325 research outputs found
Rural Reconstruction: Towards a New Synthesis in Canadian History
Recent works in the field of rural history are offering a critical challenge to the
historiography of nineteenth- and early twentieth-century Canada. The first part of
this article draws on a variety of rural studies to outline some problems that arise
in the growing discord between recent literature on rural Canada and traditional
Canadian historiography. These anomalies are linked to an historical discourse that
trivializes and obscures what is arguably the most important institution of rural
society: the household. Finally, the author reviews some recent rural studies that
explicitly search for ways to give the pre- and post-industrial rural household a
conceptual depth that it lacks within the constraints of neoclassical and Marxist
'evolutionist' constructions of the political economy.Les travaux récents dans le domaine de l'histoire rurale mettent en doute l'historiographie
du Canada du 19e siÚcle et du début du 20e siÚcle. La premiÚre partie de
l'article est fondée sur diverses études rurales et souligne quelques-uns des problÚmes
causés par l'écart qui s'agrandit sans cesse entre les ouvrages récents sur
le Canada rural et l'historiographie canadienne traditionnelle. Ces anomalies sont
reliées à un discours historique qui rend banale et obscure l'institution qui est
probablement la plus importante de la société rurale, soit le foyer. Enfin, l'auteur
examine certaines études rurales récentes dans lesquelles on cherche explicitement
des moyens de donner aux foyers canadiens remontant aux périodes pré-industrielle
et post-industrielle, la profondeur conceptuelle qui leur manque, compte tenu des
contraintes imposées par les interprétations évolutionnistes néoclassiques et marxistes
de l'Ă©conomie politique
Deposition gradients across mangrove fringes
Observations in a mangrove in the Whangapoua Harbour, New Zealand, have shown that deposition rates are greatest in the fringing zone between the tidal flats and the mangrove forest, where the vegetation is dominated by a cover of pneumatophores (i.e. pencil roots). Current speeds and suspended sediment concentrations dropped substantially across this zone. Near-bed turbulence within the fringe was substantially lower where the pneumatophore canopy was denser, facilitating the enhanced deposition in this zone. However, the near-bed conditions were not the primary control on the instantaneous sediment concentrations at this site. The total deposition across the different zones was the combined result of the reduced near-bed turbulence inside the vegetation and the larger-scale dynamics over the spatially variable vegetation cover, along with other confounding factors such as changing sediment inputs
Mapping Status and Conservation of Global At-Risk Marine Biodiversity
To conserve marine biodiversity, we must first understand the spatial distribution and status of atârisk biodiversity. We combined range maps and conservation status for 5,291 marine species to map the global distribution of extinction risk of marine biodiversity. We find that for 83% of the ocean, \u3e25% of assessed species are considered threatened, and 15% of the ocean shows \u3e50% of assessed species threatened when weighting for rangeâlimited species. By comparing mean extinction risk of marine biodiversity to noâtake marine reserve placement, we identify regions where reserves preferentially afford proactive protection (i.e., preserving lowârisk areas) or reactive protection (i.e., mitigating highârisk areas), indicating opportunities and needs for effective future protection at national and regional scales. In addition, elevated risk to high seas biodiversity highlights the need for credible protection and minimization of threatening activities in international waters
Can early years professionals determine which preschoolers have comprehension delays? A comparison of two screening tools
Language comprehension delays in pre-schoolers are predictive of difficulties in a range of developmental domains. In England, early years setting staff are required to assess the language comprehension of two-year-olds in their care. Many use a format based on the Early Years Foundation Stage My Unique Child (EYFS:UCCS ) in which the childâs language comprehension is assigned to an age band based on written guidance. Seventy 2Âœ-3-year-olds were assessed on the comprehension component of the Preschool Language Scale (PLS) by psychology graduates. Early years practitioners assessed language comprehension in the same children using the EYFS:UCCS and the WellComm which involves some direct testing. The EYFS:UCCS had poor sensitivity and specificity and the understanding section did not correlate with the PLS. The WellComm had good-acceptable levels of sensitivity and specificity and significantly correlated with the PLS. Early years setting staff can accurately assess the language comprehension of two-year-olds if provided with a tool which gives specific instructions on administration, but current frequently used procedures (EYFS:UCCS) are not fit for this purpose
The role of mini-grids for electricity access and climate change mitigation in India
Sustainable Development Goal 7 aims to achieve access to sustainable, affordable, reliable, and modern energy for all. Access to electricity is critical for development and economic growth and can support productive livelihoods and power critical community services such as for healthcare and education. Solar mini-grids can offer the most cost-effective option for rural and remote communities not yet connected to the grid and can deliver reliable, high-quality power which is able to serve multiple uses and meet growing demand over time
Deformation-related volcanism in the Pacific Ocean linked to the Hawaiian-Emperor bend
Ocean islands, seamounts and volcanic ridges are thought to form above mantle plumes. Yet, this mechanism cannot explain many volcanic features on the Pacific Ocean floor and some might instead be caused by cracks in the oceanic crust linked to the reorganization of plate motions. A distinctive bend in the HawaiianâEmperor volcanic chain has been linked to changes in the direction of motion of the Pacific Plate, movement of the Hawaiian plume, or a combination of both. However, these links are uncertain because there is no independent record that precisely dates tectonic events that affected the Pacific Plate. Here we analyse the geochemical characteristics of lava samples collected from the Musicians Ridges, lines of volcanic seamounts formed close to the HawaiianâEmperor bend. We find that the geochemical signature of these lavas is unlike typical ocean island basalts and instead resembles mid-ocean ridge basalts. We infer that the seamounts are unrelated to mantle plume activity and instead formed in an extensional setting, due to deformation of the Pacific Plate. 40Ar/39Ar dating reveals that the Musicians Ridges formed during two time windows that bracket the time of formation of the HawaiianâEmperor bend, 53â52 and 48â47 million years ago. We conclude that the HawaiianâEmperor bend was formed by plateâmantle reorganization, potentially triggered by a series of subduction events at the Pacific Plate margins
Crustal structure of the Kermadec arc from MANGO seismic refraction profiles
Three active-source seismic refraction profiles are integrated with morphological and potential field data to place the first regional constraints on the structure of the Kermadec subduction zone. These observations are used to test contrasting tectonic models for an along-strike transition in margin structure previously known as the 32°S boundary. We use residual bathymetry to constrain the geometry of this boundary and propose the name Central Kermadec Discontinuity (CKD). North of the CKD, the buried Tonga Ridge occupies the forearc with VP 6.5â7.3âkmâs-1 and residual free-air gravity anomalies constrain its latitudinal extent (north of 30.5°S), width (110â±â20âkm) and strike (~005° south of 25°S). South of the CKD the forearc is structurally homogeneous down-dip with VP 5.7â7.3âkmâs-1. In the Havre Trough backarc, crustal thickness south of the CKD is 8-9âkm, which is up-to 4âkm thinner than the northern Havre Trough and at least 1âkm thinner than the southern Havre Trough. We suggest that the Eocene arc did not extend along the current length of the Tonga-Kermadec trench. The Eocene arc was originally connected to the Three Kings Ridge and the CKD was likely formed during separation and easterly translation of an Eocene arc substrate during the early Oligocene. We suggest that the first-order crustal thickness variations along the Kermadec arc were inherited from before the Neogene and reflect Mesozoic crustal structure, the Cenozoic evolution of the Tonga-Kermadec-Hikurangi margin and along-strike variations in the duration of arc volcanism
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