Chemistry of lakes in the Nordic region - Denmark, Finland with Åland, Iceland, Norway with Svalbard and Bear Island, and Sweden

This report presents the first common evaluation of water chemistry in the Nordic countries (except for the Faroe Islands and Greenland): Denmark, Finland including Åland, Iceland, Norway including Svalbard and Bear Island, and Sweden. The Nordic countries exhibit large gradients in many chemical constituents in lake water, from Iceland in the west, Svalbard and Bear Island in the north via Denmark to Sweden, Finland and Norway, due to large differences in geology, hydrology, vegetation and air pollution. The data are interpreted relative to these factors

On the nature of the short duration GRB 050906

The definitive version is available at www.blackwell-synergy.com. Copyright Blackwell Publishing DOI : 10.1111/j.1365-2966.2007.11953.xPeer reviewe

Three-Body Halos. II. from Two- to Three-Body Asymptotics

The large distance behavior of weakly bound three-body systems is investigated. The Schr\"{o}dinger equation and the Faddeev equations are reformulated by an expansion in eigenfunctions of the angular part of a corresponding operator. The resulting coupled set of effective radial equations are then derived. Both two- and three-body asymptotic behavior are possible and their relative importance is studied for systems where subsystems may be bound. The system of two nucleons outside a core is studied numerically in detail and the character of possible halo structure is pointed out and investigated.Comment: 16 pages, compressed and uuencoded PosrScript file, IFA-94/3

Biosynthesis of bioactive diterpenoids in the medicinal plant Vitex agnus‐castus

Vitex agnus‐castus L. (Lamiaceae) is a medicinal plant historically used throughout the Mediterranean region to treat menstrual cycle disorders, and is still used today as a clinically effective treatment for premenstrual syndrome. The pharmaceutical activity of the plant extract is linked to its ability to lower prolactin levels. This feature has been attributed to the presence of dopaminergic diterpenoids that can bind to dopamine receptors in the pituitary gland. Phytochemical analyses of V. agnus‐castus show that it contains an enormous array of structurally related diterpenoids and, as such, holds potential as a rich source of new dopaminergic drugs. The present work investigated the localisation and biosynthesis of diterpenoids in V. agnus‐castus . With the assistance of matrix‐assisted laser desorption ionisation‐mass spectrometry imaging (MALDI‐MSI), diterpenoids were localised to trichomes on the surface of fruit and leaves. Analysis of a trichome‐specific transcriptome database, coupled with expression studies, identified seven candidate genes involved in diterpenoid biosynthesis: three class II diterpene synthases (diTPSs); three class I diTPSs; and a cytochrome P450 (CYP). Combinatorial assays of the diTPSs resulted in the formation of a range of different diterpenes that can account for several of the backbones of bioactive diterpenoids observed in V. agnus‐castus . The identified CYP, Vac CYP76BK1, was found to catalyse 16‐hydroxylation of the diol‐diterpene, peregrinol, to labd‐13Z ‐ene‐9,15,16‐triol when expressed in Saccharomyces cerevisiae . Notably, this product is a potential intermediate in the biosynthetic pathway towards bioactive furan‐ and lactone‐containing diterpenoids that are present in this species

Developing a Methodology to Prioritize Texas Watersheds for Environmental Restoration Efforts

During the past 150 years, several Texas watersheds have undergone significant changes that affect land use, the amount of water flowing through these systems, water quality, and the numbers and types of fish and aquatic species that live in rivers and lakes (McKinney, 2002). For the most part, these changes can be attributed to human activities such as dam building and reservoir management, population growth and resulting increased water use, increased runoff from paved surfaces, the introduction of non-native plant species, and others (Jensen, 2003a). As a consequence, competition for waters between human uses and environmental purposes has now increased to such an extent that some habitats and ecosystems that rely on water may be in peril, especially in semiarid and arid regions of Texas (TWDB, 2002). Recently, there has been increased public interest in investigating whether policies and management strategies could be implemented to restore watersheds, riparian zones, and other natural areas critically important to support wildlife, fisheries, and forests (Brown, 2000 and Alnwick, 2003). Often, the goal is to restore these sites to conditions that approximate conditions that existed prior to intensive human settlement in the 1800s. Interest in restoring watersheds and ecosystems has been expressed by several agencies including the U.S. EPA (2000 and 2001) and the U.S. Fish and Wildlife Service (2000). At a local or regional level, efforts have been undertaken to identify restoration opportunities along the Texas Gulf Coast by General Land Office Natural Resources Inventory program (1998). In addition, organizations including the Nature Conservancy (2000), the National Wildlife Federation (1998), and the Galveston Bay Foundation (19980 have also examined the need to set priorities for environmental restoration. For example, the Nature Conservancy published a report, Designing a Geography of Hope (Groves et al, 2000), that describes one method of assessing restoration opportunities across ecosystems and watersheds. A special challenge facing restoration efforts is in developing management strategies that will benefit ecological conditions in watersheds while, at the same time, preserving existing land uses (including homes and businesses) as well as dams and other infrastructure. Activities to identify estuaries and other watersheds that may be in need of restoration efforts have been initiated by the U.S. Army Corps of Engineers (2000) and the National Oceanic and Atmospheric Administration (2002). To deal with these public concerns, the U.S. Army Corps of Engineers Fort Worth District Office has expressed interest in determining how watershed restoration programs could be designed and implemented. One of the primary needs in this regard is to develop a science-based process that could objectively evaluate, prioritize, and identify watersheds that most need restoration efforts as well as regions where these measures are most likely to succeed. If such a methodology were developed, the Corps could use these recommendations, in conjunction with non-Federal sponsors, to develop full-fledged feasibility studies within targeted watersheds. Obviously, such a method could potentially be used by other natural resources agencies and organizations in Texas and elsewhere. It should be noted that the Corps is already engaged in ecosystem restoration studies and projects in some parts of Texas, though these efforts are developed as a part of comprehensive Corps projects. Some of these Texas projects include efforts in San Antonio (Salado Creek), Dallas, Houston, the North Bosque River watershed, and other regions. This project seeks to create a methodology that can be used to prioritize watersheds throughout Texas for possible restoration projects, the feasibility of which would be determined in subsequent detailed studies. Environmental operating principles that should guide the Corps in its public works and water resources projects were identified in a March 2002 speech in Louisiana by Lt. General Robert Flowers (Corps of Engineers, 2002). Some of the main points he addressed include the following: * The Corps should strive to achieve environmental sustainability, * Balance should be sought between human activities and natural systems * Potential problems should be resolved by designing environmental and economic solutions that complement one another. * The Corps should seek ways to assess and mitigate potential adverse affects caused by Corps of Engineers projects on the environment

On the Afterglow of the X-ray Flash of 2003 July 23: Photometric evdence for an Off-Axis Gamma-Ray burst with an Associated Supernova

Peer reviewe

Selection of Wavelet Subbands Using Genetic Algorithm for Face Recognition

Abstract. In this paper, a novel representation called the subband face is proposed for face recognition. The subband face is generated from selected subbands obtained using wavelet decomposition of the original face image. It is surmised that certain subbands contain information that is more significant for discriminating faces than other subbands. The problem of subband selection is cast as a combinatorial optimization problem and genetic algorithm (GA) is used to find the optimum subband combination by maximizing Fisher ratio of the training features. The performance of the GA selected subband face is evaluated using three face databases and compared with other wavelet-based representations.

Nonlinear excitations in CsNiF3 in magnetic fields perpendicular to the easy plane

Experimental and numerical studies of the magnetic field dependence of the specific heat and magnetization of single crystals of CsNiF3 have been performed at 2.4 K, 2.9 K, and 4.2 K in magnetic fields up to 9 T oriented perpendicular to the easy plane. The experimental results confirm the presence of the theoretically predicted double peak structure in the specific heat arising from the formation of nonlinear spin modes. The demagnetizing effects are found to be negligible, and the overall agreement between the data and numerical predictions is better than reported for the case when the magnetic field was oriented in the easy plane. Demagnetizing effects might play a role in generating the difference observed between theory and experiment in previous work analyzing the excess specific heat using the sine-Gordon model.Comment: 6 pages, 5 figures, submitted to Phys. Rev.

Solitons in Triangular and Honeycomb Dynamical Lattices with the Cubic Nonlinearity

We study the existence and stability of localized states in the discrete nonlinear Schr{\"o}dinger equation (DNLS) on two-dimensional non-square lattices. The model includes both the nearest-neighbor and long-range interactions. For the fundamental strongly localized soliton, the results depend on the coordination number, i.e., on the particular type of the lattice. The long-range interactions additionally destabilize the discrete soliton, or make it more stable, if the sign of the interaction is, respectively, the same as or opposite to the sign of the short-range interaction. We also explore more complicated solutions, such as twisted localized modes (TLM's) and solutions carrying multiple topological charge (vortices) that are specific to the triangular and honeycomb lattices. In the cases when such vortices are unstable, direct simulations demonstrate that they turn into zero-vorticity fundamental solitons.Comment: 17 pages, 13 figures, Phys. Rev.