Environmental conditions during breeding modify the strength of mass-dependent carry-over effects in a migratory bird

This is the final version of the article. Available from the publisher via the DOI in this record.In many animals, processes occurring in one season carry over to influence reproductive success and survival in future seasons. The strength of such carry-over effects is unlikely to be uniform across years, yet our understanding of the processes that are capable of modifying their strength remains limited. Here we show that female light-bellied Brent geese with higher body mass prior to spring migration successfully reared more offspring during breeding, but only in years where environmental conditions during breeding were favourable. In years of bad weather during breeding, all birds suffered reduced reproductive output irrespective of pre-migration mass. Our results suggest that the magnitude of reproductive benefits gained by maximising body stores to fuel breeding fluctuates markedly among years in concert with conditions during the breeding season, as does the degree to which carry-over effects are capable of driving variance in reproductive success among individuals. Therefore while carry-over effects have considerable power to drive fitness asymmetries among individuals, our ability to interpret these effects in terms of their implications for population dynamics is dependent on knowledge of fitness determinants occurring in subsequent seasons. XAH was funded by NERC grant (NE⁄F008058⁄1) with a Wildfowl & Wetlands Trust CASE partnership and RI by NERC grant (NE⁄F021690⁄1), both awarded to SB. SB is funded by an ERC Consolidator's Grant: STATEMIG 310820. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Fluid effects in model granular flows

Pore fluid plays a crucial role in many granular flows, especially those in geophysical settings. However, the transition in behaviour between dry flows and fully saturated flows and the underlying physics that relate to this are poorly understood. In this paper, we report the results of small-scale flume experiments using monodisperse granular particles with varying water content and volume in which the basal pore pressure, total pressure, flow height and velocity profile were measured at a section. We compare the results with theoretical profiles for granular flow and with flow regimes based on dimensional analysis. The runout and the centre of mass were also calculated from the deposit surface profiles. As the initial water content by mass was increased from zero to around 10%, we first observed a drop in mobility by approximately 50%, as surface tension caused cohesive behaviour due to matric suction. As the water content was further increased up to 45%, the mobility also increased dramatically, with increased flow velocity up to 50%, increased runout distance up to 240% and reduced travel angle by up to 10° compared to the dry case. These effects can be directly related to the basal pore pressure, with both negative pressures and positive pore pressures being measured relative to atmospheric during the unsteady flow. We find that the initial flow volume plays a role in the development of relative pore pressure, such that, at a fixed relative water content, larger flows exhibit greater positive pore pressures, greater velocities and greater relative runout distances. This aligns with many other granular experiments and field observations. Our findings suggest that the fundamental role of the pore fluid is to reduce frictional contact forces between grains thus increasing flow velocity and bulk mobility. While this can occur by the development of excess pore pressure, it can also occur where the positive pore pressure is not in excess of hydrostatic, as shown here, since buoyancy and lubrication alone will reduce frictional forces. Graphical abstract

Sensitive aerial hearing within a noisy nesting soundscape in a deep-diving seabird, the common murre Uria aalge

Diving seabirds face a combination of sound exposure in marine and terrestrial environments due to increasing human encroachment on coastal ecosystems. Yet the sound-sensitivity and sensory ecology of this threatened group of animals is largely unknown, complicating effective management and conservation. Here, we characterize aspects of the acoustic ecology of the common murre Uria aalge, one of the deepest diving alcid seabirds. Electrophysiological aerial hearing thresholds were measured for 12 wild, nesting individuals and compared to conspecific vocalizations and short-term aerial soundscape dynamics of their cliff nesting habitat. Auditory responses were measured from 0.5 to 6 kHz, with a lowest mean threshold of 30 dB at 2 kHz and generally sensitive hearing from 1 to 3.5 kHz. The short-term murre nesting soundscape contained biotic sounds from con- and heterospecific avifauna; broadband sounds levels of 56-69 dB re: 20 µPa rms (0.1-10 kHz) were associated with both diel and tidal-cycle factors. Five murre vocalization types showed dominant spectral emphasis at or below the region of best hearing. Common murre hearing appears to be less sensitive than a related alcid, the Atlantic puffin Fratercula arctica, but more sensitive than other non-alcid diving birds described to date, suggesting that adaptations for deep diving have not caused a loss of the species’ hearing ability above water. Overall, frequencies of common murre hearing and vocalization overlap with many anthropogenic noise sources, indicating that the species is susceptible to disturbance from a range of noise types

Cold-to-warm flow regime transition in snow avalanches

Large avalanches usually encounter different snow conditions along their track. When they release as slab avalanches comprising cold snow, they can subsequently develop into powder snow avalanches entraining snow as they move down the mountain. Typically, this entrained snow will be cold (T‾&lt;-1&thinsp;∘C) at high elevations near the surface, but warm (T‾&gt;-1&thinsp;∘C) at lower elevations or deeper in the snowpack. The intake of warm snow is believed to be of major importance to increase the temperature of the snow composition in the avalanche and eventually cause a flow regime transition. Measurements of flow regime transitions are performed at the Vallée de la Sionne avalanche test site in Switzerland using two different radar systems. The data are then combined with snow temperatures calculated with the snow cover model SNOWPACK. We define transitions as complete when the deposit at runout is characterized only by warm snow or as partial if there is a warm flow regime, but the farthest deposit is characterized by cold snow. We introduce a transition index Ft, based on the runout of cold and warm flow regimes, as a measure to quantify the transition type. Finally, we parameterize the snow cover temperature along the avalanche track by the altitude Hs, which represents the point where the average temperature of the uppermost 0.5&thinsp;m changes from cold to warm. We find that Ft is related to the snow cover properties, i.e. approximately proportional to Hs. Thus, the flow regime in the runout area and the type of transition can be predicted by knowing the snow cover temperature distribution. We find that, if Hs is more than 500&thinsp;m above the valley floor for the path geometry of Vallée de la Sionne, entrainment of warm surface snow leads to a complete flow regime transition and the runout area is reached by only warm flow regimes. Such knowledge is of great importance since the impact pressure and the effectiveness of protection measures are greatly dependent on the flow regime.</p

Approximate Decoherence of Histories and 't Hooft's Deterministic Quantum Theory

This paper explores the possibility that an exactly decoherent set of histories may be constructed from an approximately decoherent set by small distortions of the operators characterizing the histories. In particular, for the case of histories of positions and momenta, this is achieved by doubling the set of operators and then finding, amongst this enlarged set, new position and momentum operators which commute, so decohere exactly, and which are ``close'' to the original operators. The enlarged, exactly decoherent, theory has the same classical dynamics as the original one, and coincides with the so-called deterministic quantum theories of the type recently studied by 't Hooft. These results suggest that the comparison of standard and deterministic quantum theories may provide an alternative method of characterizing emergent classicality. A side-product is the surprising result that histories of momenta in the quantum Brownian motion model (for the free particle in the high-temperature limit) are exactly decoherent.Comment: 41 pages, plain Te

Somewhere in the Universe: Where is the Information Stored When Histories Decohere?

We investigate the idea that decoherence is connected with the storage of information about the decohering system somewhere in the universe. The known connection between decoherence of histories and the existence of records is extended from the case of pure initial states to mixed states. Records may still exist but are necessarily imperfect. We formulate an information-theoretic conjecture about decoherence due to an environment: the number of bits required to describe a set of decoherent histories is approximately equal to the number of bits of information thrown away to the environment in the coarse-graining process. This idea is verified in a simple model consisting of a particle coupled to an environment that can store only one bit of information. We explore the decoherence and information storage in the quantum Brownian motion model. It is shown that the variables that the environment naturally measures and stores information about are the Fourier components of the function $x(t)$ (describing the particle trajectory). The records storing the information about the Fourier modes are the positions and momenta of the environmental oscillators at the final time. Decoherence is possible even if there is only one oscillator in the environment. The information count of the histories and records in the environment add up according to our conjecture. These results give quantitative content to the idea that decoherence is related to ``information lost''.Comment: 48 pages, plain Tex. Second revisio

The Rosetta Stone Project – Integrating experimental results on debris flow mechanics across the scales: Next results

We present the combined efforts of a research network designed to address the many challenges in the experimental modelling of debris flow phenomena. The approach has been to use apparatuses of different functional arrangement and at different scale with identical and commonly sourced flow materials from the highly idealised (dry, coarse and uniform) to the highly complex (well graded, segregating, fluid saturated). Here we briefly present some key findings of the network and point to the research questions that are currently being addressed. This complementary view of experimental debris flows helps to constrain methodological artefacts/scale effects and to identify key processes responsible for the diverse appearance and often high mobility of debris flows

The effectiveness of an intervention in increasing community health clinician provision of preventive care: a study protocol of a non-randomised, multiple-baseline trial

<p>Abstract</p> <p>Background</p> <p>The primary behavioural risks for the most common causes of mortality and morbidity in developed countries are tobacco smoking, poor nutrition, risky alcohol use, and physical inactivity. Evidence, guidelines and policies support routine clinician delivery of care to prevent these risks within primary care settings. Despite the potential afforded by community health services for the delivery of such preventive care, the limited evidence available suggests it is provided at suboptimal levels. This study aims to assess the effectiveness of a multi-strategic practice change intervention in increasing clinician's routine provision of preventive care across a network of community health services.</p> <p>Methods/Design</p> <p>A multiple baseline study will be conducted involving all 56 community health facilities in a single health district in New South Wales, Australia. The facilities will be allocated to one of three administratively-defined groups. A 12 month practice change intervention will be implemented in all facilities in each group to facilitate clinician risk assessment of eligible clients, and clinician provision of brief advice and referral to those identified as being 'at risk'. The intervention will be implemented in a non-random sequence across the three facility groups. Repeated, cross-sectional measurement of clinician provision of preventive care for four individual risks (smoking, poor nutrition, risky alcohol use, and physical inactivity) will occur continuously for all three facility groups for 54 months via telephone interviews. The interviews will be conducted with randomly selected clients who have visited a community health facility in the last two weeks. Data collection will commence 12 months prior to the implementation of the intervention in the first group, and continue for six months following the completion of the intervention in the last group. As a secondary source of data, telephone interviews will be undertaken prior to and following the intervention with randomly selected samples of clinicians from each facility group to assess the reported provision of preventive care, and the acceptability of the practice change intervention and implementation.</p> <p>Discussion</p> <p>The study will provide novel evidence regarding the ability to increase clinician's routine provision of preventive care across a network of community health facilities.</p> <p>Trial registration</p> <p>Australian Clinical Trials Registry <a href="http://www.anzctr.org.au/ACTRN12611001284954.aspx">ACTRN12611001284954</a></p> <p>Universal Trial Number (UTN)</p> <p>U1111-1126-3465</p