scholarly journals Ecophysiological responses to the effect of annual management on an endemic viviparous fish in central plateau of Mexico

2013 ◽  
Vol 11 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Fernando Garcia-Trejo ◽  
Silvia Laura Hurtado-Gonzalez ◽  
Genaro Soto-Zarazua ◽  
Oscar Alatorre-Jacome ◽  
Enrique Rico-Garcia ◽  
...  
Keyword(s):  
Hydrological Cycle ◽  
Central Plateau ◽  
Temperature Changes ◽  
Structure And Dynamics ◽  
Viviparous Fish ◽  
Ecophysiological Responses ◽  
The Subject ◽  
Biological Aspects ◽  
Population Structure And Dynamics ◽  
Meristic Data

Studies on the biological aspects of fish typically focus on species that currently have commercial value, causing species that lack such market value to be ignored. This is the case of several freshwater fish, specifically of several members of the Goodeidae family. In the State of Querétaro there are several species of this family characterized for being viviparous and having distinctive sexual dimorphism that may have commercial potential. The subject of this study is Girardinichthys multiradiatus, a viviparous fish endemic to the upper-half of the Lerma River basin. The lack of knowledge regarding its biology and ecology has prevented the development of guidelines to manage its habitat and to preserve its population. The objective was to determine the ecophysiological responses of G. multiradiatus to its environmental management. From the sampling (24 hours every two months) population structure and dynamics were analyzed throughout a hydrological cycle using meristic data (standard length). Trophic and ecophysiological responses to fluctuations in environmental factors were also identified. Although the mexcalpique is a polytrophic species, results show that it prefers feeding on Diptera or Cladocera, while detritus is the third substance frequently found in their stomachs. Environmentally, the water regime is responsible for fluctuations in the population dynamics of the species, while temperature changes are the most influence its energy balance. These results can guide efforts to conserve this species and its habitat.

Population structure and dynamics of the freshwater shrimp Atyaephyra desmarestii (Millet, 1831) in the lower River Minho (NW Portugal)

Crustaceana ◽  
2015 ◽  
Vol 88 (6) ◽  
pp. 657-673 ◽  
Author(s):  
Maria L. Fidalgo ◽  
Paulo Santos ◽  
Cláudia Ferreira ◽  
Andreia Silva
Keyword(s):  
Water Quality ◽  
Reproductive Period ◽  
Specific Knowledge ◽  
Nw Portugal ◽  
Ecological Relevance ◽  
Structure And Dynamics ◽  
Population Structure And Dynamics ◽  
Autumn And Winter ◽  
The Relationship ◽  
Fast Increase

This paper reports population dynamics, growth, and reproductive features ofAtyaephyra desmarestii(Millet, 1831) from the estuary of the River Minho. Also, data were compared to information available from its distribution range. Samples were taken monthly between October 2010 and September 2011. Males were less abundant and smaller than females. The growth pattern showed hardly any increase during the autumn and winter, but a fast increase in size was recorded in spring, followed by slower growth in summer. The life span was 11-12 months. The reproductive period was from April to August, and mean fecundity reached 643 ± 254 eggs/female. Juveniles started to appear in July and a strong recruitment occurred in summer and autumn. The ecological relevance of the shrimp supports the need of obtaining further and more specific knowledge on the relationship between geographical distribution and water quality. Our results coupled with longer time series in different localities will be essential to the conservation of the species.

Social and genetic analysis of a population of free-living cats (Felis catus L.) exploiting a resource-rich habitat

2002 ◽  
Vol 29 (4) ◽  
pp. 405 ◽  
Author(s):  
Elizabeth Denny ◽  
Paul Yakovlevich ◽  
Mark D. B. Eldridge ◽  
Chris Dickman
Keyword(s):  
Waste Disposal ◽  
Ad Hoc ◽  
Survival Rates ◽  
Felis Catus ◽  
Male Dominance ◽  
Disposal Site ◽  
Free Living ◽  
Structure And Dynamics ◽  
Population Structure And Dynamics ◽  
Rural Australia

Free-living cats (Felis catus L.) exploiting a waste-disposal site in rural Australia were studied for two years to investigate population structure and dynamics, and the relatedness of constituent individuals. The density of the population was equivalent to 700–750 cats km–2, the sex ratio was heavily skewed towards males, breeding occurred from July to April, and kitten survival rates were low. A combination of observational data, biometrics and microsatellite loci analyses was used to assess the relatedness of individuals in the population; these methods yielded highly congruent results. Thus, a female kin-group of three was identified, there was no female immigration, the average relatedness amongst the population was high and there was no indication of male dominance. The results indicate that cats at the site formed a tightly structured group, rather than an ad hoc collection of individuals. The stable, resource-rich habitat of waste-disposal sites may generally support high densities of group-forming cats in rural Australia, and pose broad-scale but previously unrecognised problems for effective management of free-living cats.

An International Relations Perspective on the Reform Needs of the Human Rights Council

2021 ◽  
Vol 62 (1) ◽  
pp. 43-80
Author(s):  
Wolfgang S. Heinz
Keyword(s):  
Human Rights ◽  
International Relations ◽  
International Law ◽  
Structure And Dynamics ◽  
Human Rights Council ◽  
Local Actors ◽  
Protection Of Human Rights ◽  
The Subject

Abstract: This article approaches the matter of institutional reform of the United Nations Human Rights Council from an international relations perspective. A well-known tension exists between State representatives acting for their governments in international organisations, but whose decisions are presented as UN policies. The latter should be guided primarily by the UN Charter and public international law. However, in reality, different worldviews and foreign policy considerations play a more significant role. In a comprehensive stock-take, the article looks at four major dimensions of the Council, starting with structure and dynamics and major trends, followed by its country and thematic activities, and the role of key actors. Council reform proposals from both States and civil society are explored. Whilst the intergovernmental body remains the most important authority responsible for the protection of human rights in the international sphere, it has also been the subject of considerable criticism. Although it has made considerable progress towards enlarging its coverage and taking on more challenging human rights crises, among some of its major weaknesses are the election of human rights-unfriendly countries into its ranks, the failure to apply stronger sanctions on large, politically influential countries in the South and North, and lack of influence on human rights crises and chronic human rights problems in certain countries. Whilst various reform proposals have emerged from States and NGOs, other more far reaching propositions are under sometimes difficult negotiations. In the mid- to long-term, the UN human rights machinery can only have a stronger and more lasting impact if support from national/local actors and coalitions in politics and society can be strengthened.

scholarly journals Structure and dynamics of a Cariniana estrellensis (Lecythidaceae) population in a fragment of Atlantic Forest in Minas Gerais, Brazil

Rodriguésia ◽  
2012 ◽  
Vol 63 (2) ◽  
pp. 257-267 ◽  
Author(s):  
Yule Roberta Ferreira Nunes ◽  
Miguel Petrere Jr.
Keyword(s):  
Population Structure ◽  
Seed Production ◽  
Size Structure ◽  
Canopy Cover ◽  
High Rate ◽  
Structure And Dynamics ◽  
Seedling Bank ◽  
Phase Size ◽  
Population Structure And Dynamics ◽  
Establishment Phase

We aimed to describe population structure and dynamics of Cariniana estrellensis (Raddi) Kuntze to test the hypothesis that this species survives in the forest by forming a seedling bank. We evaluated seed germination, spatial distribution, and recruitment, growth and mortality rates of young individuals. To characterize population structure a 1.2-ha plot was defined, where reproductive adults were mapped; also 100 6 m² sub-plots were established to characterize structure and monitor dynamics of young individuals. We estimated seed production using seed collectors and determined the percentage of canopy cover by hemispherical photographs. Seed rain and saplings showed clustered distribution indicating habitat-patch formation. Sapling mortality occurred mainly during the initial establishment phase. Size structure was characterized by many saplings (X = 9,763 individuals ha-1) and few adults (X = 5 individuals ha-1), associated with a high rate of seed production (X = 60,800 seeds ha-1), low growth rates (X = 2.37 cm ano-1) and mortality (15.66%) of established saplings, showing that species invest in seedling bank formation as a reproductive strategy.

Population structure and dynamics of Arctic willow (Salix arctica ) in the High Arctic

2014 ◽  
Vol 41 (10) ◽  
pp. 1967-1978 ◽  
Author(s):  
Noémie Boulanger-Lapointe ◽  
Esther Lévesque ◽  
Stéphane Boudreau ◽  
Gregory H. R. Henry ◽  
Niels Martin Schmidt
Keyword(s):  
Population Structure ◽  
High Arctic ◽  
Structure And Dynamics ◽  
Salix Arctica ◽  
Population Structure And Dynamics

scholarly journals Isochrones for late-type stars

2008 ◽  
Vol 4 (S258) ◽  
pp. 383-394 ◽  
Author(s):  
Pierre Demarque
Keyword(s):  
Three Dimensional ◽  
Radiation Hydrodynamics ◽  
Late Type ◽  
Chemical Abundances ◽  
Low Mass Stars ◽  
Structure And Dynamics ◽  
History Of ◽  
Low Mass ◽  
The Subject ◽  
Stellar Interiors

AbstractA brief summary of the history of stellar evolution theory and the use of isochrones is given. The present state of the subject is summarized. The major uncertainties in isochrone construction are considered: chemical abundances and color calibrations, and the treatment of turbulent convection in stellar interior and atmosphere models. The treatment of convection affects the modeling of stellar interiors principally in two ways: convective core overshoot which increases evolutionary lifetimes, and the depth of convection zones which determines theoretical radii. Turbulence also modifies atmospheric structure and dynamics, and the derivation of stellar abundances. The symbiosis of seismic techniques with increasingly more realistic three-dimensional radiation hydrodynamics simulations is transforming the study of late-type stars. The important case of very low mass stars, which are fully convective, is briefly visited.

scholarly journals Experimental study of the use of electric car powered with stationary solar and electrochemical batteries in Northern Poland

2018 ◽  
Vol 180 ◽  
pp. 02009
Author(s):  
Dariusz Karkosiński ◽  
Michał Pacholczyk ◽  
Łukasz Sienkiewicz
Keyword(s):  
Process Efficiency ◽  
Energy Sources ◽  
Temperature Changes ◽  
Charging Station ◽  
Electric Car ◽  
University Of Technology ◽  
The Subject ◽  
Electrochemical Battery ◽  
Photo Voltaic ◽  
The Impact

The subject of this paper is an experimental analysis of a Nissan LEAF electric car equipped with 24 kWh battery, powered from the standalone photo-voltaic (PV) charging station in Gdańsk, Poland. The calculations of charging process efficiency and range of test drives were conducted in two extreme situations (winter and summer) of sunlight and road conditions. Experiments were performed in the Laboratory of Innovative Power Technologies and Integration of Innovative Energy Sources (LINTE^2) at Gdańsk University of Technology. The car was night-charged with the stationary electrochemical battery, which, in turn, was powered with PV panels during the day. The impact of sunlight and ambient temperature changes on daily urban and highway drive ranges was analysed. The efficiency of energy conversion in multiple current converters was determined.

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