Preparation and optical properties of CdTe/CdO center dot nH(2)O core/shell nano-composites in aqueous solution

The deposition of CdO center dot nH(2)O On CdTe nanoparticles was studied in an aqueous phase. The CdTe nanocrystals (NCs) were prepared in aqueous solution through the reaction between Cd2+ and NaHTe in the presence of thioglycolic acid as a stabilizer. The molar ratio of the Cd2+ to Te2- in the precursory solution played an important role in the photoluminescence of the ultimate CdTe NCs. The strongest photoluminescence was obtained under 4.0 of [Cd2+]/[Te2-] at pH similar to 8.2. With the optimum dosage of Cd(II) hydrous oxide deposited on the CdTe NCs, the photoluminescence was enhanced greatly. The photoluminescence of these nanocomposites was kept constant in the pH range of 8.0-10.0, but dramatically decreased with an obvious blue-shifted peak while the pH was below 8.0. In addition, the photochemical oxidation of CdTe NCs with cadmium hydrous oxide deposition was markedly inhibited.

A comparison of seafloor habitats and associated benthic fauna in areas open and closed to bottom trawling along the central California Continental Shelf

Executive Summary: A number of studies have shown that mobile, bottom-contact fishing gear (such as otter trawls) can alter seafloor habitats and associated biota. Considerably less is known about the recovery of these resources following such disturbances, though this information is critical for successful management. In part, this paucity of information can be attributed to the lack of access to adequate control sites – areas of the seafloor that are closed to fishing activity. Recent closures along the coast of central California provide an excellent opportunity to track the recovery of historically trawled areas and to compare recovery rates to adjacent areas that continue to be trawled. In June 2006 we initiated a multi-year study of the recovery of seafloor microhabitats and associated benthic fauna inside and outside two new Essential Fish Habitat (EFH) closures within the Cordell Bank and Gulf of the Farallones National Marine Sanctuaries. Study sites inside the EFH closure at Cordell Bank were located in historically active areas of fishing effort, which had not been trawled since 2003. Sites outside the EFH closure in the Gulf of Farallones were located in an area that continues to be actively trawled. All sites were located in unconsolidated sands at equivalent water depths. Video and still photographic data collected via a remotely operated vehicle (ROV) were used to quantify the abundance, richness, and diversity of microhabitats and epifaunal macro-invertebrates at recovering and actively trawled sites, while bottom grabs and conductivity/temperature/depth (CTD) casts were used to quantify infaunal diversity and to characterize local environmental conditions. Analysis of still photos found differences in common seafloor microhabitats between the recovering and actively trawled areas, while analysis of videographic data indicated that biogenic mound and biogenic depression microhabitats were significantly less abundant at trawled sites. Each of these features provides structure with which demersal fishes, across a wide range of size classes, have been observed to associate. Epifaunal macro-invertebrates were sparsely distributed and occurred in low numbers in both treatments. However, their total abundance was significantly different between treatments, which was attributable to lower densities at trawled sites. In addition, the dominant taxa were different between the two sites. Patchily-distributed buried brittle stars dominated the recovering site, and sea whips (Halipteris cf. willemoesi) were most numerous at the trawled site though they occurred in only five of ten transects. Numerical classification (cluster analysis) of the infaunal samples also revealed a clear difference between benthic assemblages in the recovering vs. trawled areas due to differences in the relative abundances of component species. There were no major differences in infaunal species richness, H′ diversity, or J′ evenness between recovering vs. trawled site groups. However, total infaunal abundance showed a significant difference attributable to much lower densities at trawled sites. This pattern was driven largely by the small oweniid polychaete Myriochele gracilis, which was the most abundant species in the overall study region though significantly less abundant at trawled sites. Other taxa that were significantly less abundant at trawled sites included the polychaete M. olgae and the polychaete family Terebellidae. In contrast, the thyasirid bivalve Axinopsida serricata and the polychaetes Spiophanes spp. (mostly S. duplex), Prionospio spp., and Scoloplos armiger all had significantly to near significantly higher abundances at trawled sites. As a result of such contrasting species patterns, there also was a significant difference in the overall dominance structure of infaunal assemblages between the two treatments. It is suggested that the observed biological patterns were the result of trawling impacts and varying levels of recovery due to the difference in trawling status between the two areas. The EFH closure was established in June 2006, within a month of when sampling was conducted for the present study, however, the stations within this closure area are at sites that actually have experienced little trawling since 2003, based on National Marine Fishery Service trawl records. Thus, the three-year period would be sufficient time for some post-trawling changes to have occurred. Other results from this study (e.g., similarly moderate numbers of infaunal species in both areas that are lower than values recorded elsewhere in comparable habitats along the California continental shelf) also indicate that recovery within the closure area is not yet complete. Additional sampling is needed to evaluate subsequent recovery trends and persistence of effects. Furthermore, to date, the study has been limited to unconsolidated substrates. Ultimately, the goal of this project is to characterize the recovery trajectories of a wide spectrum of seafloor habitats and communities and to link that recovery to the dynamics of exploited marine fishes. (PDF has 48 pages.)

An Open and Social Spaced Repetition System for Language Learning

In the last decades big improvements have been done in the field of computer aided learning, based on improvements done in computer science and computer systems. Although the field has been always a bit lagged, without using the latest solutions, it has constantly gone forward taking profit of the innovations as they show up. As long as the train of the computer science does not stop (and it won’t at least in the near future) the systems that take profit of those improvements will not either, because we humans will always need to study; Sometimes for pleasure and some other many times out of need. Not all the attempts in the field of computer aided learning have been in the same direction. Most of them address one or some few of the problems that show while studying and don’t take into account solutions proposed for some other problems. The reasons for this can be varied. Sometimes the solutions simply are not compatible. Some other times, because the project is an investigation it’s interesting to isolate the problem. And, in commercial products, licenses and patents often prevent the new projects to use previous work. The world moved forward and this is an attempt to use some of the options offered by technology, mixing some old ideas with new ones.

Open Media Classes at Coventry University: Final Evaluation Report 2015

This report offers a reflection on findings from a one year evaluation study into the distributed open media classes at Coventry University The study team comprised Lou McGill and Tim Gray of Lou McGill Consultancy Ltd. This report is augmented by an open wiki (bit.ly/1KqL4nH) which includes more detail about the approaches used during the study and findings are also presented as a series of web pages (comc.loumcgill.co.uk). We would like to thank the Department of Media in the School of Art and Design for their input, openness and patience during the study.

Sustainability of Open Access Services - Phases 1 & 2

Although some services that support Open Access have developed a sustainable business model, many started as projects and continue to run on recurrent project funding or goodwill. If these are critical components of the evolving scholarly communication system the foundation of Open Access is vulnerable. Knowledge Exchange has commissioned this study as part of a larger programme of work to look at the issue of sustaining key services into the long term. This report focuses on phases one and two of the programme. Phase one was a scoping exercise, carried out mainly through a literature review and an extensive stakeholder interview exercise, to describe the services that are currently available or would be valuable in the future. It also investigated what roles stakeholders could play in this future scenario. Phase two was a stakeholder consultation and engagement exercise. The aim was to engage stakeholders with the work programme so that they could contribute their views, get involved with the work and have a voice in the thinking about future scenarios. The key services are presented for three future scenarios: ‘Gold’ Open Access, fully ‘Green’ Open Access and Green’ Open Access supplementing subscription access as ‘Gold’ OA grows. Three strategic areas are identified as having particular potential for future work. These are embedding business development expertise into service development; consideration of how to move money around the system to enable Open Access to be achieved optimally; and governance and coordination of the infrastructural foundation of Open Access. The report concludes with seven recommendations, both high-level and practical, for further work around these strategic areas.

SUSTAINABILITY OF OPEN ACCESS SERVICES: Phase 3: The Collective Provision of Open Access Resources

The report ‘Sustainability of Open Access Services - Phase 3: The Collective Provision of Open Access Resources’ discusses the economic and institutional issues faced by those sustaining free infrastructure services. It also identifies strategies to coordinate the collective provision of infrastructure services. These considerations are valuable input for the phases 4 and 5 of the project ‘Sustainability of Open Access Services’. This body of work will lead to practical recommendations for funders and project planners to consider when initiating an infrastructure service. The report was written by Raym Crow and funded by SPARC. Several key messages from the report are of interest. Providing infrastructure services as a public good imposes specific requirements on the design of the sustainability model. The challenge is to get enough institutions to reveal their demand for the service and support this. Arguments for an institution to support can be altruism or reciprocity or there being sufficient benefit to the institution for supporting a service. Institutions can also work together on a service through collective action (collecting voluntary contributions) and cross subsidies (funding collected by offering exclusive benefits to contributors).

Report on Knowledge Exchange workshop Sustainable Business Models for Open Access Services

The work on the sustainability of organisations which exist to provide services to the Open Access community, commissioned by Knowledge Exchange, identified that such organisations need to have a business-like approach and that the absence of rigorous attention to all aspects of the business may lead to sub-optimal performance and, potentially, failure. With this in mind, a Sustainability Index was drafted for consideration by attendees at the Knowledge Exchange workshop on sustainability in Utrecht (February 2014). Over fifty participants, representing Open Access service providers, IT-infrastructure and research funders, and users,worked to making past recommendations from KE work on Open Access actionable.

Effects of the Maryland hydraulic clam dredge on populations of the soft-shell clam, Mya arenaria: final contract report

Final report on a three year study designed to investigate the effects of the Maryland hydraulic escalator clam dredge on populations and recruitment of the soft-shell clam, Mya arenaria. Experimental plots were established in the Potomac river, Maryland, and were dredged ina commerical manner by removing only legal size clams. quarterly samples were taken in the experimental and control plots by means of a van Veen grab for juvenile clams and the hydraulic dredge for older, deeper burrowing clams. Sediment samples were taken at selected periods for organic carbon and grain size analysis. Clams were separated into two size-groups. (PDF contains 38 pages)