scholarly journals Potential distribution of fall armyworm in Africa and beyond, considering climate change and irrigation patterns

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Bipana Paudel Timilsena ◽  
Saliou Niassy ◽  
Emily Kimathi ◽  
Elfatih M. Abdel-Rahman ◽  
Irmgard Seidl-Adams ◽  
...  
Keyword(s):  
Central Africa ◽  
Fall Armyworm ◽  
Large Area ◽  
Western Africa ◽  
The North ◽  
Management Interventions ◽  
Population Establishment ◽  
Almost All ◽  
North And South ◽  
Irrigation Patterns

AbstractThe fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security. We re-parameterized the existing CLIMEX model to assess the FAW global invasion threat, emphasizing the risk of transient and permanent population establishment in Africa under current and projected future climates, considering irrigation patterns. FAW can establish itself in almost all countries in eastern and central Africa and a large part of western Africa under the current climate. Climatic barriers, such as heat and dry stresses, may limit the spread of FAW to North and South Africa. Future projections suggest that FAW invasive range will retract from both northern and southern regions towards the equator. However, a large area in eastern and central Africa is projected to have an optimal climate for FAW persistence. These areas will serve as FAW ‘hotspots’ from where it may migrate to the north and south during favorable seasons and then pose an economic threat. Our projections can be used to identify countries at risk for permanent and transient FAW-population establishment and inform timely integrated pest management interventions under present and future climate in Africa.

Potential Distribution of Fall Armyworm in Africa and Beyond, Considering Climate Change and Irrigation Patterns

2021 ◽  
Author(s):  
Bipana Paudel Timilsena ◽  
Saliou Niassy ◽  
Emily Kimathi ◽  
Elfatih. M. Abdel-Rahman ◽  
Irmgard Seidl-Adams ◽  
...  
Keyword(s):  
Central Africa ◽  
Fall Armyworm ◽  
Large Area ◽  
Western Africa ◽  
The North ◽  
Management Interventions ◽  
Population Establishment ◽  
Almost All ◽  
North And South ◽  
Irrigation Patterns

Abstract The fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security. We re-parameterized the existing CLIMEX model to assess the FAW global invasion threat, emphasizing the risk of transient and permanent population establishment in Africa under current and predicted future climates, considering irrigation patterns. FAW can establish itself in almost all countries in eastern and central Africa and a large part of western Africa under the current climate. Climatic barriers, such as heat and dry stresses, may limit the spread of FAW to North and South Africa. Future predictions suggest that FAW invasive range will retract from both northern and southern regions towards the equator. However, a large area in eastern and central Africa is predicted to have an optimal climate for FAW persistence. These areas will serve as FAW ‘hotspots’ from where it may migrate to the north and south during winter seasons and then pose an economic threat. Our projections can be used to identify countries at risk for permanent and transient FAW-population establishment and inform timely integrated pest management interventions under present and future climate in Africa.

scholarly journals Morphology of various strains of the trypanosome causing disease in man in Nyasaland.—The mzimba strain

1913 ◽  
Vol 87 (592) ◽  
pp. 26-35 ◽  
Keyword(s):  
Central Africa ◽  
Medical Officer ◽  
Sleeping Sickness ◽  
Separate Species ◽  
North East ◽  
The North ◽  
Western Shore ◽  
Trade Route ◽  
Almost All ◽  
North And South

Up to the present time it has usually been considered that almost all the cases of Human trypanosome disease in man in Nyasaland have been confined to a small area. This, the so-called Sleeping-Sickness District, has been described in a former paper, but it may be repeated here that it is the part of the “fly-country” lying along the western shore of Lake Nyasa, between S. lat. 13° 20' and 13° 50', and extending some twenty miles inland. Through the centre of this area a road runs from Domira Bay on the Lake into North-East Rhodesia. This road, until lately, was a principal highway between the coast and Central Africa. Dr. Aylmer May, the Principal Medical Officer of North-East Rhodesia, who lately visited Kasu, informed the Commission that it was along this trade-route that all the North-East Rhodesian, cases of Human trypanosome disease have occurred. It is said that some 25,000 native porters passed along this road every year, and as they entered a Glossina palpalis area at the Congo end of their journey, it seemed at first natural to suspect that the disease was true Sleeping Sickness, and had spread from west to east along this trade-route. This suspicion was shown to be groundless by the discovery that the parasite causing the disease in North-East Rhodesia and Nyasaland is not Trypanosoma gambiense , but a distinct and separate species giving rise to a totally different disease. The question then arose as to whether this was an imported or indigenous disease. It has, therefore, been one of the objects of this Commission to determine whether the trypanosome causing Human trypanosome disease in Nyasaland is restricted to the game and “fly” of the Proclaimed Area, or if it extends to the north and south along the “fly-belt.” If it is found to extend over all the “fly-area” in Nyasaland, then the disease is probably native to the soil and not an importation from Tanganyika or the Congo. But it will be well at this point to lay down definitely the various opinions or theories at issue. These are three in number.

scholarly journals Return migration of adult Atlantic salmon (Salmo salar L.) to northern Norway

2017 ◽  
Vol 75 (2) ◽  
pp. 653-661 ◽  
Author(s):  
Eva Marita Ulvan ◽  
Anders Foldvik ◽  
Arne Johan Jensen ◽  
Bengt Finstad ◽  
Eva Bonsak Thorstad ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
North Atlantic ◽  
Return Migration ◽  
Barents Sea ◽  
North Atlantic Ocean ◽  
Catch Per Unit Effort ◽  
Large Area ◽  
The North ◽  
Natal Homing ◽  
North And South

Abstract The return migration of adult Atlantic salmon was investigated by analysing recaptures of individuals tagged and released as smolts in the River Altaelva and the River Halselva using a catch per unit effort approach. Although the salmon were recaptured over a large area along the coastline (from >1100 km south to > 500 km northeast of their home rivers), the results indicated a relatively accurate homeward navigation for most individuals. The straying rate to rivers other than the home river was 9%. Multi-sea-winter salmon returned earlier in the season than one-sea-winter salmon, but the geographical distribution of recaptures did not differ. Recaptures were equally distributed north and south of the home rivers, implying that salmon were arriving to the coast both north and south of their home rivers and that they may have returned from different ocean areas. This was supported by the fact that several salmon were recaptured in both the southern and northern parts of the North Atlantic Ocean, including at the Faroes, south coast of Greenland, Svalbard and in the Barents Sea. This study supports the hypothesis that the coastal phase of the natal homing in migrating fish species is neither passive nor guided by currents alone.

scholarly journals The Flare and Warp of the Young Stellar Disk Traced with LAMOST DR5 OB-type Stars

2021 ◽  
Vol 922 (1) ◽  
pp. 80
Author(s):  
Yang Yu ◽  
Hai-Feng Wang ◽  
Wen-Yuan Cui ◽  
Lin-Lin Li ◽  
Chao Liu ◽  
...  
Keyword(s):  
Galactic Plane ◽  
Scale Height ◽  
Stellar Disk ◽  
Spatial Density ◽  
Galactocentric Distance ◽  
Secular Evolution ◽  
The North ◽  
Red Giant ◽  
Almost All ◽  
North And South

Abstract We present an analysis of the spatial density structure for the outer disk from 8–14 kpc with the LAMOST DR5 13,534 OB-type stars and observe similar flaring on the north and south sides of the disk, implying that the flaring structure is symmetrical about the Galactic plane, for which the scale height at different Galactocentric distances is from 0.14 to 0.5 kpc. By using the average slope to characterize the flaring strength, we find that the thickness of the OB stellar disk is similar but that flaring is slightly stronger compared to the thin disk as traced by red giant branch stars, possibly implying that secular evolution is not the main contributor to the flaring but rather perturbation scenarios such as interactions with passing dwarf galaxies could be possible. When comparing the scale height of the OB stellar disk on the north and south sides with the gas disk, the former one is slightly thicker than the latter one by ≈33 and 9 pc, meaning that one could tentatively use young OB-type stars to trace the gas properties. Meanwhile, we determine that the radial scale length of the young OB stellar disk is 1.17 ± 0.05 kpc, which is shorter than that of the gas disk, confirming that the gas disk is more extended than the stellar disk. What is more, by considering the midplane displacements (Z 0) in our density model we find that almost all values of Z 0 are within 100 pc, with an increasing trend as Galactocentric distance increases.

scholarly journals Determinate pigeon pea [Cajanus cajan (L) Millsp] genotypes on the north and south coasts of Puerto Rico

1969 ◽  
Vol 72 (4) ◽  
pp. 545-556
Author(s):  
Abad Morales ◽  
Brunilda Luciano ◽  
Francisco H. Ortiz ◽  
Nabor Mendoza
Keyword(s):  
Cajanus Cajan ◽  
Seed Weight ◽  
Pigeon Pea ◽  
Date Seed ◽  
The North ◽  
Agricultural Experiment ◽  
Almost All ◽  
North And South ◽  
Number Of Seeds ◽  
Better Than

Seven experiments were established at the Juana Díaz and Isabela agricultural experiment substations to evaluate the performance of determinate pigeon pea [Cajanus cajan (L.) Millsp] genotypes. Significant differences were found for yield, height, flowering date, seed weight and number of seeds per pod in almost all the experiments. Many genotypes performed better than the commercial cultivar 2B-Bushy used as check.

Excavations at Caerau Ancient Village, Clynnog, Caernarvonshire, 1933 and 1934

1936 ◽  
Vol 16 (3) ◽  
pp. 295-320 ◽  
Author(s):  
B. H. St. J. O'Neil
Keyword(s):  
Large Area ◽  
Mountain Slope ◽  
Ordnance Survey ◽  
North West ◽  
The Road ◽  
The North ◽  
Excellent Preservation ◽  
A Site ◽  
North And South ◽  
Agricultural Settlement

Mynydd Craig-goch, the westernmost height of a rocky ridge of the Snowdon mountains, slopes gently down to a watershed at the head of the Afon Dwyfach, over which run the railway and the main road from Criccieth and Portmadoc to Caernarvon. Between the ninth and tenth milestones from Caernarvon, immediately to the east of the road and thus on the lowest part of the mountain slope, there lie the remains of a most extensive primitive agricultural settlement. It is not marked on the Ordnance Survey map (6 in. 26 NE.), but was known locally, and the farm within which most of it lies bears the significant name Caerau. Its recognition as a site of great possibilities on account of its excellent state of preservation is due to Mr. W. J. Hemp, F.S.A. The settlement must originally have extended north and south for a distance of about half a mile. It may, indeed, have been contiguous with other settlements on the north and north-west, thus forming part of a large area of cultivated land, since there exists in excellent preservation a house or hut-group of the same type with at least one typical field about one mile to the west on the farm of Cefn Graianog. This point, however, cannot now be determined on account of more recent agricultural developments around the farm of Bodychain.

The Orientation of Middle American Sites

1945 ◽  
Vol 11 (2) ◽  
pp. 118-118 ◽  
Author(s):  
Kenneth Macoowan
Keyword(s):  
American Culture ◽  
General Pattern ◽  
Common Axis ◽  
The North ◽  
The Individual ◽  
Almost All ◽  
South Axis ◽  
The City ◽  
North And South ◽  
Of Greece

One of the first aspects of Middle American culture which strikes an amateur as interesting and possibly significant is the ordered arrangement of the buildings in almost all sites. Like those of Egypt—and unlike those of Greece and Rome —the sites seem to have been planned on a large pattern. The individual buildings are arranged according to a scheme which gives them space and which orients them on a common axis. They are not dropped in helter-skelter, crowded cheek-by-jowl, and set at odd angles to one another. Further, the city plans of Middle America seemollow fhe another and larger pattern. This is the pattern of the north and south axis of each site and each building. This orientation almost invariably follows one of three schemes. I t is sometimes true north, sometimes about 7 degrees east of north, sometimes about 17 degrees east of north, but practically never west of north. There are some sites which have no general pattern, and therefore no orientation.

The Trade between Western Africa and the Atlantic World, 1600–90: Estimates of Trends in Composition and Value

1992 ◽  
Vol 33 (3) ◽  
pp. 369-385 ◽  
Author(s):  
Ernst Van Den Boogaart
Keyword(s):  
Seventeenth Century ◽  
Slave Trade ◽  
Central Africa ◽  
Terms Of Trade ◽  
Gold Coast ◽  
Coastal Regions ◽  
Commodity Trade ◽  
North West ◽  
Western Africa ◽  
The North

Extending the approach of D. Eltis and L. C. Jennings to the seventeenth century, the author takes estimates for the decades 1623–32 and 1680–90 as the starting points for his discussion of trends in the composition and value of the Atlantic imports and exports of Western Africa. Contrary to prevalent opinion, he argues that at least from 1600 onwards the value of slave exports was two to three times higher than that of commodity exports, as measured according to the prices in America and Europe. However, during most of the century more imports were bartered in the commodity trade than in the slave trade, since the trading margin in the latter sector was considerably higher than in the former. The different margins go some way to explaining why the Portuguese concentrated on the slave trade from Angola between 1600 and 1635, which they could carry on with fewer European imports and more effectively protect, while the more efficient Dutch merchants achieved primacy in the competitive commodity trade of West Africa. The different margins also meant a very uneven distribution of imports over coastal regions. Owing to the predominance of Akan gold in the commodity trade, the Gold Coast drew an estimated fifty per cent of all imports at the beginning of the century and still accounted for 34 per cent at the end. Owing to its predominance in the slave trade, West-Central Africa drew 25 per cent of all imports throughout the century. The few available data on the composition of imports suggest that there may have been a shift from metal goods to textiles and a marked increase of Asian textiles and cowries. From 1593 on the Dutch may have initiated a shift in the gross barter terms of trade in favour of the African merchants which spread from the Gold Coast to other areas when the North-west Europeans obtained the major share in the Atlantic slave trade.

Sign in / Sign up

Export Citation Format

Share Document