cssi/SciSciGPT-SciSciNet huggingface dataset:
H1 receptor-mediated vasodilatation contributes to postexercise hypotension

In normally active individuals, postexercise hypotension after a single bout of aerobic exercise is due to an unexplained peripheral vasodilatation. Histamine has been shown to be released during exercise and could contribute to postexercise vasodilatation via H1 receptors in the peripheral vasculature. The purpose of this study was to determine the potential contribution of an H1 receptor-mediated vasodilatation to postexercise hypotension. We studied 14 healthy normotensive men and women (ages 21.9 +/- 2.1 years) before and through to 90 min after a 60 min bout of cycling at 60% on randomized control and H1 receptor antagonist days (540 mg oral fexofenadine hydrochloride; Allegra). Arterial blood pressure (automated auscultation) and femoral blood flow (Doppler ultrasound) were measured in the supine position. Femoral vascular conductance was calculated as flow/pressure. Fexofenadine had no effect on pre-exercise femoral vascular conductance or mean arterial pressure (P > 0.5). At 30 min postexercise on the control day, femoral vascular conductance was increased (Delta+33.7 +/- 7.8%; P < 0.05 versus pre-exercise) while mean arterial pressure was reduced (Delta-6.5 +/- 1.6 mmHg; P < 0.05 versus pre-exercise). In contrast, at 30 min postexercise on the fexofenadine day, femoral vascular conductance was not elevated (Delta+10.7 +/- 9.8%; P = 0.7 versus pre-exercise) and mean arterial pressure was not reduced (Delta-1.7 +/- 1.2 mmHg; P = 0.2 versus pre-exercise). Thus, ingestion of an H1 receptor antagonist markedly reduces vasodilatation after exercise and blunts postexercise hypotension. These data suggest H1 receptor-mediated vasodilatation contributes to postexercise hypotension.
On the necessity of the matching condition in robust stabilization

The authors consider a class of scalar-input uncertain linear systems which contain a single structured uncertain term. The main result is that the matching condition is necessary to achieve quadratic stability with an arbitrary degree of stability. The results are illustrated with a simple example. >
Emotions and the Self: Depression and Identity Change

Emotions hold a central place in sociological understandings of the self, both as a facet of identity management and as an outcome of self-processes. We extend identity theory and research on emotions by suggesting that emotion may be another source of identity change and examine this using a longitudinal sample of newly married couples, focusing on person identities and depression. We find that individuals' identities change to become consistent with others' views. We also find that the more depressive symptoms that individuals experience, the more negative their identities. The identity meanings that change, however, are different for men and women.
Step-Size Independent Approach for Multidisciplinary Sensitivity Analysis

A multidisciplinary sensitivity analysis technique based on a complex Taylor series expansion method is implemented. This technique is shown to be independent of step-size selection as it pertains to cancellation errors. The primary focus of this research is to validate a new aero ‐structural analysis and sensitivity analysis procedure. This validation consists of comparing computed and experimental data obtained for an aeroelastic research wing. Because the aero ‐structural analysis procedure has the complex variable modie cations already included into the software, sensitivity derivatives are automatically computed. Other than for design purposes, sensitivity derivatives can be used for predicting the solution at nearby conditions. The use of sensitivity derivatives for predicting the aero ‐structural characteristics of this cone guration is demonstrated and compared with experimental measurements.
Welding of Plastics: Fundamentals and New Developments

Abstract This paper provides a general introduction to welding fundamentals (section 2) followed by sections on a few selected welding processes that have had significant developments or improvemen...
Characterization of vesicular stomatitis virus nucleocapsids I. Complementary 40 S RNA molecules in nucleocapsids

Abstract Intracellular nucleocapsids synthesized by vesicular stomatitis virus (VSV) were obtained by deoxycholate treatment of cytoplasmic extracts and isolated in sucrose gradients containing ethylenediaminetetraacetate. They were found to sediment at 110–120 S and to be composed of single-stranded 40 S virion RNA and 40 S RNA complementary to virion RNA. Nascent messenger RNA associated with nucleocapsids was sensitive to ribonuclease digestion whereas the 40 S RNA's were resistant to ribonuclease digestion. Both 40 S virion RNA and its complementary 40 S RNA molecule were encased in nucleocapsids. The significance of nucleocapsids in VSV RNA synthesis and maturation is discussed.
Spark-Gap-Trigger Amplifier

Short over-all time delay, low time jitter, and excellent long-term reliability are among the desirable features designed into a pulse generator that produces a 2-MW output pulse 30 nsec after the application of a 1-V signal at its 50-ohm input connector. The 10-kV output pulse can be used to trigger simultaneously several spark gaps of the type used in spark-chamber pulse modulators. The 10 power gain of the spark-gaptrigger amplifier is achieved by four stages of amplification packaged in a 5-1/4 in. rack-mount chassis that operates directly from a 117-V line. The individual stages, each selected to give minimum time delay for a given power gain at their respective power levels are: avalanche transistors, planar triode, grounded-grid planar triode, and a triggered-spark gap. The techniques used for the last stage, a spark gap triggered by a corona light, are of particular interest since the same techniques are applicable to obtaining short time delays and long-term reliability from the larger spark gaps that the amplifier was designed to trigger. During 10 months of operation, there have been no failures and no adjustments necessary in any of the seven spark-gap trigger amplifiers used in various spark-chamber experiments at the Lawrence Radiation Laboratory of the University of California (UCLRL) in Berkeley.
A chemical model for predicting zinc(II) binding by organic ligands as hypothetical therapeutic agents

Designing small molecules useful for the biological chelation of cations like zinc is a possibly beneficial research area in discovering or developing effective natural or synthetic chelating agents. Synthetic chemists need to estimate how strongly the hypothetical cation chelates would bind to the cation before they synthesize them. The most desirable approach is to use quantitative structure–property relationships (QSPRs) to predict binding constants using elemental composition and functional group data only. This article develops a QSPR for predicting zinc binding by organic ligands, including thiol-containing ligands. The QSPR has the desired S pred of ~1 log unit and an Adjusted R 2 of 0.934. It is a simple mathematical relationship which allows predicting binding constants of zinc with small organic molecules robustly using minimal structural information about the molecules. Therefore, it is suitable for use with small natural or synthetic organic ligands as hypothetical therapeutic agents, provided that an accuracy of ±1 log unit in the conditional binding constants is acceptable.
Three Dimensional Analysis of Advanced Swirl Vane/Nozzle Assemblies

The performance of high shear axial inflow/radial outflow airblast fuel injectors for advanced gas turbine combustors is highly dependent on the design of the swirl vanes. Curved vanes usually exhibit lower losses but straight vanes are also used due to lower cost and ease of manufacture. These type of vanes often operate under highly stalled conditions with high total pressure loss and a highly non-uniform exit velocity profile. This may produce poor fuel atomization with a non-uniform combustor fuel distribution resulting in lowered combustor efficiency and increased pollutant emissions.Properly designed vanes result in a greatly reduced total pressure loss. The exit velocity distribution is more uniform and higher in magnitude which can result in improved fuel atomization and distribution in the combustor.The present study investigates two curved swirler/nozzle shroud configurations operating at 1 and 10 atmospheres pressure for the same inlet temperature of 293°K. The first configuration was a twisted curved vane with thickness where the turning angle varied non-linearly from hub to tip with a maximum turning at the tip of 70 degrees. The second configuration was a curved vane with a linear variation of turning with 70 degrees turning at the tip. The results from a three dimensional viscous numerical flow simulation of these configurations shows similar performance for all cases investigated. The non-linear twisted vane however, had an approximately 3% higher mass flow rate than the vane with the linear variation in turning for the same exit static pressure at the hub. One problem which existed for all the conditions analyzed was a high loss region near the vane tip. This was due to the interaction with the shroud. As the flow exits the vane row and progresses along the nozzle outer lip, the flow area increases. This condition along with the streamline curvature effect of the outer nozzle lip causes an adverse pressure gradient to be formed in this region. This adverse pressure gradient causes the flow to separate from the vane suction surface. The problem initiated in the region of 70% span and increased in magnitude to the vane tip.Copyright © 1996 by ASME
Jet Propagation Through Irregular Media and the Impact of Lobes on Galaxy Formation

We review results of two- and three-dimensional simulations of jets striking clouds with a view toward determining the conditions under which extragalactic jets might stably survive such collisions, and thereby produce “dog-leg” or wide-angle-tail morphologies. Under most circumstances, the jet either destroys the cloud and has its stability little affected or it stalls and is rapidly destabilized by the impact. But there does appear to be a limited range in parameter space where jets can be deflected by clouds but still survive for an extended period. Some of the effects of radio lobes on protogalactic clouds are also considered. At redshifts above 2, the number of radio galaxies (RGs) is much larger than it is in the local universe, and their lobes may well have filled a large fraction of the web of baryonic matter that is still forming galaxies at that epoch. The overpressures in those lobes can trigger extensive star formation on galactic scales and also may have major implications for the spreading of magnetic fields and metals through the intergalactic medium.
Formation of ganglia in the gut of the chick embryo

We have examined the formation of myenteric ganglia in the developing avian enteric nervous system. The monoclonal antibody HNK-1 was used to identify neural-crest-derived cells in whole mounts of fore- and midgut of chick embryos. We find that the crest-derived cells extend processes to their neighbors and form a complex network in the wall of the gut. Formation of this network is an unusual behavior of crest-derived cells and suggests the gut microenvironment is critical to this behavior. This cellular network disappears after ablation of the vagal neural crest, indicating the HNK-1-stained cellular network arises from crest-derived cells. The network is found in the gut wall before the vagal nerve fibers are present. This network is first found in the primordium of the proventriculus, distal to the evagination of the lung buds, and progresses just proximal to the yolk stalk at embryonic day (E) 3.5 and almost to the ileocecal junction at E5.5. The number of cells and the complexity of the network decrease in a rostral-caudal direction down the length of the gut at these stages. The leading edge of the network consists of cells serially arranged in longitudinally running strands. The organization of the network changes with increasing embryonic age; we have focused on network changes in the proventriculus. In the primordium of the proventriculus at E3.5, the network consists of a cluster of one or two adjacent crest-derived cells, which extend processes to a number of neighboring crest-derived cells. At E5.5 large increases in the number of cells per cluster and in the length of cellular connectives between clusters are apparent. At E6.5 a crude meshwork of clusters is seen. At E10.5 the arrangement of cell clusters resembles the pattern of ganglia found in the adult myenteric plexus. This network may provide the environmental cues for the differentiation of enteric neurons and a framework for the pattern of ganglia found in the adult enteric nervous system.
The Additive Effects of Semistructured Classroom Activities on Student Learning: An Application of Classroom-Based Experiential Learning Techniques

Many authors have suggested the use of experiential techniques, such as semistructured classroom activities, as a means of encouraging and facilitating student learning. This article reports a study that investigated the relationship between the use of multiple experiential techniques and student learning. The study found that student learning increased when multiple experiential techniques were used relative to learning that occurred when a single experiential technique was combined with a lecture format. In addition, the data suggest that the use of multiple experiential techniques also influenced the type of information students learned.
Interleaved echo planar imaging on a standard MRI system

This work describes an interleaved echo planar imaging (EPI) method for use on a standard whole body scanner. The data acquisition is divided into two to eight repetitions rather than one to two, as implemented by dedicated EPI systems. Interleaving allows the use of a lower sampling bandwidth with a significant increase in signal-to-noise. The method also has the advantages of relative ease of implementation, no need for postprocessing to remove image distortion, and no need for shimming on a case-by-case basis. The interleaved EPI method was applied to two applications ideally suited to EPI: breathhold T2-weighted abdominal imaging and functional imaging. In vivo liver-lesion contrast as measured in a 35-patient study showed increased contrast for the Interleaved EPI by an average factor of 1.21 (± 0.34) over conventional spin-echo imaging. CNR measurements showed the EPI to be comparable with conventional spin echo with a relative factor of 1.00 (± 0.36). Functional imaging with an eight-shot interleaved EPI sequence provided 128 × 128 images of cerebral activation during bilateral finger tapping.
Suppression of probe background signals via B1 field inhomogeneity

A new approach combining a long pulse with the DEPTH sequence (Cory and Ritchey, Journal of Magnetic Resonance, 1988) greatly improves the efficiency for suppressing probe background signals arising from spinning modules. By applying a long initial excitation pulse in the DEPTH sequence, instead of a π/2 pulse, the inhomogeneous B(1) fields outside the coil can dephase the background coherence in the nutation frame. The initial long pulse and the following two consecutive EXORCYCLE π pulses function complementarily and prove most effective in removing background signals from both strong and weak B₁ fields. Experimentally, the length of the long pulse can be optimized around odd multiples of the π/2 pulse, depending on the individual probe design, to preserve signals inside the coil while minimizing those from probe hardware. This method extends the applicability of the DEPTH sequence to probes with small differences in B₁ field strength between the inside and outside of the coil, and can readily combine with well-developed double resonance experiments for quantitative measurement. In general, spin systems with weak internal interactions are required to attain efficient and uniform excitation for powder samples, and the principles to determine the applicability are discussed qualitatively in terms of the relative strength of spin interactions, r.f. power and spinning rate.
Urban transportation in North America 4. para‐transit

Para-transit is defined as a form of public transportation since the user is transported in a vehicle driven by someone else, the ride is shared with others, and service is provided in an organized and systematic way. It is considered that para-transit can take many forms such as dial-a-bus, jitneys, shared taxis, subscription services, van pools, and public automobile service using small vehicles. In summary, para-transit refers to a class of urban transportation modes that utilises small vehicles on existing streets and highways. The author describes various forms of para-transit and provides information on the operations of existing demand responsive transit systems in the United States, Canada and Europe. Reference is also made to the jitney, or shared taxi, and examples quoted of their operation in the USA, Caracas, Venezuela and Manila in the Philippines. Other systems are also described, and it is suggested that the objective of all such systems is to improve mobility by making better use of what already exists and at a reasonable cost. The major impediments to realizing these benefits are felt to be in the areas of regulations, insurance, control of vehicles and drivers, and labour. /TRRL/
Indented plate problem revisited

An interactive boundary layer method, together with the en approach to the calculation of transition, has been used to investigate the flow over an indented surface for which previous calculations had led to numerical instabilities. The results show two possible reasons for these numerical difficulties. First, it is shown that the gradients of wall shear become very steep at larger Reynolds numbers, particularly in the vicinity of reattachment. Extremely fine numerical grids are required to resolve these gradients. Secondly, and perhaps of greater importance, transition is shown to occur within the region of recirculation for all Reynolds numbers except for the lowest ones. Thus, the calculated flows downstream of the transition locations are fictitious and may be expected to deviate from the corresponding real flows by increasing amounts as the Reynolds number becomes larger. Calculations involving laminar, transitional and turbulent flow have been performed and confirm this conjecture.
High speed automated DNA sequencing in ultrathin slab gels.

Publisher Summary The demands of the human genome initiative for improved DNA sequencing technology are considerable. At this time, virtually all DNA sequencing is based on the separation of DNA fragments in high-resolution polyacrylamide gels. One reasonable approach to improved sequencing is, thus, to increase the performance of such gel-based sequencing methods. To increase the overall throughput of automated sequencing instruments, by a comparable factor, it is necessary to obtain a similar parallelism, in conjunction with these extremely rapid separations. There are two obvious approaches to this problem: (1) employ many gel-filled capillaries in parallel or (2) perform the separations in a slab gel format. This chapter describes the instrumentation and methods that have been developed for high-speed automated DNA sequencing, by ultrathin slab gel electrophoresis. A sketch of the system is discussed in detail in this chapter. It consists of a horizontal gel electrophoresis cell, a laser, and optical components to provide a line of fluorescence excitation across the gel near its bottom, collection optics, a charge-coupled device (CCD) detector system to measure the emitted fluorescence, and a computer system to control the CCD camera as well as to store and analyze the resultant data.
Language Teacher Educators Collaborative Conversations.

Hawkins, E. (1984). Awareness of language. Cambridge: Cambridge University Press. James, C., & Garrett, P. (Eds.). (1991). Language awareness in the classroom. Harlow, England: Longman. Knowles, J. G. (1991). Life-history accounts as mirrors: A practical avenue for the conceptualization of reflection in teacher education. In J. Calderhead & P. Gates (Eds.), Conceptualizing reflection in teacher development (pp. 70-92). London: Falmer Press.
Should we subsidize work? Welfare reform, the earned income tax credit and optimal transfers

During the 1990s, US income-transfer and tax policies shifted towards trying to encourage work among low-income families. Optimal tax theory, however, suggests that work subsidies are usually an inefficient way to raise the incomes of poor families unless the work effort of recipients has external benefits and/or taxpayer/voters prefer redistributing income to the working poor rather than the idle poor. This paper discusses the conditions under which work subsidies may be economically efficient and assesses empirical evidence suggesting that welfare reform and expansions of the EITC have increased work effort among low income families, but is inconclusive about whether the policy shift has enabled them to advance beyond entry-level jobs or benefited their children.
Neuroplastic effects of neonatal capsaicin on barrel cortex of adult rat. An electrophysiological and autoradiographic study

Capsaicin (50 mg/kg s.c./25 mu l) was administered to rats on the 2nd and 5th days after birth. The animals were raised, and from the age of 3 months the properties of the evoked activity were tested in the contralateral barrelfield. This neonatal capsaicin treatment was found to induce profound changes in the responsiveness of the barrel cortex in the adult rats: (1) the receptive field of the neurons in the C1 barrel was expanded; units within a particular barrel were driven by a significantly larger number of vibrissae than in the controls. (2) The rate of discharge evoked by the related vibrissa deflection was enhanced, while (3) the angular sensitivity of the neurons was decreased. (4) The most prominent change in cortical activity was observed by autoradiography: capsaicin-treated rats exhibited an enhanced labelling of different types of neurons throughout the hemisphere (surpassing the cortical representation of stimulated vibrissae). The present observations indicate that neonatal capsaicin affects the functional activity of the rat somatosensory cortex. It is suggested that unmyelinated sensory afferents play a role in the development of the rat somatosensory system.
Gender and Runaways Risk Factors, Delinquency, and Juvenile Justice Experiences

Runaway is a status offense for which there is concern that youths, particularly girls, are vulnerable to the “evils of the streets.” Prior research suggests that many personal and family risks of ...
Asymptotic behavior and steady state solutions of a myelinated axon model with FitzHugh-Nagumo dynamics

A mathematical model of a myelinated nerve fiber is used in which the fiber has passive loading between nodes and has FitzHugh-Nagumo dynamics on each node. Existence of steady state solutions is investigated by superimposing phase diagrams of the nodal and internodal (myelin) equations. The stability of steady state solutions is investigated by construction of an appropriate Liapunov function; the trivial solution is an attractor. It is found that if the length of the nodal segments is sufficiently large compared to the length of the internodal segments, there are always nontrivial, stable 1-periodic steady state solutions. For the shorter nodal segments, stability and even existence of nontrivial 1-periodic steady state solution may fail.
Human pituitary tumor-transforming gene induces angiogenesis.

Angiogenesis is a key determinant and rate-limiting step in tumor progression and metastatic spread. As pituitary tumor-transforming gene (PTTG) induces basic fibroblast growth factor (bFGF), we tested angiogenesis induced by conditioned medium (CM) derived from NIH-3T3 transfectants overexpressing wild-type human PTTG (WT-hPTTG-CM). We also examined the relationship between PTTG expression and tumor vascularity in a series of human tumors. CM from Wt-hPTTG transfectants induced proliferation, migration, and tube formation of human umbilical vein endothelial cells in vitro. The bFGF concentration in WT-hPTTG-CM was elevated (10.5 ± 0.56) compared with CM from nontransfected NIH-3T3 cells (3.3 ± 0.56 pg/mL), and addition of anti-bFGF antibody to CM abrogated these angiogenesis markers (P < 0.01). In vivo, concentrated WT-hPTTG-CM induced chick chorioallantoic membrane spoke-wheel-like appearances. Moreover, CM derived from hPTTG transfectants harboring a point mutation on the C-terminus proline-rich region...
Developing Trust in M-commerce: A Vendor and Certificate Authority Model

AbstractThe goal of creating a secure wireless network in which to conduct commerce is an elusive one. Mobile commerce, (m-commerce) therefore, relies on the wired network to deliver services to its consumers. Trust of the service delivery is a security concern that has prevented a greater acceptance of m-commerce by consumers. This research proposes a new network model that can ensure trust in a mobile commerce environment. A goal of the trusted relationship is to guarantee data and relational integrity in the wireless environment. Research in progress provides a diverse array of solutions from mobile agent systems (Critchlow, 2004, Wang, 2005, Zhang, 2004), the use of a unique asymmetric authentication protocol (He, 2003), to the use of XML to enable Web service efficiencies in architecture (Chang, 2005). This work recognizes and provides plausible solutions to the four elements of challenges and threats to wireless networks outlined by Claessens (2003) and the model is proposed to ensure trust in the m...
Principal components analysis of the inventory of drinking situations: Empirical categories of drinking by alcoholics☆

Male alcoholics (n = 336) were given the Inventory of Drinking Situations (IDS), a 100-item questionnaire that asks subjects to rate the frequency with which they drank in various situations during the previous year. A principal components analysis of the responses suggests there are three major categories of situations in which alcoholics are likely to drink: negative affect states, positive affect states combined with social cues to drink, and attempts to test one's ability to control one's drinking. These categories are compared with recent empirical attempts to define categories of alcohol and smoking relapse.
Cobalt-mediated Dimerization of the Human Natural Killer Cell Inhibitory Receptor

Abstract Upon engagement of specific class I major histocompatibility complex (MHC) molecules on target cells, inhibitory receptors on natural killer (NK) cells deliver a negative signal that prevents the target cell lysis by NK cells. In humans, killer cell immunoglobulin-related receptors (KIR) with two immunoglobulin-like domains (KIR2D) modulate the lysis of target cells bearing specific HLA-C alleles (Moretta, A., Vitale, M., Bottino, C., Orengo, A. M., Morelli, L., Augugliaro, R., Barbaresi, M., Ciccone, E., and Moretta, L. (1993) J. Exp. Med. 178, 597–604). The transduction of inhibitory signals by KIR2D molecules is impaired by the zinc chelator, 1,10-phenanthroline, and mutation of a putative zinc-binding site (Rajagopalan, S., and Long, E. O. (1998)J. Immunol. 161, 1299–1305), but the mechanism by which zinc may affect the function of KIR remains unknown. In this study, the inhibitory NK receptor KIR2DL1 was discovered to dimerize in the presence of Co2+ as observed on native gel electrophoresis and by gel filtration column chromatography. Furthermore, Co2+-mediated KIR2DL1 dimer binds to HLA-Cw4 with higher affinity than the wild type KIR2DL1 monomer. Replacement of the amino-terminal His residue by Ala abolishes the ability of KIR2DL1 to bind Co2+, indicating that Co2+-mediated KIR2DL1 dimerization involves pairing of the D1 domain. Although not observed on native gels, the inhibitory receptor KIR2DL1 can be chemically cross-linked into dimers in the presence of Zn2+and its related divalent metal ions, suggesting that Co2+-mediated dimerization of KIR2DL1 may mimic a weaker interaction between KIR2DL1 and zinc in vivo.
Application of correlation-gas chromatography to evaluate the vaporization enthalpy of a component in an equilibrium mixture

Abstract The vaporization enthalpies and vapor pressures of acetoin, ethyl 3-hydroxybutyrate and ethyl 3-hydroxyhexanoate, found in a variety of foods and flavors, are evaluated at T = 298.15 K using correlation-gas chromatography; values of (48.7 ± 0.4), (55.9 ± 0.6) and (61.9 ± 0.6) kJ mol −1 , respectively, were obtained. These values are in good agreement with estimated values. Vapor pressures of the standards as a function of temperature were also used to calculate vapor pressures of the target compounds and all resulting data were fit to second order polynomials. These polynomials were then used to predict boiling temperatures of both standards and target substances. Agreement with experimental boiling temperatures was generally within 10 K suggesting that vapor pressures are accurate to within a factor of two. Acetoin exists as an equilibrium mixture of monomer and dimer. This report provides an example of the utility of using correlation-gas chromatography to obtain thermochemical data on an impure material.
Crosstalk Between Vascular Endothelial Growth Factor, Notch, and Transforming Growth Factor-β in Vascular Morphogenesis

Vascular morphogenesis encompasses a temporally regulated set of morphological changes that endothelial cells undergo to generate a network of interconnected tubules. Such a complex process inevitably involves multiple cell signaling pathways that must be tightly coordinated in time and space. The formation of a new capillary involves endothelial cell activation, migration, alignment, proliferation, tube formation, branching, anastomosis, and maturation of intercellular junctions and the surrounding basement membrane. Each of these stages is either known or suspected to fall under the influence of the vascular endothelial growth factor, notch, and transforming growth factor-β/bone morphogenetic protein signaling pathways. Vascular endothelial growth factor is essential for initiation of angiogenic sprouting, and also regulates migration of capillary tip cells, proliferation of trunk cells, and gene expression in both. Notch has been implicated in the regulation of cell fate decisions in the vasculature, especially the choice between arterial and venular endothelial cells, and between tip and trunk cell phenotype. Transforming growth factor-β regulates cell migration and proliferation, as well as matrix synthesis. In this review, we emphasize how crosstalk between these pathways is essential for proper patterning of the vasculature and offer a transcriptional oscillator model to explain how these pathways might interact to generate new tip cells during retinal angiogenesis.
Some Observations on the Cured Shape of Thin Unsymmetric Laminates

This paper discusses the fact that the cured shape of thin unsymmetric laminates do not conform to the predictions of classical lamination theory. Rather than being saddle shaped, as predicted by the classical theory, the paper shows that thin unsymmetric laminates cure into a shape of a right circular cylinder. This anomalous behavior has been observed by many but the paper serves to quantify the effect and to inspire investigators to begin thinking about using the phenomenon to advantage. The paper indicates that the anomalous behavior is repeatable and that thicker laminates con form to the predictions of the classical theory. Laminates of the [0/902 /θ ]T, [02 /θ2 ] T and [04 /θ4 ] T families are investigated for this be havior and it is shown the principal curvature directions of the cylindrical shapes are predictable.
Microscopic and biochemical characterization of lectin binding sites in the cephalopod retina.

Using light and electron microscope cytochemistry and lectin blotting techniques, we have shown that the lectins concanavalin A (Con A), Ricinus communis agglutinin (RCA), and peanut agglutinin (PNA) bind to specific glycoconjugants in the adult cephalopod retina. For light microscope lectin cytochemistry, aldehyde-fixed, frozen, or Araldite-embedded, etched sections of cephalopod retinas were incubated with FITC- or TRITC-conjugated lectins and examined by using epifluorescence microscopy. Con A labeled structures in the entire retina including the inner limiting membrane (ILM), rhabdomeric membranes, interphotoreceptor matrix (IPM), and structures in the photoreceptor inner segments. RCA labeling was similar to that of Con A except that there was a decrease in the staining of the rhabdom tips near the ILM. PNA labeled only the interphotoreceptor matrix between apposing rhabdomeres. The intensity of staining of the IPM by PNA also decreased or was absent toward the rhabdom tips. None of the lectins labeled the myeloid bodies located in the photoreceptor inner segments. Electron microscope (EM) lectin cytochemistry was performed on aldehyde-fixed, LR White–embedded tissue or on Araldite-embedded, periodate-etched sections by using gold-conjugated lectins. EM results confirmed the observations made by light microscopy. Lectin blots with a retinal extract or light-sensitive membrane fraction revealed a variety of protein bands labeled by all three lectins. Con A and RCA labeled opsin and its aggregates whereas PNA did not. None of the lectins labeled retinochrome. The labeling of the cephalopod IPM by PNA suggests a structural similarity between the IPM of vertebrates and invertebrates. In other studies, we have demonstrated the presence of a retinoid binding protein in the IPM of cephalopods. Thus, cephalopods may serve as a model for further investigations on the structure and function of the IPM and its role in the vitamin A cycle of the retina.
Gender differences in motivation and L2 accent attainment: an investigation of young Kurdish learners of Turkish

Although some earlier studies reported female and child superiority in learning a second language (L2), current research has been inconclusive as to whether, and why, this might be the case. Using a socio-cultural paradigm, this study addresses how motivation, gender and age relate to the attainment of a native-like accent for young Kurdish learners of Turkish. A mixed methodological design was used to collect data from 56 girls and 65 boys at middle and high schools. Results suggested that as the level of integrated orientation increased, accent ratings increased for all participants; introjection, however, was a significant negative predictor of accent native-likeness only for boys. Furthermore, integrated orientation was associated with accent native-likeness for both middle- and high-school students while introjection orientation was a significant negative predictor only for high-school students. Interpreting the qualitative data, the study also presents indicative evidence of the gendered forms of mo...
Constructing Mothers: Scientific Motherhood in the Nineteenth and Twentieth Centuries

Aux XIX e et XX e siecles, des maternites ont ete construites, afin de permettre aux femmes d'avoir des conseils medicaux pour elever sainement leurs enfants
On the syntactic structures of unrestricted grammars I. Generative grammars and phrase structure grammars

Formal definitions for the syntactic structures of unrestricted grammars are given. The traditional forms for grammar productions give rise to “generative grammars” with “derivation structures” (where productions have the form α → β), and “phrase structure grammars” with “phrase structures” (where productions have the form A → B/μ-ν), two distinct notions of grammar and syntactic structure which become indistinguishable in the context free case, where the structures are trees. Parallel theories are developed for both kinds of grammar and structure. We formalize the notion of structural equivalence for derivations, extended to unrestricted grammars, and we prove that two derivations are structurally equivalent if and only if they have the same syntactic structure. Structural equivalence is an equivalence relation over the derivations of a grammar, and we give a simpler proof of a theorem by Griffiths that each equivalence class contains a rightmost derivation. We also give a proof for the uniqueness of the rightmost derivation, following a study of some of the properties of syntactic structures. Next, we investigate the relationship between derivation structures and phrase structures and show that the two concepts are nonisomorphic. There is a natural correspondence between generative productions and phrase structure productions, and, by extension, between the two kinds of grammars and between their derivations. But we show that the correspondence does not necessarily preserve structural equivalence, in either direction. However, if the correspondence from the productions of a phrase structure grammar to the productions of a generative grammar is a bijection, then structural equivalence on the generative derivations refines the image under the correspondence of structural equivalence on the phrase structure derivations.
High-pressure experimental studies on geo-liquids using synchrotron radiation at the Advanced Photon Source

We review recent progress in studying silicate, carbonate, and metallic liquids of geological and geophysical importance at high pressure and temperature, using the large-volume high-pressure devices at the third-generation synchrotron facility of the Advanced Photon Source, Argonne National Laboratory. These integrated high-pressure facilities now offer a unique combination of experimental techniques that allow researchers to investigate structure, density, elasticity, viscosity, and interfacial tension of geo-liquids under high pressure, in a coordinated and systematic fashion. Experimental techniques are described, along with scientific highlights. Future developments are also discussed.
Why are postwar cycles smoother? Impulses or propagation?

This paper asks whether the remarkable decrease in business-cycle variability after the end of World War II has been the result of a more stable structure (the propagation mechanism) or less volatile shocks (the impulses). Using data from the pre-World War I, interwar, and post-World War II periods, for the US, Australia, Italy, Sweden, and the UK, our evidence suggests that the reduced volatility is mostly the result of calmer shocks, and less the consequence of a more stable structure. In the US, for example, we calculate that milder shocks have been responsible for around 80% of the reduction in output variability between interwar and postwar periods, while a more stable structure is responsible for the remaining 20%.
An analysis of submandibular salivary gland function with desipramine and age in female NIA Fischer 344 rats

Dry mouth is one of the major side effects of cyclic antidepressants, which are still a dominating group of psychotherapeutic drugs used in the treatment of depression. In this study we analyzed the effects of 28 day tricyclic antidepressant administration and the reversibility of this treatment following a 15 day washout period on different parameters in submandibular gland function in aging rats. We postulated that desipramine would decrease gland function, accented with age, and delay recovery in senescent animals. In contrast to body weight, desipramine had no effect on glandular wet weight. While glandular DNA synthesis was changed with age and treatment, the concentration of total membrane and soluble proteins was not affected. Flow rate was significantly changed with age, but desipramine increased salivary flow in the youngest animals only. Neither age nor treatment influenced salivary protein concentrations, but the total amount of proteins secreted, revealed perturbation with age. SDS- polyacrylamide gel analysis revealed changes in protein expression with treatment and age. Desipramine decreased epidermal growth factor (EGF) levels in all age groups, but increased the secretion of peroxidase and lysozyme. Analysis of total RNA showed a pronounced decrease with age. These data indicate that desipramine has profound effects on submandibular salivary gland function.
The first polar body does not predict accurately the location of the metaphase II meiotic spindle in mammalian oocytes

Abstract Objective: To evaluate how well polar body location predicts spindle localization and to examine spindle morphology. Design: Randomized, controlled animal study. Setting: University-affiliated research laboratory. Animal(s): Mature, female golden hamsters. Intervention(s): After superovulation with pregnant mare serum gonadotropin and hCG, metaphase II oocytes were obtained and imaged under digital polarization microscopy. Main Outcome Measure(s): Identify the meiotic spindle in living, unfixed hamster oocytes and determine spindle location relative to the polar body. Result(s): Spindles were imaged in 30 oocytes and only in 5 of them could the polar body predict the spindle localization. In the remaining oocytes, the spindles presented a random distribution within the cytoplasm. Conclusion(s): These data show that the polar body location is not an accurate predictor for meiotic spindle location in mammalian oocytes.
IpaC from Shigella and SipC from Salmonella possess similar biochemical properties but are functionally distinct

Invasion plasmid antigen C (IpaC) is secreted via the type III secretion system (TTSS) of Shigella flexneri and serves as an essential effector molecule for epithelial cell invasion. The only homologue of IpaC identified thus far is Salmonella invasion protein C (SipC/SspC), which is essential for enterocyte invasion by Salmonella typhimurium. To explore the biochemical and functional relatedness of IpaC and SipC, recombinant derivatives of both proteins were purified so that their in vitro biochemical properties could be compared. Both proteins were found to: (i) enhance the entry of wild-type S. flexneri and S. typhimurium into cultured cells; (ii) interact with phospholipid membranes; and (iii) oligomerize in solution; however, IpaC appeared to be more efficient in carrying out several of the biochemical properties examined. Overall, the data indicate that purified IpaC and SipC are biochemically similar, although not identical with respect to their in vitro activities. To extend these observations, complementation analyses were conducted using S. flexneri SF621 and S. typhimurium SB220, neither of which is capable of invading epithelial cells because of non-polar null mutations in ipaC and sipC respectively. Interestingly, both ipaC and sipC restored invasiveness to SB220 whereas only ipaC restored invasiveness to SF621, suggesting that SipC lacks an activity possessed by IpaC. This functional difference is not at the level of secretion because IpaC and SipC are both secreted by SF621 and it does not appear to be because of SipC dependency on this native chaperone as coexpression of sipC and sicA in SF621 still failed to restore detectable invasiveness. Taken together, the data suggest that IpaC and SipC differ in either their ability to be translocated into host cells or in their function as effectors of host cell invasion. Because IpaB shares significant sequence homology with the YopB translocator of Yersinia species, the ability for IpaC and SipC to associate with this protein was explored as a potential indicator of translocation function. Both proteins were found to bind to purified IpaB with an apparent dissociation constant in the nanomolar range, suggesting that they may differ with respect to effector function. Interestingly, whereas SB220 expressing sipC behaved like wild-type Salmonella, in that it remained within its membrane-bound vacuole following entry into host cells, SB220 expressing ipaC was found in the cytoplasm of host cells. This observation indicates that IpaC and SipC are responsible for a major difference in the invasion strategies of Shigella and Salmonella, that is, they escape into the host cell cytoplasm. The implications of the role of each protein's biochemistry relative to its in vivo function is discussed.
On multi-version coding for distributed storage

The multi-version coding problem described previously by Wang and Cadambe is motivated by applications to distributed storage and computing. Here, we consider a modification to the previously described multi-version coding problem that retains the essence of the earlier definition, and show that our modification leads to a reduced storage cost. We consider a setting where there are n servers that aim to store ν versions of a message, where there is a total ordering on the versions from the earliest to the latest. We assume that each message version has size log 2 M bits. Each server can receive any subset of the ν versions and stores over an alphabet of size q a function of the message versions it receives. The (n, c, ν, M, q) multi-version code we consider ensures that, a decoder that connects to any c of the n servers can recover the message corresponding to the latest common version stored among those servers, or a message corresponding to a version that is later than the latest common version. Unlike our earlier paper, we allow for the message version that is decoded to be one that is later than the latest common version. Through an achievable scheme and a tight converse, we describe the optimal multi-version code for ν = 2 versions from the perspective of the storage cost log 2 q/ log 2 M. In particular, we show that for ν = 2, the optimal multi-version code has a storage cost of 2/c+1 when c is odd and 2(c+1)/c(c+2) when c is even. We also present achievable code constructions for arbitrary values of the parameter ν.
ANAMICA: A Medical Data Visualisation and Characterisation .

This paper reports the design and implementation of ANAMICA, a three-dimensional (3-D) medical data visualisation and characterisation system which provides a complete set of image processing options. Constructions of internal surfaces from total or partial volume of 3-D data and cut-out views are supported by means of 'volume rendering' as well as object space methods. Arbitrary planar and curved sections of 3-D data can be obtained and processed subsequently as standard 2-D images. Volumetrics and a preliminary characterisation of tissues based on histograms are also supported. A window based user-interface provides convenient access to all these options.