2,851 research outputs found

    Population dynamics of two sympatric intertidal fish species (the shanny, Lipophrys pholis, and long-spined scorpion fish,Taurulus bubalis) of Great Britain

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    The shanny/common blenny (Lipophrys pholis) and long-spined scorpionfish/bullhead (Taurulus bubalis) are commonly encountered, sympatric species within much of Great Britain’s rocky intertidal zones. Despite being prey items of the cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) respectively, and both contributors to the diet of the near-threatened European otter (Lutra lutra), little is known on the population dynamics of the temperate specimens of Great Britain. It is further less known of the degrees of sympatricy between the two fish species and to what extent they are able to coexist. The current study examines spatio-temporal distributions and abundances at various resolutions: monthly population dynamics of both species along England’s Yorkshire coast and seasonal population dynamics along the Yorkshire coast and around the Isle of Anglesey, Wales. Studies of their abundances, sizes, degrees of rock pool co-occurrence and diel activities are further examined, which indicate coexistence is maintained when interspecific co-occurrence takes place only between specimens of similar sizes, thus demoting size-related dominance hierarchies

    Assessment of Knowledge Management’s Growth in South Africa

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    This article revisits a debate surrounding Knowledge Management (KM) to report on an empirical study conducted in 86 South African based organizations, specifically regarding growth in KM maturity over a five year period. The findings indicate that KM is fairly well institutionalized in South African industry, with most organizations indicating that significant growth occurred in KM over the past five years. Analysis of the growth in KM maturity, as it relates to different organizational sizes, reveals that there are statistical differences between the score reported by Small, Medium, Large and Extra-Large organizations. Similarly, scores reported by Senior, Middle and Operational personnel differ primarily between the scores decided upon by Operational personnel and Senior managers. Viewed holistically, findings suggest that there could be a “break-even point” between resources available and KM growth with Extra-Large organizations given their advantage in KM growth. Findings also indicated that growth in KM differs between industry groupings, with Construction, Building Materials and Mining companies achieving high growth (+/- 70%), Consumer Goods and Utilities (+/- 60%), Banks and Insurance, Automotive and Transport, Government and ICT companies, moderate growth (+/- 50%), and Educational institutions, low growth (+/- 40%)

    Can tillage and agronomy be integrated with herbicide application to control resistant weeds?

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    Non-Peer ReviewedThe prevalence of group 2 resistant broadleaved weeds threatens successful lentil production on the Canadian Great Plains. The objective of this study was to develop an integrated weed management strategy combining physical, cultural and chemical weed control methods for lentil producers dealing with group 2 resistant wild mustard. The study was conducted for 3 years between 2011 and 2013 at 2 locations at Saskatoon and Scott, Saskatchewan. It was a randomized two way factorial with weed control method and seeding rate as the main effects. Weed control treatments tested consisted of a control treated with a glyphosate burnoff, saflufenacil (Heat ™) herbicide, rotary hoeing, half rate metribuzin (Sencor ™) herbicide, a fully integrated treatment, and a full herbicide treatment. Three seeding rates representing 1, 2, and 4 times the recommended seeding rate were tested (130, 260, and 520 plants m-2). Increasing seeding rate consistently lowered mustard biomass at both locations. The full herbicide treatment provided the greatest reduction in mustard biomass followed by the integrated treatment. The integrated treatment relied more on increased seeding rate to reduce mustard biomass and produce yield, and at the highest seeding rate it was able to provide equivalent yield to the full herbicide system. The results of this study show that an integrated system utilizing an increased seeding rate can control resistant weeds and maintain yields to a similar level as a strategy that relies only on herbicides for weed control

    Evaluation of harvest aids application timing for lentil dry down

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    Non-Peer ReviewedHarvesting stage is a critical step for lentil producers to maintain high seed yield and good quality. Desiccating lentil with desiccants/harvest aids can dry down lentil evenly and quickly, and control late-growing green weeds, which enhances lentil harvest efficiency and allows early harvesting. Since the harvest aids are applied at a late growth stage, high herbicide residue in seeds may cause commercial issues with marketing lentil. Application timing of harvest aids is critical for producers. Improper application timing may reduce yield and thousand seed weight, but increase herbicide residue in seeds. Therefore, the objective of the harvest aids application timing (% seed moisture) trial was to evaluate the responses of lentil to different herbicide application timings at Saskatoon and Scott, Saskatchewan, over 2 years (2012 and 2013). For this trial, glyphosate (900 g a.e. ha-1), saflufenacil (50 g a.i. ha-1), and the combination of glyphosate plus saflufenacil (900 g a.e. ha-1 and 36 g a.i. ha-1) were applied when seed moisture content was 60%, 50%, 40%, 30% and 20%. Apart from these herbicide treatments, there was also an untreated control, which is desiccated naturally. Significant relationships between evaluated variables and application timing on the basis of seed moisture content were detected. Also, this trial indicated that early application timing (60% application seed moisture) could result in reductions in lentil yield and thousand seed weight. Glyphosate residue in seeds was less than 4 mg kg-1 when glyphosate was applied alone at 30% and 20% average seed moisture. Glyphosate residue decreased when adding saflufenacil to glyphosate. Saflufenacil residue consistently increased with earlier application timing of the harvest aids

    Direct and indirect orthotic management of medial compartment osteoarthritis of the knee

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    Osteoarthritis (OA) is a painful condition and affects approximately 80% of individuals by the age of 55 [1], with knee OA occurring two times more frequently than OA of the hand or hip [2].The condition is more prevalent in the medial compartment and restricts the daily lives of individuals due to pain and a lack of functional independence. Patients with medial compartment osteoarthritis often have a varus alignment, with the mechanical axis and load bearing passing through this compartment with a greater adduction moment leading to greater pain and progression of osteoarthritis [3]. Surgery for the condition is possible although in some cases, particularly younger patients or those not yet requiring surgery, clinical management remains a challenge. Before surgery is considered, however, conservative management is advocated, though no one treatment has been shown to be most effective, and there are few quality biomechanical or clinical studies. Of the conservative approaches the principal orthotic treatments are valgus knee braces and laterally wedged foot inlays. Studies of knee valgus bracing have consistently demonstrated an associated decreased pain and improved function [4], and greater confidence [5]. A laterally wedged foot inlay has a thicker lateral border and applies a valgus moment to the heel. It is theorised that by changing the position of the ankle and subtalar joints during weight-bearing [6] the lateral wedges may apply a valgus moment across the knee as well as the rearfoot, with the assumed reduction on load in the medial knee compartment [7]. However, there has been no study to directly compare these orthotic treatments in the same study. The aim of this research is to investigate the efficacy of valgus knee braces and laterally wedged foot inlays in reducing the varus knee moment

    Evaluation of new and existing desiccants in lentil

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    Non-Peer ReviewedGlobally, herbicide resistance has become a major challenge for many producers. In western Canada, many lentil (Lens culinaris L.) producers have great difficulty controlling Group 2 resistant biotypes. Two of these problematic weeds, wild mustard (Sinapis arvensis L.) and kochia (Kochia scoparia), are particularly challenging for lentil growers and can cause extensive yield loss when not adequately controlled. Desiccation is primarily used to dry down lentil for harvest ease and efficiency but can also be used as a late season control for actively growing weeds. The objective of this project is to evaluate the response of wild mustard and kochia to different herbicides, tank mixed with two different rates of glyphosate (450 g a.e. ha-1 and 900 g a.e. ha-1) at Saskatoon and Scott, Saskatchewan over a 2 year period. Desiccation occurred when the lentil seed moisture content was approximately 30%. Preliminary results are under investigation. Evaluation of seed and plant moisture of the treated plots is ongoing, along with an evaluation of the effects of the treatments on viability and vigour of affected weed seeds

    Mechanisms of decadal North Atlantic climate variability and implications for the recent cold anomaly

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    Decadal sea surface temperature (SST) fluctuations in the North Atlantic Ocean influence climate over adjacent land areas and are a major source of skill in climate predictions. However, the mechanisms underlying decadal SST variability remain to be fully understood. This study isolates the mechanisms driving North Atlantic SST variability on decadal time scales using low-frequency component analysis, which identifies the spatial and temporal structure of low-frequency variability. Based on observations, large ensemble historical simulations, and preindustrial control simulations, we identify a decadal mode of atmosphere–ocean variability in the North Atlantic with a dominant time scale of 13–18 years. Large-scale atmospheric circulation anomalies drive SST anomalies both through contemporaneous air–sea heat fluxes and through delayed ocean circulation changes, the latter involving both the meridional overturning circulation and the horizontal gyre circulation. The decadal SST anomalies alter the atmospheric meridional temperature gradient, leading to a reversal of the initial atmospheric circulation anomaly. The time scale of variability is consistent with westward propagation of baroclinic Rossby waves across the subtropical North Atlantic. The temporal development and spatial pattern of observed decadal SST variability are consistent with the recent observed cooling in the subpolar North Atlantic. This suggests that the recent cold anomaly in the subpolar North Atlantic is, in part, a result of decadal SST variability.publishedVersio

    Multiplexed FBG sensor recorded in multimode microstructured polymer optical fibre

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    Fibre Bragg gratings have been inscribed in multimode microstructured polymer optical fibre (POF), with a core size of 50μm. The microstructured POF (mPOF) consists of a three ring hole structure and is made purely from poly(methyl methacrylate) (PMMA). In comparison to silica fibre, POF has a much smaller Young's modulus and a much greater breaking strain; additionally multimode fibre holds advantages of ease of handling and launching conditions. A linear strain sensitivity of 1.32 ± 0.01pm/με has been measured in the range 0 to 2% strain. The fibre drawing process leads to a degree of molecular alignment along the fibre axis. This alignment can be thermally annealed out; this can induce a permanent blue shift in the Bragg wavelength of a grating fabricated prior to annealing by up to 20 nm. Utilising this, wavelength demultiplexed gratings can be fabricated using a single phase mask. As an illustration of this we present for the first time wavelength division multiplexing of the spectral response of three Bragg gratings in POF within the C-band region. Complementing this work, a technique of splicing mPOF to step index silica fibre is described using UV curing optical adhesive, allowing characterisation of Bragg gratings fabricated in this fibre
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