
Cerebral Cortex Docosahexaenoic Acid Is Lower in Formula-Fed than in Breast-Fed Infants

Docosahexaenoic acid (22:6n-3) is abundant in the brain and retina and may be important for optimal nervous system development. Although current infant formulas available in the United States do not contain this fatty acid, it is found in human milk. In a recent study, the concentration of 22:6n-3 in cerebral cortex phospholipids was lower in full-term formula-fed infants than in infants who were breast-fed.
A sum of simple and complex motions on the eardrum and manubrium in gerbil.

Abstract Based on comparisons of ear canal and scala vestibuli pressures the gerbil middle ear transmits sound with a gain of ∼25 dB that is almost flat from 2 to 40 kHz, and with a delay-like phase corresponding to a 25–30 μs delay. How the middle ear is able to transmit sound with such high temporal and amplitude fidelity is not known, and is particularly mysterious given the complex motion the ossicles and tympanic membrane (TM) are known to undergo. To explore this question, we looked at the velocities of the manubrium and along a line on the TM. The TM motion was complex, and could be approximated as the combination of a wave-like motion and an in-and-out piston-like motion. The manubrium underwent bending at some stimulus frequencies and therefore its motion was not like a rigid body. It had a complex motion with frequency fine structure that seemed likely to be derived from resonances on the drum-like TM.
Evolution, population dynamics, and stability: A comment

Abstract A recently proposed criterion for community coevolution is shown to be equivalent to requiring that a mutant have a positive selective advantage if it is to spread through a population. This is one of the basic conclusions of deterministic population genetics.
Life History of Bangia fuscopurpurea (Dillw.) Lyngb. in Culture

Two types of spore germination occur in the genus Bangia. The bipolar type is the most frequent, the resultant germlings developing into filaments which resemble the parent thallus. In addition, unipolar germination of certain spores to form filamentous growths with elongate cells has been reported1–6. Drew7 was able to identify similar filamentous growths obtained from spore germination in Porphyra as the alga previously described as Conchocelis rosea Batters. Later, Drew referred to Conchocelis, the product of germination of certain spores in Bangia, although she was not able to obtain the complete life history in culture3,4. Kurogi5 reported completion of the life history in culture for Bangia gloiopeltidicola, giving no details, while Ogata8 reported numerous uniseriate plants, presumably of Bangia fuscopurpurea, growing on calcite in which the Conchocelis-phase of that species had been grown, without being able to indicate their origin.
Sputtering Studies Using the Matrix Isolation Technique

The application of the matrix isolation technique to the study of the sputtering process is reported. Equations are derived which relate the experimentally measured absorbance data to the sputtering yield. These equations are applied to data from the sputtering of Nb metal by 50 keV rare gas ions. Relative sputtering yields obtained in this manner are in good agreement with sputtering yields obtained by weight loss measurements. The potential of the technique for studies of both physical and chemical sputtering and for the determination of oscillator strengths is discussed.
Nonlinguistic Knowledge, Hemispheric Laterality, and the Conservation of Inequality in Nonconserving Children.

Summary Nonconserving children may fail to conserve because of difficulties in verbally expressing nonlinguistic knowledge of equivalence relationships. This may be partly due to an inability of the right hemisphere, which mediates the performance of internal reversals and conservation, to communicate with the speaking left hemisphere because of the immaturity of the corpus callosum. This relationship presumably results in the asymmetrical activation of the left hemisphere when verbal responses are required. To assess the possibility that nonconservers have an awareness of the reversibility of these operations, three groups of nonconserving children (N = 42) were either asked which of two containers (one of which appeared to contain more liquid, but had previously been shown to contain less) had more in it, or which (pretending they were very thirsty and it was their favorite drink) they would prefer. To assess whether nonconservers respond primarily with left hemisphere activation, patterns of lateral ey...
Heat Capacity Study of Monolayer Propane on Graphite

Heat capacity measurements have been conducted for monolayer propane films adsorbed on graphite in the vicinity ofthe melting transition. Films at ten coverages between 0.4 and 1.07 layers were studied. For coverages below n = 1.0 a very weak heat capacity peak of height ∼2 C/Nk B , is found at melting; the transition is centered about 67 K, in good agreement with the melting temperature found in structural studies. Above n = 1.0 the melting peak moves to higher temperatures with increasing coverage. Data for propane are compared to those found for other hydrocarbon systems on graphite and to current theories of two-dimensional melting.
Community College Dual Enrollment Faculty Orientation: A Utilization-Focused Approach

The current climate of accountability demands that institutions engage in data-driven program evaluation. In order to promote quality dual enrollment (DE) programs, institutions must support the adjunct faculty teaching college courses in high schools. This study uses Patton's utilization-focused model (1997) to conduct a formative evaluation of a pilot Dual Enrollment Faculty Orientation Program (DEFOP) at a community college. Data from surveys, interviews, observations, and analysis of syllabi indicated faculty appreciated establishing relationships with the college and gained an understanding of DE expectations. While participants did not make changes to syllabi or pedagogy, they employed effective teaching strategies to deliver successful, college-level DE courses. Implications for future DE orientation programs include focusing on the cultivation of institutional relationships and establishing expectations while deemphasizing information related to specific instructional strategies.
Ethnicity and Status Attainment: The Case of the Roman Catholic Clergy*

This paper examines the influence of ethnic background on organizational status attainment. The data are taken from a national sample of 2,755 Roman Catholic diocesan priests and bishops. The sampl...
A flexible VXML interpreter for non-visual web access

VoiceXML (VXML) is a W3C's standard for specifying interactive dialogs. It finds multiple uses in variousWeb applications. VXML can also be used in non-visual Web browsing. There is no suitable, complete, open-source, flexible VXML interpreter to process VXML dialogs. My project is focusing on developing a VXML interpreter, VXMLSurf, that will be fully compliant with VXML 2.0 specifications and geared toward accessing Web content. VXMLSurf implements a number of extended features that provide blind users with more control over interactive browsing dialogs. VXMLSurf is a part of the HearSay project for developing a non-visual Web browser. The goal of the project is to make the Web more accessible for blind people.
Visual stimulation enhances auditory processing in 3‐month‐old infants and adults

Behavioral work demonstrates human infants are sensitive to a host of intersensory properties and this sensitivity promotes early learning and memory. However, little is known regarding the neural basis of this ability in infants. Using event-related potentials (ERPs) with infants and adults, we show that during passive viewing auditory evoked brain responses are increased with the presence of simultaneous visual stimulation. Results converge with previous adult neuroimaging studies, single-cell recordings in nonhuman animals, and behavioral studies with human infants to provide evidence for an elevated status of multisensory stimulation in infancy. Furthermore, these results may provide a neural marker of multisensory audio-visual processing in infants that can be used to test developmental theories of how information is integrated across the senses to form a unitary perception of the world. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 52:181–189, 2010
A mouse model to test the in vivo efficacy of chemical chaperones

In vitro studies in transfected cells have indicated that chemical chaperones including glycerol (0.5-1.2 M) and trimethylamine oxide (TMAO, 50-100 mM) can correct defective trafficking of some proteins, including deltaF508 CFTR in cystic fibrosis and AQP2 mutants in nephrogenic diabetes insipidus. To develop a mouse model to test the efficacy of chemical chaperones in vivo, glycerol and TMAO were administered by intraperitoneal (i.p.), subcutaneous (s.c.), and oral routes. Glycerol and TMAO assays that utilized 1-5 microL of tail vein blood were developed. Administration by the i.p. and s.c. routes gave maximum serum glycerol concentrations of approximately 100 mM, levels that were well below the effective in vitro concentrations. Single i.p. or s.c. doses of TMAO (7 g/kg, 8% solution in water) resulted in serum [TMAO] greater than 50 mM, with a long half-life (t1/2 approximately equal to 18-21 h). Sustained high serum and tissue [TMAO] > 52 mM for 3 days was achieved by s.c. administration of TMAO (7 g/kg) in water every 8 h. Although approximately 50% of the mice died with this multiple-dose regimen, the remaining mice had nearly normal liver, renal, and pancreatic function. A lower dose of TMAO (5 g/kg) given by the s.c. route every 8 h resulted in serum [TMAO] concentration of 22 mM, a level that was well tolerated by all mice for 72 h. These mice also had high [TMAO] in urine, 400 mM. These results demonstrate that potentially therapeutic concentrations of TMAO can be sustained in mice in vivo, permitting the testing of chemical chaperones in transgenic mouse models of diseases caused by defective protein trafficking.
COOPERATIVE INTERACTIONS IN A PLASMA

Aspects of cooperative plasma interactions, with emphasis on nonequilibrium, at high temperature and low density are discussed. Under the conditions assumed, particle collisions played a negligible role. A description of plasma hydrodynamics based on turbulent scattering of electrons and ions is presented. The effect of streaming instability on the initial excitation of plasma waves is also discussed. It was concluded that the interactions between collective plasma excitations may provide the significant mechanisms for irreversible phenomena. (M.C.G.)
Misuse of analysis of covariance in aging research and some partial solutions

Abstract Geron-tological researchers are reminded of the inappropriateness of analysis of covariance wherein the covariate is correlated with the independent variable, typically age. Two partial solutions are suggested that deal with the confounding of age effects with such uncontrolled variables as, for example, initial ability level or level of education.
Plasma From Preeclamptic Women Stimulates Transendothelial Migration of Neutrophils

Neutrophils infiltrate systemic vasculature of women with preeclampsia, so we tested the hypothesis that factors in plasma of preeclamptic women activate endothelial cells to produce IL-8 resulting...
Learning curve for percutaneous transluminal coronary angioplasty: Skill, technology or patient selection

As with all sophisticated techniques, operators who perform PTCA show a learning curve. It can best be visualized by observing changes in success rate with growing numbers of patients. Thus, the current success rate and complication rate of a particular operator may permit an estimate of the accumulated number of patients treated by that operator. Most likely, the learning curve is also reflected in the rate of long-term success, although it may be obscured by other factors in the variable natural course of CAD. The initial steep upslope of the learning curve is mainly caused by the growing skill of the particular operator. The later, flatter part appears to be secondary to improvements in technical equipment, which take more time. Patient selection has 2 effects on the learning curve that may be self-compensating. If lessons from the past are used for selection and conservatism is preserved, the learning curve will become more pronounced.
Statistics of Multicharge Centers in Semiconductors - Applications

A general formula is derived for the electron occupation numbers appropriate for multicharge centers in semiconductors, including excited states. The results are used to rederive and generalize several formulas of interest in the literature, in order to show exactly how the degeneracies of individual states enter in. Particular attention is paid to certain subjects which are sometimes confusing, such as how the statistics of band states differ from those those of localized states. Another subject of much recent interest, negative-$U$ centers, is dealt with in some detail. We show how the dependence of the average occupation number on Fermi energy and the temperature dependence of the free-carrier concentration differ between positive- and negative-$U$ centers.
Relation of invasive capacity to passage of lymphocytic cells through cellulose membrane filters.

IN a previous paper1 it was reported that when three lymphocytic tumours, each with a different capacity to invade host tissues, were grown in Millipore Type AA filters (pore size 0.8 ± 0.05µ) (Millipore Filter Corporation, Bedford, Mass.) in double diffusion chambers, the cells of the tumours were unable to penetrate the filter after growing for 60 days in an isologous host. More recent experiments with this filter have shown that while the cells of these tumours are able to pass through the AA filter, there is nevertheless a striking difference in the capacity of the cells of an invasive and a non-invasive tumour to penetrate the pores of this membrane and establish a growing cell population on the other side.
Humoral Immune Response to AAV.

Adeno-associated virus (AAV) is a member of the family parvoviridae that has been widely used as a vector for gene therapy because of its safety profile, its ability to transduce both dividing and non-dividing cells, and its low immunogenicity. AAV has been detected in many different tissues of several animal species but has not been associated with any disease. As a result of natural infections, antibodies to AAV can be found in many animals including humans. It has been shown that pre-existing AAV antibodies can modulate the safety and efficacy of AAV vector-mediated gene therapy by blocking vector transduction or by redirecting distribution of AAV vectors to tissues other than the target organ. This review will summarize antibody responses against natural AAV infections, as well as AAV gene therapy vectors and their impact in the clinical development of AAV vectors for gene therapy. We will also review and discuss the various methods used for AAV antibody detection and strategies to overcome neutralizing antibodies in AAV-mediated gene therapy.
Contribution of extrastriate area V4 to the surface-recorded flash VEP in the awake macaque.

Abstract This study compared striate and extrastriate contributions to the surface-recorded flash VEP. Laminar visual evoked potential, current source density and multiunit activity profiles were obtained with multicontact electrodes from areas V1 and V4 in three awake macaques. As found earlier, the major striate contribution is to early (N40, P55–80) components. Major contributions to the later (N95, P120, Late Negativity) components arise from V4. Early, afferent-triggered inhibition in V4 also produces a small contribution to N40. Response latencies in V4 vs V1 suggest an input to V4, bypassing VI, emphasizing a parallel processing component of visual system organization.
Medial frontal lesions, postoperative treatment with an ACTH(4–9) analog, and acquisition of a win-shift spatial strategy

Forty adult rats of both genders were randomly assigned to one of four factorial groups and prepared with either medial frontal or sham lesions. On the day of surgery osmotic mini-pumps that had been prepared to deliver either 12.5 μg of ACTH(4–9) analog per 24 h or saline for the next 14 days were installed in a subcutaneous location. One month following surgery, these animals were studied in an avoidance conditioning experiment. Four to 6 months later their abilities to learn a water maze win-shift spatial strategy was investigated. The brain-damaged rats were found to be deficient on all behavioral measures examined: errors to criterion, days to criterion, and perseverative errors. Although post-neurosurgical administration of the ACTH 4–9 analog has been shown to improve behavioral recovery from brain damage in some studies, the peptide failed to improve the behaviors examined here.
Ozone diurnal variations in the stratosphere and lower mesosphere, based on measurements from SABER on TIMED

[1] We report on derived results of global zonal mean ozone diurnal variations over 24 h of local solar time, based on satellite measurements from SABER on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, with focus on the stratosphere and lower mesosphere. On a global scale, results in this altitude range are new. We had previously reported on ozone diurnal variations, but the focus was at higher altitudes, where the variations can be relatively large. In the stratosphere, there can be systematic diurnal variations on the order of a few percent, with multiple local maxima over a day, and these can exist down to altitudes of ∼31 hPa (∼24 km) and lower. At these altitudes, photochemistry is expected to be less effective, and dynamics (e.g., tides) can be more important. The diurnal variations also depend on latitude and season. As a function of altitude, for low latitudes at least, the ozone diurnal variations show a pattern of local-time phase progression such that beginning at ∼31 hPa the mixing ratios are smaller in the afternoon (compared to values at midnight), then (as the altitude increases) become mostly larger in the afternoon beginning from ∼10 to 4.6 hPa, revert back to intermediate afternoon values near 2.2, 1.5 hPa, and again return to lower daytime values at about 1 hPa, with this last trend continuing to higher altitudes in the mesosphere. This pattern of variation is generally supported by previous results by us and by others, based on data from MLS UARS, MLS Aura, rocket-borne, and ground-based measurements.
Long-term response of a Concanavalin-A based fluorescence glucose sensing assay

Competitive binding assays comprised of the protein Concanavalin A (ConA) have shown potential for use in continuous glucose monitoring devices. However, its time-dependent, thermal instability can impact the lifetime of these ConA based assays. In an attempt to design sensors with longer in vivo lifetimes, different groups have immobilized the protein to various surfaces. For example, Ballerstadt et al. have shown that immobilizing ConA onto the interior of a micro-dialysis membrane and allowing dextran to be freely suspended within solution allowed for successful in vivo glucose sensing up to 16 days. This work explores the glucose response of an assay comprised of modified ConA and a single fluorescently labeled competing ligand in free solution to increase the in vivo sensing lifetime without immobilization,. The behavior of this assay in the presence of varying glucose concentrations is monitored via fluorescence anisotropy over a 30 day period.
Management of Conditioned Fear

The procedure in which a previously neutral conditioned stimulus (CS) is followed repeatedly by a painful electric shock is frequently used as a basis for classically conditioning fear. With human Ss, the growth in amplitude of the GSR to the CS typically is taken as evidence of this effect. While it is initially of adaptive value to S to learn which of the multitude of stimuli constantly impinging upon his sense receptors signal impending pain, this information can altimately only be of adaptive value if a response is available that enables avoidance or reduction of the pain. Being afraid is, after all, itself unpleasant. Having learned to fear the CS, S is in the unfortunate position of having to suffer twice instead of only once, first when the CS starts and, again, when the shock is delivered. The present experiment used an unconventionally long interval between the onsets of the CS and unconditioned stimulus (UCS), 8 sec. Eight college-student Ss came to the laboratory every day at the same hour for nine consecutive days. Ss received 8 reinforced trials each day, the CS being a 1,000-cps tone of 8 sec. duration and the UCS an electric shock to the fingertips, sharing with the tone the last one-tenth sec. of the CS-UCS interval. The shock had an intensity sufficient to register a voltage drop of 100 V across an arbitrary resistance of 25,000 ohms.
"You can't always get what you want"--or can you?

You can't always get what you want But if you try sometimes You just might find You just might find You get what you need — Mick Jagger / Keith Richards, Let it Bleed, 1969 In the dawn of this new millennium, industrialized nations are struggling with
Estimation for Polynomial Structural Equation Models

Abstract Structural equation analysis is one of the most widely used statistical methods in social and behavioral science research and has become a popular tool in marketing. Subject matter needs for considering nonlinear structural models have been well documented. But current fitting procedures are available only for a limited class of models. In this article a systematic statistical approach is developed for the general polynomial structural equation model. The new procedure applies a method of moments procedure similar to the one used in errors-in-variables regression to the factor score estimates from the measurement model fit. The asymptotic properties of the estimator are derived, and a modified estimator with better small-sample properties is introduced. Simulation studies are reported to show the usefulness of the procedure and to compare its performance to other methods. An example from a substance abuse prevention study is also discussed.
The Transformation of the Pacific Electric Railway: Bradford Snell, Roger Rabbit, and the Politics of Transportation in Los Angeles

In his account of the motorization of transit in Los Angeles, Bradford Snell focused on industry-based interest group politics and on modal conflict. These obscure the politicization of transport issues at the metropolitan level. Competition between place-based coalitions to attract and retain mobile capital investment structured not only urban transport politics but also controversial efforts to create governmental transit agencies. In this article the author critiques Snell's account and provides an alternative analysis of the fate of the Pacific Electric Railway that is grounded in the political economy of the Los Angeles region in the period immediately preceding and following World War II.
Fabrication and Optimization of Properties of Polymer Laminated Nanoreinforced Automobile Glasses: Experiments and Modeling

This paper describes the fabrication process for the thin cast-in-place laminate glazing systems to be used in cars of the future to achieve the weight reduction goals of FreedomCAR. The primary objective of the project is to reduce vehicle weight, improve fuel economy, and reduce vehicle emissions through the use of structurally reliable, high acoustic performance, and lightweight glazing systems with low manufacturing costs. Energy savings come from reducing weight by using thinner glazing: prior studies at Pacific Northwest National Laboratory (PNNL) have demonstrated a potential of 30% weight reductions compared with standard glazing system. Energy savings will also come from reducing interior heat loads; that, in turn, will reduce the demand for air conditioning. The evaluation of alternative glazing concepts seeks to improve acoustical performance such that reduced interior noise levels can be achieved while maintaining glazing at minimal thickness and weight levels. The most important factor in utilizing laminated glazing systems as vehicle side glass is its advantage in cost savings for material and manufacturing processes.
Structural transformation of CsI thin film photocathodes under exposure to air and UV irradiation

Transmission electron microscopy has been employed to study the structure of polycrystalline CsI thin "lms and its transformation under exposure to humid air and UV irradiation. The catastrophic degradation of CsI thin "lm photocathode performance is shown to be associated with the "lm dissolving followed by its re-crystallization. This results in the formation of large lumps of CsI crystal on the substrate surface, so that the "lm becomes discontinuous and its performance as a photocathode is permanently degraded. No change in the surface morphology and the "lm crystalline structure was observed after the samples were UV irradiated. ( 2000 Elsevier Science B.V. All rights reserved.
Performance evaluation of an integrated instrumentation system

With increasing sophistication of parallel tool development technologies, runtime data collection and management activities are receiving greater attention from tool developers. We define an instrumentation system (IS) as a set of modules and functions that collect runtime data from concurrent processes and support an integrated tool environment by sharing this data along with specific control information. Presently, it is not standard practice to formally evaluate the performance and functionality of a tool early in its development. Usability and efficiency studies of prototypical tools are emerging to alleviate this situation. However; the underlying IS is removed from the end-user and is part of system infrastructure, thus necessitating more rigorous evaluation. We are developing a structured approach to plan, design, model, realize, and test an IS, called the Vista IS, to appropriately address these issues.
Prevalence of Coronary Blood Flow Reserve Abnormalities Among Patients With Nonobstructive Coronary Artery Disease and Chest Pain

Objective To determine the prevalence of abnormalities in endothelium-dependent and endothelium-independent coronary flow reserve among patients with non-obstructive coronary artery disease and chest pain. Material and Methods We studied endothelium-dependent (after infusion of 10 -6 M to 10 -4 M of acetylcholine) and endothelium-independent (after administration of 18 to 36 μg of adenosine) coronary flow reserve among patients with nonobstructive coronary artery disease and chest pain who were undergoing assessment at Mayo Clinic Rochester. Coronary blood flow was derived from coronary artery diameter assessed by quantitative angi-ography and Doppler flow velocities. Results The cohort consisted of 203 patients (158 female and 45 male patients), who ranged in age from 17 to 78 years (mean, 51). Most patients (92%) had at least one risk factor for atherosclerosis; a substantial proportion had undergone extensive cardiac and noncardiac evaluation. Whereas 41.5% of the patients had normal coronary flow reserve, 58.5% had an abnormal response: 11.3% an impaired response to adenosine (flow velocity ratio of 2.5 or less), 29.2% an impaired response to acetylcholine (flow reserve ratio of 1.5 or less), and 18% a combined abnormality. No correlation ( r 2 = 0.03) was noted between endothelium-dependent and endothelium-independent flow reserve. Conclusion Most study patients with chest pain and nonobstructive coronary artery disease undergoing coronary vasomotor evaluation had risk factors for coronary artery disease and diverse abnormalities in endothelium-dependent or endothelium-independent coronary flow reserve (or both). These findings underscore the need for a comprehensive assessment.
Lactation and weaning effects on physiological and behavioral response to stressors

Two experiments tested the effects of lactation and weaning on heart rate (HR), corticosterone, and behavioral responses to stress in Wistar rats. In Experiment 1, HRs in lactating, weaning, and control animals were recorded for 10-min periods before, during, and after immobilization stress. Compared with control animals, lactating and weaning animals showed a diminished initial HR response. In addition, HRs of weaning animals failed to habituate and showed a delayed decline after stress termination. In Experiment 2, behaviors, HRs, and corticosterone levels in the elevated plus maze (EPM) were compared among lactating, weaning, and control animals. Compared with control animals, weaning animals exhibited more anxiety behaviors. Contrary to expectation, compared to the other two groups, lactating animals exhibited more closed-arm entries, although they may have been motivated by maternal behavior, rather than anxiety. Initial HR responses to the plus maze were attenuated in lactating animals. Corticosterone levels after the plus maze were lowest in the lactating dams and highest in the control animals. The results from these two experiments are consistent with effects of breast-feeding and weaning observed in humans. In general, lactation is associated with an attenuated initial HR response to stress, while weaning is associated with exacerbated response to stressors.