Search for Neutrinoless Quadruple-ß Decay of

We report the results of a first experimental search for lepton number violation by four units in the neutrinoless quadruple-ß decay of ^{150}Nd using a total exposure of 0.19 kg yr recorded with the NEMO-3 detector at the Modane Underground Laboratory. We find no evidence of this decay and set lower limits on the half-life in the range T_{1/2}>(1.1-3.2)×10^{21} yr at the 90% C.L., depending on the model used for the kinematic distributions of the emitted electrons.

Measurement of the ßß decay half-life of 130Te with the NEMO-3 detector.

We report results from the NEMO-3 experiment based on an exposure of 1275 days with 661 g of (130)Te in the form of enriched and natural tellurium foils. The ßß decay rate of (130)Te is found to be greater than zero with a significance of 7.7 standard deviations and the half-life is measured to be T(½)(2ν) = [7.0 ± 0.9(stat) ± 1.1(syst)] × 10(20) yr. This represents the most precise measurement of this half-life yet published and the first real-time observation of this decay.

Watchers do not follow the eye movements of Walkers.

Eye movements are a functional signature of how the visual system effectively decodes and adapts to the environment. However, scientific knowledge in eye movements mostly arises from studies conducted in laboratories, with well-controlled stimuli presented in constrained unnatural settings. Only a few studies have attempted to directly compare and assess whether eye movement data acquired in the real world generalize with those in laboratory settings, with same visual inputs. However, none of these studies controlled for both the auditory signals typical of real-world settings and the top-down task effects across conditions, leaving this question unresolved. To minimize this inherent gap across conditions, we compared the eye movements recorded from observers during ecological spatial navigation in the wild (the Walkers) with those recorded in laboratory (the Watchers) on the same visual and auditory inputs, with both groups performing the very same active cognitive task. We derived robust data-driven statistical saliency and motion maps. The Walkers and Watchers differed in terms of eye movement characteristics: fixation number and duration, saccade amplitude. The Watchers relied significantly more on saliency and motion than the Walkers. Interestingly, both groups exhibited similar fixation patterns towards social agents and objects. Altogether, our data show that eye movements patterns obtained in laboratory do not fully generalize to real world, even when task and auditory information is controlled. These observations invite to caution when generalizing the eye movements obtained in laboratory with those of ecological spatial navigation.

First results of the search for neutrinoless double-beta decay with the NEMO 3 detector.

The NEMO 3 detector, which has been operating in the Fréjus underground laboratory since February 2003, is devoted to the search for neutrinoless double-beta decay (beta beta 0v). The half-lives of the two neutrino double-beta decay (beta beta 2v) have been measured for 100Mo and 82Se. After 389 effective days of data collection from February 2003 until September 2004 (phase I), no evidence for neutrinoless double-beta decay was found from approximately 7 kg of 100Mo and approximately 1 kg of 82Se. The corresponding limits are T1/2(beta beta0v) > 4.6 x 10(23) yr for 100Mo and T1/2(beta beta 0v) > 1.0 x 10(23) yr for 82Se (90% C.L.). Depending on the nuclear matrix element calculation, the limits for the effective Majorana neutrino mass are < 0.7-2.8 e/v for 100Mo and < 1.7-4.9 eV for 82Se.

Characterization of new bacterial transformation products of 1,1,1-trichloro-2,2-bis-(4-chlorophenyl) ethane (DDT) by gas chromatography/mass spectrometry.

The microbial transformation of DDT, DDD and DDE was studied in Gram-negative strain B-206 and a number of phenolic metabolites were identified as the trimethylsilyl derivatives in the bacterial extracts by gas chromatography/mass spectrometry. The major metabolites of DDT were DDD, DDE, DDMU, 1,1,1-trichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethane, 1,1,1-trichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-hydroxyphenyl) ethane, and 1,1,1-trichloro-2,2-bis-(2-hydroxy-4-chlorophenyl) ethane. Conversely, DDD was mainly degraded into DDE, 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethane and 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-hydroxyphenyl) ethane. Finally, DDE was transformed into DDMU, 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethylene, 1,1-dichloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'hydroxyphenyl) ethylene and 1-chloro-2-(2-hydroxy-4-chlorophenyl)-2-(4'-chlorophenyl) ethylene. The phenolic metabolites exhibited [M - TMSCl]+., [M - HCl - TMSCl]+. and/or [M - HCl - TMSCl - Me]+ fragment ions which reflect the presence of an ortho hydroxyl group in these molecules. Other mass spectral features used to determine their structure are presented and a metabolic scheme accounting for their formation is proposed.