Canada's Atlantic Coastal Action Program: A community-based approach to collective governance

The Atlantic Coastal Action Program (ACAP) is a community-based coastal management initiative that has been underway on Canada's east coast for the past 6 years. Coalitions of local stakeholders have been assisted by government in taking a lead role for the planning and management activities in 13 coastal ecosystems throughout Atlantic Canada. The program was initiated and originally facilitated by the federal government (Environment Canada) but has come to be led and owned at the local level. The objective is to have all those affecting and/or affected by local decisions involved in this process. In ACAP, the traditional role of government is shared with the local roundtables that are established in each coastal ecosystem. Instead of government departments being the lead agencies that set policy and priorities, the communities assume this function and the government agencies become partners in responding to their identified needs. ACAP is a practical demonstration of the joint management, or collective governance approach to Integrated Coastal Management and offers lessons to governments and coastal communities looking to establish lasting partnership approaches that have the potential to achieve the sustainable development of coastal ecosystems.     

Proper elements: What are they?

The general ideas about the calculation of proper elements are given here, followed by a comparison of the hypotheses and simplifications made in three different theories: YKM theory, composition of the contributions of Yuasa, Kneevi and Milani, W theory corresponding to Williams's work and HLM theory, paper of Lemaitre and Morbidelli, based on Henrard's semi numerical method. Some short numerical comparisons conclude the paper.     

Secular resonances in the primitive solar nebula

We present here a very simple model that could explain the relatively high eccentricities and inclinations observed in the minor planet belt. This model is based upon the sweeping of the secular resonances ₆ and ₁₆ through the belt due to the gravitational effect of the dissipation of a primitive solar nebula. The sweeping of the ₁₆ secular resonance (responsible for the high inclinations) is very sensitive to the density profile of the nebula. For the model to work we need a density profile proportional to ^–k with between 1.0 and 1.5.     

Well Conditioning in Object Models

This paper presents two object models with corresponding simulation algorithms, which aim to condition well data correctly while still converging in reasonable time. The first model is devoted to fluvial channels and the second one is mainly intended for smaller objects. To verify the conditioning, a method for validating well conditioning algorithms for object models is given. The purpose is to determine the extent to which the well conditioning introduces a bias in the models. To do this, we check that the double expectation of a parameter conditioned to wells is equal to the unconditional expectation. This method is applied to two different object models. Both the conditioning algorithms presented here give good results using this test.     

Finite-frequency sensitivity of body waves to anisotropy based upon adjoint methods

We investigate the sensitivity of finite-frequency body-wave observables to mantle anisotropy based upon kernels calculated by combining adjoint methods and spectral-element modelling of seismic wave propagation. Anisotropy is described by 21 density-normalized elastic parameters naturally involved in asymptotic wave propagation in weakly anisotropic media. In a 1-D reference model, body-wave sensitivity to anisotropy is characterized by 'banana–doughnut' kernels which exhibit large, path-dependent variations and even sign changes. P -wave traveltimes appear much more sensitive to certain azimuthally anisotropic parameters than to the usual isotropic parameters, suggesting that isotropic P -wave tomography could be significantly biased by coherent anisotropic structures, such as slabs. Because of shear-wave splitting, the common cross-correlation traveltime anomaly is not an appropriate observable for S waves propagating in anisotropic media. We propose two new observables for shear waves. The first observable is a generalized cross-correlation traveltime anomaly, and the second a generalized 'splitting intensity'. Like P waves, S waves analysed based upon these observables are generally sensitive to a large number of the 21 anisotropic parameters and show significant path-dependent variations. The specific path-geometry of SKS waves results in favourable properties for imaging based upon the splitting intensity, because it is sensitive to a smaller number of anisotropic parameters, and the region which is sampled is mainly limited to the upper mantle beneath the receiver.     

Thermal diffusivity of quartz to 1,000°C: effects of impurities and the α-β phase transition

Lattice thermal diffusivities of eleven orientated natural and synthetic quartz samples were measured using a laser-flash apparatus (LFA). For α-quartz, thermal diffusivity (D) decreases with temperature, so that directionally averaged values of D(T) between 20° and 500°C can be fit with D(T) = 1/(0.0017T + A), where A varies from 0.12 to 0.18 among the samples and D is in mm²/s. For β-quartz, D decreases very slightly or is constant with temperature. Values of D measured along [001] exceed those measured along [100] at all temperatures studied. A sharp decrease of D(T) marks the α-β phase transition, consistent with correlation of 1/D with C _P in the damped harmonic oscillator model. Due to the rapidity of the laser-pulse and the dynamic nature of the measurements, the raw data show evidence of latent heat being released at the transition temperature over ∼50 ms. D(T) values within 10 K of the transition are affected both by latent heat release and by the phase change. For our suite of samples, D at all temperatures varies by ±7% from the overall average. This range is outside the 2% experimental uncertainty. To ascertain causes of D variations, we characterized out samples using infrared absorption spectroscopy, electron microprobe analyses and secondary ion mass spectrometry. Differences between the samples seem to result from the interplay of different impurity types: cations that replace Si in the silicate tetrahedra, cations squeezing into the lattice, and OH. Although limitations in quantifying amounts of trace impurities and poor understanding of where impurities reside in the lattice hamper interpretation, it seems that samples containing more substitutional impurities (e.g., Al³⁺) have higher diffusivities along [001], those with more interstitial defects (e.g., Li⁺) have higher diffusivities along [100], and that OH reduces D.     

δC variation in scallop shells: Increasing metabolic carbon contribution with body size?

We examined δ¹³C values of shallow and deep-water scallop shells as well as δ¹³C of dissolved inorganic carbon (DIC) from the Bay of Brest in western Brittany. Time series of shell calcite δ¹³C do not reflect seasonal variation in seawater δ¹³C, but rather show a consistent pattern of decreasing δ¹³C with age, suggesting a metabolic effect rather than direct environmental control. This δ¹³C trend reflects an increasing contribution of metabolic CO₂ to skeletal carbonate throughout ontogeny, although this respired CO₂ does not seem to be the major source of skeletal carbon (contribution of only 10% over the first year of life). We propose a model of this effect that depends on the availability of metabolic carbon relative to the carbon requirements for calcification. A ratio of “respired to precipitated carbon” is calculated, and represents the amount of metabolic carbon available for calcification. Interestingly, this ratio increases throughout ontogeny suggesting a real increase of metabolic carbon utilization into the skeleton relative to carbon from seawater DIC. This ratio allows us to separate two different populations of Pecten maximus of different water depth. It is therefore suggested that shell δ¹³C might be used to track differences in the metabolic activity of scallops from different populations.