Is the middle Cambrian a hexactinellid sponge, trace fossil or pseudofossil?

First described as a medusoid jellyfish, the "star-shaped" from the Conasauga shale Lagerstätten, Southeastern USA, was variously reconsidered as algae, feeding traces, gas bubbles, and most recently hexactinellid sponges. In this work, we present new morphological, chemical, and structural data to evaluate its hexactinellid affinities, as well as whether it could be a trace fossil or pseudofossil. External and cross-sectional surfaces, thin sections, X-ray computed tomography (CT) and micro-CT imaging, revealed no evidence that is a hexactinellid sponge or a trace fossil.

Population Dynamics and Parasite Load of a Foraminifer on Its Antarctic Scallop Host with Their Carbonate Biomass Contributions.

We studied the population dynamics and parasite load of the foraminifer Cibicides antarcticus on its host the Antarctic scallop Adamussium colbecki from three localities differing by sea ice cover within western McMurdo Sound, Ross Sea, Antarctica: Explorers Cove, Bay of Sails and Herbertson Glacier. We also estimated CaCO3 biomass and annual production for both species. Cibicides populations varied by locality, valve type, and depth.

Pan-Arctic distributions of continental runoff in the Arctic Ocean.

Continental runoff is a major source of freshwater, nutrients and terrigenous material to the Arctic Ocean. As such, it influences water column stratification, light attenuation, surface heating, gas exchange, biological productivity and carbon sequestration. Increasing river discharge and thawing permafrost suggest that the impacts of continental runoff on these processes are changing.

Root resorption during orthodontic treatment.

Data Sources: Medline, Embase, LILACS, The Cochrane Library (Cochrane Database of Systematic Reviews, CENTRAL, and Cochrane Oral Health Group Trials Register) Web of Science, EBM Reviews, Computer Retrieval of Information on Scientific Project (CRISP, www.crisp.cit.

Abnormal tooth size and morphology in subjects with cleft lip and/or palate in the north of England.

The aim of this study was to investigate tooth size and morphology in subjects with unilateral cleft palate (UCLP), bilateral cleft palate (BCLP), and isolated cleft palate (ICP) living in the north of England and to compare these with a control group. The measurements were undertaken retrospectively using dental study casts. To assess tooth size, the mesiodistal and buccolingual dimensions of each fully erupted permanent tooth were measured using digital Vernier callipers.

National threatened species listing based on IUCN criteria and regional guidelines: current status and future perspectives.

As countries worldwide become increasingly interested in conserving biodiversity, the profile of national threatened species lists expands and these lists become more influential in determining conservation priorities. The World Conservation Union (IUCN) Categories and Criteria for evaluating extinction risk, originally intended for use at the global level, are increasingly being used at the national level. To facilitate this process, the IUCN recently published guidelines for the application of the criteria at subglobal levels.