BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: research (Page 1 of 3)

Secure Passcodes : Not Just For Your Computer… But For Your Gut

What is the Human Gut Microbiome?

Human gut microbiomes are made up of all the bacteria present in your gut. The Bacteria in your gut outnumbers the cells by a ratio of 10 to 1. While the presence of that much bacteria sounds like a bad thing, it can be confirmed that “the gut microbiome is very important for human health—that much we certainly know”.  The nearly 100 billion Bacteria cells per gram are actually what helps the body digest food and remove the bacteria that is bad for your gut.

 

(Left) Bacteria on vs not on the intestines       (Right) Gut Microbiome Graphic

A Unique Passcode

As said above, the human gut microbiome is essential to digesting food but more importantly keeping our body healthy. The thought of controlling a person’s gut bacteria in order to keep them healthy and fight illness is fascinating to scientists. The key to using the microbiome to fight sickness is in the “passcode” that is essential to unlocking its potential. Each microbe, according to recent research, requires a unique passcode. The research done by scientists according to phys.org says that once there is a way to determine the “passcode” it will unlock a whole new world of probiotic treatment in the future.

Why Else is the Microbiome important

According to other research done within the past few years, it has been found that sleep can also be linked to the human gut and stomach. The quality of sleep a person gets can be linked to their “biological rhythms, immune function, and nutrient metabolism” however it is still unknown to what extent the microbiome is affecting human sleep.

Conclusion

While researchers still have many questions about the human gut microbiome and how it contributes to health, wellness, and overall human biology, once they have come to some more concrete conclusions the impacts of controlling the bacteria in the human gut would exponentially improve the health of many people. It may sound weird that your bacteria have a “passcode” with which to be controlled, but hey, conclusive findings of the microbiome could even help you get a better night’s sleep! And who doesn’t want that?

Can Microbes Create Healthier Food?

A specific human gut microbe is making processed foods healthier. 

Researchers at Washington University School of Medicine in St. Louis wanted to find the chemicals in processed foods that correlate to diabetes and heart disease. In their study, the scientists used a bacteria called Collinsella intestinal (bacteria that contains an enzyme to break down Fructoselysine), which breaks down fructoselysine into small, harmless parts. According to Ashley R. Wolf, a researcher in the lab, “Fructoselysine is common in processed food, including ultra-pasteurized milk, pasta, chocolate and cereals.” This chemical has been linked to the cause of many diseases of aging.

When Wolf and her team tested the effects of feeding fructoselysine to mice that had Collinsella intestinalis, they not only discovered an increase in the amount of microbes in the stomach, but also found that the mice’s gut microbes had a stronger ability to break down fructoselysine.

“The new tools and knowledge gained from this initial study could be used to develop healthier, more nutritious foods as well as design potential strategies to identify and harness certain types of gut bacteria shown to process potentially harmful chemicals into innocuous ones,” says Jeffrey I. Gordon, a researcher of the lab.

Picture of human gut microbes

(“Courtesy of Pacific Northwest National Laboratory”)

Another study by Harvard University and the University of San Francisco, discovered that raw food was healthier than cooked food. They found that “cooked food allows the host to soak up more calories in the small intestine, leaving less for hungry microbes further down the gut; on the other hand, many raw foods contain potent antimicrobial compounds that appear to directly damage certain microbes.”

Although more research still has to be done to determine the effectiveness of the microbe, these discoveries help lead people into a healthier lifestyle. 

Can your diet’s effect on gut bacteria play a role in reducing Alzheimer’s risk?

Could following a certain type of diet affect the gut microbiome in ways that decrease the risk of Alzheimer’s disease? According to researchers at Wake Forest School of Medicine, that is a possibility.

In a small study, researchers were able to identify several distinct gut microbiome signatures in study participants with mild cognitive impairment (MCI), but not in the other participants with normal cognition. Researchers found that these bacterial signatures correlated with higher levels of markers of Alzheimer’s disease in the cerebrospinal fluid of the participants with MCI. Additionally, through cross-group dietary intervention, the study also revealed that a modified Mediterranean-ketogenic diet resulted in changes in the gut microbiome and its metabolites that correlated with reduced levels of Alzheimer’s markers in the members of both study groups.

“The relationship of the gut microbiome and diet to neurodegenerative diseases has recently received considerable attention, and this study suggests that Alzheimer’s disease is associated with specific changes in gut bacteria and that a type of ketogenic Mediterranean diet can affect the microbiome in ways that could impact the development of dementia,” said Hariom Yadav, Ph.D., assistant professor of molecular medicine at Wake Forest School of Medicine.

The randomized, double-blind, single-site study involved 17 older adults, 11 diagnosed with MCI and six with normal cognition. These participants were randomly assigned to follow either the low-carbohydrate modified Mediterranean-ketogenic diet or a low-fat, higher carbohydrate diet for six weeks then, after a six week “washout” period, to switch to the other diet. Gut microbiome, fecal short chain fatty acids, and markers of Alzheimer’s in the cerebrospinal fluid were measured before and after each dieting period.

The limitations of the study included the subject’s group size, which also accountns for the lack of diversity in terms of gender, ethnicity, and age.

“Our findings provide important information that future interventional and clinical studies can be based on,” Yadav said. “Determining the specific role these gut microbiome signatures have in the progression of Alzheimer’s disease could lead to novel nutritional and therapeutic approaches that would be effective against the disease.”

Each human contains trillions of organisms that influence our metabolism, immune function, weight, and even cognitive health. It is so fascinating to examine the role of gut microbiomes in the progression of Alzheimer’s disease. I believe diets can be very controversial, and I find it interesting to see researchers in this study show how the Mediterranean-ketogenic diet may be effective against Alzheimer’s. However, I am so intrigued to see where these findings may take us with approaches that may be effective against Alzheimer’s, whether they be nutritional or therapeutic approaches.

Human Disruption: Main Cause of Climate Change

 

Live Science, in a recent article about climate change, claims that according to a report released by the Intergovernmental Panel on Climate Change, there are many significant impacts that have occurred on our precious planet. Marine life overheating as it grasps for oxygen in warming oceans, rising seas swallowing islands and coastal areas, storms growing and causing flooding, coral reefs dying, rare species going extinct, are just some of the events that have occurred due to climate change. These are now used as a wake up call, implying that there’s far worse to come if we do not control human-driven climate disruption. 

The Special Report on the Ocean and Cryosphere in a Changing Climate presents its latest evidence that climate change is already underway and we are “on thin ice and running out of time to act,” said Bruce Stein, chief scientist for the National Wildlife Federation (NWF).

One of the main causes of this climate change are fossil fuels. If the use of these fossil fuels isn’t reduced and if global warming continues, it could have a huge negative impact on both wildlife and humans. Researchers recently found more than 200 dead reindeer in Norway; they starved to death due to climate change, which disrupted their access to the plants they eat. After the precipitation froze, creating “tundra ice caps,” a thick layer of ice that prevented the reindeer from reaching vegetation in their usual winter grazing pastures. This forced them to dig pits in shoreline snow to find seaweed and kelp, which are less nutritious than the reindeer’s usual fare.

In addition, there are several other effects that human activity has had on the environment. According to the IPCC report, 50% of the coastal wetlands have been lost over the last 100 years due to the results of human pressures and extreme climate events. They predict that by 2100, seas could rise by more than three feet, which could result in the displacement of millions of people. They also predict that by 2050, marine heat waves will be 50 times more frequent and the uppermost ocean zones could lose more than 3% of their oxygen, eliminating populations of marine animals and harming fisheries. Glaciers could be reduced by as much as 36%, affecting about 4 million people who live in the Arctic and around 670 million people who inhabit mountainous regions. The widespread loss of ice and snow could lead to water shortages, affect food security, and cause intense droughts and wildfires. Evidence has also suggested that warming oceans have caused an increase in tropical hurricanes according to the report. 

The Earth’s fate lies in our hands.  Debra Roberts, co-chair of the IPCC, says that we can control global warming if we create advances to all aspects of our societies, such as energy, land and ecosystems, urban and infrastructure, and industry. Roberts also suggests we must as early and decisively to avoid permanent changes and risks, all in an effort to improve our lives and achieve sustainability around the world. It will require “unprecedented” political actions to eliminate all the impacts that human-made carbon has created on our oceans. The youth are our strongest supporters to prevent the most severe consequences to our planet. 

 

Does Exposure to Toxins In the Environment Affect One’s Offspring’s Immune System?

A study has recently surfaced stating that maternal exposure to industrial pollution may harm the immune system of one’s offspring and that this impairment is then passed from generation to generation, resulting in weak body defenses against viruses.

Paige Lawrence, Ph.D., with the University of Rochester Medical Center’s Department of Environmental Medicine, led the study and conducted research in mice, which have similar immune system functions as humans. Previously, studies have shown that exposure to toxins in the environment can have effects on the respiratory, reproductive, and nervous system function among generations; however, Lawrence’s research is the first study to declare that the immune system is also impacted.

“The old adage ‘you are what you eat’ is a touchstone for many aspects of human health,” said Lawrence. “But in terms of the body’s ability to fights off infections, this study suggests that, to a certain extent, you may also be what your great-grandmother ate.”

“When you are infected or receive a flu vaccine, the immune system ramps up production of specific kinds of white blood cells in response,” said Lawrence. “The larger the response, the larger the army of white blood cells, enhancing the ability of the body to successfully fight off an infection. Having a smaller size army — which we see across multiple generations of mice in this study — means that you’re at risk for not fighting the infection as effectively.”

In the study, researchers exposed pregnant mice to environmentally relevant levels of a chemical called dioxin, which is a common by-product of industrial production and wast incineration, and is also found in some consumer products. These chemicals eventually are consumed by humans as a result of them getting into the food system, mainly found in animal-based food products.

The scientists found the production and function of the mice’s white blood cells was impaired after being infected with the influenza A virus. Researchers observed the immune response in the offspring of the mice whose mothers were exposed to dioxin. Additionally, the immune response was also found in the following generations, as fas as the great-grandchildren (or great- grandmice). It was also found that this immune response was greater in female mice.  This discovery now allows researchers to have more information and evidence to be able to more accurately create a claim about this theory.

As a result of the study, researchers were able to state that the exposure to dioxin alters the transcription of genetic instructions. According to the researchers, the environmental exposure to pollutants does not trigger a genetic mutation. Instead, ones cellular machinery is changed and the immune response is passed down generation to generation. This discovery explains information that was originally unexplainable. It is obviously difficult to just avoid how much toxins you are exposed to in the environment, but it is definitely interesting to see the extent of the immune responses in subsequent generations. We can only hope that this new information, and further discoveries, help people adjust what they release into this world that results in these harmful toxins humans are exposed to, and their offsprings.

 

 

 

Boogers: The Real MVP

You know that yellow gooey stuff that you blow out of your nose during allergy season? That’s mucus and although it may look and feel disgusting, it is actually a vital part of our body. Recent studies have looked into the the variety of roles that mucus plays in protecting the body and introduced new focuses. Mucus is composed of water, lipids, and glycoproteins called mucins. There are many different types of mucins that give mucus its different properties. For example, the mucus in our eyes that keeps them from drying out is composed of different mucins than the mucus in our intestine. The gel-like mucus contains mucins called MUC5BC and MUC5A, which help to clear out our airways by lining our cells so that bacteria cannot penetrate them. However, infections can also cause a buildup of mucus, since the mucins are produced at a faster rate in order to fight the bacteria. We sneeze out all of that mucus when we are sick in order to clear out all of that excess mucus.

Remember those kids in the back of your kindergarten class who used to eat their own boogers? There are actually bacteria in our intestines that feed on the glycans on mucins as an energy source. Even this may seem detrimental to the mucus in our intestines, the bacteria actually secrete butyrate, which the gut cells in our intestines use to manufacture more mucins.

Mucins risk their lives in order to insure that our cells are protected from harmful viruses and bacteria. Recent research has shown that the glycans that are attached to mucins have the ability to stop the spread of pathogens within the body. Mucins often act as decoys when bacteria try to bind to cells. The bacteria bind to certain molecules on the surface of the cell, which includes glycans. Instead of binding to the cell, the bacteria bind to the glycans from the mucins and the mucin takes the bacteria into a pool of gastric acid along with itself. A true hero!

Since mucins are so essential to the fight against the harmful pathogens invading our body, scientists are researching the molecular make-up of mucins in order to one day create a synthetic mucin. These could be used to repair mucus linings that are ineffective in protecting our cells.

First Nanolaser That Can Function in Tissue With No Harm

Researchers in Northwestern and Columbia Universities, created a nanolaser that can be used in the near future for the imaging of living tissue. 

Being very thin, “1/1000th the thickness of a single human hair”, and made mostly of glass, which is biocompatible, the nanolaser is able to fit in the tissue with ease. 

Besides the specificity of the shape, the nanolaser can “effectively deliver visible laser light at penetration depths accessible to longer wavelengths,” said Northwestern’s Teri Odom, who co-led the research. The nanolaser has to not only be able to emit longer wavelengths in order to penetrate deeper into the tissues, but also be able to emit shorter wavelengths that are needed in the tissue.

Other scientists have created small-sized nanolasers before, but they all needed ultraviolet light to power them. “This is bad because the unconventional environments in which people want to use small lasers are highly susceptible to damage from UV light and the excess heat generated by inefficient operation,” says P. James Schuck, an associate professor of mechanical engineering at Columbia.

The researchers at Columbia and Northwestern were able to solve the issue using photon upconversion. This process creates a pattern of absorbing two or more photons that leads to a shorter wavelength and higher energy than the original. The researchers were able to generate visible photons from infrared photons. 

Pictured above is photon upconversion

With all these benefits, the nanolaser can be used potentially to create different types of laser therapy in order to help alleviate neurological disorders, such as Alzheimer’s and Parkinson’s. Furthermore, it can also help diagnose diseases. As discovered in University of Arkansas, the laser can be used to heat up tumor cells to be detected through ultrasound. 

 

Are Species We See Everyday Going Extinct Before Our Very Eyes?

A theory has recently surfaced declaring the possibility that there are around 700 species around the world that should be considered threatened species, many of whom who were possibly inaccurately declared non-threatened on the Red List of Threatened Species.

Luca Santini, an ecologist at Radboud University, was quite discouraged by this news and took it upon himself to create a more efficient and precise method when it comes to assessing the extinction risk of a particular animal. On January 17th, Conservation Biology did a segment on Santini’s new approach.

This new approach proved that as much as “20% of 600 species that were impossible to assess before by Red List experts, are likely under threat of extinction, such as the brown-banded rail and Williamson’s mouse-deer.”  In addition, it found that around 600 different species that had been officially declared non-threatened species, were actually likely to be extremely threatened. As Santini, himself, said “This indicates that urgent re-assessment is needed of the current statuses of animal species on the Red List.”

The (IUCN) Red List of Threatened Species is the “world’s most comprehensive information source on the global conservation status of animal, fungi, and plant species.” That being said, every few years, researchers evaluate and record the conservation status of different species, which then gets uploaded into the Red List’s database for the general public to have access to. According to Santini, however, “Often these data are of poor quality because they are outdated or inaccurate because certain species that live in very remote areas have not been properly studied. This might lead to species to be misclassified or not assessed at all.”

Santini’s method provides experts with additional independent information in attempt to help them better assess the species. It uses information gathered from land cover maps, showing how the distribution of different species has changed over time. This then allows said researcher to have more information to be able to more accurately classify species.

Santini describes his goal for this new method in saying “Our vision is that our new method will soon be automated so that data is re-updated every year with new land cover information. Thus, our method really can speed up the process and provide an early warning system by pointing specifically to species that should be re-assessed quickly.” We can only hope that this new method provides better and more accurate information in regards to what and who we will continue to share the planet with, and who we won’t.

 

Message Intercepted – Commence attack on bacteria!

Tevenphage – Photo credit to Wikimedia Commons

While experimenting, a group of scientists noticed that a A virus, VP882, was able to intercept and read the chemical messages between the bacteria to determine when was the best time to strike. Cholera bacteria communicate through molecular signals, a phenomenon known as quorum sensing, to check their population number.  The signal in question is called DPO.  VP 882, a subcategory of bacteria’s natural predator, the bacteriophage, waits for the bacteria to multiply and is able to check for the DPO.  Once there is enough bacteria, in the experiment’s case they observed cholera, the virus multiples and consumes the bacteria like an all-you-can-eat buffet. The scientists tested this by introducing DPO to a mixture of the virus and bacteria not producing DPO and found that that the bacteria was in fact being killed.

The great part about VP 882 is it’s shared characteristic with a plasmid, a ring of DNA that floats around the cell. This makes it easier to possibly genetically engineer the virus so that it will consume other types of bacteria. This entails it can be genetically altered to defeat other harmful bacterial infections, such as salmonella.

Ti plasmid – Photo credit to Wikimedia Commons

Current phage therapy is flawed because phages can only target a single type of bacteria, but infections can contain several types of different bacteria.  Patients then need a “cocktail” with a variety of phages, which is a difficult due to the amount of needed testing in order to get approved for usage.  With the engineering capability of using a single type of bacteria killer and the ability to turn it to kill bacteria, phage therapy might be able to advance leaps and bounds.

As humans’ storage of effective antibiotics depletes, time is ticking to find new ways to fight bacterial infections.  Are bacteriophages and bacteria-killing viruses like VP 882, the answers?

A NEW “Organ” Has Been Discovered!

What is it?

In March of last year, scientists discovered a new organ inside humans. It is called an Interstitium. Located all over the body from under the skin to lining the digestive track, these fluid filled spaces are believed to act as shock absorbers to protect tissues during daily functions.

These sacs do not appear on standard microscope slides because the process of treating tissue samples with chemicals drains away the fluid which explains why they have been missed for so long. They were discovered by using newer imaging techniques that did not require the use of chemicals.

The Interstitium could help cancer research as these findings explain why cancer tumors that invade this layer of tissue which are filled with lymph spread to the lymph nodes.

lymph and lymph nodes

Is it an organ?

In order for a body part to become an organ, there needs to be a general consensus in the research community. Thus it will take a little time in order to characterize it as an official organ. One case for calling it an organ is the fact that 1/3 of the body’s water called interstitial fluid is in this connective network of the interstitium. In addition, the interstitium helped cast a light on what the other 1/3 of the body’s water does.

Personally, I do believe it should be categorized as an organ as an organ is defined according to the Webster Dictionary as a part of an organism that is typically self-contained and has a specific vital function. The interstitium is self contained and while there is no definitive answer to what it does yet, it does seem to play a vital role in shock absorption and containment of lymph. As it becomes more clear what the interstitium specifically does.

I am also excited to see future research on it because it might lead to new medical advances especially in the field of cancer.

 

Survival of the Fittest or Laziest?

For hundreds of years biologists have essentially fully accepted Darwin’s theory of “Survival of the Fittest;” but, have they been wrong all this time? Scientists believe that there could be a link from high metabolic rates to extinction. Luke Strotz, scientist and researcher at the University of Kansas, studied the effect of metabolic intake, energy intake by an organism, in mollusks.

Strotz and his team decided to use mollusks as their objects of interest due to the sheer abundance of data that they could retrieve from the past 5 million years. Strotz observed that certain mollusk species with higher energy intakes are extinct; while, mollusks species that have considerably lower metabolic intakes are still in existence today. Thus, in the mollusk group, it was quite clear that the higher metabolic rate correlated with faster extinction. Although this study is quite primitive in nature, and thus should not be compared to humans, it is perplexing to see that a species in the mollusk group can continue to exist because of its “laziness” or low metabolic intake.

Although Strotz’s evidence is convincing, I personally do not believe that “Survival of the Laziest” should be taken seriously, as mollusks are extremely different from humans. Thus, it would be illogical to compare the correlation of this study to that of the lives of humans. So, unfortunately, it appears laziness is most likely not a trait that the human race should endorse.

What do you think? Can laziness really save the human race? Only time will tell.

 

The research from Luke Strotz is published in the journal: Proceedings of the Royal Society B.

 

Did You Know Plants Can Talk?

 

For thousands of years language has been a crucial part of cultures around the world, and a method unique to humanity of transmitting ideas, thoughts, emotions between us. Language has allowed us to work harmoniously together for our mutual improvement and survival. Recently, however, two researchers, Dr. Kim Valenta and her colleague Omar Nevo, have discovered that plants too, have developed their own unique and intricate method of conveying information to their pollinators; “the easier it is for fruit eaters to identify ripe fruits, the better the chance for both [, the plant and the fruit,] to survive.

The most vivid example of plant communication can be found in Madagascar’s Ranomafana National Park and Uganda’s Kiabale National Park where berry plants have evolved “to match each animal’s sensory capacities, [thus] signal[ing] dinner time in the jungle…” Dr. Valenta and Nevo analyzed the exact colors of each fruit with a spectrometer, and “with a model based on the visual capacities of the seed-dispersing animals, they also determined who was most likely to detect different fruit colors contrasting against an assortment of backgrounds.” The researchers concluded that “the colors of each fruit were optimized against their natural backdrops to meet the demands of the visual systems of their primary seed dispersers,” i.e. pollinators. Thus, red-green color-blind lemurs, in Madagascar were best able to detect the fruit with a blue yellow color scheme and monkeys and apes in Uganda, with tricolor vision like humans, were clearly able to distinguish red berries against a green backdrop.

Also recently discovered was that plants can communicate to their pollinators through scent. Dr. Nevo performed a scent-based study on the lemurs in Madagascar. His team collected various ripe and unripe fruits from all over the jungle of Ranomafana. “He suspected the leumur-eaten fruits would have a greater difference in odor after they ripened than the bird-eaten fruits.” To discover exactly how this scent-based communication worked, Nevo used the “semi-static headspace technique.” From this experiment it was confirmed that “fruits dispersed solely by lemurs produced more chemicals and a greater assortment of compounds upon ripening. It is now known that wild lemurs actually spend quite a lot of time smelling for the vivid difference in odor between ripe and unripe fruits in the jungle.

It is astonishing how plants have evolved over the years to be able to communicate with their pollinators for the betterment and expansion of their species. I would be interested to find out, what other organisms communicate (single cellular, multi-cellular, etc.) and what kind of information they find necessary to convey to others for their survival?

 

 

 

 

Why Are Some Kids Aggressive? A Biological Understanding

A research team at the University of Iowa has identified a brain wave (P3) that is associated with aggressive tendencies in toddlers.

 

What does this mean?
Researchers used a sample of 153 toddlers between the ages of 2.5 – 3.5, of whom had individual sessions in which they wore a net of head sensors to mark brain activity while hearing different pitches sounded throughout the room. The noise of the tones occurred while the toddlers watched silent cartoons.

Each pitch change during the toddlers’ session exemplified a change in the environment. This “testing” corresponds with most changes within a setting, and is particularly similar to a transitional phase in a social interaction. It is important to note that the brains of aggressive kids are usually unable to successfully detect a change in the tone of a person they are interacting with. For example, while one neutral kid may be playfully making fun of another, the aggressive kid might interpret that as bullying and will respond with hostility.

When evaluating the head sensors, researchers found that “toddlers who had smaller spikes in the P3 brain wave when confronted with a situational change were more aggressive than children registering larger P3 brain-wave peaks,” as cited in the Science Daily.

Why is this important?

This finding in research will allow for earlier interventions in stopping aggressive impulses in toddlers, which is usually a tendency that continues throughout their adolescence. When confronting aggressive behaviors at an older age, it is harder to treat and dispose of combative traits that are instilled within a child’s demeanor.

As someone who has worked with kids with special needs of ages 4-10, I have watched kids grow up and continuously get more aggressive as they age. Although it is hard to combat these tendencies at the age of 4, it is easier to help them better react to social interactions they do not understand at 4 years old rather than at 10 years old. Therefore, in helping parents recognize key behavioral issues with their children at the young age of 2, this brain wave scanning of P3 will allow said parents to find new ways to decrease the aggressive behaviors their child will exhibit.

However, I am unsure whether or not this will become a routine thing doctors check for in toddlers, or how much it will cost. Do you think it is necessary for parents to know this information? If you were a parent, would you want your child to go under this “testing?”

Single father birds taking care of their babies

 Researchers at University of Bath, studied six different populations of plovers located across Africa, Asia and Latin America. The three populations of plover birds had a balance in the sex ratio of males to females and shared parenting of their offspring. The scientists found that in populations when there were more males than females, or vice versa, the parenting roles shifted leaving the males to look after the chicks.

Professor Tamás Székely, Professor of Biodiversity at the Milner Centre for Evolution at the University of Bath said: “When there are more males in the population, the females have more opportunities to find partners and so they are more likely to leave the family and mate with multiple partners in the breeding season, leaving their male partner to look after the chicks.”

According to the researchers, it is harder for male plovers  to get another partner. Therefore, they are more likely to stay monogamous and be the primary parent and invest time in raising their offspring. Influencing mate availability, the adult sex ratio can change social behaviour with divorce, infidelity, and parental antagonism due to being more common in sex-biased populations.

The study, published in Nature Communications, took data collected over 10 years from six wild shorebird populations that were closely related but displayed different parental strategies.

Dr Luke Eberhart-Phillips said: “We found that the chicks had a 50:50 sex ratio at hatching in all these species, and that the skewed adult sex ratios were caused by a difference in survival of male and female juveniles, although it’s still unclear why this happens.

“Our study highlights the knock-on effects that differences in survival rates between the sexes can have on population dynamics and social behaviour.”

The researchers continue to investigate how sex ratio and population affects social behavior.

The Science Behind Decision Making!

I consider myself, like most people, to be extremely indecisive. I also do not do very well when I find myself in stressful last minute decision making scenarios. A study done proves that it has to do with science!! According to a study done at Johns Hopkins University, it has been concluded that last-minute decision making and changing your mind is a complicated neural process involving complex neural coordination and communication among multiple brain areas.

Photo Credit: Affen Ajlfe (www.modup.net/)

 

Using functional magnetic resonance imaging, or fMRI, (a technique that monitors brain activity in real time), the research group found that changing your mind about a decision requires ultrafast communication between specific zones of the prefrontal cortex and a region of your brain called the frontal eye field. The frontal eye field is involved in controlling eye movements and visual awareness. The study found that the longer a decision takes to make, the longer it is held in the brain, and therefore the harder it is to reverse. This means that we are less likely to change our minds about a decision we have thought long and hard about.

Kitty Xu, the leader of experiment says  “If we change our mind about pressing the gas pedal even a few milliseconds after the original “go” message has been sent to our muscles, we simply can’t stop.  If we change our minds within roughly 100 milliseconds of making a decision, we can successfully revise our plans. If we wait more than 200 milliseconds, however, we may be unable to make the desired change—”. This finding is used to explain why sometimes, with age, adults are more likely to fall. As we age, our neural communicators slow which contributes to a message not reaching our muscles, or elsewhere fast enough to change our behavior.

The study’s next goal was to identify the brain regions involved in canceling a decision entirely. Participants took part in a fMRI and were instructed to watch a screen and stare at a black dot when it appeared. After focusing on the black dot, a colored dot would appear. The addition of a new stimulus caused the participants to abandon the original directed plan. The researchers watched on the fMRI which parts of the brain lit up during the decision making step to disregard the directions and look at the new dot. They found the prefrontal cortex and the frontal eye fields were the most active brain regions.

Xu hopes that these insights on how difficult it is for the brain to quickly change original plans can eventually lead researchers to find a way to lead us, specifically seniors, to safer decision making!

Metagenomics will stare into your soul… and beyond?

If you ever feel lonely, take solace in the fact that at any given time there are thousands of bacteria cells living in your gut, (inside your skin!).

As it turns out, there’s a whole lot of ‘not you‘, living in you.

Admittedly, they don’t make the best company as they tend to be on the quieter side.

They make up for it by being fantastic listeners.

Improving Human Intestinal Health

https://www.flickr.com/photos/pnnl/8146322408

Courtesy of Pacific Northwest National Laboratory.

They also serve as an essential part of our bodily systems, referred to by Valeria D’argenio in her essay The role of the gut microbiome in the healthy adult statusas “our forgotten organ”.

One great measure of how important something is is how wrong things go when the original thing isn’t doing it’s thing properly. Put eloquently by D’argenio “Quantitative and qualitative alterations in the composition of the gut microbiome could lead to pathological dysbiosis, and have been related to an increasing number of intestinal and extra-intestinal diseases”. The Human Gut micro biome is important to maintaining good health. Interestingly though (and somewhat alarmingly), the human gut micro biome has historically been fairly hard to study. as D’argenio puts it “microbial studies were based on the direct cultivation and isolation of microbes” and then later states that “it is estimated that up to 99% of microbes are currently uncultivable”. These facts make it clear that with old methods, the human gut micro biome has been extremely hard to study effectively. Which is crazy because the human gut micro biome is so important. Metagenomics are changing the game.

Recently new strategies  known as Metagenomics have been discovered that avoid the inefficient and ineffective cultivation step. Using the “Shotgun Sequencing” strategy, scientists have become able to sequence the DNA directly and have gained the ability to sequence entire microbial communities. This new method represents a significant step in understanding the human but microbiome but it is not perfect. D’argenio references limitations to current DNA sequence databases and difficulty in deciphering DNA function as obstacles that have yet to be totally overcome.

16s rRNA Sequencing is another form of metagenomics helping to illuminate the mysteries of the human gut micro biome. All bacteria contain the 16s rRNA. The 16s rRNA Sequencing gene takes advantage of this fact by identifying this gene in a large sequence and gaining a clearer view of which bacteria species are present in certain environments. This strategy is cost effective and can be performed rapidly but offers no insight as to bacterial function.

Metatranscriptomics succeeds where 16s rRNA Sequencing fails. In the words of D’argenio “Metatranscriptomics serves to analyze the entire transcriptome of an environmental site to obtain a comprehensive view of gene expression profiles and functional data”. Put simply metatranscriptomics, a form of metagenomics, is able to attain data on gene expression, not just sequencing. This is a major step in the analysis of the human gut microbiome as with this advancement we move closer to finding out exactly which aspects of the micro biome lead to which effects on the human body.

I’m personally excited about advancements in this field, because it seems like the human gut micro biome is important to our health and well being. The more we know about it the more we’ll be able to treat our bodies healthily. Which would be great!

Gut Microbes and the Brain

Neuroscientists are studying the idea that intestinal microbiota might influence brain development and behavior.

Neuroscientist Knickmeyer is looking to study 30 newborns and how they have grown into inquisitive, curious one-year olds through a series of behavioral and temperament tests. She is eager to see their faecal microbiota, bacteria, viruses and other microbes that live in their guts.

Studies of animals raised in sterile, germ-free conditions showed that these microbes in the gut influence behavior and can alter brain neurochemistry and physiology. Some research has drawn links with gut bacteria and their interactions with the brain.

Escherichia coli, a species of bacteria present in the human gut https://en.wikipedia.org/wiki/Gut_flora#/media/File:EscherichiaColi_NIAID.jpg

Gut Reactions

Prior to recent research, microbes and the brain have rarely been known to interact, with the exception of when pathogens penetrate the blood brain barrier. When they do, there can be intense effects. For example, the virus causing rabies elicits aggression, agitation and a fear of water. The idea that gut microbes could influence neurobiology was not ever thought of, but this is changing.

One research study showed that IBS lead to issues such as depression and anxiety. This lead scientists to wonder if psychiatric symptoms are driven by inflammation or a whacky microbiome caused by infection.

One 2011 study showed that germ-free mice were less-anxious than mice with indigenous microbes. These studies also showed that many of these behaviors are formed during a critical period during which microbes have their strongest effects. Another problem is that “germ-free” is an unnatural situation. However, it allows for researchers to learn which microbial functions are important for development of organs or cell types.

Chemical Exploration

Recent studies have found that gut microbes directly alter neurotransmitter levels, enabling their communication with neurons.

Scientists are also studying whether or not altered serotonin levels in the gut trigger a cascade of molecular events, therefore affecting brain activity.

In 2015 research showed that myelination can also be influenced by gut microbes, at least in a specific part of the brain. Germ-free mice are protected from some conditions, for example multiple sclerosis, because it is characterized by demyelination of nerve fibers. These scientists wish to use these studies to help humans who suffer from MS.

A Move to Therapy

Tracy Bale, a neuroscientist, sought to study how microbes of pregnant mothers affect their offspring. Maria Dominguez-Bello, microbiologist, wants to see if babies born through Caesarean sections end up with microbiota similar to babies born vaginally if they are swabbed on the mouth and skin with gauze taken from their mothers’ vaginas.

For Knickmeyer, the amygdala and prefrontal cortex are the brain areas that interest her the most in her studies with the newborn infants. This is because both of these areas have been affected by microbiota manipulations in rodent models. Something she is worried might affect the study is the confounding factors such as diet, home lives and environmental exposure.

Source: http://www.nature.com/news/the-tantalizing-links-between-gut-microbes-and-the-brain-1.18557

For more information:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4228144/

https://www.sciencenews.org/article/microbes-can-play-games-mind

http://www.huffingtonpost.com/healthline-/gut-bacteria-and-the-brai_b_11898980.html

The Human Gut Microbiome and Autism Spectrum Disorders

Researchers of the human gut microbiome have made connections to the autism spectrum disorder.  A gut microbiome involves the digestive tract microbes.  To learn more general information click here.  Studies tested DNA of children with gastrointestinal complaints.  Researches compared children with Autism Spectrum Disorder, and mainstream children.  It was found that children with Autism Spectrum Disorder had too many Clostridium or Desulfovibrio clusters.  To learn more about these gene clusters click here. Developing fever, receiving oral antibiotics, or ingesting probiotics are all likely to alter the gut microflora.  When children with Autism Spectrum Disorder do the above, they have exhibited improvement in their gastrointestinal pains; however, there hasn’t been scientific research, as it has only been found anecdotally. Research has been limited due to the difficult culture-dependent techniques; however, metagenomic technology could be used to discover and reduce the effects of the gut microbiome as a part in Autism Spectrum Disorder.

A longitudinal study completed in May 2016 shows more progress that scientists have made in discovering different aspects of autism in relation to the microbiome.  For two weeks, stool samples were collected from patients with autism and their siblings without autism in order to be compared. Sarcina ventriculi, Barnesiella intestihominis, and Clostridium bartlettii are organisms that are related to autism. They were found in the stool samples of children with autism, but not their siblings. Gastrointestinal symptoms were reported on days 6-8 of the study for children with Autism Spectrum Disorder, where Haemophilus parainfluenzae was detected at the onset. These patients also exhibited behavioral challenges during these days.

Though scientists have not found a diagnosis for Autism Spectrum Disorder yet, it is clear that the gut microbiome plays a role in the development. Further research that is not merely based off of a handful of patients needs to be completed to learn more.

Photo of Gut Flora

Number of strokes increased in children!

Sean Maloney stroke brainscan

Intel Free Press Image Link

Statistics 

According to new studies, strokes have been affecting younger generations more than ever. The average age for people having a first stroke has dropped from  71.1 in 2000 to 69.3 in 2012.What’s interesting is that in general, the number of strokes in the U.S. has actually gone down over the last few decades, according to Chengwei Li, an epidemiologist at the University of Michigan School of Public Health. However, Li’s study, shows that the rate of strokes in people under the age of 65 have not gone down, and that the rate of strokes in people under the age of 55 has actually increased.

Treatment

According to a study on WebMD, it is in some ways easier to treat the younger patients affected. People who get to the hospital within 4 and a half hours of their episode, or attack, can receive a drug that breaks up the clot in the brain and restores the blood flow. However, studies have shown that this treatment is more likely to benefit younger patients opposed to elder patients. Although this may be the case, young adults and females in particular, are often not eligible for the treatment because they ignore early symptoms or wait until the symptoms get severe, before they seek help.

As stated in an article from Live Science  and a journal from NCBI, the increase in stroke incidents at younger ages has great significance because strokes in younger patients carry out for a greater lifetime burden of disability.

While the total number of strokes in the U.S. has decreased, the number and severity of strokes in younger generations has increased. As a result, researchers, doctors, and medical staff continue to work together in order to seek ways to treat the newer generation of stroke patients.

CRISPR/Cas9 Provides Promising Treatment for Duchenne Muscular Dystrophy

There are nine kinds of muscular dystrophy and of these, Duchenne MD is the most common severe form of childhood MD. It affects about 1 in 5000 newborn males, only in very rare cases has it affected females. DMD is a genetic disorder that causes progressive muscle degeneration and weakness. Patients usually die by age 30 to 40.

DMD is caused by the absence of a protein, dystrophin, that helps keep muscle cells intact. In 1986 it was discovered that there was a gene on the X chromosome that, when mutated, lead to DMD. Later, researchers discovered that the protein associated with this gene was dystrophin. From this information, we can tell that this disorder is sex-linked, which explains why women are mainly carriers.

No one has found an absolute cure for this genetic disorder until now. Even in recent years, people have discovered treatments that will make patients’ lives more bearable, but never reverse the disorder. As a result of these advances, mostly in cardiac and respiratory care, patients are able to live past teen year and as long as in to their fifties, though this is rare. Although there are still drugs being tested like Vamorolone (a “dissociative steroid,” is an anti-inflammatory compound), more treatments on the molecular level are now being considered. However, thanks to recent discoveries and research with the new genetic technology, CRISPR/ Cas9, scientists may have found a treatment for DMD.

This new approach to gene correction by genome editing has shown promise in studies recently. This particular correction can be achieved in a couple ways: one is by skipping exon 51 of the DMD gene using eterplirsen (a morpholino-based oligonucleotide). Studies over four years show prolonged movement abilities, and a change in the rate of decline compared to controls. The newest approach to gene correction using CRISPR/Cas9, which the article I’m writing about focuses on, was performed in this study as next described: the CRISPR/Cas9 system targets the point mutation in exon 23 of the mdx mouse that creates a premature stop codon and serves as a representative model of DMD. Multiple studies in three separate laboratories have provided a path and laid the groundwork for clinical translation addressing many of the critical questions that have been raised regarding this system. The labs also discovered by further demonstrations, that this is a feasible treatment for humans. Functional recovery was demonstrated in the mice, including grip strength, and improved force generation- all of which are very important and hopeful discoveries. It is estimated from these studies that this new method will pass clinical trials and go on to benefit as many as 80% of DMD sufferers. Even greater success rates are expected if this is performed in young and newborn DMD patients.

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