scholarly journals Spatial and Temporal Distributions of Ionospheric Irregularities Derived from Regional and Global ROTI Maps

2021 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
Chinh Thai Nguyen ◽  
Seun Temitope Oluwadare ◽  
Nhung Thi Le ◽  
Mahdi Alizadeh ◽  
Jens Wickert ◽  
...  
Keyword(s):  
South America ◽  
Southeast Asia ◽  
South Asia ◽  
Ionospheric Irregularities ◽  
Ionospheric Disturbances ◽  
The Sun ◽  
Spatial And Temporal Distributions ◽  
The Earth ◽  
The Pacific ◽  
Ionospheric Scintillations

Major advancements in the monitoring of both the occurrence and impacts of space weather can be made by evaluating the occurrence and distribution of ionospheric disturbances. Previous studies have shown that the fluctuations in total electron content (TEC) values estimated from Global Navigation Satellite System (GNSS) observations clearly exhibit the intensity levels of ionospheric irregularities, which vary continuously in both time and space. The duration and intensity of perturbations depend on the geographic location. They are also dependent on the physical activities of the Sun, the Earth’s magnetic activities, as well as the process of transferring energy from the Sun to the Earth. The aim of this study is to establish ionospheric irregularity maps using ROTI (rate of TEC index) values derived from conventional dual-frequency GNSS measurements (30-s interval). The research areas are located in Southeast Asia (15°S–25°N latitude and 95°E–115°E longitude), which is heavily affected by ionospheric scintillations, as well as in other regions around the globe. The regional ROTI map of Southeast Asia clearly indicates that ionospheric disturbances in this region are dominantly concentrated around the two equatorial ionization anomaly (EIA) crests, occurring mainly during the evening hours. Meanwhile, the global ROTI maps reveal the spatial and temporal distributions of ionospheric scintillations. Within the equatorial region, South America is the most vulnerable area (22.6% of total irregularities), followed by West Africa (8.2%), Southeast Asia (4.7%), East Africa (4.1%), the Pacific (3.8%), and South Asia (2.3%). The generated maps show that the scintillation occurrence is low in the mid-latitude areas during the last solar cycle. In the polar regions, ionospheric irregularities occur at any time of the day. To compare ionospheric disturbances between regions, the Earth is divided into ten sectors and their irregularity coefficients are calculated accordingly. The quantification of the degrees of disturbance reveals that about 58 times more ionospheric irregularities are observed in South America than in the southern mid-latitudes (least affected region). The irregularity coefficients in order from largest to smallest are as follows: South America, 3.49; the Arctic, 1.94; West Africa, 1.77; Southeast Asia, 1.27; South Asia, 1.24; the Antarctic, 1.10; East Africa, 0.89; the Pacific, 0.32; northern mid-latitudes, 0.15; southern mid-latitudes, 0.06.

scholarly journals Specific Formation of the Bermuda and Dragon Triangles as a Result of a Change in the Axis of the Earth’s Rotation

2020 ◽  
pp. 19-25
Keyword(s):  
South America ◽  
Southeast Asia ◽  
Earth’S Rotation ◽  
Earth's Rotation ◽  
Axis Of Rotation ◽  
The Earth ◽  
Rotation Of The Earth ◽  
North And South America ◽  
North And South

The Bermuda Triangle is located in the area of the archipelago between North and South America and the Dragon Triangle is located in the area of the archipelago in Southeast Asia. There is a great resemblance between these two triangular areas; both were formed following special geological and tectonic conditions. It is herein proposed that their creation stems from the change in location of the axis of rotation of the earth and, accordingly, the change in the location of the equator.

scholarly journals European and Asian contribution to the genetic diversity of mainland South American chickens

2020 ◽  
Vol 7 (2) ◽  
pp. 191558 ◽  
Author(s):  
Michael B. Herrera ◽  
Spiridoula Kraitsek ◽  
Jose A. Alcalde ◽  
Daniel Quiroz ◽  
Herman Revelo ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
South America ◽  
Southeast Asia ◽  
Fifteenth Century ◽  
Control Region ◽  
Pacific Islands ◽  
Mitochondrial Control Region ◽  
South American ◽  
Island Southeast Asia ◽  
The Pacific

Chickens ( Gallus gallus domesticus ) from the Americas have long been recognized as descendants of European chickens, transported by early Europeans since the fifteenth century. However, in recent years, a possible pre-Columbian introduction of chickens to South America by Polynesian seafarers has also been suggested. Here, we characterize the mitochondrial control region genetic diversity of modern chicken populations from South America and compare this to a worldwide dataset in order to investigate the potential maternal genetic origin of modern-day chicken populations in South America. The genetic analysis of newly generated chicken mitochondrial control region sequences from South America showed that the majority of chickens from the continent belong to mitochondrial haplogroup E. The rest belongs to haplogroups A, B and C, albeit at very low levels. Haplogroup D, a ubiquitous mitochondrial lineage in Island Southeast Asia and on Pacific Islands is not observed in continental South America. Modern-day mainland South American chickens are, therefore, closely allied with European and Asian chickens. Furthermore, we find high levels of genetic contributions from South Asian chickens to those in Europe and South America. Our findings demonstrate that modern-day genetic diversity of mainland South American chickens appear to have clear European and Asian contributions, and less so from Island Southeast Asia and the Pacific Islands. Furthermore, there is also some indication that South Asia has more genetic contribution to European chickens than any other Asian chicken populations.

scholarly journals Retrospective seroepidemiological study of chikungunya infection in South Asia, Southeast Asia and the Pacific region

2016 ◽  
Vol 144 (11) ◽  
pp. 2268-2275 ◽  
Author(s):  
M. M. NGWE TUN ◽  
S. INOUE ◽  
K. Z. THANT ◽  
N. TALEMAITOGA ◽  
A. ARYATI ◽  
...  
Keyword(s):  
Southeast Asia ◽  
South Asia ◽  
Indirect Elisa ◽  
Neutralization Test ◽  
The Philippines ◽  
Asian Countries ◽  
Serum Samples ◽  
Chikv Infection ◽  
The Pacific ◽  
Focus Reduction

SUMMARYChikungunya virus (CHIKV) and Ross River virus (RRV) of the genusAlphavirus, family Togaviridae are mainly transmitted byAedesmosquitoes and the symptoms they cause in patients are similar to dengue. A chikungunya (CHIK) outbreak re-emerged in several Asian countries during 2005–2006. This study aimed to clarify the prevalence of CHIKV infection in suspected dengue patients in six countries in South Asia and Southeast Asia. Seven hundred forty-eight serum samples were from dengue-suspected patients in South Asia and Southeast Asia, and 52 were from patients in Fiji. The samples were analysed by CHIKV IgM capture ELISA, CHIKV IgG indirect ELISA and focus reduction neutralization test against CHIKV or RRV. CHIK-confirmed cases in South Asia, particularly Myanmar and Sri Lanka, were 4·6%, and 6·1%, respectively; and in Southeast Asia, particularly Indonesia, the Philippines and Vietnam, were 27·4%, 26·8% and 25·0%, respectively. It suggests that CHIK was widely spread in these five countries in Asia. In Fiji, no CHIK cases were confirmed; however, RRV-confirmed cases represented 53·6% of suspected dengue cases. It suggests that RRV is being maintained or occasionally entering from neighbouring countries and should be considered when determining a causative agent for dengue-like illness in Fiji.

A Royal Society appointment with Venus in 1769: the voyage of Cook and Banks in the Endeavour In 1768-1771 and its botanical results

1969 ◽  
Vol 24 (1) ◽  
pp. 64-90 ◽  
Keyword(s):  
Pacific Ocean ◽  
Royal Society ◽  
The Sun ◽  
Royal Navy ◽  
The Earth ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Set Up ◽  
George Iii ◽  
Made In

A little over two hundred years ago a number of serious and learned men in Copenhagen, London, Paris, St Petersbourg, Stockholm and elsewhere, men who were academicians, Fellows of the Royal Society, Lords of the Admiralty, politicians and the like, had been thinking seriously and learnedly about the behaviour of Venus, not, of course, about Venus as represented coldly and chastely by the marble statues being imported from Italy or more warmly in the paintings of Boucher and his contemporaries, but about her far distant planet which was calculated to pass across the disk of the Sun in 1769 and not to make another such transit until 1874. Observations of the 1769 transit at widely separated stations would provide, it was hoped, the means of calculating the distance of the Earth from the Sun. The Royal Society in London, having set up in November 1767 a sub-committee ‘to consider the places proper to observe the coming Transit of Venus’ and other particulars relevant to the same, presented a memorial to King George III outlining possible benefits to science and navigation from observations made in the Pacific Ocean and received in return the promise of £4000 and a suitable ship provided by the Royal Navy (8).

Eragrostis amabilis (Japanese lovegrass).

2021 ◽  
Author(s):  
Manuel Angel Duenas-Lopez
Keyword(s):  
Southeast Asia ◽  
South Asia ◽  
Central America ◽  
Pacific Islands ◽  
Upland Rice ◽  
Native Range ◽  
Natural Habitats ◽  
The Pacific

Abstract Eragrostis amabilis is an annual terrestrial grass with pan-tropical distribution, naturalized elsewhere in the neo-tropics, that is used as an ornamental grass and for lawns. It is a common weed in disturbed, open areas, such as those close to forest margins and along roadsides, and often grows as a weed in upland rice crops in South Asia and Southeast Asia. It is listed as invasive in the Pacific Islands, Central America and Cuba, but no further information is available about its impacts or invasiveness in natural or semi-natural habitats in its non-native range.

scholarly journals Latitudinal distribution of earthquakes in the Andes and its peculiarity

2009 ◽  
Vol 22 ◽  
pp. 139-145 ◽  
Author(s):  
B. W. Levin ◽  
E. V. Sasorova
Keyword(s):  
South America ◽  
Temporal Distribution ◽  
Seismic Events ◽  
Spatial And Temporal Distribution ◽  
Latitudinal Distribution ◽  
The Andes ◽  
The Earth ◽  
The Pacific

Abstract. In the last decade, there has been growing interest in problems related to searching global spatiotemporal regularities in the distribution of seismic events on the Earth. The worldwide catalogs ISC were used for search of spatial and temporal distribution of earthquakes (EQ) in the Pacific part of South America. We extracted all EQ from 1964 to 2004 with Mb>=4.0. The total number of events under study is near 30 000. The entire set of events was divided into six magnitude ranges (MR): 4.0

Asian Development Outlook Supplement July 2021

2021 ◽  
Keyword(s):  
Southeast Asia ◽  
East Asia ◽  
South Asia ◽  
Central Asia ◽  
Regional Growth ◽  
Asian Development ◽  
The Pacific ◽  
Growth Projection ◽  
Development Outlook

This publication provides updated economic projections for developing Asia and the Pacific. It notes that recovery is underway but that regional growth in 2021 is expected to be 7.2%, which is 0.1% lower than was projected in April. Forecast upgrades for Central Asia and East Asia in 2021 partly offset downgrades for South Asia, Southeast Asia, and the Pacific. The regional growth projection for 2022 is upgraded from 5.3% to 5.4%.

Mikania micrantha (bitter vine).

2021 ◽  
Author(s):  
Michael Day
Keyword(s):  
South America ◽  
Southeast Asia ◽  
Plant Species ◽  
Agricultural Crops ◽  
Mikania Micrantha ◽  
Fast Growing ◽  
Native Trees ◽  
The Pacific ◽  
Plantation Species ◽  
Biological Programme

Abstract M. micrantha is a fast growing vine, native to Central and South America. It was intentionally introduced into a number of countries and has since become a major weed in Southeast Asia and the Pacific and is still extending its range. However, it has not yet been recorded in Africa. Once established, M. micrantha can quickly smother other vegetation, including native trees, plantation species and agricultural crops, killing plants and/or decreasing yield and biodiversity. In Nepal, the vulnerable greater one-horned rhinoceros is under threat as M. micrantha outcompetes plant species on which it browses. Control of this species is difficult as it produces are large number of seed, can readily shoot from runners and suckers and can regenerate from stem fragments. This species has been the target of a biological programme in many countries.

scholarly journals Self-supplied drinking water in low- and middle-income countries in the Asia-Pacific

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Tim Foster ◽  
Cindy Priadi ◽  
Krishna Kumar Kotra ◽  
Mitsunori Odagiri ◽  
Emily Christensen Rand ◽  
...  
Keyword(s):  
Drinking Water ◽  
Southeast Asia ◽  
South Asia ◽  
Urban Areas ◽  
Temporal Trends ◽  
Asia Pacific ◽  
Middle Income ◽  
Middle Income Countries ◽  
The Pacific ◽  
Low And Middle Income

AbstractThere is increasing awareness of household self-supply and the role it can play in securing water for domestic needs in low- and middle-income countries (LMICs), but its scale across the Asia-Pacific has not previously been quantified. This study analysed 77 datasets from 26 countries to estimate the prevalence of self-supplied drinking water, and its associated trends in LMICs in South Asia, Southeast Asia and the Pacific. When factoring in temporal trends, results suggest that >760 million people—or 31% of the population—relied on self-supply for their drinking water in these regions in 2018, with the number of users increasing by >9 million each year. Reliance on self-supply for drinking water is greater in rural areas than in urban areas (37% of rural population vs 20% of urban population), though results vary considerably between countries. Groundwater sources constitute the most common form of self-supply in South Asia and Southeast Asia, while rainwater collection is dominant in the Pacific. The results confirm the significance of self-supply in the Asia-Pacific and suggest that households are a major but often overlooked source of financing within the water sector. The findings raise important questions about how policy and practice should respond to this widespread phenomenon.

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