Photosynthesis is a mechanism developed by terrestrial life to utilize the energy from photons of solar origin for biological use. Subsurface regions are isolated from the photosphere, and consequently are incapable of utilizing this energy. This opens up the opportunity for life to evolve alternative mechanisms for harvesting available energy. Apna Sapna Money Money Hindi Movie Video Songs Download.
Bacterium Candidatus Desulforudis audaxviator, found 2.8 km deep in a South African mine, harvests energy from radiolysis, induced by particles emitted from radioactive U, Th and K present in surrounding rock. Another radiation source in the subsurface environments is secondary particles generated by galactic cosmic rays (GCRs). Using Monte Carlo simulations, it is shown that it is a steady source of energy comparable to that produced by radioactive substances, and the possibility of a slow metabolizing life flourishing on it cannot be ruled out. Two mechanisms are proposed through which GCR-induced secondary particles can be utilized for biological use in subsurface environments: (i) GCRs injecting energy in the environment through particle-induced radiolysis and (ii) organic synthesis from GCR secondaries interacting with the medium. Laboratory experiments to test these hypotheses are also proposed. Implications of these mechanisms on finding life in the Solar System and elsewhere in the Universe are discussed. 1. Introduction Radiation in the form of photons is the primary way by which solar energy is transferred to living systems.
The core of the shower is clearly visible, as well as the outlines of each of 35 one square meter chambers. Unlike the cover photo, this picture shows a typical shower with its axis (core) nearly perpendicular to the. Cosmic Rays and Particle. Notable Publications. Gaisser and T. Stanev, 'Particle astrophysics and high-energy cosmic rays', in 'Reviews of Particle Physics', Phys. B667, 254 (2008).
The energy of a typical photon is between 2 and 3 eV (visible red, 1. Honestech 2.5 Serial Key more. 8 eV and visible blue, 3.1 eV), and an abundant supply of such photons makes it convenient for life to utilize it for metabolic purposes. Even though most of the energy is lost in heat, the overall efficiency of 0.1–8% is sufficient to power metabolism . Studies of ionizing radiation, on the other hand, have mostly been associated with health-effects on humans [,] and studies of radiation resistance on microbes [,].
By definition, ionizing radiation has the energy to ionize, or to eject at least one electron from a neutral atom or a molecule, which is 13.6 eV for a neutral hydrogen atom, for example. Ionizing radiation can interact with DNA and cause reparable or irreparable damage, depending on the type and energy of the radiation .
Such damages have the potential to modify the genetic code through mutations, alter the way DNA functions, and transfer mutations to the next generation(s) [,]. Radiation damage can also cause cancer as seen in a number of studies with ultraviolet (UV) and particle interactions with humans, primarily in context of oncological studies, nuclear accidents and astronaut health in outer space [–]. Nevertheless, a high dosage of ionizing radiation can force organisms to develop mechanisms that enable them to survive in extreme conditions . Geochemical processes are well known to support subsurface life [,]. An important shift in our understanding came about when studies revealed that subsurface life can be independently supported by radiolysis, where the source of radiation is particles emitted from the decay of radioactive substances [,]. Radioactive materials present deep underground produce secondary particles such as alpha, beta and gamma radiation.