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91.
Pauline Kamermans Ainhoa Blanco Sandra Joaquim Domitília Matias Thorolf Magnesen Jean Louis Nicolas Bruno Petton Rene Robert 《Aquaculture International》2016,24(3):827-842
In order to increase production of bivalves in hatcheries and nurseries, the development of new technology and its integration into commercial bivalve hatcheries is important. Recirculation aquaculture systems (RASs) have several advantages: high densities of the species can be cultured resulting in a cost-effective production system; optimal temperature maximizes production and allows rapid turnover of the product; stable water quality improves growth rate and minimizes stress and potential loss by diseases. Pilot RAS systems were developed for seed rearing of oysters (Crassostrea gigas), scallops (Pecten maximus), mussels (Mytilus edulis) and clams (Ruditapes decussatus). Optimal feed addition and waste matrix were determined. Based on this, system flow rates were designed. Seed growth in the pilot RAS systems was compared at different renewal rates and with growth in flow-through systems (FTS). All four species can be reared in RAS and showed similar growth in RAS and in FTS or in RAS with a higher renewal rate. RAS can keep O2, nitrogen and pH within the desired range. Temperature was generally higher in RAS than in FTS, probably due to heat induced by the pump circulating the water. The supply of sufficient amount of food in combination with a desire to reduce the renewal rate calls for use of concentrated feed in RAS. 相似文献
92.
As the various components of the cadmium (Cd) root sink have not been clearly described, there is a need to precisely measure the respective contributions of apoplast and symplast to short‐term root Cd uptake and to explain the linear component of the absorption isotherms. A new method of fractionating Cd in roots was applied to two plant species with contrasting abilities to accumulate Cd: maize (Zea mays) and a Cd‐hyperaccumulating ecotype of alpine pennycress (Noccaea caerulescens). Their roots were exposed for 1 h to increasing concentrations of labeled Cd. Series of desorption baths were used to obtain the root apoplastic Cd in combination with a brief freezing step in liquid nitrogen to separate the intracellular metal from the apoplastic one. The apoplastic uptake accounted for 15% to 82% and for 48% to 96% of the total Cd uptake of maize and of alpine pennycress roots, respectively. In the case of maize, the concentration‐dependent symplastic net flux fitted a biphasic Michaelis‐Menten function, while in the case of alpine pennycress, a Michaelis‐Menten‐plus‐linear function proved a better fit. The second component of the symplastic net flux may reflect absorption through a low‐affinity transport system. Short‐term Cd uptake by roots is dominated by the high‐affinity transport system for exposure concentrations below 1 μM for maize and 0.2 μM for alpine pennycress, while cell‐wall binding prevailed for higher exposure concentrations. 相似文献
93.
Tim S. Bugni Cynthia D. Andjelic Ann R. Pole Prem Rai Chris M. Ireland Louis R. Barrows 《Fitoterapia》2009
A traditional preparation of Parmotrema saccatilobum (Taylor) Hale (Family: Parmeliaceae) is being considered for inclusion into the PNG national drug formulary by the Ministry of Health Taskforce on Traditional Medicines. The lichen preparation is traditionally used in the Milne Bay province of Papua New Guinea for analgesic and anti-inflammatory activities. A hexane extract of P. saccatilobum yielded the principle components atranorin and chloroatranorin. Atranorin and chloroatranorin were tested in a COX-1 and -2 enzyme inhibition assay, which showed that atranorin inhibited COX-1 in a dose dependent manner and suggests partial inhibition by atranorin and chloroatranorin of COX-2 and COX-1, respectively. 相似文献
94.
95.
Jean-Paul Laclau Joseph Levillain Philippe Deleporte Jean de Dieu Nzila Jean-Pierre Bouillet Laurent Saint André Antoine Versini Louis Mareschal Yann Nouvellon Armel Thongo M’Bou Jacques Ranger 《Forest Ecology and Management》2010
Tropical plantation forests are meeting an increasing proportion of global wood demand and comprehensive studies assessing the impact of silvicultural practices on tree and soil functioning are required to achieve sustainable yields. The objectives of our study were: (1) to quantify the effects of contrasting organic residue (OR) retention methods on tree growth and soil nutrient pools over a full Eucalyptus rotation and (2) to assess the potential of soil analyses to predict yields of fast-growing plantations established on tropical sandy soils. An experiment was set up in the Congo at the harvesting of the first rotation after afforestation of a native herbaceous savanna. Six treatments were set up in 0.26 ha plots and replicated in 4 blocks, with OR mass at planting ranging from 0 to 46.5 Mg ha−1. Tree growth over the whole rotation was highly dependent on OR management at planting. Over-bark trunk volume 7 years after planting ranged from 96 m3 ha−1 in the treatment with forest floor and harvest residue removal at planting to 164 m3 ha−1 in the treatment with the largest amount of OR. A comparison of nutrient stocks within the ecosystem at planting and at the end of the rotation suggested that nutrient contents in OR were largely involved in the different response observed between treatments. OR management treatments did not significantly modify most of the nutrient concentrations in the upper layers of the mineral soil. Conventional soil analyses performed before planting and at ages 1 and 3 years were unable to detect differences between treatments despite large differences in tree growth. In contrast, linear regressions between stand aboveground biomass at harvesting and OR mass at planting (independent variable) showed that OR mass was an excellent predictor of stand yield (R2 = 0.99). A large share of soil fertility comes from organic material above the mineral soil in highly weathered sandy soils and OR mass at planting might be used in conjunction with soil analyses to assess the potential of these soils to support forest plantations. 相似文献
96.
Modeling the invasive emerald ash borer risk of spread using a spatially explicit cellular model 总被引:1,自引:0,他引:1
Anantha M. Prasad Louis R. Iverson Matthew P. Peters Jonathan M. Bossenbroek Stephen N. Matthews T. Davis Sydnor Mark W. Schwartz 《Landscape Ecology》2010,25(3):353-369
The emerald ash borer (EAB, Agrilus planipennis) is decimating native ashes (Fraxinus sp.) throughout midwestern North America, killing millions of trees over the years. With plenty of ash available throughout
the continent, the spread of this destructive insect is likely to continue. We estimate that the insect has been moving along
a “front” at about 20 km/year since about 1998, but more alarming is its long-range dispersal into new locations facilitated
by human activities. We describe a spatially explicit cell-based model used to calculate risk of spread in Ohio, by combining
the insect’s flight and short-range dispersal (“insect flight”) with human-facilitated, long-range dispersal (“insect ride”).
This hybrid model requires estimates of EAB abundance, ash abundance, major roads and traffic density, campground size and
usage, distance from the core infested zone, wood products industry size and type of wood usage, and human population density.
With the “insect flight” model, probability of movement is dependent on EAB abundance in the source cells, the quantity of
ash in the target cells, and the distances between them. With the “insect-ride” model, we modify the value related to ash
abundance based on factors related to potential human-assisted movements of EAB-infested ash wood or just hitchhiking insects.
We attempt to show the advantage of our model compared to statistical approaches and to justify its practical value to field
managers working with imperfect knowledge. We stress the importance of the road network in distributing insects to new geographically
dispersed sites in Ohio, where 84% were within 1 km of a major highway. 相似文献
97.
Bryan C. Pijanowski Louis R. Iverson C. Ashton Drew Henry N. N. Bulley Jeanine M. Rhemtulla Michael C. Wimberly Annett Bartsch Jian Peng 《Landscape Ecology》2010,25(1):5-16
We argue for the landscape ecology community to adopt the study of poverty and the ecology of landscapes as a Grand Challenge
Topic. We present five areas of possible research foci that we believe that landscape ecologists can join with other social
and environmental scientists to increase scientific understanding of this pressing issue: (1) scale and poverty; (2) landscape
structure and human well-being; (3) social and ecological processes linked to spatial patterns in landscapes; (4) conservation
and poverty, and (5) applying the landscape ecologist’s toolkit. A brief set of recommendations for landscape ecologists is
also presented. These include the need to utilize broad frameworks that integrate social and ecological variables, build capacity
to do this kind of work through the development of strong collaborations of researchers in developed and developing countries,
create databases in international locations where extreme poverty exists, and create a new generation of researchers capable
of addressing this pressing social and environmental issue. 相似文献
98.
99.
We studied the influence of spent mushroom substrate (SMS) land application on water resources. Four study sites, including mushroom farms with low or high density land applications of SMS, and two controls, an alfalfa field and a woodland, were instrumented with soilwater lysimeters and groundwater monitoring wells. Water samples were collected during the dormant season (winter) and growing season (spring). Samples were analyzed for a number of water quality parameters, including dissolved organic carbon (DOC), dissolved organic nitrogen (DON), ammonia, chloride, nitrate, nitrite, phosphate, sulfate, aluminum, cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, mercury, nickel, potassium, silicon, sodium, and zinc. Additional analyses were performed for pesticides commonly used in the cultivation of alfalfa or corn, or for insect control, including methomyl, dimethoate, hexazinone, atrazine, diuron and permethrin.All agricultural sites had elevated salt concentrations relative to the woodland site. The mushroom farm where SMS was applied in high concentrations had salt concentrations in the soilwater that were 10 to 100 times higher than the other agricultural sites. Of particular note were ammonium, nitrate, chloride, sulfate, calcium, magnesium, sodium, and potassium. Each of these were also elevated in the groundwater. The high salt concentrations were reflected in measurements of electrical conductivity. DOC and DON concentrations were also elevated in the soilwater and groundwater. Groundwater from each agricultural site, including the agricultural control, exceeded the primary drinking water standard for nitrate.No pesticide residues were detected in well or lysimeter water collected at either site amended with SMS. Water samples collected from the woodland and at the alfalfa field not receiving SMS contained part per trillion quantities of a few pesticides. 相似文献
100.
Vishalakshi Iyer Professor D. K. Salunkhe S. K. Sathe Louis B. Rockland 《Plant foods for human nutrition (Dordrecht, Netherlands)》1980,30(1):27-43
Soaking three beans cultivars (Phaseolus vulgaris L.: Great Northern, kidney, and pinto) in mixed salt solution (sodium chloride 2.5% + sodium bicarbonate 1.5% + sodium tripolyphosphate 1.0% + sodium carbonate 0.5%) resulted in 80%–85% reduction in cooking time over corresponding controls. Irradiation (-rays) at 500 krads of soaked and dehydrated beans caused a reduction of nearly 50% in cooking time. Water uptake and leaching losses for each treatment during soaking at 22°, 37°, and 45°C were investigated. High temperature (37° and 45°C) and pH (9.0) caused greater water imbibition and total solid loss than at room temperature (22°C). Organoleptic evaluation revealed that quick-cooking Great Northern beans appear to be more acceptable than kidney and pinto beans. Quick-cooking cooked beans had better in vitro protein digestibility than conventionally cooked beans. Phenolic content was found to be inversely related to in vitro digestibility.Utah Agricultural Experiment Station Journal article no. 2481. 相似文献