Naked Scientists Weekly: Malaria Relapse Trials, Organ Tolerance Breakthroughs, Contagious Urination in Chimpanzees, Aviation Carbon Solutions, and a Tinnitus Mystery

Podcast snapshot

The Naked Scientists cover five diverse science stories in this episode, led by a UK malaria vivax relapse trial to understand how dormant liver stages reawaken, followed by a transplantation study revealing how including a donor kidney with a bone marrow transplant may reprogram immunity to accept another organ. The show also reports contagious urination in captive chimpanzees and expert commentary on possible ways to reduce aviation emissions. A final QOTW explores the somatosensory links to tinnitus with a clinical perspective.

Key insights

• Deliberate infection in volunteers aims to illuminate relapse biology of vivax malaria and enable vaccine and drug testing platforms.
• Kidney-tolerant transplantation via donor bone marrow challenges conventional immunosuppression, hinting at a kidney driven immune-regulation mechanism.
• Contagious urination in chimpanzees may reflect state matching and social bonding mechanisms in primates.
• Aviation emissions reductions require planning, efficiency improvements, sustainable fuels, eco-friendly airports, and smarter travel practices.
• Tinnitus in some people relates to the temporomandibular joint and somatosensory pathways, offering a potential therapeutic angle.

Overview

The Naked Scientists podcast assembles five science stories in this episode, moving from infectious disease research to transplant immunology, animal behavior, aviation sustainability, and hearing science. The program blends interviews with researchers and expert commentary to unpack complex topics in accessible ways. The first segment highlights a UK malaria vivax relapse trial designed to dissect how dormant liver-stage parasites reawaken and cause relapse, and how this model could serve as a platform for vaccines and anti-malarial drugs. The second segment shifts to transplantation, reporting a surprising finding that pairing a kidney with a bone marrow transplant from the same donor can enable a transplanted heart to be tolerated, suggesting the kidney plays a special immune-regulatory role. The show also covers contagious urination in chimpanzees observed in a Kyoto University study, then pivots to aviation, exploring practical steps the industry could take to reduce its carbon footprint. The final portion of the show features the Question of the Week asking why tinnitus improves when gum chewing stops, with a clinical perspective on somatosensory tinnitus.

UK vivax malaria relapse study

The Oxford vaccine group is planning a small, tightly controlled study in five healthy UK volunteers to be deliberately infected with Plasmodium vivax malaria. Vivax can relapse months or years after an initial infection because dormant parasites hide in the liver. The goal is to create a controlled scenario that makes relapse easier to study, enabling researchers to identify triggers, immune responses, and molecular processes involved in reactivation. Volunteers will be exposed to a box-contained group of infected mosquitoes, and daily blood tests will monitor infection onset using quantitative PCR. After active infection is cleared with treatment, the dormant liver-stage parasites are left undisturbed to study relapse, with close monitoring for six months. The team sees this as a potential platform for testing vaccines and new drugs, providing insights that are difficult to obtain from natural infections alone. Primaquine is noted as a drug capable of clearing dormant parasites, though its mechanism remains not fully understood. The long-term data set will include serial blood samples and advanced analyses to identify markers of relapse and host responses. This research could reshape how relapse is understood and how interventions are developed to prevent relapse worldwide.

Kidney tolerance and bone marrow transplantation

In a separate segment, the Naked Scientists discuss a US-led study that extends a bone marrow transplant strategy to other organs. Historically, organ transplants outside the kidney have required ongoing immunosuppression with side effects including cancer risk and infections. The researchers show that adding a donor kidney to a simultaneous heart transplant can result in tolerance for the heart that survives without rejection, a phenomenon not seen when a donor heart is transplanted alone. The proposed mechanism centers on regulatory T cells associated with the kidney and their possible role in conditioning the recipient’s immune system to accept the heart. The team used a chimera concept, where the immune systems of donor and recipient mix in a controlled way, potentially reducing reliance on long-term immunosuppressive therapy. The discussion underscores open questions about why the kidney has this unique tolerance effect and whether these cells could be harnessed in non-surgical ways in the future. The Cambridge faculty member John Trousdale contributes expert commentary on the paper, its significance, and the broader implications for transplant medicine.

Contagious urination in chimpanzees

The program then travels to Japan, reporting observations of contagious urination among captive chimpanzees in a Kyoto University study. The researchers note that contagious urination resembles contagious yawning in that it appears to be socially contagious rather than an intentional act. Observations from a group of 20 chimpanzees across four subgroups revealed that lower-ranked individuals were more likely to copy others, and proximity increased the likelihood of contagion. Possible explanations include state matching that coordinates group readiness for collective movements and bonding through copying behaviour. The study suggests contagious urination may occur in the wild and could be a broader feature across primates, opening questions about communication, social structure, and the evolution of cooperative behavior.

Aviation sustainability and policy ideas

The discussion shifts to the aviation industry, with Mark Maslin of University College London outlining five recommendations to reduce emissions while the sector seeks long-term alternatives. The five points include optimizing flight planning and routing using artificial intelligence to minimize fuel use and avoid traffic delays, retrofitting older aircraft with efficiency-enhancing features, adopting sustainable aviation fuels (SAFs) and policies that fairly distribute SAFs, making airports eco-friendly by using renewable energy and electrifying airport vehicles and processes, and finally rethinking passenger travel to reduce overall demand and weight carried by travellers. Maslin emphasizes data sharing with airlines to quantify the carbon savings from optimized routes and other efficiency gains, highlighting the need for practical, near-term actions to move toward net-zero by 2050.

Question of the Week and tinnitus

The final segment presents the Question of the Week about tinnitus, where George reports tinnitus relief after stopping gum chewing. ENT specialist Malcolm Hilton explains somatosensory tinnitus, where jaw-related signals influence auditory pathways, particularly via the temporomandibular joint. The somatosensory system can modulate spontaneous neural activity and influence tinnitus pitch and loudness, suggesting that temporomandibular disorders may increase tinnitus risk in some individuals. The exchange highlights a potential clinical angle for somatosensory tinnitus and points to broader links between jaw function, neural processing, and hearing.

Wrap and context

The Naked Scientists episode concludes with credits and a note that future updates will continue to report on these stories as they unfold. The breadth of topics demonstrates the program’s aim to connect breakthroughs across biology, medicine, environment, and technology with up-to-date science communication.