Monthly Archives: February 2013

allergic reactions to woodsmoke – katie

from google images

What is it?
It is as a result of a hypersensitive immune system. The B-lymphocytes in the immune system misidentify a harmless substance (an allergen) as harmful and so return back to the lymph node where they came from and change into a plasma cell. These plasma cells then produce antibodies designed to attack the allergen. In an allergic reaction the antibodies associated with it are IgE antibodies which are a type of protein (also known as immunoglobulin E). The IgE antibodies then attach themselves to mast cells.
When this happens the mast cells break open .These are located in body tissues and derived from bone marrow. These cells contain many chemicals including histamine. The histamine is then what causes the allergic symptoms. One of these symptoms is inflammation. The histamine causes this reaction by dilating the blood vessels, allowing blood to enter the area which causes swelling.
Another symptom of an allergic reaction is tightness of the chest and a shortness of breath. This is due to the fact that the histamine causes the constriction of muscle. Therefore muscle around the airways constricts causing difficulty breathing. Other symptoms can include vomiting, itching and a rash. Often, the symptoms you experience depend on the parts of the body involved and where in your body the histamine is released.
How might wood smoke cause it?
When you breathe in the smoke from wood, this can sometimes cause an allergic reaction. This could be due to a couple of factors. One of these is that in some types of wood burnt, the allergen present in the pollen on the tree is also present within the wood. These can survive combustion and therefore are within the smoke. Examples of trees this could happen with include oak, hickory and mesquite.
Another aspect of wood smoke that can cause allergic reactions is the irritants contained in it. These include nitrogen dioxide, formaldehyde, phenols and sulphur oxides. These can aggravate the respiratory system and irritate the eyes and nose and trigger an allergic reaction.
References
http://science.howstuffworks.com/life/human-biology/allergy.htm
http://www.phadia.com/en/Public/Allergy/Allergy-explained/

Click to access AsthmaAllergybook.pdf

http://www.ncbi.nlm.nih.gov/pubmed/9354811
http://www.bio.davidson.edu/courses/immunology/students/spring2000/lamar/mfirp.htm

Click to access WoodsmokeWA04.pdf

http://www.livestrong.com/article/532681-mesquite-tree-allergies/
http://www.healthguidance.org/entry/952/1/Beware-Your-Fireplace-Or-Wood-Burning-Stove-May-Be-Harming-Your-Health.html

Badger setts – katie

image from google images

Name and Family
• Kingdom – Animalia
• Phylum – Chordata
• Class – Mammalia
• Order – Carnivora
• Family – Mustelidae
• Genus – Meles
• Species – Meles
The European badger is part of the Mustelidae family which also stands for those possessing musk glands. It is also known as the weasel family. Others in this family include the otter, stoat, polecat and ferret.
Badger Setts
Badgers live in setts. These are a network of tunnels and chambers which sometimes include several entrances. They can stretch for hundreds of yards. They can be distinguished from rabbit and fox holes due to the fact that they are larger. Within the setts there are different compartments for sleeping, living and nesting. There are also separate holes built that badgers use for the toilet.
In their setts badgers put in bedding. This is made up of dry grass and plants. Every so often this bedding is dragged up and replaced with cleaner bedding. Badgers can live in the same set for many years. Some sets have even been found that are over 100 years old. These setts have had many generations of badger live in them.
Habitat
Badger setts can be found in a wide variety of habitats which can include moorlands, quarries and even open fields however most commonly are in woodlands or hedgerows. You can tell if the badger sett is active by looking to see if there is any loose earth around the sett. There may also be trampled vegetation around the holes. To provide extra stability and safety, badgers often build their setts under tree roots.
Physiology
An adult badger is usually between 25 and 31 inches long. Their weight varies depending on the season due to the availability of food but generally badgers will weigh between 8 and 12 Kg with the males weighing slightly more than females
Badgers have a small head and small eyes with a thick neck. They are stocky animals with short back legs. Their paws are adapted with long sharp claws useful for digging and they have 5 toes on each. They are recognisable by their black and white stripes.
It is thought that badgers have very poor eyesight. However they have very good hearing and an excellent sense of smell. A badgers life expectancy in the wild is up to 15 years, but generally they often live for 3. A lot of this is due to road accidents. In captivity they can live for up to 19 years.
Food
Although coming from the order carnivore, badgers are actually omnivores. They eat small animals including young rabbits and birds. They will also eat lizards, frogs and insects. The main part of a badger’s diet however, is earthworms.
Depending on the time of year, if the above food sources are short badgers will also eat bulbs, plants and berries. During the autumn it is said that badgers eat acorns. If planting food near a badger sett it has been found they also like Apple, Blackberry and Pear.
Behaviour
Badgers live in setts of between 5 and 10. They are all related and there is a hierarchy. Badgers communicate predominantly by scent from a gland under their tail. Badgers are nocturnal meaning they come out of their setts to find food at night. Although they do not hibernate in the winter, they do adapt to conserve energy when food is scarce.

The law

Under the protection of badger’s act 1992 it is illegal to kill or mistreat a badger. It is also against the law to intentionally destroy a badger sett or cause a dog to enter it. However there are exceptions where licenses can be issued to move the badgers from their sett and find other territory. For example if a road is being built by a badger sett.

 References
http://badgerland.co.uk/animals/sett.html
http://www.naturalengland.org.uk/ourwork/regulation/wildlife/species/badgers.aspx
http://www.bbc.co.uk/insideout/south/series7/badgers.shtml
http://www.badger.org.uk
http://www.wildlife-web.org.uk/badger/facts/factfile.html
http://www.animalcorner.co.uk/britishwildlife/badger.html
http://badgerwatcher.com/about-badgers/
http://www.rspca.org.uk/allaboutanimals/wildlife/laws/badgers

Log cross section – katie

log cross section

From looking at my cross section of wood I can see that it has about 15 lots of rings. This means that the tree which it came from was about 15 years old. There are 2 different types of rings – the pale ones and the dark ones; a pale and dark ring represents one year’s growth. The pale rings are formed in the spring, when growth is rapid and the darker rings in the summer when growth is slower and the wood is therefore denser. These rings are made up of cambium cells. Some parts of the rings have dark marks where the wood looks dead. This could be due to the fact that at the time they were growing they were very near to the bark and because the cells are quite easily damaged, the cells were killed.  The first few rings of the tree are much thicker. This could be due to the fact that there was significantly more rain during these years.

Looking at the wood, when you look closely you can also see vertical lines. These run from the pith to the bark. These are known as medullary rays and they are vertical sheets of cells. Their role is to transport nutrients between the core of the tree and the outer parts of the tree during the growth phase.

The role of the pith which is formed during the first year of growth is to store impurities that are deposited. Looking at the wood, the pith is slightly off centre.  This could mean that the tree didn’t grow straight due to where the light shone – the tree would have grown towards the light.

The wood also has interesting black lines that run through and around the wood. This could signify that the tree is infected and could be rot caused by fungi.  Finally the tree has a thick layer of bark surrounding the tree. The bark is made up of dead cells and looks almost corky in appearance which can help with making the tree waterproof.

Natural dyeing using a mordant – katie

Process

  • Soak wool (to ensure even take up) – several hours
  • Fill pot with water and add mordant. Make sure it dissolves completely by stirring with a clean stick. Bring to room temperature and add wool. Simmer – 1 hour
  • Remove from heat and let cool – overnight if possible
  • Can dry wool out as long as it is soaked before dyeing
  • Put wool in to cold water with dye in
  • Heat slowly and dye until desired shade is reached
  • Let bath cool and remove wool
  • Rinse until there is no run off and allow to dry

 The most common mordant is ALUM (potassium aluminium sulphate)

Chemical formula = KAl(SO4)2·12H2O

 Why do we use a mordant

  • The term mordant literally means ‘to bite’
  • The mordant contains a metal ion which fixes to the material. This means that when the dye is added, although it is not attracted to the material, it is attracted to the metal ion and because the mordant is fixed into the material it means the dye now is too.
  • The mordant forms insoluble coloured compounds of the dye in the fibre. These are called lakes. Because different mordants will react differently with the dye the chemical formula of the insoluble compound will be different and so the colour will vary.
  • Because the compounds are insoluble it means that the dye will not wash out of the fabric when rinsed with water and will be less prone to fading over time.

Why is cream of tartar used?

  • Cream of tartar is used when using an alum mordant to help brighten the end colour.
  • It also softens the fabric
  • Cream of tartar helps with the evenness of the dye

 Alum Vs Iron sulphate

  • Alum is the most widely used mordant
  • Great care must be taken when using Iron sulphate as a mordant that it is thoroughly dissolved before the fabric is added or else it could stain the wool
  • Alum does not generally affect the ultimate colour of the fabric, however iron tends to sadden or darken colours

Vinegar

  • Vinegar is not a mordant because it does not contain a metal ion, it is a dye auxiliary chemical.
  • Vinegar lowers the PH of the dye bath which allows the protein fibres in the natural material you are dyeing to ionise. This then helps the material to form Hydrogen bonds with the dyes.
  • However vinegar is easily removed by washing, whereas because a mordant acts as a connector between the dye and the material, it is not.

References

http://www.pburch.net/dyeing/FAQ/mordants_and_assists.shtml

http://www.earthguild.com/products/riff/rnatdye.htm

http://www.cs.arizona.edu/patterns/weaving/webdocs/mnm_mt29.pdf

http://www.spin-knit-dye.com/natural-dyes-mordants.html

 

 

Homo Heidelbergensis – Katie

Depiction of what homo Heidelbergensis is thought to have looked like (image obtained from google images)

Depiction of what homo Heidelbergensis is thought to have looked like (image obtained from google images)

Origins
Homo Heidelbergensis originated from Africa and Europe. He is thought to have lived between 600,000 to 250,000 years ago. He is believed to have been the common ancestor to our species Homo sapiens and Neanderthals. The first fossil identified as Homo Heidelbergensis was found in Heidelberg, Germany. This is how it gained its name. The first fossil found was a Jaw.

What did Homo Heidelbergensis look like?
Because fossils of Homo Heidelbergensis have been found throughout the world, and they inhabited the world for many thousands of years, there are physical variations in the fossils that have been found. However fossils found in Europe suggest that Homo Heidelbergensis was slightly shorter and wider than modern day humans tend to be however not significantly so. This would have been because in Europe at this time the climate was colder and this shape meant less surface area and therefore they could conserve heat better. Women tended to be around 5 foot 2 inches and weighed about 51 Kg whereas Men were about 5 foot 9 and weighed about 62 Kg.
From the fossils, it has been predicted that the brains of Homo Heidelbergensis was actually only 10% smaller than our own, however there were significant differences in their head shape to ours. They had large brow ridges and a lower forehead. They also had a more elongated skull.  Homo Heidelbergensis did not have the pointed chin of Homo sapiens.

Tools
Tools made by Homo Heidelbergensis were mainly used for hunting. Most tools they used had been used by a previous species of human known as Homo Ergaster They are believed to have used axes and cleavers made out of stone. Some later populations of Homo Heidelbergensis are also thought to have made tools out of antler from deer, bone and wood.

What did they eat?
It is thought that Homo Heidelbergensis was a hunter rather than a scavenger. This is because the tools that have been found look like they were used for killing animals. Furthermore fossil bones found from large animals have been covered with cut marks and beneath these marks are teeth marks; suggesting humans hunted the animals before the scavengers finished it off.It is thought that they hunted horses, elephants, hippos and rhinos.

Social skills
Scientists found debris from stone tool making in Israel that had been scorched by fire and nearby burnt seeds and wood. This suggests that they were capable of controlling fire, which in turn suggests that in their groups, Homo Heidelbergensis gathered round fires to keep warm, protect themselves from predators and possibly even to socialise.
Furthermore, at a site in Terra Amata in France, evidence was found that seems to indicate that homo Heidelbergensis was the first form of human to build shelters. This in turn suggests that they may have been providing protection for their families.
From comparing the ear canal of Homo Heidelbergensis and those of modern day humans it has been found that the hearing patterns of Homo Heidelbergensis overlapped with modern day humans. Although this does not prove that Homo Heidelbergensis used language, it does suggest that this could have been around the time when a primitive form of language did start to develop

Rituals

In the 1980’s archaeologists uncovered fossils from 32 individuals from a 14 metre deep pit which were identified as Homo Heidelbergensis in Atapuerca, Spain. Most of these were adolescents. Some archaeologists believe this shows evidence that Homo Heidelbergensis were the first species of humans to bury their dead and the first evidence of symbolic thinking. However some speculate that they could have fallen into the pit due to a mudflow.

Box grove Man

In 1994 in Box grove, West Sussex, England a shin bone was discovered which was thought to belong to Homo Heidelbergensis. The bones had been chewed at the edges , suggesting Homo Heidelbergensis was sometimes prey to other animals but the bone itself showed that this species of human was more strongly built than present day humans. There were also two teeth found there. At the site, many animal bones were found supporting the theory that Homo Heidelbergensis was a hunter. Stone tools were also found there, however whilst it is widely agreed that the stones found had been shaped by Homo Heidelbergensis, some archaeologists argue that because there are so many stones at the site, if you look long enough you will find some that look as if they have been artificially shaped.

References