Feeds:
Posts
Comments

Archive for November, 2010

It’s hard to talk about biodiversity without becoming a little bit depressed at the nature of things.  This month’s catch is the particularly gut-wrenching case of bluefin tuna.

Bluefin tuna can by known by many names, including Atlantic bluefin tuna, northern bluefin tuna or giant bluefin tuna.  They are capable of reaching in excess of 1000lbs with lifespans of around 30 years.  Feeding on smaller fish such as sardines or squids, bluefin tuna are also important predators in the marine food chain.  Unfortunately for them, they are considered a prize food fish in many human cultures, and fetch astronomical prices in the Japanese sushi market.

While bluefin tuna have always been fished, the relatively recent popularity of sushi in Western cultures as well as the advent of seine fishing poses an immense threat to this fish.  Indeed, bluefin populations are approaching collapse in many areas of the world and are already extinct in certain regions. Rough estimates put populations at approximately 30% of historic numbers.

Nature News recently commented on the sad state of the bluefin tuna industry, noting that under-reporting and illegal fisheries are common.

The International Commission for the Conservation of Atlantic Tunas (ICCAT)meets this November 17th in Madrid to discuss the bluefin tuna fisheries and set quotas. But as Nature News noted, this commission has largely been ineffective and a recent report released by the International Consortium of Investigative Journalists (ICIJ) highlights the many faults of this lax and under-regulated industry.

As always, the most effective avenue of change still lies with the consumer.  Eating a species into extinction is just a little bit ridiculous and completely unnecessary.  Add bluefin tuna to your list of seafood no-no’s and check out the Vancouver Aquarium’s Oceanwise program for a list of seafoods that should not be ending up on your dinner plate.

[Photo from http://www.oceanriver.org/AtlanticBluefinTuna.php, original by Chris Park]

Read Full Post »

Hi all,

My third blog for the Stem Cell Network is up!  It’s about public perception of stem cells.  Please check it out!!!

Thanks to everyone who gave their opinion for this blog.

For those that didn’t leave a comment, or those who would like to post again (!!!), I would love it if you left a comment on the SCN post.

My next blog for the Stem Cell Network will be about stem cell mobility.  Stay tuned!

Read Full Post »

This post turned out a bit longer than I expected, so I broke it up into two parts.  Excuse my science-y jargon and please do leave comments if anything is unclear!

*****

Rodent anesthesia falls into two main types: Chemical or Inhalant.

Chemical anesthesia involves the administration of a drug or several drugs via subcutaneous injection.  The most common drug of choice is a combination of ketamine and xylazine.

Xylazine is an alpha-2-adrenergic agonist sedative with short lived analgesia. As a sedative, the drug depresses, or slows down, the respiratory and cardiovascular system and relaxes the muscles.  Too much “slowing down” can be dangerous, especially in mice, where surgeries are generally conducted be a single technician and changes in respiration and cardiovascular function are usually monitored only by visual inspection.  If a person is occupied with the technical aspects of the surgery, slight changes may be easy to miss.  When the respiratory or cardiovascular systems become over-depressed, this is an overdose and death can result.

Ketamine is a “dissociative anesthetic” which renders animals unable to move.  Lubrication of the eyes is absolutely required because the eyes remain open while the animal is in this dissociative state.  Failing to lubricate the eyes during surgery can result in blindness due to drying of the cornea.  Recovery from ketamine can take up to several hours and during this time, the animal must be monitored closely.

By combining the two drugs, you are able to produce a sedate animal which is unable to move.  This is suitable for short surgeries.  However, the recovery period is often rough.  Animals often appear “groggy” and may not resume normal activities for some time after.

Ketamine-xylazine is favoured because it is relatively cheap and non-technical, requiring only the drugs and needles with which to administer the injection.  As well, there are no wastes produced from these chemicals which may be dangerous to the animal or the handler.

However, it is not suitable for long or invasive surgeries and comes with a few complications:

Ketamine-xylazine injection also does not produce lasting analgesia, or pain relief.  Additional painkillers are generally recommended before and after the surgery.

Many animals react differently to ketamine-xylazine injection.  A dosage which works well in one strain of mice may not work well in another.  As well, individual mice may metabolize the drug at slightly different rates, such that a dose that results in 1 hour of anesthesia in one mouse may only give 45 minutes in its cagemate.  This can be disastrous if a surgery is predicated to take 50 minutes to complete.  As such, the appropriate dosage must always be tested for each new strain of mice and for each new experiment, and allowing plenty of time for unexpected results.  The technician should also always have extra drug ready, should the animal show signs of waking up.

The amount of cardiovascular and respiratory depression is also dangerous, as I mentioned, and this danger increases during longer or more complicated surgeries.  Every time you have to administer a bit of extra drug to keep the animal unconscious, you risk administrating an overdose.

Luckily, there are other methods for producing a surgical level of anesthesia, which I will discuss in the next post.

[Photo by Dale Tidy]

Read Full Post »

There was another flurry articles appearing in student media this past week over UBC’s animal use.

UBC publication The Ubyssey published an article and a well written opinion piece, remarking on the difficult nature of the debate.  Indeed, they echo many of my own sentiments when they remark that “moderate, progressive voices” are needed in this debate.  Mud slinging and fear mongering on both sides does nothing for animal welfare.  Until people are willing to talk rationally about the issues, no real progress can be made for either side.

It’s gotten to the point where being concerned about animal welfare is enough to send people into a frenzy of recrimination and accusations, while being a biomedical researcher arouses suspicion and distrust.  No doubt this blog will get passed around in numerous clandestine emails where I will be alternately skewered or praised by people too afraid to talk about their own opinions.  And why are people afraid?  Part of it is because we have not done a good enough job of educating our researchers and technicians about ethics and educating our public about science.

That’s one of the reasons I found my university ethics classes to be so insightful – it taught you to leave the emotion aside, think critically about an issue, and look at the scientific, ethical and philosophical arguments on both sides of a debate.   This is an important skill that I feel a lot of people are lacking.

Unsurprisingly, I was the only science-oriented researcher present in a 40-person class on biomedical ethics.  😛

Read Full Post »

New header photo!

Attentive readers may notice that my header photo has changed!  Apparently I am not allowed to use images I took while working in the research lab – intellectual property, but not my property sadly.  *shrug*  I find myself suspicious of the timing of the complaint, but it is a small thing all in all.

So here is my new header, taken by local photographer Dale Tidy, whose work is also featured in each of my Stem Cell Network blogs.  It shows human blood being processed for transplantation.  Neat hm?

Read Full Post »

In my undergrad, I took a course on phytogeography.  When I chose it, it was mainly because there was no lab and I liked the prof!  But it turned out to be one of the most interesting classes I took – the things I learned were wide-ranging in scope and helped me to understand why the world is the way it is.  🙂

This new 5 part series is a peek into biogeography – what it is, how we study it and why it’s important.  And although the focus of the class was on plant dispersal, I will include many animal examples, as most of the core principles apply to all living things.

***
Have you ever wondered why Australia is home to so many unique mammals?  Questioned the limited range of species such as Dawn Redwood or California’s Clarkia?  Compared your garden cucumbers to that of the cucumber tree? Or perhaps you’ve fished in both the Atlantic and the Pacific and noticed the striking similarities between shrimp species in these very separate oceans.

All these examples are the result of different types of distribution and can be explained by an interesting field of study called “biogeography”.

Biogeography is defined by Wikipedia as “the study of the distribution of species spatially and temporally”.  This field looks at how species and populations are distributed, usually in references to animals.  Phytogeography is the branch of biogeography that is concerned with the geographic distribution of plant species specifically, from controls on the distribution of individual species ranges (at both large and small scales, see species distribution) to the factors that govern the composition of entire communities and floras.

Biogeography can be divided into two main branches: Ecological biogeography and Historical biogeography. The former investigates the role of current day biotic and abiotic interactions in influencing species distributions; the latter are concerned with historical reconstruction of the origin, dispersal, and extinction of taxa.

When we talk about species distribution, we might be talking about local populations or species as a whole. In both cases, the distribution is affected by factors which include: dispersal ability, abiotic factors (temperature, light, salinity), biological factors (competition, breeding systems, pollinators), historical factors (plate tectonics, glaciation), and human interactions. Over time, some of these factors may become more important than others.

Over the next few blogs, I’ll be taking a closer look at some of these factors and discussing how they have affected current and historical species distribution.

References:

UBC BIOL412 notes, Professor Michael Hawkes

http://en.wikipedia.org/wiki/Biogeography [accessed Nov 23, 2010]

Read Full Post »

Only a week and a bit  before Florida!  AHHHHHH! I’m super excited to meet with people and get some writing in.

(Also more than a little excited about the Harry Potter theme park! *blush*)

So if anyone’s going to ASH, shoot me a message or a tweet!

Links that caught my eye this past week:

  1. This has been languishing in my “to do” list for a while – Check out this excellent imaging job of two cancer cells multiplying, reported on Gizmodo.  Amazing colour on that shot.
  2. National Geographic writes about the origin of whales – again, amazing photos.  Thanks to the Beaty Biodiversity Museum’s Facebook page for sharing that!
  3. Serious Monkey Business discusses a newly discovered population of yellow-tailed woolly monkeys.  For the charismatic animal lovers out there, these guys are pretty cute and, perhaps unsurprisingly, critically endangered.
  4. Nature News reports that South Korea is launching an inquiry following the deaths of two Koreans from “stem cell treatments” offered by questionable clinics.  While stem cell treatments are not legal in South Korea, a Korean-based firm has been formulating and marketing the stem cells, then sending them to satellite clinics located in other countries.  Shady business…

Coming up in the near future: In recognition of OceanWise month, I have one blog upcoming on bluefin tuna.  The rodent anesthesia blog is in-progress and I have a blog on wild tobacco that has been languishing and will hopefully be finished post-haste.

I also found a good reference for my post on laboratory rodent euthanasia.  From the Laboratory Animal Limited website, under Education and Training, you can find a huge repository of reviews and scholarly papers on the usage laboratory animals.  In particular, take a peek at the Euthanasia tab >  Newcastle consensus meeting on carbon dioxide euthanasia of laboratory animals PDF.  There wasn’t a direct link available, sorry! But this PDF article is full of really good data on the good and the bad of CO2 euthanasia.

Read Full Post »

Older Posts »