Wednesday 29 August 2018

Plants at the PNE Fair: Black-Eyed Susans

Wherever I go for a walk—in cities or in rural areas—I'm on the lookout for plants and animals. Even when other sights are interesting, I'm glad to see signs of nature. The annual fair at the PNE in Vancouver is a popular event. Exploring nature may not be high on many people’s list when they walk through the fair, but it is on mine.

The Fair at the PNE

The Pacific National Exhibition and the neighbouring Playland Amusement Park are permanent facilities in Hastings Park in east Vancouver. In the last two weeks of August, the number of enclosures in the area temporarily increases in order to create the fair. Many people appreciate the fair for the rides, the food, the entertainment, and the wide variety of items that can be purchased. The event started out as an agricultural exhibition, however, and still stays true to its roots.

Animals and Plants on Display

While viewing so-called “market animals” at the PNE fair is always sad, looking at the other ones is enjoyable. The horse show is always interesting. The show includes horse jumping competitions and Clydesdale draft horses demonstrating their skills. The fair contains plant displays as well. In addition, there are two gardens and one natural park on the fairground, which are interesting to explore. The Italian Garden always has a beautiful display of blooming black-eyed Susans during the fair. The flowers bloom in late summer and early fall and are at their prime at the start of the fair. The species is found in the wild and in cultivation. Multiple cultivars exist. Some bloom earlier in the summer than the ones on the PNE grounds. The plants are perennials, biennials, or annuals, depending on the variety.

The Black-Eyed Susan

The black-eyed Susan’s scientific name is Rudbeckia hirta. Its genus was named after Olaus Rudbeck the younger (1660-1740)  He was a professor at the University of Uppsala in Sweden and taught Carl Linnaeus. The latter scientist is credited with the creation of the binomial system of naming organisms (genus plus species).

The black-eyed Susan is native to eastern and central North America but has been introduced to other areas. The vibrant flowers of the species are greatly admired. The plant belongs to the sunflower family, which is not hard to believe when the beautiful yellow to orange petals of the flowers are seen. The “petals” aren’t what they seem, however. The plant has a composite flower, or an inflorescence. The raised, black or purple disk in the centre is composed of disk florets and each yellow extension is part of a ray floret. The flowers are pollinated by insects. When I visited the fair and took the photos in this article, the day was sunny and bees were visiting the flowers. Watching their activities can be an absorbing pastime.

The leaves of the plant are oval and toothed and have a pointed tip. They are also hairy. They are mostly basal, but some can be found on the flowering stems. Parts of the the black-eyed Susan plant have been used medicinally by the indigenous people of North America. The plant as a whole isn’t considered to be edible, however, so it’s important that it’s not eaten.

The Italian Garden 

The stone face that can be seen on the left in the photo of the flowers below is a depiction of Canio. He's the character who plays the role of a clown in the theatre troop depicted in the opera Pagliacci. The face on the right represents Turandot. The area of the garden with the statues and the black-eyed Susans in front is called the Opera Walk. Characters from several famous Italian operas can be seen along the walk.


When the fair is not in operation, the fence between the Italian Garden and the road that passes by it (Renfrew Street) is removed. This allows people to freely access the garden, the PNE grounds, and the other garden and park areas of the fairground (but not Playland). The Italian Garden is quite small but has several attractions, including fountains and statues other than those of the Opera Walk. It’s well worth visiting at any time of year, but especially in the summer. Hastings Park beyond the PNE and Playland offers natural attractions and is also worth visiting. Attractive landscaping and a walking trail have been established in the area and a stream that was covered for sixty years has been revealed. Hastings Park, which has long been commercialized, is being partially returned to nature.

Attending the Fair

The fair generally has promotional days when people can enter the fairground for a reduced price if certain conditions are met. On specific days they can even enter the site for free. The possibilities for reduced or free entry rates vary each year, however. The PNE’s website has information about the special admission days. The days can be useful for people who would like to save their money for rides, foods, and entertainment (although most of the performances at the fair are free). They can also be useful for visitors who are curious about what the fair offers but are particularly interested in late-August nature on the fairground, like me. The area of the park beyond the PNE and Playland is free to explore at any time of the year.

Tuesday 21 August 2018

Elephant Genes and Protection From Cancer

Very interesting research has revealed why elephants—at least in captivity—have a much lower cancer rate than us. Elephants live about as long as humans yet have far more cells. Like all cells, elephant ones could potentially become cancerous. It would seem that elephants should have a higher rate of cancer than humans instead of a lower one because of their larger size and their greater number of cells. Researchers have discovered two interesting genetic reasons that might explain why this isn’t the case.

An estimated 17 percent of humans worldwide die from cancer, but less than five percent of captive elephants—who also live for about 70 years, and have about 100 times as many potentially cancerous cells as humans—die from the disease. Quote from the University of Chicago Medical Center via the phys.org news service

An African elephant
ajoheyho, CC0 public domain license
The P53 Gene

A gene known as P53 seems to be important in protecting elephants from cancer. It’s sometimes referred to as a master tumour suppressor gene. We have the gene, too. The difference is that we have only one copy of the gene (on paired chromosomes) while elephants have twenty. The activated gene causes the destruction of cells with DNA damage. This damage often precedes the conversion of the cell to a cancerous one. The extra genes in elephants likely enables their body to destroy more potentially dangerous cells.

A Resurrected Pseudogene

The second genetic benefit in elephants is linked to something called a pseudogene, which is sometimes referred to as a dead gene. When genes are copied, a mistake is sometimes made and non-functional copies are produced. While the researchers were studying P53 genes in elephant cells, they encountered an active form of the LI6 gene, which was a surprise. The gene was inactivated long ago in the elephant’s evolutionary history and was though to be still “dead”.

The full name of the LI6 gene is the leukaemia inhibitory factor 6 gene. Like other genes, it codes for proteins. In this case, the protein molecules travel to the mitochondria of cells with damaged DNA. As a result, the mitochondria of the cell are damaged and the cell dies. Mitochondria generate most of the energy required by the cell and are vital organelles. Studies in elephant cells suggest that the P53 gene activates the LI6 gene.

A young African elephant
Mariamichelle, CC0 public domain license

Manipulating the Human Genome

More studies are needed in order to understand the function and interactions of the elephant genes. The exploration might not only be fascinating biologically but also useful in understanding and treating cancer in humans. Researchers are making progress in treating cancer and have made significant discoveries recently, but the disease is still serious. Although we are smaller than elephants, we have many cells and many chances for DNA errors and damage to occur.  The actual number of cells in the human body is unknown.

The short answer is that the body of an average man contains around 30 to 40 trillion cells. The long answer is that scientists do not yet know the exact number. Plus, it depends on whether or not you include the bacteria that are present in and on our bodies. Quote from Yelia Hewings-Martin, Medical News Today

Humans have 20,000 to 25,000 genes. Gene activation and activity are complex processes. Trying to manipulate the human genome without understanding what we’re doing could have unintended consequences. Still, the research in elephant cells may help us learn about useful genes or chemicals in human cells and perhaps lead to beneficial discoveries that don't require the manipulation of genes. Understanding the human body and developing better treatments for diseases are wonderful goals.

References

Resisting cancer by waking a zombie gene from the phys.org news service
Cancer rarely strikes elephants from National Geographic
Number of cells in the human body from Medical News Today