A study using Ontario's 34 Public Health Units over the course of two months found that wearing a mask can have a significant impact on the spread of COVID-19.

No argument there, anyone would be worried if their surgeon showed up in the operating room without a mask on, but the economists go a little further and claim mask mandates are the reason. They statistically associate mandates with a 25 percent reduction in COVID-19 cases.
For some reason today I remembered that 11 years ago (wow time flies) I wrote a two-parts piece on advices for PhD students doing a thesis in experimental particle physics. As I checked it out, I found that I mostly share the views I had back then (TBH that's not necessarily a good thing - consistency requires you to be as ignorant as you were earlier on). Since I think that stuff I posted over 10 years ago are otherwise lost in oblivion and not picked up by generic google searches, I decided it is time to recycle that text - here it is below, unamended but collated into a single longish article. Enjoy!
A new paper seeks to take some of the guesswork out of subjective "sustainable" diets. Activists like True Health Initiative try to claim that a meatless diet is better for human health and the environment, for example, but their corporate sponsorships lead to skepticism. Claims about the emissions impact of meat production are often exaggerated by 700 percent. Environmentalists have never visited a farm if they think all grazing land could be growing tomatoes.
Have you been told you have a greater risk of heart disease based on family history? What does that even mean?
A small percentage of farmers engage in an alternative form of agriculture termed "organic" because they believe it is a more natural manufacturing process, since it was used in the past.

The scientific flaws in that logic are well known, but the higher profits and environmental effects are real. Though California has only a tiny amount of organic produce, it requires 300 percent more pesticides to grow the same food as it would if they used regular farming. Organic farmers believe the higher profits are worth the higher economic and environmental costs.
Like with kids, when it comes to galaxies adolescent blemishes disappear over time.

Exponential disks, common in spiral galaxies, dwarf elliptical galaxies and some irregular galaxies, appear smooth and have an exponential fade. How did they get it way?

It's not possible to know but using inference, simulations help provide insight. 

Graohic showing how two sample star orbits are scattered from nearly circular orbits by the gravity of massive clumps within galaxies. Image: Illustration by Jian Wu/Iowa State University. Galaxy image from the Sloan Digital Sky Survey.
Marco Fulvio Barozzi (b.
Bristol-Meyers Squibb has received the first drug regimen approved for mesothelioma in 16 years and the second FDA-approved systemic therapy for mesothelioma has gotten U.S. Food and Drug Administration approval.

The combination therapy is Opdivo (nivolumab) and Yervoy (ipilimumab) for the first-line treatment of adults with malignant pleural mesothelioma that cannot be removed by surgery.
The overwhelming majority who have gotten or ever will get COVID-19, resulting from the third coronavirus pandemic, named SARS-CoV-2, of this century, won't know it. Most who are not asymptomatic will have it be the same as a cold.

Yet a few will have severe reactions and require hospitalization. Just like with flu or any cause of respiratory distress, age is the biggest risk factor, as are preexisting conditions that can aggravate numerous health issues, but research by the COVID-19 Host Genetics Initiative has shown that genetic variants in one region on chromosome 3 impose a larger risk that their carriers will develop a severe form of the disease. Across all ages and strata of health.
In the Cueva de la Dehesilla of Cádiz on the Iberian Peninsula, two human skulls and a juvenile goat were discovered in a funerary structure dating to the Middle Neolithic period, 4800-4000 B.C.

The archaeological structures and materials from a funerary ritual tell a tale of human and animal sacrifice, ancestral cults and propitiatory rituals, or they could be divine prayers in commemorative festivities.

The two adult human skulls are an older male and a younger female. The female skull shows a depression in the frontal bone, which probably comes from an incomplete trepanation, as well as cuts in the occipital bone produced by decapitation.