The Physiology Behind Mastering the Pull-up

We’ve all been here: in front of you hangs a metal bar dauntingly suspended a couple of feet in the air — and you think to yourself, how do I do a pull-up?

Muscles used during a pull-up excercise. Image from [1].

For those who don’t yet know how to do a pull-up, there’s a long road ahead. But just like any other exercise, with proper training, mastery is possible by properly activating the groups of muscles involved through repetition. The muscle groups most involved in the pull-up are the rectus abdominis (one of the many muscles that constitute the core) latissimus dorsi (lats), middle and lower trapezius (traps), and biceps brachii (biceps) [1]. It’s especially important to understand the physiological aspects of each exercise to find the most effective ways to master it in the least amount of trips to your local gym. 

Image from [2].

Pull-up training begins with kneeling lat pulldowns. This variation of a lat pulldown, which is a common workout that targets your shoulder and back for an upper-body workout, activates muscles to a similar magnitude and pattern as pull-ups, more so than other exercises such as assisted pull-ups and seated lat pulldowns [3]. To properly perform a kneeling lat pulldown, you first kneel and use an overhand grip on a lat pulldown attachment. Afterward, set the weight until it is heavy enough to pull your knees above the ground by about an inch. Then, for the actual pulldown part, make sure that your back is aligned straight and pull your shoulder blades together to achieve maximum muscle activation. Make sure to do 3 sets of 5 reps!

Another great exercise is a negative pull-up, which essentially constitutes the downward half of the pull-up. Many studies have shown that this “negative” portion of the exercise (known as eccentric exercise) might be more effective at building muscle than performing the entire rep [4]. The negative pull-up is especially suited for beginners. Even though you might not have the strength for the upward part of the pull-up, many will have the strength to execute the downward motion with the right technique. To properly perform a negative pull-up, you first raise yourself to the top of the pull-up position using a stool or other high platform and simply do 5 sets of 1 rep [1].

With these two exercises, you will begin to see progress in your pull-up attempts. It might take a while, but we all have to start somewhere!

References

[1] AMM Fitness. https://www.ammfitness.co.uk/information-advice/pull-ups-benefits-muscles-worked (accessed Nov 15, 2021)

[2] Fitness Lane. https://fitnesslane.com/product/kneeling-lat-pulldown/ (accessed Nov 15, 2021)

[3] Hewit J.K.; Jaffe D.A.; Crowder T. A Comparison of Muscle Activation during the Pull-up and Three Alternative Pulling Exercises. J Phy Fit Treatment & Sports [Online] 2018, 5.4, 1-7. https://juniperpublishers.com/jpfmts/JPFMTS.MS.ID.555669.php (accessed Nov 15, 2021).

[4] Hedayatpour N.; Falla D. Physiological and Neural Adaptations to Eccentric Exercise: Mechanisms and Considerations for Training. BioMed Research International [Online], 2015, 2015. https://doi.org/10.1155/2015/193741 (accessed Nov 15, 2021)

[5] Muscle & Performance. https://www.muscleandperformance.com/training/killer-pull-up-workouts/ (accessed Nov 15, 2021)

Composting: Fad Trend, or Way to Give New Life to Food Waste?

We produce a lot of trash. This sheer amount of waste produced places enormous pressure on waste management systems. In response, composting aims to provide a way of decreasing food waste and has steadily grown in popularity over the past decade. Sometime over the last few semesters, you’ve probably seen the Moonshot composting bins accompanied by instructional posters by the trash cans in the serveries. The mission of Moonshot Compost Services is to divert excess food from landfills and return the nutrients back to the soil [1]. Rice students are welcomed to be a part of this mission by discarding their plates, food, and any other acceptable biodegradable items into a Moonshot composting bin.

Let’s zoom out from our campus and take a look at large-scale composting operations as a whole. What is the fate of the food waste once it’s out of our hands?

Once compost is collected and sent off for processing, there are a few commercially viable methods in practice to break it down into usable organic materials: windrow, aerated stack pile, and in-vessel composting [2]. In windrow composting, compost is piled in long rings and the organic material is rotated at regularly occurring intervals. Downsides of this method include the need for large amounts of land and constant supervision of the composting process. In aerated stack pile composting, wood chips are layered in with the compost to create spaces for airflow throughout the compost pile; pipes are often used to provide an upward stream of air from the base of the pile. Although this method is able to degrade compost fairly quickly, the machinery and equipment required to set up the system are quite expensive and labor-intensive. Finally, in-vessel composting shifts away from exposing compost to open air and opts to place compost into a temperature- and moisture-controlled environment within a container. This in-vessel composting may turnout compost quicker than the other two methods, but is fairly expensive [3].

If done in an efficient manner, these methods of composting food waste can provide a viable and continuous pipeline from food waste to nutrient-rich soil that can be used to grow crops. A key take away from all of this is that regardless of the method used for composting, there are some drawbacks to the composting process, whether it be high costs, large amounts of land use, or the production of foul odors (yikes!). Zooming back into our campus serveries, it’s important to recognize that although we don’t have control over what exactly happens to our compost, decreasing the amount of food waste by taking advantage of our Moonshot bins is an easy way to decrease Rice’s waste.

References

[1] Impact. Retrieved November 5, 2021, from http://www.moonshotcompost.com/impact/.

[2] Alexander, G. How commercial composting works. Retrieved November 5, 2021, from https://earth911.com/business-policy/how-commercial-composting-works/.

[3] Sustainable Management of Food: Types of Composting and Understanding the Process. Retrieved November 5, 2021, from http://www.epa.gov/sustainable-management-food/types-composting-and-understanding-proces s#aeratedstatic.

[4] Image: https://images.app.goo.gl/3oPXQsGWQVnNS1858

Changing Habits With Activity Dependent Neural Plasticity

Changing one’s habits and the most action-oriented approaches to doing so has remained an age-old question yielding a diverse array of answers. Perhaps, the idea that your brain is in a perpetual state of change is something you have encountered previously, through a television show, a book, or maybe even as you peruse the local newspaper. At first, notions pertaining to this scientific phenomenon, known as activity-dependent neural plasticity, may come across as slightly contradictory: all throughout our schooling years, we’ve been told that our brains are subject to the modular outputs of a dynamic biochemical environment prevailing within our brain’s cells after all. So how could it be that these ostensibly inanimate ions, voltage-gated channels, and synaptic clefts are operating independently of stimuli perception? 

Recent advancements within the realm of neuroscience have conferred mankind with a uniquely nuanced insight into the intricate mechanisms facilitating neural modulation. Analogous to how your plastic water bottle warps in conformity to direct sunlight, scientists have recently discovered that our brain is increasingly implicated by everything occurring in transcendence of our subconscious thought: every single observation, interaction, smell, sight… as it turns out, there is not much information that goes unnoticed by our minds [1]. Contemporary neuroimaging techniques have served to capture the extent of this dynamic rewiring that prevails within each of our brains; this redefines our collective approach to the interplay between the mind, brain, and body necessary to ensure the fruition of our consciousness [2]. 

What exactly does this information mean for us, as individual agents embedded within the crosshairs of highly developed sociocultural institutions around the world? Like many other things prominent within our day-to-day lives, neural plasticity can be reverse engineered to promote only the most positive feelings within people: namely, contentment, satisfaction, and ultimately, serve to provide such individuals with a way of altering their negative habits. For instance, the persistent practice of one’s desired habits under a number of different conditions has the potential to change the functional activity of neurons across the brain, housing over 100 billion neurons which strive to communicate across 100 trillion synaptic connections [3]. Contemporary somatic therapeutic interventions, predicated upon the functioning of neural plasticity mechanisms to incite positive development, can be revitalized by the maintenance of a persistently positive personal state with repeated practice and a defined goal.

So the next time your mother scolds you for habitually consuming your fingernails, or falls victim to the notion that it simply is not possible to develop a highly outcome-oriented habit, try to remember that you have immediate access to a dynamic community of 100 billion neurons communicating over 100 trillion gaps in space. Similar to your favorite hiking trail, the neuronal circuitry constituting the foundation of basic actions remains vulnerable to changes in one's habits, strengthening over time as the status quo is challenged with sheer willpower.

References

[1] Taylor, B. Breaking Bad Habits, With Neuroplasticity. EduGuide Developmental Biology - Lumina Foundation [Online] 2015. https://www.eduguide.org/content/2015/02/13/breaking-bad-habits-with-neuroplasticity/

[2] Foss, R. How to Change Your Behavior and The Science Behind Neuroplasticity. Kwik Learning for Academic Success [Online] 2018. https://kwiklearning.com/kwik-tips/how-to-change-your-behavior-the-science-behind-neuroplasticity/ 

[3] Ganguly, K.; Poo, M. Activity-Dependent Neural Plasticity from Bench to Bedside. Cell Neuron [Online] 2013, 86, 122-134.. https://doi.org/10.1016/j.neuron.2013.10.028 

[4] Bergland, C. How Do Neuroplasticity and Neurogenesis Rewire Your Brain? Psychology Today [Online] 2017. https://www.psychologytoday.com/us/blog/the-athletes-way/201702/how-do-neuroplasticity-and-neurogenesis-rewire-your-brain 

Attacking Cancer: A Golden Opportunity

You don’t have to be a historian to grasp the significant impact gold has made in the world. From a sought-out treasure to a method of currency, there’s no doubt that this element is one of the most influential metals in human history. Yet, a much less known aspect of gold is its incredible potential in biomedicine. This is especially true of gold nanoparticles in the context of cancer.

Cancer is a condition wherein cells proliferate and divide in an uncontrolled manner. [1] While cancer can often be treated, the side effects of those treatments can be severe and can include possibly hurting non-cancer cells and the immune system. Inducing hyperthermia, or causing a part of the body to heat up, has been shown to have an anticancer potential as it can lead to programmed cell death as well as make tumors more susceptible to radiotherapy. Yet, a central issue arises: unless the heat is localized, other parts of the body can be harmed. This is where gold nanoparticles come in. [2]

In the simplest terms, gold nanoparticles are small pieces of gold. Very small pieces of gold. As a result, gold nanoparticles have a lot of different properties compared to, say, a block of gold that we often think about when talking about the element. For instance, gold nanoparticles are not yellow: particles less than 100 nm are red while bigger particles are blue/purple. [3] These nanoparticles have amazing properties which allow them to act as a contrast in CT scans or assist with drug delivery. [4] Yet, one of the most fascinating applications of these gold nanoparticles is their use in photothermal therapy. Because the blood vessels near the tumor site are often leaky, gold nanoparticles that have been placed in a cancer patient's body will passively concentrate near a tumor. Once they have concentrated, they can be activated by near-infrared light, a special type of light which can easily pass through human tissues. The gold nanoparticles will absorb the light energy and convert it to heat energy near the tumor, essentially stimulating the cancer cells’ deaths. [2]

Has this technique been tested in humans? In fact, yes–a clinical trial done at Mt. Sinai hospital which used gold-silica nanoparticles to treat prostate cancer patients revealed no severe side effects from the treatment. After the gold nanoparticles had concentrated at the tumor site of the patients, they were irradiated by near-infrared light from optical fibers. These nanoparticles absorbed the light and heated the tumor site, essentially destroying it. [5]

The promise of such a localized treatment strategy is encouraging. Hopefully, further research can be done to explore this opportunity that is, indeed, worth its weight in gold.

References

[1] Gupta, N.; Malviya, R. Understanding and advancement in gold nanoparticle targeted photothermal therapy of cancer. Biochimica et Biophysica Acta (BBA) - Reviews on Cancer [Online] 2021. 1875, 188532. https://www.sciencedirect.com/science/article/pii/S0304419X21000305?via%3Dihub (accessed November 2021)

[2] Vines, J.B.; Yoon, J.-H.; Ryu, N.-E.; Lim, D.-J.; Park, H. Gold nanoparticles for photothermal cancer therapy. Front. Chem. [Online] 2019. 7, 167. https://www.frontiersin.org/articles/10.3389/fchem.2019.00167/full (accessed November 2021) 

[3] Sztandera, K.; Gorzkiewicz, M.; Klajnert-Maculewicz, B. Gold Nanoparticles in Cancer Treatment. Mol. Pharmaceutics [Online] 2019. 16, 1-23. https://pubs.acs.org/doi/10.1021/acs.molpharmaceut.8b00810 (accessed November 2021)

[4] Wang, S.; Lu, G. Noble and Precious Metals - Properties, Nanoscale Effects and Applications. In Applications of gold nanoparticles in cancer imaging and treatment; Intechopen: Online, 2017.

[5] Stephens, M. PhysicsWorld. https://physicsworld.com/a/gold-nanoshell-based-cancer-treatment-is-safe-for-the-clinic/ (accessed November 2021)

[6] Pxfuel. https://p1.pxfuel.com/preview/830/131/627/cancer-cells-cells-scan-electron-microscope-scan.jpg (accessed November 2021)

What the Oink? Pigs May Hold the Key to our Transplant Troubles

In 1954, John Murray of Harvard Medical School commenced a new era in modern medicine by performing the first successful kidney transplant in a human patient [1]. 67 years later, organ transplantation is a widely-utilized medical procedure, frequently used to combat organ failure and a variety of other diseases. The new hurdle in this field of transplantation surgery is the ever-growing list of patients in need of new organs with no way for the supply to ever meet the demand. There currently are over 100,000 patients on the US transplant waiting list, many of whom depend on the hope of organ transplantation as their last chance of survival [2]. To combat this mismatch between the supply and demand of transplantable organs, scientists have been looking to other organisms in hopes that cross-species transplantations could alleviate some of the issues that make the organ transplant list so intimidatingly long.

The concept of organ transplantation using donor organs from non-human organisms is not a completely novel idea. In the 1960’s, a surgeon at Tulane University, Keith Reemtsma, transplanted kidneys from chimpanzees to 13 human patients as a last resort treatment option (these procedures would likely not fly under today’s ethical guidelines). While one of Reemtsma’s patients had a short recovery term of around 8 months, all of these transplanted organs ultimately failed due to immune rejection by the human recipient [3]. The human immune system mounts a significant immune response to transplanted organs, triggered by specific sugars present on the external surfaces of transplanted organs and their cells. For instance, the alpha-gal sugar present on pig kidneys makes successful transplantation of organs from the native organism to humans impossible [4]. Genetic engineering technology has allowed scientists to remove sugars from potential donor organisms, facilitating the first successful transplant of a pig organ to a human in mid-October of this year. 

At NYU’s Langone Health, physicians transplanted a kidney from a pig genetically engineered to lack the alpha-gal sugar, and the kidney remained viable for 54 hours [5]. The patient had been considered brain dead for about a month before the procedure took place, and their organs were deemed unusable for transplantation into another patient. Upon consent of the family, physicians at NYU performed the xenotransplantation and observed healthy urine output for 54 hours after the procedure (54 hours was the length of time deemed ethical by a board of medical ethicists — the experiment was ended after that period of time) [4]. 

This procedure validates the assumptions that removing immune system-triggering sugars from the surface of transplant organs can prevent immediate rejection by the host. While this is just a small step in the direction of making xenotransplantation a universally accepted treatment option, it opens the possibilities for future clinical work and applications. Due to the manifold of ethical issues surrounding human clinical trials, progress in this area of research will inevitably be quite slow. However, slow progress is a small price to pay to avoid repeating the same mistakes as past xenotransplantation experiments. 

References

[1] A transplant makes history – Harvard Gazette https://news.harvard.edu/gazette/story/2011/09/a-transplant-makes-history/ (accessed 2021 -11 -29).

[2] Organ Donation Statistics | organdonor.gov https://www.organdonor.gov/learn/organ-donation-statistics (accessed 2021 -11 -29).

[3] Cooper, D. K. C. A Brief History of Cross-Species Organ Transplantation. Baylor University Medical Center Proceedings 2012, 25 (1), 49–57. https://doi.org/10.1080/08998280.2012.11928783.

[4] What the successful test of a pig-to-human kidney transplant means | Science News https://www.sciencenews.org/article/xenotransplantation-pig-human-kidney-transplant (accessed 2021 -11 -29).

[5] U.S. surgeons successfully test pig kidney transplant in human patient | Reutershttps://www.reuters.com/business/healthcare-pharmaceuticals/us-surgeons-successfully-test-pig-kidney-transplant-human-patient-2021-10-19/ (accessed 2021 -11 -29).