A novel approach to analysing the regimes of temporary streams in relation to their controls on the composition and structure of aquatic biota

Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The structure and composition of biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. Therefore, the structural and functional characteristics of aquatic fauna to assess the ecological quality of a temporary stream reach cannot be used without taking into account the controls imposed by the hydrological regime. This paper develops methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the transient sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: Hyperrheic, Eurheic, Oligorheic, Arheic, Hyporheic and Edaphic. When the hydrological conditions lead to a change in the aquatic state, the structure and composition of the aquatic community changes according to the new set of available habitats. We used the water discharge records from gauging stations or simulations with rainfall-runoff models to infer the temporal patterns of occurrence of these states in the Aquatic States Frequency Graph we developed. The visual analysis of this graph is complemented by the development of two metrics which describe the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of temporary streams in four aquatic regimes in terms of their influence over the development of aquatic life is updated from the existing classifications, with stream aquatic regimes defined as Permanent, Temporary-pools, Temporary-dry and Episodic. While aquatic regimes describe the long-term overall variability of the hydrological conditions of the river section and have been used for many years by hydrologists and ecologists, aquatic states describe the availability of mesohabitats in given periods that determine the presence of different biotic assemblages. This novel concept links hydrological and ecological conditions in a unique way. All these methods were implemented with data from eight temporary streams around the Mediterranean within the MIRAGE project. Their application was a precondition to assessing the ecological quality of these streams.

Riqueza y rareza de los insectos acuáticos de la laguna temporal de Espolla (Pla de l’Estany, Cataluña)

The richness and rarity of an insect community were analysed in a Mediterranean temporary pond located in NE of the Iberian Peninsula. The aquatic community was sampled weekly over 7 periods of flooding during y years (1996-1999). Distribution of rare species (with scarce presence at regional or peninsular levels, is detailed. The richness of the Espolla pond has been compared with that of other aquatic environments. The number of rare species of insects (8 taxa: 5 Corixidae, 1 Limnephilidae and 2 Chironomidae) and the insect richness (82 taxa) contrast with the traditional attribution of a low richness and rarity to the temporary aquatic environments

Community structure in mediterranean shallow lentic ecosystems: size-based vs. taxon-based approaches

The main environmental variables determining the community structure and the functioning of Mediterranean shallow lentic ecosystems are described. These ecosystems are characterized by the unpredictability of their water inputs and the high variability in their water level and physical and chemical composition. Variations in flooding, salinity, and water turnover are determinant in species composition and nutrient dynamics. Taxon-based and size-based approaches to the study of the community structure of aquatic organisms that colonise these ecosystems are also compared. The conventional taxonomic approach, based on the determination of species composition, has been used for the identification of patterns in species richness, distribution and temporal dynamics, and for ecological requirements of species and their potential use as ecological indicators. This taxonbased approach has been compared with a size-based approach, where individuals are classified by their size. Size-based approach gives complementary information about community structure and dynamics, especially when communities are dominated by a single species. The use of size diversity combined with species diversity is suggested for a more complete understanding of community structuring in this type of ecosystem. Detailed examples of two Mediterranean shallow lentic ecosystems, the salt marshes of the Empordà wetlands and the Espolla temporary karstic pond, which differ in hydrology and water origin, are used to discuss the suitability of these different approaches

Assessment of the water chemistry and the macroinvertebrate community changes produced during the creation of the new Llobregat river mouth (Barcelona, NE Spain)

In 1999, a set of coordinated projects and investments whose principal objective was to transform Barcelona into one of the main distribution points of southern Europe resulted in the relocation of the Llobregat River mouth. The mouth was relocated by draining the old river mouth and constructing a new one. The aim of this study was to characterise the physico-chemical properties and the aquatic macroinvertebrate communities of the new river mouth and to monitor the changes experienced by the estuarine environment during its creation. A sampling point was established in the river 1.8 km upstream from its connection with the new mouth, and two sampling points were established in the new mouth. Samples of water and macroinvertebrates were collected every two months from May 2004 to June 2005, covering the periods before (from May to September 2004) and after (from September 2004 to June 2005) the new mouth was connected to the river and the sea. During the period before its connection to the river and the sea, the new mouth was functionally similar to a lagoon, with clear waters, charophytes and a rich invertebrate community. After the connection was completed, seawater penetrated the river mouth and extended to the connection point with the river (approximately 3.9 km upstream). An increase in conductivity from 4-6 mS cm 1 to 24-30 mS cm 1 caused important changes in the macroinvertebrate community of the new mouth. An initial defaunation was followed by a colonisation of the new mouth by brackish-water and marine invertebrate species. Due to its design (which allows the penetration of the sea) and the decreased discharge from the lower part of the Llobregat River, the new mouth has become an arm of the sea

Effects of Temperature, Salinity and Fish in Structuring the Macroinvertebrate Community in Shallow Lakes: Implications for Effects of Climate Change

Climate warming may lead to changes in the trophic structure and diversity of shallow lakes as a combined effect of increased temperature and salinity and likely increased strength of trophic interactions. We investigated the potential effects of temperature, salinity and fish on the plant-associated macroinvertebrate community by introducing artificial plants in eight comparable shallow brackish lakes located in two climatic regions of contrasting temperature: cold-temperate and Mediterranean. In both regions, lakes covered a salinity gradient from freshwater to oligohaline waters. We undertook day and night-time sampling of macroinvertebrates associated with the artificial plants and fish and free-swimming macroinvertebrate predators within artificial plants and in pelagic areas. Our results showed marked differences in the trophic structure between cold and warm shallow lakes. Plant-associated macroinvertebrates and free-swimming macroinvertebrate predators were more abundant and the communities richer in species in the cold compared to the warm climate, most probably as a result of differences in fish predation pressure. Submerged plants in warm brackish lakes did not seem to counteract the effect of fish predation on macroinvertebrates to the same extent as in temperate freshwater lakes, since small fish were abundant and tended to aggregate within the macrophytes. The richness and abundance of most plant-associated macroinvertebrate taxa decreased with salinity. Despite the lower densities of plant-associated macroinvertebrates in the Mediterranean lakes, periphyton biomass was lower than in cold temperate systems, a fact that was mainly attributed to grazing and disturbance by fish. Our results suggest that, if the current process of warming entails higher chances of shallow lakes becoming warmer and more saline, climatic change may result in a decrease in macroinvertebrate species richness and abundance in shallow lakes

Estudi de la successió primària en esculls artificials en un port marítim

Treball de recerca realitzat per una alumna d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l'any 2009. La llum i el temps són factors importants en tots els ecosistemes i especialment en ecosistemes aquàtics, ja que constitueixen variables ambientals que condicionen la seva evolució i equilibri. L’objectiu principal del treball de recerca és estudiar el desenvolupament de les successions primàries all llarg del temps en esculls artificials submergits en un ambient marí i observar les conseqüències de la incidència, directa o no, de la llum en aquests esculls pel que fa al desenvolupament de la successions primàries. Els resultats obtinguts demostren satisfactòriament que la incidència de la llum és un factor determinant en la constitució de les successions primàries en ambients marins. Per altra part, els resultats també demostren que el temps és un factor que actua condicionant la diversitat de les formes de vida que colonitzen aquests medis marins, concretament la diversitat s’incrementa amb el temps.

Stream Radio Community : comunitat web per la difusió de radio via streaming

Desenvolupament d'una aplicació web amb projecció a comunitat virtual d’usuaris, que també integra un sistema de transmissió de streaming. Mitjançant aquest sistema els usuaris són capaços d’emetre o d’escoltar un programa radiofònic en temps real o offline.

AgShare : Building Community and Content with Multiple Partners

Michigan State University and OER Africa are creating a win-win collaboration of existing organizations for African publishing, localizing, and sharing of teaching and learning materials that fill critical resource gaps in African MSc agriculture curriculum. By the end of the 18-month planning and pilot initiative, African agriculture universities, faculty, students, researchers, NGO leaders, extension staff, and farmers will participate in building AgShare by demonstrating its benefits and outcomes and by building momentum and support for growth.

The Quest for the Oracle Birds: Researching the Chinese Community in Colonial Mexico (1565-1700)

The Asian Diaspora in the Americas in the 16th and 17th has been neglected by scholars for a long time. This fact is baffling, not only for the great interest of this topic in of itself, but also because it could provide new knowledge of colonial Mexico, especially in terms of the interaction among the many groups that populated the colony. This early movement of people and ideas across the largest extension of water in the planet is characteristic of what has been called the ¿archaic globalization,¿ and thus research on these matters could contribute to the history of globalization.In this presentation, I seek to further elaborate on the themes outlined by Edward Slack in The Chinos in New Spain: A Corrective Lens for a Distorted Image, an article published in 2009 in the Journal of World History. Firstly, I would like to bring forth some evidence that indicates that Asian religious practices were present in Mexico in the 1600s. Furthermore, I will argue that the traces of these practices are still visible today, in the form of a popular fortune-telling tradition. Secondly, I intend to provide some information about the arrival, settlement and distribution of the Asian Diaspora. I will focus on their distribution within Mexico City. Thirdly, I will elaborate on their occupations, social status and daily life, as well as in the patterns in marriages and relations with other groups. And lastly, I will show how the guild of barbers served as an Asian immigrant reception network.

Social Determinants of Child Health in Colombia: Can Community Education Moderate the Effect of Family Characteristics?

Contextual effects on child health have been investigated extensively in previous research. However, few studies have considered the interplay between community characteristics and individual-level variables. This study examines the influence of community education and family socioeconomic characteristics on child health (as measured by height and weight-for-age Z-scores), as well as their interactions. We adapted the Commission on Social Determinants of Health (CSDH) framework to the context of child health. Using data from the 2010 Colombian Demographic and Health Survey (DHS), weighted multilevel models are fitted since the data are not self-weighting. The results show a positive impact of the level of education of other women in the community on child health, even after controlling for individual and family socioeconomic characteristics. Different pathways through which community education can substitute for the effect of family characteristics on child nutrition are found. The interaction terms highlight the importance of community education as a moderator of the impact of the mother’s own education and autonomy, on child health. In addition, the results reveal differences between height and weight-for-age indicators in their responsiveness to individual and contextual factors. Our findings suggest that community intervention programmes may have differential effects on child health. Therefore, their identification can contribute to a better targeting of child care policies.

Diversity of the bacterial community in the surface soil of a pear orchard based on 16S rRNA gene analysis

A cultivation-independent approach based on polymerase chain reaction (PCR)-amplified partial small subunit rRNA genes was used to characterize bacterial populations in the surface soil of a commercial pear orchard consisting of different pear cultivars during two consecutive growing seasons. Pyrus communis L. cvs Blanquilla, Conference, and Williams are among the most widely cultivated cultivars in Europe and account for the majority of pear production in Northeastern Spain. To assess the heterogeneity of the community structure in response to environmental variables and tree phenology, bacterial populations were examined using PCR-denaturing gradient gel electrophoresis (DGGE) followed by cluster analysis of the 16S ribosomal DNA profiles by means of the unweighted pair group method with arithmetic means. Similarity analysis of the band patterns failed to identify characteristic fingerprints associated with the pear cultivars. Both environmentally and biologically based principal-component analyses showed that the microbial communities changed significantly throughout the year depending on temperature and, to a lesser extent, on tree phenology and rainfall. Prominent DGGE bands were excised and sequenced to gain insight into the identities of the predominant bacterial populations. Most DGGE band sequences were related to bacterial phyla, such as Bacteroidetes, Cyanobacteria, Acidobacteria, Proteobacteria, Nitrospirae, and Gemmatimonadetes, previously associated with typical agronomic crop environments

A portrait of the Spanish accounting community

This study presents a portrait of the Spanish academic accountingcommunity in 1995, based upon a questionnaire circulated to Spanishaccounting academics in 1995 and upon an analysis of authorship andcitations in the main Spanish accounting journals. The approach tothese analyses is grounded in similar studies which have been carriedout in the United States, Spain and elsewhere. but the combination oftechniques used in this study is particularly broad in range.The results of the study are used to describe a range ofcharacteristics of Spanish accounting academics, for example,publications records and length of academic experience. The analysisof publications produces a ranking by institutional affiliation ofthe most significant contributors to current debates on accounting.Citation analysis is used to identify the range and extent ofinternational influences upon the Spanish academic accountingcommunity, and to provide an additional ranking by institutionalaffiliation of the most frequently cited sources A significantfinding was that the nature and extent of international influence hadchanged very little over the ten year period since Spain entered theEuropean Union and started to implement European Directives.Perceptions of journal quality were elicited by questionnaire. Fortyfive journals, Spanish and international are included in a listranked for perceived importance as outlets for publication. and assources of support for teaching and research. The results of thisexercise show that Spanish journals were ranked low relative tojournals published in the United Kingdom and United States.Finally the study examines the extent of purpose upon Spanishaccounting academies to publish, by presenting results of a questionabout criteria for promotion, and also by examining and increasingtendency to publish co-authored work.

One hundred issues of Revista Española de Financiación y Contabilidad (REFC)-insights into trends in the Spanish academic community

From the year of its foundation, until the foundation of Revista deContabilidad in 1997, REFC has been the only referred accounting journalin Spain. Published by the Spanish Association for Accounting and BusinessAdministration (AECA), this journal is at the heart of the emergence ofa distinctly Spanish academic accounting community.Our study is based on:1. An analysis of 100 issues of REFC covering the period from 1985 to 1999.2. A questionnaire to Spanish accounting academics on their perceptionsand experience of the journal.Key points emerging from this study include:a) A move away from interest in accounting concepts and rules, as wellas accounting history, and towards positive accounting theory, the impactof accounting information on capital markets, and financial analysis.b) The emergence of a small number of universities as the driving forcein Spanish accounting research.c) Spanish academics rate REFC highly compared to other Spanish journalsfor publication status, as a support for research, and as a support forteaching. A number of English language journals are rated more highly forboth publication status and as a support for teaching.