bluuebunny/crossref_metadata_2025 huggingface dataset:
Mucosal Innate and Adaptive Immune Responses against Herpes Simplex Virus Type 2 in a Humanized Mouse Model
Authors: Kwant-Mitchell Amanda , Ashkar Ali A. , Rosenthal Kenneth L.
Published: August 2009

Genital herpes, caused by herpes simplex virus type 2 (HSV-2), is one of the most prevalent sexually transmitted diseases worldwide and a risk factor for acquiring human immunodeficiency virus. Although many vaccine candidates have shown promising results in animal models, they have failed to be effective in human trials. In this study, a humanized mouse strain was evaluated as a potential preclinical model for studying human immune responses to HSV-2 infection and vaccination. Immunodeficient mouse strains were examined for their abilities to develop human innate and adaptive immune cells after transplantation of human umbilical cord stem cells. A RAG2−/−γc−/−mouse strain with a BALB/c background was chosen as the most appropriate model and was then examined for its ability to mount innate and adaptive immune responses to intravaginal HSV-2 infection and immunization. After primary infection, human cells in the lymph nodes were able to generate a protective innate immune response and produce gamma interferon (IFN-γ). After intravaginal immunization and infection, human T cells and NK cells were found in the genital tract and iliac lymph nodes. In addition, human T cells in the spleen, lymph nodes, and vaginal tract were able to respond to stimulation with HSV-2 antigens by replicating and producing IFN-γ. Human B cells were also able to produce HSV-2-specific immunoglobulin G. These adaptive responses were also shown to be protective and reduce local viral replication in the genital tract. This approach provides a means for studying human immune responses in vivo using a small-animal model and may become an important preclinical tool.
Mechanisms of high temperature frictional sliding in Westerly granite
Authors: Stesky R. M.
Published: August 2009

The mechanisms of frictional sliding in faulted Westerly granite were studied in two ways. Firstly, the experimental activation energy was measured from 300 to 700 °C at 2.5 kbar (2.5 × 105 kPa) pressure and sliding rates from 10−5 to 10−2 cm/s. Secondly, fault samples were examined with an optical and a transmission electron microscope. Below 500 °C the activation energy was about 30 kcal/mol (1.3 × 105 J/mol). The fault gouge was porous and consisted of angular randomly oriented grains. The quartz and the feldspars were unstrained, similar to the grains in a room-temperature fault. Above 500 °C the activation energy increased to about 85 kcal/mol (3.6 × 105 J/mol). Plasticity in quartz about 500 °C was observed optically by the presence of highly strained gouge grains and with the transmission electron microscope by a marked increase in dislocation density from 3 × 108 cm−2 initially to greater than 1011 cm−2 at 700 °C. The quartz grains away from the fault were strain-hardened with inhomogeneously distributed, dense tangles of dislocations. In contrast, the small grains (<10 μm) in the gouge contained a low density of dislocations. The feldspars showed no sign of plasticity up to 700 °C. Biotite and muscovite were plastic at all temperatures, forming thin ribbons along slip surfaces in the fault zone. Glass was not identified in any of the faulted samples studied.
Geophysical study of basement fractures on the western European and eastern Canadian shelves: transatlantic correlations, and late Hercynian movements
Authors: Lefort J. P. , Haworth R. T.
Published: August 2009

Geological interpretation of geophysical data (magnetic, gravimetric and seismic) on the western European and eastern Canadian shelves indicates a transatlantic correlation between the major late Paleozoic fractures of those areas.East–west megafractures, which are primarily grouped in two latitudinal belts at 44° N and 48° N, are the most obvious and correlative. The first zone of fractures was an extension of the South Armorican shear zone, which continued to the north of Flemish Cap. The second was an eastwards extension of the Cobequid–Chedabucto–Scatarie Fault, which crossed Galicia Bank, northern Spain and southern France. A third zone possibly existed between the Clinton–Newbury Fault of New England and mid-Spain, Corsica and Sardinia (when they are moved back to their late Paleozoic positions). The location of the shortening trajectories shows that the first two zones (and perhaps the third one) belonged to the same stress system during late Carboniferous. As a hypothesis, different rates of displacement between 'peri-Atlantic' plates during their northward movement in Late Carboniferous time could be the source of the stress.
Elsonian magmatism in Labrador: age, characteristics and tectonic setting
Authors: Emslie R. F.
Published: August 2009

Paleohelikian Elsonian magmatism (~ −1500 to −1400 Ma) in central Labrador occurred in the interval following the Hudsonian Orogeny (~ −1700 Ma) and preceding the Grenvillian Orogeny (after −1200 Ma). Elsonian plutons, dominated by anorthosite and adamellite compositions, have physical and petrogenetic characteristics of anorogenic intrusions and were intruded into stable, continental crust; evidence to support the existence of a 'pre-Elsonian' orogenic event (thus making the intrusions postorogenic) is slim. An average depth of intrusion about 15–20 km implies that the ambient country rock temperatures were at or near the argon blocking temperature for biotite; strong uplift and cooling, during and (or) immediately following Elsonian plutonism, is the probable cause of 'Elsonian' ages in surrounding country rock terrane.The Elsonian plutonic suite has characteristics consistent with derivation from bimodal magmatic processes. Products of basic magmas (relatively older) and of silicic magmas (relatively younger) are well represented but intermediate compositions are much less common and small in volume.Consideration of the geological record succeeding Elsonian magmatism suggests that it was a precursor of a sequence of events that led ultimately to intracontinental rifting or incipient rifting.
Precambrian muscovite–quartz (agalmatolite) palaeosols from Scotland and Canada
Authors: Allison Iain , Ferguson Lindsay K. , Cardenas Fidel A. , Kronberg Barbara I.
Published: August 2009

Weathering, during late Precambrian times, of pink granitic gneisses and pegmatites of the Middle Proterozoic Lewisian Complex in northwest Scotland has produced a characteristic pea-green palaeosaprolite called agalmatolite, which occurs from centimetres to metres beneath the planar unconformity with the overlying quartz sandstones of the Lower Cambrian marine transgression. Agalmatolite consists predominantly of massive, felted, very fine-grained muscovite of the form called pinite together with variable amounts of relict quartz. Pyrophyllite may also occur in the most altered parts, close to the unconformity, and the proportions of precursor minerals, mainly quartz and feldspar, increase as the parent gneisses are approached. Trends in whole-rock elemental variations are consistent with a weathering hypothesis, and the present mineralogy reflects the burial of the saprolite subjected to conditions of anchimetamorphism.Palaeosols developed on both granitic and basaltic basement rocks, with ages ranging up to about 3.0 Ga, have been described from a number of areas throughout the world. In all these palaeosols, muscovite, usually referred to as sericite, is the dominant mineral. In northwest Ontario weathering of the granitic basement beneath the Steep Rock Lake Group has produced a rock almost identical to the Scottish agalmatolite and consisting of muscovite, of the form pinite, relict quartz, and rutile. From published descriptions of other palaeosols, we conclude that the term agalmatolite may be applied to most Precambrian palaeosols, as it conveys more information than terms such as argillite and saprolith that have previously been in use.Compared with the less well-exposed alteration profiles of older palaeosols, the clear field relationships of agalmatolite in northwest Scotland allow more confidence to be placed on interpretations that such alteration profiles have been caused by surficial weathering, with subsequent changes due to burial and even low-grade metamorphism.
Trench and slope basin deposits in an Archean metasedimentary belt, Superior Province, Canadian Shield
Authors: Fralick Philip , Wu Jinhua , Williams Howard R.
Published: August 2009

The identification of a late Archean arc–trench assemblage in northwestern Ontario provides the opportunity to compare depositional systems developed in a Precambrian convergent setting with Cenozoic examples. Two types of sedimentary associations exist in the accretionary complex. Medium- to thick-bedded Bouma A, AB, and ABC felsic turbidites dominate the belt. These are primarily organized into unstructured sequences and reflect deposition in a ramp-like environment with multiple feed points supplying sediment from a forearc basin. Mafic turbidites with possible shallow water reworked intervals form isolated pods within the metasedimentary belt. Erosion of upthrust blocks of sedimentary strata containing ultramafic masses supplied this sediment to elevated slope basins. These types of depositional systems are similar in many respects to those developed in Cenozoic and Holocene arc–trench settings.
Petrology, petrochemistry, and stromatolites of the Middle to Late Proterozoic Beck Spring Dolomite, eastern Mojave Desert, California
Authors: Marian Melinda L. , Osborne Robert H.
Published: August 2009

The Beck Spring Dolomite is the medial unit of the Middle to Late Proterozoic Pahrump Group, the oldest sequence of sedimentary rocks in eastern California. Stratigraphic sections of the Beck Spring Dolomite examined in the eastern Mojave Desert and Death Valley regions consist of four members. These are, in ascending order, a lower cherty member, a lower laminated member, an oolitic–pisolitic member, and an upper cherty member. More than 80% of the Beck Spring Dolomite is algal-laminated dolomite with a possible Middle to Late Riphean stromatolite assemblage characterized by cf. Conophyton, eroded, irregular columnar forms similar to Kussiella or Baicalia, and several types of stratiform Stratifera. Petrographic, X-ray diffraction, and atomic absorption spectroscopic analyses indicate that the formation is composed of well-ordered replacement dolomite with less than 25% acid-insoluble residue. Concentrations of Fe and Mn are two to six times higher in the algal-laminated members than in the oolitic–pisolitic member, whereas the concentrations of Ca, Mg, Ba, Sr, Na, and K show no systematic variations. Stratigraphic relationships, primary and secondary sedimentary structures, petrology, and stromatolite assemblages suggest deposition during Middle to Late Proterozoic time on a platform that most likely included offshore shoals, restricted lagoons, and broad tidal flats with ponds, channels, and levees.
Geochemical characteristics of contaminated surficial sediments in Halifax Harbour: impact of waste discharge
Authors: Buckley Dale E. , Winters Gary V.
Published: August 2009

Analyses of 274 surface sediment samples collected from Halifax inlet between 1986 and 1990 permit assessment of the chemical environmental quality of this major east coast Canadian harbour. Contamination of the marine sediments is due to discharge of untreated sewage and industrial waste directly into the harbour, and leaching of solid waste deposits on land. Concentrations of total Cu, Pb, Zn, Hg, and Cd in the uppermost 2 cm of sediments on the sea floor ranks Halifax Harbour among the most contaminated marine areas in the industrialized world. Statistical factor analysis has been used to identify five types of sediments based on sedimentological and geochemical characteristics. The dominant factor type accounts for 41% of the chemical variance and represents sediments that are highly contaminated with metals and organics derived from sewage effluents and waste deposits. More than 50% of the total Cu, Zn, and Pb in the sediments is potentially reactive as reducible or oxidizable metal.A simple two-layer estuarine circulation model has been used to assess the significance of dissolved metal sources and sinks in the harbour. The contribution to sediment contamination from dissolved metal inputs is relatively minor, with more than 88% of the potentially reactive Cu, Zn, Pb, and Hg being directly associated with particulate deposition. However, the model suggests that high proportions of the dissolved annual inputs of Zn (40% of 5.5 t), Pb (100% of 1.3 t), Hg (100% of 0.02 t), and Mn (89% of 19.6 t) are taken up by the bottom sediments.Future environmental quality management of Halifax Harbour should take into consideration the geochemical stability of sediments. New sewage treatment facilities may reduce the loading of contaminants, but some remobilization of metals from sediments may reduce long-term improvements in contaminant levels in the water column.
Identification of deep groundwater discharge areas in the Boggy Creek catchment, southeastern Manitoba, using excess aqueous helium
Authors: Stephenson M. , Schwartz W. J. , Evenden L. D. , Bird G. A.
Published: August 2009

The hydrogeology of the Lac du Bonnet batholith at the Whiteshell Research Area (WRA) in southeastern Manitoba has been studied extensively. Although the general structure of the batholith is well known, its near-surface structure is less well known because of the overburden. Consequently, the precise locations of groundwater discharge from deep fractures into local surface water remain uncertain. Deep groundwater in the WRA is highly enriched with radiogenic He from the decay of natural U and Th ([He] is up to 50 mL∙L−1). Surface waters normally equilibrate with atmospheric He and contain a standard [He] of 47 nL∙L−1. We hypothesized that areas of deep groundwater discharge from the Lac du Bonnet batholith should be characterized by elevated aqueous He concentrations. We surveyed Boggy Creek and Boggy Lake at the WRA in the late winter of 1989 for such He anomalies. In Boggy Creek, three significant anomalies were identified, whereas in Boggy Lake several were found, the largest occupying the southeast quarter of the 80 ha lake. All the He anomalies were closely associated with the mapped or projected locations of faults in the underlying granite. A calculation of the total mass of excess He trapped under winter ice in Boggy Lake suggests that the total volume of deep groundwater seepage is small.
Restudy of Permo-Carboniferous synapsid Edaphosaurus novomexicanus Williston and Case, the oldest known herbivorous amniote
Authors: Modesto S. P. , Reisz R. R.
Published: August 2009

Reexamination of the holotype and the description of new material of Edaphosaurus novomexicanus from the Permo-Pennsylvanian Cutler Formation of north-central New Mexico reveals that this species is the most primitive member of the Edaphosaurus clade. This assignment, based previously upon supposed plesiomorphies of the postcrania, is supported here by two primitive character states that occur in a derived form in the Texan species of Edaphosaurus. The presence of two autapomorphies in E. novomexicanus suggests that this species is probably not a morphological relict, as previously supposed, but may be part of a lineage that did not exhibit the level of diversification seen in its probable sister group, the clade of Texan edaphosaurids (E. boanerges, E. cruciger, and E. pogonias).
Comparative petrology of gneissic rocks in southwestern Newfoundland
Authors: Owen J. Victor
Published: August 2009

In southwestern Newfoundland, pelitic migmatites of the Meelpaeg Subzone of the Gander Zone are separated by faults and plutons from metasedimentary rocks of the Port-aux-Basques gneiss complex (PBGC). The PBGC is a polymetamorphic sequence of amphibolite-facies, pelitic, semipelitic, and psammitic rocks (and associated metabasic dykes). Maximum metamorphic grade surpassed the first sillimanite (i.e., staurolite-consuming) isograd. Metamorphic conditions approached 650–700 °C at Pmax approximately 6.5–8.5 kbar (1 kbar = 100 MPa).The Meelpaeg gneisses also include sillimanite-grade, two-mica rocks, but they lack the Barrovian mineralogy (e.g., kyanite, staurolite, rutile) characterizing parts of the PBGC. The Meelpaeg rocks attained temperatures similar to those of the PBGC, but confining pressure was substantially lower (approx. 4 kbar), indicating uplift from relatively shallow structural levels.Both groups of paragneisses also differ in some aspects of their bulk chemistry (notably CaO/K2O ratios) and their lithologic associations. The Meelpaeg metapelites are less calcic and relatively potassic (mean CaO/K2O = 0.32) compared with their counterparts in the PBGC (mean CaO/K2O = 1.12), but both groups of rocks have similar bulk Fet/(Fet + Mg) ratios (mean XFe ≈ 0.75). In contrast with the PBGC, which contains abundant metabasites and thin coticule-like (garnet + quartz) seams, the Meelpaeg metapelites are associated with biotite + garnet "tonalitic" gneiss and, despite their relatively lime-poor composition, calc-silicate layers and pods.In terms of contrasting lithologic associations and bulk chemistry, paragneiss of the PBGC is distinct from gneissic rocks in the Meelpaeg Subzone. This underscores difficulties in relating rocks in the Port-aux-Basques area to well-established lithotectonic entities elsewhere in Newfoundland. Despite apparent differences in their protoliths and contrasts in metamorphic pressure, available U–Pb data suggest that high-grade metamorphism in both areas occurred during the middle Silurian.
Relation between salt diapirism and the tectonic history of the Sverdrup Basin, Arctic Canada
Authors: Stephenson Randell A. , Berkel Jean T. van , Cloetingh Sierd A. P. L.
Published: August 2009

The Sverdrup Basin is a pericratonic sedimentary trough in northern Canada containing up to 13 km of Carboniferous to Tertiary strata. The basin formed by late Paleozoic continental rifting and was subsequently affected by a series of alternating tectonic settings. Evaporite diapirs are well exposed at the present erosion level and occur mainly along the basin axis. The diapiric source layer consists of about 400 m of anhydrite underlain by salt of unknown stratigraphic thickness, deposited during the initial Permo-Carboniferous synrift phase of basin subsidence. Large salt–anhydrite diapirs rose into the sedimentary overburden when the overburden had reached a thickness of several kilometres. They grew during a relatively long period of modest horizontal compression from the Permo-Triassic to Early Cretaceous. Much smaller, tabular anhydrite diapirs were rapidly emplaced during periods of high horizontal compression, in the middle Cretaceous, when large flexural stresses were induced by sedimentary loading, and during the early Tertiary when high intraplate compression resulted from far-field tectonic forces during the Eurekan orogeny.The diapiric behaviour of dense anhydrite implies that buoyancy alone was incapable of driving the diapirism in the Sverdrup Basin. The importance of other driving forces, such as differential loading, basement or overburden faulting, extension, and thermal convection, is thought to be secondary. This suggests a correlation between diapirism and periods of significant horizontal compression, implying that plate-tectonic forces and flexural loading are important driving mechanisms of evaporite diapirism in the Sverdrup Basin.
Deformation of Early Cretaceous volcanic-arc assemblages, southern Coast Belt, British Columbia
Authors: Lynch Gregory
Published: August 2009

Early Cretaceous clastic volcanic-arc rocks of the Gambier Group in the southern Coast Belt were deposited in estuarine and marine environments on a deeply incised unconformity exposing Jurassic plutonic and arc assemblages. The Cretaceous arc was deformed in response to Late Cretaceous oblique subduction, producing orogen-parallel and orogen-normal shortening. Supracrustal Early Cretaceous rocks are preserved, in part, within the footwalls of overthrust sheets.Basal conglomerate and transgressive clastic successions underlie the volcanic edifices, with clasts reflecting volcanic – plutonic provenance. Volcanic rocks are calc-alkalic and span the complete basalt–andesite–dacite–rhyolite association typical of composite volcanoes. Extensive coarse pyroclastic deposits record an explosive volcanic environment.The Gambier Group occurs within the foreland of the major structural and metamorphic culmination of the southeastern Coast Belt. Early thin-skinned thrusting occurred to the east, repeating the Cretaceous stratigraphy. Overturned detached folds are associated with southerly directed thrusting developed during orogen-parallel shortening, likely in relation to large strike-slip fault systems. Later southwest-directed thrusting and associated large-amplitude folding occurred during Late Cretaceous arc-normal shortening, folding the earlier thrusts. To the southwest, tectonic wedging developed, with much of the Gambier Group preserved in the footwall of opposite southwest- and northeast-facing thrust systems; here southwest-directed thrusts emplaced Late Jurassic plutonic rocks, an unconformity, and lower Gambier strata over younger members, whereas concomitant or younger northeast-directed back thrusts emplaced the mid-Cretaceous plutonic roots of the arc above its volcanic derivative.
QUANTUM ANOMALIES AND SOME RECENT DEVELOPMENTS
Authors: FUJIKAWA KAZUO
Published: August 2009

Some of the developments related to quantum anomalies and path integrals during the past 10 years are briefly discussed. The covered subjects include the issues related to the local counter term in the context of 2-dimensional path integral bosonization and the treatment of chiral anomaly and index theorem on the lattice. We also briefly comment on a recent analysis of the connection between the two-dimensional chiral anomalies and the four-dimensional black hole radiation.
ABELIAN DECOMPOSITION OF GENERAL RELATIVITY
Authors: CHO Y. M.
Published: August 2009

We present an Abelian decomposition of Einstein's general relativity, viewing Einstein's theory as a gauge theory of Lorentz group and identifying the gravitational connection as the gauge potential of Lorentz group. The decomposition confirms the existence of the restricted gravity which is much simpler than Einstein's theory but which has the full local Lorentz invariance (and thus the full general invariance). Moreover, it tells that Einstein's theory can be viewed as the restricted gravity which has the Lorentz covariant valence connection as the gravitational source. With the Abelian decomposition we show how to construct all possible vacuum gravitational connections, which can be classified by the knot topology π3(S3) = π3(S2). We discuss the physical implications of our result in quantum gravity.
T′ AND THE CABIBBO ANGLE
Authors: FRAMPTON PAUL H.
Published: August 2009

The use of the binary tetrahedral group (T′) as flavor symmetry is discussed. I emphasize the CKM quark and PMNS neutrino mixings. I present a novel formula for the Cabibbo angle.
ELECTROWEAK PRECISION PHYSICS FROM LEP TO LHC AND ILC
Authors: HOLLIK W.
Published: August 2009

Electroweak precision physics is reviewed from the LEP era with implications for Higgs bosons and supersymmetry, together with expectations for the LHC and a future Linear Collider ILC.
OSCILLATORY MOMENTS IN LEE-YANG ZEROS AND LHC PREDICTIONS
Authors: DEWANTO A. , CHAN A. H. , LIM Z. H. , OH C. H.
Published: August 2009

We study the moments of multiplicty distribution and its relation to the Lee-Yang zeros of the generating function in electron-positron and hadron-hadron high energy collision. Our work shows that GMD moments can reproduce the oscillatory behaviour as shown in the experimental data and predicted by quantum chromodynamics at preasymptotic energy, while it can also be used to distinguish electron-positron (e+e-) multiplicity data from hadron-hadron (pp and [Formula: see text]) multiplicity. Furthermore, there seems to be a link between the development of shoulder structure in the multiplicity distribution and the development of ear structure in the Lee-Yang zeros. We predict that these structures is going to be very obvious at 14 TeV. We argue that the development of these structures indicates an ongoing transition from quark-dominated soft scattering events to gluon-dominated semihard scattering events.
NONLINEAR DIRAC EQUATIONS WITH APPLICATIONS TO NEUTRINO OSCILLATIONS
Authors: NG WEI KHIM
Published: August 2009

We first review a method to generate nonlinear Dirac equations. The method demands the nonlinear extensions preserve several physical properties like locality, Hermiticity, Poincaré invariance and separability. The last constraint results in nonlinear extensions of non-polynomial type. A class of nonlinear extensions that simultaneously violate Lorentz invariance is also constructed. We then review, using the classes of nonlinear extensions with or without violation of Lorentz symmetry, the sub-leading modifications to the neutrino oscillation probabilities in the νµ-ντ sector. The parameters in our models are bounded using the current experimental data. These are then used to estimate corrections to the oscillation probabilities and the corresponding energies at which the corrections will be sizeable. Thus one may test quantum nonlinearities in future higher energy experiments.
PRODUCTION RATE OF SECOND KK GAUGE BOSONS IN UED MODELS AT LHC
Authors: MATSUMOTO SHIGEKI , SATO JOE , YAMANAKA MASATO , SENAMI MASATO
Published: August 2009

We calculate the production rates of the second Kaluza-Klein (KK) photon γ(2) and Z boson Z(2) at the LHC including all significant processes in the minimal universal extra dimension (MUED) model. For discrimination of the MUED model from other TeV scale models in hadron collider experiments, γ(2) and Z(2) play a crucial role. In order to discuss the discrimination and calculate their production rates, we derive effective Lagrangian containing KK number violating operators. We show that KK number violating processes are extremely important for the compactification scale larger than 800 GeV. We find that, with an integrated luminosity of 100 fb-1, γ(2) and Z(2) are produced 106 - 102 for the compactification scale between 400 GeV and 2000 GeV.
COSMOLOGICAL CONSTRAINTS ON THE LOCAL VOID WITH THE UNION SUPERNOVA COMPILATION
Authors: ANH HO LE TUAN , NG SHAO CHIN CINDY
Published: August 2009

A simple inhomogeneous cosmological model with a local void is constrained with the latest Union supernova compilation. To fit the supernova data, a large local void on the scales of 1 Gpc is found, contrary to the small scales of 200 Mpc in the previous finding. A more realistic inhomogeneous cosmological model may be required to fit the supernova data. Alternatively, a clumpy universe with α < 1 can fit the supernova data with reduced local void scales.
THE LOOP CORRECTIONS TO THE PARITY-VIOLATING ELASTIC ELECTRON-PROTON SCATTERING
Authors: CHEN YU CHUN , KAO CHUNG WEN
Published: August 2009

We calculate the two-boson-exchange (TBE) corrections to the parity-violating asymmetry of the elastic electron-proton scattering in a parton model using the formalism of generalized parton distributions (GPD's). We find that these effects can reach a few percent and are comparable in size with the current experimental measurements of strange-quark effects in the proton neutral weak current. Our result is also compared with the result of the hadronic model.
THE FORMULAS FOR THE SECONDARY ELECTRON YIELD AT HIGH INCIDENT ELECTRON ENERGY FROM GOLD AND ALUMINUM
Authors: XIE AI-GEN , LI CHUAN-QI , WANG TIE-BANG , PEI YUAN-JI
Published: August 2009

Based on the main physical processes of secondary electron emission from metals, the relation that the product of the number of secondary electron released per primary electron at high incident electron energy and the (n-1)th power of incident energy of primary electron is equal to constant C was deduced, where n is the energy exponent, based on the relation between the number of secondary electron released per primary electron at high incident electron energy and secondary electron yield. The relation that the product of the secondary electron yield at high incident electron energy and the (n-1)th power of incident energy of primary electron is equal to constant D was deduced. The constant D and the energy exponent n of the primary electron in the energy range 10 to 100 keV hitting on gold and aluminum are computed with the ESTAR program and experimental results in scanning electron microscope (SEM), respectively, therefore, the formulas for the incident energy dependence of secondary electron yield in the energy range 10 to 100 keV from gold and aluminum were deduced. The formulas were proved to be true by experimental results in SEM. The results were discussed and a conclusion was drawn. The formulas from gold and aluminum were successfully deduced.
OPTIMAL MAINTENANCE POLICY TO SUPPORT THE OPERATION OF MANUFACTURING WITH MINIMAL AND DELAYED REPAIR
Authors: LIAO GWO-LIANG , SHAW BOR-LING
Published: August 2009

This work presents a periodic preventive maintenance (PM) model for a repairable system that undergoes minimal repair or delayed repair at each failure to keep a plant operating. Two PM types are performed, i.e. imperfect PM and perfect PM. The likelihood that PM is perfect depends on the number of imperfect maintenance activities have been performed since the last renewal cycle. Mathematical formulae for expected cost per unit time are developed. The optimal period for periodic PM, which minimizes cost, is identified. Various special cases are considered, including the maintenance learning effect. A numerical example demonstrates the effectiveness of the proposed model.
A-769662 activates AMPK β1-containing complexes but induces glucose uptake through a PI3-kinase-dependent pathway in mouse skeletal muscle
Authors: Treebak Jonas T. , Birk Jesper B. , Hansen Bo F. , Olsen Grith S. , Wojtaszewski Jørgen F. P.
Published: August 2009

5′-AMP-activated protein kinase (AMPK) regulates several aspects of metabolism. Recently, A-769662 was shown to activate AMPK in skeletal muscle. However, no biological effects of AMPK activation by A-769662 in this tissue have been reported. We hypothesized that A-769662 would increase glucose uptake in skeletal muscle. We studied incubated soleus and extensor digitorum longus (EDL) muscles from 129S6/sv and C57BL/6 mice. Glucose uptake increased only in soleus from 129S6/sv when concentrations of A-769662 were 500 μM (∼15%, P < 0.05) and 1 mM (∼60%, P < 0.01). AMPK β1- but not β2-containing complexes were dose dependently activated by A-769662 in muscles from both genotypes (∼100% at 200 μM and 300–600% at 1 mM). The discrepancy between the A-769662-induced AMPK activation pattern and stimulation of glucose uptake suggested that these effects were unrelated. A-769662 increased phosphorylation of Akt in both muscles from both genotypes, with phosphorylation of T308 being significantly higher in soleus than in EDL in 129S6/sv mice ( P < 0.01). In soleus from 129S6/sv mice, insulin receptor substrate 1-associated phosphatidylinositol 3 (PI3)-kinase activity was markedly increased with A-769662, and Akt phosphorylation and glucose uptake were inhibited by wortmannin while phosphorylation of acetyl-CoA carboxylase (S227) was unaffected. Thus, A-769662 activates β1-containing AMPK complexes in skeletal muscle but induces glucose uptake through a PI3-kinase-dependent pathway. Although development of A-769662 has constituted a step forward in the search for AMPK activators targeting specific AMPK trimers, our data suggest that in intact muscle, A-769662 has off-target effects. This may limit use of A-769662 to study the role of AMPK in skeletal muscle metabolism.
Epac increases melanoma cell migration by a heparan sulfate-related mechanism
Authors: Baljinnyam Erdene , Iwatsubo Kousaku , Kurotani Reiko , Wang Xu , Ulucan Coskun , Iwatsubo Mizuka , Lagunoff David , Ishikawa Yoshihiro
Published: August 2009

Melanoma, the most malignant form of human skin cancer, has a poor prognosis due to its strong metastatic ability. It was recently demonstrated that Epac, an effector molecule of cAMP, is involved in regulating cell migration; however, the role of Epac in melanoma cell migration remains unclear. We thus examined whether Epac regulates cell migration and metastasis of melanoma. Epac activation, by either specific agonist or overexpression of Epac, increased melanoma cell migration. Deletion of endogenous Epac with small interfering RNA decreased basal melanoma cell migration. These data suggested a major role of Epac in melanoma cell migration. Epac-induced cell migration was mediated by translocation of syndecan-2, a cell-surface heparan sulfate proteoglycan, to lipid rafts. This syndecan-2 translocation was regulated by tubulin polymerization via the Epac/phosphoinositol-3 kinase pathway. Epac-induced cell migration was also regulated by the production of heparan sulfate, a major extracellular matrix. Epac-induced heparan sulfate production was attributable to the increased expression of N-deacetylase/ N-sulfotransferase-1 (NDST-1) accompanied by an increased NDST-1 translation rate. Finally, Epac overexpression enhanced lung colonization of melanoma cells in mice. Taken together, these data indicate that Epac regulates melanoma cell migration/metastasis mostly via syndecan-2 translocation and heparan sulfate production.
Augmentation of Cav1 channel current and action potential duration after uptake of S100A1 in sympathetic ganglion neurons
Authors: Hernández-Ochoa Erick O. , Prosser Benjamin L. , Wright Nathan T. , Contreras Minerva , Weber David J. , Schneider Martin F.
Published: August 2009

S100A1, a 21-kDa dimeric Ca2+-binding protein of the EF-hand type, is expressed in cardiomyocytes and is an important regulator of heart function. During ischemia, cardiomyocytes secrete S100A1 to the extracellular space. Although the effects of extracellular S100A1 have been documented in cardiomyocytes, it is unclear whether S100A1 exerts modulatory effects on other tissues in proximity with cardiac cells. Therefore, we sought to investigate the effects of exogenous S100A1 on Ca2+ signals and electrical properties of superior cervical ganglion (SCG) neurons. Immunostaining and Western blot assays indicated no endogenous S100A1 in SCG neurons. Cultured SCG neurons took up S100A1 when it was present in the extracellular medium. Inside the cell exogenous S100A1 localized in a punctate pattern throughout the cytoplasm but was excluded from the nuclei. S100A1 partially colocalized with markers for both receptor- and non-receptor-mediated endocytosis, indicating that in SCG neurons multiple endocytotic pathways are involved in S100A1 internalization. In compartmentalized SCG cultures, axonal projections were capable of uptake and transport of S100A1 toward the neuronal somas. Exogenous S100A1 applied either extra- or intracellularly enhanced Cav1 channel currents in a PKA-dependent manner, prolonged action potentials, and amplified action potential-induced Ca2+ transients. NMR chemical shift perturbation of Ca2+-S100A1 in the presence of a peptide from the regulatory subunit of PKA verifies that S100A1 directly interacts with PKA, and that this interaction likely occurs in the hydrophobic binding pocket of Ca2+-S100A1. Our results suggest the hypothesis that in sympathetic neurons exogenous S100A1 may lead to an increase of sympathetic output.
IGF-I activates the mouse type IIb myosin heavy chain gene
Authors: Shanely R. Andrew , Zwetsloot Kevin A. , Childs Thomas E. , Lees Simon J. , Tsika Richard W. , Booth Frank W.
Published: August 2009

IGF-I increases skeletal muscle mass, but whether IGF-I increases type IIb myosin heavy chain (MyHC) transcriptional activity is not known. C2C12 myotubes were cultured with or without IGF-I to determine whether IGF-I increases type IIb MyHC promoter activity, and if so, what region of the promoter might IGF-I signaling regulate. At differentiation days 3 and 4, IGF-I increased type IIb MyHC mRNA and mouse 3.0-kb type IIb MyHC promoter activity. Deletion construct studies identified a potential IGF-I-responsive region between 1.25 and 1.2 kb of the type IIb MyHC promoter, which contained an exact 6-bp T-cell factor/lymphoid enhancer factor (Tcf/Lef) binding site at position −1206 to −1201. Site-specific mutation of the putative Tcf/Lef binding site reduced IGF-I-induced 1.3-kb type IIb MyHC promoter activity. To identify potential IGF-I signaling molecules, the phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and LY-294002 were both found to markedly attenuate IGF-I activation of the 1.3-kb type IIb MyHC promoter. Downstream signaling of IGF-I can phosphorylate and inactivate GSK-3β, thereby enhancing β-catenin protein. The GSK-3β inhibitor, LiCl, dramatically enhanced IGF-I induction of the 1.3-kb type IIb MyHC promoter, and constitutively active GSK-3β attenuated IGF-I-induced 1.3-kb type IIb MyHC promoter activity. Finally, IGF-I increased nuclear β-catenin protein, and small interfering RNA knockdown of β-catenin attenuated IGF-I-induced 1.3-kb type IIb MyHC promoter activity and type IIb MyHC mRNA. In summary, IGF-I stimulation of C2C12 myotubes increases mouse type IIb MyHC promoter activity, likely through signaling of PI3K, GSK-3β, β-catenin, and a Tcf/Lef binding site at −1,206 to −1,201 bp in the promoter.
Identification of subdomains in NADPH oxidase-4 critical for the oxygen-dependent regulation of TASK-1 K+ channels
Authors: Park Su Jung , Chun Yang-Sook , Park Kyung Sun , Kim Sung Joon , Choi Si-On , Kim Hye-Lim , Park Jong-Wan
Published: August 2009

Hypoxic inhibition of K+ current is a critical O2-sensing mechanism. Previously, it was demonstrated that the cooperative action of TASK-1 and NADPH oxidase-4 (NOX4) mediated the O2-sensitive K+ current response. Here we addressed the O2-sensing mechanism of NOX4 in terms of TASK-1 regulation. In TASK-1 and NOX4-coexpressing human embryonic kidney 293 cells, hypoxia (5% O2) decreased the amplitude of TASK-1 current (hypoxia-Δ ITASK-1). To examine whether reactive oxygen species (ROS) mediate the hypoxia-Δ ITASK-1, we treated the cells with carbon monoxide (CO) which is known to reduce ROS generation from the heme-containing NOX4. Unexpectedly, CO failed to mimic hypoxia in TASK-1 regulation, rather blocked the hypoxia-Δ ITASK-1. Moreover, the hypoxia-Δ ITASK-1 was neither recovered by H2O2 treatment nor prevented by antioxidant such as ascorbic acid. However, the hypoxia-Δ ITASK-1 was noticeably attenuated by succinyl acetone, a heme synthase inhibitor. To further evaluate the role of heme, we constructed and expressed various NOX4 mutants, such as HBD(−) lacking the heme binding domain, NBD(−) lacking the NADPH binding domain, FBD(−) lacking the FAD binding domain, and HFBD(−) lacking both heme and FAD domains. The hypoxia-Δ ITASK-1 was significantly reduced in HBD(−)-, FBD(−)-, or HFBD(−)-expressing cells, versus wild-type NOX4-expressing cells. However, NBD(−) did not affect the TASK-1 response to hypoxia. We also found that p22 is required for the NOX4-dependent TASK-1 regulation. These results suggest that O2 binding with NOX4 per se controls TASK-1 activity. In this process, the heme moiety and FBD seem to be responsible for the NOX4 regulation of TASK-1, and p22 might support the NOX4-TASK-1 interaction.
Hyperosmolarity regulates SOX9 mRNA posttranscriptionally in human articular chondrocytes
Authors: Tew Simon R. , Peffers Mandy J. , McKay Tristan R. , Lowe Emma T. , Khan Wasim S. , Hardingham Timothy E. , Clegg Peter D.
Published: August 2009

The transcription factor SOX9 regulates cartilage extracellular matrix gene expression and is essential for chondrocyte differentiation. We previously showed that activation of p38 MAPK by cycloheximide in human chondrocytes leads to stabilization of SOX9 mRNA (Tew SR and Hardingham TE. J Biol Chem 281: 39471–39479, 2006). In this study we investigated whether regulation of p38 MAPK caused by changes in osmotic pressure could control SOX9 mRNA levels expression by a similar mechanism. Primary human articular chondrocytes isolated from osteoarthritic cartilage at passage 2- 4 showed significantly raised SOX9 mRNA levels when exposed to hyperosmotic conditions for 5 h. The effect was strongest and most reproducible when actin stress fibers were disrupted by the Rho effector kinase inhibitor Y27632, or by culturing the cells within alginate beads. Freshly isolated chondrocytes, used within 24–48 h of isolation, did not contain actin stress fibers and upregulated SOX9 mRNA in response to hyperosmolarity in the presence and absence of Y27632. In these freshly isolated chondrocytes, hyperosmolarity led to an increase in the half-life of SOX9 mRNA, which was sensitive to the p38 MAPK inhibitor SB202190. SOX9 protein levels were increased by hyperosmotic culture over 24 h, and, in passaged chondrocytes, the activity of a COL2A1 enhancer driven luciferase assay was upregulated. However, in freshly isolated chondrocytes, COL2A1 mRNA levels were reduced by hyperosmotic conditions and the half-life was decreased. The results showed that the osmotic environment regulated both SOX9 and COL2A1 mRNA posttranscriptionally, but in fresh cells resulted in increased SOX9, but decreased COL2A1.
The mechanism of opiorphin-induced experimental priapism in rats involves activation of the polyamine synthetic pathway
Authors: Kanika Nirmala Devi , Tar Moses , Tong Yuehong , Kuppam Dwaraka Srinivasa Rao , Melman Arnold , Davies Kelvin Paul
Published: August 2009

Intracorporal injection of plasmids encoding opiorphins into retired breeder rats can result in animals developing a priapic-like condition. Microarray analysis demonstrated that following intracorporal gene transfer of plasmids expressing opiorphins the most significantly upregulated gene in corporal tissue was the ornithine decarboxylase gene (ODC). Quantitative RT-PCR confirmed the upregulation of ODC, as well as other genes involved in polyamine synthesis, such as arginase-I and -II, polyamine oxidase, spermidine synthase, spermidine acetyltransferase (SAT), and S-adenosylmethionine decarboxylase. Western blot analysis demonstrated upregulation of arginase-I and -II, ODC, and SAT at the protein level. Levels of the polyamine putrescine were upregulated in animals treated with opiorphin-expressing plasmids compared with controls. A direct role for the upregulation of polyamine synthesis in the development of the priapic-like condition was supported by the observation that the ODC inhibitor 1,3-diaminopropane, when added to the drinking water of animals treated with plasmids expressing opiorphins, prevented experimental priapism. We also demonstrate that in sickle cell mice, another model of priapism, there is increased expression of the mouse opiorphin homologue in corporal tissue compared with the background strain at a life stage prior to evidence of priapism. At a life stage when there is onset of priapism, there is increased expression of the enzymes involved in polyamine synthesis (ODC and arginase-I and -II). Our results suggest that the upregulation of enzymes involved in the polyamine synthetic pathway may play a role in the development of experimental priapism and represent a target for the prevention of priapism.
Urotensin II modulates hepatic fibrosis and portal hemodynamic alterations in rats
Authors: Kemp William , Kompa Andrew , Phrommintikul Arintaya , Herath Chandana , Zhiyuan Jia , Angus Peter , McLean Catriona , Roberts Stuart , Krum Henry
Published: August 2009

The influence of circulating urotensin II (UII) on liver disease and portal hypertension is unknown. We aimed to evaluate whether UII executes a pathogenetic role in the development of hepatic fibrosis and portal hypertension. UII was administered by continuous infusion over 4 wk in 20 healthy rats divided into three treatment groups, controls (saline, n = 7), low dose (UII, 1 nmol·kg−1·h−1, n = 8), and high dose (UII, 3 nmol·kg−1·h−1, n = 5). Hemodynamic parameters and morphometric quantification of fibrosis were assessed, and profibrotic cytokines and fibrosis markers were assayed in hepatic tissue. UII induced a significant dose-dependent increase in portal venous pressure (5.8 ± 0.4, 6.4 ± 0.3, and 7.6 ± 0.7, respectively, P = 0.03). High-dose UII infusion was associated with an increase in hepatic transcript for transforming growth factor-β ( P < 0.05) and platelet-derived growth factor-β ( P = 0.06). Liver tissue hydroxyproline was elevated in the high-dose group ( P < 0.05). No systemic hemodynamic alterations were noted. We concluded that UII infusion elevates portal pressure and induces hepatic fibrosis in normal rats. This response may be mediated via induction of fibrogenic cytokines. These findings have pathophysiological implications in human liver disease where increased plasma UII levels have been observed.
GLP-1 secretion is enhanced directly in the ileum but indirectly in the duodenum by a newly identified potent stimulator, zein hydrolysate, in rats
Authors: Hira Tohru , Mochida Taisuke , Miyashita Kyoko , Hara Hiroshi
Published: August 2009

Glucagon-like peptide-1 (GLP-1) is released from enteroendocrine cells (L cells) in response to food ingestion. The mechanism by which dietary peptides stimulate GLP-1 secretion in the gut is unknown. In the present study, we found that a hydrolysate prepared from zein, a major corn protein [zein hydrolysate (ZeinH)], strongly stimulates GLP-1 secretion in enteroendocrine GLUTag cells. Stimulatory mechanisms of GLP-1 secretion induced by ZeinH were investigated in the rat small intestine under anesthesia. Blood was collected through a portal catheter before and after ZeinH administration into different sites of the small intestine. The duodenal, jejunal, and ileal administration of ZeinH induced dose-dependent increases in portal GLP-1 concentration. GLP-1 secretion in response to the ileal administration of ZeinH was higher than that in the duodenal or jejunal administration. Capsaicin treatment on esophageal vagal trunks abolished the GLP-1 secretion induced by duodenal ZeinH but did not affect the secretion induced by jejunal or ileal ZeinH. These results suggest that ZeinH in the jejunum or ileum directly stimulates GLP-1 secretion but duodenal ZeinH indirectly stimulates GLP-1 secretion via the vagal afferent nerve. A direct blood sampling method from the duodenal vein and ileal mesenteric vein revealed that ZeinH administered into the ligated duodenal loop enhanced GLP-1 concentration in the ileal mesenteric vein but not in the duodenal vein. This confirmed that ZeinH in the duodenum induces GLP-1 secretion from L cells located in the ileum by an indirect mechanism. These results indicate that a potent GLP-1-releasing peptide, ZeinH, induces GLP-1 secretion by direct and indirect mechanisms in the rat intestine.