Random strings and tt-degrees of Turing complete C.E. sets

We investigate the truth-table degrees of (co-)c.e.\ sets, in particular, sets of random strings. It is known that the set of random strings with respect to any universal prefix-free machine is Turing complete, but that truth-table completeness depends on the choice of universal machine. We show that for such sets of random strings, any finite set of their truth-table degrees do not meet to the degree~0, even within the c.e. truth-table degrees, but when taking the meet over all such truth-table degrees, the infinite meet is indeed~0. The latter result proves a conjecture of Allender, Friedman and Gasarch. We also show that there are two Turing complete c.e. sets whose truth-table degrees form a minimal pair.Comment: 25 page

Carnivorous sponges (<i>Porifera, Demospongiae, Poecilosclerida, Cladorhizidae</i>) from the Drake Passage (Southern Ocean) with a description of eight new species and a review of the family <i>Cladorhizidae </i>in the Southern Ocean

This study reviews the taxonomy and biogeography of carnivorous sponges (family Cladorhizidae) in the Southern Ocean. Specimens were collected from seamounts in the Drake Passage by dredging and trawling and biogeographical information from other sources was compiled and reviewed. Eight new species of carnivorous sponges are described: Abyssocladia leverhulmei, sp. nov., Asbestopluma (Asbestopluma) sarsensis, sp. nov., A. (A.) gemmae, sp. nov., A. (A.) rhaphidiophorus, sp. nov., Asbestopluma (Helophloeina) keraia, sp. nov., Chondrocladia (Chondrocladia) saffronae, sp. nov., Cladorhiza scanlonae, sp. nov. and Lycopodina drakensis, sp. nov. Specimens of three previously described species, L. callithrix, L. calyx and A. (A.) bitrichela, were also found. These new records increase the number of known carnivorous sponge species in the Southern Ocean by more than a third. We demonstrate that the Cladorhizidae is the second most species-rich family of Demospongiae in the Southern Ocean and many of its species are highly endemic, with 70% found only in this region. Southern Ocean species represent close to 20% of all known carnivorous sponges. This study highlights the importance of seamount and bathyal benthic habitats for supporting the rich and endemic carnivorous sponge fauna of the Southern Ocean.</jats:p

Extreme phenotypic plasticity in metabolic physiology of Antarctic demosponges

Seasonal measurements of the metabolic physiology of four Antarctic demosponges and their associated assemblages, maintained in a flow through aquarium facility, demonstrated one of the largest differences in seasonal strategies between species and their associated sponge communities. The sponge oxygen consumption measured here exhibited both the lowest and highest seasonal changes for any Antarctic species; metabolic rates varied from a 25% decrease to a 5.8 fold increase from winter to summer, a range which was greater than all 17 Antarctic marine species (encompassing eight phyla) previously investigated and amongst the highest recorded for any marine environment. The differences in nitrogen excretion, metabolic substrate utilization and tissue composition between species were, overall, greater than seasonal changes. The largest seasonal difference in tissue composition was an increase in CHN (Carbon, Hydrogen, and Nitrogen) content in Homaxinella balfourensis, a pioneer species in ice-scour regions, which changed growth form to a twig-like morph in winter. The considerable flexibility in seasonal and metabolic physiology across the Demospongiae likely enables these species to respond to rapid environmental change such as ice-scour, reductions in sea ice cover and ice-shelf collapse in the Polar Regions, shifting the paradigm that polar sponges always live “life in the slow lane.” Great phenotypic plasticity in physiology has been linked to differences in symbiotic community composition, and this is likely to be a key factor in the global success of sponges in all marine environments and their dominant role in many climax communities

East Weddell Sea echinoids from the JR275 expedition

Information regarding the echinoids in this dataset is based on the Agassiz Trawl (AGT) and epibenthic sledge (EBS) samples collected during the British Antarctic Survey cruise JR275 on the RRS James Clark Ross in the austral summer 2012. A total of 56 (1 at the South Orkneys and 55 in the Eastern Weddell Sea) Agassiz Trawl and 18 (2 at the South Orkneys and 16 in the Eastern Weddell Sea) epibenthic sledge deployments were performed at depths ranging from ~280 to ~2060 m. This presents a unique collection for the Antarctic benthic biodiversity assessment of an important group of benthic invertebrates. In total 487 specimens belonging to six families, 15 genera, and 22 morphospecies were collected. The species richness per station varied between one and six. Total species richness represents 27% of the 82 echinoid species ever recorded in the Southern Ocean (David et al. 2005b, Pierrat et al. 2012, Saucède et al. 2014). The Cidaridae (sub-family Ctenocidarinae) and Schizasteridae are the two most speciose families in the dataset. They comprise seven and nine species respectively. This is illustrative of the overall pattern of echinoid diversity in the Southern Ocean where 65% of Antarctic species belong to the families Schizasteridae and Cidaridae (Pierrat et al. 2012)

Defund the Police: Moving Towards an Anti-Carceral Social Work

This paper addresses social work’s place in the movement to “defund the police.” We argue that social work’s collaboration with police and use of policing constitutes carceral social work. In defining carceral social work, we specify the ways in which coercive and punitive practices are used to manage Black, Indigenous, other people of color and poor communities across four social work arenas – gender-based violence, child welfare, schools, and health and mental health. To inform anti-carceral social work, we provide examples of interventions in these arenas that dismantle police collaborations and point to life-affirming, community-centered, and mutual aid alternatives

Incorporating mesopelagic fish into the evaluation of conservation areas for marine living resources under climate change scenarios

Mesopelagic fish (meso-fish) are central species within the Southern Ocean (SO). However, their ecosystem role and adaptive capacity to climate change are rarely integrated into marine protected area (MPAs) assessments. This is a pity given their importance as crucial prey and predators in food webs, coupled with the impacts of climate change. Here, we estimate the habitat distribution of nine meso-fish using an ensemble model approach (MAXENT, random forest, and boosted regression tree). Four climate model simulations were used to project their distribution under two representative concentration pathways (RCP4.5 and RCP8.5) for short-term (2006–2055) and long-term (2050–2099) periods. In addition, we assess the ecological representativeness of established and proposed MPAs under climate change scenarios using meso-fish as indicator species. Our models show that all species shift poleward in the future. Lanternfishes (family Myctophidae) are predicted to migrate poleward more than other families (Paralepididae, Nototheniidae, Bathylagidae, and Gonostomatidae). In comparison, lanternfishes were projected to increase habitat area in the eastern SO but lose area in the western SO; the opposite was projected for species in other families. Important areas (IAs) of meso-fish are mainly distributed near the Antarctic Peninsula and East Antarctica. Proposed MPAs cover 23% of IAs at present and 38% of IAs in the future (RCP8.5, long-term future). Many IAs of meso-fish still need to be included in MPA proposals, such as the Prydz Bay and the seas around the Antarctic Peninsula. Our results provide a framework for designing new MPAs incorporating climate change adaptation strategies for MPA management

PRELIMINARY CHECKLIST OF THE UNDERSEA FAUNA OF THE ROSS SEA ANTARCTIC CONTINENTAL SHELF BASED ON YO-YO CAMERA SURVEYS

As part of an expedition aboard the Nathaniel B. Palmer RVIB, hundreds of still images were captured of the Ross Sea continental shelf seafloor. Using a crowd-sourced group of experts, we identified the fauna captured in these images, identifying over 1000 organisms to 15 major taxonomic groups (viz., anemones, bivalves, brittle stars, cephalopods, corals, crinoids, crustaceans, fishes, holothurians, isopods, pycnogonids, sea urchins, sea stars, sponges, tunicates). On the basis of the organisms we could identify to genus or species, we compiled a checklist of the fauna from this poorly-known area. The images from this yo-yo camera survey show a diverse community of life that was largely unknown for this sector and may reveal expanded ranges for some species and potentially new ecological information.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/168230/1/UMMP_MP_209-2.pdfMain ArticleSEL

Introduction : media and illiberal democracy in Central and Eastern Europe

This introductory overview opens the series of articles included in the issue entitled Media and Illiberal Democracy in Central and Eastern Europe, and sets the scene for the debate on the relationship between illiberal trends in politics and media landscapes in the region. Drawing on existing scholarship, it traces the roots and the evolution of illiberalism, focusing the discussion within the confines of particularities of media landscapes. Through the introduction of articles addressing manifestations of illiberalism in media landscapes, it argues that “illiberal turn” in Central and Eastern Europe is part of a global political shift, rather than a regional one

MNI and Sex Estimation in Two Umm an-Nar Tombs from the UAE

Commingled tombs are often overlooked in bioarchaeological studies because of the difficult nature of analysis, despite their prevalence across the ancient world. Tombs Unar 1 (U1) and Unar 2 (U2), located in the United Arab Emirates, date to the Umm an-Nar period (2700-2000 BCE), when people witnessed shifts in mortuary practices likely reflective of broader changes in subsistence and social organization. A collaborative project that trains undergraduates in anthropological research has examined tomb membership for U1 and U2 by estimating MNI and sex. Despite early descriptions of U1 and U2 holding similar numbers of individuals, this project found that MNI was greater in U2 when counting non-duplicating elements from the talus (U1: 88; U2: 228), mandible (U1: 101; U2: 290), and petrous portion of the temporal (U1: 190; U2: 403) whether using landmark or zonation methods. Metric analyses of the humerus found a relatively similar proportion of males and females in each tomb (X2=0.06, df=1, p=0.81). While an assessment of the lateral angle of the internal auditory meatus and the mastoid process found greater numbers of women entombed in both tombs, there was no difference in sex distribution between the tombs (Fisher’s exact: p\u3e0.05 for both techniques). These results suggest that U2 was open to the interment of a larger number of individuals; however, while different sex estimation methods produced similar sex distributions between the tombs, the methods themselves varied considerably in estimating overall frequencies of males and females. Future research using additional sex estimation techniques is warranted.https://jagworks.southalabama.edu/present_yr1/1005/thumbnail.jp