Extraterrestrial habitability is a complex notion. We briefly review what is known about the origin of life on Earth, that is, life based on carbon chemistry and water. We then discuss habitable conditions (past and present) for established life and for the survival of microorganisms. Based on these elements, we propose to use the term habitable only for conditions necessary for the origin of life, the proliferation of life, and the survival of life. Not covered by this term would be conditions necessary for prebiotic chemistry and conditions that would allow the recognition of extinct or hibernating life. Finally, we apply this concept to the potential emergence of life on Mars where suitable conditions for life to start, proliferate, and survive have been heterogeneous throughout its history. These considerations have a profound impact on the nature and distribution of eventual traces of martian life, or any precursor, and must therefore inform our search-for-life strategies.
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http://dx.doi.org/10.1089/ast.2013.1000 | DOI Listing |
Plant Signal Behav
December 2025
School of Medical Technology, Chongqing Three Gorges Medical College, Chongqing, China.
The most damaging disease affecting citrus globally is Huanglongbing (HLB), primarily attributed to the infection by ' asiaticus' (Las). Based on comparative transcriptome data, two cellulose synthase (CESA) genes responsive to Las infection induction were screened, and one gene cloned with higher differential expression level was selected and named . we verified the interaction between CsCESA1 and citrus exopolysaccharide 2 (CsEPS2) proteins.
View Article and Find Full Text PDFJMIR Rehabil Assist Technol
December 2024
College of Arts, Business, Law, Education and IT, Victoria University, Footscray Park, Australia.
Background: Evidence suggests that individuals with motor neuron disease (MND), a terminal illness, find enjoyment and social connection through video games. However, MND-related barriers can make gaming challenging, exacerbating feelings of boredom, stress, isolation, and loss of control over daily life.
Objective: We scoped the evidence to describe relevant research and practice regarding what may help reduce difficulties for people with MND when playing video games.
J Am Chem Soc
December 2024
School of Chemistry, University of New South Wales, Kensington, NSW 2052, Australia.
Hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs) are the leading synthetic replacements for compounds successively banned by the Montreal Protocol and amendments. HFOs and HCFOs readily decompose in the atmosphere to form fluorinated carbonyls, including CFCHO in yields of up to 100%, which are then photolyzed. A long-standing issue, critical for the transition to safe industrial gases, is whether atmospheric decomposition of CFCHO yields any quantity of CHF (HFC-23), which is one of the most environmentally hazardous greenhouse gases.
View Article and Find Full Text PDFElife
December 2024
Howard Hughes Medical Institute, Stanford University, Stanford, United States.
Defining the cellular factors that drive growth rate and proteome composition is essential for understanding and manipulating cellular systems. In bacteria, ribosome concentration is known to be a constraining factor of cell growth rate, while gene concentration is usually assumed not to be limiting. Here, using single-molecule tracking, quantitative single-cell microscopy, and modeling, we show that genome dilution in cells arrested for DNA replication limits total RNA polymerase activity within physiological cell sizes across tested nutrient conditions.
View Article and Find Full Text PDFJ Med Internet Res
December 2024
Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
Background: Mobile health (mHealth) interventions have gained popularity in augmenting psychiatric care for adults with psychosis. Interest has grown in leveraging mHealth to empower individuals living with severe mental illness and extend continuity of care beyond the hospital to the community. However, reported outcomes have been mixed, likely attributed in part to the intervention and adopted outcomes, which affected between-study comparisons.
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