Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment.

The RENO experiment has analyzed about 500 live days of data to observe an energy dependent disappearance of reactor ν[over ¯]_{e} by comparing their prompt signal spectra measured in two identical near and far detectors. In the period between August of 2011 and January of 2013, the far (near) detector observed 31 541 (290 775) electron antineutrino candidate events with a background fraction of 4.9% (2.8%). The measured prompt spectra show an excess of reactor ν[over ¯]_{e} around 5 MeV relative to the prediction from a most commonly used model. A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the observed number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.082±0.009(stat)±0.006(syst) and |Δm_{ee}^{2}|=[2.62_{-0.23}^{+0.21}(stat)_{-0.13}^{+0.12}(syst)]×10^{-3} eV^{2}.

Observation of reactor electron antineutrinos disappearance in the RENO experiment.

The RENO experiment has observed the disappearance of reactor electron antineutrinos, consistent with neutrino oscillations, with a significance of 4.9 standard deviations. Antineutrinos from six 2.8 GW(th) reactors at the Yonggwang Nuclear Power Plant in Korea, are detected by two identical detectors located at 294 and 1383 m, respectively, from the reactor array center. In the 229 d data-taking period between 11 August 2011 and 26 March 2012, the far (near) detector observed 17102 (154088) electron antineutrino candidate events with a background fraction of 5.5% (2.7%). The ratio of observed to expected numbers of antineutrinos in the far detector is 0.920±0.009(stat)±0.014(syst). From this deficit, we determine sin(2)2θ(13)=0.113±0.013(stat)±0.019(syst) based on a rate-only analysis.

Gigacycle fatigue behavior by ultrasonic nanocrystalline surface modification.

Nanocrystalline surface layer up to 84 microm in thick is produced on a specimen made of Al6061-T6 alloy by means of surface treatment called ultrasonic nanocrystalline surface modification (UNSM) technique. The refined grain size is produced in the top-layer and it is increased with increasing depth from the top surface. Vickers microhardness measurement for each nanocrystalline surface layer is performed and measurement results showed that the microhardness is increased from 116 HV up to 150 HV, respectively. In this study, fatigue behavior of Al6061-T6 alloy was studied up to 10(7)-10(9) cycles by using a newly developed ultrasonic fatigue testing (UFT) rig. The fatigue results of the UNSM-treated Al6061-T6 alloy specimens were compared with those of the untreated specimens. The microstructure of the untreated and UNSM-treated specimens was characterized by means of scanning electron microscopey (SEM) and transmission electron microscopey (TEM).

Neurobehavioral changes in shoe manufacturing workers.

A study was carried out to evaluate: (a) the value of a cumulative exposure estimate (CEE) calculated from limited information on air concentration; and (b) whether chronic exposure to mixed organic solvents at a shoe manufacturing factory has induced neurobehavioral changes. The Neurobehavioral Core Test Battery was administered to 40 female workers from a shoe manufacturing factory and 28 housekeepers as referents. The airborne concentrations of the solvents as a mixture were 0.46-0.71 at the frame making process and 1.83-2.39 at the adhesive process. Performance was analyzed by three exposure indices: current department, exposure duration, and CEE. The Santa Ana Dexterity test showed statistically significant differences only in CEE. In particular, the group with higher exposures had a significantly poorer performance than the reference group, on preferred hand trials. The results suggested that CEE appeared to be a better indicator of mixed organic solvents exposure, and neurobehavioral changes were associated with CEE over 10 years.

A Case of a Young Woman with Hepatosplenic gamadelta T-cell Lymphoma.

Most T-cell lymphomas arise from mature alpabeta T-cells and commonly involve the nodes. Lymphomas bearing the gamadelta T-cell receptor (TCR) are very rare, and involve the lymph nodes minimally, if at all. Hepatosplenic gamadelta T-cell lymphoma is a recently identified, rare entity in which lymphoma cells bearing the gamadelta TCR infiltrate the sinusoids of the liver, splenic red pulp, and bone marrow. Its leukemic transformation is even more rare. Recently, we experienced a case of hepatosplenic gamadelta T-cell lymphoma in a 19-year-old woman who presented with epigastric pain, fever, massive splenomegaly, andpancytopenia. The splenectomy specimen and excisional biopsy of the liver revealed the infiltration of atypical T lymphocytes with the immunophenotypic markers of CD3 (+), CD45RO (pan-T antigen) (+), TIA-1(+), CD4(-),CD8 (-), CD56 (-), and S100 (-) in the sinusoids of the liver and splenic red pulp. Polymerase chain reaction (PCR) showed that these cells had the expression of the TCR gama gene rearrangements. Though the pancytopenia had improved after the splenectomy, the response of chemotherapy was transient. Her disease progressed rapidly and she expired in the leukemic phase. We report a case of hepatosplenic gamadelta T-cell lymphoma that developed in a young woman, along with a brief review of the literature.

Observation of a (6)(LambdaLambda)He double hypernucleus.

A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.