RESUMO
Kelp forests (Order Laminariales) form key biogenic habitats in coastal regions of temperate and Arctic seas worldwide, providing ecosystem services valued in the range of billions of dollars annually. Although local evidence suggests that kelp forests are increasingly threatened by a variety of stressors, no comprehensive global analysis of change in kelp abundances currently exists. Here, we build and analyze a global database of kelp time series spanning the past half-century to assess regional and global trends in kelp abundances. We detected a high degree of geographic variation in trends, with regional variability in the direction and magnitude of change far exceeding a small global average decline (instantaneous rate of change = -0.018 y-1). Our analysis identified declines in 38% of ecoregions for which there are data (-0.015 to -0.18 y-1), increases in 27% of ecoregions (0.015 to 0.11 y-1), and no detectable change in 35% of ecoregions. These spatially variable trajectories reflected regional differences in the drivers of change, uncertainty in some regions owing to poor spatial and temporal data coverage, and the dynamic nature of kelp populations. We conclude that although global drivers could be affecting kelp forests at multiple scales, local stressors and regional variation in the effects of these drivers dominate kelp dynamics, in contrast to many other marine and terrestrial foundation species.
Assuntos
Ecossistema , Florestas , Kelp/crescimento & desenvolvimento , Regiões Árticas , Mudança Climática , Oceanos e MaresRESUMO
Efficient word recognition depends on the ability to overcome competition from overlapping words. The nature of the overlap depends on the input modality: spoken words have temporal overlap from other words that share phonemes in the same positions, whereas written words have spatial overlap from other words with letters in the same places. It is unclear how these differences in input format affect the ability to recognise a word and the types of competitors that become active while doing so. This study investigates word recognition in both modalities in children between 7 and 15. Children complete a visual-world paradigm eye-tracking task that measures competition from words with several types of overlap, using identical word lists between modalities. Results showed correlated developmental changes in the speed of target recognition in both modalities. In addition, developmental changes were seen in the efficiency of competitor suppression for some competitor types in the spoken modality. These data reveal some developmental continuity in the process of word recognition independent of modality but also some instances of independence in how competitors are activated. Stimuli, data, and analyses from this project are available at: https://osf.io/eav72.
Assuntos
Percepção da Fala , Criança , Humanos , Reconhecimento Psicológico , Desempenho Psicomotor , Fatores de TempoRESUMO
Word recognition occurs across two sensory modalities: auditory (spoken words) and visual (written words). While each faces different challenges, they are often described in similar terms as a competition process by which multiple lexical candidates are activated and compete for recognition. While there is a general consensus regarding the types of words that compete during spoken word recognition, there is less consensus for written word recognition. The present study develops a novel version of the Visual World Paradigm (VWP) to examine written word recognition and uses this to assess the nature of the competitor set during word recognition in both modalities using the same experimental design. For both spoken and written words, we found evidence for activation of onset competitors (cohorts, e.g., cat, cap) and words that contain the same phonemes or letters in reverse order (anadromes, e.g., cat, tack). We found no evidence of activation for rhymes (e.g., cat, hat). The results across modalities were quite similar, with the exception that for spoken words, cohorts were more active than anadromes, whereas for written words activation was similar. These results suggest a common characterisation of lexical similarity across spoken and written words: temporal or spatial order is coarsely coded, and onsets may receive more weight in both systems. However, for spoken words, temporary ambiguity during the moment of processing gives cohorts an additional boost during real-time recognition.
Assuntos
Percepção da Fala , Reconhecimento Psicológico/fisiologia , Percepção da Fala/fisiologiaRESUMO
This study presents the taxonomic description of two new sponge species that are intimately associated with the hyperarid mangrove ecosystem of Qatar. The study includes a preliminary evaluation of the sponges' potential bioactivity against pathogens. Chalinula qatari sp. nov. is a fragile thinly encrusting sponge with a vivid maroon colour in life, often with oscular chimneys and commonly recorded on pneumatophores in the intertidal and shallow subtidal zone. Suberites luna sp. nov. is a massive globular-lobate sponge with a greenish-black colour externally and a yellowish orange colour internally, recorded on pneumatophores in the shallow subtidal zone, with large specimens near the seagrass ecosystem that surrounds the mangrove. For both species, a drug extraction protocol and an antibacterial experiment was performed. The extract of Suberites luna sp. nov. was found to be bioactive against recognized pathogens such as Staphylococcus epidermidis, Staphylococcus aureus and Enterococcus faecalis, but no bioactive activity was recorded for Chalinula qatari sp. nov. This study highlights the importance of increasing bioprospecting effort in hyperarid conditions and the importance of combining bioprospecting with taxonomic studies for the identification of novel marine drugs.
Assuntos
Antibacterianos , Ecossistema , Poríferos/classificação , Animais , Secas , CatarRESUMO
Specimens were collected by SCUBA diving from 22 sites along the Antarctic Peninsula, spanning latitudes from Diomedea Island (62°12.185'S) to Jenny Island (67°43.325'S). The aims of the survey were to record the sponge biodiversity of the sublittoral and shallow-circalittoral and to provide information on in situ identification features. In total 24 sponge species were recorded, ranging from 0 to 12 species per site. The most widespread species were Dendrilla antarctica (10 sites), Sphaerotylus antarcticus (11 sites); and Mycale (Oxymycale) acerata (13 sites). Four species new to science were discovered and are described here: Megaciella cardenasi sp. nov., Crella (Crella) hennequinae sp. nov., Hymedesmia (Hymedesmia) noramaloneae sp. nov., Clathria (Clathria) priestleyae sp. nov. Suberites topsenti (Burton, 1929) is reassigned to Hemimycale topsenti (Burton, 1929) comb. nov. General habitat notes are provided for the survey sites, many of which were previously unsurveyed.
Assuntos
Poríferos , Suberites , Animais , Regiões Antárticas , Biodiversidade , Ecossistema , IlhasRESUMO
BACKGROUND: The impact of personal familiarity upon children's developing emotion-processing has been largely ignored in previous research, yet may prove particularly important given the emotional salience of such stimuli and children's greater exposure to familiar others compared to strangers. We examined the impact of personal familiarity upon developing facial expression recognition (FER). METHODS: Participants included 153 children, 4-15 years old. We employed dynamic expressions of five emotions (happy, sad, anger, fear, disgust), posed by familiar (parents, teachers) and unfamiliar identities. RESULTS: Accuracy improved with age for recognising sad and fear expressions, but not anger. Children tended to correctly recognise happiness and fear at lower intensities. The impact of familiarity on FER depended on emotion-category. Familiarity did not affect recognition of sad expressions, but children were less accurate at recognising anger, fear, and disgust in familiar individuals compared to strangers. CONCLUSION: Personal familiarity may exert a distracting effect on children's performance. Findings highlight the importance of incorporating different emotion-categories and familiarity when examining the development of FER. Clinical implications are discussed.
Assuntos
Desenvolvimento Infantil , Emoções , Expressão Facial , Reconhecimento Psicológico , Percepção Social , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Relações Interpessoais , Masculino , Análise de Regressão , Fatores Sexuais , Reino UnidoRESUMO
The Drake Passage has over 20 seamounts and ridges but it is notorious for large waves, fierce storms and strong currents that make benthic sampling difficult and therefore infrequent. Seamounts often have diverse sponge communities and may have high levels of endemism. Hexactinellida from Sars Seamount, an area in which the sponges had not previously been studied, and the Shackleton fracture zone were collected on a research cruise by the Nathaniel B Palmer in the Drake Passage, Southern Ocean. In total, from all cruise stations, 103 specimens of Hexactinellida were collected, however many appeared to be fragments of dead specimens and could not be identified due to missing microscleres. From Sars Seamount 127 sponge specimens were taken and from the Shackleton Fracture Zone 76 sponge specimens were taken; of these 36 and 16 respectively were Hexactinellida. From these two areas three new species of Hexactinellida are described: Doconesthes robinsoni sp. nov., Sympagella walleri sp. nov. and Caulophacus palmeri sp. nov and new records were made of Aulocalyx irregularis and Rossella antarctica.
Assuntos
Poríferos/anatomia & histologia , Poríferos/classificação , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , Oceanos e Mares , Tamanho do Órgão , Poríferos/crescimento & desenvolvimentoRESUMO
We examined whether two decades of rising sea surface temperatures have resulted in significant changes in the benthic community and frequency of occurrence of Northern and Southern species in three areas of Northern Ireland, using visual census data collected by SCUBA surveys undertaken during two periods: pre-1986 and post-2006. We found little evidence to suggest that rising sea surface temperatures have contributed to the changes in benthic assemblage structure between the pre-1986 and post-2006 surveys. However, there were slight but not significant declines in extreme Northern species at Rathlin Island, and increases in the mean number and frequency of occurrence of extreme Southern species in all three areas. There were also substantial declines in the spatial presence of 7 extreme Northern species and notable increases in distribution of 19 extreme Southern species. In contrast, there were no clear trends in the intermediate to Northern and intermediate to Southern species. These results suggest that rising sea surface temperatures have had significant impacts on the occurrence of rarer marine invertebrate species at the edges of their biogeographic range however the trends differed between areas in Northern Ireland.