Measurement of the electron neutrino charged-current interaction rate on water with the T2K ND280 π0 detector

This paper presents a measurement of the charged current interaction rate of the electron neutrino beam component of the beam above 1.5 GeV using the large fiducial mass of the T2K π0 detector. The predominant portion of the νe flux (∼85%) at these energies comes from kaon decays. The measured ratio of the observed beam interaction rate to the predicted rate in the detector with water targets filled is 0.89 ± 0.08 (stat.) ± 0.11 (sys.), and with the water targets emptied is 0.90 ± 0.09 (stat.) ± 0.13 (sys.). The ratio obtained for the interactions on water only from an event subtraction method is 0.87 ± 0.33 (stat.) ± 0.21 (sys.). This is the first measurement of the interaction rate of electron neutrinos on water, which is particularly of interest to experiments with water Cherenkov detectors.

Simulation of plasma flows in divergent magnetic nozzles

Images from the simulation code DIMAGNO illustrate the roles of pressure, electric, and magnetic forces in the 2-D plasma expansion in a magnetic nozzle and the generation of thrust

Echolocation detections and digital video surveys provide reliable estimates of the relative density of harbour porpoises

Acknowledgements We would like to thank Erik Rexstad and Rob Williams for useful reviews of this manuscript. The collection of visual and acoustic data was funded by the UK Department of Energy & Climate Change, the Scottish Government, Collaborative Offshore Wind Research into the Environment (COWRIE) and Oil & Gas UK. Digital aerial surveys were funded by Moray Offshore Renewables Ltd and additional funding for analysis of the combined datasets was provided by Marine Scotland. Collaboration between the University of Aberdeen and Marine Scotland was supported by MarCRF. We thank colleagues at the University of Aberdeen, Moray First Marine, NERI, Hi-Def Aerial Surveying Ltd and Ravenair for essential support in the field, particularly Tim Barton, Bill Ruck, Rasmus Nielson and Dave Rutter. Thanks also to Andy Webb, David Borchers, Len Thomas, Kelly McLeod, David L. Miller, Dinara Sadykova and Thomas Cornulier for advice on survey design and statistical approache. Data Accessibility Data are available from the Dryad Digital Repository: http://dx.doi.org/10.5061/dryad.cf04g

On the electronic nature of low-barrier hydrogen bonds in enzymatic reactions

The electronic nature of low-barrier hydrogen bonds (LBHBs) in enzymatic reactions is discussed based on combined low temperature neutron and x-ray diffraction experiments and on high level ab initio calculations by using the model substrate benzoylacetone. This molecule has a LBHB, as the intramolecular hydrogen bond is described by a double-well potential with a small barrier for hydrogen transfer. From an “atoms in molecules” analysis of the electron density, it is found that the hydrogen atom is stabilized by covalent bonds to both oxygens. Large atomic partial charges on the hydrogen-bonded atoms are found experimentally and theoretically. Therefore, the hydrogen bond gains stabilization from both covalency and from the normal electrostatic interactions found for long, weak hydrogen bonds. Based on comparisons with other systems having short-strong hydrogen bonds or LBHBs, it is proposed that all short-strong and LBHB systems possess similar electronic features of the hydrogen-bonded region, namely polar covalent bonds between the hydrogen atom and both heteroatoms in question.

Increased levels of plasma lysosomal enzymes in patients with Lowe syndrome

Lowe syndrome is an X-linked disorder that has a complex phenotype that includes progressive renal failure and blindness. The disease is caused by mutations in an inositol polyphosphate 5-phosphatase designated OCRL. It has been shown that the OCRL protein is found on the surface of lysosomes and that a renal tubular cell line deficient in OCRL accumulated substrate phosphatidylinositol 4,5-bisphosphate. Because this lipid is required for vesicle trafficking from lysosomes, we postulate that there is a defect in lysosomal enzyme trafficking in patients with Lowe syndrome that leads to increased extracellular lysosomal enzymes and might lead to tissue damage and contribute to the pathogenesis of the disease. We have measured seven lysosomal enzymes in the plasma of 15 patients with Lowe syndrome and 15 age-matched male controls. We find a 1.6- to 2.0-fold increase in all of the enzymes measured. When the data was analyzed by quintiles of activity for all of the enzymes, we found that 95% of values in the lowest quintile come from normal subjects whereas in the highest quintile 85% of the values are from patients with Lowe syndrome. The increased enzyme levels are not attributable to renal insufficiency because there was no difference in enzyme activity in the four patients with the highest creatinine levels compared with the six patients with the lowest creatinine values.

Three-dimensional structure of human electron transfer flavoprotein to 2.1-Å resolution

Mammalian electron transfer flavoproteins (ETF) are heterodimers containing a single equivalent of flavin adenine dinucleotide (FAD). They function as electron shuttles between primary flavoprotein dehydrogenases involved in mitochondrial fatty acid and amino acid catabolism and the membrane-bound electron transfer flavoprotein ubiquinone oxidoreductase. The structure of human ETF solved to 2.1-Å resolution reveals that the ETF molecule is comprised of three distinct domains: two domains are contributed by the α subunit and the third domain is made up entirely by the β subunit. The N-terminal portion of the α subunit and the majority of the β subunit have identical polypeptide folds, in the absence of any sequence homology. FAD lies in a cleft between the two subunits, with most of the FAD molecule residing in the C-terminal portion of the α subunit. Alignment of all the known sequences for the ETF α subunits together with the putative FixB gene product shows that the residues directly involved in FAD binding are conserved. A hydrogen bond is formed between the N5 of the FAD isoalloxazine ring and the hydroxyl side chain of αT266, suggesting why the pathogenic mutation, αT266M, affects ETF activity in patients with glutaric acidemia type II. Hydrogen bonds between the 4′-hydroxyl of the ribityl chain of FAD and N1 of the isoalloxazine ring, and between αH286 and the C2-carbonyl oxygen of the isoalloxazine ring, may play a role in the stabilization of the anionic semiquinone. With the known structure of medium chain acyl-CoA dehydrogenase, we hypothesize a possible structure for docking the two proteins.

Correlation of regional cerebral blood flow and change of plasma sodium concentration during genesis and satiation of thirst

Positron emission tomography studies were conducted during genesis of moderate thirst by rapid i.v. infusion of hypertonic saline (0.51 M) and after satiation of thirst by drinking water. The correlation of regional cerebral blood flow with the change in the plasma Na concentration showed a significant group of cerebral activations in the anterior cingulate region and also a site in the middle temporal gyrus and in the periaqueductal gray. Strongest deactivations occurred in the parahippocampal and frontal gyri. The data are consistent with an important role of the anterior cingulate in the genesis of thirst.

Cohort study of plasma natriuretic peptides for identifying left ventricular systolic dysfunction in primary care

Objectives: To determine whether blood natriuretic peptide concentrations are helpful in identifying or excluding left ventricular systolic dysfunction in stable survivors of acute myocardial infarction.

Chronic elevation of plasma thioredoxin: Inhibition of chemotaxis and curtailment of life expectancy in AIDS

Thioredoxin (Trx) is an intracellular redox protein with extracellular cytokine-like and chemokine-like activities. We show here that, although plasma Trx levels are unrelated to survival of HIV-infected individuals with CD4 cell counts above 200/μl blood, survival is significantly impaired (P = 0.003) when plasma Trx is chronically elevated in HIV-infected subjects with CD4 T cell counts below this level (i.e., with Centers for Disease Control (CDC)-defined AIDS). Relevant to the mechanism potentially underlying this finding, we also present data from experimental studies in mice showing that elevated plasma Trx efficiently blocks lipopolysaccharide (LPS)-induced chemotaxis, an innate immune mechanism that is particularly crucial when adaptive immunity is compromised. Thus, we propose that elevated plasma Trx in HIV-infected individuals with low CD4 T cell counts directly impairs survival by blocking pathogen-induced chemotaxis, effectively eliminating the last (innate) barrier against establishment of opportunistic and other infections in these immunodeficient individuals.

Control of Cl− Efflux in Chara corallina by Cytosolic pH, Free Ca2+, and Phosphorylation Indicates a Role of Plasma Membrane Anion Channels in Cytosolic pH Regulation1

Enhanced Cl− efflux during acidosis in plants is thought to play a role in cytosolic pH (pHc) homeostasis by short-circuiting the current produced by the electrogenic H+ pump, thereby facilitating enhanced H+ efflux from the cytosol. Using an intracellular perfusion technique, which enables experimental control of medium composition at the cytosolic surface of the plasma membrane of charophyte algae (Chara corallina), we show that lowered pHc activates Cl− efflux via two mechanisms. The first is a direct effect of pHc on Cl− efflux; the second mechanism comprises a pHc-induced increase in affinity for cytosolic free Ca2+ ([Ca2+]c), which also activates Cl− efflux. Cl− efflux was controlled by phosphorylation/dephosphorylation events, which override the responses to both pHc and [Ca2+]c. Whereas phosphorylation (perfusion with the catalytic subunit of protein kinase A in the presence of ATP) resulted in a complete inhibition of Cl− efflux, dephosphorylation (perfusion with alkaline phosphatase) arrested Cl− efflux at 60% of the maximal level in a manner that was both pHc and [Ca2+]c independent. These findings imply that plasma membrane anion channels play a central role in pHc regulation in plants, in addition to their established roles in turgor/volume regulation and signal transduction.

The Regulation of Photosynthetic Electron Transport during Nutrient Deprivation in Chlamydomonas reinhardtii1

The light-saturated rate of photosynthetic O2 evolution in Chlamydomonas reinhardtii declined by approximately 75% on a per-cell basis after 4 d of P starvation or 1 d of S starvation. Quantitation of the partial reactions of photosynthetic electron transport demonstrated that the light-saturated rate of photosystem (PS) I activity was unaffected by P or S limitation, whereas light-saturated PSII activity was reduced by more than 50%. This decline in PSII activity correlated with a decline in both the maximal quantum efficiency of PSII and the accumulation of the secondary quinone electron acceptor of PSII nonreducing centers (PSII centers capable of performing a charge separation but unable to reduce the plastoquinone pool). In addition to a decline in the light-saturated rate of O2 evolution, there was reduced efficiency of excitation energy transfer to the reaction centers of PSII (because of dissipation of absorbed light energy as heat and because of a transition to state 2). These findings establish a common suite of alterations in photosynthetic electron transport that results in decreased linear electron flow when C. reinhardtii is limited for either P or S. It was interesting that the decline in the maximum quantum efficiency of PSII and the accumulation of the secondary quinone electron acceptor of PSII nonreducing centers were regulated specifically during S-limited growth by the SacI gene product, which was previously shown to be critical for the acclimation of C. reinhardtii to S limitation (J.P. Davies, F.H. Yildiz, and A.R. Grossman [1996] EMBO J 15: 2150–2159).

The roles of coenzyme Q10 and vitamin E on the peroxidation of human low density lipoprotein subfractions.

The aim of our study was to investigate the relationships between the levels of coenzyme Q10 (CoQ10) and vitamin E and the levels of hydroperoxide in three subfractions of low density lipoproteins (LDL) that were isolated from healthy donors. LDL3, the densest of the three subfractions, has shown statistically significant lower levels of CoQ10 and vitamin E, which were associated with higher hydroperoxide levels when compared with the lighter counterparts. After CoQ10 supplementation, all three LDL subfractions had significantly increased CoQ10 levels. In particular, LDL3 showed the highest CoQ10 increase when compared with LDL1 and LDL2 and was associated with a significant decrease in hydroperoxide level. These results support the hypothesis that the CoQ10 endowment in subfractions of LDL affects their oxidizability, and they have important implications for the treatment of disease.

Surface, Thermal and Antimicrobial Release Properties of Plasma-Treated Zein Films

The effects of dielectric barrier discharge plasma treatment on zein film containing thymol as an active ingredient were evaluated. The plasma discharge was optically characterized to identify the reactive species. A significant increase in the film roughness (p < 0.05) was observed due to the etching effect of DBD plasma, which was correlated with the increase in the diffusion rate of thymol in the food simulant. The diffusion of thymol from the zein film was measured in aqueous solution. The kinetics of thymol release followed the Fick’s law of diffusion as shown by the high correlation coefficients between experimental and theoretical data. No significant change (p > 0.05) was observed for the thermal properties of the antimicrobial films after DBD plasma treatment.

Modulation of the Silica Sol–Gel Composition for the Promotion of Direct Electron Transfer to Encapsulated Cytochrome c

The direct electron transfer between indium–tin oxide electrodes (ITO) and cytochrome c encapsulated in different sol–gel silica networks was studied. Cyt c@silica modified electrodes were synthesized by a two-step encapsulation method mixing a phosphate buffer solution with dissolved cytochrome c and a silica sol prepared by the alcohol-free sol–gel route. These modified electrodes were characterized by cyclic voltammetry, UV–vis spectroscopy, and in situ UV–vis spectroelectrochemistry. The electrochemical response of encapsulated protein is influenced by the terminal groups of the silica pores. Cyt c does not present electrochemical response in conventional silica (hydroxyl terminated) or phenyl terminated silica. Direct electron transfer to encapsulated cytochrome c and ITO electrodes only takes place when the protein is encapsulated in methyl modified silica networks.

Diagnoses of new East African mammals, including a new genus of Muridae, by Wilfred H. Osgood.

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