Histological investigations on the thyroid glands of marine mammals (Phoca vitulina, Phocoena phocoena) and the possible implications of marine pollution

In 1988 and 1989, thousands of harbor seals (Phoca vitulina) died in the North Sea from phocine distemper infection. The morphology of thyroid glands from 40 harbor seals found dead on the North Sea coastlines of Schleswig-Holstein, Federal Republic of Germany, during an epizootic of phocine distemper, was compared with the morphology of thyroid glands from five healthy harbor seals collected in Iceland. Thyroid glands from seven harbor porpoises (Phocoena phocoena) found dead in 1990 on the North Sea coastlines also were evaluated. Colloid depletion and fibrosis were found in the thyroid glands of harbor seals which died during the epizootic, but not in animals from Iceland. Thyroid glands of the porpoises showed similar lesions, but to a lesser degree, than those observed in the North Sea seals

Exploring the relationship between adiposity and fitness in young children

PURPOSE: High levels of cardiorespiratory fitness (CRF) may attenuate the association between excessive adiposity and the risks of cardiovascular and metabolic disease. The purpose of this study was to stratify children according to their BMI and adiposity (body fat percentage, BF%) and compare levels of CRF across subgroups. METHODS: This prospective cohort study comprises a cross-sectional and longitudinal analyses of data collected at baseline (n=641) and two years later (n=579) on children (7.4-11.6y) attending public school in Denmark. Levels of CRF were measured using the Andersen test, while BF% was measured by dual-energy x-ray absorptiometry (DXA). RESULTS: There were 560 (87.4%) children classified as normal weight according to BMI at baseline, of which 46 (7.4%) were identified as having excessive BF%. These children had significantly lower CRF (mean [95% Confidence Interval]: −63.1m [−100.2,-25.9]) than children with normal BMI and normal BF%; and the effect of BF% on CRF was significantly worse in boys than girls. Overweight children with high BF%, had significantly lower prospective (2 years) CRF levels (−34.4m [−58.0,-10.7]) than children with normal BMI and BF%. Though children who improved their BMI and/or BF% classification over the two year period achieved CRF levels (8.9m [−30.2,47.9]) which were comparable to children with normal BMI and BF% at both measurement time points. CONCLUSION: The CRF levels in children are impacted by BMI and BF%, although BF% appears to play a greater role. This association between BF% and CRF is sex-dependent, with CRF levels in boys being impacted to a greater extent by BF%. Children identified as ‘normal weight’ by BMI but presenting with excessive BF% had significantly lower CRF than ‘normal weight’ children with low BF%

Quantum key distribution using non-classical photon number correlations in macroscopic light pulses

We propose a new scheme for quantum key distribution using macroscopic non-classical pulses of light having of the order 10^6 photons per pulse. Sub-shot-noise quantum correlation between the two polarization modes in a pulse gives the necessary sensitivity to eavesdropping that ensures the security of the protocol. We consider pulses of two-mode squeezed light generated by a type-II seeded parametric amplification process. We analyze the security of the system in terms of the effect of an eavesdropper on the bit error rates for the legitimate parties in the key distribution system. We also consider the effects of imperfect detectors and lossy channels on the security of the scheme.Comment: Modifications:added new eavesdropping attack, added more references Submitted to Physical Review A [email protected]

Orbitally Driven Spin Pairing in the 3D Non-Magnetic Mott Insulator BaVS3: Evidence from Single Crystal Studies

Static electrical and magnetic properties of single crystal BaVS_3 were measured over the structural (T_S=240K), metal-insulator (T_MI=69K), and suspected orbital ordering (T_X=30K) transitions. The resistivity is almost isotropic both in the metallic and insulating states. An anomaly in the magnetic anisotropy at T_X signals a phase transition to an ordered low-T state. The results are interpreted in terms of orbital ordering and spin pairing within the lowest crystal field quasi-doublet. The disordered insulator at T_X<T<T_MI is described as a classical liquid of non-magnetic pairs.Comment: 4 pages, 5 figures, revtex, epsf, and multicol style. Problem with figures fixed. To appear in Phys. Rev. B Rap. Com

George Biersack Selected to Serve on the Nominators Committee of the Emerson College

News release announces that Chairman of Communication Arts at the University of Dayton, George Biersack, has been selected to serve on the Nominators Committee of the Emerson College

Electromagnetic induced transparency and slow light in interacting quantum degenerate atomic gases

We systematically develop the full quantum theory for the electromagnetic induced transparency (EIT) and slow light properties in ultracold Bose and Fermi gases. It shows a very different property from the classical theory which assumes frozen atomic motion. For example, the speed of light inside the atomic gases can be changed dramatically near the Bose-Einstein condensation temperature, while the presence of the Fermi sea can destroy the EIT effect even at zero temperature. From experimental point of view, such quantum EIT property is mostly manifested in the counter-propagating excitation schemes in either the low-lying Rydberg transition with a narrow line width or in the D2 transitions with a very weak coupling field. We further investigate the interaction effects on the EIT for a weakly interacting Bose-Einstein condensate, showing an inhomogeneous broadening of the EIT profile and nontrivial change of the light speed due to the quantum many-body effects beyond mean field energy shifts.Comment: 7 figure