Aquaculture in North America: An Assessment of Future Prospects

1982 ◽  
Vol 39 (1) ◽  
pp. 151-154 ◽  
Author(s):  
P. A. Larkin
Keyword(s):  
North America ◽  
Large Scale ◽  
Geographical Location ◽  
Aquatic Environments ◽  
Future Prospects ◽  
Growing Period ◽  
Close Proximity ◽  
Cheap Alternative ◽  
Alternative Sources ◽  
Simple Technology

The farming of aquatic environments is already a large-scale world enterprise involving relatively simple technology, but aquacultural production in North America is only a small part of the world total. Aquaculture is only economically rewarding where high rates of production over a long growing period can be coupled with close proximity to large markets in which there are few cheap alternative sources of protein. Much of North American aquaculture is aimed at meeting demands of recreational fishermen rather than as a way of producing food. There are many opportunities for development of aquaculture in North America and it seems reasonable to project substantial increases in production in the next two decades.Key words: aquaculture, geographical location, North America, future prospects, economics

Interpreting Seventeenth-Century Probate Documents: John Carter, Master Carpenter in St Albans

2011 ◽  
pp. 66-83
Author(s):  
Jane Harris ◽  
Pat Howe
Keyword(s):  
Seventeenth Century ◽  
Large Scale ◽  
Local Context ◽  
Social Standing ◽  
Close Proximity ◽  
Market Town ◽  
Consumer Age

This is a study of a successful seventeenth-century carpenter in St Albans, John Carter, using probate and other documents, assisted by a large-scale computer database of St Albans residents of the period. Sections of the article cover his family, his work and his house and its contents, which have been reconstructed from his probate inventory and from knowledge of the structure of other local houses of the period. Carter's social standing is discussed, both in its local context and in relation to previous probate inventory analyses. This micro-study sheds unusual light upon aspects of the life of a 'middling sort' of person, living in a thriving market town in close proximity to London, at the beginning of the consumer age.

Assessment of bioenergy development potential in agricultural enterprises

2020 ◽  
pp. 165-171
Author(s):  
Iryna Hryhoruk
Keyword(s):  
Renewable Energy ◽  
Large Scale ◽  
Agricultural Waste ◽  
General Structure ◽  
Geographical Location ◽  
Economic Assessment ◽  
Energy Resources ◽  
Industrial Complex ◽  
Renewable Energy Resources ◽  
Energy Potential

Exhaustion of traditional energy resources, their uneven geographical location, and catastrophic changes in the environment necessitate the transition to renewable energy resources. Moreover, Ukraine's economy is critically dependent on energy exports, and in some cases, the dependence is not only economic but also political, which in itself poses a threat to national security. One of the ways to solve this problem is the large-scale introduction and use of renewable energy resources, bioenergy in particular. The article summarizes and offers methods for assessing the energy potential of agriculture. In our country, a significant amount of biomass is produced every year, which remains unused. A significant part is disposed of due to incineration, which significantly harms the environment and does not allow earning additional funds. It is investigated that the bioenergy potential of agriculture depends on the geographical distribution and varies in each region of Ukraine. Studies have shown that as of 2019 the smallest share in the total amount of conventional fuel that can be obtained from agricultural waste and products suitable for energy production accounts for Zakarpattya region - 172.5 thousand tons. (0.5% of the total) and Chernivtsi region - 291.3 thousand tons. (0.9%). Poltava region has the greatest potential - 2652.2 thousand tons. (7.8%) and Vinnytsia - 2623.7 thousand tons. (7.7%). It should be noted that the use of the energy potential of biomass in Ukraine can be called unsatisfactory. The share of biomass in the provision of primary energy consumption is very small. For bioenergy to occupy its niche in the general structure of the agro-industrial complex, it is necessary to develop mechanisms for its stimulation. In addition, an effective strategy for the development of the bioenergy sector of agriculture is needed. The article considers the general energy potential of agriculture, its indicative structure. The analysis is also made in terms of areas. In addition, an economic assessment of the possible use of existing potential is identified.

scholarly journals A therapeutic vascular conduit to support in vivo cell-secreted therapy

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Edward X. Han ◽  
Hong Qian ◽  
Bo Jiang ◽  
Maria Figetakis ◽  
Natalia Kosyakova ◽  
...  
Keyword(s):  
Vascular Graft ◽  
Large Scale ◽  
Biological Effects ◽  
Therapeutic Protein ◽  
Close Proximity ◽  
Delivery Platform ◽  
Stage Renal Disease ◽  
End Stage

AbstractA significant barrier to implementation of cell-based therapies is providing adequate vascularization to provide oxygen and nutrients. Here we describe an approach for cell transplantation termed the Therapeutic Vascular Conduit (TVC), which uses an acellular vessel as a scaffold for a hydrogel sheath containing cells designed to secrete a therapeutic protein. The TVC can be directly anastomosed as a vascular graft. Modeling supports the concept that the TVC allows oxygenated blood to flow in close proximity to the transplanted cells to prevent hypoxia. As a proof-of-principle study, we used erythropoietin (EPO) as a model therapeutic protein. If implanted as an arteriovenous vascular graft, such a construct could serve a dual role as an EPO delivery platform and hemodialysis access for patients with end-stage renal disease. When implanted into nude rats, TVCs containing EPO-secreting fibroblasts were able to increase serum EPO and hemoglobin levels for up to 4 weeks. However, constitutive EPO expression resulted in macrophage infiltration and luminal obstruction of the TVC, thus limiting longer-term efficacy. Follow-up in vitro studies support the hypothesis that EPO also functions to recruit macrophages. The TVC is a promising approach to cell-based therapeutic delivery that has the potential to overcome the oxygenation barrier to large-scale cellular implantation and could thus be used for a myriad of clinical disorders. However, a complete understanding of the biological effects of the selected therapeutic is absolutely essential.

Interannual Variability of North American Winter Temperature Extremes and Its Associated Circulation Anomalies in Observations and CMIP5 Simulations

2020 ◽  
Vol 33 (3) ◽  
pp. 847-865 ◽  
Author(s):  
B. Yu ◽  
H. Lin ◽  
V. V. Kharin ◽  
X. L. Wang
Keyword(s):  
North America ◽  
Surface Temperature ◽  
Atmospheric Circulation ◽  
North American ◽  
North Pacific ◽  
Large Scale ◽  
Temperature Extremes ◽  
Temperature Extreme ◽  
Central Canada ◽  
Leading Mode

AbstractThe interannual variability of wintertime North American surface temperature extremes and its generation and maintenance are analyzed in this study. The leading mode of the temperature extreme anomalies, revealed by empirical orthogonal function (EOF) analyses of December–February mean temperature extreme indices over North America, is characterized by an anomalous center of action over western-central Canada. In association with the leading mode of temperature extreme variability, the large-scale atmospheric circulation features an anomalous Pacific–North American (PNA)-like pattern from the preceding fall to winter, which has important implications for seasonal prediction of North American temperature extremes. A positive PNA pattern leads to more warm and fewer cold extremes over western-central Canada. The anomalous circulation over the PNA sector drives thermal advection that contributes to temperature anomalies over North America, as well as a Pacific decadal oscillation (PDO)-like sea surface temperature (SST) anomaly pattern in the midlatitude North Pacific. The PNA-like circulation anomaly tends to be supported by SST warming in the tropical central-eastern Pacific and a positive synoptic-scale eddy vorticity forcing feedback on the large-scale circulation over the PNA sector. The leading extreme mode–associated atmospheric circulation patterns obtained from the observational and reanalysis data, together with the anomalous SST and synoptic eddy activities, are reasonably well simulated in most CMIP5 models and in the multimodel mean. For most models considered, the simulated patterns of atmospheric circulation, SST, and synoptic eddy activities have lower spatial variances than the corresponding observational and reanalysis patterns over the PNA sector, especially over the North Pacific.

scholarly journals Atmospheric Conditions Associated with Labrador Sea Deep Convection: New Insights from a Case Study of the 2006/07 and 2007/08 Winters

2016 ◽  
Vol 29 (14) ◽  
pp. 5281-5297 ◽  
Author(s):  
Who M. Kim ◽  
Stephen Yeager ◽  
Ping Chang ◽  
Gokhan Danabasoglu
Keyword(s):  
North America ◽  
North Atlantic ◽  
Large Scale ◽  
Initial Conditions ◽  
Deep Convection ◽  
La Niña ◽  
Labrador Sea ◽  
Atmospheric Conditions ◽  
Circulation Anomaly ◽  
La Nina

Abstract Deep convection in the Labrador Sea (LS) resumed in the winter of 2007/08 under a moderately positive North Atlantic Oscillation (NAO) state. This is in sharp contrast with the previous winter with weak convection, despite a similar positive NAO state. This disparity is explored here by analyzing reanalysis data and forced-ocean simulations. It is found that the difference in deep convection is primarily due to differences in large-scale atmospheric conditions that are not accounted for by the conventional NAO definition. Specifically, the 2007/08 winter was characterized by an atmospheric circulation anomaly centered in the western North Atlantic, rather than the eastern North Atlantic that the conventional NAO emphasizes. This anomalous circulation was also accompanied by anomalously cold conditions over northern North America. The controlling influence of these atmospheric conditions on LS deep convection in the 2008 winter is confirmed by sensitivity experiments where surface forcing and/or initial conditions are modified. An extended analysis for the 1949–2009 period shows that about half of the winters with strong heat losses in the LS are associated with such a west-centered circulation anomaly and cold conditions over northern North America. These are found to be accompanied by La Niña–like conditions in the tropical Pacific, suggesting that the atmospheric response to La Niña may have a strong influence on LS deep convection.

Wildfires in the southern Canadian Rocky Mountains and their relationship to mid-tropospheric anomalies

1993 ◽  
Vol 23 (6) ◽  
pp. 1213-1222 ◽  
Author(s):  
E.A. Johnson ◽  
D.R. Wowchuk
Keyword(s):  
North America ◽  
Rocky Mountains ◽  
Large Scale ◽  
Fire Frequency ◽  
Fuel Moisture ◽  
Large Fire ◽  
Canadian Rocky Mountains ◽  
Area Burned ◽  
Upper Level ◽  
Moisture Conditions

In this paper we present evidence for a large-scale (synoptic-scale) meteorological mechanism controlling the fire frequency in the southern Canadian Rocky Mountains. This large-scale control may explain the similarity in average fire frequencies and timing of change in average fire frequencies for the southern Canadian Rocky Mountains. Over the last 86 years the size distribution of fires (annual area burned) in the southern Canadian Rockies was distinctly bimodal, with a separation between small- and large-fire years at approximately 10–25 ha annual area burned. During the last 35 years, large-fire years had significantly lower fuel moisture conditions and many mid-tropospheric surface-blocking events (high-pressure upper level ridges) during July and August (the period of greatest fire activity). Small-fire years in this period exhibited significantly higher fuel moisture conditions and fewer persistent mid-tropospheric surface-blocking events during July and August. Mid-tropospheric surface-blocking events during large-fire years were teleconnected (spatially and temporally correlated in 50 kPa heights) to upper level troughs in the North Pacific and eastern North America. This relationship takes the form of the positive mode of the Pacific North America pattern.

scholarly journals Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions

2016 ◽  
Vol 113 (3) ◽  
pp. 526-531 ◽  
Author(s):  
Yanxu Zhang ◽  
Daniel J. Jacob ◽  
Hannah M. Horowitz ◽  
Long Chen ◽  
Helen M. Amos ◽  
...  
Keyword(s):  
North America ◽  
Large Scale ◽  
Elemental Mercury ◽  
Atmospheric Mercury ◽  
Small Scale ◽  
Commercial Products ◽  
Earth Observing System ◽  
Global Emission ◽  
Emission Controls ◽  
Phase Out

Observations of elemental mercury (Hg0) at sites in North America and Europe show large decreases (∼1–2% y−1) from 1990 to present. Observations in background northern hemisphere air, including Mauna Loa Observatory (Hawaii) and CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) aircraft flights, show weaker decreases (<1% y−1). These decreases are inconsistent with current global emission inventories indicating flat or increasing emissions over that period. However, the inventories have three major flaws: (i) they do not account for the decline in atmospheric release of Hg from commercial products; (ii) they are biased in their estimate of artisanal and small-scale gold mining emissions; and (iii) they do not properly account for the change in Hg0/HgII speciation of emissions from coal-fired utilities after implementation of emission controls targeted at SO2 and NOx. We construct an improved global emission inventory for the period 1990 to 2010 accounting for the above factors and find a 20% decrease in total Hg emissions and a 30% decrease in anthropogenic Hg0 emissions, with much larger decreases in North America and Europe offsetting the effect of increasing emissions in Asia. Implementation of our inventory in a global 3D atmospheric Hg simulation [GEOS-Chem (Goddard Earth Observing System-Chemistry)] coupled to land and ocean reservoirs reproduces the observed large-scale trends in atmospheric Hg0 concentrations and in HgII wet deposition. The large trends observed in North America and Europe reflect the phase-out of Hg from commercial products as well as the cobenefit from SO2 and NOx emission controls on coal-fired utilities.

scholarly journals Charcoal in soils of the Allerød-Younger Dryas transition were the result of natural fires and not necessarily the effect of an extra-terrestrial impact

2008 ◽  
Vol 87 (4) ◽  
pp. 359-361 ◽  
Author(s):  
T. van der Hammen ◽  
B. van Geel
Keyword(s):  
North America ◽  
Large Scale ◽  
Sand Dunes ◽  
Younger Dryas ◽  
Natural Fires ◽  
Water Tables ◽  
Pine Trees ◽  
Climate Cooling ◽  
Fossil Records ◽  
Terrestrial Material

AbstractDuring the warm Bølling-Allerød interstadial, tree species migrated from their refugia in southern Europe northwards into the area within the present temperate climatic zone. It is evident from high levels of charcoal in fossil records in this region that, especially during the later part of the Bølling-Allerød interstadial, many fires occurred. The start of the Younger Dryas was characterised by rapid and intense cooling and rising water tables, with catastrophic effects on the vegetation. Thermophilous pine trees could not survive the cold Younger Dryas climate. Dead wood provided an abundant source of fuel for intense, large-scale fires seen in many records as a concentration of charcoal particles in so-called ’Usselo-soils’ dated to ca 10,95014C BP. A similar trend in increased charcoal indicating increased burning is seen at many sites across North America at this time and it has been suggested by Firestone et al. (2007) that this was caused by an explosion of extra-terrestrial material over northern North America, causing the Younger Dryas climate cooling and Megafaunal extinction. We argue that there is no need to invoke an extraterrestrial cause to explain the charcoal in the fossilized soils. The volume of forest trees that died as a result of the cold Younger Dryas climate would easily have supplied sufficient fuel for intense, large-scale fires and can be used to account for the concentration of charcoal particles. As soils were no longer covered by dense vegetation, much erosion occurred during the Younger Dryas and therefore, at many places, Usselo soils, rich in charcoal, were preserved under aeolian sand dunes.

Invasive Cereal Aphids of North America: Ecology and Pest Management

2019 ◽  
Vol 64 (1) ◽  
pp. 73-93 ◽  
Author(s):  
Michael J. Brewer ◽  
Frank B. Peairs ◽  
Norman C. Elliott
Keyword(s):  
North America ◽  
Pest Management ◽  
Great Plains ◽  
Large Scale ◽  
Production Systems ◽  
Cereal Crops ◽  
Cereal Aphids ◽  
Sugarcane Aphid ◽  
Cereal Production ◽  
Abundance And Diversity

Aphid invasions of North American cereal crops generally have started with colonization of a new region or crop, followed by range expansion and outbreaks that vary in frequency and scale owing to geographically variable influences. To improve understanding of this process and management, we compare the invasion ecology of and management response to three cereal aphids: sugarcane aphid, Russian wheat aphid, and greenbug. The region exploited is determined primarily by climate and host plant availability. Once an area is permanently or annually colonized, outbreak intensity is also affected by natural enemies and managed inputs, such as aphid-resistant cultivars and insecticides. Over time, increases in natural enemy abundance and diversity, improved compatibility among management tactics, and limited threshold-based insecticide use have likely increased resilience of aphid regulation. Application of pest management foundational practices followed by a focus on compatible strategies are relevant worldwide. Area-wide pest management is most appropriate to large-scale cereal production systems, as exemplified in the Great Plains of North America.

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