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14 p.-4 fig., The coming enterprises of space exploration by humans, e.g. the future colonization of the Moon and Mars, will require the utilization of plants as key components of Bioregenerative Life Support Systems. The space environment is very different from the Earth environment in many factors. Many of these adverse factors can be counteracted in spaceships, or in Martian or Lunar settlements, but the living beings must adapt to grow and survive in microgravity. The Earth gravity has remained constant in magnitude and direction throughout the entire history of our planet, including biological evolution. Gravity establishes the direction of plant growth through the process called gravitropism and this orientation is essential for the normal function of roots, stems and leaves, assuring the adequate nutrition of the plant. The phytohormone auxin is known to play a main role in gravitropism. Auxin is also a major regulator of plant development, since this hormone is ultimately responsible of the maintenance of meristematic cells, which are totipotent cells, continuously engaged in the cell cycle, and are the suppliers of differentiated cells for plant development. Meristematic competence is the balance between cell growth and cell proliferation occurring in meristematic cells. A major effect of the microgravity environment is the disruption of meristematic competence, comprising the increase of the proliferation rate and the decrease of the growth rate,estimated through the rate of production of ribosomes, the cellular factories of proteins. Microgravity also induces a noticeable reprogramming of gene expression. In meristematic cells, genes driving the cell cycle regulation are affected. In general, the systems responsible of the plant defense against abiotic stresses and the energy/redox systems are major targets of the gene reprogramming. Noticeably, no specific genes related to gravity alteration have been identified, although a significant proportion of altered genes encode unknown functions. Despite these cellular and molecular alterations, plants are capable of surviving, developing until the adult stage, and even reproducing under microgravity conditions. This means that plants indeed adapt to this environment, although the mechanisms of adaptation are currently unknown. A major challenge of current research is to identify environmental cues that may replace gravity in driving growth and development. Light can be one of these cues and understanding the role of light, as a countermeasure for gravitational stress, will contribute to the success of the culture of plants in extraterrestrial habitats., Work performed in the author’s laboratory was funded by the Spanish National Plan for Research, Development and Innovation of the Spanish Government (Grants No. ESP2015-64323-R and AYA2012-33982).Funding for experiments performed in spaceflights and ground based facilities was provided by the European Space Agency.

Zero gravity is an environmental challenge unknown to organisms throughout evolution on Earth. Nevertheless, plants are sensitive to altered gravity, as exemplified by changes in meristematic cell proliferation and growth. We found that synchronized Arabidopsis‐cultured cells exposed to simulated microgravity showed a shortened cell cycle, caused by a shorter G2/M phase and a slightly longer G1 phase. The analysis of selected marker genes and proteins by quantitative polymerase chain reaction and flow cytometry in synchronic G1 and G2 subpopulations indicated changes in gene expression of core cell cycle regulators and chromatin‐modifying factors, confirming that microgravity induced misregulation of G2/M and G1/S checkpoints and chromatin remodelling. Changes in chromatin‐based regulation included higher DNA methylation and lower histone acetylation, increased chromatin condensation, and overall depletion of nuclear transcription. Estimation of ribosome biogenesis rate using nucleolar parameters and selected nucleolar genes and proteins indicated reduced nucleolar activity under simulated microgravity, especially at G2/M. These results expand our knowledge of how meristematic cells are affected by real and simulated microgravity. Counteracting this cellular stress is necessary for plant culture in space exploration.

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Environmental gravity modulates plant growth and development, and these processes are influenced by the balance between cell proliferation and differentiation in meristems. Meristematic cells are characterized by the coordination between cell proliferation and cell growth, that is, by the accurate regulation of cell cycle progression and the optimal production of biomass for the viability of daughter cells after division. Thus, cell growth is correlated with the rate of ribosome biogenesis and protein synthesis. We investigated the effects of simulated microgravity on cellular functions of the root meristem in a sequential study. Seedlings were grown in a clinostat, a device producing simulated microgravity, for periods between 3 and 10days. In a complementary study, seedlings were grown in a Random Positioning Machine (RPM) and sampled sequentially after similar periods of growth. Under these conditions, the cell proliferation rate and the regulation of cell cycle progression showed significant alterations, accompanied by a reduction of cell growth. However, the overall size of the root meristem did not change. Analysis of cell cycle phases by flow cytometry showed changes in their proportion and duration, and the expression of the cyclin B1 gene, a marker of entry in mitosis, was decreased, indicating altered cell cycle regulation. With respect to cell growth, the rate of ribosome biogenesis was reduced under simulated microgravity, as shown by morphological and morphometric nucleolar changes and variations in the levels of the nucleolar protein nucleolin. Furthermore, in a nucleolin mutant characterized by disorganized nucleolar structure, the microgravity treatment intensified disorganization. These results show that, regardless of the simulated microgravity device used, a great disruption of meristematic competence was the first response to the environmental alteration detected at early developmental stages. However, longer periods of exposure to simulated microgravity do not produce an intensification of the cellular damages or a detectable developmental alteration in seedlings analyzed at further stages of their growth. This suggests that the secondary response to the gravity alteration is a process of adaptation, whose mechanism is still unknown, which eventually results in viable adult plants. (C) 2016 Elsevier GmbH. All rights reserved.

Objetivo: Dar a conocer la utilidad de la Tomografía de Coherencia Óptica (OCT) para el estudio de patología del segmento anterior así como presentar sus posibles ventajas frente a la biomicroscopía ultrasónica (BMU). Material y métodos: Presentamos 5 pacientes con diversas patologías del segmento anterior estudiados mediante OCT: 2 pacientes con ataque agudo de glaucoma de ángulo estrecho, 1 paciente con rubeosis iridis, 1 paciente con un traumatismo ocular penetrante y un paciente con un quiste estromal primario del iris. Resultados: En los pacientes con ataque agudo de glaucoma, el OCT ha mostrado ser una herramienta tan útil como la BMU para la detección del cierre angular. Además, la tomografía óptica fue más cómoda y rápida en la obtención de las imágenes que la BMU, así la el tiempo medio de exploración con OCT suele ser inferior a 5 minutos, a diferencia de la BMU cuyo tiempo suele ser superior a 10 minutos. El OCT también ha demostrado ser una prueba útil para el estudio de otras patologías del iris, permitiendo valorar la permeabilidad de las iridotomías, mostrar neovascularización iridiana e incluso estudiar masas iridianas como el quiste estromal de iris. En estos casos, el OCT permite la obtención de imágenes con una mayor resolución espacial que la BMU. Conclusiones: El OCT 3 mediante el ajuste del enfoque puede servir para obtener imágenes del ángulo camerular así como de otras estructuras del segmento anterior ayudando así a establecer determinados diagnósticos de forma no invasiva, cómoda y segura para el paciente. Purpose: To show the utility of optical coherence tomography (OCT) for studying the anterior segment and to explain its potential advantages as compared to ultrasonic biomicroscopy (UBM). Materials and methods: We have described the findings in 5 patients with different pathologies of the anterior segment, all of whom were studied with UBM and OCT-3 adjusted for the anterior segment. There were 2 cases of an acute attack of closed angle glaucoma, 1 case of rubeosis iridis, 1 case of penetrating ocular trauma and 1 case of a primary stromal iris cyst. Results: OCT was found to be as useful as UBM in detecting angle closure in patients affected by an acute attack of glaucoma. In addition, OCT was more comfortable for the patient and faster than UBM in obtaining images, with the exploration mean time using OCT being less than five minutes while that with UBM was over ten minutes. OCT has also been demonstrated to be a safe and valuable non-contact examination in other iris pathologies such as rubeosis iridis, for checking the permeability of iridotomies and even for studying iris masses such as primary stromal iris cysts. In these entities OCT may reach a higher resolution than ultrasonic biomicroscopy. Conclusion: OCT-3, with an adjustable focus, can obtain images from the scleral angle, as well as from other ocular structures like the iris, thus assisting in the diagnosis of numerous pathologies.

Es va estudiar la presència de cigonyes blanques anellades a l'abocador de Càceres durant les temporades de cria de 1989 i 1990. La mitjana més alta del nombre d'ocells es va donar durant l'abril, mentre que al maig va ser el mes amb el menor nombre d'ocells. Els exemplars més joves de quatre anys foren més freqüents i amb proporcions majors del que s'esperava tenint en compte els percentatges de mortalitat d'aquesta espècie. Entre els ocells més joves de quatre anys els més abundants foren els individus d'un any, els quals eren més freqüents de l'esperat. Durant el període d'estudi les cigonyes van estar a l'abocador el mateix temps amb independència de les dues classes d'edats definides. Aquests resultats mostren la importància del menjar addicional per als ocells immadurs.

This open access book opens up the black box of mediation in collective conflicts through the analyses and comparisons of various systems. Mediation and related third party interventions such as conciliation and facilitation are discussed as effective prevention and regulation tools for different types of collective labor conflicts. These interventions fit in a new developed five-phase model of collective conflicts in organizations, going from capacity building in latent conflicts, through conciliation, mediation and arbitration in escalating phases, to rebuilding of trust after hot conflicts. The authors promote understanding and discussion with regards to labor mediation systems, presenting comparative research on the perspectives of mediators and users of mediation. This book describes and analyses laws, regulations and practices of mediation in seventeen countries, with a relative strong emphasis on Europe. Part 1 presents theoretical frameworks on conciliation and mediation in collective labor conflicts. Part 2 presents regulations and practices in 12 European countries: Belgium, Denmark, Estonia, France, Italy, Poland, Portugal, Spain, The Netherlands, and the United Kingdom. Part 3 discusses mediation in these collective conflicts in Australia, China, India, South Africa and the USA. Part 4 offers conclusions and ways forward. This book offers analyses, good practices and developments for third party intervention in collective labor conflicts in global and local changing environments. This book is a must-read for policy makers, , social partners at different levels, as well as scholars and practitioners in industrial relations, human resources management and conflict management, particularly conciliators and mediators. info:eu-repo/semantics/publishedVersion