Evaluación de riesgo ecológico

Se desarrolló una Evaluación de Riesgo Ecológico (ERE) mediante un taller de trabajo con 29 representantes de todos los usuarios de la pesquería de anchoveta (stock norte-centro), en sus tres dimensiones, “bienestar ecológico”, “bienestar humano” y “capacidad de logro”. Se dio prioridad a los temas conflictivos de la pesquería clasificando su riesgo tomando en cuenta el nivel de impacto que tendría al ocurrir y la probabilidad de que ocurra. Se identificó 99 problemas de riesgo de los cuales más de dos tercios fueron clasificados por consenso como alto o extremo. Casi la mitad de los riesgos altos y extremos estuvieron en la dimensión “capacidad de logro”

Post crisis challenges to bank regulation

The current crisis has swept aside not only the whole of the US investment banking industry butalso the consensual perception of banking risks, contagion and their implication for bankingregulation. As everyone agrees now, risks where mispriced, they accumulated in neuralgic pointsof the financial system, and where amplified by procyclical regulation as well as by the instabilityand fragility of financial institutions.The use of ratings as carved in stone and lack of adequate procedure to swiftly deal withsystemic institutions bankruptcy (whether too-big-to-fail, too complex to fail or too-many to fail).The current paper will not deal with the description and analysis of the crisis, already covered inother contributions to this issue will address the critical choice regulatory authorities will face. Inthe future regulation has to change, but it is not clear that it will change in the right direction. Thismay occur if regulatory authorities, possibly influenced by public opinion and political pressure,adopt an incorrect view of financial crisis prevention and management. Indeed, there are twoapproaches to post-crisis regulation. One is the rare event approach, whereby financial crises willoccur infrequently, but are inescapable.

La paleolaguna de Otuma como potencial para la reconstrucción de las condiciones paleoceanográficas de Pisco.

Se describe la geomorfología del relieve de la paleolaguna de Otuma y se evalúa la preservación de sus registros calcáreos y su potencialidad para la reconstrucción paleoceanográfica y paleoecológica. Un pequeño acantilado marino y una plataforma de abrasión de suave pendiente con predominancia de arena y grava, sugieren un fondo submareal somero de 3,5 m de profundidad a 80 m de distancia de la orilla. La distribución de los registros calcáreos in situ, sobre el fondo de la paleolaguna sugiere un patrón de zonación ecológica. La abundancia de Argopecten purpuratus en los conchales demuestra su dominancia y la presencia de un antiguo y muy productivo banco natural de concha de abanico con una estructura de tallas 40 -140 mm. La preservación de las conchas permitió el análisis de sus anillos o líneas de crecimiento y la reconstruccion de sus ritmos y patrones de crecimiento que son valiosos para la reconstrucción de la variabilidad ambiental.

Trophic dynamics in the northern Humboldt Current system: insights from stable isotopes and stomach content analyses

The northern Humboldt Current system (NHCS) off Peru is one of the most productive world marine regions. It represents less than 0.1% of the world ocean surface but presently sustains about 10% of the world fish catch, with the Peruvian anchovy or anchoveta Engraulis ringens as emblematic fish resource. Compared with other eastern boundary upwelling systems, the higher fish productivity of the NHCS cannot be explained by a corresponding higher primary productivity. On another hand, the NHCS is the region where El Niño, and climate variability in general, is most notable. Also, surface oxygenated waters overlie an intense and extremely shallow Oxygen Minimum Zone (OMZ). In this context, the main objective of this study is to better understand the trophic flows in the NHCS using both stomach content and stable isotope analyses. The study focuses on a variety of organisms from low trophic levels such as zooplankton to top predators (seabirds and fur seals). The approach combines both long-term and specific studies on emblematic species such as anchoveta, and sardine Sardinops sagax and a more inclusive analysis considering the 'global' food web in the recent years (2008 – 2012) using stable isotope analysis. Revisiting anchovy and sardine we show that whereas phytoplankton largely dominated anchoveta and sardine diets in terms of numerical abundance, the carbon content of prey items indicated that zooplankton was by far the most important dietary component. Indeed for anchovy euphausiids contributed 67.5% of dietary carbon, followed by copepods (26.3%). Selecting the largest prey, the euphausiids, provide an energetic advantage for anchoveta in its ecosystem where oxygen depletion imposes strong metabolic constrain to pelagic fish. Sardine feed on smaller zooplankton than do anchoveta, with sardine diet consisting of smaller copepods and fewer euphausiids than anchoveta diet. Hence, trophic competition between sardine and anchovy in the northern Humboldt Current system is minimized by their partitioning of the zooplankton food resource based on prey size, as has been reported in other systems. These results suggest an ecological role for pelagic fish that challenges previous understanding of their position in the foodweb (zooplanktophagous instead of phytophagous), the functioning and the trophic models of the NHCS. Finally to obtain a more comprehensive vision of the relative trophic position of NHCS main components we used stable isotope analyses. For that purpose we analyzed the δ13C and δ15N stable isotope values of thirteen taxonomic categories collected off Peru from 2008 - 2011, i.e., zooplankton, fish, squids and air-breathing top predators. The δ15N isotope signature was strongly impacted by the species, the body length and the latitude. Along the Peruvian coast, the OMZ get more intense and shallow south of ~7.5ºS impacting the baseline nitrogen stable isotopes. Employing a linear mixed-effects modelling approach taking into account the latitudinal and body length effects, we provide a new vision of the relative trophic position of key ecosystem components. Also we confirm stomach content-based results on anchoveta Engraulis ringens and highlight the potential remarkable importance of an often neglected ecosystem component, the squat lobster Pleuroncodes monodon. Indeed, our results support the hypothesis according to which this species forage to some extent on fish eggs and larvae and can thus predate on the first life stages of exploited species. However, the δ13C values of these two species suggest that anchoveta and squat lobster do not exactly share the same habitat. This would potentially reduce some direct competition and/or predation.

Adaptive diversity in heterogeneous environments for populations regulated by a mixture of soft and hard selection

The stable co-existence of two haploid genotypes or two species is studied in a spatially heterogeneous environment submitted to a mixture of soft selection (within-patch regulation) and hard selection (outside-patch regulation) and where two kinds of resource are available. This is analysed both at an ecological time-scale (short term) and at an evolutionary time-scale (long term). At an ecological scale, we show that co-existence is very unlikely if the two competitors are symmetrical specialists exploiting different resources. In this case, the most favourable conditions are met when the two resources are equally available, a situation that should favour generalists at an evolutionary scale. Alternatively, low within-patch density dependence (soft selection) enhances the co-existence between two slightly different specialists of the most available resource. This results from the opposing forces that are acting in hard and soft regulation modes. In the case of unbalanced accessibility to the two resources, hard selection favours the most specialized genotype, whereas soft selection strongly favours the less specialized one. Our results suggest that competition for different resources may be difficult to demonstrate in the wild even when it is a key factor in the maintenance of adaptive diversity. At an evolutionary scale, a monomorphic invasive evolutionarily stable strategy (ESS) always exists. When a linear trade-off exists between survival in one habitat versus that in another, this ESS lies between an absolute adjustment of survival to niche size (for mainly soft-regulated populations) and absolute survival (specialization) in a single niche (for mainly hard-regulated populations). This suggests that environments in agreement with the assumptions of such models should lead to an absence of adaptive variation in the long term.

Temperature-dependent turnovers in sex-determination mechanisms: a quantitative model.

Sex determination is often seen as a dichotomous process: individual sex is assumed to be determined either by genetic (genotypic sex determination, GSD) or by environmental factors (environmental sex determination, ESD), most often temperature (temperature sex determination, TSD). We endorse an alternative view, which sees GSD and TSD as the ends of a continuum. Both effects interact a priori, because temperature can affect gene expression at any step along the sex-determination cascade. We propose to define sex-determination systems at the population- (rather than individual) level, via the proportion of variance in phenotypic sex stemming from genetic versus environmental factors, and we formalize this concept in a quantitative-genetics framework. Sex is seen as a threshold trait underlain by a liability factor, and reaction norms allow modeling interactions between genotypic and temperature effects (seen as the necessary consequences of thermodynamic constraints on the underlying physiological processes). As this formalization shows, temperature changes (due to e.g., climatic changes or range expansions) are expected to provoke turnovers in sex-determination mechanisms, by inducing large-scale sex reversal and thereby sex-ratio selection for alternative sex-determining genes. The frequency of turnovers and prevalence of homomorphic sex chromosomes in cold-blooded vertebrates might thus directly relate to the temperature dependence in sex-determination mechanisms.

Integrative analyses of speciation and divergence in Psammodromus hispanicus (Squamata: Lacertidae).

BackgroundGenetic, phenotypic and ecological divergence within a lineage is the result of past and ongoing evolutionary processes, which lead ultimately to diversification and speciation. Integrative analyses allow linking diversification to geological, climatic, and ecological events, and thus disentangling the relative importance of different evolutionary drivers in generating and maintaining current species richness.ResultsHere, we use phylogenetic, phenotypic, geographic, and environmental data to investigate diversification in the Spanish sand racer (Psammodromus hispanicus). Phylogenetic, molecular clock dating, and phenotypic analyses show that P. hispanicus consists of three lineages. One lineage from Western Spain diverged 8.3 (2.9-14.7) Mya from the ancestor of Psammodromus hispanicus edwardsianus and P. hispanicus hispanicus Central lineage. The latter diverged 4.8 (1.5-8.7) Mya. Molecular clock dating, together with population genetic analyses, indicate that the three lineages experienced northward range expansions from southern Iberian refugia during Pleistocene glacial periods. Ecological niche modelling shows that suitable habitat of the Western lineage and P. h. edwardsianus overlap over vast areas, but that a barrier may hinder dispersal and genetic mixing of populations of both lineages. P. h. hispanicus Central lineage inhabits an ecological niche that overlaps marginally with the other two lineages.ConclusionsOur results provide evidence for divergence in allopatry and niche conservatism between the Western lineage and the ancestor of P. h. edwardsianus and P. h. hispanicus Central lineage, whereas they suggest that niche divergence is involved in the origin of the latter two lineages. Both processes were temporally separated and may be responsible for the here documented genetic and phenotypic diversity of P. hispanicus. The temporal pattern is in line with those proposed for other animal lineages. It suggests that geographic isolation and vicariance played an important role in the early diversification of the group, and that lineage diversification was further amplified through ecological divergence.

Challenges to the implementation of behavioural survellance for HIV/STI in Europe

Background: Well-conducted behavioural surveillance (BS) is essential for policy planning and evaluation. Data should be comparable across countries. In 2008, the European Centre for Disease Prevention and Control (ECDC) began a programme to support Member States in the implementation of BS for Second Generation Surveillance. Methods: Data from a mapping exercise on current BS activities in EU/EFTA countries led to recommendations for establishing national BS systems and international coordination, and the definition of a set of core and transversal (UNGASS-Dublin compatible) indicators for BS in the general and eight specific populations. A toolkit for establishing BS has been developed and a BS needs-assessment survey has been launched in 30 countries. Tools for BS self-assessment and planning are currently being tested during interactive workshops with country representatives. Results: The mapping exercise revealed extreme diversity between countries. Around half had established a BS system, but this did not always correspond to the epidemiological situation. Challenges to implementation and harmonisation at all levels emerged from survey findings and workshop feedback. These include: absence of synergy between biological and behavioural surveillance and of actors having an overall view of all system elements; lack of awareness of the relevance of BS and of coordination between agencies; insufficient use of available data; financial constraints; poor sustainability, data quality and access to certain key populations; unfavourable legislative environments. Conclusions: There is widespread need in the region not only for technical support but also for BS advocacy: BS remains the neglected partner of second generation surveillance and requires increased political support and capacity-building in order to become effective. Dissemination of validated tools for BS, developed in interaction with country experts, proves feasible and acceptable.

Visualization of aqueous shunt position and patency using anterior segment optical coherence tomography.

PURPOSE: To describe the use of anterior segment optical coherence tomography (AS-OCT) to clarify the position and patency of aqueous shunt devices in the anterior chamber of eyes where corneal edema or tube position does not permit a satisfactory view. DESIGN: Noncomparative observational case series. METHODS: Four cases are reported in which aqueous shunt malposition or obstruction was suspected but the shunt could not be seen on clinical examination. The patients underwent AS-OCT to identify the position and patency of the shunt tip. RESULTS: In each case, AS-OCT provided data regarding tube position and/or patency that could not be obtained by slit-lamp examination or by gonioscopy that influenced management. CONCLUSIONS: AS-OCT can be used to visualize anterior chamber tubes in the presence of corneal edema that precludes an adequate view or in cases where the tube is retracted into the cornea. In such cases, AS-OCT is useful in identifying shunt patency and position, which helps guide clinical decision making.

En busca de la lengua perfecta: pasado, presente y futuro

Análisis de las lenguas artificiales más importantes que se han creado a lo largo de la historia con el objetivo de encontrar una lengua perfecta común para todos y presentación del Rodinio, una nueva lengua artificial basada en una serie de criterios en busca de esa perfección.

Cities, skills, and regional change

One approach to urban areas emphasizes the existence of certain immutable relationships, such as Zipf's or Gibrat's Law. An alternative view is that urban changereflects individual responses to changing tastes or technologies. This paper examinesalmost 200 years of regional change in the U.S. and finds that few, if any, growth relationships remain constant, including Gibrat's Law. Education does a reasonable jobof explaining urban resilience in recent decades, but does not seem to predict countygrowth a century ago. After reviewing this evidence, we present and estimate a simple model of regional change, where education increases the level of entrepreneurship.Human capital spillovers occur at the city level because skilled workers produce moreproduct varieties and thereby increase labor demand. We find that skills are associatedwith growth in productivity or entrepreneurship, not with growth in quality of life, atleast outside of the West. We also find that skills seem to have depressed housing supplygrowth in the West, but not in other regions, which supports the view that educatedresidents in that region have fought for tougher land-use controls. We also present evidence that skills have had a disproportionately large impact on unemployment duringthe current recession.

Networking of differentially expressed genes in human cancer cells resistant to methotrexate

BACKGROUND: The need for an integrated view of data obtained from high-throughput technologies gave rise to network analyses. These are especially useful to rationalize how external perturbations propagate through the expression of genes. To address this issue in the case of drug resistance, we constructed biological association networks of genes differentially expressed in cell lines resistant to methotrexate (MTX). METHODS: Seven cell lines representative of different types of cancer, including colon cancer (HT29 and Caco2), breast cancer (MCF-7 and MDA-MB-468), pancreatic cancer (MIA PaCa-2), erythroblastic leukemia (K562) and osteosarcoma (Saos-2), were used. The differential expression pattern between sensitive and MTX-resistant cells was determined by whole human genome microarrays and analyzed with the GeneSpring GX software package. Genes deregulated in common between the different cancer cell lines served to generate biological association networks using the Pathway Architect software. RESULTS: Dikkopf homolog-1 (DKK1) is a highly interconnected node in the network generated with genes in common between the two colon cancer cell lines, and functional validations of this target using small interfering RNAs (siRNAs) showed a chemosensitization toward MTX. Members of the UDP-glucuronosyltransferase 1A (UGT1A) family formed a network of genes differentially expressed in the two breast cancer cell lines. siRNA treatment against UGT1A also showed an increase in MTX sensitivity. Eukaryotic translation elongation factor 1 alpha 1 (EEF1A1) was overexpressed among the pancreatic cancer, leukemia and osteosarcoma cell lines, and siRNA treatment against EEF1A1 produced a chemosensitization toward MTX. CONCLUSIONS: Biological association networks identified DKK1, UGT1As and EEF1A1 as important gene nodes in MTX-resistance. Treatments using siRNA technology against these three genes showed chemosensitization toward MTX.

Reconstruction of the recent history of a large deep prealpine lake (Lake Bourget, France) using subfossil chironomids, diatoms, and organic matter analysis: towards the definition of a lake-specific reference state

This paper presents the recent history of a large prealpine lake (Lake Bourget) using chironomids, diatoms and organic matter analysis, and deals with the ability of paleolimnological approach to define an ecological reference state for the lake in the sense of the European Framework Directive. The study at low resolution of subfossil chironomids in a 4-m-long core shows the remarkable stability over the last 2.5 kyrs of the profundal community dominated by a Micropsectra-association until the beginning of the twentieth century, when oxyphilous taxa disappeared. Focusing on this key recent period, a high resolution and multiproxy study of two short cores reveals a progressive evolution of the lake's ecological state. Until AD 1880, Lake Bourget showed low organic matter content in the deep sediments (TOC less than 1%) and a well-oxygenated hypolimnion that allowed the development of a profundal oxyphilous chironomid fauna (Micropsectra-association). Diatom communities were characteristic of oligotrophic conditions. Around AD 1880, a slight increase in the TOC was the first sign of changes in lake conditions. This was followed by a first limited decline in oligotrophic diatom taxa and the disappearance of two oxyphilous chironomid taxa at the beginning of the twentieth century. The 1940s were a major turning point in recent lake history. Diatom assemblages and accumulation of well preserved planktonic organic matter in the sediment provide evidence of strong eutrophication. The absence of profundal chironomid communities reveals permanent hypolimnetic anoxia. From AD 1995 to 2006, the diatom assemblages suggest a reduction in nutrients, and a return to mesotrophic conditions, a result of improved wastewater management. However, no change in hypolimnion benthic conditions has been shown by either the organic matter or the subfossil chironomid profundal community. Our results emphasize the relevance of the paleolimnological approach for the assessment of reference conditions for modern lakes. Before AD 1900, the profundal Micropsectra-association and the Cyclotella dominated diatom community can be considered as the Lake Bourget reference community, which reflects the reference ecological state of the lake.

Functional remediation for bipolar disorder

Neurocognitive impairment constitutes a core feature of bipolar illness. The main domains affected are verbal memory, attention, and executive functions. Deficits in these areas as well as difficulties to get functional remission seem to be increased associated with illness progression. Several studies have found a strong relationship between neurocognitive impairment and low functioning in bipolar disorder, as previously reported in other illnesses such as schizophrenia. Cognitive remediation strategies, adapted from work conducted with traumatic brain injury patients and applied to patients with schizophrenia, also need to be adapted to individuals with bipolar disorders. Early intervention using functional remediation, involves neurocognitive techniques and training, but also psychoeducation on cognition-related issues and problem-solving within an ecological framework.