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What does ADHD look like in the brain of a preschooler?

According to the National Survey of Children’s Health from 2016, 9.4% of children in the United States have been diagnosed with ADHD, almost 1 in 10 children. ADHD, or attention-deficit/hyperactivity disorder, is a neurological disorder characterized by impulsive behavior, different attention patterns, restlessness, and disorganization. You might hear a coworker casually claim, “I can’t focus on these emails.. my ADHD is acting up!” However, ADHD is not something that comes and goes. It is a different way of thinking, which stems from abnormal brain developmental patterns.

Although ADHD can manifest as early as 4 years old, most studies have only analyzed older school-age children. A new study published online in March 2018 in the Journal of the International Neuropsychological Society recruited a group of 4-5 year olds, including 52 children exhibiting ADHD symptoms and 38 children without ADHD symptoms to use as a comparison group. With consent from both the parents and children of course, they performed MRI scans to get a look at their brain structure.

Brain scan
A brain scan showing gray matter borders (cell bodies) with white matter in the inner regions of the brain (cell axons); Credit: Wikipedia Commons.

Overall, the researchers found that some regions of the brain had a smaller volume in children with ADHD, compared to the group of children with no ADHD symptoms. In particular, gray matter volumes were decreased. Gray matter, named for its natural brownish-gray color, is tissue comprised of the cell bodies of neurons in the brain and spinal cord. A neuron cell has a central body, and a long axon “branch” which sends messages to other neurons. The neuron cell bodies tend to congregate together in the brain and arrange themselves as “gray matter.” The axons also form groupings and are visualized as white matter.

In the brains of children with ADHD, the researchers noticed that the gray matter volume was reduced most significantly in subregions of the right frontal lobe and the left temporal lobe of the brain, and greater losses in volume corresponded with greater severity of ADHD symptoms. These brain areas with smaller gray matter volume are involved in inhibitory control (for example, preventing one’s self from blurting out an answer instead of raising a hand in class), working memory (for example, remembering the question on a worksheet while in the middle of writing an answer), planning (for example, deciding to clean up the desk, then turn in homework, then put books in backpack in that order), and response control (for example, correctly following a teacher’s directions).

Brain schematic
A schematic of the brain showcasing the frontal lobe and temporal lobe, each of which play a role in ADHD symptoms; Credit: w:User:Washington irving, Wikipedia Commons.

Previously, gray matter volume differences have been assessed in older children, but this study demonstrates that brain structure developments are discernible in children as young as four. The gray matter volume of another brain area, the anterior cingulate cortex, which plays a role in attention, decision-making, and impulsivity, has been evaluated in other studies. In older children with ADHD, there is a reduction in volume of the anterior cingulate cortex, but there was no difference between groups in the 4-5 year olds, suggesting that neural development is transpiring during the course of several years.

Scientists are gaining a better understanding of developmental trajectories of  ADHD with this kind of research. The hope is that these research studies will one day shed light on what triggers the differences in gray matter volume. These neurological differences are believed to be shared by Albert Einstein, Walt Disney, and John F. Kennedy, who also had ADHD symptoms. With this knowledge, we can gain a greater appreciation of what makes us who we are.

Sources:

Children and Adults with Attention-Deficit/Hyperactivity Disorder (CHADD). (2018). General Prevalence. CHADD: The National Resource on ADHD. Retrieved Apr 3, 2018 from http://www.chadd.org/Understanding-ADHD/About-ADHD/Data-and-Statistics/General-Prevalence.aspx.

Growl, J.M. (2018). Famous people with ADHD. PsychCentral. Retrieved Apr 3, 2018 from https://psychcentral.com/lib/famous-people-with-adhd/.

Jacobson, L.A., Crocetti, D., Dirlikov, B., Slifer, K., Denckla, M.B., Mostofsky, S.H., & Mahone, E.M. (2018). Anomalous brain development is evident in preschoolers with attention-deficit/hyperactivity disorder. Journal of the International Neuropsychological Society, First View [Published online]. https://doi.org/10.1017/S1355617718000103.

Mayo Clinic Staff. (2018). Adult attention-deficit/hyperactivity disorder (ADHD). Mayo Clinic. Mayo Foundation for Medical Education and Research. Retrieved Apr 3, 2018 from https://www.mayoclinic.org/diseases-conditions/adult-adhd/symptoms-causes/syc-20350878.

 

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Health Screening for Military Veterans: Do It Right Now!

Marine Corps

Alcohol use disorder (AUD) and post traumatic stress disorder (PTSD) are two of the most common disorders among U.S. military veterans that often occur concurrently. Although both disorders are individually associated with poor health and wellbeing, past studies have shown that the rates of physical and mental health problems are higher in patients with co-occurring AUD and PTSD. Researchers from the National Center for PTSD and the VA San Diego Healthcare System published a study in 2018 that examined the burden associated with the co-occurrence of AUD/PTSD relative to either disorder occurring alone among US military veterans.

The study was conducted using data from the the National Health and Resilience in Veterans Study, which surveyed a nationally representative sample of 3,157 US veterans aged 21 and older. Overall, the sample group consisted of 14.8% probable current AUD, and 16.4% current PTSD, but only 2.8% comorbid AUD/PTSD. Comorbid is a term used when two or more disorders or diseases occur at the same time. As part of the study, veterans were asked about their primary source of healthcare and their current mental health care situation.

The study assessed AUD and PTSD along with probable depressive and anxiety disorder, physical and mental functioning, quality of life, and cognitive functioning.

Results showed that, patients with comorbid AUD/PTSD or PTSD only were more likely to have co-occurring depression and anxiety, and current suicidal ideation compared to veterans with AUD only. Additionally, they also scored lower on mental, physical and cognitive functioning, and quality of life measures. Compared to PTSD only, the comorbid group was, again, much more likely to have attempted suicide in their lifetime. The difference in the rates of depression and anxiety between the two groups was also very high. However, some similarities between the two groups suggests that the increased burden associated with PTSD/AUD is largely driven by problems associated with PTSD. This may have been because the AUD/PTSD group was very small and there was unevenness in the size of the diagnostic groups.

There were also some other limitations associated with the study, which could have brought about discrepancies in the final results. The prevalence of AUD could have been underestimated because AUD is primarily associated with young adults, but the study mostly consisted of older white men. Moreover, suicide attempts were asked in terms of entire lifetime, so it is not certain if they had occurred before or after military service. Nevertheless, the overall findings reflect the mental and physical health burden associated with co-occurring AUD and PTSD.

The results stress the importance of screening veterans for AUD and PTSD given that less than half of veterans with these disorders are receiving mental health treatment. It also highlights the need for further research to understand how to reach out to and engage these veterans in screening, assessment, and treatment for such disorders.

Reference: Norman, S.B., Haller, M., Hamblen, J.L., Southwick,S.M., Pietrzak, R.H. 2018 The Burden of Co-Occurring Alcohol Use Disorder and PTSD in U.S. Military Veterans: Comorbidities, Functioning, and Suicidality. Psychology of Addictive Behaviors 32(2): 224-229

Link to article

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Experimental Fix to Melting Ice Sheets

Is there a cost to global sea level rise? Yes, approximately $50 trillion per year in damages.  The infrastructure needed to create and maintain sea walls and flood defenses cost tens of billions of dollars a year according to John C. Moore. What is adding to the cost? The infrastructure costs approximately $20-33 billion to build. For the installment of the Three Gorges Dam in China spend $33 billon to construct the dam.

Most of the water from sea level rise will come from the melting ice sheets in Greenland and Antarctica.

ice melting in Antarctica

In their research, they explore three ways we can delay the loss of ice sheets. They suggest to block warm water, support ice shelves, and dry subglacial streams. Note that all of these potential solutions could disrupt natural ecosystems, fisheries, tourism, and water flow. However, Moore and his co-authors argue their solutions may be worth the risk to the present dilemma in the rise of global sea levels.

To block warm water from the Atlantic Ocean, the authors suggest constructing a 100-meter-high wall with sliding sides along the 5-kiometer fjord in front of the Jakobshavn glacier near western Greenland. A fjord is a narrow inlet with steep sides or cliffs created by a glacier. The importance of this project would be similar to other large civil-engineering projects like the Suez Canal in Egypt, Hong Kong airport, Three Gorges Dam in China. However, this project would need 0.1 cubic kilometers of gravel and sand compared to 1, 0.3, or 0.028 cubic kilometers of material needed for the projects in Egypt, Hong Kong, or China.

The Jakobshavn glacier is one of the fastest moving ice masses on Earth, and it contribute to most of the sea level rise than other glaciers located in the Northern Hemisphere. Furthermore, 4% of twentieth century seal level rise can be attribute to this glacier.

For their second solution, Moore and his co-authors they would construct a berm (raised banks bordering river or canal) and islands to artificially pin ice shelves in front of the Pine Island and Thwaites glaciers in West Antarctica. Ideally, this would temporary prevent the movement of the glacier. Similar to the first plan, these materials need to be outsourced to material to build the berm and island.   Models predict that Pine Island Glacier and Thwaites will be the largest source of se level rise in the next two centuries, contributing 4 centimeters a year.

For dry subglacial streams, they want to reduce the rate of melting by removing the glacier’s ice bed to reduce frictional heating in Antarctica. When they remove the ice bed, they will use a pumping station to extract or freeze the water at the glacier’s base to slow sliding. This process would be important to mitigate sea level rise because glacier ice beds supply 90% of ice in the sea.

With this intensive construction and extraction of materials, do their plans sound plausibly or worthwhile? The authors leave it to other glaciologist and engineers to test their projects.  Also, if this plan does carryon, who will need to approve this project? This project may result in global consequences if they do not structure it properly. What are your thoughts on this project?

 

Source:

Moore, John C. et al. 2018. Geoengineer polar glaciers to slow seal-level rise. Springer Nature 555: 303-305.

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Storm Chasers: SPACE EDITION

View of a Cyclone from Space.

The Deep Space Gateway is back and better than ever! On February 28th Timothy Lang, a Research Aerospace Technologist at NASA’s Marshall Space Flight Center, gave a talk a about The Deep Space Gateway Lightning Mapper (DLM) at a Deep Space Gateway Concept Science Workshop in Denver, Colorado. Lang introduced the concept of the Lightning Mapper, what it will do, and why it is important to be incorporated on the Deep Space Gateway. The Deep Space Gateway Lighting Mapper will be used to help track global change and thunderstorm processes by looking at high latitude lightning. It is planned to combine data from the sampling of individual thunderstorms with observations of the lightning at high latitudes. High latitudes are the areas greater than 50 degrees and occur nearer to the north and south poles of the Earth. Some questions the scientists want to answer are, “How is global change affecting thunderstorm patterns?” and “How do high-latitude thunderstorms differ from low-latitude?”

The Deep Space Gateway’s orbit provides a continuous view of the high latitudes of Earth and makes it the best place to monitor lightning. These regions are not well covered by current lighting mappers and other types of orbits have many drawbacks that prevent continuous coverage. Lang continued to pitch the project in the rest of his presentation. He highlighted the fact that the World Meteorological Organization (WMO) has declared lightning an essential climate variable that can provide important information about our ozone and atmospheric precipitation. Also, 75% of wildfires in high latitudes are caused by lightning, so many governmental departments are interested in becoming partners in the effort. In other words, we hope he gets the money!

LINK: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180001589.pdf

Lang, T., R. J. Blakeslee, D. J., Blakeslee, R.J., Cecil, D.J., Christian, H.J., Gatlin, P.N., Goodman, S.J., Koshak, W.A., Petersen, W.A., Quick, M. and Schultz, C.J. 2018. The Deep Space Gateway Lighting Mapper (DLM) – Monitoring Global Change and Thunderstorm Processes Through Observations of Earth’s High-Latitude Lighting from Cis-Lunar Orbit. NASA Technical Reports Server. 20180001589.

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4 Herbal Supplements for Anxiety and Depression

Passionflower image
Passionflower; Credit: Martin Thomas, Creative Commons
Saffron flowers
Saffron flowers; Credit: Ioulrc, Creative Commons
Chaste berry
Flowering chaste-tree; Credit: Tatters, Creative Commons
Lavender; Credit: Amanda Slater, Creative Commons

 

 

 

 

 

 

 

 

 

 

 

 

 

According to a recent study, one-third of cancer patients suffer from anxiety, depression, or adjustment disorder in the months following their diagnosis. As a result, many of them add prescription anxiolytic (anti-anxiety) and antidepressant drugs to their cocktail of chemotherapy, radiation therapy, anti-coagulants, and antibiotic drugs.

The problem is that some of these anxiolytic and antidepressant drugs interact with cancer treatments and are less effective in cancer patients. They also trigger a horde of negative side effects that compound the side effects of regular cancer treatments, including seizures, headaches, and addiction.

A group of scientists at the Memorial Sloan Kettering Cancer Center in New York City decided to take a closer look at alternative herbal remedies to treat anxiety and depression in cancer patients. Research done on herbal supplements and plant extracts has been scarce, so the scientists examined a collection of studies completed between 1996 and 2016. By gathering and organizing the data, they noticed that not only are several alternative remedies helpful in ameliorating anxiety and depression, they also counteract aversive effects of chemotherapy and even combat cancer themselves. While not a perfect substitute, the following herbs have promising potential:

1. Extracts of saffron, a spice derived from a Middle Eastern flower, may be able to treat mild to moderate anxiety about as well as fluoxetine (Prozac) and imipramine (Tofranil). It has also been successful in easing anxiety and depression caused by PMS in women.

2. Lavender pills, made from oil of the lavender plant, are able to treat anxiety comparable to the drugs paroxetine (Paxil) and lorazepam (Ativan), but with fewer side effects. Lavender lotions and diffuser oils are often advertised for their calming and relaxation properties, and this holds true for lavender tea and extract drops, which may increase the efficacy of antidepressants citalopram (Celexa) and imipramine (Tofranil).

3. Passionflower, although no better than prescription drugs, seems to perform similarly but with fewer side effects, when compared to oxazepam (Serax) and sertraline (Zoloft). This substance also comes from a flower, which Native Americans have historically used to prevent insomnia.

4. Chasteberry, typically used for PMS symptoms, was compared to fluoxetine (Prozac), and while it didn’t seem to address psychological symptoms of depression, including persistent sadness, hopelessness, and loss of interest, it did alleviate physical symptoms, such as sleep trouble, digestive problems, muscle aches, and headaches.

Overall, researchers found that the herbs are not as potent, but are safer than the prescription counterparts. Clinical trials are needed to further analyze the potential of these herbal supplements and determine their benefits, especially within a oncology context. Because these supplements can be purchased over the counter, physicians don’t always know which supplements their patients are taking. It’s important to discuss an alternative treatment plan with a doctor before use.

Source:

Simon Yeung, K., Hernandez, M., Mao, J.J, Haviland, I., & Gubili, J. (2018). Herbal medicine for depression and anxiety: A systematic review with assessment of potential psycho-oncologic relevance. Phythother Res. [Epub ahead of print]. doi: 10.1002/ptr.6033

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Poaching: How bad is it?

elephant

On March 19th, 2018 the last male Northern White Rhino died. Two of his kind remain, but both are older females that are unable to reproduce. The decline in the Northern White Rhino population is much attributed to uncontrolled mass hunting and poaching. Although, rhinos aren’t in this alone. An increasing number of large mammals are being threatened for their meat and skin. Elephants, are among those.

A recent study examines just how horrific elephant poaching is in the nation of Myanmar. The Asian Elephant population here has declined drastically over the last couple of decades due to poachers who hunt the animals for their meat and skin, which is thought to have medicinal purposes. Researchers collared 19 elephants with a goal of better understanding where conflicts with humans arise and educating local communities on how to live in proximity to the elephants. They studied elephants from three different areas in Myanmar. The first was the Bago Yoma foothills where the creation of two dams and the settlement of dam workers is causing conflicts with the elephants who reside there. Second was the Ayeyarwady Delta where elephants have been displaced due to the increase of agricultural land and highway construction. The last location was in the Tanintharyi region where elephants were also affected by an expansion of agriculture. After a year of GPS tracking the animals, 7 out of 19 were lost. 5 of the 7 elephants bodies were found, with the other 2 unable to be located. Researchers were not able to identify the age or sex of the carcasses because their deaths were so brutal. By the end of the study, the team of researchers and associates had come across numerous elephant carcasses and kill sites throughout the areas of study.

This work shows the need for better management practices and policy geared towards illegal poaching and trafficking of elephant parts, meat, and skin. With 25 known elephants poached in 2016 alone, the population is sure to come to the fate of the Northern White Rhino if nothing is done. In addition to collecting survival data of several elephants in Myanmar, researchers also conducted community outreach programs in all three areas of study. Hopefully people will learn to live with the animals and protect their species from another anthropogenic extinction.

 

Source: Sampson, C., et al. 2018. New elephant crisis in Asia- Early warning signs from Myanmar. Plos One 13 (3): e0194113.

Image: Flickr

 

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Prediabetes Causing Post Stroke Cognitive Impairment

diabetes

Scientists at Wenzhou Medical University in China have established an association between prediabetes and the development of post-stroke cognitive impairment (PSCI). Prediabetes is a state between normal blood-sugar conditions and diabetes mellitus (DM). Cognitive impairment after stroke is fairly common, but varies based on country, race and diagnostic criteria. Prediabetes and DM are both common risk factors of stroke. DM has already been related to PSCI by previous studies, however, as far as the authors’ understanding goes, this was the first study to explore a relationship between PSCI and prediabetes.

Prediabetes is a strong predictor of DM and can be diagnosed by characteristic changes in blood sugar level. Based on these levels, the patients were categorized into diabetes mellitus (DM), prediabetes and non-DM groups. The study evaluated the cognitive function of 201 patients 1 month after a stroke.The study diagnosed 74 of the total 201 patients with PSCI. Data showed the percentage of PSCI patients to be 18.1%, 35.7% and 49.3% respectively for the non-DM, prediabetes, and DM patients.

Analysis based on sex and smoking history surprisingly showed that patients who were female and non-smokers are at a greater risk of PSCI than any other group.

A statistical test conducted to adjust for confounders showed an association between PSCI and prediabetes. Confounders lead to bias that distorts the magnitude of the relationship between two factors of interest. For example, results showed that age and educational level also influenced the effects of prediabetes on PSCI. However, this was found to be untrue after adjusting for confounders.

The study included individuals who had suffered a stroke less than 7 days before admission and were diagnosed using CT scan and MRI. However, it excluded all individuals who had a history of severe depression and other psychiatric disorders or severe nervous system diseases. PSCI was evaluated by experienced neurological physicians who were not aware about the patients’ clinical examination and lab results.

The results were strong, but there were limitations to the study. The use of antidiabetic medicine post stroke was not recorded. Patients with speech and language disorders were excluded, which could have cause biases in the study. Moreover, the time span between stroke and PSCI assessment would have provided more appropriate results if it was longer than one month, for example, 3 to 6 months. Nevertheless, the study proved that prediabetes is a determinant of PSCI and suggests prediabetes patients to maintain normal blood sugar level as a preventive measure.

Reference:

Wang, Q., Zhao, K., Cai, Y., Tu, X., Liu, Y., He, J. 2017. Prediabetes is associated with post-stroke cognitive impairment in ischaemic stroke patients. Elsevier/North-Holland Biomedical Press 1687:137-143

 Link to article

Image 1,  Image 2

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Sea Ice, Warming, and Bears Oh my

Whenever I think of global climate change one of the first images that pops into my mind is that of a polar bear stranded out on a glacier. To me this image alluding to the polar bear’s ‘impending demise’ has in a way become s a rallying point in the fight against global warming. Polar bears always seem to be brought up in conversation when talking about issues that are caused by global warming, yet in the past there’s been little known information about the actual details causing the polar bear’s declining population.

Polar Bear
Polar Bear jumping between masses of ice

Receding and changing sea ice conditions throughout the Arctic is mostly to blame. However, further details of why that is has been relative limited until fairly recently. Researchers from around the U.S. as part of the U.S. Geological survey, Alaska Science Center, attempted to find out more on these causing mechanisms. By simultaneously measuring a number of factors in polar bears lives including body condition, field metabolic rates, daily activity patterns, and their foraging success, the scientists found high metabolism rates and a deficiency in fat-rich food sources resulted in about half of the bears studied having far less energy intake then they should. For 91% of the polar bears time studied (8-11 days each), the animals were located on sea ice, meaning their food source would come almost entirely from ringed seals. Over a course of 10 to 12 days, 1 ringed seal adult, 3 sub-adult ringed seals, or 19 newborn ringed seal pups are needed simply to break even in energy needed to survive as a freelance bear. However, with reducing amounts of sea ice, scavenging for this food source becomes harder and harder. The researchers observed that 4 of the 9 bears lost over 10% of their fat in the 8-11 days they were observed.

What the researchers also found was that during late spring/early summer time, when the bears are supposed to be gaining weight for the coming winter, polar bears would not be able to reach their goal of 1kg of wight to 1kg of lean body mass (the preferred fatness) unless they either reduced their energy demands or increased food consumption. Yet, these two motives are much easier said then done. The polar bears energy needed for survival is directly correlated with how far the polar bears have to roam around in order to find their next meal. And with the fragmenting sea ice caused by global warming the distance they have to travel increases each year leading to increased amounts of energy being used. The end result, is that these fragmentation’s could be a big factor in the declining body condition and mortality of this species.

Source:

Pagano, A. M., et al. 2018. High-energy, high-fat lifestyle challenges an Arctic apex predator, the polar bear. Science Magazine, V. 359(6375): 568-572.

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Want to be an Astronaut? Better Start Eating Your Fruits and Veggies Now

Even Astronauts in space get sick and NASA is trying to help them live healthier lives. In 2017, Researches at NASA, The University of Texas Medical Branch, and the J. Craig Venter Institute started a program to study how spaceflight impacts human physiology, the immune system, and the microbiota in the gut. Microbiota are organisms that live in your digestive tract that help to break down the food that you eat. Since diet is one of the few thing that NASA can actually control on spaceflights, the team designed an experiment to study diet of astronauts in a stimulation on earth. The scientist believed that eating more fruits and vegetables and things like omega-3 fatty acids and lycopene would actually improve the immune response, gut microbiota, and nutrition of astronauts. This improved diet should improve the health of the crew and reduce any negative physiological effects caused by space flight.

In order to perform this study, the researchers will compare what astronauts eat now on the International Space Station to the new diets that included more fruits and veggies. Four 45 day mission tests will be executed in a closed chamber that mimics flight in space. The participants will have bio sampling done both before and after their time in the simulation chamber. The research team plans to record dietary intake, immune markers, profiles of gut microbiomes, and nutritional status biomarkers and metabolites. After the data is collected, statistical evaluations will determine if the new diet improved the health of our astronauts. There has already been data collected from two crew members during the first mission, entitled Campaign 4 Mission 1. A second mission was attempted but the results were not valid because it had to be cut short due to the effects of Hurricane Harvey. After the completion of the study, the hope is that an improved diet will keep our astronauts healthier and hopefully ease the transition back to Earth!

 

LINK: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170008859.pdf

Douglas, G. L., Zwart, S. R., Young, M., Kloeris, V., Crucian, B., Smith, S. M., Lorenzi, H. 2018. The Integrated Impact of Diet on Human Immune Response, The Gut Microbiota, and Nutritional Status During Adaptation to a Spaceflight Analog. NASA Technical Reports Server. JSC-CN-40467.

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Winter is Coming and Staying

Snowfall in Boston
Snowfall in the Greater Boston area has been so severe this year that some public schools have extended classes until July. Source: Flickr

Extreme winters have become the new norm in northeastern states of the United States, and researchers have recently found the reason why. In March of 2018, scientists at Rutgers University published a study in Nature Communications on their findings that there is a correlation between the frequency of extreme winter weather in the North-Eastern region of the United States to changes in Arctic temperatures.

Recently warm temperatures in the Arctic cause the jet stream – a band of strong westerly air currents that encircle the globe several miles above the earth’s surface – to occasionally move farther south, causing cold air to reach all the way down to the eastern United States. The timing of this research is somewhat convenient, as it follows increasingly extreme winters, as well as record warm Arctic temperatures and low sea ice, record-breaking disruptions in the polar vortex (a large area of low pressure and cold air surrounding both of the Earth’s poles), and record-breaking disruptive snowfall in the United States and Europe.

Researchers found that severe winter weather is two to four times more likely to occur in eastern United States when the Arctic is abnormally warm than when it is colder than normal. The study also showed that colder winters in the northern latitudes of Europe and Asia are significantly related to the warming of Arctic. On the other hand, the study also showed a correlation between the likelihood of severe winter weather in the western United States when the Arctic is colder than normal.

Researchers found that when warming of the Arctic occurs on the Earth’s surface, there is only a weak connection to severe winter weather in the northeastern region of the United States. However, when warming is extended to the stratosphere, it disrupts the polar vortex and severe weather is more likely.

To make these conclusions, researchers used three metrics of Arctic variability to diagnose the relationship between severe winter weather in the Northeast and Arctic temperatures. These measurements are called the polar cap geopotential height anomaly index (PCH), polar cap air temperature anomaly index (PCT), and the Accumulated Winter Season Severity Index (AWSSI).

The PCT and PCH indices measure geopotential height (the vertical coordinate system referenced to Earth’s mean sea level) and temperature anomalies that occur between the 65th parallel north (a circle of latitude that is 65 degrees north of the Earth’s equator) and the north pole. The AWSSI identifies severe weather owning to snowfall and temperatures at individual locations across the United States. Researchers analyzed changes in AWSSI in relation to changes in PCT and PCH to explore the relationship between Arctic variability and severe winter weather.  They found that an increase in abnormalities occurring in polar cap temperatures and geopotential height are correlated with higher values of the AWSSI, meaning an increase in cold spells and heavy snowfalls.

Inevitably, there will be an increase in certain types of weather extremes due to the effects of anthropogenic global warming. Researchers at Rutgers University have presented a quantitative analysis of the link between Arctic variability and severe winter weather, suggesting that the pattern of colder and harsher winters in the Northeast are attributed to Arctic warming is no coincidence.

Judah Cohen, Karl Pfeiffer, Jennifer A. Francis. Warm Arctic episodes linked with increased frequency of extreme winter weather in the United States. Nature Communications, 2018; 9 (1) DOI: 10.1038/s41467-018-02992-9

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What do wastewater and earthquakes have in common?

Researchers predict that the second highest earthquake in Kansas between 2013-2016 resulted from the deep injection of wastewater from the oil and gas production. These earthquakes occurred in southern Kansas, frequently in Harper County and neighboring counties. Historically, the magnitude of earthquakes in southern Kansas where below 2.0. However, they peaked in 2015 with 51 earthquakes above the magnitude of 3.0.

For their study, they focused on Sumner and Harper County in southern Kansas. Oil and gas operation began in Sumner County in 1915 and in Harper County in 1950. This contributed 1 million barrels of oil and 1 billion cubic feet of natural gas in Kansas. However, oil production decreased between 1960 and 2010; while gas production remained constant until 2015, especially in Harper County, according to the authors. This interest resulted from the Mississippi Limestone Play that promised a plentiful source of natural gas to companies through hydraulic fracturing or horizontal drilling in Oklahoma and Kansas.  Wastewater disposal, typically, is deposited in the Arbuckle group, which is an aquifer that covers most of the state of Kansas. The Arbuckle group lies on the Precambrian basement that creates fractures and faults in the Arbuckle geological formation. Therefore, if water withdraws and wastewater injections disrupt Precambrian basement, this could lead to frequent earthquakes. Within this study area, there was a correlation between the highest total volume wells and the wells with most documented seismic activity. From their results, earthquakes appeared to lag 2 to 6 months after the wastewater injection.

To ensure their link between wastewater injection from oil and gas deep injection, Rubinstein  and his co-authors investigated if hydraulic fracturing led to seismic activity. They found that this possibility was low in this location because they did not spatially or temporally correlate in their results.

Rubinstein and his authors, also, found that They, also, found that the seismic activity in Kansas is parallel to the activity in Oklahoma which has a similar problem with frequent earthquakes. Recently, the rate of earthquakes decreased in Oklahoma and Kansas. The authors suggested that this was due to the economic and regulatory forces that prompted the decline in injection. In 2016, the Kansas Corporation Commission ordered the reduction of injection in southern Kansas. However, in future research, they will assess how other factors led to the decline in earthquakes.

Source: Rubinstein, J. L., Ellsworth, W.L., Dougherty, S.L. 2018. The 2013-2016 induced earthquakes in harper and sumner Counties, southern kansas. Bulletin of Seismological Society of America 20:20.