"There are some tragic cases of children whose brains failed to develop because of their parents being ill-informed vegans," says David Benton, who studies the link between our diets and brain chemistry at Swansea University. In one example, the child was unable to sit or smile. In another, they slipped into a coma.

Later in life, the amount of B12 in a person's blood has been directly correlated with their IQ. In the elderly, one study found that the brains of those with lower B12 were six times more likely to be shrinking.

Even so, low B12 is widespread in vegans. One British study found that half of the vegans in their sample were deficient. In some parts of India, the problem is endemic — possibly as a consequence of the popularity of meat-free diets.

With COVID-19, vaccines still fulfill their primary role: protecting against severe disease. According to the US Centers for Disease Control and Prevention, vaccinated people who catch the Delta variant are 25 times less likely to have a severe case or die. The overwhelming majority who do catch it will have mild or no symptoms.

But growing evidence suggests that, with the Delta variant, fully vaccinated people can still transmit the virus.

Most countries have land borders and voters. For them isolation was never feasible. Instead, they have adopted a confusing, illogical mess of rules. America bars travellers from Britain and the European Union, its closest allies and trade partners, and also two of the most vaccinated big places in the world, while admitting those from South-East Asia, where the Delta variant is rampant. Thailand bans entry from some countries and requires all other travellers to submit to a two-week quarantine. Yet of 21,038 cases identified on August 10th, only 19 were imported. Once a variant of the virus has started to spread in the local population, infections double every couple of weeks. Entry bans make very little difference to the total caseload.

One conspiracy site even claimed vaccinated people were dying at higher rates than those who had not received the jab, which is untrue.

This site and others use real figures in a misleading way, to arrive at a completely false conclusion - that the vaccine may not be working or even doing more harm than good.

Herbs are a fantastic addition to your Parrot's diet, not only for their abundance of health benefits, but also in the variety they provide as part of a balanced diet. They can be presented in a chop, threaded through the cage bars, or even strung together as a shredding toy.

The standard story about nuclear costs is that radiation is dangerous, and therefore safety is expensive. The book argues that this is wrong: nuclear can be made safe and cheap. It should be 3 c/kWh — cheaper than coal.

As covid-19 has spread around the world, people have become grimly familiar with the death tolls that their governments publish each day. Unfortunately, the total number of fatalities caused by the pandemic may be even higher, for several reasons. First, the official statistics in many countries exclude victims who did not test positive for coronavirus before dying — which can be a substantial majority in places with little capacity for testing. Second, hospitals and civil registries may not process death certificates for several days, or even weeks, which creates lags in the data. And third, the pandemic has made it harder for doctors to treat other conditions and discouraged people from going to hospital, which may have indirectly caused an increase in fatalities from diseases other than covid-19.

One way to account for these methodological problems is to use a simpler measure, known as "excess deaths": take the number of people who die from any cause in a given region and period, and then compare it with a historical baseline from recent years. We have used statistical models to create our baselines, by predicting the number of deaths each region would normally have recorded in 2020.

Experimental and epidemiological data support community masking to reduce the spread of SARS-CoV-2. The prevention benefit of masking is derived from the combination of source control and personal protection for the mask wearer. The relationship between source control and personal protection is likely complementary and possibly synergistic¹⁴, so that individual benefit increases with increasing community mask use. Further research is needed to expand the evidence base for the protective effect of cloth masks and in particular to identify the combinations of materials that maximize both their blocking and filtering effectiveness, as well as fit, comfort, durability, and consumer appeal. Adopting universal masking policies can help avert future lockdowns, especially if combined with other non-pharmaceutical interventions such as social distancing, hand hygiene, and adequate ventilation.

Any book of Why We Sleep's length is bound to contain some factual errors. Therefore, to avoid potential concerns about cherry-picking the few inaccuracies scattered throughout, in this essay, I'm going to highlight the five most egregious scientific and factual errors Walker makes in Chapter 1 of the book. This chapter contains 10 pages and constitutes less than 4% of the book by the total word count.

At its root, the problem we face is that we have entered a space age world with Stone Age genes – genes that evolved to produce jaws adapted to a hunter-gatherer diet. Today's jaws epidemic is concealed behind the commonplace. Its most obvious symptoms are oral and facial: crooked teeth (and the accompanying very common use of braces), receding jaws, a smile that shows lots of gums, mouth breathing, and interrupted breathing during sleep. A bother, but hardly an 'epidemic' – at least until one recognizes the relationship between malocclusion and a veritable host of downstream health consequences.