The relationship between physical variables on topographically simple and complex reefs and algal assemblage structure beneath an Ecklonia radiata canopy

2007 ◽  
Vol 71 (1-2) ◽  
pp. 232-240 ◽  
Author(s):  
Benjamin D. Toohey
Keyword(s):  
Assemblage Structure ◽  
Algal Assemblage ◽  
Ecklonia Radiata ◽  
Physical Variables ◽  
The Relationship

The relationship between sediment metal concentration and Odonata (Insecta) larvae assemblage structure in Cerrado streams

Limnetica ◽  
2022 ◽  
Vol 41 (1) ◽  
pp. 27-41
Author(s):  
Cyntia Goulart Corrêa Bruno ◽  
Regina Célia Gonçalves ◽  
Ademir dos Santos ◽  
Kátia Gomes Facure ◽  
Juliano José Corbi ◽  
...  
Keyword(s):  
Metal Concentration ◽  
Assemblage Structure ◽  
The Relationship ◽  
Sediment Metal

Effect of fire on benthic algal assemblage structure and recolonization in intermittent streams

2006 ◽  
Vol 31 (6) ◽  
pp. 696-707 ◽  
Author(s):  
AMANDA L. COWELL ◽  
TY G. MATTHEWS ◽  
PETER R. LIND
Keyword(s):  
Assemblage Structure ◽  
Intermittent Streams ◽  
Algal Assemblage

To what extent do geographic and associated environmental variables correlate with kelp morphology across temperate Australia?

2005 ◽  
Vol 56 (6) ◽  
pp. 877 ◽  
Author(s):  
Meegan J. Fowler-Walker ◽  
Sean D. Connell ◽  
Bronwyn M. Gillanders
Keyword(s):  
Plant Density ◽  
Morphological Variability ◽  
Wave Exposure ◽  
Mixed Stands ◽  
Ecklonia Radiata ◽  
Exposure Temperature ◽  
Ecological Patterns ◽  
Geographical Distances ◽  
Physical Variables ◽  
Australian Coastline

Intraspecific variation in morphology is common among marine algae and may allow plants to exist across a wide geography and range of environmental conditions. Morphological variation of Ecklonia radiata has been described over thousands of kilometres of the temperate Australian coastline; however, the degree to which this morphological variability is related to geographic and environmental variation is unknown. We tested the hypotheses that: (1) variation in the morphology of Ecklonia radiata, growing in both monospecific and mixed stands, is related to variation in latitude, longitude, wave exposure, temperature, depth and plant density (collectively referred to as ‘physical variables’); and (2) measures of morphological dissimilarity in E. radiata are greatest among locations that are separated by the largest geographic distances. The combined effect of the physical variables accounted for 74% of the variation in both monospecific and mixed stands. The majority of this variation was related to longitude and the remainder to wave exposure, water temperature and plant density. In monospecific stands, measures of morphological dissimilarity were consistently large between locations that were separated by the greatest geographical distances (>2500 km). The existence of such relationships may not indicate causality, but do contribute to a broad based understanding of major ecological patterns across temperate Australia’s coastline.

Prematurity and Deafness: The Magnitude and Nature of the Problem among Deaf Children

1967 ◽  
Vol 33 (5) ◽  
pp. 289-298 ◽  
Author(s):  
McCay Vernon
Keyword(s):  
Hearing Loss ◽  
Psychological Adjustment ◽  
Premature Birth ◽  
Normative Data ◽  
Educational Achievement ◽  
Deaf Children ◽  
Physical Variables ◽  
Relationship Of ◽  
The Relationship

The relationship of premature birth to deafness is investigated, with particular emphasis on the role of prematurity as a factor in multiple handicaps among deaf children. One thousand sixty-eight cases are involved in the research. Those born prematurely are carefully studied in terms of: (a) multiple handicaps, (b) educational achievement, (c) psychological adjustment, (d) intelligence, (e) audiometric responses, and (f) psychodiagnostic evidence of brain damage. Results of these behavioral and physical variables are quantified and compared to normative data and to data on other groups of deaf children having different etiologies of hearing loss. Significant differences are found among the premature deaf youths. The neurophysiological origins of these are discussed, and implications for the future are given.

Abundance of the sponge Hymeniacidon cf. perlevis in a stressful environment of Patagonia: relationships with Ulva lactuca and physical variables

2015 ◽  
Vol 96 (2) ◽  
pp. 465-472 ◽  
Author(s):  
Marianela Gastaldi ◽  
Fausto Nahuel Firstater ◽  
Pedro Daleo ◽  
Maite Andrea Narvarte
Keyword(s):  
Human Activities ◽  
Ulva Lactuca ◽  
Coastal Communities ◽  
Fast Growing ◽  
Stressful Environment ◽  
Abundance Patterns ◽  
Coastal Systems ◽  
Physical Variables ◽  
Relationship Of ◽  
The Relationship

Understanding the variables (biotic or abiotic) controlling coastal communities is the main goal of ecology research and it is crucial to predict how communities will evolve under the increasing pressure on coastal systems by human activities. The general aims of this study were to assess the variables affecting the distribution of the fast-growing sponge Hymeniacidon cf. perlevis, and to evaluate if physical stressful conditions have an influence in the relationship between Hymeniacidon and the sea lettuce Ulva lactuca. Specifically, the aims were to evaluate the abundance patterns of Hymeniacidon and Ulva and to assess the relationship of Ulva and physical variables on the abundance of Hymeniacidon at both intertidal and subtidal. Hymeniacidon and Ulva showed opposite abundance patterns. Hymeniacidon was more abundant in sites without Ulva, and negatively correlated with Ulva abundance at both heights. Intertidal Hymeniacidon abundance was not correlated with physical variables, but subtidal Hymeniacidon was.

The effects of light and thallus scour from Ecklonia radiata canopy on an associated foliose algal assemblage: the importance of photoacclimation

2004 ◽  
Vol 144 (5) ◽  
pp. 1019-1027 ◽  
Author(s):  
Benjamin Toohey ◽  
Gary A. Kendrick ◽  
Thomas Wernberg ◽  
Julia C. Phillips ◽  
Sairah Malkin ◽  
...  
Keyword(s):  
Algal Assemblage ◽  
Ecklonia Radiata

scholarly journals Psychosocial and Somatosensory Factors in Women with Chronic Migraine and Painful Temporomandibular Disorders

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Alfonso Gil-Martínez ◽  
Mónica Grande-Alonso ◽  
Roy La Touche ◽  
Manuel Lara-Lara ◽  
Almudena López-López ◽  
...  
Keyword(s):  
Chronic Migraine ◽  
Temporomandibular Disorders ◽  
Pain Catastrophizing ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Left And Right ◽  
Physical Variables ◽  
Asymptomatic Subjects ◽  
The Relationship

Introduction. Psychosocial and somatosensory factors are involved in the pathophysiology of chronic migraine (CM) and chronic temporomandibular disorders (TMD).Objective. To compare and assess the relationship between pain catastrophizing and kinesiophobia in patients with CM or chronic TMD.Method. Cross-sectional study of 20 women with CM, 19 with chronic TMD, and 20 healthy volunteers. Pain catastrophizing and kinesiophobia were assessed. The level of education, pain intensity, and magnitude of temporal summation of stimuli in the masseter (STM) and tibialis (STT) muscles were also evaluated.Results. There were significant differences between the CM and chronic TMD groups, compared with the group of asymptomatic subjects, for all variables (p<.05) except kinesiophobia when comparing patients with CM and healthy women. Moderate correlations between kinesiophobia and catastrophizing (r=0.46;p<.01) were obtained, and the strongest association was between kinesiophobia and magnification (r=0.52;p<.01). The strongest associations among physical variables were found between the STM on both sides (r=0.93;p<.01) and between the left and right STT (r=0.76;p<.01).Conclusion. No differences were observed in pain catastrophizing and kinesiophobia between women with CM and with chronic TMD. Women with CM or chronic TMD showed higher levels of pain catastrophizing than asymptomatic subjects.

scholarly journals Ecological Effects of Undaria pinnatifida (Harvey) Suringar and Nutrient-Enrichment  on Intertidal Assemblages in the Wellington Region of New Zealand

2021 ◽  
Author(s):  
◽  
Bionda Morelissen
Keyword(s):  
New Zealand ◽  
Community Composition ◽  
Undaria Pinnatifida ◽  
Assemblage Structure ◽  
Ecological Effects ◽  
South Coast ◽  
Algal Community ◽  
Algal Assemblage ◽  
Algal Assemblages ◽  
Growth And Reproduction

<p>The introduction of non-native species and the alteration of seawater nutrient regimes due to anthropogenic impacts are two important threats to marine environments. Moreover, these disturbances may interact in such a way that promotes the success of invasive species in coastal habitats. This thesis contributes to current gaps in knowledge in these areas for low-intertidal communities. Algal community dynamics and ecological effects of the invasive kelp Undaria pinnatifida on low shores in the Wellington region, New Zealand, were examined, using field surveys and experiments. In addition, the role of variability in nutrient concentrations in coastal waters in mediating algal community structure and diversity, and the success of U. pinnatifida reproduction were investigated. Algal surveys were used in two locations thought to differ in nutrient regimes, the Wellington Harbour and the Wellington south coast, to explore the structure and dynamics of algal assemblages. Results showed high variability of low-intertidal algal communities among sites, but no consistent differences in algal community composition were found between the two locations, despite higher U. pinnatifida cover in the harbour. Over the duration of the study, nutrient regimes did not differ greatly between the locations. The response of rocky intertidal algal assemblages to chronic exposure to high nutrient effluent was investigated using two nearshore sewage outfalls in the Wellington region. The Titahi Bay outfall showed a stronger relationship between nutrients and algal community composition. Variation in algal assemblage structure and diversity was best explained by phosphate concentrations. By contrast, at the more wave-exposed Pencarrow outfall, patterns of change in the algal community were less clear and there was a much weaker relationship with seawater nutrients. Because removal of native algal canopy species may facilitate the establishment of invasive macroalgae, the invasion process of U. pinnatifida in disturbed patches in a rocky low-intertidal habitat was investigated. In a site where U. pinnatifida had not yet established, patches were scraped clear of native algal cover at two different times of year, and recruitment of U. pinnatifida was monitored. While U. pinnatifida invaded the site, it recruited in control plots at a similar rate as cleared plots, suggesting that physical disturbance of the native algal assemblage is not a key requirement for this kelp to invade and establish in new areas in the low intertidal zone. The response of native algal assemblages to removal of U. pinnatifida individuals was investigated at intertidal sites in the Wellington Harbour and on the south coast. No significant effect of U. pinnatifida on community composition, diversity, and species richness was detected. Removal of this invader did not change native intertidal assemblage structure in either harbour or south coast sites. Lastly, effects of different nutrient regimes and light intensities on early development and reproduction of U. pinnatifida were studied using a laboratory experiment. Under low light conditions U. pinnatifida gametophyte growth and reproduction stalled and was not increased by the addition of nutrients. However, at medium and high light levels, gametophyte growth and reproduction, and particularly early stage sporophyte growth rates increased when exposed to higher nutrient concentrations.These effects could have implications for U. pinnatifida population dynamics in intertidal habitats where light is not often a limiting resource. This research contributed to a better understanding of factors that underlie invasion dynamics, distribution, and ecological effects of U. pinnatifida and seawater nutrient regimes on low-intertidal assemblages in the Wellington region. The outcomes can assist in setting up strategic environmental protection and conservation plans.</p>

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