scholarly journals An experimental assessment of social tolerance and den ecology in a high-density octopus population

2021 ◽  
Vol 168 (5) ◽  
Author(s):  
Duncan A. O’Brien ◽  
Michelle L. Taylor ◽  
Heather D. Masonjones ◽  
Philipp H. Boersch-Supan ◽  
Owen R. O’Shea
Keyword(s):  
Deep Sea ◽  
Marine Species ◽  
High Density ◽  
Behavioural Plasticity ◽  
High Population Density ◽  
Social Tolerance ◽  
Potential Prey ◽  
The Bahamas ◽  
The Social ◽  
Den Use

AbstractLong held notions of the universally asocial octopus are being challenged due to the identification of high-density and interacting octopus populations in Australia, Indonesia, Japan and the deep sea. This study experimentally assessed the social tolerance and presence of potential prey items of Caribbean reef octopus, Octopus briareus, in a tropical marine lake (25°21′40″N, 76°30′40″W) on the island of Eleuthera, The Bahamas, by deploying artificial dens in multi-den groups or ‘units’ in the months of May and June 2019. Fifteen octopus were observed occupying dens (n = 100), resulting in 13 den units being occupied (n = 40). Two examples of adjacent occupation within a single den unit were identified but with zero examples of cohabitation/den sharing. Ecological models showed den and den unit occupation was predicted to increase with depth and differ between sites. Octopus also displayed no preference for isolated or communal units but preferred isolated dens over dens adjacent to others. Additionally, 47 % of occupied dens contained bivalve or crustacean items with no epifauna on their interior surface. The lack of epifauna suggests that these items have been recently ‘cleaned’ by occupying octopus and so represent likely prey. This study presents evidence of possible antisocial den use by O. briareus, a modification of the default ‘asocial’ ignoring of conspecifics typically attributed to octopus. This is likely in response to the high population density and may imply behavioural plasticity, making this system appropriate for further scrutiny as a research location on the influence of large, insular environments on marine species.

Prevalence of small high-density microplastics in the continental shelf and deep sea waters of East Asia

2021 ◽  
pp. 117238
Author(s):  
Soeun Eo ◽  
Sang Hee Hong ◽  
Young Kyoung Song ◽  
Gi Myung Han ◽  
Seongbong Seo ◽  
...  
Keyword(s):  
Continental Shelf ◽  
East Asia ◽  
Deep Sea ◽  
High Density

scholarly journals Ontogenetic adaptations in the visual systems of deep-sea crustaceans

2017 ◽  
Vol 372 (1717) ◽  
pp. 20160071 ◽  
Author(s):  
Tamara M. Frank
Keyword(s):  
Temporal Resolution ◽  
Deep Sea ◽  
Life Histories ◽  
Marine Species ◽  
Light Regime ◽  
Life History Stages ◽  
Visual Systems ◽  
Juvenile Stages ◽  
Dim Light ◽  
Effects Of Temperature

For all visually competent organisms, the driving force behind the adaptation of photoreceptors involves obtaining the best balance of resolution to sensitivity in the prevailing light regime, as an increase in sensitivity often results in a decrease in resolution. A number of marine species have an additional problem to deal with, in that the juvenile stages live in relatively brightly lit shallow (100–200 m depth) waters, whereas the adult stages have daytime depths of more than 600 m, where little downwelling light remains. Here, I present the results of electrophysiological analyses of the temporal resolution and irradiance sensitivity of juvenile and adult stages of two species of ontogenetically migrating crustaceans ( Gnathophausia ingens and Systellaspis debilis ) that must deal with dramatically different light environments and temperatures during their life histories. The results demonstrate that there are significant effects of temperature on temporal resolution, which help to optimize the visual systems of the two life-history stages for their respective light environments. This article is part of the themed issue ‘Vision in dim light’.

scholarly journals IMPACTS OF AEROBIC EXERCISE ON HDL LEVEL OF ADULTS; IT’S SOCIAL IMPLICATIONS IN EDUCATIONAL INSTITUTES

2021 ◽  
Vol 9 (4) ◽  
pp. 65-68
Author(s):  
Noor Muhammad Marwat ◽  
Shah Khalid ◽  
Pir Muhammad Abdul Aziz Shah ◽  
Fayaz ul Hasnain ◽  
Rashid Naeem Khan
Keyword(s):  
High Density Lipoprotein ◽  
Aerobic Exercise ◽  
Heart Valves ◽  
Density Lipoprotein ◽  
High Density ◽  
Social Implications ◽  
Exercise Protocol ◽  
Post Intervention ◽  
The Social ◽  
Significant Difference

Purpose: The purpose of this study to find out the impacts of a 6-weeks supervised aerobic exercise protocol on High-Density Lipoprotein among adults aged between 25-35 years was evaluated. Methodology: Researchers through a non-probability sampling procedure selected thirty (30) volunteers ranging from 25-35 untrained adults from Lakki Marwat. Researchers used a six-week aerobic exercise protocol to collect relevant information from the targeted dependent variables. The CHOD PAP method was used to measure the High-Density Lipoprotein (HDL) of adults. All the data collected from pre-and post- (HDL) tests were recorded in numerical form and analyzed by using a t-test. Main Findings: The results of the study indicate that the six-week aerobic exercise protocol program had no significant difference on pre-and post-intervention quantities of HDL of Experimental Group which is (P>0.05). The implication of the Study: The aerobic exercise programs used for this particular study may help adults to improve and maintain their health status, proper social stature, and lipid profile. An increase in the HLD is ideal as this increase in the HDL helps to prevent cardiovascular diseases particularly the heart valves from stroke and cardiac arrest and academic achievements of the participants. Novelty: So far, no particular research has been conducted on the social implications of exercise effects on adults. Future researchers may work on the social habits of physically fit adults and their input to society.

scholarly journals Psychosocial and Demographic Factors That Compound Alcohol Abuse Amongst Youth: A Case Study of Musina High School

2019 ◽  
Vol 11 (7) ◽  
pp. 69 ◽  
Author(s):  
Frans Koketso Matlakala ◽  
Jabulani Calvin Makhubele ◽  
Prudence Mafa
Keyword(s):  
High School ◽  
Young People ◽  
Alcohol Abuse ◽  
Rural Areas ◽  
Demographic Factors ◽  
High Density ◽  
Design Data ◽  
Alcohol Outlets ◽  
The Social

The risk factors that compound alcohol abuse by young people have significant effects of individuals. The sole purpose of social work is to enhance the social functioning of clients and in most cases, clients have impairments as the result of high density of alcohol outlets, affordability of alcohol, which later give birth to psychosocial challenges. The aim of this study is to describe psychosocial and demographic factors compounding alcohol abuse amongst youth. The study employed quantitative approach and descriptive case study design. Data was collected at Musina High School and 96 learners were sampled using stratified sampling to complete the questionnaire. Data was analysed descriptively with the aid of Statistical Package for the Social Science. The study revealed that psychosocial and environmental factors compound to alcohol abuse amongst youth in Musina High School. The study concludes that the context determines the excessive use of alcohol abuse by youth. Young people especially those who reside in rural areas are exposed to high density of alcohol outlets and they are left without guardianship. Due to lack of guardian or parental involvement they end up indulging in excessive use of alcohol.

scholarly journals The Effect of Conspecific Density on Emergence ofLestes bipupillatusCalvert, 1909 (Odonata: Lestidae)

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Ricardo Cardoso-Leite ◽  
Gabriel C. Vilardi ◽  
Rhainer Guillermo-Ferreira ◽  
Pitágoras C. Bispo
Keyword(s):  
Population Dynamics ◽  
Density Dependence ◽  
Social Environment ◽  
Growth Rates ◽  
High Density ◽  
Conspecific Density ◽  
Simulated Environments ◽  
The Social ◽  
Emergence Date

Conspecific density may influence adult recruitment and consequently population dynamics. Several studies have shown the density dependence of larvae growth rates in Odonata. However, few studies studied how conspecific density influence final instar larvae emergence date decisions. Considering that larvae may choose the date of emergence, the present study investigated if density affects larvae choice. For this, we reared eight final instar larvae in individual aquaria and other 24 larvae in aquaria with three larvae each. This way, we simulated environments with low and high larval densities. We then noted the days that larvae took to emerge and compared it between low and high density groups. The results showed that larvae seem to emerge earlier when in high densities (Mann-Whitney,U=10.000,P=0.03). These results support the hypothesis that damselfly last instar larvae may postpone or hasten emergence in response to the social environment and related constraints.

No waves from surface knowledge: diving into the social representations of the deep sea

2021 ◽  
pp. 1-20
Author(s):  
Carla Morais ◽  
Luciano Moreira ◽  
Ana Sofia Teixeira ◽  
Teresa Aguiar
Keyword(s):  
Deep Sea ◽  
Social Representations ◽  
The Social

Social Capital of Youth in a Modern City: Opportunities for Empirical Research

2021 ◽  
Vol 23 (1) ◽  
pp. 130-140
Author(s):  
Anna Vladimirovna Shentyakova
Keyword(s):  
Social Capital ◽  
Social Capital Theory ◽  
High Population Density ◽  
Behavioral Models ◽  
Capital Theory ◽  
Large Cities ◽  
Institutional Approach ◽  
The Social ◽  
Behavior Motivation ◽  
Network Component

Modern megalopolis concentrates all groups of resources including economic, political, cultural, information, human resources, etc. The high population density, economic and geographic situation, complex multiethnic and multicultural structure of large cities contribute to certain types of values and behavioral models in the younger generation. The neo-institutional approach and social capital theory were chosen as a methodological basis. The article examines a number of methodological works devoted to various aspects of the social capital and explores the opportunity for this concept application for analysis of the protest behavior motivation and assessment of the protest potential of young people. Combination of the economic model of multilevel analysis for measuring social capital by S.А. Sysoev and socio-political parameters for the empirical part allowed to clearly defining the main categories and indicators of analysis. Measuring the levels of social capital of a megalopolis with the inclusion a network component expands the range of opportunities for assessing and identifying the protest potential of large Russian cities residents.

Introduction

2009 ◽  
Author(s):  
John S. Gray ◽  
Michael Elliott
Keyword(s):  
Marine Sediments ◽  
Deep Sea ◽  
Marine Species ◽  
Dark Side ◽  
Marine Animals ◽  
Linnaean System ◽  
Lofoten Islands ◽  
Linnaean Classification ◽  
Marine Biologist ◽  
New System

As the oceans cover 70% of the earth’s surface, marine sediments constitute the second largest habitat on earth, after the ocean water column, and yet we still know more about the dark side of the moon than about the biota of this vast habitat. The primary aim of this book is to give an overview of the biota of marine sediments from an ecological perspective—we will talk of the benthos, literally the plants and animals at the bottom of the sea, but we will also use the term to include those organisms living on the intertidal sediments, the sands and muds of the shore. Given that most of that area is below the zone where light penetrates, the photic zone, the area is dominated by the animals and so we will concentrate on this component. Many of the early studies of marine sediments were taxonomic, describing new species. One of the pioneers was Carl von Linnaeus (1707–1778), the great Swedish biologist who developed the Linnaean classification system for organisms that is still used today (but under threat from some molecular biologists who argue that the Linnaean system is outdated and propose a new system called Phylocode). Linnaeus described hundreds of marine species, many of which come from marine sediments. The British marine biologist Edward Forbes was a pioneer who invented the dredge to sample marine animals that lived below the tidemarks. Forbes showed that there were fewer species as the sampled depth increased and believed that the great pressures at depths meant that no animals would be found deeper than 600 m. This was disproved by Michael Sars who in 1869 used a dredge to sample the benthos at 600 m depth off the Lofoten islands in Norway. Sars found 335 species and in fact was the first to show that the deep sea (off the continental shelf) had high numbers of species. Following these pioneering studies, one of the earliest systematic studies of marine sediments was the HMS Challenger expedition of 1872–1876, the first global expedition. The reports of the expedition were extensive but were mostly descriptive, relating to taxonomy and general natural history.

Turning the Tide in Acadian Nova Scotia: How Heritage Tourism is Changing Language Practices and Representations of Language

2004 ◽  
Vol 49 (3-4) ◽  
pp. 327-351 ◽  
Author(s):  
Annette Boudreau ◽  
Chantal White
Keyword(s):  
Cultural Differences ◽  
Deep Sea ◽  
Heritage Tourism ◽  
The Other ◽  
Marked Influence ◽  
Cape Breton Island ◽  
Cape Breton ◽  
The Social ◽  
Ethnographic Data ◽  
The One

AbstractDrawn from ethnographic data collected in a small coastal village on Cape Breton Island, where tourism-related industries are emerging in response to the deep sea fishing crisis that hit the area in the early 1980s, this analysis focusses on the effects of tourism on linguistic practices and representations. It is argued that these effects are not without consequence on the way French-speakers in the region (re)construct their identity.Increased contact with outsiders leads to two seemingly contradictory tendencies: differentiation and standardization. These two strategies exert a marked influence on the social structure of the Acadian community. In this particular case, speakers must constantly negotiate an equilibrium between the desire to assert their specificity through discriminating traits that showcase their linguistic as well as cultural differences, on the one hand, and their need to communicate with a broader audience, on the other, the latter entailing a certain degree of linguistic standardization. This analysis focusses on how these speakers manage to perform this balancing act between differentiation and standardization.

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