Archive | January, 2014
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Rules

27 Jan

Hernia

I’m not going to pretend that shifting two solid beech carpenters benches all the way from my studio to the beautifully restored old school that is the Grenoside Reading room was not a complete pain in the lower back.

But it was worth it to provide a decent stable work surface for the students, young and old, who joined my basic letter carving course on Sunday 26th January. The event was part of a Sheffield Wildlife Project in association with the Working Woodland Trust to encourage community understanding of the importance of Grenoside Woods for their own and the landscapes sustainability.

All 18 participants went away with a hard wood plaque with their own, or those of a significant other’s names – carved crisply with the aid of a small sweep chisel and a few gouges.

Max, Merlin, their dad Nigel and Sarah all had a good go with some decent off-cuts of Sapele, ash, sycamore, elm and cherry acting as a substrate. I have developed a method using shadow printed letters (120 pt plus) glued to the wooden plaque with aerosol glue – the students carve straight through the letters; a very simple method yielding a high success rate.

carving 2

When I was eleven my old woodwork teacher allowed me to use the very best tools in his collection, knowing that he could trust me to treat them with reverence. I think this can only be instilled if a teacher is generous with knowledge and the tools of knowledge. Novices may damage the edge of  a chisel, but it can always be resharpened. Students will not learn the respect and patience needed to achieve skill unless they are allowed to make their own mistakes.

Having said that when one young student (not pictured) started playing around with a mallet and waving a chisel around – un-chastised by the accompanying parent – I said this:

“I am not a teacher, and I play by very different rules. If you want to discover my rules please carry on messing about”

He stopped and carved his name rather well.

 

Special thanks to Sarah Sidgwick of SWT for organising the day.

Shooting Dinosaurs by Peter Grandbois

15 Jan

A very thought provoking essay on parenthood

Bending Genre

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Yesterday, I took my nine-year-old son to the video arcade at the local mall.  He wanted to play any game that involved shooting someone or something.  I hadn’t been to the video arcade since I was a teenager, so I was shocked to find so many realistic video games where the goal is to kill another human being. Fathers and sons fed their electronic game cards to the machines (they no longer accept quarters), shooting away, bonding as each looked to the other and smiled before wasting a “terrorist” or two or twenty in a bloody shootout.  My son wanted to play, but I was appalled.  I tried to get him interested in shooting dinosaurs instead.  It worked for a short time, but in the end, he wanted to play the “real” games.  I gave in and soon felt the kick of the machine gun recoil in my chest…

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Imagination

13 Jan

Imagination

Princess Velvet Violet was a figment of my daughter’s fertile imagination back in the late 1980’s when we lived in Newcastle-upon-Tyne. Her mum made this lovely gown for her so that she could play at dressing up, augmenting the avid reading she used to do (generally under her bunk bed, with a glass of milk and some chocolate biscuits) through dramatic re-enactment.

She would spend hours buried in a novel, or story book developing her life long passion for literature.

On Saturdays, my daughter and I would stroll down to the Tyneside Cinema to watch a matinee with an ice lolly. The little Art Cinema would show runs of 1950 black and white films with Errol Flynn, Claudette Colbert, Marlene Dietrich, transporting us both into the silver screen. It is one of my fondest memories of being a parent – sharing that magical medium with my daughter.

The greatest gift we can give our children is to take responsibility for freeing their minds so that they can develop their imagination. The greatest gift they give us is the courage they express as they show their individuality through the life they lead as adults.

No national curriculum, refurbished education policy, or political cant will achieve this: only the instinct, love, openness, and muddle of a parent will do. Politicians and teachers on the left and right would do well to remember the old riddle:

“What can you be given, but you can never give back?”
Answer = an Education.

Thigmotaxis

1 Jan

Centipedes, like many other small creatures exhibit a curious behaviour called thigmotaxis – they like to squash themselves into corners in order to maximise body contact with surfaces.

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This is a common brown centipede resting against the side of a plastic sandwich box.

The reason small soil dwelling creatures do this is because they are particularly vulnerable to changes in humidity, they dry out quickly, or become water logged. The behaviour is so overwhelming that it can mask other reactions to external stimuli such as vibration, chemicals, etc..

Years ago I spent long hours studying the behaviour of Lithobius forficatus L. (the common brown centipede) as a Ph.D. student in order to discover what the beautiful structures on its hind legs were for:

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This is a diagram of the underside of a male centipede. You can see that the fattest segments of the last four pairs of legs, closest to the body, are equipped with a row of interesting pores. These are the coxal pores. Under the pores lies a curious tissue, known as the coxal organ.

You can see the pores more clearly here:

Coxal pores dimensions

At very high magnification the organ looks like this:

LM coxal pores

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Under the electron microscope the cells look for all the world like ‘kidney’ or ‘malpighian tubule’ (insect kidney) cells. On this basis it was classified as a ‘typical transporting epithelium’, a not very helpful description as we had not a clue what might be transported.

The Behavioural experiments proved compelling and, using a circular choice chamber to get around the centipede’s natural tendency to flatten itself to a wall I was able to demonstrate that the coxal pores were responsible for releasing a sex hormone, or pheromone attractive to members of the opposite sex.

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I came to the conclusion that the main problem facing centipedes (and anyone living under ground) was not drying out, but becoming water logged. So the coxal organ is most probably very good at getting rid of excess water (centipedes living in xeric or dry habitats have very small coxal pores, or none at all), and in so doing chucking out a useful ‘come on’ signal to other centipedes of the same species. The pheromone chemistry is phenolic and related to the chemistry of centipede cuticle (hardly surprising given that the coxal organ is modified cuticular epithelium which normally secretes the centipedes exoskeleton).

Sticking closely to a surface is not my thing. I prefer to venture out and discover things anew. Multifunctionality is common amongst amongst biological systems – it is the stuff of evolution and natural selection: a hand becomes a wing (pterosaur, bird, bat); a wing becomes a diving tank (Great Diving Beetle’s plastron); a zoologist become a woodworker…… A close study of centipede backsides was instructive in beginning a small voyage of discovery for me, a gift by a true mentor J.Gordon Blower, the ecologist and millipede man who pointed them out to me whilst smoking a number 6 filter tipped in his nicotine stained lab way back in 1979.

JG Blower 1

I have always thought the phrase ‘there is no need to re-invent the wheel’ the dullest of aphorisms. Re-invention is human, discovery and rediscovery a divine gift. Get out there and look at something very small, or something very big, but please do go and look, because your discoveries will be unique.

PMH Littlewood. Fine structure and function of the coxal glands of lithobiomorph centipedes: Lithobius forficatus and L. crassipes (Chilopoda, Lithobiidae) 1983. J. Morphology  Vol 177

PMH Littlewood. The chemosensory behaviour of Lithobius forficatus. 1. Evidence for a pheromone released by the coxal organs (Myriapoda: Chilopoda).Journal of Zoology Vol 211 January 1987

PMH Littlewood and JG Blower. The chemosensory behaviour of Lithobius forficatus. 1. Evidence for a pheromone released by the coxal organs (Myriapoda: Chilopoda).Journal of Zoology, Vol 211, 1987

PMH Littlewood.The water relations of Lithobius forficatus and the role of the coxal organs (Myriapoda: Chilopoda).J.Zoology, Vol  223, 1991