Selasa, 26 Oktober 2010

Drug Safety in the Workplace

Should a company be permitted to fire a worker for taking a drug that is legally prescribed by a physician to treat a medical condition? That’s what happened to a worker on an auto-parts assembly line who was taking hydrocodone for back pain, according to an article in The New York Times.

You might say, “That’s not fair!”, but it’s not that simple. After all, companies have a responsibility to maintain a safe work environment. Companies can be held responsible for accidents on the job and for product defects caused by impaired workers. And in “safety-sensitive” jobs, such as airline pilot, the public has a right to expect that the employee is not impaired.

The question becomes, then, how does society achieve the right balance between the rights of workers and the responsibilities of employers? At present we know very little about just how safe various prescription drugs are in the workplace, because testing for workplace safety is not part of the normal approval process for pharmaceutical drugs.

More and more companies are requiring drug tests of their employees. Employees who test positive are sometimes fired, in part because companies aren’t sure whether or not the drug creates a safety issue and just aren’t willing to take the risk. It’s a societal problem that needs to be addressed by valid scientific research into drug safety in the workplace.

Minggu, 24 Oktober 2010

Long Beach Bans Smoking in Public Outdoor Areas

The City Council of Long Beach, California voted unanimously last week to ban smoking in nearly all public outdoor areas, including parks, hiking trials, and biking paths. Supporters of the ban argued that the ban was necessary to protect children’s health.

The ban exempts public golf courses because of a potential loss of income to Long Beach (and because not many children golf). It also makes exceptions for special events like filming. Does anybody else see the double standard being applied here - that smoking is banned in public places in Long Beach unless it’s in Long Beach’s financial best interests to allow it?

Disclaimer: I’m not a smoker. I am convinced that the evidence is pretty solid that smoking is harmful for the smoker, and I wish that smokers would see the wisdom of quitting for their own good. But let’s be clear about one thing; banning smoking in public places outdoors is not likely to improve children’s health. There is no scientific evidence to support the notion that a brief whiff of smoke causes any damage to children or to adults. A better way to improve children’s health would be to encourage them to exercise more, even if they occasionally smelled a whiff of smoke while doing it.

If we’re going to ban smoking in public places, let’s at least be honest with smokers about why we’re doing it.

Minggu, 17 Oktober 2010

Canada Declares BPA Plastic to be Toxic

Canada recently declared a plastic called BPA (bisphenol A) to be a toxic substance. BPA is commonly used in the manufacture of refillable polycarbonate water bottles and in the linings of metal food and beverage cans.

BPA falls into a category of substances known as endocrine disruptors. As a group, endocrine disruptors either mimic or block the action of hormones, thereby disrupting the body’s functions. In laboratory animals, high concentrations of BPA have been shown to mimic the female hormone estrogen. Several studies reported by The Endocrine Society, a well-known scientific group, suggest that endocrine disruptors such as BPA may have adverse health affects that include infertility and cancer.

Canada and about half a dozen states in the U.S. have already banned the use of BPA in children’s products. Canada’s recent action paves the way for future bans on the use of BPA in food and beverage containers for adults as well, and for increased control over manufacturing processes involving BPA.

So far the U.S. government has taken no action, saying there is not enough evidence that the substance harms humans. But research is underway, and time will tell.

Jumat, 15 Oktober 2010

Lab opportunity

Subject: Freshman/Sophomore Lab Position Available in Collin's Lab

Research Project:
The overall research is to determine the influence of environmental and hormonal factors on the constituent phase of embryo and larval development as they occur within the ovaries of viviparous nearshore rockfish(Sebastes spp)

Undergraduate Contribution:
The undergraduate will be responsible for validating protocols for incubating embryos and larvae aspirated from the ovaries of rockfish at various stages of development. The student will carry out incubations at different osmolalities and in the presence of various potential growth promoting factors. The student will assess development by morphometric analysis of fresh specimens and histological sections.

If you are interested, please contact Adam Karevoll at
akarevoll at

Rabu, 13 Oktober 2010

HPV Vaccination Rates in College Women

It’s been more than three years since the FDA approved Gardasil, the vaccine against the sexually transmitted Human Papilloma Virus (HPV) that is responsible for most cases of cervical cancer. How is the vaccine being accepted by young college-age women?

To find out, researchers conducted a survey of 972 female college students at a large Midwestern state university. Most of the women were freshmen or sophomores. Sixty-five % of the women reported being sexually active, and by the Spring of 2009 57% had already received at least the first of the three shots required by the vaccination protocol for Gardasil. (The vaccine was available on request at the university student health center, at a cost of $360).

Vaccination coverage of 57% in this age group within three years of vaccine availability is welcome news, considering that these college-age women were already 15 or 16 years old when the vaccine first became available. Current recommendations are that girls should be vaccinated as early as 11-12 years of age. Significantly, young women who believed that their mothers would approve of their receiving the vaccine were more likely to have been vaccinated or to have an interest in being vaccinated.

More than a third of the women reported having had three or more sexual partners, and over 25% had had vaginal sex with a casual partner (not a serious or steady dating partner) without using protection against sexually transmitted diseases. All the more reason they should be vaccinated…

Senin, 11 Oktober 2010

Dance your Ph.D.

"The dreaded question. "So, what's your Ph.D. research about?" You could bore them with an explanation. Or you could dance.
That's the idea behind "Dance Your Ph.D." Over the past 3 years, scientists from around the world have teamed up to create dance videos based on their graduate research."
Thought you all might enjoy this! A good way to both relieve stress and study science at the same time... Enjoy :)

Minggu, 10 Oktober 2010

Cell Phones Can't Cause Cancer?

One of the limitations of the scientific method is that it is virtually impossible to prove that something doesn’t exist or could never happen based on empirical data alone. And if that “something” has the potential for great harm, then common sense would dictate that we should err on the side of caution and continue to assume that it could exist, or might happen. It’s what’s known as the precautionary principle.

Take cell phones and cancer, for example. Despite tens of millions of dollars spent on research, no one has ever proven that mobile phones cause brain cancer. And yet, researchers (and the public) are still unwilling to conclude that they don’t. Even the authors of a major study that once again showed no relationship between cell phones and cancer concluded: “The possible effects of long-term heavy use of mobile phones require further investigation”. Of course, that might mean more funding for their laboratory….

Physicist Bernard Leikind has taken an entirely different approach. He claims that, based on well-accepted physical principles, cell phones cannot cause cancer. He argues that the energy emitted by cell phones is not strong enough to disrupt the chemical bonds in biological molecules, period. Indeed, he claims that if it were possible for radiation energy of this type to disrupt cellular biochemical processes, there would be no life on earth because of natural sources of similar radiation energy in the environment.

Dr. Leikind has taken a lot of heat (no pun intended) from readers – see the reader-response thread after the article. But I have yet to find the flaw in his logic.

Rabu, 06 Oktober 2010

Seeing is believing

I know at least one of you mentioned an interest in stem cells. The MCDB seminar looks like it might be of interest:

MCDB Seminar
Speaker: Pete Coffey
Head of Ocular Biology & Therapeutics
Professor, Cellular Therapy and Visual Sciences
Director, London Project to Cure Blindness

Title: "Stemming Vision Loss Using Stem Cells - Seeing Is Believing"
Location: Rathmann Auditorium, LSB 1001
Thursday October 7th 3:30 p.m. - 4:30 p.m.

Popular Joint Pain Supplements Don't Work

The popular joint-pain supplements glucosamine and chondroitin are ineffective in reducing knee or hip pain due to osteoarthritis, according to a recent report in the British Medical Journal. The latest meta-analysis reviewed 10 previous large, randomized, controlled studies. The authors conclude that the two supplements have no effect on either patient perception of joint pain or minimum width of joint space (a clinical measure of improvement) when compared to a placebo.

Glucosamine and chondroitin are among the most popular over-the-counter supplements, with annual sales of nearly $2 billion per year. Some people swear by the two supplements because they genuinely do feel better when taking them, and I sincerely believe they’re telling the truth. But the improvements could be due to the well-known placebo effect, or to the fact that in some patients, joint pain declines over time due to natural healing processes. Anecdotal evidence can’t be generalized to a larger population.

The authors of the study see no harm in patients continuing to take the supplements if it makes them feel better. They say that neither supplement does any harm (except to lighten your wallet a little).

Jumat, 01 Oktober 2010

Texting and Fatal Driving Accidents

Text messages sent per month from hand-held phones increased more than 15-fold from 2002 to 2008. Over the same years the percentage of fatalities in which distracted driving was listed as a possible contributing factor increased from about 12% to nearly 16%.

Based on these data, the authors of a recent report speculate that texting while driving may have contributed to 16,000 additional driving fatalities between 2001 and 2007. The claim was reported in the Los Angeles Times and other papers, but is it true?

There are several problems with this report. First, the authors defined a fatality as caused by driver distraction whenever a distraction was merely listed as present. Other factors such as equipment failure, alcohol, or driver age were not considered. Second, distractions are anything that takes the driver’s attention away from driving, including texting or talking on a hand-held phone, reading an on-board navigation system (also increasingly popular these days), reaching for something, eating, drinking, putting on makeup, etc. Searching for street signs or rubbernecking another accident are also distractions. None of these were factored out in this study.

All the report really shows is that text-messaging volumes (in and out of cars) and the number of fatal accidents due to all distractions are both going up. The authors call it a correlation, but so what? A correlation does not prove causation. I’m reminded of the example presented by my thesis advisor years ago of the tight correlation between the rise in the number of telephones in the U.S. and the decline in the incidence of tuberculosis. Do telephones prevent tuberculosis? Hardly.

Is texting while driving a problem? Probably yes. Does this paper convince me that texting while driving has caused 16,000 additional fatalities? Sadly, no.


We don't get a lot of biomechanics talks here so I'll highlight this one. There was a nice article about this work at ScienceDaily recently.

Swimming and filtration in the ocean by jet-propelled salps
Dr. Kelly R. Sutherland
Postdoctoral Scholar in Bioengineering, California Institute of Technology

Engineering Sciences Building, ESB 1001
Thursday, October 4th, 4.00 p.m.

Salps are barrel-shaped marine organisms that are common in the open ocean and swim using a pulsed jet.  Among salp species, there are a variety of body shapes and swimming styles that correspond to differences in ecological function.  Dye visualization via bluewater SCUBA techniques and laboratory Digital Particle Image Velocimetry (DPIV) were used to describe jet wake structure and swimming performance variables including thrust, drag and propulsive efficiency among three salp species (Pegea confoederata, Weelia (Salpa) cylindrica, Cyclosalpa sp.).  Locomotion by each species was achieved using vortex ring ring propulsion.   Different combinations of swimming speed and hydrodynamic efficiency were observed and can be considered in light of metabolic constraints and ecological roles.  Though nature does not strive for optimality, this work shows the value of a comparative approach for understanding how underlying structure and mechanism influence performance.     

During swimming, the same fluid that propels the salp forward also contains food particles, which are captured on a mucous mesh as fluid passes through the mostly hollow body.  Though salps are centimeters in length and swim at speeds of ~1-10 cm s-1, filtration occurs on a fine, mucous mesh (fiber diameter ~0.1 μm) at low velocity (1.6 cm s−1) and is thus a low Reynolds number (Re ~10−3) process.  A model of particle capture efficiency by a rectangular mesh was used to estimate particle capture rates on the salp filtering mesh based on realistic oceanic particle concentrations.  Particle feeding experiments using 0.5, 1 and 3 µm fluorescent polystyrene microspheres were then performed to test the theoretical model.  Results from both the model and from experiments showed that smaller particles are captured at considerably higher rates than larger particles.  Though particles smaller than mesh openings (1.4 µm) are expected to supply substantially less carbon than larger particles, they can still completely satisfy salp energetic needs.  By removing different sized particles with nonuniform efficiency and packaging them into fast-sinking fecal pellets, salps have the potential to structure oceanic particle size spectra.
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