2,124 research outputs found
Transforming Indigenous Chicken into Commercial Business, is it Possible?
Indigenous chicken needs to be preserved, because it has been decreased seriously. Its situation is caused by poor housing and low nutritional feed. Conservation of indigenous chickens is a very important mission for many countries in order to maintain genetic diversity. Indigenous chickens could be preserved by several methods, namely (1) Characterization of indigenous chickens; (2) Identification of special quality of indigenous chickens; (3) Combination between conservation and development of indigenous chickens; (4) Establishing association of indigenous chicken producers; and (5) Building up the distribution channels of indigenous chickens. The indigenous chickens need to be not only preserved but integrated into commercial business too. These two missions have mutual interaction. If the indigenous chicken conservation mission is well performed, it will also be a good addition to commercial business and the trading will in return push the development of indigenous chickens preservation.
Keywords: indigenous chicken, commercial busines
Male-Male Competition as a Force in Evolutionary Diversification: Evidence in Haplochromine Cichlid Fish
It has been suggested that intrasexual competition can be a source of negative frequency-dependent selection, causing agonistic character displacement and facilitating speciation and coexistence of (sibling) species. In this paper we synthesise the evidence that male-male and female-female competition contributes to cichlid diversification, showing that competition is stronger among same-coloured individuals than those with different colours. We argue that intrasexual selection is more complex because there are several examples where males do not bias aggression towards their own type. In addition, sibling species or colour morphs often show asymmetric dominance relationships. We briefly discuss potential mechanisms that might promote the maintenance of covariance between colour and aggression-related traits even in the face of gene-flow. We close by proposing several avenues for future studies that might shed more light on the role of intrasexual competition in cichlid diversification
Citizenship and social justice
Discussions on the problems of the welfare state are increasingly framed in terms of citizenship rather than social justice. The popularity of the concept of citizenship raises the question of its implications for social justice theory and research. In this article it is argued that whereas the dominant approach in social justice is essentially individualistic, the concept of citizenship focuses rather on individuals as members of a societal community, from which both rights and obligations are derived. This focus on communal membership suggests three important topics for social justice theory and research: (i) the need to distinguish between a civic and a justice motive for human behavior, (ii) the need to specify the frame of reference respondents should use when they make their justice judgments, and (iii) the need to recognize the fact that justice judgments may result from both adhering to criteria of justice and considering the consequences of their application
Multiplicity, Invariants and Tensor Product Decomposition of Tame Representations of U(\infty)
The structure of r-fold tensor products of irreducible tame representations
of the inductive limit U(\infty) of unitary groups U(n) are are described,
versions of contragredient representations and invariants are realized on
Bargmann-Segal-Fock spaces.Comment: 48 pages, LaTeX file, to appear in J. Math. Phy
NITROGEN LEVELS OF GOAT MANURE AND CHICKEN EXCRETA BIOCULTURE WITH ADDITION OF GRADUAL YOUNG COCONUT HUSK WASTE
Indonesia is an agricultural country where farming is the main occupation of its people. Therefore fertilizer becomes an indispensable item. At present, the majority of fertilizer used is met by chemical fertilizer. Long term application of chemical fertilizer and low content of micronutrients in common fertilizer causes quality degradation of the chemical, physical, and biological properties of the soil. Organic fertilizer is one of the strategic solutions to overcome these problems. Agricultural and livestock waste, including coconut husk, goat manure, and chicken excreta can be used as potential raw material for liquid organic fertilizer. The experiment was aimed to identify the best composition of coconut husk addition in liquid organic fertilizer. Various compositions of coconut husk used were 0; 0.65; 1.25; 2.5; and 5%. The analysis method was used One-Way Annova. Fermentation was carried out for one week in anaerobic conditions. Ammonium, nitrate, and nitrite levels of bioculture with the addition of 5% young coconut husk were significantly higher than other treatments, which obtained values 0.139; 0.705; and 0.523% respectively. The bioculture made has not met the quality of liquid fertilizer as in Standar Nasional Indonesi
Color polymorphism and intrasexual competition in assemblages of cichlid fish
The origin and maintenance of phenotypic polymorphisms is a classical problem in evolutionary ecology. Aggressive male-male competition can be a source of negative frequency-dependent selection stabilizing phenotypic polymorphisms when aggression is biased toward the own morph. We studied experimental assemblages of red and blue color morphs of the Lake Victoria cichlid fish Pundamilia. Aggression was investigated in mixed-color and single-color assemblages. We found that aggression was indeed biased toward males of the same color, which could in theory reduce aggression levels in mixed-color assemblages and promote coexistence. However, previous studies showed high aggression levels in red and dominance of red over blue males in dyadic interactions, which could hinder coexistence. We found that coexistence in mixed-color assemblages reduced the level of aggression in red males but not in blue males. Red and blue males were equally dominant in mixed-color assemblages, suggesting that predictions derived from dyadic interactions may not be valid for an assemblage situation. The results are consistent with field data: the geographic range of red is nested within that of blue, suggesting that red cannot displace blue. Our study suggests that male-male competition may be a significant force for maintaining phenotypic diversit
The role of visual adaptation in cichlid fish speciation
D. Shane Wright (1) , Ole Seehausen (2), Ton G.G. Groothuis (1), Martine E. Maan (1) (1) University of Groningen; GELIFES; EGDB(2) Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, Kastanienbaum AND Institute of Ecology and Evolution, Aquatic Ecology, University of Bern.In less than 15,000 years, Lake Victoria cichlid fishes have radiated into as many as 500 different species. Ecological and sexual sel ection are thought to contribute to this ongoing speciation process, but genetic differentiation remains low. However, recent work in visual pigment genes, opsins, has shown more diversity. Unlike neighboring Lakes Malawi and Tanganyika, Lake Victoria is highly turbid, resulting in a long wavelength shift in the light spectrum with increasing depth, providing an environmental gradient for exploring divergent coevolution in sensory systems and colour signals via sensory drive. Pundamilia pundamila and Pundamilia nyererei are two sympatric species found at rocky islands across southern portions of Lake Victoria, differing in male colouration and the depth they reside. Previous work has shown species differentiation in colour discrimination, corresponding to divergent female preferences for conspecific male colouration. A mechanistic link between colour vision and preference would provide a rapid route to reproductive isolation between divergently adapting populations. This link is tested by experimental manip ulation of colour vision - raising both species and their hybrids under light conditions mimicking shallow and deep habitats. We quantify the expression of retinal opsins and test behaviours important for speciation: mate choice, habitat preference, and fo raging performance
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