Nerdy Science Blog

Air New Zealand successfully test fly a jumbo jet, Boeing 747-400, with biofuel for two hours on Tuesday.  The passenger jet took off from Auckland International Airport on Tuesday.  This test flight is a joint venture by Air New Zealand, airplane maker Boeing, engine maker Rolls Royce and biofuel specialist UOP Llc.  This flight biofuel experiment aims to reduce carbon footprint and tackling the problem of rising oil prices.

The biofuel is a 50-50 blend of jatropha oil and standard air jet fuel.  This biofuel is also known as second generation biofuel, which has less emission than traditional biofuel ethanol.  The jatropha nuts for this biofuel were harvested from trees grown in India, Mozambique, Malawi and Tanzania.  The fuel was freezing at -47C and burning at 38C.

According to the International Air Transport Association, other plant materials such as grass, algae and salt-tolerant plants called halophytes have been considered to replace traditional fuel.  New technology is also invested to design lighter and air resistance fleets to replace the outdated ones.  Currently air travel contributes 3% of global carbon dioxide emissions.

A common gene variant links to high blood pressure a.k.a. hypertension has been identified by researchers from the University of Maryland School of Medicine.

Scientists believe that there are multiple genes involved in hypertension.  By using a new technique called genome-wide association study, the first hypertension susceptibility gene, STK39 gene, has been uncovered.  The DNA of 542 members of the Old Order Amish community in Lancaster County, Pa, were analyzed to examine the connection between STK39 gene and blood pressure.  The STK39 gene is located on chromosome 2.  Chromosome 2 is a gene that produce proteins involve in kidney regulation for salt processing, which is essential in controlling blood pressure.  It is found that 20% of the Caucasians in the United States and Europe possess the gene variant.  Senior author Yen-Pei Christy Chang envisioned that the finding can lead to the development of personalized medicine.

The ideal systolic and diastolic blood pressure should be less than 120/80.  Common high blood pressure a.k.a. essential hypertension can be caused by environment and lifestyle factors, such as diet, exercise, and stress level.  It can cause cardiovascular disease, stoke, or kidney failure.

The study is published online on Dec 29th, 2008 in the Proceedings of the National Academy of Sciences (PNAS), titled ‘Whole-genome association study identifies STK39 as a novel hypertension susceptibility gene’.

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Researchers from Oregon State University, Cornell University and the University of North Carolina published their work in Proceedings of the National Academy of Sciences showing the effect of herbivores and omnivores on the prevalence of barley and cereal yellow dwarf viruses.  It is found that grazers such as deer, rabbits and feral pigs actually help to spread plant disease, which is contrary with findings that suggested grazers actually contain or reduce disease.  Elizabeth Borer, an assistant professor of zoology at OSU explained their study is about the interaction of plant pathogens with the complexity of natural ecosystems.  Any small change in the elements of ecosystems can cause butterfly effects with seemingly unrelated diseases, and these changes can be caused by climate change, species population, human manipulation, etc.  One obvious example is that the increase of white-footed mice population is correlated to the increase of Lyme disease risk in humans.  Although the grazers increase the amount of annual grasses, these grasses are preferred by the aphids which transmitted the viral plant disease.

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Love it or hate it.  Garlic can embellish a dish making it the tastiest dish you ever eat, but it can also gives you a really bad breath that makes everyone cover their nose when you are talking.  Do you know that garlic is not only used for culinary purposes, but also medicinal purposes?

The allicin (sulfur compound) produced by garlic when it is wounded (chopped or chewed) has the anti-bacterial effect.  Garlic can be beneficial to one’s health by enhancing the body’s immune system against common cold.  Garlic is also subject in cancer treatment research.  Garlic is also found to control cholesterol level and preventing heart disease.  There are numerous health benefits of garlic.

Many animal studies suggested that traditional Chinese treatment for cardiovascular disease by using garlic can actually reduce blood pressure (hypertension).  Although there are no strong evidences showing that garlic can reduce blood pressure in human, the research data  showed that the use of garlic has the potential in high blood pressure reduction.  There are also many studies in human showed that garlic does not have any effect on blood pressure.  Raw garlic were consumed in the studies.

Figure. Garlic uses, effects, and consumption advises (modified from Messina, 2006).

There are insufficient evidences showing a strong relation between garlic and hypertension reduction.  Please note that although garlic has a lot of medicinal benefits, garlic (or its supplements) should not be overdose.  It can also cause bad breath, indigestion, nausea, emesis, diarrhoea and other side effects.  You are also being reminded not to feed your dogs with garlic as it can be toxic to them.

References:

Capraz, M., Dilek, M., and Akpolat, T. (2007), Garlic, Hypertension and Patient Education, Int J. Cardiol., 121(1), pp. 130-1.

Duda, G., Suliburska, J., and Pupek-Musialik, D. (2008), Effects of Short-term Garlic Supplementation on Lipid Metabolism and Antioxidant Status in Hypertensive Adults, Pharmacol Rep., 60(2), pp. 163 – 70.

Messina, B.A. (2006), Herbal Supplements: Facts and Myths — Talking to Your Patients About Herbal Supplements, J Perianesth Nurs, 21(4), pp. 268-78.

Pittler, M.H. and Ernst, E. (2007), Clinical Effectiveness of Garlic (Allium sativum), Mol Nutr Food Res, 51(11), pp. 1382 – 5.

Reinhart, K.M., Coleman, C.I., Teevan, C., Vachhani, P., and White C.M. (2008), Effects of Garlic on Blood Pressure in Patients With and Without Systolic Hypertension: A Meta-analysis, Ann Pharmacother, 42(12), pp. 1766 – 71.

Ried,K., Frank, O.R., Stocks, N.P., Fakler, P., and Sullivan, T. (2008), Effect of Garlic on Blood Pressure: A Systematic Review and Meta-Analysis, BMC Cardiovasc Disord., 8:13.

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Scientists from the Brigham and Women’s Hospital in Boston, USA, identified a gene, hexokinase-1, that is linked to blood concentration variation of glycated hemoglobin.  Glycated hemoglobin has been used as index of long-term blood glucose concentration in the follow-up of type 2 diabetes patients.  This study involved 14,618 Caucasian women from the Women’s Genome Health Study.  Scientists analyzed their glycated hemoglobin concent日ation and study their genetic variation.  Hexokinase-1 gene which encodes the enzyme hexokinase, involved in early glucose utilization, is found to link to the blood glucose concentration variation.  However the full metabolic role of the genetic variants has not been understood and will be studied further.  The study, led by Guillaume Paré, is published in the December 19 journal, PLoS Genetics.

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British scientists from Loughborough University have developed a method to predict how likely a person to catch a cold.  This method can be easily done by individuals at home.  The test measures the protein concentration in saliva to study if a person is at risk of infection.  Bacteria-fighting antibody, immunoglobulin A (IgA), is being tested in this method.  IgA usually fell significantly before a person catch a cold.  The cold-prediction saliva test has not been released to the market yet, more research need to be done to increase accuracy.

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Saprolegnia is a fungus that is a normal component of freshwater aquarium environments. It feeds on dead and decaying matter helping to rid the aquarium of waste. When an aquarium is properly maintained, Saprolegnia is harmless to healthy fish. However, when the water of an aquarium becomes overly littered with decaying matter, or when fish become sick or develop wounds, Saprolegnia can harm fish.

Saprolegnia spores are present in most all freshwater aquariums. The spores are not visible and will circulate silently until a suitable substrate is present for its attachment. Saprolegnia spores target dead fish that have not been removed from the tank, uneaten fish food, infertile fish eggs, and wounds that may be present on live fish. Saprolegnia presents as white to gray patches on the skin of fish that become more hair-like, and cottony as the disease progresses. If left untreated, Saprolegnia can erode into deeper tissues of the fish and disrupt internal body fluids leading to death of the fish.

Treatment of Saprolegnia in aquarium fish involves removing infected fish from the tank, placing them in a separate tank or bowl, and adding an agent to the water of this tank to disrupt the growth process of the fungus. Success of treatment depends on the extent of the body of the fish that is covered with the fungus. Some agents that can be added to the treatment tank include, salt, malachite green, potassium permanganate, methylene blue, antifungal medications, and copper. Each agent should be used under certain conditions and directions should be followed carefully to avoid causing further damage to infected fish.

Though there are many treatments that can be effective when Saprolegnia attacks aquarium fish, preventative measures are easy and necessary to ensure aquarium fish remain free of Saprolegnia infections. Preventing Saprolegnia outbreaks in an aquarium begins by maintaining healthy water. Fostering healthy aquarium water includes, small and frequent water changes, removing dead fish, vacuuming excessive decaying food, keeping the pH of the water in certain parameters, maintaining minerals, such as calcium at proper levels, preventing the buildup of ammonia and nitrites in the tank, not overfeeding fish, and adding live plants to the aquarium.

Water change is essential in removing waste products, nitrates, phosphates, ammonia and nitrites and also for replacing trace elements in the tank. Monitoring the levels of ammonia, nitrites, and pH of the water is also very important. High levels of ammonia and extremes of pH can cause burns to fish resulting in wounds to which Saprolegnia can attach and proliferate. High nitrite levels are toxic to fish and should also be monitored.

In addition to maintaining clean, healthy water, monitoring fish for wounds that may be caused by attacks from aggressive fish, sharp surfaces in the tank, or from rough netting and fish handling technique is helpful in prevention. Removing these hazards and handling fish carefully can help prevent wounds that become surfaces for Saprolegnia attachment and infection.

Saprolegnia is a normal part of clean, healthy, freshwater aquariums. Healthy fish are generally safe from infection by Saprolegnia. Clean water, vigilant monitoring, and removal of waste products from the aquarium will promote healthy fish. Prevention is the easiest method for controlling Saprolegnia outbreaks. However, when prevention fails, there are treatments available that can be effective in curing infected fish.

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According to University of New South Wales (UNSW) researchers, some people are more likely to suffer severe and prolonged illness due to their gene combinations.  The research focused on cytokine (protein hormone messengers of the immune system) genetic variants.  The cytokines involved are tumor necrosis factor–α, interleukin-6, interleukin-10, and interferon-γ which play an important role in early immune response.  The study examined the duration of patients after infected by Epstein-Barr virus, Coxiella burnetii (the causative agent of Q fever), or Ross River virus.  People with certain gene combination are more likely to have an intense illness during infection.  The study is published in the journal Clinical Infectious Diseases.  It is suggested people with these vulnerable gene combinations will be given vaccination first.

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