Climate change affects how organic materials are decomposed 

intestinal tumours, molecular scissors, disease, genetic, immune cells, drug development, Diabetes, Antibiotic, hydrogen generation, chronic obstructive pulmonary disease, malaria, photosynthesis, kidney failure, Brain tumours, mental health, blood cancer, cancer, dementia, cancer treatment, antibiotic resistance, blood vessel leakage, quantum simulations, atrial fibrillation, batteries, goiter treatment, terahertz radiation, organic materials , Guild of European Research Intensive Universities, gene copies, social anxiety, blue light screens, ‘Our hope is that these findings will make it possible to discover a way to selectively inhibit the TGF-beta signals that stimulate tumour development without knocking out the signals that inhibit tumour development, and that this can eventually be used in the fight against cancer,’ says Eleftheria Vasilaki, postdoctoral researcher at Ludwig Institute for Cancer Research at Uppsala University and lead author of the study. TGF-beta regulates cell growth and specialisation, in particular during foetal development. In the context of tumour development, TGF-beta has a complicated role. Initially, it inhibits tumour formation because it inhibits cell division and stimulates cell death. At a late stage of tumour development, however, TGF-beta stimulates proliferation and metastasis of tumour cells and thereby accelerates tumour formation. TGF-beta’s signalling mechanisms and role in tumour development have been studied at the Ludwig Institute for Cancer Research at Uppsala University for the past 30 years. Recent discoveries at the Institute, now published in the current study in Science Signaling, explain part of the mechanism by which TGF-beta switches from suppressing to enhancing tumour development. Uppsala researchers, in collaboration with a Japanese research team, discovered that TGF-beta along with the oncoprotein Ras, which is often activated in tumours, affects members of the p53 family. The p53 protein plays a key role in regulating tumour development and is often altered – mutated – in tumours. TGF-beta and Ras suppress the effect of mutated p53, thereby enhancing the effect of another member of the p53 family, namely delta-Np63, which in turn stimulates tumour development and metastasis.

A new study by researchers at Uppsala University and the Swedish University of Agricultural Sciences shows that the decomposition of organic materials in lakes, rivers and streams is controlled on a large scale by the climate, and in particular by the water balance. Knowing how quickly this decomposition happens is key to our ability to understand how the turnover of organic materials is affected by environmental changes.

Large amounts of organic material are carried from land ecosystems through rivers and streams down to the oceans. On its way, some of this material is broken down by micro-organisms in the water.

The wetter the climate, the faster water flows through the landscape to the ocean. This shortens the amount of time the water spends inland, reducing the time micro-organisms have to decompose different organic materials in the water.

To study how this affects the rate of organic material decomposition, researchers at Uppsala University, the Swedish University of Agricultural Sciences, and the University of Girona in Spain, compiled data from more than 300 published studies, where decomposition rate was measured for different water retention times. The researchers found that the organic material was decomposed at a higher rate when water turnover was higher – due to more easily decomposed compounds remaining in the water to a higher extent. They then compared that connection to how water turnover is expected to change with different future climatic scenarios. Some areas will get wetter, with water flowing faster into the oceans, while others will get dryer. Therefore decomposition rate is expected to increase in many northern areas, but decrease in for example the Mediterranean region.

The researchers found that the average half-life of organic material in lakes and watercourses is 2.5 years. This is significantly shorter than in most other environments, for example earths, oceans and sediment. Inland water can therefore be viewed as a kind of global hot spot for decomposition of organic material.

The research is a collaboration between the Swedish University of Agricultural Sciences and a Spanish research institute, and has been funded by the Swedish Research Council Formas, the Knut and Alice Wallenberg Foundation, and a grant from the Wenner-Gren Foundations to Núria Catalán who is lead author of the article.

The findings have been published in Nature Geoscience.

Reference: Catalán, N., Marcé, R., Kothawala, D.N., and Tranvik. L. J. Organic carbon decomposition rates controlled by water retention time across inland waters. Nature Geoscience