Bycatch in longline fisheries is believed to govern the adverse conservation status of many seabird species, but no comprehensive global assessment has been undertaken. We reviewed the extent of ...seabird bycatch in all longline fisheries for which data are available. Despite the many inadequacies and assumptions contained therein, we estimated that at least 160 000 (and potentially in excess of 320 000) seabirds are killed annually. Most frequently caught are albatrosses, petrels and shearwaters, with current levels of mortality liable to be unsustainable for some species and populations. Where realistic comparisons can be made, with data from the 1990s, there is evidence of substantially reduced bycatch in some key fisheries. Reductions stem from decreased fishing effort (especially in illegal, unreported and unregulated fishing in the Southern Ocean), and greater and more effective use of technical mitigation measures, notably in demersal fisheries. However, bycatch problems in other fisheries have also emerged. Current concerns include those with previously unidentified bycatch problems (e.g. Spanish Gran Sol demersal fleet) and those where bycatch was identified, but where persistent data gaps prevented adequate assessments of the scale of the impact (e.g. Nordic demersal fisheries). Future assessments will only achieve greater precision when minimum standards of data collection, reporting and analysis are implemented by longline fishing fleets and the relevant regional fishery management organisations. Those fisheries in which bycatch has been substantially reduced demonstrate that the problem of seabird bycatch could be reduced to negligible proportions by enforced implementation of appropriate best-practice mitigation devices and techniques.
A fundamental assumption in bioacoustics is that large animals tend to produce vocalizations with lower frequencies than small animals. This inverse relationship between body size and vocalization ...frequencies is widely considered to be foundational in animal communication, with prominent theories arguing that it played a critical role in the evolution of vocal communication, in both production and perception. A major shortcoming of these theories is that they lack a solid empirical foundation: rigorous comparisons between body size and vocalization frequencies remain scarce, particularly among mammals. We address this issue here in a study of body size and vocalization frequencies conducted across 91 mammalian species, covering most of the size range in the orders Primates (n = 50; ~0.11-120 Kg) and Carnivora (n = 41; ~0.14-250 Kg). We employed a novel procedure designed to capture spectral variability and standardize frequency measurement of vocalization data across species. The results unequivocally demonstrate strong inverse relationships between body size and vocalization frequencies in primates and carnivores, filling a long-standing gap in mammalian bioacoustics and providing an empirical foundation for theories on the adaptive function of call frequency in animal communication.
Metacognitive Evaluation in the Avoidance of Demand Dunn, Timothy L; Lutes, David J. C; Risko, Evan F
Journal of experimental psychology. Human perception and performance,
09/2016, Volume:
42, Issue:
9
Journal Article
Peer reviewed
In the current set of experiments our goal was to test the hypothesis that individuals avoid courses of action based on a kind of metacognitive evaluation of demand in a Demand Selection Task (DST). ...Individuals in Experiment 1 completed a DST utilizing visual stimuli known to yield a dissociation between performance and perceived demand. Patterns of demand avoidance followed that of perceived demand. Experiment 2 provided a replication of the aforementioned results, in addition to demonstrating a second dissociation between a peripheral physiological measure of demand (i.e., blink rates) and demand avoidance. Experiment 3 directly tested the assumption that individuals make use of a general metacognitive evaluation of task demand during selections. A DST was utilized in a forced-choice paradigm that required individuals to either select the most effortful, time demanding, or least accurate of 2 choices. Patterns of selections were similar across all rating dimensions, lending credit to this notion. Findings are discussed within a metacognitive framework of demand avoidance and contrasted to current theories.
Ediacaran developmental biology Dunn, Frances S.; Liu, Alexander G.; Donoghue, Philip C. J.
Biological reviews of the Cambridge Philosophical Society,
20/May , Volume:
93, Issue:
2
Journal Article
Peer reviewed
Open access
ABSTRACT
Rocks of the Ediacaran System (635–541 Ma) preserve fossil evidence of some of the earliest complex macroscopic organisms, many of which have been interpreted as animals. However, the ...unusual morphologies of some of these organisms have made it difficult to resolve their biological relationships to modern metazoan groups. Alternative competing phylogenetic interpretations have been proposed for Ediacaran taxa, including algae, fungi, lichens, rhizoid protists, and even an extinct higher‐order group (Vendobionta). If a metazoan affinity can be demonstrated for these organisms, as advocated by many researchers, they could prove informative in debates concerning the evolution of the metazoan body axis, the making and breaking of axial symmetries, and the appearance of a metameric body plan. Attempts to decipher members of the enigmatic Ediacaran macrobiota have largely involved study of morphology: comparative analysis of their developmental phases has received little attention. Here we present what is known of ontogeny across the three iconic Ediacaran taxa Charnia masoni, Dickinsonia costata and Pteridinium simplex, together with new ontogenetic data and insights. We use these data and interpretations to re‐evaluate the phylogenetic position of the broader Ediacaran morphogroups to which these taxa are considered to belong (rangeomorphs, dickinsoniomorphs and erniettomorphs). We conclude, based on the available evidence, that the affinities of the rangeomorphs and the dickinsoniomorphs lie within Metazoa.
Long-term tracer data collected over an 8
year period were analyzed to explore the transit times of two small (∼1
km
2), contrasting headwater catchments in the uplands of Scotland. At Loch Ard, the ...catchment was characterized by low permeability gleyed soils overlying metamorphic geology. At Sourhope, more freely draining podzolic soils were dominant, which mantled fractured and faulted volcanic rocks. Hydrometric data and chemically-based hydrograph separations indicated that Loch Ard was a flashy catchment dominated by runoff processes in the upper soil horizons. In contrast, around 77% of annual flow at Sourhope was sustained by well-buffered groundwater sources. Weekly Cl
− time series in precipitation and stream flow revealed similar variability in inputs at both sites, but much greater damping in outputs at Sourhope. Despite this, both catchments filtered white noise frequencies in precipitation inputs into 1/
f outputs. These input–output relationships were modeled with a range of transit time distributions (TTD). At the responsive Loch Ard catchment, mean transit times (MTT) for the study period were estimated at 135–202
days. Models based on a gamma distribution or two parallel linear reservoirs were best able to capture the short- and long-term fluctuations in stream water in response to input variations. At Sourhope, the highly damped tracer signal in stream waters was poorly captured by all the TTDs used. Resulting MTT estimates of 1830–1970
days are based on weak model fits and poorly identifiable parameter sets, indicating that natural tracers such as Cl
− are inadequate for catchments where MTTs are greater than a few years. At both sites, estimates of MTT using moving windows over the 8
year data sets revealed sensitivity to precipitation amounts and the length of monitoring period. It is concluded that time series of around 4
years are required to adequately constrain MTT estimates.
Deputy ministers in Canada Dunn, Christopher; Bourgault, Jacques
Deputy ministers in Canada,
2014, 2014, 2014-01-27, 2014-02-05
eBook
Collectively, provincial deputy ministers command the largest assembly of government budgets, employees, and influence in Canada, but despite their importance, they have not been the subject of ...systematic study until now. This unique volume, which deals with a uniquely significant topic, reviews the role of deputy ministers within government, providing a major new understanding of their responsibilities and interactions at both the federal and provincial levels. It also contributes important comparative analysis not previously available.
Featuring contributions by many of Canada’s most prominent scholars of public administration, Deputy Ministers in Canada examines a number of factors in the evolution of deputies’ roles. Taking into account social, political, and administrative history, the essays probe topics such as the socio-economic characteristics of administrative elites, the politicization of recruitment processes, the impact of New Public Management, and varieties of ministerial-bureaucratic relations. Together, the essays in Deputy Ministers in Canada make an important contribution to the political science and public administration literature.
ELABELA (ELA) is a peptide hormone required for heart development that signals via the Apelin Receptor (APLNR, APJ). ELA is also abundantly secreted by human embryonic stem cells (hESCs), which do ...not express APLNR. Here we show that ELA signals in a paracrine fashion in hESCs to maintain self-renewal. ELA inhibition by CRISPR/Cas9-mediated deletion, shRNA, or neutralizing antibodies causes reduced hESC growth, cell death, and loss of pluripotency. Global phosphoproteomic and transcriptomic analyses of ELA-pulsed hESCs show that it activates PI3K/AKT/mTORC1 signaling required for cell survival. ELA promotes hESC cell-cycle progression and protein translation and blocks stress-induced apoptosis. INSULIN and ELA have partially overlapping functions in hESC medium, but only ELA can potentiate the TGFβ pathway to prime hESCs toward the endoderm lineage. We propose that ELA, acting through an alternate cell-surface receptor, is an endogenous secreted growth factor in human embryos and hESCs that promotes growth and pluripotency.
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•ELA is a peptide hormone secreted by hESCs that activates the PI3K/AKT pathway•ELA promotes self-renewal via cell-cycle progression and protein translation•ELA potentiates the TGFβ pathway, priming hESCs toward the endoderm lineage•hESCs do not express APLNR, so ELA may have an alternate unknown receptor
Ho et al. show that ELA is an endogenous peptide hormone produced by human embryonic stem cells that supports self-renewal through auto/paracrine activation of PI3K/AKT signaling. ELA promotes cell-cycle progression and protein translation, prevents apoptosis upon cellular stress, and primes hESCs for endodermal differentiation via activation of TGFβ signaling.
Satellite retrieval of total suspended solids (TSS) and chlorophyll-a (chl-a) was performed for the Gold Coast Broadwater, a micro-tidal estuarine lagoon draining a highly developed urban catchment ...area with complex and competing land uses. Due to the different water quality properties of the rivers and creeks draining into the Broadwater, sampling sites were grouped in clusters, with cluster-specific empirical/semi-empirical prediction models developed and validated with a leave-one-out cross validation approach for robustness. For unsampled locations, a weighted-average approach, based on their proximity to sampled sites, was developed. Confidence intervals were also generated, with a bootstrapping approach and visualised through maps. Models yielded varying accuracies (R2 = 0.40–0.75). Results show that, for the most significant poor water quality event in the dataset, caused by summer rainfall events, elevated TSS concentrations originated in the northern rivers, slowly spreading southward. Conversely, high chl-a concentrations were first recorded in the southernmost regions of the Broadwater.
•Chl-a and TSS predicted for large estuarine lagoon from satellite data•Empirical models for clusters of sampling sites•Distance-specific weighted average prediction for unsampled sites•Bootstrapping approach for confidence intervals generation and visualisation•TSS originating from Northern rivers, chl-a in southern region during wet periods
Using measurements from the Cassini spacecraft in Saturn's magnetosphere, we propose a 3D physical picture of a corotating reconnection site, which can only be driven by an internally generated ...source. Our results demonstrate that the corotating magnetic reconnection can drive an expansion of the current sheet in Saturn's magnetosphere and, consequently, can produce Fermi acceleration of electrons. This reconnection site lasted for longer than one of Saturn's rotation period. The long-lasting and corotating natures of the magnetic reconnection site at Saturn suggest fundamentally different roles of magnetic reconnection in driving magnetospheric dynamics (e.g., the auroral precipitation) from the Earth. Our corotating reconnection picture could also potentially shed light on the fast rotating magnetized plasma environments in the solar system and beyond.
Variation in dissolved organic carbon (DOC) concentrations of surface waters is a consequence of process changes in the surrounding terrestrial environment, both within annual cycles and over the ...longer term. Long-term records (1987-2006) of DOC concentrations at six catchments (0.44-10.0 km²) across a climatic transect in Scotland were investigated for intra-annual relationships to evaluate potential long-term seasonal patterns. The intra-annual mode of DOC export contrasted markedly between catchments and appeared dependent on their hydrological characteristics. Catchments in wetter Central Scotland with high rainfall-runoff ratios, short transit times and well-connected responsive soils show a distinct annual periodicity in DOC concentrations throughout the long-term datasets. Increased DOC concentrations occurred between June and November with correspondingly lower DOC concentrations from December to May. This appears unrelated to discharge, and is dependent mainly on higher temperatures driving biological activity, increasing decomposition of available organic matter and solubility of DOC. The drier eastern catchments have lower rainfall-runoff ratios, longer transit times and annual drying-wetting regimes linked to changing connectivity of soils. These are characterised by seasonal DOC concentration-discharge relationships with an autumnal flush of DOC. Temperature influences the availability of organic matter for DOC transport producing a high DOC concentration-discharge relationship in summer/autumn and low DOC concentration-discharge relationship in winter/spring. These two distinct modes of seasonal DOC transport have important implications for understanding changes in DOC concentrations and export brought about by climate change (temperature and precipitation) and modelling of aquatic carbon losses from soil-types under different hydrological regimes.
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