Estudio genetico de la osteoporosis: heredabilidad de las propiedades densitométricas, estructurales y de resistencia ósea y distribución fenotípica familiar.

La base genética de la osteoporosis primaria es compleja. Involucra a múltiples genes y factores ambientales que actúan de manera conjunta para determinar el riesgo. Actualmente disponemos de exploraciones genómicas, como el estudio de miRNA, que facilitan la identificación de los determinantes genéticos de las enfermedades poligénicas complejas. Presentamos un estudio prospectivo realizado en familias con genealogia extensa para estudiar e identificar la heredabilidad de las propiedades densitométricas, estructurales y de resistencia ósea con el fin de profundizar en el conocimiento de las bases genéticas de la osteoporosis.

The “Death of environmentalism” debates: forging links between SEA and civil society discourses

Social and environmental accounting (SEA) is currently going through a period of critical selfanalysis.Challenging questions are being raised about how SEA should be defined, who should be doing the defining, and what the agenda should be. We attempt to engage and enrich these debates from both a process and content perspective by drawing on the political philosophy of agonistic pluralism and a set of debates within the environmental movement – “the death of environmentalism” debates. The contribution of the paper is twofold: to set forth the death of environmentalism debates in the accounting literature and, in doing so, to contextualize and theorize the contested nature of SEA using agonistic pluralism. In contrast to consensually oriented approaches to SEA, the desired outcome is not necessarily resolution of ideological differences but to imagine, develop, and support democratic processes wherein these differences can be recognized and engaged. We construe the “Death” debates as illustrative of the contestable practical and political issues facing both SEA and progressive social movements generally, demonstrating the context and content of the deliberations necessary in contemplating effective programs of engagement. The SEA community, and civil society groups, can benefit from the more overtly political perspective provided by agonistic pluralism. By surfacing and engaging with various antagonisms in this wider contested civic sphere, SEA can more effectively respond to, and move beyond, traditional politically conservative, managerialist approaches to sustainability.

Introducing diversity in public organisations : diminishing theoretical ambiguity and controversy by empirical research

Many theoretical dissertations have an unclear definition of diversity and when interpreting strategies of organizational diversity policies, theories often contradict each other. It is argued that this ambiguity and controversy can be diminished by basing theory on diversity and diversity policy more on qualitative structured descriptive empirical comparisons.This argument is elaborated in two steps. First, diversity is shown to be a social construction: dynamic and plural in nature, dependent on the social-historical context. Second, the common theoretical dichotomy between diversity policy as equal opportunities or as diversity management in shown to be possibly misleading; empirical studies indicate more practical differentiation in types of diversity policy, manifested in public and private organizations. As qualitative comparisons are rare, especially in the European context and especially among public organizations, this article calls for more contributions of this kind and provides an analytical framework to assist scholars in the field of diversity studies.

Riding the South Sea bubble

This paper presents a case study of a well-informed investor in the South Sea bubble. We argue that Hoare's Bank, a fledgling West End London banker, knew that a bubble was in progress and nonetheless invested in the stock; it was profitable to "ride the bubble." Using a unique dataset on daily trades, we show that this sophisticated investor was not constrained by institutional factors such as restrictions on short sales or agency problems. Instead, this study demonstrates that predictable investor sentiment can prevent attacks on a bubble; rational investors may only attack when some coordinating event promotes joint action.

Recreating the South Sea bubble: Lessons from an experiment in financial history

Major bubble episodes are rare events. In this paper, we examine what factors might cause some asset price bubbles to become very large. We recreate, in a laboratory setting, some of the specific institutional features investors in the South Sea Company faced in 1720. Several factors have been proposed as potentially contributing to one of the greatest periods of asset overvaluation in history: an intricate debt-for-equity swap, deferred payment for these shares, and the possibility of default on the deferred payments. We consider which aspect might have had the most impact in creating the South Sea bubble. The results of the experiment suggest that the company?s attempt to exchange its shares for government debt was the single biggest contributor to the stock price explosion, because of the manner in which the swap affected fundamental value. Issuing new shares with only partial payments required, in conjunction with the debt-equity swap, also had a significant effect on the size of the bubble. Limited contract enforcement, on the other hand, does not appear to have contributed significantly.

Determination of sea surface salinity and wind speed by L-band microwave radiometry from a fixed platform

The European Space Agency Soil Moisture andOcean Salinity (SMOS) mission aims at obtaining global maps ofsoil moisture and sea surface salinity from space for large-scale andclimatic studies. It uses an L-band (1400–1427 MHz) MicrowaveInterferometric Radiometer by Aperture Synthesis to measurebrightness temperature of the earth’s surface at horizontal andvertical polarizations ( h and v). These two parameters will beused together to retrieve the geophysical parameters. The retrievalof salinity is a complex process that requires the knowledge ofother environmental information and an accurate processing ofthe radiometer measurements. Here, we present recent resultsobtained from several studies and field experiments that were partof the SMOS mission, and highlight the issues still to be solved.

Experimental evidence that intra-specific competition in seagrass meadows reduces reproductive potential in the sea urchin Paracentrotus lividus (Lamarck)

To better understand the biological controls that regulate sea urchin dynamics, we studied the effects of potential inter- and intra-specific competition for food on several biological variables of the main sea urchin in the Mediterranean (Paracentrotus lividus). We carried out a caging experiment in which we manipulated sea urchin density (natural vs. high density) and herbivorous fish (Sarpa salpa) accessibility (free access vs. exclusion) in a Posidonia oceanica meadow. No evidence of competition between fish and urchins was detected. Neither density-dependent mortality nor changes in the somatic variables were found; however, we detected that intra-specific competition affected the reproductive potential of P. lividus. The gonad index of urchins at high population densities was ca. 30% lower than that of urchins at natural densities. As a spawning event had just occurred when urchins were collected, these differences probably reflect differences in reserve content, which may compromise the following reproductive period and decrease survival in the long term, as the gonads are also used as storage organs. For the time period studied, mortality rates appeared to be independent of local densities. The results indicate that a long-term negative feedback mechanism appears to take place in P. lividus in response to increased population density.

Microsatellite markers reveal shallow genetic differentiation between cohorts of the common sea urchin Paracentrotus lividus (Lamarck) in northwest Mediterranean

Temporal variability was studied in the common sea urchin Paracentrotus lividus through the analysis of the genetic composition of three yearly cohorts sampled over two consecutive springs in a locality in northwestern Mediterranean. Individuals were aged using growth ring patterns observed in tests and samples were genotyped for five microsatellite loci. No reduction of genetic diversity was observed relative to a sample of the adult population from the same location or within cohorts across years. FST and amova results indicated that the differentiation between cohorts is rather shallow and not significant, as most variability is found within cohorts and within individuals. This mild differentiation translated into estimates of effective population size of 90100 individuals. When the observed excess of homozygotes was taken into account, the estimate of the average number of breeders increased to c. 300 individuals. Given our restricted sampling area and the known small-scale heterogeneity in recruitment in this species, our results suggest that at stretches of a few kilometres of shoreline, large numbers of progenitors are likely to contribute to the larval pool at each reproduction event. Intercohort variation in our samples is six times smaller than spatial variation between adults of four localities in the western Mediterranean. Our results indicate that, notwithstanding the stochastic events that take place during the long planktonic phase and during the settlement and recruitment processes, reproductive success in this species is high enough to produce cohorts genetically diverse and with little differentiation between them. Further research is needed before the link between genetic structure and underlying physical and biological processes can be well established.

Some like it hot: temperature and acidification modulate larval development and settlement of the sea urchin Arbacia lixula

We studied the effects of temperature and pH on larval development, settlement and juvenile survival of a Mediterranean population of the sea urchin Arbacia lixula. Three temperatures (16, 17.5 and 19 °C) were tested at present pH conditions (pHT 8.1). At 19 °C, two pH levels were compared to reflect present average (pHT 8.1) and near-future average conditions (pHT 7.7, expected by 2100). Larvae were reared for 52-days to achieve the full larval development and complete the metamorphosis to the settler stage. We analyzed larval survival, growth, morphology and settlement success. We also tested the carry-over effect of acidification on juvenile survival after 3 days. Our results showed that larval survival and size significantly increased with temperature. Acidification resulted in higher survival rates and developmental delay. Larval morphology was significantly altered by low temperatures, which led to narrower larvae with relatively shorter skeletal rods, but larval morphology was only marginally affected by acidification. No carry-over effects between larvae and juveniles were detected in early settler survival, though settlers from larvae reared at pH 7.7 were significantly smaller than their counterparts developed at pH 8.1. These results suggest an overall positive effect of environmental parameters related to global change on the reproduction of A. lixula, and reinforce the concerns about the increasing negative impact on shallow Mediterranean ecosystems of this post-glacial colonizer.

The Hercynian ore deposits from the Catalonian Coastal Ranges

Many mineralizations, showings and geochemical anomalies have been found in the Hercynian of the Catalonian Coastal Ranges during the last ten years. Many of them are enclosed in the Paleozoic sediments and volcanics and display pre-metamorphic syngenetic characteristics. The lower carboniferous manganese and base meta1 deposits appear to be formed from hydrothermal fluids springing up in the sea floor through active fractures controlling the filling of the basins in a extensional geotectonic setting. Although less evidence and more controversy is available, similar ore forming processes could have taken place in older Paleozoic times. The deformation and metamorphism have not played an important remobilization role, and most epigenetic deposits of Hercynian age are related to the hydrothermal cells induced by the post-metamorphic granitic intrusives.

Impacts on the deep-sea ecosystem by a severe coastal storm

Major coastal storms, associated with strong winds, high waves and intensified currents, and occasionally with heavy rains and flash floods, are mostly known because of the serious damage they can cause along the shoreline and the threats they pose to navigation. However, there is a profound lack of knowledge on the deep-sea impacts of severe coastal storms. Concurrent measurements of key parameters along the coast and in the deep-sea are extremely rare. Here we present a unique data set showing how one of the most extreme coastal storms of the last decades lashing the Western Mediterranean Sea rapidly impacted the deep-sea ecosystem. The storm peaked the 26th of December 2008 leading to the remobilization of a shallow-water reservoir of marine organic carbon associated with fine particles and resulting in its redistribution across the deep basin. The storm also initiated the movement of large amounts of coarse shelf sediment, which abraded and buried benthic communities. Our findings demonstrate, first, that severe coastal storms are highly efficient in transporting organic carbon from shallow water to deep water, thus contributing to its sequestration and, second, that natural, intermittent atmospheric drivers sensitive to global climate change have the potential to tremendously impact the largest and least known ecosystem on Earth, the deep-sea ecosystem.

An introduction to Mediterranean deep-sea biology

This chapter presents the state of the art concerning the deep-sea Mediterranean environment: geology, hydrology, biology and fisheries. These are the fields of study dealt with in the scientific papers of this volume. The authors are specialists who have addressed their research to the Mediterranean deep-sea environment during the last years. This introduction is an overview but not an exhaustive review.