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Thursday, June 11, 2020
Tuesday, June 9, 2020
Study proves that magma chambers can be totally molten
Study proves that magma chambers can be totally molten: The paper shows that basaltic magma chambers may develop as large bodies of crystal-free melts in the Earth's crust. This study challenges a recently-emerged paradigm that magma chambers are huge masses of crystal-rich mush - in other words, crystals with just a very small amount of melt.
Wednesday, March 11, 2020
Symptomless cases raise coronavirus control fear
Symptomless cases raise coronavirus control fears
By Fiona Broom, Julien Chongwang, Washington Castilhos
As evidence builds that people can carry coronavirus without showing any symptoms, fears mount that the disease may be impossible to control in some regions.
More than 74,000 people in 25 countries have been infected and over 2,000 people have died since the virus, officially known as COVID-19, broke out in China in December.
Controlling the spread of this coronavirus in Africa – including Egypt, where at least one case has been confirmed – will “heavily rely on a country’s health capacity”, a new study published in The Lancet says.
The review found that African countries at high and medium risk of transmission from China are “ill-prepared to detect cases and limit transmission”.
Diagnostics are fundamental to epidemic control, but developing tests to identify diseases is technically challenging and time consuming, and many tests are not available in a way that’s easily deployable in the field, a BMJ Global Health analysis shows.
Chinese medical workers in virus-hit provinces have told the World Health Organization they lack the ability to immediately diagnose cases at ground-level.
“Our greatest fear remains the damage this coronavirus could do in a country like DRC,” WHO chief Tedros Adhanom Ghebreyesus says.
Symptom-based screening
Researchers in Germany have found that people can be infected without appearing sick, after symptom-based screening missed two cases of coronavirus in a group evacuated from China to Germany.
Several tests, including a throat swab, later confirmed the two people had the virus, the infectious disease unit at University Hospital Frankfurt says.
“We discovered that shedding of potentially infectious virus may occur in persons who have no fever and no signs or only minor signs of infection,” the researchers say. “It is unclear whether persons who show no signs or symptoms of respiratory infection shed [the virus].”
“When you do screening for people you can’t rely just on whether or not they’re symptomatic, you’d have to do a test.”
Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases, US
Anecdotal evidence suggests that people with no symptoms of the virus are able to spread it to others, says Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases.
“I think that’s going to turn out to be a real phenomenon,” he says. “The question that still remains unanswered is: what is the extent of that asymptomatic transmission? Is it a minor component of the outbreak, or is it a substantial component?
“If it is a substantial component, that then becomes problematic, because that would mean that when you do screening for people you can’t rely just on whether or not they’re symptomatic, you’d have to do a test."
But diagnostic tests, especially those that are new, can give false results, says Michael J. Ryan, the WHO Health Emergencies Programme executive director. He says clinical suspicion is important, particularly in countries where cases are first appearing.
And, symptom-based diagnosis may be the only option for many countries lacking the equipment and training needed for lab testing.
In Brazil, researchers have been trialling a real-time diagnostic technique – used to detect measles, zika virus, and leishmaniasis – to check for COVID-19. But the technique’s use in lower-income countries will likely be limited, as it requires sophisticated and expensive equipment that many systems do not have. In Brazil, each machine costs about US$45,000.
Francioli Koro Koro, a molecular microbiologist and epidemiologist at Cameroon’s University of Douala, says many African countries will struggle with a COVID-19 outbreak. “If the coronavirus appears here in Africa and basic rules are not followed, it would be a disaster that we may not be able to manage,” he told SciDev.Net.
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He adds health systems in Africa don’t have the ability to carry out contact tracing – a staple of infectious disease control in countries such as the United Kingdom. “In Africa, we cannot trace to find out who took the same bus, the same taxi, the same motorcycle,” he says.
Adhanom Ghebreyesus says this coronavirus epidemic highlights why it is critical to strengthen health systems in the global South.
But Koro Koro says infectious disease crises are often due to political failures at both national and global levels.
“The problem is, how do politicians view the information given to them?”, he says. “For the WHO, for example, to consider a situation as critical, a certain number of conditions must be met. Meanwhile, the disease is spreading.”
This article was originally published on SciDev.Net. Read the original article.
Saturday, February 11, 2017
Egyptian invention cuts rice irrigation water by half
By Mohamed El-Sayed
[Cairo] Experts and stakeholders in Egypt warn of imminent water poverty as a result of the Ethiopian Renaissance Dam, which is about to become operational. Meanwhile, agricultural production consumes about 85 per cent of the country’s water resources, half of which goes towards rice irrigation.
Rice cultivation consumes more than 10 billion cubic meters of water annually, or more than one-sixth of Egypt's share of Nile water, Khaled Ghanem, professor of Organic Farming in Al-Azhar University, told SciDev.Net. And this does not account for the water used for cultivation in unauthorized areas, estimated to be about a third of that used in authorized ones, he explained.
But there could be a solution, in the form of a machine that ploughs fields in a manner that saves about half the amount of water usually used for irrigation, and a quarter of fertilizers used in cultivation. A specially imported unit, which sows rice seedlings mechanically, is mounted on the machine.
The machine’s Egyptian inventor, Mohamed El-Sayyed El-Hagarey, a researcher at the Desert Research Center in Cairo, was granted the prestigious WatSave Award for Young Professionals from the International Commission on Irrigation and Drainage (ICID) during the Second World Irrigation Forum held in Thailand in mid-November.
Rice cultivation consumes more than 10 billion cubic meters of water annually via traditional methods
Sowing rice seedlings mechanically costs US$ 400 per acre, while sowing it manually cost US$ 150
The new machine ploughs fields in a manner that saves about half the amount of water usually used for irrigation, and a quarter of fertilizers used in cultivation, and a lot of time consumed in sowing seedlings
The machine makes ‛V’ shaped lines into the soil at a depth and width of 20cm, and sows rice seedlings automatically
The V-shaped troughs maintains the water level necessary for rice to grow, but with less water than that is used in conventional agriculture that requires the entire plot of land to be completely submerged
The machine also helped increasing the crop yield by 4.6 per cent
In an interview with SciDev.Net, El-Hagarey explained his motivation for inventing the machine. He said that during cultivation, rice requires complete submersion in a layer of water 10-15 cm above the soil surface, which demands huge amounts of water and fertilizers.
He designed the soil and water management machine to tackle this. The machine makes ‛V’ shaped lines into the soil, at a depth and width of 20cm, and sows rice seedlings automatically. This operation maintains the water level necessary for rice to grow in the V-shaped troughs, which is less than the water used in conventional agriculture that requires the entire plot of land to be completely submerged.
The machine was tested in a field in Kafr el-Sheikh governorate, which is known for rice crop cultivation in Egypt, with good results. It reduced the amount of water used by half, and “the crop yield increased by 4.6 per cent,” Al-Hagary said.
“Saving water and fertilizers does not mean much for farmers, who get water for free and fertilizers subsidized by the state,” Sweilem explained.
Therefore, he believes that Egypt’s ministries of Agriculture and Water Resources and Irrigation should play an important role in supporting farmers financially and with training in using the machine.
Al-Hagary said the machine costs about US$5000, but needs further development before it is ready for commercial production.
He intends to re-submit a proposal to the Academy of Scientific Research and Technology in Egypt, hoping it would support further development of the innovation. An earlier proposal made in 2014 went unanswered, and he had to design it at his own expense.
Ghanem believes that “Egypt needs to use this machine widely range for several reasons,” the most important of which is the implications of Ethiopia’s Renaissance Dam on Egypt's share of water. He also referred to the effects of climate change including drought, desertification, and an increase in evaporation rates, as well as the water wasted along the Nile. “This machine will save a lot of irrigation water in Egypt each year, which will help the country face these challenges and direct the water saved towards cultivating other crops,” Ghanem said.
He added: “The concerned ministries might not pay attention to this innovation. The solution is to establish major companies to market similar innovations that can be funded by low-priced stocks, making them available to a larger number of consumers.”
This piece was produced by SciDev.Net’s Middle East and North Africa desk.
Rice cultivation consumes more than 10 billion cubic meters of water annually, or more than one-sixth of Egypt's share of Nile water, Khaled Ghanem, professor of Organic Farming in Al-Azhar University, told SciDev.Net. And this does not account for the water used for cultivation in unauthorized areas, estimated to be about a third of that used in authorized ones, he explained.
But there could be a solution, in the form of a machine that ploughs fields in a manner that saves about half the amount of water usually used for irrigation, and a quarter of fertilizers used in cultivation. A specially imported unit, which sows rice seedlings mechanically, is mounted on the machine.
The machine’s Egyptian inventor, Mohamed El-Sayyed El-Hagarey, a researcher at the Desert Research Center in Cairo, was granted the prestigious WatSave Award for Young Professionals from the International Commission on Irrigation and Drainage (ICID) during the Second World Irrigation Forum held in Thailand in mid-November.
Rice cultivation consumes more than 10 billion cubic meters of water annually via traditional methods
Sowing rice seedlings mechanically costs US$ 400 per acre, while sowing it manually cost US$ 150
The new machine ploughs fields in a manner that saves about half the amount of water usually used for irrigation, and a quarter of fertilizers used in cultivation, and a lot of time consumed in sowing seedlings
The machine makes ‛V’ shaped lines into the soil at a depth and width of 20cm, and sows rice seedlings automatically
The V-shaped troughs maintains the water level necessary for rice to grow, but with less water than that is used in conventional agriculture that requires the entire plot of land to be completely submerged
The machine also helped increasing the crop yield by 4.6 per cent
In an interview with SciDev.Net, El-Hagarey explained his motivation for inventing the machine. He said that during cultivation, rice requires complete submersion in a layer of water 10-15 cm above the soil surface, which demands huge amounts of water and fertilizers.
He designed the soil and water management machine to tackle this. The machine makes ‛V’ shaped lines into the soil, at a depth and width of 20cm, and sows rice seedlings automatically. This operation maintains the water level necessary for rice to grow in the V-shaped troughs, which is less than the water used in conventional agriculture that requires the entire plot of land to be completely submerged.
The machine was tested in a field in Kafr el-Sheikh governorate, which is known for rice crop cultivation in Egypt, with good results. It reduced the amount of water used by half, and “the crop yield increased by 4.6 per cent,” Al-Hagary said.
Atef Sweilem, water management and irrigation expert at the International Center for Agricultural Research in the Dry Areas, (ICARDA), praised the machine, but added that “saving water and fertilizers would not tempt small farmers to buy it, as the increase in the yield was not huge”. He pointed out that the rice agricultural plots owned by most farmers do not exceed half an acre.“This machine will save a lot of irrigation water in Egypt each year, which will help the country face these challenges and direct the water saved towards cultivating other crops.”
Khaled Ghanem, Al-Azhar University
“Saving water and fertilizers does not mean much for farmers, who get water for free and fertilizers subsidized by the state,” Sweilem explained.
Therefore, he believes that Egypt’s ministries of Agriculture and Water Resources and Irrigation should play an important role in supporting farmers financially and with training in using the machine.
Al-Hagary said the machine costs about US$5000, but needs further development before it is ready for commercial production.
He intends to re-submit a proposal to the Academy of Scientific Research and Technology in Egypt, hoping it would support further development of the innovation. An earlier proposal made in 2014 went unanswered, and he had to design it at his own expense.
Ghanem believes that “Egypt needs to use this machine widely range for several reasons,” the most important of which is the implications of Ethiopia’s Renaissance Dam on Egypt's share of water. He also referred to the effects of climate change including drought, desertification, and an increase in evaporation rates, as well as the water wasted along the Nile. “This machine will save a lot of irrigation water in Egypt each year, which will help the country face these challenges and direct the water saved towards cultivating other crops,” Ghanem said.
He added: “The concerned ministries might not pay attention to this innovation. The solution is to establish major companies to market similar innovations that can be funded by low-priced stocks, making them available to a larger number of consumers.”
This piece was produced by SciDev.Net’s Middle East and North Africa desk.
This article was originally published on SciDev.Net. Read the original article.
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