我区青少年犯罪分析与预防

本从我区青少年犯罪问题入手，对我区青少年违法犯罪的状况、特点、原因进行了分析和研究，提出了一些可行性预防措施。     

Tracking apex marine predator movements in a dynamic ocean

Pelagic marine predators face unprecedented challenges and uncertain futures. Overexploitation and climate variability impact the abundance and distribution of top predators in ocean ecosystems. Improved understanding of ecological patterns, evolutionary constraints and ecosystem function is critical for preventing extinctions, loss of biodiversity and disruption of ecosystem services. Recent advances in electronic tagging techniques have provided the capacity to observe the movements and long-distance migrations of animals in relation to ocean processes across a range of ecological scales. Tagging of Pacific Predators, a field programme of the Census of Marine Life, deployed 4,306 tags on 23 species in the North Pacific Ocean, resulting in a tracking data set of unprecedented scale and species diversity that covers 265,386 tracking days from 2000 to 2009. Here we report migration pathways, link ocean features to multispecies hotspots and illustrate niche partitioning within and among congener guilds. Our results indicate that the California Current large marine ecosystem and the North Pacific transition zone attract and retain a diverse assemblage of marine vertebrates. Within the California Current large marine ecosystem, several predator guilds seasonally undertake north-south migrations that may be driven by oceanic processes, species-specific thermal tolerances and shifts in prey distributions. We identify critical habitats across multinational boundaries and show that top predators exploit their environment in predictable ways, providing the foundation for spatial management of large marine ecosystems.     

Quantitative determination of amino acids in the 10−14 molar range by scanning microscope photometry

Zusammenfassung Die beschriebene Methode stellt eine Kombination der Mikrochromatographie und der Scanning-Mikroskop-Photometrie dar und ermöglicht eine quantitative Bestimmung von C¹⁴-markierten Dansyl-Aminosäuren in biologischen Material im Bereich von 10^–14 M.

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Supported by the Deutsche Forschungsgemeinschaft.

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We would like to thank Prof. Dr.K. H. Gertz and Priv.-Doz. Dr.H. Stolte for helpful discussion.     

A young massive planet in a star-disk system

There is a general consensus that planets form within disks of dust and gas around newly born stars. Details of their formation process, however, are still a matter of ongoing debate. The timescale of planet formation remains unclear, so the detection of planets around young stars with protoplanetary disks is potentially of great interest. Hitherto, no such planet has been found. Here we report the detection of a planet of mass (9.8+/-3.3)M(Jupiter) around TW Hydrae (TW Hya), a nearby young star with an age of only 8-10 Myr that is surrounded by a well-studied circumstellar disk. It orbits the star with a period of 3.56 days at 0.04 au, inside the inner rim of the disk. This demonstrates that planets can form within 10 Myr, before the disk has been dissipated by stellar winds and radiation.