Pollen microphotographs from Georgia, Caucasus.

Contains 166 photographs of pollen grains that are commonly encountered in sediments from Georgia, are difficult to identify or are endemic to the regio

Cam-based passive variable friction device for structural control

A solution to increasing the resiliency of civil structures with respect to natural and man-made hazards is the implementation of supplemental damping systems. These systems can be constructed using passive, active, and semi-active devices. In particular, passive devices are widely accepted in the field of structural engineering, because they do not require power to operate and can be holistically integrated into the structural design process. This paper investigates the use of 3D printing technology to expand on the possibilities in passive damping, notably in the fabrication of a variable friction device. This device uses a 3D printed cam with a pre-defined surface profile to vary the normal forces applied to a traditional sliding plate friction system. It follows that these varying forces develop a variable damping force that is dependent on the device’s displacement. In this work, a friction model is developed to characterize the device’s behavior. This model is then validated on various cam profiles by exposing the device to a set of harmonic motions and to a nonstationary motion. Results show a high level of agreement between the experimental results and analytical model

Ecological zonation of benthic foraminifera in the lower Guadiana Estuary (southeastern Portugal)

The present study analyzes the spatial distribution and seasonal distribution of live benthic foraminiferal communities in the estuary of Guadiana, the fourth largest river on the Iberian Peninsula, and establishes, through statistical analysis, their relationships with a series of environmental parameters. Forty-four superficial sediment samples were collected along distance-to-sea and elevation gradients in the winter and summer of 2010. Fifty-three foraminifera species were identified along the intertidal margins of the estuary. Foraminiferal distribution reflected seasonal variation of environmental factors, whose relative importance varied according to species tolerances. Elevation in relation to mean sea level appeared to be the most important parameter controlling foraminiferal distribution, probably because it combines the effects of a series of other variables (i.e. organic matter, sediment texture, pH and temperature). In the highest marsh areas, where environmental conditions approach survival thresholds, only some agglutinated species are able to survive. In the lower intertidal zone, where subaerial exposure is diminished and environmental conditions are generally less variable, more diverse faunas, mainly composed of calcareous species, prevail. During winter, when fluvial discharge peaks, agglutinated species represent more than 80% of the total individuals. In summer, when marine conditions prevail, calcareous species become more competitive, increase their densities and expand into higher marsh zones and estuarine upper reaches. In the estuary, three different foraminiferal assemblages are distinguished: i) Miliammina fusca assemblage, which dominates in unvegetated areas of the lower marsh and tidal flats of the mid-upper estuary; ii)Jadammina macrescens assemblage, which dominates in the highest marsh areas in the lower estuary; and iii) Ammonia aberdoveyensis assemblage, which dominates the areas of low marsh and tidal flats of the lower estuary. (C) 2014 Elsevier B.V. All rights reserved.Portuguese Foundation for Science and Technology (FCT) [SFRH/BD/28265/2006]info:eu-repo/semantics/publishedVersio

Current developments in UK tax compliance research.

Conference paperOverview of Talk • Context of Tax Research in UK – Culture of government • Role of Inland Revenue – Policy, structure, external links • Current Tax Compliance Research – Individual developments explored • Future Challenge

Características geoquímicas das margens dum estuário Atlanto-Mediterrânico (o Guadiana, Sudeste de Portugal): variação espacial e sazonal

The present work describes spatial and seasonal variability in grain-size, pH and elemental characteristics (TOC, TIC, TN and C/N) in superficial sediments, as well as salinity, temperature and oxygen in the water, within the intertidal range of the Guadiana Estuary, SW Iberian Peninsula, during the year 2010. The results indicate that environmental parameters in the estuary are strongly dependent on spatial patterns, which reflect seasonal oscillations in freshwater discharge. The sediment is generally poorly sorted, with a symmetrical to very finely skewed distribution, in accordance with the low-energy conditions typical of the deposition areas. During winter, heavy rains forced the continuous discharge of Europe’s largest reservoir, the Alqueva dam, creating exceptional hydrodynamic conditions and causing coarser sediment deposition in the estuary. High marsh areas are controlled by flood tides, promoting vertical accretion of muddy sediments, especially silts. The lower areas of the saltmarsh and-mud flat areas are controlled by the ebb, with more efficient export of fines toward the platform and retention of sands, sometimes with significant amounts of bioclasts. In winter (average Q = 654 m3 s -1), salinity remained low throughout the estuary with the highest values (< 3) recorded up to 3 km inland from the river mouth, except in the most confined environments subject to greater evaporation. In summer (average Q = 52 m3 s -1), the estuarine waters are better mixed and significant saltwater intrusion extends approximately 8 km inland. The seasonal variation in surface water temperature was very high, with a difference of ca 14 º C in the maximum temperature recorded in winter and summer. A clear relationship between elevation (in relation to mean sea level) and organic matter, pH and particle size was observed. In the higher areas of the marsh, where the hydrodynamics is attenuated, differential deposition of fine sediments promotes organic matter entrapment and low pH. Sedimentary organic matter derives from a mixture of native aquatic and terrestrial sources. The mid-upper estuary areas and higher zones of the saltmarsh in the lower estuary incorporate a greater terrestrial component, whereas the low-middle marsh areas of the lower estuary experience a substantial contribution from indigenous aquatic sources. The present data help to understand the present environmental condition of the Guadiana Estuary and contribute baseline data for future climatic and environmental management studies based on sediment-dependent proxiesO presente estudo descreve a variabilidade espacial e sazonal das propriedades físico-químicas da água (salinidade, temperatura e oxigénio) e dos sedimentos superficiais (granulometria, pH, COT, CIT, NT e C/N) da faixa intermareal do estuário do rio Guadiana, SW da Península Ibérica durante o ano 2010. Os resultados indicam que as condições ambientais do estuário estão fortemente dependentes dos padrões espaciais e das oscilações sazonais na descarga de água doce. Os sedimentos apresentaram-se geralmente mal calibrados e com uma assimetria tendencialmente fina, de acordo com as condições de baixa energia típicas de áreas de deposição. As fortes chuvas sentidas durante o inverno forçaram a descarga contínua do maior reservatório artificial da Europa, o Alqueva, criando condições hidrodinâmicas excecionais, promovendo o aumento de sedimentos grosseiros no estuário. A granulometria dos sedimentos ao longo da zona intertidal tende a aumentar das zonas mais elevadas às zonas mais baixas. As zonas de sapal alto são controladas pela enchente, promovendo a acreção vertical de sedimentos lodosos, sobretudo siltes. As zonas mais baixas do sapal e zonas de planície lodosa são controladas pela vazante, com exportação mais eficiente de finos para a plataforma e retenção de areias, por vezes com conteúdo significativo em bioclastos. No inverno (média Q = 654 m3 s -1), a salinidade manteve-se baixa ao longo de todo o estuário, com os valores mais elevados (< 3) registados até cerca de 3 km para montante a partir da foz do rio, exceto nos ambientes mais confinados, mais expostos à evaporação. No verão (média Q = 52 m3 s -1), as águas estuarinas apresentaram-se melhor misturadas e a intrusão salina estendeu-se até cerca de 8 km para montante. A variação sazonal da temperatura das águas superficiais foi muito elevada, verificando-se uma diferença de ca 14ºC entre as temperaturas máximas registadas no Inverno e no Verão. No estuário, observou-se uma clara relação entre a elevação (relativa ao nível médio do mar) e a quantidade de matéria orgânica, o tamanho do grão e o pH. Nas zonas mais elevadas do sapal, onde o hidrodinamismo é atenuado, a deposição diferencial de sedimentos finos promove o aprisionamento de matéria orgânica e a diminuição do pH. A matéria orgânica sedimentar deriva de uma mistura de matéria orgânica aquática e terrestre de origem autóctone. As zonas do estuário médio-superior e as zonas mais elevadas do sapal do estuário inferior incorporam uma maior componente orgânica de origem terrestre, enquanto que as áreas de baixo-médio sapal do estuário inferior experienciam uma contribuição substancial proveniente de fontes aquáticas de origem alóctone. A presente informação contribui para o melhor entendimento da atual condição ambiental do Estuário do Rio Guadiana e fornece dados de base para futuros estudos de gestão ambiental e evolução climática que assentem em indicadores ambientais sedimentares.info:eu-repo/semantics/publishedVersio

Taxonomy, ecology and biogeographical trends of dominant benthic foraminifera species from an Atlantic-Mediterranean estuary (the Guadiana, southeast Portugal)

This study analyses the taxonomy, ecology and biogeography of the species of benthic foraminifera living on the intertidal margins of the Guadiana Estuary (SE Portugal, SW Spain). Of the 54 taxa identified during sampling campaigns in winter and summer, 49 are systematically listed and illustrated by scanning electron microscope (SEM) photographs. Ammonia spp. were the most ubiquitous calcareous taxa in both seasons. Morphological analysis and SEM images suggested three distinct morphotypes of the genus Ammonia, two of which proved to be Ammonia aberdoveyensis on the basis of partial rRNA analyses. Jadammina macrescens and Miliammina fusca were the most ubiquitous agglutinated taxa in the estuary. Jadammina macrescens dominates the upper-marsh zones almost exclusively, occurring at very high densities. Ammonia spp. are the most abundant in the low-marsh and tidal-flats of the lower reaches of the Guadiana Estuary, but are widespread throughout the estuary, especially during summer when environmental conditions favor their proliferation. Miliammina fusca dominates the sparsely vegetated low-marsh and tidal-flat zones of the upper reaches, where it is associated with calcareous species. Due to its geographical position, the Guadiana system shares characteristics of both Atlantic and Mediterranean estuaries. This is reflected in the foraminiferal assemblages, with a dominance of thermophilous species and an ecological zonation typical of the Mediterranean climatic zone.info:eu-repo/semantics/publishedVersio

Oral Motor and Gesture Abilities Independently Associated With Preschool Language Skill:Longitudinal and Concurrent Relationships at 21 Months and 3-4 Years

Purpose Early motor abilities (gesture, oral motor, and gross/fine skills) are related to language abilities, and this is not due to an association with cognitive or symbolic abilities: Oral motor skills are uniquely associated with language abilities at 21 months of age. It is important to determine whether this motor-language relationship continues beyond the earliest stage of language development to understand language acquisition better and better predict which children may have lasting language difficulties. Method In this longitudinal study, we assessed language comprehension and production, oral motor skill, gross/fine motor skill, and meaningless manual gesture at ages 3 years (N = 89) and 4 years (N = 71), comparing the contribution of motor skill and earlier (at 21 months of age) language ability. We also examined covariates: nonverbal cognitive ability, socioeconomic status, and stimulation in the home as measured on the Home Screening Questionnaire. Results Motor abilities continue to have a significant relationship with language abilities independent of other factors in the preschool years. Meaningless manual gesture ability, gross/fine motor skill, and oral motor skill were still associated with language skill at 3 years of age; these relationships are not explained by the contribution of cognitive abilities or earlier language abilities. Conclusions Relationships between early motor skill and language development persist into preschool years and are not explained by other cognitive or home factors, nor by a relationship with earlier language ability. This finding should lead to a better understanding of the origins of language abilities