HILT : a terminology mapping service with a DDC spine

The role of DDC in the ongoing HILT (High-level Thesaurus) project is discussed. A phased initiative, funded by JISC in the UK, HILT addresses an issue of likely interest to anyone serving users wishing to cross-search or cross-browse groups of networked information services, whether at regional, national or international level - the problem of subject-based retrieval from multiple sources using different subject schemes for resource description. Although all three phases of HILT to date are covered, the primary concern is with the subject interoperability solution piloted in phase II, and with the use of DDC as a spine in that approach

Secluded Connectivity Problems

Consider a setting where possibly sensitive information sent over a path in a network is visible to every {neighbor} of the path, i.e., every neighbor of some node on the path, thus including the nodes on the path itself. The exposure of a path $P$ can be measured as the number of nodes adjacent to it, denoted by $N[P]$. A path is said to be secluded if its exposure is small. A similar measure can be applied to other connected subgraphs, such as Steiner trees connecting a given set of terminals. Such subgraphs may be relevant due to considerations of privacy, security or revenue maximization. This paper considers problems related to minimum exposure connectivity structures such as paths and Steiner trees. It is shown that on unweighted undirected $n$-node graphs, the problem of finding the minimum exposure path connecting a given pair of vertices is strongly inapproximable, i.e., hard to approximate within a factor of $O(2^{\log^{1-\epsilon}n})$ for any $\epsilon>0$ (under an appropriate complexity assumption), but is approximable with ratio $\sqrt{\Delta}+3$, where $\Delta$ is the maximum degree in the graph. One of our main results concerns the class of bounded-degree graphs, which is shown to exhibit the following interesting dichotomy. On the one hand, the minimum exposure path problem is NP-hard on node-weighted or directed bounded-degree graphs (even when the maximum degree is 4). On the other hand, we present a polynomial algorithm (based on a nontrivial dynamic program) for the problem on unweighted undirected bounded-degree graphs. Likewise, the problem is shown to be polynomial also for the class of (weighted or unweighted) bounded-treewidth graphs

Ichthyotoxism in Capoeta capoeta gracilis (Keyserling, 1861) from west of Urmia (Marmisho Lake), Iran

Fish egg poisoning is a public health hazard although usually the incident rate, mortality and fish species involved are not well reported (Halstead,1970). Four species of Cyprinidae in Iran have been suggested as ichthyotoxic by Coad (1979) .namely Abramis brama. Cyprinus carpio .Schizothorax zarudnyi and Tinca tinca and it was thought that other species may be discovered subsequently.Najafpour and Coad (2002) reported ichthyotoxin in the cyprinid Barbus luteus from Iran ,and the study records another species. The Cyprinid fish Capoeta capoeta known as Siah mahi or gara balig in Iran

Gunn Effect in Silicon Nanowires: Charge Transport under High Electric Field

Gunn (or Gunn-Hilsum) Effect and its associated negative differential resistivity (NDR) emanates from transfer of electrons between two different energy bands in a semiconductor. If applying a voltage (electric field) transfers electrons from an energy sub band of a low effective mass to a second one with higher effective mass, then the current drops. This manifests itself as a negative slope or NDR in the I-V characteristics of the device which is in essence due to the reduction of electron mobility. Recalling that mobility is inversely proportional to electron effective mass or curvature of the energy sub band. This effect was observed in semiconductors like GaAs which has direct bandgap of very low effective mass and its second indirect sub band is about 300 meV above the former. More importantly a self-repeating oscillation of spatially accumulated charge carriers along the transport direction occurs which is the artifact of NDR, a process which is called Gunn oscillation and was observed by J. B. Gunn. In sharp contrast to GaAs, bulk silicon has a very high energy spacing (~1 eV) which renders the initiation of transfer-induced NDR unobservable. Using Density Functional Theory (DFT), semi-empirical 10 orbital ($sp^{3}d^{5}s^{*}$) Tight Binding (TB) method and Ensemble Monte Carlo (EMC) simulations we show for the first time that (a) Gunn Effect can be induced in narrow silicon nanowires with diameters of 3.1 nm under 3 % tensile strain and an electric field of 5000 V/cm, (b) the onset of NDR in I-V characteristics is reversibly adjustable by strain and (c) strain can modulate the value of resistivity by a factor 2.3 for SiNWs of normal I-V characteristics i.e. those without NDR. These observations are promising for applications of SiNWs in electromechanical sensors and adjustable microwave oscillators.Comment: 18 pages, 6 figures, 63 reference

Arts Districts, Universities, and the Rise of Digital Media

In the last decade, arts and culture have been placed at the center of attention when discussing economic growth. In particular, studies on the “creative class” have been using arts and culture as an important factor impacting local economies. In addition, studies on local economic development have frequently viewed universities as a major factor in economic growth. In the middle of this discussion is new economic growth via creativity, via new recipes and new combinations of local capital, and via innovation centers. Combining these disparate literatures brings to center stage both clusters of arts and culture and concentrations of research and human capital development. Hence, the focus of this paper is to analyze the dual impacts of universities and arts districts on innovation and economic growth through employment in digital media. The results indicate that cultural districts have a consistently positive effect on local digital media economic activity—employment and innovation. The same cannot be said for research universities

Fishing trend and fisheries potential analyses for the Persian Gulf and Sea of Oman, 1973-2003

Catch data from Persian Gulf and Sea of Oman during 1973 to 2001 were used to assess the state of the fishery development in these ecosystems. Also, fishery trends were analyzed to determine catch fluctuations during the period. Catch trend for each species from 1997 to 2003 was analyzed and fishing potential of the species for the following year was predicted. Based on the assessments, we can summarize fishing development in the southern waters of Iran into three periods: undeveloped, rapid development stage and developed stage. The undeveloped stage continued till early 1981, continued by a rapid stage until 1997, reaching to maximum level of at this year and continuing ever since. Catch trend analyses for each species during 1997 to 2003 showed different patterns for each species depending on its economic value. However, the mean catch of all species showed a sustainable trend in the two marine ecosystems. It is concluded that the catch quantity for most of the species have already reached a maximum level. Therefore, in order to keep fisheries sustainable in the region, excess fishing should be avoided