WorldWideScience

Sample records for aquatic peer input

  1. Water quality and avian inputs as sources of isotopic variability in aquatic macrophytes and macroinvertebrates

    OpenAIRE

    Esther Sebastian-Gonzalez; José Antonio Sanchez-Zapata; Joan Navarro; Antonio Delgado; Francisco Botella

    2012-01-01

    Different factors can affect the isotopic values of aquatic organisms. Nevertheless, water quality may be very important for aquatic organisms because they directly depend on it. In this article, we aimed to investigate if variations in the chemical and biological water characteristics affect the stable isotope values of aquatic organisms. We also wished to discuss alternative sources of isotopic variability. We analysed the water chemical characteristics, the input of extra nitrates from bir...

  2. Young mangrove stands produce a large and high quality litter input to aquatic systems

    NARCIS (Netherlands)

    Nga, B.T.; Tinh, H.Q.; Tam, D.T.; Scheffer, M.; Roijackers, R.M.M.

    2005-01-01

    Mangrove swamps are key ecosystems along the Vietnam coast. Although mangrove litter is thought to represent an important input of organic matter and nutrients to the coastal aquatic systems, the factors determining the quality and size of this litter flux have not been studied so far. We monitored

  3. A sugar biomarker proxy for assessing terrestrial versus aquatic sedimentary input

    Science.gov (United States)

    Hepp, Johannes; Rabus, Max; Laforsch, Christian; Anhäuser, Tobias; Glaser, Bruno; Zech, Michael

    2016-04-01

    Lake sediments are valuable, often continuous and potentially high resolution archives for studying past climate changes. Thereby, one of the crucial questions is often whether the origin of the organic matter in lake sediments is allochthonous (terrestrial) or autochthonous (aquatic). Here we present patterns of neutral sugars of various plants and algae species to answer the question whether the deoxyhexoses (fucose, rhamnose) to pentoses (arabinose, xylose) ratio can serve as a proxy for aquatic versus terrestrial sedimentary lake input, respectively. Our sugar pattern results show that the fucose + rhamnose content plotted against arabinose and xylose in a ternary diagram can be used to distinguish between algae and other (namely aquatic plants, emergent plant, and terrestrial plants) sugar sources. This finding is confirmed by a compilation with sugar data from the literature. Mosses plot within the range of algae. Although the (fucose + rhamnose)/(arabinose + xylose) ratio yields some overlapping between algae and soil/litter samples, we recommend this ratio, particularly when applied within a multiproxy approach, as promising proxy for distinguishing between aquatic vs. terrestrial organic matter in sedimentary archives. Regarding the sugar concentrations of the investigated samples, emergent plants show the highest values as well as the highest variability. Mosses, aquatic plants and algae yield lower sugar concentrations comparable to those of terrestrial plants.

  4. Young mangrove stands produce a large and high quality litter input to aquatic systems

    OpenAIRE

    Nga, B.T.; Tinh, H.Q.; Tam, D.T.; Scheffer, M.; Roijackers, R.M.M.

    2005-01-01

    Mangrove swamps are key ecosystems along the Vietnam coast. Although mangrove litter is thought to represent an important input of organic matter and nutrients to the coastal aquatic systems, the factors determining the quality and size of this litter flux have not been studied so far. We monitored leaf, stipule, twig, and reproductive litter monthly in monocultures of Rhizophora apiculata mangrove forests of 7, 11, 17 and 24 years old in the Camau province, Mekong Delta, Vietnam. Litter trap...

  5. Benzotriazole and tolyltriazole as aquatic contaminants. 1. Input and occurrence in rivers and lakes.

    Science.gov (United States)

    Giger, Walter; Schaffner, Christian; Kohler, Hans-Peter E

    2006-12-01

    The complexing agents benzotriazole (BT) and tolyltriazole (TT) are not only widely applied as anticorrosives, e.g., in aircraft deicer and anti-icer fluid (ADAF), but they are also used for so-called silver protection in dishwasher detergents. Due to their low biodegradability and limited sorption tendency, BT and TT are only partly removed in wastewater treatment. Residual concentrations of BT and TT were determined in ambient surface waters in Switzerland including 7 rivers which have distinct water flows and receive treated wastewater effluents at various dilution ratios. A maximum BT concentration of 6.3 microg/L was found in the Glatt River, and a maximum mass flow of 277 kg BT per week was observed in the Rhine River. In most cases, TT was about a factor 5-10 less abundant. During winter 2003/4, BT mass flows at 2 locations in the lower stretch of the Glatt River clearly indicated the input from nearby Zurich airport, where BT was applied as an anticorrosive ADAF component. BT concentrations measured in the three lakes Greifensee, Lake Zurich, and Lake Geneva were approximately 1.2, 0.1-0.4, and 0.2 microg/L, respectively. The observed environmental occurrences indicate that BT and TT are ubiquitous contaminants in the aquatic environment and that they belong to the most abundant individual water pollutants. PMID:17180965

  6. Variable role of aquatic macroinvertebrates in initial breakdown of seasonal leaf litter inputs to a cold-desert river

    Science.gov (United States)

    Nelson, S.M.; Andersen, D.C.

    2007-01-01

    We used coarse-mesh and fine-mesh leafpacks to examine the importance of aquatic macroinvertebrates in the breakdown of floodplain tree leaf litter that seasonally entered a sand-bedded reach of the sixth-order Yampa River in semiarid Colorado. Leafpacks were positioned off the easily mobilized channel bed, mimicking litter trapped in debris piles. Organic matter (OM) loss was fastest for leaves collected from the floodplain and placed in the river in spring (k = 0.029/day) and slowest for leaves collected and placed in the river in winter (0.006/day). Macroinvertebrates were most abundant in winter and spring leaves, but seemed important to processing only in spring, when exclusion by fine mesh reduced OM loss by 25% and nitrogen loss by 65% in spring leaves. Macroinvertebrates seemed to have little role in processing of autumn, winter, or summer leaves over the 50-day to 104-day monitoring periods. Desiccation during bouts of low discharge and sediment deposition on leaves limited invertebrate processing in summer and autumn, whereas processing of winter leaves, which supported relatively large numbers of shredders, might have been restricted by ice formation and low water temperatures. These results were consistent with the concept that microbial processing dominates in higher-order rivers, but suggested that macroinvertebrate processing can be locally important in higher-order desert rivers in seasons or years with favorable discharge and water quality conditions.

  7. Erosion-Induced Carbon Fluxes from Semiarid Rangelands: Implications of Vegetation Cover and Enrichment Dynamics for Carbon Inputs to Aquatic Systems

    Science.gov (United States)

    Cunliffe, Andrew; Puttock, Alan; Turnbull, Laura; Wainwright, John; Brazier, Richard

    2016-04-01

    Dryland ecosystems are a globally significant of the global carbon cycle. They cover ca. 40% of the land surface, and dominate both the long-term trend and interannual variability in the terrestrial carbon sink. Therefore, developing process-based understanding of carbon dynamics in drylands is essential for understanding terrestrial carbon dynamics globally. This study focuses on the amounts of organic carbon (OC) eroded from semiarid hillslopes. Dryland ecosystems are characteristically susceptible to change. One example of this is the encroachment of woody shrubs into former grasslands, substantially altering the structure and function of these landscapes. We established four, 30 x 10 m runoff plots across an ecotone from grass- to shrub dominated landscapes, which we monitored during natural rainstorm events over four monsoon seasons. The OC fluxes associated with the eroded sediment were analysed, yielding detailed information on the lateral efflux of OC from these hillslopes. Previous monitoring by our group has demonstrated that production of dissolved OC from these dryland soils is very low. Erosion-induced effluxes of OC were found to systematically increase across the grass-shrub ecotone, resulting in six-fold increases in event-average OC fluxes. The increases were caused by to changes in both erosion rates (three and a half-fold increase) and OC enrichment (almost two-fold increase). Eroded sediments were enriched in OC by up to an order of magnitude, and OC enrichment was a persistent phenomenon. Systematic differences in OC enrichment between different plant functional types in unmanaged ecosystems have not been examined closely in previous work. Together, these findings suggest that (i) failing to consider OC enrichment risks substantially underestimating the input of OC to aquatic systems, and (ii) given the magnitude of systematic differences observed between different plant functional types, attempting to represent OC enrichment via a single

  8. New Rhizon in situ sampler for pore water studies in aquatic sediments: For example nutrient input from submarine groundwater discharge in costal areas.

    OpenAIRE

    Seeberg-Elverfeldt, J.; Schlüter, Michael; Kölling, M.; Feseker, T.

    2005-01-01

    To investigate coastal biogeochemical cycles, especially at the sediment/water interface,improved sampling methods are necessary. For this purpose, we developed apore water in situ sampler with miniature sampling devices, so called Rhizons. Rhizonsoil moisture samplers have been used as sampling devices in unsaturated soilsfor the last ten years. In aquatic science they have been rarely used to extract porewater from sediments. This study presents a new developed Rhizon In Situ Sampler(RISS) ...

  9. Review on environmental alterations propagating from aquatic to terrestrial ecosystems.

    Science.gov (United States)

    Schulz, Ralf; Bundschuh, Mirco; Gergs, René; Brühl, Carsten A; Diehl, Dörte; Entling, Martin H; Fahse, Lorenz; Frör, Oliver; Jungkunst, Hermann F; Lorke, Andreas; Schäfer, Ralf B; Schaumann, Gabriele E; Schwenk, Klaus

    2015-12-15

    Terrestrial inputs into freshwater ecosystems are a classical field of environmental science. Resource fluxes (subsidy) from aquatic to terrestrial systems have been less studied, although they are of high ecological relevance particularly for the receiving ecosystem. These fluxes may, however, be impacted by anthropogenically driven alterations modifying structure and functioning of aquatic ecosystems. In this context, we reviewed the peer-reviewed literature for studies addressing the subsidy of terrestrial by aquatic ecosystems with special emphasis on the role that anthropogenic alterations play in this water-land coupling. Our analysis revealed a continuously increasing interest in the coupling of aquatic to terrestrial ecosystems between 1990 and 2014 (total: 661 studies), while the research domains focusing on abiotic (502 studies) and biotic (159 studies) processes are strongly separated. Approximately 35% (abiotic) and 25% (biotic) of the studies focused on the propagation of anthropogenic alterations from the aquatic to the terrestrial system. Among these studies, hydromorphological and hydrological alterations were predominantly assessed, whereas water pollution and invasive species were less frequently investigated. Less than 5% of these studies considered indirect effects in the terrestrial system e.g. via food web responses, as a result of anthropogenic alterations in aquatic ecosystems. Nonetheless, these very few publications indicate far-reaching consequences in the receiving terrestrial ecosystem. For example, bottom-up mediated responses via soil quality can cascade over plant communities up to the level of herbivorous arthropods, while top-down mediated responses via predatory spiders can cascade down to herbivorous arthropods and even plants. Overall, the current state of knowledge calls for an integrated assessment on how these interactions within terrestrial ecosystems are affected by propagation of aquatic ecosystem alterations. To fill

  10. Aquatic plants

    DEFF Research Database (Denmark)

    Madsen, T. V.; Sand-Jensen, K.

    2006-01-01

    Aquatic fl owering plants form a relatively young plant group on an evolutionary timescale. The group has developed over the past 80 million years from terrestrial fl owering plants that re-colonised the aquatic environment after 60-100 million years on land. The exchange of species between...... terrestrial and aquatic environments continues today and is very intensive along stream banks. In this chapter we describe the physical and chemical barriers to the exchange of plants between land and water....

  11. An Analysis of Peer-Submitted and Peer-Reviewed Answer Rationales, in an Asynchronous Peer Instruction Based Learning Environment

    Science.gov (United States)

    Bhatnagar, Sameer; Lasry, Nathaniel; Desmarais, Michel; Dugdale, Michael; Whittaker, Chris; Charles, Elizabeth S.

    2015-01-01

    This paper reports on an analyis of data from a novel "Peer Instruction" application, named DALITE. The Peer Instruction paradigm is well suited to take advantage of peer-input in web-based learning environments. DALITE implements an asynchronous instantiation of peer instruction: after submitting their answer to a multiple-choice…

  12. Peer Pressure

    Science.gov (United States)

    ... How Can I Help a Friend Who Cuts? Peer Pressure KidsHealth > For Teens > Peer Pressure Print A A A Text Size What's in ... She'd just had a big dose of peer pressure. Who Are Your Peers? When you were a ...

  13. Aquatic Sediments.

    Science.gov (United States)

    Sanville, W. D.; And Others

    1978-01-01

    Presents a literature review of aquatic sediments and its effect upon water quality, covering publications of 1976-77. This review includes: (1) sediment water interchange; (2) chemical and physical characterization; and (3) heavy water in sediments. A list of 129 references is also presented. (HM)

  14. Spatial Pattern Dynamics in Aquatic Ecosystem Modelling

    NARCIS (Netherlands)

    Hong Li

    2009-01-01

    In this thesis, several modelling approaches are explored to represent spatial pattern dynamics of aquatic populations in aquatic ecosystems by the combination of models, knowledge and data in different scales. It is shown that including spatially distributed inputs retrieved from Remote Sensing i

  15. Aquatic adventitious roots of the wetland plant Meionectes brownii can photosynthesize

    DEFF Research Database (Denmark)

    Rich, Sarah Meghan; Ludwig, Martha; Pedersen, Ole;

    2011-01-01

    roots during submergence. • Underwater photosynthetic light and CO(2) response curves were determined for aquatic-adapted leaves, stems and aquatic roots of M. brownii. Oxygen microelectrode and (14)CO(2)-uptake experiments determined shoot inputs of O(2) and photosynthate into aquatic roots. • Aquatic...... m(-3) dissolved CO(2), aquatic roots fix carbon at 0.016 µmol CO(2) g(-1) DM s(-1). Illuminated aquatic roots do not rely on exogenous inputs of O(2). • The photosynthetic ability of aquatic roots presumably offers an advantage to submerged M. brownii as aquatic roots, unlike sediment roots, need...

  16. Is there something like a peer to peer science?

    Directory of Open Access Journals (Sweden)

    Michel Bauwens

    2010-03-01

    Full Text Available How will peer to peer infrastructures, and the underlying intersubjective and ethical relational model that is implied by it, affect scientific practice? Are peer-to-peer forms of cooperation, based on open and free input of voluntary contributors, participatory processes of governance, and universal availability of the output, more productive than centralized alternatives? In this short introduction, Michel Bauwens reviews a number of open and free, participatory and commons oriented practices that are emerging in scientific research and practice, but which ultimately point to a more profound epistemological revolution linked to increased participatory consciousness between the scientist and his human, organic and inorganic research material.

  17. Peer Review

    OpenAIRE

    Robert P. Ferguson; Griffin, Stephanie M.

    2012-01-01

    Peer review seems to have had its origins in 18th century England to combat plagiarism. But today, the objectives of peer review are to provide evaluations of the quality of scientific or editorial material submitted. Peer review provides a check on the validity of manuscripts and sets standards for scientific merit. Peer review should help editors in making decisions about the manuscripts by offering second and third opinions. It lifts the quality of published articles to a higher standard. ...

  18. Peer Support.

    Science.gov (United States)

    Forchuk, Cheryl; Solomon, Michelle; Viran, Tazim

    2016-01-01

    The Mental Health Commission of Canada defines peer support as "a supportive relationship between people who have a lived experience in common … in relation to a mental health challenge or illness … related to their own mental health or that of a loved one" (Sunderland et al. 2013: 11). In Ontario, a key resource for peer support is the Ontario Peer Development Initiative (OPDI), which is an umbrella organization of mental health Consumer/Survivor Initiatives (CSIs) and peer support organizations across the province of Ontario. Member organizations are run by and for people with lived experience of a mental health or addiction issue and provide a wide range of services and activities within their communities. The central tenet of member organizations is the common understanding that people can and do recover with the proper supports in place and that peer support is integral to successful recovery. Nationally, Peer Support Accreditation and Certification Canada has recently been established. The relatively new national organization focuses on training and accrediting peer support workers. This paper focuses on a range of diverse peer support groups and CSIs that operate in London and surrounding areas. PMID:26854546

  19. A Dynamic Self-Adjusted Buffering Mechanism for Peer-to-Peer Real-Time Streaming

    Directory of Open Access Journals (Sweden)

    Jun-Li Kuo

    2011-05-01

    Full Text Available Multimedia live stream multicasting and on-line real-time applications are popular recently. Real-time multicast system can use peer-to-peer technology to keep stability and scalability without any additional support from the underneath network or a server. Our proposed scheme focuses on the mesh architecture of peer-to-peer live streaming system and experiments with the buffering mechanisms. We design the dynamic buffer to substitute the traditional fixed buffer.According to the existing measurements and our simulation results, using the traditional static buffer in a dynamic peer-to-peer environment has a limit of improving quality of service. In our proposed method, the buffering mechanism can adjust buffer to avoid the frozen or reboot of streaming based on the input data rate. A self-adjusted buffer control can be suitable for the violently dynamic peer-to-peer environment. Without any support of infrastructure and modification of peer-to-peer protocols, our proposed scheme can be workable in any chunk-based peer-to-peer streaming delivery. Hence, our proposed dynamic buffering mechanism varies the existing peer-to-peer live streaming system less to improve quality of experience more.

  20. Peer-to-Peer Secure Multi-Party Numerical Computation

    CERN Document Server

    Bickson, Danny; Dolev, Danny; Pinkas, Benny

    2008-01-01

    We propose an efficient framework for enabling secure multi-party numerical computations in a Peer-to-Peer network. This problem arises in a range of applications such as collaborative filtering, distributed computation of trust and reputation, monitoring and numerous other tasks, where the computing nodes would like to preserve the privacy of their inputs while performing a joint computation of a certain function. Although there is a rich literature in the field of distributed systems security concerning secure multi-party computation, in practice it is hard to deploy those methods in very large scale Peer-to-Peer networks. In this work, we examine several possible approaches and discuss their feasibility. Among the possible approaches, we identify a single approach which is both scalable and theoretically secure. An additional novel contribution is that we show how to compute the neighborhood based collaborative filtering, a state-of-the-art collaborative filtering algorithm, winner of the Netflix progress ...

  1. Spreading of Oil Spill on Placid Aquatic Medium

    OpenAIRE

    Derrick O. NJOBUENWU; Millionaire F. N. ABOWEI

    2008-01-01

    Continuous research in the development of suitable predictive model is vital as the input of oil spills into the aquatic environment particularly in the Niger Delta area of Nigeria is alarming due to frequent oil spills. This eventually affects aquatic organisms and shoreline activities. This work developed an semi-empirical expression that can predict the horizontal spreading of Niger Delta Oil Spills (NDOS) on a placid water body using simple physical coefficients of the oil and the aquatic...

  2. Peer Review

    DEFF Research Database (Denmark)

    Dannesboe, Christian

    Peer-teknikker brugt i undervisning vinder frem mange steder. Teknikkerne er skalerbare til meget store hold af studerende, og ses derfor som et af de værktøjer, der med fordel kan introduceres som underviser, når holdstørrelserne vokser.......Peer-teknikker brugt i undervisning vinder frem mange steder. Teknikkerne er skalerbare til meget store hold af studerende, og ses derfor som et af de værktøjer, der med fordel kan introduceres som underviser, når holdstørrelserne vokser....

  3. Peer abuse

    OpenAIRE

    Alikaşifoğlu, Müjgan

    2011-01-01

    Peer abuse is commonly seen as bullying behaviors The most common definition of bullying used in the literature was formulated by Dan nbsp;Olweus According to Olweus bullying is an aggressive behavior that: a is intended to cause harm or distress b occurs repeatedly over nbsp;time and c occurs in a relationship in which there is an imbalance of power Peer abuse shares many characteristics with other types of nbsp;abuse namely child maltreatment and domestic violence Bullying behaviors may be ...

  4. An updated Quantitative Water Air Sediment Interaction (QWASI) model for evaluating chemical fate and input parameter sensitivities in aquatic systems: application to D5 (decamethylcyclopentasiloxane) and PCB-180 in two lakes.

    Science.gov (United States)

    Mackay, Donald; Hughes, Lauren; Powell, David E; Kim, Jaeshin

    2014-09-01

    The QWASI fugacity mass balance model has been widely used since 1983 for both scientific and regulatory purposes to estimate the concentrations of organic chemicals in water and sediment, given an assumed rate of chemical emission, advective inflow in water or deposition from the atmosphere. It has become apparent that an updated version is required, especially to incorporate improved methods of obtaining input parameters such as partition coefficients. Accordingly, the model has been revised and it is now available in spreadsheet format. Changes to the model are described and the new version is applied to two chemicals, D5 (decamethylcyclopentasiloxane) and PCB-180, in two lakes, Lake Pepin (MN, USA) and Lake Ontario, showing the model's capability of illustrating both the chemical to chemical differences and lake to lake differences. Since there are now increased regulatory demands for rigorous sensitivity and uncertainty analyses, these aspects are discussed and two approaches are illustrated. It is concluded that the new QWASI water quality model can be of value for both evaluative and simulation purposes, thus providing a tool for obtaining an improved understanding of chemical mass balances in lakes, as a contribution to the assessment of fate and exposure and as a step towards the assessment of risk. PMID:24997940

  5. Aquatic subsidies transport anthropogenic nitrogen to riparian spiders

    International Nuclear Information System (INIS)

    Stable nitrogen isotopic composition (δ15N) of aquatic biota increases with anthropogenic N inputs such as sewage and livestock waste downstream. Increase in δ15N of riparian spiders downstream may reflect the anthropogenic pollution exposure through predation on aquatic insects. A two-source mixing model based on stable carbon isotopic composition showed the greatest dependence on aquatic insects (84%) by horizontal web-building spiders, followed by intermediate (48%) and low (31%) dependence by cursorial and vertical web-building spiders, respectively. The spider body size was negatively correlated with the dietary proportion of aquatic insects and spider δ15N. The aquatic subsidies transported anthropogenic N to smaller riparian spiders downstream. This transport of anthropogenic N was regulated by spider's guild designation and body size. - Highlights: → δ15N of aquatic insects increases downstream with anthropogenic nitrogen inputs. → δ15N of riparian spiders increases with a high dietary proportion of aquatic insects and smaller spider body size. → The aquatic subsidies transport anthropogenic nitrogen to smaller riparian spiders downstream. - Smaller spiders assimilate anthropogenic nitrogen through the predation on aquatic subsides.

  6. The "Peer" in "Peer Review"

    Science.gov (United States)

    Perry, Gad; Bertoluci, Jaime; Bury, Bruce; Hansen, Robert W.; Jehle, Robert; Measey, John; Moon, Brad R.; Muths, Erin; Zuffi, Marco A.L.

    2011-01-01

    Peer review is the best available mechanism for assessing and improving the quality of scientific work. As herpetology broadens its disciplinary and geographic boundaries, high-quality external review is ever more essential. We are writing this editorial jointly because the review process has become increasingly difficult. The resulting delays slow publication times, negatively affect performance reviews, tenure, promotions, and grant proposal success. It harms authors, agencies, and institutions (Ware 2011).

  7. Lake Bathymetric Aquatic Vegetation

    Data.gov (United States)

    Minnesota Department of Natural Resources — Aquatic vegetation represented as polygon features, coded with vegetation type (emergent, submergent, etc.) and field survey date. Polygons were digitized from...

  8. Allelopathy of Aquatic Autotrophs

    OpenAIRE

    Gross, Elisabeth

    2003-01-01

    Allelopathy in aquatic environments may provide a competitive advantage to angiosperms, algae, or cyanobacteria in their interaction with other primary producers. Allelopathy can influence the competition between different photoautotrophs for resources and change the succession of species, for exarnple, in phytoplankton cornmunities. Field evidence and laboratory studies indicate that allelopathy occurs in all aquatic habitats (marine and freshwater), and that ail prirnary producing organisms...

  9. Peer-to-Peer Service Sharing Platforms

    DEFF Research Database (Denmark)

    Andersson, Magnus; Hjalmarsson, Anders; Avital, Michel

    2013-01-01

    cost. Whereas early peer-to-peer platforms were designed to enable file sharing and goods trading, we recently witness the emergence of a new breed of peer-to-peer platforms that are designed for ordinary service sharing. Ordinary services entail intangible provisions and are defined as an economic...... entail specific consequences for platform use as well as provide insights about their overall design imperative....

  10. Adaptive search in mobile peer-to-peer databases

    Science.gov (United States)

    Wolfson, Ouri (Inventor); Xu, Bo (Inventor)

    2010-01-01

    Information is stored in a plurality of mobile peers. The peers communicate in a peer to peer fashion, using a short-range wireless network. Occasionally, a peer initiates a search for information in the peer to peer network by issuing a query. Queries and pieces of information, called reports, are transmitted among peers that are within a transmission range. For each search additional peers are utilized, wherein these additional peers search and relay information on behalf of the originator of the search.

  11. Peer to Peer Networks Management Survey

    CERN Document Server

    Amad, Mourad; Aïssani, Djamil

    2012-01-01

    Peer-to-Peer systems are based on the concept of resources localization and mutualisation in dynamic context. In specific environment such as mobile networks, characterized by high variability and dynamicity of network conditions and performances, where nodes can join and leave the network dynamically, resources reliability and availability constitute a critical issue. The resource discovery problem arises in the context of peer to peer (P2P) networks, where at any point of time a peer may be placed at or removed from any location over a general purpose network. Locating a resource or service efficiently is one of the most important issues related to peer-to-peer networks. The objective of a search mechanism is to successfully locate resources while incurring low overhead and low delay. This paper presents a survey on P2P networks management: classification, applications, platforms, simulators and security.

  12. Peer-review thoughts

    Science.gov (United States)

    Barnes, Bill; Goodman, Maurice

    2016-03-01

    In reply to the news article on challenges for peer-review by Michael Banks “Peer review under the spotlight” (February pp12-13), the editorial by Matin Durrani “Handle with care” cautioning against reforming peer review too fast (February p15) and Robert P Crease's article “Peer review's value” (February p17).

  13. Aquatic Life Benchmarks

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Aquatic Life Benchmarks is an EPA-developed set of criteria for freshwater species. These benchmarks are based on toxicity values reviewed by EPA and used in...

  14. Aquatic Research Laboratory (ARL)

    Data.gov (United States)

    Federal Laboratory Consortium — Columbia River and groundwater well water sources are delivered to the Aquatic Research Laboratory (ARL), where these resources are used to conduct research on fish...

  15. Molecular ecology of aquatic microbes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Abstracts of reports are presented from a meeting on Molecular Ecology of Aquatic Microbes. Topics included: opportunities offered to aquatic ecology by molecular biology; the role of aquatic microbes in biogeochemical cycles; characterization of the microbial community; the effect of the environment on aquatic microbes; and the targeting of specific biological processes.

  16. Introducing Aquatic Biology

    OpenAIRE

    Kinne, Otto; Browman, Howard I.; Seaman, Matthias

    2007-01-01

    The Inter-Research Science Center (IR) journals Marine Ecology Progress Series (MEPS) and Aquatic Microbial Ecology (AME) have been receiving increasing numbers of high-quality manuscripts that are principally biological, rather than ecological. With regret, we have had to turn these submissions away. Also, leading limnologists have for many years suggested that IR should provide an outlet for top quality articles on freshwater biology and ecology. Aquatic Biology (...

  17. Restoring Damaged Aquatic Ecosystems

    OpenAIRE

    Cairns, John

    2006-01-01

    Aquatic ecosystems must play a major role to ensure that water, which is both essential and scarce, is always available for both present and future generations. This has become even more urgent in light of the ongoing increase in total world population and predicted changes in the world climate. Since aquatic ecosystems have been damaged at a rate far in excess of both natural restoration and anthropogenic restoration, it is essential that both restorative processes be accelerated. However, e...

  18. Automatic input rectification

    OpenAIRE

    Long, Fan; Ganesh, Vijay; Carbin, Michael James; Sidiroglou, Stelios; Rinard, Martin

    2012-01-01

    We present a novel technique, automatic input rectification, and a prototype implementation, SOAP. SOAP learns a set of constraints characterizing typical inputs that an application is highly likely to process correctly. When given an atypical input that does not satisfy these constraints, SOAP automatically rectifies the input (i.e., changes the input so that it satisfies the learned constraints). The goal is to automatically convert potentially dangerous inputs into typical inputs that the ...

  19. Modeling structured peer-to-peer systems

    Institute of Scientific and Technical Information of China (English)

    HAN Li; LEI Zhen-ming

    2006-01-01

    Distributed network architecture and dynamic change of nodes makes the operation of structured peer-to-peer networks unpredictable. This article aims to present a research on the running rule of structured peer-to-peer networks through a mathematical model. The proposed model provides a low-complexity means to estimate the performance of a structured peer-to-peer network from two aspects: the average existent time of a node and probability of returning to a temporarily steady state of network. On the basis of the results, it can be concluded that the proposed structured peer-to-peer network is suitable for those conditions where the frequency of node change is under limited value, and this value mainly depends on the initializing time of the node. Otherwise,structured peer-to-peer network can be abstracted as a network queuing system, which is composed of many node queuing systems in a meshy way and the relation between the throughput of the node system and network system is analyzed.

  20. Effects of Peers on Agricultural Productivity in Rural Northern India

    OpenAIRE

    Songsermsawas, Tisorn; Baylis, Katherine R.; Chhatre, Ashwini

    2014-01-01

    Using a unique dataset from a household survey containing explicit social relationships among individual farmers, this study estimate the effect of peers on the revenue from cash crop sales among small-scale farmers in Northern India. We explore the learning mechanism through which peer effect occurs through improved input use and higher degree of commercialization. The significant and positive peer effects support the evidence of social learning. We control for the reflection problem using t...

  1. Do peer groups matter? Peer groups versus schooling effects on academic attainment

    OpenAIRE

    Robertson, D; Symons, J.

    1996-01-01

    In this paper we estimate an educational production function. Educational attainment is a function of three types of inputs: peer group, parental and schooling. We find that conventional measures of school quality are not good predictors for academic attainment, once we control for peer group effects. Parental qualities also have strong effects on academic atainment. This academic attainment is then a key determinant of subsequent labour market success, as measured by earnings.

  2. HyperPeer

    DEFF Research Database (Denmark)

    Larsen, R.D.; Bouvin, N.O.

    2004-01-01

    This paper presents HyperPeer, a framework for developing peer-to-peer based hypermedia. The distribution of hypermedia structures is handled through a peer-to-peer (P2P) network, allowing for highly scalable sharing between users. A central challenge of all decentralized systems is to locate...... material of interest and this paper presents the HyperPeer Hierarchy of Resemblance (HR) searching algorithm, which provides an efficient search as well as partitioning of the network into groups of common interest....

  3. Sustaining America's Aquatic Biodiversity. Why is Aquatic Biodiversity Declining?

    OpenAIRE

    Helfrich, Louis A.; Neves, Richard J.; Parkhurst, James A. (James Albert)

    2005-01-01

    Discusses reasons for declining aquatic biodiversity and focuses mainly on the issues of habitat loss, introduced species (aquatic exotics), and water pollution; document also includes web links to more information on exotic, invasive species and endangered animals.

  4. Mobility Helps Peer-to-Peer Security

    DEFF Research Database (Denmark)

    Capkun, Srdjan; Hubaux, Jean-Pierre; Buttyan, Levente

    2006-01-01

    We propose a straightforward technique to provide peer-to-peer security in mobile networks. We show that far from being a hurdle, mobility can be exploited to set up security associations among users. We leverage on the temporary vicinity of users, during which appropriate cryptographic protocols...

  5. Input reallocation within firms

    OpenAIRE

    Vandenbussche, Hylke; Viegelahn, Christian

    2016-01-01

    This paper documents the within firm reallocation of inputs and outputs as a result of a trade policy shock on the input side. A unique firm-input level dataset for India with information on different raw material inputs used in production, enables us to identify firms with imported inputs subject to trade policy. To guide the empirics, we first develop a back-bone model of heterogeneous firms that source inputs from abroad. We find that affected firms engage in input reallocation and lower t...

  6. Peer Leadership Manual.

    Science.gov (United States)

    Lovell, Nikki; Hachmeister, Paula

    This is a manual for peer counselors and parents in an alcohol and drug abuse prevention program for teenagers. The document opens with the training objectives for the peer helpers: to know yourself, to be a resource, and to promote and establish a drug-free peer group and drug-free activities in school. Discussion on these topics is provided: (1)…

  7. Contaminated Aquatic Sediments.

    Science.gov (United States)

    Jaglal, Kendrick

    2016-10-01

    A review of the literature published in 2015 relating to the assessment, evaluation and remediation of contaminated aquatic sediments is presented. The review is divided into the following main sections: policy and guidance, methodology, distribution, fate and transport, risk, toxicity and remediation. PMID:27620103

  8. Aquatic Environment 2000

    DEFF Research Database (Denmark)

    Svendsen, L. M.; Bijl, L. van der; Boutrup, S.; Iversen, T. M.; Ellermann, T.; Hovmand, M. F.; Bøgestrand, J.; Grant, R.; Hansen, J.; Jensen, J. P.; Stockmarr, J.; Laursen, K. D.

    The report summarizes the results of the Danish Aquatic Monitoring and Assessment Programme 1998-2003. Danish Environmental Protection Agency 2000: NOVA-2003. Programbeskrivelse for det nationale program for overvågning af vandmiljøet 1998-2003. 397 pp. - Redegørelse fra Miljøstyrelsen nr. 1 (in...

  9. NASA Product Peer Review Process

    Science.gov (United States)

    Jenks, Ken

    2009-01-01

    This viewgraph presentation describes NASA's product peer review process. The contents include: 1) Inspection/Peer Review at NASA; 2) Reasons for product peer reviews; 3) Different types of peer reviews; and 4) NASA requirements for peer reviews. This presentation also includes a demonstration of an actual product peer review.

  10. Aquatic Pest Control. Manual 99.

    Science.gov (United States)

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet the minimum EPA standards for certification as a commercial applicator of pesticides in the aquatic pest control category. The text discusses various water use situations; aquatic weed identification; herbicide use and effects; and aquatic insects and their control. (CS)

  11. Introduced aquatic plants and algae

    Science.gov (United States)

    Non-native aquatic plants such as waterhyacinth and hydrilla severely impair the uses of aquatic resources including recreational faculties (lakes, reservoirs, rivers) as well as timely delivery of irrigation water for agriculture. Costs associated with impacts and management of all types of aquatic...

  12. Eutrophication of aquatic ecosystems: Bistability and soil phosphorus

    OpenAIRE

    Stephen R Carpenter

    2005-01-01

    Eutrophication (the overenrichment of aquatic ecosystems with nutrients leading to algal blooms and anoxic events) is a persistent condition of surface waters and a widespread environmental problem. Some lakes have recovered after sources of nutrients were reduced. In others, recycling of phosphorus from sediments enriched by years of high nutrient inputs causes lakes to remain eutrophic even after external inputs of phosphorus are decreased. Slow flux of phosphorus from overfertilized soils ...

  13. Cooperation in Peer-to-Peer Networks

    International Nuclear Information System (INIS)

    This paper presents results of a research conducted on a simple model of a peer-to-peer network (a network in which users exchange files directly, without any central server involved). The conditions necessary for the file exchange process to be efficient and stable are investigated through numerical simulations and analytical calculations based on the master equation. Ways of preventing free-riding (selfish behavior, when users download files without sharing them) are also discussed.(author)

  14. Aquatic Ecology Section

    International Nuclear Information System (INIS)

    Population studies were concerned with predicting long-term consequences of mortality imposed on animal populations by man's activities. These studies consisted of development of a generalized life cycle model and an empirical impingement model for use in impact analysis. Chemical effects studies were conducted on chlorine minimization; fouling by the Asiatic clam; identification of halogenated organics in cooling water; and effects of halogenated organics in cooling systems on aquatic organisms. Ecological transport studies were conducted on availability of sediment-bound 137Cs and 60Co to fish; 137Cs and 60Co in White Oak Lake fish; and chromium levels in fish from a lake chronically contaminated with chromates from cooling towers. Progress is also reported on the following: effects of irradiation on thermal tolerance of mosquito fish; toxicity of nickel to the developing eggs and larvae of carp; accumulation of selected heavy metals associated with fly ash; and environmental monitoring of aquatic ecosystems

  15. Aquatic CAM photosynthesis: a brief history of its discovery

    Science.gov (United States)

    Keeley, Jon E.

    2014-01-01

    Aquatic CAM (Crassulacean Acid Metabolism) photosynthesis was discovered while investigating an unrelated biochemical pathway concerned with anaerobic metabolism. George Bowes was a significant contributor to this project early in its infancy. Not only did he provide me with some valuable perspectives on peer review rejections, but by working with his gas exchange system I was able to take our initial observations of diel fluctuations in malic acid to the next level, showing this aquatic plant exhibited dark CO2 uptake. CAM is universal in all aquatic species of the worldwide Lycophyta genus Isoetes and non-existent in terrestrial Isoetes. Outside of this genus aquatic CAM has a limited occurrence in three other families, including the Crassulaceae. This discovery led to fascinating adventures in the highlands of the Peruvian Andes in search of Stylites, a terrestrial relative of Isoetes. Stylites is a plant that is hermetically sealed from the atmosphere and obtains all of its carbon from terrestrial sources and recycles carbon through CAM. Considering the Mesozoic origin of Isoetes in shallow pools, coupled with the fact that aquatic Isoetes universally possess CAM, suggests the earliest evolution of CAM photosynthesis was most likely not in terrestrial plants.

  16. TART input manual

    International Nuclear Information System (INIS)

    The TART code is a Monte Carlo neutron/photon transport code that is only on the CRAY computer. All the input cards for the TART code are listed, and definitions for all input parameters are given. The execution and limitations of the code are described, and input for two sample problems are given

  17. TART input manual

    Energy Technology Data Exchange (ETDEWEB)

    Kimlinger, J.R.; Plechaty, E.F.

    1982-04-01

    The TART code is a Monte Carlo neutron/photon transport code that is only on the CRAY computer. All the input cards for the TART code are listed, and definitions for all input parameters are given. The execution and limitations of the code are described, and input for two sample problems are given. (WHK)

  18. Peer-to-Peer Secure Multi-Party Numerical Computation Facing Malicious Adversaries

    CERN Document Server

    Bickson, Danny; Dolev, Danny; Pinkas, Benny

    2009-01-01

    We propose an efficient framework for enabling secure multi-party numerical computations in a Peer-to-Peer network. This problem arises in a range of applications such as collaborative filtering, distributed computation of trust and reputation, monitoring and other tasks, where the computing nodes is expected to preserve the privacy of their inputs while performing a joint computation of a certain function. Although there is a rich literature in the field of distributed systems security concerning secure multi-party computation, in practice it is hard to deploy those methods in very large scale Peer-to-Peer networks. In this work, we try to bridge the gap between theoretical algorithms in the security domain, and a practical Peer-to-Peer deployment. We consider two security models. The first is the semi-honest model where peers correctly follow the protocol, but try to reveal private information. We provide three possible schemes for secure multi-party numerical computation for this model and identify a singl...

  19. Tool use by aquatic animals

    OpenAIRE

    Mann, Janet; Patterson, Eric M.

    2013-01-01

    Tool-use research has focused primarily on land-based animals, with less consideration given to aquatic animals and the environmental challenges and conditions they face. Here, we review aquatic tool use and examine the contributing ecological, physiological, cognitive and social factors. Tool use among aquatic animals is rare but taxonomically diverse, occurring in fish, cephalopods, mammals, crabs, urchins and possibly gastropods. While additional research is required, the scarcity of tool ...

  20. Input-output supervisor

    International Nuclear Information System (INIS)

    The input-output supervisor is the program which monitors the flow of informations between core storage and peripheral equipments of a computer. This work is composed of three parts: 1 - Study of a generalized input-output supervisor. With sample modifications it looks like most of input-output supervisors which are running now on computers. 2 - Application of this theory on a magnetic drum. 3 - Hardware requirement for time-sharing. (author)

  1. Expertise-based peer selection in Peer-to-Peer networks

    NARCIS (Netherlands)

    Haase, Peter; Siebes, Ronny; Harmelen, van Frank

    2007-01-01

    Peer-to-Peer systems have proven to be an effective way of sharing data. Modern protocols are able to efficiently route a message to a given peer. However, determining the destination peer in the first place is not always trivial. We propose a a message to a given peer. However, determining the des

  2. Expertise-based peer selection in Peer-to-Peer networks

    NARCIS (Netherlands)

    Haase, Peter; Siebes, Ronny; Harmelen, van Frank

    2007-01-01

    Peer-to-Peer systems have proven to be an effective way of sharing data. Modern protocols are able to efficiently route a message to a given peer. However, determining the destination peer in the first place is not always trivial. We propose a model in which peers advertise their expertise in the

  3. Peer review of teaching.

    Science.gov (United States)

    Fernandez, Charles E; Yu, Jenny

    2007-01-01

    This article provides an overview and description of peer review of teaching for faculty members and administrators who would like to implement a peer review program. This may include classroom and clinical settings. A brief overview, procedure, and a teaching competence evaluation rubric are provided. PMID:18483580

  4. Peer Review of Teaching

    OpenAIRE

    Fernandez, Charles E.; Yu, Jenny

    2007-01-01

    This article provides an overview and description of peer review of teaching for faculty members and administrators who would like to implement a peer review program. This may include classroom and clinical settings. A brief overview, procedure, and a teaching competence evaluation rubric are provided

  5. Peer Review Undergoing Revitalization

    Science.gov (United States)

    Sawchuk, Stephen

    2009-01-01

    Established in the 142,000-student Montgomery County, Maryland, district in 1999, peer assistance and review (PAR)--or "peer review," as it is occasionally called--is actually an old idea. In 1981, the then-president of the Toledo Federation of Teachers, Dal Lawrence, helped create the first PAR program. Almost 30 years later, only a handful of…

  6. Talking Speech Input.

    Science.gov (United States)

    Berliss-Vincent, Jane; Whitford, Gigi

    2002-01-01

    This article presents both the factors involved in successful speech input use and the potential barriers that may suggest that other access technologies could be more appropriate for a given individual. Speech input options that are available are reviewed and strategies for optimizing use of speech recognition technology are discussed. (Contains…

  7. SSYST-2 input description

    International Nuclear Information System (INIS)

    The codes system SSYST-2 is designed to analyse the thermal and mechanical behaviour of a fuel rod during a LOCA. The report contains a short introduction into the SSYST structure, a complete input-list for all modules and several tested input-list for a LOCA-analysis. (orig.)

  8. SSYST-3. Input description

    International Nuclear Information System (INIS)

    The code system SSYST-3 is designed to analyse the thermal and mechanical behaviour of a fuel rod during a LOCA. The report contains a complete input-list for all modules and several tested inputs for a LOCA analysis. (orig.)

  9. Peer2ref: a peer-reviewer finding web tool that uses author disambiguation

    Directory of Open Access Journals (Sweden)

    Andrade-Navarro Miguel A

    2012-09-01

    Full Text Available Abstract Background Reviewer and editor selection for peer review is getting harder for authors and publishers due to the specialization onto narrower areas of research carried by the progressive growth of the body of knowledge. Examination of the literature facilitates finding appropriate reviewers but is time consuming and complicated by author name ambiguities. Results We have developed a method called peer2ref to support authors and editors in selecting suitable reviewers for scientific manuscripts. Peer2ref works from a text input, usually the abstract of the manuscript, from which important concepts are extracted as keywords using a fuzzy binary relations approach. The keywords are searched on indexed profiles of words constructed from the bibliography attributed to authors in MEDLINE. The names of these scientists have been previously disambiguated by coauthors identified across the whole MEDLINE. The methods have been implemented in a web server that automatically suggests experts for peer-review among scientists that have authored manuscripts published during the last decade in more than 3,800 journals indexed in MEDLINE. Conclusion peer2ref web server is publicly available at http://www.ogic.ca/projects/peer2ref/.

  10. Tool use by aquatic animals.

    Science.gov (United States)

    Mann, Janet; Patterson, Eric M

    2013-11-19

    Tool-use research has focused primarily on land-based animals, with less consideration given to aquatic animals and the environmental challenges and conditions they face. Here, we review aquatic tool use and examine the contributing ecological, physiological, cognitive and social factors. Tool use among aquatic animals is rare but taxonomically diverse, occurring in fish, cephalopods, mammals, crabs, urchins and possibly gastropods. While additional research is required, the scarcity of tool use can likely be attributable to the characteristics of aquatic habitats, which are generally not conducive to tool use. Nonetheless, studying tool use by aquatic animals provides insights into the conditions that promote and inhibit tool-use behaviour across biomes. Like land-based tool users, aquatic animals tend to find tools on the substrate and use tools during foraging. However, unlike on land, tool users in water often use other animals (and their products) and water itself as a tool. Among sea otters and dolphins, the two aquatic tool users studied in greatest detail, some individuals specialize in tool use, which is vertically socially transmitted possibly because of their long dependency periods. In all, the contrasts between aquatic- and land-based tool users enlighten our understanding of the adaptive value of tool-use behaviour. PMID:24101631

  11. Child Pornography in Peer-to-Peer Networks

    Science.gov (United States)

    Steel, Chad M. S.

    2009-01-01

    Objective: The presence of child pornography in peer-to-peer networks is not disputed, but there has been little effort done to quantify and analyze the distribution and nature of that content to-date. By performing an analysis of queries and query hits on the largest peer-to-peer network, we are able to both quantify and describe the nature of…

  12. Efficient Skyline Computation in Structured Peer-to-Peer Systems

    DEFF Research Database (Denmark)

    Cui, Bin; Chen, Lijiang; Xu, Linhao;

    2009-01-01

    skyline computation problem on a structured peer-to-peer network. In order to achieve low communication cost and quick response time, we utilize the iMinMax(\\theta ) method to transform high-dimensional data to one-dimensional value and distribute the data in a structured peer-to-peer network called BATON...

  13. Exposures from aquatic pathways

    International Nuclear Information System (INIS)

    Methods for estimation aquatic pathways contribution to the total population exposure are discussed. Aquatic pathways are the major factor for radionuclides spreading from the Chernobyl Exclusion zone. An annual outflow of 90Sr and 137Cs comprised 10-20 TBq and 2-4 TBq respectively and the population exposed by this effluence constitutes almost 30 million people. The dynamic of doses from 90Sr and 'Cs, which Dnieper water have to delivered, is calculated. The special software has been developed to simulate the process of dose formation in the of diverse Dnieper regions. Regional peculiarities of municipal tap, fishing and irrigation are considered. Seventy-year prediction of dose structure and function of dose forming is performed. The exposure is estimated for 12 regions of the Dnieper basin and the Crimea. The maximal individual annual committed effective doses due to the use of water by ordinary members of the population in Kiev region from 90Sr and 137Cs in 1986 are 1.7*10-5 Sv and 2.7*10-5 Sv respectively. A commercial fisherman on Kiev reservoir in 1986 received 4.7*10-4 Sv and 5*10-3 Sv from 90Sr and 137Cs, respectively. The contributions to the collective cumulative (over 70 years) committed effective dose (CCCED70) of irrigation, municipal tap water and fish consumption for members of the population respectively are 18%, 43%, 39% in Kiev region, 8%, 25%, 67% in Poltava region, and 50%, 50%, 0% (consumption of Dnieper fish is absent) in the Crimea. The predicted contribution of the Strontium-90 to CCCED70 resulting from the use of water is 80%. The CCCED70 to the population of the Dnieper regions (32.5 million people) is 3000 person-Sv due to the use the Dnieper water

  14. ColloInputGenerator

    DEFF Research Database (Denmark)

    2013-01-01

    it as input for basic collexeme collostructional analysis (Stefanowitsch & Gries 2003) in Gries' (2007) program. ColloInputGenerator is, in its current state, based on programming commands introduced in Gries (2009). Projected updates: Generation of complete work-ready frequency lists.......This is a very simple program to help you put together input files for use in Gries' (2007) R-based collostruction analysis program. It basically puts together a text file with a frequency list of lexemes in the construction and inserts a column where you can add the corpus frequencies. It requires...

  15. The Special Column of Aquatic Invasive Species Science

    Institute of Scientific and Technical Information of China (English)

    Gerard van der Velde; Rob S.E.W. Leuven; Guest Editors

    2011-01-01

    We were delighted when Zhi-Yun Jia,Executive Editor of Current Zoology,approached us with a proposal to engage in a special column on invasive species science.Six papers have been written for this special column,all containing new information and approaches in the field of aquatic invasive species science.Each paper has gone through the rigorous peer review process used at Current Zoology,and Zhi-Yun Jia was very helpful by contacting reviewers and improving the manuscripts.

  16. Format( )MEDIC( )Input

    Science.gov (United States)

    Foster, K.

    1994-09-01

    This document is a description of a computer program called Format( )MEDIC( )Input. The purpose of this program is to allow the user to quickly reformat wind velocity data in the Model Evaluation Database (MEDb) into a reasonable 'first cut' set of MEDIC input files (MEDIC.nml, StnLoc.Met, and Observ.Met). The user is cautioned that these resulting input files must be reviewed for correctness and completeness. This program will not format MEDb data into a Problem Station Library or Problem Metdata File. A description of how the program reformats the data is provided, along with a description of the required and optional user input and a description of the resulting output files. A description of the MEDb is not provided here but can be found in the RAS Division Model Evaluation Database Description document.

  17. Incentives in peer-to-peer and grid networking

    OpenAIRE

    Ackemann, T.; Gold, R; Mascolo, C.; Emmerich, W.

    2002-01-01

    Today, most peer-to-peer networks are based on the assumptionthat the participating nodes are cooperative. Thisworks if the nodes are indifferent or ignorant about the resourcesthey offer, but limits the usability of peer-to-peernetworks to very few scenarios. It specifically excludes theirusage in any non-cooperative peer-to-peer environment, beit Grid networks or mobile ad-hoc networks. By introducingsoft incentives to offer resources to other nodes, we seean overall performance gain in tra...

  18. Measuring Database Objects Relatedness in Peer-to-Peer Databases

    OpenAIRE

    M. Basel Almourad

    2013-01-01

    Peer-to-Peer database management systems have become an important topic in the last few years. They rise up p2p technology to exploit the power of available distributed database management system technologies. Identifying relationship between different peer schema objects is one of the main activities so semantically relevant peer database management systems can be acquainted and become close in the overlay. In this paper we present our approach that measures the similarity of peer schema obj...

  19. Input chains and industrialization

    OpenAIRE

    Ciccone, Antonio

    2000-01-01

    A key aspect of industrialization is the adoption of increasing-returns-to-scale, industrial, technologies. Two other, well-documented aspects are that industrial technologies are adopted throughout intermediate-input chains and that they use intermediate inputs intensively relative to the technologies they replace. These features of industrial technologies combined imply that countries with access to similar technologies may have very different levels of industrial...

  20. (Indirect) Input Linkages

    OpenAIRE

    Marcela Eslava; Ana Cecília Fieler; Daniel Yi Xu

    2015-01-01

    Relative to backward firms, technologically-advanced firms source inputs from other advanced firms. These sourcing patterns lead to a magnification effect of technology adoption. A firm that adopts higher-technology increases the relative supply and demand for higher-technology inputs. As a result, it positively influences the technology of other firms in its production chain. Using data from a Colombian manufacturing survey, we provide evidence that advanced firms disproportionately value ad...

  1. The Potential of Peer Review

    Science.gov (United States)

    Johnson, Susan Moore; Fiarman, Sarah E.

    2012-01-01

    Peer review of teachers is controversial for several reasons. Some say peer reviewers encroach on the rightful domain of the principal as instructional leader. Others argue that, because peer evaluators are fellow teachers, they may be biased or unwilling to make hard decisions. Many teachers find the prospect of peer evaluation unsettling because…

  2. EERE Peer Review Guide

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-01-18

    The primary purpose of this guide is to provide managers and staff guidance in establishing formal in-progress peer review that provides intellectually fair expert evaluation of EERE RD3 and supporting business administration programs, both retrospective and prospective.

  3. Unstructured Peer-to-Peer Network Architectures

    Science.gov (United States)

    Jin, Xing; Chan, S.-H. Gary

    With the rapid growth of the Internet, peer-to-peer P2P networks have been widely studied and deployed. According to CacheLogic Research, P2P traffic has dominated the Internet traffic in 2006, by accounting for over 72% Internet traffic. In this chapter, we focus on unstructured P2P networks, one key type of P2P networks. We first present several unstructured P2P networks for the file sharing application, and then investigate some advanced issues in the network design. We also study two other important applications, i.e., media streaming and voice over Internet Protocol (VoIP). Finally, we discuss unstructured P2P networks over wireless networks.

  4. EXPLORING PEER-TO-PEER DATA MINING

    Directory of Open Access Journals (Sweden)

    Andrea Marcozzi

    2016-05-01

    Full Text Available The emerging widespread use of Peer-to-Peer computing is making the P2P Data Mining a natural choice when data sets are distributed over such kind of systems. The huge amount of data stored within the nodes of P2P networks and the bigger and bigger number of applications dealing with them as p2p file-sharing, p2p chatting, p2p electronic commerce etc.., is moving the spotlight on this challenging field. In this paper we give an overview of two different approaches for implementing primitives for P2P Data Mining, trying then to show differences and similarities. The first one is based on the definition of Local algorithms; the second one relies on the Newscast model of computation.

  5. Victims of peer violence

    OpenAIRE

    Mršević Zorica

    2013-01-01

    This paper presents facts on peer violence victims, committed by minor perpetrators against other minors. The author analyses four main characteristics of peer violence: imbalance of power between perpetrators and victims, identified intention to cause injuries, permanent treats of repeated violence and afraidness of the victims. Otherness and weakness (physical and social) of the victims are identified as the main motives of the perpetrators who decide to attack, and these characterist...

  6. Peer Bullying During Early Childhood

    OpenAIRE

    Hatice UYSAL; Çağlayan DİNÇER

    2012-01-01

    Peer bullying during early childhood is discussed along with the literature reviewed in this article with the purpose of drawing attention to peer bullying during early childhood and its significance, and contributing to studies which are few in number in Turkey. Peer bullying during early childhood was considered with its definition and types, people who play key roles in peer bullying, factors (gender, age, parents, and friendship) that relate to peer bullying, and what should be done befor...

  7. Use-Exposure Relationships of Pesticides for Aquatic Risk Assessment

    OpenAIRE

    Luo, Yuzhou; Spurlock, Frank; Deng, Xin; Gill, Sheryl; Goh, Kean

    2011-01-01

    Field-scale environmental models have been widely used in aquatic exposure assessments of pesticides. Those models usually require a large set of input parameters and separate simulations for each pesticide in evaluation. In this study, a simple use-exposure relationship is developed based on regression analysis of stochastic simulation results generated from the Pesticide Root-Zone Model (PRZM). The developed mathematical relationship estimates edge-of-field peak concentrations of pesticides...

  8. Tunison Laboratory of Aquatic Science

    Data.gov (United States)

    Federal Laboratory Consortium — Tunison Laboratory of Aquatic Science (TLAS), located in Cortland, New York, is a field station of the USGS Great Lakes Science Center (GLSC). TLAS was established...

  9. Role Models in Aquatic Occupations.

    Science.gov (United States)

    Brown, Mabel C.

    1982-01-01

    Provided for each of 12 minority group role models in aquatic occupations are job responsibilities, educational requirements, comments on a typical day at the job, salary range, and recommendations for students wishing to enter the field described. (JN)

  10. Peer-to-Peer Feedback: A Novel Approach to Nursing Quality, Collaboration, and Peer Review.

    Science.gov (United States)

    LeClair-Smith, Colleen; Branum, Brandi; Bryant, Lindsay; Cornell, Betty; Martinez, Heather; Nash, Erin; Phillips, Lacy

    2016-06-01

    This article describes how an acute care organization in Texas, a peer review mandated state, created a nonpunitive peer feedback structure and process for nursing staff. Strategies were targeted to improve patient outcomes. A peer feedback committee designed, implemented, and evaluated the feedback model to coexist with the state-required formal peer review committee structure. Peer feedback provided opportunities to advance skill development, enhance quality improvement, improve patient outcomes, and support a culture of safety within the healthcare environment. PMID:27163874

  11. Peer-Led and Adult-Led Programs--Student Perceptions.

    Science.gov (United States)

    Erhard, Rachel

    1999-01-01

    Examines whether peer-led drug prevention programs are preferable to adult-led programs for students (N=2,447) in eighth through eleventh grades. Results show that all input measures and outcome measures were perceived as more positive in the peer-led model. Since the differences found were small this study does not prove with certainty that the…

  12. Unit 07 - Data Input

    OpenAIRE

    Unit 07, CC in GIS; Star, Jeffrey L.

    1990-01-01

    This unit examines the common methods of data input. It describes the hardware and methods used for digitizing and scanning spatial information from maps and photographs, and it discusses conversion of data between digital formats and associated issues of projection, scale and resolution.

  13. Peer Bullying During Early Childhood

    Directory of Open Access Journals (Sweden)

    Hatice UYSAL

    2012-10-01

    Full Text Available Peer bullying during early childhood is discussed along with the literature reviewed in this article with the purpose of drawing attention to peer bullying during early childhood and its significance, and contributing to studies which are few in number in Turkey. Peer bullying during early childhood was considered with its definition and types, people who play key roles in peer bullying, factors (gender, age, parents, and friendship that relate to peer bullying, and what should be done before and after peer bullying.

  14. Peer Instruction for Astronomy

    Science.gov (United States)

    Green, Paul

    Peer Instruction for Astronomy is an instructor's guide to an exciting and easily-implemented enhancement for lecture classes in introductory astronomy. Application of this powerful and efficient teaching technique requires that the instructor have on hand a large number of thought-provoking, conceptual short answer questions aimed at a variety of levels. While significant numbers of such questions have been published for use in Physics, Peer Instruction for Astronomy provides the first such compilation for Astronomy, and includes hints on use of the technique and applications of the method. KEY TOPICS: Covers peer instruction, incentives, a large database of conceptual questions for use in class, and a list of readings and resources. MARKET: Ideal for introductory astronomy instructors at the undergraduate or advanced high school level.

  15. Peer-to-Peer Data Mining, Privacy Issues, and Games

    Data.gov (United States)

    National Aeronautics and Space Administration — Peer-to-Peer (P2P) networks are gaining increasing popularity in many distributed applications such as file-sharing, network storage, web caching, sear- ching and...

  16. Distributed Data Mining in Peer-to-Peer Networks

    Data.gov (United States)

    National Aeronautics and Space Administration — Peer-to-peer (P2P) networks are gaining popularity in many applications such as file sharing, e-commerce, and social networking, many of which deal with rich,...

  17. Peer feedback: The learning element of peer assessment

    OpenAIRE

    Carless, D; Liu, MF

    2006-01-01

    This paper focuses on peer feedback in relation to assessment processes. It examines the rationale for peer feedback, emphasizing its potential for enhanced student learning. We draw on relevant literature to argue that the dominance of peer assessment processes using grades can undermine the potential of peer feedback for improving student learning. The paper throws further light on the issue by drawing on a large-scale questionnaire survey of tertiary students (1740) and academics (460) in ...

  18. Adaptation and Robustness in Peer-to-Peer Streaming

    OpenAIRE

    2011-01-01

    The rapid development of network communication infrastructure enables networked multimedia streaming applications ranging from on-demand video streaming to highly interactive video conferencing. Peer-to-Peer (P2P) technologies have emerged as a powerful and popular paradigm for bringing such emerging multimedia services to a large number of users. The essential advantage of P2P systems is that the system capacity scales up when more peers join, as peer upload capacity is utilized. However, pr...

  19. Analysis of peer-to-peer locking of magnetrons

    International Nuclear Information System (INIS)

    The condition for mutual, or peer-to-peer, locking of two magnetrons is derived. This condition reduces to Adler's classical phase-locking condition in the limit where one magnetron becomes the ''master'' and the other becomes the ''slave.'' The formulation is extended to the peer-to-peer locking of N magnetrons, under the assumption that the electromagnetic coupling among the N magnetrons is modeled by an N-port network.

  20. Open Hypermedia in a Peer-to-Peer Context

    DEFF Research Database (Denmark)

    Bouvin, Niels Olof

    This paper revisits the general hypermedia architecture based on a perspective of peer-to-peer (P2P) networking and pervasive computing, and argues that P2P has much to offer open hypermedia.......This paper revisits the general hypermedia architecture based on a perspective of peer-to-peer (P2P) networking and pervasive computing, and argues that P2P has much to offer open hypermedia....

  1. Childhood Peer Relationships: Social Acceptance, Friendships, and Peer Networks.

    Science.gov (United States)

    Gifford-Smith, Mary E.; Brownell, Celia A.

    2003-01-01

    This review addresses several areas of contemporary research in children's peer relationships during the elementary and middle school years, with primary foci on children's peer acceptance, the ability to make and maintain friendships, and their participation in larger peer networks. It is argued that children's psychosocial development may be…

  2. Tritium in the aquatic environment

    International Nuclear Information System (INIS)

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products

  3. Tritium in the aquatic environment

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G.; Hoffman, F.O.; Frank, M.L.

    1986-02-01

    Tritium is of environmental importance because it is released from nuclear facilities in relatively large quantities and because it has a half life of 12.26 y. Most of the tritium released into the atmosphere eventually reaches the aqueous environment, where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered studies of algae, aquatic macrophytes, invertebrates, fish, and the food chain, were that aquatic organisms incorporate tritium into their tissue-free water very rapidly and reach concentrations near those of the external medium. The rate at which tritium from tritiated water is incorporated into the organic matter of cells is slower than the rate of its incorporation into the tissue-free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster, and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water alone. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the ''carrier'' molecule. No evidence was found that biomagnification of tritium occurs at higher trophic levels. Radiation doses from tritium releases to large populations of humans will most likely come from the consumption of contaminated water rather than contaminated aquatic food products.

  4. Tritium in the aquatic environment

    International Nuclear Information System (INIS)

    Most of the tritium released from nuclear facilities into the atmosphere eventually reaches the aqueous environment where it is rapidly taken up by aquatic organisms. This paper reviews the current literature on tritium in the aquatic environment. Conclusions from the review, which covered algae, aquatic plants, invertebrates, fish, and food chain studies, were that aquatic organisms incorporate tritium into their tissue free water very rapidly and reach concentrations near that of the external medium. Incorporation of tritium from triated water into the organic matter of cells is at a slower rate than incorporation into the tissue free water. If organisms consume tritiated food, incorporation of tritium into the organic matter is faster and a higher tritium concentration is reached than when the organisms are exposed to only tritiated water. Incorporation of tritium bound to molecules into the organic matter depends on the chemical form of the 'carrier' molecule. No evidence was found that biomagnification of tritium occurs at higher tropic levels. Radiation doses to large populations of humans from tritium releases will most likely be from the consumption of contaminated water rather than contaminated aquatic food products. (author)

  5. Waste Stream Input Model

    OpenAIRE

    ALS-NSCORT,

    2004-01-01

    5 worksheets Provider Notes:This model calculates the exact quantities of fecal matter, inedible biomass, food, and water needed to make Solid Thermophilic Aerobic Reactor (STAR)'s input feedstock. It also calculates HRT. The model is based off the desired solids content, scale, volume, diet, and other assumptions. Previous versions are also included in this page. Related Documents:WS152, WWAS17a, WWAS17b

  6. Peer Gynti tagasitulek / Hilve Rebane

    Index Scriptorium Estoniae

    Rebane, Hilve, 1938-2012

    1999-01-01

    Arvustus: Ibsen, Henrik. Peer Gynt / tõlkinud Marie Under. 2. tr. Tallinn : Eesti Raamat, 1998. Ka "Peer Gynti" mõjutusi eesti kirjanduses: August Gailiti, Marie Underi, A. H. Tammsaare ja eriti Karl Ristikivi loomingus

  7. Peer Country Comments Paper - Denmark

    DEFF Research Database (Denmark)

    Bredgaard, Thomas

    Bidrag til EU-kommissionens peer-review on "Strategies for Employment policy Reform. Implementation Challenges in Decentralised Countries"......Bidrag til EU-kommissionens peer-review on "Strategies for Employment policy Reform. Implementation Challenges in Decentralised Countries"...

  8. Editorial behaviors in peer review

    OpenAIRE

    Wang, Wei; Kong, Xiangjie; Jun ZHANG; Chen, Zhen; Xia, Feng; Wang, Xianwen

    2016-01-01

    Editors play a critical role in the peer review system. How do editorial behaviors affect the performance of peer review? No quantitative model to date allows us to measure the influence of editorial behaviors on different peer review stages such as, manuscript distribution and final decision making. Here, we propose an agent-based model in which the process of peer review is guided mainly by the social interactions among three kinds of agents representing authors, editors and reviewers respe...

  9. Using Peer Feedback to Promote Reflection on Open-Ended Problems

    CERN Document Server

    Reinholz, Daniel L

    2016-01-01

    This paper describes a new approach for learning from homework, called Peer-Assisted Reflection (PAR). PAR involves students using peer feedback to improve their work on open-ended homework problems. Collaborating with peers and revising one's work based on the feedback of others are important aspects of doing and learning physics. While notable exceptions exist, homework and exams are generally individual activities that do not support collaboration and refinement, which misses important opportunities to use assessment for learning. In contrast, PAR provides students with a structure to iteratively engage with challenging, open-ended problems and solicit the input of their peers to improve their work.

  10. On Being a Peer

    DEFF Research Database (Denmark)

    Bertel, Lykke Brogaard; Rasmussen, Dorte Malig

    2013-01-01

    This paper investigates and discusses the persuasive principles of social actors in relation to other theories of technologies as social agents, particularly within the field of Social Robotics and Persuasive Educational and Entertainment Robotics (PEERs). Based on related research and results fr...

  11. Victims of peer violence

    Directory of Open Access Journals (Sweden)

    Mršević Zorica

    2013-01-01

    Full Text Available This paper presents facts on peer violence victims, committed by minor perpetrators against other minors. The author analyses four main characteristics of peer violence: imbalance of power between perpetrators and victims, identified intention to cause injuries, permanent treats of repeated violence and afraidness of the victims. Otherness and weakness (physical and social of the victims are identified as the main motives of the perpetrators who decide to attack, and these characteristics form the basis of the victim typology. Due to the fact that the research is phenomenologically based mostly on media report on peer violence cases in the period between September 2011 and the end of 2012, the author illustrates all main statements with the real cases which took place in the focused period. Measures to combat peer violence are presented, like the already established such as the school without violence program, and those recently proposed, such as the so called Aleksa’s class. [Projekat Ministarstva nauke Republike Srbije: Društvene transformacije u procesu evropskih integracija - multidisciplinarni pristup

  12. Approaching Authentic Peer Review

    Science.gov (United States)

    Graff, Nelson

    2009-01-01

    Some scholars writing about improving students' reading and integrating reading and writing instruction suggest using think-aloud techniques to teach students reading comprehension skills. Using think-alouds to teach reading comprehension and then the read-aloud protocol technique (which is based on think-alouds) for peer review has two major…

  13. Further thoughts on peer review

    Science.gov (United States)

    Cottey, Alan; noamsoker

    2016-04-01

    In reply to the news article “Peer review under the spotlight” (February pp12–13), the editorial “Handle with care” cautioning against reforming peer review too quickly (February p15) and Robert P Crease's article “Peer review's value” (February p17, http://ow.ly/Ya9gg).

  14. The Myth of Peer Pressure.

    Science.gov (United States)

    Ungar, Michael T.

    2000-01-01

    The construct of peer pressure was examined as part of a qualitative study of the determinants of mental health for 41 high-risk adolescents. While the concept of peer pressure enables adults to explain youths' troubling behaviors, content analysis of the participants' accounts of their lives reveals peer pressure to be a myth. (Author/MKA)

  15. Peer Influence and Addiction Recurrence

    OpenAIRE

    Paul Markdissi

    2009-01-01

    In this paper we highlight the role of peers in the recurrence of addictive behavior. To do so, we use a simple “forward looking” model with procrastination and peers influence. Our results show that while procrastination can explain the decision to postpone rehabilitation, peers influence is essential to explain the cyclical patterns of addiction-rehabilitation-addiction.

  16. Peer Review in the Classroom.

    Science.gov (United States)

    Liu, Jianguo; Pysarchik, Dawn Thorndike; Taylor, William W.

    2002-01-01

    Explains the importance of peer assessment in professional life and describes a course using peer review processes to teach modeling in natural resource management. Uses a typical scientific research protocol and assigns students to review peer proposals considering their expertise and area of interest. Presents guidelines for proposal review,…

  17. Re-Viewing Peer Review

    Science.gov (United States)

    Flynn, Elizabeth A.

    2011-01-01

    In this article, the author revisits her essay, "Students as Readers of Their Classmates' Writing," by providing a review of the literature on peer review over the past three decades and comments on patterns she sees in waves of peer review research and theorizing. She describes her subsequent experience with peer review in her own classes, and…

  18. Peer review online, wat werkt?

    NARCIS (Netherlands)

    van der Hulst, J.; van den Berg, I.

    2008-01-01

    Bij peer review geven studenten elkaar feedback op elkaars werkstukken. Er bestaan verschillende systemen om dit online te organiseren. In deze workshop gaan we in op selectiecriteria voor peer review systemen. In het PROOF-project (Peer Review Online Opschalen en Faciliteren) is gewerkt met twee so

  19. Production in aquatic macrophyte communities

    DEFF Research Database (Denmark)

    Binzer, Thomas; Sand-Jensen, Kaj

    2002-01-01

    combined a simple mechanistic model and empirical measurements on artificially structured macroalgal communities (Ulva lactuca) with varying thallus absorptance and community density. Predicted and measured values corresponded closely and revealed that gross production in high-light environments...... that inefficient distribution of light can account for the low community production rates in aquatic habitats and the depth distribution of form-functional groups of macroalgae with different canopy structure.......-dimensional structure because of the strong drag and shear forces of moving water. This difference in canopy structure has been suggested to account for the three- to fivefold higher gross production rates in terrestrial than aquatic communities. To evaluate the effect of community structure in aquatic habitats, we...

  20. Innovative Rated-Resource Peer-to-Peer Network

    OpenAIRE

    Abhishek Sharma; Hao Shi

    2010-01-01

    Peer-to-Peer (P2P) networks provide a significant solution for file sharing among peers connected to Internet. It is fast and completely decentralised system with robustness. But due to absence of a server documents on a P2P network are not rated which makes it difficult for a peer to obtain precise information in result of a query. In past, some researchers tried to attach ratings to the peers itself but it was complex and less effective. In this paper, a novel P2P architecture is proposed w...

  1. Comprehensible input and learning outcomes

    OpenAIRE

    Salazar Campillo, Patricia

    1996-01-01

    Segones Jornades de Foment de la Investigació de la FCHS (Any 1996-1997) In Krashen’s terms, optimal input has to be comprehensible to the learner if we want acquisition to take place. An overview of the literature on input indicates two ways of making input comprehensible: the first one is to premodify input before it is offered to the learner, (premodified input), and the second one is to negotiate the input through interaction (interactionally modified input). The aim of the...

  2. Hypermnesia using auditory input.

    Science.gov (United States)

    Allen, J

    1992-07-01

    The author investigated whether hypermnesia would occur with auditory input. In addition, the author examined the effects of subjects' knowledge that they would later be asked to recall the stimuli. Two groups of 26 subjects each were given three successive recall trials after they listened to an audiotape of 59 high-imagery nouns. The subjects in the uninformed group were not told that they would later be asked to remember the words; those in the informed group were. Hypermnesia was evident, but only in the uninformed group. PMID:1447564

  3. FLUTAN input specifications

    International Nuclear Information System (INIS)

    FLUTAN is a highly vectorized computer code for 3-D fluiddynamic and thermal-hydraulic analyses in cartesian and cylinder coordinates. It is related to the family of COMMIX codes originally developed at Argonne National Laboratory, USA. To a large extent, FLUTAN relies on basic concepts and structures imported from COMMIX-1B and COMMIX-2 which were made available to KfK in the frame of cooperation contracts in the fast reactor safety field. While on the one hand not all features of the original COMMIX versions have been implemented in FLUTAN, the code on the other hand includes some essential innovative options like CRESOR solution algorithm, general 3-dimensional rebalacing scheme for solving the pressure equation, and LECUSSO-QUICK-FRAM techniques suitable for reducing 'numerical diffusion' in both the enthalphy and momentum equations. This report provides users with detailed input instructions, presents formulations of the various model options, and explains by means of comprehensive sample input, how to use the code. (orig.)

  4. Aquatic Plants and Lake Ecosystems

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jan; Květ, Jan

    Oxford : Blackwell Science Ltd, 2003 - (O´Sullivan, P.; Reynolds, C.), s. 309-340 ISBN 0-632-04797-6 R&D Projects: GA ČR GA206/01/1113 Institutional research plan: CEZ:AV0Z6087904 Keywords : Aquatic macrophytes * green algae Subject RIV: EH - Ecology, Behaviour

  5. Macrophytes: Ecology of aquatic plants

    NARCIS (Netherlands)

    Bornette, G.; Puijalon, S.

    2009-01-01

    Aquatic plants contribute to maintaining key functions and related biodiversity in freshwater ecosystems, and to provide the needs of human societies. The way the ecological niches of macrophytes are determined by abiotic filters and biotic ones is considered. A simple, broadly applicable model of t

  6. Security properties in an open peer-to-peer network

    CERN Document Server

    Lalande, Jean-Francois; Toinard, Christian

    2010-01-01

    This paper proposes to address new requirements of confidentiality, integrity and availability properties fitting to peer-to-peer domains of resources. The enforcement of security properties in an open peer-topeer network remains an open problem as the literature have mainly proposed contribution on availability of resources and anonymity of users. That paper proposes a novel architecture that eases the administration of a peer-to-peer network. It considers a network of safe peer-to-peer clients in the sense that it is a commune client software that is shared by all the participants to cope with the sharing of various resources associated with different security requirements. However, our proposal deals with possible malicious peers that attempt to compromise the requested security properties. Despite the safety of an open peer-to-peer network cannot be formally guaranteed, since a end user has privileges on the target host, our solution provides several advanced security enforcement. First, it enables to for...

  7. MELCOR Peer Review

    Energy Technology Data Exchange (ETDEWEB)

    Boyack, B.E. [Los Alamos National Lab., NM (United States); Dhir, V.K. [Santa Monica, CA. (United States); Gieseke, J.A. [Battelle, Columbus, OH (United States); Haste, T.J. [AEA Technology, Winfrith (United Kingdom); Kenton, M.A. [Gabor, Kenton and Associates, Inc., Westmont, IL (United States); Khatib-Rahbar, M. [Energy Research, Inc., Rockville, MD (United States); Leonard, M.T. [Science Applications International Corp., Wolfheze (Netherlands); Viskanta, R. [Purdue Univ., Lafayette, IN (United States). Heat Transfer Lab.

    1992-03-01

    MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. The newest version of MELCOR is Version 1.8.1, July 1991. MELCOR development has reached the point that the United States Nuclear Regulatory Commission sponsored a broad technical review by recognized experts to determine or confirm the technical adequacy of the code for the serious and complex analyses it is expected to perform. For this purpose, an eight-member MELCOR Peer Review Committee was organized. The Committee has completed its review of the MELCOR code: the review process and findings of the MELCOR Peer Review Committee are documented in this report. The Committee has determined that recommendations in five areas are appropriate: (1) MELCOR numerics, (2) models missing from MELCOR Version 1.8.1, (3) existing MELCOR models needing revision, (4) the need for expanded MELCOR assessment, and (5) documentation.

  8. MELCOR Peer Review

    International Nuclear Information System (INIS)

    MELCOR is a fully integrated, engineering-level computer code that models the progression of severe accidents in light water reactor nuclear power plants. The newest version of MELCOR is Version 1.8.1, July 1991. MELCOR development has reached the point that the United States Nuclear Regulatory Commission sponsored a broad technical review by recognized experts to determine or confirm the technical adequacy of the code for the serious and complex analyses it is expected to perform. For this purpose, an eight-member MELCOR Peer Review Committee was organized. The Committee has completed its review of the MELCOR code: the review process and findings of the MELCOR Peer Review Committee are documented in this report. The Committee has determined that recommendations in five areas are appropriate: (1) MELCOR numerics, (2) models missing from MELCOR Version 1.8.1, (3) existing MELCOR models needing revision, (4) the need for expanded MELCOR assessment, and (5) documentation

  9. Personalised Peer-Supported Leraning: The Peer-to-Peer Learning environment (P2PLE

    Directory of Open Access Journals (Sweden)

    Joseph Corneli

    2011-12-01

    Full Text Available The Peer-to-Peer Learning Environment (P2PLE is a proposed approach to helpinglearners co-construct their learning environment using recommendations aboutpeople, content, and tools. The work draws on current research on PLEs, andparticipant observation at the Peer-to-Peer University (P2PU. We are particularlyinterested in ways of eliciting explicit, coded, user feedback, and in monitoring thetransitions from state to state within the PLE. We discuss the ways in which theseideas can inform the design of a platform for peer-supported study of universitylevelmathematics.

  10. Peers at work

    OpenAIRE

    Mas, Alexandre; Moretti, Enrico

    2006-01-01

    We investigate how and why the productivity of a worker varies as a function of the productivity of her co-workers in a group production process. In theory, the introduction of a high productivity worker could lower the effort of incumbent workers because of free riding; or it could increase the effort of incumbent workers because of peer effects induced by social norms, social pressure, or learning. Using scanner level data, we measure high frequency, worker-level productivity of checkers fo...

  11. : Peer evaluation in projects

    OpenAIRE

    Bachelet, Rémi

    2011-01-01

    International audience This paper presents learning by projects as it is implemented at école Centrale de Lille. Starting from a series of interviews diagnosing the main issues with our evaluation system, we study a social skill peer self-evaluation system called the "pme matrix". We adapt it through our own framework for groupwork social skills evaluation, and design appropriate software and documentary tools. Finally, six years after the launching of our pme matrix system, we examine how...

  12. On Being a Peer

    DEFF Research Database (Denmark)

    Bertel, Lykke Brogaard; Rasmussen, Dorte Malig

    2013-01-01

    This paper investigates and discusses the persuasive principles of social actors in relation to other theories of technologies as social agents, particularly within the field of Social Robotics and Persuasive Educational and Entertainment Robotics (PEERs). Based on related research and results from...... a case study on social robots as persuasive social actors in education an extension of the persuasive principles is proposed and related design guidelines for Persuasive Technology as social actors in teaching are presented....

  13. Aquatic Macrophyte Risk Assessment for Pesticides

    NARCIS (Netherlands)

    Maltby, L.; Arnold, D.; Arts, G.H.P.; Davies, J.; Heimbach, F.; Pickl, C.; Poulsen, V.

    2009-01-01

    Given the essential role that primary producers play in aquatic ecosystems, it is imperative that the potential risk of pesticides to the structure and functioning of aquatic plants is adequately assessed. This book discusses the assessment of the risk of pesticides with herbicidal activity to aquat

  14. Access to Research Inputs

    DEFF Research Database (Denmark)

    Czarnitzki, Dirk; Grimpe, Christoph; Pellens, Maikel

    The viability of modern open science norms and practices depend on public disclosure of new knowledge, methods, and materials. However, increasing industry funding of research can restrict the dissemination of results and materials. We show, through a survey sample of 837 German scientists in life...... sciences, natural sciences, engineering, and social sciences, that scientists who receive industry funding are twice as likely to deny requests for research inputs as those who do not. Receiving external funding in general does not affect denying others access. Scientists who receive external funding...... of any kind are, however, 50% more likely to be denied access to research materials by others, but this is not affected by being funded specifically by industry....

  15. Access to Research Inputs

    DEFF Research Database (Denmark)

    Czarnitzki, Dirk; Grimpe, Christoph; Pellens, Maikel

    2015-01-01

    The viability of modern open science norms and practices depends on public disclosure of new knowledge, methods, and materials. However, increasing industry funding of research can restrict the dissemination of results and materials. We show, through a survey sample of 837 German scientists in life...... sciences, natural sciences, engineering, and social sciences, that scientists who receive industry funding are twice as likely to deny requests for research inputs as those who do not. Receiving external funding in general does not affect denying others access. Scientists who receive external funding...... of any kind are, however, 50 % more likely to be denied access to research materials by others, but this is not affected by being funded specifically by industry...

  16. Fast similarity search in peer-to-peer networks

    OpenAIRE

    Bocek, T; Hunt, E; Hausheer, D; Stiller, B.

    2008-01-01

    Peer-to-peer (P2P) systems show numerous advantages over centralized systems, such as load balancing, scalability, and fault tolerance, and they require certain functionality, such as search, repair, and message and data transfer. In particular, structured P2P networks perform an exact search in logarithmic time proportional to the number of peers. However, keyword similarity search in a structured P2P network remains a challenge. Similarity search for service discovery can significantly impr...

  17. Assessment of potential aquatic herbicide impacts to California aquatic ecosystems.

    Science.gov (United States)

    Siemering, Geoffrey S; Hayworth, Jennifer D; Greenfield, Ben K

    2008-10-01

    A series of legal decisions culminated in 2002 with the California State Water Resources Control Board funding the San Francisco Estuary Institute to develop and implement a 3-year monitoring program to determine the potential environmental impacts of aquatic herbicide applications. The monitoring program was intended to investigate the behavior of all aquatic pesticides in use in California, to determine potential impacts in a wide range of water-body types receiving applications, and to help regulators determine where to direct future resources. A tiered monitoring approach was developed to achieve a balance between program goals and what was practically achievable within the project time and budget constraints. Water, sediment, and biota were collected under "worst-case" scenarios in close association with herbicide applications. Applications of acrolein, copper sulfate, chelated copper, diquat dibromide, glyphosate, fluridone, triclopyr, and 2,4-D were monitored. A range of chemical analyses, toxicity tests, and bioassessments were conducted. At each site, risk quotients were calculated to determine potential impacts. For sediment-partitioning herbicides, sediment quality triad analysis was performed. Worst-case scenario monitoring and special studies showed limited short-term and no long-term toxicity directly attributable to aquatic herbicide applications. Risk quotient calculations called for additional risk characterizations; these included limited assessments for glyphosate and fluridone and more extensive risk assessments for diquat dibromide, chelated copper products, and copper sulfate. Use of surfactants in conjunction with aquatic herbicides was positively associated with greater ecosystem impacts. Results therefore warrant full risk characterization for all adjuvant compounds. PMID:18293029

  18. Proposed Release Guides to Protect Aquatic Biota

    Energy Technology Data Exchange (ETDEWEB)

    Marter, W.L.

    2001-03-28

    At the request of South Carolina Department of Health and Environmental Control (SCDHEC) and the Department of Energy (DOE), the Savannah River Laboratory was assigned the task of developing the release guides to protect aquatic biota. A review of aquatic radioecology literature by two leading experts in the field of radioecology concludes that exposure of aquatic biota at one rad per day or less will not produce detectable deleterious effects on aquatic organisms. On the basis of this report, DOE recommends the use of one rad per day as an interim dose standard to protect aquatic biota.

  19. Optimal media sharing policies in peer-to-peer networks

    Science.gov (United States)

    Sood, Ritesh; van der Schaar, Mihaela

    2004-11-01

    Multimedia content distribution through a distributed system, a peer-to-peer (P2P) network for instance, is attractive since it harnesses the resources available with the numerous peers in the network. Another advantage of such a system is that the potentially available resources scale in proportion to the demand as more and more peers join the system. Recent studies have concentrated mainly on such aspects of these distributed networks as querying, indexing, etc. These studies however take for granted the voluntary contribution of resources by peers in the system. Empirical evidence however points to the contrary, i.e. in existing P2P systems, a substantial fraction of peers do not contribute resources to the system, while benefiting from the services it provides at the expense of the contributing peers. In this paper we analyze a P2P system in a game-theoretic setting in which games involving content exchange are played repeatedly. The model takes into account the manner in which a peer adapts his contribution to the system depending on the benefit he has derived from the system so far and expects to derive in the long run. The model enables us to formulate an optimization problem that yields optimal content sharing strategies that a peer should adopt in order to maximize his net benefit by participating in the system.

  20. Collaborative work model based on peer-to-peer network

    Institute of Scientific and Technical Information of China (English)

    JIANG Jian-zhong; FU Li; ZHANG Xuan-peng; XU Chuan-yun

    2007-01-01

    In this paper, we incorporated peer-to-peer (P2P) concept with agent technology and put forward a collaborative work model based on peer-to-peer network (P2PCWM) after investigating into business demands of modern enterprises and problems prevailing in mainstream collaborative work systems based on central server. Theoretically, the P2PCWM can effectively overcome the problems in a conventional system with a central server and meet the practical demands of modern businesses. It is distinguished from other systems by its features of equality, openness, promptness, fairness, expandability and convenience.

  1. The missing piece syndrome in peer-to-peer communication

    Directory of Open Access Journals (Sweden)

    Bruce Hajek

    2011-01-01

    Full Text Available Typical protocols for peer-to-peer file sharing over the Internet divide files to be shared into pieces. New peers strive to obtain a complete collection of pieces from other peers and from a seed. In this paper we investigate a problem that can occur if the seeding rate is not large enough. The problem is that, even if the statistics of the system are symmetric in the pieces, there can be symmetry breaking, with one piece becoming very rare. If peers depart after obtaining a complete collection, they can tend to leave before helping other peers receive the rare piece. Assuming that peers arrive with no pieces, there is a single seed, random peer contacts are made, random useful pieces are downloaded, and peers depart upon receiving the complete file, the system is stable if the seeding rate (in pieces per time unit is greater than the arrival rate, and is unstable if the seeding rate is less than the arrival rate. The result persists for any piece selection policy that selects from among useful pieces, such as rarest first, and it persists with the use of network coding.

  2. Measurement of undisturbed di-nitrogen emissions from aquatic ecosystems

    Science.gov (United States)

    Qin, Shuping, Clough, Timothy, Lou, Jiafa; Hu, Chunsheng; Oenema, Oene; Wrage-Mönnig, Nicole; Zhang, Yuming

    2016-04-01

    Increased production of reactive nitrogen (Nr) from atmospheric di-nitrogen (N2) during the last century has greatly contributed to increased food production1-4. However, enriching the biosphere with Nr through N fertilizer production, combustion, and biological N2 fixation has also caused a series of negative effects on global ecosystems 5,6, especially aquatic ecosystems7. The main pathway converting Nr back into the atmospheric N2 pool is the last step of the denitrification process, i.e., the reduction of nitrous oxide (N2O) into N2 by micro-organisms7,8. Despite several attempts9,10, there is not yet an accurate, fast and direct method for measuring undisturbed N2 fluxes from denitrification in aquatic sediments at the field scale11-14. Such a method is essential to study the feedback of aquatic ecosystems to Nr inputs1,2,7. Here we show that the measurement of both N2O emission and its isotope signature can be used to infer the undisturbed N2 fluxes from aquatic ecosystems. The microbial reduction of N2O increases the natural abundance of 15N-N2O relative to 14N-N2O (δ15N-N2O). We observed linear relationships between δ15N-N2O and the logarithmic transformed N2O/(N2+N2O) emission ratios. Through independent measurements, we verified that the undisturbed N2 flux from aquatic ecosystems can be inferred from measurements of N2O emissions and the δ15N-N2O signature. Our method allows the determination of field-scale N2 fluxes from undisturbed aquatic ecosystems, and thereby allows model predictions of denitrification rates to be tested. The undisturbed N2 fluxes observed are almost one order of magnitude higher than those estimated by the traditional method, where perturbation of the system occurs, indicating that the ability of aquatic ecosystems to remove Nr may have been severely underestimated.

  3. Peer-Based Control in Self-Managing Teams: Linking Rational and Normative Influence with Individual and Group Performance

    Science.gov (United States)

    Stewart, Greg L.; Courtright, Stephen H.; Barrick, Murray R.

    2012-01-01

    The authors use a multilevel framework to introduce peer-based control as a motivational state that emerges in self-managing teams. The authors specifically describe how "peer-based rational control", which is defined as team members perceiving the distribution of economic rewards as dependent on input from teammates, extends and interacts with…

  4. Reprocessing input data validation

    International Nuclear Information System (INIS)

    The Isotope Correlation Technique (ICT), in conjunction with the gravimetric (Pu/U ratio) method for mass determination, provides an independent verification of the input accountancy at the dissolver or accountancy stage of the reprocessing plant. The Isotope Correlation Technique has been applied to many classes of domestic and international reactor systems (light-water, heavy-water, graphite, and liquid-metal) operating in a variety of modes (power, research, production, and breeder), and for a variety of reprocessing fuel cycle management strategies. Analysis of reprocessing operations data based on isotopic correlations derived for assemblies in a PWR environment and fuel management scheme, yielded differences between the measurement-derived and ICT-derived plutonium mass determinations of (-0.02 ± 0.23)% for the measured U-235 and (+0.50 ± 0.31)% for the measured Pu-239, for a core campaign. The ICT analyses has been implemented for the plutonium isotopics in a depleted uranium assembly in a heavy-water, enriched uranium system and for the uranium isotopes in the fuel assemblies in light-water, highly-enriched systems. 7 refs., 5 figs., 4 tabs

  5. Peer Effects in the Workplace

    OpenAIRE

    Cornelissen, Thomas; Dustmann, Christian; Schönberg, Uta

    2013-01-01

    Existing evidence on peer effects in a work environment stems from either laboratory experiments or from real-word studies referring to a specific firm or specific occupation. Yet, it is unclear to what extent these findings apply to the labor market in general. In this paper, therefore, we investigate peer effects in the workplace for a representative set of workers, firms, and occupations with a focus on peer effects in wages rather than productivity. Our estimation strategy – which links t...

  6. Smoking Initiation: Peers and Personality

    OpenAIRE

    Hsieh, Chih-Sheng; van Kippersluis, Hans

    2015-01-01

    Social interactions are generally thought to play an important role in smoking initiation among adolescents. In this paper we exploit detailed friendship nominations in the US Add Health data, and extend the Spatial Autoregressive Model (SAR) model to deal with (i) endogenous peer selection, and (ii) unobserved contextual effects, in order to identify the endogenous peer effect. We show that peer effects in the uptake of smoking are predominantly affecting individuals who are emotionally unst...

  7. Implicit Theories of Peer Relationships

    OpenAIRE

    Rudolph, Karen D.

    2010-01-01

    This research investigated the role of children’s implicit theories of peer relationships in their psychological, emotional, and behavioral adjustment. Participants included 206 children (110 girls; 96 boys; M age = 10.13 years, SD = 1.16) who reported on their implicit theories of peer relationships, social goal orientation, need for approval, depressive and aggressive symptoms, and exposure to peer victimization. Parents also provided reports on aggressive symptoms. Results confirmed that h...

  8. Pre-natal Aquatic Preparation

    OpenAIRE

    Frias, Ana; Serra, Célia

    2013-01-01

    Introduction: Water, a source of well-being, peace, fullness, freedom and harmony. For quite some time now, water is sought after for its renowned benefits in terms of relieving the physical and emotional changes which commonly occur during pregnancy. Objectives: 1) Describe the process of intervention, arising from the use of the aquatic environment in prenatal preparation 2) Relate the gains in health from prenatal preparation aquatica Method: Descriptive creating and applying a prep...

  9. Carcinogenic hazards in aquatic ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Black, J.J.

    1979-01-01

    The chemical characterization of contaminants in bottom sediments from the Great Lakes in western New York (Lake Erie) was carried out by applying reversed-phase high-pressure liquid chromatography (HPLC) to fractions derived by routine organic extraction and separation methods. A comparison of the chromatograms from the sediments with those from analogous fractions isolated from tissue samples of aquatic biota showed correlations in the polynuclear aromatic hydrocarbon (PAH) composition. In the HPLC analysis of fractions isolated from sediment, Tubifex worms, aquatic snails, and fish tissue samples clearly indicated a characteristic PAH ''fingerprint' in all segments of the aquatic food chain. The patterns of horizontal distribution of the relative PAH levels indicated a point source of the pollution in the Buffalo River. Feral fish population samples showed several kinds of lesions that appear to be neoplasms. The histology of these lesions is described, and the significance of the data in terms of a possible human health hazard is discussed.

  10. Peer bullying in schools

    OpenAIRE

    Rıza Gökler

    2009-01-01

    In this study, the term of "Peer Bullying" has been observed according to definitions and approaches variety in Turkey and abroad. "Bullying" is used synonym of violence and aggressiveness today and spread of all cultures in the world as an international concept. "Bullying" is a widespread fact which consists of physical, verbal and social damage to a feeble one. It is a kind of violence and can be defined as incapability of someone to a person or more than one person's violence. Bullying can...

  11. Aquatic Organic Matter Fluorescence - from phenomenon to application

    Science.gov (United States)

    Reynolds, Darren

    2014-05-01

    The use of fluorescence to quantify and characterise aquatic organic matter in river, ocean, ground water and drinking and waste waters has come along way since its discovery as a phenomenon in the early 20th century. For example, there are over 100 papers published each year in international peer reviewed journals, an order of magnitude increase since a decade ago (see Figure taken from ISI database from 1989 to 2007 for publications in the fields of river water and waste water). Since then it has been extensively used as a research tool since the 1990's by scientists and is currently used for a wide variety of applications within a number of sectors. Universities, organisations and companies that research into aquatic organic matter have either recently readily use appropriate fluorescence based techniques and instrumentation. In industry and government, the technology is being taken up by environmental regulators and water and wastewater companies. This keynote presentation will give an overview of aquatic organic matter fluorescence from its conception as a phenomenon through to its current use in a variety of emerging applications within the sectors concerned with understanding, managing and monitoring the aquatic environment. About the Speaker Darren Reynolds pioneered the use of fluorescence spectroscopy for the analysis of wastewaters in the 1990's. He currently leads a research group within the Centre for Research in Biosciences and sits on the Scientific Advisory Board for the Institute of Bio-Sensing Technology at the University of the West of England, Bristol. He is a multidisciplinary scientist concerned with the development of technology platforms for applications in the fields of environment/agri-food and health. His current research interests include the development of optical technologies and techniques for environmental and biological sensing and bio-prospecting applications. He is currently involved in the development and use of synthetic biology

  12. Peer-Assessing Peers' Contribution to EFL Group Presentations

    Science.gov (United States)

    Saito, Hidetoshi; Fujita, Tomoko

    2009-01-01

    The aim of this study is three-fold: (1) to examine the similarities and differences between instructor and peer assessments of EFL group presentations; (2) to understand the utility of peer assessment for discriminating each group member's contribution to group presentations in college EFL classrooms; and (3) to investigate the relationship…

  13. Estimating peer effects in networks with peer encouragement designs.

    Science.gov (United States)

    Eckles, Dean; Kizilcec, René F; Bakshy, Eytan

    2016-07-01

    Peer effects, in which the behavior of an individual is affected by the behavior of their peers, are central to social science. Because peer effects are often confounded with homophily and common external causes, recent work has used randomized experiments to estimate effects of specific peer behaviors. These experiments have often relied on the experimenter being able to randomly modulate mechanisms by which peer behavior is transmitted to a focal individual. We describe experimental designs that instead randomly assign individuals' peers to encouragements to behaviors that directly affect those individuals. We illustrate this method with a large peer encouragement design on Facebook for estimating the effects of receiving feedback from peers on posts shared by focal individuals. We find evidence for substantial effects of receiving marginal feedback on multiple behaviors, including giving feedback to others and continued posting. These findings provide experimental evidence for the role of behaviors directed at specific individuals in the adoption and continued use of communication technologies. In comparison, observational estimates differ substantially, both underestimating and overestimating effects, suggesting that researchers and policy makers should be cautious in relying on them. PMID:27382145

  14. Computer-Mediated Peer-to-Peer Mentoring

    Science.gov (United States)

    Cavallaro, Francesco; Tan, Kenneth

    2006-01-01

    An online collaborative writing project was carried between two report writing classes from two separate institutions, Nanyang Technological University (NTU) and Singapore Polytechnic (SP). The aim was to test how successfully a peer-to-peer mentoring system could be established using asynchronous and synchronous communication features. The…

  15. Active Minds: Creating Peer-to-Peer Mental Health Awareness

    Science.gov (United States)

    Walther, Willliam A.; Abelson, Sara; Malmon, Alison

    2014-01-01

    Utilizing student peers is one vital avenue for improving the prevention, detection, and treatment of mental health disorders on college campuses (The Campus Suicide Prevention Center of Virginia, 2011). This article will briefly review research findings indicating the importance of student peers and then focus on a promising model and growing…

  16. CONTAIN independent peer review

    Energy Technology Data Exchange (ETDEWEB)

    Boyack, B.E. [Los Alamos National Lab., NM (United States); Corradini, M.L. [Univ. of Wisconsin, Madison, WI (United States). Nuclear Engineering Dept.; Denning, R.S. [Battelle Memorial Inst., Columbus, OH (United States); Khatib-Rahbar, M. [Energy Research Inc., Rockville, MD (United States); Loyalka, S.K. [Univ. of Missouri, Columbia, MO (United States); Smith, P.N. [AEA Technology, Dorchester (United Kingdom). Winfrith Technology Center

    1995-01-01

    The CONTAIN code was developed by Sandia National Laboratories under the sponsorship of the US Nuclear Regulatory Commission (NRC) to provide integrated analyses of containment phenomena. It is used to predict nuclear reactor containment loads, radiological source terms, and associated physical phenomena for a range of accident conditions encompassing both design-basis and severe accidents. The code`s targeted applications include support for containment-related experimental programs, light water and advanced light water reactor plant analysis, and analytical support for resolution of specific technical issues such as direct containment heating. The NRC decided that a broad technical review of the code should be performed by technical experts to determine its overall technical adequacy. For this purpose, a six-member CONTAIN Peer Review Committee was organized and a peer review as conducted. While the review was in progress, the NRC issued a draft ``Revised Severe Accident Code Strategy`` that incorporated revised design objectives and targeted applications for the CONTAIN code. The committee continued its effort to develop findings relative to the original NRC statement of design objectives and targeted applications. However, the revised CONTAIN design objectives and targeted applications. However, the revised CONTAIN design objectives and targeted applications were considered by the Committee in assigning priorities to the Committee`s recommendations. The Committee determined some improvements are warranted and provided recommendations in five code-related areas: (1) documentation, (2) user guidance, (3) modeling capability, (4) code assessment, and (5) technical assessment.

  17. CONTAIN independent peer review

    International Nuclear Information System (INIS)

    The CONTAIN code was developed by Sandia National Laboratories under the sponsorship of the US Nuclear Regulatory Commission (NRC) to provide integrated analyses of containment phenomena. It is used to predict nuclear reactor containment loads, radiological source terms, and associated physical phenomena for a range of accident conditions encompassing both design-basis and severe accidents. The code's targeted applications include support for containment-related experimental programs, light water and advanced light water reactor plant analysis, and analytical support for resolution of specific technical issues such as direct containment heating. The NRC decided that a broad technical review of the code should be performed by technical experts to determine its overall technical adequacy. For this purpose, a six-member CONTAIN Peer Review Committee was organized and a peer review as conducted. While the review was in progress, the NRC issued a draft ''Revised Severe Accident Code Strategy'' that incorporated revised design objectives and targeted applications for the CONTAIN code. The committee continued its effort to develop findings relative to the original NRC statement of design objectives and targeted applications. However, the revised CONTAIN design objectives and targeted applications. However, the revised CONTAIN design objectives and targeted applications were considered by the Committee in assigning priorities to the Committee's recommendations. The Committee determined some improvements are warranted and provided recommendations in five code-related areas: (1) documentation, (2) user guidance, (3) modeling capability, (4) code assessment, and (5) technical assessment

  18. Peer til peer i arbejdet med udsatte mennesker

    DEFF Research Database (Denmark)

    Dindler, Camilla; Ahlmark, Nanna; Norrhäll, Oskar;

    mænd i risiko for at udvikle type 2 diabetes. En del af evalueringsopdraget har været at tilvejebringe viden om relevant litteratur om peer-metoder. I denne forbindelse er dette notat udarbejdet til Københavns Kommunes Forebyggelsescenter Nørrebro af evaluerings-teamet, som består af forsker, Nanna......Statens Institut for Folkesundhed, Syddansk Universitet har fået til opdrag at lave en formativ procesevaluering af Københavns Kommunes projekt Mænd i København. Projektet omhandler udvikling og implementering af en peer til peer indsats med henblik på at forbedre sundhed og trivsel blandt udsatte...... Ahlmark, adjunkt ved Aalborg Universitet Camilla Dindler, praktikant og specialestuderende Oskar Norrhäll og specialestuderende Pernille Hartvig Jensen. Notatet er en sammenfatning af udvalgt forskningslitteratur og rapporter om peer til peer-relaterede projekter målrettet udsatte grupper i forbindelse...

  19. Commercial Lighting Solutions, Webtool Peer Review Report

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Carol C.; Meyer, Tracy A.

    2009-06-17

    The Commercial Lighting Solutions (CLS) project directly supports the U.S. Department of Energy’s Commercial Building Energy Alliance efforts to design high performance buildings. CLS creates energy efficient best practice lighting designs for widespread use, and they are made available to users via an interactive webtool that both educates and guides the end user through the application of the Lighting Solutions. This report summarizes the peer review of the beta version of the CLS webtool, which contains retail box lighting solutions. The methodology for the peer review process included data collection (stakeholder input), analysis of the comments, and organization of the input into categories for prioritization of the comments against a set of criteria. Based on this process, recommendations were developed about which feedback should be addressed for the release of version 1.0 of the webtool at the Lightfair conference in New York City in May 2009. Due to the volume of data (~500 comments) the methodology for addressing the peer review comments was central to the success of the ultimate goal of improving the tool. The comments were first imported into a master spreadsheet, and then grouped and organized in several layers. Solutions to each comment were then rated by importance and feasibility to determine the practicality of resolving the concerns of the commenter in the short-term or long-term. The rating system was used as an analytical tool, but the results were viewed thoughtfully to ensure that they were not the sole the factor in determining which comments were recommended for near-term resolution. The report provides a list of the top ten most significant and relevant improvements that will be made within the webtool for version 1.0 as well as appendices containing the short-term priorities in additional detail. Peer review comments that are considered high priority by the reviewers and the CLS team but cannot be completed for Version 1.0 are listed as

  20. Positive Peer Support or Negative Peer Influence? The Role of Peers among Adolescents in Recovery High Schools

    OpenAIRE

    Karakos, Holly

    2014-01-01

    Evidence from previous research suggests that peers at times exert negative influence and at other times exert positive influence on drug and alcohol use among adolescents in recovery. This study explores recovery high school staff members' perceptions of peer support among students in recovery high schools using qualitative interview data. Themes of peer support are discussed in terms of positive peer support, negative peer influence, peer relationships, and sense of community. In general, r...

  1. Serial Input Output

    Energy Technology Data Exchange (ETDEWEB)

    Waite, Anthony; /SLAC

    2011-09-07

    Serial Input/Output (SIO) is designed to be a long term storage format of a sophistication somewhere between simple ASCII files and the techniques provided by inter alia Objectivity and Root. The former tend to be low density, information lossy (floating point numbers lose precision) and inflexible. The latter require abstract descriptions of the data with all that that implies in terms of extra complexity. The basic building blocks of SIO are streams, records and blocks. Streams provide the connections between the program and files. The user can define an arbitrary list of streams as required. A given stream must be opened for either reading or writing. SIO does not support read/write streams. If a stream is closed during the execution of a program, it can be reopened in either read or write mode to the same or a different file. Records represent a coherent grouping of data. Records consist of a collection of blocks (see next paragraph). The user can define a variety of records (headers, events, error logs, etc.) and request that any of them be written to any stream. When SIO reads a file, it first decodes the record name and if that record has been defined and unpacking has been requested for it, SIO proceeds to unpack the blocks. Blocks are user provided objects which do the real work of reading/writing the data. The user is responsible for writing the code for these blocks and for identifying these blocks to SIO at run time. To write a collection of blocks, the user must first connect them to a record. The record can then be written to a stream as described above. Note that the same block can be connected to many different records. When SIO reads a record, it scans through the blocks written and calls the corresponding block object (if it has been defined) to decode it. Undefined blocks are skipped. Each of these categories (streams, records and blocks) have some characteristics in common. Every stream, record and block has a name with the condition that each

  2. Aquatic ecosystem characterisation strategy at a repository site

    International Nuclear Information System (INIS)

    Olkiluoto Island on the western coast of Finland has been selected as a repository site for spent nuclear fuel disposal. According to regulatory requirements, the safety assessment for the repository should have an assessment timeframe of several millennia. Due to the post-glacial land uplift, the relatively shallow sea areas around Olkiluoto Island will change gradually to lakes, rivers and terrestrial areas. As there are no limnic systems at present Olkiluoto site, the reference area was delineated and reference lakes and rivers were selected as an analogue. For the modelling of the transport and accumulation of possible radionuclide releases in the surface environment, aquatic ecosystems were identified and divided into biotopes. Despite the number of available templates, the division of aquatic environment for the biosphere assessment of the Olkiluoto spent fuel repository was necessary to made separately. In this contribution, the processes behind the identification of aquatic ecosystems (e.g. legislation, physical and chemical properties) together with the biotope selection methodology (e.g. light and bottom conditions) and the challenges related to the amount of variable input parameters for each biotope in the modelling are presented. (authors)

  3. Uranium in Aquatic Sediments; Where are the Guidelines?

    International Nuclear Information System (INIS)

    Sediment data has been collected on and around the Ranger uranium mine for over 20 years. This included studies such as annual routine monitoring of metal concentrations, adsorption-desorption conditions, phase associations, transport mechanism, release potential, bioaccumulation and bioconcentration etc. Building on this, performance-based monitoring of the sediments from on-site water bodies was undertaken to ascertain the spatial and temporal distribution of contaminants as a basis to determine ecological risks associated with the sediments which in turn underpins closure planning. Highlights of these studies are interpreted using an ecological risk assessment approach. Ideally interpretation of aquatic sediment contamination in Australia is guided by the national guidelines for water quality and a weighted multiple lines of evidence approach whereby the chemistry of sediments is compared with reference and guideline values and predictions of bio-availability, and biological effects data allows cause and effect relationships to be derived. However, where uranium in aquatic sediments is concerned there is a lack of national (Australian) and international guidelines that are applicable to tropical sediments and the biological effects data available are limited or confounded by other variables. In the absence of clear uranium guidelines for sediments an internationally reported “Predicted No Effect Concentration” (PNEC) for uranium in temperate sediments was used as a “pseudo-guideline” value to identify sites with concentrations that might present an environmental risk and that should be further investigated. The applicability of the PNEC to the tropical Ranger site was understandably questioned by stakeholders and peers. The issues raised highlighted the need for international guidelines for uranium in aquatic sediments for tropical and temperate climates and an internationally accepted approach for deriving same. (author)

  4. SDR Input Power Estimation Algorithms

    Science.gov (United States)

    Nappier, Jennifer M.; Briones, Janette C.

    2013-01-01

    The General Dynamics (GD) S-Band software defined radio (SDR) in the Space Communications and Navigation (SCAN) Testbed on the International Space Station (ISS) provides experimenters an opportunity to develop and demonstrate experimental waveforms in space. The SDR has an analog and a digital automatic gain control (AGC) and the response of the AGCs to changes in SDR input power and temperature was characterized prior to the launch and installation of the SCAN Testbed on the ISS. The AGCs were used to estimate the SDR input power and SNR of the received signal and the characterization results showed a nonlinear response to SDR input power and temperature. In order to estimate the SDR input from the AGCs, three algorithms were developed and implemented on the ground software of the SCAN Testbed. The algorithms include a linear straight line estimator, which used the digital AGC and the temperature to estimate the SDR input power over a narrower section of the SDR input power range. There is a linear adaptive filter algorithm that uses both AGCs and the temperature to estimate the SDR input power over a wide input power range. Finally, an algorithm that uses neural networks was designed to estimate the input power over a wide range. This paper describes the algorithms in detail and their associated performance in estimating the SDR input power.

  5. Cultivating Change through Peer Teaching

    Science.gov (United States)

    Velez, Jonathan J.; Cano, Jamie; Whittington, M. Susie; Wolf, Kattlyn J.

    2011-01-01

    The purpose of this qualitative research study was to describe the impact of peer teaching on both the students and the classroom environment. Students, enrolled in two Introduction to Teaching courses in agricultural and extension education, were asked to engage in peer teaching activities. The researchers utilized discourse analysis, textual…

  6. Teachers Seek Specialized Peer Networks

    Science.gov (United States)

    Tomassini, Jason

    2013-01-01

    Within the wide expanse of social networking, educators appear to be gravitating to more protected and exclusive spaces. While teachers often use such popular mainstream social networks as Facebook, they are more likely to seek out and return to less-established networks that offer the privacy, peer-to-peer connections, and resource sharing that…

  7. Peer Assessment without Assessment Criteria

    Science.gov (United States)

    Jones, Ian; Alcock, Lara

    2014-01-01

    Peer assessment typically requires students to judge peers' work against assessment criteria. We tested an alternative approach in which students judged pairs of scripts against one another in the absence of assessment criteria. First year mathematics undergraduates (N?=?194) sat a written test on conceptual understanding of multivariable…

  8. The Neuroscience Peer Review Consortium

    Directory of Open Access Journals (Sweden)

    Maunsell John HR

    2009-03-01

    Full Text Available Abstract As the Neuroscience Peer Review Consortium (NPRC ends its first year, it is worth looking back to see how the experiment has worked. In order to encourage dissemination of the details outlined in this Editorial, it will also be published in other journals in the Neuroscience Peer Review Consortium.

  9. Quality assurance in radiology: peer review and peer feedback.

    Science.gov (United States)

    Strickland, N H

    2015-11-01

    Peer review in radiology means an assessment of the accuracy of a report issued by another radiologist. Inevitably, this involves a judgement opinion from the reviewing radiologist. Peer feedback is the means by which any form of peer review is communicated back to the original author of the report. This article defines terms, discusses the current status, identifies problems, and provides some recommendations as to the way forward, concentrating upon the software requirements for efficient peer review and peer feedback of reported imaging studies. Radiologists undertake routine peer review in their everyday clinical practice, particularly when reporting and preparing for multidisciplinary team meetings. More formal peer review of reported imaging studies has been advocated as a quality assurance measure to promote good clinical practice. It is also a way of assessing the competency of reporting radiologists referred for investigation to bodies such as the General Medical Council (GMC). The literature shows, firstly, that there is a very wide reported range of discrepancy rates in many studies, which have used a variety of non-comparable methodologies; and secondly, that applying scoring systems in formal peer review is often meaningless, unhelpful, and can even be detrimental. There is currently a lack of electronic peer feedback system software on the market to inform radiologists of any review of their work that has occurred or to provide them with clinical outcome information on cases they have previously reported. Learning opportunities are therefore missed. Radiologists should actively engage with the medical informatics industry to design optimal peer review and feedback software with features to meet their needs. Such a system should be easy to use, be fully integrated with the radiological information and picture archiving systems used clinically, and contain a free-text comment box, without a numerical scoring system. It should form a temporary record

  10. Peer influence on adolescent snacking

    DEFF Research Database (Denmark)

    Nørgaard, Maria Kümpel; Hansen, Kathrine Nørgaard; Grunert, Klaus G

    2013-01-01

    show that the youngest adolescents and the girls perceived the highest influence from peers, and that peer social influence has more effect on what adolescents perceive as important snack attributes as compared to more personal factors. The focus group results show that adolescents purchase and consume......Purpose – The purpose of the research presented in this paper is 1) To explore peer influence and the social and symbolic meaning that adolescents (10 to 16 years) attach to snacks; and 2) to investigate the relative influence of peer influence compared to personal factors in explaining perceived...... importance of snack attributes; and 3) To investigate age and gender differences in the peer influence process. Design/methodology/approach – A web-based survey distributed via email was combined with follow-up focus groups including adolescents aged 10 to 16 years in Denmark. Findings – The survey results...

  11. A peer-to-peer music sharing system based on query-by-humming

    Science.gov (United States)

    Wang, Jianrong; Chang, Xinglong; Zhao, Zheng; Zhang, Yebin; Shi, Qingwei

    2007-09-01

    Today, the main traffic in peer-to-peer (P2P) network is still multimedia files including large numbers of music files. The study of Music Information Retrieval (MIR) brings out many encouraging achievements in music search area. Nevertheless, the research of music search based on MIR in P2P network is still insufficient. Query by Humming (QBH) is one MIR technology studied for years. In this paper, we present a server based P2P music sharing system which is based on QBH and integrated with a Hierarchical Index Structure (HIS) to enhance the relation between surface data and potential information. HIS automatically evolving depends on the music related items carried by each peer such as midi files, lyrics and so forth. Instead of adding large amount of redundancy, the system generates a bit of index for multiple search input which improves the traditional keyword-based text search mode largely. When network bandwidth, speed, etc. are no longer a bottleneck of internet serve, the accessibility and accuracy of information provided by internet are being more concerned by end users.

  12. Advanced combustion, emission control, health impacts, and fuels merit review and peer evaluation

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2006-10-01

    This report is a summary and analysis of comments from the Advisory Panel at the FY 2006 DOE National Laboratory Advanced Combustion, Emission Control, Health Impacts, and Fuels Merit Review and Peer Evaluation, held May 15-18, 2006 at Argonne National Laboratory. The work evaluated in this document supports the FreedomCAR and Vehicle Technologies Program. The results of this merit review and peer evaluation are major inputs used by DOE in making its funding decisions for the upcoming fiscal year.

  13. Phytoremediation Potential of Aquatic Macrophyte, Azolla

    OpenAIRE

    Sood, Anjuli; Uniyal, Perm L.; Prasanna, Radha; Ahluwalia, Amrik S.

    2011-01-01

    Aquatic macrophytes play an important role in the structural and functional aspects of aquatic ecosystems by altering water movement regimes, providing shelter to fish and aquatic invertebrates, serving as a food source, and altering water quality by regulating oxygen balance, nutrient cycles, and accumulating heavy metals. The ability to hyperaccumulate heavy metals makes them interesting research candidates, especially for the treatment of industrial effluents and sewage waste water. The us...

  14. Wireless Peer-to-Peer Mutual Broadcast via Sparse Recovery

    CERN Document Server

    Zhang, Lei

    2011-01-01

    Consider a problem frequently seen in wireless peer-to-peer networks: Every node has messages to broadcast to its peers, namely, all nodes within one hop. Conventional schemes allow only one transmission to succeed at a time in a two-hop neighborhood, because 1) simultaneous transmissions in the neighborhood collide, and 2) affordable radio is half-duplex and cannot simultaneously transmit and receive useful signals. In this paper, we propose a novel solution for the peer-to-peer mutual broadcast problem, which exploits the multiaccess nature of the wireless medium and addresses the half-duplex constraint at the fundamental level. The defining feature of the scheme is to let all nodes send their messages at the same time, where each node broadcasts a codeword (selected from its unique codebook) consisting of on-slots and off-slots, where it transmits only during its on-slots, and listens to its peers through its own off-slots. Each node decodes the messages of its peers based on the received superposed signal...

  15. Innovative Rated-Resource Peer-to-Peer Network

    CERN Document Server

    Sharma, Abhishek; 10.5121/ijcnc.2010.2206

    2010-01-01

    Peer-to-Peer (P2P) networks provide a significant solution for file sharing among peers connected to Internet. It is fast and completely decentralised system with robustness. But due to absence of a server documents on a P2P network are not rated which makes it difficult for a peer to obtain precise information in result of a query. In past, some researchers tried to attach ratings to the peers itself but it was complex and less effective. In this paper, a novel P2P architecture is proposed which attaches ratings to the uploaded document directly. These ratings then become as element in its XML advertisement which has several child elements for information classification. The attached element is extracted from the advertisement in real time and the document is then sorted accordingly. Therefore, the information can be easily sorted based on a request by a peer according to the relevance of matter. The information regarding relevance is obtained by the peer issuing the query. This research leads to a smart P...

  16. Innovative Rated-Resource Peer-to-Peer Network

    Directory of Open Access Journals (Sweden)

    Abhishek Sharma

    2010-03-01

    Full Text Available Peer-to-Peer (P2P networks provide a significant solution for file sharing among peers connected to Internet. It is fast and completely decentralised system with robustness. But due to absence of a serverdocuments on a P2P network are not rated which makes it difficult for a peer to obtain precise information in result of a query. In past, some researchers tried to attach ratings to the peers itself but itwas complex and less effective. In this paper, a novel P2P architecture is proposed which attaches ratings to the uploaded document directly. These ratings then become as element in its XML advertisement which has several child elements for information classification. The attached element is extracted from the advertisement in real time and the document is then sorted accordingly. Therefore, the information can be easily sorted based on a request by a peer according to the relevanceof matter. The information regarding relevance is obtained by the peer issuing the query. This research leads to a smart P2P model, the Rated-Resource P2P network (R2P2P.

  17. Peer-to-Peer Multimedia Sharing based on Social Norms

    CERN Document Server

    Zhang, Yu

    2011-01-01

    Empirical data shows that in the absence of incentives, a peer participating in a Peer-to-Peer (P2P) network wishes to free-riding. Most solutions for providing incentives in P2P networks are based on direct reciprocity, which are not appropriate for most P2P multimedia sharing networks due to the unique features exhibited by such networks: large populations of anonymous agents interacting infrequently, asymmetric interests of peers, network errors, and multiple concurrent transactions. In this paper, we design and rigorously analyze a new family of incentive protocols that utilizes indirect reciprocity which is based on the design of efficient social norms. In the proposed P2P protocols, the social norms consist of a social strategy, which represents the rule prescribing to the peers when they should or should not provide content to other peers, and a reputation scheme, which rewards or punishes peers depending on whether they comply or not with the social strategy. We first define the concept of a sustainab...

  18. PeerPigeon: A Web Application to Support Generalised Peer Review

    OpenAIRE

    Millard, David; Sinclair, Patrick; Newman, David

    2008-01-01

    Peer Review (also known as Peer Assessment) is an important technique in learning, but can be difficult to support through e-learning due to the complexity and variety of peer review processes. In this paper we present PeerPigeon, a Web 2.0 style application that supports generalised Peer Review by using a canonical model of Peer Review based on a Peer Review Pattern consisting of Peer Review Cycles, each defined in terms of Peer Review Transforms. We also demonstrate how PeerPigeon makes use...

  19. Aquatic and Terrestrial Environment 2004

    DEFF Research Database (Denmark)

    Andersen, J. M.; Boutrup, S.; Bijl, L. van der;

    This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected and...

  20. Aquatic plants clean wastewater lagoons

    Energy Technology Data Exchange (ETDEWEB)

    1980-09-01

    Water weeds that grow profusely in warm tropical and subtropical regions have always been considered a nuisance; current research is focusing on methods to cull benefits from such aquatic proliferations. Weeds, especially the water hyacinth, are proving to be useful in the purification of wastewater lagoons. The plants extract inorganic and organic toxicants from the effluent. Hyacinths employed in experiments conducted in Puerto Rico are removed from the lagoons to prevent overcrowding. This harvest is sent through a digester to produce methane. (2 diagrams, 3 photos)

  1. NIH Peer Review

    Science.gov (United States)

    Vancea, Adrian; Chen, Mei-Ching; Chacko, George

    2015-01-01

    The National Institutes of Health (NIH) is the largest source of funding for biomedical research in the world. Funding decisions are made largely based on the outcome of a peer review process that is intended to provide a fair, equitable, timely, and unbiased review of the quality, scientific merit, and potential impact of the research. There have been concerns about the criteria reviewers are using, and recent changes in review procedures at the NIH now make it possible to conduct an analysis of how reviewers evaluate applications for funding. This study examined the criteria and overall impact scores recorded by assigned reviewers for R01 grant applications. The results suggest that all the scored review criteria, including innovation, are related to the overall impact score. Further, good scores are necessary on all five scored review criteria, not just the score for research methodology, in order to achieve a good overall impact score. PMID:27239158

  2. EPA Region 7 Aquatic Focus Areas (ECO_RES.R7_AQUATIC_FOCUS_AREAS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This shapefile consists of 347 individual Aquatic Ecological System (AES) polygons that are the Aquatic Conservation Focus Areas for EPA Region 7. The focus areas...

  3. Radioactivity in the Canadian aquatic environment

    International Nuclear Information System (INIS)

    Sources of radionuclides arising from natural anthropogenic processes as well as technologically enhanced natural radiation are discussed. Transport, distribution and behaviour of these radionuclides in aquatic systems are influenced by physical, chemical, biological and geological processes and conditions in freshwater and marine environments. Dosimetry of aquatic organisms, as well as various methods of measuring dose rate are presented. Effects of ionizing radiation (acute and chronic exposure) on aquatic organisms, populations and ecosystems are reviewed. This review covers the entire spectrum of the aquatic environment. Results of many studies are summarized. 300+ refs

  4. Data Management in Peer-to-Peer Environment:A Perspective of BestPeer

    Institute of Scientific and Technical Information of China (English)

    ZHOU AoYing(周傲英); QIAN WeiNing(钱卫宁); ZHOU ShuiGeng(周水庚); LING Bo(凌波); XU LinHao(徐林昊); Ng Wee Siong(黄维雄); Ooi Beng Chin(黄铭钧); Tan Kian-Lee(陈建利)

    2003-01-01

    Peer-to-Peer (P2P) systems have attracted much attention in academic community and industry circles due to their promising applications in various domains. This paper presents the authors' research efforts on introducing complex query capabilities in a P2P environment consisting of numerous peers with large volume of data. An underlying hybrid P2P computing platform, named BestPeer is described first. The connection among peers within BestPeer is selfconfigurable through maintaining the nearest neighbor of peers, and the agent techniques employed in the system ensure its capability of providing sophisticated services. The designs of three P2P data management systems which are all based on BestPeer are described in detail. They provide support for information retrieval, query processing and Web services respectively. Advantages and limitations are discussed, while ongoing work is presented. Current systems can provide basic functions for keyword-based search, SQL-like query processing, and Web services querying and discovery. Some further topics on providing fully-fledged data management functionalities for P2P distributed computing systems with security guarantee are also discussed.

  5. Stability analysis of peer-to-peer networks against churn

    Indian Academy of Sciences (India)

    Bivas Mitra; Sujoy Ghose; Niloy Ganguly; Fernando Peruani

    2008-08-01

    Users of the peer-to-peer system join and leave the network randomly, which makes the overlay network dynamic and unstable in nature. In this paper, we propose an analytical framework to assess the robustness of p2p networks in the face of user churn. We model the peer churn through degree-independent as well as degree-dependent node failure. Lately, superpeer networks are becoming the most widely used topology among the p2p networks. Therefore, we perform the stability analysis of superpeer networks as a case study. We validate the analytically derived results with the help of simulation.

  6. Recommendations for peer-to-peer support for NICU parents

    OpenAIRE

    Hall, S L; Ryan, D J; Beatty, J.; Grubbs, L

    2015-01-01

    Peer-to-peer support provided by ‘veteran' neonatal intensive care unit (NICU) parents to those with current NICU babies is a legitimate and unique form of support that can complement or supplement, but not replace, services provided by professional NICU staff. Peer support can be delivered through hospital- or community-based programs that offer one-to-one in-person or telephone matches, or support groups that meet in-person or via the Internet. Issues in program development, volunteer train...

  7. An initial peer configuration algorithm for multi-streaming peer-to-peer networks

    CERN Document Server

    Ishii, Tomoyuki

    2012-01-01

    The growth of the Internet technology enables us to use network applications for streaming audio and video. Especially, real-time streaming services using peer-to-peer (P2P) technology are currently emerging. An important issue on P2P streaming is how to construct a logical network (overlay network) on a physical network (IP network). In this paper, we propose an initial peer configuration algorithm for a multi-streaming peer-to-peer network. The proposed algorithm is based on a mesh-pull approach where any node has multiple parent and child nodes as neighboring nodes, and content transmitted between these neighboring nodes depends on their parent-child relationships. Our simulation experiments show that the proposed algorithm improves the number of joining node and traffic load.

  8. Passive electroreception in aquatic mammals.

    Science.gov (United States)

    Czech-Damal, Nicole U; Dehnhardt, Guido; Manger, Paul; Hanke, Wolf

    2013-06-01

    Passive electroreception is a sensory modality in many aquatic vertebrates, predominantly fishes. Using passive electroreception, the animal can detect and analyze electric fields in its environment. Most electric fields in the environment are of biogenic origin, often produced by prey items. These electric fields can be relatively strong and can be a highly valuable source of information for a predator, as underlined by the fact that electroreception has evolved multiple times independently. The only mammals that possess electroreception are the platypus (Ornithorhynchus anatinus) and the echidnas (Tachyglossidae) from the monotreme order, and, recently discovered, the Guiana dolphin (Sotalia guianensis) from the cetacean order. Here we review the morphology, function and origin of the electroreceptors in the two aquatic species, the platypus and the Guiana dolphin. The morphology shows certain similarities, also similar to ampullary electroreceptors in fishes, that provide cues for the search for electroreceptors in more vertebrate and invertebrate species. The function of these organs appears to be very similar. Both species search for prey animals in low-visibility conditions or while digging in the substrate, and sensory thresholds are within one order of magnitude. The electroreceptors in both species are innervated by the trigeminal nerve. The origin of the accessory structures, however, is completely different; electroreceptors in the platypus have developed from skin glands, in the Guiana dolphin, from the vibrissal system. PMID:23187861

  9. Editorial behaviors in peer review.

    Science.gov (United States)

    Wang, Wei; Kong, Xiangjie; Zhang, Jun; Chen, Zhen; Xia, Feng; Wang, Xianwen

    2016-01-01

    Editors play a critical role in the peer review system. How do editorial behaviors affect the performance of peer review? No quantitative model to date allows us to measure the influence of editorial behaviors on different peer review stages such as, manuscript distribution and final decision making. Here, we propose an agent-based model in which the process of peer review is guided mainly by the social interactions among three kinds of agents representing authors, editors and reviewers respectively. We apply this model to analyze a number of editorial behaviors such as decision strategy, number of reviewers and editorial bias on peer review. We find out that peer review outcomes are significantly sensitive to different editorial behaviors. With a small fraction (10 %) of biased editors, the quality of accepted papers declines 11 %, which indicates that effects of editorial biased behavior is worse than that of biased reviewers (7 %). While several peer review models exist, this is the first account for the study of editorial behaviors that is validated on the basis of simulation analysis. PMID:27386349

  10. Peer relationships and academic achievement

    Directory of Open Access Journals (Sweden)

    Krnjajić Stevan B.

    2002-01-01

    Full Text Available After their childhood, when children begin to establish more intensive social contacts outside family, first of all, in school setting, their behavior i.e. their social, intellectual, moral and emotional development is more strongly affected by their peers. Consequently, the quality of peer relationships considerably affects the process of adaptation and academic achievement and their motivational and emotional attitude towards school respectively. Empirical findings showed that there is bi-directional influence between peer relationships and academic achievement. In other words, the quality of peer relationships affects academic achievement, and conversely, academic achievement affects the quality of peer relationships. For example, socially accepted children exhibiting prosocial, cooperative and responsible forms of behavior in school most frequently have high academic achievement. On the other hand, children rejected by their peers often have lower academic achievement and are a risk group tending to delinquency, absenteeism and drop out of school. Those behavioral and interpersonal forms of competence are frequently more reliable predictors of academic achievement than intellectual abilities are. Considering the fact that various patterns of peer interaction differently exert influence on students' academic behavior, the paper analyzed effects of (a social competence, (b social acceptance/rejection, (c child's friendships and (d prosocial behavior on academic achievement.

  11. Input and Second Language Acquisition

    Institute of Scientific and Technical Information of China (English)

    周笑盈

    2011-01-01

    The behaviorist, the mentalist and the interactionist have different emphases on the role input in Second Language Acquisition. In order to protrude the importance of second language teaching, it is indispensible to discuss the characteristics of input and to explore its effects.

  12. Decentralized control with input saturation

    OpenAIRE

    Saberi, Ali; Stoorvogel, Anton A.; Sannuti, Peddapullaiah

    2004-01-01

    In decentralized control it is known that the system can be stabilized only if the so-called fixed modes are all stable. If we have input constraints then (semi-)global stability requires all poles to be in the closed left half plane. This paper establishes that these two requirements are necessary and sufficient for stabilizability of a decentralized system with input saturation.

  13. REEXAMINING THE ROLE OF INPUT AND THE FEATURES OF OPTIMAL INPUT (Ⅱ) Features of Optimal Input

    Institute of Scientific and Technical Information of China (English)

    Niu; Qiang

    2001-01-01

    If input plays a significant role in SLA, then the nextquestion is what kind of input is most helpful to the learner?Krashen (1982) defined that optimal input should (1) becomprehensible; (2) be interesting and/or relevant; (3) not begrammatically sequened; (4) be in sufficient quantity. Wemade some modifications to this list which may still not becomprehensive either. However, if the learner can be exposed toinput having these features, it is considered that acquisition ismore likely to occur. Such input should be comprehensible,authentic, attractive and interesting, interactive, up-to-date,culture-bearing, and in great quantity.

  14. From Hazardous Behaviours to a Risk Metric for Reputation Systems in Peer to Peer Networks

    OpenAIRE

    Rosas, Erika; Bonnaire, Xavier

    2009-01-01

    International audience Peer to Peer systems have shown to be very powerful to build very large scale distributed information systems. They are self organized, and provide very high availability of the data. However, the management of malicious peers is a very open problem for the Peer to Peer research community, and building trust is a very difficult task. In this context, Reputation Systems have shown to be a very good solution to build trust in Peer to Peer systems. Nevertheless, using o...

  15. Enhanced Input in LCTL Pedagogy

    Directory of Open Access Journals (Sweden)

    Marilyn S. Manley

    2009-08-01

    Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

  16. Enhanced Input in LCTL Pedagogy

    Directory of Open Access Journals (Sweden)

    Marilyn S. Manley

    2010-08-01

    Full Text Available Language materials for the more-commonly-taught languages (MCTLs often include visual input enhancement (Sharwood Smith 1991, 1993 which makes use of typographical cues like bolding and underlining to enhance the saliency of targeted forms. For a variety of reasons, this paper argues that the use of enhanced input, both visual and oral, is especially important as a tool for the lesscommonly-taught languages (LCTLs. As there continues to be a scarcity of teaching resources for the LCTLs, individual teachers must take it upon themselves to incorporate enhanced input into their own self-made materials. Specific examples of how to incorporate both visual and oral enhanced input into language teaching are drawn from the author’s own experiences teaching Cuzco Quechua. Additionally, survey results are presented from the author’s Fall 2010 semester Cuzco Quechua language students, supporting the use of both visual and oral enhanced input.

  17. The interactive effects of excess reactive nitrogen and climate change on aquatic ecosystems and water resources of the United States

    Science.gov (United States)

    Baron, J.S.; Hall, E.K.; Nolan, B.T.; Finlay, J.C.; Bernhardt, E.S.; Harrison, J.A.; Chan, F.; Boyer, E.W.

    2012-01-01

    Nearly all freshwaters and coastal zones of the US are degraded from inputs of excess reactive nitrogen (Nr), sources of which are runoff, atmospheric N deposition, and imported food and feed. Some major adverse effects include harmful algal blooms, hypoxia of fresh and coastal waters, ocean acidification, long-term harm to human health, and increased emissions of greenhouse gases. Nitrogen fluxes to coastal areas and emissions of nitrous oxide from waters have increased in response to N inputs. Denitrification and sedimentation of organic N to sediments are important processes that divert N from downstream transport. Aquatic ecosystems are particularly important denitrification hotspots. Carbon storage in sediments is enhanced by Nr, but whether carbon is permanently buried is unknown. The effect of climate change on N transport and processing in fresh and coastal waters will be felt most strongly through changes to the hydrologic cycle, whereas N loading is mostly climate-independent. Alterations in precipitation amount and dynamics will alter runoff, thereby influencing both rates of Nr inputs to aquatic ecosystems and groundwater and the water residence times that affect Nr removal within aquatic systems. Both infrastructure and climate change alter the landscape connectivity and hydrologic residence time that are essential to denitrification. While Nr inputs to and removal rates from aquatic systems are influenced by climate and management, reduction of N inputs from their source will be the most effective means to prevent or to minimize environmental and economic impacts of excess Nr to the nation’s water resources.

  18. SECURE SHORT MESSAGE PEER-TO-PEER PROTOCOL

    Directory of Open Access Journals (Sweden)

    Saurabh Samanta

    2012-06-01

    Full Text Available Short Message Service (SMS has become an extension of our lives and plays an important role in daily chores. SMS is a popular medium for delivering Value Added Services and are suitable for mobile banking, payment reminders, SOS calls, stock and news alerts, railway and flight enquiries etc. These types of messages are normally computer generated messages sent over Short Message Peer-to-Peer (SMPP protocol. SMPP is an application layer protocol to send messages over TCP/IP connection. SMPP protocol has no security measures specified which allows fast delivery of SMS messages in bulk. Compromised messages or loss of messages can cause lot of revenue loss and fatal consequences. A secure SMPP protocol is proposed and implemented by introducing Transport Layer Security (TLS with SMPP protocol specifications. A client tool is developed to securely connect to the server. Secure Short Message Peer-to-Peer protocol will enhance the security of fast growing messaging and telecommunication world.

  19. 06131 Abstracts Collection -- Peer-to -Peer -Systems and -Applications

    OpenAIRE

    Joseph, Anthony D.; Steinmetz, Ralf; Stoica, Ion; Wehrle, Klaus

    2007-01-01

    From 26.03.06 to 29.03.06, the Dagstuhl Seminar 06131 ``Peer-to-Peer-Systems and -Applications'' was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the se...

  20. Peer-to-Peer Usage Analysis: a Distributed Mining Approach

    OpenAIRE

    Masseglia, Florent; Poncelet, Pascal; Teisseire, Maguelonne

    2006-01-01

    International audience With the huge number of information sources available on the Internet, Peer-to-Peer (P2P) systems offer a novel kind of system architecture providing the large-scale community with applications for file sharing, distributed file systems, distributed computing, messaging and real-time communication. P2P applications also provide a good infrastructure for data and compute intensive operations such as data mining. In this paper we propose a new approach for improving re...

  1. Die vermeintliche Robustheit von Peer-to-Peer-Netzen

    OpenAIRE

    Dinger, Jochen; Hartenstein, Hannes

    2006-01-01

    Peer-to-Peer- (P2P-) Netze bilden logische bzw. virtuelle Netze auf Basis existierender Netze wie dem Internet. P2P-Netze zeichnen sich insbesondere durch ihre dezentrale Struktur und selbstorganisierende Mechanismen aus, welche im Gegensatz zu Client-Server Architekturen die Last auf alle teilnehmenden Knoten gleichmaeßig verteilen. Durch die dezentrale Struktur in Kombination mit selbstorganisierenden Mechanismen ist es daher moeglich, hoch skalierbare P2P-Netze zu konstruieren. Zudem erhoe...

  2. Surfing Peer-to-Peer IPTV: Distributed Channel Switching

    Science.gov (United States)

    Kermarrec, A.-M.; Le Merrer, E.; Liu, Y.; Simon, G.

    It is now common for IPTV systems attracting millions of users to be based on a peer-to-peer (P2P) architecture. In such systems, each channel is typically associated with one P2P overlay network connecting the users. This significantly enhances the user experience by relieving the source from dealing with all connections. Yet, the joining process resulting in a peer to be integrated in channel overlay usually requires a significant amount of time. As a consequence, switching from one channel to another is far to be as fast as in IPTV solutions provided by telco operators. In this paper, we tackle the issue of efficient channel switching in P2P IPTV system. This is to the best of our knowledge the first study on this topic. First, we conducted and analyzed a set of measurements of one of the most popular P2P systems (PPlive). These measurements reveal that the set of contacts that a joining peer receives from the central server are of the utmost importance in the start-up process. On those neigbors, depends the speed to acquire the first video frames to play. We then formulate the switching problem, and propose a simple distributed algorithm, as an illustration of the concept, which aims at leveraging the presence of peers in the network to fasten the switch process. The principle is that each peer maintains as neighbors peers involved in other channels, providing peers with good contacts upon channel switching. Finally, simulations show that our approach leads to substantial improvements on the channel switching time. As our algorithmic solution does not have any prerequisite on the overlays, it appears to be an appealing add-on for existing P2P IPTV systems.

  3. SECURE SHORT MESSAGE PEER-TO-PEER PROTOCOL

    OpenAIRE

    Saurabh Samanta; Radhesh Mohandas; Alwyn R. Pais

    2012-01-01

    Short Message Service (SMS) has become an extension of our lives and plays an important role in daily chores. SMS is a popular medium for delivering Value Added Services and are suitable for mobile banking, payment reminders, SOS calls, stock and news alerts, railway and flight enquiries etc. These types of messages are normally computer generated messages sent over Short Message Peer-to-Peer (SMPP) protocol. SMPP is an application layer protocol to send messages over TCP/IP connection. SMPP ...

  4. Peer to Peer Education: OB Visits the ED.

    Science.gov (United States)

    Homan, Nancy; Chichester, Melanie

    2016-03-01

    Ongoing education, an ever-present challenge in a hectic clinical environment, can be addressed by utilizing peer-to-peer education. Enhancing nurses' comfort level with specialty topics can reduce anxiety while enhancing core knowledge and skill proficiency for the provision of safe care. Increased self-confidence in a nurse's ability to detect a new or developing concern can lead to fewer delays in care. Critical problems identified and addressed promptly support better outcomes. PMID:27002199

  5. Workflow-based semantics for peer-to-peer specifications

    Institute of Scientific and Technical Information of China (English)

    Antonio BROGI; Razvan POPESCU

    2008-01-01

    In this paper we introduce SMoL, a simplified BPEL-like language for specifying peer and service beha-viour in P2P systems. We then define a transformational semantics of SMoL in terms of Yet Another Workflow Language (YAWL) workflows, which enables the simu-lation (e.g., testing possible execution scenarios) and ana-lysis (e.g., verifying reachability or lock freedom) of the behaviour of P2P peers and services.

  6. Stream my Models: Reactive Peer-to-Peer Distributed

    OpenAIRE

    Hartmann, Thomas; Moawad, Assaad; Fouquet, François; Nain, Grégory; Klein, Jacques; Le Traon, Yves

    2015-01-01

    The paradigm promotes the use of models during the execution of cyber-physical systems to represent their context and to reason about their runtime behaviour. However, current modeling techniques do not allow to cope at the same time with the large-scale, distributed, and constantly changing nature of these systems. In this paper, we introduce a distributed approach, combining ideas from reactive programming, peer-to-peer distribution, and large-scale models@ru...

  7. Reviewing peer review: a quantitative analysis of peer review

    OpenAIRE

    Casati, Fabio; Marchese, Maurizio; Mirylenka, Katsiaryna; Ragone, Azzurra

    2010-01-01

    In this paper we focus on the analysis of peer reviews and reviewers behavior in a number of different review processes. More specifically, we report on the development, definition and rationale of a theoretical model for peer review processes to support the identification of appropriate metrics to assess the processes main properties. We then apply the proposed model and analysis framework to data sets from conference evaluation processes and we discuss the results implications and their eve...

  8. Control of Fish and Aquatic Plants.

    Science.gov (United States)

    Hesser, R. B.; And Others

    This agriculture extension service publication from Pennsylvania State University is a handbook for the water body manager. The bulk of the contents deals with aquatic plant control. The different types of aquatic plants, their reproduction and growth, and their role in the ecology of the water body are introduced in this main section. Also, the…

  9. Estimating Aquatic Insect Populations. Introduction to Sampling.

    Science.gov (United States)

    Chihuahuan Desert Research Inst., Alpine, TX.

    This booklet introduces high school and junior high school students to the major groups of aquatic insects and to population sampling techniques. Chapter 1 consists of a short field guide which can be used to identify five separate orders of aquatic insects: odonata (dragonflies and damselflies); ephemeroptera (mayflies); diptera (true flies);…

  10. Peer Review: Has It a Future?

    Science.gov (United States)

    Soh, Kay Cheng

    2013-01-01

    Although its history is short, peer review has fast become a fixture of journal publications acquiring the status of a ritual in the academia. Many relevant and important issues have been raised leading to doubts about the value of peer review. The advent of electronic publishing further threatens the future of peer review. For peer review to…

  11. 45 CFR 1388.9 - Peer review.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Peer review. 1388.9 Section 1388.9 Public Welfare... PROGRAM THE UNIVERSITY AFFILIATED PROGRAMS § 1388.9 Peer review. (a) The purpose of the peer review... D, Section 152 of the Act, must be evaluated through the peer review process. (c) Panels must...

  12. Peer review and journal models

    CERN Document Server

    Dall'Aglio, P

    2006-01-01

    Tentative analysis of alternative peer review and journal models. Open Access and Impact factor issues are not covered. The bibliography, in alphabetical order, lists articles and web sites (with brief description).

  13. Phytoremediation potential of aquatic macrophyte, Azolla.

    Science.gov (United States)

    Sood, Anjuli; Uniyal, Perm L; Prasanna, Radha; Ahluwalia, Amrik S

    2012-03-01

    Aquatic macrophytes play an important role in the structural and functional aspects of aquatic ecosystems by altering water movement regimes, providing shelter to fish and aquatic invertebrates, serving as a food source, and altering water quality by regulating oxygen balance, nutrient cycles, and accumulating heavy metals. The ability to hyperaccumulate heavy metals makes them interesting research candidates, especially for the treatment of industrial effluents and sewage waste water. The use of aquatic macrophytes, such as Azolla with hyper accumulating ability is known to be an environmentally friendly option to restore polluted aquatic resources. The present review highlights the phytoaccumulation potential of macrophytes with emphasis on utilization of Azolla as a promising candidate for phytoremediation. The impact of uptake of heavy metals on morphology and metabolic processes of Azolla has also been discussed for a better understanding and utilization of this symbiotic association in the field of phytoremediation. PMID:22396093

  14. Peer bullying in schools

    Directory of Open Access Journals (Sweden)

    Rıza Gökler

    2009-10-01

    Full Text Available In this study, the term of "Peer Bullying" has been observed according to definitions and approaches variety in Turkey and abroad. "Bullying" is used synonym of violence and aggressiveness today and spread of all cultures in the world as an international concept. "Bullying" is a widespread fact which consists of physical, verbal and social damage to a feeble one. It is a kind of violence and can be defined as incapability of someone to a person or more than one person's violence. Bullying can be classified as follows: psychological and emotional (a gossip or exclusion etc., verbal (get a nickname, impose constraints, intimidation etc. and physical (impellent, to kick a victim etc.The findings of this study can be summarized as follows: the frequency and extent of violence is very effective on espousal, insensitivity and unresponsiveness of the students. Thus, they use them as a problem solving instrument and also can move them to all parts of theri life. Bully has been determined that some precautions should be taken not to be effected from the short term and long term effects of violence.

  15. Peer bullying in schools

    Directory of Open Access Journals (Sweden)

    Rıza Gökler

    2009-10-01

    Full Text Available In this study, the term of "Peer Bullying" has been observed according to definitions and approaches variety in Turkey and abroad. "Bullying" is used synonym of violence and aggressiveness today and spread of all cultures in the world as an international concept. "Bullying" is a widespread fact which consists of physical, verbal and social damage to a feeble one. It is a kind of violence and can be defined as incapability of someone to a person or more than one person's violence. Bullying can be classified as follows: psychological and emotional (a gossip or exclusion etc., verbal (get a nickname, impose constraints, intimidation etc. and physical (impellent, to kick a victim etc. The findings of this study can be summarized as follows: the frequency and extent of violence is very effective on espousal, insensitivity and unresponsiveness of the students. Thus, they use them as a problem solving instrument and also can move them to all parts of theri life. Bully has been determined that some precautions should be taken not to be effected from the short term and long term effects of violence.

  16. DAC Peer Review of Canada

    OpenAIRE

    OECD

    2007-01-01

    Abstract: This review contains the Main Findings and Recommendations of the Development Assistance Committee (DAC) and the report of the Secretariat. It was prepared with examiners from Belgium and Switzerland for the Peer Review Meeting on 10 October 2007. This peer review of Canada’s development co-operation programme highlights Canada’s renewed commitment to Africa; a promising approach toward fragile states, such as Haiti and Afghanistan; initiatives to make Canadian aid more effective, f...

  17. Peer relationships and academic achievement

    OpenAIRE

    Krnjajić Stevan B.

    2002-01-01

    After their childhood, when children begin to establish more intensive social contacts outside family, first of all, in school setting, their behavior i.e. their social, intellectual, moral and emotional development is more strongly affected by their peers. Consequently, the quality of peer relationships considerably affects the process of adaptation and academic achievement and their motivational and emotional attitude towards school respectively. Empirical findings showed that there is bi-d...

  18. Peer assessment enhances student learning

    OpenAIRE

    Sun, Dennis L.; Harris, Naftali; Walther, Guenther; Baiocchi, Michael

    2014-01-01

    Feedback has a powerful influence on learning, but it is also expensive to provide. In large classes, it may even be impossible for instructors to provide individualized feedback. Peer assessment has received attention lately as a way of providing personalized feedback that scales to large classes. Besides these obvious benefits, some researchers have also conjectured that students learn by peer assessing, although no studies have ever conclusively demonstrated this effect. By conducting a ra...

  19. Clean Evidence on Peer Pressure

    OpenAIRE

    Falk, Armin; Ichino, Andrea

    2003-01-01

    While confounding factors typically jeopardize the possibility of using observational data to measure peer effects, field experiments over the potential for obtaining clean evidence. In this paper we measure the output of subjects who were asked to stuff letters into envelopes, with a remuneration completely independent of output. We study two treatments. In the 'pair' treatment two subjects work at the same time in the same room. Peer effects are possible in this situation and imply that out...

  20. Perception and Management of Risk in Internet-Based Peer-to-Peer Milk-Sharing

    Science.gov (United States)

    Gribble, Karleen D.

    2014-01-01

    The perception and management of the risks of peer-to-peer milk sharing was explored via a written questionnaire administered to 97 peer milk donors and 41 peer milk recipients who were recruited via Facebook. All recipients' respondents were aware that there were risks associated with using peer-shared milk and took action to mitigate these…

  1. Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing

    DEFF Research Database (Denmark)

    Baun, Anders; Hartmann, Nanna Isabella Bloch; Grieger, Khara Deanne;

    2008-01-01

    . Results show that there is a pronounced lack of data in this field (less than 20 peer-reviewed papers are published so far), and the most frequently tested engineered nanoparticles in invertebrate tests are C-60, carbon nanotubes, and titanium dioxide. In addition, the majority of the studies have used...... Daphnia magna as the test organism. To date, the limited number of studies has indicated acute toxicity in the low mgl(-1) range and higher of engineered nanoparticles to aquatic invertebrates, although some indications of chronic toxicity and behavioral changes have also been described at concentrations...

  2. Material input of nuclear fuel

    International Nuclear Information System (INIS)

    The Material Input (MI) of nuclear fuel, expressed in terms of the total amount of natural material needed for manufacturing a product, is examined. The suitability of the MI method for assessing the environmental impacts of fuels is also discussed. Material input is expressed as a Material Input Coefficient (MIC), equalling to the total mass of natural material divided by the mass of the completed product. The material input coefficient is, however, only an intermediate result, which should not be used as such for the comparison of different fuels, because the energy contents of nuclear fuel is about 100 000-fold compared to the energy contents of fossil fuels. As a final result, the material input is expressed in proportion to the amount of generated electricity, which is called MIPS (Material Input Per Service unit). Material input is a simplified and commensurable indicator for the use of natural material, but because it does not take into account the harmfulness of materials or the way how the residual material is processed, it does not alone express the amount of environmental impacts. The examination of the mere amount does not differentiate between for example coal, natural gas or waste rock containing usually just sand. Natural gas is, however, substantially more harmful for the ecosystem than sand. Therefore, other methods should also be used to consider the environmental load of a product. The material input coefficient of nuclear fuel is calculated using data from different types of mines. The calculations are made among other things by using the data of an open pit mine (Key Lake, Canada), an underground mine (McArthur River, Canada) and a by-product mine (Olympic Dam, Australia). Furthermore, the coefficient is calculated for nuclear fuel corresponding to the nuclear fuel supply of Teollisuuden Voima (TVO) company in 2001. Because there is some uncertainty in the initial data, the inaccuracy of the final results can be even 20-50 per cent. The value

  3. The Advanced LIGO Input Optics

    CERN Document Server

    Mueller, Chris; Ciani, Giacomo; DeRosa, Ryan; Effler, Anamaria; Feldbaum, David; Frolov, Valery; Fulda, Paul; Gleason, Joseph; Heintze, Matthew; King, Eleanor; Kokeyama, Keiko; Korth, William; Martin, Rodica; Mullavey, Adam; Poeld, Jan; Quetschke, Volker; Reitze, David; Tanner, David; Williams, Luke; Mueller, Guido

    2016-01-01

    The Advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they h...

  4. PEERS ORGANIZING TRUST BASED ON METRICS

    OpenAIRE

    Sheshadri Shirisha; K. Chandra Sekharaiah

    2014-01-01

    Every system in the network considered as peer, which are open to malicious activities in nature. Prevention of these malicious activities is achieved by developing trust between the peers. Trustworthiness of a peer can be calculated based on the prior interactions with other peers in the network. Peers create their own trust network in their proximity by using local information available and do not try to learn global trust information. Interactions and recommendations are ...

  5. Current and Evolving Models of Peer Review

    OpenAIRE

    Fresco-Santalla, Ana; Hernández-Pérez, Tony

    2014-01-01

    New models of scientific publishing and new ways of practicing peer review have injected a recent dynamism into the scholarly communication system. In this article, we delineate the context of the traditional peer review model, reflect upon some of the first experiences with open peer review and forecast some of the challenges that new models for peer review will have to meet. Our findings suggest that the peer review function has the potential to be divorced from the journal system, so that ...

  6. Nonlinear input-output systems

    Science.gov (United States)

    Hunt, L. R.; Luksic, Mladen; Su, Renjeng

    1987-01-01

    Necessary and sufficient conditions that the nonlinear system dot-x = f(x) + ug(x) and y = h(x) be locally feedback equivalent to the controllable linear system dot-xi = A xi + bv and y = C xi having linear output are found. Only the single input and single output case is considered, however, the results generalize to multi-input and multi-output systems.

  7. Using Stable Isotopes to Detect Land Use Change and Nitrogen Sources in Aquatic Systems

    International Nuclear Information System (INIS)

    Changing land use is one of the primary causes of increased sedimentation and nutrient levels in aquatic systems, resulting in contamination and reduction of biodiversity. Detecting and quantifying these inputs is the first step towards remediation, and enabling targeted reductions of transport processes into waterways from human impacted land surfaces. More recently, stable isotope analyses are being used as detection and quantification tools in aquatic environments. Carbon (δ13C) and nitrogen (δ15N) isotopes of sediments, as well as algae and invertebrates from aquatic systems can be used as proxies to record both short and long term environmental change. Excess nitrogen (or nitrogen-compounds) derived from urbanization, industry, forestry, farming and agriculture, increase the bioavailability of nitrogen to aquatic organisms, changing their natural δ15N isotopic signatures. Allochthonous (terrestrial) input from soil destabilization and human activity in surrounding catchments changes δ13C isotopic compositions and increases the C:N ratio of sediments. Heavy metal and other organic pollutants can also be used to indicate urbanization and industrial contamination. The combined use of carbon and nitrogen isotopes, C:N ratios and heavy metals are powerful environmental monitoring tools, which are useful indicators of source and transport pathways of terrestrial derived material and anthropogenic pollutants into streams, rivers and estuaries. (author)

  8. On Democracy in Peer-to-Peer systems

    CERN Document Server

    Baraglia, Ranieri; Mordacchini, Matteo; Ricci, Laura; Alessi, Luca

    2011-01-01

    The information flow inside a P2P network is highly dependent on the network structure. In order to ease the diffusion of relevant data toward interested peers, many P2P protocols gather similar nodes by putting them in direct contact. With this approach the similarity between nodes is computed in a point-to-point fashion: each peer individually identifies the nodes that share similar interests with it. This leads to the creation of a sort of "private" communities, limited to each peer neighbors list. This "private" knowledge do not allow to identify the features needed to discover and characterize the correlations that collect similar peers in broader groups. In order to let these correlations to emerge, the collective knowledge of peers must be exploited. One common problem to overcome in order to avoid the "private" vision of the network, is related to how distributively determine the representation of a community and how nodes may decide to belong to it. We propose to use a gossip-like approach in order t...

  9. Commercial Lighting Solutions Webtool Peer Review Report, Office Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Beeson, Tracy A.; Jones, Carol C.

    2010-02-01

    The Commercial Lighting Solutions (CLS) project directly supports the U.S. Department of Energy’s Commercial Building Energy Alliance efforts to design high performance buildings. CLS creates energy efficient best practice lighting designs for widespread use, and they are made available to users via an interactive webtool that both educates and guides the end user through the application of the Lighting Solutions. This report summarizes the peer review of the CLS webtool for offices. The methodology for the peer review process included data collection (stakeholder input), analysis of the comments, and organization of the input into categories for prioritization of the comments against a set of criteria. Based on this process, recommendations were developed for the release of version 2.0 of the webtool at the Lightfair conference in Las Vegas in May 2010. The report provides a list of the top ten most significant and relevant improvements that will be made within the webtool for version 2.0 as well as appendices containing the comments and short-term priorities in additional detail. Peer review comments that are considered high priority by the reviewers and the CLS team but cannot be completed for Version 2.0 are listed as long-term recommendations.

  10. Abiotic variability among different aquatic systems of the central Amazon floodplain during drought and flood events.

    Science.gov (United States)

    Affonso, A G; Queiroz, H L; Novo, E M L M

    2015-11-01

    This paper examines water properties from lakes, (depression lakes, sensu Junk et al., 2012), channels (scroll lakes with high connectivity, sensu Junk et al., 2012) and paleo-channels (scroll lakes with low connectivity-sensu Junk et al., 2012, locally called ressacas) located in Mamirauá Sustainable Development Reserve, in Central Amazon floodplain, Amazonas, Brazil. We analysed surface temperature, conductivity, pH, dissolved oxygen, turbidity, transparency, suspended inorganic and organic matter, chlorophyll-a, pheophytin, total nitrogen, total phosphorus, organic and inorganic carbon in 2009 high water phase, 2009 and 2010 low water phases. Multivariate statistical analyses of 24 aquatic systems (6 ressacas, 12 lakes and 6 channels, 142 samples) were applied to the variables in order to: 1) quantify differences among aquatic system types; 2) assess how those differences are affected in the different phases of the hydrological year. First, we analysed the entire set of variables to test for differences among phases of the hydrological year and types of aquatic systems using a PERMANOVA two-way crossed design. The results showed that the all measured limnological variables are distinct regarding both factors: types of aquatic systems and hydrological phases. In general, the magnitude and amplitude of all variables were higher in the low water phase than in the high water phase, except for water transparency in all aquatic system's types. PERMANOVA showed that the differences between aquatic system's types and hydrological phases of all variables were highly significant for both main factors (type and phase) and for the type x phase interaction. Limnological patterns of Amazon floodplain aquatic systems are highly dynamic, dependent on the surrounding environment, flood pulse, main river input and system type. These patterns show how undisturbed systems respond to natural variability in such a diverse environment, and how distinct are those aquatic systems

  11. Human Exploitation of Aquatic Landscapes. Editorial

    Directory of Open Access Journals (Sweden)

    Ricardo Fernandes

    2014-11-01

    Full Text Available Aquatic landscapes such as rivers, lakes, and seas played an important role in past human behaviour, affecting modes of subsistence, patterns of mobility, access to material resources, and technological choices and their developments. The interaction with aquatic landscapes was also influential in the establishment of economic and social structures and in the formation of communal identities. The aim of this special themed issue of Internet Archaeology is to contribute to a better understanding of different forms of human interaction with aquatic landscapes.

  12. Aquatic invasive species: Lessons from cancer research

    Science.gov (United States)

    Sepulveda, Adam; Ray, Andrew; Al-Chokhachy, Robert K.; Muhlfeld, Clint C.; Gresswell, Robert E.; Gross, Jackson A.; Kershner, Jeffrey L.

    2014-01-01

    Aquatic invasive species are disrupting ecosystems with increasing frequency. Successful control of these invasions has been rare: Biologists and managers have few tools for fighting aquatic invaders. In contrast, the medical community has long worked to develop tools for preventing and fighting cancer. Its successes are marked by a coordinated research approach with multiple steps: prevention, early detection, diagnosis, treatment options and rehabilitation. The authors discuss how these steps can be applied to aquatic invasive species, such as the American bullfrog (Lithobates catesbeianus), in the Northern Rocky Mountain region of the United States, to expedite tool development and implementation along with achievement of biodiversity conservation goals.

  13. A Mixed Picture of AQUATIC PRODUCTS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Aquatic products constitute an important part of China's international trade in agricultural products with the strongest competitiveness for export.The aquatic products industry of apparent competitive edge has maintained a considerable trade surplus despite the general trend of trade deficit among agricultural products in recent years.Nevertheless,the great changes taking place in the global economic and trade pattern in late years have given rise to the increasing uncertainties of the supply and demand as well as the price in the international aquatic products market.

  14. Evaluation of the Peer Helping Program Conducted For University Adjustment

    OpenAIRE

    ALADAĞ, Mine

    2009-01-01

    Evaluation of the peer helping program conducted for unıversity adjustment. the purpose of this study was to examine the peer helpers’ (university students who present peer helping program) and peer helpees’ (university students who benefit from peer helping program) evaluations of the peer helping program conducted for university adjustment. For this purpose, 47 peer helpees and 14 peer helpers were administered two different Peer Helping Program Evaluation Form developed by the researcher. ...

  15. Peer-to-Peer Time-shifted Streaming Systems

    CERN Document Server

    Liu, Yaning

    2009-01-01

    In live streaming systems (IPTV, life-stream services, etc.), an attractive service consists in allowing users to access past portions of the stream. This is called a time-shifted streaming system. In our vision, a centralized time-shifted streaming system face scalability and ethical issues, therefore, we address the problem of designing a peer-to-peer system where peers store and deliver past chunks. We first attempt to identify the main characteristics of time-shifted streaming system from well-known measurements of VoD and IPTV systems. These overlays are the first structures specifically designed for time-shifted streaming system. Although no evaluation is presented, these preliminary description aim to foster discussions on a critical service.

  16. Identifying the risk to the aquatic environment of endocrine disrupters derived from agriculture

    OpenAIRE

    Matthiessen, Peter; Arnold, David; Johnson, Andrew; Pepper, Tim; Pottinger, Tom G.; Pulman, Kim G. T.; Williams, Richard

    2005-01-01

    EXECUTIVE SUMMARY 1. The purpose of this project was to review possible inputs to UK headwater streams of steroid hormones originating from livestock, to investigate hormone contamination in some streams in which concentrations were expected to be maximal, and to draw conclusions about possible risks that these hormones may pose to aquatic organisms. 2. The review concluded that although livestock in the UK excretes more steroid sex hormones (oestradiol and testosterone) than the hu...

  17. Optimization of routing strategies for data transfer in peer-to-peer networks

    International Nuclear Information System (INIS)

    Since peer-to-peer file-sharing systems have become familiar recently, the information traffic in the networks is increasing. Therefore it causes various traffic problems in peer-to-peer networks. In this paper, we model some features of the peer-to-peer networks, and investigate the traffic problems. Peer-to-peer networks have two notable characters. One is that each peer frequently searches for a file and download it from a peer who has the requested file. To decide whether a peer has the requested file or not in modelling of the search and download process, we introduce file-parameter Pj, which expresses the amount of files stored in peer j. It is assumed that if Pj is large, peer j has many files and can meet other peers' requests with high probability. The other character is that peers leave and join into the network repeatedly. Many researchers address traffic problems of data transfer in computer communication networks. To our knowledge, however, no reports focus on those in peer-to-peer networks whose topology changes with time. For routing paths of data transfer, generally, the shortest paths are used in usual computer networks. In this paper, we introduce a new optimal routing strategy which uses weights of peers to avoid traffic congestion. We find that the new routing strategy is superior to the shortest path strategy in terms of congestion frequency in data transfer

  18. Optimization of routing strategies for data transfer in peer-to-peer networks

    Science.gov (United States)

    Morioka, Atsushi; Igarashi, Akito

    2014-03-01

    Since peer-to-peer file-sharing systems have become familiar recently, the information traffic in the networks is increasing. Therefore it causes various traffic problems in peer-to-peer networks. In this paper, we model some features of the peer-to-peer networks, and investigate the traffic problems. Peer-to-peer networks have two notable characters. One is that each peer frequently searches for a file and download it from a peer who has the requested file. To decide whether a peer has the requested file or not in modelling of the search and download process, we introduce file-parameter Pj, which expresses the amount of files stored in peer j. It is assumed that if Pj is large, peer j has many files and can meet other peers' requests with high probability. The other character is that peers leave and join into the network repeatedly. Many researchers address traffic problems of data transfer in computer communication networks. To our knowledge, however, no reports focus on those in peer-to-peer networks whose topology changes with time. For routing paths of data transfer, generally, the shortest paths are used in usual computer networks. In this paper, we introduce a new optimal routing strategy which uses weights of peers to avoid traffic congestion. We find that the new routing strategy is superior to the shortest path strategy in terms of congestion frequency in data transfer.

  19. Peer Effects and Peer Avoidance: Epidemic Diffusion in Coevolving Networks

    OpenAIRE

    Fosco, Constanza; Marsili, Matteo; VEGA-REDONDO, Fernando

    2008-01-01

    We study the long-run-emergency of behavioral patterns in dynamic complex networks. Individuals display two kinds of behavior: G("good") or B ("bad"). We assume that agents have an innate tendency towards G, but can also be led towards B though the influence of peer bad behavior. We model the implications of those peer effects as an epidemic process in the standard SIS (Susceptible-Infected-Susceptible) framework. The key novelty of our model is that, unlike in received epidemic literature, t...

  20. Small World Architecture For Peer-to-Peer Networks

    OpenAIRE

    Liu, Lu; Mackin, Stephen; Antonopoulos, Nick

    2006-01-01

    Small-world phenomenon has been observed in existing peer-to-peer (P2P) networks, such as Gnutella and Freenet. Due to the similarity of P2P networks to social networks, the previous small-world model proposed by Duncan Watts can be adopted in the design of P2P networks: each node is connected to some neighbouring nodes, and a group of nodes keep a small number of long links to randomly chosen distant nodes. Unfortunately, current unstructured search algorithms have difficulty distinguishing ...

  1. Designs and Analyses in Structured Peer-To-Peer Systems

    OpenAIRE

    El-Ansary, Sameh

    2005-01-01

    Peer-to-Peer (P2P) computing is a recent hot topic in the areas of networking and distributed systems. Work on P2P computing was triggered by a number of ad-hoc systems that made the concept popular. Later, academic research efforts started to investigate P2P computing issues based on scientific principles. Some of that research produced a number of structured P2P systems that were collectively referred to by the term "Distributed Hash Tables" (DHTs). However, the research occurred in a diver...

  2. Key agreement in peer-to-peer wireless networks

    DEFF Research Database (Denmark)

    Cagalj, Mario; Capkun, Srdjan; Hubaux, Jean-Pierre

    2006-01-01

    We present a set of simple techniques for key establishment over a radio link in peer-to-peer networks. Our approach is based on the Diffie-Hellman key agreement protocol, which is known to be vulnerable to the “man-in-the-middle” attack if the two users involved in the protocol do not share any...... first is based on visual comparison of short strings, the second on distance bounding, and the third on integrity codes; in each case, the users do not need to enter any password or other data, nor do they need physical or infrared connectivity between their devices. We base our analysis on a well...

  3. A Peer-to-Peer Database Management System

    OpenAIRE

    Roshelova, Albena

    2004-01-01

    Peer-to-Peer Database Management Systems (PDBMS) are still in the beginning of their evolution. They rise up p2p technology to exploit the power of available distributed database management technologies. The proposed PDBMS will be completely autonomous and any notions of centralization as central server or creating a cost-based global schema will be absent. In this paper a number of potential research issues in the overlap between database and p2p systems is identified, and a vision for build...

  4. Peer-to-peer television for the IP multimedia subsystem

    OpenAIRE

    Bikfalvi, Alexandru

    2012-01-01

    Peer-to-peer (P2P) video streaming has generated a significant amount of interest in both the research community and the industry, which find it a cost-effective solution to the user scalability problem. However, despite the success of Internet-based applications, the adoption has been limited for commercial services, such as Internet Protocol Television (IPTV). With the advent of the next-generation-networks (NGN) based on the IP Multimedia Subsystem (IMS), advocating for an open and inter-o...

  5. Mass exchange processes with input

    International Nuclear Information System (INIS)

    We investigate a system of interacting clusters evolving through mass exchange and supplemented by input of small clusters. Three possibilities depending on the rate of exchange generically occur when input is homogeneous: continuous growth, gelation, and instantaneous gelation. We mostly study the growth regime using scaling methods. An exchange process with reaction rates equal to the product of reactant masses admits an exact solution which allows us to justify the validity of scaling approaches in this special case. We also investigate exchange processes with a localized input. We show that if the diffusion coefficients are mass-independent, the cluster mass distribution becomes stationary and develops an algebraic tail far away from the source. (paper)

  6. Controls on metal exposure to aquatic organisms in urban streams.

    Science.gov (United States)

    Turpin-Nagel, Katelyn; Vadas, Timothy M

    2016-08-10

    Streams in urban ecosystems receive metal inputs primarily from stormwater runoff and wastewater effluent. The relative contribution of these metal sources to stream impairment is difficult to discern based on simple water characteristics and biological surveys. Stream impairment in these systems is often indicated by reduced abundance and diversity of aquatic insects, which tend to be more sensitive to chronic metal exposures. Metal species and controls on metal species in both the waterborne and dietborne exposure pathways to aquatic organisms are reviewed here. In addition, ecological changes that can control dietborne species are discussed. A main focus is on how organic matter from different anthropogenic sources may control both aqueous metal speciation as well as interaction with various inorganic or microbiological surfaces in streams. Most of the reviewed research focuses on Cu, Zn or Pb as those are the primary metals of concern in developed systems and Cu and Pb have unique and strong interactions with organic matter. Recommendations for further research are described in the context of exposure species, dynamics of exposure, stoichiometry, or advanced analytical tools, and regulatory implications are discussed. PMID:27170052

  7. Freshwater aquatic plant biomass production in Florida

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, K.R.; Sutton, D.L.; Bowes, G.

    1983-01-01

    About 8% (1.2 million ha) of the total surface area of Florida is occupied by freshwater. Many of these water bodies are eutrophic. Nutrients present in these water bodies can be potentially used to culture aquatic plants as a possible feedstock for methane production. This paper summarizes the results of known research findings on biomass production potential of freshwater aquatic plants in Florida and identifies key research needs to improve the quality and quantity of biomass yields. Among floating aquatic plants, biomass yield potential was in the order of water-hyacinth > water lettuce > pennywort > salvinia > duckweed > azolla. Pennywort, duckweed, and azolla appear to perform well during the cooler months compared to other aquatic plants. Among emergent plants, biomass yield potential was in the order of southern wild rice > cattails > soft rush > bulrush. Cultural techniques, nutrient management, and environmental factors influencing the biomass yields were discussed. 68 references.

  8. Antibiotics promote aggregation within aquatic bacterial communities

    Directory of Open Access Journals (Sweden)

    ManuelaCoci

    2014-07-01

    These results represent the first observation of co-aggregation as a successful strategy of AB resistance based on phenotype in aquatic bacterial communities, and can represent a fundamental step in the understanding of the effects of AB.

  9. Nitrous oxide emission by aquatic macrofauna

    Science.gov (United States)

    Stief, Peter; Poulsen, Morten; Nielsen, Lars Peter; Brix, Hans; Schramm, Andreas

    2009-01-01

    A large variety of aquatic animals was found to emit the potent greenhouse gas nitrous oxide when nitrate was present in the environment. The emission was ascribed to denitrification by ingested bacteria in the anoxic animal gut, and the exceptionally high N2O-to-N2 production ratio suggested delayed induction of the last step of denitrification. Filter- and deposit-feeding animal species showed the highest rates of nitrous oxide emission and predators the lowest, probably reflecting the different amounts of denitrifying bacteria in the diet. We estimate that nitrous oxide emission by aquatic animals is quantitatively important in nitrate-rich aquatic environments like freshwater, coastal marine, and deep-sea ecosystems. The contribution of this source to overall nitrous oxide emission from aquatic environments might further increase because of the projected increase of nitrate availability in tropical regions and the numeric dominance of filter- and deposit-feeders in eutrophic ecosystems. PMID:19255427

  10. Submerged Aquatic Vegetation (SAV) - Volusia County Seagrass

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — Aquatic vegetation in Volusia County. DEP SEA_GRASSES This polygon GIS data set represents a compilation of statewide seagrass data from various source agencies and...

  11. Nonindigenous Aquatic Species Database Marine Fishes

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Nonindigenous Aquatic Species Database (NAS) information resource is an established central repository for spatially referenced biogeographic accounts of...

  12. COGNITIVE INTERPRETATION OF INPUT HYPOTHESIS

    Institute of Scientific and Technical Information of China (English)

    WangHongyue; RenLiankui

    2004-01-01

    Krashen's Input Hypothesis, together with its earlier version, the Monitor Model is an influential theory in Second Language Acquisition research. In his studies, Krashen, on the one hand, emphasizes the part '“ comprehensible input” plays in learning a second language, on the other hand, he simply defines“comprehensible input” as “a little beyond the learner's current level”. What input can be considered as“a little beyond the learner's current level ”? Krashen gives no furtherexplanation. This paper tries to offer a more concrete and more detailed interpretation with Ausubel's Cognitive Assimilation theory.

  13. Strategic inputs into patent pools

    OpenAIRE

    Baron, Justus; Delcamp, Henry

    2010-01-01

    This article explores what factors determine the decision of a patent pool to accept new inputs. We propose a dynamic analysis of 1337 U.S. patent inputs into 7 important pools. This analysis highlights a trade-off between firm and patent characteristics as the determinants of inclusion of patents into pools. For instance we prove that firms already member of the pool or holding large patent portfolios are able to include lower quality patents. These findings can be explained both by bargaini...

  14. Peer assessment enhances student learning

    CERN Document Server

    Sun, Dennis L; Walther, Guenther; Baiocchi, Michael

    2014-01-01

    Feedback has a powerful influence on learning, but it is also expensive to provide. In large classes, it may even be impossible for instructors to provide individualized feedback. Peer assessment has received attention lately as a way of providing personalized feedback that scales to large classes. Besides these obvious benefits, some researchers have also conjectured that students learn by peer assessing, although no studies have ever conclusively demonstrated this effect. By conducting a randomized controlled trial in an introductory statistics class, we provide evidence that peer assessment causes significant gains in student achievement. The strength of our conclusions depends critically on the careful design of the experiment, which was made possible by a web-based platform that we developed. Hence, our study is also a proof of concept of the high-quality experiments that are possible with online tools.

  15. Peer interaction: help or distraction?

    Science.gov (United States)

    Ruzhitskaya, Lanika; Speck, A.; Dr.

    2011-01-01

    We present our results on the difference in learning effectiveness of a particular concept in astronomy when students work as individuals as compared to working in pairs. We conducted a study based on the stellar parallax concept using two versions of a computer-based tutorial: guided and unguided. In this study students were randomly assigned to work in peer groups and individually. Students’ interactions with the two versions of the tutorial and their peer interactions were recorded using MORAE software for quantitative and qualitative analysis. In addition, we used pretest and two posttest questionnaires to find conceptual gain. Here we present our preliminary results on the emergence of particular patterns in students learning behavior when they work independently and with peers, and how guided or unguided exercises affect these patterns.

  16. Feedback, Incentives and Peer Effects

    DEFF Research Database (Denmark)

    Eriksson, Tor Viking; Poulsen, Anders; Villeval, Marie Claire

    This paper experimentally investigates the impact of different pay and relative performance information policies on employee effort. We explore three information policies: No feedback, feedback given halfway through the production period, and continuously updated feedback about relative performance....... The pay schemes are a piece rate payment scheme and a winner takes-all tournament. We find that the principal should not provide any information on relative  performance, regardless of the pay scheme used, since feedback does not improve performance. Indeed, we do not find evidence of positive peer...... effects in the piece-rate pay scheme. In both pay schemes, interim feedback generates negative quality peer effects on the less able performers. We find however evidence of positive peer effects in the tournament scheme since the underdogs almost never quit the competition even when lagging significantly...

  17. Effect of Aquatic Immersion on Static Balance

    OpenAIRE

    Louder, Talin J.

    2013-01-01

    Objective To quantitatively assess measures of static balance and limits of stability (LOS) in an aquatic environment compared to on land. Methods Fifteen healthy, young adults (23 + or - 2 years) performed 90 s static balance trials on land and aquatic immersion at two different depths (greater trochanter, xiphoid process). Measures of 95% ellipse area and center of pressure (CoP) mean velocity were computed from the force data. Additionally, participants completed a visual analog scale (VAS...

  18. Human Exploitation of Aquatic Landscapes. Editorial

    OpenAIRE

    Ricardo Fernandes; John Meadows

    2014-01-01

    Aquatic landscapes such as rivers, lakes, and seas played an important role in past human behaviour, affecting modes of subsistence, patterns of mobility, access to material resources, and technological choices and their developments. The interaction with aquatic landscapes was also influential in the establishment of economic and social structures and in the formation of communal identities. The aim of this special themed issue of Internet Archaeology is to contribute to a better understandi...

  19. Peer Effects and the Indigenous/Non-Indigenous Early Test-Score Gap in Peru

    Science.gov (United States)

    Sakellariou, Chris

    2008-01-01

    This paper assesses the magnitude of the non-indigenous/indigenous test-score gap for third-year and fourth-year primary school pupils in Peru, in relation to the main family, school and peer inputs contributing to the test-score gap using the estimation method of feasible generalized least squares. The article then decomposes the gap into its…

  20. Aquatic arsenic: phytoremediation using floating macrophytes.

    Science.gov (United States)

    Rahman, M Azizur; Hasegawa, H

    2011-04-01

    Phytoremediation, a plant based green technology, has received increasing attention after the discovery of hyperaccumulating plants which are able to accumulate, translocate, and concentrate high amount of certain toxic elements in their above-ground/harvestable parts. Phytoremediation includes several processes namely, phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization. Both terrestrial and aquatic plants have been tested to remediate contaminated soils and waters, respectively. A number of aquatic plant species have been investigated for the remediation of toxic contaminants such as As, Zn, Cd, Cu, Pb, Cr, Hg, etc. Arsenic, one of the deadly toxic elements, is widely distributed in the aquatic systems as a result of mineral dissolution from volcanic or sedimentary rocks as well as from the dilution of geothermal waters. In addition, the agricultural and industrial effluent discharges are also considered for arsenic contamination in natural waters. Some aquatic plants have been reported to accumulate high level of arsenic from contaminated water. Water hyacinth (Eichhornia crassipes), duckweeds (Lemna gibba, Lemna minor, Spirodela polyrhiza), water spinach (Ipomoea aquatica), water ferns (Azolla caroliniana, Azolla filiculoides, and Azolla pinnata), water cabbage (Pistia stratiotes), hydrilla (Hydrilla verticillata) and watercress (Lepidium sativum) have been studied to investigate their arsenic uptake ability and mechanisms, and to evaluate their potential in phytoremediation technology. It has been suggested that the aquatic macrophytes would be potential for arsenic phytoremediation, and this paper reviews up to date knowledge on arsenic phytoremediation by common aquatic macrophytes. PMID:21435676

  1. Disabled Peers and Academic Achievement

    OpenAIRE

    Jane Friesen; Ross Hickey; Brian Krauth

    2010-01-01

    We use data on students in grades 4–7 in the Canadian province of British Columbia to investigate the effect of having disabled peers on value-added exam outcomes. Longitudinal data for multiple cohorts of students are used together with school-by-grade-level fixed effects to account for endogenous selection into schools. Our estimates suggest that same-grade peers with learning and behavioral disabilities have an adverse effect on the test score gains of nondisabled students in British Colum...

  2. A comparison of peer-to-peer query response modes

    CERN Document Server

    Hoschek, W

    2002-01-01

    In a large distributed system spanning many administrative domains such as a Grid (Foster et al., 2001), it is desirable to maintain and query dynamic and timely information about active participants such as services, resources and user communities. However, in such a database system, the set of information tuples in the universe is partitioned over one or more distributed nodes, for reasons including autonomy, scalability, availability, performance and security. This suggests the use of peer-to-peer (P2P) query technology. A variety of query response modes can be used to return matching query results from P2P nodes to an originator. Although from the functional perspective all response modes are equivalent, no mode is optimal under all circumstances. Which query response modes allow to express suitable trade-offs for a wide range ofP2P application? We answer this question by systematically describing and characterizing four query response modes for the unified peer-to-peer database framework (UPDF) proposed ...

  3. Using Peer Feedback to Improve Learning via Online Peer Assessment

    Science.gov (United States)

    Liu, Eric Zhi-Feng; Lee, Chun-Yi

    2013-01-01

    This study investigates the influence of various forms of peer observation and feedback on student learning. We recruited twelve graduate students enrolled in a course entitled, Statistics in Education and Psychology, at a university in northern Taiwan. Researchers adopted the case study method, and the course lasted for ten weeks. Students were…

  4. Social Networks and Aggressive Behavior: Peer Support or Peer Rejection?

    Science.gov (United States)

    Cairns, Robert B.; And Others

    1988-01-01

    Studied the aggressive behavior in school of two cohorts of boys and girls in the fourth and seventh grades. Highly aggressive subjects were usually solid members of peer clusters and typically had a network of friends. Aggressive patterns and correlated behaviors provided a basis for social cohesion and commonalities in friendships for both boys…

  5. An Evaluation of the Accuracy of Peer to Peer Surgical Teaching and the Role of the Peer Review Process

    OpenAIRE

    Sheila Oh; Noel Lynch; Nora McCarthy; Tulin Cil; Elaine Lehane; Michelle Reardon; Henry Paul Redmond; Mark Corrigan

    2014-01-01

    Background: Peer to peer learning is a well-established learning modality which has been shown to improve learning outcomes, with positive implications for clinical practice. Surgical students from across Ireland were invited to upload learning points daily while paired with their peers in a peer-reviewing process. This study was designed to assess content accuracy and evaluate the benefit of the review process. Method: A reflective content sample was selected from the database representing a...

  6. Riparian litter inputs to streams in the central Oregon Coast Range

    Science.gov (United States)

    Hart, Stephanie K.; Hibbs, David E.; Perakis, Steven S.

    2013-01-01

    Riparian-zone vegetation can influence terrestrial and aquatic food webs through variation in the amount, timing, and nutritional content of leaf and other litter inputs. We investigated how riparian-forest community composition, understory density, and lateral slope shaped vertical and lateral litter inputs to 16 streams in the Oregon Coast Range. Riparian forests dominated by deciduous red alder delivered greater annual vertical litter inputs to streams (504 g m−2 y−1) than did riparian forests dominated by coniferous Douglas-fir (394 g m−2 y−1). Deciduous forests also contributed greater lateral litter inputs per meter of stream bank on one side (109 g m−1 y−1) than did coniferous forests (63 g m−1 y−1). Total litter inputs from deciduous forests exceeded those from coniferous forests most strongly in November, coincident with an autumn peak in litter inputs. Lateral litter inputs contributed most to total inputs during winter in both forest types. Annual lateral litter movement increased with slope at deciduous sites, but only in spring/summer months at coniferous sites. Neither experimental removal of understory vegetation nor installation of mesh fences to block downslope litter movement affected lateral litter inputs to streams, suggesting that ground litter moves litter fractions were higher at deciduous sites and, when combined with greater litter amounts, yielded twice as much total litter N flux to streams in deciduous than coniferous sites. The presence of red alder in riparian forests along many small streams of the deeply incised and highly dendritic basins of the Oregon Coast Range enhances total fluxes and seasonality of litter delivery to both terrestrial and aquatic food webs in this region and complements the shade and large woody debris provided by large coniferous trees.

  7. World Input-Output Network.

    Directory of Open Access Journals (Sweden)

    Federica Cerina

    Full Text Available Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD is one of the first efforts to construct the global multi-regional input-output (GMRIO tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries.

  8. The advanced LIGO input optics

    Science.gov (United States)

    Mueller, Chris L.; Arain, Muzammil A.; Ciani, Giacomo; DeRosa, Ryan. T.; Effler, Anamaria; Feldbaum, David; Frolov, Valery V.; Fulda, Paul; Gleason, Joseph; Heintze, Matthew; Kawabe, Keita; King, Eleanor J.; Kokeyama, Keiko; Korth, William Z.; Martin, Rodica M.; Mullavey, Adam; Peold, Jan; Quetschke, Volker; Reitze, David H.; Tanner, David B.; Vorvick, Cheryl; Williams, Luke F.; Mueller, Guido

    2016-01-01

    The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design.

  9. The advanced LIGO input optics

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Chris L., E-mail: cmueller@phys.ufl.edu; Arain, Muzammil A.; Ciani, Giacomo; Feldbaum, David; Fulda, Paul; Gleason, Joseph; Heintze, Matthew; Martin, Rodica M.; Reitze, David H.; Tanner, David B.; Williams, Luke F.; Mueller, Guido [University of Florida, Gainesville, Florida 32611 (United States); DeRosa, Ryan T.; Effler, Anamaria; Kokeyama, Keiko [Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Frolov, Valery V.; Mullavey, Adam [LIGO Livingston Observatory, Livingston, Louisiana 70754 (United States); Kawabe, Keita; Vorvick, Cheryl [LIGO Hanford Observatory, Richland, Washington 99352 (United States); King, Eleanor J. [University of Adelaide, Adelaide, SA 5005 (Australia); and others

    2016-01-15

    The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design.

  10. Analog Input Data Acquisition Software

    Science.gov (United States)

    Arens, Ellen

    2009-01-01

    DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.

  11. World Input-Output Network.

    Science.gov (United States)

    Cerina, Federica; Zhu, Zhen; Chessa, Alessandro; Riccaboni, Massimo

    2015-01-01

    Production systems, traditionally analyzed as almost independent national systems, are increasingly connected on a global scale. Only recently becoming available, the World Input-Output Database (WIOD) is one of the first efforts to construct the global multi-regional input-output (GMRIO) tables. By viewing the world input-output system as an interdependent network where the nodes are the individual industries in different economies and the edges are the monetary goods flows between industries, we analyze respectively the global, regional, and local network properties of the so-called world input-output network (WION) and document its evolution over time. At global level, we find that the industries are highly but asymmetrically connected, which implies that micro shocks can lead to macro fluctuations. At regional level, we find that the world production is still operated nationally or at most regionally as the communities detected are either individual economies or geographically well defined regions. Finally, at local level, for each industry we compare the network-based measures with the traditional methods of backward linkages. We find that the network-based measures such as PageRank centrality and community coreness measure can give valuable insights into identifying the key industries. PMID:26222389

  12. Input/output interface module

    Science.gov (United States)

    Ozyazici, E. M.

    1980-01-01

    Module detects level changes in any of its 16 inputs, transfers changes to its outputs, and generates interrupts when changes are detected. Up to four changes-in-state per line are stored for later retrieval by controlling computer. Using standard TTL logic, module fits 19-inch rack-mounted console.

  13. Remote input/output station

    CERN Multimedia

    1972-01-01

    A general view of the remote input/output station installed in building 112 (ISR) and used for submitting jobs to the CDC 6500 and 6600. The card reader on the left and the line printer on the right are operated by programmers on a self-service basis.

  14. The advanced LIGO input optics.

    Science.gov (United States)

    Mueller, Chris L; Arain, Muzammil A; Ciani, Giacomo; DeRosa, Ryan T; Effler, Anamaria; Feldbaum, David; Frolov, Valery V; Fulda, Paul; Gleason, Joseph; Heintze, Matthew; Kawabe, Keita; King, Eleanor J; Kokeyama, Keiko; Korth, William Z; Martin, Rodica M; Mullavey, Adam; Peold, Jan; Quetschke, Volker; Reitze, David H; Tanner, David B; Vorvick, Cheryl; Williams, Luke F; Mueller, Guido

    2016-01-01

    The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design. PMID:26827334

  15. The advanced LIGO input optics

    International Nuclear Information System (INIS)

    The advanced LIGO gravitational wave detectors are nearing their design sensitivity and should begin taking meaningful astrophysical data in the fall of 2015. These resonant optical interferometers will have unprecedented sensitivity to the strains caused by passing gravitational waves. The input optics play a significant part in allowing these devices to reach such sensitivities. Residing between the pre-stabilized laser and the main interferometer, the input optics subsystem is tasked with preparing the laser beam for interferometry at the sub-attometer level while operating at continuous wave input power levels ranging from 100 mW to 150 W. These extreme operating conditions required every major component to be custom designed. These designs draw heavily on the experience and understanding gained during the operation of Initial LIGO and Enhanced LIGO. In this article, we report on how the components of the input optics were designed to meet their stringent requirements and present measurements showing how well they have lived up to their design

  16. 28 CFR 34.110 - Management of peer reviews.

    Science.gov (United States)

    2010-07-01

    ... Section 34.110 Judicial Administration DEPARTMENT OF JUSTICE OJJDP COMPETITION AND PEER REVIEW PROCEDURES Peer Review § 34.110 Management of peer reviews. A technical support contractor may assist in managing the peer review process....

  17. Systems and methods for reconfiguring input devices

    Science.gov (United States)

    Lancaster, Jeff (Inventor); De Mers, Robert E. (Inventor)

    2012-01-01

    A system includes an input device having first and second input members configured to be activated by a user. The input device is configured to generate activation signals associated with activation of the first and second input members, and each of the first and second input members are associated with an input function. A processor is coupled to the input device and configured to receive the activation signals. A memory coupled to the processor, and includes a reconfiguration module configured to store the input functions assigned to the first and second input members and, upon execution of the processor, to reconfigure the input functions assigned to the input members when the first input member is inoperable.

  18. Peer acceptance/rejection and academic achievement

    OpenAIRE

    Spasenović Vera Z.

    2003-01-01

    Considerations of the nature and role of peer relations in child development indicate that peer interaction is an important factor in developing social and cognitive competences. Peer relations not only influence current but also subsequent academic, behavioral and emotional development. Accepted students more often display better academic achievement, whereas the status of rejection is coupled with academic difficulties and lower academic achievement. Peer rejection is a relatively stable ch...

  19. Northern Ireland regional breastfeeding peer support training

    OpenAIRE

    Public Health Agency

    2012-01-01

    This resource�has been produced for breastfeeding coordinators and breastfeeding peer support trainers who provide training for peer support volunteers. �� The resource has been distributed by PHA directly to those involved in breastfeeding peer support programmes in Northern Ireland. Further copies can be requested as applicable from Lesley Blackstock at: The CD supports delivery of eight peer support teaching sessions (two hours each), which meet Open College Net...

  20. Incentive Effects of Peer Pressure in Organizations

    OpenAIRE

    Kohei Daido

    2006-01-01

    This paper studies the effects of peer pressure on incentives. We assume that, in addition to the material payoff, each agent's utility includes the psychological payoff from peer pressure generated by a comparison of effort costs. We show that the optimal incentive schemes depend mainly on the degree of peer pressure and of the heterogeneity of agents. Furthermore, we examine the optimal organizational forms in terms of the principal''s intention to make use of the effects of peer pressure.

  1. Rewiring Peer Connections over Semantic Overlay Networks

    OpenAIRE

    Ραφτοπούλου, Παρασκευή

    2009-01-01

    Today's content providers are naturally distributed and produce large amounts of information every day, making peer-to-peer data management a promising approach offering scalability, adaptivity to dynamics and failure resilience. The management of large volumes of data in peer-to-peer networks has generated additional interest in methods for effective network organisation based on providers' contents and consequently, in methods supporting information retrieval. Overlay architectu...

  2. Research on Intellectual Property Right Problems of Peer-to-Peer Networks.

    Science.gov (United States)

    Dong, Ying; Li, Mingshu; Chen, Meizhang; Zheng, Shengli

    2002-01-01

    Discusses digital intellectual property rights relating to peer-to-peer networks, using Napster as an example. Suggests anti-piracy solutions to prevent litigation and considers how libraries can develop potential service models using peer-to-peer networks, including the development of personal libraries on the Internet, interlibrary loan,…

  3. Managing Supply and Demand of Bandwidth in Peer-to-Peer Communities

    NARCIS (Netherlands)

    Meulpolder, M.

    2011-01-01

    On today's Internet, millions of people participate in peer-to-peer communities where they share content such as audio and video files. Contrary to websites such as Youtube, which rely on large and expensive computer servers to store and deliver all of their content, peer-to-peer communities rely on

  4. A Peer Review Training Workshop: Coaching Students to Give and Evaluate Peer Feedback

    Science.gov (United States)

    Lam, Ricky

    2010-01-01

    Trained peer review, as illustrated in a plethora of peer review or peer response scholarship, has a positive effect on students' writing in general and on improved revision quality in particular (Berg, 1999; Hu, 2005; Min, 2006; Paulus, 1999; Stanley, 1992). From these studies, it is evident that trained peer feedback does have a significant role…

  5. Distributed Reasoning in a Peer-to-Peer Setting: Application to the Semantic Web

    CERN Document Server

    Adjiman, P; Goasdoue, F; Rousset, M C; Simon, L; 10.1613/jair.1785

    2011-01-01

    In a peer-to-peer inference system, each peer can reason locally but can also solicit some of its acquaintances, which are peers sharing part of its vocabulary. In this paper, we consider peer-to-peer inference systems in which the local theory of each peer is a set of propositional clauses defined upon a local vocabulary. An important characteristic of peer-to-peer inference systems is that the global theory (the union of all peer theories) is not known (as opposed to partition-based reasoning systems). The main contribution of this paper is to provide the first consequence finding algorithm in a peer-to-peer setting: DeCA. It is anytime and computes consequences gradually from the solicited peer to peers that are more and more distant. We exhibit a sufficient condition on the acquaintance graph of the peer-to-peer inference system for guaranteeing the completeness of this algorithm. Another important contribution is to apply this general distributed reasoning setting to the setting of the Semantic Web throu...

  6. Team Projects and Peer Evaluations

    Science.gov (United States)

    Doyle, John Kevin; Meeker, Ralph D.

    2008-01-01

    The authors assign semester- or quarter-long team-based projects in several Computer Science and Finance courses. This paper reports on our experience in designing, managing, and evaluating such projects. In particular, we discuss the effects of team size and of various peer evaluation schemes on team performance and student learning. We report…

  7. Peers on Socrates and Plato

    Science.gov (United States)

    Mackenzie, Jim

    2014-01-01

    There is more to be said about two of the topics Chris Peers addresses in his article "Freud, Plato and Irigaray: A morpho-logic of teaching and learning" (2012, Educational Philosophy and Theory, 44, 760-774), namely the Socratic method of teaching and Plato's stance with regard to women and feminism. My purpose in this article is…

  8. The Power of Peer Pressure

    Science.gov (United States)

    Wingle, Jane

    2006-01-01

    In a religion class of 26 bright creative sixth graders, one student demonstrates the power of peer pressure. Part of the morning ritual is to say prayer petitions. Students seems to be calmed by their expressions of care for their families, friends, pets, their military troops, victims of natural disasters, the homeless, etc. However, one student…

  9. Classroom Composition and Peer Effects

    Science.gov (United States)

    Hattie, John A. C.

    2002-01-01

    This chapter examines the extent to which the composition of classes affects learning outcomes. The aim is to explore peer effects when students are organized into classes on the basis of ability, ethnicity, or gender, as well as the effects of multigrade and multi-age classes and class size. The argument is defended that these composition factors…

  10. The Dedisciplining of Peer Review

    Science.gov (United States)

    Frodeman, Robert; Briggle, Adam

    2012-01-01

    The demand for greater public accountability is changing the nature of ex ante peer review at public science agencies worldwide. Based on a four year research project, this essay examines these changes through an analysis of the process of grant proposal review at two US public science agencies, the National Institutes of Health (NIH) and the…

  11. Some limits in peer assessment

    Directory of Open Access Journals (Sweden)

    Joan Domingo Penya

    2014-03-01

    Full Text Available Nowadays, the known as ‘peer assessment’ is one of the pillars of formative assessment in the different levels of the educational system buts, especially, in the University level. Last years, it has been considered in order to enhance students' meaningful learning, considering it as an element of social learning from the lessons learned by other classmates, and the ability to assess their quality, compared with the level of knowledge that each student has about the subject/course evaluated, and using common evaluation criteria. Relating to this, the experience presented in this paper has been developed with two groups of students. It allows to determine how many peer assessments is prudent to ask course students in order to make a serious and reliable activity, and not as a required and mandatory exercise that has to be carried out by students simply to pass the course; in this last case, the activity could become extremely trivial and banal. Statistical analysis of the results indicates that three-peer assessments per student appraised are a good lot. In addition, on the other hand, more than thirty-peer assessments do not provide learning nor serious activities.

  12. Endogenous Peer Effects: Fact or Fiction?

    Science.gov (United States)

    Yeung, Ryan; Nguyen-Hoang, Phuong

    2016-01-01

    The authors examine endogenous peer effects, which occur when a student's behavior or outcome is a function of the behavior or outcome of his or her peer group. Endogenous peer effects have important implications for educational policies such as busing, school choice and tracking. In this study, the authors quantitatively review the literature on…

  13. Advancing Kinesiology through Improved Peer Review

    Science.gov (United States)

    Knudson, Duane V.; Morrow, James R., Jr.; Thomas, Jerry R.

    2014-01-01

    Peer review of scholarship is essential to journal quality, evidence, knowledge advancement, and application of that knowledge in any field. This commentary summarizes recent literature on issues related to peer-review quality and current review practice in kinesiology and provides recommendations to improve peer review in kinesiology journals. We…

  14. 48 CFR 201.170 - Peer Reviews.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Peer Reviews. 201.170... OF DEFENSE GENERAL FEDERAL ACQUISITION REGULATIONS SYSTEM Purpose, Authority, Issuance 201.170 Peer... Procurement and Acquisition Policy, will organize teams of reviewers and facilitate Peer Reviews...

  15. Peer Reviewers Learn from Giving Comments

    Science.gov (United States)

    Cho, Young Hoan; Cho, Kwangsu

    2011-01-01

    Research on peer reviewing has revealed that comments received from peer reviewers are helpful when it comes to making revisions in an individual's writing, but the role of providing comments to peer writers has been little explored despite the potential value of such research. In this study, we explored how student reviewers learn by reviewing…

  16. Peer Education in Campus Suicide Prevention

    Science.gov (United States)

    Catanzarite, Julie A.; Robinson, Myles D.

    2013-01-01

    Student peer educators have been used by higher education intuitions to influence the education and retention of college students for many years, and most institutions have some type of peer educator program. Newton and Ender (2010) broadly define the role of peer educators as "students who have been selected, trained, and designated by a campus…

  17. Introduction to Neuroscience Peer Review Consortium

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Introduction The Neuroscience Peer Review Consortium is an alliance of neuroscience journals that have agreed to accept manuscript reviews from other members of the Consortium.Its goals are to support efficient and thorough peer review of original research in neuroscience, speed the publication of research reports, and reduce the burden on peer reviewers.

  18. Peer Assessment in Engineering Group Projects

    DEFF Research Database (Denmark)

    Triantafyllou, Eva; Timcenko, Olga

    2014-01-01

    administrative burden is one of the common reported challenges of peer assessment, computer assisted peer assessment is also briefly reviewed. Finally, opportunities and challenges in applying peer assessment in a project-based creative engineering program are presented based on the review of the literature....

  19. Peer Pressure: An Issue That Crosses Generations.

    Science.gov (United States)

    Kittredge, Karen; McCarthy, Alice R.

    2000-01-01

    Recent research on peer pressure shows that: parents are important to teens, today's teens face unique challenges, and teaching teens to say no does not mean losing friends. The paper presents parenting tips for countering peer pressure, noting the influence of adult peer pressure on children. A sidebar examines the right age to start talking to…

  20. 48 CFR 215.270 - Peer Reviews.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Peer Reviews. 215.270 Section 215.270 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... of Proposals and Information 215.270 Peer Reviews. Agency officials shall conduct Peer Reviews...

  1. Peer Review: Promoting Efficient School District Operations

    Science.gov (United States)

    Hale, Jason S.

    2010-01-01

    Many professions recognize the benefits of peer reviews to assess processes and operations because peers can more easily identify one another's inefficiencies and provide some kind of intervention. Generally, the goal of the peer review process is to verify whether the work satisfies the standards set by the industry. A number of states have begun…

  2. 40 CFR 194.27 - Peer review.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Peer review. 194.27 Section 194.27... CFR PART 191 DISPOSAL REGULATIONS Compliance Certification and Re-certification General Requirements § 194.27 Peer review. (a) Any compliance application shall include documentation of peer review that...

  3. 42 CFR 24.5 - Peer review.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Peer review. 24.5 Section 24.5 Public Health PUBLIC....5 Peer review. An individual may not be considered for appointment into the SBRS unless his/her qualifications have been reviewed by a PHS peer review committee and the committee has recommended appointment...

  4. Peer Review of Teaching: Sharing Best Practices

    Science.gov (United States)

    Golparian, Shaya; Chan, Judy; Cassidy, Alice

    2015-01-01

    In this paper, we share examples of best peer review of teaching practices, drawing on our involvement in the design and implementation of the Peer Review of Teaching program at the Centre for Teaching, Learning and Technology. We review the history of the Peer Review of Teaching Initiative at the University of British Columbia and explain key…

  5. 7 CFR 550.17 - Peer review.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Peer review. 550.17 Section 550.17 Agriculture... § 550.17 Peer review. Upon request of the REE Agency, cooperators may be requested to provide documentation in support of peer review activities and cooperator personnel may be requested to participate...

  6. NEA international peer reviews of post-accident protection policy

    International Nuclear Information System (INIS)

    For many years, the NEA has offered international peer reviews of national, high-level radioactive waste management policies and approaches. Until recently, this service had not been requested in the area of radiological protection. However, the 3. International Nuclear Emergency Exercise (INEX-3, 2005-2006) addressed post-accident consequence management for the first time in a broad, international sense, and helped generate significant national reflections in this area. In particular, in 2005 the French government began an extensive programme of post-emergency consequence management planning, resulting in a draft national policy to address such situations. The Finnish government used the INEX-3 exercise as a vehicle to discuss post-emergency consequence management with a broad group of governmental and private stakeholders, and also began to develop national policy in this area. In order to further refine national efforts, the French Nuclear Safety Authority (ASN) invited the NEA to perform in April 2011 its first international peer review in the radiological protection area focusing on its post-emergency consequence management policy under development. Finnish experts participated in this peer review team, and as a result, subsequently invited the NEA to perform an international peer review of its developing policy in this area in September 2011. These draft national policies and their international peer reviews are briefly presented in this paper. Feedback from both the French ASN and the Finnish STUK suggests that the detailed, external input provided by the international peer review teams have been extremely valuable in refining the content of the guides so that they are more clear, concise, understandable and implementable. It should be recalled that both national policy documents reviewed are far more detailed and extensive than described here. The intent of this article was not to provide a review of the national policies themselves, but rather to give an

  7. Ways forward for aquatic conservation: Applications of environmental psychology to support management objectives.

    Science.gov (United States)

    Walker-Springett, Kate; Jefferson, Rebecca; Böck, Kerstin; Breckwoldt, Annette; Comby, Emeline; Cottet, Marylise; Hübner, Gundula; Le Lay, Yves-François; Shaw, Sylvie; Wyles, Kayleigh

    2016-01-15

    The success or failure of environmental management goals can be partially attributed to the support for such goals from the public. Despite this, environmental management is still dominated by a natural science approach with little input from disciplines that are concerned with the relationship between humans and the natural environment such as environmental psychology. Within the marine and freshwater environments, this is particularly concerning given the cultural and aesthetic significance of these environments to the public, coupled with the services delivered by freshwater and marine ecosystems, and the vulnerability of aquatic ecosystems to human-driven environmental perturbations. This paper documents nine case studies which use environmental psychology methods to support a range of aquatic management goals. Examples include understanding the drivers of public attitudes towards ecologically important but uncharismatic river species, impacts of marine litter on human well-being, efficacy of small-scale governance of tropical marine fisheries and the role of media in shaping attitudes towards. These case studies illustrate how environmental psychology and natural sciences can be used together to apply an interdisciplinary approach to the management of aquatic environments. Such an approach that actively takes into account the range of issues surrounding aquatic environment management is more likely to result in successful outcomes, from both human and environmental perspectives. Furthermore, the results illustrate that better understanding the societal importance of aquatic ecosystems can reduce conflict between social needs and ecological objectives, and help improve the governance of aquatic ecosystems. Thus, this paper concludes that an effective relationship between academics and practitioners requires fully utilising the skills, knowledge and experience from both sectors. PMID:26599566

  8. Study of Chunks Input Approach

    Institute of Scientific and Technical Information of China (English)

    马静

    2003-01-01

    This paper is to describe and investigate Chunks (Lexical Phrases ) Input Approach in vocabulary learning strategies by means of achievement tests,questionnaire surveys and interviews. The study is to reveal how different learners combine different vocabulary learning strategies in their learning process. With the data collected, the author of this paper discusses and summarizes learners' individual differences in selecting vocabulary learning strategies with the hope of giving new insights into English teaching and learning.

  9. BALLS Simulator : Evaluator of a structured Peer-to-Peer system with integrated load balancing

    OpenAIRE

    Le, Viet-Dung; Babin, Gilbert; Kropf, Peter

    2009-01-01

    Simulation is an efficient way to evaluate new peer-to-peer models. It requires two implicit properties: large scale and high dynamicity. In the context of our work that proposes a peer-to-peer structure based on partitioning a de Bruijn graph and its load balancing algorithms, we developed a simulator for evaluation purposes. This paper introduces a three- layer architecture of the simulator. This architecture allows to support simulations in two modes: centralized (where all peers are simul...

  10. Social communication interventions for preschoolers: targeting peer interactions during peer group entry and cooperative play.

    Science.gov (United States)

    Timler, Geralyn R; Olswang, Lesley B; Coggins, Truman E

    2005-08-01

    Some preschoolers with language impairment approach and manage peer interactions less effectively than typically developing peers. This article discusses assessment and intervention strategies for targeting preschoolers' social communication skills during peer entry and cooperative play situations. Essential features of effective interventions include identification of appropriate social communication targets, addressing and facilitating children's use of these targets during small group sessions with peers, and supporting generalization of newly acquired social communication behaviors to children's peer interactions within the classroom setting. PMID:16155855

  11. Developing a peer to peer library support scheme

    OpenAIRE

    Coombs, Jenny; Hollier, Carol

    2014-01-01

    The article describes a University of Nottingham scheme in which science and engineering students have been acting as library student ambassadors (Learning Resource Leaders) to engage their peers on library issues. The project was based upon the premise that science and engineering students make less use of their library resources than other disciplines, and began with a project to employ library student ambassadors, funded by a Teaching Innovation Award at Loughborough Univers...

  12. Turnover of eroded soil organic carbon after deposition in terrestrial and aquatic environments

    Science.gov (United States)

    Kirkels, Frédérique; Cammeraat, Erik; Kalbitz, Karsten; van Oost, Kristof; Ellerbrock, Ruth; Follain, Stéphane; Fuchslueger, Lucia; Gerke, Horst; Heckrath, Goswin; Kögel-Knabner, Ingrid; Kuhn, Nikolaus; van Loon, Emiel; Quinton, John; Richter, Andreas; Salvador-Blanes, Sébastien; Sommer, Michael; Steffens, Markus

    2015-04-01

    The fate of eroded soil organic carbon (SOC) after deposition is a large uncertainty in assessing the impact of soil erosion on C budgets. Globally, large amounts of SOC are transported by erosion and a substantial part is transferred into adjacent inland waters, linking terrestrial and aquatic C cycling. However, the net effect on C fluxes between soils, inland waters and atmosphere remains uncertain. In this study, we determined SOC turnover in terrestrial and aquatic environments and indentified its major controls. A European gradient of agricultural sites was sampled, spanning a wide range soil properties (e.g. texture, aggregation, etc.), SOC quantity and quality. In a 16-week incubation experiment, SOC turnover was determined for conditions reflecting downslope soils or inland waters. Moreover, we studied the impact of labile C inputs ('priming') on SOC stability using 13C labeled cellulose. Physical and chemical soil properties and SOC molecular composition were assessed as potential controls on C turnover. SOC deposition in aquatic environments resulted in upto 3.5 times higher C turnover than deposition on downslope soils. Labile C inputs enlarged total CO2 emissions, with the largest increase for aquatic conditions. Solid-state 13C NMR and FT-IR spectroscopy showed broad similarities in SOC molecular composition. Soil and SOC properties could not (yet) fully explain variation in SOC turnover between the sites. However, temporal trends in CO2 emissions clearly differed between downslope soils and inland waters. We established a quantitative model, based on the ten sites of the European gradient, that is capable to describe CO2 emissions for SOC deposited on soils and in inland waters and upon different levels of labile C inputs. Our findings indicate that deposition conditions (soils vs. inland waters) play a crucial role in determining C turnover. Erosion measures preventing deposition in aquatic environments could therefore be an important carbon saving

  13. Hierarchical Data Distribution Scheme for Peer-to-Peer Networks

    Science.gov (United States)

    Bhushan, Shashi; Dave, M.; Patel, R. B.

    2010-11-01

    In the past few years, peer-to-peer (P2P) networks have become an extremely popular mechanism for large-scale content sharing. P2P systems have focused on specific application domains (e.g. music files, video files) or on providing file system like capabilities. P2P is a powerful paradigm, which provides a large-scale and cost-effective mechanism for data sharing. P2P system may be used for storing data globally. Can we implement a conventional database on P2P system? But successful implementation of conventional databases on the P2P systems is yet to be reported. In this paper we have presented the mathematical model for the replication of the partitions and presented a hierarchical based data distribution scheme for the P2P networks. We have also analyzed the resource utilization and throughput of the P2P system with respect to the availability, when a conventional database is implemented over the P2P system with variable query rate. Simulation results show that database partitions placed on the peers with higher availability factor perform better. Degradation index, throughput, resource utilization are the parameters evaluated with respect to the availability factor.

  14. Peer-to-Peer Enclaves for Improving Network Defence

    Directory of Open Access Journals (Sweden)

    David W. Archer

    2013-07-01

    Full Text Available Information about cyberthreats within networks spreads slowly relative to the speed at which those threats spread. Typical "threat feeds" that are commercially available also disseminate information slowly relative to the propagation speed of attacks, and they often convey irrelevant information about imminent threats. As a result, hosts sharing a network may miss opportunities to improve their defence postures against imminent attack because needed information arrives too late or is lost in irrelevant noise. We envision timely, relevant peer-to-peer sharing of threat information – based on current technologies – as a solution to these problems and as a useful design pattern for defensive cyberwarfare. In our setting, network nodes form communities that we call enclaves, where each node defends itself while sharing information on imminent threats with peers that have similar threat exposure. In this article, we present our vision for this solution. We sketch the architecture of a typical node in such a network and how it might interact with a framework for sharing threat information; we explain why certain defensive countermeasures may work better in our setting; we discuss current tools that could be used as components in our vision; and we describe opportunities for future research and development.

  15. A Threshold Scheme under Peer-to-Peer Network

    Institute of Scientific and Technical Information of China (English)

    XIE Yumin; SHI Feng; MING Yang; MUHAMMAD Kamran; XU Jianqiang

    2006-01-01

    Resource sharing among peers is one of important application in Peer-to-Peer(P2P) network. Inexistence of server makes P2P network to be a less trustable tool for property owners to distribute their resource. In order to protect intelligent property, reputation management strategy is adopted in many P2P network. As long as a P2P network reputation strategy is confirmed, application designer can employ a special detailed distribution scheme to fulfill content distribution within the net. Shmir (k,n) threshold scheme, for example, is an encryption scheme to enhance the distribution security of this kind of design. (k*,n) threshold scheme is a new tool similar to Shmir scheme is proposed in this paper. The new scheme based on polynomial expansion and its security is decided by the one way function used in the secret distribution procedure. The scheme efficiency and its features as well as comparison between new and Shmir scheme are also discussed in this paper.

  16. In situ nutrient removal from aquaculture wastewater by aquatic vegetable Ipomoea aquatica on floating beds.

    Science.gov (United States)

    Li, Wenxiang; Li, Zhongjie

    2009-01-01

    Nutrient-rich effluents caused rising concern due to eutrophication of aquatic environment by utilization of a large amount of formula feed. Nutrient removal and water quality were investigated by planting aquatic vegetable on artificial beds in 36-m(2) concrete fishponds. After treatment of 120 days, 30.6% of total nitrogen (TN) and 18.2% of total phosphorus (TP) were removed from the total input nutrients by 6-m(2) aquatic vegetable Ipomoea aquatica. The concentrations of TN, TP, chemical oxygen demand (COD) and chlorophyll a in planted ponds were significantly lower than those in non-planted ponds (P<0.05). Transparency of water in planted ponds was much higher than that of control ponds. No significant differences in the concentration of total ammonia nitrogen (TAN), nitrate nitrogen (NO(3) (-)-N) and nitrite nitrogen (NO(2) (-)-N) were found between planted and non-planted ponds. These results suggested that planting aquatic vegetable with one-sixth covered area of the fishponds could efficiently remove nutrient and improve water quality. PMID:19474487

  17. Nutrition, illness, and injury in aquatic sports.

    Science.gov (United States)

    Pyne, David B; Verhagen, Evert A; Mountjoy, Margo

    2014-08-01

    In this review, we outline key principles for prevention of injury and illness in aquatic sports, detail the epidemiology of injury and illness in aquatic athletes at major international competitions and in training, and examine the relevant scientific evidence on nutrients for reducing the risk of illness and injury. Aquatic athletes are encouraged to consume a well-planned diet with sufficient calories, macronutrients (particularly carbohydrate and protein), and micronutrients (particularly iron, zinc, and vitamins A, D, E, B6, and B12) to maintain health and performance. Ingesting carbohydrate via sports drinks, gels, or sports foods during prolonged training sessions is beneficial in maintaining energy availability. Studies of foods or supplements containing plant polyphenols and selected strains of probiotic species are promising, but further research is required. In terms of injury, intake of vitamin D, protein, and total caloric intake, in combination with treatment and resistance training, promotes recovery back to full health and training. PMID:24937101

  18. Technology in the Differential Input Demand Model

    OpenAIRE

    Brown, Mark G.; Lee, Jonq-Ying

    2003-01-01

    This study considers incorporating changes in technology in the differential input demand system through effects on output and input marginal products. The effects of technology on input demand are related to Slutsky coefficients and input shares of marginal cost. Technology effects on marginal-product changes are viewed as price changes, and restrictions on technology are considered.

  19. Adaptive features of aquatic mammals' eye.

    Science.gov (United States)

    Mass, Alla M; Supin, Alexander Ya

    2007-06-01

    The eye of aquatic mammals demonstrates several adaptations to both underwater and aerial vision. This study offers a review of eye anatomy in four groups of aquatic animals: cetaceans (toothed and baleen whales), pinnipeds (seals, sea lions, and walruses), sirenians (manatees and dugongs), and sea otters. Eye anatomy and optics, retinal laminar morphology, and topography of ganglion cell distribution are discussed with particular reference to aquatic specializations for underwater versus aerial vision. Aquatic mammals display emmetropia (i.e., refraction of light to focus on the retina) while submerged, and most have mechanisms to achieve emmetropia above water to counter the resulting aerial myopia. As underwater vision necessitates adjusting to wide variations in luminosity, iris muscle contractions create species-specific pupil shapes that regulate the amount of light entering the pupil and, in pinnipeds, work in conjunction with a reflective optic tapetum. The retina of aquatic mammals is similar to that of nocturnal terrestrial mammals in containing mainly rod photoreceptors and a minor number of cones (however, residual color vision may take place). A characteristic feature of the cetacean and pinniped retina is the large size of ganglion cells separated by wide intercellular spaces. Studies of topographic distribution of ganglion cells in the retina of cetaceans revealed two areas of ganglion cell concentration (the best-vision areas) located in the temporal and nasal quadrants; pinnipeds, sirenians, and sea otters have only one such area. In general, the visual system of marine mammals demonstrates a high degree of development and several specific features associated with adaptation for vision in both the aquatic and aerial environments. PMID:17516421

  20. Self-Organizing Tunnel Peers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Tunneling is an important approach in IPv6 transition techniques. The tunnel broker model provides a way to build virtual IPv6 networks without manual configuration.However, neither it adapts performance variation on the IPv4 infrastructure,nor it is a scalable solution for a wide-area IPv6 networking environment. In this paper, a self-organizing tunnel peer (SOTP)model is presented. Tunnel peers are clustered in the SOTP system so that optimization is scalable. Four primitive operations related to cluster construction - arrest,release,division and death - endow the system with the nature of self-organization.Occurrence and behavior of the operations are decided by criteria on the IPv4 end-to-end performance; hence measurement is an indispensable component of the system. The metabolism of cluster relaxes the requirement to accuracy of measurement and optimization.

  1. Peer harassment and disordered eating.

    Science.gov (United States)

    Eisenberg, Marla; Neumark-Sztainer, Dianne

    2008-01-01

    In this paper, we review existing literature regarding peer harassment and its association with a range of weight-related attitudes and behaviors. We conceptualize peer harassment to include traditionally defined bullying behavior, other social and relational forms of bullying, as well as teasing and other verbal harassment. Weight-based teasing is particularly relevant to weight-related issues and has been associated with clinical eating disorders, unhealthy weight control behaviors, and weight-related attitudes, such as body dissatisfaction. Studies using both clinical samples of eating disorder patients and general samples of college students or adolescents have demonstrated these relations. Emerging issues in this field, including teasing by family members, research with males, teasing and weight-related issues in developing countries, and the measurement of teasing experience are also discussed. Interventions with healthcare providers, parents, school personnel, and policy can contribute to the prevention of teasing and its associated weight-related attitudes and behaviors. PMID:18714553

  2. Aquatic macroinvertebrates of the Jablanica river, Serbia

    Directory of Open Access Journals (Sweden)

    Stefanović Katarina S.

    2009-01-01

    Full Text Available Research on the community of aquatic macroinvertebrates was carried out during 2005 and 2006 at four sampling sites along the Jablanica River, a right-hand tributary of the Kolubara River. Fifty-seven taxa were recorded in the course of the investigation. The most diverse group was Ephemeroptera, followed by Trichoptera and Plecoptera. Members of the Rhitrogena semicolorata group were the most abundant. Our results could be the basis for evaluation of the influence of damming of the Jablanica River on the status of its water and can serve as a model for studying the influ­ence of hydromorphological degradation of aquatic ecosystems.

  3. Effects of modifications of aquatic ecosystems

    International Nuclear Information System (INIS)

    Studies under this program historically have been concerned with the effects of a variety of stress factors on aquatic populations and communities. Current research was focused principally on ionizing radiation, and includes studies on the interaction of acute radiation and temperature on fish, the in situ measurement of radiation exposure in an aquatic environment, and the uptake and retention of tritium in a simulated pond community. In response to the expanded responsibilities of the recently formed Energy Research and Development Administration in dealing with all forms of energy related problems, this program will be redirected in the coming year to nonnuclear energy research

  4. Aquatic ape theory and fossil hominids.

    Science.gov (United States)

    Verhaegen, M J

    1991-06-01

    While most older palaeo-anthropological studies emphasise the similarities of the fossil hominids with modern man, recent studies often stress the unique and the apelike features of the australopithecine dentitions, skulls and postcranial bones. It is worth reconsidering the features of Australopithecus, Homo erectus and Homo neanderthalensis in the light of the so-called Aquatic Ape Theory (AAT) of Hardy and Morgan, and to compare the skeletal parts of our fossil relatives with those of (semi)aquatic animals. Possible convergences are observed with proboscis monkeys, beavers, sea-otters, hippopotamuses, seals, sea-lions, walruses, sea-cows, whales, dolphins, porpoises, penguins and crocodiles. PMID:1909768

  5. Radioactive contamination of aquatic media and organisms

    International Nuclear Information System (INIS)

    After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author)

  6. Peer Influence, Peer Status, and Prosocial Behavior: An Experimental Investigation of Peer Socialization of Adolescents' Intentions to Volunteer.

    Science.gov (United States)

    Choukas-Bradley, Sophia; Giletta, Matteo; Cohen, Geoffrey L; Prinstein, Mitchell J

    2015-12-01

    Peer influence processes have been documented extensively for a wide range of maladaptive adolescent behaviors. However, peer socialization is not inherently deleterious, and little is known about whether adolescents influence each other's prosocial behaviors, or whether some peers are more influential than others towards positive youth outcomes. This study addressed these questions using an experimental "chat room" paradigm to examine in vivo peer influence of prosocial behavior endorsement. A school-based sample of 304 early adolescents (55% female, 45% male; M(age) = 12.68) believed they were interacting electronically with same-gender grademates (i.e., "e-confederates"), whose peer status was experimentally manipulated. The participants' intent to engage in prosocial behaviors was measured pre-experiment and in subsequent "public" and "private" experimental sessions. Overall, the adolescents conformed to the e-confederates' prosocial responses in public; yet, these peer influence effects were moderated by the peer status of the e-confederates, such that youth more strongly conformed to the high-status e-confederates than to the low-status ones. There also was some evidence that these peer influence effects were maintained in the private session, indicating potential internalization of prosocial peer norms. These findings help bridge the positive youth development and peer influence literatures, with potential implications for campaigns to increase prosocial behaviors. PMID:26525387

  7. A Developmental Perspective on Peer Rejection, Deviant Peer Affiliation, and Conduct Problems Among Youth.

    Science.gov (United States)

    Chen, Diane; Drabick, Deborah A G; Burgers, Darcy E

    2015-12-01

    Peer rejection and deviant peer affiliation are linked consistently to the development and maintenance of conduct problems. Two proposed models may account for longitudinal relations among these peer processes and conduct problems: the (a) sequential mediation model, in which peer rejection in childhood and deviant peer affiliation in adolescence mediate the link between early externalizing behaviors and more serious adolescent conduct problems; and (b) parallel process model, in which peer rejection and deviant peer affiliation are considered independent processes that operate simultaneously to increment risk for conduct problems. In this review, we evaluate theoretical models and evidence for associations among conduct problems and (a) peer rejection and (b) deviant peer affiliation. We then consider support for the sequential mediation and parallel process models. Next, we propose an integrated model incorporating both the sequential mediation and parallel process models. Future research directions and implications for prevention and intervention efforts are discussed. PMID:25410430

  8. Peer-to-Peer Cloud Provisioning: Service Discovery and Load-Balancing

    CERN Document Server

    Ranjan, Rajiv; Wu, Xiaomin; Liu, Anna

    2009-01-01

    This chapter presents: (i) a layered peer-to-peer Cloud provisioning architecture; (ii) a summary of the current state-of-the-art in Cloud provisioning with particular emphasis on service discovery and load-balancing; (iii) a classification of the existing peer-to-peer network management model with focus on extending the DHTs for indexing and managing complex provisioning information; and (iv) the design and implementation of novel, extensible software fabric (Cloud peer) that combines public/private clouds, overlay networking and structured peer-to-peer indexing techniques for supporting scalable and self-managing service discovery and load-balancing in Cloud computing environments. Finally, an experimental evaluation is presented that demonstrates the feasibility of building next generation Cloud provisioning systems based on peer-to-peer network management and information dissemination models. The experimental test-bed has been deployed on a public cloud computing platform, Amazon EC2, which demonstrates t...

  9. HAMALT : Genetics Based Peer-To-Peer Network Architecture to Encourage the Cooperation of Selfish Nodes

    Directory of Open Access Journals (Sweden)

    T. C. Jermin Jeaunita

    2013-07-01

    Full Text Available Since its inception, Internet has grown tremendousl y not only in the size of its customers but also with the technology used behind to run it. Fo r the well ex-istence and proper development of Peer-to-Peer Networks, all nodes in the overlay must be cooperative and donate their resources for any other peer. The paper dis-cusses the reason of peers being selfish, causes of selfish peers and the methods used so far to resolv e selfish peers problem. A Genetic Algorithm based solution has been proposed in this paper that solves the selfish nodes problem in Peer-to- Peer Networks and that also encourages the cooperat ion among all nodes in the overlay. An architecture HAMALT is proposed in this paper for d isseminating altruism among the peers.

  10. The Importance of Peer Reviewing

    OpenAIRE

    Jack Franklin

    2000-01-01

    The importance of peer reviewing articles submitted to scientific journals is a subject that conferences and journals regularly revisit. In general such visits are brief. Although a few horror stories abound: ‘competitor holds up acceptance of paper to submit his own and so get priority’ or ‘competitor pours sufficient scorn on a good paper to darken its worth.’

  11. Crime, Education and Peer Pressure

    OpenAIRE

    P. Buonanno

    2003-01-01

    We present a dynamic two-period model of individual behaviour with heterogeneous agents in which individuals decide how to allocate their disposable time between education, crime and work in the legal sector. Education has a multiple role: it implies higher expected wages in the legal sector, increasing the opportunity cost of committing crime and it has a sort of “civilization” effect that makes more costly to engage in criminal activities. We model this effect by introducing a peer pressure...

  12. Peer Review of Launch Environments

    Science.gov (United States)

    Wilson, Timmy R.

    2011-01-01

    Catastrophic failures of launch vehicles during launch and ascent are currently modeled using equivalent trinitrotoluene (TNT) estimates. This approach tends to over-predict the blast effect with subsequent impact to launch vehicle and crew escape requirements. Bangham Engineering, located in Huntsville, Alabama, assembled a less-conservative model based on historical failure and test data coupled with physical models and estimates. This white paper summarizes NESC's peer review of the Bangham analytical work completed to date.

  13. Pyramidal parent training by peers.

    OpenAIRE

    Neef, N A

    1995-01-01

    This study replicated a pyramidal model of parent training by peers and compared its effects with training by a professional with 26 parents of children with disabilities. A multiple probe design across 3 tiers of parents showed that both types of training produced acquisition, maintenance, and to varying extents, generalization of parents' teaching skills, with concomitant increases in the children's performance in most cases. Improvements were comparable for parents trained by a professiona...

  14. Some limits in peer assessment

    OpenAIRE

    Joan Domingo Penya; Herminio Martínez García; Spartacus Gomariz Castro; Juan Gámiz Caro

    2014-01-01

    Nowadays, the educational methodology known as “peer assessment” constitutes one of the pillars of formative assessment at the different levels of the educational system, particularly at the University level. In fact, in recent years, it has been increasingly used to enhance students' meaningful learning, as it is considered to be an element of social learning, in which students benefit from the lessons learned by other classmates, and draw upon the ability to assess the quality of the learni...

  15. Strategies and performances of Soft Input Decryption

    OpenAIRE

    Zivic, Natasa

    2009-01-01

    This paper analyzes performance aspects of Soft Input Decryption and L values. Soft Input Decryption is a novel method which uses L values (soft output) of a SISO channel decoder for the correction of input of Soft Input Decryption (SID blocks) which have been modified during the transmission over a noisy channel. The method is based on the combination of cryptography and channel coding improving characteristics of both of them. The algorithm, strategies and scenarios of Soft Input Decryption...

  16. Symbolic inputs : positional, reference and publicity goods

    OpenAIRE

    Khalil, Elias L.

    1997-01-01

    Symbolic value differs from intrinsic value. This paper focuses on symbolic inputs, which make up the production function, and ignores symbolic products (e.g., status, prestige), which constitute the utility function. Symbolic inputs are occasioned by incomplete information. There are three kinds of symbolic inputs, following three kinds of incomplete information. »Positional symbolic inputs» minimize search cost necessitated by local information. »Reference symbolic inputs» reduce inspection...

  17. DOE Hydrogen Program: 2006 Annual Merit Review and Peer Evaluation Report

    Energy Technology Data Exchange (ETDEWEB)

    Milliken, J.

    2006-09-01

    This report summarizes comments from the Peer Review Panel at the FY 2006 DOE Hydrogen Program Annual Merit Review, held on May 16-19, 2006, in Arlington, Virginia. The projects evaluated support the Department of Energy and President Bush's Hydrogen Initiative. The results of this merit review and peer evaluation are major inputs used by DOE to make funding decisions. Project areas include hydrogen production and delivery; hydrogen storage; fuel cells; technology validation; safety, codes and standards; education; and systems analysis.

  18. DOE Hydrogen Program: 2005 Annual Merit Review and Peer Evaluation Report

    Energy Technology Data Exchange (ETDEWEB)

    Chalk, S. G.

    2005-09-01

    This report summarizes comments from the Peer Review Panel at the FY 2005 DOE Hydrogen Program Annual Merit Review, held on May 23-26, 2005, in Arlington, Virginia. The projects evaluated support the Department of Energy and President Bush's Hydrogen Initiative. The results of this merit review and peer evaluation are major inputs used by DOE to make funding decisions. Project areas include hydrogen production and delivery; hydrogen storage; fuel cells; technology validation; safety, codes and standards; education; and systems analysis.

  19. DOE Hydrogen Program: 2007 Annual Merit Review and Peer Evaluation Report

    Energy Technology Data Exchange (ETDEWEB)

    Milliken, J.

    2007-09-01

    This report summarizes comments from the Peer Review Panel at the FY 2007 DOE Hydrogen Program Annual Merit Review, held on May 14-18, 2007, in Washington, D.C. The projects evaluated support the Department of Energy and President Bush's Hydrogen Initiative. The results of this merit review and peer evaluation are major inputs used by DOE to make funding decisions. Project areas include hydrogen production and delivery; hydrogen storage; fuel cells; technology validation; safety, codes and standards; education; and systems analysis.

  20. Managing Supply and Demand of Bandwidth in Peer-to-Peer Communities

    OpenAIRE

    Meulpolder, M

    2011-01-01

    On today's Internet, millions of people participate in peer-to-peer communities where they share content such as audio and video files. Contrary to websites such as Youtube, which rely on large and expensive computer servers to store and deliver all of their content, peer-to-peer communities rely on storage and delivery by the PCs of the users themselves. Because of this, a peer-to-peer community can only be successful if there are enough users willing to provide content and bandwidth to othe...

  1. Duty-Oriented Hybrid Peer-to-Peer Network Based on Metadata

    OpenAIRE

    Kan Li; Xin Sun; Yue He

    2009-01-01

    The topology structure of the peer-to-peer overlay network is a critical factor in dominating performance of resource discovery. In the paper, we consider that nodes have their duty or function in the real world, and we take full advantage of the characteristic of unstructured peer-to-peer network. According to these, a duty-oriented hybrid peer-to-peer network based on metadata (DHPM) is proposed.DHPM organizes nodes into a tree-structure hierarchical overlay network. Its nodes are divided i...

  2. Analytical Framework for Optimizing Weighted Average Download Time in Peer-to-Peer Networks

    OpenAIRE

    Xie, Bike; Van Der Schaar, Mihaela; Wesel, Richard D.

    2008-01-01

    This paper proposes an analytical framework for peer-to-peer (P2P) networks and introduces schemes for building P2P networks to approach the minimum weighted average download time (WADT). In the considered P2P framework, the server, which has the information of all the download bandwidths and upload bandwidths of the peers, minimizes the weighted average download time by determining the optimal transmission rate from the server to the peers and from the peers to the other peers. This paper fi...

  3. Why Care About Aquatic Insects: Uses, Benefits, and Services

    Science.gov (United States)

    Mayflies and other aquatic insects are common subjects of ecological research, and environmental monitoring and assessment. However, their important role in protecting and restoring aquatic ecosystems is often challenged, because their benefits and services to humans are not obv...

  4. Malheur NWR: Initial Survey Instructions for Lacustrine Submergent Aquatic Vegetation

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Submergent aquatic vegetation (SAV) provides the foundation for wildlife use in aquatic systems. Sago pondweed is of particular significance in providing protein by...

  5. Chapter 5. Assessing the Aquatic Hazards of Veterinary Medicines

    Science.gov (United States)

    In recent years, there has been increasing awareness of the widespread distribution of low concentrations of veterinary medicine products and other pharmaceuticals in the aquatic environment. While aquatic hazard for a select group of veterinary medicines has received previous s...

  6. Aquatics Therapy and the Halliwick Concept

    Science.gov (United States)

    Skinner, Alison; Thomson, Ann

    2008-01-01

    Aquatic therapy is the use of the properties of water for the therapeutic benefit of people of all ages and abilities. This article illustrates how people with disabilities may maximize the benefits of activities in water, including individual and group work and swimming. The overall aim is to encourage family activity and social interaction. The…

  7. SUBMERGED AQUATIC VEGETATION GARDENING MX974861

    Science.gov (United States)

    The Submerged Aquatic Vegetation Gardening project will acquire the seed/seedlings of SAVs for planting, will create an SAV gardening guide; and will create SAV plots at volunteers waterfront properties. Volunteers will gather data on plant size and spacing. Water quality test ...

  8. Altitudinal distribution limits of aquatic macroinvertebrates

    DEFF Research Database (Denmark)

    Madsen, Philip B.; Morabowen, Andrés; Andino, Patricio;

    2015-01-01

    1. Temperature and oxygen are recognised as the main drivers of altitudinal limits of species distributions. However, the two factors are linked, and both decrease with altitude, why their effects are difficult to disentangle. 2. This was experimentally addressed using aquatic macroinvertebrates...

  9. Systems and Cycles: Learning about Aquatic Ecosystems

    Science.gov (United States)

    Hmelo-Silver, Cindy E.; Jordan, Rebecca; Eberbach, Catherine; Rugaber, Spencer; Goel, Ashok

    2011-01-01

    In this research, the authors present both the design and preliminary testing of a technology-intensive classroom intervention designed to support middle schools students' understanding of an aquatic ecosystem. The goals of their intervention are to help learners develop deep understanding of ecosystems and to use tools that make the relationships…

  10. Applicator Training Manual for: Aquatic Weed Control.

    Science.gov (United States)

    Herron, James W.

    The aquatic weeds discussed in this manual include algae, floating weeds, emersed weeds, and submerged weeds. Specific requirements for pesticide application are given for static water, limited flow, and moving water situations. Secondary effects of improper application rates and faulty application are described. Finally, techniques of limited…

  11. Nitrous oxide emission by aquatic macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Poulsen, Morten; Nielsen, Lars Peter; Brix, Hans; Schramm, Andreas

    2009-01-01

      A large variety of aquatic animals was found to emit the potent greenhouse gas nitrous oxide when nitrate was present in the environment. The emission was ascribed to denitrification by ingested bacteria in the anoxic animal gut, and the exceptionally high N2O-to-N2 production ratio suggested d...

  12. AQUATIC FUNGI FROM NORTH MAHARASHTRA-VI

    Directory of Open Access Journals (Sweden)

    Wagh S. N.

    2014-07-01

    Full Text Available The paper deals with five species of aquatic fungi belonging to four genera of hyphomycetes isolated from foam samples collected from Rangawali river of Nandurbar district. The foam spora of this region represents mixture of both tropical and temperate species. Brief notes and illustration are givn for each taxon. Geographical distribution of each species of India is also provided.

  13. Aquatic Habitats: Exploring Desktop Ponds. Teacher's Guide.

    Science.gov (United States)

    Barrett, Katharine; Willard, Carolyn

    This book, for grades 2-6, is designed to provide students with a highly motivating and unique opportunity to investigate an aquatic habitat. Students set up, observe, study, and reflect upon their own "desktop ponds." Accessible plants and small animals used in these activities include Elodea, Tubifex worms, snails, mosquito larvae, and fish.…

  14. Aquatic Pest Control. Sale Publication 4071.

    Science.gov (United States)

    Wamsley, Mary Ann, Ed.; Vermeire, Donna M., Ed.

    The information in this manual applies to control of aquatic pests in recreational waters, agricultural reservoirs, ornamental ponds, coastal bays, estuaries and channels, and drinking water reservoirs. Mechanical, cultural, biological, and chemical control methods are discussed. The majority of the material is devoted to weed control in static…

  15. Aquatic ecotoxicological indicators in life cycle assessment

    DEFF Research Database (Denmark)

    Pennington, David W.; Payet, Jerome; Hauschild, Michael Zwicky

    This paper compares available options for the aquatic ecotoxicological effect factor component in life cycle assessment (LCA). The effect factor is expressed here as the change in risk per unit change in cumulative exposure, ƒ´Effect/ƒ´Exposure. The comparison is restricted to approaches linked...

  16. Toxicokinetic modeling challenges for aquatic nanotoxicology

    Directory of Open Access Journals (Sweden)

    Wei-Yu eChen

    2016-01-01

    Full Text Available Nanotoxicity has become of increasing concern since the rapid development of metal nanoparticles (NPs. Aquatic nanotoxicity depends on crucial qualitative and quantitative properties of nanomaterials that induce adverse effects on subcellular, tissue, and organ level. The dose-response effects of size-dependent metal NPs, however, are not well investigated in aquatic organisms. In order to determine the uptake and elimination rate constants for metal NPs in the metabolically active/ detoxified pool of tissues, a one-compartmental toxicokinetic model can be applied when subcellular partitioning of metal NPs data would be available. The present review is an attempt to describe the nano-characteristics of toxicokinetics and subcellular partitioning on aquatic organisms with the help of the mechanistic modeling for NP size-dependent physiochemical properties and parameters. Physiologically-based pharmacokinetic (PBPK models can provide an effective tool to estimate the time course of NP accumulation in target organs and is useful in quantitative risk assessments. NP accumulation in fish should take into account different effects of different NP sizes to better understand tissue accumulative capacities and dynamics. The size-dependent NP partition coefficient is a crucial parameter that influences tissue accumulation levels in PBPK modeling. Further research is needed to construct the effective systems-level oriented toxicokinetic model that can provide a useful tool to develop quantitatively the robustly approximate relations that convey a better insight into the impacts of environmental metal NPs on subcellular and tissue/organ responses in aquatic organisms.

  17. Nano-plastics in the aquatic environment.

    Science.gov (United States)

    Mattsson, K; Hansson, L-A; Cedervall, T

    2015-10-01

    The amount of plastics released to the environment in modern days has increased substantially since the development of modern plastics in the early 1900s. As a result, concerns have been raised by the public about the impact of plastics on nature and on, specifically, aquatic wildlife. Lately, much attention has been paid to macro- and micro-sized plastics and their impact on aquatic organisms. However, micro-sized plastics degrade subsequently into nano-sizes whereas nano-sized particles may be released directly into nature. Such particles have a different impact on aquatic organisms than larger pieces of plastic due to their small size, high surface curvature, and large surface area. This review describes the possible sources of nano-sized plastic, its distribution and behavior in nature, the impact of nano-sized plastic on the well-being of aquatic organisms, and the difference of impact between nano- and micro-sized particles. We also identify research areas which urgently need more attention and suggest experimental methods to obtain useful data. PMID:26337600

  18. Effects of radiation on aquatic organisms

    International Nuclear Information System (INIS)

    With the onset of nuclear age, nuclear fuel cycle products, nuclear medicine techniques, disposal of radio active wastes on land or in water, fall out of testing nuclear weapons has contributed large amount of radio nuclides to the water bodies. Radio nuclides can imbalance aquatic ecosystem resulting in danger to natural life. The biological effects of radiation on aquatic life are mortality, pathophysiological, reproductive, developmental and genetic changes. A broad review of the results obtained about the aquatic organisms related to different phyla indicates that the lower or less developed or more primitive organisms are more resistant than the higher or more advanced, developed and complex organisms to ionizing radiation. The algae, protozoa are more resistant than the insects, crustaceans, molluscs and fishes. The changes in sensitivity between different stages of development have also been noted. A review of the results of exposing salmonoid gametes, eggs, fingerlings and adults to X-rays supports the concepts that radio sensitivity decreases with age. This paper presents a selective review on effects of radiation and radio nuclides on the aquatic life. It include uses and sources of radiation, effective quantity of radiation, lethal and sub lethal effect, effects on survival, growth, reproduction, behaviour, metabolism, carcinogenicity and mutagenicity. (author)

  19. Secure Peer-to-Peer Networks for Scientific Information Sharing

    Science.gov (United States)

    Karimabadi, Homa

    2012-01-01

    The most common means of remote scientific collaboration today includes the trio of e-mail for electronic communication, FTP for file sharing, and personalized Web sites for dissemination of papers and research results. With the growth of broadband Internet, there has been a desire to share large files (movies, files, scientific data files) over the Internet. Email has limits on the size of files that can be attached and transmitted. FTP is often used to share large files, but this requires the user to set up an FTP site for which it is hard to set group privileges, it is not straightforward for everyone, and the content is not searchable. Peer-to-peer technology (P2P), which has been overwhelmingly successful in popular content distribution, is the basis for development of a scientific collaboratory called Scientific Peer Network (SciPerNet). This technology combines social networking with P2P file sharing. SciPerNet will be a standalone application, written in Java and Swing, thus insuring portability to a number of different platforms. Some of the features include user authentication, search capability, seamless integration with a data center, the ability to create groups and social networks, and on-line chat. In contrast to P2P networks such as Gnutella, Bit Torrent, and others, SciPerNet incorporates three design elements that are critical to application of P2P for scientific purposes: User authentication, Data integrity validation, Reliable searching SciPerNet also provides a complementary solution to virtual observatories by enabling distributed collaboration and sharing of downloaded and/or processed data among scientists. This will, in turn, increase scientific returns from NASA missions. As such, SciPerNet can serve a two-fold purpose for NASA: a cost-savings software as well as a productivity tool for scientists working with data from NASA missions.

  20. Effects of Seven Fungicides on Non-Target Aquatic Fungi

    OpenAIRE

    Dijksterhuis, Jan; van Doorn, Tineke; Samson, Rob; Postma, Jaap

    2011-01-01

    Aquatic risk assessments for fungicides are carried out without information on their toxicity to non-target aquatic fungi. This might cause an underestimation of the toxic effects to the aquatic fungal community. This study focuses on the question whether recently derived concentrations limits for fungicides considered to protect populations of primary producers and (in)vertebrates also do protect the aquatic fungi. A panel of fungal species and Oomycetes was isolated and identified from unpo...

  1. Pesticides and Aquatic Animals: A Guide to Reducing Impacts on Aquatic Systems

    OpenAIRE

    Helfrich, Louis A.; Weigmann, Diana L.; Hipkins, Patricia A.; Stinson, Elizabeth R.

    2009-01-01

    Serves as a general guide for those who may use pesticides in or around natural wetlands, lakes, ponds, rivers, and streams by providing information about the toxicity and safe use of pesticides that have the potential to enter aquatic systems.

  2. CAM Photosynthesis in Submerged Aquatic Plants

    Science.gov (United States)

    Keeley, J.E.

    1998-01-01

    Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism selected in response to aridity in terrestrial habitats, and, in aquatic environments, to ambient limitations of carbon. Evidence is reviewed for its presence in five genera of aquatic vascular plants, including Isoe??tes, Sagittaria, Vallisneria, Crassula, and Littorella. Initially, aquatic CAM was considered by some to be an oxymoron, but some aquatic species have been studied in sufficient detail to say definitively that they possess CAM photosynthesis. CO2-concentrating mechanisms in photosynthetic organs require a barrier to leakage; e.g., terrestrial C4 plants have suberized bundle sheath cells and terrestrial CAM plants high stomatal resistance. In aquatic CAM plants the primary barrier to CO2 leakage is the extremely high diffusional resistance of water. This, coupled with the sink provided by extensive intercellular gas space, generates daytime CO2(Pi) comparable to terrestrial CAM plants. CAM contributes to the carbon budget by both net carbon gain and carbon recycling, and the magnitude of each is environmentally influenced. Aquatic CAM plants inhabit sites where photosynthesis is potentially limited by carbon. Many occupy moderately fertile shallow temporary pools that experience extreme diel fluctuations in carbon availability. CAM plants are able to take advantage of elevated nighttime CO2 levels in these habitats. This gives them a competitive advantage over non-CAM species that are carbon starved during the day and an advantage over species that expend energy in membrane transport of bicarbonate. Some aquatic CAM plants are distributed in highly infertile lakes, where extreme carbon limitation and light are important selective factors. Compilation of reports on diel changes in titratable acidity and malate show 69 out of 180 species have significant overnight accumulation, although evidence is presented discounting CAM in some. It is concluded that similar proportions of the aquatic

  3. Writing to Learn and Learning to Write across the Disciplines: Peer-to-Peer Writing in Introductory-Level MOOCs

    OpenAIRE

    Denise K. Comer; Charlotte R. Clark; Canelas, Dorian A.

    2014-01-01

    This study aimed to evaluate how peer-to-peer interactions through writing impact student learning in introductory-level massive open online courses (MOOCs) across disciplines. This article presents the results of a qualitative coding analysis of peer-to-peer interactions in two introductory level MOOCs: English Composition I: Achieving Expertise and Introduction to Chemistry. Results indicate that peer-to-peer interactions in writing through the forums and through peer assessment enhance lea...

  4. An approach to the calculation of dose commitment arising from different methods for the long-term management of uranium mill tailings through aquatic pathways

    International Nuclear Information System (INIS)

    This report describes the development and use of the aquatic pathway portion of a diagnostic model. The model was developed as part of a study intended to improve methods for estimating the environmental dispersion of radionuclides from uranium mill tailings disposal sites. This, the aquatic portion of the study, investigates radionuclide dispersion through aquatic pathways from a hypothetical mill tailings disposal site and presents dose commitment calculations for human exposure to the simulated patterns of radionuclide concentrations over time. Dose commitment estimates are made, based on the simulated geochemical behaviour of the hypothetical site and tailings, aquatic dispersion from the generic site located in northern Ontario and human exposure to and utilization of aquatic products (fish, water). The dose commitment estimates are presented based upon a range of input variable assumptions. This, the 'Aquatic Technical Appendix', describes all important aspects of: the aquatic portion of the diagnostic model, the modelling of the hypothetical tailings site and tailings mass, and findings resulting from use of the models. This report does not predict real radiation doses, or real radionuclide dispersion patterns for any site whether existing or projected

  5. All wet or dried up? Real differences between aquatic and terrestrial food webs.

    Science.gov (United States)

    Shurin, Jonathan B; Gruner, Daniel S; Hillebrand, Helmut

    2006-01-01

    Ecologists have greatly advanced our understanding of the processes that regulate trophic structure and dynamics in ecosystems. However, the causes of systematic variation among ecosystems remain controversial and poorly elucidated. Contrasts between aquatic and terrestrial ecosystems in particular have inspired much speculation, but only recent empirical quantification. Here, we review evidence for systematic differences in energy flow and biomass partitioning between producers and herbivores, detritus and decomposers, and higher trophic levels. The magnitudes of different trophic pathways vary considerably, with less herbivory, more decomposers and more detrital accumulation on land. Aquatic-terrestrial differences are consistent across the global range of primary productivity, indicating that structural contrasts between the two systems are preserved despite large variation in energy input. We argue that variable selective forces drive differences in plant allocation patterns in aquatic and terrestrial environments that propagate upward to shape food webs. The small size and lack of structural tissues in phytoplankton mean that aquatic primary producers achieve faster growth rates and are more nutritious to heterotrophs than their terrestrial counterparts. Plankton food webs are also strongly size-structured, while size and trophic position are less strongly correlated in most terrestrial (and many benthic) habitats. The available data indicate that contrasts between aquatic and terrestrial food webs are driven primarily by the growth rate, size and nutritional quality of autotrophs. Differences in food-web architecture (food chain length, the prevalence of omnivory, specialization or anti-predator defences) may arise as a consequence of systematic variation in the character of the producer community. PMID:16519227

  6. On the application of text input metrics to handwritten text input

    OpenAIRE

    Read, Janet C.

    2006-01-01

    This paper describes the current metrics used in text input research, considering those used for discrete text input as well as those used for spoken input. It examines how these metrics might be used for handwritten text input and provides some thoughts about different metrics that might allow for a more fine grained evaluation of recognition improvement or input accuracy.

  7. Gambaran Peer Relationships Pada Remaja Etnis Minoritas

    OpenAIRE

    Simanjuntak, Helen Lamtiur

    2016-01-01

    Adolescence is a critical period in social development, marked by an expansion of peer networks, increased importance of close friendships, and the emergence of romantic relationships. A good peer relationships is needed for adolescent, especially for adolescent from minority ethnic and when there is a ethnic stereotype and discrimination. This research is supposed to descriptive the peer relationships among minority ethnic adolescent from Tionghoa and Tamil ethnic background. The partici...

  8. Disentangling Peer Influence On Multiple Levels

    OpenAIRE

    Valeria Ivaniushina; Daniel Alexandrov

    2014-01-01

    In this study we focus on the influence of peers on adolescents academic achievement. Specifically, how the learning motivation of peers is related to a student's school grades. We use multilevel regression to analyze the influence of peers on different levels of social circles: school, class, personal network, and compare the effects of "assigned friends" and "chosen friends". The methods of social network analysis are used to define the personal network of a student in different ways: cliqu...

  9. Peer e-assessment of oral presentations

    OpenAIRE

    Ireland, Chris

    2012-01-01

    In order to encourage greater peer involvement, help students practice higher order skills and provide richer feedback, peer assessment has been introduced in the assessment of oral presentations given by first year accountancy students. In order to ensure that feedback is provided quickly and with minimal administration, the process is conducted electronically with peers using an electronic assessment schedule to anonymously assess presentations. Following this, the tutor quickly collates th...

  10. Age Differences in Resistance to Peer Influence

    OpenAIRE

    Steinberg, Laurence; Monahan, Kathryn C.

    2007-01-01

    Prior research describes the development of susceptibility to peer pressure in adolescence as following an inverted U-shaped curve, increasing during early adolescence, peaking around age 14, and declining thereafter. This pattern, however, is derived mainly from studies that specifically examined peer pressure to engage in antisocial behavior. In the present study, age differences and developmental change in resistance to peer influence were assessed using a new self-report instrument that s...

  11. Multi-objective optimization based privacy preserving distributed data mining in Peer-to-Peer networks

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes a scalable, local privacy preserving algorithm for distributed Peer-to-Peer (P2P) data aggregation useful for many advanced data mining/analysis...

  12. Secure Peer-to-Peer Networks for Scientific Information Sharing Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our goal is to adapt the peer?to?peer technology (P2P), which has been overwhelmingly successful in popular content distribution, as the basis for development of...

  13. Scalable peer-to-peer resource discovering scheme for wireless self-organized networks

    Institute of Scientific and Technical Information of China (English)

    LI Xi; JI Hong

    2009-01-01

    Peer-to-peer technologies have attracted increasing research attention with fruitful protocols and applications proposed for wired networks. As to mobile environments, there are currently no mature deployments. A novel resource managing and discovering protocol, Cheer, is proposed to realize scalable and effective peer-to-peer lookup in wireless self-organized networks. Cheer resolves the topologies mismatch problem between peer-to-peer overlay networks and actual nodes distribution, allowing for frequent nodes membership changes. With specially designed resource storage table, Cheer also supports multikey and fuzzy lookup. Its hybrid architecture and improved routing scheme based on small-world theory may realize effective lookup routing. Theoretical analysis and simulation results both prove that Cheer makes using peer-to-peer applications in large-scale self-organized mobile networks feasible and promising.

  14. Client-side Web Mining for Community Formation in Peer-to-Peer Environments

    Data.gov (United States)

    National Aeronautics and Space Administration — In this paper we present a framework for forming interests-based Peer-to-Peer communities using client-side web browsing history. At the heart of this framework is...

  15. A Local Scalable Distributed Expectation Maximization Algorithm for Large Peer-to-Peer Networks

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper describes a local and distributed expectation maximization algorithm for learning parameters of Gaussian mixture models (GMM) in large peer-to-peer (P2P)...

  16. Distributed Decision-Tree Induction in Peer-to-Peer Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper offers a scalable and robust distributed algorithm for decision-tree induction in large peer-to-peer (P2P) environments. Computing a decision tree in...

  17. A Local Asynchronous Distributed Privacy Preserving Feature Selection Algorithm for Large Peer-to-Peer Networks

    Data.gov (United States)

    National Aeronautics and Space Administration — In this paper we develop a local distributed privacy preserving algorithm for feature selection in a large peer-to-peer environment. Feature selection is often used...

  18. Discouraged by Peer Excellence: Exposure to Exemplary Peer Performance Causes Quitting.

    Science.gov (United States)

    Rogers, Todd; Feller, Avi

    2016-03-01

    People are exposed to exemplary peer performances often (and sometimes by design in interventions). In two studies, we showed that exposure to exemplary peer performances can undermine motivation and success by causing people to perceive that they cannot attain their peers' high levels of performance. It also causes de-identification with the relevant domain. We examined such discouragement by peer excellence by exploiting the incidental exposure to peers' abilities that occurs when students are asked to assess each other's work. Study 1 was a natural experiment in a massive open online course that employed peer assessment (N = 5,740). Exposure to exemplary peer performances caused a large proportion of students to quit the course. Study 2 explored underlying psychological mechanisms in an online replication (N = 361). Discouragement by peer excellence has theoretical implications for work on social judgment, social comparison, and reference bias and has practical implications for interventions that induce social comparisons. PMID:26825105

  19. PADMINI: A PEER-TO-PEER DISTRIBUTED ASTRONOMY DATA MINING SYSTEM AND A CASE STUDY

    Data.gov (United States)

    National Aeronautics and Space Administration — PADMINI: A PEER-TO-PEER DISTRIBUTED ASTRONOMY DATA MINING SYSTEM AND A CASE STUDY TUSHAR MAHULE*, KIRK BORNE, SANDIPAN DEY*, SUGANDHA ARORA, AND HILLOL KARGUPTA...

  20. Cooperative peer-to-peer multiagent-based systems.

    Science.gov (United States)

    Caram, L F; Caiafa, C F; Ausloos, M; Proto, A N

    2015-08-01

    A multiagent based model for a system of cooperative agents aiming at growth is proposed. This is based on a set of generalized Verhulst-Lotka-Volterra differential equations. In this study, strong cooperation is allowed among agents having similar sizes, and weak cooperation if agents have markedly different "sizes", thus establishing a peer-to-peer modulated interaction scheme. A rigorous analysis of the stable configurations is presented first examining the fixed points of the system, next determining their stability as a function of the model parameters. It is found that the agents are self-organizing into clusters. Furthermore, it is demonstrated that, depending on parameter values, multiple stable configurations can coexist. It occurs that only one of them always emerges with probability close to one, because its associated attractor dominates over the rest. This is shown through numerical integrations and simulations, after analytic developments. In contrast to the competitive case, agents are able to increase their capacity beyond the no-interaction case limit. In other words, when some collaborative partnership among a relatively small number of partners takes place, all agents act in good faith prioritizing the common good, when receiving a mutual benefit allowing them to surpass their capacity. PMID:26382452

  1. Hybrid Peer-to-Peer Content Sharing in Mobile Networks

    Directory of Open Access Journals (Sweden)

    Péter Ekler

    2009-04-01

    Full Text Available As the capabilities of mobile phones are increasing and they are able to consume different type of multimedia contents, it is important to provide an efficient content sharing solution for them. Since people usually store their content on their personal computer, we need architecture for content sharing which supports mobiles and personal computers as well. In this paper we propose an innovative content sharing solution, called Swarm, which offers the following benefits to service providers: cost efficient, mobility support, necessary control points to prevent misuse of the service and backend for the stored information. Swarm is a hybrid solution, it combines the advantages of peer-to-peer and client-server systems and it also considers the special abilities of mobile phones by enabling local cooperation. During the paper we introduce the proposed architecture with the main features, discuss our experience with the reference implementation, demonstrate calculations about the cost efficiency of Swarm and propose future plans for further improvements. Index Terms

  2. Cooperative peer-to-peer multiagent-based systems

    Science.gov (United States)

    Caram, L. F.; Caiafa, C. F.; Ausloos, M.; Proto, A. N.

    2015-08-01

    A multiagent based model for a system of cooperative agents aiming at growth is proposed. This is based on a set of generalized Verhulst-Lotka-Volterra differential equations. In this study, strong cooperation is allowed among agents having similar sizes, and weak cooperation if agents have markedly different "sizes", thus establishing a peer-to-peer modulated interaction scheme. A rigorous analysis of the stable configurations is presented first examining the fixed points of the system, next determining their stability as a function of the model parameters. It is found that the agents are self-organizing into clusters. Furthermore, it is demonstrated that, depending on parameter values, multiple stable configurations can coexist. It occurs that only one of them always emerges with probability close to one, because its associated attractor dominates over the rest. This is shown through numerical integrations and simulations, after analytic developments. In contrast to the competitive case, agents are able to increase their capacity beyond the no-interaction case limit. In other words, when some collaborative partnership among a relatively small number of partners takes place, all agents act in good faith prioritizing the common good, when receiving a mutual benefit allowing them to surpass their capacity.

  3. Inspiring peer-to-peer educations with film

    Science.gov (United States)

    Vachon, R. W.

    2014-12-01

    Oceans are vast, complicated, often inaccessible, three-dimensional and dark (for the most part). The value, vulnerabilities and dynamics of marine systems are quite far removed from the consciousness of many people. However, these reasons are not alibis for not understanding and appreciating oceans deep-rooted influences on our lives. Currently, the Nereus Program, a fellowship of climate, fisheries and computer modeling scientists, are accessing school systems in person and virtually, motivating teens to tell stories about their local understanding of the ocean's influence on their communities (even if they live in a landlocked location). In it's first iteration, we are soliciting youth to communicate through the popular medium of film. These films will be assembled into an on-line digital field guide. In part, this program is designed to be a peer-to-peer educational technique, where civilians are teaching other civilians about local or regional ocean dynamics. Additionally, the act of teaching through film is a proven method for deepening engagement, learning and empowerment of the individuals producing the films.

  4. EOS: Evolutionary Overlay Service in Peer-to-Peer Systems

    Directory of Open Access Journals (Sweden)

    L. I. Zhijun

    2005-01-01

    Full Text Available The peer-to-peer (P2P systems nowadays can be mainly classified into two categories: structured and structure-less systems based on their overlay organization. The structured systems can achieve determinate efficiency due to their rigorous structure with the cost of losing robustness and vice versa. We provide a semi-structured overlay based on the separation of routing structures and overlay organizations in this paper and the new overlay can achieve determinate efficiency with high robustness. Moreover, the performance of the existing overlay is determined by the initial design and the overlay can not evolve with the information collected. But the new overlay devised in this paper is evolutionary inherent and accompanied by evolving service (EOS, EOS can improve the performance with the running of the P2P systems. Finally, our evolutionary overlay structure is constructed on the basis of linear algebra. So, the EOS can be theoretically analyzed and the results indicate that EOS can work with preferable integrated performance. The experimental results gained on the simulative platform verify the performance of EOS further.

  5. Sealed source peer review plan

    International Nuclear Information System (INIS)

    Sealed sources are known quantities of radioactive materials that have been encapsulated in quantities that produce known radiation fields. Sealed sources have multiple uses ranging from instrument calibration sources to sources that produce radiation fields for experimental applications. The Off-Site Source Recovery (OSR) Project at Los Alamos National Laboratory (LANL), created in 1999, under the direction of the Waste Management Division of the U.S. Department of Energy (DOE) Albuquerque has been assigned the responsibility to recover and manage excess and unwanted radioactive sealed sources from the public and private sector. LANL intends to ship drums containing qualified sealed sources to the Waste Isolation Pilot Plant (WIPP) for disposal. Prior to shipping, these drums must be characterized with respect to radiological content and other parameters. The U. S. Environmental Protection Agency (EPA) requires that ten radionulcides be quantified and reported for every container of waste to be disposed in the WIPP. The methods traditionally approved by the EPA include non-destructive assay (NDA) in accordance with Appendix A of the Contact-Handled Transuranic Waste Acceptance Criteria for the Waste Isolation Pilot Plant (DOE, 2002) (CH WAC). However, because of the nature and pedigree of historical records for sealed sources and the technical infeasibility of performing NDA on these sources, LANL proposes to characterize the content of these waste drums using qualified existing radiological data in lieu of direct measurement. This plan describes the process and documentation requirements for the use of the peer review process to qualify existing data for sealed radiological sources in lieu of perfonning radioassay. The peer review process will be performed in accordance with criteria provided in 40 CFR (section) 194.22 which specifies the use of the NUREG 1297 guidelines. The plan defines the management approach, resources, schedule, and technical requirements

  6. Peer support for people with mental illness

    Directory of Open Access Journals (Sweden)

    Filipa Alexandra Lourenço Campos

    2014-03-01

    Full Text Available Background Peer support is a mutual aid system based on the belief that someone who faced/overcome adversity can provide support, encouragement and guidance to those who experience similar situations. Objective To conduct a systematic review that describes this concept and characterizes peer supporters, its practice and efficacy. Method Research on ISI Web of Science, EBSCO Psychology and Behavioral Sciences Collection and Medline databases (from 2001 to December 2013 was conducted using as keywords “mental illness”, “mental health”, “psychiatric disability”, “mental health services”, combined with “peer support”, “mutual support”, “self-help groups”, “consumers as providers”, “peer-run services”, “peer-run programs” and “social support”. Results We found 1,566 articles and the application of both the exclusion (studies with children, teenagers and elderly people; disease in comorbidity; peer support associated to physical illnesses or family members/caregivers and the inclusion criteria (full text scientific papers, peer support or similar groups directed for schizophrenia, depression, bipolar or psychotic disorders lead to 165 documents, where 22 were excluded due to repetition and 31 to incomplete text. We analyzed 112 documents, identifying as main peer support categories: characterization, peer supporter, practices and efficacy. Discussion Despite an increasing interest about this topic, there is no consensus, suggesting realizing more studies.

  7. Dynamics of Peer Grading: An Empirical Study

    OpenAIRE

    Alfaro, L; Shavlovsky, M

    2016-01-01

    Peer grading is widely used in MOOCs and in standard university settings. The quality of grades obtained via peer grading is essential for the educational process. In this work, we study the factors that influence errors in peer grading. We analyze 288 assignments with 25,633 submissions and 113,169 reviews conducted with CrowdGrader, a web based peer grading tool. First, we found that large grading errors are generally more closely correlated with hard-to-grade submission, rather than ...

  8. Advantages and limitations of peer assessment

    Directory of Open Access Journals (Sweden)

    Karmen Goršak, Karmen Pižorn

    2010-05-01

    Full Text Available This article examines current theoretical work and research findings regarding the effectiveness of peer assessment. The main purpose of the article is to define peer asses sment and its subcategory peer feedback and to present the advantages and limitations of peer assessment derived from different research findings. In addition, conditions and strategies to successfully guarantee the benefits of peer assessment are presented.The main research studies, mentioned in this article, have been carried out in different disciplines in higher education programmes and their findings reveal positive students’ and teachers’ attitude to peer assessment as well as high correlation between peers’ and te achers’ grades. The main results of the studies show a positive effect of peer assessment on student’s active role in the process of learning and assessment, the development of social and professional skills, student’s autonomy, critical thinking, peer and selfassessment skills. Recommendations for implementing peer assessment within foreign language tea ching, as well as implications for future research work are provided. 

  9. Characteristics of peer violence in schools

    Directory of Open Access Journals (Sweden)

    Sinobad Sandra

    2005-01-01

    Full Text Available In this paper the author analyses types and main characteristics of peer violence in schools as well as forms of their manifestation. The analysis refers to data about the prevalence of peer violence in schools in Serbia, and in particular to forms of peer violence within our country as well as in the world. The part of the text refers to characteristics of perpetrators and their victims as well as on consequences that spring up from long term exposure to violence. Finally, the article has been pointed out an importance of introducing intervention programs in schools, by which use peer violence could be significantly decreased.

  10. Aquatic vegetation in response to increased eutrophication and degraded light climate in Eastern Lake Taihu: Implications for lake ecological restoration

    Science.gov (United States)

    Zhang, Yunlin; Liu, Xiaohan; Qin, Boqiang; Shi, Kun; Deng, Jianming; Zhou, Yongqiang

    2016-04-01

    Terrestrial and aquatic ecosystem degradation is widely recognized as a major global environmental and development problem. Although great efforts have been made to prevent aquatic ecosystem degradation, the degree, extent and impacts of this phenomenon remain controversial and unclear, such as its driving mechanisms. Here, we present results from a 17-year field investigation (1998–2014) of water quality and a 12-year remote sensing mapping (2003–2014) of the aquatic vegetation presence frequency (VPF) in Eastern Lake Taihu, a macrophyte-dominated bay of Lake Taihu in China. In the past 17 years, nutrient concentrations and water level (WL) have significantly increased, but the Secchi disk depth (SDD) has significantly decreased. These changes were associated with increased lake eutrophication and a degraded underwater light climate that further inhibited the growth of aquatic vegetation. In Eastern Lake Taihu, increased nutrients, chlorophyll a and WL, and a decreased SDD were all significantly correlated with a decreased VPF. NH4+-N concentration and SDD/WL were the most important controlling factors for VPF. Therefore, increased anthropogenic nutrient inputs and a degraded underwater light climate surely result in a decreased VPF. These results elucidate the driving mechanism of aquatic vegetation degradation and will facilitate Lake Taihu ecological restoration.

  11. Aquatic vegetation in response to increased eutrophication and degraded light climate in Eastern Lake Taihu: Implications for lake ecological restoration

    Science.gov (United States)

    Zhang, Yunlin; Liu, Xiaohan; Qin, Boqiang; Shi, Kun; Deng, Jianming; Zhou, Yongqiang

    2016-01-01

    Terrestrial and aquatic ecosystem degradation is widely recognized as a major global environmental and development problem. Although great efforts have been made to prevent aquatic ecosystem degradation, the degree, extent and impacts of this phenomenon remain controversial and unclear, such as its driving mechanisms. Here, we present results from a 17-year field investigation (1998–2014) of water quality and a 12-year remote sensing mapping (2003–2014) of the aquatic vegetation presence frequency (VPF) in Eastern Lake Taihu, a macrophyte-dominated bay of Lake Taihu in China. In the past 17 years, nutrient concentrations and water level (WL) have significantly increased, but the Secchi disk depth (SDD) has significantly decreased. These changes were associated with increased lake eutrophication and a degraded underwater light climate that further inhibited the growth of aquatic vegetation. In Eastern Lake Taihu, increased nutrients, chlorophyll a and WL, and a decreased SDD were all significantly correlated with a decreased VPF. NH4+-N concentration and SDD/WL were the most important controlling factors for VPF. Therefore, increased anthropogenic nutrient inputs and a degraded underwater light climate surely result in a decreased VPF. These results elucidate the driving mechanism of aquatic vegetation degradation and will facilitate Lake Taihu ecological restoration. PMID:27041062

  12. A Java based framework for simulating peer-to-peer overlay networks

    OpenAIRE

    Hasselrot, Daniel

    2005-01-01

    In the last few years many new structured overlay network protocols for peer-to-peer systems have appeared. Following that, the need to test and develop the protocols in a controlled environment arose and many different simulators were written, often only supporting a single protocol and designed with a specific simulation task in mind. We introduce a general component based framework in Java for writing peer-to-peer simulators, complete with methods for exporting and vis...

  13. Digital Business Models for Peer-to-Peer Networks: Analysis and Economic Issue

    OpenAIRE

    Krishnan Ramayya; Smith Michael D.; Tang Zhulei; Telang Rahul

    2007-01-01

    Peer-to-peer (P2P) services allow users to share networked resources, notably bandwidth and content, from the edges of the network. These services have been popularized because of file sharing particularly the sharing of unlicensed copyrighted files. However, content owners are increasingly exploring the ability of peer-to-peer networks to accommodate legitimate content distribution and promotion. In this article, we review the economic characteristics of P2P networks and outline the implicat...

  14. The Effectiveness of Peer Mentoring Module on the Personality of Peer Mentors

    OpenAIRE

    Haizan binti Mohd Taha; Fauziah Hanim binti Abdul Jalal; Nora binti Dato Yahya; Mardian Shah bin Omar; Evelyn Yeap Ewe Lin

    2014-01-01

    The purpose of this research is to identify the effectiveness of Peer Mentoring Module (PMM) on peer mentors with good characteristics along with their academic performance. From the Big Five Personality Dimensions, those characteristics which include extraversion, agreeableness, conscientiousness, emotional stability and openness should support peer mentors in handling the underachievers on academic mentoring program. Therefore, Big Five Inventory (BFI) was given to twenty peer mentors from ...

  15. Decoupling service and feedback trust in a peer-to-peer reputation system

    OpenAIRE

    Swamynathan, Gayatri; Ben Y. Zhao; Almeroth, Kevin C.

    2005-01-01

    Reputation systems help peers decide whom to trust before undertaking a transaction. Conventional approaches to reputation-based trust modeling assume that peers reputed to provide trustworthy service are also likely to provide trustworthy feedback. By basing the credibility of a peer's feedback on its reputation as a transactor, these models become vulnerable to malicious nodes that provide good service to badmouth targeted nodes. We propose to decouple a peer's reputation as a service provi...

  16. Designing student peer assessment in higher education: Analysis of written and oral peer feedback

    OpenAIRE

    Van den Berg, I.; Admiraal, W.; Pilot, A.

    2006-01-01

    Designing student peer assessment in higher education: analysis of written and oral peer feedback Relating it to design features, the present article describes the nature of written and oral peer feedback as it occurred in seven writing courses, each with a different PA design. Results indicate that generally, peer feedback in all courses was focused on evaluation, which is only one of the four feedback functions. Feedback on structure was hardly provided. As it turned out, the differences be...

  17. Towards Collaborative Search in Digital Libraries Using Peer-to-Peer Technology

    OpenAIRE

    Bender, Matthias; Michel, Sebastian; Zimmer, Christian; Weikum, Gerhard; Türker, Can; Agosti, Maristella; Schek, Hans-Jörg

    2005-01-01

    We consider the problem of collaborative search across a large number of digital libraries and query routing strategies in a peer-to-peer (P2P) environment. Both digital libraries and users are equally viewed as peers and, thus, as part of the P2P network. Our system provides a versatile platform for a scalable search engine combining local index structures of autonomous peers with a global directory based on a distributed hash table (DHT) as an overlay network.

  18. Darknet file sharing : application of a private peer-to-peer distributed file system concept

    OpenAIRE

    Ledung, Gabriel; Andersson, Johan

    2010-01-01

    Peer-to-peer network applications has been a tremendous success among end users and has therefore received much attention in academia and industry, as have illegal public file sharing in media. However, private peer-to-peer file sharing between family, friends and co-workers have attracted little interest from the research community. Existing approaches also limit the users by not allowing for native interaction with userspace applications. In this paper we ex- -plore how private file sharing...

  19. iPeer2Peer program: a pilot feasibility study in adolescents with chronic pain.

    Science.gov (United States)

    Ahola Kohut, Sara; Stinson, Jennifer N; Ruskin, Danielle; Forgeron, Paula; Harris, Lauren; van Wyk, Margaret; Luca, Stephanie; Campbell, Fiona

    2016-05-01

    Adolescents with chronic pain are often socially isolated, having never met others with chronic pain, and often feel misunderstood by healthy peers. Adolescence is a sensitive period for developing one's sense of self and autonomy, which often occurs in the context of peer relationships. This developmental process is disrupted in adolescents when their chronic pain interferes with their social interactions. Peer mentoring is proposed as a developmentally timely intervention. The aim of this study is to develop and test the feasibility, acceptability, and impact of the iPeer2Peer program. The iPeer2Peer program is a tailored peer mentorship program that provides modeling and reinforcement by peers (trained young adults with chronic pain aged 18-25 years who have learned to successfully manage their pain). This program aimed to enhance self-management of chronic pain in adolescents through 10 Skype video calls over the course of 8 weeks. A pilot randomized controlled trial design using waitlist controls was used in an adolescent chronic pain sample. Twenty-eight adolescents aged 14.8 ± 1.6 years (93% female) completed the trial (intervention: n = 12; control n = 16). Three adolescents completed the intervention after completing their participation in the control arm. The iPeer2Peer program was feasible and acceptable, provided the adolescents were given more time to complete all 10 calls. When compared with controls, adolescents who completed the iPeer2Peer program had significant improvement in self-management skills and their coping efforts were more successful. The iPeer2Peer program is a promising peer mentoring intervention that complements standard care for adolescents with chronic pain. PMID:26808145

  20. A Survey of Peer-to-Peer Architectures for Service Oriented Computing

    OpenAIRE

    Hughes, D.; Coulson, G.; Walkerdine, J.

    2010-01-01

    Peer-to-peer file sharing has become popular for many kinds of resource location and distribution applications including file sharing, distributed computation, multi-media messaging and content distribution. Peer-to-peer approaches also have significant potential for supporting large scale, decentralised service oriented computing. This chapter discusses each class of contemporary P2P architecture in turn and discusses the suitability of each architecture class for supporting service oriented...

  1. Adolescent Aggression: The Role of Peer Group Status Motives, Peer Aggression, and Group Characteristics

    OpenAIRE

    Faris, Robert; Ennett, Susan

    2012-01-01

    Recent studies of youth aggression have emphasized the role of network-based peer influence processes. Other scholars have suggested that aggression is often motivated by status concerns. We integrate these two veins of research by considering the effects of peer status motivations on subsequent adolescent aggression, net of their own status motivations, prior aggression, and peer behavior. We also explore different levels at which peer effects may occur, considering the effects of reciprocat...

  2. Efficient and Decentralized PageRank Approximation in a Peer-to-Peer Web Search Network

    OpenAIRE

    Parreira, Josiane Xavier; Donato, Debora; Michel, Sebastian; Weikum, Gerhard; Dayal, Umeshwar; Whang, Kyu-Young; Lomet, David B.; ALONSO Gustavo; Lohman, Guy M.; Kersten, Martin L.; Cha, Sang Kyun; Kim, Young-Kuk

    2006-01-01

    PageRank-style (PR) link analyses are a cornerstone of Web search engines and Web mining, but they are computationally expensive. Recently, various techniques have been proposed for speeding up these analyses by distributing the link graph among multiple sites. However, none of these advanced methods is suitable for a fully decentralized PR computation in a peer-to-peer (P2P) network with autonomous peers, where each peer can independently crawl Web fragments according...

  3. Online Peer-to-Peer Support for Young People With Mental Health Problems: A Systematic Review

    OpenAIRE

    Ali, Kathina; Farrer, Louise; Gulliver, Amelia; Griffiths, Kathleen M

    2015-01-01

    Background Adolescence and early adulthood are critical periods for the development of mental disorders. Online peer-to-peer communication is popular among young people and may improve mental health by providing social support. Previous systematic reviews have targeted Internet support groups for adults with mental health problems, including depression. However, there have been no systematic reviews examining the effectiveness of online peer-to-peer support in improving the mental health of a...

  4. Repositioning Recitation Input in College English Teaching

    Science.gov (United States)

    Xu, Qing

    2009-01-01

    This paper tries to discuss how recitation input helps overcome the negative influences on the basis of second language acquisition theory and confirms the important role that recitation input plays in improving college students' oral and written English.

  5. 28 CFR 34.106 - Number of peer reviewers.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Number of peer reviewers. 34.106 Section 34.106 Judicial Administration DEPARTMENT OF JUSTICE OJJDP COMPETITION AND PEER REVIEW PROCEDURES Peer Review § 34.106 Number of peer reviewers. The number of peer reviewers will vary by program...

  6. 28 CFR 34.109 - Qualifications of peer reviewers.

    Science.gov (United States)

    2010-07-01

    ... Peer Review § 34.109 Qualifications of peer reviewers. The general reviewer qualification criteria to...). Additional details concerning peer reviewer qualifications are provided in the OJJDP “Peer Review Guideline”. ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Qualifications of peer reviewers....

  7. 28 CFR 34.104 - Use of peer review.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Use of peer review. 34.104 Section 34.104 Judicial Administration DEPARTMENT OF JUSTICE OJJDP COMPETITION AND PEER REVIEW PROCEDURES Peer Review § 34.104 Use of peer review. (a) Peer review for competitive and noncompetitive applications. (1)...

  8. 28 CFR 34.102 - Peer review procedures.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Peer review procedures. 34.102 Section 34.102 Judicial Administration DEPARTMENT OF JUSTICE OJJDP COMPETITION AND PEER REVIEW PROCEDURES Peer Review § 34.102 Peer review procedures. The OJJDP peer review process is contained in an OJJDP...

  9. "Peer Pressure" and the Group Process: Building Cultures of Concern

    Science.gov (United States)

    Tate, Thomas F.; Copas, Randall L.

    2010-01-01

    Peer group treatment has been subject to two main lines of criticism. Some suggest any program which aggregates antisocial youth inevitably fosters negative peer influence. Others are concerned that certain peer programs are based on coercive peer confrontation. Positive Peer Culture [PPC] is an antidote to both of these varieties of toxic group…

  10. Controlling Linear Networks with Minimally Novel Inputs

    OpenAIRE

    Kumar, Gautam; Menolascino, Delsin; Kafashan, MohammadMehdi; Ching, ShiNung

    2014-01-01

    In this paper, we propose a novelty-based metric for quantitative characterization of the controllability of complex networks. This inherently bounded metric describes the average angular separation of an input with respect to the past input history. We use this metric to find the minimally novel input that drives a linear network to a desired state using unit average energy. Specifically, the minimally novel input is defined as the solution of a continuous time, non-convex optimal control pr...

  11. Computational Complexity of Input/Output Logic

    OpenAIRE

    Sun, Xin; Ambrossio, Diego Agustin

    2015-01-01

    Input/output logics are abstract structures designed to represent conditional norms. The complexity of input/output logic has been sparsely developed. In this paper we study the complexity of input/output logics. We show that the lower bound of the complexity of the fulfillment problem of 4 input/output logics is coNP, while the upper bound is either coNP or P^NP.

  12. Peer Teaching among Physical Therapy Students during Human Gross Anatomy: Perceptions of Peer Teachers and Students

    Science.gov (United States)

    Youdas, James W.; Hoffarth, Brianna L.; Kohlwey, Scott R.; Kramer, Christine M.; Petro, Jaime L.

    2008-01-01

    Despite nearly 200 accredited entry-level physical therapist education programs in the United States that culminate in a doctoral degree, only a paucity of reports have been published regarding the efficacy of peer teaching in gross anatomy. No one has described the usefulness of peer teaching from the viewpoint of the peer teacher. An organized…

  13. Designing student peer assessment in higher education: Analysis of written and oral peer feedback

    NARCIS (Netherlands)

    van den Berg, I.; Admiraal, W.; Pilot, A.

    2006-01-01

    Designing student peer assessment in higher education: analysis of written and oral peer feedback Relating it to design features, the present article describes the nature of written and oral peer feedback as it occurred in seven writing courses, each with a different PA design. Results indicate that

  14. Designing Student Peer Assessment in Higher Education: Analysis of Written and Oral Peer Feedback

    Science.gov (United States)

    van den Berg, Ineke; Admiraal, Wilfried; Pilot, Albert

    2006-01-01

    The nature of written and oral peer feedback will be described as it occurred in seven writing courses, each with a different design of peer assessment. In all courses, peer feedback was focused on evaluation, which is one of the four feedback functions. Feedback on structure was hardly provided. Relating feedback to design features, we suggest…

  15. Understanding the Benefits of Providing Peer Feedback: How Students Respond to Peers' Texts of Varying Quality

    Science.gov (United States)

    Patchan, Melissa M.; Schunn, Christian D.

    2015-01-01

    Prior research on peer assessment often overlooks how much students learn from providing feedback to peers. By practicing revision skills, students might strengthen their ability to detect, diagnose, and solve writing problems. However, both reviewer ability and the quality of the peers' texts affect the amount of practice available to learners.…

  16. Help Seeking among Peers: The Role of Goal Structure and Peer Climate

    Science.gov (United States)

    Shim, Sungok Serena; Kiefer, Sarah M.; Wang, Cen

    2013-01-01

    With a sample of 373 middle school students, the present longitudinal study examined the role of the classroom peer climate in mediating the relation between perceptions of classroom goal structures and academic help seeking among peers. Classroom goal structures were measured in the fall and classroom peer climate and help seeking among peers…

  17. Peer Feedback in Anonymous Peer Review in an EFL Writing Class in Spain

    Science.gov (United States)

    Coté, Robert A.

    2014-01-01

    The present study reports the results of a process of peer feedback through anonymous peer review in an EFL writing class. Numerous studies have reported on the benefits of peer review (PR) in the ESL/EFL writing classroom. However, the literature also identifies social issues that can negatively affect the outcome of face-to-face PR. In this…

  18. The Role of Child Characteristics and Peer Experiences in the Development of Peer Cooperation

    NARCIS (Netherlands)

    Endedijk, Hinke M.; Cillessen, Antonius H. N.; Bekkering, Harold; Cox, R.F.A; Hunnius, Sabine

    2015-01-01

    Cooperation with peers is challenging for young children, and there are large individual differences in the development of cooperation. The roles of child characteristics and peer experiences for peer interaction during free play have been studied extensively, but it is unclear which factors predict

  19. A coupled two-dimensional hydrodynamic and terrestrial input model to simulate CO2 diffusive emissions from lake systems

    Directory of Open Access Journals (Sweden)

    H. Wu

    2013-06-01

    Full Text Available Most lakes worldwide are supersaturated with carbon dioxide (CO2 and consequently act as atmospheric net sources. Since CO2 is a major greenhouse gas (GHG, the accurate estimation of CO2 exchanges at air/water interfaces of aquatic ecosystems is vital in quantifying the carbon budget of aquatic ecosystems overall. To date, lacustrine CO2 emissions are poorly understood, and lake carbon source proportions remain controversial, largely due to a lack of integration between aquatic and terrestrial ecosystems. In this paper a new process-based model (TRIPLEX-Aquatic is introduced incorporating both terrestrial inputs and aquatic biogeochemical processes to estimate diffusive emissions of CO2 from lake systems. The model was built from a two-dimensional hydrological and water quality model coupled with a new lacustrine CO2 diffusive flux model. For calibration and validation purposes, two years of data collected in the field from two small boreal oligotrophic lakes located in Québec (Canada were used to parameterize and test the model by comparing simulations with observations for both hydrodynamic and carbon process accuracy. Model simulations were accordant with field measurements in both calibration and verification. Consequently, the TRIPLEX-Aquatic model was used to estimate the annual mean CO2 diffusive flux and predict terrestrial dissolved organic carbon (DOC impacts on the CO2 budget for both lakes. Results show a significant fraction of the CO2 diffusive flux (~30–45% from lakes was primarily attributable to the input and mineralization of terrestrial DOC, which indicated terrestrial organic matter was the key player in the diffusive flux of CO2 from oligotropical lake systems in Québec, Canada.

  20. 7 CFR 3430.607 - Stakeholder input.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Stakeholder input. 3430.607 Section 3430.607 Agriculture Regulations of the Department of Agriculture (Continued) COOPERATIVE STATE RESEARCH, EDUCATION... § 3430.607 Stakeholder input. CSREES shall seek and obtain stakeholder input through a variety of...

  1. 7 CFR 3430.907 - Stakeholder input.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Stakeholder input. 3430.907 Section 3430.907 Agriculture Regulations of the Department of Agriculture (Continued) COOPERATIVE STATE RESEARCH, EDUCATION... Program § 3430.907 Stakeholder input. CSREES shall seek and obtain stakeholder input through a variety...

  2. 7 CFR 3430.15 - Stakeholder input.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Stakeholder input. 3430.15 Section 3430.15... Stakeholder input. Section 103(c)(2) of the Agricultural Research, Extension, and Education Reform Act of 1998... RFAs for competitive programs. CSREES will provide instructions for submission of stakeholder input...

  3. Positive Peer Support or Negative Peer Influence? the Role of Peers among Adolescents in Recovery High Schools

    Science.gov (United States)

    Karakos, Holly L.

    2014-01-01

    Evidence from previous research suggests that peers at times exert negative influence and at other times exert positive influence on drug and alcohol use among adolescents in recovery. This study explores recovery high school staff members' perceptions of peer support among students in recovery high schools using qualitative interview data.…

  4. Developing future nurse educators through peer mentoring

    Directory of Open Access Journals (Sweden)

    Rosenau PA

    2015-01-01

    Full Text Available Patricia A Rosenau, Rita F Lisella, Tracey L Clancy, Lorelli S NowellFaculty of Nursing, University of Calgary, Calgary, AB, CanadaBackground: The nursing workforce and nursing education demographic trends reinforce the urgency to cultivate future nursing leaders, educators, and mentors. The changing realities of health care environments, involving crowded student placements, overtaxed clinical mentors and preceptors, and inexperienced staff, hamper student learning and professional development. Peer mentoring has been used successfully in nursing education to enhance student engagement and the quality of the student learning experience. Although various terms like peer mentor have been used to describe the role of senior students facilitating junior student learning, the literature is silent about how peer mentoring fosters the development of future nursing education leaders.Objectives: The aim of this study was to understand how peer mentorship fosters the development of nursing education leadership in senior undergraduate nursing students enrolled in an elective undergraduate peer-mentoring credit course, Introductory Concepts in Nursing Education and Leadership Through Peer-Led Learning.Design and method: This phenomenological study explored the development of nursing education leadership in senior undergraduate students through the analysis of critical reflections of individual senior students and online discussions between triads of senior students teaching/learning across diverse junior-level theory and practice courses.Participants: Seventeen senior undergraduate nursing students enrolled in the elective course participated in the study.Results: From the critical reflections and online discussions, four themes emerged: "developing teaching philosophies and pedagogies", "learning teaching strategies", "supportive peer relationship", and "benefits of the peer mentorship program".Conclusion: The creation and promotion of peer leadership

  5. The Biosphere International Peer Review

    International Nuclear Information System (INIS)

    Abe van Luik (US DOE- YM, USA), ended the presentation by giving feedback from the IAEA peer review on the biosphere modelling strategy developed by the DOE Yucca Mountain Site Characterisation Office (YMSCO). This review was based on available international standards and guidance. The peer review team was constituted of both experts from regulatory and waste management organisations and national advisory committees. The implementation of the review consisted of an examination of biosphere reports mainly regarding the modelling and question and answer exchanges. The final report was submitted in April 2000. It contained twenty-three recommendations within two broad classifications; one concerning the regulatory framework, the other one regarding the framework to increase stakeholders' confidence in modelling. The three main categories of recommendations were outlined, namely (i) the DOE' s Biosphere assessment Approach, (ii) the definition of the biosphere system, and (iii) the model development, data and results. Regarding in particular the treatment of the uncertainties in the biosphere, it was viewed as a key issue during the review and thus it will be re-evaluated in the future performance assessment. The summary highlighted most of the recommendations received are to be acted on, and are to be included in the License Application plan for biosphere modelling

  6. Stable isotopes and Digital Elevation Models to study nutrient inputs in high-Arctic lakes

    Science.gov (United States)

    Calizza, Edoardo; Rossi, David; Costantini, Maria Letizia; Careddu, Giulio; Rossi, Loreto

    2016-04-01

    Ice cover, run-off from the watershed, aquatic and terrestrial primary productivity, guano deposition from birds are key factors controlling nutrient and organic matter inputs in high-Arctic lakes. All these factors are expected to be significantly affected by climate change. Quantifying these controls is a key baseline step to understand what combination of factors subtends the biological productivity in Arctic lakes and will drive their ecological response to environmental change. Basing on Digital Elevation Models, drainage maps, and C and N elemental content and stable isotope analysis in sediments, aquatic vegetation and a dominant macroinvertebrate species (Lepidurus arcticus Pallas 1973) belonging to Tvillingvatnet, Storvatnet and Kolhamna, three lakes located in North Spitsbergen (Svalbard), we propose an integrated approach for the analysis of (i) nutrient and organic matter inputs in lakes; (ii) the role of catchment hydro-geomorphology in determining inter-lake differences in the isotopic composition of sediments; (iii) effects of diverse nutrient inputs on the isotopic niche of Lepidurus arcticus. Given its high run-off and large catchment, organic deposits in Tvillingvatnet where dominated by terrestrial inputs, whereas inputs were mainly of aquatic origin in Storvatnet, a lowland lake with low potential run-off. In Kolhamna, organic deposits seem to be dominated by inputs from birds, which actually colonise the area. Isotopic signatures were similar between samples within each lake, representing precise tracers for studies on the effect of climate change on biogeochemical cycles in lakes. The isotopic niche of L. aricticus reflected differences in sediments between lakes, suggesting a bottom-up effect of hydro-geomorphology characterizing each lake on nutrients assimilated by this species. The presented approach proven to be an effective research pathway for the identification of factors subtending to nutrient and organic matter inputs and transfer

  7. Aquatic macroinvertebrates of the lower Missouri River

    Science.gov (United States)

    Poulton, Barry C.

    2010-01-01

    The U.S. Geological Survey (USGS) Columbia Environmental Research Center (CERC), in cooperation with the U.S. Environmental Protection Agency (USEPA), the U.S. Fish & Wildlife Service (USFWS), and the Missouri Department of Natural Resources (MDNR), has been conducting research on the aquatic macroinvertebrates of the lower Missouri River since the mid-1990s. This research was initiated in response to the need for comprehensive characterization of biological communities inhabiting aquatic habitats in large river systems that have historically been poorly studied. The USGS Status and Trends of Biological Resources Program provided partial funding for pilot studies that began in 1993 when the CERC was part of the USFWS. The purpose of this fact sheet is to provide stakeholders, scientists, management, and the general public with a basic summary of results from studies conducted by the CERC since that time period.

  8. Medical Care of the Aquatics Athlete.

    Science.gov (United States)

    Nichols, Andrew W

    2015-01-01

    Competitive swimmers are affected by several musculoskeletal and medical complaints that are unique to the sport. 'Swimmer's shoulder,' the most common overuse injury, is usually caused by some combination of impingement, rotator cuff tendinopathy, scapular dyskinesis, and instability. The condition may be treated with training modifications, stroke error correction, and strengthening exercises targeting the rotator cuff, scapular stabilizers, and core. Implementation of prevention programs to reduce the prevalence of shoulder pathology is crucial. Knee pain usually results from the breaststroke kick in swimmers, and the 'egg beater' kick in water polo players and synchronized swimmers. Lumbar back pain also is common in aquatics athletes. Among the medical conditions of particular importance in swimmers are exercise-induced bronchoconstriction, respiratory illnesses, and ear problems. Participants in other aquatics sports (water polo, diving, synchronized swimming, and open water swimming) may experience medical ailments specific to the sport. PMID:26359841

  9. Nitrous Oxide Emission by Aquatic Macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Nielsen, Lars Peter; Schramm, Andreas

    Many macrofauna species co-ingest large quantities of microorganisms some of which survive the gut passage. Denitrifying bacteria, in particular, become metabolically induced by anoxic conditions, nitrate, and labile organic compounds in the gut of invertebrates. A striking consequence of the short......, respectively. Aside from these case studies, we screened more than 20 macrofauna species in various aquatic habitats for nitrous oxide production. Filter- and deposit-feeders that ingest large quantities of microorganisms were the most important emitters of nitrous oxide. In contrast, predatory species that do...... not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. With increasing eutrophication, filter- and deposit-feeders often become the dominant feeding guilds of benthic communities. Thus, with increasing nitrate pollution, aquatic macrofauna has the potential to...

  10. [Aquatic animals of medical importance in Brazil].

    Science.gov (United States)

    Haddad Junior, Vidal

    2003-01-01

    The injuries caused by venomous and poisonous aquatic animals may provoke important morbidity in the victim. The cnidarians (jellyfishes, especially cubomedusas and Portuguese-Man-of-War) caused nearly 25% of 236 accidents by marine animals, while sea urchins were responsible for about 50% and catfish, stingrays and scorpionfish nearly 25%). In freshwater, stingrays and catfish cause injuries with a very similar mechanism to the poisoning and the effects of the toxins of marine species. In a series of about 200 injuries observed among freshwater fishermen, nearly 40% were caused by freshwater catfish, 5% freshwater stingrays and 55% by traumatogenic fish, such as piranhas and traíras. The author presents the aquatic animals that cause injuries to humans in Brazil, the clinical aspects of the envenoming and the first measures for the control of the severe pain observed mainly in the accidents caused by cnidarians and venomous fishes. PMID:14576874

  11. PREVIMER : Meteorological inputs and outputs

    Science.gov (United States)

    Ravenel, H.; Lecornu, F.; Kerléguer, L.

    2009-09-01

    PREVIMER is a pre-operational system aiming to provide a wide range of users, from private individuals to professionals, with short-term forecasts about the coastal environment along the French coastlines bordering the English Channel, the Atlantic Ocean, and the Mediterranean Sea. Observation data and digital modelling tools first provide 48-hour (probably 96-hour by summer 2009) forecasts of sea states, currents, sea water levels and temperatures. The follow-up of an increasing number of biological parameters will, in time, complete this overview of coastal environment. Working in partnership with the French Naval Hydrographic and Oceanographic Service (Service Hydrographique et Océanographique de la Marine, SHOM), the French National Weather Service (Météo-France), the French public science and technology research institute (Institut de Recherche pour le Développement, IRD), the European Institute of Marine Studies (Institut Universitaire Européen de la Mer, IUEM) and many others, IFREMER (the French public institute fo marine research) is supplying the technologies needed to ensure this pertinent information, available daily on Internet at http://www.previmer.org, and stored at the Operational Coastal Oceanographic Data Centre. Since 2006, PREVIMER publishes the results of demonstrators assigned to limited geographic areas and to specific applications. This system remains experimental. The following topics are covered : Hydrodynamic circulation, sea states, follow-up of passive tracers, conservative or non-conservative (specifically of microbiological origin), biogeochemical state, primary production. Lastly, PREVIMER provides researchers and R&D departments with modelling tools and access to the database, in which the observation data and the modelling results are stored, to undertake environmental studies on new sites. The communication will focus on meteorological inputs to and outputs from PREVIMER. It will draw the lessons from almost 3 years during

  12. Turn customer input into innovation.

    Science.gov (United States)

    Ulwick, Anthony W

    2002-01-01

    It's difficult to find a company these days that doesn't strive to be customer-driven. Too bad, then, that most companies go about the process of listening to customers all wrong--so wrong, in fact, that they undermine innovation and, ultimately, the bottom line. What usually happens is this: Companies ask their customers what they want. Customers offer solutions in the form of products or services. Companies then deliver these tangibles, and customers just don't buy. The reason is simple--customers aren't expert or informed enough to come up with solutions. That's what your R&D team is for. Rather, customers should be asked only for outcomes--what they want a new product or service to do for them. The form the solutions take should be up to you, and you alone. Using Cordis Corporation as an example, this article describes, in fine detail, a series of effective steps for capturing, analyzing, and utilizing customer input. First come indepth interviews, in which a moderator works with customers to deconstruct a process or activity in order to unearth "desired outcomes." Addressing participants' comments one at a time, the moderator rephrases them to be both unambiguous and measurable. Once the interviews are complete, researchers then compile a comprehensive list of outcomes that participants rank in order of importance and degree to which they are satisfied by existing products. Finally, using a simple mathematical formula called the "opportunity calculation," researchers can learn the relative attractiveness of key opportunity areas. These data can be used to uncover opportunities for product development, to properly segment markets, and to conduct competitive analysis. PMID:12964470

  13. Aquatic effect assessment for plant protection products

    OpenAIRE

    Brock, T.C.M.; Arts, G.H.P.; Hulscher, ten, T.E.M.; Jong, de, D.; Luttik, R.; Roex, E.; Smit, C.E.; Vliet, van, W.

    2011-01-01

    In this report new proposals for the aquatic effects assessment of plant protection products (pesticides) in the Netherlands are described for edge-of-field surface waters (drainage ditches) falling under the domain of the Plant Protection Product Regulation (pre-registration) and for water bodies falling under the domain of the Water Framework Directive (post-registration). These methods are developed on request of two Dutch ministries (Ministry of Economic Affairs, Agriculture and Innovatio...

  14. Toxicity of trifluoroacetate to aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Berends, A.G.; Rooij, C.G. de [Solvay S.A., Brussels (Belgium); Boutonnet, J.C. [Elf Atochem, Levallois-Perret (France); Thompson, R.S. [Zeneca Ltd., Devon (United Kingdom). Brixham Environmental Lab.

    1999-05-01

    As a result of the atmospheric degradation of several hydrofluorocarbons and hydrochlorofluorocarbons, trifluoroacetate (TFA) will be formed. Through precipitation, TFA will enter aquatic ecosystems. To evaluate the impact on the aquatic environment, an aquatic toxicity testing program was carried out with sodium trifluoroacetate (NaTFA). During acute toxicity tests, no effects of NaTFA on water fleas (Daphnia magna) and zebra fish (Danio retrio) were found at a concentration of 1,200 mg/L. A 7-d study with duckweed (Lemna gibba Ge) revealed a NOEC of 300 mg/L. On the basis of the results of five toxicity tests with Selenastrum capricornutum, they determined a NOEC of 0.12 mg/L. However, algal toxicity tests with NaTFA and Chlorella vulgaris, Scenedesmus subspicatus, Chlamydomonas reinhardtii, Dunaliella tertiolecta, Eugelan gracilis, Phaeodactylum tricornutum, Navicula pelliculosa, Skeletonema costatum, Anabaena flos-aquae, and Microcystis aeruginosa resulted in EC50 values that were all higher than 100 mg/L. The toxicity of TFA to S. capricornutum could be due to metabolic defluorination to monofluoroacetate (MFA), which is known to inhibit the citric acid cycle. A toxicity test with MFA and S. capricornutum revealed it to be about three orders of magnitude more toxic than TFA. However, a bioactivation study revealed that defluorination of TFA was less than 4%. On the other hand, S. capricornutum exposed to a toxic concentration of NaTFA showed a recovery of growth when citric acid was added, suggesting that TFA (or a metabolite of TFA) interferes with the citric acid cycle. A recovery of the growth of S. capricornutum was also found when TFA was removed from the test solutions. Therefore, TFA should be considered algistatic and not algicidic for S. capricornutum. On the basis of the combined results of the laboratory tests and a previously reported semi-field study, they can consider a TFA concentration of 0.10 mg/L as safe for the aquatic ecosystem.

  15. Cyanotoxins: Bioaccumulation and Effects on Aquatic Animals

    OpenAIRE

    Betina Kozlowsky-Suzuki; Ferrão-Filho, Aloysio da S.

    2011-01-01

    Cyanobacteria are photosynthetic prokaryotes with wide geographic distribution that can produce secondary metabolites named cyanotoxins. These toxins can be classified into three main types according to their mechanism of action in vertebrates: hepatotoxins, dermatotoxins and neurotoxins. Many studies on the effects of cyanobacteria and their toxins over a wide range of aquatic organisms, including invertebrates and vertebrates, have reported acute effects (e.g., reduction in survivorship, fe...

  16. Measuring Complexity in an Aquatic Ecosystem

    OpenAIRE

    Fernandez, Nelson; Gershenson, Carlos

    2013-01-01

    We apply formal measures of emergence, self-organization, homeostasis, autopoiesis and complexity to an aquatic ecosystem; in particular to the physiochemical component of an Arctic lake. These measures are based on information theory. Variables with an homogeneous distribution have higher values of emergence, while variables with a more heterogeneous distribution have a higher self-organization. Variables with a high complexity reflect a balance between change (emergence) and regularity/orde...

  17. Mechanical performance of aquatic rowing and flying.

    OpenAIRE

    Walker, J.A.; Westneat, M. W.

    2000-01-01

    Aquatic flight, performed by rowing or flapping fins, wings or limbs, is a primary locomotor mechanism for many animals. We used a computer simulation to compare the mechanical performance of rowing and flapping appendages across a range of speeds. Flapping appendages proved to be more mechanically efficient than rowing appendages at all swimming speeds, suggesting that animals that frequently engage in locomotor behaviours that require energy conservation should employ a flapping stroke. The...

  18. Antibiotics promote aggregation within aquatic bacterial communities

    OpenAIRE

    Corno, Gianluca; Coci, Manuela; Giardina, Marco; Plechuk, Sonia; Campanile, Floriana; Stefani, Stefania

    2014-01-01

    The release of antibiotics (AB) into the environment poses several threats for human health due to potential development of AB-resistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and ...

  19. Antibiotics promote aggregation within aquatic bacterial communities

    OpenAIRE

    ManuelaCoci; MarcoGiardina

    2014-01-01

    The release of antibiotics (AB) into the environment poses several threats for human health due to potential development of ABresistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and p...

  20. Aspects of Aquatic Pollution in Nigeria

    OpenAIRE

    A.T. Ekubo; J.F.N. Abowei

    2011-01-01

    Water pollution is a major problem in the global context. Yet aquatic resources consists of extremely wide range of floral and fauna resources which offer a broad array of goods with potential utilitarian application in agriculture, innovative industry and the pharmaceutical industry which renders valuable benefits and services. The slow poisoning of the waters is witnessed in Nigeria and the destruction of vegetation and agricultural land by oil spills which occur during petroleum operations...

  1. Aquatic models, genomics and chemical risk management.

    Science.gov (United States)

    Cheng, Keith C; Hinton, David E; Mattingly, Carolyn J; Planchart, Antonio

    2012-01-01

    The 5th Aquatic Animal Models for Human Disease meeting follows four previous meetings (Nairn et al., 2001; Schmale, 2004; Schmale et al., 2007; Hinton et al., 2009) in which advances in aquatic animal models for human disease research were reported, and community discussion of future direction was pursued. At this meeting, discussion at a workshop entitled Bioinformatics and Computational Biology with Web-based Resources (20 September 2010) led to an important conclusion: Aquatic model research using feral and experimental fish, in combination with web-based access to annotated anatomical atlases and toxicological databases, yields data that advance our understanding of human gene function, and can be used to facilitate environmental management and drug development. We propose here that the effects of genes and environment are best appreciated within an anatomical context - the specifically affected cells and organs in the whole animal. We envision the use of automated, whole-animal imaging at cellular resolution and computational morphometry facilitated by high-performance computing and automated entry into toxicological databases, as anchors for genetic and toxicological data, and as connectors between human and model system data. These principles should be applied to both laboratory and feral fish populations, which have been virtually irreplaceable sentinals for environmental contamination that results in human morbidity and mortality. We conclude that automation, database generation, and web-based accessibility, facilitated by genomic/transcriptomic data and high-performance and cloud computing, will potentiate the unique and potentially key roles that aquatic models play in advancing systems biology, drug development, and environmental risk management. PMID:21763781

  2. Avian Coronavirus in Wild Aquatic Birds

    OpenAIRE

    Chu, D. K. W.; Leung, C. Y. H.; Gilbert, M.; Joyner, P. H.; Ng, E. M.; Tse, T. M.; Guan, Y; Peiris, J. S. M.; Poon, L.L.M

    2011-01-01

    We detected a high prevalence (12.5%) of novel avian coronaviruses in aquatic wild birds. Phylogenetic analyses of these coronaviruses suggest that there is a diversity of gammacoronaviruses and deltacoronaviruses circulating in birds. Gammacoronaviruses were found predominantly in Anseriformes birds, whereas deltacoronaviruses could be detected in Ciconiiformes, Pelecaniformes, and Anseriformes birds in this study. We observed that there are frequent interspecies transmissions of gammacorona...

  3. Improving Fishpond Sediment by Aquatic Vegetable Rotation

    OpenAIRE

    Ling Tao; Chun-Xue Zhang; Jian-Qiang Zhu; Shi-Yang Zhang; Xiao-Li Li; Gu Li

    2012-01-01

    Continuously intensive fish farming results in pond degradation that needs to be improved. Therefore, the experiment rotating intensive fish culture with two aquatic vegetables lotus (Nelumbo nucifera) and water chestnuts (Eleocharis dulcis) cultivation is conducted aiming at determining the effect of rotation as a sediment management technique on improving the pond sediment and assessing the food safety risk of the vegetables cultivated in the pond sediment from the aspects of heavy metal. T...

  4. Impact of Organic farming on aquatic environment

    OpenAIRE

    Kristensen, Erik Steen; Knudsen, Marie Trydemann

    2004-01-01

    The effects of conversion to organic farming on N leaching are discussed in the presentation. Problems in European aquatic environment are presented along with the development of organic farming in Denmark and the rest of Europe. Recent Danish studies on the N leaching effects by conversion of mixed dairy and arable farms are presented. The studies estimate that N leaching is lower from organic compared to conventional mixed dairy farms, whereas N leaching at organic arable farms are comparab...

  5. Adaptive Routing Algorithms in Unstructured Peer-to-Peer (P2P) Systems

    OpenAIRE

    Achmad Nizar Hidayanto; Stephane Bressan

    2011-01-01

    There are a variety of peer-to-peer (P2P) systems for sharing documents currently available. According to their data organization, P2P systems are classified into two categories: structured andunstructured P2P systems. In structured P2P systems, peers are organized according to some mapping techniques, e.g. hashing function. Whereas in unstructured P2P system, peers are connected to each others randomly; resources are not moved to other peers but hosted on site. Unstructured P2P systems offer...

  6. Mycoloop: chytrids in aquatic food webs.

    Science.gov (United States)

    Kagami, Maiko; Miki, Takeshi; Takimoto, Gaku

    2014-01-01

    Parasites are ecologically significant in various ecosystems through their role in shaping food web structure, facilitating energy transfer, and controlling disease. Here in this review, we mainly focus on parasitic chytrids, the dominant parasites in aquatic ecosystems, and explain their roles in aquatic food webs, particularly as prey for zooplankton. Chytrids have a free-living zoosporic stage, during which they actively search for new hosts. Zoospores are excellent food for zooplankton in terms of size, shape, and nutritional quality. In the field, densities of chytrids can be high, ranging from 10(1) to 10(9) spores L(-1). When large inedible phytoplankton species are infected by chytrids, nutrients within host cells are transferred to zooplankton via the zoospores of parasitic chytrids. This new pathway, the "mycoloop," may play an important role in shaping aquatic ecosystems, by altering sinking fluxes or determining system stability. The grazing of zoospores by zooplankton may also suppress outbreaks of parasitic chytrids. A food web model demonstrated that the contribution of the mycoloop to zooplankton production increased with nutrient availability and was also dependent on the stability of the system. Further studies with advanced molecular tools are likely to discover greater chytrid diversity and evidence of additional mycoloops in lakes and oceans. PMID:24795703

  7. Mycoloop: chytrids in aquatic food webs

    Directory of Open Access Journals (Sweden)

    Maiko eKagami

    2014-04-01

    Full Text Available Parasites are ecologically significant in various ecosystems through their role in shaping food web structure, facilitating energy transfer, and controlling disease. Here in this review, we mainly focus on parasitic chytrids, the dominant parasites in aquatic ecosystems, and explain their roles in aquatic food webs, particularly as prey for zooplankton. Chytrids have a free-living zoosporic stage, during which they actively search for new hosts. Zoospores are excellent food for zooplankton in terms of size, shape, and nutritional quality. In the field, densities of chytrids can be high, ranging from 101-109 spores L-1. When large inedible phytoplankton species are infected by chytrids, nutrients within host cells are transferred to zooplankton via the zoospores of parasitic chytrids. This new pathway, the ‘mycoloop,’ may play an important role in shaping aquatic ecosystems, by altering sinking fluxes or determining system stability. The grazing of zoospores by zooplankton may also suppress outbreaks of parasitic chytrids. A food web model demonstrated that the contribution of the mycoloop to zooplankton production increased with nutrient availability and was also dependent on the stability of the system. Further studies with advanced molecular tools are likely to discover greater chytrid diversity and evidence of additional mycoloops in lakes and oceans.

  8. Phytoremediation using eichhornia crassipes aquatic plant

    International Nuclear Information System (INIS)

    Phytoremediation is a cost effective approach for the Treatment of polluted soil and contaminated water. The effectiveness of one aquatic plant Eichhornia crassipes was evaluated for its capability in removing copper from copper solution using atomic absorption spectroscopy (AAS). The aquatic plant was placed in solutions containing 2 mg/L, 4 mg/L an d 6 mg/L of copper, for a period of 18 days and the change in Cu concentration was measured. Results showed an increase of copper within the plants' root and shoot tissues and a decrease of copper concentration in the solution. It was found that roots tend to accumulate a higher amount of copper than shoots due to translocation process. The maximum growth of Eichhornia crassipes was in the 2 mg/L solution which shows that growth was affected by the presence of Cu in the water. The maximum removal of copper in the solutions containing Eichhornia crassipes was 87.5% from the 4 mg/L solution. Eichhornia crassipes accumulated upto 1265.0 mg/kg of Cu in its roots indicating that this aquatic plant species may be used as a hyper-accumulator for copper. (author)

  9. Agent Community based Peer-to-Peer Information Retrieval

    Science.gov (United States)

    Mine, Tsunenori; Matsuno, Daisuke; Amamiya, Makoto

    This paper proposes an agent community based information retrieval method, which uses agent communities to manage and look up information related to users. An agent works as a delegate of its user and searches for information that the user wants by communicating with other agents. The communication between agents is carried out in a peer-to-peer computing architecture. In order to retrieve information related to a user query, an agent uses two histories : a query/retrieved document history(Q/RDH) and a query/sender agent history(Q/SAH). The former is a list of pairs of a query and retrieved documents, where the queries were sent by the agent itself. The latter is a list of pairs of a query and sender agents and shows ``who sent what query to the agent''. This is useful to find a new information source. Making use of the Q/SAH is expected to cause a collaborative filtering effect, which gradually creates virtual agent communities, where agents with the same interests stay together. Our hypothesis is that a virtual agent community reduces communication loads to perform a search. As an agent receives more queries, then more links to new knowledge are achieved. From this behavior, a ``give and take''(or positive feedback) effect for agents seems to emerge. We implemented this method with Multi-Agents Kodama which has been developed in our laboratory, and conducted preliminary experiments to test the hypothesis. The empirical results showed that the method was much more efficient than a naive method employing 'broadcast' techniques only to look up a target agent.

  10. Peer Mentors Can Improve Academic Performance

    Science.gov (United States)

    Asgari, Shaki; Carter, Frederick, Jr.

    2016-01-01

    The present study examined the relationship between peer mentoring and academic performance. Students from two introductory psychology classes either received (n = 37) or did not receive (n = 36) peer mentoring. The data indicated a consistent improvement in the performance (i.e., grades on scheduled exams) of the mentored group. A similar pattern…

  11. Strengthening Controls from Within: Manipulated by Peers

    Science.gov (United States)

    Brasler, Claire E.; Laursen, Erik K.

    2004-01-01

    Since friendship and peer relationships are particularly important to teenagers, students with passive aggressive behaviors frequently and intentionally "set up" more aggressive peers to get them to react and to lose control, guaranteeing a behavioral consequence. As a result, the victim of being set up or "manipulated" also ends up being…

  12. Associations between Peer Victimization and Academic Performance

    Science.gov (United States)

    Espelage, Dorothy L.; Hong, Jun Sung; Rao, Mrinalini A.; Low, Sabina

    2013-01-01

    This article reviews the extant literature on the links between peer victimization and academic performance and engagement among children and adolescents. Although most of the research on this association is based on cross-sectional investigations, research using longitudinal designs is starting to point to the fact that peer victimization does…

  13. Peer Victimization, Depression, and Suicidiality in Adolescents

    Science.gov (United States)

    Klomek, Anat Brunstein; Marrocco, Frank; Kleinman, Marjorie; Schonfeld, Irvin Sam; Gould, Madelyn S.

    2008-01-01

    The association between specific types of peer victimization with depression, suicidal ideation, and suicide attempts among adolescents was examined. A self-report survey was completed by 2,342 high-school students. Regression analyses indicated that frequent exposure to all types of peer victimization was related to high risk of depression,…

  14. Peer Involvement in Adolescent Dating Violence

    Science.gov (United States)

    Stephenson, Pam S.; Martsolf, Donna; Draucker, Claire Burke

    2013-01-01

    This study investigated the ways in which peers are involved in adolescent dating violence. Eighty-eight young adults aged 18-21 were interviewed and asked to reflect on aggressive dating relationships they experienced as teens. The researchers used grounded theory to analyze the data. Findings showed that male and female peers were involved in…

  15. Disruptive School Peers and Student Outcomes

    DEFF Research Database (Denmark)

    Kristoffersen, Jannie H. G.; Krægpøth, Morten Visby; Nielsen, Helena Skyt;

    2015-01-01

    This paper estimates how peers’ achievement gains are affected by the presence of potentially disruptive and emotionally sensitive children in the school-cohort. We exploit that some children move between schools and thus generate variation in peer composition in the receiving school-cohort. We...... achievement of peers by about 1.7–2.3% of a standard deviation....

  16. The Problem of Humiliation in Peer Review

    Science.gov (United States)

    Comer, Debra R.; Schwartz, Michael

    2014-01-01

    This paper examines the problem of vituperative feedback from peer reviewers. We argue that such feedback is morally unacceptable, insofar as it humiliates authors and damages their dignity. We draw from social-psychological research to explore those aspects of the peer-review process in general and the anonymity of blind reviewing in particular…

  17. Peer Review: Structured, Informal, Confidential, Helpful!

    Science.gov (United States)

    Cassidy, Alice; Lee, Jack

    2011-01-01

    This paper describes an introductory workshop, Preparing to be a Peer Reviewer, presented at the University of British Columbia (UBC) to give hands-on practice to faculty members and others in order to provide formative peer review upon request. This workshop, which was designed at the request of a faculty member, is complemented by an Advanced…

  18. Writing Quality Peer Reviews of Research Manuscripts

    Science.gov (United States)

    Ward, Phillip; Graber, Kim C.; van der Mars, Hans

    2015-01-01

    Peer review is an important mechanism for advancing knowledge in a manner deemed as acceptable by the research community. It can also serve the function of providing guidance to an author(s) to improve the likelihood that manuscripts will be accepted in peer reviewed journals. There is, however, little assistance for new or existing reviewers of…

  19. Peer Managed Token Economies: Evaluation and Description.

    Science.gov (United States)

    Bedell, Jeffrey R.; Archer, Robert P.

    1980-01-01

    Results indicate equivalent levels of patient performance when contingent reinforcement in a residential token economy program was controlled by either patient peer groups or staff. Patients in a peer-managed program showed positive ward behavior, reductions in psychosocial problems, and increase in potential for adjusting to community life.…

  20. Specificity of peer conflicts in adolescence

    Directory of Open Access Journals (Sweden)

    Petrović Danijela

    2009-01-01

    Full Text Available The results of the survey conducted on the sample of 530 adolescents are presented in this paper. The sample included two age groups (13 and 16 years. The research was realized in 11 town and 26 schools. The method of the retrospection of the conflict contents, with one week retrospection interval, was used to research the perception of the conflict characteristics. The distinctive characteristics and the effects of the peer conflicts in adolescence have been identified by comparing them to the conflicts with friends, romantic partners, siblings and teachers. According to the results peer conflicts have certain specificity. Although less frequent than conflicts with parents and siblings, the peer conflicts in adolescence are widen phenomenon - on average, the adolescents get in conflict with their peers more than 13 times in a week, almost twice in a day. The most frequent causes are teasing and inappropriate jokes, deliberate provoking, gossips, insults and not respecting the differences in opinion. Peers follow the teachers as the least important persons in the conflict. Compared to the conflicts in other types of the social relations, the conflicts with peers are the least uncomfortable. Yielding is the least, competition the most present resolution strategy in peer conflicts. As well as the most conflicts in this age conflicts with peers are short time episode.

  1. Promoting wellness of peer providers through coaching.

    Science.gov (United States)

    Brice, George H; Swarbrick, Margaret A; Gill, Kenneth J

    2014-01-01

    Peer wellness coaching is workforce innovation that empowers individuals with mental and substance use disorders to achieve recovery. This article briefly describes how this approach can help peer providers develop self-care skills to improve job tenure and promote satisfaction. Promising results of this new approach are presented. PMID:24102840

  2. International Perspectives on Peer Harassment. Book Review.

    Science.gov (United States)

    Lemerise, Elizabeth A.

    2002-01-01

    Notes that Juvonen and Graham's edited work brings together perspectives on peer harassment from eight different countries in articles ranging from a focus on the individual as victim or bully to group processes that support peer harassment in school, and theoretical perspectives. Considers the book valuable for scholars interested in peer…

  3. Reducing Peer Sexual Harassment in Schools

    Science.gov (United States)

    Eckes, Suzanne

    2006-01-01

    Studies have indicated that as many as 80% of students experience some form of sexual harassment in public schools. Such statistics are troublesome, considering that peer sexual harassment can have long-term psychological effects on student victims. Public schools have a responsibility to provide a safe educational environment free of peer sexual…

  4. An Investigation into Effectiveness of Peer Feedback

    Science.gov (United States)

    Lin, Grace Hui Chin; Chien, Paul Shih Chieh

    2009-01-01

    Copious researches argue the effectiveness of peer-correction in writing courses (e.g., Connor & Asenavage, 1994). Also, Coit (2004) mentions using peer feedback for correcting articles through a student-centered environment is a beneficial pedagogy to extend learners' academic-style writing practice. Therefore, this study focused on…

  5. A Comparison of Peer and Tutor Feedback

    Science.gov (United States)

    Hamer, John; Purchase, Helen; Luxton-Reilly, Andrew; Denny, Paul

    2015-01-01

    We report on a study comparing peer feedback with feedback written by tutors on a large, undergraduate software engineering programming class. Feedback generated by peers is generally held to be of lower quality to feedback from experienced tutors, and this study sought to explore the extent and nature of this difference. We looked at how…

  6. Conformity to Peer Pressure in Preschool Children

    Science.gov (United States)

    Haun, Daniel B. M.; Tomasello, Michael

    2011-01-01

    Both adults and adolescents often conform their behavior and opinions to peer groups, even when they themselves know better. The current study investigated this phenomenon in 24 groups of 4 children between 4;2 and 4;9 years of age. Children often made their judgments conform to those of 3 peers, who had made obviously erroneous but unanimous…

  7. College Students' Attitudes toward Their ADHD Peers

    Science.gov (United States)

    Chew, Brandi L.; Jensen, Scott A.; Rosen, Lee A.

    2009-01-01

    Objective: The attitudes of college students with and without ADHD toward peers with ADHD were examined. Method: A total of 196 college students (30 diagnosed with ADHD) anonymously completed four attitude measures. General analyses of attitudes toward peers with ADHD as well as comparisons between those with and without ADHD are made. Results:…

  8. Peer Learning in Specialist Higher Music Education

    Science.gov (United States)

    Hanken, Ingrid Maria

    2016-01-01

    Research on peer learning in higher education indicates that learning from and together with peers can benefit students in a number of ways. Within higher music education in Western, classical music, however, the master-apprentice tradition with its dominant one-to-one mode of tuition focuses predominantly on knowledge transmission from teacher to…

  9. 2009 Water Power Peer Review Report

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Michael [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Higgins, Mark [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States); Reed, Mike [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2011-04-01

    This report contains the findings of the 2009 Water Power Peer Review Panel, as well as the Water Power Program's responses to those findings. This Peer Review focused on the Program's marine and hydrokinetic energy projects.

  10. Ontology-Based Peer Exchange Network (OPEN)

    Science.gov (United States)

    Dong, Hui

    2010-01-01

    In current Peer-to-Peer networks, distributed and semantic free indexing is widely used by systems adopting "Distributed Hash Table" ("DHT") mechanisms. Although such systems typically solve a. user query rather fast in a deterministic way, they only support a very narrow search scheme, namely the exact hash key match. Furthermore, DHT systems put…

  11. Online Peer Discourse in a Writing Classroom

    Science.gov (United States)

    Choi, Jessie

    2014-01-01

    This paper is an attempt to explore the interaction discourse of second language undergraduate learners in the online peer review process of a writing classroom in Hong Kong. Specifically, the writer sought to investigate the types of online discourse learners have in the peer discussions on their writing, and to examine the role of explicit…

  12. Understanding Peer Review of Scientific Research

    Science.gov (United States)

    Association of American Universities, 2011

    2011-01-01

    An important factor in the success of America's national research system is that federal funds for university-based research are awarded primarily through peer review, which uses panels of scientific experts, or "peers," to evaluate the quality of grant proposals. In this competitive process, proposals compete for resources based on their…

  13. Age Differences in Resistance to Peer Influence

    Science.gov (United States)

    Steinberg, Laurence; Monahan, Kathryn C.

    2007-01-01

    Prior research describes the development of susceptibility to peer pressure in adolescence as following an inverted U-shaped curve, increasing during early adolescence, peaking around age 14, and declining thereafter. This pattern, however, is derived mainly from studies that specifically examined peer pressure to engage in antisocial behavior. In…

  14. Peer victimization, deviant peer affiliation and impulsivity: Predicting adolescent problem behaviors.

    Science.gov (United States)

    Zhu, Jianjun; Yu, Chengfu; Zhang, Wei; Bao, Zhenzhou; Jiang, Yanping; Chen, Yuanyuan; Zhen, Shuangju

    2016-08-01

    Abundant evidence has demonstrated an association between peer victimization and adolescent problem behaviors. However, there is a large gap in knowledge about the potential mediators that associate peer victimization with problem behaviors and the potential moderators that exacerbate or buffer this association. The current study examined whether deviant peer affiliation mediated the association between peer victimization and problem behaviors and whether the direct and indirect associations were moderated by impulsivity. A sample of 1401 adolescents (50.1% boys, 11-14 years old) completed anonymous questionnaires regarding peer victimization, impulsivity, deviant peer affiliation, and problem behaviors. Gender, age and socioeconomic status (SES) were controlled for in the analyses. Structural equation models showed that peer victimization was significantly associated with more problem behaviors, and this association was mediated by deviant peer affiliation. Impulsivity moderated both the direct association (peer victimization→problem behaviors) and the second stage of the indirect path (deviant peer affiliation→problem behaviors). Specifically, these associations were especially stronger for adolescents with higher impulsivity. Identifying the processes by which peer victimization is associated with adolescent problem behaviors has important implications for an integrative framework of theory and prevention. PMID:27348798

  15. Multi-Data Source Fusion Approach in Peer-To-Peer Systems

    Directory of Open Access Journals (Sweden)

    Gilles Nachouki

    2010-02-01

    Full Text Available In this paper, a new approach for data fusion in the context of schema-basedPeer-To-Peer (P2P systems is proposed. Schema-based systems manage andprovide query capabilities for (semi-structured information: queries have to beformulated in terms of schema. Schema-based P2P are called Peer DataManagement system (PDMS. A challenging problem in a schema-based peerto-peer (P2P system is how to locate peers who have data relevant to a givenquery.Our proposal lies in application of the multi-data source fusion approach in thecontext of PDMS. Multi-data source schemas, distributed, shared andmaintained by peers, are the basis of a semantic overlay network. The semanticoverlay network and the power of Multi-data source Fusion Language (MFLare exploited for efficient query routing towards the relevant peers. We showthe design of the Peer Multi-Data source Management System (PMDMS andwe focus on the Matchmaker and routing components. We give a performanceevaluation of the semantic query routing with respect to important criteria suchas precision, recall, response time and number of messages. We give aperformance evaluation of the semantic reconciliation between peers. Wecompare this result with other systems developed according to peer/super-peerapproach. Finally, we show a prototype developed according to PMDMS. Webuild an application that shares, data between peers, in the domain of leisuresuch as, bank, cinema, restaurant, etc.

  16. What influences peer-led sex education in the classroom? A view from the peer educators.

    Science.gov (United States)

    Strange, Vicki; Forrest, Simon; Oakley, Ann

    2002-06-01

    This paper is the second of two presenting data gathered from peer educators in the RIPPLE study-a randomized controlled trial of peer-led sex education in English secondary schools. Peer educators were recruited from Year 12 students (aged 16/17 years) in 13 schools in two successive cohorts in 1997 and 1998. Following a standardized training programme they delivered sex education sessions to Year 9 students (aged 13/14 years). Through analysis of 18 focus group discussions and of post-programme questionnaire data (n = 301), this paper aims to identify the issues and processes considered by peer educators to be important in implementing a peer education programme, and to examine peer educators' views on the relationship between themselves and the Year 9 students. Methodological issues arising when collecting, analysing and presenting such data are discussed, and some recommendations are outlined for carrying out school-based peer education. PMID:12120849

  17. Minimization of Delay for Query Processing in Peer to Peer Networks

    Directory of Open Access Journals (Sweden)

    U.V. Arivazhagu

    2012-06-01

    Full Text Available Most of the research has been concentrated on sharing of files in Peer to Peer System .Our framework avoids the centralized structure of database management system and proposed the use of decentralized nature in a network. In the existing system, searching of neighbouring nodes is complex and provide more delay in communication of queries with no updation ofmapping tables. This paper explains about the topological discovery of peers and creation of the acquaintances and mapping tables.Our objective is to implements a new environment in database by Query Processing system andexplains how the execution and updation of query can be done in all the peers. In this paper, it deals with the effective query processing done with all the peers with respect to CPU execution time, creating an acquaintance, mapping tables with no communication delay in a large peer to peer system.

  18. Peer Effects and Academics’ Industry Involvement

    DEFF Research Database (Denmark)

    Aschhoff, Birgit; Grimpe, Christoph

    sample of 330 German academics in the field of biotechnology and publication data from the Science Citation Index Expanded (SCIE), we find that scientists with industry-oriented co-authors are more likely to be involved with industry (personal peer effect). Moreover, we find that the scientist’s...... the scientist. We suggest that both localized and personal peer effects drive industry involvement but that the effects from such imprinting are more pronounced for younger researchers, suggesting that professional imprinting takes place in the early stages of a scientist’s academic career. Based on a...... involvement increases with the orientation of the scientist’s department towards industry (localized peer effect). Only the latter effect turns out to be moderated by scientist’s age. While personal peer effects are independent of the scientist’s age, localized peer effects emerge for younger researchers....

  19. Censorship and the peer review system

    CERN Document Server

    Svozil, K

    2002-01-01

    In the best of all worlds, peer review amounts to benign censorship, saving trees, human efforts and money spent by attempts to cope with erroneous or badly written papers. In the worst case, ``peer review'' amounts to malign censorship, impede progress, and hence to a waste of human efforts and (mostly taxpayer's) money. It is argued that, by the way it is commonly executed by editorial boards and funding agencies, peer review does often more bad than good. In an academic environment which is increasingly ``objectivized'' and administered by quality measures of private business, careful peer review is almost punished, since it amounts to ``unproductive time.'' If paid realistically, it would be excessively expensive. Very little attention is also given to the quality of the review process. Alternatives to ``peer review'' are briefly suggested and discussed.

  20. Is peer review useful in assessing research proposals in Indigenous health? A case study

    Directory of Open Access Journals (Sweden)

    Baum Fran

    2009-02-01

    Full Text Available Abstract Background There has been considerable examination and critique of traditional (academic peer review processes in quality assessment of grant applications. At the same time, the use of traditional research processes in Indigenous research has been questioned. Many grant funding organisations have changed the composition of their peer review panels to reflect these concerns but the question remains do these reforms go far enough? In this project we asked people working in areas associated with Aboriginal health research in a number of capacities, their views on the use of peer review in assessing Indigenous research proposals. Methods In semi-structured interviews we asked 18 individuals associated with an Australian Indigenous research funding organisation to reflect on their experience with peer review in quality assessment of grant applications. We also invited input from a steering group drawn from a variety of organisations involved in Aboriginal research throughout Australia and directly consulted with three Aboriginal-controlled health organisations. Results There was consensus amongst all participants that traditional academic peer review is inappropriate for quality assessment in Indigenous research. Many expressed the view that using a competitive grant review system in Aboriginal health was counterintuitive, since good research transfer is based on effective collaboration. The consensus within the group favoured a system which built research in a collaborative manner incorporating a variety of different stakeholders in the process. In this system, one-off peer review was still seen as valuable in the form of a "critical friend" who provided advice as to how to improve the research proposal. Conclusion Peer review in the traditional mould should be recognised as inappropriate in Aboriginal research. Building research projects relevant to policy and practice in Indigenous health may require a shift to a new way of selecting

  1. Oxidative mitigation of aquatic methane emissions in large Amazonian rivers.

    Science.gov (United States)

    Sawakuchi, Henrique O; Bastviken, David; Sawakuchi, André O; Ward, Nicholas D; Borges, Clovis D; Tsai, Siu M; Richey, Jeffrey E; Ballester, Maria Victoria R; Krusche, Alex V

    2016-03-01

    The flux of methane (CH4 ) from inland waters to the atmosphere has a profound impact on global atmospheric greenhouse gas (GHG) levels, and yet, strikingly little is known about the dynamics controlling sources and sinks of CH4 in the aquatic setting. Here, we examine the cycling and flux of CH4 in six large rivers in the Amazon basin, including the Amazon River. Based on stable isotopic mass balances of CH4 , inputs and outputs to the water column were estimated. We determined that ecosystem methane oxidation (MOX) reduced the diffusive flux of CH4 by approximately 28-96% and varied depending on hydrologic regime and general geochemical characteristics of tributaries of the Amazon River. For example, the relative amount of MOX was maximal during high water in black and white water rivers and minimal in clear water rivers during low water. The abundance of genetic markers for methane-oxidizing bacteria (pmoA) was positively correlated with enhanced signals of oxidation, providing independent support for the detected MOX patterns. The results indicate that MOX in large Amazonian rivers can consume from 0.45 to 2.07 Tg CH4 yr(-1) , representing up to 7% of the estimated global soil sink. Nevertheless, climate change and changes in hydrology, for example, due to construction of dams, can alter this balance, influencing CH4 emissions to atmosphere. PMID:26872424

  2. Diets and abundances of aquatic and semi-aquatic reptiles in the Alligator Rivers Region

    International Nuclear Information System (INIS)

    The mining and milling of uranium in the Alligator River Region in the Northern Territory has raised the possibility that heavy metals and radionuclides might escape into the aquatic system and be accumulated by the reptilian fauna. Aquatic and semi-aquatic reptiles are regularly eaten by Aboriginal people of the region, and data on diets and reproduction of these species, as well as on their dispersion and abundance, are essential before the possibility that reptiles might act as pathways for these contaminants to Aboriginals can be assessed. The objectives of this study were to provide quantitative data on the diets of filesnakes, sand goannas and water goannas, to provide information on seasonal changes in their abundance and distribution within the Magela Creek system; and to describe their reproductive cycles

  3. Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

    Science.gov (United States)

    Larsen, Thomas; Ventura, Marc; Andersen, Nils; O'Brien, Diane M; Piatkowski, Uwe; McCarthy, Matthew D

    2013-01-01

    Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13)C patterns among amino acids (δ(13)CAA) could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13)CAA patterns in contrast to bulk δ(13)C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13)CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13)C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13)C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs. PMID:24069196

  4. Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

    Directory of Open Access Journals (Sweden)

    Thomas Larsen

    Full Text Available Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13C patterns among amino acids (δ(13CAA could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13CAA patterns in contrast to bulk δ(13C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs.

  5. A quantitative and qualitative comparison of aquatic and terrestrial plant lignin phenols: Critical information for paleoecological reconstructions

    Science.gov (United States)

    Thomas, E. K.; Gao, L.; Huang, Y.

    2009-12-01

    Currently, lignin phenols are used in marine and lacustrine ecosystems as proxies for terrestrial vegetation inputs. Lignins are found in all vascular plants, where they play a crucial role in conduction of water, nutrients and photosynthates through the vascular system, and where they provide structural support. Furthermore, different types of lignin phenols are found in specific types of vegetation (e.g., both syringyl and vanillyl phenols are in angiosperm wood, but only vanillyl phenols are in gymnosperm wood). The ratio of lignin phenols (e.g. syringyl:vanillyl) is indicative of the type of plant from which the lignin phenols were derived. Studies that examine lignin phenols in sedimentary archives assume that lignin phenols are derived solely from terrestrial plants, and changes in the types of lignin phenols are therefore assumed to mark changes in terrestrial vegetation. These assumptions may be flawed, however, because many aquatic plants, including those that are submerged, are vascular, yet little is known about the type and concentration of lignin phenols present in aquatic vascular plants. This knowledge is imperative to the success of paleoecological studies that utilize lignin phenols as a geochemical proxy for terrestrial vegetation. Furthermore, lignin phenols may be important targets for compound-specific radiocarbon dating, which is useful when suitable macrofossils are unavailable. Knowing the origin of the molecules used for radiocarbon dating, however, (i.e. whether they are terrestrial or aquatic) is critical to obtaining meaningful chronologies. We isolated and analyzed lignin phenol monomers from different types of aquatic vascular plants. All plants analyzed are angiosperms, but they occupy different niches in aquatic plant communities: floating, emergent and submergent. We also analyzed different parts of aquatic plants (i.e., stems and leaves). We found lignin phenols in all aquatic species that we analyzed, which highlights the need for

  6. Procedure for developing biological input for the design, location, or modification of water-intake structures

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, D.A.; McKenzie, D.H.

    1981-12-01

    To minimize adverse impact on aquatic ecosystems resulting from the operation of water intake structures, design engineers must have relevant information on the behavior, physiology and ecology of local fish and shellfish. Identification of stimulus/response relationships and the environmental factors that influence them is the first step in incorporating biological information in the design, location or modification of water intake structures. A procedure is presented in this document for providing biological input to engineers who are designing, locating or modifying a water intake structure. The authors discuss sources of stimuli at water intakes, historical approaches in assessing potential/actual impact and review biological information needed for intake design.

  7. Processing distributed inputs in coupled excitable lasers

    International Nuclear Information System (INIS)

    In many instances, networks of dynamical elements are subject to distributed input signals that enter the network through different nodes. In these cases, processing of the input signals may be mediated by coupling, in what constitutes an emerging property of the network. Here we study experimentally this effect in two mutually injected semiconductor lasers with optical feedback, operating in an excitable regime. The lasers are subject to different periodic input signals in their pump current, with distinct frequencies. Our results show that when the signals are harmonics of an absent fundamental, the laser array is able to process these signals and respond at the missing fundamental frequency. When the input frequencies are rigidly shifted from their harmonic values, the response frequency follows a simple law derived from a linear sum of the inputs, even though the array integrates the electrical inputs after having transduced them optically. The results are reproduced numerically with a dynamical model of the laser array

  8. Revenue Insurance and Chemical Input Use Rates

    OpenAIRE

    Nimon, R. Wesley; Mishra, Ashok K.

    2001-01-01

    Using farm level data and a simultaneous probit model we evaluate the input use and environmental effects of revenue insurance. A priori, the moral hazard effect on input use is indeterminate and this study empirically assesses the input use impact of the increasingly popular, and federally subsidized, risk management instrument of revenue insurance. We conclude that the moral hazard effect of federally subsidized revenue insurance products induces U.S. wheat farmers to increase expenditures ...

  9. When Can School Inputs Improve Test Scores?

    OpenAIRE

    Stefan Dercon

    2004-01-01

    Most studies fail to find an impact of school inputs on outcomes such as test scores. We argue that this might be a consequence of ignoring the possibility that households respond optimally to changes in school inputs and thus obscure the real effect of such provision on cognitive achievement. To incorporate the forward-looking behavior of households, we present a household optimization model relating household resources and cognitive achievement to school inputs. In this framework if househo...

  10. Input Scheme for Hindi Using Phonetic Mapping

    OpenAIRE

    Joshi, Nisheeth; Mathur, Iti

    2010-01-01

    Written Communication on Computers requires knowledge of writing text for the desired language using Computer. Mostly people do not use any other language besides English. This creates a barrier. To resolve this issue we have developed a scheme to input text in Hindi using phonetic mapping scheme. Using this scheme we generate intermediate code strings and match them with pronunciations of input text. Our system show significant success over other input systems available.

  11. IMPLEMENTATION OF REPUTATION EXCHANGE PROTOCOL IN PEER-TO-PEER SYSTEM

    Directory of Open Access Journals (Sweden)

    B.Udhaya,

    2011-03-01

    Full Text Available The motivation behind basing applications on peer-to-peer architectures derives to a large extent from their ability to function, scale and self-organize in the presence of a highly transient population of nodes, network and computer failures, without the need of a central server and the overhead of its administration. P2P networks are vulnerable to peers, who cheat, propagate malicious codes, or peers who do not cooperate. Traditional client-server security models are not sufficient to P2P networks because of their centralized nature. Absence of central authority in P2P poses unique challenges like identity management of the peers, secure reputation data management and Sybil attack for reputation management in the network. In this paper we present a cryptographic protocol for ensuring secure and timely availability of the reputation data of a peer extremely at low cost. The past behavior of the peer is encapsulated in its digital reputation and is subsequently used to predict the future actions. The cryptographic protocol is coupled with self-certification and cryptographic mechanisms for identitymanagement and countering Sybil attacks. The latency associated with a file replication in a P2P system consists of two components: the query search time and the time required by the peers to transmit the file. In order to model the peer level latency, we develop a queuing model to evaluate the time required at each peer to serve its replication requests.

  12. Peer Support for Clinicians: A Programmatic Approach.

    Science.gov (United States)

    Shapiro, Jo; Galowitz, Pamela

    2016-09-01

    Burnout is plaguing the culture of medicine and is linked to several primary causes including long work hours, increasingly burdensome documentation, and resource constraints. Beyond these, additional emotional stressors for physicians are involvement in an adverse event, especially one that involves a medical error, and malpractice litigation. The authors argue that it is imperative that health care institutions devote resources to programs that support physician well-being and resilience. Doing so after adverse and other emotionally stressful events, such as the death of a colleague or caring for victims of a mass trauma, is crucial as clinicians are often at their most vulnerable during such times. To this end, the Center for Professionalism and Peer Support at Brigham and Women's Hospital redesigned the peer support program in 2009 to provide one-on-one peer support. The peer support program was one of the first of its kind; over 25 national and international programs have been modeled off of it. This Perspective describes the origin, structure, and basic workings of the peer support program, including important components for the peer support conversation (outreach call, invitation/opening, listening, reflecting, reframing, sense-making, coping, closing, and resources/referrals). The authors argue that creating a peer support program is one way forward, away from a culture of invulnerability, isolation, and shame and toward a culture that truly values a sense of shared organizational responsibility for clinician well-being and patient safety. PMID:27355784

  13. Who are the victims of peer violence?

    Directory of Open Access Journals (Sweden)

    Nedimović Tanja

    2013-01-01

    Full Text Available Peer violence is a very current problem in schools. There are plenty of studies on the characteristics of perpetrators, while the characteristics of victims have been explored much less frequently. This research was aimed at determining the factors from the domain of upbringing and socio-demographic characteristics of the victims that contribute to the exposure to peer violence. The total sample comprised 504 primary school students. In order to determine the effect of victimological factors, hierarchical regression analysis was performed. The data obtained by the Questionnaire measuring the manifestation forms and frequency of peer violence were processed by factor analysis, which yielded the following three factors of exposure to peer violence: direct, manipulative and social. Factor scores on these factors were used as criterion variables. In the first step, the variable of gender was entered into the regression, the second set included three socio-demographic variables, and the third set of variables comprised parental upbringing styles and violent behavior in the family. The cold upbringing style of the mother was identified as an important predictor for the exposure to direct peer violence; for the exposure to manipulative peer violence - the cold upbringing attitude of the father and mother; and for the exposure to social peer violence - gender (female and the cold upbringing attitude of the father. The results are discussed in the context of pedagogical implications of the research, i.e. the guidelines for designing prevention programmes in schools focused on enhancing parental educational competences and students’ social skills.

  14. Responses of Aquatic Bacteria to Terrestrial Runoff: Effects on Community Structure and Key Taxonomic Groups.

    Science.gov (United States)

    Le, Huong T; Ho, Cuong T; Trinh, Quan H; Trinh, Duc A; Luu, Minh T N; Tran, Hai S; Orange, Didier; Janeau, Jean L; Merroune, Asmaa; Rochelle-Newall, Emma; Pommier, Thomas

    2016-01-01

    Organic fertilizer application is often touted as an economical and effective method to increase soil fertility. However, this amendment may increase dissolved organic carbon (DOC) runoff into downstream aquatic ecosystems and may consequently alter aquatic microbial community. We focused on understanding the effects of DOC runoff from soils amended with compost, vermicompost, or biochar on the aquatic microbial community of a tropical reservoir. Runoff collected from a series of rainfall simulations on soils amended with different organic fertilizers was incubated for 16 days in a series of 200 L mesocosms filled with water from a downstream reservoir. We applied 454 high throughput pyrosequencing for bacterial 16S rRNA genes to analyze microbial communities. After 16 days of incubation, the richness and evenness of the microbial communities present decreased in the mesocosms amended with any organic fertilizers, except for the evenness in the mesocosms amended with compost runoff. In contrast, they increased in the reservoir water control and soil-only amended mesocosms. Community structure was mainly affected by pH and DOC concentration. Compared to the autochthonous organic carbon produced during primary production, the addition of allochthonous DOC from these organic amendments seemed to exert a stronger effect on the communities over the period of incubation. While the Proteobacteria and Actinobacteria classes were positively associated with higher DOC concentration, the number of sequences representing key bacterial groups differed between mesocosms particularly between the biochar runoff addition and the compost or vermi-compost runoff additions. The genera of Propionibacterium spp. and Methylobacterium spp. were highly abundant in the compost runoff additions suggesting that they may represent sentinel species of complex organic carbon inputs. Overall, this work further underlines the importance of studying the off-site impacts of organic fertilizers as

  15. The mysteriously variable half-life of dissolved organic matter in aquatic ecosystems: artefact or insight?

    Science.gov (United States)

    Evans, Chris; Fovet, Ophelie; Jones, Tim; Jones, Davey; Moldan, Filip; Futter, Martyn

    2016-04-01

    Dissolved organic matter (DOM) fluxes from land to water represent an important loss term in the terrestrial carbon balance, a major pathway in the global carbon cycle, a significant influence on aquatic light, nutrient and energy regimes, and an important concern for drinking water production. Although freshwaters are now recognised as zones of active carbon cycling, rather than passive conduits for carbon transport, evidence regarding the magnitude of, and controls on, DOM cycling in aquatic systems is incomplete and in some cases seemingly contradictory, with DOM 'half-lives' ranging from a few days to many years. Bringing together experimental, isotopic, catchment mass balance and modelling data, we suggest that apparently conflicting results can be reconciled through understanding of differences in: i) the terrestrial sources of DOM within heterogeneous landscapes, and consequent differences in its reactivity and stoichiometry; ii) experimental methodologies (i.e. which reactions are actually being measured), and iii) the extent of prior transformation of DOM upstream of the point of study. We argue that rapid photo-degradation, particularly of peat-derived DOM, is a key process in headwaters, whilst apparently slow DOM turnover in downstream, agriculturally-influenced lakes and rivers can partly be explained by the offsetting effect of in situ DOM production. This production appears to be strongly constrained by nutrient supply, thus linking DOM turnover and composition to the supply of inorganic nutrient inputs from diffuse agricultural pollution, and also providing a possible mechanistic link between aquatic DOM production and terrestrial DOM breakdown via the mineralisation and re-assimilation of organic nutrients. A more complete conceptual understanding of these interlinked processes will provide an improved understanding of the sources and fate of aquatic DOM, its role in the global carbon cycle, and the impact of anthropogenic activities, for example

  16. Responses of Aquatic Bacteria to Terrestrial Runoff: Effects on Community Structure and Key Taxonomic Groups

    Science.gov (United States)

    Le, Huong T.; Ho, Cuong T.; Trinh, Quan H.; Trinh, Duc A.; Luu, Minh T. N.; Tran, Hai S.; Orange, Didier; Janeau, Jean L.; Merroune, Asmaa; Rochelle-Newall, Emma; Pommier, Thomas

    2016-01-01

    Organic fertilizer application is often touted as an economical and effective method to increase soil fertility. However, this amendment may increase dissolved organic carbon (DOC) runoff into downstream aquatic ecosystems and may consequently alter aquatic microbial community. We focused on understanding the effects of DOC runoff from soils amended with compost, vermicompost, or biochar on the aquatic microbial community of a tropical reservoir. Runoff collected from a series of rainfall simulations on soils amended with different organic fertilizers was incubated for 16 days in a series of 200 L mesocosms filled with water from a downstream reservoir. We applied 454 high throughput pyrosequencing for bacterial 16S rRNA genes to analyze microbial communities. After 16 days of incubation, the richness and evenness of the microbial communities present decreased in the mesocosms amended with any organic fertilizers, except for the evenness in the mesocosms amended with compost runoff. In contrast, they increased in the reservoir water control and soil-only amended mesocosms. Community structure was mainly affected by pH and DOC concentration. Compared to the autochthonous organic carbon produced during primary production, the addition of allochthonous DOC from these organic amendments seemed to exert a stronger effect on the communities over the period of incubation. While the Proteobacteria and Actinobacteria classes were positively associated with higher DOC concentration, the number of sequences representing key bacterial groups differed between mesocosms particularly between the biochar runoff addition and the compost or vermi-compost runoff additions. The genera of Propionibacterium spp. and Methylobacterium spp. were highly abundant in the compost runoff additions suggesting that they may represent sentinel species of complex organic carbon inputs. Overall, this work further underlines the importance of studying the off-site impacts of organic fertilizers as

  17. Application of portable in situ UV fluorescence sensors in natural and engineered aquatic systems.

    Science.gov (United States)

    Fox, Bethany; Rushworth, Cathy; Atrridge, John

    2016-04-01

    Natural organic matter (NOM) is ubiquitous throughout aquatic systems. This heterogeneous mixture of organic matter is central for aquatic ecosystems and, both local and global, biogeochemical cycling. Improvements in technology and data analysis has allowed for advances in the understanding and characterisation of aquatic organic matter. However, much of the technological expansions have focussed on benchtop instruments. In recent years, there has been interest in the continued development of portable in situ sensors for monitoring NOM characteristics within a wide range of applications, spanning both natural and engineered systems. The UviLux (Chelsea Technologies Group Ltd., UK) is an in situ portable UV fluorescence sensor that can be configured to monitor a range of NOM in aquatic systems, as well as anthropogenic inputs such as polycyclic aromatic hydrocarbons (PAH) and optical brighteners. Here we will focus on the use of the Tryptophan and CDOM UviLux sensors across a variety of applications in both natural systems, such as rivers and leachate into groundwater, and engineered systems, including drinking water and waste water treatment. Recent work has focused on standardising the fluorescence output across the UviLux range of sensors, reporting data in quinine sulphate units (QSU), which enables the output from two different fluorometers to be directly compared both to each other, and to bench-top data. A key advantage of deploying multiple sensors is the ability to fingerprint the fluorescence, by providing, for example, a Tryptophan/CDOM ratio. From the data collected, the ratio of the different fluorescence regions has been shown to provide more robust in situ data and help identify true temporal variations and patterns across multiple applications and sampling locations.

  18. Antibacterial activity of aquatic gliding bacteria.

    Science.gov (United States)

    Sangnoi, Yutthapong; Anantapong, Theerasak; Kanjana-Opas, Akkharawit

    2016-01-01

    The study aimed to screen and isolate strains of freshwater aquatic gliding bacteria, and to investigate their antibacterial activity against seven common pathogenic bacteria. Submerged specimens were collected and isolated for aquatic gliding bacteria using four different isolation media (DW, MA, SAP2, and Vy/2). Gliding bacteria identification was performed by 16S rRNA gene sequencing and phylogenetic analysis. Crude extracts were obtained by methanol extraction. Antibacterial activity against seven pathogenic bacteria was examined by agar-well diffusion assay. Five strains of aquatic gliding bacteria including RPD001, RPD008, RPD018, RPD027 and RPD049 were isolated. Each submerged biofilm and plastic specimen provided two isolates of gliding bacteria, whereas plant debris gave only one isolate. Two strains of gliding bacteria were obtained from each DW and Vy/2 isolation medium, while one strain was obtained from the SAP2 medium. Gliding bacteria strains RPD001, RPD008 and RPD018 were identified as Flavobacterium anhuiense with 96, 82 and 96 % similarity, respectively. Strains RPD049 and RPD027 were identified as F. johnsoniae and Lysobacter brunescens, respectively, with similarity equal to 96 %. Only crude extract obtained from RPD001 inhibited growth of Listeria monocytogenes (MIC 150 µg/ml), Staphylococcus aureus (MIC 75 µg/ml) and Vibrio cholerae (MIC 300 µg/ml), but showed weak inhibitory effect on Salmonella typhimurium (MIC > 300 µg/ml). Gliding bacterium strain RPD008 should be considered to a novel genus separate from Flavobacterium due to its low similarity value. Crude extract produced by RPD001 showed potential for development as a broad antibiotic agent. PMID:26885469

  19. Antibiotics promote aggregation within aquatic bacterial communities.

    Science.gov (United States)

    Corno, Gianluca; Coci, Manuela; Giardina, Marco; Plechuk, Sonia; Campanile, Floriana; Stefani, Stefania

    2014-01-01

    The release of antibiotics (AB) into the environment poses several threats for human health due to potential development of AB-resistant natural bacteria. Even though the use of low-dose antibiotics has been promoted in health care and farming, significant amounts of AB are observed in aquatic environments. Knowledge on the impact of AB on natural bacterial communities is missing both in terms of spread and evolution of resistance mechanisms, and of modifications of community composition and productivity. New approaches are required to study the response of microbial communities rather than individual resistance genes. In this study a chemostat-based experiment with 4 coexisting bacterial strains has been performed to mimicking the response of a freshwater bacterial community to the presence of antibiotics in low and high doses. Bacterial abundance rapidly decreased by 75% in the presence of AB, independently of their concentration, and remained constant until the end of the experiment. The bacterial community was mainly dominated by Aeromonas hydrophila and Brevundimonas intermedia while the other two strains, Micrococcus luteus and Rhodococcus sp. never exceed 10%. Interestingly, the bacterial strains, which were isolated at the end of the experiment, were not AB-resistant, while reassembled communities composed of the 4 strains, isolated from treatments under AB stress, significantly raised their performance (growth rate, abundance) in the presence of AB compared to the communities reassembled with strains isolated from the treatment without AB. By investigating the phenotypic adaptations of the communities subjected to the different treatments, we found that the presence of AB significantly increased co-aggregation by 5-6 fold. These results represent the first observation of co-aggregation as a successful strategy of AB resistance based on phenotype in aquatic bacterial communities, and can represent a fundamental step in the understanding of the effects of AB

  20. Understanding Peer Effects in Financial Decisions

    OpenAIRE

    Bursztyn, Leonardo; Ederer, Florian; Ferman, Bruno; Yuchtman, Noam

    2012-01-01

    Using a high-stakes field experiment conducted in partnership with a large financial brokerage in Brazil, we attempt to disentangle channels through which a person's financial decisions affect his peers'. When someone purchases an asset, his peers may want to purchase it as well, both because they learn from his choice (“social learning") and because his possession of the asset affects others' utility of owning the same asset (“social utility"). We randomize whether one member of a peer pair ...