Energy Drinks

Energy drinks have become extremely popular with students.  The question has always been, are they safe?

Well, millions of cans have been sold and there is little documentation of health related issues.

A new study by Leah Steinke and colleagues in the Annals of Pharmacotherapy, however, has raised some concerns about the effect of energy drinks on the cardiovascular system.  

In this study fifteen people were given two energy drinks each day (100mg taurine and 100mg caffeine) for seven days.  Their blood pressure, heart rate and electrocardiographic (ECG) characteristics were measured prior to the study and then on Day1 and Day 7 over a few hours following consumption of the energy drinks.

Steinke and colleagues found that while there were no statistically significant affects associated with the ECG characteristics, the same could not be said for heart rate or blood pressure.  Heart rate was up 11% on Day 7 and blood pressure also increased.  Systolic pressure(i.e., the 'high' number in a blood pressure reading) was up 9.6% and the diastolic pressure (i.e., the 'low' number in a blood pressure reading) was up 7.8%.

Is this concerning?  Probably not for young healthy adults, however, for those with underlying but undiagnosed heart problems or high blood pressure, this could be very concerning. Especially with long term consumption.  These products clearly push the cardiovascular system in a direction that is unhealthy.

Caveat: this study was small (15 people) and the baseline health data was taken only immediately prior to the study.  Longer monitoring of the baseline data would help to determine just how much variability was natural for this small group.

Photo Credit: Grendelkhan, Wikipedia commons.

Research citation: Steinke L, et al. 2009. Effect of "Energy Drink" consumption on hemodynamic and electrocardiographic parameters in healthy young adults.  Annals of Pharmacotherapy 43(4): 596-602.

A Better Way to Identify Healthy Food

How can you communicate nutrition information to a public that usually does not know the difference between the major macronutrients (carbohydrates, lipids, and proteins)?

The answer might be to use a system that everyone already understands, traffic lights. Bridget Kelly and colleagues have just published some research (Health Promotion International 2009) looking at how well the public understands nutrition related labelling of food products.  

The traffic light system uses the colours green, amber and red to identify food components that are good, fair, and poor respectively.  An additional traffic light provides the overall health rating of the food.  It seems easy to understand even at a glance.

Kelly and colleagues found that consumers were 3 times more likely to identify healthy foods using the traffic light system as compared to a colour coded Daily Intake label and 5 times more likely when using a monochrome Daily Intake system.

Short story: a simple, broadly understandable system that works.

Nerd alert:  Kelly and colleagues used logistic regression to come to the conclusions given above. Reading through their methods section I can't say I'm totally happy with the technique used to identify model variables for the regression.  They should have used either a more a priori technique or gone with a stepwise logistic regression.  

Photo credit: www.choice.com.au

Blurring Unemployment Statistics

Above are the unemployment statistics for the Cariboo over the past 15 months.  Currently, the Cariboo has the second highest unemployment rate in the province, second only to the North Coast-Nechako which has unemployment at 11.1%.

Is unemployment in the Cariboo currently 10% as suggested by these data above from BC Stats? No, not really.  These numbers, while indicated for specific months, are actually averages of the previous three months.  Statistians use three month averages to smooth out their data--everyone wants a smooth graph right?  Graphs that show gradual transitions make politicians less likely to hyperventilate and the public to panic.

Unfortunately, occasionally this does not reflect the situation in the real world.  This is one such occasion.

Data Source: Labour Force Statistics: BC Stats.  Plotted by me.

Ant Robots

Robot technology seems to be leaping forward right now.  

Not sure when we will need to program in Asimov's three laws of robotics, but it won't be long.

Hat tip: Myrmecos blog

YouTube and Robot credit: Kåre Halvorsen (aka Xenta) from Norway

Dead Wood is Needed for Living Forests

What do we mean by a word like 'Waste?'

Generally we mean that it is useless and is a burden just to discard.  The less the better.

Why then do we use this word to refer to the dead standing or fallen wood in our forests?  It is anything but waste.  Rather, it is a vital resource for countless animals, plants and micro-organisms in our forests.  Its decayed fibre contributes organic material to our forest soils and helps to buffer soil pH.  It also acts as a water reservoir in forests where drought is common.

It can be called it waste only if we do not understand its function in forest ecosystems or it can be called waste by those who want to use it for other purposes.  This is the term used today by the BC government and the bioenergy industry to describe this resource.

Despite the desire by the modern forest industry to emulate (i.e., imitate) natural disturbances in log harvesting operations, the massive removal of tree biomass in no way emulates what normally occurs in nature.  How much biomass can be removed before we see a serious disruption to the ability of forest soils to regenerate new growth is uncertain.  Traditionally though, forestry operations in British Columbia have left more wood behind on cutblocks than occurs most areas of the world.  Still, this may not be enough.

Now, the bioenergy industry wants to greatly reduce the volume of remaining wood.  On a visit to a local bioenergy facility I once heard a manager talk about obtaining a Swedish machine to scrape and bundle the smallest pieces of wood from the forest floor.  Worse, the claim is made that this is a 'Green' technology. 

This month the Williams Lake Field Naturalists will present a resolution to the Annual General Meeting of the Federation of BC Naturalists.  It reads:

"Whereas, coarse woody debris (CWD) is a fundamental component of forest ecosystems, critical to:

1) providing habitat to many dead wood dependent organisms (e.g., fungi, insects, vertebrates) which in turn support a broader food web (e.g., insectivorous birds, bears);

2) providing energy to support forest resilience (e.g., ability to resist extensive damage from forest pests, climate change or invasive species);

3) providing water storage in ecosystems frequently experiencing drought;

4) providing pH buffering capacity to forest soils which become acidic as a result of biomass removal;

5) providing nutrient and structural components to forest soils in a province noted for low-productivity soils.

Whereas, management guidelines for CWD retention under the Forest and Range Practices Act are inadequate for protecting this resource under existing harvesting pressures, there is concern that additional plans for biomass removal by the bioenergy industry will exacerbate this problem.

Be It Resolved:  That Nature BC communicate to the Government of BC the need to develop a science-based woody debris (organic matter) management system with the view that maintaining CWD is fundamental to the sound ecological management of our forests."

I hope this helps to raise this issue in the minds of BC naturalists.

Photo Credit: Me

Energy and the International Space Station

Last week the International Space Station unfurled the last of its 8 paired solar panel arrays (each array is composed to two long panels, 5m by 34m long). The photo above, taken last week by the departing space shuttle, Discovery, shows all of the panels now in place.

How much energy does it take to run the space station?  Well, basic life support and essential operations on the station requires about 20 kilowatts (kW).  A single array generates around 15kW but they are exposed to sunlight only half the time.  Thus, approximately three of the 8 arrays are necessary for life support.

A typical home in Canada uses a bit more than 1kW on average (about 11,000 kWhr/yr).  This means that the 5 arrays not required for life support would provide enough energy for approximately 35 homes. 

How much did those arrays cost?  Each of the eight run about $300 million.  The station shown above is now estimated to be worth $100 billion.

Worth it?  I don't think so.  For that cost we could be seriously exploring the solar system using robots.  Is there life under the ice of Europa (one of Jupiter's moons) or on Titan (a moon of Saturn)?  These are questions 100 billion could have answered.

Photo credit: NASA, Discovery (STS-119, Shuttle Crew, March 25, 2009)

Pseudoscorpions

Pseudoscorpions usually go unnoticed because of their tiny size.  When someone does notice one, however,  they are often startled by the sight of this tiny animal with the long front legs and huge pincers.

This particular specimen was found just north of Williams Lake and passed along to me for identification.  These are arachnids (related to spiders and true scorpions) but unlike their namesake, the true scorpions, are not at all dangerous.

Pseudoscorpions feed mostly on other tiny animals such as mites.  They have been found in some old libraries where they are feeding on book lice or silverfish, which in turn are eating the books themselves.  Normally, however, they are found outdoors and are only occasionally reported as an indoor pest.  Having said that, I recall frequently finding them in my house in Winnipeg when I was a kid.  I can't say I've seen many of them in British Columbia although I know someone who was studying them here several years ago.

Photo Credit: Me