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Summer dormancy is an evolutionary response that some perennial cool-season grasses adopted as an avoidance strategy to escape summer drought and heat. It is correlated with superior survival after severe summer droughts in many perennial grass species originating from Mediterranean environments. Understanding the genetic mechanism and environmental determinants of summer dormancy is important for interpreting the evolutionary history of seasonal dormancy and for the development of genomic tools to improve the efficiency of genetic selection for this important trait. The objectives of this research are to assess morphological and biochemical attributes that seem to be specific for the characterization of summer dormancy in tall fescue, and to validate the hypothesis that genes underlying stem determinacy might be involved in the mechanism of summer dormancy. Our results suggest that vernalization is an important requirement in the onset of summer dormancy in tall fescue. Non-vernalized tall fescue plants do not exhibit summer dormancy as vernalized plants do and behave more like summer-active types. This is manifested by continuation of shoot growth and high root activity in water uptake during summer months. Therefore, summer dormancy in tall fescue should be tested only in plants that underwent vernalization and are not subjected to water deficit during summer months. Total phenolic concentration in tiller bases (antioxidants) does not seem to be related to vernalization. It is most likely an environmental response to protect meristems from oxidative stress. Sequence analysis of the homolog gene from tall fescue genotypes belonging to summer-dormant and summer-active tall fescue types showed a unique deletion of three nucleotides specific to the dormant genotypes. Higher tiller bud numbers in dormant plants that were not allowed to flower and complete the reproductive cycle, confirmed that stem determinacy is a major component in the mechanism of summer dormancy. The number of variables identified in these studies as potential players in summer dormancy in tall fescue including vernalization, , water status, and protection from oxidative stress are a further confirmation that summer dormancy is a quantitative trait controlled by several genes with varying effects and prone to genotype by environment interactions.

The proliferation of regional economic organizations (REOs) is a prominent feature of the contemporary international environment. Many of these organizations aspire to promote regional peace and stability. Some strive to promote these goals only through economic cooperation, while others have expanded their mandate to include mechanisms that address security concerns more directly. A glance at the security components of such organizations indicates that their purpose and design are very diverse. This article sheds light on the sources of this poorly understood phenomenon. Specifically, it argues that organizations that enjoy greater delegated authority are in a better position to expand their mandate into the security realm and to have more far-reaching agreements in this issue area. It then develops a metric that gauges the degree of security cooperation within REOs and presents a new dataset of numerous organizations on this institutional aspect. Employing this dataset in a rigorous statistical analysis and controlling for a host of alternative explanations, it demonstrates that, indeed, REOs with greater delegated authority develop deeper security cooperation.

El "Espacio de palabras" forma parte del "Archivo del duelo", en el que se preservan las manifestaciones de duelo popular expresadas en Madrid tras los atentados terroristas del 11 de marzo de 2004. El corpus contiene un número considerable de mensajes recogidos entre los días 9 de junio de 2004 y 13 de marzo de 2005 en dos consolas de la Estación de Atocha (Madrid). Estos mensajes conforman un tipo de texto propio que, además de por su brevedad, se caracteriza por su riqueza en intensificadores. Tomando este corpus como el objeto de nuestro análisis, en esta contribución presentamos los primeros resultados de un estudio sobre la intensificación en estos mensajes, así como el análisis de la fuerza ilocutiva y la función de las formas con las que se intensifica desde la perspectiva de la relación que mantienen los autores de los mensajes con su discurso y las implicaciones de la intensificación en el nivel social de la lengna, para llegar a la conclusión de que la solidaridad, la confianza y la afectividad como recursos de intensificación caracterizan la imagen social afiliativa del "Espacio de palabras", características que también han sido observadas en los estudios de la imagen afiliativa de los espalloles en la conversación coloquial.

Intensity–duration–frequency (IDF) curves are widely used to quantify the probability of occurrence of rainfall extremes. The usual rain gauge-based approach provides accurate curves for a specific location, but uncertainties arise when ungauged regions are examined or catchment-scale information is required. Remote sensing rainfall records, e.g. from weather radars and satellites, are recently becoming available, providing high-resolution estimates at regional or even global scales; their uncertainty and implications on water resources applications urge to be investigated. This study compares IDF curves from radar and satellite (CMORPH) estimates over the eastern Mediterranean (covering Mediterranean, semiarid, and arid climates) and quantifies the uncertainty related to their limited record on varying climates. We show that radar identifies thicker-tailed distributions than satellite, in particular for short durations, and that the tail of the distributions depends on the spatial and temporal aggregation scales. The spatial correlation between radar IDF and satellite IDF is as high as 0.7 for 2–5-year return period and decreases with longer return periods, especially for short durations. The uncertainty related to the use of short records is important when the record length is comparable to the return period ( \~ 50, \~ 100, and \~ 150 % for Mediterranean, semiarid, and arid climates, respectively). The agreement between IDF curves derived from different sensors on Mediterranean and, to a good extent, semiarid climates, demonstrates the potential of remote sensing datasets and instils confidence on their quantitative use for ungauged areas of the Earth.

Water is the most precious gift of nature to life on earth. India is one of the few countries in the world which has ample quantity of this prized possession. However, the imbalances have thrown up many debatable issues, one of them being the Inter-linking of Rivers (or ILR). The Interlinking of Rivers programme is aimed at linking different surplus rivers of country with deficient ones to probably help in increasing irrigation intensity in the country, increasing water availability for both drinking and industrial purposes, mitigating effects of droughts and floods to a certain extent. The paper focuses of certain factual understanding of the project and its feasibility towards making water a more sustainable resource on planet Earth.

 

This article presents a new index for a comprehensive and systematic measurement of the level of intra-party democracy (IPD). The proposed index is designed on the basis of a comparison with state-level democracy and previous attempts to measure IPD. It examines five dimensions: participation, representation, competition, responsiveness and transparency. The way each dimension is measured is explained and justified on the basis of the procedure of its design and democratic theory. Its application and potential contribution to the analysis of democracy and party politics is demonstrated through its use to comparatively evaluate the level of internal democracy in political parties in Israel; and through examining several hypotheses concerning the relationship between party characteristics and their level of IPD and the relationship between the various dimensions of IPD.

 

According to the synaptic trace theory of memory, activity-induced changes in the pattern of synaptic connections underlie the storage of information for long periods. In this framework, the stability of memory critically depends on the stability of the underlying synaptic connections. Surprisingly however, synaptic connections in the living brain are highly volatile, which poses a fundamental challenge to the synaptic trace theory. Here we review recent experimental evidence that link the initial formation of a memory with changes in the pattern of connectivity, but also evidence that synaptic connections are considerably volatile even in the absence of learning. Then we consider different theoretical models that have been put forward to explain how memory can be maintained with such volatile building blocks.