“The obvious question that has been raised from the very beginning of our whole field is, what’s the ultimate limit at which we can predict day-to-day weather in the future,” said Fuqing Zhang, distinguished professor of meteorology and atmospheric science and director of the Center for Advanced Data Assimilation and Predictability Techniques at Penn State. “We believe we have found that limit and on average, that it’s about two weeks.”

Reliable forecasts are now possible nine to 10 days out for daily weather in the mid-latitudes, where most of Earth’s population lives. New technology could add another four to five days over the coming decades, according to research published online in the Journal of the Atmospheric Sciences.

The research confirms a long-hypothesized predictability limit for weather prediction, first proposed in the 1960s by Edward Lorenz, a Massachusetts Institute of Technology mathematician, meteorologist and pioneer of the chaos theory, scientists said.

“Edward Lorenz proved that one cannot predict the weather beyond some time horizon, even in principle,” said Kerry Emanuel, professor of atmospheric science at MIT and coauthor of the study. “Our research shows that this weather predictability horizon is around two weeks, remarkable close to Lorenz’s estimate.”

Unpredictability in how weather develops means that even with perfect models and understanding of initial conditions, there is a limit to how far in advance accurate forecasts are possible, scientists said.

“We used state-of-the-art models to answer this most fundamental question,” said Zhang, lead author on the study. “I think in the future we’ll refine this answer, but our study demonstrates conclusively there is a limit, though we still have considerable room to improve forecast before reaching the limit.”

To test the limit, Zhang and his team used the world’s two most advanced numerical weather prediction modeling systems — The European Center for Medium Range Weather Forecasting and the U.S. next generation global prediction system.

They provided a near-perfect picture of initial conditions and tested how the models could recreate two real-world weather events, a cold surge in northern Europe and flood-inducing rains in China. The simulations were able to predict the weather patterns with reasonable accuracy up to about two weeks, the scientists said.

Improvements in day-to-day weather forecasting have implications for things like storm evacuations, energy supply, agriculture and wild fires.

“We have made significant advances in weather forecasting for the past few decades, and we’re able to predict weather five days in advance with high confidence now,” Zhang said. “If in the future we can predict additional days with high confidence, that would have a huge economic and social benefit.”

Researchers said better data collection, algorithms to integrate data into models and improved computing power to run experiments are all needed to further improve our understanding of initial conditions.

“Achieving this additional predictability limit will require coordinated efforts by the entire community to design better numerical weather models, to improve observations, and to make better use of observations with advanced data assimilation and computing techniques,” Zhang said.

Story Source:

Materials provided by Penn State. Original written by Matthew Carroll. Note: Content may be edited for style and length.

Yong-Su Jin, a University of Illinois professor of food science and human nutrition, led the research team that engineered the yeast strain, which produces tagatose in much larger quantities than traditional enzymatic manufacturing techniques and could help make tagatose a cost-effective alternative to sugar or high-fructose corn syrup.

The researchers published their work in the journal Nature Communications.

“Tagatose is a sweetener that exhibits almost identical tastes and textures of sucrose, or table sugar. However, tagatose has many fewer calories than sucrose — about 40% of sucrose,” Jin said. “In addition, it does not increase blood glucose levels as much as sucrose or fructose. The glycemic index of tagatose is 3, which is much lower than that of sucrose, 68, and fructose, 24. As such, tagatose carries a lower risk for developing Type 2 diabetes and other diseases caused by rapid and repeating glucose increases in blood.”

In spite of its benefits, tagatose has a high manufacturing cost that has kept it from wide commercial use, Jin said. Although it is naturally present in fruits and dairy products, the concentrations are too low to isolate tagatose effectively. The traditional manufacturing method involves a multi-step enzymatic process that turns galactose — a component of lactose — into tagatose.

Unfortunately, the enzyme reaction is so inefficient that only 30 percent of galactose is converted into tagatose, forcing manufacturers to use an expensive process to remove the tagatose from the galactose mixture.

Jin’s team used the internal machinery of yeast cells as tiny tagatose factories, much like how ethanol manufacturers use yeast to produce fuel from corn. The researchers engineered a strain of yeast that produces tagatose from lactose by making two genetic tweaks. First, they took out a gene that let the yeast use galactose as cellular fuel during lactose metabolism. Second, they added two genes that convert galactose into tagatose.

Thus, when the yeast is fed lactose, its own metabolism drives it to produce a solution that is 90 percent tagatose — much higher than the 30 percent yield from traditional manufacturing. Yeast reactors also operate on much larger scales than enzyme-based ones, which could allow for efficient mass production of tagatose, Jin said.

“Another advantage is that our yeast-based process can use whey indirectly. Whey is an inevitable byproduct of the cheese and Greek yogurt manufacturing processes as a raw material,” Jin said. “Due to the recent popularity of Greek yogurt, the disposal of whey is an issue in the dairy industry. We hope our process can be used to resolve the surplus whey problem. As our yeast fermentation-based approach allows a higher product ratio and the direct use of inexpensive dairy waste, we expect that the production cost of tagatose can be significantly reduced.”

Next, the researchers will explore using their yeast-based approach to manufacture other products from lactose.

“We showed that lactose can be efficiently and rapidly utilized by engineered yeast. With further metabolic engineering, we can produce other valuable products from the lactose abundant in whey, using our engineered yeast strain,” Jin said.

The Energy Biosciences Institute and the U.S. Department of Energy supported this work. Jin is a member of the Carl R. Woese Institute for Genomic Biology at Illinois.

Story Source:

Materials provided by University of Illinois at Urbana-Champaign. Note: Content may be edited for style and length.

“The findings highlight the importance of raising public awareness around the risks of rabies, both for travellers visiting rabies-infected countries and from bat exposures in the UK,” says co-author Dr Kevin Brown, Head of Rabies and Immunoglobulin Service for Public Health England.

Symptoms typically take 2 to 3 months to appear, but can develop in as little as a week (following severe bites to the head) or up to several years after exposure. “Preventive treatments are 100% effective if given promptly after exposure,” says Dr Brown. “That’s why seeking prompt care is so important, even if the wound or incident seems very trivial. If you are bitten, scratched, or licked by an animal you must wash the wound or site of exposure with plenty of soap and water and seek medical advice without delay. Travellers should not delay waiting for treatment until they return to the UK.”

Rabies is a zoonotic infection (a disease that spreads from animals to humans) that can cause a rare but life-threatening infection of the brain and nervous system in humans. It usually results from a bite, scratch, or lick from an infected animal. The virus is estimated to kill around 59,000 people every year worldwide, most often as a result of a bite from a rabid dog in parts of Africa and Asia.

Rabies does not circulate in wild or domestic animals in the UK, although some species of bats can carry rabies-like viruses (European Bat Lyssavirus type 1 and type 2). Every year around 150 people in England are treated after being bitten by a bat.

People who believe they may have been exposed to rabies are advised to immediately seek treatment which involves a series of rabies vaccinations with or without immunoglobulin, an antibody treatment that gives immediate short-term protection while the vaccines start to work.

In England, national rabies advice, guidance and treatment is provided through the Rabies and Immunoglobulin Service within Public Health England, with ten issuing centres around the country.

In this study, medical staff from one of the issuing centres in Manchester, North West England conducted a review of all requests for rabies post-exposure treatment at their lab between June 2015 and June 2018.

In total, 200 patients (aged 0-77 years old) received post-exposure treatment through the virology laboratory. Over a third (69/200 patients) were aged 20-29 years old. The vast majority of patients (92%; 183/200) had not received any rabies vaccination in the past.

Results showed that over three-quarters (79% (157/200) of post-exposure treatment was given to travellers returning to the UK from 43 different countries.

However, 1 in 5 individuals (22%; 42/200) reported an exposure to a bat in the UK. “While the risk of catching rabies in the UK is extremely low, it is important that all potential bat bites are risk-assessed and treated as necessary. Bat bites in the UK often do not leave a mark, and are felt rather than seen,” says Dr Brown.

In the UK, although prompt treatment is recommended, given the prolonged incubation time it is never considered too late to receive post-exposure treatment for an exposure.

In separate research, Public Health England doctors found a 7.5-fold increase in the number of risk assessments performed for rabies post-exposure in England since 2001 — increasing from 390 in 2001 to 2949 in 2018 — the majority as a result of dog bites in South and South East Asia, whilst around 1 in 10 were for bat bites in England.

Of the previously unimmunised individuals exposed to animals overseas, 40% did not seek rabies post-exposure treatment overseas, but waited until return to the UK. Similar to the results from Manchester, more than 60% of bat bites sought treatment within 2 days.

Nationally, in addition to the advice and guidance, Public Health England provides rabies vaccine and rabies immunoglobulin for all potential rabies exposures in England. In mid-2018, the guidance on post-exposure treatment for rabies was updated. The routine vaccine schedule for unimmunised individuals was reduced from 5 doses of vaccine to 4 doses. Additionally, a composite rabies risk (red, amber, or green) was calculated for each exposure, taking into account the country and animal risk; and the category of exposure. Rabies immunoglobulin was only recommended in cases with a ‘Red’ composite rabies risk, ie a category 3 exposure (bite or laceration) in a ‘high risk’ country/animal risk combination. Rabies immunoglobulin is also no longer given for bat bites in the UK, although still advised for non-UK bat bites.

Further analysis showed that in the first 6 months following the introduction of the new guidelines, there was a significant increase in the number of calls about possible cases of rabies compared to the same period in 2017 (1727 vs 1157). Nevertheless, there was a decrease in both the number of vaccines (2.4 vs 3) and vials of immunoglobulin (256 vs 575) issued as treatment.

“Those completing the risk assessment found the process easier to follow, and there was less risk of inappropriate treatment given,” says Dr Brown. “The new guidance has led to a significant reduction in the costs of running the program, whilst still ensuring appropriate treatment for those at potential risk of rabies.”

E-waste, or Waste Electrical and Electronic Equipment (WEEE), refers to end-of-life products such as communication devices, consumer electronics and home appliances. E-waste contains substantial amounts of valuable metals to recycle, but is also considered as hazardous waste due to the presence of toxic substances such as heavy metals and many various plastic additives. A large volume of these hazardous waste materials has been recycled inappropriately, and treated informally in Asian and African developing countries using primitive methods such as circuit board heating and open burning of wires. These informal recycling activities have led to serious environmental pollution caused by the emission of not only contaminants contained in e-waste but also unintentionally formed secondary toxic chemicals.

Dioxin-like compounds, or simply dioxins, are a group of unintentional contaminants generated during informal processing of e-waste with a wide range of potential toxic effects. However, assessment of the environmental and health impacts of dioxins from e-waste is challenging due to their complex composition. Chlorinated dioxins including polychlorinated dibenzo-p-dioxins and dibenzofurans are combustion by-products of polyvinyl chloride (PVC) used in wire coating. Lesser-known brominated dioxins are thermal degradation products of brominated flame retardants (BFRs), which are plastic additives designed to prevent accidental fires. Mixed brominated/chlorinated dioxins are also generated during e-waste burning, but have not been well characterized because of the difficulties in analyzing their large number.

The research team in Ehime University used special analytical methods based on two-dimensional gas chromatography (GC×GC) and time-of-flight mass spectrometry (ToFMS) to conduct a comprehensive profiling of halogenated contaminants in the soils collected near e-waste burning and dismantling areas. Polybrominated and mixed halogenated dibenzofurans (PBDFs and PXDFs) were the major dioxins detected. Their composition profiles suggest that PBDFs were generated from polybrominated diphenyl ethers (PBDEs), a group of flame retardants commonly found in e-waste plastics; and PXDFs mainly from PBDFs through successive bromine-to-clorine exchange. High concentrations of PXDFs in e-waste burning areas indicate that these “hidden” dioxins may contribute substantially to the total toxicity of the e-waste-derived dioxin mixture, and need to be included in future environmental and human exposure risk assessment.

Story Source:

Materials provided by Ehime University. Note: Content may be edited for style and length.

But a new study suggests they may want to expand those efforts to their patients, too.

Fourteen percent of 399 hospital patients tested in the study had “superbug” antibiotic-resistant bacteria on their hands or nostrils very early in their hospital stay, the research finds. And nearly a third of tests for such bacteria on objects that patients commonly touch in their rooms, such as the nurse call button, came back positive.

Another six percent of the patients who didn’t have multi-drug resistant organisms, or MDROs, on their hands at the start of their hospitalization tested positive for them on their hands later in their stay. One-fifth of the objects tested in their rooms had similar superbugs on them too.

The research team cautions that the presence of MDROs on patients or objects in their rooms does not necessarily mean that patients will get sick with antibiotic-resistant bacteria. And they note that healthcare workers’ hands are still the primary mode of microbe transmission to patients.

“Hand hygiene narrative has largely focused on physicians, nurses and other frontline staff, and all the policies and performance measurements have centered on them, and rightfully so,” says Lona Mody, M.D., M.Sc., the University of Michigan geriatrician, epidemiologist and patient safety researcher who led the research team. “But our findings make an argument for addressing transmission of MDROs in a way that involves patients, too.”

Studying the spread

Mody and her colleagues report in the new paper in Clinical Infectious Diseases that of the six patients in their study who developed an infection with a superbug called MRSA while in the hospital, all had positive tests for MRSA on their hands and hospital room surfaces.

In addition to MRSA, short for methicillin-resistant Staphylococcus aureus, the study looked for superbugs called VRE (vancomycin-resistant enterococcus) and a group called RGNB, for resistant Gram-negative bacteria. Because of overuse of antibiotics, these bacteria have evolved the ability to withstand attempts to treat infections with drugs that once killed them.

Mody notes that the study suggests that many of the MDROs seen on patients are also seen in their rooms early in their stay, suggesting that transmission to room surfaces is rapid. She heads the Infection Prevention in Aging research group at the U-M Medical School and VA Ann Arbor Healthcare System.

Additionally, since many patients arrive at the hospital through the emergency room, and may get tests in other areas before reaching their hospital room, it will be important to study the ecology of MDROs in those areas too, she says.

“This study highlights the importance of handwashing and environmental cleaning, especially within a healthcare setting where patients’ immune systems are compromised,” says infectious disease physician Katherine Reyes, M.D., lead author for Henry Ford Health System researchers involved in the study. “This step is crucial not only for healthcare providers, but also for patients and their families. Germs are on our hands; you do not need to see to believe it. And they travel. When these germs are not washed off, they pass easily from person to person and objects to person and make people sick.”

More about the study

The team made more than 700 visits to the rooms of general medicine inpatients at two hospitals, working to enroll them in the study and take samples from their bodies and often-touched surfaces as early as possible in their stay. They were not able to test rooms before the patients arrived, and did not test patients who had had surgery, or were in intensive care or other types of units.

Using genetic fingerprinting techniques, they looked to see if the strains of MRSA bacteria on the patients’ hands were the same as the ones in their rooms. They found the two matched in nearly all cases — suggesting that transfer to and from the patient was happening. The technique is not able to distinguish the direction of transfer, whether it’s from patient to objects in the room, or from those objects to patients.

Cleaning procedures for hospital rooms between patients, especially when a patient has been diagnosed with an MDRO infection, have improved over the years, says Mody, and research has shown them to be effective when used consistently. So lingering contamination from past patients may not have been a major factor.

But the question of exactly where patients picked up the MDROs that were found on their bodies, and were transmitted to the surfaces in their rooms, is not addressed by the current study and would be an important next step based on these results.

Why MDROs matter

Also important, says Mody, is the fact that hospital patients don’t just stay in their rooms — current practice encourages them to get up and walk in the halls as part of their recovery from many illnesses, and they may be transported to other areas of the hospital for tests and procedures.

As they travel, they may pick up MDROs from other patients and staff, and leave them on the surfaces they touch.

So even if a relatively healthy person has an MDRO on their skin, and their immune system can fight it off if it gets into their body, a more vulnerable person in the same hospital can catch it and get sick. The researchers are exploring studying MDROs on patients in other types of hospital units who may be more susceptible to infections.

Patients and staff may also get colonized with MDROs in outpatient care settings that have become the site of so much of American health care, including urgent care centers, freestanding imaging and surgery centers, and others.

Mody and colleagues are presenting new data about MDROs in skilled nursing facilities at an infectious disease conference in Europe in coming days. They showed that privacy curtains — often used to separate patients staying in the same room, or to shield patients from view when dressing or being examined — are also often colonized with superbugs.

“Infection prevention is everybody’s business,” says Mody, a professor of internal medicine at the U-M Medical School. “We are all in this together. No matter where you are, in a healthcare environment or not, this study is a good reminder to clean your hands often, using good techniques — especially before and after preparing food, before eating food, after using a toilet, and before and after caring for someone who is sick — to protect yourself and others.”