Author Archives: Leslie Chiang

Little Forests, Big Problems.

In many places, there have been drastic increases in deforestation for urbanization and agriculture. Increases in the availability of housing and the space to grow foods may seem to benefit society at first glance, but urbanization and agriculture are not without their downsides. Wooded areas must be deforested to prepare land for construction and agricultural development, resulting in the destruction of natural habitats that are home to many plants and animals. As a result, endangered local wildlife will face challenges in avoiding extinction. Although humans have taken measures in attempts to preserve these forested ecosystems by preserving portions of natural forests within urban and sub-urban areas, this method of preservation is not as effective as it appears.

In this mini documentary, we will walk through Vancouver’s very own Pacific Spirit Regional Park and highlight the challenges that wildlife may face in smaller forests as a result of the continual urbanization.

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From the video, we introduced Adriana Suarez-Gonzalez, a ph.D student in the department of Botany at UBC. In her 2007 study, “Pollen limitation and reduced reproductive success are associated with local genetic effects in Prunus virginiana, a widely distributed self-incompatible shrub,” Adriana Suarez-Gonzalez shows in the video that some fruit-bearing plant species, (such as the Prunus virginiana, more commonly known as the chokecherry that her research revolves around) in fragmented forests (explained in the video) are less successful at reproducing compared to those in larger, continuous forests. Since plants are lower down the food chain, animals find it hard to sustain themselves.

Photo of choke cherries, courtesy of Born 1945 on Flickr Creative Commons

The video gave us a great idea about how fragmented forests affect animals attempting to sustain themselves, but to fully understand why fruit production is a problem, we must look at reproductive barriers of plants in fragmented sites. To understand the challenges that certain fruit-bearing plants face, Ms. Suarez discusses both ecological and genetic factors influencing the reproductive success of the chokecherry in the Podcast below. 

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In short, the podcast shows that ecological factors involve the quantity and quality of pollen available to the plant, and genetic factors involve the effects on the genetic structure of the plant as a result of biparental inbreeding (the fertilization of plants by closely related members of the same species). These two factors put together overall affects the reproductive success of the chokecherry.

Through Adriana’s research on this model berry, we can finally grasp the idea of how fragmentation can affect the health of the ecosystem as a whole. While we may not think much of a simple berry, we can appreciate how much it actually has to offer to animals that depend on it. It is true that chokecherries are abundant and therefore not an immediate problem to wildlife that depend on it, but Adriana’s research offers a argument in how the biodiversity in continuous forests offers similar fruit-bearing plants greater success, and as a result, the success of animals that rely on it.


By SCIE300-212 Group 2: Bailey Lei, Leslie Chiang, and Kia Sanjabi


Cunningham SA. 2000. Depressed pollination in habitat fragments causes lowfruit set. Proceedings: Biological Sciences 267: 1149–1152.

Bosch, Maria, and Nickolas M. Waser. “Effects of local density on pollination and reproduction in Delphinium nuttallianum and Aconitum columbianum (Ranunculaceae).” American Journal of Botany 86.6 (1999): 871-879.

Kulling, Sabine E., and Harshadai M. Rawel. “Chokeberry (Aronia melanocarpa)–a review on the characteristic components and potential health effects.” Planta medica 74.13 (2008): 1625-1634.


Dogs and humans: A match made in … brain structure?

Photo courtesy of: Garden State Hiker on Flickr Creative Commons

Dog owners can attest that communication is vital to a healthy relationship with their canine companions, but how? It seems that humans and dogs can communicate in a way that transgresses the language barrier between the two species (give it a try – watch this video and see if you can interpret the meanings behind the barks towards the end of the clip). Throughout history, dogs have developed alongside human society and presently, have become one of our most popular animal companions, but what is the scientific basis that drives the bond between humans and dogs?

Earlier research has demonstrated through eye-tracking technology that dogs’ communicative abilities with people are socially comparable to human infants. The experiment illustrated the dog’s capabilities in understanding our intentions to communicate with them through verbal cues and eye contact. Although this is interesting to prove through the technological advancement of eye-tracking, the conclusions are not groundbreaking to what we already know; dog owners can easily understand this through their daily interactions with their canine companions.

More recently, however, a study from the Cell Press Journal reveal the similarities in the physical regions of the brain responsible for processing social communication in humans and dogs through functional magnetic resonance imaging (fMRI) scans. In this experiment, human participants and dogs were given the same auditory samples of human and dog vocalizations related to different emotions, and nonvocal sounds. The results from fMRI showed similarities in the triggered “voice areas” of the dog and human brains, although expectedly these areas were triggered more by the voices from their own species (i.e., humans responded more strongly to human voices, and dogs responded more strongly to dog vocalizations). Additionally, dogs and humans show similar brain responses to the emotional aspects behind the human and dog vocalizations, such as those associated with cries and whining.

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The video above summarises findings of the study that was performed, and even includes an interview with Atilla Andics, one of the leading scientists in this study.

These findings not only demonstrate that dogs can recognize human voices as communicative cues, but it also suggests that they are able to understand the emotions tied to the voices. From this study, we can also understand why humans are able to interpret a dog’s emotions and needs through its barks and vocalizations. This similarity in the locations and brain mechanisms related to processing of social information allows dogs and humans for mutual understanding. Given the fact that dogs and humans are both social creatures, it seems reasonable that these brains developed in such similar ways. Factor in the domestication of dogs going back over tens of thousands of years, and this special interspecies bond does not seem so difficult to understand anymore. Perhaps this serves as scientific evidence to those who argue whether or not a dog truly is Man’s best friend.

– Leslie Chiang

Reasons why we should not schedule ourselves for 8:00 a.m. classes

Image: Katherine Squier via Flickr – Creative Commons License

As children, many of us were designated early bed-times by our parents. For the most part, it was easy for us at that age to go to bed accordingly, but in the process to becoming adolescents, we find ourselves struggling to abide by these schedules and likely ended up abandoning them. As a result, we also struggle with waking up early and performing optimally for those early morning classes.  While some adults may blame that on a student’s lack of discipline, multiple studies have shown that biological factors are at play, and why shifting our school schedules can be beneficial for us.

As most of us know, sleep is crucial for children, but what is often underestimated is the amount of sleep required for optimal functioning in adolescents as well. Most professionals in the field, including Mary A. Carskadon, Ph.D., director of Sleep Research at Bradley Hospital, agree that adolescents and young adults require the same amount of sleep that children do, which ranges from about 8.5 to 9.25 hours a night. The problem, however, is that due to their increased responsibilities, school workload, and extra-curricular activities, adolescents rarely are able to obtain this amount on a regular basis. In her article, “When Worlds Collide: Adolescent Need for Sleep Versus Societal Demands,” Dr. Carskadon outlines the societal demands that conflict with adolescents’ biological clock for optimal sleep times, including early school starting times competing with our circadian rhythms.

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In this short video, Dr. Katrena Lacey discusses the main points of how teenagers’ sleep habits differ from that of children and adults. All the factors listed by Dr. Lacey contribute to the problem with adolescents’ lack of sleep.

One research study attempted to solve the issue regarding adolescent sleep deprivation. The recent study was performed by psychologist and sleep expert, Julie Boergers, Ph.D., on 557 adolescents at a coeducational residential school by shifting their school’s starting time from 8:00 a.m. to 8:25 a.m. These students filled out the School Sleep Habits Survey (SSHS), a widely used survey in the US and other countries, at three equivalent time points in their school terms to compare the effects on their sleep-wake behaviours, functioning, school participation, physical and psychological health, and even caffeine use.

What they found through statistical analysis of the SSHS was an increase in sleep duration by 29 minutes, which makes logical sense due to the later start-time for school. The significant statistical finding, however, is an increased number of students obtaining over eight hours of sleep per night (from 18% to 44% of students). Overall, these students noted reduced daytime sleepiness, feelings of depression, and caffeine consumption.

Although this study showed no substantial improvement in grades and academic performance, it puts a strong case forward for shifting our school schedules just about half an hour later to reap the benefits of a good night’s sleep. For those of us who feel that sleeping earlier is nearly impossible, this study gives them good reason to start school later, mitigating sleep deprivation that seems to be such a big problem in our college lifestyle.

Avoiding the Sun for fear of Skin Cancer? You may want to Reconsider.

Image: Wikipedia Commons

Many have heard of the health benefits of vitamin D through sun exposure, but its recent media portrayals, especially during the summer months, have generally been negative due to the culture of sun tanning and its effects of prolonged UV exposure, such as cancer and premature skin aging. This has given the public reason to fear sun exposure and to justify staying indoors. Studies suggest, however, that there are more benefits to sun exposure than just vitamin D, but what exactly are they, and why would we risk getting skin cancer for these supposed benefits?

Firstly, we must discuss the effects of nitric oxides (NO) on our blood vessels. When inside the linings of our blood vessels, this compound binds to and activates specific enzymes, which trigger the relaxation of smooth muscle, resulting in the dilation of our blood vessels.  Professor Richard Weller of the University of Edinburgh, a longtime researcher in the roles of nitric oxide in human skin physiology, has shown in collaborated studies that sunlight aids in mobilising the nitric oxide species (taken in through our diet and natural production) that are stored in skin to the blood vessels, thus stimulating vasodilation. Blood pressure decrease associated with vasodilation lowers the risks of coronary related diseases, improving overall cardiovascular health.

For those attempting to replace sunlight exposure with vitamin D supplements, the study suggests otherwise. Particularly, it states that these cardiovascular health benefits are independent of vitamin D and are instead related to the nitric oxide mobilisation from the skin due to the sun’s UVA rays. In vitro tests through UVA irradiation onto skin has shown that it stimulates breakdown of the skin’s NO stores, releasing the nitric oxides. From these results, the added benefits of sun exposure that cannot be replaced by supplements is apparent.

However, the question that remains is whether or not these benefits outweigh the costs or risks. We should not deny the fact that skin cancer from overexposure to the sun is still a risk. In the video below, Dr. Michael Ruscio not only mentions the ideas covered by Weller, but also effectively includes examples of the most common cancers compared to skin cancer to put it into perspective.

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As Ruscio emphasises in an example, although the skin is ranked 10th in the 10 cancer sites, the male genitalia (ranked 3rd) and lymphoma (ranked 9th) are higher on the list and have been shown to react beneficially to sun exposure. To quantify the amount of sunlight we should receive, he suggests approximately 30 minutes a day, keeping in mind the variation in our complexions (those with darker complexions to receive more, and those with lighter complexions to receive less).

In retrospect, the right amount of sun exposure can have great benefits to cardiovascular health by lowering blood pressure and decreasing risks of cardiovascular related diseases, but like everything else we expose our bodies to, it should be in moderation. By doing so, we can avoid the painful aftermath of sunburns after an eventful day at the beach and more importantly, the risk of skin cancer.

– Leslie Chiang