Circumpolar habitat use in the southern elephant seal : implications for foraging success and population trajectories

In the Southern Ocean, wide-ranging predators offer the opportunity to quantify how animals respond to differences in the environment because their behavior and population trends are an integrated signal of prevailing conditions within multiple marine habitats. Southern elephant seals in particular, can provide useful insights due to their circumpolar distribution, their long and distant migrations and their performance of extended bouts of deep diving. Furthermore, across their range, elephant seal populations have very different population trends. In this study, we present a data set from the International Polar Year project; Marine Mammals Exploring the Oceans Pole to Pole for southern elephant seals, in which a large number of instruments (N = 287) deployed on animals, encompassing a broad circum-Antarctic geographic extent, collected in situ ocean data and at-sea foraging metrics that explicitly link foraging behavior and habitat structure in time and space. Broadly speaking, the seals foraged in two habitats, the relatively shallow waters of the Antarctic continental shelf and the Kerguelen Plateau and deep open water regions. Animals of both sexes were more likely to exhibit area-restricted search (ARS) behavior rather than transit in shelf habitats. While Antarctic shelf waters can be regarded as prime habitat for both sexes, female seals tend to move northwards with the advance of sea ice in the late autumn or early winter. The water masses used by the seals also influenced their behavioral mode, with female ARS behavior being most likely in modified Circumpolar Deepwater or northerly Modified Shelf Water, both of which tend to be associated with the outer reaches of the Antarctic Continental Shelf. The combined effects of (1) the differing habitat quality, (2) differing responses to encroaching ice as the winter progresses among colonies, (3) differing distances between breeding and haul-out sites and high quality habitats, and (4) differing long-term regional trends in sea ice extent can explain the differing population trends observed among elephant seal colonies.Publisher PDFPeer reviewe

Colloquium: Mechanical formalisms for tissue dynamics

The understanding of morphogenesis in living organisms has been renewed by tremendous progressin experimental techniques that provide access to cell-scale, quantitative information both on theshapes of cells within tissues and on the genes being expressed. This information suggests that ourunderstanding of the respective contributions of gene expression and mechanics, and of their crucialentanglement, will soon leap forward. Biomechanics increasingly benefits from models, which assistthe design and interpretation of experiments, point out the main ingredients and assumptions, andultimately lead to predictions. The newly accessible local information thus calls for a reflectionon how to select suitable classes of mechanical models. We review both mechanical ingredientssuggested by the current knowledge of tissue behaviour, and modelling methods that can helpgenerate a rheological diagram or a constitutive equation. We distinguish cell scale ("intra-cell")and tissue scale ("inter-cell") contributions. We recall the mathematical framework developpedfor continuum materials and explain how to transform a constitutive equation into a set of partialdifferential equations amenable to numerical resolution. We show that when plastic behaviour isrelevant, the dissipation function formalism appears appropriate to generate constitutive equations;its variational nature facilitates numerical implementation, and we discuss adaptations needed in thecase of large deformations. The present article gathers theoretical methods that can readily enhancethe significance of the data to be extracted from recent or future high throughput biomechanicalexperiments.Comment: 33 pages, 20 figures. This version (26 Sept. 2015) contains a few corrections to the published version, all in Appendix D.2 devoted to large deformation

Impact of the climatic changes in the Pliocene-Pleistocene transition on Irano-Turanian species. The radiation of genus Jurinea (Compositae)

Altres ajuts: acords transformatius de la UABThe Irano-Turanian region is one of the world's richest floristic regions and the centre of diversity for numerous xerophytic plant lineages. However, we still have limited knowledge on the timing of evolution and biogeographic history of its flora, and potential drivers of diversification remain underexplored. To fill this knowledge gap, we focus on the Eurasian genus Jurinea (ca. 200 species), one of the largest plant radiations that diversified in the region. We applied a macroevolutionary integrative approach to explicitly test diversification hypotheses and investigate the relative roles of geography vs. ecology and niche conservatism vs. niche lability in speciation processes. To do so, we gathered a sample comprising 77% of total genus richness and obtained data about (1) its phylogenetic history, recovering 502 nuclear loci sequences; (2) growth forms; (3) ecological niche, compiling data of 21 variables for more than 2500 occurrences; and (4) paleoclimatic conditions, to estimate climatic stability. Our results revealed that climate was a key factor in the evolutionary dynamics of Jurinea. The main diversification and biogeographic events that occurred during past climate changes, which led to colder and drier conditions, are the following: (1) the origin of the genus (10.7 Ma); (2) long-distance dispersals from the Iranian Plateau to adjacent regions (∼7-4 Ma); and (3) the diversification shift during Pliocene-Pleistocene Transition (ca. 3 Ma), when net diversification rate almost doubled. Our results supported the pre-adaptation hypothesis, i.e., the evolutionary success of Jurinea was linked to the retention of the ancestral niche adapted to aridity. Interestingly, the paleoclimatic analyses revealed that in the Iranian Plateau long-term climatic stability favoured old-lineage persistence, resulting in current high species richness of semi-arid and cold adapted clades; whereas moderate climate oscillations stimulated allopatric diversification in the lineages distributed in the Circumboreal region. In contrast, growth form lability and high niche disparity among closely related species in the Central Asian clade suggest adaptive radiation to mountain habitats. In sum, the radiation of Jurinea is the result of both adaptive and non-adaptive processes influenced by climatic, orogenic and ecological factors

Body Matters:Exploration of the Human Body as a Resource for the Design of Technologies for Meditation

Much research on meditation has shown its significant benefits for wellbeing. In turn, there has been growing HCI interest for the design of novel interactive technologies intended to facilitate meditation in real-time. In many of these systems, physiological signals have been mapped onto creative audiovisual feedback, however, there has been limited attention to the experiential qualities of meditation and the specific role that the body may play in them. In this paper, we report on workshops with 24 experts exploring the bodily sensations that emerge during meditation. Through material speculation, participants shared their lived experience of meditation and identified key stages during which they may benefit from additional aid, often multimodal. Findings emphasize the importance of recreating mindful physical sensations during moments of mind-wandering; in particular for supporting the regulation of attention through a range of embodied metaphors and haptic feedback, tailored to key transitions in the meditation process

Anthropogenic Space Weather

Anthropogenic effects on the space environment started in the late 19th century and reached their peak in the 1960s when high-altitude nuclear explosions were carried out by the USA and the Soviet Union. These explosions created artificial radiation belts near Earth that resulted in major damages to several satellites. Another, unexpected impact of the high-altitude nuclear tests was the electromagnetic pulse (EMP) that can have devastating effects over a large geographic area (as large as the continental United States). Other anthropogenic impacts on the space environment include chemical release ex- periments, high-frequency wave heating of the ionosphere and the interaction of VLF waves with the radiation belts. This paper reviews the fundamental physical process behind these phenomena and discusses the observations of their impacts.Comment: 71 pages, 35 figure

Resolving the Evolutionary History of Campanula (Campanulaceae) in Western North America

Recent phylogenetic works have begun to address long-standing questions regarding the systematics of Campanula (Campanulaceae). Yet, aspects of the evolutionary history, particularly in northwestern North America, remain unresolved. Thus, our primary goal in this study was to infer the phylogenetic positions of northwestern Campanula species within the greater Campanuloideae tree. We combined new sequence data from 5 markers (atpB, rbcL, matK, and trnL-F regions of the chloroplast and the nuclear ITS) representing 12 species of Campanula with previously published datasets for worldwide campanuloids, allowing us to include approximately 75% of North American Campanuleae in a phylogenetic analysis of the Campanuloideae. Because all but one of North American Campanula species are nested within a single campanuloid subclade (the Rapunculus clade), we conducted a separate set of analyses focused specifically on this group. Our findings show that i) the campanuloids have colonized North America at least 6 times, 4 of which led to radiations, ii) all but one North American campanuloid are nested within the Rapunculus clade, iii) in northwestern North America, a C. piperi – C. lasiocarpa ancestor gave rise to a monophyletic Cordilleran clade that is sister to a clade containing C. rotundifolia, iv) within the Cordilleran clade, C. parryi var. parryi and C. parryi var. idahoensis exhibit a deep, species-level genetic divergence, and v) C. rotundifolia is genetically diverse across its range and polyphyletic. Potential causes of diversification and endemism in northwestern North America are discussed

Use of satellite observations for operational oceanography: recent achievements and future prospects

The paper gives an overview of the development of satellite oceanography over the past five years focusing on the most relevant issues for operational oceanography. Satellites provide key essential variables to constrain ocean models and/or serve downstream applications. New and improved satellite data sets have been developed and have directly improved the quality of operational products. The status of the satellite constellation for the last five years was, however, not optimal. Review of future missions shows clear progress and new research and development missions with a potentially large impact for operational oceanography should be demonstrated. Improvement of data assimilation techniques and developing synergetic use of high resolution satellite observations are important future priorities

Flows of granular material in two-dimensional channels

Secondary cone-type crushing machines are an important part of the aggregate production process. These devices process roughly crushed material into aggregate of greater consistency and homogeneity. We apply a continuum model for granular materials (`A Constitutive Law For Dense Granular Flows', Nature 441, p727-730, 2006) to flows of granular material in representative two-dimensional channels, applying a cyclic applied crushing stress in lieu of a moving boundary. Using finite element methods we solve a sequence of quasi-steady fluid problems within the framework of a pressure dependent particle size problem in time. Upon approximating output quantity and particle size we adjust the frequency and strength of the crushing stroke to assess their impact on the output

When diving animals help us to observe the oceans: the MEOP data portal

Seals help gather information on some of the harshest environments on the planet, through the use of miniaturized ocean sensors glued on their fur. The resulting data – gathered from remote, icy seas over the last decade – are now freely available to scientists around the world from the data portal http://www.meop.net. The Polar oceans are changing rapidly as a result of global warming. Ice caps in Antarctica and Greenland are melting, releasing large quantities of freshwater into surface waters. The winter sea ice cover is receding in the Arctic and in large areas of the Southern Ocean, which promotes further warming. Southern winds are intensifying for reasons that are not fully understood. To understand the changing marine environment, it is necessary to have a comprehensive network of oceanographic measurements. Yet, until recently, the harsh climate and remoteness of these areas make them extremely difficult to observe. Diving marine animals equipped with sensors are now increasingly filling in the gaps. When diving animals help us to observe the oceans Since 2004, hundreds of diving marine animals, mainly Antarctic and Arctic seals, were fitted with a new generation of Argos tags developed by the Sea Mammal Research Unit of the University of St. Andrews in Scotland (Fig. 1). These tags can be used to investigate simultaneously the at-sea ecology (displacement, behaviour, dives, foraging success...) of these animals while collecting valuable oceanographic data (Boehme et al. 2009). Some of these species are travelling thousands of kilometres continuously diving to great depths (590 ± 200 m, with maxima around 2000m). The overall objective of most marine animal studies is to assess how their foraging behavior responds to oceanographic changes and how it affects their ability to aquire the resources they need to survive. But in the last decade, these animals have become an essential source of temperature and salinity profiles, especially for the polar oceans. For example, elephant seals and Weddell seals have contributed 98 % of the existing temperature and salinity profiles within the Southern Ocean pack ice. The sensors are non-invasive (attached to the animal’s fur, they naturally fall off when the animal moults) and the only devices of their kind that can be attached to animals. MEOP: an international data portal for ocean data collected by marine animals The international consortium MEOP (Marine mammals Exploring the Ocean Pole-to-pole), originally formed during the International Polar Year in 2008-2009, aims to coordinate at the global scale animal tag deployments, oceanographic data processing and data distribution. The MEOP consortium includes participants from 12 countries (Australia, Brazil, Canada, China, United Kingdom, United States, France, Germany, Greenland, Norway, South Africa and Sweden). The MEOP consortium is associated with GOOS (Global Ocean Observing System), POGO (Partnership for Observation of the Global Oceans), and SOOS (Southern Ocean Observing System). At the European level, the European Animal-Borne Instrument (ABI) EuroGOOS Task Team is about to be launched to facilitate and promote the use of animal-borne instruments. Over 300,000 oceanographic profiles (i.e. representing 1/3 of the total number of Argo profiles) collected by marine biologists have already been made freely available to the international community through the MEOP data portal (Fig. 2). This so-called MEOP-CTD database is a significant contribution to the observation of the world ocean that can be used to conduct regional Polar studies. The MEOP-CTD database of animal-derived temperature and salinity profiles An increasing number of studies now show the importance of these remote and inaccessible parts of the ocean, which are so difficult to observe. For example, more than 90% of extra heat in the Earth system is now stored in the oceans and the Southern Ocean in particular is a key site for understanding the uptake of heat and carbon. MEOP provides several thousand oceanographic profiles per year helping us to close gaps in our understanding of the climate system. Instrumented animals complement efficiently other existing observing systems, such as Argo buoys, providing data in sea-ice covered areas and on high-latitude continental shelves. Recent published work (Roquet et al. 2013; Roquet et al. 2014) has shown how important such observations are in predicting ice cover and mixed layer depth in large parts of the oceans where the observations were made. The inclusion of these data should improve significantly the quality of the projections provided by ocean-climate models. All these data are now available into a format file (Argo standard format) easily usable by oceanographers and accessible via the MEOP portal where it can be freely and easily downloaded by users (national data centers, researchers...) with a guaranteed quality level. This database is updated on an annual basis, and it has already been integrated into major oceanographic data centres including NODC, BODC and Coriolis. Figures Figure 1: Weddell seal carrying a SRDL-CTD instrument that collects temperature and salinity profiles while the animal is at sea (Credits: D. Costa). Figure 2: Distribution of hydrographic data in the MEOPCTD database for the Southern Ocean sector (source: meop.net). References Boehme, L. et al., 2009. Technical Note: Animal-borne CTD-Satellite Relay Data Loggers for real-time oceanographic data collection. Ocean Science, 5:685-695. Roquet F. et al., 2013. Estimates of the Southern Ocean General Circulation Improved by Animal-Borne Instruments. Geoph. Res. Letts., 40:1-5. doi: 10.1002/2013GL058304 Roquet F. et al., 2014. A Southern Indian Ocean database of hydrographic profiles obtained with instrumented elephant seals. Nature Scientific Data, 1:140028, doi: 10.1038/sdata.2014.2

An ensemble of eddy-permitting global ocean reanalyses from the MyOcean project

A set of four eddy-permitting global ocean reanalyses produced in the framework of the MyOcean project have been compared over the altimetry period 1993–2011. The main differences among the reanalyses used here come from the data assimilation scheme implemented to control the ocean state by inserting reprocessed observations of sea surface temperature (SST), in situ temperature and salinity profiles, sea level anomaly and sea-ice concentration. A first objective of this work includes assessing the interannual variability and trends for a series of parameters, usually considered in the community as essential ocean variables: SST, sea surface salinity, temperature and salinity averaged over meaningful layers of the water column, sea level, transports across pre-defined sections, and sea ice parameters. The eddy-permitting nature of the global reanalyses allows also to estimate eddy kinetic energy. The results show that in general there is a good consistency between the different reanalyses. An intercomparison against experiments without data assimilation was done during the MyOcean project and we conclude that data assimilation is crucial for correctly simulating some quantities such as regional trends of sea level as well as the eddy kinetic energy. A second objective is to show that the ensemble mean of reanalyses can be evaluated as one single system regarding its reliability in reproducing the climate signals, where both variability and uncertainties are assessed through the ensemble spread and signal-to-noise ratio. The main advantage of having access to several reanalyses differing in the way data assimilation is performed is that it becomes possible to assess part of the total uncertainty. Given the fact that we use very similar ocean models and atmospheric forcing, we can conclude that the spread of the ensemble of reanalyses is mainly representative of our ability to gauge uncertainty in the assimilation methods. This uncertainty changes a lot from one ocean parameter to another, especially in global indices. However, despite several caveats in the design of the multi-system ensemble, the main conclusion from this study is that an eddy-permitting multi-system ensemble approach has become mature and our results provide a first step towards a systematic comparison of eddy-permitting global ocean reanalyses aimed at providing robust conclusions on the recent evolution of the oceanic state