Have Bananas Lost Their Mojo?Written by Aimee Cremasco
Though their sexy shape may resemble a "GoldMember," modern-day bananas simply aren't shagadellic. According to Belgian and French scientists, bananas may become extinct within next 10 years due to their lack of genetic diversity, which makes them prone to attacks by diseases.There are two primary fungal diseases attacking banana plantation, Panama disease and black Sigatoka. Biotechnology and genetic manipulation may be only way to save fruit. Scientists hope to find disease-resistant genes from a non-edible variation of banana, and then inject them in edible ones. Unfortunately, it's difficult to develop genetic variance in asexually reproducing plants. Cross-pollination with these wild plants is possible, but scientists claim it won't be easy. Almost all bananas, as we know them today, are clones of naturally mutant wild bananas, which were discovered as many as 10,000 years ago. This rare mutation caused wild bananas to grow sterile. To keep fruit alive, ancient farmers took cuttings of mutants, then cuttings of cuttings, and so on. According to a recent article published in The Guardian, "Plants use reproduction to continuously shuffle their gene pool, building up variety so that part of species will survive an otherwise deadly disease. Because sterile mutant bananas cannot breed, they do not have that protection."
| | Shedding Light on Cheaper Solar EnergyWritten by Brenda Townsend Hall
Renewable sources of energy are key to solving two of worlds most pressing yet seemingly irreconcilable problems. On one hand developing world needs vastly to increase access to affordable energy because, at present, 1.6 billion people in world's poorest countries do not have a power supply. However, on other, we cannot go on depleting world's finite resources of fossil fuels and contributing to emission of harmful greenhouse gases by burning them. Thus sustainable development is threatened by a 'double whammy': difficulty of meeting increasing demands for energy, without which development aims cannot be met, and by environmentally harmful systems most often used to provide it. Affordable, renewable energy sources would contribute greatly to breaking this impasse. However, field is a complex one and nobody believes a single solution will be found that can answer all world's energy needs. Even renewable sources have their drawbacks - wind and solar systems, for example, may never be able to stand alone as energy providers because they are, by their very nature, intermittent. However, they can be used very effectively in conjunction with other systems. A judicious mix of energy-producing systems can contribute to sustainable development by increasing availability of energy to poor, while reducing harmful impacts on environment. But an intransigent limiting factor is cost, particularly of conversion of sunlight for energy. If systems are not affordable they will be beyond reach of poorer countries whose needs are most pressing. Recently, however, a project undertaken by a team of physicists, chemists, material scientists and engineers at Sheffield Hallam University, with funding from Engineering and Physical Sciences Research Council (EPSRC), has given a new boost to economic feasibility of solar energy. The research has shown how to reduce cost of generating solar electricity. Although electricity generation through interaction of sun's heat and light with semiconductors (called photovoltaics [PV]) has recognised environmental benefits, technology has hitherto been hampered by relatively high costs involved. Now Sheffield Hallam University team has come up with some cost-cutting ideas: a low-cost semiconductor production method called electrodeposition, less reliance on expensive semiconductor materials, and identification of alternative solar cell devices and manufacturing techniques with higher conversion efficiencies. Such efficiencies mean that more power can be produced per cell so that cost of each unit of electricity generated is reduced.
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