by Brian A. Nosek, Timothy M. Errington

Credibility of scientific claims is established with evidence for their replicability using new data. According to common understanding, replication is repeating a study’s procedure and observing whether the prior finding recurs. This definition is intuitive, easy to apply, and incorrect. We propose that replication is a study for which any outcome would be considered diagnostic evidence about a claim from prior research. This definition reduces emphasis on operational characteristics of the study and increases emphasis on the interpretation of possible outcomes. The purpose of replication is to advance theory by confronting existing understanding with new evidence. Ironically, the value of replication may be strongest when existing understanding is weakest. Successful replication provides evidence of generalizability across the conditions that inevitably differ from the original study; Unsuccessful replication indicates that the reliability of the finding may be more constrained than recognized previously. Defining replication as a confrontation of current theoretical expectations clarifies its important, exciting, and generative role in scientific progress.

by Bo Xia, Xiao Chen Shi, Bao Cai Xie, Meng Qing Zhu, Yan Chen, Xin Yi Chu, Guo He Cai, Min Liu, Shi Zhen Yang, Grant A. Mitchell, Wei Jun Pang, Jiang Wei Wu

Obesity leads to multiple health problems, including diabetes, fatty liver, and even cancer. Here, we report that urolithin A (UA), a gut-microflora–derived metabolite of pomegranate ellagitannins (ETs), prevents diet-induced obesity and metabolic dysfunctions in mice without causing adverse effects. UA treatment increases energy expenditure (EE) by enhancing thermogenesis in brown adipose tissue (BAT) and inducing browning of white adipose tissue (WAT). Mechanistically, UA-mediated increased thermogenesis is caused by an elevation of triiodothyronine (T3) levels in BAT and inguinal fat depots. This is also confirmed in UA-treated white and brown adipocytes. Consistent with this mechanism, UA loses its beneficial effects on activation of BAT, browning of white fat, body weight control, and glucose homeostasis when thyroid hormone (TH) production is blocked by its inhibitor, propylthiouracil (PTU). Conversely, administration of exogenous tetraiodothyronine (T4) to PTU-treated mice restores UA-induced activation of BAT and browning of white fat and its preventive role on high-fat diet (HFD)-induced weight gain. Together, these results suggest that UA is a potent antiobesity agent with potential for human clinical applications.

by Peter J. Hotez

In the last half of the 2010s, we saw an upswing in antiscience movements and unprecedented attacks on scientists in the United States and elsewhere. All indications suggest that this trend will not slow or reverse anytime soon, and it is now increasingly apparent that it will fall to the scientists themselves to respond, engage a skeptical public, and lead the defense of science. Accordingly, we must recognize opportunities to both reorganize science doctoral and postdoctoral training and incentivize senior scientists as a means to establish a new ecosystem for science public engagement. Such activities may become essential if the assaults on our profession continue or expand. Today, the commitment of young scientists to public service is at an all-time high. However, we must work quickly to capture that enthusiasm and channel it into a social good, lest we lose this opportunity. Potentially, open-access publishers could play a central role.

The latest coronavirus news updated every day including coronavirus cases, the latest news, features and interviews from New Scientist and essential information about the covid-19 pandemic

The latest coronavirus news updated every day including coronavirus cases, the latest news, features and interviews from New Scientist and essential information about the covid-19 pandemic

The latest coronavirus news updated every day including coronavirus cases, the latest news, features and interviews from New Scientist and essential information about the covid-19 pandemic

The peak of the UK coronavirus epidemic now looks likely to arrive within the next month, according to analysis by the government’s science advisers

The peak of the UK coronavirus epidemic now looks likely to arrive within the next month, according to analysis by the government’s science advisers

The peak of the UK coronavirus epidemic now looks likely to arrive within the next month, according to analysis by the government’s science advisers

Meteorologists rely on a steady stream of weather data collected by planes to produce accurate forecasts, but most commercial flights have been grounded to slow the spread of the coronavirus

Meteorologists rely on a steady stream of weather data collected by planes to produce accurate forecasts, but most commercial flights have been grounded to slow the spread of the coronavirus

Meteorologists rely on a steady stream of weather data collected by planes to produce accurate forecasts, but most commercial flights have been grounded to slow the spread of the coronavirus

UK prime minister Boris Johnson has said a mass-produced antibody test for covid-19 that can be done at home will be a game changer - but this type of test has limitations

UK prime minister Boris Johnson has said a mass-produced antibody test for covid-19 that can be done at home will be a game changer - but this type of test has limitations

UK prime minister Boris Johnson has said a mass-produced antibody test for covid-19 that can be done at home will be a game changer - but this type of test has limitations

Does being exposed to more virus particles mean you’ll develop more severe illness? Data suggests the relationship between infection and severity may be complex

Does being exposed to more virus particles mean you’ll develop more severe illness? Data suggests the relationship between infection and severity may be complex

Does being exposed to more virus particles mean you’ll develop more severe illness? Data suggests the relationship between infection and severity may be complex

Inspired by a series of artworks, Tales From The Loop is an Amazon series about the strange goings-on in a town set atop an experimental physics research facility

Inspired by a series of artworks, Tales From The Loop is an Amazon series about the strange goings-on in a town set atop an experimental physics research facility