scholarly journals Microbial pollution of the Mezam river system and its health impact in Bamenda (North-West Cameroon)

2013 ◽  
Vol 7 (42) ◽  
pp. 4940-4948 ◽  
Author(s):  
Margaret Awah TITA ◽  
Alice MAGHA ◽  
KABEYENE Veacute ronique Beyala KAMGANG
Keyword(s):  
River System ◽  
Health Impact ◽  
Microbial Pollution ◽  
North West

Sprat – A Simple River Quality Impact Model for Intermittent Discharges

1989 ◽  
Vol 21 (12) ◽  
pp. 1793-1796
Author(s):  
C. P. Crockett ◽  
R. W. Crabtree ◽  
H. R. Markland
Keyword(s):  
Plug Flow ◽  
River System ◽  
Response Assessment ◽  
River Basin Management ◽  
Impact Model ◽  
Basin Management ◽  
Potential Accuracy ◽  
North West ◽  
River Quality ◽  
Receiving Waters

The detrimental influence of storm sewer overflows on urban river quality has been widely recognised for many years. One objective of the WRc River Basin Management programme is the development of a river impact model capable of predicting the transient quality changes in receiving waters due to intermittent storm sewage discharges. The production of SPRAT (Spill Pollution Response Assessment Technique) is the first step in the development of such a model. SPRAT incorporates a number of significant simplifications, most notably plug flow and instantaneous mixing, and does not implicitly take into account the effects of dispersion. These simplifications reflect the large errors associated with the model inputs. These errors severely limit the potential accuracy of any river impact model. The model has been applied to the Bolton river system in North West England. The development and application of SPRAT has enabled the requirements for a more sophisticated river quality impact model to be clearly defined, in addition to highlighting the problems associated with gathering suitable data with which to build and calibrate such a model.

scholarly journals Albert Peter Low — The Iron Man of Labrador

2018 ◽  
Vol 45 (1) ◽  
pp. 43-58
Author(s):  
Derek H.C. Wilton
Keyword(s):  
River System ◽  
Ore Deposits ◽  
Mining District ◽  
North West ◽  
North American Continent ◽  
The North ◽  
Wilderness Areas ◽  
Iron Ore Deposits ◽  
History Of ◽  
Scientific Results

In 1893–1894, Albert Peter Low of the Geological Survey of Canada, along with D.I.V. Eaton and four indigenous assistants explored the Labrador Peninsula, then perceived as one of the last great unexplored wilderness areas of North America. The expedition left Lake St. John (now Lac St. Jean) on June 17, 1893, canoeing across the northeastern edge of the North American continent, arriving at Fort Chimo (now Kuujjuaq) on August 27, 1893. They departed Fort Chimo by steamer for Rigolet on the Labrador coast and the Hudson Bay Company post at North West River in the fall of 1893. On March 6, 1894 the party started up the Grand (now Churchill) River continuing through large central lakes into the Ashuanipi river system in western Labrador, then out via the Attikonak River to the Romaine River and finally the Saint Jean river system to arrive at Mingan on the north shore of the St. Lawrence River on August 23, 1894. Low described their fifteen-month journey as having covered over 8700 km including 1600 km on foot, over 4700 km in canoe, 800 km by dog team and 1600 km by steamer. The report from the expedition provides a compendium on the natural history of the region as well as the first geological maps. In terms of economic and scientific results, the greatest was documentation of the vast iron ore deposits of western Labrador; a world-class mining district that has been producing for sixty-three years since 1954. Low’s account also provides details on the essence of such an epic journey, which stands as a classic in the annals of Canadian geological surveying.RÉSUMÉEn 1893–1894, Albert Peter Low de la Commission géologique du Canada, accompagné du D.I.V. Eaton et quatre assistants autochtones ont exploré la péninsule du Labrador, alors perçue comme l'une des dernières grandes étendues sauvages inexplorées d’Amérique du Nord. L’équipe a quitté le Lake St. John (aujourd'hui le lac Saint-Jean) le 17 juin 1893, a traversé la bordure nord-est du continent nord-américain en canoë, et est arrivé à Fort Chimo (aujourd'hui Kuujjuaq) le 27 août 1893. À l'automne de 1893, ils ont quitté Fort Chimo à bord d'un vapeur pour Rigolet, sur la côte du Labrador, et le poste de la Compagnie de la Baie d'Hudson sur la rivière North West. Le 6 mars 1894, les membres de l'équipe ont remonté la rivière Grand (aujourd'hui Churchill), puis à travers les grands lacs centraux jusqu'au bassin de la rivière Ashuanipi, dans l'ouest du Labrador, puis, par la rivière Attikonak jusqu' à la rivière Romaine et, enfin, le réseau de la rivière Saint-Jean jusqu’à Mingan, sur la rive nord du fleuve Saint-Laurent, le 23 août 1894. L’excursion décrite par Low a duré quinze mois et parcouru plus de 8700 km dont 1600 km à pied, plus de 4700 km en canoë, 800 km en attelage de chiens et 1600 km en bateau à vapeur. Le rapport de l'expédition constitue un recueil sur l'histoire naturelle de la région ainsi que des premières cartes géologiques. En ce qui concerne les répercussions économiques et scientifiques, la plus importante en a été la documentation des vastes gisements de minerai de fer de l'ouest du Labrador, un district minier de classe mondiale, en production pendant soixante-trois ans depuis 1954. Le récit de Low fournit également des détails sur le caractère épique d’une telle expédition, laquelle est un classique dans les annales de la Commission géologique du Canada.

Fish community structure in an intermittent river: the importance of environmental stability, landscape factors and within-pool habitat descriptors

2010 ◽  
Vol 61 (5) ◽  
pp. 605 ◽  
Author(s):  
L. S. Beesley ◽  
J. Prince
Keyword(s):  
Species Richness ◽  
River System ◽  
Habitat Diversity ◽  
Underground Water ◽  
Environmental Stability ◽  
Fish Community Structure ◽  
North West ◽  
Distribution Of Fish ◽  
Intermittent River

In rivers worldwide, hydrological persistence and variability (i.e. environmental stability) typically parallel longitudinal changes in habitat. This interaction complicates determination of the hierarchy of mechanisms that structure fish communities along rivers. In this study, we examined fish species richness and presence–absence in pools of an intermittent river system containing underground water storages (Fortescue River, north-west Australia), a system that was predicted to uncouple this relationship. Stability, measured by pool persistence, was unrelated to a pool's maximum depth or its position in the catchment, indicating partial decoupling. However, pool stability remained correlated with habitat diversity and log-transformed surface area. Model selection indicated that species richness was better described by pool stability and the landscape factor stream order than by within-pool habitat descriptors. Permanent pools low in the catchment contained more species than unstable pools in headwater streams. We conclude that the distribution of fish in the Fortescue River is shaped predominantly by processes of extirpation and re-colonisation. Management efforts in this river and similar intermittent systems should focus on the preservation of refuge pools, and limit the construction of barriers that limit dispersal.

scholarly journals The reasons of genetic heterogeneity of Siberian whitefish Coregonus lavaretus pidschian in the Anabar river

2017 ◽  
Vol 15 (3) ◽  
pp. 20-26
Author(s):  
Dmitry S. Sendek ◽  
Eugenie V. Ivanov
Keyword(s):  
Genetic Heterogeneity ◽  
River System ◽  
Coregonus Lavaretus ◽  
Population Genetic Study ◽  
North West ◽  
Siberian Whitefish ◽  
Anabar River ◽  
Environmental Measures ◽  
Phylogenetic Lineages ◽  
Ecological Forms

Background. A population genetic study of Siberian whitefish or pidschian Coregonus lavaretus pidschian Gmelin of the Anabar River (North-West Yakutia) has been done to study genetic structure of the species within a river system and for revealing its phylogeographic relations. Materials and Methods. Five samples of pidschian from different parts of the river were analyzed for 30 isozyme loci. Results and Discussion. The results has demonstrated a significant genetic heterogeneity of the species sampled from lower and middle reaches of the river (0.001 < DN< 0.056). The most likely reason for genetic differentiation of the species within the river system is a colonization of the watershed by independent phylogenetic lineages of whitefish. At present the phylogenetic lineages in Anabar River are presented by sympatric ecological forms of the species – eastern-siberian whitefish and glacial-plains whitefish – which maintain their reproductive isolation. The relationships of ecological forms of whitefish dwelling the Anabar River with other populations of the species in Siberia, and possible ways of penetration of discrete phylogenetic lineages of pidschian in the basin of studied river are discussed. Conclusions. A genetic heterogeneity of whitefish from Anabar River should be taken into account while creating adequate intraspecific taxonomy and considered in conducting fisheries and environmental measures.

Substantial degradation in Air Quality due to Saddleworth Moor Wildfire

2020 ◽  
Author(s):  
Ailish Graham ◽  
James McQuaid ◽  
Stephen Arnold ◽  
Kirsty Pringle ◽  
Richard Pope ◽  
...  
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Excess Mortality ◽  
Health Impact ◽  
Short Term ◽  
North West ◽  
The North ◽  
Short Term Exposure ◽  
The Uk ◽  
The Impact

&lt;p&gt;On June 24&lt;sup&gt;th&lt;/sup&gt; 2018 one of the largest UK wildfires in recent history broke out on Saddleworth Moor, close to Manchester, in north-west England. June 2018 was anomalously hot and dry across the UK which led to the peat on the moor drying out and becoming suscpetible to ignition. Since wildfires close to large populations in the UK have been relatively small and rare in the past, there is little knowledge about the impacts. This has prevented the development of effective strategies to reduce them. This paper uses a high-resolution coupled atmospheric-chemistry model to assess the impact of the fires on particulate matter with a diameter less than 2.5 &amp;#181;m (PM&lt;sub&gt;2.5&lt;/sub&gt;) air quality (AQ) across the north-west region and the subsequent impact on health from short-term exposure. We find that the fires substantially degraded AQ across the north-west. PM&lt;sub&gt;2.5 &lt;/sub&gt;concentrations increased by more than 300% in Oldham and Manchester and up to 50% in areas up to 80 km away such as Liverpool, Wigan and Warrington. This led to a third of the population (4.7 million people) in the simulation domain (-4.9-0.7&amp;#176;E and 53.0-54.4&amp;#176;N) being exposed to moderate PM&lt;sub&gt;2.5 &lt;/sub&gt;concentrations on at least one day, according to the Daily Air Quality Index (36-53 &amp;#181;g m&lt;sup&gt;-3&lt;/sup&gt;), between June 23&lt;sup&gt;rd&lt;/sup&gt; and 30&lt;sup&gt;th &lt;/sup&gt;2018. This equates to 4.5 million people being exposed to PM&lt;sub&gt;2.5 &lt;/sub&gt;above the WHO 24-hour safe-limit exposure of 25 &amp;#181;g m&lt;sup&gt;-3&lt;/sup&gt; on at least one day. Using a concentration-response function we calculate the short-term health impact which indicates that up to 60% of excess mortality between June 23&lt;sup&gt;rd&lt;/sup&gt; and 30&lt;sup&gt;th&lt;/sup&gt; 2018 was attributable to the fires. This represents up to a 165% increase in excess mortality across the region compared to a simulation with no fires. We find the impact of mortality due to PM&lt;sub&gt;2.5 &lt;/sub&gt;from the fires on the economy was also substantial (&amp;#163;5.5m). Thus, our results indicate the need to introduce legislation and education to both reduce the likelihood of wildfires and reduce the population&amp;#8217;s exposure to harmful air pollutants during their occurrence. This is particularly relevant given that wildfires are projected to become more common in the future through climate change and land-use change.&lt;/p&gt;

scholarly journals Fish species using the fish passage between Jamuna and Bangali river at Sariakandi, Bogra

2020 ◽  
Vol 5 (2) ◽  
pp. 53-62
Author(s):  
M Zaman ◽  
MN Naser
Keyword(s):  
Focus Group ◽  
Fish Species ◽  
Group Discussion ◽  
River System ◽  
Fish Passage ◽  
Fish Diversity ◽  
Fish Migration ◽  
Migration Routes ◽  
North West ◽  
Fish Pass

Sariakandi fish pass is unique connecting Jamuna and Bangali rivers through an engineered channel. A study was conducted on the fish pass aiming to improve fish diversity in north-west Bangladesh. Sampling at the fish pass, market census, interviewing the locals and focus group discussion were done to collect data from the study area. A total of 69 fish species under 9 orders and 26 families were recorded. Cypriniformes (22 species) was the most dominant order followed by Siluriformes (21 species), Perciformes (13 species), Clupeiformes (4 species), Synbranchiformes (4 species), Osteoglossiformes (2 species), Mugiliformes (1 species), Anguilliformes (1 species) and Tetraodontiformes (1 species). In total 30 threatened species in Bangladesh and globally recognized 9 species were recorded. This fish pass is not working during the dry or winter seasons but helps in the diversified fish migration diversity of Bengali and Jamuna river system during the flood time of Bangladesh. The present study recommends establishing effective fish passages in flood protection structures or dams in Bangladesh to retain the connectivity of fish migration routes and the improving of fish diversity. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(2): 53-62

scholarly journals Planktonic algae and cyanoprokaryotes as indicators of ecosystem quality in the Mooi River system in the North-West Province, South Africa

Water SA ◽  
2013 ◽  
Vol 39 (5) ◽  
pp. 707 ◽  
Author(s):  
A Venter ◽  
S Barnard ◽  
MA Dickinson ◽  
S Janse van Vuuren ◽  
A Levanets ◽  
...  
Keyword(s):  
South Africa ◽  
River System ◽  
North West ◽  
Planktonic Algae ◽  
Ecosystem Quality ◽  
The North ◽  
North West Province

The Origin of the Amphibole-Schist Series of Pahang, Malaya

1947 ◽  
Vol 84 (4) ◽  
pp. 241-249 ◽  
Author(s):  
J. A. Richardson
Keyword(s):  
River System ◽  
North West

The Amphibole-Schist Series appears to be confined to Malaya east of the Main Range, and it is most abundantly developed in north-west Pahang. It occurs partly in the Main Range Foothills, partly between them and the Main Range granite in the Sua-Kerla-Kelubi-Tempoi river system of the Telom Valley, in the Jelai Kechil valley, in the Sungei Lipis and in the Chembatu-Batu-Cheroh system between Batu Malim and Cheroh, Raub District. So far as is known these crystalline schists do not extend far northwards into Kelantan, and they are likewise but poorly developed south of Pahang in Negri Sembilan. They are everywhere associated with the Arenaceous Formation of the Main Range Foothills, quartzites, quartzite-conglomerates, shales, cherts, phyllites, quartz- and mica-schists, which may be either Triassic according to Scrivenor (1911, 1931) or perhaps older than the adjacent Permocarboniferous shales and limestones according to Service, Alexander, and the writer (Ann. Rep., 1940, para. 39; 1939, 1946). In some areas they lie partly on the Main Range granite (Text-fig. 1).

The Mersey Basin Campaign–The Technical Challenge

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1489-1498 ◽  
Author(s):  
B. Alexander ◽  
E. Harper
Keyword(s):  
Financial Support ◽  
Sewage Treatment ◽  
River System ◽  
Cost Effective ◽  
Substantial Improvement ◽  
Environmental Standards ◽  
North West ◽  
The Right ◽  
Investment Choices

The Mersey Basin Campaign is a major initiative launched in 1984 to revitalise the river system of the River Mersey and the adjacent waterfront. The long-term programme of major investment by North West Water to tackle the seriously polluted conditions of the river and estuary of the basin forms the central core of the Campaign. This programme provides for the substantial improvement of the ageing and inadequate sewerage and sewage disposal systems. The paper will review the technical challenges facing North West Water in the investigations, research and plans to meet the objectives for river water quality throughout the basin. The extensive pollution and the exceptional concentration of urban development and population require the production of integrated catchment plans for the most cost-effective investments for the achievement of modern environmental standards. The complex investment choices will require optimum solutions for the achievement of the right infrastructure balance between improved sewerage systems and effective sewage treatment. A key feature of the Campaign has been the commitment in terms of considerable financial support from the European Community.

Electron Microscopic Examination of a Transplantable Rat Mammary Carcinoma

1968 ◽  
Vol 26 ◽  
pp. 20-21
Author(s):  
S. Shirahama ◽  
G. C. Engle ◽  
R. M. Dutcher
Keyword(s):  
Electron Microscope ◽  
Osmium Tetroxide ◽  
Electron Microscopic Examination ◽  
Undifferentiated Carcinoma ◽  
Uranyl Acetate ◽  
Sprague Dawley ◽  
Electron Microscopic ◽  
North West ◽  
X Irradiation ◽  
Tissue Specimens

A transplantable carcinoma was established in North West Sprague Dawley (NWSD) rats by use of X-irradiation by Engle and Spencer. The tumor was passaged through 63 generations over a period of 32 months. The original tumor, an adenocarcinoma, changed into an undifferentiated carcinoma following the 19th transplant. The tumor grew well in NWSD rats of either sex at various ages. It was invariably fatal, causing death of the host within 15 to 35 days following transplantation.Tumor, thymus, spleen, and plasma from 7 rats receiving transplants of tumor at 3 to 9 weeks of age were examined with an electron microscope at intervals of 8, 15, 22 and 30 days after transplantation. Four normal control rats of the same age were also examined. The tissues were fixed in glutaraldehyde, postfixed in osmium tetroxide and embedded in Epon. The plasma was separated from heparanized blood and processed as previously described for the tissue specimens. Sections were stained with uranyl acetate followed by lead citrate and examined with an RCA EMU-3G electron microscope.

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