887 research outputs found

    Callisto: a cryptographic approach to detecting serial perpetrators of sexual misconduct

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    Sexual misconduct is prevalent in workplace and education settings but stigma and risk of further damage deter many victims from seeking justice. Callisto, a non-profit that has created an online sexual assault reporting platform for college campuses, is expanding its work to combat sexual assault and harassment in other industries. In this new product, users will be invited to an online "matching escrow" that will detect repeat perpetrators and create pathways to support for victims. Users submit encrypted data about their perpetrator, and this data can only be decrypted by the Callisto Options Counselor (a lawyer), when another user enters the identity of the same perpetrator. If the perpetrator identities match, both users will be put in touch independently with the Options Counselor, who will connect them to each other (if appropriate) and help them determine their best path towards justice. The client relationships with the Options Counselors are structured so that any client-counselor communications would be privileged. A combination of client-side encryption, encrypted communication channels, oblivious pseudo-random functions, key federation, and Shamir Secret Sharing keep data confidential in transit, at rest, and during the matching process with the guarantee that only the lawyer ever has access to user submitted data, and even then only when a match is identified.Accepted manuscrip

    Effects of an experimental resource pulse on the macrofaunal assemblage inhabiting seagrass macrophytodetritus

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    Physical disturbances and resource pulses are major structuring drivers of terrestrial and aquatic ecosystems. The accumulations of exported dead leaves from the Neptune grass, Posidonia oceanica (L.) Delile are ephemeral and highly dynamic detrital habitats offering food sources and shelter for vagile macrofauna community. These habitats are frequently subject to wind and storms which can add “new” detrital material to previous accumulations; these can be defined as resource pulses and could potentially impact the associated macrofauna. This study assesses the impact of an experimental resource pulse on the macrofauna associated with exported P. oceanica litter accumulations. The experimental design consisted of two pulse treatments (the addition of dead leaves with and without the associated fauna), and two controls (one procedural, and one total control), where the added material was left underwater for 14 days. Invertebrates then present in the sampled detritus were all identified and counted. Our data suggest that the responses of these invertebrates to resource pulses present intermediate characteristics between aquatic and terrestrial ecosystems responses. Inputting a moderate amount of dead P. oceanica leaves into experimental mesocosms had a non-negligible impact and rapidly affected the macrofauna community. Specialist detritivores species were boosted while herbivore/detritivore species dramatically decreased. Predators also showed a modest but significant density increase, demonstrating the fast propagation of the pulse response throughout the entire community and through several trophic levels. Strict hypoxia-tolerant species were also only observed in the treated mesocosms, indicating the strong influence of resource pulses on physico-chemical conditions occurring inside litter accumulations

    Tropicalization of seagrass macrophytodetritus accumulations and associated food webs

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    Seagrass, systems export significant amounts of their primary production as large detritus (i.e. macrophytodetritus). Accumulations of exported macrophytodetritus (AEM) are found in many areas in coastal environment. Dead seagrass leaves are often a dominant component of these accumulations, offering shelter and/or food to numerous organisms. AEM are particular habitats, different from donor habitats (i.e. seagrass meadow, kelp or macroalgae habitats) and with their own characteristics and dynamics. They have received less attention than donor habitats despite the fact they often connect different coastal habitats, are the place of intense remineralization processes and shelter associated detritus food web. As for seagrass meadows themselves, AEM are potentially affected by global change and by tropicalization processes. Here, we review briefly general characteristic of AEM with a focus on Mediterranean Sea and Western Australia and we provide some hypotheses concerning their tropicalization in a near future. We conclude that AEM functioning could change either through: (1) declines in biomass or loss of seagrass directly due to increased ocean temperatures or increased herbivory from tropicalized herbivores; (2) increased degradation and processing of seagrass detritus within seagrass meadows leading to reduced export; (3) replacement of large temperate seagrass species with smaller tropical seagrass species; and/or (4) loss or changes to macroalgae species in neighboring habitats that export detritus. These processes will alter the amount, composition, quality, timing and frequency of inputs of detritus into ecosystems that rely on AEM as trophic subsidies, which will alter the suitability of AEM as habitat and food for invertebrates

    Epiphytic bryozoans on Neptune grass – a sample-based data set

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    peer reviewedBackground The seagrass Posidonia oceanica L. Delile, commonly known as Neptune grass, is an endemic species of the Mediterranean Sea. It hosts a distinctive and diverse epiphytic community, dominated by various macroalgal and animal organisms. Mediterranean bryozoans have been extensively studied but quantitative data assessing temporal and spatial variability have rarely been documented. In Lepoint et al. (2014a, b) occurrence and abundance data of epiphytic bryozoan communities on leaves of P. oceanica inhabiting the Revellata Bay (Corsica, Mediterranean Sea) were reported and trophic ecology of Electra posidoniae Gautier assessed. New information Here, we provide metadata information on data set discussed in Lepoint et al. 2014a and published on the GBIF portal as a sampling-event data set: http://ipt.biodiversity.be/resource?r=ulg_bryozoa&v=1.0). The data set, compared to Lepoint et al. 2014a, is enriched by data concerning species settled on Posidonia scales (dead petiole of Posidonia leaves, remaining after limb abscission)
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