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  • 1
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    Measurements of the Higgs boson production and decay rates and constraints on its couplings from a combined ATLAS and CMS analysis of the LHC pp collision data at s = 7 $$ sqrt{s}=7 $$ and 8 TeV (2016)
    Springer
    Details
    Publication Date: 2016-08-01
    Print ISSN: 1126-6708
    Electronic ISSN: 1029-8479
    Topics: Physics
    Published by Springer
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    PAPER CURRENT
  • 2
    Electronic Resource
    Electronic Resource
    DNA fingerprints of a gorgonian coral: a method for detecting clonal structure in a vegetative species (1992)
    Springer
    Marine biology 114 (1992), S. 317-325 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clonal reproduction, a common life history strategy among sessile marine invertebrates, can lead to high local abundances of one to a few genotypes in a population. Analysis of the clonal structure of such populations can provide insight into the ecological and evolutionary history of the population, but requires markers that can identify individual genets. Forensic and demographic studies have demonstrated that DNA fingerprinting can provide markers that are unique for an individual genotype. We have generated DNA fingerprints for over 70 colonies of the clonal gorgonian, Plexaura A (Plexaura sp. A) collected from June 1990 through July 1991 in the San Blas Islands, Panama. DNA fingerprints within a singic individual were identical and fingerprinting resolved multiple genotypes within and among reefs. On one reef in the San Blas Islands, Panama, 59% of the colonies sampled were of one genotype and this genotype was not found on any other sampled reefs. A previous study using tissue grafts identified 13 putative clones on these reefs, while DNA fingerprints of the same colonies differentiated 17 genotypes. The present study demonstrates the utility of DNA fingerprinting for distinguishing clones and for identifying clonal structure of marine invertebrate populations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00349534
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  • 3
    Electronic Resource
    Electronic Resource
    Discrimination of monovalent inorganic cations by “tight” junctions of gallbladder epithelium (1974)
    Springer
    The journal of membrane biology 15 (1974), S. 277-318 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Relative permeability coefficients (P's) for Li+, Na+, K+, Rb+, Cs+, NH 4 + and Tl+ have been measured in gallbladders of several animal species. Small differences are observed among individual animals of the same species in theP values for a given ion. Individual variations inP values of different ions are closely correlated, permitting construction of so-called selectivity isotherms. Exposure to pH 4 reversibly shiftsP values along the same isotherms as those defined by individual variation. Changes in partial conductances with pH indicate that cation conductance is controlled by acidic sites with an apparent pK a value near 4.5, anion conductance by basic sites with an apparent pK a value below 3. Isotherms for rabbit gallbladder and bullfrog gallbladder are quite similar, and the small differences between them are probably attributable to a narrower permeation channel in rabbit in bullfrog. Permeability ratios for eight other epithelia with leaky “tight junctions” fall close to the isotherms for rabbit and bullfrog gallbladders. The observed isotherms, sequences, and pH-dependence of alkali cation permeability are strikingly consistent with Eisenman's interpretation that selectivity is controlled by site field strength. Variation inP Tl andP NH4 is also correlated with variation in site field strength. Comparison with isotherms or “selectivity fingerprints” for glass electrodes and macrocyclic carriers suggests that the permeation channel in gallbladder tight junctions is highly hydrated; and that sites in the gallbladder may possess net charge and may not be in a precisely regular spatial array.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01870092
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  • 4
    Electronic Resource
    Electronic Resource
    Molecular motion of small nonelectrolyte molecules in lecithin bilayers (1978)
    Springer
    The journal of membrane biology 40 (1978), S. 315-342 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary We have used magnetic resonance spectroscopy, both ESR and13C spin relaxation, to measure translational and rotational mobilities and partition coefficients of small nitroxide solutes in dipalmitoyl lecithin liposomes. Above the bilayer transition temperature,T c, the bilayer interior is quite fluid, as determined from the solutes' rapid rotational and moderately rapid translational motion; the rotational and translational viscosities within the bilayer are η R 〈1cP and ητ=6−10cP, respectively. ητ and η R are independent of molecular size for all solutes studied, but all were small compared to the size of the phospholipids. ητ, and probably η R , are relatively independent of temperature aboveT c, but both increase very sharply as temperature is lowered belowT c; at 32°C, η R increases to 6cP and ητ is greater than 1000 cP. Anisotropy of rotational motion increases gradually as temperature is lowered toT c, and changes little belowT c; anisotropy of translational motion was not investigated.13C nuclear spin relaxation measurements indicate that translational motion of nitroxide solutes is more rapid in the center of the bilayer than near the polar interface. It takes at least 100 nsec for a solute molecule to cross the bilayer/water interface. We estimate a lower limit of 2 sec/cm for the interfacial resistance to solute diffusion; this result indicates that interfacial resistance dominates permeation across the membrane. The relative solubility, or partition coefficient, is a strong function of solute structure, and decreases abruptly on cooling through the transition temperature. From the partition coefficient and its temperature dependence we calculate the free energy, enthalpy, and entropy of partition. Effects of cholesterol on partition and diffusion coefficients are compatible with the interpretation that bilayers containing cholesterol consist of two phases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01874162
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  • 5
    Electronic Resource
    Electronic Resource
    An estimate of the salt concentration in the lateral intercellular spaces of rabbit gall-bladder during maximal fluid transport (1969)
    Springer
    The journal of membrane biology 1 (1969), S. 194-213 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The ability of the gall-bladder to transport water between identical bathing solutions depends on active NaCl transport, which is thought to maintain the salt concentration in the lateral intercellular spaces above bathing solution levels and thus to create a local osmotic gradient. The mean value of this gradient has been estimated by an electrical procedure, based on measuring the small diffusion potential resulting from this gradient and from the preferential cation permeability of the gall-bladder. The electrical potential difference (p.d.) in maximally transporting rabbit gall-bladders is 1.4 mV, mucosal-solution positive to serosal solution. This p. d. is reversibly abolished or greatly reduced by six procedures which abolish or greatly reduce fluid transport (low temperature, replacement of Cl− by SO 4 -- , replacement of Cl− and HCO 3 − by SO 4 -- , replacement of Na+ by choline, removal of HCO 3 − , and metabolic poisoning). The p. d. is increased by symmetrical partial replacement of NaCl by sucrose, which is expected to increase the salt concentration gradient between the lateral spaces and the bathing solutions. Since the transport mechanism of the gall-bladder is a neutral NaCl pump that cannot produce a p. d. directly, it is concluded that the observed p. d. is the expected diffusion potential. From this diffusion potential and from the measured value of a diffusion potential resulting from a known NaCl concentration gradient, the mean concentration of NaCl in the lateral spaces is calculated to be of the order of 10mm above the bathing solution value. Comparison of the external osmotic gradient required to stop water flow with the p. d. recorded under this condition of zero flow supports the validity of interpreting the p.d. in this fashion as a measure of the excess local salt concentration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869781
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  • 6
    Electronic Resource
    Electronic Resource
    Comparison of nonelectrolyte permeability patterns in several epithelia (1972)
    Springer
    The journal of membrane biology 10 (1972), S. 93-135 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Reflection coefficients (σ's) have been determined for 13 to 36 non-electrolytes in goldfish gallbladder, bullfrog gallbladder, bullfrog intestine, and guineapig intestine. These results have been compared with the results of similar previous studies in rabbit gallbladder, bullfrog choroid plexus, and guinea-pig gallbladder to determine types of species variation, organ variation, and individual variation. Two principal types of variation were established: (1) Branched solutes are much less permeant than straight-chain analogues in gallbladders of all four species studied, whereas this effect is small in intestine and negligible in choroid plexus. This variation in degree of discrimination against branched solutes is attributed to variation in closeness of packing of membrane lipids. (2) In certain epithelia, small polar solutes are more permeant than expected from their bulk nonpolar-solvent/water partition coefficients and from their size. This feature is very marked in rabbit gallbladder, somewhat marked in guineapig gallbladder and intestine and in bullfrog choroid plexus, apparent mainly just for formamide (the smallest polar nonelectrolyte) in bullfrog intestine, and virtually absent in goldfish and bullfrog gallbladders. Analysis of individual variability in preparations of guinea-pig intestine and rabbit gallbladder from different animals shows covariation in σ's of small polar nonelectrolytes uncorrelated with variation in σ's of other solutes. Small polar solutes, in epithelia where their permeability is as expected from size and from nonpolar-solvent/water partition coefficients, resemble other solutes in having markedly temperature-dependent σ's (high apparent activation energies of permeation), but have nearly temperature-independent σ's (low activation energies, as for diffusion in aqueous solution) in epithelia where their permeability is enhanced. These findings suggest that additional size-restricted permeation pathways by-passing membrane lipid (“pores”) are present in some tissues and smaller or virtually absent in others.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01867849
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  • 7
    Electronic Resource
    Electronic Resource
    Na+ transport by rabbit urinary bladder, a tight epithelium (1976)
    Springer
    The journal of membrane biology 28 (1976), S. 1-40 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary By in vitro experiments on rabbit bladder, we reassessed the traditional view that mammalian urinary bladder lacks ion transport mechanisms. Since the ratio of actual-to-nominal membrane area in folded epithelia is variable and hard to estimate, we normalized membrane properties to apical membrane capacitance rather than to nominal area (probably 1 μF ∼ 1 cm2 actual area). A new mounting technique that virtually eliminates edge damage yielded resistances up to 78,000 ΩμF for rabbit bladder, and resistances for amphibian skin and bladder much higher than those usually reported. This technique made it possible to observe a transport-related conductance pathway, and a close correlation between transepithelial conductance (G) and short-circuit current (I sc) in these tight epithelia.G andI sc were increased by mucosal (Na+) [I sc∼0 when (Na+)∼0], aldosterone, serosal (HCO 3 − ) and high mucosal (H+); were decreased by amiloride, mucosal (Ca++), ouabain, metabolic inhibitors and serosal (H+); and were unaffected by (Cl−) and little affected by antidiuretic hormone (ADH). Physiological variation in the rabbits' dietary Na+ intake caused variations in bladderG andI sc similar to those caused by the expectedin vivo changes in aldosterone levels. The relation betweenG andI sc was the same whether defined by diet changes, natural variation among individual rabbits, or most of the above agents. A method was developed for separately resolving conductances of junctions, basolateral cell membrane, and apical cell membrane from thisG−I sc relation. Net Na+ flux equalledI sc. Net Cl− flux was zero on short circuit and equalled only 25% of net Na+ flux in open circuit. Bladder membrane fragments contained a Na+−K+-activated, ouabain-inhibited ATPase. The physiological significance of Na+ absorption against steep gradients in rabbit bladder may be to maintain kidney-generated ion gradients during bladder storage of urine, especially when the animal is Na+-depleted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869689
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  • 8
    Electronic Resource
    Electronic Resource
    The mechanism of Na+ transport by rabbit urinary bladder (1976)
    Springer
    The journal of membrane biology 28 (1976), S. 41-70 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The mechanism of Na+ transport in rabbit urinary bladder has been studied by microelectrode techniques. Of the three layers of epithelium, the apical layer contains virtually all the transepithelial resistance. There is radial cell-to-cell coupling within this layer, but there is no detectable transverse coupling between layers. Cell coupling is apparently interrupted by intracellular injection of depolarizing current. The cell interiors are electrically negative to the bathing solutions, but the apical membrane of the apical layer depolarizes with increasingI sc. Voltage scanning detects no current sinks at the cell junctions or elsewhere. The voltage-divider ratio, α, (ratio of resistance of apical cell membrane,R a, to basolateral cell membrane,R b) decreases from 30 to 0.5 with increasingI sc, because of the transportrelated conductance pathway in the apical membrane. Changes in effective transepithelial capacitance withI sc are predicted and possibly observed. The transepithelial resistance,R t, has been resolved intoR a, Rb, and the junctional resistance,R j, by four different methods: cable analysis, resistance of uncoupled cells, measurements of pairs of (R t, α) values in the same bladder at different transport rates, and the relation betweenR t andI sc and between α andI sc.R j proves to be effectively infinite (nominally 300 kΩ μF) and independent ofI sc, andR a decreases from 154 to 4 kΩ μF with increasingI sc. In the resulting model of Na+ transport in “tight” epithelia, the apical membrane contains an amiloride-inhibited and Ca++-inhibited conductance pathway for Na+ entry; the basolateral membrane contains a Na+−K+-activated ATPase that extrudes Na+; intracellular (Na+) may exert negative feedback on apical membrane conductance; and aldosterone acts to stimulate Na+ entry at the apical membrane via the amiloride-sensitive pathway.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869690
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  • 9
    Electronic Resource
    Electronic Resource
    Lithium's inhibition of erythrocyte cation countertransport involves a slow process in the erythrocyte (1983)
    Springer
    The journal of membrane biology 75 (1983), S. 233-240 
    Details
    ISSN: 1432-1424
    Keywords: countertransport ; erythrocyte ; lithium ; manicdepressive illness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Chronic administration of lithium (Li+) to human subjects results in reduction of Li+/Na+ countertransport in their erythrocytes (RBC). The time course of development of inhibition is much slower than one would expect for an immediate effect of Li+ on the RBC membrane. Possible explanations include pharmacokinetic delays, a mediating humoral agent, and a slow process in the RBC. To discriminate among these possibilities, we incubated human RBC in sterile culture by the method of Freedman (Freedman, J. C. 1983J. Membrane Biol. 75:225–231), which permits much longer incubations than other methods. As gauged by eight measures, the incubated RBC remain viable for two weeks. Small changes in intracellular concentrations with time during incubation are in the same direction as the changes associated with natural aging of RBCin vivo, except for a rise in ATP and related cation shifts during the first few days of incubation. Treatment of incubated RBC with 2mm Li+ inhibits countertransport by 48% without affecting Li+ leak efflux. The inhibition develops slowly: it is half-maximal after 1–2 days and maximal by 4–7 days. Differences betweenin vivo results and our incubated cells in the time course of inhibition are as expected from the pharmacokinetic delays operatingin vivo. The inhibition is reversible on removing Li+. Li+ inhibits countertransport similarly slowly and to a similar degree from inside the RBC and from outside. Hence the slow time course of inhibitionin vivo is not due to a humoral factor or to the time required for intracellular Li+ accumulation and is only partly due to pharmacokinetic delays. The delay must involve an unidentified slow process at the level of the RBC.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01871954
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  • 10
    Electronic Resource
    Electronic Resource
    Studies of sodium channels in rabbit urinary bladder by noise analysis (1984)
    Springer
    The journal of membrane biology 80 (1984), S. 135-151 
    Details
    ISSN: 1432-1424
    Keywords: Na+ channels ; channel turnover ; fluctuation analysis ; tight epithelium ; mammalian urinary bladder
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Sodium channels in rabbit urinary bladder were studied by noise analysis. There are two components of short-circuit current (I sc) and correspondingly two components of apical Na+ entry, one amiloride-sensitive (termedI A and the A channel, respectively) and one amiloride-insensitive (I L and the leak pathway, respectively). The leak pathway gives rise tol/f noise, while the A channel in the presence of amiloride gives rise to Lorentzian noise. A two-state model of the A channel accounts well for how the corner frequency and plateau value of Lorentzian noise vary with amiloride concentration. The single-channel current is 0.64 pA, and the conducting channel density is on the order of 40 copies per cell. Triamterene blocks the A channel alone, and increasing external Na+ decreases the number but not the single-channel permeability of the A channel. Hydrostatic pressure pulses (“punching”) increase the number of both pathways. Repeated washing of the mucosal surface removes most of the leak pathway without affecting the A channel. Properties of the A channel revealed by noise analysis of various tight epithelia are compared, and the mechanism ofl/f noise is discussed. It is suggested that the A channel is synthesized intracellularly, stored in intracellular vesicles, transferred with or from vesicular membrane into apical membrane under the action of microfilaments, and degraded into the leak pathway, which is washed out into urine or destroyed. The A channel starts withP Na/P K∼30 and loses selectivity in stages untilP Na/P K reaches the free-solution mobility ratio (∼0.7) for the leak pathway. This turnover cycle functions as a mechanism of repair and regulation for Na+ channels, analogous to the repair and regulation of most intracellular proteins by turnover. Vesicular delivery of membrane channels may be operating in several other epithelia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01868770
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