Spatial patterns and response to wave exposure of shallow water algal assemblages across the Canarian Archipelago: A multi-scaled approach

We conducted a mensurative survey to investigate spatial variability and the effect of wave exposure at a range of spatial scales including islands (100s of kilometres apart), locations within islands (10s of kilometres apart), and sites within locations (100s of meters apart), on the composition, abundance and distribution of shallow water algal assemblages across subtidal hard bottoms of the Canarian Archipelago (eastern Atlantic). A multi-scaled hierarchical sampling design provided the framework for quantifying the variation among samples due to each spatial scale and level of wave exposure. Haphazardly placed 50 x 50 cm quadrats were deployed in shallow rocky-reefs to assess community structure and dominance. Non-parametric multivariate techniques, as well as univariate tests, provided evidence to collectively suggest that shallow water algal assemblages differed between protected (leeward) and exposed (windward) shores, with a consistency of its effects across islands, while different spatial scales were also involved in the variability and patchiness of these assemblages. In this sense, differences were clearly taxon and/or group-specific. In general, the presence and abundance of frondose fucoid species was greater at exposed shores compared to protected shores, whereas turf-algae dominated protected shores at each island. Dissimilarities between islands for the overall algal assemblage generally increased with the distance between islands. In particular, the presence and abundance of fucoid species was larger in the eastern islands, while in contrast turf and bush-like algae increased in the western islands. The large-scale gradient of the oceanographic conditions in an east-to-west direction across the Canarian Archipelago provided a parsimonious explanation for this observation, yet some inconsistencies were observed in the overall regional pattern

Spatial patterns and response to wave exposure of shallow water algal assemblages across the Canarian Archipelago: a multiscaled approach

We conducted a mensurative survey to investigate spatial variability and the effect of wave exposure at a range of spatial scales including islands (100s of kilometres apart), locations within islands (10s of kilometres apart), and sites within locations (100s of meters apart), on the composition, abundance and distribution of shallow water algal assemblages across subtidal hard bottoms of the Canarian Archipelago (eastern Atlantic). A multi-scaled hierarchical sampling design provided the framework for quantifying the variation among samples due to each spatial scale and level of wave exposure. Haphazardly placed 50 x 50 cm quadrats were deployed in shallow rocky-reefs to assess community structure and dominance. Non-parametric multivariate techniques, as well as univariate tests, provided evidence to collectively suggest that shallow water algal assemblages differed between protected (leeward) and exposed (windward) shores, with a consistency of its effects across islands, while different spatial scales were also involved in the variability and patchiness of these assemblages. In this sense, differences were clearly taxon and/or group-specific. In general, the presence and abundance of frondose fucoid species was greater at exposed shores compared to protected shores, whereas turf-algae dominated protected shores at each island. Dissimilarities between islands for the overall algal assemblage generally increased with the distance between islands. In particular, the presence and abundance of fucoid species was larger in the eastern islands, while in contrast turf and bush-like algae increased in the western islands. The large-scale gradient of the oceanographic conditions in an east-to-west direction across the Canarian Archipelago provided a parsimonious explanation for this observation, yet some inconsistencies were observed in the overall regional pattern

Can one identify the intrinsic structure of the yrast states in 48^{48}Cr after the backbending?

The backbending phenomenon in $^{48}$Cr has been investigated using the recently developed Projected Configuration Interaction (PCI) method, in which the deformed intrinsic states are directly associated with shell model (SM) wavefunctions. Two previous explanations, (i) $K=0$ band crossing, and (ii) $K=2$ band crossing have been reinvestigated using PCI, and it was found that both explanations can successfully reproduce the experimental backbending. The PCI wavefunctions in the pictures of $K=0$ band crossing and $K=2$ band crossing are highly overlapped. We conclude that there are no unique intrinsic states associated with the yrast states after backbending in $^{48}$Cr.Comment: 5 pages, 5 figure

Coverage Based Testing for Service Level Agreements

Service level agreements (SLAs) are typically used to specify rules regarding the consumption of services that are agreed between the providers of the service-based applications (SBAs) and their consumers. An SLA includes a list of terms that contain the guarantees that must be fulfilled during the provisioning and consumption of the services. Since the violation of such guarantees may lead to the application of potential penalties, it is important to assure that the SBA behaves as expected. In this paper, we propose a proactive approach to test SLA-aware SBAs by means of identifying test requirements, which represent situations that are relevant to be tested. To address this issue, we define a four-valued logic that allows evaluating both the individual guarantee terms and their logical relationships. Grounded in this logic, we devise a test criterion based on the modified condition decision coverage (MCDC) in order to obtain a cost-effective set of test requirements from the structure of the SLA. Furthermore by analyzing the syntax and semantics of the agreement, we define specific rules to avoid non-feasible test requirements. The whole approach has been automated and applied over an eHealth case study

Patrones espaciales en la estructura poblacional del caracol Stramonita haemastoma (Linnaeus, 1766) (Gastropoda: Muricidae) en el Archipiélago Canario (Atlántico oriental).

The goal of this study was to determine the consistency of the vertical distribution patterns of the predatory whelk, Stramonita haemastoma, in the rocky intertidal zone of the Canarian Archipelago (eastern Atlantic) across a hierarchy of five orders of magnitude of horizontal spatial variability (from tens of m to hundreds of km). In general, this species showed a consistent vertical zonation pattern across islands, with the majority of the specimens (74.65%) found in the mid intertidal zone. This result most likely reflects the whelk’s preference for a habitat with a large amount of potential prey but minimal stress induced by swells and desiccation. The mean abundance (0 to 1.73 ± 0.40 ind m-2, mean ± SE) and size structure (7 to 45 mm in shell length) of S. haemastoma in the Canarian Archipelago was considerably lower compared to those from continental areas in the Atlantic Ocean, which suggests that there are some differences between these populations. Natural mechanisms (e.g. isolation or poor recruitment events) and human perturbations (e.g. exploitation of intertidal resources) might influence the spatial distribution patterns.El objetivo de este estudio fue determinar la consistencia de los patrones de distribución vertical del caracol predador, Stramonita haemastoma, en el intermareal rocoso del archipiélago Canario (Atlántico oriental), a través de un modelo jerárquico que incluyó cinco órdenes de magnitud de variabilidad espacial horizontal (desde decenas de m hasta centenares de km). En general, esta especie mostró un patrón de zonación vertical consistente entre islas, con la mayoría de los ejemplares (74.65%) presentes en la zona intermareal media. Este resultado probablemente refleja una preferencia hacia un hábitat con mayor disponibilidad de presas, pero minimizando el estrés inducido por la exposición al oleaje y la desecación. El rango de abundancias (0 a 1.73 ind m-2, media ± SE) y la estructura de tallas (7-45 mm en longitud de concha) fueron notablemente bajos en relación a los observados en la costa continental del Atlántico, sugiriendo diferencias entre dichas poblaciones. Procesos naturales (e.g. aislamiento o eventos de escaso reclutamiento) y perturbaciones humanas (e.g. explotación de los recursos intermareales) pueden haber influido sobre estos patrones de distribución espacial

Identifying Test Requirements by Analyzing SLA Guarantee Terms

Service Level Agreements (SLAs) are used to specify the negotiated conditions between the provider and the consumer of services. In this paper we present a stepwise method to identify and categorize a set of test requirements that represent the potential situations that can be exercised regarding the specification of each isolated guarantee term of an SLA. This identification is addressed by means of devising a set of coverage levels that allow grading the thoroughness of the tests. The utilization of these test requirements would focus on twofold objectives: (1) the generation of a test suite that allows exercising the situations described in the test requirements and (2) the support for the derivation of a monitoring plan that checks the compliance of these requirements at runtime. The approach is illustrated over an eHealth case study

Multi-dimensional criteria for testing web services transactions

Web services (WS) transactions are important in order to reliably compose distributed and autonomous services into composite web services and to ensure that their execution is consistent and correct. But such transactions are generally complex and they require longer processing time, and manipulate critical data. Thus various techniques have been developed in order to perform quality assessment of WS transactions in terms of response time efficiency, failure recovery and throughput. This paper focuses on the testing aspect of WS transactions - another key quality issue that has not been examined in the literature. Accordingly it proposes multi-dimensional criteria for testing the WS transactions. The proposed criteria have the potential to capture the behaviour of WS transactions and to analyse and classify the possible (failure) situations that effect the execution of such transactions. These criteria are used to generate various test cases and to provide (WS transactions) ! tester with flexibility of adjusting the method in terms of test efforts and effectiveness. The proposed criteria have been designed, implemented and evaluated through a case study and a number of experiments have been performed. The evaluation shows that these criteria have the capability to effectively generate test cases for testing WS transactions as well as enable tester to decide on the trade-off between test efforts and the quality

Herbivory drives kelp recruits into ‘hiding’ in a warm ocean climate

Assessing effects of herbivory across broad gradients of varying ocean climate conditions and over small spatial scales is crucial for understand- ing its influence on primary producers. Effects of her- bivory on the distribution and abundance of kelp re- cruits were examined experimentally at two regions under contrasting ocean climate. Specifically, the abundance and survivorship of kelp recruits and the abundance of macro-herbivores were compared be- tween a ‘cool’ and a ‘warm’ region in northern and central Portugal, respectively. In each region, the abundance of kelp recruits and the intensity of grazing were compared between habitats of different topography within reefs (open reef vs. crevices). Com- pared to the ‘warm’ region, the abundance of kelp re- cruits was 3.9 times greater in the ‘cool’ region, where 85% of recruits were found in open reef habitats. In contrast, 87% of recruits in the ‘warm’ region were re- stricted to crevices. The ‘warm’ region had 140 times greater abundances of sea urchins, 45 times more herbivorous fish and 4.1 times more grazing marks on kelp recruits than the ‘cool’ region. Grazing assays showed ca. 50 times higher rates of kelp biomass con- sumption, mainly by fishes, and zero survivorship of kelp recruits in the ‘warm’ relative to the ‘cool’ region. This study suggests both temperature and herbivores affect abundances of kelp recruits across latitudes, and demonstrates how herbivores affect their distri- bution at local scales, driving kelp recruits into ‘hiding’ in crevices under intense herbivory. Conse- quently, where net recruitment success is compro- mised by herbivory, the persistence of kelps will be contingent on availability of topographical refuges

Explosión demográfica de un hidrozoo exótico en una isla oceánica

The arrival of non-indigenous species into new areas is one of the main processes altering the oceans globally. Macrorhynchia philippina is a large-sized colonial hydrozoan of an invasive nature. To obtain a deeper understanding of the process of colonization of new areas, it is essential to describe the ecological pattern through scales of temporal and spatial variation. In this study, we describe the colonization by M. Philippina of an oceanic island (Gran Canaria Island, Canary Islands, eastern Atlantic). We describe the abundance and size structure patterns of M. Philippina in three nearshore habitats, rocky reefs, seagrass meadows and rhodolith seabeds, at times before (2014), during (2016) and after (2017) the demographic explosion of this species. On rocky reefs and rhodolith seabeds, the abundance of colonies increased dramatically in 2017 rel­ative to 2014, e.g. from 0 to 138 colonies/100 m2. On seagrass meadows, however, the colonies were smaller. In summary, M. Philippina shows an ecological plasticity to rapidly colonize different types of nearshore habitats, but with varying success.La aparición de especies exóticas es uno de los principales factores que alteran los océanos de forma global. Mac­rorhynchia philippina es un hidrozoo colonial de tamaño grande y naturaleza invasora. Para tener un mejor conocimiento del proceso de colonización es fundamental describir los patrones ecológicos a escalas de variación temporal y espacial. En este estudio, describimos el proceso de colonización por M. Philippina en una isla oceánica (Gran Canaria, Islas Canarias, Atlántico oriental). Se describen los patrones de abundancia y estructura de tallas de M. Philippina en tres hábitats costeros: arrecifes rocosos, praderas de fanerógamas marinas y fondos de rodolitos, antes (2014), durante (2016) y después (2017) de la explosión demográfica de la especie. Sobre arrecifes rocosos y en fondos de rodolitos, la abundancia de las colonias se incrementó drásticamente en 2017 con relación a 2014, e.g. desde 0 hasta 138 colonias/100 m2; este incremento fue menor en las praderas de fanerógamas marinas. En las praderas marinas, la longitud de las colonias fue más pequeña que sobre ar­recifes rocosos y fondos de rodolitos. Consecuentemente, la colonización rápida por M. Philippina demuestra su plasticidad ecológica para colonizar diferentes tipos de hábitats costeros, aunque con diferente éxito