The first comprehensive description of the biodiversity and biogeography of Antarctic and Sub-Antarctic intertidal communities

Aim To describe the distribution of biodiversity and biogeographical patterns of intertidal organisms in southern temperate and polar waters. We hypothesized that there would be differences in community structure between the Antarctic, which is most affected by ice, and the sub-Antarctic and other neighbouring regions. We also hypothesized that rafting and West Wind Drift will be the significant drivers of biogeographical patterns. Additionally, the size, age, isolation, volcanic or glacial history of a region and the presence of large, beach dwelling, mammals and birds would all play a role in determining the level of biodiversity observed. Location South Atlantic, Indian and Pacific Oceans and the Southern Ocean. Methods We examined all available intertidal records from the Antarctic and sub-Antarctic with additional data from neighbouring regions for comparison and context. We compiled 3902 occurrences of 1416 species of high southern latitude intertidal organisms from 229 locations and used PRIMER 6 to perform multivariate statistical analyses. Results The Antarctic and sub-Antarctic are shown to be distinct biogeographical regions, with patterns driven by a small number of widely distributed species. These wide-ranging molluscs and macroalgae dominate the biogeographical structure of the Southern Ocean intertidal, most likely as a result of rafting in the Antarctic Circumpolar Current. East Antarctic intertidal habitats are potentially isolated by the Ross and Weddell Sea ice shelves but represent a great unknown in this biogeographical scheme. Main Conclusions The view that the Antarctic intertidal is a lifeless desert does not hold true, with Antarctic Peninsula intertidal communities being richer and more diverse than those in southern South America and the sub-Antarctic islands. Changing conditions in the Antarctic and sub-Antarctic intertidal mean that a representative baseline is needed (acquired through standardized and quantitative sampling) to assess future changes and to detect any invasive species

Variations of Hodge Structure Considered as an Exterior Differential System: Old and New Results

This paper is a survey of the subject of variations of Hodge structure (VHS) considered as exterior differential systems (EDS). We review developments over the last twenty-six years, with an emphasis on some key examples. In the penultimate section we present some new results on the characteristic cohomology of a homogeneous Pfaffian system. In the last section we discuss how the integrability conditions of an EDS affect the expected dimension of an integral submanifold. The paper ends with some speculation on EDS and Hodge conjecture for Calabi-Yau manifolds

Whole body vibration training and its application to age-related performance decrements:an exploratory analysis

Middle age is associated with a pronounced decline in power and flexibility. Whilst whole body vibration training (WBVT) improves performance in a range of populations, whether WBVT can improve muscle power and flexibility in a middle-aged population is not known. The present study aimed to determine the influence of 5 weeks progressive WBVT in middle-aged (45-55 yrs.) and younger (20-30 yrs.) recreationally active females. Participants in each age group were randomly allocated to an intervention (WBVT) or control group. The WBVT groups trained for five weeks on a vibration platform, while the control groups performed identical exercises, with no vibration. Prior to, and after, the five-week study vertical countermovement jump (VCMJ) and range of motion (ROM) performance were measured. WBVT significantly (P = 0.001) improved VCMJ performance when compared to the control groups. This improvement was significantly (P = 0.001) greater in the middle-aged compared with the younger WBVT group. WBVT significantly (P = 0.001) improved ROM irrespective of age. Taken together, these results suggest that WBVT can off-set age related performance decrements, which has therapeutic implications for musculoskeletal aging. Therefore, WBVT could be undertaken to minimise age-related performance deterioration in middle-aged female populations

Comment on ``Consistent Sets Yield Contrary Inferences in Quantum Theory''

In a recent paper Kent has pointed out that in consistent histories quantum theory it is possible, given initial and final states, to construct two different consistent families of histories, in each of which there is a proposition that can be inferred with probability one, and such that the projectors representing these two propositions are mutually orthogonal. In this note we stress that, according to the rules of consistent history reasoning two such propositions are not contrary in the usual logical sense namely, that one can infer that if one is true then the other is false, and both could be false. No single consistent family contains both propositions, together with the initial and final states, and hence the propositions cannot be logically compared. Consistent histories quantum theory is logically consistent, consistent with experiment as far as is known, consistent with the usual quantum predictions for measurements, and applicable to the most general physical systems. It may not be the only theory with these properties, but in our opinion, it is the most promising among present possibilities.Comment: 2pages, uses REVTEX 3.

Brain evolution in bats (Mammalia, Chiroptera): auditory, Olfactory and Sensorimotor systems

Data for brain structure volumes was analysed using multiple regression to test for correlated volumetric evolution in bats (Mammalia, Chiroptera). Significant partial correlations were found between major brain subdivisions, and between structures within the Auditory, Olfactory and Sensonmotor Systems that were predicted to have evolved together on the basis of anatomical connectivity and known functional relationships. Results were clearest in the auditory and sensorimotor systems and weakest for the olfactory system which included many limbic structures. Megachiroptera and microchiroptera were analysed separately; there was good general agreement between the patterns of correlated evolution in both of these clades. When compared to previous studies of con elated volumetric evolution in Insectivores and Primates, it was found that the pattern of correlations found in bats showed features that are unique to the order. These results strongly suggest that brain evolution in bats has proceeded in a mosaic fashion with individual functional systems being the targets of selection

Zoogeographic and Richness Patterns in Southern Ocean Benthos

This thesis describes the large scale biogeographic patterns found in the Southern Ocean benthos. Using SOMBASE and SCAR-MarBIN, the two most comprehensive, georeferenced databases of Antarctic marine biodiversity ever compiled, a range of taxa were investigated but focusing on the Mollusca, Bryozoa and Pycnogonida. Over 8,000 species of marine invertebrates from over 5,000 sites constituting -34,000 records were used in the analyses. The strong faunal links between the Antarctic and South America were confirmed but I found little evidence for a biogeographical relationship between the Antarctic or South America and New Zealand or Tasmania. Regional levels of Southern Ocean endemism proved the influence of the Antarctic Circumpolar Current upon the distribution of Southern Ocean benthos. My study shows the Southern Ocean as a ‘single functional unit’ with no evidence for an earlier proposed biogeographical split between East and West Antarctica. Some general rules on Antarctic benthic biogeography are viable, including species endemism rates of around 50% and a definite distinction between the sub-Antarctic islands influenced by either South America or by New Zealand. In the context of potential shifts in species distribution with climate change I investigated the current ranges of selected Southern Ocean taxa (Mollusca, Amphipoda, Ophiuroidea and Hexacorala), and looked for hotspots of coinciding northern and southern geographic range limits. Southern Patagonia, South Georgia and Kerguelen had the greatest range-limit hotspots. Monitoring range shifts in these key places and taxa will enable us to track the influence and effects of climate change on benthic species distributions in the Southern Ocean