Global Climate Report. NOAA National Centers for Environmental Information (http://www.ncdc.noaa.gov). July 2019.

It’s summer, and it is hot out there; but if it feels like record-breaking temperatures are becoming more common globally, they are. The National Oceanic and Atmospheric Administration and European Copernicus Climate Change Service announced that July 2019 was the hottest month across the globe ever measured since measurements began, in 1880. Global temperatures averaged 16.73°C in July, which is 0.95 °C higher than the 20th-century average of 15.78°C . Average Antarctic sea-ice coverage was 8.5% below the 1981-2010 average. And sea ice coverage was 10.5% below the overall average, which is based on records beginning in 1979. The scientists also released geographical data, showing that the regions where temperatures varied furthest from averages, were Alaska, Central Europe, Northern and Southwestern parts of Asia, and certain regions in Africa and Australia. These findings corroborate scientific predictions regarding the effects of man-made climate change. Human activities, primarily from burning fossil fuels, emit carbon dioxide and other greenhouse gases that trap heat in the atmosphere. Increasing greenhouse gas emissions are associated with warmer global surface temperatures. The planet’s 10 hottest years on record have all fallen in the past two decades. Scientists and policymakers around the globe are also feeling this heat.

Unless significant measures to curb greenhouse gas emissions are adopted, scientists expect temperature records to keep falling. Scientists say global temperatures could increase by at least 3°C this century, which will create conditions on Earth that have not been seen in more than 2 million years. Given the notable trends in higher temperatures and natural disasters, we might be pushing the climate system toward states that we haven’t seen in our societal experience – and even in our species’ experience.

Manipulation of brain circuits using smartphone-controlled device

Qazi R et al. Wireless optofluidic brain probes for chronic neuropharmacology and photostimulation. Nature Biomedical Engineering, August 2019.

Scientists recently designed a device that can regulate brain circuits using a tiny brain implant controlled by a smartphone. This bluetooth-enabled device utilizes replaceable lego-like drug cartridges to target neurons with drugs and light. Existing methods to deliver drugs and light to the brain typically involve metal tubes and optical fibers. These tools are rigid and can substantially damage the brain’s soft tissue over time. Moreover, this bulky equipment often limits the patient’s movement because of the wired connections, making them unfit for long-term use. To achieve chronic remote-controlled drug delivery without exhaustion and evaporation of drugs, scientists invented a neural device with a replaceable drug cartridge, which could allow neuroscientists to study the same brain networks for several months without depleting the drug supply. These “plug-n-play” drug cartridges were integrated into a brain implant for mice with a soft and ultrathin probe (about the thickness of a human hair), which consisted of microfluidic channels and tiny LEDs (smaller than a grain of salt), for unlimited drug doses and light delivery. The implant is regulated via a smartphone, allowing researchers to trigger precise combinations and sequences of drug and light delivery. In animal models, these stimuli can be triggered with the target outside of the laboratory, allowing researchers to wirelessly instill changes in the animal’s brain while in its natural habitat. Using these neural devices, researchers are now able to perform fully automated animal studies where the behavior of one animal could positively or negatively affect behavior in other animals by conditional triggering of light and/or drug delivery. This device will allow researchers to better dissect the neural circuit basis of behavior and how specific neuromodulators in the brain tune behavior in various ways. In addition, the device can be utilized in complex pharmacological studies to develop potentially new therapeutics for pain, addiction, and emotional disorders.

The secret weapon of E.Coli 

Melson E. at al. The sRNA DicF integrates oxygen sensing to enhance enterohemorrhagic Escherichia colivirulence via distinctive RNA control mechanisms. Proceedings of the National Academy of Sciences, June 2019.

Scientists have revealed how E. coli (Escherichia coli) bacteria seeks out the most oxygen-free parts of your colon to cause the worst infection possible. E. coli normally live in the intestines of healthy people and animals. Most varieties of E. coli are harmless or cause relatively brief diarrhea. But a few particularly nasty strains can cause cramps, diarrhea, vomiting – even kidney failure and death. Children are particularly at risk. A new study uncovers how this foodborne pathogen knows where and when to begin colonizing the colon on its way to making you sick. Bacterial pathogens typically colonize a specific tissue or organ in the host. Therefore, as part of their infection strategies, bacterial pathogens precisely time deployment of proteins and toxins to these specific colonization niches in the human host. This allows the pathogens to save energy and avoid detection by our immune systems and ultimately cause disease. The researchers in this study identified how E.Coli detects low oxygen levels in the large intestine and then produces proteins that allow it to attach to host cells and establish infection. Oxygen actually diffuses from the intestinal tissue into the gut, and there are comparably higher levels in the small intestine than the large. Remarkably, E. coli specifically waits until it has reached the-low oxygen large intestine before striking. E. coli controls this process via a small form of RNA that activates particular genes when oxygen levels are low. This is the point when the infection really gets established and the bacteria are able to begin to manufacture harmful Shiga toxins. The researchers predict that other bacterial pathogens, such as Shigella and Salmonella, likely utilize a similar control mechanism. Researchers suggest that if we can find a way to block oxygen sensing, we may be able to prevent the infection by allowing E. coli to pass harmlessly through the body.

For nearly a century, chlorine has been used to disinfect drinking water. The use of chlorine in water started when John Snow used to purify the cholera-causing water of the Broad Street Pump, in London. After seeing that chlorine curbed deaths from cholera, Great Britain started chlorinating their public drinking water. Then chlorination began in New Jersey, and after that it was soon used throughout the United States. Measuring the benefits and risks, it’s clear that the advantages of adding chlorine to drinking water outweigh the potential dangers. Scientific research also shows that the benefits of chlorinated water are more than the risks from THM’s and other by-products (Health Canada, 2004).

There continue to be many people in developing countries who do not have access to clean water. In some parts of the world, people collect water from available sources and store it in containers without treatment and further protection from contamination (Sobsey, Handzal & Venczel, 2003).

Sobsey, Handzal & Venczel (2003) conducted an experiment to see the effects of chlorine when added to a container with contaminated water. These experiments were conducted in Bangladesh and Bolivia. Community families were divided into two groups: intervention (household water chlorination and storage in special container) and control (no intervention). The results in Bangladesh were: in the intervention households, only 12.9% of the containers were E.coli positive; in the control households, 55.2% of containers were E.coli positive. The results were equally stark in Bolivia: only 33.7% of intervention households were contaminated by E.coli, whereas 93.8% of control households were contaminated.

There was also a decrease in the diarrhoeal illness in the experimental findings for samples in both countries’ households where the water was treated with chlorine. During the eight-month trial period, the mean diarrhea incidence rates of children younger than five years old in Bangladesh was 20.8 episodes/1000 days in the intervention group and 24.3 episodes/1000 days in the control group. In Bolivia, where the experiment lasted for six months, the mean diarrhea episodes/person for all age groups was 0.21 for the intervention group 0.38 for the control group. 43% of all cases of diarrhea were preventable by the intervention (Sobsey et al., 2003).

The study noted other successes. In some countries, like Saudi Arabia, chlorine was used in household tanks, which resulted in a 48% reduction of diarrhea; and in India, chlorine was used in earthenware, which resulted in a decrease of cholera cases, from 17% to 7.3%. (Sobsey et al., 2003).

In another study, Coulliette, Enger, Weir & Rose (2013), evaluated the effect of chlorinated HaloPure beads on the reduction of bacterial pathogens with concurrent sewage contamination. They estimated the risk reduction of waterborne typhoid fever and cholera within a hypothetical community of 1000 people treating their water with the chlorinated HaloPure beads. Seeded well water resulted in log10 reductions of 5.44 for S. Typhi and 6.07 for V. cholera (Coulliette et al., 2013). In well water with 10% sewage and seeded bacteria, the log10 reductions were 6.06 for S. Typhi and 7.78 for V. cholera (Coulliette et al., 2013). If an individual drinks from the contaminated water that was taken from the water source that had fecal material leaked into it, the risk of disease according to the Monte Carlo analysis would be a median of 0.21 for typhoid fever and a median of 0.11 for cholera (Coulliette et al., 2013). If that same water was treated, then the result would be: median of 4.1*10^-7 for typhoid and a median of 3.5*10^-9 for cholera (Coulliette et al., 2013).

These are important results: in developing counties, diarrhea is one of the greatest health issues. Arnold & Colford JR. (2007) conducted a systematic review of all studies that measured diarrheal health impacts in children and the impact on water quality of point-of-use chlorine drinking water treatment. Of the 10 studies that were analysed, nine of them showed a reduction of diarrhea in children. Across the 10 studies, the intervention led to an 80% reduction in the proportion of stored water samples with detectable E. coli (Arnold & Colford JR, 2007).

Water chlorination has been a very useful strategy for treating contaminated water for years. Currently, chlorination is the only method that disinfects the pathogens from the point of treatment to the point of consumption. As the scientific research above indicates, the benefits of chlorinating water supplies, particularly in the developing part of the world, is essential for disease prevention and reduction. Water is an essential element for life, and clean water is what keeps us alive. Although chlorine in large doses can be harmful for our health, it can also be a lifesaver. Nothing on earth is created without reason. Chlorine has obviously been created to directly benefit humanity.

References

• Arnold, B. F., & Colford JR., J. M. (2007). Treating water with chlorine at point-of-use to improve water quality and reduce child diarrhoea in developing countries: A systemic review and meta-analysis.The American Society of Tropical Medicine and Hygiene, 76 (2), 354-364.
• Coulliette, A. D., Enger, K. S., Weir, M. H., & Rose, J. B. (2013). Risk reduction assessment of waterborne Salmonella and Vibrio by a chlorine contact disinfectant point-of-use device.International journal of hygiene and environmental health,216(3), 355-361.
• Sobsey, M. D., Handzel, T., & Venczel, L. (2003). Chlorination and safe storage of household drinking water in developing countries to reduce waterborne disease.Water science and technology : a journal of the International Association on Water Pollution Research, 47 (3), 221-228.
• It’s Your Health – Drinking Water Chlorination [Health Canada, 2004]. (n.d.). Retrieved June 5, 2013, from http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/environ/chlor-eng.php