Diatom Epibionts on Amphipod Crustaceans: A Possible Vector for Co-Introductions?

Epibiotic associations can result in co-introductions of non-indigenous species, which may affect ecosystems in several ways. In fouling communities of three estuaries in southern Brazil, a number of amphipods was found to harbour a dense coverage of epibionts. Three different species, the two globally widespread caprellids Caprella equilibra and Paracaprella pusilla, as well as the ischyrocerid Jassa valida, had been colonised by diatoms. Further scanning electron microscope analyses assigned these diatoms to 14 different species that had previously been reported from benthic habitats. This is one of the scarce records of diatoms attached to amphipods. The occurrence of the diatom Amphora helenensis represents the first report for Brazilian waters as well as the second record for the whole SW Atlantic Ocean. As some diatoms were associated with common fouling amphipods, a possible regional spread aided by these crustaceans seems likely. Possible effects of this amphipod-diatom association on the animals and their implications for the underlying ecosystems of this remain to be elucidated.

Vascular Plant Herbarium at the Kandalaksha Strict Nature Reserve (KAND), Russia

The present-day demand for digital availability of distributional data in biodiversity studies requires a special effort in assembling and editing the data otherwise scattered in paper literature and herbarium collections, which can be poorly accessible or little understood to present-day users and especially automatic data processors. Our project on developing the information resource for the vascular plant flora of Murmansk Region, Russia, includes processing and making digitally available all the data on the taxonomy and distribution of this flora. So far, published distribution maps are limited to the old set in the Flora of Murmansk Region (published in 1953–1966) and the Red Data Book of Murmansk Region (ed. 2, published in 2014). These publications did not take into account the main part of the herbarium collections kept at the Kandalaksha Strict Nature Reserve, which are the basis for numerous local publications that appear scattered and, therefore, little accessible nowadays. We present a complete dataset of all holdings of vascular plants in the Herbarium of the Kandalaksha Strict Nature Reserve, totalling 10,218 specimens collected during 1947–2019, which are referable to 764 species and 19 subspecies. All specimens were georeferenced with the utmost precision available. This dataset offers a complete and dense coverage of the Nature Reserve's territory (islands and adjacent mainland coastal areas of the Barents and White Seas, Murmansk Region and Republic of Karelia, Russia); these data are little represented in herbarium collections elsewhere.

Hydrothermal Activity at a Cretaceous Seamount, Canary Archipelago, Caused by Rejuvenated Volcanism

Our knowledge of venting at intraplate seamounts is limited. Almost nothing is known about past hydrothermal activity at seamounts, because indicators are soon blanketed by sediment. This study provides evidence for temporary hydrothermal circulation at Henry Seamount, a re-activated Cretaceous volcano near El Hierro island, close to the current locus of the Canary Island hotspot. In the summit area at around 3000–3200 m water depth, we found areas with dense coverage by shell fragments from vesicomyid clams, a few living chemosymbiotic bivalves, and evidence for sites of weak fluid venting. Our observations suggest pulses of hydrothermal activity since some thousands or tens of thousands years, which is now waning. We also recovered glassy heterolithologic tephra and dispersed basaltic rock fragments from the summit area. Their freshness suggests eruption during the Pleistocene to Holocene, implying minor rejuvenated volcanism at Henry Seamount probably related to the nearby Canary hotspot. Heat flow values determined on the surrounding seafloor (49 ± 7 mW/m2) are close to the expected background for conductively cooled 155 Ma old crust; the proximity to the hotspot did not result in elevated basal heat flow. A weak increase in heat flow toward the southwestern seamount flank likely reflects recent local fluid circulation. We propose that hydrothermal circulation at Henry Seamount was, and still is, driven by heat pulses from weak rejuvenated volcanic activity. Our results suggest that even single eruptions at submarine intraplate volcanoes may give rise to ephemeral hydrothermal systems and generate potentially habitable environments.

Global dependences in hexagonal tiling

Tiling is a widely used technique to solve the problems of the efficient use of multilevel memory and optimize data exchanges when developing both sequential and parallel programs. This paper investigates the problem of obtaining global dependencies, i.e. informational dependencies between tiles. The problem is solved in the context of parametrized hexagonal tiling in application to algorithms with a two-dimensional computational domain. The paper includes a formalized definition of the hexagonal tile and the criteria for dense coverage of the computational domain with hexagonal tiles. Herein, we have formulated a statement that permits to obtain all global dependencies between tiles. Formulas are constructed for the determination of sets of iterations of hexagonal tiles generating these dependencies. The sets of iterations that generate global dependencies are obtained in the form of polyhedra with an explicit expression of their boundaries.

New Rainfall Datasets for the Congo Basin and Surrounding Regions

This paper describes three new rainfall datasets that have been developed for equatorial Africa. The development relies on acquisition of recent gauge data from the relevant countries and statistical methods to fill in gaps in coverage. Two of the three datasets are gridded with spatial resolutions of 2.5° and 5.0°, and the third is regionally aggregated and based purely on gauge data. The work is based on a total of 1826 gauge records in the analysis sector, of which only several hundred operate in recent years. The gridded datasets were produced and validated by using a period of dense coverage (1947–72) to “calibrate” a spatial reconstruction method, which is then utilized to grid data for the remaining years. The period 1973–2010 served as a validation period. The validation was carried out by comparing the gridded values with values obtained by simple averaging of station data in grid boxes with an adequate number of stations. This exercise clearly showed that the statistical reconstruction approach based on principal components produced far superior results than those from the more commonly used kriging. The gridded datasets cover each month of the year, six seasons, and annual rainfall, and they commence in 1921 and extend through 2014. In contrast, the gauge-only regional dataset covers varied time periods, depending on the geographical region in question. Records for several regions cover nearly all of the twentieth century and most extend to 2014.

A Taxonomic Revision of the genus Dialium (Leguminosae: Dialiinae) in the Netotropics

Dialium (Leguminosae, Dialiinae) is pantropical and comprises about 40 species. Presently, only one species occurs in the Neotropics, Dialium guianense, which is found from eastern Mexico to northeastern Minas Gerais, Brazil. The objective of this study was to carry out a thorough taxonomic revision of Dialium in the Neotropics, to determine if species diversity of the genus in this region is underestimated. The study analyzed 765 collections, from 18 herbaria throughout the world, which revealed three groups of specimens that clearly differ from each other and from D. guianense. Morphology and biogeography support their recognition as new species. Dialium hexaestaminatum occurs in northern Colombia and western Venezuela, and is characterized by generally having six stamens, while the other neotropical species have only two. Dialium congestum occurs in Ecuador and southern Colombia and is mainly characterized by the presence of congested inflorescences, unlike the lax inflorescences found in the other neotropical species. Dialium rondoniense occurs in the state of Rondônia and the most southern part of the state of Amazonas, Brazil. It is characterized by the dense coverage of trichomes on the abaxial surface of the leaflets, as well as the petiolules, petioles, leaf rachis and branches, while the other neotropical species are generally glabrous or covered with sparse trichomes that are imperceptible to the bare eye. The results show that the diversity of Dialium in the Neotropics was underestimated and that the genus has four species in the region. An identification key, illustrations and descriptions of the species are provided.

Análise geoespacial do processo de desmatamento da Caatinga no município de Catolé do Rocha – PB

Objetivou-se analisar o processo de desmatamento no município de Catolé do Rocha-PB. Com o presente trabalho estabelecemos uma análise multitemporal das mudanças no uso e ocupação do solo no município de Catolé do Rocha entre os anos de 2005 e 2013. Foram utilizadas imagens do sensor TM Landsat-7, ano 2005 Bandas 3, 4, 5, ponto 216 e órbita 064, e Landsat-8 Banda 8, ponto 216, órbita 064, (georreferenciada). No ano de 2013 as imagens foram corrigidas no Regeemy 0.2.43, e processadas, filtradas e classificadas no SPRING 5.2, a classificação foi efetuada pelo método pixel a pixel, foi obtido 9 amostras para cada classe, com desempenho médio acima de 90%. A imagem resultante da sobreposição dos planos de informação foi obtida por cruzamento usando lógica booleana, no ambiente de programação em LEGAL. A vegetação manteve os níveis degradação principalmente sobtre as regiões de classes (Caatinga Estépica Florestada Mantida e Caatinga Estépica Arborizada Mantida), representando respectivamente, 14,7% e 27,0%. Isso descreve os elevados níveis de degradação que as atividades impõem sobre a paisagem. Também pode-se observar nessas áreas, condições de raleamento da cobertura mais densa e aumento da cobertura menos densa. Caracterizando um aumento do processo de degradação da vegetação natural. Geospatial analysis process of deforestation Caatinga in the municipality of Catolé do Rocha – PBAbstract: This study aimed to analyze the process of deforestation in the municipality of Catolé do Rocha-PB. The present work established a multi-temporal analysis of changes in the use and occupation of land in the municipality Catolé do Rocha between the years 2005 and 2013. They were used sensor images TM Landsat-7, 2005 Bands 3, 4, 5, point 216 and orbit 064, and Landsat-8 Band 8, paragraph 216, orbiting 064 (georeferenced), 2013, The images were corrected in Regeemy 0.2.43, and processed, filtered and sorted in SPRING 5.2, the rating was performed by the pixel-by-pixel method, 9 samples was obtained for each class, with an average performance above 90%. The resulting overlay of information layers was obtained by crossing using Boolean logic, at Legal in programming environment. The vegetation degradation levels remained mainly on the classes of regions (Caatinga Caatinga and Maintained Forested Steppe Steppe Tree Maintained), representing respectively 14.7% and 27.0%. This describes the high levels of degradation that activities impose on the landscape. It can also be observed in these areas, thinning conditions of denser coverage and increased less dense coverage. Featuring an increased degradation of natural vegetation process.

Preparation and Performance of Titanium Matrix (SnO2/Sb2O3/IrO2) Catalytic Electrode

The anode of DSA (SnO2/Sb2O3/IrO2) was prepared with the brush coating thermal decomposition method. The surface crystal particles of the DSA were plump, evenly distributed dense coverage and less cracks. The electro catalytic has been enhanced. Compared with the original titanium board, the useful life of electrode was extended obviously, and removal efficiency of N, N-dimethylformamide (DMF) increased to 85.4%.