Friday, September 30, 2011

Rumors of this bird's extinction have been greatly exaggerated.

After being believed to be extinct for 150 years, DNA testing confirmed that the New Zealand Storm Petrel is not quite as extinct as previously thought. Though spotted a few times since 2003 by bird watchers, this is the first verified evidence of the tiny bird’s return. Very little is known about where the birds have been breeding and living during all this time or even how many of them are alive, but flocks of up to 40 birds have been seen every mating season since the first (re)sighting. Unfortunately, this species lives at sea for most of the year and only returns to shore to mate. The location of the mating site remains a mystery, despite use of radio transmitters attached to the birds.

BirdLife International donated $20,000 to the group that rediscovered this thought to be extinct species to continue to search for enough evidence to put the bird onto official Department of Conservation programs for endangered species.

Have a great weekend!

Researched and written by Dr. Rebecca Malamed, M.D. with assistance from Mr. Malcolm Potter.

Friday, September 23, 2011

Bacteria on the Beach - The Seagull Menace

Antibiotic-resistant super-bugs aren’t just a problem in hospitals anymore. Unlike the antibiotic resistant bacteria we discussed previously, antibiotic misuse may not be the culprit. But, spending an afternoon at the beach may give you more than you bargained for.

Wired Magazine’s blog reported on a study that tries to determine what is causing the rapid and unpredictable spread of multiple-antibiotic resistant E. coli bacteria in Miami Beach, Florida. The answer may give us clues as to how resistant bacteria spread world wide.

Apparently, seagulls are becoming carriers (literally) of drug resistant strains of E. coli. Let’s face it, seagulls will eat just about anything. Just driving through a coastal city, you can see seagulls dumpster diving for a meal, fighting over scraps of trash to eat, and that’s just what we see. It’s not much of a stretch to imagine that they could eat something contaminated with E. coli. Once they get E. coli inside of them, the bacteria can mutate or simply “learn” resistance to antibiotics from other bacteria. Then, not only are they carrying this highly antibiotic resistant strain everywhere they fly, but they also drop off little colonies of them everywhere they go (in the form of poop).

The specific resistances of the bacteria in this study are called “extended-spectrum ß-lactamase” (ESBL) resistance. This mutation allows the bacteria to resist most of the commonly used antibacterial drugs. While E. coli itself is usually not deadly (with the exception of the O157:H7 strain), the spread of the resistant genes in any bacteria is cause for concern.

The dangers of a highly mobile (thanks to the seagulls) multi-drug resistant strain of bacteria are pretty clear. The more places these bacteria are “deposited”, the more likely it is that the antibiotic resistant genes will work their way into other local bacteria through the process of horizontal gene transfer. Suddenly, communities could face outbreaks of several different bacterial infections that are untreatable by most antibiotics.

A quick review of the literature shows that this is not just a local phenomenon in Florida. The very same resistant strains of E. coli have popped up around the world, documented in places all over the world like Sweden, Alaska, France, Portugal, and the United Kingdom, to name a few. In most of these cases, birds were suspected to be the culprits responsible for the unexpected spread of resistant bacteria. Drug resistant bacteria has been linked to birds (chickens) before, but seagulls are far more mobile than chickens and so present a much bigger problem.

This research sheds light on how antibiotic strains of bacteria spread around the world. Hopefully, we will be able to learn how to prevent widespread resistance to our antibiotic arsenal. Drug resistance is a worldwide problem and hopefully, this research will help to battle against the superbugs.

Researched and written by Dr. Rebecca Malamed, M.D. with assistance from Mr. Malcolm Potter.

Friday, September 16, 2011

Greener Roofs Are... White?

On a hot day, a large city like Los Angeles can be up to 5°F hotter than surrounding suburbs. Cities like Los Angeles, New York, and Chicago create what are called “heat islands”. Heat Islands are literally, areas of heat that resemble islands when compared to rural surrounding areas. Within these cities areas develop that are considerably warmer than their surroundings, called “hot spots”. This stems mainly from the fact that buildings, concrete, and roads tend to retain heat better than rural countryside.

If you take a bird’s eye view of most cities, you will find that a large percentage of surface area is dark colored. Between asphalt roads, parking lots, and dark roofs, there is a lot of space that is exposed to the sun, essentially soaking up heat energy all day from the sunlight that hits it. Most of the roofs in the world (including over 90% of the roofs in the United States) are dark-colored, typically made of a dark composite material consisting of tar and small rocks.

On very hot days, people often joke that it’s so hot that you can fry an egg on the sidewalk. That may not be far from the truth! In the heat of the full sun, a dark surface (like roofs or asphalt) can increase in temperature as much as 120°F, easily reaching temperatures of up to 150-190°F. That heat usually has nowhere to go. Some of the heat will radiate away in the air, but most of it will simply get stored in the “thermal mass” of the material in which it is generated. For roads, this heat can last well into the evening, basically giving off heat during the hottest parts of the day. For roofs, the building absorbs the heat and basically becomes an oven, forcing you to use air conditioning to get back to a comfortable temperature.

Air conditioning is an expensive solution to the heat generated this way. It’s also an expensive solution in general, both in terms of money, environmental impact, and also energy use. What if there could be an easy, low cost solution to this problem? How about if it could not only help solve the problem for you, but also for the people around you? What if it helped the environment without you having to do anything on an ongoing basis? Does that sound too good to be true?