Wednesday, 28 January 2009

Scientists identify the molecule responsible for the wrinkly Shar-pei


As cute as they look, Chinese Shar-pei dogs are afflicted with a potentially dangerous skin disorder which causes mild to severe wrinkling and thickening of the skin. Severe wrinkling can lead to bacterial infection in the skin and entropion (the inward folding of eyelids which can cause eyelashes to rub against the cornea). Scientists recently identified the molecule primarily responsible for this skin condition and its cause. The technical term for this type of skin wrinkling is cutaneous mucinosis, where cutaneous refers to the skin and mucinosis refers to deposits of mucin in the skin. Mucin is a clear jelly-like substance and the main component of mucin is hyaluronic acid (yes, the dermal filler). The researchers hypothesised that the accumulation of hyaluronic acid in the dermis caused mucinosis in the Shar-pei. By examining the correlation between mucinosis and the levels of blood hyaluronic acid, the researchers identified that the accumulation of hyaluronic acid was responsible for the mucinosis. The results of the study showed a strong and clear correlation between the severity of mucinosis and levels of blood hyaluronic acid ie. dogs with greater wrinkling had higher levels of hyaluronic acid in their blood.

References:
(1) Zanna G, Fondevila D, Bardagi M, Docampo MJ, Bassols A and Ferrer L (2008) Cutaneous mucinosis in shar-pei dogs is due to hyaluronic acid deposition and is associated with high levels of hyaluronic acid in serum. Veterinary Dermatology. 19. p.314-318.
(2) http://en.wikipedia.org/wiki/Hyaluronan
(3) Image: Wikimedia Commons

Let’s look to the stars


2009 is the International Year of Astronomy (IYA). Celebrations in Australia were officially launched today by Australia’s chief scientist, Professor Penny Sackett. Australia will play a part in the IYA by raising awareness about astronomy and promoting the science. There will many events held throughout the year where the general public can get involved.

For more information, visit:
The Australian IYA site - www.astronomy2009.org.au
The International IYA site - www.astronomy2009.org

References:
(1) www.astronomy2009.org.au
(2) Image: International Astronomical Union (www.iau.org)

Friday, 23 January 2009

Attention contact lens wearers!















Have you ever wondered how your contact lens (CL) solution rates in anti-bacterial effectivity when compared to other CL solutions? Or whether the silver impregnation of a CL case enhances the anti-bacterial effectivity of the case? If you have then read on...
All CL wearers are vulnerable to contaminating bacteria regardless of rigorous CL cleaning practices. To minimise the time and tediousness of cleaning CLs, manufacturers of CL solutions have experimented with the ingredients of their solutions and other factors such as composition of CL cases, cleaning techniques and time required to soak CLs in CL solutions. A 2008 study examined the killing effectivity of three multi-purpose CL solutions, and the effectivity of silver impregnations in CL cases. Details of solutions used in this study were given, including their shelf name, manufacturer and active ingredients. However, to make this blog-post non-discriminatory against the different CL solutions on the market, and as you can never be fully certain whether published studies testing products from pharmaceutical companies provide unbiased results, I decided to re-name the CL solutions but include their respective active ingredients. This way you can check to see whether the CL solution you use contains the important active ingredients.

Method:
Three different CL solutions (see table below) were tested for their anti-bacterial effectivity. Biofilms (a layer of bacteria which forms on the surface of an object) of bacteria* were grown on CL cases and incubated with each CL solution and 0.9% sodium chloride (a control). Similarly, planktonic bacteria* (bacteria floating freely in solution) were tested by suspending the bacteria in each CL solution. The killing effectivity of both types of bacterial forms were tested. Additionally, the numbers of live and dead bacteria transmitted from CL solution to lens were measured using both bacterial counts and microscopy (fluorescence). The effectivity of silver impregnated CL cases was also tested.


Summary of results: The results showed that:
(1) Solution A had the highest killing effectivity for both biofilm and planktonic bacteria.

(2) The silver impregnation of CL cases with added CL solution increased the killing effectivity of one type of bacteria (Pseudomonas aeruginosa) but not the other.

(3) Solution A transmitted the lowest number of bacteria from solution to CL and silver impregnation of the CL case did not make any difference when solution A was used.

Conclusions: Solution A has the most effective anti-bacterial effectivity as seen in this study. Silver impregnation of CL cases is useful in enhancing anti-bacterial effectivity but is redundant if solution A is used. According to the paper, other researchers have found opposing results however these studies were not carried out in “real-life” conditions ie. other studies carried out their incubations of CLs in CL solution for 7 days as opposed to over-night which is more realistic of a CL wearer.

* Bacteria tested include Staphylococcus aureus and Pseudomonas aeruginosa.

References:
(1) Vermeltfoort PBJ, Hooymans JMM, Busscher HJ and Van der mei HC (2008) Bacterial transmission from lens storage cases to contact lenses - Effects of lens care solutions and silver impregnation of cases. Journal of Biomedical Materials Research part B 87(1) p.237-243.
(2) Image: Wikimedia Commons

Friday, 16 January 2009

Nature pooh-poohs?












Readers, did you know that 'pooh-pooh' was a legitimate word? I didn’t, and was completely shocked to read the word nonchalantly used (see below) in an article (Squint of the fossil flatfish) in the prominent science journal ‘Nature’.

"On occasion, this property has been pooh-poohed, even by palaeontologists who have considered that fossils can help in refining relationships already inferred from living species, but tell us little about the process of evolutionary character transformation."

Sure, I was aware of the term ‘poo-poo’ meaning faeces but not ‘pooh-pooh’?!?! When did pooh-pooh become a word? The definition of ‘pooh-pooh’ is ‘to express disdain or contempt for’ or ‘dismiss lightly’.

Can anyone empathise with me? Please let me know whether you knew 'pooh-pooh' was a word by participating in the poll on the RHS panel near the top of the page.

References:
(1) Janvier P (2008) Squint of the fossil flatfish. Nature. 454. p169-170.
(2) http://dictionary.reference.com/browse/pooh-pooh
(3) Image: http://dailymobile.se/2008/07/page/6

Seeing ‘eye-to-eye’












The flatfish (namely the sole, plaice and halibut), named for the shape of its body, is a remarkable fish I only recently heard about. What is so interesting about this creature is that the young flatfish starts off ‘normal’ with its eyes placed on both sides of its body (think of a typical looking fish) and a symmetrical skull. But, as the fish rapidly develops into an adult, one eye migrates from one side of its body close to the other eye and the skull becomes asymmetrical! At this point, the body of the flatfish remains the same but both eyes are on one side – named the ‘eyed’ side, as opposed to the ‘blind’ side. For a long time, evolutionary biologists speculated the origin and asymmetrical nature of the flatfish but with no conclusive evidence. Some biologists proposed the asymmetrical flatfish arose through natural section whilst others proposed the fish arose through evolutionary leaps - a process known as 'saltation'. However in 2008, Dr Matt Friedman became the first scientist to provide the most conclusive evidence of the origin of the asymmetrical nature of the flatfish. Dr Friedman was given permission to study 45 million year-old fish fossils using computer tomography imaging which lead to the finding of an ‘intermediate’ fish which had an eye on either side of its body but with an asymmetrical skull. This was the ‘intermediate’ fish which all evolutionary biologists had been looking for. Interestingly, one eye of this intermediate fish was found to be normal whilst the other eye was a squinting eye.
A good image of a flatfish can be found here. An explanation for the migration of the flatfish eye (from an evolutionary point-of-view) is presented by Richard Dawkins in the YouTube clip here.

References:
(1) Janvier P (2008) Squint of the fossil flatfish. Nature. 454. p169-170.
(2) http://en.wikipedia.org/wiki/Flatfish
(3)Image:www.lessonplanspage.com/SciencePEArtLAMDFlatfishDataCollectionActivityK2.htm

Wednesday, 14 January 2009

Male face preferences during the menstural cycle

Oooh la la, Tyson Beckford - I must be in the follicular phase of my menstrual cycle :) Image: Wikimedia Commons.







Hormones - chemicals released by the endocrine organs in our body - are important molecules which have control over many of our bodily functions. It has been known for sometime that a woman’s preference for male traits (including but not limited to facial features, depth of the voice, behaviour, height, odour and body shape) changes according to the different phases in her menstrual cycle. Hormonal influence is one of many factors that is able to dictate a woman's preference for a male during a particular phase of her menstrual cycle. Several studies since the late 1990s up until now have examined the relationship between timing during the menstrual cycle and male trait preferences, with all studies having small variations in research method. I thought I would closely examine and summarise the findings of one of the early studies that looked at the relationship between the menstrual cycle and male face preference. This particular study employed Japanese women who had regular menstrual cycles and were not on the pill. The women were asked to select computer generated-faces which they considered physically attractive. The faces were a mix of five Caucasian and five Japanese men. The findings of this study strongly indicated that the women preferred male faces that were more masculine in the follicular phase of the menstrual cycle – the phase prior to ovulation/end of menses which allows the greatest chance of conception. During the luteal phase (post-ovulation, pre-menses), the women preferred men with feminised male faces. The reasoning behind this preference is as follows….Women prefer masculine facial features during the follicular phase because masculinity is supposedly thought of as an indicator of high quality males (although this relationship is controversial). During the follicular phase, a woman wants a “masculine” man – one with a strong immune system, one that is able to provide quality children and one that is able to confer resistance to disease. During the luteal phase, women prefer feminised male features which is thought to be an indicator of a man’s potential investment as a long-term partner ie. a man with a feminine face supposedly indicates cooperation in parental care and one that is unlikely to cheat.

Other studies examining the relationship between the menstrual cycle and male traits have reported vocal masculinity, dominant behaviour, taller men, facial symmetry, masculine body shapes as preferable during the follicular phase.

This may explain my preference for more feminised male features in an on-line experiment I participated in last year. After taking the test, I came up preferring feminised male faces. I may have been in the luteal phase of my menstrual cycle.

Reference: Penton-Voak IS, Perrett DI, Castles DL, Kobayashi T, Burt DM, Murray LK and Minamisawa R (1999) Menstrual cycle alters face preference. Nature 399 p. 741-742.

Tuesday, 6 January 2009

12 random facts about the author….

I have to give credit to my friend Li for inspiring this blog post. I thought it would add a personal touch to my blog in which I endeavour to protect my identity. So here are some random snippets about the Afro Scientress…

1. I love people who can make me laugh alot. I don’t mean this in a sexual way but personality-wise. It applies to guys and gals.

2. My favourite colour is orange.

3. I love taking photos and being creative when taking photos. My next camera purchase will hopefully be a SLR or something more professional than the digital camera I use now.

4. I hate it when people say things they don’t mean.

5. I have only 24 teeth in my mouth as opposed to the standard 32.

6. The older I get, the more I fear the future. Ironically, I look forward to change.

7. I love nearly everything about summer.

8. In high school I was voted ‘nicest person’ and ‘person with the best smile’ – how things have changed.

9. I drink a banana milkshake on most mornings. One whole banana, half a cup of milk, a teaspoon of honey and a sprinkle of cinnamon. Blend.

10. I would hate to be famous.

11. 2008 will be considered as one of the best years of my life. It was a year that was filled with opportunities and experience. I had several opportunities for personal and uni-related interstate and overseas travel. I had wonderful and not-so-wonderful experiences in personal relationships all of which I have taken something away from. I turned a hobby into something that provided me with an additional income. I did some teaching/demonstrating, which is something I have wanted to try for a long time. I learned to appreciate the beautiful state I live in: Western Australia. Edit: A couple of things i forgot to mention because i was too consumed in personal matters include our prime-minister, Kevin Rudd, delivering a formal aplogy to the stolen generation, and the election of Barack Obama. These things, although not personal, made 2008 an even better year.
It’s only a week in to the new-year but unfortunately 2009 is not a year I am looking forward to. It started off fine but quickly went down-hill in my personal life and I can sense that this trend is set to continue. I have been dreading this year mainly because I know I have to finish most of my PhD. My supervisor has asked me to do additional lab work on top of the lab work of my own project which means longer hours in the lab on top of writing a thesis. As an incentive, my supervisor has agreed to give me a top-up on my scholarship. In my circle of friends, most of my closest friends are either getting hitched, moving away or both whereas I am still single and have no plans to move away for at least two years. To top it off, 2009 has quite literally hit me in the face a week into the new year. True story: I was half asleep in bed this morning when all of a sudden my annual calendar slid down the wall behind my bed, rebounded off my bed-head and fell smack-bang right onto my face. The really scary thing was the hook on the wall hadn’t come off nor did the hook holding the calendar to the wall. I think 2009 is trying to tell me something. I recently came across a 2008 website which I think appropriately describes my 2009 so far.

And finally…

12. The next blog post will be science-related :)