541 research outputs found

    Nucleotide Sequence and Expression in Escherichia coli of the Lactococcus lactis Citrate Permease Gene

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    The plasmid-encoded citrate determinant of the Lactococcus lactis subsp. lactis var. diacetylactis NCDO176 was cloned and functionally expressed in a Cit- Escherichia coli K-12 strain. From deletion derivative analysis, a 3.4-kilobase region was identified which encodes the ability to transport citrate. Analysis of proteins encoded by the cloned fragment in a T7 expression system revealed a 32,000-dalton protein band, which correlated with the ability of cells to transport citrate. Energy-dependent [1,5-14C]citrate transport was found with membrane vesicles prepared from E. coli cells harboring the citrate permease-expressing plasmid. The gene encoding citrate transport activity, citP, was located on the cloned fragment by introducing a site-specific mutation that abolished citrate transport and resulted in a truncated form of the 32,000-dalton expression product. The nucleotide sequence for a 2.2-kilobase fragment that includes the citP gene contained an open reading frame of 1,325 base pairs coding for a very hydrophobic protein of 442 amino acids, which shows no sequence homology with known citrate carriers

    The differential analytic index in Simons-Sullivan differential K-theory

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    We define the Simons-Sullivan differential analytic index by translating the Freed-Lott differential analytic index via explicit ring isomorphisms between Freed-Lott differential K-theory and Simons-Sullivan differential K-theory. We prove the differential Grothendieck-Riemann-Roch theorem in Simons-Sullivan differential K-theory using a theorem of Bismut.Comment: 14 pages. Comments are welcome. Final version. To appear in Annals of Global Analysis and Geometr

    Closedness type regularity conditions for surjectivity results involving the sum of two maximal monotone operators

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    In this note we provide regularity conditions of closedness type which guarantee some surjectivity results concerning the sum of two maximal monotone operators by using representative functions. The first regularity condition we give guarantees the surjectivity of the monotone operator S(+p)+T()S(\cdot + p)+T(\cdot), where pXp\in X and SS and TT are maximal monotone operators on the reflexive Banach space XX. Then, this is used to obtain sufficient conditions for the surjectivity of S+TS+T and for the situation when 00 belongs to the range of S+TS+T. Several special cases are discussed, some of them delivering interesting byproducts.Comment: 11 pages, no figure

    D0-branes in Black Hole Attractors

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    Configurations of N probe D0-branes in a Calabi-Yau black hole are studied. A large degeneracy of near-horizon bound states are found which can be described as lowest Landau levels tiling the horizon of the black hole. These states preserve some of the enhanced supersymmetry of the near-horizon AdS_2xS^2xCY attractor geometry, but not of the full asymptotically flat solution. Supersymmetric non-abelian configurations are constructed which, via the Myers effect, develop charges associated with higher-dimensional branes wrapping CY cycles. An SU(1,1|2) superconformal quantum mechanics describing D0-branes in the attractor geometry is explicitly constructed.Comment: 27 page

    Acute Pain Assessment in Prematurely Born Infants Below 29 Weeks A Long Way to Go

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    Objectives: Neonates born extremely prematurely are at high risk of acute and prolonged pain. Effective treatment requires reliable pain assessment, which is currently missing. Our study explored whether existing pain assessment tools and physiological indicators measure pain and comfort accurately in this population. Materials and Methods: We prospectively collected data in 16 neonates born at less than 29 weeks’ gestational age during 3 conditions: skin-to-skin care, rest, and heelstick procedure for capillary blood sampling in the incubator. The neonates were video recorded in these situations, and recordings were coded using 5 observational pain assessment tools and numeric rating scales for pain and distress. We simultaneously collected heart rate, respiratory rate, arterial oxygen saturation, regional cerebral oxygenation, and the number of skin conductance peaks. All measures across the 3 conditions were compared using general linear modeling. Results: The median gestational age was 27.1 weeks (range: 24.1 to 28.7). Forty measurement periods across the 3 conditions were analyzed. Heart rate was significantly higher during heelstick procedures compared with during rest, with a mean difference of 10.7 beats/min (95% confidence interval [CI]: 2.7-18.6). Oxygen saturation was significantly higher during skin-to-skin care compared with during heelstick procedures with a mean difference of 5.5% (95% CI: 0.2-10.8). The Premature Infant Pain Profile-revised (PIPP-R) score was significantly higher during heelstick procedures compared with skin-to-skin care with a mean difference of 3.2 points (95% CI: 1.6-5.0). Discussion: Pain measurement in clinical practice in prematurely born infants below 29 weeks remains challenging. The included behavioral and physiological indicators did not adequately distinguish between a painful situation, rest, and skin-to-skin care in premature neonates
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