̽��ֱ�� of Cambridge - Cambridge-Africa Partnership for Research Excellence (CAPREx)

Of cabbages and cows: increasing agricultural yields in Africa

lw355 — Mon, 13 Feb 2017 11:17:32 +0000

̽��ֱ��humble cabbage, universally despised by British schoolchildren, has found unexpected popularity on another continent. But just as the people of Ghana have developed an appetite – and a market – for this leafy green, so too has something else: a virus carried by aphids that causes the cabbages to wilt and die

By contrast, a parasite that emaciates cattle across sub-Saharan Africa has been around for thousands of years but continues to take its toll on certain species of the animals it infects. Prominent ribs are the frequent hallmarks of trypanosomiasis – caused by the presence of a cunning parasite that evades the animal’s immune system by periodically changing its protein ‘coat’.

Meanwhile, farmers in Ethiopia are turning away from the traditional zebu cattle towards breeds that produce greater quantities of milk. As a result they are exposing their herds – and themselves – to increasing levels of tuberculosis (TB) that are brought about by intensified animal husbandry practices.

What links cabbages and cows are three programmes that hope to connect fundamental research with improving farm yields, and in so doing contribute to solving a looming pan-African problem. More than half of global population growth between now and 2050 is expected to occur in Africa. And more people means a requirement for more food.

Ethiopia, for example, has the largest livestock population in Africa but, with a growing population and increasing urbanisation, even its 53 million cattle are not enough. And now efforts to intensify farming in the country are bringing a significant health concern. “ ̽��ֱ��new breeds are more vulnerable than zebu to bovine TB,” explains Professor James Wood from Cambridge’s Department of Veterinary Medicine. “This may have health implications for those who work with and live alongside infected cattle, and also raises concerns about transmission to areas with previously low TB.”

Wood leads a £2.9 million research programme, ETHICOBOTS, which is looking at the feasibility of control strategies, including cattle vaccination. ̽��ֱ��programme combines partners in eight Ethiopian and UK institutions, and brings together veterinary scientists, epidemiologists, geneticists, immunologists and social scientists. “We need this mix because we are not only asking how effective strategies will be, but also whether farmers will accept them, and what the consequences are for prosperity and wellbeing.”

̽��ֱ��difference that increasing productivity can have on farmers’ livelihoods is not lost on an insect expert at the ̽��ֱ�� of Ghana, Dr Ken Fening, who is working on another food-related research project. Cabbages are not indigenous to the continent but have become a major cash crop for Ghanaian farmers and an important source of income for traders to markets and hotels.

“A good crop can bring in money to buy fertilisers and farm equipment, and also help to pay for healthcare and education for the family,” he says. Recently, however, fields of stunted, yellowing, wilting cabbages, their leaves curled and dotted with mould, have become an all too familiar and devastating sight for the farmers of Ghana.

From his field station base in Kpong, Ghana, Fening works closely with smallholder farmers on pest control strategies. Two years ago they started reporting that a new disease was attacking their crops. “It seemed to be associated with massive infestations of pink and green aphids,” says Fening, “and from my studies of the way insects interact with many different vegetables, I’m familiar with the types of damage they can cause.”

Farmers were typically seeing the total loss of their crops and he realised that the devastation couldn’t just be caused by sap-sucking insects. Despite no previous reports of viral diseases affecting cabbage crops in Ghana, the symptoms suggested a viral pathogen.

With funding through the CAPREx programme, Fening began work with Cambridge plant biologist Dr John Carr. ̽��ֱ��pair collected samples of cabbage plants in Ghana showing signs of disease, and also aphids on the diseased plants. Back in Cambridge, Fening used screening techniques including a type of DNA ‘fingerprinting’ to identify the aphid species, and sophisticated molecular biology methods to try to identify the offending virus.

“Aphids are a common carrier of plant-infecting viruses,” explains Carr, whose research is funded by the Biotechnology and Biological Sciences Research Council as part of the £16 million SCPRID (Sustainable Crop Production Research for International Development) initiative. “ ̽��ֱ��‘usual suspects’ are turnip mosaic virus and cauliflower mosaic virus, which affect cabbages in Europe and the US.”

“We found that two different species of aphids, pink and green, were generally found on the diseased cabbages,” says Fening. “It turned out this was the first record of the green aphid species, Lipaphis erysimi (Kaltenbach), ever being seen in Ghana.” ̽��ֱ��pink aphid was identified as Myzus persicae (Sulzer).

What’s more, the virus was not what Carr expected, and work is now ongoing to identify the culprit. ̽��ֱ��sooner it can be characterised, the sooner sustainable crop protection strategies can be developed to prevent further spread of the disease not only in Ghana, but also in other countries in the region.

Another researcher who hopes that eradication strategies will be the outcome of her research project is Dr Theresa Manful. Like Fening, she is a researcher at the ̽��ֱ�� of Ghana and a CAPREx fellow. She has been working with Cambridge biochemist Professor Mark Carrington on African animal trypanosomiasis.

̽��ֱ��trypanosome that causes the disease is carried by the tsetse fly, which colonises vast swathes of sub-Saharan Africa. “This is a major constraint to cattle rearing in Africa,” she explains. “Although trypanosomiasis is also a disease of humans, the number of cases is low, and the more serious concerns about the disease relate to the economic impact on agricultural production.”

Carrington has worked for a quarter of a century on the parasite that causes the disease. He understands how the organism evades the immune system of the animal by changing its coat proteins so as to remain ‘invisible’.

“When you first start working on these parasites you are enamoured with the molecular mechanisms, which we now know a huge amount about,” he says. “But then when you look at the effect on large animals like cows you realise that there is almost nothing known about the dynamics of an infection, and even whether an infection acquired at an early age persists for its lifetime.”

Manful and Carrington set about testing herds in Ghana. They discovered that several trypanosome species can be found in the cattle at one time and that nearly all cattle were infected most of the time.

For Manful, one of the important gains has been the ability to expand the research in Ghana: “I now have a fully functional lab and can do DNA extraction and analysis in Ghana – I don’t have to bring samples to Cambridge. We are teaching students from five Ghanaian institutions the diagnostic methods.” She and Carrington have been recently funded through a Royal Society Leverhulme Trust Africa Award to continue their work.

“Agriculture faces increasing challenges,” adds Carr. “Bioscience is playing a crucial part in developing ways to mitigate pest impact and reduce the spread of parasites.

“We want to ensure not only that every harvest is successful, but also that it’s maximally successful.”

ETHICOBOTS is funded under the Zoonoses and Emerging Livestock Systems (ZELS) programme, a research initiative in the UK jointly funded by six research council and government bodies. Dr Ken Fening and Dr Theresa Manful were funded by the Cambridge-Africa Partnership for Research Excellence (CAPREx) and ̽��ֱ��ALBORADA Trust, through the Cambridge-Africa Programme.

Images: top: cabbage aphids (credit: Dr Ken Fening); bottom: cattle in Ghana (credit: Dr Theresa Manful and Professor Mark Carrington).

To keep up to date with the latest stories about Cambridge’s engagement with Africa, follow #CamAfrica on Twitter.

Africa’s food requirements, along with its population, are growing fast. Three research programmes ask how a better understanding of viruses, parasites and the spread of disease can pave the way to improving agricultural yields.

A good crop can bring in money to buy fertilisers and farm equipment, and also help to pay for healthcare and education for the family

Ken Fening

Hendrik Terbeck

Greengrocer at Arusha Market

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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̽��ֱ��Bible as a weapon of war

sjr81 — Wed, 08 Feb 2017 12:13:21 +0000

In 2012, one of the world’s most wanted war criminals, Joseph Kony, became one of the most repeated names on the planet thanks to a YouTube documentary (Kony 2012) and a call to action that sought to expose the terror and slaughter he inflicted on thousands of men, women and children in Central Africa.

Indicted by the International Criminal Court for crimes against humanity, Kony is now believed to be in hiding with his followers. He remains the genocidal leader of the murderous Lord’s Resistance Army (LRA) who claimed to have been sent by God to liberate the people of Northern Uganda from the rival National Resistance Army (NRA). From the start of their insurgency in 1987, Kony’s LRA claimed as their major objective the establishment of a government based on the Ten Commandments.

In the decades since, his army – often made up of thousands of forcibly conscripted child soldiers – have wounded, widowed and orphaned indiscriminately as they prosecuted a campaign of violence with a vigour befitting Kony’s vengeful readings of the Old Testament.

In the process, the LRA are thought to have displaced as many as two million Ugandans, the vast majority from Uganda’s Acholiland, where Kony originally hails from.

Today, Acholiland is a haunted place; haunted by the ghosts and memories of a recent past that has been written in blood rather than ink during nearly two decades of conflict.

But what happens when former LRA soldiers, those who have used the Bible as a weapon of war, return home from the front lines? How do former soldiers – male and female, adults and children – learn to reread and reinterpret scriptures that once spoke to them of fire and brimstone?

Kony says it is God who sent him to kill people so nobody should stop him. You know this thing is very difficult to understand as Kony refers us to the Bible... In Kony’s time, God has sent the Holy Spirit, and it is the one which is doing the work through Kony.
Zacchaeus, a former LRA commander

This is the puzzle facing Dr Helen Nambalirwa Nkabala from Makerere ̽��ֱ�� in Uganda. As a CAPREx fellow, she spent time in Cambridge working with Dr Emma Wild-Wood, from the Faculty of Divinity and the Cambridge Centre for Christianity Worldwide.

Nambalirwa Nkabala interviewed returning LRA soldiers in Uganda in order to examine how a positive engagement with biblical texts – especially those that seem to support violence – can help to promote peace instead.

She says: “My project identifies difficult texts in the Old Testament and seeks to identify the means by which they can be used in a constructive and meaningful way – with the central focus being on whether a particular interpretation promotes human dignity or not.

“ ̽��ֱ��way the LRA used the Bible, in a literal sense, to justify their violent actions has caused a complete overturn of the social and generational structures of the Acholi people.

“ ̽��ֱ��former LRA members I interviewed claim that all their actions are in accordance with Bible teachings; obedience to the law meant that anyone considered to have broken the Ten Commandments had to be destroyed.”

Kelly, a former child soldier, told Nambalirwa Nkabala that the Bible teaches that ‘somebody who does not obey must be killed’. This is the level of indoctrination that Cambridge researchers are trying to untangle as they work alongside Acholi leaders of varying denominations to promote peace and reconciliation using texts that were once wielded to justify murder on an industrial scale.

However, their work is complicated by the fact that Acholi cultural beliefs – as well as some readings of the Old Testament – also permit killing in exceptional circumstances, meaning that the LRA may have appropriated elements of Acholi culture to justify their own murderous ideology. For instance, the Achioli Chief and elders can pass ngolo kop me too – or ‘judgement of death’ – where killing is permitted, Likewise, Kony, a former altar boy in the Catholic Church, was brought up by a catechist father whom Nambalirwa Nkabala believes exposed him to Old Testament passages of death and punishment from an early age.

“Former LRA soldiers must be ready to reread the texts they were exposed to in a different way,” adds Nambalirwa Nkabala. “Texts with a violent message should be read with an ethical and nonviolent stance. Rather than passively accept what the text says, we must engage in dialogue with it. It is every Christian’s duty to expose and challenge any textual message which permits violence.

“ ̽��ֱ��Bible must be read contextually. By asking about the role of the text to a particular context, interpreters will automatically be pushed into the habit of checking what implications a particular reading/interpretation could have on a particular community.”

Wild-Wood met with Christian and Muslim leaders of the Acholi Religious Leaders Peace Initiative (ARLPI) during her trip to Uganda in 2015 as she sought to understand how the Bible is now being used to rebuild society. She was struck by the commitment to peace across differing faiths and denominations.

“A great deal of thought has gone into how former combatants can be rehabilitated,” says Wild-Wood. “From my focus groups, the religious leaders were optimistic about the future, but the challenges are many. They are dealing with people who are very traumatised. Some see the LRA soldiers as perpetrators, some see them as victims. But there is a recognition that people have dealt with awful situations – and may fall apart afterwards.”

When you look at what happened in the north and you go to the Bible and you read from the beginning to the last part you may find that 90 per cent of what happened here is in the Bible. Whatever has happened is exactly how God designed it.
Steve, a former LRA commander

Wild-Wood says that the ARLPI’s initial desire to publicise the atrocities being carried out by the LRA – and to protect civilians where possible – has now refocused to aid the process of reintegrating former combatants, and is working alongside international charities like World Vision to facilitate the transfer of former LRA soldiers from reception centres back to their communities.

“Projects of post-war reconciliation often engage with traditional beliefs and customs in order to effect lasting peace,” adds Wild-Wood. “Acholiland is no exception, and Acholi practices have been ultilised in restoring human relations. However, in the LRA and the wider population there are many Christians and a significant number of Muslims. It is important to engage the beliefs of those religious traditions when working towards long-term solutions to the destruction of society.”

While there may be a distance yet to travel, Nambalirwa Nkabala remains optimistic about Uganda’s future as it seeks to heal the deep scars caused by Kony and the decades of division and war he brought to his country.

“ ̽��ֱ��advantage in all this is that the Acholi have a deep sense of community and solidarity,” she says. “This is exemplified in the various means they use to reincorporate wrongdoers back into their community. If the Acholi communities can be encouraged to maintain their cultural values of healing and reconciliation – even while reading texts that may have a violent message – then they can in the future avoid situations that can lead to the destruction and erosion of these most important of values.”

Dr Helen Nambalirwa Nkabala was funded by the Cambridge-Africa Partnership for Research Excellence (CAPREx) and ̽��ֱ��ALBORADA Trust, through the Cambridge-Africa Programme.

To keep up to date with the latest stories about Cambridge’s engagement with Africa, follow #CamAfrica on Twitter.

How do former Lord’s Resistance Army soldiers – men, women and children who have used the Bible as a weapon of war – learn to reread the scriptures once they return home? This is the puzzle facing researchers from Uganda and Cambridge.

̽��ֱ��way the LRA used the Bible, in a literal sense, to justify their violent actions has caused a complete overturn of the social and generational structures of the Acholi people."

Helen Nambalirwa Nkabala

Charles Roffey

Kony 2012

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Keeping the lights on in Ghana

sc604 — Tue, 07 Feb 2017 09:00:56 +0000

In Ghana, ‘Dumsor’ is a part of life. An annoyance, a risk, an impediment to be sure, but a part of life all the same.

̽��ֱ��half-joking, half-serious term, which roughly translates to ‘off-and-on’, refers to the frequent blackouts in the country. Entire neighbourhoods go dark in an instant. ̽��ֱ��patchwork electrical grid can leave one side of a street in darkness and the other fully lit. So widespread are the blackouts that John Mahama, until recently the country’s President, was often referred to as ‘Mr Dumsor’ by Ghanaians.

Like many countries in sub-Saharan Africa, Ghana doesn’t produce enough power to meet demand. Its power supply has been erratic since the early 2000s, when water levels in the Akosombo Dam, the country’s main hydroelectric dam, dropped to dangerously low levels, and they have yet to recover fully. Although Ghana has one of the highest rates of access to electricity in Africa, in 2015 the country still experienced blackouts on 159 days.

“Ghana’s not so different from the UK, really – both countries have an electrical grid that’s under enormous strain,” says Dr Kevin Knowles of Cambridge’s Department of Materials Science and Metallurgy. “ ̽��ֱ��difference is we’d be up in arms if the lights went out all the time, whereas in Ghana it’s just a fact of life. But there are things that researchers in Ghana are doing to help improve the electrical infrastructure.”

One such researcher is Dr Abu Yaya, Head of the Department of Materials Science and Engineering at the ̽��ֱ�� of Ghana. Yaya has been working with Knowles with the aim of developing a home-grown industry back in Ghana to make a small but crucial component for power transmission: electroporcelain.

For electricity to get from the places where it is generated, such as the Akosombo Dam, to homes and businesses, it needs a well-established electrical grid made up of pylons, substations and transmission lines. Whereas high-voltage power lines are insulated by the surrounding air, a physical insulator is required at the point where the power lines are supported by utility poles or transmission towers, or where power lines enter buildings. These insulators prevent the loss of current and concentrate its flow, as well as help prevent electric shock.

Most insulators for high-voltage power transmission are made from glass or porcelain. Knowles describes the electroporcelain manufacturing industry as “mature”. In fact, in the UK it’s been around since the 1860s – a reason perhaps why the insulators can look curiously old-fashioned and incongruous, like small white ceramic bowls or brown spiral candlesticks perched on the arms of pylons.

However, despite the prevalence of raw materials to make electroporcelain in Ghana, electroporcelain ceramics are imported from other countries at great expense.

Ghana’s not so different from the UK, really – both countries have an electrical grid that’s under enormous strain. ̽��ֱ��difference is we’d be up in arms if the lights went out all the time, whereas in Ghana it’s just a fact of life
Kevin Knowles

It’s a frustrating situation says Yaya, who has now developed a method of making electrical insulators out of the materials available in Ghana. His aim is to scale up the process for commercial use in the country, and possibly to other sub-Saharan countries as well. ̽��ֱ��process is economical because all it needs is the raw materials, water and a furnace.

Yaya grew up in the slums in Nima, a suburb of Accra in Ghana. After completing his undergraduate studies in his home country, he received funding from the European Union to complete his Master’s degree in materials science at the ̽��ֱ�� of Aveiro, Portugal, and the ̽��ֱ�� of Aalborg, Denmark, and his PhD at the ̽��ֱ�� of Nantes, France, after which he returned home to take up a post at the ̽��ֱ�� of Ghana.

It was when he returned to Ghana that Yaya first became interested in developing electroporcelain, after a discussion with a retired lab technician who had a stockpile of clays and feldspar, but wasn’t sure what to do with it. “I figured out the clays and feldspar could be used to make electroporcelain, and at the same time I realised that Ghana imports all of its electroporcelain from Asian countries,” he says. “So I asked myself why can’t we make these products – and that is how I ended up in Cambridge.”

In 2015, Yaya won a six-month CAPREx fellowship at Cambridge to work with Knowles, an expert in materials for use in challenging engineering environments. Most of Knowles’ research focuses on how small changes to the microstructure of materials can improve their mechanical, electronic or optical properties for use in components such as connecting rods, fan blades, glass and fuel cells.

“In electroporcelain, the raw materials are clay, feldspar and silica,” explains Knowles. “When these raw materials are mixed together in the right proportions and fired together, at a temperature such as 1,200°C, an electrical insulator is produced. What happens during firing is that the feldspar melts and this helps to bind the particles together inducing further chemical reactions and reducing porosity. ̽��ֱ��result is a dense product that can be given a surface glaze to enable it to pass national safety standards tests for porcelain insulators.”

Yaya adds: “Normally, imported electroporcelains are made to suit the original country’s specifications, and are not made specifically for Ghana or other African countries, where the climatic conditions could vary. By producing these products in Ghana using local raw materials, they are subjected to our own environmental conditions.

They would be sent to the Ghana Standards Authority for further testing to ensure that failure does not occur rapidly when the electroporcelains are in use.”

Dumsor is an irritation at times but it also shows the power crisis we must overcome
Abu Yaya

As well as working closely with Knowles, Yaya has also spent time working with UK-based company Almath Crucibles to optimise his process. His aim from the outset was to develop a manufacturing process for electroporcelain that would meet international standards so it can be sold to Ghana’s electricity company.

It’s a crucial time for Ghana, which has committed itself to universal electricity access by 2020. Making sure the electricity supply is widely available and reliable will aid the growth of industries and the economic development of the country. It will also support the demand for power by an increasing population.

“If we are able to manufacture insulators in Ghana then they will be far more affordable than imported insulators, and we stand a better chance of expanding our electrical infrastructure to improve capacity,” explains Yaya. Meanwhile, foreign investors are beginning to take notice of Ghana’s richness in materials: in August 2016, a Chinese-owned company opened the first phase of a US$60m factory in the Free Zone in Eshiem in Ghana to manufacture floor tiles and other ceramic products to supply domestic and international ceramics markets.

Yaya continues to collaborate with Knowles, as well as with other researchers in Europe. He is currently in the process of patenting his technique through a ̽��ֱ�� of Ghana Technology Transfer Grant, and is now looking for potential commercial partners to help him bring the technology from a laboratory to an industrial scale.

“Dumsor is an irritation at times but it also shows the power crisis we must overcome,” he says. “We need to be sure that limitations in generating and distributing electricity do not become a development challenge for the country.

Dr Abu Yaya is at the ̽��ֱ�� of Ghana. His research with Dr Kevin Knowles was funded by the Cambridge-Africa Partnership for Research Excellence (CAPREx) and ̽��ֱ��ALBORADA Trust, through the Cambridge-Africa Programme.

To keep up to date with the latest stories about Cambridge’s engagement with Africa, follow #CamAfrica on Twitter.

When Ghanaian Abu Yaya wondered why his country imports all of its electroporcelain – a small but crucial component for electrical power transmission – it led to a collaboration with Cambridge materials scientist Kevin Knowles that might one day result in Ghana being able to reduce its frequent blackouts.

So I asked myself why can’t we make these products – and that is how I ended up in Cambridge"

Abu Yaya

jbdodane on flickr

Akosombo Dam, Ghana

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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