Proximity of the manganese cluster of photosystem II to the redox-active tyrosine YZ.

Electron spin echo electron-nuclear double resonance (ESE-ENDOR) experiments performed on a broad radical electron paramagnetic resonance (EPR) signal observed in photosystem II particles depleted of Ca2+ indicate that this signal arises from the redox-active tyrosine YZ. The tyrosine EPR signal width is increased relative to that observed in a manganese-depleted preparation due to a magnetic interaction between the photosystem II manganese cluster and the tyrosine radical. The manganese cluster is located asymmetrically with respect to the symmetry-related tyrosines YZ and YD. The distance between the YZ tyrosine and the manganese cluster is estimated to be approximately 4.5 A. Due to this close proximity of the Mn cluster and the redox-active tyrosine YZ, we propose that this tyrosine abstracts protons from substrate water bound to the Mn cluster.

Photolabeling reveals the proximity of the alpha-neurotoxin binding site to the M2 helix of the ion channel in the nicotinic acetylcholine receptor.

A photoactivatable derivative of neurotoxin II from Naja naja oxiana containing a 125I-labeled p-azidosalicylamidoethyl-1,3'-dithiopropyl label at Lys-25 forms a photo-induced cross-link with the delta subunit of the membrane-bound Torpedo californica nicotinic acetylcholine receptor (AChR). The cross-linked radioactive receptor peptide was isolated by reverse-phase HPLC after tryptic digestion of the labeled delta subunit. The sequence of this peptide, delta-(260-277), and the position of the label at Ala-268 were established by matrix-assisted laser-desorption-ionization mass spectrometry based on the molecular mass and on post-source decay fragment analysis. With the known dimensions of the AChR molecule, of the photolabel, and of alpha-neurotoxin, finding the cross-link at delta Ala-268 (located in the upper part of the channel-forming transmembrane helix M2) means that the center of the alpha-neurotoxin binding site is situated at least approximately 40 A from the extracellular surface of the AChR, proximal to the channel axis.

Measurement of electrons from heavy-flavour hadron decays in p-Pb collisions at $\\sqrt{s_{NN}} = 5.02$ TeV using TPC and EMCal detectors with ALICE at LHC

Heavy-ion collisions are a powerful tool to study hot and dense QCD matter, the so-called Quark Gluon Plasma (QGP). Since heavy quarks (charm and beauty) are dominantly produced in the early stages of the collision, they experience the complete evolution of the system. Measurements of electrons from heavy-flavour hadron decay is one possible way to study the interaction of these particles with the QGP. With ALICE at LHC, electrons can be identified with high efficiency and purity. A strong suppression of heavy-flavour decay electrons has been observed at high $p_{m T}$ in Pb-Pb collisions at 2.76 TeV. Measurements in p-Pb collisions are crucial to understand cold nuclear matter effects on heavy-flavour production in heavy-ion collisions. The spectrum of electrons from the decays of hadrons containing charm and beauty was measured in p-Pb collisions at $\\sqrt = 5.02$ TeV. The heavy flavour decay electrons were measured by using the Time Projection Chamber (TPC) and the Electromagnetic Calorimeter (EMCal) detectors from ALICE in the transverse-momentum range $2 < p_ < 20$ GeV/c. The measurements were done in two different data set: minimum bias collisions and data using the EMCal trigger. The non-heavy flavour electron background was removed using an invariant mass method. The results are compatible with one ($R_ \\approx$ 1) and the cold nuclear matter effects in p-Pb collisions are small for the electrons from heavy-flavour hadron decays.

Transfer in third language phonology: Does L3 typological proximity play a role?

Les investigacions recents sobre la transferència i l'adquisició d’una L3 han indagat sobre les interferències lingüístiques quan hi ha més d'una font de transferència. Els participants en aquest estudi de cas van ser parlants d’espanyol i d’anglès, que apreninen una tercera llengua, el català, tipològicament més pròxima a l’espanyol. Aquest estudi va investigar la producció dels bilingües del català fosc /ɫ/, un segment que no és present en espanyol ja que tots els laterals es produeixen com una clara /l/, i que, tanmateix, es realitza en anglès en posició final després de vocal. Contràriament al model que planteja la proximitat d'idiomes prèviament adquirids com un dels factors determinants per a la transferència de competències, l’estudi va mostrar que la proximitat tipològica a un dels L1 no és determinista per a la transferència en el nivell fonològic en l’aprenentatge d’una L3, ja que els participants produeixen laterals catalanes similars a /ɫ/. En aquest estudi de cas es constata, d’acord amb el Model de Millora Acumulativa, com es transfereix aquest segment fonològic des de l’anglés al català.

Bibliography on semiconductor nuclear radiation detectors /

"December 6, 1960."

Bibliography on semiconductor nuclear radiation detectors /

Included are 464 selected references on the theory, manufacture, properties, performance, and utliization of semiconductor materials for the detection of nuclear radiation. Reports and open literature references are covered through January 1962.

Measurements of electromagnetic fields in the close proximity of CB antennas /

Mode of access: Internet.

Smoke detectors : moving the public.

Vol. 2 of a series of smoke detector public education manuals.

A status report on vehicle detectors. Final report.

Mode of access: Internet.

Effective placement of detectors for computerized traffic control summary report. Final report.

Texas Department of Transportation, Austin

Detector location for computerized arterial street sampling detectors.

Texas Department of Transportation, Austin

Leakage in the proximity of microwave diathermy applications used on humans or phantom models /

Mode of access: Internet.