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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

Two is Better than One: A Study of Conjoined Twins

If anyone has siblings, or even a twin, could you imagine being physically joined together with them? And no, I don’t mean metaphorically. Could you imagine being conjoined and having to share the same body with them? Conjoined Twins, or sometimes known as Siamese Twins, may have been something you’ve seen on TV, like in Grey’s Anatomy or American Horror Story.

What are Conjoined Twins?

Conjoined twins are twins that are born with physically connected bodies. Every case of conjoined twins are different, as they could be joined at different parts of the body. For instance, they could share only a small amount of tissue, and each pair could have their own set of organs and structures they need to essentially stay alive if they are able to be separated.
Others, the connection can become quite complex. The twins could share a vital organ, like the heart, or digestive, genital, and urinary systems. They could also share a huge portion of the body, like sharing the entire lower half of the body, or be conjoined at the head where they share parts of the brain and skull.

Approximately 75% of conjoined twins are joined at least partially in the chest, or share organs.

The Success Rate

The progression of advances in imaging studies, surgical techniques, and anesthesia, the rate of successful separation of conjoined twins have increased more now than in the past.

However, at birth, ~40% of conjoined twins are not alive.

~35% die within a day after birth because their organs are not able to support them both.

Schematic diagram showing the various types of conjoined twins

Source: Research Gate

The succession of separating conjoined twins depends on so many factors:

Where the twins are connected
Which structures they share

and this can get quite complicated

This could result in both twins surviving, but because of a serious birth defect, there is a risk of one or both twins dying.

In the cases the structures and organs they share may be too high of a risk, or not able to perform the separation. Lots of conjoined twins live happy and healthy lives by remaining connected.

Causes of Conjoined Twins

Identical twins are called monozygotic twins, and this occurs when a single fertilized egg splits and develops into two individuals. 8-12 days after conception, the embryonic layers split, forming into specific organs and structures.

When the embryo splits later than that time period; usually between 13-15 days after conception, the separation stops before the process is completed, and the twins result in conjoinment.

An alternate theory is that two separate embryos somehow fuse together in early development, but what might cause either of those theories is unknown.

A Case of a Successful Separation

Conjoined Rital and Ritag Gaboura Source: NewScientist

Rital and Ritag Gaboura were joined at the head – and it took a team of more than 15 surgeons and doctors at Great Ormond Street Hospital in London to completely separate the conjoined twins.

Magnetic resonance imaging (MRI) and X-ray computed tomography (CT) was done to show how their skulls were fused. The Gaboura twins turned out to be craniopagus twins – meaning they shared a skull but not a brain. This is extremely rare, and occurs once out of every 2.5 million births.

If they shared the same brain, the surgery would have been too risky to perform.

The surgeons needed to study the twin’s skull and brain to meticulously strategize the network of delicate arteries and veins that transported blood to and from the brain. Most craniopagus twins do not share arteries that feed the brain, but their veins are tangled together, and some can run from one twin’s brain to the other.

When separating the veins, if one twin ends up with too many veins, it would cause the heart to collapse.

Leaving the other twin with not enough veins, the brain would swell up with blood.

Studying their blood flow was done by injecting dyes into the twins’ arteries and tracing the blood’s in and out pathway of the brain with a series of X-rays.

A media production company was involved, using the images to make a CGI video of the blood rushing in and out of the brain.

The surgery was chosen to be done in stages, so the skull and veins could recover between each operation.

The two major systems of veins drain blood from the brain:

A superficial system woven into outer layers of dura mater (envelope of protective tissue surrounding the brain)
Deep system in internal brain structures

One twin would be given most of the superficial system, and the other most of the deep system, and hopefully the brains would adapt to the loss by expanding small collateral blood vessels that could connect the two systems.

To divide each vein, the surgeons opened a window in the twins’ skulls and operated on the veins in that little window. A craniotome, which is a high speed drill was used to drill through the skull to reach the blood vessels, and essentially it would push the brain out of the way so only the bone would be cut.

The veins were sliced through, and tied off with ligatures and dissolvable sutures.

When it was possible, the shared veins were split at a junction so each twin could receive one part of the brain.

The final hurdle of full separation was that craniopagus twins do not have enough bone and skin between them to form a complete skull and scalp when it was time to sew everything up.

The problem was solved by putting four silicone balloons filled with saline solution under the scalps, between the bone and skin. The balloons would progressively stretch the skin of the scalp.

Inflatable balloons stretch the skin. Source: https://www.bbc.com/news/health-14969823

The skull bone has three main layers:

Tough outer layer
Spongy middle layer
Tough inner layer

By driving chisels between each layer, the surgeons were able to split the bone and lift up a section so it would double the original area of the skull.

Rital and Ritag were able to recover after their separation, and the surgery was deemed a success as they were separated, and each child was getting the blood it needs and draining blood from the brain in the correct ways.

Source: BBCNews

The Development of Bacteria Eating Plastics

Discovery of plastics

A century ago, the discovery of plastics brought the convenience of a strong and affordable structure. However, finding something so strong and easily disposable creates environmental concerns. Science is rapidly developing to accommodate issues caused by the developments. Science has now permitted the development of bacteria to decompose the plastics that have long contaminated Earth. Using bacteria to destroy plastics may be a long-term sustainable way to preserve the planet.

Plastics and their damage

Plastics are continuing to plague and damage Earth’s environment. Single-use plastics are wasteful and environmentally unfriendly. More than 8.3 billion tons of plastics were manufactured since the 1950s, and over 60% have been buried in landfills. Plastic waste ends up in rivers, dumps, and oceans. Plastics harm aquatic life, increase disease spread, and may lie in waste for centuries. Scientifically, there needs to be a method to destroy PET’s (Polyethylene terephthalate). PET’s common uses include water bottles and plastic containers, many of which are consumed once then immediately disposed of. PET’s are not biodegradable.

Source: rsscience.com

The chemical composition of PET allows bacteria to decompose the structure. The bacteria are capable of decomposing the polyester bond. The C, H, and O bonds are capable of being decomposed by the bacteria.

Bacteria: a solution?

In March 2016, there was a breakthrough scientific discovery. Japanese scientists found that bacteria could consume PET plastics. The idea of bacteria eating plastics empowers the thought of opening industry scale to demolish plastics. The plastic-eating bacteria could open doors to many other forms of waste that would end up in landfills. In 2017, the fungus Ideonella Sakaiensis was seen to be able to decompose plastics. In 2020, strains of bacteria were seen as capable of eating polyurethane plastics.

Implications

Researchers and industry are far from determining measures to implementing bacteria that will safely and quickly decompose plastics. Further research must be done to seek if the measures are truly environmental. There are unknowns of the side effects of bacteria decomposing plastic. There are uncertainties if toxins to the environment will harm the environment in the long run. Moreover, the rate of decomposition of plastics is currently too slow. There needs to be genetic engineering for faster industrial processes.

Source: Beautiful News Daily

The different forms of bacteria decompose different plastics. Bacteria mainly break down Polyurethane, and bacterial enzymes mainly break down Polyethylene. Mealworms are capable of decomposing Polystyrene. These are all plastics that contaminate the planet.

Developments moving forward

Scientists are currently working on implementing the enzymes of bacteria to break down plastics at a rate six times faster than the current rate. Recently, 12000 new enzymes having the capability of breaking down plastics were discovered. 60% of these newly determined enzymes are unclassified. These enzymes have the potential for industrial use to break down environmentally harmful plastics. With the progress of science, there are many adaptable forms of preserving the environment.