Ocean Thermal Energy Conversion: The Future of Energy Production?

Ocean Thermal Energy Conversion: The Future of Energy Production?

A long-rejected form of clean energy has now been revived. Ocean Thermal Energy Conversion (OTEC) provides renewable, non-polluting power, day and night and could theoretically supply  ‘4000 times the world’s energy needs in any given year’ (Knight, H., 2014, pp.49).

Two centuries ago Jules Verne mused about the idea of OTEC in Twenty Thousand Leagues Under the Sea and ever since there have been lofty claims for its potential. So why OTEC’s 21^st century renaissance? The oceans are the world’s largest energy system and OTEC is a technology that harnesses this potential energy source. The temperature difference between cold deep-ocean water and warm surface water is exploited to generate steam energy. A mechanism pumps warm surface water past pipes that contain a liquid with a low boiling point, such as ammonia. The liquid subsequently boils and the steam powers a turbine connected to a generator in order to produce electricity. The steam is then condensed by seawater pumped from the deep-ocean so it can be reused.

 

Fig. 1. Knight, H., 2014, p.51

In the real world the concept has long been deemed as impractical and a major setback was accessing the cold deep water. Pumping the vast volume of water warrants the need for 1000-metre-long pipes that are both wide and resilient enough to withstand ocean currents in order accommodate the necessary temperature difference of at least 20^oC between the surface and deep water for the system to work. To overcome this complication, developers looked to wind-turbine manufacturing for their inspiration. Pipes can now be made from fibreglass and resin composites that are both strong and flexible enough to endure the pressures of ocean currents whilst also being cost effective. The advantage of this innovative development is that the entire network of pipes can now be ‘assembled on the ocean-surface platform of the OTEC plant itself’ (Knight, H., 2014, p.50), thus eliminating the risk of dropping a pre-assembled structure into the ocean.

Aside from the technical difficulties the other major concern is that the technology is 6-8% efficient. The most pressing question is whether it realistically compete against the giants of energy production like coal and natural gas in terms of profit made. The recent emergence of fracking has also pushed OTEC to the back of our minds and it seemed unlikely we would ever see it in actuality. However, unexpected collaborations with other renewables as well as myriad lessons from the oil and gas industry have potentially allowed OTEC to become a genuine contender in the 21^st century’s renewable energy mix. Currently, there are even projections that it could eventually become 60% efficient (Masutani, S.M, AND Takahashi, P.K., 2001. pp.1994) and recent advancements mean that now, the construction of a 100-megawatt floating plant would cost $790 million (Vega, L.A., 2010, p.11). Such a plant would produce electricity at a price of 18 US cents per kilowatt hour which is not far short of other main non-polluting competitors - ‘the US Department of Energy estimates… 14 cents for coal with carbon capture and storage, and 14 to 26 cents for solar energy’ (Knight, H., 2014, p.50).

OTEC’s resurgence is timely and was spearheaded last year by Lockheed Martin following their announcement that they were to begin construction of a 10-megawatt plant off the coast of southern China. Unstable oil prices, elevated pollution from non-renewables and the threat of climate change make this alternative form of clean energy truly an attractive option. Indeed, just this month a UN-backed expert panel declared that, ‘if the world is to avoid dangerous climate change’, the ‘unrestricted use of fossil fuels should be phased out by 2100’ (McGrath, M., 2014).

The need for OTEC is furthered as a result of the limitations of intermittent renewables such as wind and solar energy. Their electricity production is unreliable and climate change is proving to be a serious issue: ‘higher temperatures could reduce the amount of fresh water for both hydropower generation and concentrated solar power plants’ (Knight, H., 2014, p.51). Conversely, not only can OTEC produce electricity day and night but global warming might even increase the technology’s global output by expanding the “equatorial waistband” for productive OTEC plants by warming surface water found further north or south of the equator.

The technology is most effective in equatorial areas due to a constant temperature differential of at least 20^oC. Whilst 98 nations or territories could presently accommodate OTEC, in reality only Kume Island in Japan (50-kilowatt plant) and South Korea (20-kilowatt plant) have working plants. Having said this, Hawaii has a 100-kilowatt plant in development whilst India, Bahamas and Curacao have plans or proposals for OTEC (Knight, H., 2014, p. 50). Likewise, China has planned the creation of a 10-megawatt plant which is certainly a welcome development. In 2009 China surpassed the USA as the world’s biggest energy consumer, in turn leading to rising carbon dioxide emissions which pose a serious threat to the environment.

OTEC also offers the possibility of generating other products: ‘fresh water, nutrients for enhanced fish farming and seawater cooled greenhouses enabling food production’ (OTEC foundation, 2000-2003). This would be a godsend for poorer nations suffering food shortages and drought, hence Tanzania’s proposition for an OTEC plant - a 50-megawatt plant could support a developing community of approximately 300, 000 (Vega, L.A., 2010, p. 15). For developing nations, a more tantalising prospect is using the cold water for refrigeration systems as well as in air conditioning units.

Figure 2. Knight, H., 2014, p.50

So, in truth can OTEC truly become the future of energy production without any impact on the environment? OTEC plants could purportedly extract ‘7 million megawatts before they would have any noticeable effect on ocean temperatures’ which is equivalent to ‘nearly 50 percent of global energy consumption’ (Knight, H., 2014, p.51). Indeed there are concerns that environmental damage could be caused by leakage - ammonia is toxic in moderate concentrations and there are fears that water packed with nutrients being introduced to algae in warmer waters could cause algal blooms. However, this could be avoided if the cold water is returned to the ocean at depths lower than 60 metres. OTEC could in fact yield environmental benefits: organisms sustained by nutrient-rich, deep ocean water could enhance uptake of atmospheric carbon dioxide whilst ‘energy extraction and the artificial upwelling of deep water’ (Masutani, S.M, AND Takahashi, P.K., 2001. p.1994) could preserve diminishing coral populations by limiting temperature rise at the surfaces of oceans.

The future seems bright for OTEC.  Combining OTEC with other power sources appears the most promising idea. A study has investigated using solar power to increase the temperature of surface water before it is used to boil the ammonia and has found it could triple a plant’s daytime electricity output (Bombarda, P., AND Invernizzi, C., AND Gaia, M., 2012, p. 42302). Similar techniques are being developed at the Korean Ocean Research and Development Institute. South Korea’s 20-kilowatt plant can only operate during summer when the temperature differential exceeds 20^oC so in order to make it work year-round there are plans to harness heat from solar power and waste incineration to pre-heat the surface water.

More promising is the concept of coupling OTEC with another 24 hour power source - suggestions have been made for a ‘GeOTEC’ plant that would use geothermal energy to heat the seawater used to boil ammonia. Nonetheless, the greatest prospect lies in OTEC ships which could search for spots with best temperature ratios in order to make the technology even more cost effective. The electricity generated could be used onsite to split seawater into hydrogen and oxygen – the hydrogen being stored in fuel cells before being transported for use around the world. A 100-megawatt ship could produce over 1 tonne of liquid nitrogen per hour and whilst this would currently be expensive, the hydrogen economy is just emerging so the cost will surely decrease (Knight, H., 2014. p.51).

To conclude it is clear that Ocean Thermal Energy Conversion could provide significant global benefits and merits serious consideration from governments and businesses as a viable, future solution to energy production.

Bibliography

Knight, H.K., 2014. Sea Change. New Scientist, 2958, pp.49-51

OTEC Foundation, 2013. What is OTEC [online]. Available from: http://www.otecnews.org/what-is-otec/ [Accessed 2 November 2014]

Masutani, S.M, AND Takahashi, P.K., 2001. Ocean Thermal Energy Conversion. pp.1994-1999. Available from: http://curry.eas.gatech.edu/Courses/6140/ency/Chapter2/Ency_Oceans/OTEC.pdf. [Accessed 3 November 2014]

McGrath, M., 2014. Fossil fuels should be phased out by 2100 says IPCC. Available from: http://www.bbc.co.uk/news/science-environment-29855884. [Accessed 1 November 2014].

Vega, L.A., 2010. Economics of Ocean Thermal Energy Conversion (OTEC): An Update, pp.1-18. Available from: http://hinmrec.hnei.hawaii.edu/wp-content/uploads/2010/01/OTEC-Economics-2010.pdf. [Accessed 4 November 2014]).

Watts, J, 2010. China overtakes US as world's biggest energy consumer. Guardian [online], Tuesday 3 August. Available from: http://www.theguardian.com/environment/2010/aug/03/china-overtakes-us-energy-consumer

Bombarda, P, Invernizzi, C and Gaia, M, 2012. Performance Analysis of OTEC Plants With Multilevel Organic Rankine Cycle and Solar Hybridization. Journal of Engineering for Gas Turbines and Power [online], vol. 135, p.42303. Available from: http://gasturbinespower.asmedigitalcollection.asme.org/article.aspx?articleid=1671877. [Accessed 2 November 2014]

Chillies Inspire Medicinal Revolution

Chillies Inspire Medicinal Revolution

     The mechanism within our body that explains the burning sensation we feel when eating chillies could prove fundamental in treating chronic pain conditions and even cancerous tumours.The same mechanisms that explain piquant flavours and soothing cooling flavours such as menthol are also vital in the maintenance of internal body temperature. The key component within chillies that is the source of their fire is called capsaicin. Our sensory perception depends on specific channels, known as TRP (transient receptor potential) channels,

on the surface of certain cells, usually neurones, each responding to different stimuli. When the channel is activated, its pores open up, allowing electrical charge in the form of ions to flow in, in turn triggering an electrical impulse. The channel essential for detecting capsaicin is called TRPV1. This channel also responds to extreme temperatures (43^oC or above) which would be enough to damage tissue - this explains why chillies feel as though they are burning the mouth.

      The functions of aforementioned channels are wide-ranging, hence possibly implicating them in a range of disorders. Particular interest in them is a result of their location on nerves that respond to painful stimuli, and consequently their potential for heightening of dampening the nerve’s sensitivity. The radical concept is that these channels present promising avenues for research for new kinds of painkillers that could use the pathway as an entry point. For example, a protein has recently been discovered that controls TRPV1 function during inflammation. AKAP79 shifts the cell’s molecules into certain formations so that when in excess, the TRPV1 channel has a lower threshold for generating nerve impulses. This results in regular temperatures feeling painful – a prevalent issue in chronic pain conditions including migraine and certain injuries. In order to reverse this unwanted effect, a chemical can be used to prevent AKAP79 from binding to the TRPV1 channel, reducing the pain associated with inflammation.

      These channels could also be crucial in delivering drugs to a far more precise region in the body, for better local anaesthetics. Currently, a local anaesthetic at the dentist dampens all your nerve cells, leaving your face temporarily paralysed. One solution is to use capsaicin or similar molecules to unlock pain nerves : by momentarily opening the heat channel a pathway would arise through which an analgesic could progress into the cell. Since the nerves involved in moving  muscles don’t have the same receptor, they would be unaffected.  As a result of  thermal channels on nerve cells, it is highly likely there are other targets – for example cooling has analgesic effects in painful conditions such as osteoarthritis, and has a soothing effect in inflammation. However presently, there is yet to be a drug that ‘achieves a comfortable medium’, without inducing an aching hypersensitivity to cold which emanates from too much activity in several of the pathways (such as TRPM8 and potentially TRPA1) associated with lower temperatures.

    Perhaps a more commercially viable option would be to use the TRP channels to alter the body’s thermostat to control energy expenditure. This could possibly result in loss of excess fat – a welcome prospect for our increasingly obese society. Unfortunately there are currently some issues. It would be seemingly obvious to suggest that removing our heat sensing mechanism would have the same response as a cold temperature, inducing a response such that more energy is used to generate heat. Nevertheless, conflicting studies have illustrated mice lacking the TRPV1 receptor in reality put on weight. On account of this, it is  proposed that the solution should be to gently stimulate these receptors instead. The activation of the TRPV1 channel appears to suppress the production of adipocytes (specialised cells that store energy as fat), whilst other studies have suggested that the body burns fat already stored. Another proposal is that as TRPV1 is involved in taste, we may be fuller after a smaller portion of food. There is so far modest proof that these theories have solid grounding – subjects who took a regular dose of capsaicin every fay showed a noticeable increase in the calories they burned; ‘enough for a steady weight loss over the course of months’.

    What, is in my opinion, most intriguing is the theory that these channels may be involved in tumour growth. For instance TRPM8, which allows us to taste mint, is present at abnormally high levels in prostate cancer – the more the severe the cancer, the higher the levels of said protein in the cancerous cells. The channel may have become integrated in the cellular signalling pathway that triggers cell division, and since they are also found in the cells that line blood vessels, they might contribute to the spread of cancer by promoting the formation of blood vessels which supply tumours with nutrients. Targeting the TRPM8 thus offers the tantalising thought of controlling the growth of cancers, and so far this revelation seems to be entirely true – a recent experiment that used chemicals to inhibit TRPM8 activity reduced the proliferation of cultured prostate cancer cells. Such success has led to the first clinical trial that aims to discover drugs that prevent the spread of the disease. These prospects are compelling and present the possibility of several treatments. For the time being though, at least one thing is evident: these channels are imperative for the future of therapeutics. 

Source: 

http://en.wikipedia.org/wiki/Transient_receptor_potential_channel

http://gbiomed.kuleuven.be/english/research/50000618/50753342/TRPchannels

New Scientist 'Catching Fire'

Fishing for Space Junk

Fishing for Space Junk

The Japanese space agency, JAXA, announced that next month it will pilot its ‘electrodynamic tether’ for the first time. It is one of the possible solutions suggested to deal with the increasing number of space debris. Nearly a million pieces of spacecraft, satellites and other astronautic equipment speed round our planet, posing devastating consequences. An object just 10 centimetres across could ‘catastrophically damage’ a satellite and a piece just 1 centimetre across could disable a spacecraft; the Kessler Syndrome is the worst-case scenario – it refers to the collision between pieces of junk that would ultimately result in more and more debris.

JAXA aims to use a ‘debris-catching net’ - a 700 metre long mesh of aluminium and steel wires that hangs tethered from an unmanned spacecraft. The net is fitted with sensors that detect light changes resulting from reflections off small pieces of debris, the net then aligns itself accordingly so that it can attract the waste material. The electrical current flowing through the wires induces an electromagnetic field that attracts the debris and pushes the net away from the Earth’s magnetic field. Once enough junk has been collected, the spacecraft and net and made to slow down so they burn up as they enter Earth’s atmosphere.

JAXA claims the main advantage is the net’s simplicity. It’s lightweight and doesn’t require propellant to move, and JAXA hopes to build a 10 kilometre version to capture satellites that no longer have use. However not everybody is so confident. One concern is that the spacecraft will take too long to de-orbit and others fear that the net may ‘run into operational satellites’. A JAXA spokesperson also warned that ‘there is a possibility of the tether being severed by debris of micrometeoroids’.

Using a net is just one of many proposed solutions to the space junk issue. European company EADS Astrium wants to give satellites built in ‘sails’ to act as an orbital brake, dragging them into Earth’s atmosphere; whilst a team in Switzerland is currently building a robot, CleanSpaceOne, that will sweep up junk by deploying jellyfish like grippers to collect the target. Boeing on the other hand wants to send up a rocket that could dispel the debris with jets of gas and other companies want to use lasers to clear the debris. 

Space debris surrounding Earth

Source: New Scientist

Stardust - The Fountain of Life

Stardust - The Fountain of Life

The dust grains that travel through our solar system contain the vital components needed to form water. Similar dust grains are thought to be found all over the universe and this bodes well for the existence of life in other galaxies. Hope Ishii commented on the discovery, saying ‘it is a thrilling possibility that this influx of dust on…solar system bodies has acted as a continuous rainfall of little reaction vessels containing both the water and organics needed for the… origin of life’. This magic stardust is a result of many processes, though primarily the breakup of comets.

Particles extracted from the Earth’s stratosphere were found to contain minuscule pockets of water. The reason for this phenomenon is the product of a reaction between dust and solar wind. The dust is made mostly of silicates, which contain oxygen - as it travels through space; it meets the solar wind which is a stream of charged particles, including high energy hydrogen ions, ejected from the sun’s atmosphere. When the two collide, hydrogen and oxygen combine to form water.

Of course, this can’t solely account for the sheer mass of water that covers Earth today; a more probable origin is saturated asteroids that hit Earth billions of years ago. Nonetheless, the water producing reaction is likely to happen all over the cosmos wherever there is a star present. Furthermore, the interplanetary dust contains organic carbon which, too, is fundamental for life. If stardust contains carbon and water, ‘the essentials of life could be present in solar systems anywhere in the universe and raining down on their planets’.

Source: New Scientist 

Smart Glasses Allow Blind People to See

Smart Glasses Allow Blind People to See

     A new prototype pair of smart glasses developed by Assisted Vision are able to translate visual information into images that blind people can interprate. They simplify the more ambiguous elements of the everyday environment and then display these more basic and relevant details for the user; essentially allowing them to gain partial sight. The system works because 75% of registered blind people have the ability to detect light, and the glasses could be especially useful for users with cataracts, age-related macular degeneration and diabetic retinopathy, among other eye-related conditions.

    

    Assisted Vision's sensors gather data through two cameras, a gyroscope, a compass and GPS. The sensors can capture movement, direction and the exact location of the objects in front of a user. The sensors send data to a processor, which translates the images. The processor then transmits the data to a display inside the glasses, where objects in front of the user are rendered as a series of lights. The OLED technology can show different colors and intensities of light to indicate an object's distance, for example, objects can be made clearer against the background, or the distance to obstacles can be indicated by the varying brightness of an image. It can also differentiate between objects that are moving and those that are still.  The smart glasses also come with a headphone and text-to-speech software, which helps users ascertain other important information such as directions, bus numbers and even signs.

Assisted Vision Displaying the Movement of a Person

The Matrix

The Matrix 

    

          Loboa, a materials engineer has developed a ‘self-destructing super-bandage’ that is capable of ‘healing infected wounds quickly, without scarring or standard antibiotics’. It is essentially a material that degrades until only your own regenerated, healthy cells remain; allowing for the concept to eventually heal damaged muscle, destroyed digestive tissue and even broken bone.

 

          Loboa’s work relies on the research into the extracellular matrix. This is the framework that ‘gives the various parts of our body their detailed shape and solidarity’, supporting and structuring the cells of a blood vessel or organ. However this isn’t its only function. Although the matrix chiefly consists of inanimate structural proteins, for instance collagen and elastin, it also comprises of proteins that essentially coax specific cells to be in a certain place. Once such animate proteins have induced the correct cells, the matrix then determines whether they become bone, muscle or fat cells, depending on the tension they experience once inside the matrix.

 

            In your body this tension is the consequence of the stresses of every-day muscle movement; high tension persuades stem cells to become muscle or bone whilst a matrix with a lower tension promotes fat cells. Another role of the matrix is to nourish the cells in order for them to mature into larger structures. This is the result of the matrix containing powerful growth factors that aids in the formation of blood vessels which subsequently provide oxygen for the developing organs. 

      It is the exploitation of these properties that have revolutionised the way in which both tissue and organs can be regenerated. The natural human extracellular matrix has allowed for the world’s first artificial kidney to be built courtesy of Harald Ott. Rather than using various stem cell types, only two cell types were essential in forming the organ. Blood-like stem cells were placed in the blood vessels of the decullularised kidney matrix whilst endothelial cells were positioned into the various sections of the filtering system - this ultimately caused the other kinds of cells to form in the sites they were supposed to.

          In terms of using the matrix to attract and grow muscle from a person’s own cells, this technique has already been successfully performed, primarily through the use of decullularised tracheas from corpses to create new fully functional tracheas.  In spite of this, its application hasn’t truly extended far beyond said method, and so a study has involved the matrix from a pig bladder being used to grow muscle in people who had lost more than half of a muscle in several types of trauma. Residual scar tissue was surgically cleared, and then a strip of the matrix was placed into the exposed void, made taut enough to indicate to the body that it should become muscle. Eventually the pig matrix becomes completely replaced by the natural matrix of the patient as well as healthy muscle.  The natural matrix can also be used to repair shattered bone. Research has suggested that a matrix made from human blood is the most effective mechanism, as it is essentially a highly concentrated blood clot which contains large amounts of growth factors that promotes bone repair.

         Nonetheless there are drawbacks to natural matrices. The issue of them not being naturally antimicrobial is a particular concern due to the risk of the wound being infected by the ever increasing number of drug-resistant superbugs. It is thus clear of the importance of a synthetic matrix that could ‘turn slowly into the patient’s own tissue without ever exposing the flesh beneath to microbes’.

  

         Loboa developed a biodegradable material using polylactic acid (often used in medical implants) and shaped it into fibres that mimicked the structure of skin. Such fibres can be made solid, porous of hollow; however a porous construction is preferred as it can be permeated with a variety of anti-inflammatory drugs and Silvadur – a substance that contains small amounts of silver ions lethal to most drug-resistant bacteria including MRSA. The material works in two phases: the first release overcomes all present bugs, and the second guard ‘leaks out’ slowly to destroy any other interlopers. Soon the scaffold or plaster disappears too, leaving only a small scar where the wound once was.

         Another benefit of a synthetic matrix is that it ‘can be used as a template to build body parts far stronger than those nature provides’. A treatment where this would be especially beneficial would be for kidney dialysis. A fast-decaying biodegradable polymer can be constructed into a tube exactly the same dimensions of a vein, but with a thicker vessel wall, and coated in human muscle cells. Within days the cells replace the tube with a matrix of natural collagen which is thicker and thus better able to withstand extra pressures of dialysis. After decellularisation, the tubes can be surgically implanted into the patient, serving as the vein for dialysis; thus eradicating the risk of the natural veins from collapsing.

         The potential for synthetic matrices is seemingly endless; nevertheless an artificial matrix does not have the countless properties of natural matrix, which will forever be crucial for building organs as ‘it retains so many factors to bind and differentiate cells’.  However, for some applications, hybrids are a possibility; a mechanism that incorporates both the artificial and natural matrices. For example, a synthetic matrix can provide a stronger scaffold, that can be tailored to requirements, i.e. providing extra ‘niches’ for cells, whilst a natural matrix can then aid wound healing through fibrinogen – to encourage the body to accept the component, the hybrid can then be coated with surface cells derived from the patient’s fat.

         There are other future possibilities for the matrix too. A multi-layered version could ‘simultaneously regenerate multiple kinds of tissues damaged in severe accidents ‘, and be potentially used by the military to treat war wounds on site at a lower cost. It even has potential for repairing brain damage; a signalling molecule released from the brain matrix that has been damaged by stroke, called DV, promotes the growth of new blood vessels. This molecule, once injected into mice who had suffered strokes, had entirely repaired the brain damage within only a couple of weeks. The promises of these discoveries appear infinite, and I hope it won’t be long before they become a reality.

Reference:

http://www.smh.com.au/technology/sci-tech/the-body-builders-20131005-2v0yd.html

Anti-Quorum Sensing Molecules

Anti-Quorum Sensing Molecules: The Future of Bacterial Resistance

The misuse of antibiotics has meant that some bacteria have become resistant, such as strains like the ‘superbug’ MRSA, and has caused for extensive research to be taken into other methods that will prevent harmful bacteria. Although new antibiotics have been created from different microbes, they are a finite source for antibiotics and so are only a short term solution. However, Bonnie Bassler, a microbiologist has discovered the crucial element in the on-going war with bacteria; the way in which bacteria co-ordinate collective behaviours and function as multi-cellular organisms through a mechanism known as quorum sensing.

Quorum Sensing

   
      Quorum sensing is the bacterial communication phenomenon; during quorum sensing, bacteria produce, detect, and exchange signalling molecules known as auto inducers. The concentration of a particular auto inducer enables a population of bacteria to collectively regulate gene expression, thus meaning specific genes are only synthesized as particular population densities. This process is crucial to disease development because it ultimately controls the way that bacteria express virulence factors—the molecules that enable the bacteria to colonize a host. In bacteria, virulence factors are often encoded on mobile genetic elements, such as bacteriophages, and can easily be spread through horizontal gene transfer. Auto inducers bind to receptors in the bacteria, forming receptor:autoinducer complexes which bind to certain sites along the cell’s DNA, triggering the bacterium’s virulence genes.

Anti-Quorum Sensing

     
      Anti-quorum sensing molecules would essentially prevent bacteria from communicating by strongly inhibiting quorum sensing through binding to the receptors in place of the autoinducers, thus upsetting the process. Said compounds would be specialised to target specific receptors of a bacteria type, and thus by being unable to carry out collective virulence activities that are critical for enabling bacteria to stay in the host, the immune system would have more time to get eliminate said pathogens. 

       

       Recently, researchers from Princeton University and the Howard Hughes Medical Institute developed a molecule to block quorum-sensing in the bacteria Chromobacterium violaceum which has a close homolog to a bacteria that causes particular trouble for cystic fibrosis patients. Due to the effectiveness of the mechanism of anti-quorum sensing, many scientists are now investigating other bacterial traits that could be similarly exploited.

The Benefits

       
     Because anti-quorum-sensing molecules do not kill bacteria, only keep them from communicating, it is probable that bacteria would be less likely to develop resistance; nonetheless if a resistance does develop, it will be expected to progress far slower than resistance occurs in response to current antibiotics. Furthermore, ‘quorum-sensing antagonists represent potential lead molecules in the search for new antibacterial therapeutics’, and so coupled with the success in this particular field, it shouldn’t be too far in the future that this treatment becomes available for a wider audience.

Diagram to Show How Quorum-Sensing Occurs

References:

http://www.bnl.gov/newsroom/print/friendly.php?a=22674

http://en.wikipedia.org/wiki/Quorum_sensing

http://molbio.princeton.edu/faculty/molbio-faculty/31-bassler

Malaria Vaccine

Malaria Vaccine Available in 3 Years

 

    GlaxoSmithKline, a major UK drug firm, seeks to market the world's first malaria vaccine within three years. Promising testing results showed that the drug, RTS,S/AS01 (commercially named as Mosquirix) was effective in protecting young infants for up to 18 months, nearly ‘halving the number of malaria cases in children between five and 17 months old’. The vaccine was engineered using genes from the outer protein of the malaria parasite and a division of a hepatitis B virus as well as a chemical adjuvant (a substance or agent) to boost the immune system response; its funding has stemmed from £124 million from the Bill and Melinda Gates Foundation, and its development has been aided by GSK’s partnership with the PATH Malaria Vaccine Initiative.

   

      However, a major setback appears to be that the effectiveness of the vaccine wanes over time, only protecting fewer than 20% of children for 4 years. Despite this, because of the vast influence of malaria (660,000 people killed by malaria in 2010) the number of cases of the disease the vaccine can help is immense, and thus the vaccine ‘does not need to be fully effective to make a huge difference’. Nonetheless, the cost of issuing the vaccine is a major concern, with economics presenting a significant barrier to the distribution amongst LEDCs who rely on NGOs and charitable foundations. 

References:

The Daily Telegraph

http://en.wikipedia.org/wiki/Malaria_vaccine

Alzeheimer's Beaten?

The Turning Point in the Battle to Beat Alzheimer’s

       Scientists have acclaimed the discovery of a drug-like compound that acts in preventing brain cell death in mice for the first time.  It works by blocking a faulty signal in brains affected by various neurodegenerative diseases including Alzheimer’s and Parkinsons.  In debilitating brain diseases, the production of new, essential proteins is inhibited by an accumulation of amyloids (misfolded proteins). Such build-up of amyloids triggers the ‘over-activation’ of a defence mechanism which is essentially activated by an enzyme known as PERK, and ultimately stops the synthesis of proteins. Without the presence of proteins, the cells are unable to function and thus eventually die – leading to the symptoms of diseases such as Alzheimer’s.  The compound itself works by preventing PERK, and therefore allows for the restoration and continuation of production of proteins.

     

         The compound was tested on mice with prion’s disease, and it successfully ‘stopped the disease in its tracks’, reinstating some normal behaviours and preventing memory loss. However the compound also caused significant side effects such as weight loss and diabetes, which would be a serious concern for the elderly population who would most likely benefit from this treatment. Although Professor Malucci argued that it would ‘not be impossible’ to develop a drug that protected the brain without said side effects. The huge benefit of such a compound is that it can be given orally, and directs itself into the brain to prevent the disease, meaning it has great potential to be turned into an accessible medicine.

   

        For those who question the viability of whether the compound will translate into other mammalian brains, the professors argue that it hopefully will, as prion disease is the best animal equivalent of human neurodegenerative disorders. On the other hand, although the breakthrough was met with excitement by scientists, they said whilst ‘it is not a guarantee of an Alzheimer’s cure in the near future; it remains a significant proof of principle'. Other critics weren't as convinced and contended that ‘many a new treatment has fallen by the wayside making the leap between mice and man’. 

References:

i - 'Scienticts Hail 'Historic' Alzheimer's Discovery'

http://en.wikipedia.org/wiki/Unfolded_protein_response

Soylent - The Cure for World Hunger?

Soylent - The Cure for World Hunger?

 

  Rob Rhinehart, a 24 year old is pioneering a potentially world changing product branded as 'Soylent'. It is essentially a food substitute that supposedly supplies all of a human body's daily nutritional needs. It is, in effect a mixture of everything the body requires.  This list of ingredients includes vital elements such as iron,magnesium and copper as well as vitamins, minerals and macronutrients such as amino acids, carbohydrates and fat. Soylent also includes non-essential substances such as antioxidants in order to help prevent cell damage, and probiotics to maintain symbiosis between harmful and 'friendly' bacteria. Rhinehart has also experimented with nootropics (drugs, supplements, nutraceuticals, and functional foods that purportedly improve mental functions such as cognition, memory, intelligence, motivation, attention, and concentration) in order to allow the consumer to become fully sustained on Soylent alone.

            

       The project, however, didn’t come without its shortcomings.  Any minute change in the proportion of an ingredient can result in an illness which Rhinehart experienced on numerous occasions, when first tested, the formula omitted iron, which caused Rhinehart to report his heart had begun to race. In other early experiments, Soylent caused Rhinehart to have cardiac arrhythmia and burning sensations. There are other drawbacks too; it doesn't keep long after mixing with water which would make it entirely impractical for those living in LIDCs due to the lack of clean water. In terms of first world problems, most people would deem it unthinkable to only have Soylent for their way of food.

        

          So Soylent is not all perfect then? Well it’s not surprising that nutritional experts were quick to criticise it, deeming it as "dangerous", "ludicrous", and "a red flag for a potential eating disorder".  It does seem rather improbable that one could survive completely off a food substitute; sceptics arguing that in its present form, Soylent may lack some nutrients essential for normal body functioning and/or may fail to provide nutrients in appropriate proportions, potentially causing medical problems if used long-term. However Rhinehart has supposedly managed to subsist almost solely off Soylent for a total of seven months without any apparent problems. He argued  that ‘we need fruits and veggies, though – we need vitamins and minerals. We need carbs, not bread. Amino acids, not milk’; which is entirely reasonable. I admit, at first I was dubious at the prospect of a complete food substitute but it seems unfaultable, our body needs essential nutrients, and in their pure form, in the correct balance you avoid the toxins, allergens, carcinogens as well as waste that you get with conventional food, thus preventing an extensive array of illnesses, to name a few – diabetes, obesity and cancer.  Not only this but Rhinehart claims it slightly boosts the capability of the brain and says he feels far more alert and active.

           

      The reason I am particularly interested in this revolutionary development, however, is its potential to greatly benefit developing nations. Soylent can be mostly produced from the products of local agriculture  which means this could be a truly permanent solution for LICs.  At a world wide scale it would be immensely cheap to produce, Rhinehart suggests it would cost no more than $35 for one fully grown man per month to have a complete Soylent diet of 2500 calories a day. Not only this but due to the lack of excess substances, it means that the body produces less excrement -  this would be particularly beneficial for countries in the developing world, where inadequate sanitation is a prevalent source of disease. Concerning the environment, currently agriculture is having a colossal impact on global warming, cattle farming and rice paddies being amongst the major causes of greenhouse gases. These adverse effects on the climate would be greatly reduced if Soylent were to be produced instead.

     The only issue remaining is for Soylent to actually be funded and distributed through the help of organisations such as UNICEF, the World Food Program, USAID and Action Against Hunger. However with over $1 million in preorders already received for Soylent worldwide, it appears that the solution to "the future of food" may come to fruition sooner than anticipated.

Rob Rhinehart - Pioneer of Soylent

References:

http://www.vice.com/en_uk/read/rob-rhinehart-no-longer-requires-food

http://www.vice.com/en_uk/read/rob-rhinehart-interview-soylent-never-eat-again

http://en.wikipedia.org/wiki/Soylent_(food_substitute)

Sperm Counts Falling Rapidly in Males in the Western World

Sperm Count Decreasing in Males 

     

Over the past 50 years, there has been a noticeable drop in the sperm count of the male demographic. There appears to be numerous factors that are contributing to this potentially disastrous phenomenon, and the possible extinction of the human race due to the decrease in fertility of our male species. Because these changes are recent and appear to have occurred internationally, though more drastically in the Western world,  it has been presumed that they are caused by the effects of environmental or lifestyle factors on the male rather genetic changes – which has been deemed impossible given such the short space of time. If the decrease in sperm counts were to continue at the rate that it is then in a few years it is a realisation that we will witness widespread male infertility.

       

   As many as one in five healthy young men between the ages of 18 and 25 produce abnormal sperm counts, even the sperm t produced however is usually poor quality. Only between 5 and 15 per cent of their sperm is good enough to be classed as "normal" under strict World Health Organisation rules – and the study taken was on healthy participants. The reasons for poor sperm counts are vague to say the least, however, compiled below is a list of the most likely causes.

Food sources: Today, a higher proportion of farm animals are being fed hormones such as growth hormone, oestrogen and testosterone to increase their size and reproductive competence as increased protein to fat ratios result in increased yields, for example cattle and battery  hens. These hormones may be transferred across species barriers directly when we eat them and so there is a potential risk that we may be ingesting food that carries oestrogen in it. The consumption of fats (especially animal fats), proteins, and refined carbohydrates can substantially affect oestrogen excretion and metabolism, so the overall effect of eating a modern western diet, high in fat and low in fibre, is increasing our exposure to endogenous substances are those that originate from within an organism, tissue, or cell) oestrogens. A study, published in the journal Human Reproduction, found 41 million fewer sperm per millilitre of semen after just one portion of soya every two days, the authors stated that plant oestrogens in foods such as tofu, soy mince or milk may interfere with hormonal signals. Milk particularly is of an increasing concern, with oestrogen like chemicals being added when it is pasteurised and there already being oestrogen similar compounds present in the milk due to the cows being fed a diet rich in such additives.

Plastics: Plastics are often treated with substances that are similar to oestrogen such as Bisphenol A (BPA). Bisphenol A is an additive to plastics found in many household products. A 2008 study in the journal Fertility and Sterility showed that men with high concentrations of BPA in their urine also had low sperm counts. Food packaging is a major source of BPA, which can leach into the food contents, especially vegetables and fatty foods . A man called Boockfor et al carried out experiments injecting rats with a chemical called octylphenol, another plastic used in detergents, plastics and paints. a decrease of FSH secretion in the foetus which consequently decreased Sertoli cell number and thus spermatozoa number was observed. It is still uncertain as to the extent to which the human body is actually exposed to chemicals such as octylphenol, and as yet there is no direct proof that there is any link between chemical exposure and changes in sperm counts in man, however . Likewise, for years dentists have widely used these sorts of agent in fillings. In these patients oestrogen like compounds have been found at high concentration in their saliva.

Sexually transmitted infections: Sexually transmitted infections can have a great  impact on the testicles, which in turn affects sperm production. One example of this would be gonorrhoea, an infection that has become particularly rife in recent years; the reason sperm become damaged is because when bacteria become present in the ejaculate, the body produces chemicals that can hinder sperm function.

Stress: Stress can decrease sexual function and interfere with the hormones needed to produce sperm. Research led by the Population Council  in 1997 found that stress hormones overpower the enzymes responsible for ensuring that cells in the testes produce testosterone, which is necessary for sperm formation.

Obesity: Animal studies have shown that embryo implantation and fetal development decreased when sperm came from obese fathers. And a study in France found that obese men were 42 percent more likely to have low sperm counts than non-obese men, and an 80 percent chance of having ejaculate with no sperm in it at all. However, it is suggested that it is not the excess fat itself that disrupts healthy sperm production but rather the toxins and chemicals found in fat-based foods which come from the processes used in their production.

Pesticides: Modern pesticides tend to contain many agents that have oestrogen mimicking properties; the most potent being  Vinclozolin, a fungicide used on many types of fruits and vegetables, is thought to be blocking the effects of the male sex hormones and causing a decrease in sperm count. Furthermore the runoff of pesticides and insecticides flows into rivers, which often lead into our water supply, potentially disrupting hormonal processes. A recent study showed that the excess of oestrogen like chemicals in rivers are causing fish to not only become infertile, but in some cases change sex, although it is not clear whether this has an effect on males as yet.

Use of drugs, alcohol or tobacco: The use of tobacco and drugs could dramatically decrease the sperm count however there are no yet proven studies as with most of the other theories. The effect is probably worse in the case of the mother however who is bearing the child rather than the child using drugs etc him/herself.

Testicular Cancer: There have been a rise in the number of testicular cancer cases in the past 50 years and it could be that the cancer is disrupting the Sertoli cells in the testes or harming sperm production in some other way. However, it is perhaps the treatment of the cancer that could be the greater danger. Since sperm cells divide quickly, they are an easy target for damage by chemotherapy. The higher the dose of chemo, the longer it takes for sperm production to get back to normal, and the more likely it is to stop. Permanent infertility results if all the stem cells in the testicles are damaged to the point that they can no longer produce maturing sperm cells. The damage is most severe when men are treated with both chemo and radiation therapy to the abdomen or pelvis.

 

Rates of Testicular Cancer

Decrease in Sperm Counts of Adults

As is clear from the two graphs shown above, there could potentially be a strong link between a rise in cases of testicular cancer and a decrease in sperm count over the past 35 years. However as written multiple times this cannot be officially recognised it could be caused due to a number of other potential contributing factors.

Radiation: With increasing ozone layer depletion due to the use of aerosols in the past and still in some countries, more radiation is reaching man. Exposure to radiation has further increased with the invention of televisions, microwaves, x-rays, nuclear weapons and the construction of power stations. It has been proven that radiation reduces sperm production in adult males, though to not such a great difference. The effects of radiation on sperm production is more pronounced in children and the effects are seen at lower doses than those seen in adults.

      
        Although these elements could all potentially increase the risk of a poor sperm count, scientists believe that the most crucial influence on fertility is the development of the foetus in the womb. Sertoli cells, which in the adult act as guardians for the development of sperm cells, are the very first cells to form from a "genital ridge" of the human male foetus. The number of sperm that can be produced in an adult man is critically dependent on the number of Sertoli cells that develop in his foetus, so anything that interferes with the formation of Sertoli cells in a mother's womb will affect sperm production many years later. "Maternal-lifestyle factors in pregnancy can have quite substantial effects on sperm counts in sons in adulthood, and the most logical mechanism by which this could occur is via reducing the number of Sertoli cells,", in essence this means that it is the mother who essentially determines the condition of the sperm, and that the foetus can greatly affected by any of the above causes.

      
            In summary, the causes for the decrease in sperm count are unknown and are just being theorised; the major triggers being speculated as an increasingly poor health of the mother which can directly affect the health of sperm of the offspring, and also environmental oestrogen mimickers. The reason for this ambiguity is that there are simply too many possible contributing factors. Other suggestions include taking hot baths and placing laptop computers on the lap or keeping the groin too warm just from clothing can negatively impact sperm count; even the radiation from mobile phones has been questioned. However perhaps the most certifying outcome of the research into sperm counts is that if we don't do anything to change exposure to possible influences then it is almost certain that not too far into the future, we, homo sapiens could become extinct because of something so fundamental as a poor quality of male, human gametes.

NB:  The effect of ‘false’ oestrogens, is that they latch on to hormone receptor sites in the body, in turn possibly blocking the action of the naturally occurring hormone. Another explanation is that the chemicals may mimic its action, switching on or turning off biochemical pathways, and remaining in the body far longer than natural oestrogen. The result is that false oestrogens have 'potentially devastating effects on oestrogen-sensitive tissues in both sexes, particularly in the developing foetus.’



References:

http://www.telegraph.co.uk/health/healthnews/9722963/Male-fertility-under-threat-as-average-sperm-counts-drop.html

http://www.independent.co.uk/news/science/out-for-the-count-why-levels-of-sperm-in-men-are-falling-1954149.html

http://en.wikipedia.org/wiki/Endocrine_disruptor#Types_of_endocrine_disruptors

http://www.independent.co.uk/environment/male-fertility-fears-over-pollution-in-water-supply-654356.html

http://archive.ispub.com/journal/the-internet-journal-of-urology/volume-2-number-1/the-sperm-count-has-been-decreasing-steadily-for-many-years-in-western-industrialised-countries-is-there-an-endocrine-basis-for-this-decrease.html#sthash.uJaqEtVM.dpbs