Monthly Archives: February 2022

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Caribou habitat restoration

 

Motivation

Caribou are critical indicator of forest heath, and they play important role in many places: they are important resource for indigenous people, prey species for many carnivores. However, recent years, there has been a decline in Caribou population.

I want to explore the effectiveness of habitat restoration as a caribou conservation strategy. Habitat restoration has been studied previously, but generally, I am still unsure of how impactful it really is because it is a long-term solution. Therefore, it is important to research this topic and discover whether or not habitat restoration is a strategy government should continue to use.

What is habitat restoration?

  •  Habitat restoration is the renewing and repairing of damaged or degraded habitats back to a more stable state. This involves physically going to sites of habitat destruction and manipulating the environment. An example would be positioning trees and branches to create barriers to reduce the sightlines of linear features.
  • The main goal of habitat restoration is to reduce predator use of linear features like seismic lines and roads in hopes of reestablishing the predator-prey dynamics that caribou and wolves shared prior to human industrialization and exploration. As a result, the caribou population should be better conserved. (graph from MLR images Flickr)

 

 Caribou population declines

During my research, we find that the primary cause of caribou population decline is the unstable predation of caribou which is caused by human-mediated changes to predator-prey dynamics. For example, Industrial exploration which is human-caused destruction impacts predation that impacts the caribou population.

 

source from Daniel images

Methods to insist caribou population

  • Wildlife cameras planted in restored and unrestored areas; comparing the use of these linear features for caribou, bears, wolves, moose 
  • Overall prediction: less likely to use restored vs unrestored, increased response with increased treatment intensity 
  • GPS Collars to quantify individual animal use of restored vs unrestored lines
  • Overall prediction: Restored areas used more than unrestored, effect increases with treatment intensity 

Solution

After analyzing the cause of the decline, there are two main goals for habitat restoration reverse the effects that clear cut logging and pipeline Another goal is to promote a sustainable environment for caribous to live in without human intervention. These two ways will benefit to caribous population. But We need a large area and time scale to observe the response of caribous population levels to understand how changes in habitat use after habitat restoration treatment translate into increased survival rates of caribou.

Conclusion

Human activities have caused the destruction of many organisms. What we can do is stimulate the action of habitat restoration. However, the complexity of the ecosystem will cause limitations for habitat restoration. The near local communities opposed habitat restoration because of the impact on their daily life. In addition, high economic costs can be perceived as having a negative impact on the restoration process. Overall, there are pros and cons to habitat restoration but it is necessary for us to consider the best solution to address the consequences of human destruction.

——Chenyang Luo

 

First Genetically Modified Pig Heart Transplant

If due to an unfortunate accident, you were on the National Organ Waitlist for a heart transplant, would you consider receiving a heart from an animal?

For decades, doctors have tried to transplant animal organs in human bodies, but have not been successful. Partly, because of how complex the human body is.

Human Body & Organ Transplant

The human body is like a very complex machine, with microscopic vessels and delicate tissues. So complex that if one part of the body is injured, the rest of the body will be affected by it. This becomes fatal if the injured body part happens to be a vital organ, such as the heart.

Since the dawn of medicine, scientists and doctors have researched and studied techniques to perfect human organ transplants. Due to the complexity of the human body, organ transplants can commonly result in complications and possibly death. 

One of the biggest challenges of organ transplants is finding a matching blood type. If the recipient’s blood type does not match the donor’s blood type, the recipient’s body will attack the organ. During organ rejection, the transplanted organ is nothing more than a foreign object to the body, like bacteria, it will try to remove it which usually ends in the death of the patient.

Another side of the problem is finding organ donors because there is a shortage of healthy organ donors all around the world. For example, as you can see from the image below, last year in Canada, about 280 people died while waiting for an organ transplant. This shortage is much greater in more populated countries such as the US. 

https://www.cihi.ca/en/organ-transplants-in-canada-2020-donations-and-need-infographic

Genetically Modified Pig Heart Transplant

However, on January 7th, scientists and doctors made a huge advancement in this field. They were able to transplant the first-ever genetically modified pig heart into a 57-year-old man, who was suffering from life-threatening heart disease. David Bennett has been recovering from the operation but is currently healthy and stable.

Why use a genetically modified pig heart?

There are many reasons why scientists used a pig as the donor, mainly because pigs are very anatomically similar to humans. In both adulthood and childhood, their organs are similar in size and function to humans, making them well suited for transplant. Additionally, pigs reproduce at a fast pace and can be bred at high health standards in labs. There are labs in the world that breed and clone pigs for organ transplants.

https://www.theguardian.com/science/2022/feb/03/german-researchers-to-breed-pigs-for-human-heart-transplants

Using advanced technology, scientists were able to edit parts of the DNA of a pig and turned off genes (the building blocks of DNA) that resulted in organ rejection. This eliminated the need to find a compatible blood type donor.

In Conclusion:

If more research is completed on genetically modifying animals for organ transplants, we might be able to solve the organ donor shortage entirely. Patients will not have to wait on long lists to receive organs to live and we could minimize the risks of organ transplants significantly.

 

By Shayan Abbaszadeh

Cancer Therapy – Breakthroughs in Cancer Cell Research and Treatment

Imagine this:

You’re living your life but suddenly you lose the urge to eat. Not a big deal, maybe it’s just a phase.

A week passes and you notice that those juicy arms you’ve worked so hard to grow seem to start looking like sticks. You face seems a bit discoloured, somewhere on the paler side. You weigh yourself, and you’re down 10 pounds. You start feeling a bit concerned but maybe it’s the keto diet that you started.

A few more weeks pass and you feel a small bump on your lower back. Now you’re freaking out and head to the hospital. After a diagnosis, the doctor says the three dreaded words: “you have cancer.”

What is cancer?

In the most general sense, cancer is a disease which causes cells to rapidly divide and grow uncontrollably and spread to different parts of the body. Cancer cells can also aggregate in certain areas and disrupt bodily functions, also known as tumours.

Current treatments for cancer:

Currently, there are three main types of treatment: surgery, chemotherapy, and radiation. As surgery suggests, it is the physical removal of a tumour. Chemotherapy uses drugs to target to rapidly growing cells, even healthy cells such as hair. Finally, radiation uses x-rays, particles, or radioactive seeds to kill cancer cells. Of course there are other types of treatment such as targeted therapy but it is less used in the medical industry.

Example of Cancer Treatment (Chemotherapy) – Image by VeryWell

A newer type of treatment, car t-cell therapy:

Chimera antigen receptor (CAR) T-cell therapy is a newer type of treatment that was tested back in 2010. Essentially, T-cells from a patient are extracted, genetically modified with CAR, and reintroduced into the patient. These modified T-cells are more adept at targeting only cancer cells. In a 2022 study by Melenhorst et al., it was found that two patients suffering from lymphocytic leukaemia entered remission right after treatment and after a decade, still continues to be in remission and even contains detectable CAR T-cells. This study shows that CAR T-cell therapy has it’s merits as being a legitimate treatment.

CAR T-cell Therapy Cycle – Image by Genetic Engineering & Biotechnology News

Side effects of treatment:

Like all types of cancer treatments, there are some side effects associated. In a 2022 New York Times article by Gina Kolata, some side effects include high fevers, comas, and dangerously low blood pressure. However, some of these symptoms were resolved given time.

Overall takeaways:

Recent studies showing the results of CAR T-cell therapy has given it a chance to display the potential of it being a legitimate cancer treatment. Although some nasty side effects are associated with treatment, we cannot deny the positive effects it has shown. However, further research and testing would be crucial in  developing this medical knowledge.

– Jimmy Huang

 

From Wolves to Dogs. From Foxes to … Dogs? A Study About domesticated Foxes

As a kid, have you ever thought it might be awesome to have a monkey, dog or maybe even a fox as a pet? Or maybe you considered a more fearsome animal, like a lion or tiger, but realized it might be too difficult to domesticate.

In a famous 60 year long (1959-2017) experiment, Russian researchers Lyudmila Trut and Dmitry Belyayev selectively bred silver foxes to view the evolution that occurred to transform wolves into dogs. In essence, the two researchers were trying to selectively breed for tameness in the foxes.

Romeo the wolf with a labrador
Credit: Reddit

how is it possible?

Up until the study, the silver fox had never been domesticated before. To maximize the possibility that tameness was from genetic selection, the foxes were untrained, given minimal exposure to humans and were kept in cages. This tameness trait was evaluated once the pup reached the age of one month. The researcher would approach the fox in its cage while wearing a two-inch-thick glove and place a stick inside its cage.

Reactions were graded on the scale such that the highest score would be given to the calmest subjects. Criteria for some low-scoring foxes included extreme aggression or shrinking at the back of their cages. Those foxes who did not react would receive highscores and go on to breed for the next generation.

An aggressive silver fox pup
Credit: Darya Shepeleva

wait you’re happy to see me?

In the first few generations, the foxes were fairly hostile towards the researchers. Even the calmer foxes in these cohorts were notably not social towards humans. However, around the sixth generation of foxes, some fox pups seemed to seek human contact ‘not only [tail] wagging [but] also whining’. This behaviour was coined to be part of the ‘elites’.

In the sixth generation, only about 2% of the domesticated foxes exhibited this behaviour. Over the generations, the proportion of domesticated silver foxes that were deemed to be part of the ‘elites’ continuously expanded. By the 20th generation, the proportion reached 35%. In 2017, the elites made up 70% of the domesticated foxes.

Lyudmila Trut with a domesticated silver fox
Credit: Wikipedia

Can i have my own pet fox?

Yes, domesticated foxes are still obtainable from Russia. Although the experiment is no longer running, the foxes themselves are still being bred. Assuming you can pay the hefty price (approximately $8000) and it’s legal to own one in your country, it is still possible to have a pet fox.

The researchers were able to mostly domesticate the silver fox given that they had never been domesticated before. Being able to do so only by grading the calmness of the foxes as well makes the experiment even more fascinating. Despite being a very slow process, it creates the question of what other kinds of animals could we possibly domesticate purely based on their ‘tameness’?

-Darryl Ma