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Structural basis for the changed substrate specificity of Drosophila melanogaster deoxyribonucleoside kinase mutant N64D

The Drosophila melanogaster deoxyribonucleoside kinase (Dm-dNK) double mutant N45D/N64D was identified during a previous directed evolution study. This mutant enzyme had a decreased activity towards the natural substrates and decreased feedback inhibition with dTTP, whereas the activity with 3'-modified nucleoside analogs like 3'-azidothymidine (AZT) was nearly unchanged. Here, we identify the mut

The CO2 inhibition of terrestrial isoprene emission significantly affects future ozone projections

Simulations of future tropospheric composition often include substantial increases in biogenic isoprene emissions arising from the Arrhenius-like leaf emission response and warmer surface temperatures, and from enhanced vegetation productivity in response to temperature and atmospheric CO2 concentration. However, a number of recent laboratory and field data have suggested a direct inhibition of le

Patterns and dynamics of rest-phase hypothermia in wild and captive blue tits during winter.

We evaluated biotic and abiotic predictors of rest-phase hypothermia in wintering blue tits (Cyanistes caeruleus) and also assessed how food availability influences nightly thermoregulation. On any given night, captive blue tits (with unrestricted access to food) remained largely homeothermic, whereas free-ranging birds decreased their body temperature (T (b)) by about 5 degrees C. This was not an

Grids for scientific computing: Minisymposium abstract

Grid technologies are still evolving, with standards yet to be defined and reliable production-level solutions yet to be found. Nevertheless, Grid already stepped out of the cradle and slowly but steadily finds its way to the world of the modern information technologies. Early testers and adopters of this innovative technology are researchers in various fields of science, primarily those that trad

Observation of Isomeric Decays in the r-Process Waiting-Point Nucleus 130Cd

The gamma decay of excited states in the waiting-point nucleus 130Cd82 has been observed for the first time. An 8+ two-quasiparticle isomer has been populated both in the fragmentation of a 136Xe beam as well as in projectile fission of 238U, making 130Cd the most neutron-rich N=82 isotone for which information about excited states is available. The results, interpreted using state-of-the-art nucl

Altered nucleotide sugar metabolism in Streptococcus thermophilus interferes with nitrogen metabolism

Exopolysaccharide (EPS)-producing Streptococcus thermophilus strains have attracted interest recently, since the EPSs act as natural viscosifiers and texture enhancers of fermented foods. We have previously reported that the low level of EPS production by S. thermophilus LY03 could be improved by altering the activities of enzymes in the central carbon metabolism involved in the nucleotide sugar m

Origin and destination of globules and irregular masses in the gonadotropin cells from the pituitary of the African catfish, Clarias gariepinus: a morphological study

The possible function of globules and irregular membrane-bound masses in the gonadotropin cells of the pituitary of Clarias gariepinus was studied. Strong secretory stimulation led to the disappearance of the secretory granules from gonadotropin cells but globules and irregular masses remained present. Acid phosphatase was detected enzyme-cytochemically in both globules and irregular masses. Radio

Evidence for inhibitory effect of the agonist gaboxadol at human alpha(1)beta(2)gamma S-2 GABA(A) receptors

Gaboxadol (THIP; 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) is an agonist at GABA(A) receptors. THIP concentrations (0.01-50 mM) were applied rapidly to Sf9 cells expressing the human alpha(1)beta(2)gamma(2S) GABA(A) receptors. The EC50 values for the peak current in THIP alone or THIP plus 1 muM diazepam were 154 and 53 muM, respectively. In supersaturating THIP (10-50 mM) the rate of curren

Functional relation between corticonuclear input and movements evoked on microstimulation in cerebellar nucleus interpositus anterior in the cat

The functional relation between receptive fields of climbing fibres projecting to the C1, C3 and Y zones and forelimb movements controlled by nucleus interpositus anterior via the rubrospinal tract were studied in cats decerebrated at the pre-collicular level. Microelectrode tracks were made through the caudal half of nucleus interpositus anterior. This part of the nucleus receives its cerebellar

Tissue transglutaminase immunoglobulin isotypes in children with untreated and treated celiac disease

Objectives: Tissue transglutaminase (tTG) autoantibodies are serologic markers for celiac disease (CD). The aim was to determine the diagnostic sensitivity and specificity of different immunoglobulin isotypes against tTG. Methods: Immunoglobulin A (IgA)-tTG, IgG-tTG, and IgGl-tTG were measured in radioligand binding assays in 67 children with untreated and 89 children with treated CD and compared

Moraxella-Dependent {alpha}1-Antichymotrypsin Neutralization - A Unique Virulence Mechanism.

The acute phase reactant and protease inhibitor alpha1-antichymotrypsin is considered to play a protective role in the airways, but it is not known. Objectives: We analyzed whether the common respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis interact with antichymotrypsin. Methods: We compared a series of clinical isolates in addition to wild type and

Probing doubly excited ionic states of N-2(+) via a triple excitation above the N 1s threshold in the N-2 molecule

Angle-resolved resonant Auger-electron spectroscopy has been carried out on the nitrogen molecule at selected photon energies around 419 eV, where a 1s core electron and two valence electrons are promoted into the lowest unoccupied molecular orbital 1pi(g). Significant enhancement of a specific band, which cannot be disentangled in direct photoionization, is observed at a binding energy of 37.6 eV

Structural requirements for the intracellular subunit polymerization of the complement inhibitor C4b-binding protein.

C4b-binding protein (C4BP), an important inhibitor of complement activation, has a unique spider-like shape. It is composed of six to seven identical alpha-chains with or without a single beta-chain, the chains being linked by disulfide bridges in their C-terminal parts. To elucidate the structural requirements for the assembly of the alpha-chains, recombinant C4BP was expressed in HEK 293 cells.

Rapid hydrological changes during the Holocene revealed by stable isotope records of lacustrine carbonates from Lake Igelsjon, southern Sweden

A Holocene sediment sequence from Lake Igelsjon, south central Sweden, was studied by stable oxygen- and carbon-isotope analyses of different carbonate components. The deposit, which covers the time-span from ca 11,500 cal BP to the present, was laid down in a small, kettle-hole lake, the hydrological balance of which is presently dominated by groundwater flow. Isotopic records obtained on bulk ca

Routine formal fetal movement counting and risk of antepartum late death in normally formed singletons

The routine recommendation to women to count fetal movements daily during late pregnancy for the prevention of antepartum late fetal death in normally formed singletons has been evaluated. 68,000 women were randomly allocated within thirty-three pairs of clusters either to a policy of routine counting or to standard care, which might involve selective use of formal counting or informal noting of m

Accuracy of q-space related parameters in MRI: Simulations and phantom measurements

The accuracy of q-space measurements was evaluated at a 3.0-T clinical magnetic resonance imaging (MRI) scanner, as compared with a 4.7-T nuclear magnetic resonance (NMR) spectrometer. Measurements were performed using a stimulated-echo pulse-sequence on n-decane as well as on polyethylene glycol (PEG) mixed with different concentrations of water, in order to obtain bi-exponential signal decay cur