MODIFICATION OF TROPICAL COASTAL LANDSCAPES BY BRACHYURAN CRABS: NEOICHNOLOGY OF BIOTIC INNOVATION AND SPACE PARTITIONING

Within the Pattern Recognition field, two representations are generally considered for encoding the data: statistical codifications, which describe elements as feature vectors, and structural representations, which encode elements as high-level symbolic data structures such as strings, trees or graphs. While the vast majority of classifiers are capable of addressing statistical spaces, only some particular methods are suitable for structural representations. The kNN classifier constitutes one of the scarce examples of algorithms capable of tackling both statistical and structural spaces. This method is based on the computation of the dissimilarity between all the samples of the set, which is the main reason for its high versatility, but in turn, for its low efficiency as well. Prototype Generation is one of the possibilities for palliating this issue. These mechanisms generate a reduced version of the initial dataset by performing data transformation and aggregation processes on the initial collection. Nevertheless, these generation processes are quite dependent on the data representation considered, being not generally well defined for structural data. In this work we present the adaptation of the generation-based reduction algorithm Reduction through Homogeneous Clusters to the case of string data. This algorithm performs the reduction by partitioning the space into class-homogeneous clusters for then generating a representative prototype as the median value of each group. Thus, the main issue to tackle is the retrieval of the median element of a set of strings. Our comprehensive experimentation comparatively assesses the performance of this algorithm in both the statistical and the string-based spaces. Results prove the relevance of our approach by showing a competitive compromise between classification rate and data reduction.

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Stable minimum space partitioning in linear time

BIT Numerical Mathematics ◽

10.1007/bf01994842 ◽

1992 ◽

Vol 32 (4) ◽

pp. 580-585 ◽

Cited By ~ 18

Author(s):

Jyrki Katajainen ◽

Tomi Pasanen

Keyword(s):

Linear Time ◽

Space Partitioning

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Integrating Geomorphological Data, Geochronology and Archaeological Evidence for Coastal Landscape Reconstruction, the Case of Ammoudara Beach, Crete

Water ◽

10.3390/w13091269 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1269

Author(s):

George Alexandrakis ◽

Stelios Petrakis ◽

Nikolaos A. Kampanis

Keyword(s):

Bronze Age ◽

Coastal Area ◽

Luminescence Dating ◽

Coastal Sediments ◽

Aerial Photographs ◽

Coastal Landscape ◽

Archaeological Evidence ◽

Dune Field ◽

Coastal Landscapes ◽

Coastal Deposits

Understanding the processes that govern the transformation of the landscape through time is essential for exploring the evolution of a coastal area. Coastal landscapes are dynamic sites, with their evolution strongly linked with waves and sea level variations. Geomorphological features in the coastal area, such as beachrock formations and dune fields, can function as indicators of the coastal landscape evolution through time. However, our knowledge of the chronological framework of coastal deposits in the Aegean coasts is limited. Optically Stimulated Luminescence dating techniques are deemed to be very promising in direct dating of the coastal sediments, especially when they are linked with archaeological evidence. The dating of the sediments from different sediment core depths, determined by the method of luminosity, allowed us to calculate the rate of sediment deposition over time. More recent coastal evolution and stability were examined from 1945 to 2020 with the use of aerial photographs and satellite images. This paper presents the 6000 ka evolution of a coastal landscape based on geomorphological, archaeological, and radio-chronological data. Based on the results, the early stages of the Ammoudara beach dune field appears to have been formed ~9.0–9.6 ka BP, while the OSL ages from 6 m depth represented the timing of its stabilization (OSL ages ~5–6 ka). This indicates that the dune field appears to already have been formed long before the Bronze Age (5–10 ka BP). It became stabilized with only localized episodes of dune reactivation occurring. In contrast, while high coastal erosion rates were calculated for modern times.

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Toxicity of petroleum hydrocarbons to Brachyuran crabs: a review of deleterious effects of oil-related xenobiotics on life stages

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315421000370 ◽

2021 ◽

pp. 1-16

Author(s):

Qusaie Karam ◽

Zainab Al-Wazzan

Keyword(s):

Petroleum Hydrocarbons ◽

Marine Pollution ◽

Human Consumption ◽

Life Stages ◽

Crab Species ◽

Research Attention ◽

Larval Stages ◽

Effects Of Ph ◽

Ph Toxicity ◽

Brachyuran Crabs

Abstract Petroleum hydrocarbons (PH) toxicity and bioaccumulation in aquatic organisms have been investigated for almost 50 years. Continuous oil spillages necessitate a further understanding of the toxicological effects of PH on brachyuran crabs. Crabs can be exposed to PH through various routes such as the water column, sediment and diet. Numerous investigations have been dedicated to evaluating PH toxicity on different life stages of crab species, but the majority of them have focused on the blue crab Callinectes sapidus as it represents an edible and favourable seafood commodity for human consumption. The objective of the review is to critically assess studies related to PH toxicity on different life stages of 41 crab species representing 13 families across the world. Several physiological, biochemical and genetic endpoints of marine crabs were evaluated in addition to the sublethal effects of PH on crab metabolism, behaviour, moulting, growth and survival. A concise summary of PH deleterious effects on different taxonomic species of marine crabs is discussed and provides evidence that crabs can be used as indicator organisms of biomarker significance for marine pollution. Overall, larval stages appeared to be the most sensitive to the deleterious effects of PH compared with juveniles and adults. However, adult stages have received more research attention than other life stages, followed by larval stages, and juvenile stages are the least investigated stages with respect to PH toxicity. Finally, hepatopancreas and gills were the organs where greatest accumulation of PH was recorded.

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The environmental and ecological determinants of elevated Ross River Virus exposure in koalas residing in urban coastal landscapes

Scientific Reports ◽

10.1038/s41598-021-83919-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Brian J. Johnson ◽

Amy Robbins ◽

Narayan Gyawali ◽

Oselyne Ong ◽

Joanne Loader ◽

...

Keyword(s):

Animal Movement ◽

Ross River Virus ◽

Mosquito Vector ◽

Large Numbers ◽

Culex Annulirostris ◽

Coastal Landscapes ◽

In The Wild ◽

Virus Exposure ◽

Elevated Exposure ◽

The Impact

AbstractKoala populations in many areas of Australia have declined sharply in response to habitat loss, disease and the effects of climate change. Koalas may face further morbidity from endemic mosquito-borne viruses, but the impact of such viruses is currently unknown. Few seroprevalence studies in the wild exist and little is known of the determinants of exposure. Here, we exploited a large, spatially and temporally explicit koala survey to define the intensity of Ross River Virus (RRV) exposure in koalas residing in urban coastal environments in southeast Queensland, Australia. We demonstrate that RRV exposure in koalas is much higher (> 80%) than reported in other sero-surveys and that exposure is uniform across the urban coastal landscape. Uniformity in exposure is related to the presence of the major RRV mosquito vector, Culex annulirostris, and similarities in animal movement, tree use, and age-dependent increases in exposure risk. Elevated exposure ultimately appears to result from the confinement of remaining coastal koala habitat to the edges of permanent wetlands unsuitable for urban development and which produce large numbers of competent mosquito vectors. The results further illustrate that koalas and other RRV-susceptible vertebrates may serve as useful sentinels of human urban exposure in endemic areas.

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Regional differences in recreational preferences of Estonian coastal landscapes

Journal of Coastal Research ◽

10.2112/si70-071.1 ◽

2014 ◽

Vol 70 ◽

pp. 420-425 ◽

Cited By ~ 1

Author(s):

Mart Reimann ◽

Üllas Ehrlich ◽

Hannes Tõnisson

Keyword(s):

Regional Differences ◽

Coastal Landscapes

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Habitat ecology and substratum preference of brachyuran crabs of a tropical estuary, South-West coast of India

Regional Studies in Marine Science ◽

10.1016/j.rsma.2021.101709 ◽

2021 ◽

pp. 101709

Author(s):

Prabhullachandran Lakshmi Devi ◽

Aneykutty Joseph ◽

Alphi Korath

Keyword(s):

West Coast ◽

Tropical Estuary ◽

Habitat Ecology ◽

West Coast Of India ◽

South West ◽

South West Coast ◽

Brachyuran Crabs ◽

Substratum Preference

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Learning Mesh Representations via Binary Space Partitioning Tree Networks

IEEE Transactions on Pattern Analysis and Machine Intelligence ◽

10.1109/tpami.2021.3093440 ◽

2021 ◽

pp. 1-1

Author(s):

Zhiqin Chen ◽

Andrea Tagliasacchi ◽

Hao Zhang

Keyword(s):

Space Partitioning ◽

Tree Networks ◽

Binary Space Partitioning

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Intermittent but Rapid Changes to Coastal Landscapes: The Tsunami and El Niño Wave-Formed Sea Arch at Laie Point, Oahu, Hawaii, U.S.A.

Geosciences ◽

10.3390/geosciences11030147 ◽

2021 ◽

Vol 11 (3) ◽

pp. 147

Author(s):

Benjamin R. Jordan

Keyword(s):

El Niño ◽

El Nino ◽

Sand Dunes ◽

Tsunami Source ◽

Tsunami Waves ◽

Storm Waves ◽

The Pacific ◽

Coastal Landscapes ◽

Wave Heights ◽

First Time

Kukuiho’olua Island is an islet that lies 164 m due north of Laie Point, a peninsula of cemented, coastal, Pleistocene and Holocene sand dunes. Kukuiho’olua Island consists of the same dune deposits as Laie Point and is cut by a sea arch, which, documented here for first time, may have formed during the 1 April 1946 “April Fools’s Day Tsunami.” The tsunami-source of formation is supported by previous modeling by other authors, which indicated that the geometry of overhanging sea cliffs can greatly strengthen and focus the force of tsunami waves. Additional changes occurred to the island and arch during the 2015–2016 El Niño event, which was one of the strongest on record. During the event, anomalous wave heights and reversed wind directions occurred across the Pacific. On the night of 24–25 February 2016, large storm waves, resulting from the unique El Niño conditions washed out a large boulder that had lain within the arch since its initial formation, significantly increasing the open area beneath the arch. Large waves also rose high enough for seawater to flow over the peninsula at Laie Point, causing significant erosion of its upper surface. These changes at Laie Point and Kukuio’olua Island serve as examples of long-term, intermittent change to a coastline—changes that, although infrequent, can occur quickly and dramatically, potentially making them geologic hazards.

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