OaklandTeenZone: Humming its own new tune

On January 17, 2009, after years of planning, fundraising, and construction delays, the Oakland Public Library (OPL) finally overcame all obstacles and opened its much-anticipated, newly remodeled TeenZone Department. Planning began in 2001 with the vision that OPL TeenZone would accommodate, educate, and celebrate the city\u27s youth; eight years later this teen space is fulfilling that mission

Studying the small scale ISM structure with supernovae

AIMS. In this work we explore the possibility of using the fast expansion of a Type Ia supernova photosphere to detect extra-galactic ISM column density variations on spatial scales of ~100 AU on time scales of a few months. METHODS. We constructed a simple model which describes the expansion of the photodisk and the effects of a patchy interstellar cloud on the observed equivalent width of Na I D lines. Using this model we derived the behavior of the equivalent width as a function of time, spatial scale and amplitude of the column density fluctuations. RESULTS. The calculations show that isolated, small (<100 AU) clouds with Na I column densities exceeding a few 10^11 cm^-2 would be easily detected. In contrast, the effects of a more realistic, patchy ISM become measurable in a fraction of cases, and for peak-to-peak variations larger than ~10^12 cm^-2 on a scale of 1000 AU. CONCLUSIONS. The proposed technique provides a unique way to probe the extra-galactic small scale structure, which is out of reach for any of the methods used so far. The same tool can also be applied to study the sub-AU Galactic ISM structure.Comment: 6 pages, 3 figures. Accepted for publication in Astronomy & Astrophysic

SPATIAL COMPARISONS OF POPULATIONS OF AN INDIGENOUS LIMPET SCUTELLASTRA ARGENVILLEI AND AN ALIEN MUSSEL MYTILUS GALLOPROVINCIALIS ALONG A GRADIENT OF WAVE ENERGY

In the 1970s, the Mediterranean mussel Mytilus galloprovincialis invaded the South African coast and spread rapidly to dominate much of the West Coast, indicating either the opportunity to occupy a vacant niche or its superior competitive capability over indigenous species. In Namaqualand on the West Coast it appears to compete with a large indigenous limpet, Scutellastra argenvillei, which is capable of forming dense, almost monospecific stands low on the shore. A survey on the Namaqualand coast indicated that the abundance of M. galloprovincialis changes with wave exposure. At wave-exposed locations, the mussel covered up to 90&#37 of the primary substratum, whereas in semi-exposed situations it was never abundant. As the cover of M. galloprovincialis increased, the abundance and size of S. argenvillei on rock declined and it became confined to patches within a matrix of mussel bed. Both species were absent from sheltered shores and diminished where wave action was extreme. Comparisons with previous surveys indicated that exposed sites now largely covered by the alien mussel were once dominated by dense populations of the limpet. Therefore, the results of this survey provide circumstantial correlative evidence of a competitive interaction between M. galloprovincialis and S. argenvillei, and suggest that wave action mediates the strength of this interaction. The presence of mussel beds provides a novel settlement and living substratum for recruits and juveniles of S. argenvillei, albeit at much lower densities than in limpet patches. Adult limpets were virtually excluded from the mussel beds owing to their large size, which indicates the unsuitability of this habitat as a replacement substratum after competitive exclusion from primary rock space.Afr. J. mar. Sci. 25: 195–21

Spectroscopically Peculiar Type Ia Supernovae and Implications for Progenitors

In a recent paper Li et al. (2000) reported that 36 percent of 45 Type Ia supernovae (SNe Ia) discovered since 1997 in two volume-limited supernova searches were spectroscopically peculiar, and they suggested that because this peculiarity rate is higher than that reported for an earlier observational sample by Branch et al. (1993), it is now more likely that SNe Ia are produced by more than one kind of progenitor. In this paper I discuss and clarify the differences between the results of Li et al. and Branch et al. and I suggest that multiple progenitor systems are now less likely than they were before.Comment: 11 pages; accepted by PASP; several minor changes, 2 references added, main conclusions unchange

Strategic Review of Tropical Fisheries Management

This project addresses the constraints to tropical fisheries development with sustainable exploitation through a strategic assessment of tropical fisheries management with the following purposes: (1) To evaluate relevant research methods for the development of assessment models appropriate to the circumstances of tropical coastal fisheries; and (2) To evaluate the utility of existing strategies for the implementation of management advice. The report consists of three substantive chapters. Chapter 2 contains a detailed socio-economic assessment of various instruments and implementation strategies applicable to tropical capture fisheries. In Chapter 3, a detailed assessment of the fisheries for tropical large marine ecosystems has been conducted using a technique developed by FAO (Granger & Garcia 1996). The data used were the FAO statistics published regularly by FAO. This analysis has been conducted for each of the tropical large marine ecosystems and indicates that there is the potential for increased fishing in a number of these ecosystems. One of the clear requirements identified in Chapter 2 and implicit in Chapter 3, is that there is a significant need for simple and robust fisheries assessment methods which can estimate the potential of a particular resource, its capacity in terms of the level of fishing effort and its current status ie whether it is currently exploited sustainably or not. In Chapter 4, these problems are addressed directly and, using two approaches, significant simplification of fishery methods is developed. In the first approach, simple empirical relationships between the life history parameters of a species are used to develop models of potential yield which can be determined by a simple assessment of fish growth. In the second approach, optimal life history theory is applied to the key demographic parameters of exploited fish populations and using estimates of the Beverton & Holt invariants a significant simplifying of the basic stock assessment equations is developed

Electrochemistry in supercritical fluids

A wide range of supercritical fluids (SCFs) have been studied as solvents for electrochemistry with carbon dioxide and hydrofluorocarbons (HFCs) being the most extensively studied. Recent advances have shown that it is possible to get well-resolved voltammetry in SCFs by suitable choice of the conditions and the electrolyte. In this review, we discuss the voltammetry obtained in these systems, studies of the double-layer capacitance, work on the electrodeposition of metals into high aspect ratio nanopores and the use of metallocenes as redox probes and standards in both supercritical carbon dioxide–acetonitrile and supercritical HFCs

The recoverability of fingerprints on paper exposed to elevated temperatures - Part 1: comparison of enhancement techniques

This research investigates the recoverability of fingerprints which have been exposed to elevated temperatures in order to mimic the environment a piece of paper may be exposed to within an arson scene. Arson is an expensive crime, costing the UK economy, on average, £53.8 million each week [1]. Anything which may give rise to the identity of the fire setter should be analysed and as such, unburnt paper may be a potential source of fingerprints. While it is true that even a moderate fire will obscure and render partially useless some types of evidence, many items, including fingerprints, may still survive [2-4]. This research has shown that fingerprints are still retrievable from paper which has been subjected to the maximum testing conditions of 200˚C for 320min. In fact, some fingerprints naturally enhance themselves by the heating process. This investigation has also shown that the most effective enhancement technique was found to be 1,8-diazafluoren-9-one (DFO) for exposure temperatures upto 100˚C. Physical developer (PD) is the most effective enhancement technique for exposure temperatures from 100˚C to 200˚C. For porous surfaces, there are fingerprint development techniques which are effective at enhancing fingerprints exposed upto a temperature of 200˚C, irrespective of the firefighting extinguishing technique, as PD, in addition to developing fingerprints exposed to high temperatures, is one of the few processes which will enhance fingermarks on wetted surfaces

TEMPORAL CHANGES IN AN INTERACTION BETWEEN AN INDIGENOUS LIMPET SCUTELLASTRA ARGENVILLEI AND AN ALIEN MUSSEL MYTILUS GALLOPROVINCIALIS: EFFECTS OF WAVE EXPOSURE

A previous survey of 15 sites off the Namaqualand coast on the west coast of South Africa provided evidence of a competitive interaction between an alien mussel Mytilus galloprovincialis and an indigenous limpet Scutellastra argenvillei, and indicated that wave action mediates the strength of this interaction. In this study, the temporal persistence of these patterns was tested by selecting six sites, ranging from sheltered to very exposed, and monitoring them over a two-year period. The patterns remained consistent over time. Both S. argenvillei and M. galloprovincialis were perpetually absent from the most sheltered site. The limpet consistently dominated rock space at the semi-exposed site where mussel cover was always low. At exposed sites, M. galloprovincialis was dominant but its percentage cover varied temporally as a result of wave action, creating free space and allowing temporary expansion of limpet patches. However, with time the mussel recolonized the cleared rock space and repeatedly displaced the limpet from it. This provides additional observational evidence of competition for space between the alien invader and the indigenous limpet. It is concluded that S. argenvillei has a spatial refuge from M. galloprovincialis in areas with moderate wave action. However, the limpet is likely to become locally extinct on exposed shores because mussels outcompete it there and rapidly recolonize patches from which they have been temporarily eliminated by wave action.Afr. J. mar. Sci. 25: 213–22

The recoverability of fingerprints on paper exposed to elevated temperatures - Part 2: natural fluorescence

Previous work by the authors [1] investigated the recoverability of fingerprints on paper which had been exposed to elevated temperatures by comparing various chemical enhancement techniques (ninhydrin, 1,8-diazafluoren-9-one (DFO), and physical developer (PD)). During that study, it became apparent, as a consequence of observations made in operational work [2], that fingerprints on paper subjected to 150˚C fluoresced under examination with green light of waveband 473-548nm with a 549nm viewing filter. This work examined the three types of prints (eccrine, sebaceous, and ungroomed) after 20 min exposure to the temperature range 110˚C to 190˚C (in 10˚C increments) and found that the eccrine fingerprints fluoresced more brightly. This indicated that it was a component of the eccrine deposit which was causing the fluorescence. Luminance measurements found that the maximum fluorescence was experienced at 170˚C on both types of paper. As a consequence, eccrine heat-treated fingerprints were viewed under violet-blue (350-469nm), blue (352-509nm), and green light (473-548nm) which indicated that the greatest luminance intensities were obtained under blue light and the smallest under green light. In order to determine what component of the eccrine fingerprint was causing this fluorescence, five of the most prevalent amino acids (alanine, aspartic acid, glycine, lysine, and serine) [3-4] were exposed to this temperature range. The luminance measurements were taken under exposure to the green light in order for the minimum fluorescence to be observed, with an assumption that blue-violet or blue illumination will provide brighter fluorescence in practice. The results indicated that four of the amino acids are behaving similarly across the temperature range, but with slightly different luminance measurements, but all are exhibiting some level of fluorescence. Thermal degradation products of alanine and aspartic acid have been suggested by Richmond-Aylor et al. [5]. The structure of these thermal degradation products is cyclic in nature, and as such, there is a possibility that two of these products would fluorescence. Sodium chloride and urea were also exposed to the temperature range and they also fluoresced to some extent. This work shows that eccrine fingerprints that have been exposed to temperatures of between 130˚C to 180˚C will fluoresce under violet-blue, blue, and green light. This level of fluorescence for ungroomed fingerprints is much less but this will be dependent on the individual, the more eccrine the deposit, the stronger the fluorescence. This work shows that the amino acids, sodium chloride, and urea present in fingerprint deposits are all contributing to the fluorescence of the print, but may not be the sole contributor as other eccrine components have not yet been tested

Chemical enhancement of footwear impressions in blood deposited on fabric — evaluating the use of alginate casting materials followed by chemical enhancement

Most footwear marks made in blood on a surface such as fabric tend to be enhanced in situ rather than physically recovered using a lifting technique prior to enhancement. This work reports on the use of an alginate material to recover the impressed footwear marks made in blood and deposited on a range of fabric types and colours. The lifted marks were then enhanced using acid black 1 and leuco crystal violet with excellent results. This presents a new method for the lifting and recovery of blood impressions in situ from crime scene followed by subsequent mark enhancement of the lifted impression