bluuebunny/crossref_metadata_2025 huggingface dataset:
Holocene sea-level history of the Canadian Beaufort shelf
Authors: Hill Philip R. , Héquette Arnaud , Ruz Marie-Hélène
Published: June 2009

New radiocarbon ages pertaining to the Holocene sea-level history of the Canadian Beaufort shelf are presented. The ages were obtained on samples of freshwater and tidal-marsh peat beds from offshore boreholes and shallow cores in the coastal zone and on molluscs and a single piece of wood deposited in foraminifera-bearing marine sediments. Although none of the samples record directly the position of relative sea level, the suite of ages constrains the regional curve sufficiently to suggest a faster rate of mid Holocene sea level rise (7–14 mm/a) than previously thought. The rate of relative rise slowed markedly in the last 3000 years, approaching the present at a maximum probable rate of 2.5 mm/a.
Proper determination of the δ18O–δD relationship for ice and water by least-squares cubic regression
Authors: Burn C. R. , Maxwell M. G.
Published: June 2009

The δ18O–δD relationship for ice and water is frequently summarized with a line fitted by least-squares linear regression. This technique assumes that one variable is known exactly and all error can be ascribed to the other. Unfortunately, determinations by mass spectrometry of both δ18O and δD are subject to experimental error. Often a blanket laboratory precision is provided for δ18O and δD, in which case functional analysis, accounting for the relative error in the variables, is appropriate. Properly, however, each sample has an individual analytical error in both variables, defined by the variance in estimates of isotope concentration provided by the mass spectrometer. Where individual errors are known, the least-squares cubic method, which assigns a weight to each sample and generates the summary line by an iterative method, may be used. An algorithm sufficient to determine both the functional fit and the least-squares cubic regression line is presented. Illustrations are provided, one of which demonstrates that if the plot of δ18O versus δD is scattered (r2 < 0.9), both the functional fit and the least-squares cubic regression line may be significantly different from the least-squares linear regression lines.
Injections multiples de magmas dans un conduit nourricier: implications sur le remplissage des plutons et l'extraction des magmas
Authors: Bédard L. Paul
Published: June 2009

For some plutons, periodic replenishment is required to explain trends in magmatic differentiation. The Houghton pluton, located in the northern Abitibi Greenstone Belt, contains breccias (interpreted as feeder dykes) that document the periodic replenishment of the chamber and the expulsion of the interstitial liquid between the enclaves. Interpretation of the textures in these breccias provides a mechanism for efficient magma extraction (which maybe applicable, for example, to partially molten rocks). There are two types of breccia: (i) polymictic breccias made of various enclaves with an interstitial leucotonalite of 5–20% and (ii) foliated block breccias made of foliated tonalite and deformed hornblendite enclaves with an interstitial leucotonalite of 0–5%. Dykes ending in enclaves, enclaves indented together and separated afterwards, and enclaves rimmed by a magma different from the interstitial one all argue in favour of periodic replenishment. Magma expulsion is explained by compaction of enclaves until they touch one another and deformation of some enclaves or borders of some enclaves. If the composition is appropriate and the nonhydrostatic stress is large enough, solution–precipitation and (or) stress-induced mass transfer can further increase the proportion of enclaves. It appears possible to expell all the liquid from an enclave–liquid mixture, contrary to the prediction of theoretical studies. These textures and their interpretation can also be applied to melt extraction in partially molten rocks.
Stratigraphy and geochemistry of the Itcha Volcanic Complex, central British Columbia
Authors: Charland Anne , Francis Don , Ludden John
Published: June 2009

The Itcha Volcanic Complex is the youngest and easternmost felsic shield volcano of the Anahim Volcanic Belt of central British Columbia. The main body of the shield erupted over an area of ~300 km2 forming Itcha Mountain and Mount Downton. Volcanism associated with the Itcha Shield extended 20 km south to the Satah Mountain area, where lavas erupted along a north-northwest – south-southeast fault system and covered an additional area of 250 km2. The Itcha Volcanic Complex is characterized by a bimodal population of volcanic rocks, which are dominated by felsic lavas. There were two stages of volcanism: (i) an early felsic shield-building stage dominated by felsic lavas ranging in composition from phonolite to minor quartz-normative trachytes, which erupted as flows, domes, and pyroclastic deposits to form a low-angled shield; and (ii) a late mafic capping stage, which comprises a thin veneer of hawaiite and more primitive mafic lavas ranging in composition from alkali olivine basalt to basanite. The late mafic capping stage lavas erupted from satellite cinder cones and fissures concentrated on the eastern side of the shield.The hawaiites that dominate the late mafic capping stage cannot have been derived from the more primitive basalts with which they are associated by low-pressure crystal fractionation but may instead have originated from the fractionation of a clinopyroxene-dominated assemblage at high pressures. The presence of mafic xenocrysts in a megacrystic trachyte unit, whose eruption terminated the felsic shield-building stage, and anorthoclase xenocrysts in the most evolved alkali olivine basalts of the mafic capping stage indicate that the mafic and the felsic magmas interacted prior to eruption. An overlap in 87Sr/86Sr ratios and a similarity in the high-field-strength element ratios of the felsic and the mafic lavas suggest that they are genetically related. Elevated ratios of large-ion lithophile elements to high-field-strength elements (e.g., Rb/Zr) in the trachytes, however, indicates that the felsic magmas were not derived by closed-system fractional crystallization from the mafic magmas and may instead suggest the assimilation of a crustal component.
Petrology of syenites from center III of the Coldwell alkaline complex, northwestern Ontario, Canada
Authors: Mitchell Roger H. , Platt R. Garth , Lukosius-Sanders Jurate , Artist-Downey Maureen , Moogk-Pickard Shelley
Published: June 2009

Center III of the Coldwell alkaline complex consists of metaluminous hypersolvus syenites, which in order of intrusion are magnesiohornblende syenite, contaminated ferro-edenite syenite, ferroedenite syenite, and quartz syenite. Contaminated syenites were formed by the assimilation of coeval basaltic volcanic rocks. The suite as a whole is characterized by the presence of a wide variety of amphiboles ranging in composition from magnesiohornblende through ferroedenite and ferrorichterite to arfvedsonite. Pyroxenes are rare and hedenbergite is present in significant amounts only in quartz syenite. Whole-rock major element data indicate that the majority of the syenites do not represent liquid compositions. The syenites have high contents of Nb, Zr, Th, U, Y, and Ga and have the geochemical character of A-type granitoids. Rare earth and other trace element abundances suggest that the quartz syenites cannot be differentiates of the magma that formed the ferroedenite syenites. All syenites are considered to have originated by the extensive fractional crystallization of mantle-derived basalt magma within the plutonic infrastructure of the complex. The syenite suite does not represent the differentiation products of a single batch of magma. Multiple intrusion, contamination, and brecciation of preexisting syenite plutons have resulted in the complex geological relationships characteristic of center III.
Eclogitized gabbros from the eastern Grenville Province: textures, metamorphic context, and implications
Authors: Indares Aphrodite
Published: June 2009

Undeformed lenses of olivine–orthopyroxene–gabbro belonging to the 1429 Ma Shabogamo Intrusive Suite (Parautochthonous Belt of the eastern Grenville Province) host the first occurrence of eclogite mineral assemblages reported from the Grenville Province. These rocks preserve igneous textures overprinted by eclogite mineralogy and by textures related to subsequent unloading. High-pressure signatures include omphacite pseudomorphs after augite, plagioclase replacement by garnet + kyanite + corundum, and orthopyroxene–omphacite–garnet coronas between olivine and plagioclase. Transformations related to decompression include replacement of garnet + kyanite + corundum by spinel + plagioclase, growth of plagioclase collars between clinopyroxene and garnet, and de-jadeitization of omphacite. Clinopyroxenes with numerous plagioclase inclusions and garnets surrounded by clinopyroxene–plagioclase symplectites in granoblastic mafic rocks from the same area are also evidence of decompression from high pressures. These rocks record pressure–temperature (P–T) conditions of 1600 MPa at 700–800 °C and steep subsequent P–T paths. It is suggested that the entire parautochthon in this part of the Grenville Province experienced deep burial during the Grenvillian metamorphism. In contrast, the Grenvillian metamorphic signature in the overlying allochthonous sheet is known to be minor, thus precluding any relationship between its emplacement and very high Grenvillian pressures in the parautochthon.
Structure and expression of ubiquitin gene transcripts in pine
Authors: Carter M. Carol Alosi , Kulikauskas Rima M. , Park Roderic B.
Published: June 2009

Clones encoding polyubiquitin proteins were isolated from a cDNA library derived from Pinussabiniana phloem tissue. Two different polyubiquitin clones were sequenced. The amino acid sequences of the clones were compared with angiosperm polyubiquitin sequences and with corresponding sequences reported for animal, fungal, and protist polyubiquitins. A computer-aided analysis showed (i) that pine and angiosperm polyubiquitin amino acid sequences correspond perfectly, (ii) that plant polyubiquitins differ from animal polyubiquitins by three amino acids, and (iii) that fungal and protist polyubiquitins are variable, differing by one to eight amino acids from higher organisms. The expression of ubiquitin was studied in bark, cone, needle, phloem, root, and xylem tissues of pine by Northern blot analysis. In all of these tissues, transcripts of about 1000 base pairs were observed. A minor species of 1200 base pairs was seen in longer exposures of autoradiograms. Ubiquitin transcripts were more abundant (in relationship to total RNA) in phloem, cones, and roots than in bark, needles, or xylem.
Frost hardiness and winter photosynthesis of Thujapiicata and Pseudotsugamenzlesll seedlings grown at three rates of nitrogen and phosphorus supply
Authors: Hawkins B.J. , Davradou M. , Pier D. , Shortt R.
Published: June 2009

One-year-old seedlings of western red cedar (Thujapiicata Donn ex D.Don) and Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were grown for one season in five nutrient treatments with nitrogen (N) supplied in solution at rates of 20, 100, or 250 mg•L−1 and phosphorus (P) supplied at rates of 4, 20, or 60 mg•L−1. Growth, onset of dormancy, frost hardiness on six dates, and foliar nutrient concentrations in autumn and spring were measured. Midwinter rates of net photosynthesis and transpiration were measured at air temperatures of 4, 7, and 11 °C in seedlings from all nutrient treatments. Recovery of net photosynthesis and transpiration in whole seedlings from the three N treatments was assessed at intervals for 28 days after the seedlings were frozen to −5, −15, and −25°C. Foliar N content differed significantly among nutrient treatments and was positively correlated with supply. Mitotic activity ceased earliest in plants with low N supply. Douglas-fir seedlings in the low-N treatment also ceased height growth earliest. These differences in growth had no significant correlation with frost hardiness. No consistent differences in frost hardiness among nutrient treatments were observed. Higher rates of N and P supply resulted in higher rates of winter net photosynthesis. Net photosynthesis was reduced dramatically by night frost, with greater damage occurring at lower temperatures. Net photosynthesis recovery occurred most quickly in seedlings with the midrate of N and P supply.
Predicting growth of plantation conifers in the Adirondack Mountains in response to climate change
Authors: Pan Yude , Raynal Dudley J.
Published: June 2009

Three conifer species grown in plantations in the southeastern Adirondack Mountains of New York were chosen to model tree growth. Annual growth of trees was decomposed into several components that reflect various intrinsic or extrinsic factors. Growth signals indicative of climatic effects were used to construct growth-climate models using both multivariate regression analysis and Kalman filter methods. Two growth models were used to simulate tree growth response to future climate change projected by GCMs. The consistent results of both models indicate that different conifer species have individualistic growth responses to future climatic change. The response behaviors of trees are affected greatly by local stand conditions and species tolerance to drought.
Predicting tree crown ratio for unthinned and thinned Scots pine stands
Authors: Hynynen Jari
Published: June 2009

A nonlinear model that yields logical predictions for tree crown ratio is presented. The model is based on data from permanent experimental plots located in even-aged Scots pine (Pinussylvestris L.) stands in southern and central Finland. Regressor variables in the model are stand dominant height, stand basal area, tree diameter, and tree height. The effect of thinning on tree crown ratio is modelled by incorporating a thinning response variable into the model. Thinning effect is dependent on thinning intensity and time elapsed from thinning, the latter of which is represented by the difference between current stand dominant height and dominant height at the time of thinning.
Reduction of Phellinusweirii inoculum in Douglas-fir stumps by the fumigant Telone ll-B
Authors: Fraser R.G. , Beale J.D. , Nevill R.J.
Published: June 2009

Two dosages of Teione II-B (1,3-dichloropropene) at 3.4 and 6.7 mL/kg of stump and root biomass were tested to determine the efficacy in reducing Phellinusweirii (Murr.) Gilb. inoculum in infected Douglas-fir, Pseudotsugamenziesii (Mirb.) Franco, stumps. After 21 months, both doses of Teione II-B proved equally effective and significantly (p < 0.05) reduced residual P. weirii mycelium in infected roots. Fumigation reduced residual endotrophic P. weirii in the large-diameter root classes nearest the stump, but survival of the fungus was less affected with increasing distance from the stump and in the smaller root diameter classes. Treated stumps also had significantly (p < 0.05) fewer roots with ectotrophic mycelium than untreated stumps. Four weeks after application, soil samples taken near treated stumps revealed no evidence of the fumigant. These findings suggest that application of Teione II-B could be used as an effective control measure for P. weirii.
Growth response to thinning and its relation to site resources in Eucalyptusregnans
Authors: West P.W. , Osier G.H.R.
Published: June 2009

The factors determining individual tree growth response are examined during the 4 years following thinning in experiments in even-aged, 8- or 12-year-old regrowth Eucalyptusregnans F. Muell. forest at two sites in southern Australia. At one site, a vigorous understorey dominated by a sedge developed after the thinning. At that site, light-use efficiency by the trees was unaffected by thinning and the aboveground biomass production by the trees in the thinned stand was substantially less than that in the unthinned stand. At the other site, little understorey developed, light-use efficiency by trees in the thinned stand was greater than that in the unthinned stand, and aboveground biomass production was unaffected by thinning even though the leaf weight of the thinned stand was far below that of the unthinned stand. Where the understorey developed, it was concluded that it competed successfully with the trees for water, thereby reducing production in the thinned stand when compared with the unthinned stand. The individual tree growth response that occurred in the thinned stand at that site appeared to be due soley to the extra light available to individual trees following the canopy opening. Where the understorey did not develop, it was concluded that individual tree growth response was due not only to the extra light available to individual trees but also to the increased availability of belowground resources, most probably soil water. Application of a pre-existing stand growth model suggested that at that site the tendency for increased growth resulting from extra water availability in the thinned stand was just balanced by decreased growth due to lower radiation absorption by the reduced canopy, so that net production was unaffected by thinning.
Effect of Seiridium cardinale on growth of cypress (Cupressus sempervirens) clones
Authors: Panconesi Alberto , Casini Niccolô , Santini Alberto , Stefanini Federico M.
Published: June 2009

To determine whether cypress bark canker, caused by the fungus Seiridiumcardinale (Wag.) Sutton & Gibson, affects height and diameter growth of common cypress (Cupressussempervirens L.), these parameters were measured over 4 years on inoculated and uninoculated ramets of 50 cypress clones at two locations in Italy. An analysis of covariance, using the pre-trial diameter and height of the ramets as the covariates, showed that the disease had no effect on either height or diameter growth.
Design-based estimation of forest volume within a model-based sample selection framework
Authors: Schreuder Hans T. , Williams M.S.
Published: June 2009

Equations for predicting tree volume are often developed using data collected either by a model-based method such as purposive sampling or by stratified random sampling so that an "adequate" number of trees from each diameter class are sampled across the range of classes expected in populations of interest. Such equations are then used together with a design-based (probabilistic) sample such as variable radius plot sampling from a specific population to generate estimates of total volume. The probabilities of selection of the sample trees used in developing the volume equation are ignored, may not be known, or may not be appropriate for populations to which the equation are applied. Less biased and more efficient estimates of the population volume can be generated by using known frequencies or estimated frequencies of the diameter classes in the population from the probabilistic sample used for estimating total volume in the population. These frequencies are used as weighting factors in the construction of population-specific volume equations. We show a reduction in bias and increased efficiency in a simulation study for several forest populations with strong linear relationships between variables and reasonably well known error structure. A model-based sampling procedure called pscx sampling or a large-sample extension thereof is used to select sample trees for volume equations. Such bias reduction did not happen for other populations with weak linear relationships and unknown error structure.
Seedling microenvironment in full-tree and tree-length logging slash
Authors: Mclnnis Bryce G. , Roberts Mark R.
Published: June 2009

In response to concerns about the effects of slash removal on natural regeneration, a microenvironment study was conducted in logging slash using weighed full-tree (FT) and tree-length (TL) slash loads, and no slash (control), in the first summer after harvesting a mixed stand in New Brunswick. Significantly higher temperatures at the litter surface occurred in control and FT plots than in TL plots. Potentially lethal temperatures for new conifer germinants were recorded 18 times in FT and control plots combined, and once in TL plots. Differences among treatments in temperature peaks diminished in prolonged droughty weather. There were no differences in soil moisture tension at 10 cm depth, apparently because of restricted drainage. An average of 95% of full solar radiation (W/m2, response range of measuring device 0.35–2.5 μm) was measured in FT slash and 66% in TL slash. No significant differences in mortality or height growth of established coniferous advance growth (Picea spp. and Abiesbalsamea (L.) Mill., mean height = 28.5 cm) occurred, but significantly less mortality and significantly greater height growth of small AcerrubrumL. seedlings (mean height = 7 cm) occurred in the FT and control treatments than in the TL treatment. Results suggest that harvesting methods that involve slash removal could result in increased mortality of small conifer seedlings from direct heat damage and in increased competition from pioneering hardwoods.
Linear modelling of irregularly spaced, unbalanced, longitudinal data from permanent-plot measurements
Authors: Grégoire Timothy G. , Schabenberger Oliver , Barrett James P.
Published: June 2009

A linear mixed-effects model that accounts for the covariances among repeated measurements and for random plot effects is developed. A continuous-time autocorrelation error structure permits the model to be applied to irregularly spaced, unbalanced data. A strategy for fitting this model and diagnostic tools for assessing its goodness of fit are presented and demonstrated. The model is fitted to two permanent-plot data bases and shows marked improvement compared with models that do not account for the error structure.
Upper stem volumes from stem analysis data: an overlapping bolts method
Authors: Bailey Robert L.
Published: June 2009

Studies to develop equations for upper stem taper, volume, and weight require observed values of upper stem volume. Tree volumes up to various upper stem diameters calculated using Smalian's formula throughout the stem length on 4- to 8-ft (1 ft = 0.30 m) bolts may overestimate true volumes by 1 to 4%. Calculating the butt bolt's volume with Newton's formula improves the estimates considerably. A new approach that uses Newton's formula on successive overlapping pairs of bolts produces even more improvement and still gives volume estimates for each bolt. The overlapping bolts method on 6-ft bolts is equally as precise as the conventional non-overlapping method on 4-ft bolts and would result in a 33.3% savings in sampling effort.
FULL REGULARITY FOR A C*-ALGEBRA OF THE CANONICAL COMMUTATION RELATIONS
Authors: GRUNDLING HENDRIK , NEEB KARL-HERMANN
Published: June 2009

The Weyl algebra — the usual C*-algebra employed to model the canonical commutation relations (CCRs), has a well-known defect, in that it has a large number of representations which are not regular and these cannot model physical fields. Here, we construct explicitly a C*-algebra which can reproduce the CCRs of a countably dimensional symplectic space (S, B) and such that its representation set is exactly the full set of regular representations of the CCRs. This construction uses Blackadar's version of infinite tensor products of nonunital C*-algebras, and it produces a "host algebra" (i.e. a generalized group algebra, explained below) for the σ-representation theory of the Abelian group S where σ(·,·) ≔ eiB(·,·)/2. As an easy application, it then follows that for every regular representation of [Formula: see text] on a separable Hilbert space, there is a direct integral decomposition of it into irreducible regular representations (a known result).
TIME DELAY FOR DISPERSIVE SYSTEMS IN QUANTUM SCATTERING THEORY
Authors: TIEDRA DE ALDECOA RAFAEL
Published: June 2009

We consider time delay and symmetrized time delay (defined in terms of sojourn times) for quantum scattering pairs {H0 = h(P), H}, where h(P) is a dispersive operator of hypoelliptic-type. For instance, h(P) can be one of the usual elliptic operators such as the Schrödinger operator h(P) = P2 or the square-root Klein–Gordon operator [Formula: see text]. We show under general conditions that the symmetrized time delay exists for all smooth even localization functions. It is equal to the Eisenbud–Wigner time delay plus a contribution due to the non-radial component of the localization function. If the scattering operator S commutes with some function of the velocity operator ∇h(P), then the time delay also exists and is equal to the symmetrized time delay. As an illustration of our results, we consider the case of a one-dimensional Friedrichs Hamiltonian perturbed by a finite rank potential.

Our study puts into evidence an integral formula relating the operator of differentiation with respect to the kinetic energy h(P) to the time evolution of localization operators.
REPORT ON THE DETAILED CALCULATION OF THE EFFECTIVE POTENTIAL IN SPACETIMES WITH S1 × Rd TOPOLOGY AND AT FINITE TEMPERATURE
Authors: OIKONOMOU V. K.
Published: June 2009

In this paper, we review the calculations that are needed to obtain the bosonic and fermionic effective potential at finite temperature and volume (at one loop). The calculations at finite volume correspond to S1 × Rd topology. These calculations appear in the calculation of the Casimir energy and of the effective potential of extra dimensional theories. In the case of finite volume corrections, we impose twisted boundary conditions and obtain semi-analytic results. We mainly focus in the details and validity of the results. The zeta function regularization method is used to regularize the infinite summations. Also the dimensional regularization method is used in order to renormalize the UV singularities of the integrations over momentum space. The approximations and expansions are carried out within the perturbative limits. After the end of each section, we briefly present applications associated to the calculations. Particularly the calculation of the effective potential at finite temperature for the standard model fields, the effective potential for warped and large extra dimensions, and the topological mass creation. In the end, we discuss on the convergence and validity of one of the obtained semi-analytic results.
A PARTICLE SWARM OPTIMIZATION ALGORITHM ON JOB-SHOP SCHEDULING PROBLEMS WITH MULTI-PURPOSE MACHINES
Authors: PONGCHAIRERKS PISUT , KACHITVICHYANUKUL VORATAS
Published: June 2009

This paper is a contribution to the research which aims to provide an efficient optimization algorithm for job-shop scheduling problems with multi-purpose machines or MPMJSP. To meet its objective, this paper proposes a new variant of particle swarm optimization algorithm, called GLN-PSOc, which is an extension of the standard particle swarm optimization algorithm that uses multiple social learning topologies in its evolutionary process. GLN-PSOc is a metaheuristic that can be applied to many types of optimization problems, where MPMJSP is one of these types. To apply GLN-PSOc in MPMJSP, a procedure to map the position of particle into the solution of MPMJSP is proposed. Throughout this paper, GLN-PSOc combined with this procedure is named MPMJSP-PSO. The performance of MPMJSP-PSO is evaluated on well-known benchmark instances, and the numerical results show that MPMJSP-PSO performs well in terms of solution quality and that new best known solutions were found in some instances of the test problems.
AN EFFICIENTLY NOVEL MODEL FOR VEHICLE ROUTING PROBLEMS WITH STOCHASTIC DEMANDS
Authors: İŞLEYEN SELÇUK KÜRŞAT , BAYKOÇ ÖMER FARUK
Published: June 2009

In this paper, the Vehicle Routing Problem with Stochastic Demands (VRPSD) is considered where customer demands are normally distributed. We propose a new model for computing the expected length of a tour. Monte Carlo simulation is used to demonstrate the accuracy of the model on randomly generated test problems. It is assumed that the service policy is non-divisible, meaning that the entire demand at each customer must be served in a single visit by a unique vehicle.
VECTOR-VALUED IMPLICIT LAGRANGIAN FOR SYMMETRIC CONE COMPLEMENTARITY PROBLEMS
Authors: KONG LINGCHEN , TUNÇEL LEVENT , XIU NAIHUA
Published: June 2009

The implicit Lagrangian was first proposed by Mangasarian and Solodov as a smooth merit function for the nonnegative orthant complementarity problem. It has attracted much attention in the past ten years because of its utility in reformulating complementarity problems as unconstrained minimization problems. In this paper, exploiting the Jordan-algebraic structure, we extend it to the vector-valued implicit Lagrangian for symmetric cone complementary problem (SCCP), and show that it is a continuously differentiable complementarity function for SCCP and whose Jacobian is strongly semismooth. As an application, we develop the real-valued implicit Lagrangian and the corresponding smooth merit function for SCCP, and give a necessary and sufficient condition for the stationary point of the merit function to be a solution of SCCP. Finally, we show that this merit function can provide a global error bound for SCCP with the uniform Cartesian P-property.
LINEAR PROGRAMMING TECHNIQUE TO SOLVE TWO PERSON MATRIX GAMES WITH INTERVAL PAY-OFFS
Authors: NAYAK PRASUN KUMAR , PAL MADHUMANGAL
Published: June 2009

A fuzzy two person interval game problem is proposed and treated in this paper which is not easily tackled by the conventional methods. First, with respect to this pay-off values, a necessary and sufficient condition for the existence of a saddle point is proved. Based on interval value model, we are to find the value of interval game without saddle point. Finally, example is given to illustrate the procedure and to indicate the performance of the proposed method.
A BATCHING PROBLEM WITH LEARNING EFFECT CONSIDERATIONS
Authors: YANG WEN-HUA
Published: June 2009

Consider a batch-sizing problem, where all jobs are identical or similar, and a unit processing time (p = 1) is specified for each job. To minimize the total completion time of jobs, partitioning jobs into batches may be necessary. Learning effect from setup repetition makes small-sized batches; on the contrary, job's learning effect results in large-sized batches. With their collaborative influence, we develop a forward dynamic programming (DP) algorithm to determine the optimal number of batches and their optimal integer sizes. The computation effort required by this DP algorithm is a polynomial function of job size.
SUB-10 NM DIRECT PATTERNING OF OXIDES USING AN ELECTRON BEAM — A REVIEW
Authors: SAIFULLAH M. S. M.
Published: June 2009

This article reviews the progress made in the sub-10 nm electron beam patterning of metal oxides over the last thirty years. The patterning of inorganic resists began with metal halides, they were soon taken over by metal oxides due to their excellent environmental stability. However, these inorganic materials, both halides and oxides, suffered from the requirement of very steep dose, thus rendering them useless for practical applications. This gave way to highly electron beam-sensitive stabilized metal alkoxides and metal naphthenates, with sensitively close to conventional electron beam resists such as poly(methylmethacrylate) (PMMA) and calixarene. Furthermore, they show excellent line edge roughness characteristics at sub-10 nm scale, which is currently unmatched by any other electron beam resist. Recent applications of these resists such as an etch mask and their suitability as gate oxides will be highlighted.
Chromosome Odds and Ends
Authors: Gall Joseph G.
Published: June 2009

Here I give a brief history of my scientific career, beginning with my early interest in natural history and my introduction to the microscope and the wonderful world of the cell. My studies have focused on chromosomes, nucleoli, and other nuclear structures, with a few forays into the cytoplasm. In each case, I have tried to understand how proteins and nucleic acids are physically organized to give rise to the structures seen under the microscope. I describe how studies in my laboratory on amplified ribosomal RNA genes led to the development of in situ hybridization, a technique that permitted us to localize specific nucleic acid sequences with high precision. My early exposure to the diversity of animals and plants made it seem natural to choose organisms best suited to a particular problem, hence the use of salamanders, frogs, and mice, as well as protozoa, fruit flies, and other invertebrates.
Erythropoietin activates nitric oxide synthase in murine erythrocytes
Authors: Mihov Deyan , Vogel Johannes , Gassmann Max , Bogdanova Anna
Published: June 2009

Erythropoietin (Epo) is the main regulator of erythrocyte production and a potent cytoprotective factor. It was suggested that some of Epo cytoprotective properties are due to its regulation of nitric oxide (NO) production. Recently, functionally active endothelial type NO synthase (eNOS) was discovered in mature murine and human red blood cells (RBC-eNOS). The goal of the present study was to characterize the effect of physiological and therapeutic doses of Epo on RBC-eNOS function. We found that recombinant human Epo (rHuEpo) binds specifically to mouse erythrocytes. Epo binding sites are not equally distributed through the RBC population but prevail in reticulocytes and young erythrocytes with about 105 receptors/cell, compared with adult and old erythrocytes containing 1–4 receptors/cell. The treatment of mouse erythrocytes with rHuEpo resulted in a time- and dose-dependent upregulation of NO production mediated via activation of the phosphatidylinositol-3-kinase /Akt pathway and RBC-eNOS phosphorylation at Ser-1177. Finally, when erythrocytes were incubated in l-arginine-free medium, rHuEpo treatment resulted in upregulation of superoxide radical production with concomitant shifting of the cellular redox state toward more oxidized state. Epo-induced changes in erythrocyte redox potential were absent in erythrocytes from eNOS-deficient mice.
Dynasore inhibits rapid endocytosis in bovine chromaffin cells
Authors: Tsai Chia-Chang , Lin Chih-Lung , Wang Tzu-Lun , Chou Ai-Chuan , Chou Min-Yi , Lee Chia-Hsueh , Peng I-Wei , Liao Jia-Hong , Chen Yit-Tsong , Pan Chien-Yuan
Published: June 2009

Vesicle recycling is vital for maintaining membrane homeostasis and neurotransmitter release. Multiple pathways for retrieving vesicles fused to the plasma membrane have been reported in neuroendocrine cells. Dynasore, a dynamin GTPase inhibitor, has been shown to specifically inhibit endocytosis and vesicle recycling in nerve terminals. To characterize its effects in modulating vesicle recycling and repetitive exocytosis, changes in the whole cell membrane capacitance of bovine chromaffin cells were recorded in the perforated-patch configuration. Constitutive endocytosis was blocked by dynasore treatment, as shown by an increase in membrane capacitance. The membrane capacitance was increased during strong depolarizations and declined within 30 s to a value lower than the prestimulus level. The amplitude, but not the time constant, of the rapid exponential decay was significantly decreased by dynasore treatment. Although the maximal increase in capacitance induced by stimulation was significantly increased by dynasore treatment, the intercepts at time 0 of the curve fitted to the decay phase were all ∼110% of the membrane capacitance before stimulation, regardless of the dynasore concentration used. Membrane depolarization caused clathrin aggregation and F-actin continuity disruption at the cell boundary, whereas dynasore treatment induced clathrin aggregation without affecting F-actin continuity. The number of invagination pits on the surface of the plasma membrane determined using atomic force microscopy was increased and the pore was wider in dynasore-treated cells. Our data indicate that dynamin-mediated endocytosis is the main pathway responsible for rapid compensatory endocytosis.
Structural rearrangements of the motor protein prestin revealed by fluorescence resonance energy transfer
Authors: Gleitsman Kristin Rule , Tateyama Michihiro , Kubo Yoshihiro
Published: June 2009

Prestin is a membrane protein expressed in the outer hair cells (OHCs) in the cochlea that is essential for hearing. This unique motor protein transduces a change in membrane potential into a considerable mechanical force, which leads to a cell length change in the OHC. The nonlinear capacitance in cells expressing prestin is recognized to reflect the voltage-dependent conformational change of prestin, of which its precise nature remains unknown. In the present work, we aimed to detect the conformational changes of prestin by a fluorescence resonance energy transfer (FRET)-based technique. We heterologously expressed prestin labeled with fluorophores at the COOH- or NH2-terminus in human embryonic kidney-293T cells, and monitored FRET changes on depolarization-inducing high KCl application. We detected a significant decrease in intersubunit FRET both between the COOH-termini and between the COOH- and NH2-termini. A similar FRET decrease was observed when membrane potential was directly and precisely controlled by simultaneous patch clamp. Changes in FRET were suppressed by either of two treatments known to abolish nonlinear capacitance, V499G/Y501H mutation and sodium salicylate. Our results are consistent with significant movements in the COOH-terminal domain of prestin upon change in membrane potential, providing the first dynamic information on its molecular rearrangements.
Loss of M2muscarinic receptor function inhibits development of hypoxic bradycardia and alters cardiac β-adrenergic sensitivity in larval zebrafish (Danio rerio)
Authors: Steele Shelby L. , Lo Kwok Hong Andy , Li Vincent Wai Tsun , Cheng Shuk Han , Ekker Marc , Perry Steve F.
Published: June 2009

Fish exposed to hypoxia develop decreased heart rate, or bradycardia, the physiological significance of which remains unknown. The general muscarinic receptor antagonist atropine abolishes the development of this hypoxic bradycardia, suggesting the involvement of muscarinic receptors. In this study, we tested the hypothesis that the hypoxic bradycardia is mediated specifically by stimulation of the M2muscarinic receptor, the most abundant subtype in the vertebrate heart. Zebrafish ( Danio rerio) were reared at two levels of hypoxia (30 and 40 Torr Po2) from the point of fertilization. In hypoxic fish, the heart rate was significantly lower than in normoxic controls from 2 to 10 days postfertilization (dpf). At the more severe level of hypoxia (30 Torr Po2), there were significant increases in the relative mRNA expression of M2and the cardiac type β-adrenergic receptors ( β1AR, β2aAR, and β2bAR) at 4 dpf. The hypoxic bradycardia was abolished (at 40 Torr Po2) or significantly attenuated (at 30 Torr Po2) in larvae experiencing M2receptor knockdown (using morpholino antisense oligonucleotides). Sham-injected larvae exhibited typical hypoxic bradycardia in both hypoxic regimens. The expression of β1AR, β2aAR, β2bAR, and M2mRNA was altered at various stages between 1 and 4 dpf in larvae experiencing M2receptor knockdown. Interestingly, M2receptor knockdown revealed a cardioinhibitory role for the β2-adrenergic receptor. This is the first study to demonstrate a specific role of the M2muscarinic receptor in the initiation of hypoxic bradycardia in fish.
Expression of ENaC subunits, chloride channels, and aquaporins in ovine fetal lung: ontogeny of expression and effects of altered fetal cortisol concentrations
Authors: Jesse Nathan M. , McCartney Jarret , Feng Xiaodi , Richards Elaine M. , Wood Charles E. , Keller-Wood Maureen
Published: June 2009

Transition of the epithelium of the fetal lung from fluid secretion to fluid reabsorption requires changes in the expression of ion channels. Corticosteroids regulate expression of several of these channels, including the epithelium sodium channel (ENaC) subunits and aquaporins (AQP). We investigated the ontogenetic changes in these ion channels in the ovine fetal lung during the last half of gestation, a time of increasing adrenal maturation. Expression of the mRNAs for the chloride channels, cystic fibrosis transmembrane conductance regulator (CFTR), and chloride channel 2 (CLCN2) decreased with age. Expression of mRNAs for AQP1, AQP5, and for subunits of ENaC (α, β, γ) increased with age. In the fetal sheep the expression of ENaCβ mRNA was dramatically higher than the expression of ENaCα or ENaCγ, but expression of ENaCβ protein decreased with maturation, although the ratio of the mature (112 kDa) to immature (102 kDa) ENaCβ protein increased with age, particularly in the membrane fraction. In contrast, ENaCα mRNA and protein both increase with maturation, and the mature form of ENaCα (68 kDa) predominates at all ages. A modest increase in fetal cortisol, within the range expected to occur naturally in late gestation but prior to active labor, increased ENaCα mRNA but not ENaCβ, ENaCγ, or AQP mRNAs. We conclude that in the ovine fetal lung, appearance of functional sodium channels is associated with induction of ENACα and ENaCγ, and that ENaCα expression may be induced by even small, preterm increases in fetal cortisol.
Are animal models relevant to key aspects of human parturition?
Authors: Mitchell Bryan F. , Taggart Michael J.
Published: June 2009

Preterm birth remains the most serious complication of pregnancy and is associated with increased rates of infant death or permanent neurodevelopmental disability. Our understanding of the regulation of parturition remains inadequate. The scientific literature, largely derived from rodent animal models, suggests two major mechanisms regulating the timing of parturition: the withdrawal of the steroid hormone progesterone and a proinflammatory response by the immune system. However, available evidence strongly suggests that parturition in the human has significantly different regulators and mediators from those in most of the animal models. Our objectives are to critically review the data and concepts that have arisen from use of animal models for parturition and to rationalize the use of a new model. Many animal models have contributed to advances in our understanding of the regulation of parturition. However, we suggest that those animals dependent on progesterone withdrawal to initiate parturition clearly have a limitation to their translation to the human. In such models, a linear sequence of events (e.g., luteolysis, progesterone withdrawal, uterine activation, parturition) gives rise to the concept of a “trigger” mechanism. Conversely, we propose that human parturition may arise from the concomitant maturation of several systems in parallel. We have termed this novel concept “modular accumulation of physiological systems” (MAPS). We also emphasize the urgency to determine the precise role of the immune system in the process of parturition in situations other than intrauterine infection. Finally, we accentuate the need to develop a nonprimate animal model whose physiology is more relevant to human parturition. We suggest that the guinea pig displays several key physiological characteristics of gestation that more closely resemble human pregnancy than do currently favored animal models. We conclude that the application of novel concepts and new models are required to advance translational research in parturition.
Role of purinergic P2Y1 receptors in regulation of vasopressin and oxytocin secretion
Authors: Song Zhilin , Gomes Dayane A. , Stevens Wanida
Published: June 2009

Pharmacological studies demonstrated that ATP elevates intracellular calcium ([Ca2+]i) in supraoptic nucleus (SON) neurons primarily by activation of P2X2 and P2Y1 purinergic receptors [P2Y1R; ( 18 )]. The current studies provide evidence for the presence of P2Y1R protein in SON neurons, evidence that activation of these P2Y1Rs induces an increase in [Ca2+]i from both intracellular stores and Ca2+ influx, and functional evidence that activation of P2Y1Rs induces vasopressin (VP) and oxytocin (OT) hormone release. Pretreatment of Fura-2 AM-loaded explants of the hypothalamo-neurohypophyseal system (HNS) with thapsigargin (TG) significantly (∼80%) reduced the increase in [Ca2+]i induced by the P2Y1R-specific agonist, 2-methylthio-ADP (2-MeSADP). In contrast, the increase in [Ca2+]i was slightly (∼20%) decreased in calcium-free medium. The calcium response to 2-MeSADP was completely blocked by the P2Y1R-specific antagonist, MRS2179 or by a combination of TG pretreatment and calcium-free medium. It was absent in P2Y1R knockout mice (P2Y1R−/−). 2-MeSADP significantly increased VP and OT release from perifused rat and wild-type mouse HNS explants compared with control. MRS2179 prevented this response in wild-type mouse, but it did not prevent ATP-induced hormone release from rat explants. 2-MeSADP did not induce hormone release from P2Y1R−/− explants. These findings support a potential role for P2Y1Rs in regulation of VP and OT release. The finding that P2Y1R activation induces a small Ca2+ influx suggests that P2Y1Rs may regulate VP release by modifying ion channels such as stretch-inactivated cation channels.
Central acetylcholinesterase inhibition improves hemodynamic counterregulation to severe blood loss in alcohol-intoxicated rats
Authors: Mathis Keisa W. , Molina Patricia E.
Published: June 2009

Acute alcohol intoxication results in impaired hemodynamic counterregulation to blood loss and is associated with an attenuated hemorrhage-induced release of catecholamines and AVP. We speculated that restoration of the neuroendocrine response to hemorrhage would improve mean arterial blood pressure (MABP) recovery during acute alcohol intoxication. Previously, we demonstrated that intracerebroventricular (ICV) choline, a precursor of acetylcholine, transiently increases sympathetic nervous system (SNS) outflow but is not capable of improving neuroendocrine and hemodynamic compensation to hemorrhage in alcohol-treated rats. We hypothesized that prolongation of the observed effect via ICV neostigmine, an acetylcholinesterase inhibitor, would enhance SNS outflow, restore the neuroendocrine response, and in turn improve hemodynamic responses to hemorrhage during acute alcohol intoxication. ICV neostigmine (1 μg) increased MABP, catecholamines, and AVP within 5 min and reversed hypotension due to 40% hemorrhage and intragastric alcohol (30% wt/vol, 2.5 g/kg) administration in chronically catheterized male Sprague-Dawley rats (225–250 g body wt). Acute alcohol intoxication before 50% hemorrhage decreased basal MABP, accentuated hypotension midhemorrhage, suppressed the hemorrhage-induced release of norepinephrine and AVP, and prevented restoration of MABP to basal levels after fluid resuscitation with lactated Ringer solution. ICV neostigmine (0.5 μg) produced a sustained increase in MABP beginning at 30 min of hemorrhage that persisted throughout fluid resuscitation in control and alcohol-treated animals. ICV neostigmine enhanced epinephrine responses and restored the hemorrhage-induced release of norepinephrine and AVP in alcohol-treated rats. These results demonstrate that inhibition of acetylcholinesterase in the central nervous system enhances SNS outflow, restores the neuroendocrine response to severe blood loss, and thereby improves hemodynamic counterregulation during acute alcohol intoxication. This study provides evidence for a central (and not peripheral) role of alcohol in impairing hemodynamic stability during hemorrhagic shock.