cssi/SciSciGPT-SciSciNet huggingface dataset:
Modulation of hypoxic ventilatory response by systemic platelet-activating factor receptor antagonist in the rat

Platelet activating factor (PAF) has recently emerged as an important modulator of neuronal excitability by enhancing synaptic glutamate release. Since PAF receptors (PAFR) are ubiquitously distributed in the brain, we hypothesized that PAF may play a role in respiratory control. To examine this issue, hypoxic (10% O2 for 15 min, n = 14) and hypercapnic (5% CO2 for 30 min, n = 6) challenges were performed in chronically-instrumented, unrestrained adult rats following administration of the pre-synaptic PAFR antagonist BN52021 (i.p. 20 mg/kg in 0.5 ml) or vehicle (Veh). In normoxia, BN52021 elicited VT decreases and corresponding f increases such that minute ventilation (VE) was unaffected. During hypercapnia, peak VE increased similarly after both treatments (103+/-18% in BN52021 vs. 94+/-19% in Veh, p-NS). In contrast, significant reductions in the peak hypoxic VE response occurred after BN52021 (42+/-10% vs. 104+/-18% in Veh, P<0.002). BN52021 increased normoxic arterial blood pressure and decreased heart rate. However, hypoxia-induced chronotropic responses were attenuated and depressor responses were enhanced by BN52021. We further examined protein kinase C (PKC) translocation patterns during acute hypoxia after systemic BN52021 administration. Activation of PKC beta and delta was blocked by BN52021, PKC gamma was attenuated, with no effects on PKC alpha, epsilon, theta, iota, mu, and zeta. We conclude that systemic administration of a PAFR antagonist attenuates cardioventilatory recruitment to hypoxia and selectively attenuates activation of PKC in the rat brainstem. We speculate that enhanced regional PAF production and release during hypoxic conditions may contribute important excitatory inputs and signal transduction pathways within neuronal structures underlying cardiovascular and respiratory control.
The Phycomyces lens: measurement of the sporangiophore intensity profile using a fiber optic microprobe

A fiber optic microprobe, 5.5 μm in diameter, was used as a detector to measure the light intensity profile at the distal cell surface of Phycomyces blakesleeanus (Burgeff) sporangiophores that were irradiated unilaterally by a collimated xenon source. The light intensity at a fixed location of the cell surface showed large random variations over time which were probably the result of optical effects of particles being carried past the probe by cytoplasmic streaming. The intensity profile, formed around the distal periphery of the cell by the lens action of the sporangiophore, was determined from intensity measurements made while the probe was held fixed and the incident beam direction was varied in angle of azimuth. The resulting profile consisted of two steeply rising sides enclosing a central plateau or shallow well which ranged in fluence rate from 1.6 to 2.2 times that of the incident beam. These experimental findings differ from theoretical modeling where much greater contrast between the sides and central portion of the lens profile was predicted. These results also indicate that the mechanism of phototropic sensory perception in Phycomyces may filter out cytoplasmic light flicker and may not require strong contrasting regions within the lens profile to detect light direction.
Rigorous Design of Distillation Columns: Integration of Disjunctive Programming and Process Simulators

The economic optimization of a distillation column involves the selection of the number of trays and the feed- and side-streams locations, as well as the operating conditions that minimize the tota...
Functional specialization of transcription elongation factors

Elongation factors NusG and RfaH evolved from a common ancestor and utilize the same binding site on RNA polymerase (RNAP) to modulate transcription. However, although NusG associates with RNAP transcribing most Escherichia coli genes, RfaH regulates just a few operons containing ops, a DNA sequence that mediates RfaH recruitment. Here, we describe the mechanism by which this specificity is maintained. We observe that RfaH action is indeed restricted to those several operons that are devoid of NusG in vivo. We also show that RfaH and NusG compete for their effects on transcript elongation and termination in vitro. Our data argue that RfaH recognizes its DNA target even in the presence of NusG. Once recruited, RfaH remains stably associated with RNAP, thereby precluding NusG binding. We envision a pathway by which a specialized regulator has evolved in the background of its ubiquitous paralogue. We propose that RfaH and NusG may have opposite regulatory functions: although NusG appears to function in concert with Rho, RfaH inhibits Rho action and activates the expression of poorly translated, frequently foreign genes.
Preference elicitation in proxied multiattribute auctions

We consider the problem of minimizing preference elicitation in efficient multiattribute auctions, that support dynamic negotiation over non-price based attributes such as quality, time-of-delivery, and processor speed. We introduce asynchronous price-based multiattribute auctions, with proxy bidding agents that sit between the auctioneer and the participants. Empirical results demonstrate the preference elicitation savings that are provided with minimal price spaces, asynchronous updates, and proxy agents.
Comparative statics of mixed-strategy equilibria in noncooperative two-person games

Approfondir l'exemple identifiant le principe general fondamental de Von Neumann et Morgenstern au-dela du cas 2×2
ALF: a facility for x-ray lithography

In the previous paper, you heard a description of the electron storage ring system that IBM has ordered for X-ray Lithography. In this paper we shall describe the facility that is being constructed for the ESR and explain some of the decisions made in its design. The facility, which we have dubbed ALF for Advanced Lithographic Facility, is a part of the $O.5B Advanced Semiconductor Technology Center now being occupied at IBM's East Fishkill, New York semiconductor plant. Ground was broken in October of 1988 and the ALF building is expected to be ready for occupancy in July of this year. At that time, initial preparations for installation of the ESR and the lithographic tooling will begin. Bechtel National of San Francisco is the Design-Build contractor. As you may have concluded from Dave Andrew's paper, an ESR and its associated cryogenic, cooling, power and control systems is a complex tool which requires specialized support. In addition, the facility must support the vibration control and clean room requirements of submicron lithographic processing. Also, significant concerns of safety and security must be met. We will now describe our solutions to these requirements.
Class of models leading to depletions of solar nu e and atmospheric nu micro fluxes.

A model incorporating three left-handed ${\mathrm{SU}(2)}_{L}\ifmmode\times\else\texttimes\fi{}{\mathrm{U}(1)}_{Y}$ doublet neutrinos and three right-handed singlet neutrinos, with leptonic Dirac mass submatrices similar to empirical forms which work well for quarks, is required to yield both the nonadiabatic Mikheyev-Smirnov-Wolfenstein solar neutrino effect and the depleted flux of atmospheric muon neutrinos observed by Kamiokande. We find a small segment of the ${\ensuremath{\delta}m}_{23}^{2}$ vs ${sin}^{2}{2\ensuremath{\theta}}_{23}$ plane exists where such solutions can be achieved and identify the class of right-handed Majorana submatrices required.
Ecosystem variability and early human habitats in eastern Africa

The role of savannas during the course of early human evolution has been debated for nearly a century, in part because of difficulties in characterizing local ecosystems from fossil and sediment records. Here, we present high-resolution lipid biomarker and isotopic signatures for organic matter preserved in lake sediments at Olduvai Gorge during a key juncture in human evolution about 2.0 Ma—the emergence and dispersal of Homo erectus (sensu lato). Using published data for modern plants and soils, we construct a framework for ecological interpretations of stable carbon-isotope compositions (expressed as δ13C values) of lipid biomarkers from ancient plants. Within this framework, δ13C values for sedimentary leaf lipids and total organic carbon from Olduvai Gorge indicate recurrent ecosystem variations, where open C4 grasslands abruptly transitioned to closed C3 forests within several hundreds to thousands of years. Carbon-isotopic signatures correlate most strongly with Earth’s orbital geometry (precession), and tropical sea-surface temperatures are significant secondary predictors in partial regression analyses. The scale and pace of repeated ecosystem variations at Olduvai Gorge contrast with long-held views of directional or stepwise aridification and grassland expansion in eastern Africa during the early Pleistocene and provide a local perspective on environmental hypotheses of human evolution.
Biological effects of radiofrequency/microwave radiation

Over the past 50 years, significant advances have been made in the characterization of radiofrequency/microwave (RF/MW) fields (3 kHz-300 GHz) and energy absorption, as well as in the quantification of biological responses of organisms exposed to this kind of electromagnetic energy. The known biological effects and hazards have been demonstrated to be largely thermal in nature. This paper reviews key developments in experimental and theoretical dosimetry, as well as confirmed biological effects that have formed the basis of ever more sophisticated human-exposure standards generated through the IEEE consensus process. It also suggests some potential benefits to mankind of systems based on the thermogenic character of RF/MW energy absorption.
Effects of vertebrate adipokinetic hormones on the rate of in vitro lipid release in insects

1. 1. The adipokinetic effects of l-epinephrine, glucagon, insulin and cyclic 3′,5′-AMP (adenosine 3′,5′-cyclic-monophosphoric acid) on the rates of lipid release from fat body tissue of the monarch butterfly [Danaus plexippus (L.)] and sweetpotato hornworm [Agrius cingulata (Fabricius)] larvae were studied. 2. 2. In vitro time-course profiles of lipid release from 14C-labelled monarch butterfly fat body (incubated over a 2-hr period with each of the above hormones in buffer-saline) reveal appreciable rates of lipid release in the order: triglyceride >diglyceride>free fatty acid>monoglyceride>cholesteryl ester (TGL>DGL>FFA>MGL>CE). 3. 3. When whole hemolymph (inclusive of hemocytes) is used as the incubation medium, the rates are FFA>DGL>MGL>TGL>CE. 4. 4. Short-term 60 min experiments with 14C-labelled sweetpotato hornworm fat body (incubated with each of the above hormones in buffer-saline) exhibits rates of lipid release in the order: TGL>FFA>MGL>DGL>CE. 5. 5. When whole hemolymph is used as the incubation medium, the rates of lipid release are low and in the order: FFA>DGL>MGL>TGL>CE. 6. 6. The results are discussed in the light of available information on the effects of these hormones on other insects and the vertebrates.
The International Space University

The International Space University (ISU) was founded on the premise that any major space program in the future would require international cooperation as a necessary first step toward its successful completion. ISU is devoted to being a leading center for educating future authorities in the world space industry. ISU's background, goals, current form, and future plans are described. The results and benefits of the type of education and experience gained from ISU include technical reports describing the design projects undertaken by the students, an exposure to the many different disciplines which are a part of a large space project, an awareness of the existing activities from around the world in the space community, and an international professional network which spans all aspects of space activities and covers the globe.
The Role of E3 in pH Protection during Alphavirus Assembly and Exit

Alphaviruses are small enveloped viruses whose surface is covered by spikes composed of trimers of E2/E1 glycoprotein heterodimers. During virus entry, the E2/E1 dimer dissociates within the acidic endosomal environment, freeing the E1 protein to mediate fusion of the viral and endosome membranes. E2 is synthesized as a precursor, p62, which is cleaved by furin in the late secretory pathway to produce mature E2 and a small peripheral glycoprotein, E3. The immature p62/E1 dimer is acid resistant, but since p62 is cleaved before exit from the acidic secretory pathway, low pH-dependent binding of E3 to the spike complex is believed to prevent premature fusion. Based on analysis of the structure of the Chikungunya virus E3/E2/E1 complex, we hypothesized that interactions of E3 residues Y47 and Y48 with E2 are important in this binding. We then directly tested the in vivo role of E3 in pH protection by alanine substitutions of E3 Y47 and Y48 (Y47/48A) in Semliki Forest virus. The mutant was nonviable and was blocked in E1 transport to the plasma membrane and virus production. Although the Y47/48A mutant initially formed the p62/E1 heterodimer, the dimer dissociated during transport through the secretory pathway. Neutralization of the pH in the secretory pathway successfully rescued dimer association, E1 transport, and infectious particle production. Further mutagenesis identified the critical contact as the cation-π interaction of E3 Y47 with E2. Thus, E3 mediates pH protection of E1 during virus biogenesis via interactions strongly dependent on Y47 at the E3-E2 interface.
Peroxidase-catalyzed oxidation of (bi)sulfite: reaction of free radical metabolites of (bi)sulfite with (±)-7,8-dihydroxy-7,8-di-hydrobenzo[ a ]pyrene

The peroxidase-catalyzed metabolism of (bi)sulfite (hydrated sulfur dioxide) in the presence of (+/-)-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP-7,8-diol) was examined. Both horseradish peroxidase and prostaglandin peroxidase catalyze the one-electron oxidation of (bi)sulfite. This results in the formation of a sulfur trioxide radical anion which then reacts with molecular oxygen to form a peroxyl radical. This (bi)sulfite-derived peroxyl radical then reacts with BP-7,8-diol to form BP-7,8-diol-9,10-epoxides, the ultimate carcinogenic form of benzo[a]pyrene (BP). Addition of (bi)sulfite to incubations containing BP-7,8-diol and an active peroxidase resulted in significantly increased levels of BP diol-epoxide formation. This result may, in part, explain the reported co-carcinogenic effect of sulfur dioxide on BP-induced tumors in the respiratory tracts of rats and hamsters. The sulfur trioxide radical anion also reacts directly with BP-7,8-diol to form a sulfonate adduct. This reaction was particularly significant under conditions where molecular oxygen was depleted from the incubations. While the significance of this particular adduct is not known, its formation suggests that the sulfur trioxide radical anion generated during the peroxidase-catalyzed oxidation of (bi)sulfite could react with a wide assortment of compounds to form sulfonate adducts.
Quantitative separation of 1:8 cineole and β-phellandrene in eucalyptus leaf extracts

Abstract A method is described for separating 1:8-cineole and β-phellandrene in extracts of eucalyptus leaves on a silica gel column by elution with selective solvents and quantitative analysis of the separates by gas-liquid chromatography.
Fracture of Pacing Electrode Mimicking Failure of Pulse Generator

To our knowledge, this is the first reported case off spontaneous fracture of a pacing electrode with decreased amplitude of the pacing artifact, failure to capture, and intact sensing. We postulate that the difference in impedance of the pacemaker for sensing and stimulation may account for this phenomenon.
Youth and politics in Kenya: promise or peril?

This article discusses the contribution of youth to the democratisation politics of Kenya. It focuses on the heterogeneity of young people as a constituency through a discussion of two youth movements in Kenya's recent political history, Youth for KANU '92 and the University Student Movement. It assesses the contribution of young people to the democratic movement, arguing that they have the power to insert themselves into emerging political spaces in multiple ways. The article calls for a reorientation of African politics to mainstream youth into policy development and political debates.
Plasma developable photoresist systems based on chemical amplification.

This paper reports work on two chemically amplified resist systems that can be developed in an oxygen plasma environment. These systems are based on the catalytic photogeneration of functional groups within the resist film which react, in a subsequent step, with a silylating agent that is delivered in the gas phase. As a result, the organosilicon species is selectively and covalently incorporated into the exposed regions of the resist film. When the silylated film is exposed to an oxygen plasma, the regions that do not contain the organosilicon species are etched to substrate, while those areas containing silicon are not etched. This generates a negative tone relief image. The chemical mechanisms and lithographic properties of these systems will he discussed.
"Hot spots," magic angles, and magnetoresistance in quasi-1D metals.

A simple quasiclassical model is presented to explain the large, highly anisotropic magnetoresistance and striking magnetoresistance dips at magic angles in the Bechgaard salts, (TMTSF) 2 X. In the presence of a magnetic field the electrons are swept along the open orbit sheets of the Fermi surface into «hot spots» where the scattering rate is high. At magic angles the commensurate motion allows some fraction of the electrons to avoid the hot spots
Measuring estrogens using flow injection immunoanalysis with liposome amplification.

Abstract A solid-phase competitive immunoassay is performed in flow injection analysis for the measurement of the hormone 17-β-estradiol. The flow injection analysis system incorporates a column-type reactor packed with solid silica particles onto which we have covalently immobilized the antigen 17-β-estradiol. Anti-estradiol is noncovalently conjugated to the liposome through a streptavidin-biotin linkage. When mixed with a sample containing the antigen, the antibody binding sites on the liposomes are complexed which reduces the binding of liposomes to the solid support in a concentration-dependent manner. Sequential immunoassays are performed on-column following a simple regeneration step.
The kinetics of intergranular oxygen penetration in nickel and its relevance to weldment cracking

The ductility of nickel and nickel-base superalloys is severely reduced by intergranular penetration of oxygen at elevated temperatures. Using Ni270 as a model material, quantitative diffusion parameters are obtained for the penetration of oxygen along grain boundaries. The technique involves observation of gas bubbles, believed to be carbon dioxide, resulting from a reaction between diffusing oxygen and residual carbon concentrated at the grain boundaries. The kinetics are such as to embrittle nickel subjected to a typical superalloy heat treatment. The implications of this observation taken in conjunction with previous publications are discussed relative to the role of oxygen attack in heat-affected zone cracking of superalloys.
Use of randomly cloned DMA fragments for the identification of oral spirochetes

DNA probes were produced for the detection and identification of 4 cultivable species of oral spirochetes, Treponema denticola, Treponema socranskii, Treponema vincentii and Treponema pectinovorum. To obtain probe sequences, chromosomal DNA, isolated from representative strains within each species, was cloned in Escherichia coli K-12. Cloned DNA fragments were screened for the ability to hybridize to DNA only from homologous strains. Several such fragments were identified and shown to be specific when tested against a series of DNAs from gram-negative and gram-positive oral bacteria. The selected probe sequences were semi-conserved within strains of T. denticola and T. socranskii such that restriction fragment length polymorphism (RFLP) was observed. In the case of T. socranskii, RFLP was useful in distinguishing between the 3 known subspecies. Chromosomal DNA fragments from 2 strains of T. vincentii failed to cross-hybridize, under stringent conditions, to genomic DNA from each of these strains. The hybridization probes were suitable for the identification of clinical isolates of T. denticola and could be used to detect the presence of individual Treponema species in mixed cultures. On this basis, the probes were used successfully to detect T. denticola in uncultured plaque samples.
Colon cancer and apoptosis

Abstract Background The implementation of new therapeutic options for the management of metastatic colon cancer mandates a revisit to apoptosis and its role in colon cancer tumorigenesis with an emphasis on the mechanisms leading to chemotherapeutic resistance and immune system evasion of colon cancer cells. Data sources Literature regarding molecular apoptosis mechanisms and the role of apoptosis in colon cancer progression are reviewed by this article. Conclusion Programmed cell death has rapidly emerged as a potential target for cancer treatment at various stages of tumor progression. Chemoprevention, immuno-regulation, and metastasis are prospective targets by which apoptotic mechanisms could be utilized in the prevention and management of tumorigenesis. Understanding how defects in the death receptor pathway of apoptosis permit colon cancer cells to escape the immune system would allow for treatment options whereby the body’s immune system could again recognize and eliminate unwanted cells.
Self-Assembly of an Amphiphilic Siloxane Graft Copolymer in Water

The micelle formation and micelle structure of an amphiphilic poly(dimethylsiloxane)-graft-polyether copolymer in aqueous solution were investigated with a variety of experimental techniques. We measured the CMC by three different methodsDPH solubilization, methyl orange hypsochromic shift, and pyrene fluorescence I1/I3 ratio. The microviscosity was evaluated from DPH anisotropy values that were obtained by fluorescence polarization measurements. The microviscosity in the siloxane copolymer micelles was found lower than that in Pluronic block copolyether micelles. The micelle size and structure were obtained from small-angle neutron scattering (SANS) using the hard sphere model. The micelle hydrodynamic radius and the micelle size distribution were monitored by dynamic light scattering (DLS). The degree of hydration was estimated from a combination of DLS and SANS results. The temperature effect on CMC was found to be small; however, a structural transition of micelles from spheres to ellipsoids was obser...
Spatiotemporal retinoid-X receptor activation detected in live vertebrate embryos

Most studies on the nuclear retinoid-X receptor (RXR) have focused on its role as a heterodimeric partner but less about its own activation pattern during development and the distribution of potential endogenous ligands. The aim of this study is to visualize the distribution of activated RXRα in live transgenic Xenopus laevis embryos across a wide range of developmental stages. We adopted a nuclear receptor–Gal4 fusion/upstream activation sequence-based reporter system for our assay. Strong activation of the RXRα ligand-binding domain was observed in a segment of the spinal cord just posterior to the hindbrain. This activation is first detected in neurula stage embryos and persists up to swimming tadpole stages, after which activation strongly declines. Addition of exogenous ligands, such as 9-cis retinoic acid or all-trans retinoic acid, expands the activation of RXR throughout the spinal cord but not in the brain, whereas the RXR-specific ligand LG268 expanded the Gal4–RXR activation into the brain and olfactory epithelia. Treatment with the RAR-specific ligand 4-(E-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl)benzoic acid or thyroid hormone had no effect on Gal4–RXR activation, whereas these compounds significantly increased their corresponding Gal4/receptor fusion proteins under similar conditions. Embryos expressing a Gal4–RXR fusion protein with a deletion in the ligand-dependent activation domain (AF2) show no reporter gene activation. The results shown in this paper reveal a specific activation pattern for Gal4–RXRα specifically in the developing spinal cord and suggest the existence of RXR ligand “hot-spots” in this region.
A Regional Analysis of the Impact of Trade and Foreign Direct Investment on Wages in Mexico, 1984–2000

The conventional Heckscher–Ohlin model of trade predicts an equalizing effect of trade on wages in developing countries abundant in less-skilled labor. Contrary to these predictions, skill premiums and skill demand increased in Mexico following trade liberalization. “New” trade theories have offered several channels through which trade can increase relative wages and demand for skilled workers. One such channel is foreign direct investment and outsourcing. Using the Mexican Household Income and Expenditure Survey (ENIGH) covering 1984–2000, the author examines the relationship between the demand for skill and maquiladora employment across regions and states. In contrast to previous studies based on manufacturing data for the 1980s, little evidence is found that growth in maquiladora employment is positively related to the increase in relative wages or wage-bill share of more educated workers.
A 100KS/s 65dB DR Σ — Δ ADC with 0.65V supply voltage

We present a low-power Sigma - Delta modulator to be used in the baseband sections of wireless sensor network receivers with 0.65 V Vdd operation. The design is optimized for low-power consumption and low operating supply by minimizing operational amplifier open-loop gain. Simple differential pair amplifiers with ap 40 dB of open loop gain and low noise factor are employed as the integrator cores and guarantee a spurious-free dynamic range(SFDR) of 63 dB. The prototype employs only standard Vth devices and dissipates 27 muW to achieve 65 dB dynamic range in a 50 KHz bandwidth, including regulated bias. The peak SNDR of 59.5 dB corresponds to a figure of merit (FOM) of 0.36 pJ/Conv.Step.
Getting the Right Mix of Experts

The Bayesian approach to combining expert opinions is well developed, providing a decision maker's posterior beliefs after receiving advice from people with deep knowledge in a given subject. A necessary part of these models is the inclusion of dependencies between the experts' judgments, often justified by an overlap in the information on which the experts base their judgments. In this paper, we propose a hierarchical structure different than those previously proposed, where the mixing distribution is treated nonparametrically with a Dirichlet process. This makes our overall model a Dirichlet process mixture and allows for experts' model parameters to be equal in the mixture. We apply this approach to published expert judgment data, demonstrating that the decision maker's posterior distributions on the quantities of interest are not restricted to specific parametric forms, even allowing for multiple modes, and are thus more intuitively appealing.
Add(l)ed value in librarianship

Cet article traite des consequences de l'arrivee de la notion de valeur ajoutee dans le travail du bibliothecaire, notammant au niveau du departement des acquisitions. L'auteur de cet article, un bibliothecaire, donne son opinion sur l'utilisation de cette nouvelle notion et explique les bouleversements et quelles incidences cela a eu sur son mode de travail. Cet article est une critique d'un autre article paru dans cette meme revue, dans ce meme numero
Denaturalized identities: Class-based perceptions of self and others among Latin American immigrants in South Florida

In the 1990s, many middle-class Latin American professional men and women left their countries because of political or economic problems and emigrated to Miami, Florida in search of better prospects. This article examines social class identity in the context of immigration. My study builds on the early work of class identity theorists and analyzes how perceptions of class change when people move from one country to another. In that context, I examine the impact of cultural and social capital in (re) shaping immigrants’ class-based perceptions and their contribution to their ability to adjust to a new life in the United States.
Rejection of established mouse pancreatic islet allografts by active immunization requires class I (H-2 K, D) antigen disparities.

Abstract In certain donor-recipient mouse strain combinations with class I (H-2 K, D, and K + D) or with classes I and II (H-2 D + I) disparities the incidence of islet allograft rejection is low. Furthermore pancreatic islet allografts transplanted between strains with class II (H-2 Ia) differences alone are rarely acutely rejected. In this experiment the ability of donor strain or third-party allogeneic splenocytes (active immunization) to induce rejection of established (>100 days) islet allografts when the donor and recipient differed only for class I or class II antigens was tested. Class I disparate islet allografts are rejected if challenged with donor or third-party allogeneic splenocytes. The frequency of rejection is similar (80–89%) if the third-party splenocytes share the class I allele with the islet donor strain. In contrast, class II disparate islet allografts are not rejected after challenge with donor splenocytes or third-party splenocytes even when the third-party strain shares the class II disparity with the islet donor strain as well as class I antigens common to the donor and recipient. Furthermore, rejection of class II disparate islets did not occur following passive transfer of recipient strain splenocytes sensitized in vitro to donor strain lymphocytes. These results show that rejection of established islet allografts can only be induced if (1) the islet graft expresses H-2 K or H-2 D gene products that are different than the recipient strain, i.e., only class I antigens can serve as targets; and (2) challenging splenocytes also have class I disparities with the recipient.
Mechanisms of Cell Regeneration, Development, and Propagation within a Two-Dimensional Multicell Storm

In this study, mechanisms of cell regeneration, development, and propagation within a two-dimensional multicell storm are investigated using a numerical cloud model. The cell regeneration is explained by the advection mechanism. The following processes occur periodically during cell regeneration: (i) Near the edge of the gust front, the gust front updraft is formed by low-level convergence ahead of the gust front near the surface. (ii) The upper portion of the gust front updraft grows by midlevel inflow since the gust front propagates faster than the basic wind. (iii) The growing cell tends to produce and is flanked by strong compensating downdrafts. The upstream downdraft tends to cut off the growing cell from the gust front updraft. It is found that the period of cell regeneration is inversely proportional to the midlevel, strong relative wind speed. This advection mechanism is different from that proposed by Yang and Houze, which views the rearward propagating cell as gravity waves generated by the quasi-steady updraft moving through the ambient flow. Cell development and propagation within a two-dimensional multicell storm may be described in terms of two distinctive modes: (i) a growing mode and (ii) a propagating mode. When a growing cell reaches its maximum intensity, it splits and then propagates downstream without amplification. The dynamics of cell development and propagation is explained here by critical level argument. For the growing mode there is growth because of a conditionally unstable environment leading to steering level propagation, while for the propagating mode there is no growth because of a more stable environment leading to propagation relative to the flow (i.e., absence of critical level). It is found that the phase relationship between w9 and u9 (w9 and u9) in the growing mode is different from that in the propagating mode and can be explained by the dominance of latent heating in the thermodynamic equation. The propagating mode is dominated by horizontal advection. The propagating mode exhibits gravity wave properties and propagates faster than the growing mode.
Developmental Changes in Intracellular Calcium Regulation in Rat Cerebral Cortex during Hypoxia

During the first weeks of life, injury to the central nervous system caused by brief periods of oxygen deprivation greatly increases. To investigate possible causes for this change, the effects of ...
The Association of Transient Ischemic Attack Symptoms With Memory Impairment Among Elderly Participants of the Third US National Health and Nutrition Examination Survey

Background and Purpose: Stroke is a well-known risk factor for vascular dementia. However, the association of transient ischemic attacks with cognitive impairment is less well-established.Methods: Records from Third National Health and Nutrition Examination Survey were abstracted for demographic and medical information for participants with an age !60 years who reported being free of stroke. Five self-reported symptoms (weakness, numbness, loss of vision, inability to speak, and severe dizziness) were used as surrogates representing transient ischemic attacks. Information on conventional risk factors for vascular dementia was also obtained. Multivariable logistic regression was used to examine risk factors for memory impairment. Results: 4617 participants were included with a sample-weighted prevalence of memory impairment of 6.6% (1417 participants). The final multivariable analysis revealed a significant association between transient weakness and memory impairment (odds ratio 1.52, 95% CI 1.11-2.07). Th...
Modeling Peroxidase-Oxidase Interactions

Reactive oxygen species (ROS) and peroxidase-oxidase (PO) reactions are Janus-faced contributors to cellular metabolism. At low concentrations, reactive oxygen species serve as signaling molecules; at high concentrations, as destroyers of proteins, lipids and DNA. Correspondingly, PO reactions are both sources and consumers of ROS. In the present paper, we study a well-tested model of the PO reaction based on horseradish peroxidase chemistry. Our principal predictions are these: 1. Under hypoxia, the PO reaction can emit pulses of hydrogen peroxide at apparently arbitrarily long intervals. 2. For a wide range of input rates, continuing infusions of ROS are transduced into bounded dynamics. 3. The response to ROS input is hysteretic. 4. With sufficient input, regulatory capacity is exceeded and hydrogen peroxide, but not superoxide, accumulates. These results are discussed with regard to the episodic nature of neurodevelopmental and neurodegenerative diseases that have been linked to oxidative stress and to downstream interactions that may result in positive feedback and pathology of increasing severity.Copyright © 2011 by ASME
A biological speech recognition system by using associative neural networks

Speech recognition has been one of the most challenging subjects in the field of signal processing for years. The recognition of the speech becomes more difficult when there is a noise in the place. Most of the time human beings are able to ignore the environment noise. The secret of this phenomenon is in the ability of human auditory cortex. Therefore knowing about the functionality of human auditory cortex and its implementation can be helpful to improve the quality of a speech recognition system. The presented system in this paper has two parts. The first part filters the input signal and packs it. Then it gets the average of three packets as an identification of the signal and sends it to the second part. This part which is based on the human auditory cortex is an associative neural network that maps the input set to a desired output set. This system is able to recognize a word even a noisy one.
The architectural organization and mechanistic function of group II intron structural elements

Group II introns are large, self-splicing RNAs and mobile genetic elements that provide good model systems for studies of RNA folding. The structures and mechanistic functions of individual domains are being elucidated, and long-range tertiary interactions between the domains are being identified, thus helping to define the three-dimensional architecture of the intron.
Level by level equivalence and strong compactness

We force and construct models in which there are non-supercompact strongly compact cardinals which aren't measurable limits of strongly compact cardinals and in which level by level equivalence between strong compactness and supercompactness holds non-trivially except at strongly compact cardinals. In these models, every measurable cardinal κ which isn't either strongly compact or a witness to a certain phenomenon first discovered by Menas is such that for every regular cardinal λ > κ, κ is λ strongly compact iff κ is λ supercompact. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Regional and Temporal Variation in Susceptibility to λ-Cyhalothrin in Onion Thrips, Thrips tabaci (Thysanoptera: Thripidae), in Onion Fields in New York

Populations of onion thrips, Thrips tabaci Lindeman, from commercial onion fields in New York were evaluated for their susceptibility to the commonly used pyrethroid, λ-cyhalothrin (Warrior T), using a novel system called the Thrips Insecticide Bioassay System (TIBS). To use TIBS, thrips are collected directly from the plant into an insecticide-treated 0.5-ml microcentrifuge tube that has a flexible plastic cap with a small well into which 0.08 ml of a 10% sugar-water solution with food colorant is deposited. The solution is sealed into the well with a small piece of stretched parafilm through which the thrips can feed on the solution. Thrips mortality is assessed after 24 h with the help of a dissecting stereoscope. In 2001, onion thrips populations were collected from 16 different sites and resistance ratios were >1,000 in five populations. Percent mortality at 100 ppm, a recommended field rate, varied from 9 to 100%, indicating high levels of variation in susceptibility. Particular instances of resistance appeared to be the result of practices within an individual field rather than a regional phenomenon. In 2002, we also observed large differences in onion thrips susceptibility, not only between individual fields but also between thrips collected in a single field at mid season and late season, again suggesting that insecticide-use practices within an individual field caused differences in susceptibility. Additional tests indicated no differences in susceptibility between adult and larval onion thrips populations and only relatively minor differences between populations collected from different parts of the same field. Using TIBS, several populations of onion thrips with different susceptibilities to λ-cyhalothrin were identified and then subjected to λ-cyhalothrin-treated onion plants. There was a highly significant positive relationship between percent mortality of thrips from TIBS and percent mortality from the treated onion plants, indicating that results from TIBS could be used to predict spray performance. These data suggest that use of TIBS for evaluating susceptibility to particular insecticides could be instrumental for developing a resistance management strategy for onion thrips.
Continent urinary diversion and diverting colostomy in the therapy of non-healing pressure sores in paraplegic patients

Immobilization and subsequent sacral decubitus or pressure sore formation is a danger faced by the paraplegic. We report on 4 patients treated with non-healing pressure sores. Three male patients had decubiti eroding into the posterior urethra and bladder neck area. One female patient had bladder neck and urethral loss secondary to Foley catheter erosion and a sacral pressure sore. All 4 had non-healing decubiti secondary to urinary contamination and, in addition, gross fecal contamination in the male patients. All patients failed previous muscular flaps and urinary diversion per suprapubic tube. In the male patients, suprapubic continent urinary diversion included bladder neck mobilization, closure of the distal urethra by oversewing and patching with bovine dura, and augmentation of the bladder with a Miami pouch. Fecal diversion was provided with a sigmoid colostomy. In the female patient, continent diversion was performed by forming a Miami pouch. Total diversion allowed healing of the pressure sores and provided a simpler method of personal hygiene. Details of the diversion and case studies will be presented.
Asymptotic Series for the Ground State Energy of Schrödinger Operators

Abstract We find sufficient conditions for the ground state energy e (λ) of −Δ + λ V to have an asymptotic series ∑ an λ ↓ 0. Included are a class of almost periodic functions.
Tunnel characteristics of partially gapped non-superconducting metals with charge- or spin-density waves

Abstract Current-voltage characteristics for symmetrical and non-symmetrical tunnel junctions involving non-superconducting partially dielectrized metals are calculated. Root singularities at eV = ±Σ and jumps at eV = ±2Σ, where V is the bias voltage, Σ is the dielectric gap, and e is the elementary charge, are obtained for symmetrical junctions. For non-symmetrical ones current-voltage characteristics are non-symmetrical and depend on the sign of Σ. The results obtained agree qualitatively with tunnel and point-contact measurements for layered dichalcogenides, NbSe3, and URu2Si2.
Evaluation of the FIAX semiautomatic fluorescent immunoassay system for the detection of IgG antibodies to Toxoplasma gondii

A commercially available solid phase fluoroimmunoassay system (FIAX, International Diagnostic Technology, Santa Clara, CA) was evaluated in parallel with a standard indirect fluorescent-antibody test (IFAT) for the detection of IgG antibodies to Toxoplasma gondii. Titers obtained by the FIAX method on the 101 patient samples correlated well with the standard procedure. Sensitivity of the FIAX system was 96% and specificity was 93%. A method for measuring serum titer reproducibility applicable to both conventional doubling dilution and to automated procedures was employed, allowing a meaningful comparison of precision in the two systems. It was found that titer reproducibility in the FIAX system was better than that of the IFAT and exceeded that expected with most conventional double-dilution serological procedures. The FIAX system will most benefit those laboratories with relatively large numbers of samples which can be batch tested.
Mouse ES and iPS cells can form similar definitive endoderm despite differences in imprinted genes.

ThedirecteddifferentiationofiPSandEScellsintodefinitiveendoderm�(DE)�wouldallowthederivation� ofotherwiseinaccessibleprogenitorsforendodermaltissues.�However,�aglobalcomparisonoftherelative� equivalencyofDEderivedfromiPSandESpopulationshasnotbeenperformed.�Recentreportsofmolecular� differencesbetweeniPSandEScellshaveraiseduncertaintyastowhetheriPScellscouldgenerateautolo- gousendodermallineagesinvitro.�Here,�weshowthatbothmouseiPSandparentalEScellsexhibitedhighly� similarinvitrocapacitytoundergodirecteddifferentiationintoDEprogenitors.�Withfewexceptions,�both� celltypesdisplayedsimilarsurgesingeneexpressionofspecificmastertranscriptionalregulatorsandglobal� transcriptomesthatdefinethedevelopmentalmilestonesofDEdifferentiation.�Microarrayanalysisshowed� considerableoverlapbetweenthegeneticprogramsofDEderivedfromES/iPScellsinvitroandauthenticDE� frommouseembryosinvivo.�Intriguingly,�iPScellsexhibitedaberrantsilencingofimprintedgenesknown� toparticipateinendodermdifferentiation,�yetretainedarobustabilitytodifferentiateintoDE.�Ourresults� showthat,�despitesomemoleculardifferences,�iPScellscanbeefficientlydifferentiatedintoDEprecursors,� reinforcingtheirpotentialfordevelopmentofcell-basedtherapiesfordiseasedendoderm-derivedtissues.
Chemiluminescence of shock-pyrolyzed benzene

Abstract C 2 and other small molecules produced during shock-induced (24–63 GPa) decomposition of liquid benzene (initially at 1 bar at 295 K) have been detected by time-resolved (50–120 ns) spectroscopy. These molecular products have been identified by characteristic electronic bands observed together with a gray-body background in visible and near-ultraviolet shock-induced chemiluminescence spectra collected during the passage of the shock front through the focus of spectrographs equipped with gated, intensified diode-array detectors. The spectroscopic techniques are described, and the dependence of the spectra on shock parameters will be discussed in terms of known decomposition mechanisms of highly excited benzene molecules.
Structures of the van der Waals Isomers of Halosulfuric Acids: Microwave Spectra of HX-SO3 (X = F, Cl, Br).

Abstract The complexes of SO 3 with HF, HCl, and HBr have been studied by microwave spectroscopy. In all three systems, the halogen atom approaches the SO 3 on or near its C 3 axis, and the vibrationally averaged structure is that of a symmetric top. The S–X bond lengths are 2.655(10), 3.1328(57), and 3.2339(85) A for the HF, HCl, and HBr complexes, respectively, and in all three systems the out-of-plane distortion of the SO 3 is negligible. In HF–SO 3 , the hydrogen points away from the SO 3 and hyperfine structure in the DF complex gives an average angle of 47.7° with respect to the vibrationally averaged C 3 axis of the complex. In the HCl and HBr complexes, however, the HX unit is nearly parallel to the SO 3 plane. In HCl–SO 3 , the HCl forms a 72.8° angle with the average C 3 axis of the complex, with the proton tilting slightly toward the SO 3 . In HBr–SO 3 , the average orientation of the HBr is 73.0° off the symmetry axis of the complex, but the direction of the tilt (toward or away from the SO 3 ) is not determined. Although the hydrogen halides react with SO 3 in bulk to produce halosulfuric acids, these gas-phase complexes are much like weakly bound dimers.
Permeation of hydrogen through platinum: A re-evaluation of the data of Chou et al

Abstract The calculations of Chou et al . are revised to include effects that were neglected in the original work. The measured data are associated with permeability rather than diffusivity. The hydrogen concentration in the platinum membrane is assumed to be proportional to the square root of the hydrogen fugacity in the gas phase in conformity with experimental measurements at lower pressures. An approximate solution to the resulting mass transport equations is derived which simplifies the data analysis. The calculated permeabilities agree within experimental uncertainty with those determined by time lag experiments.