Poliovirus may be spreading in London; virus detected in sewage for months

A vaccine-derived version of poliovirus has repeatedly surfaced in London sewage over the past several months, suggesting there may be cryptic, or hidden, spread among some unvaccinated people, UK health officials announced Wednesday.

No cases of polio have been reported so far, nor have there been any identified cases of paralysis. But sewage sampling in one London treatment plant has repeatedly detected closely related vaccine-derived polioviruses between February and May. This suggests "it is likely there has been some spread between closely-linked individuals in North and East London and that they are now shedding the type 2 poliovirus strain in their feces," the UK Health Security Agency (UKHSA) said.

Though the current situation raises alarm, the agency notes that it's otherwise common to see a small number of vaccine-like polioviruses pop up in sewage from time to time, usually from people who have recently been vaccinated out of the country. This is because many countries use oral polio vaccines that include weakened (attenuated) polioviruses, which can still replicate in the intestines and thus be present in stool. They can also spread to others via poor hygiene and sanitation (i.e. unwashed hands and food or water contaminated by sewage), which can become very concerning amid poor vaccination rates.

A little after noon on June 21, National Indigenous People's Day, a young miner working in Yukon's Eureka Creek, south of Dawson City, was digging up muck using a front end loader when he struck something.

He stopped and called his boss who went to see him right away.

When he arrived, Treadstone Mining's Brian McCaughan put a stop to the operation on the spot.

Within half an hour, Zazula received a picture of the discovery.

According to Zazula, the miner had made the "most important discovery in paleontology in North America."

It was a whole baby woolly mammoth, only the second one ever found in the world, and the first in North America.

"She has a trunk. She has a tail. She has tiny little ears. She has the little prehensile end of the trunk where she could use it to grab grass," said Zazula.

"She's perfect and she's beautiful."

Humans can't endure temperatures and humidities as high as previously thought

UNIVERSITY PARK, Pa. — As climate change nudges the global temperature higher, there is rising interest in the maximum environmental conditions like heat and humidity to which humans can adapt. New Penn State research found that in humid climates, that temperature may be lower than previously thought.

It has been widely believed that a 35°C wet-bulb temperature (equal to 95°F at 100% humidity or 115°F at 50% humidity) was the maximum a human could endure before they could no longer adequately regulate their body temperature, which would potentially cause heat stroke or death over a prolonged exposure.

Wet-bulb temperature is read by a thermometer with a wet wick over its bulb and is affected by humidity and air movement. It represents a humid temperature at which the air is saturated and holds as much moisture as it can in the form of water vapor; a person’s sweat will not evaporate at that skin temperature.

But in their new study, the researchers found that the actual maximum wet-bulb temperature is lower — about 31°C wet-bulb or 87°F at 100% humidity — even for young, healthy subjects. The temperature for older populations, who are more vulnerable to heat, is likely even lower.

Controversy Continues Over Whether Hot Water Freezes Faster Than Cold


Decades after a Tanzanian teenager initiated study of the “Mpemba effect,” the effort to confirm or refute it is leading physicists toward new theories about how substances relax to equilibrium.

Whether hot or cold water freezes faster remains unknown.

It sounds like one of the easiest experiments possible: Take two cups of water, one hot, one cold. Place both in a freezer and note which one freezes first. Common sense suggests that the colder water will. But luminaries including Aristotle, Rene Descartes and Sir Francis Bacon have all observed that hot water may actually cool more quickly. Likewise, plumbers report hot water pipes bursting in subzero weather while cold ones remain intact. Yet for more than half a century, physicists have been arguing about whether something like this really occurs.

The modern term for hot water freezing faster than cold water is the Mpemba effect, named after Erasto Mpemba, a Tanzanian teenager who, along with the physicist Denis Osborne, conducted the first systematic, scientific studies of it in the 1960s. While they were able to observe the effect, follow-up experiments have failed to consistently replicate that result. Precision experiments to investigate freezing can be influenced by many subtle details, and researchers often have trouble determining if they have accounted for all confounding variables.

A better heat engine

A new design with no moving parts converts heat to electricity more efficiently than a steam turbine and could lead to a fully decarbonized power grid.

Engineers at MIT and the National Renewable Energy Laboratory (NREL) have designed a heat engine with no moving parts. It converts heat to electricity with over 40% efficiency—making it more efficient than steam turbines, the industrial standard.

The invention is a thermophotovoltaic (TPV) cell, similar to a solar panel’s photovoltaic cells, that passively captures high-energy photons from a white-hot heat source. It can generate electricity from sources that reach 1,900 to 2,400 °C—too hot for turbines, with their moving parts. The previous record efficiency for a TPV cell was 32%, but the team improved this performance by using materials that are able to convert higher-­temperature, higher-energy photons.

The researchers plan to incorporate the TPV cells into a grid-scale thermal battery. The system would absorb excess energy from renewable sources such as the sun and store that energy in heavily insulated banks of hot graphite. Cells would convert the heat into electricity and dispatch it to a power grid when needed.

The international LHCb collaboration at the Large Hadron Collider (LHC) has observed three never-before-seen particles: a new kind of “pentaquark” and the first-ever pair of “tetraquarks”, which includes a new type of tetraquark. The findings, presented today at a CERN seminar, add three new exotic members to the growing list of new hadrons found at the LHC. They will help physicists better understand how quarks bind together into these composite particles.

Quarks are elementary particles and come in six flavours: up, down, charm, strange, top and bottom. They usually combine together in groups of twos and threes to form hadrons such as the protons and neutrons that make up atomic nuclei. More rarely, however, they can also combine into four-quark and five-quark particles, or “tetraquarks” and “pentaquarks”. These exotic hadrons were predicted by theorists at the same time as conventional hadrons, about six decades ago, but only relatively recently, in the past 20 years, have they been observed by LHCb and other experiments.

Most of the exotic hadrons discovered in the past two decades are tetraquarks or pentaquarks containing a charm quark and a charm antiquark, with the remaining two or three quarks being an up, down or strange quark or their antiquarks. But in the past two years, LHCb has discovered different kinds of exotic hadrons. Two years ago, the collaboration discovered a tetraquark made up of two charm quarks and two charm antiquarks, and two “open-charm” tetraquarks consisting of a charm antiquark, an up quark, a down quark and a strange antiquark. And last year it found the first-ever instance of a “double open-charm” tetraquark with two charm quarks and an up and a down antiquark. Open charm means that the particle contains a charm quark without an equivalent antiquark.

The discoveries announced today by the LHCb collaboration include new kinds of exotic hadrons. The first kind, observed in an analysis of “decays” of negatively charged B mesons, is a pentaquark made up of a charm quark and a charm antiquark and an up, a down and a strange quark. It is the first pentaquark found to contain a strange quark. The finding has a whopping statistical significance of 15 standard deviations, far beyond the 5 standard deviations that are required to claim the observation of a particle in particle physics.

Do corporate tax cuts boost economic growth?

Tl;dr: No.