Sediment records of the influence of river damming on the dynamics of the Nelson and Churchill Rivers, western Hudson Bay, Canada, during the last centuries

The Holocene ◽  
2016 ◽  
Vol 27 (5) ◽  
pp. 712-725 ◽  
Author(s):  
Quentin Duboc ◽  
Guillaume St-Onge ◽  
Patrick Lajeunesse
Keyword(s):  
River Mouth ◽  
Sediment Concentration ◽  
Hudson Bay ◽  
Continuous Control ◽  
Dam Construction ◽  
Physical Chemical ◽  
Hyperpycnal Flows ◽  
Western Hudson Bay ◽  
The 1960S ◽  
The Impact

Two gravity cores (778 and 780) sampled at the Nelson River mouth and one (776) at the Churchill River mouth in western Hudson Bay, Canada, were analyzed in order to identify the impact of dam construction on hydrology and sedimentary regime of both rivers. Another core (772) was sampled offshore and used as a reference core without a direct river influence. Core chronology was established using 14C and 210Pb measurements. Cores 778 and 780 show greater variability than the others, and the physical, chemical, magnetic, and sedimentological properties measured on these cores reveal the presence of several hyperpycnites, indicating the occurrence of hyperpycnal flows associated with floods of the Nelson River. These hyperpycnal flows were probably caused by ice-jam formation, which can increase both the flow and the sediment concentration following the breaching of such natural dams. However, these hyperpycnites are only observed in the lower parts of cores 778 and 780. It was not possible to establish a precise chronology because of the remobilization of sediments by the floods. Nevertheless, some modern 14C ages suggest that this change in sedimentary regime is recent and could be concurrent with the dam construction on the Nelson River, which allows a continuous control of its flow since the 1960s. This control prevented the formation of hyperpycnal flows and the deposition of hyperpycnites. Finally, core 776 contains only one rapidly deposited layer. This lower frequency may be related to the enclosed estuary of the Churchill River, its weaker discharge, and the distance of the site from shore.

scholarly journals Community composition of zooplankton exported from a shallow polymictic reservoir linked to wind conditions

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7611
Author(s):  
Nathan Ruhl ◽  
Desireé Haban ◽  
Caitlyn Czajkowski ◽  
Michael Grove ◽  
Courtney E. Richmond
Keyword(s):  
Community Composition ◽  
Resource Availability ◽  
Dam Construction ◽  
Atmospheric Conditions ◽  
Future Studies ◽  
Factors Influencing ◽  
Physical Chemical ◽  
Biodiversity And Ecosystem Function ◽  
The Impact ◽  
Lentic Systems

Zooplankton exported from lentic systems provision lotic systems with easily captured, consumed, and assimilated prey items. Previous studies have demonstrated that the community composition of zooplankton exports (CCZE) vary over time, which introduces temporal differences in lotic resource availability (zooplankton prey) in downstream habitats. In the study presented here, we monitored variation in CCZE from a polymictic reservoir outfall in response to physical–chemical and atmospheric conditions bi-hourly over three different 24-h periods. Community composition of zooplankton export varied over the course of the day, and exports were most closely associated with wind directionality. Future studies of temporal variation in CCZE should incorporate wind conditions, especially in shallow systems where holomixis occurs frequently. Polymictic reservoirs are becoming increasingly common as the global pace of small dam construction quickens, making both the identification of factors influencing CCZE and the impact of zooplankton exports on local biodiversity and ecosystem function increasingly important to understand.

scholarly journals Status and Trends of the Lake Ontario Macrobenthos

1991 ◽  
Vol 48 (8) ◽  
pp. 1558-1567 ◽  
Author(s):  
Thomas F. Nalepa
Keyword(s):  
Great Lakes ◽  
River Mouth ◽  
Lake Ontario ◽  
The Other ◽  
Niagara River ◽  
Major River ◽  
Trends Over Time ◽  
The 1960S ◽  
River Mouths ◽  
The Impact

The benthic macroinvertebrate community of Lake Ontario was examined relative to communities found in the other Great Lakes and also relative to trends over time. In the nearshore, populations are heavily influenced by municipal and industrial inputs. For example, oligochaete abundances in the nearshore are higher than in any of the other Great Lakes (excluding shallow Lake Erie), communities have been altered even to relatively deep depths near the major river mouths, and the pollution-sensitive Pontoporeia hoyi is scarce along the southern shoreline east of the Niagara River mouth. In the profundal, benthic composition is similar to that found in the other Great Lakes, but biomass is less than might be expected given the amount of organic material settling to the bottom. Benthic standing stocks in this region have apparently declined almost threefold since the 1960s. Reasons for this decline do not appear to be related to trends in water column productivity or to predation pressure, but may be related to the accumulation of contaminants. Research needs include studies to assess benthic trends over a much broader area of the lake and studies to examine the impact of sublethal levels of contaminants.

The ‘Modernisation’ of Scotland and its Impact on Glasgow, 1955–1979: ‘Unwanted Side Effects’ and Vulnerabilities

2016 ◽  
Vol 25 (3) ◽  
pp. 294-316 ◽  
Author(s):  
Chik Collins ◽  
Ian Levitt
Keyword(s):  
Side Effects ◽  
Government Policy ◽  
Regional Policy ◽  
Excess Mortality ◽  
Policy Agenda ◽  
Policy Makers ◽  
Uk Government ◽  
1960S And 1970S ◽  
The 1960S ◽  
The Impact

This article reports findings of research into the far-reaching plan to ‘modernise’ the Scottish economy, which emerged from the mid-late 1950s and was formally adopted by government in the early 1960s. It shows the growing awareness amongst policy-makers from the mid-1960s as to the profoundly deleterious effects the implementation of the plan was having on Glasgow. By 1971 these effects were understood to be substantial with likely severe consequences for the future. Nonetheless, there was no proportionate adjustment to the regional policy which was creating these understood ‘unwanted’ outcomes, even when such was proposed by the Secretary of State for Scotland. After presenting these findings, the paper offers some consideration as to their relevance to the task of accounting for Glasgow's ‘excess mortality’. It is suggested that regional policy can be seen to have contributed to the accumulation of ‘vulnerabilities’, particularly in Glasgow but also more widely in Scotland, during the 1960s and 1970s, and that the impact of the post-1979 UK government policy agenda on these vulnerabilities is likely to have been salient in the increase in ‘excess mortality’ evident in subsequent years.

Submikroninių aerozolio dalelių kilmės ir fizikinių-cheminių parametrų įtaka atmosferos šiluminei pusiausvyrai

2020 ◽  
Author(s):  
◽  
Julija Pauraitė-Dudek
Keyword(s):  
Chemical Parameters ◽  
Radiative Balance ◽  
Submicron Aerosol ◽  
Physical Chemical ◽  
The Impact ◽  
Aerosol Source

The impact of submicron aerosol source and physical-chemical parameters on atmospheric radiative balance

Novel Coronavirus 2019 Outbreak: A Global Epidemic

2020 ◽  
Vol 17 (12) ◽  
pp. 1458-1464
Author(s):  
Sweta Kamboj ◽  
Rohit Kamboj ◽  
Shikha Kamboj ◽  
Kumar Guarve ◽  
Rohit Dutt
Keyword(s):  
World Health ◽  
Upper Respiratory Tract ◽  
Global Epidemic ◽  
The Public ◽  
The Government ◽  
Tract Disease ◽  
The 1960S ◽  
Novel Coronavirus ◽  
Health Organization ◽  
The Impact

Background: In the 1960s, the human coronavirus was designated, which is responsible for the upper respiratory tract disease in children. Back in 2003, mainly 5 new coronaviruses were recognized. This study directly pursues to govern knowledge, attitude and practice of viral and droplet infection isolation safeguard among the researchers during the outbreak of the COVID-19. Introduction: Coronavirus is a proteinaceous and infectious pathogen. It is an etiological agent of severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS). Coronavirus, appeared in China from the seafood and poultry market last year, which has spread in various countries, and has caused several deaths. Methods: The literature data has been taken from different search platforms like PubMed, Science Direct, Embase, Web of Science, who.int portal and complied. Results: Corona virology study will be more advanced and outstanding in recent years. COVID-19 epidemic is a threatening reminder not solely for one country but all over the universe. Conclusion: In this review article, we encapsulated the pathogenesis, geographical spread of coronavirus worldwide, also discussed the perspective of diagnosis, effective treatment, and primary recommendations by the World Health Organization, and guidelines of the government to slow down the impact of the virus are also optimistic, efficacious and obliging for the public health. However, it will take a prolonged time in the future to overcome this epidemic.

scholarly journals Modeling the Impact of Atmospheric Warming on Staple Crop Growth in China in the 1960s and 2000s

Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 36
Author(s):  
Qing Zhang ◽  
Wen Zhang ◽  
Yongqiang Yu ◽  
Tingting Li ◽  
Lijun Yu
Keyword(s):  
Winter Wheat ◽  
Climate Warming ◽  
Northeast China ◽  
Cropping Systems ◽  
Crop Growth ◽  
East China ◽  
Frequency Distributions ◽  
Before And After ◽  
The 1960S ◽  
The Impact

Responses of crop growth to climate warming are fundamental to future food security. The response of crops to climate change may be subtly different at their growing stages. Close insights into the differentiated stage-dependent responses of crops are significantly important in making adaptive adjustments of crops’ phenological optimization and cultivar improvement in diverse cropping systems. Using the Agro-C model, we studied the influence of past climate warming on crops in typical cropping systems in China. The results showed that while the temperature had increased distinctly from the 1960s to 2000s, the temperature frequency distributions in the growth season of crops moved to the high-temperature direction. The low temperature days during the crop growth periods that suppress crop growth decreased in the winter wheat area in North and East China, rice and maize areas in Northeast China, and the optimum temperature days increased significantly. As a result, the above ground biomass (AGB) of rice and maize in Northeast China and winter wheat in North and East China increased distinctly, while that of rice in South China had no significant change. A comparison of the key growth periods before and after heading (silking) showed that the warming before heading (silking) made a great contribution to the increase in the AGB, especially for winter wheat.

scholarly journals When Machines Take the Beans: Ex-Ante Socioeconomic Impact Evaluation of Mechanized Harvesting of Mungbean in Bangladesh and Myanmar

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 925
Author(s):  
Lutz Depenbusch ◽  
Cathy Rozel Farnworth ◽  
Pepijn Schreinemachers ◽  
Thuzar Myint ◽  
Md Monjurul Islam ◽  
...  
Keyword(s):  
Well Being ◽  
Careful Consideration ◽  
Women Farmers ◽  
Men And Women ◽  
Farm Work ◽  
Weather Shocks ◽  
Budget Analysis ◽  
Ex Ante ◽  
The 1960S ◽  
The Impact

Agricultural mechanization has spread across much of Asia since the 1960s. It has increased agricultural productivity and reduced arduous farm work. However, differing impacts for smallholders and hired laborers, and for men and women, require careful consideration. This study analyzed, ex-ante, the likely social and economic tradeoffs of mechanizing the mungbean harvest in Bangladesh and Myanmar. We used a mixed methods approach combining survey data from 852 farm households with in-depth interviews in four villages. Partial budget analysis shows that mechanical harvesting of mungbean is not yet profitable for most farms. There is nevertheless an incentive to mechanize as the associated timeliness of the harvest reduces the risk of harvest losses from weather shocks. Men and women farmers expect time savings and reduced drudgery. The results confirm that hired workers depend on manual harvesting for income and status in both countries. Most hired workers are landless married women with limited access to other sources of income. In the short term, farmers are likely to combine manual harvests and a final mechanized harvest of the indeterminate crop. This could mediate the impact on hired workers. However, in the long term, it will be necessary to facilitate income-generating opportunities for women in landless rural families to maintain their well-being and income.

scholarly journals Arthrospira Platensis (Spirulina) Supplementation on Laying Hens’ Performance: Eggs Physical, Chemical, and Sensorial Qualities

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 386 ◽  
Author(s):  
Omri ◽  
Amraoui ◽  
Tarek ◽  
Lucarini ◽  
Durazzo ◽  
...  
Keyword(s):  
Laying Hens ◽  
Control Diet ◽  
Dietary Supplementation ◽  
Basal Diet ◽  
Egg Yolk ◽  
Arthrospira Platensis ◽  
Cholesterol Concentration ◽  
Physical Chemical ◽  
Egg Yolks ◽  
The Impact

The present study evaluated the effects of dietary supplementation of spirulina on laying hens’ performances: Eggs’ physical, chemical, and sensorial qualities. A total of 45 Lohman White hens, 44 weeks of age, were randomized into 3 groups of 15 birds. Hens were given 120 g/d of a basal diet containing 0% (control), 1.5%, and 2.5% of spirulina for 6 weeks. Albumen height and consequently Haugh unit were significantly affected by dietary supplementation of spirulina (p < 0.05) and by weeks on diet (p < 0.05). This supplement did not affect (p > 0.05) egg yolk weight or height. However, spirulina increased egg yolk redness (a*) from 1.33 (C) to 12.67 (D1) and 16.19 (D2) and reduced (p < 0.05) the yellowness (b*) parameter from 62.1(C) to 58.17 (D1) and 55.87 (D2). Egg yolks from hens fed spirulina were darker, more red, and less yellow in color than egg yolks from hens fed the control-diet (p < 0.0001). However, spirulina did not affect (p > 0.05) egg yolks’ total cholesterol concentration. In conclusion, a significant enhancement of egg yolk color was found in response to spirulina supplementation. Further investigations are needed to evaluate the impact of spirulina on egg yolks’ fatty acids profile.

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