Investigations of the potential influence of environmental contaminants on the thymus and spleen of harbor porpoises (Phocoena phocoena)

Harbor porpoises from the German North and Baltic Seas exhibit a higher incidence of bacterial infections compared to whales from less polluted arctic waters. The potential adverse effect of environmental contaminants such as polychlorinated biphenyls (PCBs) and heavy metals on the immune system and the health status of marine mammals is still discussed controversially. The aim of the present study was to investigate the possible influence of PCB, polybrominated diphenyl ether (PBDE), toxaphene, (p,p'-dichlorodiphenyl)trichlorethane (DDT), and (p,p'-dichlorodiphenyl)dichlorethene (DDE) on the immune system of harbor porpoises. Lymphoid organs are influenced by a variety of factors, and therefore special emphasis was given to separating the confounding effect of age, health status, nutritional state, geographical location, and sex from the effect of contaminant levels upon thymus and spleen. Contaminant analysis and detailed pathological examinations were conducted on 61 by-caught and stranded whales from the North and Baltic Seas and Icelandic and Norwegian waters. Stranded harbor porpoises were more severely diseased than by-caught animals. Thymic atrophy and splenic depletion were significantly correlated to increased PCB and PBDE levels. However, lymphoid depletion was also associated with emaciation and an impaired health status. The present report supports the hypothesis of a contaminant-induced immunosuppression, possibly contributing to disease susceptibility in harbor porpoises. However, further studies are needed to determine if lymphoid depletion is primarily contaminant-induced or secondary to disease and emaciation in this cetacean species.     

Potential contamination of shipboard air samples by diffusive emissions of PCBs and other organic pollutants: implications and solutions

Air samples were taken onboard the RRS Bransfield on an Atlantic cruise from the United Kingdom to Halley, Antarctica, from October to December 1998, with the aim of establishing PCB oceanic background air concentrations and assessing their latitudinal distribution. Great care was taken to minimize pre- and post-collection contamination of the samples, which was validated through stringent QA/QC procedures. However, there is evidence that onboard contamination of the air samples occurred,following insidious, diffusive emissions on the ship. Other data (for PCBs and other persistent organic pollutants (POPs)) and examples of shipboard contamination are presented. The implications of these findings for past and future studies of global POPs distribution are discussed. Recommendations are made to help critically appraise and minimize the problems of insidious/diffusive shipboard contamination.     

Blinking statistics of silicon quantum dots

The blinking statistics of numerous single silicon quantum dots fabricated by electron-beam lithography, plasma etching, and oxidation have been analyzed. Purely exponential on- and off-time distributions were found consistent with the absence of statistical aging. This is in contrast to blinking reports in the literature where power-law distributions prevail as well as observations of statistical aging in nanocrystal ensembles. A linear increase of the switching frequency with excitation power density indicates a domination of single-photon absorption processes, possibly through a direct transfer of charges to trap states without the need for a bimolecular Auger mechanism. Photoluminescence saturation with increasing excitation is not observed; however, there is a threshold in excitation (coinciding with a mean occupation of one exciton per nanocrystal) where a change from linear to square-root increase occurs. Finally, the statistics of blinking of single quantum dots in terms of average on-time, blinking frequency and blinking amplitude reveal large variations (several orders) without any significant correlation demonstrating the individual microscopic character of each quantum dot.     

草浆的改良漂白

实验室用过氧化氢部分或全部替代含氯化学药品漂白目前中国非木浆的典型代表物－Soda蒸煮麦草浆,通过产品的质量和环境的特性来评价这种改变的结果。另一方面,次氯酸盐被过氧化氢完全替代时,终点白度稍低于参考的漂序,而白度逆转作用则显著降低,浆的质量也有某些明显的改善。当降低氯时,环境特性通过污水中AOX（吸收有机卤素）的降低而得以戏剧性的改善。     

Mucocutaneous lymph node syndrome in Denver

Four children with acute febrile mucocutaneous lymph node syndrome (MLNS) were hospitalized in Denver over a two-year period. The children had most of the principle features of this recently described syndrome, including prolonged fever unresponsive to antibiotics, an erythematous rash, conjunctivitis, pharyngitis, and nonsuppurative cervical lymphadenitis. Three of the children exhibited characteristic desquamation from the fingertips or toes during convalescence. None developed clinical or electrocardiographic evidence of coronary thromboarteritis, the most serious complication of the disease. Additional cases undoubtedly will be reported in the United States as physicians become famililar with this new syndrome and learn to distinguish it from the other acute febrile exanthems.     

Proteaseinhibitors in potatoes Protein-, Trypsin- und Chymotrypsininhibitorenmuster durch isoelektrisches Fokussieren in Polyacrylamidgel. Eine Schnellmethode zur Identifizierung von Kartoffelsorten

Summary By applying iscelectric focusing in polyacrylamide gel, 42 proteins and 21 inhibitors were detected in 12 potato varieties. The protein- and inhibitor-patterns are very characteristic, and can be used for rapid variety identification. The protein distribution is not the same in the whole tuber. Germination tests showed a smaller inhibitor content in sprouts than in tubers. The alkaline and neutral inhibitors decreased, whereas more acidic inhibitors appeared.

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Proteaseinhibitoren in Kartoffeln Protein-, trypsin- and chymotrypsininhibitor patterns by isoelectric focusing in polyacrylamidegel. A rapid method for identification of potato varieties

Zusammenlassung Durch isoelektrisches Fokussieren in Polyacrylamidgel wurden in 12 Kartoffelsorten 42 Proteine und 21 Inhibitoren nachgewiesen. Die Protein- und Inhibitormuster sind sehr charakteristisch und können zur schnellen Sortendiagnose heraugezogen werden.Die Proteinverteilung ist nicht über die gesamte Knolle gleich. Keimversuche ergaben eine Verminderung des Inhibitorgehalts in Keimen gegenüber der Knolle. Während die basischen und neutralen Inhibitoren abnehmen, treten zusätzlich saure Inhibitoren auf.

     

Understanding,Optimising, and Extending Data Compression with Anisotropic Diffusion

Gali? et al. (Journal of Mathematical Imaging and Vision 31:255–269, 2008) have shown that compression based on edge-enhancing anisotropic diffusion (EED) can outperform the quality of JPEG for medium to high compression ratios when the interpolation points are chosen as vertices of an adaptive triangulation. However, the reasons for the good performance of EED remained unclear, and they could not outperform the more advanced JPEG 2000. The goals of the present paper are threefold: Firstly, we investigate the compression qualities of various partial differential equations. This sheds light on the favourable properties of EED in the context of image compression. Secondly, we demonstrate that it is even possible to beat the quality of JPEG 2000 with EED if one uses specific subdivisions on rectangles and several important optimisations. These amendments include improved entropy coding, brightness and diffusivity optimisation, and interpolation swapping. Thirdly, we demonstrate how to extend our approach to 3-D and shape data. Experiments on classical test images and 3-D medical data illustrate the high potential of our approach.