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Identifying the Main Idea Video Lesson

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Welcome to NurseHub’s Finding The Main Idea lesson. This lesson will help you to prepare for the reading test on the HESI A2.


Sensing Maturity

As we grow up and mature, it is not uncommon to experience a plethora of changes ranging from height, weight, and even distinct shifts in our various preferences. However, a recent experiment has proven that even the mere smell we emit to others is influenced by our age, as well as other factors, ranging from our nutrition and the level of bacteria presented in the body. Further, studies suggest that the majority of humans are able to correctly recognize the age of a person just by coming into contact with their scent.

According to a study published in a peer-reviewed scientific journal, human body odor undergoes perceptible shifts that can be obvious to even the most problematic olfactory systems. In other words, the human nose is advanced enough to detect even the slightest differences in human scents, especially when it involves perspiration. Scientists leading the experiment asked one group of volunteers (whose ages ranged quite drastically) to wear the same t-shirt for five consecutive nights. Then, a second group of volunteers was asked to smell the shirts and estimate the age of the people who had worn them. Interestingly enough, almost all of the answers were correct.

When it came time for the participants to comment on the smells, there was a clear preference for t-shirts that had been worn by the “elderly” category. This finding has led scientists to believe that as we mature and grow older, we give off an aroma that is either more pleasant to the olfactory system, or perhaps less overpowering or distinctive. While the results have shed light on new findings regarding the functions of the human nose, scientists are still working out potential problems regarding the study, mostly in terms of the participants’ ages and accurateness regarding the senses of smell. 

Thanks to stem-cell research performed in mammals, it has been discovered that the precision of the olfactory system may decrease with age. This is partly due to the fact that the ability of these specialized neurons to “self-renew” drops over time. Thus, it is possible that the responses from older participants were not as accurate as their younger counterparts, which could have possibly skewed the results. That is, what older participants may have believed to be “less pleasing” smells could have been perceived as neutral to others in the study. In any case, while similar research experiments will likely be dedicated to this sphere, one thing is for certain: human senses undergo prominent changes throughout one’s lifespan.

Underwater UFOs and New Discoveries

Despite the innumerable amount of distance between the two areas, space exploration can be quite similar to scientific investigation in the deep waters of the ocean. That is, foreign beings that are drastically different from human beings, including plants and even unidentified foreign objects (UFO), can be found both under water and in outer space. Most recently, in fact, an unidentified object has been discovered 630 meters below Western Australia, deep in the Indian Ocean. Interestingly enough, the finding is more than just any regular object. In fact, it may be the longest animal ever recorded in history.

With the help of an underwater robotic research system, scientists from the Western Australian Museum came across a 120 meter-long creature, known to be part of the siphonophore animal classification, which contains organisms such as corals and jellyfish. Of course, this deep-sea predator is extremely different from what one would consider a “typical” sea creature, in that it is made up of jelly-like strings that extend into various clones in the water. In other words, the creature is able to physically spread itself out and develop multiple rings, similar to a radar system. In fact, researchers have verified that the creature’s outer ring is at least 47 meters long.

After a thorough investigation, it was confirmed that the animal is not only enormous, but a dangerous predator to its fellow underwater inhabitants as well. The creature’s unique set of rings allows it to capture prey by blocking it from escape and subsequently unleashing a series of paralyzing stings. Once the prey has been successfully enveloped within the siphonophore, it is eaten and then quickly digested, a process which allows nutrients to be transferred to each ring. Although scientists were able to identify this specific predator and understand its habits and aspects, research is still being done to pinpoint the exact type of prey on which it survives. However, this was just one of many groundbreaking discoveries made during the mission.

In addition to this surprising finding, the research team also identified more than 30 new underwater species from the exploration. Thanks to the myriad of technological capabilities of the robotic system used in the experiment, Rov SuBastian, the team not only captured visual evidence of each species, but also collected specific DNA samples from the animals for further research. This was made possible by an element on the robotic device, which mimicked a toothbrush, which effortlessly scraped the sides of each underwater creature, thereby collecting an adequate amount of DNA. Samples of the surrounding water were also collected in order to examine pH levels and quality. Scientists hope to utilize these findings to further understand some of the greatest mysteries surrounding marine life.

Nature's Pharmacy

Paracelsus, a Swiss physician and alchemist who was considered a pioneer in medicinal practices during the Renaissance, was once quoted as saying, “Amidst the plains and mountains lie the best pharmacies”. While a branch of homeopathic healers have long believed that nature may hold the secret to curing ailments, recent studies have also suggested that plants may be valid alternatives when fighting illness and disease. Even so, will patients be willing to rely solely on nature’s pharmacy, rather than their trusted brick and mortar drug stores? The latest research on the topic leads to interesting facts and figures.

In past centuries, the use of plants and herbs to cure ailments was a popular solution, but began to lose credibility in the 19th century, when pharmaceutical drugs came into development. Phytotherapy, an allopathic discipline that uses natural extracts as medicines, was the most prominent medicinal therapy in the 1800s. In the 1900s, however, controversy regarding the lack of control measures in the manufacturing process, coupled with the advent of pharmaceutical medicine, led to the decline of natural remedies and their popularity. Thanks to the current, more stringent protocol in the manufacturing process, though, alternative medicine is making a comeback.

Unbeknownst to most of the population, phytotherapy must be studied by a trained and qualified professional. With this in mind, simply browsing the “Botanicals and Natural Remedies” aisle at the local pharmacy, or using lavender oil to help get rid of a headache, could actually do more harm than good. Without in-depth and accurate knowledge regarding the potential healing properties and side effects of various plants, using these natural supplements could alter the body’s healing cycles and possibly interfere with the use of other pharmaceutical drugs. Thanks to the fact that phytotherapy has become an internationally-recognized area of study, universities around the world offer academic programs dedicated to understanding the chemical properties of plants.

However, access to more knowledge on a topic may not automatically persuade people to turn to natural supplements when battling general ailments. In fact, according to a recent survey, psychologists believe that it will take at least a few years before the average person includes natural supplements in their medicine cabinets. Moreover, people are unlikely to trust the input of holistic medical practitioners, even if they hold advanced degrees in phytotherapy. On the other hand, research suggests that once these facts become part of the mainstream medical industry, people may be open to new therapies. Until then, the potential curing effects of nature’s pharmacy may likely remain in classroom universities and history textbooks.