Temporal population dynamics of the swarming shrimp, Acetes sibogae australis, in a tropical near-shore system

2000 ◽  
Vol 51 (3) ◽  
pp. 249 ◽  
Author(s):  
S. L. Omundsen ◽  
M. J. Sheaves ◽  
B. W. Molony
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Temporal Scale ◽  
Length Frequency ◽  
Eastern Australia ◽  
Large Fluctuations ◽  
Region Length ◽  
Near Shore ◽  
Sample Time ◽  
Over Time

Acetes sibogae australis, a small swarming crustacean, is an important component of near-shore systems in eastern Australia. It is considered that densities of A. s. australis are highly variable. However, this variability has never been tested on a fine temporal scale. In this study, densities of A. s. australiswithin swarms, as well as swarm length and width, were recorded once a week for seven months at one locality in Townsville, Australia, and once a fortnight for seven months at two other localities in the region. Length frequency of a sub-sample of individuals caught at each sample time was also recorded. Density of A. s. australis fluctuated significantly during the seven months, with numbers per replicate varying between 0 and 1000 individuals. Swarm width and length were significantly correlated with density, contributing to large-scale differences in overall abundance. Length frequencies revealed at least three dominant cohorts present during the seven months, although appearance and disappearance of these did not correspond to density changes. Patterns recorded were similar at the three spatially separate localities. The large fluctuations in A. s. australis abundance over time are likely to have important effects on the near-shore system of Townsville.

scholarly journals Analysis of 220 Years of Floodplain Population Dynamics in the US at Different Spatial Scales

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 141
Author(s):  
Firoza Akhter ◽  
Maurizio Mazzoleni ◽  
Luigia Brandimarte
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Spatial Scales ◽  
National Level ◽  
State Level ◽  
Economic Activities ◽  
Protection Measures ◽  
Management Planning ◽  
The Us ◽  
Over Time

In this study, we explore the long-term trends of floodplain population dynamics at different spatial scales in the contiguous United States (U.S.). We exploit different types of datasets from 1790–2010—i.e., decadal spatial distribution for the population density in the US, global floodplains dataset, large-scale data of flood occurrence and damage, and structural and nonstructural flood protection measures for the US. At the national level, we found that the population initially settled down within the floodplains and then spread across its territory over time. At the state level, we observed that flood damages and national protection measures might have contributed to a learning effect, which in turn, shaped the floodplain population dynamics over time. Finally, at the county level, other socio-economic factors such as local flood insurances, economic activities, and socio-political context may predominantly influence the dynamics. Our study shows that different influencing factors affect floodplain population dynamics at different spatial scales. These facts are crucial for a reliable development and implementation of flood risk management planning.

scholarly journals Fencing affects African wild dog movement patterns and population dynamics

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Helen M. K. O'Neill ◽  
Sarah M. Durant ◽  
Stefanie Strebel ◽  
Rosie Woodroffe
Keyword(s):  
Population Dynamics ◽  
Large Scale ◽  
Animal Movement ◽  
Landscape Connectivity ◽  
Ecological Impact ◽  
Movement Patterns ◽  
Wrong Side ◽  
African Wild Dog ◽  
Wild Dog ◽  
Wild Dogs

Abstract Wildlife fences are often considered an important tool in conservation. Fences are used in attempts to prevent human–wildlife conflict and reduce poaching, despite known negative impacts on landscape connectivity and animal movement patterns. Such impacts are likely to be particularly important for wide-ranging species, such as the African wild dog Lycaon pictus, which requires large areas of continuous habitat to fulfil its resource requirements. Laikipia County in northern Kenya is an important area for wild dogs but new wildlife fences are increasingly being built in this ecosystem. Using a long-term dataset from the area's free-ranging wild dog population, we evaluated the effect of wildlife fence structure on the ability of wild dogs to cross them. The extent to which fences impeded wild dog movement differed between fence designs, although individuals crossed fences of all types. Purpose-built fence gaps increased passage through relatively impermeable fences. Nevertheless, low fence permeability can lead to packs, or parts of packs, becoming trapped on the wrong side of a fence, with consequences for population dynamics. Careful evaluation should be given to the necessity of erecting fences; ecological impact assessments should incorporate evaluation of impacts on animal movement patterns and should be undertaken for all large-scale fencing interventions. Where fencing is unavoidable, projects should use the most permeable fencing structures possible, both in the design of the fence and including as many purpose-built gaps as possible, to minimize impacts on wide-ranging wildlife.

scholarly journals China’s Investments in Germany and the Impact of the COVID-19 Pandemic

2021 ◽  
Vol 56 (2) ◽  
pp. 113-119
Author(s):  
Xinming Xia ◽  
Wan-Hsin Liu
Keyword(s):  
Large Scale ◽  
Know How ◽  
Advanced Technologies ◽  
The Future ◽  
Potential Impact ◽  
Chinese State ◽  
The Impact ◽  
Gain Access ◽  
Over Time

AbstractThis paper analyses how China’s investments in Germany have developed over time and the potential impact of the COVID-19 pandemic in this regard, based on four different datasets, including our own survey in mid-2020. Our analysis shows that Germany is currently one of the most attractive investment destinations for Chinese investors. Chinese state-owned enterprises have played an important role as investors in Germany — particularly in large-scale projects. The COVID-19 pandemic has had some negative but rather temporary effects on Chinese investments in Germany. Germany is expected to stay attractive to Chinese investors who seek to gain access to advanced technologies and know-how in the future.

Pioneers in International Administration: A Prosopography of the Directors of the League of Nations Secretariat

2019 ◽  
Vol 13 (2) ◽  
pp. 190-227 ◽  
Author(s):  
Torsten Kahlert
Keyword(s):  
International Organizations ◽  
Large Scale ◽  
Second World War ◽  
League Of Nations ◽  
World War ◽  
Clear Trend ◽  
Organizational Contexts ◽  
Career Trajectories ◽  
Second World ◽  
Over Time

AbstractThis article investigates interwar internationalism from the perspective of the highest personnel of the first large-scale international administration, the League of Nations Secretariat. It applies a prosopographical approach in order to map out the development of the composition of the group of the section directors of the Secretariat over time in terms of its social and cultural characteristics and career trajectories. The analysis of gender, age, nationality, as well as educational and professional backgrounds and careers after their service for the League’s Secretariat gives insight on how this group changed over time and what it tells us about interwar internationalism. I have three key findings to offer in this article: First, the Secretariat was far from being a static organization. On the contrary, the Secretariat’s directors developed in three generations each with distinct characteristics. Second, my analysis demonstrates a clear trend towards professionalization and growing maturity of the administration over time. Third, the careers of the directors show a clear pattern of continuity across the Second World War and beyond. Even though the careers continued in different organizational contexts, the majority of the directors remained closely connected to the world of internationalism of the League, the UN world and its surrounding organizations. On a methodological level, the article offers an example of how prosopographical analysis can be used to study international organizations.

Influence of rainfall on population dynamics and survival of a threatened rodent (Pseudomys novaehollandiae) under a drying climate in coastal woodlands of south-eastern Australia

2017 ◽  
Vol 65 (1) ◽  
pp. 60 ◽  
Author(s):  
Mandy Lock ◽  
Barbara A. Wilson
Keyword(s):  
Population Dynamics ◽  
Population Decline ◽  
Resource Depletion ◽  
Mammal Species ◽  
Eastern Australia ◽  
Apparent Decrease ◽  
Mediterranean Systems ◽  
Precipitous Decline ◽  
Breeding Seasons ◽  
Successional Vegetation

In Mediterranean systems, such as south-east Australia, predictions of climate change including lower rainfall and extended drought, threaten vulnerable mammal species. We investigated the relationship between rainfall and population dynamics for a native rodent at risk of extinction, the New Holland mouse (Pseudomys novaehollandiae). In the eastern Otways, the species was significantly influenced by rainfall, exhibiting a population irruption (15–20 individuals ha–1) following six years of above-average rainfall and a precipitous decline to site extinction during subsequent drought. The decline was predominantly related to loss of adults before and during breeding seasons, together with an apparent decrease in juvenile survival. Population abundance was positively correlated with a rainfall lag of 0–9 months. We propose that the response of this omnivore to high rainfall was mediated through increased productivity and that rainfall decline resulted in resource depletion and population decline. Under a drying climate the direct impacts of rainfall decline will continue. However management of other threats may increase the species’ resilience. Burning to provide optimal successional vegetation, protection of refugia, and predator control are priorities. However, burning should be avoided during drought, as the likelihood of local extinctions is substantial.

Large-scale patterns in species richness and composition of temperate riverine fish communities, south-eastern Australia

2000 ◽  
Vol 51 (2) ◽  
pp. 165 ◽  
Author(s):  
Peter C. Gehrke ◽  
John H. Harris
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Fish Communities ◽  
Fish Fauna ◽  
South Coast ◽  
North Coast ◽  
Large Spatial Scale ◽  
River Types ◽  
Eastern Australia ◽  
Riverine Fish

Riverine fish in New South Wales were studied to examine longitudinal trends in species richness and to identify fish communities on a large spatial scale. Five replicate rivers of four types (montane, slopes, regulated lowland and unregulated lowland) were selected from North Coast, South Coast, Murray and Darling regions. Fishwere sampled during summer and winter in two consecutive years with standardized gear that maximized the range of species caught. The composition of fish communities varied among regions and river types, with little temporal variation. Distinct regional communities converged in montane reaches and diverged downstream. The fish fauna can be classified into North Coast, South Coast, Murray and Darling communities, with a distinct montane community at high elevations irrespective of the drainage division. Species richness increased downstream in both North Coast and South Coast regions by both replacement and the addition of new species. In contrast, species richness in the Darling and Murray regions reached a maximum in the slopes reaches and then declined, reflecting a loss of species in lowland reaches. The small number of species is typical of the freshwater fish faunas of similar climatic regions world-wide. Fish communities identified in this study form logical entities for fisheries management consistent with the ecosystem-focused, catchment-based approach to river management and water reform being adopted in Australia.

A Framework and Case Study for Earthquake Vulnerability Assessment of Incrementally Expanding Buildings

2017 ◽  
Vol 33 (4) ◽  
pp. 1369-1384 ◽  
Author(s):  
David Lallemant ◽  
Henry Burton ◽  
Luis Ceferino ◽  
Zach Bullock ◽  
Anne Kiremidjian
Keyword(s):  
Large Scale ◽  
Building Construction ◽  
Risk Assessment Models ◽  
Earthquake Vulnerability ◽  
Valley Area ◽  
Common Understanding ◽  
Dynamic Structural Analysis ◽  
Neighborhood Level ◽  
Over Time

This study proposes a framework for incorporating time-dependent fragility into large-scale risk assessment models, focusing on incremental building expansion as a significant driver of changes in vulnerability. In rapidly urbanizing areas in developing countries, the pay-as-you-go process of informal building construction and staged expansion is the de facto pattern of growth. While there is a common understanding that such expansions increase the earthquake vulnerability of buildings, this study proposes a framework to model and quantify this increase. Vulnerability curves are developed through incremental dynamic structural analysis for common building expansion typologies. Building expansions are modeled as Markov chain processes and used to simulate stochastic expansion sequences over a building's lifetime. The model is then used to simulate a hypothetical neighborhood in the Kathmandu valley area to understand neighborhood-level risk over time. The study provides a new methodology to analyze changing seismic risk over time, driven by any building modification that impacts the building's vulnerability (incremental expansion, deterioration, retrofit, etc.).

scholarly journals Rapid Spread of the SARS-CoV-2 Variant of Concern 202012/01 in Southern Italy (December 2020–March 2021)

2021 ◽  
Vol 18 (9) ◽  
pp. 4766
Author(s):  
Daniela Loconsole ◽  
Francesca Centrone ◽  
Caterina Morcavallo ◽  
Silvia Campanella ◽  
Anna Sallustio ◽  
...  
Keyword(s):  
Clinical Characteristics ◽  
Large Scale ◽  
Southern Italy ◽  
Whole Genome ◽  
Third Wave ◽  
Gene Target ◽  
The Third ◽  
Rapid Spread ◽  
Pharmaceutical Interventions ◽  
Over Time

Epidemiological and virological studies have revealed that SARS-CoV-2 variants of concern (VOCs) are emerging globally, including in Europe. The aim of this study was to evaluate the spread of B.1.1.7-lineage SARS-CoV-2 in southern Italy from December 2020–March 2021 through the detection of the S gene target failure (SGTF), which could be considered a robust proxy of VOC B.1.1.7. SGTF was assessed on 3075 samples from week 52/2020 to week 10/2021. A subset of positive samples identified in the Apulia region during the study period was subjected to whole-genome sequencing (WGS). A descriptive and statistical analysis of the demographic and clinical characteristics of cases according to SGTF status was performed. Overall, 20.2% of samples showed SGTF; 155 strains were confirmed as VOC 202012/01 by WGS. The proportion of SGTF-positive samples rapidly increased over time, reaching 69.2% in week 10/2021. SGTF-positive cases were more likely to be symptomatic and to result in hospitalization (p < 0.0001). Despite the implementation of large-scale non-pharmaceutical interventions (NPIs), such as the closure of schools and local lockdowns, a rapid spread of VOC 202012/01 was observed in southern Italy. Strengthened NPIs and rapid vaccine deployment, first among priority groups and then among the general population, are crucial both to contain the spread of VOC 202012/01 and to flatten the curve of the third wave.

Out in the wash: spatial ecology of a temperate marine shallow rocky-reef species derived using acoustic telemetry

2015 ◽  
Vol 66 (6) ◽  
pp. 559 ◽  
Author(s):  
Jerom R. Stocks ◽  
Charles A. Gray ◽  
Matthew D. Taylor
Keyword(s):  
Spatial Ecology ◽  
Large Scale ◽  
Spatial Information ◽  
Activity Space ◽  
Rocky Reef ◽  
Temperate Reef ◽  
Detection Frequency ◽  
Detection Depth ◽  
Eastern Australia ◽  
Temperate Reef Fish

Characterising the movement and habitat affinities of fish is a fundamental component in understanding the functioning of marine ecosystems. A comprehensive array of acoustic receivers was deployed at two near-shore coastal sites in south-eastern Australia, to examine the movements, activity-space size and residency of a temperate rocky-reef, herbivorous species Girella elevata. Twenty-four G. elevata individuals were internally tagged with pressure-sensing acoustic transmitters across these two arrays and monitored for up to 550 days. An existing network of coastal receivers was used to examine large-scale movement patterns. Individuals exhibited varying residency, but all had small activity-space sizes within the arrays. The species utilised shallow rocky-reef habitat, displaying unimodal or bimodal patterns in depth use. A positive correlation was observed between wind speed and the detection depth of fish, with fish being likely to move to deeper water to escape periods of adverse conditions. Detection frequency data, corrected using sentinel tags, generally illustrated diurnal behaviour. Patterns of habitat usage, residency and spatial utilisation highlighted the susceptibility of G. elevata to recreational fishing pressure. The results from the present study will further contribute to the spatial information required in the zoning of effective marine protected areas, and our understanding of temperate reef fish ecology.

scholarly journals Kinetically driven successive sodic and potassic alteration of feldspar

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gan Duan ◽  
Rahul Ram ◽  
Yanlu Xing ◽  
Barbara Etschmann ◽  
Joël Brugger
Keyword(s):  
Hydrothermal Fluid ◽  
Large Scale ◽  
Ore Deposits ◽  
Potassic Alteration ◽  
Positive Feedbacks ◽  
Micro Scale ◽  
Equilibrium Reaction ◽  
Earth's Crust ◽  
Mineral Transformations ◽  
Over Time

AbstractThe dynamic evolutions of fluid-mineral systems driving large-scale geochemical transformations in the Earth’s crust remain poorly understood. We observed experimentally that successive sodic and potassic alterations of feldspar can occur via a single self-evolved, originally Na-only, hydrothermal fluid. At 600 °C, 2 kbar, sanidine ((K,Na)AlSi3O8) reacted rapidly with a NaCl fluid to form albite (NaAlSi3O8); over time, some of this albite was replaced by K-feldspar (KAlSi3O8), in contrast to predictions from equilibrium reaction modelling. Fluorine accelerated the process, resulting in near-complete back-replacement of albite within 1 day. These findings reveal that potassic alteration can be triggered by Na-rich fluids, indicating that pervasive sequential sodic and potassic alterations associated with mineralization in some of the world’s largest ore deposits may not necessarily reflect externally-driven changes in fluid alkali contents. Here, we show that these reactions are promoted at the micro-scale by a self-evolving, kinetically-driven process; such positive feedbacks between equilibrium and kinetic factors may be essential in driving pervasive mineral transformations.

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