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tolerate a disease, don't fight it!

Submitted by mlabib on Wed, 09/25/2019 - 18:10

At the Salk Institute for Biological Studies in La Jolla, California, Janelle Ayres and her colleagues’ had many mice that got sick. Ayres and her colleagues had infected mice with Citrobacter rodentium, which in turn inflamed the colons of the mice. Half of the mice lived, and half died. These mice all had an identical lifestyle, they all ate the same and did the same activities during the day. The point of this experiment was to determine what causes genetically identical mice to respond differently to certain pathogens. She realized that the mice that died, did not have sufficient iron. Thus, she decided to treat the living mice (with pathogen C. rodentium) with iron supplements. This was a rather holistic approach, as she did not go in with full war to try to use antibiotics, and drugs that can later develop resistance in the mouse. This approach supplies to the internal system of the mouse, which boosts the immunity of the mouse, rather than targeting the pathogen with an antibiotic. 

Bio

Submitted by bpmccarthy on Wed, 09/25/2019 - 18:09

The diversity in the field of biology is part of why I am attracted to the subject. Biology encompasses many subdisciplines and can range from macro-scale ecology type studies, to more microscopic studies such as biological cellular mechanisms. Many biology students I've encountered are on the pre-med track, aiming to be doctors and sepcialists after their time at UMass. Other biology majors I've encountered are more interested in conserving the environment, or specializing in certain organisms such as mammals, fish, or birds. An undergraduate degree in biology can open many doors, and combining the degree with research experience in your desired subdiscipline can be very helpful in finding a job right out of school. When i joined the College of Natural Sciences, I was pretty sure I knew what I wanted to do with my biology major, but I also learned a lot about things I never considered I might learn about. My undergraduate experience in biology has been very educational and fulfilling, and has so much value. 

sonoran desert

Submitted by mlabib on Wed, 09/25/2019 - 17:20

 The Sonoran Desert's location is at latitude 25° to 33° N. Hot deserts contain sparse populations of plants, due to periods of high temperatures and low water availability. This high temperature results in high rates of evapotranspiration levels, which in turn results to very little water available for this biome.  The temperature is a lot higher than the average annual precipitation. This has a large influence on plant forms. Because it is so dry, stem succulents occur in the cacti of these desert plants. Plants with succulent stems can store water in their stems so they are not left dry during dry seasons. Cactuses are the main desert plants. Cactuses can absorb a large amount of water, which is beneficial as this desert has a higher annual precipitation than most hot deserts. Most the flowers located in this desert also depend on rainfall so they can flower, and for a hot desert, this has a high amount of annual precipitations, so vegetation numbers must be high

Allergies: Helminth Theory

Submitted by asalamon on Wed, 09/25/2019 - 11:16

As a species, humans have recently become vunerable to allergies.  Even if your parents are asked, they will say allergies were not as much of a concern as they were not.  One theory explaining the prevelence of allergies in humans, particularly those of first world countries involves helminth infections.  When an antigen enters the human body, the antigen bind to T cells which then stimulate B cells.  B cells differentiate to form antibodies like IGF which binds to other cells of the immune system and arm them against the antigen.  IGF is an important form of antibody because it is key to the fighting of helminth infections.  The armed cell can then react to antigens like cats and dust that do not pose of risk to the health of the individual.  In populations with high levels of helminth infections, the IGE levels are very high compared to populations lacking helminth infections and none of the individuals have allergies.  It is thought that the helminth infections keep the IGE "busy" so it does not have time to react to antigens that are not dangerous (those causign allergic reactions).

Plant pathology

Submitted by semans on Wed, 09/25/2019 - 09:53

Plant pathology differs greatly from animal pathology. First and foremost, animals have an adaptive immune system that allows them to generate defences as new infections arise, but plants lack this capacity. Plants have a fixed immune system that either confers them resistance to a pathogen or doesn’t. Plant pathogens come in three general classes, necrotrophs, biotrophs, and hemibiotrophs. Necrotrophs are organisms that simply kill plant tissue upon infection using cellulase and hemicellulase, they tend to be generalists that can infect many plants. For biotrophs to go through their reproductive cycle they require live plant tissue and thus tend to infect specific hosts. Biotrophs will cause slowed senescence and will hijack plant cell machinery to generate metabolites for themselves rather than the plant. Lastly, hemibiotrophs are a mix between necrotrophs and biotrophs. In the first stage of their life cycle hemibiotrophs will act like biotrophs, hijacking plant tissue for their own purposes. In the second stage of their life cycle they will act as necrotrophs and kill the plant. Pathogens utilize three main ways of egress into a plant. They can either directly penetrate the plant through the use of a pilus or penetration cap, enter through pre-existing openings such as stomata, or enter through wounds. Plants have a series of defencive strategies to resist and counter infection. The first line of defence is physical, plants have a waxy cuticle and cell walls that aim to prevent direct access to plant cells. The second line of defence is specific, and is known as resistance (R) gene immunity that follows a gene for gene model. Pathogens produce effectors that aim to mask their presence, and plants produce proteins that are able to detect effectors. If a plant can produce a detector that recognizes even a single effector in a pathogen then it can defend against it, otherwise the plant will be infected. The methods of defence include production of toxins that kill the pathogen, synthesis of papillae to reinforce the cell wall, and a hypersensitive response that involves rapid cell death around the area of infection.

Ant. disc. 2 Death pits and Bullfighting

Submitted by mpetracchi on Wed, 09/25/2019 - 00:19

I have chosen Spanish bullfighting as my public event and it shares many similarities and differences with the death pits of Ur. Both are spectacles set before a public audience to show might. They are both considered the heritage of their civilization, that is, they are a part of the culture. Also, they both happen to revolve around cruelty of some kind. It’s interesting how both events are separated by so much time, yet some form of cruelty remains present. Maybe our interest in violence could be understood better by studying ancient civilization? Although they share some similarities, there are plenty of differences as well. The royal graves were the result of human sacrifice, which does not happen in Spanish bullfighting (however sacrifice of some kind does). Also, Spanish bullfighting is a spectacle not meant to incite fear anymore. It’s a public event enjoyed by the masses, who willingly attend. This is opposed to the death pits as those were made to inspire terror in anyone who saw it.

    As I previously mentioned the death pits of Ur were made to terrorize the commoners. This way the elites in power could demonstrate their might and keep everyone in check. There was no overthrowing the government if they could kill all the people in the death pits. It's no wonder the elites enacted such an event as the motive was very strong. Keep themselves in power by squashing any sign of a rebellious hope. Now with bullfighting, the intentions are slightly different. The public event is not meant to insight terror, rather provide entertainment. And it is continued to be enacted because if a politician were to deny it, public backlash may remove them from power. Therefore politicians must also carry out this ritual in order to stay in power, however, the severity of the event is arguably lesser than Urs’.

 
 

AQ 9/24 Draft

Submitted by atquang on Tue, 09/24/2019 - 23:37

One topic of life science I’d like to explore is the human eye. Light has both wave and particle-like properties. When resistance (a resistor) is placed against the electrical current, the resistance heats up and glows, converting electrical energy into light energy. The light energy then radiates photons towards the human eye, where it is reflected onto a focal point. This energy then radiates down a signal pathway consisting of neurons. Simply put, the brain creates an image based on the pattern of lights we are receiving, allowing us to see. The most fortunate thing that I believe people take for granted is the ability to see. Eye disease symptoms include hazy vision, eye pain, light sensitivity, and seeing flashes of light at a young age. It is not uncommon to see adolescents wear glasses in today’s age. One research that has been pointing to this is the dangers of blue light reflecting off screens. Short-wave blue light with a wavelength between 415 nm and 455 nm is closely related to eye light damage. Visible blue light is already between 490 and 450nm. The human eye creates a picture that may last a second, but the mistreatment of our eyes will last for a lifetime because our bodies do not reproduce eye cells.

Organic Chemistry

Submitted by asalamon on Tue, 09/24/2019 - 23:08

During the lab, melting points of both the phthalic acid and unknown 1 were taken before and after recrystallization.  Before recrystallization, phthalic acid had a melting point of 200-203°C.  The range being greater than 2°C difference is indicative of impurities in the sample. After recrystallization, the melting point of phthalic acid was determined to be 207-208°C.  The increase in temperature as well as the narrowing range is consistent with purifying the solvent.  The presence of impurities in a compound will cause a melting point depression.  This depression will be lower than the actual range for the pure compound and at a higher range of values.  Both these trends are shown with the data.  The melting point of phthalic acid is known to be 207°C (National Center for Biotechnology Information).  Due to this information and the trends of melting points before and after recrystallization, the phthalic acid had been successfully purified during the recrystallization.  Before being purified, unknown 1 had a melting point of 105-110°C.  After recrystallization, the new melting point was 124-125°C.  Like the melting point changes seen in phthalic acid, the impure sample of unknown 1 had a wide melting point range, greater than 2°C, which is indicative of an impure compound.  The new melting range is also larger, showing the melting point depression which occurring when impurities are found with a compound.  Like with phthalic acid, the unknown 1 was successfully purified based on the melting point values.   

Methods Project

Submitted by asalamon on Tue, 09/24/2019 - 22:20
  1. While on campus at UMass Amherst, enter the Campus Center through the east entrance.
  2. Roughly 10 meters forward on the right is Harvest Market
  3. The perspective photograph of phytophagy was taken in landscape view with the "Harvest" sign framing the top of the photograph and the sides of the store outlining the left and right side borders
  4. Enter Harvest Market and proceed straight forward to the salad bar.  
  5. Remain on the south side of the salad bar
  6. Take another photograph focused on the left side of the salad bar with the three types of lettuce for selection in the frame
  7.  

Antibiotic Resistance

Submitted by rbudnick on Tue, 09/24/2019 - 21:32

Antibiotic resistant bacteria have become a terror for doctors, researchers, and patients in the last few decades. Overuse of antibiotics has led to mutations for resistance becoming commonplace in some bacteria species. This threatens our modern medical system, as well as the lives of all humans exposed to these bacterias. One possibly alternative is to simply work on developing a new antibiotic which bacteria are not yet immune to. As the new antibiotic is administered and (hopefully) kills off the bacteria, the process of lowering antibiotic use can begin. This combined process would hopefully eliminate the possibility of resistance occurring, at least at such a high rate and across multiple species of bacteria. Of course, this process is not perfect, and could result in new resistances being developed and individuals not getting the antibiotics they truly need. There is still room for genetic changes to happen spontaneously and result in resistance, but by killing off the resistant bacteria there is hope that acquired AR in bacteria can be lowered, or at least controlled.  

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