Causal mediation analysis provides techniques for defining and estimating effects that may be endowed with mechanistic interpretations. With many scientific investigations seeking to address mechanistic questions, causal direct and indirect effects have garnered much attention. The natural direct and indirect effects, the most widely used among such causal mediation estimands, are limited in their practical utility due to stringent identification requirements. Accordingly, considerable effort has been invested in developing alternative direct and indirect effect decompositions with relaxed identification requirements. Such efforts often yield effect definitions with nuanced and challenging interpretations. By contrast, relatively limited attention has been paid to relaxing the identification assumptions of the natural direct and indirect effects. Motivated by a secondary aim of a recent non-randomized vaccine prospective cohort study (NCT05168813), we present a set of relaxed conditions under which the natural direct effect is identifiable in spite of unobserved baseline confounding of the exposure-mediator pathway; we use this result to investigate the effect mediated by putative immune correlates of protection. Relaxing the commonly used but restrictive cross-world counterfactual independence assumption, we discuss strategies for evaluating the natural direct effect in non-randomized settings that arise in the analysis of vaccine studies. We revisit prior studies of semi-parametric efficiency theory to demonstrate the construction of flexible, multiply robust estimators of the natural direct effect and discuss efficient estimation strategies that do not place restrictive modeling assumptions on nuisance functions.

The fungi prefer to grow in cow dung. A newly described African species in the magic mushroom family confirms its evolutionary origin. 'Psilocybe ochraceocentrata' is found growing on cattle dung in the grasslands of southern Africa and Zimbabwe. Breakthroughs, discoveries, and DIY tips sent six days a week. The discovery of a new magic mushroom species in Africa is forcing mycologists to take another look at the famous psychedelic fungi's evolutionary history.

The vast amount of data required to model wildfires at a larger scale presents difficulties in the collection and curation of the data.

Text-to-Image (T2I) has witnessed significant advancements, demonstrating superior performance for various generative tasks.

Annotateddimensionsinclude Valence, Arousal and Emotion label, with annotations gathered using Prolific.

Could Ukraine hold a presidential election right now? Will Europe use frozen Russian assets to fund war? How can Ukraine rebuild China ties? 'Ukraine is running out of men, money and time' A Russian drone strike hit a residential building in the Ukrainian city of Dnipro, injuring seven people and causing significant damage, according to local officials. Residents said the blast shattered windows and sparked a fire in the apartment block.

President Trump's favourite word is tariffs. He reminded the world of that in his pre-Christmas address to the nation. With the world still unwrapping the tariffs gift from the first year of his second term in office, he said they were bringing jobs, higher wages and economic growth to the US. What is less debatable is that they've refashioned the global economy, and will continue to do so into 2026. The International Monetary Fund (IMF) says that although the tariff shock is smaller than originally announced, it is a key reason why it now expects the rate of global economic growth to slow to 3.1% in 2026.

Science Archaeology World's oldest poison-tipped arrow discovered in South Africa The 60,000-year-old relic contains traces of a toxic onion. Breakthroughs, discoveries, and DIY tips sent every weekday. For thousands of years, hunters around the world have employed poison-tipped arrows to assist in taking down prey. For example, the curare plant poisons used by South and Central American hunters paralyzes the respiratory system. Meanwhile, inhabitants of the Kalahari Desert have relied on the toxins harvested from beetle larvae .

The Swampy Black Iguana is the oldest specimen living at the Iguana Station scientific station, where they have a breeding and conservation project for black spiny-tailed iguanas. This species, endemic to Utila, is in danger of extinction. The Utila Iguana Conservation Project seeks to ensure the survival of this species. Breakthroughs, discoveries, and DIY tips sent every weekday. With the turning of the calendar comes a new year and new vulnerable endangered plant and animal species to keep a watchful eye on.

Speech technology remains out of reach for most of the over 2300 languages in Africa. We present the first systematic assessment of large-scale synthetic voice corpora for African ASR. We apply a three-step process: LLM-driven text creation, TTS voice synthesis, and ASR fine-tuning. Eight out of ten languages for which we create synthetic text achieved readability scores above 5 out of 7. We evaluated ASR improvement for three (Hausa, Dholuo, Chichewa) and created more than 2,500 hours of synthetic voice data at below 1% of the cost of real data. Fine-tuned Wav2Vec-BERT-2.0 models trained on 250h real and 250h synthetic Hausa matched a 500h real-data-only baseline, while 579h real and 450h to 993h synthetic data created the best performance. We also present gender-disaggregated ASR performance evaluation. For very low-resource languages, gains varied: Chichewa WER improved about 6.5% relative with a 1:2 real-to-synthetic ratio; a 1:1 ratio for Dholuo showed similar improvements on some evaluation data, but not on others. Investigating intercoder reliability, ASR errors and evaluation datasets revealed the need for more robust reviewer protocols and more accurate evaluation data. All data and models are publicly released to invite further work to improve synthetic data for African languages.