bluuebunny/crossref_metadata_2025 huggingface dataset:
Macroinvertebrate Communities and Environment in a Southern African Mountain Stream
Authors: King J. M. , Day J. A. , Hurly P. R. , Henshall-Howard M-P. , Davies B. R.
Published: August 2009

In a study of a second-order southern African stream, complementary classification and multidimensional scaling (MDS) techniques revealed longitudinal changes in macroinvertebrate community structure, but no temporal changes. Stepwise discriminant analysis and multiple linear regression were used to identify environmental variables correlated with the community changes but produced conflicting results depending on the information used, possibly because of strong correlations between some of the variables. The MDS plot of biotic samples illustrated that potassium levels correlated most strongly with community distribution. Because of the large number of variables now shown worldwide to correlate with faunal distributions, we suggest ways to choose the variables to suit the kind of study to be undertaken. Attempts to assign the invertebrates to functional feeding groups (FFGs) were unsatisfactory as the relevant categories are poorly defined and often inadequate for classifying the fauna. We suggest that until these categories are more clearly defined, and more uniformly applied, concepts relating to FFGs cannot be tested satisfactorily. The stream community in Langrivier is more similar to communities found in two other mediterranean ecosystems than to those in other southern African rivers, probably because of the greater predictability of flow in the former.
Gustatory Responses to Tetrodotoxin and Saxitoxin in Fish: A Possible Mechanism for Avoiding Marine Toxins
Authors: Yamamori Kunio , Nakamura Moritaka , Matsui Takashi , Hara Toshiaki j.
Published: August 2009

The gustatory responses to tetrodotoxin (TTX) and saxitoxin (STX) recorded from the palatine nerve (VIIth cranial nerve) were studied electrophysiological in rainbow trout (Salmo gairdneri) and Arctic char (Salvelinus alpinus). Both toxins were highly effective gustatory stimuli in both species, in rainbow trout, TTX had a threshold concentration 2 × 10−7 mol/L and at 10−5 mol/L evoked a response four times that of 10−3 mol L-proline/L, the most potent amino acid for this species. The threshold for STX was Sower (10−8 mol/L), but unlike TTX the response magnitude reached a maximum at 10−6 mol/L. The reverse occurred in Arctic char; lower threshold for TTX (10−8 mol/L) than STX (10−7 mol/L) and the response magnitude never exceeded that of 10−3 mol L-proline/L. Cross-adaptation experiments indicated that the receptor(s) for TTX are distinct from those which detect amino acids and bile salts and that TTX and STX do not share the same receptor populations. Furthermore, the integrated response to TTX or STX was a fast-adapting, phasic response and rapidly returned to baseline even with continued stimulation. Perfusion of the gustatory organs with these toxins had little toxic effect. The sensitive, specific gustatory receptor system for the toxins suggests the existence of a mechanism for avoiding poisonous prey organisms that has adaptive advantage to the receiver (predator).
Effect of Diets Containing Herring Oil Oxidized to Different Degrees on Growth and Immunocompetence of Juvenile Coho Salmon (Oncorhynchus kisutch)
Authors: Forster Ian , Higgs David A. , Bell Gordon R. , Dosanjh B. S. , March B. E.
Published: August 2009

Growth rate and efficiency of feed conversion were reduced by inclusion of oxidized herring oil in the diet, presumably as a result of reduced digestibility of the oxidized oil and suboptimal dietary concentrations of ω3 fatty acids. There was no evidence of any toxic factors in the oxidized oil. There was no significant difference in growth rate or the efficiency of feed conversion between juvenile coho fed diets supplemented with 30 and 1030 IU vitamin E/kg. Dietary treatment did not affect haematocrit values. Immunocompetence, judged by antibody titres in response to vibrio vaccination, was similar for all treatments. Disease resistance, assessed by the rate of mortality induced by exposure of nonvaccinated fish to challenge with Vibrio anguillarum or V. ordali, was likewise unaffected by the dietary treatments.
Effects of Winter Floods on Fishes in the Sierra Nevada
Authors: Erman Don C. , Andrews Edmund D. , Yoder-Williams Michael
Published: August 2009

Winter floods in the Sierra Nevada mountains kill age 0 class brook trout (Salvelinus fontinalis) and Paiute sculpin (Cottus beldingi) because bed-material transport increases greatly when high flows are constrained by snow banks. In February 1982, dead Paiute sculpin were collected while sampling bedload during a rain-on-snow flood. Population estimates by electrofishing at nine permanent stations the following summer showed that density (3586∙ha−1) and biomass(12.9 kg∙ha−1) of Paiute sculpin were lower than the respective means (12 017∙ha−1 and 40.3 kg∙ha−1) obtained during previous studies from 1952 to 1961. These estimates were also below those obtained in 1956, after the largest winter flood from 1952 to 1961. Brook trout fry were also less abundant in 1982 than previously reported. Maximum flow depth, rather than discharge, were the likely cause offish mortality. Winter floods are severe because accumulated snowpack increases the effective height of the streambank and confines most or all of a rain-on-snow flood within the channel. Shear forces on the bed increase and as a result bed-material transport increases rapidly. These conditions directfy kill many benthic-living fishes such as the Paiute sculpin or buried eggs of fall-spawning fishes such as the brook trout by mechanical grinding or crushing. The impact of snow-constrained floods was not uniform along Sagehen Creek due to patchiness in types of riparian canopy. The relationship among canopy cover, snow accumulation, and winter floods points to one more critical role that buffer strips may play in ameliorating effects of timber harvesting.
Zinc Influx Across the Isolated, Perfused Head Preparation of the Rainbow Trout (Salmo gairdneri) in Hard and Soft Water
Authors: Spry Douglas J. , Wood Chris M.
Published: August 2009

At a waterborne [Zn] of 1.9 mg∙L−1in hard water (~1 mmol Ca∙L−1), Zn influx across an isolated, saline-perfused head preparation of rainbow trout (Salmo gairdneri) was about 1.5 nmol∙kg−1∙h−1through the lamellar pathway and about 1 nmol∙kg−1∙h−1through the filamental route. Flux rates came rapidly to steady state in both pathways. Trout preexposed to artificial soft water (~0.05 mmol Ca∙L−1) for 5 d showed differential stimulation of flux rates to about 42 and 5 nmol Zn∙kg−1∙h−1through the lamellar and filamental pathways, respectively. Under these conditions, steady-state fluxes across the lamellae did not occur until 15–20 min after the start of perfusion. Preparations from hardwater-acclimated trout tested in soft water gave typical hardwater fluxes showing that these changes in influx were not simply due to acute exposure of the gill surface to low waterborne [Ca]. Influxes in softwater trout, studied over [Zn] from 0.4 to 7.5 mg Zn∙L−1, revealed a saturable, first-order uptake with apparent Jmaxand Kmof 150 nequiv∙kg−1∙h−1and 1.5 mg Zn∙L−1(23 μmol∙L−1), respectively. Because the apparent Kmis in the toxic range, Zn is clearly not the primary substrate. Scanning electron micrography revealed hypertrophy and increased apical exposure of chloride cells; this stimulation, coupled with the increase in Zn influx, suggests that chloride cells may be the site of entry of Zn across the gill.
Orthophosphate Concentrations in Lake Water: Analysis of Rigler's Radiobioassay Method
Authors: Tarapchak Stephen J. , Herche Lynn R.
Published: August 2009

Riger's radiobioassay method is frequently used to estimate maximum possible orthophosphate (P) concentrations in natural waters. An evaluation of the method, based on simulated P uptake by hypothetical phytoplankton communities, reveals that the Rigler value is not a consistent estimator of true maximum possible P concentration. Analyses show that all members of that family of curves for which the difference between true and assumed (or estimated) values of P is below the minimum half-saturation constant of a component species will pass through the plot's origin. A new upper bound, termed [Formula: see text] (Rigler), which is the sum of the true ambient P concentration and the lowest half-saturation constant of a component species, is identified as a consistently distinguishable bound on maximum possible P concentrations in lake water. The [Formula: see text] curve cannot be distinguished in a lake water experiment because of the complex behavior of uptake curves in the unobservable substrate region. A theoretical procedure, based on comparing uptake parameters for lake water samples and multispecific hypothetical communities, offers potential for calculating upper and lower limits on [Formula: see text] in P-limited lake water samples.
Tests of Competition between Native and Introduced Salmonids in Streams: What Have We Learned?
Authors: Fausch Kurt D.
Published: August 2009

Salmonids have been introduced worldwide to regions where they were not indigenous, usually without considering the effects on native species. This has led to many combinations of species in unnatural sympatry, some of which are suspected to interact strongly, but we currently have inadequate knowledge to allow us to predict the outcome of most such introductions. For example, despite current controversy about the potential effects of Pacific salmonids now stocked in Atlantic waters, we have only empirical evidence with which to judge whether they will be detrimental to Atlantic salmon (Salmo salar). Moreover, most experimental tests of interspecific competition between other pairs of stream salmonids have not been rigorous. A review of literature about the suspected competition between brook trout (Salvelinus fontinalis) and rainbow trout (Salmo gairdneri) in streams reveals that despite empirical evidence that water temperature and velocity play a critical interacting role in determining the outcome, most experiments have failed to elucidate the important mechanisms involved. Carefully designed experiments that compare the strength of interspecific versus intraspecific competition for different size classes will allow us to improve predictions about the effects of introduced salmonids on native species in streams.
Étude du spectre d'absorption du méthane 13CD4 dans la region de 1000 cm−1 analyse de la diade ν2/ν4
Authors: Pierre G. , Millot G. , Valentin A. , Henry L. , Foy B. , Steinfeld J. I.
Published: August 2009

The Fourier transform absorption spectrum of 13CD4 methane has been recorded from 924 to 1190 cm−1. The full width half maximum (3 × 10−3 cm−1) of the lines in the experimental spectrum is close to the Doppler–Fizeau width (2.7 × 10−3 cm−1) and the accuracy of the line frequency is better than 10−4 cm−1. The reduced effective Hamiltonian is formulated in terms of irreducible tensorial operators set in the Td group. With 1147 isolated infrared lines, we have determined 10 Hamiltonian parameters for the ground state up to sixth order and 30 parameters of the 0100 and 0001 vibrational states up to the fifth order of approximation. The standard deviation obtained is 10−4 cm−1.
Influences of riparian logging and in-stream large wood removal on pool habitat and salmonid density and biomass: a meta-analysis
Authors: Mellina Eric , Hinch Scott G.
Published: August 2009

We conducted a meta-analysis using data from 37 studies to assess whether the effects of streamside clear-cut logging on large wood (LW), pool size and number, and summertime salmonid density and standing crop biomass were influenced by stream size and gradient, time since logging was last conducted (1–100 years), and removal of in-stream LW. Age-specific (age 0 (fry) and age 1+ (juveniles)) and species-specific (coho salmon ( Oncorhynchus kisutch ), cutthroat trout ( Oncorhynchus clarki ), and steelhead and rainbow trout ( Oncorhynchus mykiss )) comparisons were also made. The majority of studies reported negative postlogging responses for LW and pool habitat but positive responses for salmonid density and biomass, with the greatest reductions in all variables generally associated with a thorough removal of in-stream LW. The magnitude of postlogging responses was largely independent of stream size, gradient, and time since logging last occurred. In terms of density and biomass, juveniles were more negatively affected by logging than fry. Of the surveyed species, steelhead trout appeared to be most resilient to riparian logging. Within the time frame covered by the analyses, streams whose riparian zones have been logged may be able to sustain salmonid populations (and even exceed preharvest levels) as long as rigorous removal of LW is not undertaken.
Attraction of the emerald ash borer to ash trees stressed by girdling, herbicide treatment, or wounding
Authors: McCullough Deborah G. , Poland Therese M. , Cappaert David
Published: August 2009

New infestations of emerald ash borer, Agrilus planipennis Fairmaire, an invasive pest native to Asia, are difficult to detect until densities build and symptoms appear on affected ash ( Fraxinus spp). We compared the attraction of A. planipennis to ash trees stressed by girdling (bark and phloem removed from a 15 cm wide band around the tree (2003–2005)), vertical wounding (same area of bark and phloem removed in a vertical strip (2004)), herbicide treatment (Pathway applied with a Hypo-Hatchet tree injector (2003) or basal bark application of Garlon 4 (2004, 2005)), exposure to the volatile stress elicitor methyl jasmonate (2005), or left untreated (2003–2005). The number and density of captured adults and density of larvae were recorded for 24, 18, and 18 replicates of each treatment at four, three, and five sites in 2003, 2004, and 2005, respectively. Girdled trees generally captured more adult A. planipennis and consistently had higher larval densities than untreated trees, and at most sites, than trees stressed by other treatments. Differential attraction to girdled trees was more pronounced at sites with lower densities of A. planipennis. Rates of capture of adults and densities of larvae were higher on trees in full or nearly full sun than on shaded trees. Girdled trees could be a useful tool for use in operational programs to detect or manage localized A. planipennis infestations.
Invasion of tallow tree into southern US forests: influencing factors and implications for mitigation
Authors: Gan Jianbang , Miller James H. , Wang Hsiaohsuan , Taylor John W.
Published: August 2009

We identify species–environment relationships to predict the occurrence of Chinese tallow ( Triadica sebifera (L.) Small) on forestlands in the southern US, where it has emerged as the most pervading, stand-replacing, alien tree species. Tallow invasions are more likely to be observed on low and flat lands, areas adjacent to water and roadways, sites recently harvested or disturbed, younger stands, and private forestlands. The winter extreme minimum temperature tends to restrain tallow northward migration. Increases in both range and severity of tallow invasions are predicted with a warming climate trend, and the situation could be worse if the warming is coupled with an increased frequency and intensity of disturbances. Monitoring and mitigation strategies are proposed to assist this region and other countries threatened by tallow invasions.
Response of ectomycorrhizal community structure to gap opening in natural and managed temperate beech-dominated forests
Authors: Grebenc Tine , Christensen Morten , Vilhar Urša , Čater Matjaž , Martín María P. , Simončič Primož , Kraigher Hojka
Published: August 2009

Data on the impact of forest management practices on ectomycorrhizal community structure remains fragmentary and mainly originates from studies in northern coniferous forests. This study focuses on a comparison of ectomycorrhizal communities between canopy gaps and closed canopy areas within natural and managed beech-dominated forests at four locations in Europe. We used high resolution rDNA techniques to identify ectomycorrhiza-forming fungi and attempted to extract potential stand-, gap-, soil-, and selected environmentally derived variables by applying multivariate analysis and ordination for pooling of ecological groups of ectomycorrhiza. A significant reduction of diversity indices, ectomycorrhizal and fine root dynamics, in gaps in comparison with closed canopy stands indicates an effect of forest management practice and the high importance of maintaining and protecting natural forest areas for conservation of soil biodiversity and forest genetic resources. The ordination analysis revealed three groups of ectomycorrhiza correlated with changing environmental conditions. The litter and soil pH, number of beech seedlings, and presence of a gap had a pronounced effect on the ectomycorrhizal community. Combined analysis of ectomycorrhiza and environmental factors using correspondence analysis provided an insight into the ecological preferences of the analysed species and confirmed that environmental factors drive ectomycorrhizal community changes.
Fire history of a central Nevada pinyon–juniper woodland
Authors: Bauer John M. , Weisberg Peter J.
Published: August 2009

Our study reconstructed fire history (1445–2006) from tree rings for a Great Basin single-needle pinyon pine ( Pinus monophylla Torr & Frém.) – Utah juniper ( Juniperus osteosperma (Torr.) Little) woodland. Information from multiple lines of evidence, including dateable fire scars (n = 83), tree demography, and charred coarse woody debris, was used to quantify fire frequency, severity, and extent. Fire cycle models were developed using survivorship analysis of time-since-fire estimates. We investigated the spatial and temporal variation in historical fire regime, addressing the plausibility of postsettlement fire exclusion as an explanation for increased woodland area and density since the late 1800s. Historical fire regime was characterized by infrequent, small, high-severity fires. Estimated fire cycle (1570–1880) was 427 years, with no evidence of postsettlement stand-replacing fires. Topographic analyses indicated that in this drought-prone landscape, more mesic conditions favor continuous fuels that lead to more frequent or extensive fire. Superposed epoch analysis showed increased fire occurrence during drought years but with no influence of antecedent climatic conditions. More frequent grassland and shrubland fires were recorded by fire scars near valley floors. Thus, anthropogenic fire exclusion in adjacent, shrub-dominated communities presents a plausible mechanism for woodland expansion in the study area. However, there is little ecological justification for reintroducing fire to areas of historic woodland, where effects of fire exclusion have been minimal.
ERRATA: "CONTINUITY OF A CLASS OF ENTROPIES AND RELATIVE ENTROPIES"
Authors: NAUDTS JAN
Published: August 2009

Conditions are given under which the inequality (B.1) of the cited paper is valid.
DETERMINATION OF CHROMIUM(VI) IN WATER BY PIXE ANALYSIS USING ION EXCHANGE PAPER — LIMIT OF DETECTION AND INTERFERENCE BY COEXISTING ANIONS
Authors: THOMYASIRIGUL SUREERAT , FUKUDA HITOSHI , HASEGAWA JUN , OGURI YOSHIYUKI
Published: August 2009

Concerning the PIXE analysis of Cr ( VI ) in water using ion-exchange filters, the limit of detection (LOD) and the influence of matrix anions were investigated. In order to look for the experimental condition for obtaining the minimum LOD, we measured the Cr - K α X-ray counts and background counts under the K α X-ray peak as a function of the incident proton energy and the thickness of the Mylar absorber foil in front of the detector. To investigate the interference by coexisting anions, each of PO 43-, SO 42-, NO 3-, Cl -, and F - ions and Cr ( VI ) ions were mixed in aqueous solutions and adsorbed on DE81-DEAE cellulose paper, a weakly basic anion exchanger with diethylaminoethyl functional groups. Then the filter samples were measured by PIXE using 2.5 MeV proton beams. We obtained a LOD of 0.16 µg or 8 ppb for 20 mL samples at a proton energy of 2.5 MeV and a Mylar film thickness of 50 or 100 µm. The experimental results on the mixed solutions indicated that NO 3-, Cl -, and F - as coexisting ions didn't interfere significantly with determination of a 50 µ g / L Cr ( VI ) concentration for 40 mL total solution volume, despite the total amount of anions was about 90% of ion exchange capacity of a filter. On the other hand, slight interferences by PO 43- ions were observed. However, under the same condition, we found that if the total amount of SO 42- ions was higher than 20% of ion exchange capacity, they induced significant interferences in determining Cr ( VI ).
STUDIES ON CHANGES OF ELEMENTAL CONCENTRATION IN A HUMAN BODY BY MEANS OF ANALYSES OF LONG HAIRS BASED ON THE STANDARD-FREE METHOD
Authors: SERA K. , TERASAKI K. , SASAKI T. , GOTOH S. , SAITOH Y. , ITOH J.
Published: August 2009

We established and reported two years ago the original methods for evaluating daily changes of elemental concentration in a body by means of a standard-free method for powdered beard samples daily taken with electric shaver. It was found that the method is quite useful for investigating short- and long-term changes of elemental concentration in a body. However, the method for beard analysis is applicable only to men. In order to estimate daily changes of elemental concentration in a body for women and children, a new method which allows us to quantitatively analyze hair samples cut into 1 mm pieces has been developed and applied to three long hair samples taken from three persons. It is found that the method enables us to estimate both long- and short-term changes in elemental concentration in a body as well as beard analysis. It is found that sulfur keeps almost constant over a long period, and arsenic shows very rapid changes with a few days' period, while mercury shows only long-term changes with the period of a few months. These behaviors are almost the same as those observed in beard analyses. On the other hand, bromine shows a certain seasonal changes; its concentration shows a certain trend of increasing in summer and decreasing in winter. Lead and calcium show very long-term changes, and the behavior of strontium is quite similar to that of calcium. The method is expected to give us information about history of changes in elemental concentration in a human body over a few or more years. It is expected that the behavior of arsenic showing rapid elevation within a few days can be explained as a response to intakes of arsenic-rich foods. It is expected that the method gives us a clue to the identification of the main pathways of human exposure to certain toxic elements.
3D IMAGING OF HUMAN CELLS BY USING PIXE-µ-CT
Authors: KAWAMURA Y. , ISHII K. , MATSUYAMA S. , NAKHOSTIN M. , FUJIWARA M. , WATANABE M. , OKURA S. , HAMADA N. , TSUBOI S. , YAMANAKA K. , HASHIMOTO Y. , FUJIKAWA M. , CATELLA G. , HATORI Y. , FUJIKI K. , YAMAZAKI H. , ORTEGA R. , DEVES G. , CARMONA A.
Published: August 2009

Particulate matter (PM) such as chromium compound ( PbCrO 4) is highly cytotoxic and carcinogenic. Several hexavalent chromium, compounds, Cr ( VI ), compounds are known to generate hydroxyl radical with in the cell and contribute to tissue damage. The way that theses compounds interact with human bodies at a cellular level is still unknown. To investigate the intracellular mechanism of chromium compounds, the 3D imaging techniques at the micro level are needed. In this paper, we report on the improvement of the PIXE-µ-CT system which was developed at Tohoku University and measured intracellular distribution images of PbCrO 4.particles on human lung cell.
IN-AIR MICRO-PIXE ANALYSIS FOR METAL ELEMENTS IN RAT HEPATOCYTES TREATED WITH FUCOIDAN
Authors: TAKADA H. , NAGAMINE T. , TOKITA Y. , OIKAWA M. , SATOH H. , KAMIYA T. , ARAKAWA K. , IHA M.
Published: August 2009

This study was undertaken to elucidate physiological properties of fucoidan extracted from Cladosiphon okamuranus TOKITA (C. okamuranus) and Fucus vesiculosus (F.vesilurosus). According to the data on MTT assay and TUNEL staining, F. vesiculosus possessed more anti-proliferate activity than C. okamuranus through apoptosis induction. We determined the metal contents of fucoidan to evaluate the relevance of metal elements in its biological effects. Al , Fe and Zn levels were significantly increased in F. vesiculosus than in C. okamuranus. The intracellular changes of metal elements following the administration of fucoidan was analyzed by in-air micro-PIXE in TRL1215 cells (normal rat liver cell line). At 24 h after 5-bromo-2'-deoxyuridine ( BrdU ) dosing, TRL1215 cells were treated with 1.0 mg/mL of each fucoidan for 9 h. The X-ray spectra showed that F. vesiculosus-treated cells markedly increased the yield of aluminum ( Al ) compared to those of C. okamuranus -treated cells and the control. In F. vesiculosus -treated cells, the focal accumulation of Br was spatially correlated with Al map, suggesting that Al was localized within the nucleus. These findings suggest that F. vesiculosus fucoidan increases the accumulations of Al in rat hepatocytes, which may participate in anti-proliferate activity of this fucoidan.
MEASUREMENT OF GERMANIUM ESCAPE PEAKS IN PIXE SPECTRA RECORDED USING HIGH PURITY Ge (HPGe) DETECTOR
Authors: KUMAR SANJIV , REDDY G. L. N. , RAJU V. S.
Published: August 2009

This paper deals with studies on Ge K α and K β escape peaks in particle induced X-ray emission (PIXE) spectra recorded by a high purity germanium (HPGe) detector. A knowledge of the energies and intensities of these escape peaks is desirable for accurate qualitative as well as quantitative analysis of elements by PIXE. The spectral interferences caused by Ge K escape peaks in the determination of Fe in U by PIXE are highlighted for illustration. A simple theoretical approach based on the production of Ge K X-rays inside the Ge crystal of the detector during the process of detection of the incident characteristic X-rays and the subsequent escape of a fraction of the produced radiations from the crystal, is described to calculate the intensity ratio of the Ge escape peak to its parent characteristic X-rays. The calculated values are in agreement with the experimental values and those estimated using the formulation provided in GUPIX software for PIXE. The Ge K escape peaks are very prominent; the intensities of Ge K α escape peaks, from bromine to silver, range from 15% to 6% of those of their respective K α X-rays. These intensities are, in general, considerably higher compared to those of Si escape peaks in spectra recorded by Si ( Li ) detector. Ge K escape peaks therefore may give rise to severe interferences. The present approach provides a precise (~8%) determination of the intensity of an escape peak and thereby facilitates a reliable PIXE analysis.
TEST OF EFFECT FROM FUTURE IN LARGE HADRON COLLIDER: A PROPOSAL
Authors: NIELSEN HOLGER B. , NINOMIYA MASAO
Published: August 2009

We have previously proposed the idea of performing a card-drawing experiment of which the outcome potentially decides whether the Large Hadron Collider (LHC) should be closed or not. The purpose is to test theoretical models such as our own model that have an action with an imaginary part that has a similar form to the real part. The imaginary part affects the initial conditions not only in the past but even from the future. It was speculated that all the accelerators producing large amounts of Higgs particles such as the Superconducting Super Collider (SSC) would mean that the initial conditions must have been arranged so as not to allow these accelerators to work. If such effects existed, we could perhaps cause a very clear-cut "miracle" by having the effect of a drawn card to be the closure of the LHC. Here we shall, however, argue that the closure of an accelerator is hardly needed to demonstrate such an effect and seek to calculate how one could perform a verification experiment for the proposed type of effect from the future in the statistically least disturbing and least harmful way.

We shall also discuss how to extract the maximum amount of information about such as effect or model in the unlikely case that a card preventing the running of the LHC or the Tevatron is drawn, by estimating the relative importance of high beam energy or high luminosity for the purpose of our effect.
INFLATION FROM THE SUPERSTRING VACUUM
Authors: POLLOCK M. D.
Published: August 2009

Quartic higher-derivative gravitational terms in the effective Lagrangian of the heterotic superstring theory renormalize the bare, four-dimensional gravitational coupling [Formula: see text], due to the reduction process [Formula: see text], according to the formula [Formula: see text], where A r and B r are the moduli for the physical space gij(xk) and internal space [Formula: see text], respectively. The Euler characteristic [Formula: see text] is negative for a three-generation Calabi–Yau manifold, and therefore both the additional terms, of tree-level and one-loop origin, produce a decrease in κ-2, which changes sign when κ-2 = 0. The corresponding tree-level critical point is [Formula: see text], if we set [Formula: see text] and λ = 15π2, for compactification onto a torus. Values [Formula: see text] yield the anti-gravity region κ-2 < 0, which is analytically accessible from the normal gravity region κ-2 > 0. The only non-singular, vacuum minimum of the potential [Formula: see text] is located at the point [Formula: see text], where [Formula: see text], the quadratic trace anomaly [Formula: see text] dominates over [Formula: see text], and a phase of de Sitter expansion may occur, as first envisaged by Starobinsky, in approximate agreement with the constraint due to the effect of gravitational waves upon the anisotropy of the cosmic microwave background radiation. There is no non-singular minimum of the potential [Formula: see text].
A COVARIANT APPROACH TO THE GENERALIZED MULTI-INFLATON COSMOLOGICAL PERTURBATION
Authors: LAHIRI JOYDEV , BHATTACHARYA GAUTAM
Published: August 2009

Following the formalism developed in Astrophys. J.375, 443 (1991), differential equations for the gauge invariant scalar part of the metric perturbation in the Friedmann–Robertson–Walker background with multiple inflatons with arbitrary field metric are obtained without any specific choice of gauge. Subsequently, an algorithm for the solution of these equations in the slow-roll approximation is given without any prior choice of the basis system in the field manifold. Vector and tensor perturbations are also briefly reviewed.
INFLUENCE OF GAUGE BOSON MASS ON FERMION CHIRAL CONDENSATE IN QED3
Authors: LI JIAN-FENG , FENG HONG-TAO , SUN WEI-MIN , ZONG HONG-SHI
Published: August 2009

For the number of fermion flavors N = 2, we numerically solve the coupled Dyson–Schwinger equation for the fermion and gauge boson propagators of QED3 using the fermion–gauge-boson vertex ansatz [Formula: see text] for a range of finite gauge boson mass ζ and chemical potential μ. For small chemical potential μ it is found that chiral symmetry gets restored when ζ is larger than a critical mass ζc and the value of ζc is not sensitive to the variation of chemical potential.
GRAVITATIONAL INSTANTON AND COSMOLOGICAL TERM
Authors: XUE SHE-SHENG
Published: August 2009

Quantum fluctuation of unstable modes about gravitational instantons causes the instability of flat space at finite temperature, leading to the spontaneous process of nucleating quantum black holes. The energy-density of quantum black holes, depending on the initial temperature, gives the cosmological term, which naturally accounts for the inflationary phase of the early universe. The reheating phase is attributed to the Hawking radiation and annihilation of these quantum black holes. Then, the radiation energy-density dominates over the energy-density of quantum black holes, the universe started the standard cosmology phase. In this phase the energy-density of quantum black holes depends on the reheating temperature. It asymptotically approaches to the cosmological constant in matter domination phase, consistently with current observations.
CROSSTALK FACILITATES SPATIAL SIGNAL PROPAGATION THROUGH MAPK CASCADES
Authors: ZHANG YANBIN , CHEN KENIAN , WANG JUNWEI , CHEN AIMIN , ZHAO MEICHUN , ZHOU TIANSHOU
Published: August 2009

In intracellular mitogen-activated protein kinase (MAPK) cascades, it has been shown that signals can be propagated across the cell cytosol in the form of phosphoprotein waves arising from the bistable response of MAPK to active MAPK kinase. Without such a bistable response, however, they can not propagate into distant cell compartments, although a long positive feedback endows a mechanistically-distinct bistable response of MAPK to extracellular signal. Here we provide a compensate means that uses crosstalk between parallel identical pathways of MAPK cascades. For a spherical cell, we find that both unidirectional and bidirectional crosstalk with enhancement of phosphorylation can facilitate phosphoprotein signal propagation from the plasma membrane to the periphery of cell nucleus. Moreover, different shallow spatial gradients of biphosphorylated MAPK occur in the cytosol under different strengths of pathway interactions. These results suggest that crosstalk would be utilized by living organisms for spatial information transfer and cellular decision-making processing.
NONLINEAR DYNAMICS OF CELL CYCLES WITH STOCHASTIC MATHEMATICAL MODELS
Authors: MELNIK RODERICK V. N. , WEI XILIN , MORENO–HAGELSIEB GABRIEL
Published: August 2009

Cell cycles are fundamental components of all living organisms and their systematic studies extend our knowledge about the interconnection between regulatory, metabolic, and signaling networks, and therefore open new opportunities for our ultimate efficient control of cellular processes for disease treatments, as well as for a wide variety of biomedical and biotechnological applications. In the study of cell cycles, nonlinear phenomena play a paramount role, in particular in those cases where the cellular dynamics is in the focus of attention. Quantification of this dynamics is a challenging task due to a wide range of parameters that require estimations and the presence of many stochastic effects. Based on the originally deterministic model, in this paper we develop a hierarchy of models that allow us to describe the nonlinear dynamics accounting for special events of cell cycles. First, we develop a model that takes into account fluctuations of relative concentrations of proteins during special events of cell cycles. Such fluctuations are induced by varying rates of relative concentrations of proteins and/or by relative concentrations of proteins themselves. As such fluctuations may be responsible for qualitative changes in the cell, we develop a new model that accounts for the effect of cellular dynamics on the cell cycle. Finally, we analyze numerically nonlinear effects in the cell cycle by constructing phase portraits based on the newly developed model and carry out a parametric sensitivity analysis in order to identify parameters for an efficient cell cycle control. The results of computational experiments demonstrate that the metabolic events in gene regulatory networks can qualitatively influence the dynamics of the cell cycle.
EFFECTS OF MUTATION OPERATORS ON DEVELOPMENTAL BIAS IN ARTIFICIAL CELL LINEAGES
Authors: LIN XIANGHONG , ZHANG TIANWEN
Published: August 2009

This paper is no longer available. Please contact "jbs@wspc.com"
A METHODOLOGY FOR THE STOCHASTIC MODELING AND SIMULATION OF SYMPATRIC SPECIATION BY SEXUAL SELECTION
Authors: BARBUTI ROBERTO , MAGGIOLO-SCHETTINI ANDREA , MILAZZO PAOLO , TROINA ANGELO
Published: August 2009

In the evolution literature, sympatric speciation is the origin of two, or more, species from a single local population. Many models have been developed to study the role of ecological competition and sexual selection in sympatric speciation.

In this paper we propose a methodology for systematically deriving efficient computational models to study speciation in populations evolving with overlapping generations. As a particular case, we consider sympatric speciation by sexual selection and we follow an individual based approach: a population is represented as a set of individuals that can mate and survive according to given probabilities.

We use our methodology to construct four different models for sympatric speciation, based on male traits and female preferences. These models differ in the genotypical representation of the individuals. Results of simulations in the different models are shown and discussed.

The study of the models show that sympatric speciation by sexual selection is unlikely, also with a favorable distribution of genotypes in the initial population.
ANALYTIC CONTINUATION OF NONANALYTIC VECTOR-VALUED EISENSTEIN SERIES
Authors: TAYLOR KAREN
Published: August 2009

In this paper, we introduce a vector-valued nonanalytic Eisenstein series appearing naturally in the Rankin–Selberg convolution of a vector-valued modular cusp form associated to a monomial representation ρ of SL(2,ℤ). This vector-valued Eisenstein series transforms under a representation χρ associated to ρ. We use a method of Selberg to obtain an analytic continuation of this vector-valued nonanalytic Eisenstein series to the whole complex plane.
MODULAR LATTICES OVER CM FIELDS
Authors: SUAREZ IVAN
Published: August 2009

We study some properties of Arakelov-modular lattices, which are particular modular ideal lattices over CM fields. There are two main results in this paper. The first one is the determination of the number of Arakelov-modular lattices of fixed level over a given CM field provided that an Arakelov-modular lattice is already known. This number depends on the class numbers of the CM field and its maximal totally real subfield. The first part gives also a way to compute all these Arakelov-modular lattices. In the second part, we describe the levels that can occur for some multiquadratic CM number fields.
SUPERSINGULAR RANK TWO DRINFEL'D MODULES AND ANALOGS OF ATKIN'S ORTHOGONAL POLYNOMIALS
Authors: DOBI DORIS , WAGE NICHOLAS , WANG IRENA
Published: August 2009

The theory of elliptic curves and modular forms provides a precise relationship between the supersingular j-invariants and the congruences between modular forms. Kaneko and Zagier discuss a surprising generalization of these results in their paper on Atkin orthogonal polynomials. In this paper, we define an analog of the Atkin orthogonal polynomials for rank two Drinfel'd modules.
An Astronomical Life Salted by Pure Chance
Authors: Kraft Robert P.
Published: August 2009

My childhood upbringing in no way suggested that I would become an astronomer, but accidents of fate pushed me in the direction of science, and I have benefited greatly from being in the right place at the right time. I grew up in Seattle, earned B.S. and M.S. degrees in mathematics at the University of Washington, and eventually a Ph.D. in astronomy from the University of California, Berkeley. I was a postdoc at the Mt. Wilson Observatory, an assistant professor at Indiana University, later the Yerkes Observatory (University of Chicago), and still later I became a staff member of the Mt. Wilson and Palomar Observatories. After several years, I returned to the University of California, this time with the Lick Observatory staff at its new academic home on the Santa Cruz campus, where I have been ever since. My research has focused on the relation of Cepheids and RR Lyrae stars to problems of Galactic structure, the binary nature of cataclysmic variables, the decay of angular momentum of solar type stars, and the chemical history of the Galaxy as revealed by the abundances of very old stars in globular clusters and the Galactic halo field. None of this work would have been possible without the help of excellent teachers and mentors, great colleagues, and superb postdocs and graduate students. Most of all, I am grateful for the educational opportunities afforded me by state-supported public Universities.
Magnetic Fields of Nondegenerate Stars
Authors: Donati J.-F. , Landstreet J.D.
Published: August 2009

Magnetic fields are present in a wide variety of stars throughout the HR diagram and play a role at basically all evolutionary stages, from very-low-mass dwarfs to very massive stars, and from young star-forming molecular clouds and protostellar accretion discs to evolved giants/supergiants and magnetic white dwarfs/neutron stars. These fields range from a few μG (e.g., in molecular clouds) to TG and more (e.g., in magnetic neutron stars); in nondegenerate stars in particular, they feature large-scale topologies varying from simple nearly axisymmetric dipoles to complex nonaxsymmetric structures, and from mainly poloidal to mainly toroidal topologies. After recalling the main techniques of detecting and modeling stellar magnetic fields, we review the existing properties of magnetic fields reported in cool, hot, and young nondegenerate stars and protostars, and discuss our understanding of the origin of these fields and their impact on the birth and life of stars.
The Functional Annotation of Mammalian Genomes: The Challenge of Phenotyping
Authors: Brown Steve D.M. , Wurst Wolfgang , Kühn Ralf , Hancock John M.
Published: August 2009

The mouse is central to the goal of establishing a comprehensive functional annotation of the mammalian genome that will help elucidate various human disease genes and pathways. The mouse offers a unique combination of attributes, including an extensive genetic toolkit that underpins the creation and analysis of models of human disease. An international effort to generate mutations for every gene in the mouse genome is a first and essential step in this endeavor. However, the greater challenge will be the determination of the phenotype of every mutant. Large-scale phenotyping for genome-wide functional annotation presents numerous scientific, infrastructural, logistical, and informatics challenges. These include the use of standardized approaches to phenotyping procedures for the population of unified databases with comparable data sets. The ultimate goal is a comprehensive database of molecular interventions that allows us to create a framework for biological systems analysis in the mouse on which human biology and disease networks can be revealed.
Maize Centromeres: Structure, Function, Epigenetics
Authors: Birchler James A. , Han Fangpu
Published: August 2009

The ability of centromeres to organize the kinetochore has an epigenetic component in that DNA sequence alone does not necessarily serve as the determinant of activity. The centromeres of maize have been well characterized with regard to the sequence repeats present at all primary constrictions. The supernumerary B chromosome centromere contains an additional specific repeat that is represented in the active core and that allows it to be studied against the background of the other centromeres. The foundational proteins of the kinetochore have been characterized, and an RNA component has been defined. Numerous examples of inactive centromeres have been characterized for both A and B chromosomal centromeres indicating the ease with which plant centromeres become inactive. Under some circumstances, inactive centromeres can exhibit reactivation at their formerly inactive sites. This observation suggests that a DNA-based topological component also operates for centromere identity.
Gamma-Ray Bursts in theSwiftEra
Authors: Gehrels N. , Ramirez-Ruiz E. , Fox D.B.
Published: August 2009

With its rapid-response capability and multiwavelength complement of instruments, the Swift satellite has transformed our physical understanding of γ-ray bursts (GRBs). Providing high-quality observations of hundreds of bursts, and facilitating a wide range of follow-up observations within seconds of each event, Swift has revealed an unforeseen richness in observed burst properties, shed light on the nature of short-duration bursts, and helped realize the promise of GRBs as probes of the processes and environments of star formation out to the earliest cosmic epochs. These advances have opened new perspectives on the nature and properties of burst central engines, interactions with the burst environment from microparsec to gigaparsec scales, and the possibilities for nonphotonic signatures. Our understanding of these extreme cosmic sources has thus advanced substantially; yet, more than 40 years after their discovery, GRBs continue to present major challenges on both observational and theoretical fronts.
Bicarbonate homeostasis in excitable tissues: role of AE3 Cl−/HCO3− exchanger and carbonic anhydrase XIV interaction
Authors: Casey Joseph R. , Sly William S. , Shah Gul N. , Alvarez Bernardo V.
Published: August 2009

Bicarbonate transport and metabolism are key elements of normal cellular function. Two alternate transcripts of anion exchanger 3 (AE3), full-length (AE3fl) and cardiac (AE3c), are expressed in central nervous system (CNS), where AE3 catalyzes electroneutral Cl−/HCO3− exchange across the plasma membrane of neuronal and glial cells of CNS. Anion exchanger isoforms, AE3fl and AE3c, associate with the carbonic anhydrases (CA) CAII and CAIV, forming a HCO3− transport metabolon, to maximize HCO3− flux across the plasma membrane. CAXIV, with catalytic domain anchored to the extracellular surface, is also expressed in CNS. Here physical association of AE3 and CAXIV was examined by coimmunoprecipitation experiments, using mouse brain and retinal lysates. CAXIV immunoprecipitated with anti-AE3 antibody, and both AE3 isoforms were immunoprecipitated using anti-CAXIV antibody, indicating CAXIV and AE3 interaction in the CNS. Confocal images revealed colocalization of CAXIV and AE3 in Müller and horizontal cells, in the mouse retina. Cl−/HCO3− exchange activity of AE3fl was investigated in transiently transfected human embryonic kidney 293 cells, using intracellular fluorescence measurements of BCECF, to monitor intracellular pH. CAXIV increased the rate of AE3fl-mediated HCO3− transport by up to 120%, which was suppressed by the CA inhibitor acetazolamide. Association of AE3 and CAXIV may represent a mechanism to enhance disposal of waste CO2 and to balance pH in excitable tissues.