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Saving Soil: Case studies from the Great Plains

soybean field

They say you don’t know what you have until it’s gone, and that may very well be the case of Great Plains farmers and ranchers who are experiencing significant losses of soil due to erosion. A recently published study uses numerous case studies from the Great Plains states to highlight the importance of soil health to ensure soil security. Soil security recognizes the role soil has in meeting today’s global challenges of food security, water security, and climate change. Soil health influences the goods and services we receive from the soil, so it is necessary that we understand how soil is being both compromised and sustained. By making growers and consumers aware of the externalities of degraded soil health, we can hope to better the agricultural system. 

Land used for cultivation has increased over the last several years in the area of interest, drastically changing the landscape. Clearing land for crop use by conventional means, entails the removal of grasslands and perennial crop cover such as grasses and trees. In doing so, the soil becomes loose as it is no longer held together by roots and the topsoil becomes exposed. This allows for erosion by wind or water to occur. Wind can carry the soil into the air, creating dust storms capable of blocking sunlight. Water that runs off of the land can create gullies and carry sediment to nearby streams, affecting water quality and life within the streams. A gully formed 25 m wide by 95 m long and almost 10 m deep at a ranch in Texas.

The ranch owner notes,

“We’re still fighting erosion up here on all our land, is a constant battle, and we’re consistently losing creek bank after storms due to the severity of runoff upland of us…most creeks here hadn’t moved 5 feet [≈1.5 m] in decades, but now they’re moving 50–60 ft per year [≈17 m].”

The need for sustainable agricultural practices and improved land use planning with incentives for farmers to adopt soil or water conservation practices, is necessary. Conservation agriculture practices include no tillage or reduced soil disturbance, diversifying crop rotations, maintaining high levels of crop residue between plantings (corn stalks and stems left on the field between growing seasons), incorporating cover crops into crop rotations and integrating livestock into the cropping system. Soil is essential for nutrient cycling, biodiversity, and water regulation- not to mention, providing our world with food. Traditional farming practices cannot feed the world in a way that is both good for humans and the environment.

 

 

 

Source:

Benjamin L. Turner, Jay Fuhrer, Melissa Wuellner, Hector M. Menendez, Barry H. Dunn, Roger Gates. 2018. Scientific case studies in land-use driven soil erosion in the central United States: Why soil potential and risk concepts should be included in the principles of soil health. International Soil and Water Conservation Research. DOI.

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Hormones Do It Again

T-cells

Researchers at the UPCM Sorbonne University in France have linked Autoimmune Regulator (AIRE) proteins to the high predisposition of women to autoimmune diseases (AD). Results from numerous studies correlated mutations in AIRE to the occurrence of ADs. Further research was conducted that showed a negative effect of female hormones on the functioning of AIRE.

ADs are results of abnormal immune responses caused by T cells (immune cells in the blood) that recognize body cells as foreign and attack them. AIRE are proteins present in cells of the inner lining of the thymus. They recognize such T cells and eliminate them through apoptosis (cell death) in a natural process called central immune tolerance. To back this hypothesis, research conducted on an autoimmune thyroid mouse model showed an increase in the presence of autoantibodies in the blood upon blocking AIRE expression in the thymus.

T-cells

The relationship between autoantibodies and female sex hormones is most prominent through the high incidence of ADs in females after puberty, a time of significant hormonal differences between males and females.

A study showed that the female sex hormones estrogen and progesterone caused a decrease in the expression of AIRE whereas the hormone DHT (formed from testosterone) showed an increase in expression. Estrogen has been found to contribute to this by causing hypermethylation of the AIRE gene. In this process, methyl groups are added to DNA molecules, hence changing their function without causing significant change in the structure. This is but one method by which female sex hormones lead to ADs. However, there is much more to be learned by exploring the multitude of pathways involved in the relationship between sex hormones, AIRE and ADs.

As an example, in certain body cells, AIRE has been shown to activate genes that are responsible for insulin tolerance by binding to them. Low AIRE expression has been associated with type I diabetes. Besides AIRE, there are other proteins being investigated to check for possible correlations between sex hormones and AD.

PRDM1 (PR domain zinc finger protein 1) is a protein in our body that helps prevent ADs through the deletion of defective T cells in the thymus. Research studies conducted on mice have shown gender dependence on the workings of PRDM1. However, there is no direct evidence of a connection between PRDM1 and autoimmune diseases in humans. There is much more to be explored in regard to these new results.

The reasons behind the gender based difference in AD must surely not be limited to a few proteins or sex hormones. And just how much do our hormones come into play in the determination of our susceptibility to ADs? What factors contribute to strengthen or alleviate this vulnerability? Many such questions can be raised and the answer to them all would be to dig deeper into the mysteries hidden inside of us.

Reference:

Berrih-Aknin, S., Le Panse, R., and Dragin, N.2018. AIRE: a missing link to explain female susceptibility to autoimmune diseases. Annals of the New York Academy of Sciences 1412: 21-32.

Link to article

NASA’s Marshall Space Flight Center

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Cooling powers of reflection

Image of city and water.

Researchers found a way to reduce the effects of greenhouse gas through regional land radiative management (LRMreg). As an alternative approach in climate engineering and climate adaption, this method alters the radiative properties of agricultural land and high population areas to change the average temperature, extreme temperature, and precipitation within the region. For this study, the researchers focused on climate and weather changes in North America, Europe, and Asia.

The use of LRMreg is seen as a better method than using the global solar radiation management (SRMglob) because it does not use sulfate aerosol injection (SAI). SAI is met with contention and controversy because it can lead to the depletion of the ozone layer and contribute to the increase of carbon dioxide (CO2) leading to ocean acidification. Furthermore, this process would decrease monsoon precipitation, and prompt higher temperature at the regional level. However, this approach is for scientists that want to reduce global mean temperature, instead of the extreme regional temperatures. Furthermore, there is concern that this technology would encourage higher CO2 levels rather than adapting ways to mitigate or eliminate them.

Even though the researchers portray LRMreg as the better option, there are still risks associated with this method. For instance, this method could increase the use of herbicide and other chemicals to control crop infestations. Secondly, there is a high chance of second crops freezing which can alter the plant management. Similar to SRMglob, LRMreg can increase CO2 concentration leading to ocean acidification.  Despite this, LRMreg presents as an ideal approach because it counteracts the effects of climate change at the regional and local level in densely populated and agricultural regions. Results from their study indicate that LRMreg reduces the effects of extreme hot and dry temperature that would impact human health and crop production. In agricultural production, this approach increases water use efficiency for dry land and crops, and enhances drying techniques during the intercropping period. In urban space, white roofs or reflective paving could reduce the use of air conditioning, which would provide energy savings.

Seneviratne and coauthors, argue that LRMreg is worth the risks because it provides efficiencies to land and urban management. Moreover, the results in their study indicated that the LRMreg could reduce hot extreme temperatures in densely populated and crop-producing regions by 2-3 C°. This could be helpful because cities and agriculture are crucial to the global economy.

Citation:

Seneviratene, S.I., Phipps, S.J., Pitman, A.J., Hirsch, A.L., Davin, E.L., Donat, M.D., Hirschi M., Lenton, A., Wilhelm, M., Kravitz, B. 2018. Land radiative management as a contributor to regional –scale climate adaption and mitigation. Nature Geoscience 11:88-96.

 

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Reading Bones: How Ocean Acidification Affects Coral Reef Health

coral reef
Credit: flickr

Climate change impacts everything around us, from weather to the land, air, and water itself. Due to the rise of carbon dioxide in the atmosphere, ocean acidification levels are rising, which in turn threatens the health and wellbeing of coral reef ecosystems. A study was recently published on how ocean acidification directly affects the health of coral reefs, which are essential for protecting coastlines, providing a habitat for aquatic life, and assisting in the chemical conversions of carbon and nitrogen fixing that are essential for life on earth.

A research team at Woods Hole Oceanographic Institute in Massachusetts published a study on January 28, 2018 that identifies the specific way various coral species is affected by ocean acidification and display the effects of future environment conditions on reefs.  They determined that ocean acidification hinders growth of coral skeleton in the thickening process, which in turn reduces the skeleton’s density and leaves it more vulnerable to breakage.

While it had been theorized that coral calcification rates decline as ocean acidification increases, these predictions hadn’t been consistent in a laboratory setting or when studying corals inhabiting reefs with low pH levels. The WHOI was able to study coral skeletons and determine how pH levels and carbonate ion concentrations effect coral reefs and create a mathematical model that predicts how skeletal density will be effected by climate change and ocean acidification in the 21st century. This research plays an important role in examining the impact we have on the world around us and how human actions will effect ecosystem’s future health.

The team took core skeletal samples of Porites, a common coral, from four locations all over the world where sea water conditions vary in pH level and carbonate ion concentrations. Using a 3-D computerized tomography scanner to image the cores, the researchers found annual growth bands on the skeletons (similar to the growth rings of trees) that imply the skeletons of coral in more acidic environments were significantly thinner.

After developing a numerical model that modeled the growth mechanism of coral skeletons and comparing it to projected changes in ocean acidity caused by climate change, the researchers concluded that declines in coral skeletal density will occur in coral reefs all over the world. The Indo-Pacific region in particular will be greatly impacted; it has been predicted that there will be up to 20% in reductions in skeletal density by 2100. This in turn will affect the overall health of coral and the ecosystems coral provides for a vast array of marine life.

Ocean acidification does not happen in isolation and other environmental effects caused by climate change will inevitably also affect the health of these important ecosystems.

Source:

Mollica, N.R., Guo, W., Cohen, A.L., Huang, K.F., Foster, G.L., Donald, H.K., and Solow, A.R. 2018. Ocean acidification affects coral growth by reducing skeletal density. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas. 1712806115 

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Another Rainforest Biting the Dust?

 

river
Kwa falls in Cross River state Rainforest, Nigeria Taken by Shiraz Chakera https://www.flickr.com/photos/shirazc/130088242/in/photolist-cuJGJ

Deforestation though necessary for industrialization, has a long-standing history of being severely detrimental to the environment. Deforestation, especially to that of tropical rainforest, plays a huge part in habitat loss, loss of biodiversity, and is a lead factor in global climate change. Sadly, rainforests in Wilberforce Island in Bayelsa State, Nigeria are no different.

The department of Geography and Environmental Management at the Niger Delta University located in Wilberforce island, conducted a survey around the reasoning behind the deforestation of the local area tropical rainforest. Using 125 questionnaires given out to the local inhabitants and satellite photos taken in 2002 and 2015 respectively, they came to several conclusions. They found that, through their questionnaire, that most of the destruction of the forest came in part to logging followed closely behind by farming. This was then backed up by the satellite images that revealed an increase of land usage due to agriculture from 10.71% in 2002 to 30.57% in 2015. Within just 13 years, land use from farming increased by 185.35%, mainly impart to the population growth that came from the construction of the Niger Delta University in 2000. Furthermore, this new designated farm land had to come from somewhere, and you probably guessed it by now, it came from land previously held by the rainforest.

No other research has been done into the deforestation of the forests on Wilberforce Island, and so it’s good that this study shed some light on what’s happening. Between 2002 and 2015 forest cover dropped by 30.02%, destroying millions of species habitats along with it. That rate is unheard of and much more outside of this study needs to be done to stop it.

My final personal note is I find it quite ironic and irritating that this survey was conducted by the Niger Delta University, the same establishment that was the underlying factor for the increased deforestation rates of the island in the first place. I hope they take their study to the next step and work to prevent the further logging and destruction of the forests.

For more information on the study see the full text at www.ajol.info or www.bioline.rg.br/ja.

Source

Bariweni, P.A., and Andrew, C.E., October 2017. Land use/Land Cover Changes and Causes of Deforestation in the Wilberforce Island Beyelsa State, Nigeria. J. Appl. Sci. Environ. Manage. 21

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Researchers Stimulate the Amygdala to Stimulate Memory

Think back to your first kiss, your soccer championship game, or hearing about the death of a loved one. Do you remember what you were wearing? Do you remember who was there with you and specifically where you were? You might even remember the exact words from what people said around you. These crystal-clear memories are called flashbulb memories, and are processed by the amygdala, a region of the brain associated with regulating emotions and emotional memory.

A new study now reveals that directly stimulating the amygdala can result in improved memory without a combined emotional experience. Participants in a study at Emory University Hospital received brief, low-amplitude electrical stimulation to the amygdala and demonstrated improved declarative memory the next day without any subjective emotional feelings or involuntary emotional responses, such as increased heart rate or faster breathing.

The study, published online in December 2017 in the journal PNAS, took place in conjunction with the Emory University School of Medicine. Epilepsy patients with electrodes already implanted in their brains were recruited to participate, and fourteen individuals took part in the study. Participants were shown numerous neutral images (i.e. a picture of a basketball or a key), and then either given a short stimulation of the amygdala or no stimulation. Immediately afterwards and again the following day, participants were shown more neutral images in a recognition-memory test. The patients who received the stimulation exhibited greater memory retention of images after one day, compared to the control group.

While the participants in the study were simultaneously receiving treatment for epilepsy, they showed substantial memory enhancement due to the amygdala stimulation. One patient, who suffered from brain damage and memory impairment and rarely recognized researchers and physicians, displayed the most memory improvement. Other patients who experienced seizures in between the initial stimulation and the test the following day showed improved memory, presenting evidence that the amygdala stores memories in spite of other neurologically debilitating disorders. None of the patients reported being able to feel the stimulation.

brain
Illustration of the amygdala (blue), hippocampus (orange), and perirhinal cortex (pink). Credit: Cory Inman, Emory University.

Researchers speculate that the amygdala plays a role in delegating non-emotional declarative memory to other structures, namely the hippocampus and the perirhinal cortex. Specific stimulation to the hippocampus and perirhinal cortex to improve memory has been erratic in prior studies, and the amygdala might be the missing link. According to co-author Joseph Manns, “the long-term goal of this research program is to understand how modulation of the hippocampus by the amygdala can at times lead to memory enhancement and at times lead to memory dysfunction, such as that observed in post-traumatic stress disorder (PTSD).”

Regarding the targeted amygdala stimulation, co-author Cory Inman explained, “One day, this could be incorporated into a device aimed at helping patients with severe memory impairments, like those with traumatic brain injuries or mild cognitive impairment associated with various neurodegenerative diseases.” Small deep-brain stimulation implants are already being used to treat Parkinson’s disease. This study may be utilized in future research to develop similar clinical treatments for patients with memory disorders, so that their non-emotional memories like what they ate for last night’s dinner or what they read in a good book, can be remembered the next day.

Amygdala and hippocampus highlighted in brain
Limbic system imbedded in the brain. Amygdala is shown in red and the hippocampus is shown in purple. Credit: Paul Wissmann, Santa Monica College.

Sources:

Inman, C.S., Manns, J.R., Bijanki, K.R., Bass, D.I., Hamann, S., Drane, D.L., Fasano, R.E., Kovach, C.K., Gross, R.E., and Willie, J.T. 2018. Direct electrical stimulation of the amygdala enhances declarative memory in humans. PNAS 115: 98-103.

Emory Health Sciences. 2017. Direct amygdala stimulation can enhance human memory for a day: Preliminary study of time-specific electrical stimulation. ScienceDaily. Retrieved January 31, 2018 from www.sciencedaily.com/releases/2017/12/171218151808.htm.

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Space Headaches?! : NASA Looks at How Cephalad Fluid Shifts Affect Retinal Blood Vessels

On October 25th, 2017 (published by NASA in 2018), researchers at NASA’s Ames Research Center in Mountain View California explored the differences in pre and post vascular pressure in International Space Station Crew members and Head Down Tilted (HDT) Bed Rest patients. This study found that venous responses to these long-duration phenomena were marked by a decrease in vascular densities in the retinas of crew members and an increase in subjects after HDT. It is well known that long term space travelers experience “Space” headaches due to cephalad fluid shifts increasing fluid pressure in the upper body. Cephalad fluid shifts occur when an astronaut experiences more fluid then normal in their upper body due to the lack of gravity forcing the fluid down. This effect is easily seen in the puffy faces of astronauts in space.

Astronaut floating in space on the ISS
Astronaut Karen Nyberg floating in the International Space Station. You can somewhat see her puffier face in this image.

The researchers used a 30 infrared (IR) Heidelberg Spectralis® machine (a more advanced version of that fun puff test you get at the doctors) to determine that the vascular part of the retina in the eyes decreased in crew members after space flight yet increased in subjects after HDTBR. Pictures from Spectralis were looked at by VESGEN, a new automated software developed to discover vascular diseases in the retina and other tissue. The pictures created a map of blood vessel diameters and densities utilizing a new measure of vascular space-filling capacity called . The experiment used four people who experienced HDT and eight ISS crewmembers for the project. The VESGEN program performed two distinct tests on these individuals. Test one did not disclose if the left and right retinas were from the ISS travelers or HDT patients, while test two matched the pairs for each subject to display the effects of either HDT or space flight.

The researchers were surprised to see that 11 out of 16 retinas of the crew members’ space-filling capacity of their retinal vessels decreased and that 6 out of 10 retinas of the HDT patients vascular densities increased. The researchers believe that this difference mostly comes from lack of imaging that can capture smaller vessels rather than from vessel growth or decay. They also said that six months on the ISS compared to seventy days on HDT and the presence of microgravity and gravity may also have a large effect. However, there is still room to improve! The biostatistical and medical analyses of the images will have the final say on whether the VESGEN findings were correct or not.

OPINION: Who knew that main reason astronauts have space headaches was because of excess fluid on on their optic nerves! I think it’s very possible that VESGEN outcomes are true. As an aspiring optometrist myself, I found these results to be pretty cool. I’ve never really heard about the effects of almost no gravity on vision, but it makes sense right? Vision has to be compromised somehow with all of that extra fluid in the upper body. However it was a very small sample size so the VESGEN outcomes might be wrong, but then again its expensive to send people to space and hard to get people to do HDT for seventy days.

Link: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170009912.pdf

Murray, M.C., Vizzeri, G., Taibbi, G., Mason, S. S., Young, M. H., Zanello, S. B., and Parsons-Wingerter, P. A. 2018. Differences in Pre and Post Vascular Patterning of Retinas from ISS Crew Members and HDT Subjects by VESGEN Analysis. NASA Technical Reports Server: JSC-CN-40700.

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Throwing the Baby in With the Bathwater: Underwater Bubble CPAP

ubCPAP

A new method of Continuous Positive Airway Pressure may be less invasive, more effective, and a far lower cost than traditional methods. A CPAP ventilator system is essential for ensuring the normal breathing of newborn, particularly pre-term infants. CPAP has been shown to increase the survival rates of infants and the Underwater Bubble technique would allow it to be used with fewer limitations.

 

The underwater bubble technique is named such because as air is pumped into the infants lungs, it exhales into a tube the end of which is submerged in a container of water, regulating the pressure of the entire system. Pressure can be adjusted simply by raising or lowering the depth of the tube.

 

This study did not conduct trials and experiments but rather evaluated the techniques and their effectiveness in a newborn intensive care unit at a Brazilian university hospital.

 

The underwater bubble method does not require the insertion of a breathing apparatus making it minimally invasive, and is much lower cost than present alternatives, making the technique more readily available to the developing world.

 

Really the goal of CPAP is to ensure that newborns are able to breathe without the need for mechanical ventilation or intubation, two invasive and high risk techniques that are fortunately becoming less needed as CPAP progresses.

 

Another study (Dunn 2011) found that CPAP allowed 48% and 54% of newborns to be managed without mechanical respiration or lung inflating fluid.

Sources:

Abelenda V.L.B., Valente T.C.O,. Marinho C.L., and Lopes A.J. 2018 Effects of underwater bubble CPAP on very-low-birthweight preterm newborns in the delivery room and after transport to the neonatal intensive care unit. Journal of Child Health Care: XX(X) 1-12

 

Dunn MS, Kaempf J, de Klerk A, et al. (2011) Randomized trial comparing 3 approaches to the initial respiratory management of preterm neonates. Pediatrics 128(5): 1069–1076.

 

http://journals.sagepub.com/doi/pdf/10.1177/1367493517752500

ubCPAP
The Under water Bubble CPAP machine, seen facilitating respiration for a newborn
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Hello!

Welcome to the Writing Science News 2018 Course blog. This blog seeks to highlight and explain the latest scientific discoveries in the areas of space, the environment, and human health. The posts here are written by Dickinson College undergraduates based on recent findings published in the primary scientific literature.