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Sample records for cichlid feeding architecture

  1. More than Meets the Eye: Functionally Salient Changes in Internal Bone Architecture Accompany Divergence in Cichlid Feeding Mode

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    R. Craig Albertson

    2012-01-01

    Full Text Available African cichlids have undergone extensive and repeated adaptive radiations in foraging habitat. While the external morphology of the cichlid craniofacial skeleton has been studied extensively, biomechanically relevant changes to internal bone architecture have been largely overlooked. Here we explore two fundamental questions: (1 Do changes in the internal architecture of bone accompany shifts in foraging mode? (2 What is the genetic basis for this trait? We focus on the maxilla, which is an integral part of the feeding apparatus and an element that should be subjected to significant bending forces during biting. Analyses of μCT scans revealed clear differences between the maxilla of two species that employ alternative foraging strategies (i.e., biting versus suction feeding. Hybrids between the two species exhibit maxillary geometries that closely resemble those of the suction feeding species, consistent with a dominant mode of inheritance. This was supported by the results of a genetic mapping experiment, where suction feeding alleles were dominant to biting alleles at two loci that affect bone architecture. Overall, these data suggest that the internal structure of the cichlid maxilla has a tractable genetic basis and that discrete shifts in this trait have accompanied the evolution of alternate feeding modes.

  2. Bentho-pelagic divergence of cichlid feeding architecture was prodigious and consistent during multiple adaptive radiations within African rift-lakes.

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    W James Cooper

    Full Text Available BACKGROUND: How particular changes in functional morphology can repeatedly promote ecological diversification is an active area of evolutionary investigation. The African rift-lake cichlids offer a calibrated time series of the most dramatic adaptive radiations of vertebrate trophic morphology yet described, and the replicate nature of these events provides a unique opportunity to test whether common changes in functional morphology have repeatedly facilitated their ecological success. METHODOLOGY/PRINCIPAL FINDINGS: Specimens from 87 genera of cichlid fishes endemic to Lakes Tanganyka, Malawi and Victoria were dissected in order to examine the functional morphology of cichlid feeding. We quantified shape using geometric morphometrics and compared patterns of morphological diversity using a series of analytical tests. The primary axes of divergence were conserved among all three radiations, and the most prevalent changes involved the size of the preorbital region of the skull. Even the fishes from the youngest of these lakes (Victoria, which exhibit the lowest amount of skull shape disparity, have undergone extensive preorbital evolution relative to other craniofacial traits. Such changes have large effects on feeding biomechanics, and can promote expansion into a wide array of niches along a bentho-pelagic ecomorphological axis. CONCLUSIONS/SIGNIFICANCE: Here we show that specific changes in trophic anatomy have evolved repeatedly in the African rift lakes, and our results suggest that simple morphological alterations that have large ecological consequences are likely to constitute critical components of adaptive radiations in functional morphology. Such shifts may precede more complex shape changes as lineages diversify into unoccupied niches. The data presented here, combined with observations of other fish lineages, suggest that the preorbital region represents an evolutionary module that can respond quickly to natural selection when fishes

  3. Detection of artificial water flows by the lateral line system of a benthic feeding cichlid fish.

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    Schwalbe, Margot A B; Sevey, Benjamin J; Webb, Jacqueline F

    2016-04-01

    The mechanosensory lateral line system of fishes detects water motions within a few body lengths of the source. Several types of artificial stimuli have been used to probe lateral line function in the laboratory, but few studies have investigated the role of flow sensing in benthic feeding teleosts. In this study, we used artificial flows emerging from a sandy substrate to assess the contribution of flow sensing to prey detection in the peacock cichlid, Aulonocara stuartgranti, which feeds on benthic invertebrates in Lake Malawi. Using a positive reinforcement protocol, we trained fish to respond to flows lacking the visual and chemical cues generated by tethered prey in prior studies with A. stuartgranti Fish successfully responded to artificial flows at all five rates presented (characterized using digital particle image velocimetry), and showed a range of flow-sensing behaviors, including an unconditioned bite response. Immediately after lateral line inactivation, fish rarely responded to flows and the loss of vital fluorescent staining of hair cells (with 4-di-2-ASP) verified lateral line inactivation. Within 2 days post-treatment, some aspects of flow-sensing behavior returned and after 7 days, flow-sensing behavior and hair cell fluorescence both returned to pre-treatment levels, which is consistent with the reported timing of hair cell regeneration in other vertebrates. The presentation of ecologically relevant water flows to assess flow-sensing behaviors and the use of a positive reinforcement protocol are methods that present new opportunities to study the role of flow sensing in the feeding ecology of benthic feeding fishes.

  4. Replicated divergence in cichlid radiations mirrors a major vertebrate innovation.

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    McGee, Matthew D; Faircloth, Brant C; Borstein, Samuel R; Zheng, Jimmy; Darrin Hulsey, C; Wainwright, Peter C; Alfaro, Michael E

    2016-01-13

    Decoupling of the upper jaw bones--jaw kinesis--is a distinctive feature of the ray-finned fishes, but it is not clear how the innovation is related to the extraordinary diversity of feeding behaviours and feeding ecology in this group. We address this issue in a lineage of ray-finned fishes that is well known for its ecological and functional diversity--African rift lake cichlids. We sequenced ultraconserved elements to generate a phylogenomic tree of the Lake Tanganyika and Lake Malawi cichlid radiations. We filmed a diverse array of over 50 cichlid species capturing live prey and quantified the extent of jaw kinesis in the premaxillary and maxillary bones. Our combination of phylogenomic and kinematic data reveals a strong association between biting modes of feeding and reduced jaw kinesis, suggesting that the contrasting demands of biting and suction feeding have strongly influenced cranial evolution in both cichlid radiations.

  5. Genetic architecture of feed efficiency in mid-lactation Holstein dairy cows

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    The objective of this study was to explore the genetic architecture and biological basis of feed efficiency in lactating Holstein cows. In total, 4,918 cows with actual or imputed genotypes for 60,671 SNP had individual feed intake, milk yield, milk composition, and body weight records. Cows were ...

  6. Genetic architecture underlying convergent evolution of egg-laying behavior in a seed-feeding beetle.

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    Fox, Charles W; Wagner, James D; Cline, Sara; Thomas, Frances Ann; Messina, Frank J

    2009-05-01

    Independent populations subjected to similar environments often exhibit convergent evolution. An unresolved question is the frequency with which such convergence reflects parallel genetic mechanisms. We examined the convergent evolution of egg-laying behavior in the seed-feeding beetle Callosobruchus maculatus. Females avoid ovipositing on seeds bearing conspecific eggs, but the degree of host discrimination varies among geographic populations. In a previous experiment, replicate lines switched from a small host to a large one evolved reduced discrimination after 40 generations. We used line crosses to determine the genetic architecture underlying this rapid response. The most parsimonious genetic models included dominance and/or epistasis for all crosses. The genetic architecture underlying reduced discrimination in two lines was not significantly different from the architecture underlying differences between geographic populations, but the architecture underlying the divergence of a third line differed from all others. We conclude that convergence of this complex trait may in some cases involve parallel genetic mechanisms.

  7. Sensory drive in cichlid speciation

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    Maan, Martine E.; Hofker, Kees D.; van Alphen, Jacques J. M.; Seehausen, Ole

    2006-01-01

    The role of selection in speciation is a central yet poorly understood problem in evolutionary biology. The rapid radiations of extremely colorful cichlid fish in African lakes have fueled the hypothesis that sexual selection can drive species divergence without geographical isolation. Here we prese

  8. Using Cichlids for Illustrating Mendel's Laws

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    Gennaro, Eugene D.; Winters, Charlotte M.

    1978-01-01

    A classroom experiment is proposed in which students can mate a banded or spotted convict cichlid with a pink convict cichlid and observe the markings of their "children" and "grandchildren" as a way of illustrating Mendel's Laws of Dominance and Segregation. (MN)

  9. Adaptive phenotypic plasticity in the Midas cichlid fish pharyngeal jaw and its relevance in adaptive radiation

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    Salzburger Walter

    2011-04-01

    Full Text Available Abstract Background Phenotypic evolution and its role in the diversification of organisms is a central topic in evolutionary biology. A neglected factor during the modern evolutionary synthesis, adaptive phenotypic plasticity, more recently attracted the attention of many evolutionary biologists and is now recognized as an important ingredient in both population persistence and diversification. The traits and directions in which an ancestral source population displays phenotypic plasticity might partly determine the trajectories in morphospace, which are accessible for an adaptive radiation, starting from the colonization of a novel environment. In the case of repeated colonizations of similar environments from the same source population this "flexible stem" hypothesis predicts similar phenotypes to arise in repeated subsequent radiations. The Midas Cichlid (Amphilophus spp. in Nicaragua has radiated in parallel in several crater-lakes seeded by populations originating from the Nicaraguan Great Lakes. Here, we tested phenotypic plasticity in the pharyngeal jaw of Midas Cichlids. The pharyngeal jaw apparatus of cichlids, a second set of jaws functionally decoupled from the oral ones, is known to mediate ecological specialization and often differs strongly between sister-species. Results We performed a common garden experiment raising three groups of Midas cichlids on food differing in hardness and calcium content. Analyzing the lower pharyngeal jaw-bones we find significant differences between diet groups qualitatively resembling the differences found between specialized species. Observed differences in pharyngeal jaw expression between groups were attributable to the diet's mechanical resistance, whereas surplus calcium in the diet was not found to be of importance. Conclusions The pharyngeal jaw apparatus of Midas Cichlids can be expressed plastically if stimulated mechanically during feeding. Since this trait is commonly differentiated - among

  10. Mandibular gnathobases of marine planktonic copepods – feeding tools with complex micro- and nanoscale composite architectures

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    Jan Michels

    2015-03-01

    Full Text Available Copepods are dominant members of the marine zooplankton. Their diets often comprise large proportions of diatom taxa whose silicified frustules are mechanically stable and offer protection against grazers. Despite of this protection, many copepod species are able to efficiently break even the most stable frustule types. This ability requires specific feeding tools with mechanically adapted architectures, compositions and properties. When ingesting food, the copepods use the gnathobases of their mandibles to grab and, if necessary, crush and mince the food items. The morphology of these gnathobases is related to the diets of the copepods. Gnathobases of copepod species that mainly feed on phytoplankton feature compact and stable tooth-like structures, so-called teeth. In several copepod species these gnathobase teeth have been found to contain silica. Recent studies revealed that the siliceous teeth are complex microscale composites with silica-containing cap-like structures located on chitinous exoskeleton sockets that are connected with rubber-like bearings formed by structures with high proportions of the soft and elastic protein resilin. In addition, the silica-containing cap-like structures exhibit a nanoscale composite architecture. They contain some amorphous silica and large proportions of the crystalline silica type α-cristobalite and are pervaded by a fine chitinous fibre network that very likely serves as a scaffold during the silicification process. All these intricate composite structures are assumed to be the result of a coevolution between the copepod gnathobases and diatom frustules in an evolutionary arms race. The composites very likely increase both the performance of the siliceous teeth and their resistance to mechanical damage, and it is conceivable that their development has favoured the copepods’ dominance of the marine zooplankton observed today.

  11. Species-specific differences in adaptive phenotypic plasticity in an ecologically relevant trophic trait: hypertrophic lips in Midas cichlid fishes.

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    Machado-Schiaffino, Gonzalo; Henning, Frederico; Meyer, Axel

    2014-07-01

    The spectacular species richness of cichlids and their diversity in morphology, coloration, and behavior have made them an ideal model for the study of speciation and adaptive evolution. Hypertrophic lips evolved repeatedly and independently in African and Neotropical cichlid radiations. Cichlids with hypertrophic lips forage predominantly in rocky crevices and it has been hypothesized that mechanical stress caused by friction could result in larger lips through phenotypic plasticity. To test the influence of the environment on the size and development of lips, we conducted a series of breeding and feeding experiments on Midas cichlids. Full-sibs of Amphilophus labiatus (thick-lipped) and Amphilophus citrinellus (thin-lipped) each were split into a control group which was fed food from the water column and a treatment group whose food was fixed to substrates. We found strong evidence for phenotypic plasticity on lip area in the thick-lipped species, but not in the thin-lipped species. Intermediate phenotypic values were observed in hybrids from thick- and thin-lipped species reared under "control" conditions. Thus, both a genetic, but also a phenotypic plastic component is involved in the development of hypertrophic lips in Neotropical cichlids. Moreover, species-specific adaptive phenotypic plasticity was found, suggesting that plasticity is selected for in recent thick-lipped species.

  12. Temporal diversification of Central American cichlids

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    Hulsey C Darrin

    2010-09-01

    Full Text Available Abstract Background Cichlid fishes are classic examples of adaptive radiation because of their putative tendency to explosively diversify after invading novel environments. To examine whether ecological opportunity increased diversification (speciation minus extinction early in a species-rich cichlid radiation, we determined if Heroine cichlids experienced a burst of diversification following their invasion of Central America. Results We first reconstructed the Heroine phylogeny and determined the basal node to use as the root of Central American Heroine diversification. We then examined the influence of incomplete taxon sampling on this group's diversification patterns. First, we added missing species randomly to the phylogeny and assessed deviations from a constant rate of lineage accumulation. Using a range of species numbers, we failed to recover significant deviations from a pure-birth process and found little support for an early burst of diversification. Then, we examined patterns of lineage accumulation as nodes were increasingly truncated. We assumed that as we removed more recently diverged lineages that sampling would become more complete thereby increasing the power to detect deviations from a pure-birth model. However, truncation of nodes provided even less support for an early burst of diversification. Conclusions Contrary to expectations, our analyses suggest Heroine cichlids did not undergo a burst of diversification when they invaded from South America. Throughout their history in Central America, Heroine cichlids appear to have diversified at a constant rate.

  13. The relationships among jaw-muscle fiber architecture, jaw morphology, and feeding behavior in extant apes and modern humans.

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    Taylor, Andrea B; Vinyard, Christopher J

    2013-05-01

    The jaw-closing muscles are responsible for generating many of the forces and movements associated with feeding. Muscle physiologic cross-sectional area (PCSA) and fiber length are two architectural parameters that heavily influence muscle function. While there have been numerous comparative studies of hominoid and hominin craniodental and mandibular morphology, little is known about hominoid jaw-muscle fiber architecture. We present novel data on masseter and temporalis internal muscle architecture for small- and large-bodied hominoids. Hominoid scaling patterns are evaluated and compared with representative New- (Cebus) and Old-World (Macaca) monkeys. Variation in hominoid jaw-muscle fiber architecture is related to both absolute size and allometry. PCSAs scale close to isometry relative to jaw length in anthropoids, but likely with positive allometry in hominoids. Thus, large-bodied apes may be capable of generating both absolutely and relatively greater muscle forces compared with smaller-bodied apes and monkeys. Compared with extant apes, modern humans exhibit a reduction in masseter PCSA relative to condyle-M1 length but retain relatively long fibers, suggesting humans may have sacrificed relative masseter muscle force during chewing without appreciably altering muscle excursion/contraction velocity. Lastly, craniometric estimates of PCSAs underestimate hominoid masseter and temporalis PCSAs by more than 50% in gorillas, and overestimate masseter PCSA by as much as 30% in humans. These findings underscore the difficulty of accurately estimating jaw-muscle fiber architecture from craniometric measures and suggest models of fossil hominin and hominoid bite forces will be improved by incorporating architectural data in estimating jaw-muscle forces.

  14. Eggspot number and sexual selection in the cichlid fish Astatotilapia burtoni.

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    Henning, Frederico; Meyer, Axel

    2012-01-01

    Sexual selection on male coloration is one of the main mechanisms proposed to explain the explosive speciation rates in East African cichlid fish. True eggspots are color patterns characteristic of the most species-rich lineage of cichlids, the Haplochromini, and have been suggested to be causally related to the speciation processes. Eggspots are thought to have originated by sensory exploitation and subsequently gained several roles in sexual advertisement. However, for most of these functions the evidence is equivocal. In addition, the genetic architecture of this trait still is largely unknown. We conducted bidirectional selective breeding experiments for eggspot numbers in the model cichlid, Astatotilapia burtoni. After two generations, low lines responded significantly, whereas the high lines did not. Body size was both phenotypically and genotypically correlated with eggspot number and showed correlated response to selection. Males with higher numbers of eggspots were found to sire larger offspring. Despite the potential to act as honest indicators of fitness, the behavioral experiments showed no evidence of a role in either intra- or inter-sexual selection. Visual-based female preference was instead explained by courtship intensity. The evolution of this trait has been interpreted in light of adaptive theories of sexual selection, however the present and published results suggest the influence of non-adaptive factors such as sensory exploitation, environmental constraints and sexual antagonism.

  15. Eggspot number and sexual selection in the cichlid fish Astatotilapia burtoni.

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    Frederico Henning

    Full Text Available Sexual selection on male coloration is one of the main mechanisms proposed to explain the explosive speciation rates in East African cichlid fish. True eggspots are color patterns characteristic of the most species-rich lineage of cichlids, the Haplochromini, and have been suggested to be causally related to the speciation processes. Eggspots are thought to have originated by sensory exploitation and subsequently gained several roles in sexual advertisement. However, for most of these functions the evidence is equivocal. In addition, the genetic architecture of this trait still is largely unknown. We conducted bidirectional selective breeding experiments for eggspot numbers in the model cichlid, Astatotilapia burtoni. After two generations, low lines responded significantly, whereas the high lines did not. Body size was both phenotypically and genotypically correlated with eggspot number and showed correlated response to selection. Males with higher numbers of eggspots were found to sire larger offspring. Despite the potential to act as honest indicators of fitness, the behavioral experiments showed no evidence of a role in either intra- or inter-sexual selection. Visual-based female preference was instead explained by courtship intensity. The evolution of this trait has been interpreted in light of adaptive theories of sexual selection, however the present and published results suggest the influence of non-adaptive factors such as sensory exploitation, environmental constraints and sexual antagonism.

  16. Eggspot Number and Sexual Selection in the Cichlid Fish Astatotilapia burtoni

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    Henning, Frederico; Meyer, Axel

    2012-01-01

    Sexual selection on male coloration is one of the main mechanisms proposed to explain the explosive speciation rates in East African cichlid fish. True eggspots are color patterns characteristic of the most species-rich lineage of cichlids, the Haplochromini, and have been suggested to be causally related to the speciation processes. Eggspots are thought to have originated by sensory exploitation and subsequently gained several roles in sexual advertisement. However, for most of these functions the evidence is equivocal. In addition, the genetic architecture of this trait still is largely unknown. We conducted bidirectional selective breeding experiments for eggspot numbers in the model cichlid, Astatotilapia burtoni. After two generations, low lines responded significantly, whereas the high lines did not. Body size was both phenotypically and genotypically correlated with eggspot number and showed correlated response to selection. Males with higher numbers of eggspots were found to sire larger offspring. Despite the potential to act as honest indicators of fitness, the behavioral experiments showed no evidence of a role in either intra- or inter-sexual selection. Visual-based female preference was instead explained by courtship intensity. The evolution of this trait has been interpreted in light of adaptive theories of sexual selection, however the present and published results suggest the influence of non-adaptive factors such as sensory exploitation, environmental constraints and sexual antagonism. PMID:22937082

  17. Dealing with food and eggs in mouthbrooding cichlids: structural and functional trade-offs in fitness related traits.

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    Tim Tkint

    Full Text Available BACKGROUND: As in any vertebrate, heads of fishes are densely packed with functions. These functions often impose conflicting mechanical demands resulting in trade-offs in the species-specific phenotype. When phenotypical traits are linked to gender-specific parental behavior, we expect sexual differences in these trade-offs. This study aims to use mouthbrooding cichlids as an example to test hypotheses on evolutionary trade-offs between intricately linked traits that affect different aspects of fitness. We focused on the oral apparatus, which is not only equipped with features used to feed and breathe, but is also used for the incubation of eggs. We used this approach to study mouthbrooding as part of an integrated functional system with diverging performance requirements and to explore gender-specific selective environments within a species. METHODOLOGY/PRINCIPAL FINDINGS: Because cichlids are morphologically very diverse, we hypothesize that the implications of the added constraint of mouthbrooding will primarily depend on the dominant mode of feeding of the studied species. To test this, we compared the trade-off for two maternal mouthbrooding cichlid species: a "suction feeder" (Haplochromis piceatus and a "biter" (H. fischeri. The comparison of morphology and performance of both species revealed clear interspecific and intersex differences. Our observation that females have larger heads was interpreted as a possible consequence of the fact that in both the studied species mouthbrooding is done by females only. As hypothesized, the observed sexual dimorphism in head shape is inferred as being suboptimal for some aspects of the feeding performance in each of the studied species. Our comparison also demonstrated that the suction feeding species had smaller egg clutches and more elongated eggs. CONCLUSIONS/SIGNIFICANCE: Our findings support the hypothesis that there is a trade-off between mouthbrooding and feeding performance in the two

  18. Radio Astronomy Data Model for Single-Dish Multiple-Feed Telescopes, and Robledo Archive Architecture

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    Santander-Vela, J D; Gómez, J F; Verdes-Montenegro, L; Leon, S; Gutíerrez, R; Rodrigo, C; Morata, O; Solano, E; Suárez, O

    2008-01-01

    All the effort that the astrophysical community has put into the development of the Virtual Observatory (VO) has surpassed the non-return point: the VO is a reality today, and an initiative that will self-sustain, and to which all archival projects must adhere. We have started the design of the scientific archive for the DSS-63 70-m antenna at NASA's DSN station in Robledo de Chavela (Madrid). Here we show how we can use all VO proposed data models to build a VO-compliant single-dish, multiple-feed, radio astronomical archive data model (RADAMS) suitable for the archival needs of the antenna. We also propose an exhaustive list of Universal Content Descriptors (UCDs) and FITS keywords for all relevant metadata. We will further refine this data model with the experience that we will gain from that implementation.

  19. Annotation of expressed sequence tags for the East African cichlid fish Astatotilapia burtoni and evolutionary analyses of cichlid ORFs

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    Braasch Ingo

    2008-02-01

    Full Text Available Abstract Background The cichlid fishes in general, and the exceptionally diverse East African haplochromine cichlids in particular, are famous examples of adaptive radiation and explosive speciation. Here we report the collection and annotation of more than 12,000 expressed sequence tags (ESTs generated from three different cDNA libraries obtained from the East African haplochromine cichlid species Astatotilapia burtoni and Metriaclima zebra. Results We first annotated more than 12,000 newly generated cichlid ESTs using the Gene Ontology classification system. For evolutionary analyses, we combined these ESTs with all available sequence data for haplochromine cichlids, which resulted in a total of more than 45,000 ESTs. The ESTs represent a broad range of molecular functions and biological processes. We compared the haplochromine ESTs to sequence data from those available for other fish model systems such as pufferfish (Takifugu rubripes and Tetraodon nigroviridis, trout, and zebrafish. We characterized genes that show a faster or slower rate of base substitutions in haplochromine cichlids compared to other fish species, as this is indicative of a relaxed or reinforced selection regime. Four of these genes showed the signature of positive selection as revealed by calculating Ka/Ks ratios. Conclusion About 22% of the surveyed ESTs were found to have cichlid specific rate differences suggesting that these genes might play a role in lineage specific characteristics of cichlids. We also conclude that the four genes with a Ka/Ks ratio greater than one appear as good candidate genes for further work on the genetic basis of evolutionary success of haplochromine cichlid fishes.

  20. Introgressive hybridization in a trophically polymorphic cichlid.

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    Hulsey, C Darrin; García-de-León, Francisco J

    2013-11-01

    Trophically polymorphic species could represent lineages that are rapidly diverging along an ecological axis or could phenotypically mark the collapse of species through introgressive hybridization. We investigated patterns of introgression between the trophically polymorphic cichlid fish Herichthys minckleyi and its relative H. cyanoguttatus using a combination of population genetics and species tree analyses. We first examined the distribution of mitochondrial haplotypes within the alternative H. minckleyi pharyngeal jaw morphotypes that are endemic to the small desert valley of Cuatro Ciénegas. We recovered two clusters of mitochondrial haplotypes. The first contained a number of slightly differentiated cytochrome b (cytb) haplotypes that showed some phylogeographic signal and were present in both jaw morphotypes. The other haplotype was monomorphic, highly differentiated from the other cluster, present in equal frequencies in the morphotypes, and identical to H. cyanoguttatus haplotypes found outside Cuatro Ciénegas. Then, we investigated whether H. minckleyi individuals with the H. cyanoguttatus cytb were more evolutionarily similar to H. cyanoguttatus or other H. minckleyi using a species tree analysis of 84 nuclear loci. Both H. minckleyi pharyngeal morphotypes, regardless of their cytb haplotype, were quite distinct from H. cyanoguttatus. However, hybridization could be blurring subdivision within H. minckleyi as the alternative jaw morphotypes were not genetically distinct from one another. Accounting for introgression from H. cyanoguttatus will be essential to understand the evolution of the trophically polymorphic cichlid H. minckleyi.

  1. Identification of cichlid fishes from Lake Malawi using computer vision.

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    Deokjin Joo

    Full Text Available BACKGROUND: The explosively radiating evolution of cichlid fishes of Lake Malawi has yielded an amazing number of haplochromine species estimated as many as 500 to 800 with a surprising degree of diversity not only in color and stripe pattern but also in the shape of jaw and body among them. As these morphological diversities have been a central subject of adaptive speciation and taxonomic classification, such high diversity could serve as a foundation for automation of species identification of cichlids. METHODOLOGY/PRINCIPAL FINDING: Here we demonstrate a method for automatic classification of the Lake Malawi cichlids based on computer vision and geometric morphometrics. For this end we developed a pipeline that integrates multiple image processing tools to automatically extract informative features of color and stripe patterns from a large set of photographic images of wild cichlids. The extracted information was evaluated by statistical classifiers Support Vector Machine and Random Forests. Both classifiers performed better when body shape information was added to the feature of color and stripe. Besides the coloration and stripe pattern, body shape variables boosted the accuracy of classification by about 10%. The programs were able to classify 594 live cichlid individuals belonging to 12 different classes (species and sexes with an average accuracy of 78%, contrasting to a mere 42% success rate by human eyes. The variables that contributed most to the accuracy were body height and the hue of the most frequent color. CONCLUSIONS: Computer vision showed a notable performance in extracting information from the color and stripe patterns of Lake Malawi cichlids although the information was not enough for errorless species identification. Our results indicate that there appears an unavoidable difficulty in automatic species identification of cichlid fishes, which may arise from short divergence times and gene flow between closely related species.

  2. Species tree estimation and the historical biogeography of heroine cichlids.

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    Hulsey, C Darrin; Keck, Benjamin P; Hollingsworth, Phillip R

    2011-01-01

    Heroine cichlids are major components of the fish faunas in both Central America and the Caribbean. To examine the evolutionary patterns of how cichlids colonized both of these regions, we reconstructed the phylogenetic relationships among 23 cichlid lineages. We used three phylogenetically novel nuclear markers (Dystropin b, Myomesin1, and Wnt7b) in combination with sequence data from seven other gene regions (Nd2, Rag1, Enc1, Sreb2, Ptr, Plagl2, and Zic1) to elucidate the species tree of these cichlids. The species examined represent major heroine lineages in South America, Central America, and the Greater Antilles. The individual gene trees of these groups were topologically quite discordant. Therefore, we combined the genetic partitions and inferred the species tree using both concatenation and a coalescent-based Bayesian method. The two resulting phylogenetic topologies were largely concordant but differed in two fundamental ways. First, more nodes in the concatenated tree were supported with substantial or 100% Bayesian posterior support than in the coalescent-based tree. Second, there was a minor, but biogeographically critical, topological difference between the concatenated and coalescent-based trees. Nevertheless, both analyses recovered topologies consistent with the Greater Antillean heroines being phylogenetically nested within the largely Central American heroine radiation. This study suggests that reconstructions of cichlid phylogeny and historical biogeography should account for the vagaries of individual gene histories.

  3. Colour forms of Amazonian cichlid fish represent reproductively isolated species.

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    Ready, J S; Sampaio, I; Schneider, H; Vinson, C; Dos Santos, T; Turner, G F

    2006-07-01

    Laboratory mate choice experiments have confirmed species status for cichlid fish in the African Great Lakes that differ in colour and little else. Colour differences between allopatric populations of the South American cichlid genus Apistogramma are known for many species, yet the status of such populations has not been previously tested. Analysis of the genetic relationships and mate choice characteristics of populations previously described as Apistogramma caetei from eastern Amazonia indicates genetic differentiation into at least three allopatric lineages, which also show strong prezygotic isolation through female mate choice, confirming them as Biological species. If future studies confirm that this result is indicative of a general trend, the species richness of the South American cichlid fishes may presently be seriously underestimated.

  4. Mating and Parental Care in Lake Tanganyika's Cichlids

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    Kristina M. Sefc

    2011-01-01

    Full Text Available Cichlid fishes of Lake Tanganyika display a variety of mating and parental care behaviors, including polygamous and monogamous mouthbrooding and substrate breeding, cooperative breeding, as well as various alternative reproductive tactics such as sneaking and piracy. Moreover, reproductive behaviors sometimes vary within species both in space and in time. Here, I survey reports on mating and parenting behaviors of Lake Tanganyika cichlid species and address the evolution of mating and parental care patterns and sexual dimorphism. Notes on measures of sexual selection intensity and the difficulties of defining mating systems and estimating selection intensities at species level conclude the essay.

  5. Predator-induced neophobia in juvenile cichlids.

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    Meuthen, Denis; Baldauf, Sebastian A; Bakker, Theo C M; Thünken, Timo

    2016-08-01

    Predation is an important but often fluctuating selection factor for prey animals. Accordingly, individuals plastically adopt antipredator strategies in response to current predation risk. Recently, it was proposed that predation risk also plastically induces neophobia (an antipredator response towards novel cues). Previous studies, however, do not allow a differentiation between general neophobia and sensory channel-specific neophobic responses. Therefore, we tested the neophobia hypothesis focusing on adjustment in shoaling behavior in response to a novel cue addressing a different sensory channel than the one from which predation risk was initially perceived. From hatching onwards, juveniles of the cichlid Pelvicachromis taeniatus were exposed to different chemical cues in a split-clutch design: conspecific alarm cues which signal predation risk and heterospecific alarm cues or distilled water as controls. At 2 months of age, their shoaling behavior was examined prior and subsequent to a tactical disturbance cue. We found that fish previously exposed to predation risk formed more compact shoals relative to the control groups in response to the novel disturbance cue. Moreover, the relationship between shoal density and shoal homogeneity was also affected by experienced predation risk. Our findings indicate predator-induced, increased cross-sensory sensitivity towards novel cues making neophobia an effective antipredator mechanism.

  6. Complete mitochondrial DNA sequences of the threadfin cichlid (Petrochromis trewavasae and the blunthead cichlid (Tropheus moorii and patterns of mitochondrial genome evolution in cichlid fishes.

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    Christoph Fischer

    Full Text Available The cichlid fishes of the East African Great Lakes represent a model especially suited to study adaptive radiation and speciation. With several African cichlid genome projects being in progress, a promising set of closely related genomes is emerging, which is expected to serve as a valuable data base to solve questions on genotype-phenotype relations. The mitochondrial (mt genomes presented here are the first results of the assembly and annotation process for two closely related but eco-morphologically highly distinct Lake Tanganyika cichlids, Petrochromis trewavasae and Tropheus moorii. The genomic sequences comprise 16,588 bp (P. trewavasae and 16,590 bp (T. moorii, and exhibit the typical mitochondrial structure, with 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes, and a non-coding control region. Analyses confirmed that the two species are very closely related with an overall sequence similarity of 96%. We analyzed the newly generated sequences in the phylogenetic context of 21 published labroid fish mitochondrial genomes. Consistent with other vertebrates, the D-loop region was found to evolve faster than protein-coding genes, which in turn are followed by the rRNAs; the tRNAs vary greatly in the rate of sequence evolution, but on average evolve the slowest. Within the group of coding genes, ND6 evolves most rapidly. Codon usage is similar among examined cichlid tribes and labroid families; although a slight shift in usage patterns down the gene tree could be observed. Despite having a clearly different nucleotide composition, ND6 showed a similar codon usage. C-terminal ends of Cox1 exhibit variations, where the varying number of amino acids is related to the structure of the obtained phylogenetic tree. This variation may be of functional relevance for Cox1 synthesis.

  7. Tempo and mode of diversification of lake Tanganyika cichlid fishes.

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    Julia J Day

    Full Text Available BACKGROUND: Understanding the causes of disparities in species diversity across taxonomic groups and regions is a fundamental aim in evolutionary biology. Addressing these questions is difficult because of the need for densely sampled phylogenies and suitable empirical systems. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigate the cichlid fish radiation of Lake Tanganyika and show that per lineage diversification rates have been more than six times slower than in the species flocks of Lakes Victoria and Malawi. The result holds even at peak periods of diversification in Lake Tanganyika, ruling out the age of the lake as an explanation for slow average rates, and is robust to uncertainties over the calibration of cichlid radiations in geological time. Moreover, Lake Tanganyika lineages, irrespective of different biological characteristics (e.g. sexually dichromatic versus sexually monochromatic clades, have diversified at similar rates, falling within typical estimates across a range of plant and animal clades. For example, the mostly sexually dichromatic haplochromines, which have speciated explosively in Lakes Victoria and Malawi, have displayed modest rates in Lake Tanganyika (where they are called Tropheini. CONCLUSION/SIGNIFICANCE: Our results show that either the Lake Tanganyika environment is less conducive for cichlid speciation or the remarkable diversifying abilities of the haplochromines were inhibited by the prior occupancy of older radiations. Although the results indicate a dominant role for the environment in shaping cichlid diversification, differences in the timing of diversification among the Tanganyikan tribes indicate that biological differences were still important for the dynamics of species build-up in the lake. While we cannot resolve the timing of the radiation relative to the origin of the lake, because of the lack of robust geological date calibrations for cichlids, our results are consistent with a scenario that the

  8. Social regulation of reproduction in male cichlid fishes.

    Science.gov (United States)

    Maruska, Karen P

    2014-10-01

    Social interactions and relative positions within a dominance hierarchy have helped shape the evolution of reproduction in many animals. Since reproduction is crucial in all animals, and rank typically regulates access to reproductive opportunities, understanding the mechanisms that regulate socially-induced reproductive processes is extremely important. How does position in a dominance hierarchy impact an individual's reproductive behavior, morphology, and physiology? Teleost fishes, and cichlids in particular, are ideally-suited models for studying how social status influences reproduction on multiple levels of biological organization. Here I review the current knowledge on the reproductive behavioral and physiological consequences of relative position in a dominance hierarchy, with a particular focus on male cichlids. Dominant and subordinate social status is typically associated with distinct differences in activity along the entire hypothalamic-pituitary-gonadal axis. Further, when transitions in social status occur between subordinate and dominant individuals, there are plastic changes from whole-organism behavior to molecular-level gene expression modifications that occur quickly. These rapid changes in behavior and physiology have allowed cichlids the flexibility to adapt to and thrive in their often dynamic physical and social environments. Studies in cichlid fishes have, and will continue, to advance our understanding of how the social environment can modulate molecular, cellular, and behavioral outcomes relevant to reproductive success. Future studies that take advantage of the extreme diversity in mating systems, reproductive tactics, and parental care strategies within the cichlid group will help generate hypotheses and careful experimental tests on the mechanisms governing the social control of reproduction in many vertebrates.

  9. Evolution of cichlid vision via trans-regulatory divergence

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    O’Quin Kelly E

    2012-12-01

    Full Text Available Abstract Background Phenotypic evolution may occur through mutations that affect either the structure or expression of protein-coding genes. Although the evolution of color vision has historically been attributed to structural mutations within the opsin genes, recent research has shown that opsin regulatory mutations can also tune photoreceptor sensitivity and color vision. Visual sensitivity in African cichlid fishes varies as a result of the differential expression of seven opsin genes. We crossed cichlid species that express different opsin gene sets and scanned their genome for expression Quantitative Trait Loci (eQTL responsible for these differences. Our results shed light on the role that different structural, cis-, and trans-regulatory mutations play in the evolution of color vision. Results We identified 11 eQTL that contribute to the divergent expression of five opsin genes. On three linkage groups, several eQTL formed regulatory “hotspots” associated with the expression of multiple opsins. Importantly, however, the majority of the eQTL we identified (8/11 or 73% occur on linkage groups located trans to the opsin genes, suggesting that cichlid color vision has evolved primarily via trans-regulatory divergence. By modeling the impact of just two of these trans-regulatory eQTL, we show that opsin regulatory mutations can alter cichlid photoreceptor sensitivity and color vision at least as much as opsin structural mutations can. Conclusions Combined with previous work, we demonstrate that the evolution of cichlid color vision results from the interplay of structural, cis-, and especially trans-regulatory loci. Although there are numerous examples of structural and cis-regulatory mutations that contribute to phenotypic evolution, our results suggest that trans-regulatory mutations could contribute to phenotypic divergence more commonly than previously expected, especially in systems like color vision, where compensatory changes in the

  10. Geographical ancestry of Lake Malawi's cichlid fish diversity

    OpenAIRE

    Genner, Martin J; Ngatunga, Benjamin P.; Mzighani, Semvua; Smith, Alan; Turner, George F

    2015-01-01

    The Lake Malawi haplochromine cichlid flock is one of the largest vertebrate adaptive radiations. The geographical source of the radiation has been assumed to be rivers to the south and east of Lake Malawi, where extant representatives of the flock are now present. Here, we provide mitochondrial DNA evidence suggesting the sister taxon to the Lake Malawi radiation is within the Great Ruaha river in Tanzania, north of Lake Malawi. Estimates of the time of divergence between the Lake Malawi flo...

  11. New record of a fossil haplotilapiine cichlid from Central Kenya

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    Stefanie B. R. Penk

    2015-11-01

    Full Text Available African freshwater cichlids (Cichlidae: Pseudocrenilabrinae are well known for their exceptionally great diversity and their capability of rapid speciation as well as diverse adaptations. The extant Pseudocrenilabrinae can be grouped into 27 tribes, with more than 2000 species harbored in the Great Lakes and surrounding water bodies of the East African Rift System. However, this unique diversity is not reflected in the fossil record because fossil cichlids were predominantly reported based on isolated teeth and bones. Moreover, the few articulated specimens that are known have not been analyzed sufficiently with regard to their systematic position due to lack of comparative material. Here we present a new extraordinarily well-preserved cichlid fish fossil from the Middle Miocene (c. 12.5 Ma Lagerstaette Kabchore, which was recovered during recent fieldwork in the Tugen Hills (Baringo County, Central Kenya Rift. Based on the evidence of tricuspid teeth, the Kabchore fossil can be assigned to the subclade of the Haplotilapiines within the Pseudocrenilabrinae. The multivariate analysis of a large meristic data set, derived from 1014 extant specimens (encompassing all main lineages of Haplotilapiines and usage of available osteological data suggest that this fossil is most likely related to one of the three haplotilapiine tribes Tilapiini, Haplochromini or Oreochromini. Moreover, the fossil specimen closely resembles the extinct cichlid Oreochromis martyni (Van Couvering, 1982, previously described as species of Sarotherodon from the Middle Miocene alkaline Kapkiamu Lake in the Tugen Hills. The analysis of the greatly preserved fossil fish specimen from Kabchore definitely supplements the fragmentary fossil record of Africa’s Cichlidae and will afford new insights into its evolutionary history. We also expect that this fossil will be useful as calibration point for new divergence-time estimates.

  12. Interactions between aggression, boldness and shoaling within a brood of convict cichlids (Amatitlania nigrofasciatus).

    Science.gov (United States)

    Moss, Sarah; Tittaferrante, Stephanie; Way, Gregory P; Fuller, Ashlei; Sullivan, Nicole; Ruhl, Nathan; McRobert, Scott P

    2015-12-01

    A behavioral syndrome is considered present when individuals consistently express correlated behaviors across two or more axes of behavior. These axes of behavior are shy-bold, exploration-avoidance, activity, aggression, and sociability. In this study we examined aggression, boldness and sociability (shoaling) within a juvenile convict cichlid brood (Amatitlania nigrofasciatus). Because young convict cichlids are social, we used methodologies commonly used by ethologists studying social fishes. We did not detect an aggression-boldness behavioral syndrome, but we did find that the aggression, boldness, and possibly the exploration behavioral axes play significant roles in shaping the observed variation in individual convict cichlid behavior. While juvenile convict cichlids did express a shoaling preference, this social preference was likely convoluted by aggressive interactions, despite the small size and young age of the fish. There is a need for the development of behavioral assays that allow for more reliable measurement of behavioral axes in juvenile neo-tropical cichlids.

  13. Microprobing the molecular spatial distribution and structural architecture of feed-type sorghum seed tissue (Sorghum Bicolor L.) using the synchrotron radiation infrared microspectroscopy technique.

    Science.gov (United States)

    Yu, Peiqiang

    2011-09-01

    Sorghum seed (Sorghum bicolor L.) has unique degradation and fermentation behaviours compared with other cereal grains such as wheat, barley and corn. This may be related to its cell and cell-wall architecture. The advanced synchrotron radiation infrared microspectroscopy (SR-IMS) technique enables the study of cell or living cell biochemistry within cellular dimensions. The objective of this study was to use the SR-IMS imaging technique to microprobe molecular spatial distribution and cell architecture of the sorghum seed tissue comprehensively. High-density mapping was carried out using SR-IMS on beamline U2B at the National Synchrotron Light Source (Brookhaven National Laboratory, NY, USA). Molecular images were systematically recorded from the outside to the inside of the seed tissue under various chemical functional groups and their ratios [peaks at ∼1725 (carbonyl C=O ester), 1650 (amide I), 1657 (protein secondary structure α-helix), 1628 (protein secondary structure β-sheet), 1550 (amide II), 1515 (aromatic compounds of lignin), 1428, 1371, 1245 (cellulosic compounds in plant seed tissue), 1025 (non-structural CHO, starch granules), 1246 (cellulosic material), 1160 (CHO), 1150 (CHO), 1080 (CHO), 930 (CHO), 860 (CHO), 3350 (OH and NH stretching), 2960 (CH(3) anti-symmetric), 2929 (CH(2) anti-symmetric), 2877 (CH(3) symmetric) and 2848 cm(-1) (CH(2) asymmetric)]. The relative protein secondary structure α-helix to β-sheet ratio image, protein amide I to starch granule ratio image, and anti-symmetric CH(3) to CH(2) ratio image were also investigated within the intact sorghum seed tissue. The results showed unique cell architecture, and the molecular spatial distribution and intensity in the sorghum seed tissue (which were analyzed through microprobe molecular imaging) were generated using SR-IMS. This imaging technique and methodology has high potential and could be used for scientists to develop specific cereal grain varieties with targeted food and

  14. Monogeneans in introduced and native cichlids in México: evidence for transfer.

    Science.gov (United States)

    Jiménez-García, M I; Vidal-Martínez, V M; López-Jiménez, S

    2001-08-01

    We examined 2 cichlid fish species native to México, Cichlasoma callolepis and C. fenestratum, and 2 introduced African cichlids, Oreochromis aureus and O. niloticus, from 3 localities in southeastern México for monogeneans. Six monogenean species infected the African cichlids: Cichlidogyrus haplochromii, C. dossoui, C. longicornis longicornis, C. sclerosus, C. tilapiae, and Enterogyrus malmbergi. We found all these parasite species, except C. haplochromii and C. dossoui, on the native C. fenestratum and C. callolepis. Prevalences of Cichlidogyrus spp. were 3-10% and abundances ranged from 0.03 +/- 0.2 to 0.1 +/- 0.3 for native cichlids. We only recovered a single E. malmbergi from 1 C. callolepis. We found Sciadicleithrum bravohollisae, a monogenean of native Cichlasoma spp., on the gills of the introduced O. aureus from Lake Catemaco (prevalence 3%, abundance 0.03 +/- 0.2). Although prevalence and abundance in atypical hosts were fairly low, the present findings provide evidence of monogenean transfer from African to American cichlids and vice versa. This is the first record of exotic monogeneans in the genus Cichlidogyrus and Enterogyrus infecting native American cichlid fish. It is also the first record from southeastern México of a native American monogenean infecting introduced African cichlids.

  15. Monogeneans of West African cichlid fish: evolution and cophylogenetic interactions.

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    Monika Mendlová

    Full Text Available The goals of this paper were to investigate phylogenetic and evolutionary patterns of cichlid fish from West Africa and their Cichlidogyrus and Scutogyrus monogenean parasites, to uncover the presence of host-parasite cospeciation and to assess the level of morphological adaptation in parasites. This required the following steps, each one representing specific objectives of this paper: (1 to build phylogenetic trees for Cichlidogyrus and Scutogyrus species based on ribosomal DNA sequences, (2 to investigate phylogenetic relationships within West African cichlid fish based on the analysis of mitochondrial cytochrome b DNA sequences, (3 to investigate host-parasite cophylogenetic history to gain clues on parasite speciation process, and (4 to investigate the link between the morphology of the attachment apparatus and parasite phylogeny. Phylogenetic analyses supported the monophyletic origin of the Cichlidogyrus/Scutogyrus group, and suggested that Cichlidogyrus is polyphyletic and that Scutogyrus is monophyletic. The phylogeny of Cichlidae supported the separation of mouthbrooders and substrate-brooders and is consistent with the hypothesis that the mouthbrooding behavior of Oreochromis and Sarotherodon evolved from substrate-brooding behavior. The mapping of morphological characters of the haptor onto the parasite phylogenetic tree suggests that the attachment organ has evolved from a very simple form to a more complex one. The cophylogenetic analyses indicated a significant fit between trees using distance-based tests, but no significant cospeciation signal using tree-based tests, suggesting the presence of parasite duplications and host switches on related host species. This shed some light on the diversification process of Cichlidogyrus species parasitizing West African cichlids.

  16. Protective Effects of Silymarin Extract on Malthion-Induced Zebra Cichlid (Cichlasoma Nigrofasciatum Hepatotoxicity

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    Mahdi Banaee

    2015-03-01

    Full Text Available Background: There is much evidence indicating that natural substances from edible and medicinal plants possess powerful antioxidant and hepatoprotective activities. The objective of the present study was to investigate the potential hepatoprotective effect of silymarin in fish exposed to malathion. Methods: Zebra cichlid fish were allocated into five groups of which one group received normal feed and served as control. Fish from group 2 were treated with 0.1 mg.L-1 malathion. Fish from group 3 and 4 were fed with enriched diet with 1400 mg and 2100 mg silymarin per 1 kg feed, respectively. While fish from group 5 and 6 were fed with enriched diet with 1400 mg and 2100 mg silymarin per 1 kg feed, respectively and simultaneously were treated with 0.1 mg.L-1 malathion for 15 days. Activities of hepatic enzymes including alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase were evaluated. Oxidative stress was ascertained by measuring malondialdehyde as marker of lipid peroxidation and total cellular antioxidant capacity. Results: Exposure to malathion caused a significant increase in MDA levels and altered AST, ALT, ALP and LDH activities in liver tissues (p<0.05. The hepatic antioxidant capacity was significantly lowered in malathion treated fish as compared to the control group (p<0.05. Treatment with silymarin significantly ameliorated these changes in the malathion-treated groups. Conclusion: These finding demonstrated that silymarin have protective effects against the toxic influence of malathion on the examined biochemical parameters in liver tissue of fish.

  17. Gross morphology and histology of the alimentary tract of the convict cichlid Amatitlania nigrofasciata.

    Science.gov (United States)

    Hopperdietzel, C; Hirschberg, R M; Hünigen, H; Wolter, J; Richardson, K; Plendl, J

    2014-11-01

    The primary objectives of this study were to document the macroscopic and histological structure of the alimentary tract (AT) of the convict cichlid Amatitlania nigrofasciata, because there are no data available for this omnivorous freshwater fish of the family Cichlidae. The morphology of the AT of A. nigrofasciata resembles that of related species. While having morphological criteria of the AT typical of most omnivorous fishes, such as a blind sac stomach and medium length intestine, A. nigrofasciata also has some structural peculiarities: the oesophagus is lined by a uniform stratified squamous epithelial layer with interspersed goblet cells along its entire length. Additionally, it has well-developed layers of the tunica muscularis including muscle fibre bundles that ascend into its mucosal folds. Occasionally, taste buds are present. In the transitional area between oesophagus and stomach, a prominent torus-like closure device is present. The mucosa of the stomach cannot be divided into different regions according to mucosal and morphological properties. The simple pattern of intestinal loops of A. nigrofasciata has few variations, irrespective of sex, mass and length of the individual fish. The first segment of the intestine is characterized by the largest mucososerosal ratio and the most complex mucosal surface architecture. A distinction of midgut and hindgut was not possible in A. nigrofasciata due to lack of defining structural components as described for other fish species.

  18. Rearing-group size determines social competence and brain structure in a cooperatively breeding cichlid.

    Science.gov (United States)

    Fischer, Stefan; Bessert-Nettelbeck, Mathilde; Kotrschal, Alexander; Taborsky, Barbara

    2015-07-01

    Social animals can greatly benefit from well-developed social skills. Because the frequency and diversity of social interactions often increase with the size of social groups, the benefits of advanced social skills can be expected to increase with group size. Variation in social skills often arises during ontogeny, depending on early social experience. Whether variation of social-group sizes affects development of social skills and related changes in brain structures remains unexplored. We investigated whether, in a cooperatively breeding cichlid, early group size (1) shapes social behavior and social skills and (2) induces lasting plastic changes in gross brain structures and (3) whether the development of social skills is confined to a sensitive ontogenetic period. Rearing-group size and the time juveniles spent in these groups interactively influenced the development of social skills and the relative sizes of four main brain regions. We did not detect a sensitive developmental period for the shaping of social behavior within the 2-month experience phase. Instead, our results suggest continuous plastic behavioral changes over time. We discuss how developmental effects on social behavior and brain architecture may adaptively tune phenotypes to their current or future environments.

  19. Ecology and life history of an Amazon floodplain cichlid: the discus fish Symphysodon (Perciformes: Cichlidae

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    William G. R. Crampton

    Full Text Available The discus fishes of the genus Symphysodon are popular ornamental cichlids that occur in floodplain lakes and flooded forests of the lowland Amazon Basin. These habitats are characterized by extreme seasonal fluctuations in the availability of food, shelter and dissolved oxygen, and also the densities of predators and parasites. Most aspects of discus biology are influenced by these fluctuating conditions. This paper reports an autoecological study of the western Amazonian discus S. haraldi (until recently classified as S. aequifasciatus. This species feeds predominantly on algal periphyton, fine organic detritus, plant matter, and small aquatic invertebrates. At high water it forages alone or in small groups in flooded forests. At low water it forms large aggregations in fallen tree crowns along lake margins. Breeding occurs at the beginning of the flood season, ensuring that the progeny are well grown before the next low water period. Symphysodon haraldi is an iteroparous partial spawner, reaches reproductive maturity within a year, and undertakes parental care of its eggs and larvae. The timing of spawning events, and/or the rate of brood survival, may be influenced by fluctuations in the flood level, resulting in a non-unimodal distribution of size classes for the subsequent 1+ cohort.

  20. 自适应前馈神经网络结构优化设计%An adaptive algorithm for designing optimal feed-forward neural network architecture

    Institute of Scientific and Technical Information of China (English)

    张昭昭; 乔俊飞; 杨刚

    2011-01-01

    针对多数前馈神经网络结构设计算法采取贪婪搜索策略而易陷入局部最优结构的问题,提出一种自适应前馈神经网络结构设计算法.该算法在网络训练过程中采取自适应寻优策略合并和分裂隐节点,达到设计最优神经网络结构的目的.在合并操作中,以互信息为准则对输出线性相关的隐节点进行合并;在分裂操作中,引入变异系数,有助于跳出局部最优网络结构.算法将合并和分裂操作之后的权值调整与网络对样本的学习过程结合,减少了网络对样本的学习次数,提高了网络的学习速度,增强了网络的泛化性能.非线性函数逼近结果表明,所提算法能得到更小的检测误差,最终网络结构紧凑.%Due to the fact that most algorithms use a greedy strategy in designing artificial neural networks which are susceptible to becoming trapped at the architectural local optimal point, an adaptive algorithm for designing an optimal feed-forward neural network was proposed. During the training process of the neural network, the adaptive optimization strategy was adopted to merge and split the hidden unit to design optimal neural network architecture. In the merge operation, the hidden units were merged based on mutual information criterion. In the split operation, a mutation coefficient was introduced to help jump out of locally optimal network. The process of adjusting the connection weight after merge and split operations was combined with the process of training the neural network. Therefore, the number of training samples was reduced, the training speed was increased, and the generalization performance was improved. The results of approximating non-linear functions show that the proposed algorithm can limit testing errors and a compact neural network structure.

  1. Intraspecific sexual selection on a speciation trait, male coloration, in the Lake Victoria cichlid Pundamilia nyererei

    NARCIS (Netherlands)

    Maan, ME; Seehausen, O; Soderberg, L; Johnson, L; Ripmeester, EAP; Mrosso, HDJ; Taylor, MI; van Dooren, TJM; van Alphen, JJM

    2004-01-01

    The haplochromine cichlids of Lake Victoria constitute a classical example of explosive speciation. Extensive intra- and interspecific variation in male nuptial coloration and female mating preferences, in the absence of postzygotic isolation between species, has inspired the hypothesis that sexual

  2. Repeatability and Heritability of Behavioural Types in a Social Cichlid

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    Noémie Chervet

    2011-01-01

    Full Text Available Aim. The quantitative genetics underlying correlated behavioural traits (‘‘animal personality’’ have hitherto been studied mainly in domesticated animals. Here we report the repeatability ( and heritability (ℎ2 of behavioural types in the highly social cichlid fish Neolamprologus pulcher. Methods. We tested 1779 individuals repeatedly and calculated the ℎ2 of behavioural types by variance components estimation (GLMM REML, using 1327 offspring from 162 broods from 74 pairs. Results. Repeatability of behavioural types was significant and considerable (0.546, but declined from 0.83 between tests conducted on the same day, to 0.19 on tests conducted up to 1201 days apart. All ℎ2 estimates were significant but low (e.g., pair identity ℎ2=0.15±0.03 SE. Additionally, we found significant variation between broods nested within the parent(s, but these were not related to several environmental factors tested. Conclusions. We conclude that despite a considerable , ℎ2 in this cichlid species is low, and variability in behavioural type appears to be strongly affected by other (nongenetic effects.

  3. MHC adaptive divergence between closely related and sympatric African cichlids.

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    Jonatan Blais

    Full Text Available BACKGROUND: The haplochromine cichlid species assemblages of Lake Malawi and Victoria represent some of the most important study systems in evolutionary biology. Identifying adaptive divergence between closely-related species can provide important insights into the processes that may have contributed to these spectacular radiations. Here, we studied a pair of sympatric Lake Malawi species, Pseudotropheus fainzilberi and P. emmiltos, whose reproductive isolation depends on olfactory communication. We tested the hypothesis that these species have undergone divergent selection at MHC class II genes, which are known to contribute to olfactory-based mate choice in other taxa. METHODOLOGY/PRINCIPAL FINDINGS: Divergent selection on functional alleles was inferred from the higher genetic divergence at putative antigen binding sites (ABS amino acid sequences than at putatively neutrally evolving sites at intron 1, exon 2 synonymous sequences and exon 2 amino acid residues outside the putative ABS. In addition, sympatric populations of these fish species differed significantly in communities of eukaryotic parasites. CONCLUSIONS/SIGNIFICANCE: We propose that local host-parasite coevolutionary dynamics may have driven adaptive divergence in MHC alleles, influencing odor-mediated mate choice and leading to reproductive isolation. These results provide the first evidence for a novel mechanism of adaptive speciation and the first evidence of adaptive divergence at the MHC in closely related African cichlid fishes.

  4. The interaction of sexually and naturally selected traits in the adaptive radiations of cichlid fishes.

    Science.gov (United States)

    Salzburger, Walter

    2009-01-01

    The question of how genetic variation translates into organismal diversity has puzzled biologists for decades. Despite recent advances in evolutionary and developmental genetics, the mechanisms that underlie adaptation, diversification and evolutionary innovation remain largely unknown. The exceptionally diverse species flocks of cichlid fishes are textbook examples of adaptive radiation and explosive speciation and emerge as powerful model systems to study the genetic basis of animal diversification. East Africa's hundreds of endemic cichlid species are akin to a natural mutagenesis screen and differ greatly not only in ecologically relevant (hence naturally selected) characters such as mouth morphology and body shape, but also in sexually selected traits such as coloration. One of the most fascinating aspects of cichlid evolution is the frequent occurrence of evolutionary parallelisms, which has led to the question whether selection alone is sufficient to produce these parallel morphologies, or whether a developmental or genetic bias has influenced the direction of diversification. Here, I review fitness-relevant traits that could be responsible for the cichlids' evolutionary success and assess whether these were shaped by sexual or natural selection. I then focus on the interaction and the relative importance of sexual vs. natural selection in cichlid evolution. Finally, I discuss what is currently known about the genes underlying the morphogenesis of adaptively relevant traits and highlight the importance of the forthcoming cichlid genomes in the quest of the genetic basis of diversification in this group.

  5. Evolution of bower building in Lake Malawi cichlid fish: Phylogeny, morphology, and behavior

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    Ryan eYork

    2015-03-01

    Full Text Available Despite considerable research, we still know little about the proximate and ultimate causes behind behavioral evolution. This is partly because understanding the forces acting on behavioral phenotypes requires the study of species-rich clades with extensive variation in behavioral traits, of which we have few current examples. In this paper, we introduce the bower-building cichlids of the Lake Malawi adaptive radiation, a lineage with over 100 species, each possessing a distinct male extended phenotype used to signal reproductive fitness. Extended phenotypes are useful units of analysis for the study of behavior since they are static structures that can be precisely measured within populations. To this end we recognize two core types of bowers - mounds (castles and depressions (pits. We employ an established framework for the study of adaptive radiations to ask how traits related to other stages of radiations, macrohabitat and feeding morphology, are associated with the evolution of pit and castle phenotypes. We demonstrate that pits and castles are evolutionarily labile traits and have been derived numerous times in multiple Malawi genera. Using public ecological and phenotypic data sets we find significant and correlated differences in macrohabitat (depth, sensory ability (opsin expression, and feeding style (jaw morphology and biomechanics between pit-digging and castle-building species. Phylogeny-corrected comparisons also show significant differences in several measures of jaw morphology while indicating non-significant differences in depth. Finally, using laboratory observations we assay courtship behaviors in a pit-digging (Copadichromis virginalis and a castle-building species (Mchenga conophoros. Together, these results show that traits at multiple biological levels act to regulate the evolution of a courtship behavior within natural populations.

  6. Novel insight into the genomic architecture of feed and nitrogen efficiency measured by residual energy intake and nitrogen excretion in growing pigs

    NARCIS (Netherlands)

    Shirali, M.; Duthie, C.A.; Doeschl-Wilson, A.; Knap, P.W.; Kanis, E.; Arendonk, van J.A.M.; Roehe, R.

    2013-01-01

    Background Improvement of feed efficiency in pigs is of great economical and environmental interest and contributes to use limited resources efficiently to feed the world population. Genome scans for feed efficiency traits are of importance to reveal the underlying biological causes and increase the

  7. Ancient hybridization fuels rapid cichlid fish adaptive radiations

    Science.gov (United States)

    Meier, Joana I.; Marques, David A.; Mwaiko, Salome; Wagner, Catherine E.; Excoffier, Laurent; Seehausen, Ole

    2017-01-01

    Understanding why some evolutionary lineages generate exceptionally high species diversity is an important goal in evolutionary biology. Haplochromine cichlid fishes of Africa's Lake Victoria region encompass >700 diverse species that all evolved in the last 150,000 years. How this ‘Lake Victoria Region Superflock' could evolve on such rapid timescales is an enduring question. Here, we demonstrate that hybridization between two divergent lineages facilitated this process by providing genetic variation that subsequently became recombined and sorted into many new species. Notably, the hybridization event generated exceptional allelic variation at an opsin gene known to be involved in adaptation and speciation. More generally, differentiation between new species is accentuated around variants that were fixed differences between the parental lineages, and that now appear in many new combinations in the radiation species. We conclude that hybridization between divergent lineages, when coincident with ecological opportunity, may facilitate rapid and extensive adaptive radiation. PMID:28186104

  8. The impact of the geologic history and paleoclimate on the diversification of East african cichlids.

    Science.gov (United States)

    Danley, Patrick D; Husemann, Martin; Ding, Baoqing; Dipietro, Lyndsay M; Beverly, Emily J; Peppe, Daniel J

    2012-01-01

    The cichlid fishes of the East African Great Lakes are the largest extant vertebrate radiation identified to date. These lakes and their surrounding waters support over 2,000 species of cichlid fish, many of which are descended from a single common ancestor within the past 10 Ma. The extraordinary East African cichlid diversity is intricately linked to the highly variable geologic and paleoclimatic history of this region. Greater than 10 Ma, the western arm of the East African rift system began to separate, thereby creating a series of rift basins that would come to contain several water bodies, including the extremely deep Lakes Tanganyika and Malawi. Uplifting associated with this rifting backponded many rivers and created the extremely large, but shallow Lake Victoria. Since their creation, the size, shape, and existence of these lakes have changed dramatically which has, in turn, significantly influenced the evolutionary history of the lakes' cichlids. This paper reviews the geologic history and paleoclimate of the East African Great Lakes and the impact of these forces on the region's endemic cichlid flocks.

  9. Social status, breeding state, and GnRH soma size in convict cichlids (Cryptoheros nigrofasciatus).

    Science.gov (United States)

    Chee, San-San Amy; Espinoza, Walter A S; Iwaniuk, Andrew N; Pakan, Janelle M P; Gutiérrez-Ibáñez, Cristian; Wylie, Douglas R; Hurd, Peter L

    2013-01-15

    Gonadotropin-releasing hormone (GnRH) expressing neurons in the preoptic area (POA) of the hypothalamus plays a key role in regulating reproductive function through the control of gonadotropin release. Several studies have illustrated the importance of the social environment in modulating the size of GnRH expressing neurons. In the African cichlid fish Astatotilapia burtoni, the size of the soma of GnRH expressing neurons in the POA varies with social status in males, and with breeding state in females. Territorial males have larger GnRH+ cells than non-territorial males, while brooder females have smaller GnRH+ cells than control females. The lek-like breeding system of A. burtoni is, however, only one type of social system within the diverse assemblage of cichlids. To gain a better understanding of GnRH neuronal plasticity in response to the changes in the social environment, we tested whether similar effects occur in the monogamous New World cichlid, the convict cichlid (Cryptoheros nigrofasciatus), a model species for the study of social behaviour. Our results indicate that, indeed GnRH expressing neuron soma size, and not cell number, varies with both male territorial status, and manipulations of female breeding state in this monogamous, biparental, New World cichlid.

  10. Extraordinarily long sperm in the socially monogamous cichlid fish Pelvicachromis taeniatus

    Science.gov (United States)

    Thünken, Timo; Bakker, Theo C. M.; Kullmann, Harald

    2007-06-01

    The main function of the spermatozoon is the transfer of the male haploid genome during fertilisation. In animals in general and in fishes in particular, there is huge variation in sperm size. In fishes, sperm size ranges from 13 μm in Mugil cephlus to nearly 100 μm in the channel catfish Ictalurus punctatus. We examined intra-specific variation in sperm morphometry in the socially monogamous cichlid Pelvicachromis taeniatus using scanning electron microscopy. The mean total sperm length of nearly 70 μm was extraordinarily large for cichlids. Furthermore, within-male variation was remarkably high. To our knowledge, P. taeniatus produces the longest cichlid sperm ever documented. Several hypotheses concerning the adaptive significance of these results are presented.

  11. Divergence in cis-regulatory sequences surrounding the opsin gene arrays of African cichlid fishes

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    Streelman J Todd

    2011-05-01

    Full Text Available Abstract Background Divergence within cis-regulatory sequences may contribute to the adaptive evolution of gene expression, but functional alleles in these regions are difficult to identify without abundant genomic resources. Among African cichlid fishes, the differential expression of seven opsin genes has produced adaptive differences in visual sensitivity. Quantitative genetic analysis suggests that cis-regulatory alleles near the SWS2-LWS opsins may contribute to this variation. Here, we sequence BACs containing the opsin genes of two cichlids, Oreochromis niloticus and Metriaclima zebra. We use phylogenetic footprinting and shadowing to examine divergence in conserved non-coding elements, promoter sequences, and 3'-UTRs surrounding each opsin in search of candidate cis-regulatory sequences that influence cichlid opsin expression. Results We identified 20 conserved non-coding elements surrounding the opsins of cichlids and other teleosts, including one known enhancer and a retinal microRNA. Most conserved elements contained computationally-predicted binding sites that correspond to transcription factors that function in vertebrate opsin expression; O. niloticus and M. zebra were significantly divergent in two of these. Similarly, we found a large number of relevant transcription factor binding sites within each opsin's proximal promoter, and identified five opsins that were considerably divergent in both expression and the number of transcription factor binding sites shared between O. niloticus and M. zebra. We also found several microRNA target sites within the 3'-UTR of each opsin, including two 3'-UTRs that differ significantly between O. niloticus and M. zebra. Finally, we examined interspecific divergence among 18 phenotypically diverse cichlids from Lake Malawi for one conserved non-coding element, two 3'-UTRs, and five opsin proximal promoters. We found that all regions were highly conserved with some evidence of CRX transcription

  12. Social familiarity modulates personality trait in a cichlid fish

    Science.gov (United States)

    Galhardo, L.; Vitorino, A.; Oliveira, R. F.

    2012-01-01

    Personality traits, such as exploration–avoidance, are expected to be adaptive in a given context (e.g. low-risk environment) but to be maladaptive in others (e.g. high-risk environment). Therefore, it is expected that personality traits are flexible and respond to environmental fluctuations, given that consistency across different contexts is maintained, so that the relative individual responses in relation to others remains the same (i.e. although the magnitude of the response varies the differences between high and low responders are kept). Here, we tested the response of male cichlid fish (Oreochromis mossambicus) to a novel object (NO) in three different social contexts: (i) social isolation, (ii) in the presence of an unfamiliar conspecific, and (iii) in the presence of a familiar conspecific. Males in the familiar treatment exhibited more exploratory behaviour and less neophobia than males in either the unfamiliar or the social isolation treatments. However, there were no overall correlations in individual behaviour across the three treatments, suggesting a lack of consistency in exploration–avoidance as measured by the NO test in this species. Moreover, there were no differences in cortisol responsiveness to an acute stressor between the three treatments. Together, these results illustrate how behavioural traits usually taken as measures of personality may exhibit significant flexibility and lack the expected consistency across different social contexts. PMID:22859562

  13. Ontogenesis of agonistic vocalizations in the cichlid fish Metriaclima zebra.

    Science.gov (United States)

    Bertucci, Frédéric; Scaion, Delphine; Beauchaud, Marilyn; Attia, Joël; Mathevon, Nicolas

    2012-08-01

    While acoustic communication has been described in adults of various fish species, our knowledge about the ontogeny of fish sound production is limited. In adults, sound signals are known to be involved during aggressive interactions. However, aggressive behaviour may appear early in the life of fishes due to the possible competition for food and space. If acoustic signals are used to send information to competitors, sounds are likely to play a role during interactions between juvenile fish as well. The apparition and evolution of sound production were monitored in a group of juveniles of the cichlid fish Metriaclima zebra from hatching to 4 months of age. In addition, the link between vocalizations and agonistic behaviour was studied during dyadic interactions at three different ages. Sounds production appeared to be present early in the development of this fish and increased along with the number of aggressive behaviours. Recorded sounds consisted, in juveniles, in isolated pulses showing a decrease in frequency and duration as the fish grew. In adults, sounds became bursts of pulses but the transition from isolated to repetitive pulses was not observed. These results are compared to the existing literature on sound production ontogeny in fishes.

  14. Parasitic infections in ornamental cichlid fish in the Peruvian Amazon.

    Science.gov (United States)

    Aguinaga, Jefferson Yunis; Marcusso, Paulo Fernandes; Claudiano, Gustavo da Silva; Lima, Bruno Tadeu Marotta; Marotta, Bruno L; Sebastião, Fernanda de Alexandre; Fernandes, João Batista Kochenborger; de Moraes, Flávio Ruas; de Moraes, Julieta Rodini Engracia

    2015-01-01

    The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57%) was the most parasitized, followed by Aequidens diadema (26.32%), Pterophyllum scalare (22.69%), Cichlasoma sp. (9.52%), Apistogramma sp. (3.88%) and Symphysodon aequifasciatus (3.66%). Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

  15. Parasitic infections in ornamental cichlid fish in the Peruvian Amazon

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    Jefferson Yunis Aguinaga

    Full Text Available The aim of this study was to evaluate the prevalence and seasonal distribution of the main parasite species in Amazonian ornamental cichlids that affect their trade. The study was conducted from August 2007 to September 2009. We sampled 3042 specimens from 9 different species, of which 9.47% had at least one type of external parasite. 81.25% of the cases occurred in the dry season. Crenicichla anthurus (28.57% was the most parasitized, followed by Aequidens diadema (26.32%, Pterophyllum scalare (22.69%, Cichlasoma sp. (9.52%, Apistogramma sp. (3.88% and Symphysodon aequifasciatus (3.66%. Monogenea was the most abundant group of parasites, occurring in 66.67% of the cases, of which 96.88% occurred in the dry season. This parasite infested 95.68% of Pterophyllum scalare, 76.67% of Apistogramma sp, 33.33% of Cichlasoma sp. and 23.81% of Symphysodon aequifasciatus cases. Ichthyophthirius multifiliis infested 100% of Aequidens diadema, 76.19% of Symphysodon aequifasciatus, 66.67% of Cichlasoma sp, 41.67% of Crenicichla anthurus and 23.33% of Apistogramma sp cases. Myxosporidia infested 58.33% of Crenicichla anthurus. Trichodina infested 4.32% of Pterophyllum scalare. The prevalence of these parasites is related to the season, preferred habitat, fish behavior, individual susceptibility and handling of animals during transportation by fishermen.

  16. Paternity of subordinates raises cooperative effort in cichlids.

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    Rick Bruintjes

    Full Text Available BACKGROUND: In cooperative breeders, subordinates generally help a dominant breeding pair to raise offspring. Parentage studies have shown that in several species subordinates can participate in reproduction. This suggests an important role of direct fitness benefits for cooperation, particularly where groups contain unrelated subordinates. In this situation parentage should influence levels of cooperation. Here we combine parentage analyses and detailed behavioural observations in the field to study whether in the highly social cichlid Neolamprologus pulcher subordinates participate in reproduction and if so, whether and how this affects their cooperative care, controlling for the effect of kinship. METHODOLOGY/PRINCIPAL FINDINGS: We show that: (i male subordinates gained paternity in 27.8% of all clutches and (ii if they participated in reproduction, they sired on average 11.8% of young. Subordinate males sharing in reproduction showed more defence against experimentally presented egg predators compared to subordinates not participating in reproduction, and they tended to stay closer to the breeding shelter. No effects of relatedness between subordinates and dominants (to mid-parent, dominant female or dominant male were detected on parentage and on helping behaviour. CONCLUSIONS/SIGNIFICANCE: This is the first evidence in a cooperatively breeding fish species that the helping effort of male subordinates may depend on obtained paternity, which stresses the need to consider direct fitness benefits in evolutionary studies of helping behaviour.

  17. Spawning Coordination of Mates in a Shell Brooding Cichlid

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    Dolores Schütz

    2012-01-01

    Full Text Available Aim. External fertilisation requires synchronisation of gamete release between the two sexes. Adequate synchronisation is essential in aquatic media because sperm is very short-lived in water. In the cichlid Lamprologus callipterus, fertilisation of the eggs takes place inside an empty snail shell, where females stay inside the shell and males have to ejaculate into the shell opening. This spawning pattern makes the coordination of gamete release difficult. Methods. This study examined the synchronisation of males and females during egg laying. Results. The results showed that the male initiates each spawning sequence and that sperm release and egg laying are very well synchronised. 68% of all sperm releases occurred at exactly the same time when the female laid an egg, and 99% of ejaculations occurred within ±5 seconds from egg deposition. On average 95 eggs are laid one by one with intervals of several minutes between subsequent eggs, leading to a total spawning duration in excess of six hours. Conclusions. We discuss this exceptional spawning pattern and how it might reflect a conflict between the sexes, with males attempting to induce egg laying and females extending the egg laying period to raise the chance for parasitic males to participate in spawning.

  18. Architecture on Architecture

    DEFF Research Database (Denmark)

    Olesen, Karen

    2016-01-01

    This paper will discuss the challenges faced by architectural education today. It takes as its starting point the double commitment of any school of architecture: on the one hand the task of preserving the particular knowledge that belongs to the discipline of architecture, and on the other hand...... that is not scientific or academic but is more like a latent body of data that we find embedded in existing works of architecture. This information, it is argued, is not limited by the historical context of the work. It can be thought of as a virtual capacity – a reservoir of spatial configurations that can...... the autonomy of architecture, not as an esoteric concept but as a valid source of information in a pragmatic design practice, may help us overcome the often-proclaimed dichotomy between formal autonomy and a societally committed architecture. It follows that in architectural education there can be a close...

  19. Acquisition of Lateralized Predation Behavior Associated with Development of Mouth Asymmetry in a Lake Tanganyika Scale-Eating Cichlid Fish.

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    Yuichi Takeuchi

    Full Text Available The scale-eating cichlid Perissodus microlepis with asymmetric mouth is an attractive model of behavioral laterality: each adult tears off scales from prey fishes' left or right flanks according to the direction in which its mouth is skewed. To investigate the development of behavioral laterality and mouth asymmetry, we analyzed stomach contents and lower jaw-bone asymmetry of various-sized P. microlepis (22 ≤ SL<115 mm sampled in Lake Tanganyika. The shapes of the pored scales found in each specimen's stomach indicated its attack side preference. Early-juvenile specimens (SL<45 mm feeding mainly on zooplankton exhibited slight but significant mouth asymmetry. As the fish acquired scale-eating (45 mm ≤ SL, attack side preference was gradually strengthened, as was mouth asymmetry. Among size-matched individuals, those with more skewed mouths ate more scales. These findings show that behavioral laterality in scale-eating P. microlepis is established in association with development of mouth asymmetry which precedes the behavioral acquisition, and that this synergistic interaction between physical and behavioral literalities may contribute to efficient scale-eating.

  20. Frequency-Dependent Social Dominance in a Color Polymorphic Cichlid Fish

    NARCIS (Netherlands)

    Dijkstra, Peter; Lindström, Jan; Metcalfe, Neil B.; Hemelrijk, Charlotte K.; Brendel, Mischa; Seehausen, Ole; Groothuis, Ton G.G.

    2010-01-01

    A mechanism commonly suggested to explain the persistence of color polymorphisms in animals is negative frequency-dependent selection. It could result from a social dominance advantage to rare morphs. We tested for this in males of red and blue color morphs of the Lake Victoria cichlid, Pundamilia.

  1. Habitat structure directly affects aggression in convict cich-lids Archocentrus nigrofasciatus

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    Anthony J. BARLEY, Ronald M. COLEMAN

    2010-02-01

    Full Text Available Aggressive behavior can be an important factor in determining how animals use and divide space and resources. Previous studies have shown that aggression in fishes can be influenced by a variety of factors, including water temperature and resource levels. In this study, we tested if the amount of habitat structure in the environment affected aggression levels in female convict cichlids Archocentrus nigrofasciatus. We performed a laboratory experiment in which we placed female convict cichlids into an aquarium with low or high amounts of habitat structure and monitored the dominant female's behavior toward the subordinate female. Aggressive behavior in convict cichlids primarily consists of chases and bites. We found that the total time the dominant female spent chasing the subordinate female was greater when there was a low amount of habitat structure as compared to when there was a high amount of habitat structure. We also found that both the average duration of a chasing bout and the number of bites directed at the subordinate fish increased when there was a low amount of structure, but the number of chases did not. These results indicate that increased habitat structural complexity decreases aggressive behavior in convict cichlids [Current Zoology 56 (1: 52–56, 2010].

  2. Divergent mating preferences and nuptial coloration in sibling species of cichlid fish

    NARCIS (Netherlands)

    Sluijs, Inke van der

    2008-01-01

    Mate choice by female cichlid fish from Lake Victoria plays an important role in speciation and the maintenance of species. Females are expected to select against males that are intermediate in their phenotype during the process of speciation driven by sexual selection. To test this, we hybridized t

  3. Notes on the Fishes of the Cichlid Family I. Apistogramma cacatuoides sp. n

    NARCIS (Netherlands)

    Hoedeman, J.J.

    1951-01-01

    The Dwarf-cichlid genus Apistogramma, very popular among aquarists and at present among students of animal behaviour, hitherto comprises about 16 forms, several of them hardly specifically distinguished, and probably only based on stages or sexes of other species. Nevertheless I found a new form amo

  4. An Evaluation of the Role of Sensory Drive in the Evolution of Lake Malawi Cichlid Fishes

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    Adam R. Smith

    2012-01-01

    Full Text Available Although the cichlids of Lake Malawi are an important model system for the study of sensory evolution and sexual selection, the evolutionary processes linking these two phenomena remain unclear. Prior works have proposed that evolutionary divergence is driven by sensory drive, particularly as it applies to the visual system. While evidence suggests that sensory drive has played a role in the speciation of Lake Victoria cichlids, the findings from several lines of research on cichlids of Lake Malawi are not consistent with the primary tenets of this hypothesis. More specifically, three observations make the sensory drive model implausible in Malawi: (i a lack of environmental constraint due to a broad and intense ambient light spectrum in species rich littoral habitats, (ii pronounced variation in receiver sensory characteristics, and (iii pronounced variability in male courtship signal characteristics. In the following work, we synthesize the results from recent studies to draw attention to the importance of sensory variation in cichlid evolution and speciation, and we suggest possible avenues of future research.

  5. Molecular phylogeny and revised classification of the haplotilapiine cichlid fishes formerly referred to as "Tilapia".

    Science.gov (United States)

    Dunz, Andreas R; Schliewen, Ulrich K

    2013-07-01

    African cichlids formerly referred to as "Tilapia" represent a paraphyletic species assemblage belonging to the so called haplotilapiine lineage which gave rise to the spectacular East African cichlid radiations (EARs) as well as to globally important aquaculture species. We present a comprehensive molecular phylogeny of representative haplotilapiine cichlids, combining in one data set four mitochondrial and five nuclear loci for 76 species, and compare it with phylogenetic information of a second data set of 378 mitochondrial ND2 haplotypes representing almost all important "Tilapia" or Tilapia-related lineages as well as most EAR lineages. The monophyly of haplotilapiines is supported, as is the nested sister group relationship of Etia and mouthbrooding tilapiines with the remaining haplotilapiines. The latter are consistently placed in eight monophyletic clades over all datasets and analyses, but several dichotomous phylogenetic relationships appear compromised by cytonuclear discordant phylogenetic signal. Based on these results as well as on extensive morphological evidence we propose a novel generic and suprageneric classification including a (re-)diagnosis of 20 haplotilapiine cichlid genera and nine tribes. New tribes are provided for the former subgenera Coptodon Gervais, 1853, HeterotilapiaRegan, 1920 and PelmatolapiaThys van den Audenaerde, 1969, in addition for "Tilapia" joka, Tilapia sensu stricto and Chilochromis, Etia, Steatocranus sensu stricto, the mouthbrooding tilapiines and for a clade of West African tilapiines.

  6. On gonads and reproductive behaviour in the cichlid fish Aequidens portalegrensis (Hensel)

    NARCIS (Netherlands)

    Polder, Johan Jan Willem

    1971-01-01

    In this paper on the cichlid fish Aequidensp ortalegrensis,in formation is given on 1) the anatomy and histology of the gonads, 2) the functional anatomy of the accessory organs, 3) the occurrence of cyclical changes in the gonads, 4) the mutual behaviour of male and female under different condition

  7. Large group size yields group stability in the cooperatively breeding cichlid Neolamprologus pulcher

    NARCIS (Netherlands)

    Heg, D; Bachar, Z; Taborsky, M

    2005-01-01

    Group size has been shown to positively influence survival of group members in many cooperatively breeding vertebrates, including the Lake Tanganyika cichlid Neolamprologus pulcher, suggesting Allee effects. However, long-term data are scarce to test how these survival differences translate into cha

  8. Sexual conflict over breeding substrate causes female expulsion and offspring loss in a cichlid fish

    NARCIS (Netherlands)

    Maan, Martine E.; Taborsky, Michael

    2008-01-01

    Females of the Lake Tanganyika cichlid Lamprologus callipterus exclusively breed in empty snail shells that males collect in their territories. Male-male competition for shells is severe, leading to frequent shell stealing and territory takeover. As a consequence, males have breeding females in thei

  9. Colour variation in cichlid fish : Developmental mechanisms, selective pressures and evolutionary consequences

    NARCIS (Netherlands)

    Maan, Martine E.; Sefc, Kristina M.

    2013-01-01

    Cichlid fishes constitute one of the most species-rich families of vertebrates. In addition to complex social behaviour and morphological versatility, they are characterised by extensive diversity in colouration, both within and between species. Here, we review the cellular and molecular mechanisms

  10. Female mating preferences and male coloration covary with water transparency in a Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Maan, Martine E.; Seehausen, Ole; Van Alphen, Jacques J. M.

    2010-01-01

    Rapid speciation in Lake Victoria cichlid fish of the genus Pundamilia may be facilitated by sexual selection: female mate choice exerts sexual selection on male nuptial coloration within species and maintains reproductive isolation between species. However, declining water transparency coincides wi

  11. Mitogenomic evaluation of the historical biogeography of cichlids toward reliable dating of teleostean divergences

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    Miya Masaki

    2008-07-01

    Full Text Available Abstract Background Recent advances in DNA sequencing and computation offer the opportunity for reliable estimates of divergence times between organisms based on molecular data. Bayesian estimations of divergence times that do not assume the molecular clock use time constraints at multiple nodes, usually based on the fossil records, as major boundary conditions. However, the fossil records of bony fishes may not adequately provide effective time constraints at multiple nodes. We explored an alternative source of time constraints in teleostean phylogeny by evaluating a biogeographic hypothesis concerning freshwater fishes from the family Cichlidae (Perciformes: Labroidei. Results We added new mitogenomic sequence data from six cichlid species and conducted phylogenetic analyses using a large mitogenomic data set. We found a reciprocal monophyly of African and Neotropical cichlids and their sister group relationship to some Malagasy taxa (Ptychochrominae sensu Sparks and Smith. All of these taxa clustered with a Malagasy + Indo/Sri Lankan clade (Etroplinae sensu Sparks and Smith. The results of the phylogenetic analyses and divergence time estimations between continental cichlid clades were much more congruent with Gondwanaland origin and Cretaceous vicariant divergences than with Cenozoic transmarine dispersal between major continents. Conclusion We propose to add the biogeographic assumption of cichlid divergences by continental fragmentation as effective time constraints in dating teleostean divergence times. We conducted divergence time estimations among teleosts by incorporating these additional time constraints and achieved a considerable reduction in credibility intervals in the estimated divergence times.

  12. The species flocks of East African cichlid fishes: recent advances in molecular phylogenetics and population genetics

    Science.gov (United States)

    Salzburger, Walter; Meyer, Axel

    With more than 3,000 species, the fish family Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central America, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive radiations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been something of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hundreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayr's analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this problem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be monophyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in

  13. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes.

    Science.gov (United States)

    Yoshida, Kohta; Terai, Yohey; Mizoiri, Shinji; Aibara, Mitsuto; Nishihara, Hidenori; Watanabe, Masakatsu; Kuroiwa, Asato; Hirai, Hirohisa; Hirai, Yuriko; Matsuda, Yoichi; Okada, Norihiro

    2011-08-01

    The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85%) in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb) revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  14. B chromosomes have a functional effect on female sex determination in Lake Victoria cichlid fishes.

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    Kohta Yoshida

    2011-08-01

    Full Text Available The endemic cichlid fishes in Lake Victoria are a model system for speciation through adaptive radiation. Although the evolution of the sex-determination system may also play a role in speciation, little is known about the sex-determination system of Lake Victoria cichlids. To understand the evolution of the sex-determination system in these fish, we performed cytogenetic analysis in 11 cichlid species from Lake Victoria. B chromosomes, which are present in addition to standard chromosomes, were found at a high prevalence rate (85% in these cichlids. In one species, B chromosomes were female-specific. Cross-breeding using females with and without the B chromosomes demonstrated that the presence of the B chromosomes leads to a female-biased sex ratio in this species. Although B chromosomes were believed to be selfish genetic elements with little effect on phenotype and to lack protein-coding genes, the present study provides evidence that B chromosomes have a functional effect on female sex determination. FISH analysis using a BAC clone containing B chromosome DNA suggested that the B chromosomes are derived from sex chromosomes. Determination of the nucleotide sequences of this clone (104.5 kb revealed the presence of several protein-coding genes in the B chromosome, suggesting that B chromosomes have the potential to contain functional genes. Because some sex chromosomes in amphibians and arthropods are thought to be derived from B chromosomes, the B chromosomes in Lake Victoria cichlids may represent an evolutionary transition toward the generation of sex chromosomes.

  15. A tribal level phylogeny of Lake Tanganyika cichlid fishes based on a genomic multi-marker approach.

    Science.gov (United States)

    Meyer, Britta S; Matschiner, Michael; Salzburger, Walter

    2015-02-01

    The species-flocks of cichlid fishes in the East African Great Lakes Victoria, Malawi and Tanganyika constitute the most diverse extant adaptive radiations in vertebrates. Lake Tanganyika, the oldest of the lakes, harbors the morphologically and genetically most diverse assemblage of cichlids and contains the highest number of endemic cichlid genera of all African lakes. Based on morphological grounds, the Tanganyikan cichlid species have been grouped into 12-16 distinct lineages, so-called tribes. While the monophyly of most of the tribes is well established, the phylogenetic relationships among the tribes remain largely elusive. Here, we present a new tribal level phylogenetic hypothesis for the cichlid fishes of Lake Tanganyika that is based on the so far largest set of nuclear markers and a total alignment length of close to 18kb. Using next-generation amplicon sequencing with the 454 pyrosequencing technology, we compiled a dataset consisting of 42 nuclear loci in 45 East African cichlid species, which we subjected to maximum likelihood and Bayesian inference phylogenetic analyses. We analyzed the entire concatenated dataset and each marker individually, and performed a Bayesian concordance analysis and gene tree discordance tests. Overall, we find strong support for a position of the Oreochromini, Boulengerochromini, Bathybatini and Trematocarini outside of a clade combining the substrate spawning Lamprologini and the mouthbrooding tribes of the 'H-lineage', which are both strongly supported to be monophyletic. The Eretmodini are firmly placed within the 'H-lineage', as sister-group to the most species-rich tribe of cichlids, the Haplochromini. The phylogenetic relationships at the base of the 'H-lineage' received less support, which is likely due to high speciation rates in the early phase of the radiation. Discordance among gene trees and marker sets further suggests the occurrence of past hybridization and/or incomplete lineage sorting in the cichlid

  16. Alternative reproductive tactics in snail shell-brooding cichlids diverge in energy reserve allocation.

    Science.gov (United States)

    von Kuerthy, Corinna; Tschirren, Linda; Taborsky, Michael

    2015-05-01

    Life history theory predicts that the amount of resources allocated to reproduction should maximize an individual's lifetime reproductive success. So far, resource allocation in reproduction has been studied mainly in females. Intraspecific variation of endogenous energy storage and utilization patterns of males has received little attention, although these patterns may vary greatly between individuals pursuing alternative reproductive tactics (ARTs). ARTs are characterized by systematic variation of behavioral, physiological, and often morphological traits among same-sex conspecifics. Some individuals may rely on previously accumulated reserves, because of limited foraging opportunities during reproduction. Others may be able to continue foraging during reproduction, thus relying on reserves to a lesser extent. We therefore predicted that, if male tactics involve such divergent limitations and trade-offs within a species, ARTs should correspondingly differ in energy reserve allocation and utilization. To test this prediction, we studied short-term and long-term reserve storage patterns of males in the shell-brooding cichlid Lamprologus callipterus. In this species, bourgeois males investing in territory defense, courtship, and guarding of broods coexist with two distinct parasitic male tactics: (1) opportunistic sneaker males attempting to fertilize eggs by releasing sperm into the shell opening when a female is spawning; and (2) specialized dwarf males attempting to enter the shell past the spawning female to fertilize eggs from inside the shell. Sneaker males differed from other male types by showing the highest amount of accumulated short-term and long-term fat stores, apparently anticipating their upcoming adoption of the nest male status. In contrast, nest males depleted previously accumulated energy reserves with increasing nest holding period, as they invest heavily into costly reproductive behaviors while not taking up any food. This conforms to a capital

  17. Architecture on Architecture

    DEFF Research Database (Denmark)

    Olesen, Karen

    2016-01-01

    that is not scientific or academic but is more like a latent body of data that we find embedded in existing works of architecture. This information, it is argued, is not limited by the historical context of the work. It can be thought of as a virtual capacity – a reservoir of spatial configurations that can...... the obligation to prepare students to perform in a profession that is largely defined by forces outside that discipline. It will be proposed that the autonomy of architecture can be understood as a unique kind of information: as architecture’s self-reliance or knowledge-about itself. A knowledge...... be transformed and reapplied endlessly through its confrontation with shifting information from outside the realms of architecture. A selection of architects’ statements on their own work will be used to demonstrate how in quite diverse contemporary practices the re-use of existing architectures is applied...

  18. Molecular phylogeny and evidence for an adaptive radiation of geophagine cichlids from South America (Perciformes: Labroidei).

    Science.gov (United States)

    López-Fernández, Hernán; Honeycutt, Rodney L; Winemiller, Kirk O

    2005-01-01

    Nucleotide sequences from the mitochondrial ND4 gene and the nuclear RAG2 gene were used to derive the most extensive molecular phylogeny to date for the Neotropical cichlid subfamily Geophaginae. Previous hypotheses of relationships were tested in light of these new data and a synthesis of all existing molecular information was provided. Novel phylogenetic findings included support for : (1) a 'Big Clade' containing the genera Geophagus sensu lato, Gymnogeophagus, Mikrogeophagus, Biotodoma, Crenicara, and Dicrossus; (2) a clade including the genera Satanoperca, Apistogramma, Apistogrammoides, and Taeniacara; and (3) corroboration for Kullander's clade Acarichthyini. ND4 demonstrated saturation effects at the third code position and lineage-specific rate heterogeneity, both of which influenced phylogeny reconstruction when only equal weighted parsimony was employed. Both branch lengths and internal branch tests revealed extremely short basal nodes that add support to the idea that geophagine cichlids have experienced an adaptive radiation sensu Schluter that involved ecomorphological specializations and life history diversification.

  19. Morphology, molecules, and monogenean parasites: an example of an integrative approach to cichlid biodiversity.

    Directory of Open Access Journals (Sweden)

    Maarten Van Steenberge

    Full Text Available The unparalleled biodiversity of Lake Tanganyika (Africa has fascinated biologists for over a century; its unique cichlid communities are a preferred model for evolutionary research. Although species delineation is, in most cases, relatively straightforward, higher-order classifications were shown not to agree with monophyletic groups. Here, traditional morphological methods meet their limitations. A typical example are the tropheine cichlids currently belonging to Simochromis and Pseudosimochromis. The affiliations of these widespread and abundant cichlids are poorly understood. Molecular work suggested that genus and species boundaries should be revised. Moreover, previous morphological results indicated that intraspecific variation should be considered to delineate species in Lake Tanganyika cichlids. We review the genera Simochromis and Pseudosimochromis using an integrative approach. Besides a morphometric study and a barcoding approach, monogenean Cichlidogyrus (Platyhelminthes: Ancyrocephalidae gill parasites, often highly species-specific, are used as complementary markers. Six new species are described. Cichlidogyrus raeymaekersi sp. nov., C. muterezii sp. nov. and C. banyankimbonai sp. nov. infect S. diagramma. Cichlidogyrus georgesmertensi sp. nov. was found on S. babaulti and S. pleurospilus, C. franswittei sp. nov. on both S. marginatus and P. curvifrons and C. frankwillemsi sp. nov. only on P. curvifrons. As relatedness between Cichlidogyrus species usually reflects relatedness between hosts, we considered Simochromis monotypic because the three Cichlidogyrus species found on S. diagramma belonged to a different morphotype than those found on the other Simochromis. The transfer of S. babaulti, S. marginatus, S. pleurospilus and S. margaretae to Pseudosimochromis was justified by the similarity of their Cichlidogyrus fauna and the intermediate morphology of S. margaretae. Finally parasite data also supported the synonymy between S

  20. Alarm cue induces an antipredator morphological defense in juvenile Nicaragua cichlids Hypsophrys nicaraguensis

    Directory of Open Access Journals (Sweden)

    Maria E. ABATE, Andrew G. ENG, Les KAUFMAN

    2010-02-01

    Full Text Available Olfactory cues that indicate predation risk elicit a number of defensive behaviors in fishes, but whether they are sufficient to also induce morphological defenses has received little attention. Cichlids are characterized by a high level of morphological plasticity during development, and the few species that have been tested do exhibit defensive behaviors when exposed to alarm cues released from the damaged skin of conspecifics. We utilized young juvenile Nicaragua cichlids Hypsophrys nicaraguensis to test if the perception of predation risk from alarm cue (conspecific skin extract alone induces an increased relative body depth which is a defense against gape-limited predators. After two weeks of exposure, siblings that were exposed to conspecific alarm cue increased their relative body depth nearly double the amount of those exposed to distilled water (control and zebrafish Danio rerio alarm cue. We repeated our measurements over the last two weeks (12 and 14 of cue exposure when the fish were late-stage juveniles to test if the rate of increase was sustained; there were no differences in final dimensions between the three treatments. Our results show that 1 the Nicaraguan cichlid has an innate response to conspecific alarm cue which is not a generalized response to an injured fish, and 2 this innate recognition ultimately results in developing a deeper body at a stage of the life history where predation risk is high [Current Zoology 56 (1: 36–42 2010].

  1. Segregation of Species-Specific Male Attractiveness in F2 Hybrid Lake Malawi Cichlid Fish

    Directory of Open Access Journals (Sweden)

    Ola Svensson

    2011-01-01

    Full Text Available Among the huge radiations of haplochromine cichlid fish in Lakes Malawi and Victoria, closely related species are often reproductively isolated via female mate choice although viable fertile hybrids can be produced when females are confined only with heterospecific males. We generated F2 hybrid males from a cross between a pair of closely related sympatric cichlid fish from Lake Malawi. Laboratory mate choice experiments using microsatellite paternity analysis demonstrated that F2 hybrid males differed significantly in their attractiveness to females of the two parental species, indicating heritable variation in traits involved in mate choice that may contribute to reproductive isolation between these species. We found no significant correlation between male mating success and any measurement of male colour pattern. A simple quantitative genetic model of reproductive isolation suggests that there may be as few as two chromosomal regions controlling species-specific attractiveness. We propose that adaptive radiation of Lake Malawi cichlids could be facilitated by the presence of genes with major effects on mate choice and reproductive isolation.

  2. Investigation of Acute Toxicity Diazinon, Deltamethrin, Butachlor and pretilachlor on Zebra Cichlid (Cryptoheros nigrofasciatus

    Directory of Open Access Journals (Sweden)

    Ali Sadeghi

    2014-06-01

    Full Text Available Background: The presence of pesticide due to the huge demand for agricultural purposes is very prevalent in surface waters of Iran. These pesticides could finally accumulate in aquatic ecosystems and have been proved to have toxic effects on aquatic animals. The aim of this study was to assess the acute toxicity of Diazinon, Deltamethrin, Butachlor and Pretilachlor on Zebra Cichlid (Cryptoheros nigrofasciatus. Methods: Fish samples were exposed to different concentrations of Diazinon (60% (0, 2, 4, 8, 16 and 32 ppm, Deltamethrin (2.5% (0, 0.02, 0.04, 0.10, 0.20 and 0.40 ppm, butachlor (60% (0, 2, 4, 8, 16 and 32 ppm and pretilachlor (50% (0, 5, 10, 20, 30 and 40 ppm for 96 h within the 100 L glass aquaria and cumulative mortality of Zebra Cichlid fish was calculated in 24-h interval. Results: The very low LC50 obtained for diazinon (5.06±0.37 ppm, deltamethrin (0.15±0.39 ppm, butachlor (8.93±0.26 ppm and pretilachlor (20.72±0.58 ppm indicated that these are highly toxic chemicals. Conclusion: Our results demonstrate that deltamethrin and pretilachlor had the lowest and highest rate of mortality on the Zebra Cichlid respectively.

  3. Regulatory gene networks that shape the development of adaptive phenotypic plasticity in a cichlid fish.

    Science.gov (United States)

    Schneider, Ralf F; Li, Yuanhao; Meyer, Axel; Gunter, Helen M

    2014-09-01

    Phenotypic plasticity is the ability of organisms with a given genotype to develop different phenotypes according to environmental stimuli, resulting in individuals that are better adapted to local conditions. In spite of their ecological importance, the developmental regulatory networks underlying plastic phenotypes often remain uncharacterized. We examined the regulatory basis of diet-induced plasticity in the lower pharyngeal jaw (LPJ) of the cichlid fish Astatoreochromis alluaudi, a model species in the study of adaptive plasticity. Through raising juvenile A. alluaudi on either a hard or soft diet (hard-shelled or pulverized snails) for between 1 and 8 months, we gained insight into the temporal regulation of 19 previously identified candidate genes during the early stages of plasticity development. Plasticity in LPJ morphology was first detected between 3 and 5 months of diet treatment. The candidate genes, belonging to various functional categories, displayed dynamic expression patterns that consistently preceded the onset of morphological divergence and putatively contribute to the initiation of the plastic phenotypes. Within functional categories, we observed striking co-expression, and transcription factor binding site analysis was used to examine the prospective basis of their coregulation. We propose a regulatory network of LPJ plasticity in cichlids, presenting evidence for regulatory crosstalk between bone and muscle tissues, which putatively facilitates the development of this highly integrated trait. Through incorporating a developmental time-course into a phenotypic plasticity study, we have identified an interconnected, environmentally responsive regulatory network that shapes the development of plasticity in a key innovation of East African cichlids.

  4. A novel molecular marker for the study of Neotropical cichlid phylogeny.

    Science.gov (United States)

    Fabrin, T M C; Gasques, L S; Prioli, S M A P; Prioli, A J

    2015-12-22

    The use of molecular markers has contributed to phylogeny and to the reconstruction of species' evolutionary history. Each region of the genome has different evolution rates, which may or may not identify phylogenetic signal at different levels. Therefore, it is important to assess new molecular markers that can be used for phylogenetic reconstruction. Regions that may be associated with species characteristics and are subject to selective pressure, such as opsin genes, which encode proteins related to the visual system and are widely expressed by Cichlidae family members, are interesting. Our aim was to identify a new nuclear molecular marker that could establish the phylogeny of Neotropical cichlids and is potentially correlated with the visual system. We used Bayesian inference and maximum likelihood analysis to support the use of the nuclear opsin LWS gene in the phylogeny of eight Neotropical cichlid species. Their use concatenated to the mitochondrial gene COI was also tested. The LWS gene fragment comprised the exon 2-4 region, including the introns. The LWS gene provided good support for both analyses up to the genus level, distinguishing the studied species, and when concatenated to the COI gene, there was a good support up to the species level. Another benefit of utilizing this region, is that some polymorphisms are associated with changes in spectral properties of the LWS opsin protein, which constitutes the visual pigment that absorbs red light. Thus, utilization of this gene as a molecular marker to study the phylogeny of Neotropical cichlids is promising.

  5. Altering an extended phenotype reduces intraspecific male aggression and can maintain diversity in cichlid fish

    Directory of Open Access Journals (Sweden)

    Isabel Santos Magalhaes

    2013-11-01

    Full Text Available Reduced male aggression towards different phenotypes generating negative frequency-dependent intrasexual selection has been suggested as a mechanism to facilitate the invasion and maintenance of novel phenotypes in a population. To date, the best empirical evidence for the phenomenon has been provided by laboratory studies on cichlid fish with different colour polymorphisms. Here we experimentally tested the hypothesis in a natural population of Lake Malawi cichlid fish, in which males build sand-castles (bowers to attract females during seasonal leks. We predicted that if bower shape plays an important role in male aggressive interactions, aggression among conspecific males should decrease when their bower shape is altered. Accordingly, we allocated randomly chosen bowers in a Nyassachromis cf. microcephalus lek into three treatments: control, manipulated to a different shape, and simulated manipulation. We then measured male behaviours and bower shape before and after these treatments. We found that once bower shape was altered, males were involved in significantly fewer aggressive interactions with conspecific males than before manipulation. Mating success was not affected. Our results support the idea that an extended phenotype, such as bower shape, can be important in maintaining polymorphic populations. Specifically, reduced male conspecific aggression towards males with different extended phenotypes (here, bower shapes may cause negative frequency-dependent selection, allowing the invasion and establishment of a new phenotype (bower builder. This could help our understanding of mechanisms of diversification within populations, and in particular, the overall diversification of bower shapes within Lake Malawi cichlids.

  6. Tol2-mediated generation of a transgenic haplochromine cichlid, Astatotilapia burtoni.

    Directory of Open Access Journals (Sweden)

    Scott A Juntti

    Full Text Available Cichlid fishes represent one of the most species-rich and rapid radiations of a vertebrate family. These ~2200 species, predominantly found in the East African Great Lakes, exhibit dramatic differences in anatomy, physiology, and behavior. However, the genetic bases for this radiation, and for the control of their divergent traits, are unknown. A flood of genomic and transcriptomic data promises to suggest mechanisms underlying the diversity, but transgenic technology will be needed to rigorously test the hypotheses generated. Here we demonstrate the successful use of the Tol2 transposon system to generate transgenic Astatotilapia burtoni, a haplochromine cichlid from Lake Tanganyika, carrying the GFP transgene under the control of the ubiquitous EF1α promoter. The transgene integrates into the genome, is successfully passed through the germline, and the widespread GFP expression pattern is stable across siblings and multiple generations. The stable inheritance and expression patterns indicate that the Tol2 system can be applied to generate A. burtoni transgenic lines. Transgenesis has proven to be a powerful technology for manipulating genes and cells in other model organisms and we anticipate that transgenic A. burtoni and other cichlids will be used to test the mechanisms underlying behavior and speciation.

  7. Experimentally increased temperature and hypoxia affect stability of social hierarchy and metabolism of the Amazonian cichlid Apistogramma agassizii.

    Science.gov (United States)

    Kochhann, Daiani; Campos, Derek Felipe; Val, Adalberto Luis

    2015-12-01

    The primary goal of this study was to understand how changes in temperature and oxygen could influence social behaviour and aerobic metabolism of the Amazonian dwarf cichlid Apistogramma agassizii. Social hierarchies were established over a period of 96h by observing the social interactions, feeding behaviour and shelter use in groups of four males. In the experimental environment, temperature was increased to 29°C in the high-temperature treatment, and oxygen lowered to 1.0mg·L(-1)O2 in the hypoxia treatment. Fish were maintained at this condition for 96h. The control was maintained at 26°C and 6.6mg·L(-1)O2. After the experimental exposure, metabolism was measured as routine metabolic rate (RMR) and electron transport system (ETS) activity. There was a reduction in hierarchy stability at high-temperature. Aggression changed after environmental changes. Dominant and subdominant fish at high temperatures increased their biting, compared with control-dominant. In contrast, hypoxia-dominant fish decreased their aggressive acts compared with all other fish. Shelter use decreased in control and hypoxic dominant fish. Dominant fish from undisturbed environments eat more than their subordinates. There was a decrease of RMR in fish exposed to the hypoxic environment when compared with control or high-temperature fish, independent of social position. Control-dominant fish had higher RMR than their subordinates. ETS activity increased in fish exposed to high temperatures; however, there was no effect on social rank. Our study reinforces the importance of environmental changes for the maintenance of hierarchies and their characteristics and highlights that most of the changes occur in the dominant position.

  8. Architectural slicing

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2013-01-01

    a system and a slicing criterion, architectural slicing produces an architectural prototype that contain the elements in the architecture that are dependent on the ele- ments in the slicing criterion. Furthermore, we present an initial design and implementation of an architectural slicer for Java.......Architectural prototyping is a widely used practice, con- cerned with taking architectural decisions through experiments with light- weight implementations. However, many architectural decisions are only taken when systems are already (partially) implemented. This is prob- lematic in the context...... of architectural prototyping since experiments with full systems are complex and expensive and thus architectural learn- ing is hindered. In this paper, we propose a novel technique for harvest- ing architectural prototypes from existing systems, \\architectural slic- ing", based on dynamic program slicing. Given...

  9. Rapid sympatric ecological differentiation of crater lake cichlid fishes within historic times

    Directory of Open Access Journals (Sweden)

    Harrod Chris

    2010-05-01

    Full Text Available Abstract Background After a volcano erupts, a lake may form in the cooled crater and become an isolated aquatic ecosystem. This makes fishes in crater lakes informative for understanding sympatric evolution and ecological diversification in barren environments. From a geological and limnological perspective, such research offers insight about the process of crater lake ecosystem establishment and speciation. In the present study we use genetic and coalescence approaches to infer the colonization history of Midas cichlid fishes (Amphilophus cf. citrinellus that inhabit a very young crater lake in Nicaragua-the ca. 1800 year-old Lake Apoyeque. This lake holds two sympatric, endemic morphs of Midas cichlid: one with large, hypertrophied lips (~20% of the total population and another with thin lips. Here we test the associated ecological, morphological and genetic diversification of these two morphs and their potential to represent incipient speciation. Results Gene coalescence analyses [11 microsatellite loci and mitochondrial DNA (mtDNA sequences] suggest that crater lake Apoyeque was colonized in a single event from the large neighbouring great lake Managua only about 100 years ago. This founding in historic times is also reflected in the extremely low nuclear and mitochondrial genetic diversity in Apoyeque. We found that sympatric adult thin- and thick-lipped fishes occupy distinct ecological trophic niches. Diet, body shape, head width, pharyngeal jaw size and shape and stable isotope values all differ significantly between the two lip-morphs. The eco-morphological features pharyngeal jaw shape, body shape, stomach contents and stable isotopes (δ15N all show a bimodal distribution of traits, which is compatible with the expectations of an initial stage of ecological speciation under disruptive selection. Genetic differentiation between the thin- and thick-lipped population is weak at mtDNA sequence (FST = 0.018 and absent at nuclear

  10. Architectural Prototyping

    DEFF Research Database (Denmark)

    Bardram, Jakob; Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2004-01-01

    A major part of software architecture design is learning how specific architectural designs balance the concerns of stakeholders. We explore the notion of "architectural prototypes", correspondingly architectural prototyping, as a means of using executable prototypes to investigate stakeholders......' concerns with respect to a system under development. An architectural prototype is primarily a learning and communication vehicle used to explore and experiment with alternative architectural styles, features, and patterns in order to balance different architectural qualities. The use of architectural...... prototypes in the development process is discussed, and we argue that such prototypes can play a role throughout the entire process. The use of architectural prototypes is illustrated by three distinct cases of creating software systems. We argue that architectural prototyping can provide key insights...

  11. Architectural prototyping

    DEFF Research Database (Denmark)

    Bardram, Jakob Eyvind; Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2004-01-01

    A major part of software architecture design is learning how specific architectural designs balance the concerns of stakeholders. We explore the notion of "architectural prototypes", correspondingly architectural prototyping, as a means of using executable prototypes to investigate stakeholders......' concerns with respect to a system under development. An architectural prototype is primarily a learning and communication vehicle used to explore and experiment with alternative architectural styles, features, and patterns in order to balance different architectural qualities. The use of architectural...... prototypes in the development process is discussed, and we argue that such prototypes can play a role throughout the entire process. The use of architectural prototypes is illustrated by three distinct cases of creating software systems. We argue that architectural prototyping can provide key insights...

  12. Temperature and Ca2+-dependence of the sarcoplasmic reticulum Ca2(+)-ATPase in haddock, salmon, rainbow trout and zebra cichlid

    DEFF Research Database (Denmark)

    Godiksen, Helene; Jessen, Flemming

    2002-01-01

    in the enzyme or its membrane lipid environment is still a matter of discussion. In this study we compared the temperature dependence and Ca2+-dependence of SR Ca2+-ATPase in haddock (Melanogrammus aeglefinus), salmon (Salmo, salar), rainbow trout (Oncorhynchus mykiss) and zebra cichlid (Cichlasoma...... nigrofasciatum). The Arrhenius plot of zebra cichlid showed a break point at 20 degreesC, and the haddock Arrhenius plot was non-linear with pronounced changes in slope in the. temperature area, 6-14 degreesC. In Arrhenius plot from both salmon and rainbow trout a plateau exists with an almost constant SR Ca2...

  13. Feed training of peacock bass (Cichla sp.).

    Science.gov (United States)

    Moura, M A; Kubitza, F; Cyrino, J E

    2000-11-01

    The Amazonian cichlid peacock bass (Cichla sp.) is a highly marketable food and sport fish, therefore a suitable species for aquaculture. However, because of its piscivorous feeding preferences, the species does not accept dry feeds voluntarily, turning its intensive culture difficult and costly. This study aimed to wean fingerling peacock bass from inert moist food to dry diets. In a first experiment, 1,134 fingerlings weighting 0.27 g were divided in two 0.37 m3 hapas and fed ground fish flesh with 35% success. Then, 1.3 g fish were pooled, stocked in six 25 L cages and fed two pellet sequences with 80%, 60%, 40%, 20% and 0% ground fish flesh (GFF). One sequence was flavored with 10% krill meal (Euphausia sp.). Training success of fish fed the GFF-00 diet flavored with krill reached 12%a compared to 11.6%a (p GFF with 39.8% success. After the feed training period, 2.2 g fish were then fed a sequence of moist pellets containing 80%, 60% and 45% GFF. Fish trained to feed on moist pellets with 45% ground fish were pooled and stocked into nine 25 L cages. Fish were weaned to dry pellets without ground fish flesh (GFF-00) using three diet sequences: 1) dry pellets; 2) moist pellets; and 3) dry pellets flavored with 4% cod liver oil; all three diets contained 30, 10 and 0% GFF. The three sequences yielded, respectively 30.8%a, 23.6%a, and 24.7%a (p GFF-00. There were no apparent beneficial effects of increasing moisture or addition of cod liver oil as flavor enhancers in the weaning diets. This study revealed the feasibility of training peacock bass to accept dry pellets, but feeding young fish ground fish flesh seemed to be a major bottleneck in improving feed training success.

  14. Assortative mating among Lake Malawi cichlid fish populations is not simply predictable from male nuptial colour

    Directory of Open Access Journals (Sweden)

    Taylor Martin I

    2009-03-01

    Full Text Available Abstract Background Research on the evolution of reproductive isolation in African cichlid fishes has largely focussed on the role of male colours and female mate choice. Here, we tested predictions from the hypothesis that allopatric divergence in male colour is associated with corresponding divergence in preference. Methods We studied four populations of the Lake Malawi Pseudotropheus zebra complex. We predicted that more distantly-related populations that independently evolved similar colours would interbreed freely while more closely-related populations with different colours mate assortatively. We used microsatellite genotypes or mesh false-floors to assign paternity. Fisher's exact tests as well as Binomial and Wilcoxon tests were used to detect if mating departed from random expectations. Results Surprisingly, laboratory mate choice experiments revealed significant assortative mating not only between population pairs with differently coloured males, but between population pairs with similarly-coloured males too. This suggested that assortative mating could be based on non-visual cues, so we further examined the sensory basis of assortative mating between two populations with different male colour. Conducting trials under monochromatic (orange light, intended to mask the distinctive male dorsal fin hues (blue v orange of these populations, did not significantly affect the assortative mating by female P. emmiltos observed under control conditions. By contrast, assortative mating broke down when direct contact between female and male was prevented. Conclusion We suggest that non-visual cues, such as olfactory signals, may play an important role in mate choice and behavioural isolation in these and perhaps other African cichlid fish. Future speciation models aimed at explaining African cichlid radiations may therefore consider incorporating such mating cues in mate choice scenarios.

  15. Cutting the Gordian knot:Complex signaling in African cichlids is more than multimodal

    Institute of Scientific and Technical Information of China (English)

    Moira J.VAN STAADEN; Adam R.SMITH

    2011-01-01

    The active transmission of information from sender to recelver is a fundamental component of communication,and is therefore a primary facet in evolutionary models of sexual selection.Research in several systetms has underlined the importance of multiple sensory modalities in courtship signals.However,we still tend to think of individuals as having a relatively static signal in consecutive communicative events.While this may be true for certain traits such as body size or coloration,behaviorally modulated signals can quickly violate this assumption.In this work,we explore how intraspecific variation may be an important component of interspeclfic signal divergence using cichlid fishes from Lake Maiawi.Behavloral analyses were made using six species of Malawian cichlids from two divergent genera.while interspecific differences were found between congeners based on species-level analyses of both acoustic and audiovisual signais,intraspecific variation was of a similar magnitude.Specifically,individual fishes were found to possess highiy plastic signal repertoires.This finding was ubiquitous across all species and resulted in a great deal of overlap between heterospecific individuals,despite statistically distinct species means.These results demonstrate that some aspects of courtship in Malawian cichlids are more plastic than previously proposed,and that studies must account for signal variability within individuals.We propose here that bebavioral variability in signaling is important in determining the communication landscape on which signals are perceived.We review potential complexity deriving from multimodal signaling,discuss the sources for such lability,and suggest ways in which is issue may be approached experimentally.

  16. Genetic basis of continuous variation in the levels and modular inheritance of pigmentation in cichlid fishes.

    Science.gov (United States)

    Albertson, R Craig; Powder, Kara E; Hu, Yinan; Coyle, Kaitlin P; Roberts, Reade B; Parsons, Kevin J

    2014-11-01

    Variation in pigmentation type and levels is a hallmark of myriad evolutionary radiations, and biologists have long been fascinated by the factors that promote and maintain variation in coloration across populations. Here, we provide insights into the genetic basis of complex and continuous patterns of colour variation in cichlid fishes, which offer a vast diversity of pigmentation patterns that have evolved in response to both natural and sexual selection. Specifically, we crossed two divergent cichlid species to generate an F2 mapping population that exhibited extensive variation in pigmentation levels and patterns. Our experimental design is robust in that it combines traditional quantitative trait locus (QTL) analysis with population genomics, which has allowed us to move efficiently from QTL interval to candidate gene. In total, we detected 41 QTL and 13 epistatic interactions that underlie melanocyte- and xanthophore-based coloration across the fins and flanks of these fishes. We also identified 2 QTL and 1 interaction for variation in the magnitude of integration among these colour traits. This finding in particular is notable as there are marked differences both within and between species with respect to the complexity of pigmentation patterns. While certain individuals are characterized by more uniform 'integrated' colour patterns, others exhibit many more degrees of freedom with respect to the distribution of colour 'modules' across the fins and flank. Our data reveal, for the first time, a genetic basis for this difference. Finally, we implicate pax3a as a mediator of continuous variation in the levels of xanthophore-based colour along the cichlid flank.

  17. Integrating cytogenetics and genomics in comparative evolutionary studies of cichlid fish

    Directory of Open Access Journals (Sweden)

    Mazzuchelli Juliana

    2012-09-01

    Full Text Available Abstract Background The availability of a large number of recently sequenced vertebrate genomes opens new avenues to integrate cytogenetics and genomics in comparative and evolutionary studies. Cytogenetic mapping can offer alternative means to identify conserved synteny shared by distinct genomes and also to define genome regions that are still not fine characterized even after wide-ranging nucleotide sequence efforts. An efficient way to perform comparative cytogenetic mapping is based on BAC clones mapping by fluorescence in situ hybridization. In this report, to address the knowledge gap on the genome evolution in cichlid fishes, BAC clones of an Oreochromis niloticus library covering the linkage groups (LG 1, 3, 5, and 7 were mapped onto the chromosomes of 9 African cichlid species. The cytogenetic mapping data were also integrated with BAC-end sequences information of O. niloticus and comparatively analyzed against the genome of other fish species and vertebrates. Results The location of BACs from LG1, 3, 5, and 7 revealed a strong chromosomal conservation among the analyzed cichlid species genomes, which evidenced a synteny of the markers of each LG. Comparative in silico analysis also identified large genomic blocks that were conserved in distantly related fish groups and also in other vertebrates. Conclusions Although it has been suggested that fishes contain plastic genomes with high rates of chromosomal rearrangements and probably low rates of synteny conservation, our results evidence that large syntenic chromosome segments have been maintained conserved during evolution, at least for the considered markers. Additionally, our current cytogenetic mapping efforts integrated with genomic approaches conduct to a new perspective to address important questions involving chromosome evolution in fishes.

  18. Robotic Architectures

    Directory of Open Access Journals (Sweden)

    Mbali Mtshali

    2010-01-01

    Full Text Available In the development of mobile robotic systems, a robotic architecture plays a crucial role in interconnecting all the sub-systems and controlling the system. The design of robotic architectures for mobile autonomous robots is a challenging and complex task. With a number of existing architectures and tools to choose from, a review of the existing robotic architecture is essential. This paper surveys the different paradigms in robotic architectures. A classification of the existing robotic architectures and comparison of different proposals attributes and properties have been carried out. The paper also provides a view on the current state of designing robot architectures. It also proposes a conceptual model of a generalised robotic architecture for mobile autonomous robots.Defence Science Journal, 2010, 60(1, pp.15-22, DOI:http://dx.doi.org/10.14429/dsj.60.96

  19. Brain structure evolution in a basal vertebrate clade: evidence from phylogenetic comparative analysis of cichlid fishes

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    Kolm Niclas

    2009-09-01

    Full Text Available Abstract Background The vertebrate brain is composed of several interconnected, functionally distinct structures and much debate has surrounded the basic question of how these structures evolve. On the one hand, according to the 'mosaic evolution hypothesis', because of the elevated metabolic cost of brain tissue, selection is expected to target specific structures mediating the cognitive abilities which are being favored. On the other hand, the 'concerted evolution hypothesis' argues that developmental constraints limit such mosaic evolution and instead the size of the entire brain varies in response to selection on any of its constituent parts. To date, analyses of these hypotheses of brain evolution have been limited to mammals and birds; excluding Actinopterygii, the basal and most diverse class of vertebrates. Using a combination of recently developed phylogenetic multivariate allometry analyses and comparative methods that can identify distinct rates of evolution, even in highly correlated traits, we studied brain structure evolution in a highly variable clade of ray-finned fishes; the Tanganyikan cichlids. Results Total brain size explained 86% of the variance in brain structure volume in cichlids, a lower proportion than what has previously been reported for mammals. Brain structures showed variation in pair-wise allometry suggesting some degree of independence in evolutionary changes in size. This result is supported by variation among structures on the strength of their loadings on the principal size axis of the allometric analysis. The rate of evolution analyses generally supported the results of the multivariate allometry analyses, showing variation among several structures in their evolutionary patterns. The olfactory bulbs and hypothalamus were found to evolve faster than other structures while the dorsal medulla presented the slowest evolutionary rate. Conclusion Our results favor a mosaic model of brain evolution, as certain

  20. Architecture & Environment

    Science.gov (United States)

    Erickson, Mary; Delahunt, Michael

    2010-01-01

    Most art teachers would agree that architecture is an important form of visual art, but they do not always include it in their curriculums. In this article, the authors share core ideas from "Architecture and Environment," a teaching resource that they developed out of a long-term interest in teaching architecture and their fascination with the…

  1. A COMPARATIVE-STUDY OF STIMULUS SELECTION IN THE FILIAL FOLLOWING RESPONSE OF FRY OF SUBSTRATE SPAWNING CICHLID FISH

    NARCIS (Netherlands)

    BAERENDS, GP

    1993-01-01

    This paper reports on experimental research undertaken to analyse the information processing mechanism by which the fry of substrate spawning cichlid fish visually recognise their guarding parent(s), already from the earliest time they are able to swim. The study is inspired by LORENZ' concept of 'i

  2. Intrasexual competition among females and the stabilization of a conspicuous colour polymorphism in a Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Dijkstra, Peter D.; Seehausen, Ole; Groothuis, Ton G. G.

    2008-01-01

    The maintenance of colour polymorphisms within populations has been a long-standing interest in evolutionary ecology. African cichlid fish contain some of the most striking known cases of this phenomenon. Intrasexual selection can be negative frequency dependent when males bias aggression towards ph

  3. Genetic isolation and morphological divergence mediated by high-energy rapids in two cichlid genera from the lower Congo rapids

    Directory of Open Access Journals (Sweden)

    Stiassny Melanie LJ

    2010-05-01

    Full Text Available Abstract Background It is hypothesized that one of the mechanisms promoting diversification in cichlid fishes in the African Great Lakes has been the well-documented pattern of philopatry along shoreline habitats leading to high levels of genetic isolation among populations. However lake habitats are not the only centers of cichlid biodiversity - certain African rivers also contain large numbers of narrowly endemic species. Patterns of isolation and divergence in these systems have tended to be overlooked and are not well understood. Results We examined genetic and morphological divergence among populations of two narrowly endemic cichlid species, Teleogramma depressum and Lamprologus tigripictilis, from a 100 km stretch of the lower Congo River using both nDNA microsatellites and mtDNA markers along with coordinate-based morphological techniques. In L. tigripictilis, the strongest genetic break was concordant with measurable phenotypic divergence but no morphological disjunction was detected for T. depressum despite significant differentiation at mtDNA and nDNA microsatellite markers. Conclusions The genetic markers revealed patterns of philopatry and estimates of genetic isolation that are among the highest reported for any African cichlid species over a comparable geographic scale. We hypothesize that the high levels of philopatry observed are generated and maintained by the extreme hydrology of the lower Congo River.

  4. Early learning and speciation : the effects of early experience on sexual and aggressive behaviour in Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Verzijden, Machteld Nicolette

    2008-01-01

    The great Lakes of East Africa are inhabited by a great number of haplochromine cichlid species, which form a diverse group in both ecology and nuptial coloration. The large number of sympatrically occuriring closely related species has raised questions about the underlying mechanism for reproductiv

  5. A sensory bias has triggered the evolution of egg-spots in cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Bernd Egger

    Full Text Available Although, generally, the origin of sex-limited traits remains elusive, the sensory exploitation hypothesis provides an explanation for the evolution of male sexual signals. Anal fin egg-spots are such a male sexual signal and a key characteristic of the most species-rich group of cichlid fishes, the haplochromines. Males of about 1500 mouth-brooding species utilize these conspicuous egg-dummies during courtship--apparently to attract females and to maximize fertilization success. Here we test the hypothesis that the evolution of haplochromine egg-spots was triggered by a pre-existing bias for eggs or egg-like coloration. To this end, we performed mate-choice experiments in the basal haplochromine Pseudocrenilabrus multicolor, which manifests the plesiomorphic character-state of an egg-spot-less anal fin. Experiments using computer-animated photographs of males indeed revealed that females prefer images of males with virtual ('in-silico' egg-spots over images showing unaltered males. In addition, we tested for color preferences (outside a mating context in a phylogenetically representative set of East African cichlids. We uncovered a strong preference for yellow, orange or reddish spots in all haplochromines tested and, importantly, also in most other species representing more basal lines. This pre-existing female sensory bias points towards high-quality (carotenoids-enriched food suggesting that it is adaptive.

  6. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum Exposed to Sublethal Concentrations of Permethrin

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-12-01

    Full Text Available Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Methods: Acute toxicity (LC50 of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM. In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1 combined with 20 µg.L-1 mercury chloride for 15 days. At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV. Results: 96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Conclusion: Increasing the concentration of permethrin had synergistic effects on the bioaccumulation of mercury in fish.

  7. Color changing and behavioral context in the Amazonian Dwarf Cichlid Apistogramma hippolytae (Perciformes

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    Raoni Rosa Rodrigues

    Full Text Available Animal coloration has many functions, and fishes are noted among vertebrates for presenting a wide variety of color patterns. Although in marine fishes the relationship between body coloration and behavioral context is well documented, there's not much information about freshwater fishes. Here we describe color patterns displayed by the dwarf cichlid Apistogramma hippolytae and suggest that these patterns are dependent on different social and behavioral settings. Field observations were conducted underwater in a pond in Central Amazonia, Brazil. We recorded six body coloration patterns related to seven different kinds of behavioral activities: foraging, resting, reproductive and agonistic displays, aggression (attacking and fleeing and parental care. Changes in coloration occur rapidly and take only a few seconds. Females on parental care exhibited a unique pattern that are more persistent and probably manifests more slowly. In the shallow and clear waters of the natural environment of this dwarf cichlid, color communication seems to constitute an efficient way to display information about individual mood, social status and reproductive readiness, contributing to minimize loss of energy in unnecessary interactions.

  8. Reproductive behavior and parental roles of the cichlid fish Laetacara araguaiae

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    Fabrício Barreto Teresa

    Full Text Available We described the reproductive behavior of the small South American cichlid Laetacara araguaiae in streams from Brazil. We predicted that this species will show reproductive cooperation and division of labor between males and females in a similar way presented by other substrate-spawner cichlids. Thus, we studied 34 pairs in the pre-spawning (n = 11, egg/wriggler (n = 11 and fry (n = 12 phases. In the pre-spawning phase both sexes become involved in nest building and territorial defense, but females emphasizes building nest (p = 0.03, while males invest more time in territorial defense (p = 0.04. After spawning, male and female alternate between rearing eggs and defending nest in the territory. In the egg/wriggler phase females devotes more time rearing the brood while males remain defending territory (p = 0.02. These differences disappear when young are in the fry stage, and parents jointly stay closer to fry (p = 0.98. However, at this phase, there is a reduction in the frequency of threats shown by males (p<0.01 and an increase in the frequency of attacks shown by female (p<0.01 that could be a response to an increased demand for parental defense. Our results indicate that the reproductive cooperation between males and females of L. araguaiae is marked by division of labor in the early reproductive phases and by sharing of parental duties as brood develops.

  9. The Monogenean Parasite Fauna of Cichlids: A Potential Tool for Host Biogeography

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    Antoine Pariselle

    2011-01-01

    Full Text Available We discuss geographical distribution and phylogeny of Dactylogyridea (Monogenea parasitizing Cichlidae to elucidate their hosts' history. Although mesoparasitic Monogenea (Enterogyrus spp. show typical vicariant distribution, ectoparasitic representatives from different continents are not considered sister taxa, hence their distribution cannot result from vicariance alone. Because of the close host-parasite relationship, this might indicate that present-day cichlid distribution may also reflect dispersal through coastal or brackish waters. Loss of ectoparasites during transoceanic migration, followed by lateral transfer from other fish families might explain extant host-parasite associations. Because of its mesoparasitic nature, hence not subject to salinity variations of the host's environment, Enterogyrus could have survived marine migrations, intolerable for ectoparasites. Host-switches and salinity transitions may be invoked to explain the pattern revealed by a preliminary morphological phylogeny of monogenean genera from Cichlidae and other selected Monogenea genera, rendering the parasite distribution explicable under both vicariance and dispersal. Testable hypotheses are put forward in this parasitological approach to cichlid biogeography. Along with more comprehensive in-depth morphological phylogeny, comparison with molecular data, clarifying dactylogyridean evolution on different continents and from various fish families, and providing temporal information on host-parasite history, are needed to discriminate between the possible scenarios.

  10. Genetic structure of pelagic and littoral cichlid fishes from Lake Victoria.

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    Miyuki Takeda

    Full Text Available The approximately 700 species of cichlids found in Lake Victoria in East Africa are thought to have evolved over a short period of time, and they represent one of the largest known examples of adaptive radiation. To understand the processes that are driving this spectacular radiation, we must determine the present genetic structure of these species and elucidate how this structure relates to the ecological conditions that caused their adaptation. We analyzed the genetic structure of two pelagic and seven littoral species sampled from the southeast area of Lake Victoria using sequences from the mtDNA control region and 12 microsatellite loci as markers. Using a Bayesian model-based clustering method to analyze the microsatellite data, we separated these nine species into four groups: one group composed of pelagic species and another three groups composed mainly of rocky-shore species. Furthermore, we found significant levels of genetic variation between species within each group at both marker loci using analysis of molecular variance (AMOVA, although the nine species often shared mtDNA haplotypes. We also found significant levels of genetic variation between populations within species. These results suggest that initial groupings, some of which appear to have been related to habitat differences, as well as divergence between species within groups took place among the cichlid species of Lake Victoria.

  11. Architectural freedom and industrialised architecture

    DEFF Research Database (Denmark)

    Vestergaard, Inge

    2012-01-01

    compares "best practice" in Denmark and "best practice" in Austria. The modern architects accepted the fact that industrialized architecture told the storey of repetition and monotonous as basic condition. This article aims to explain that architecture can be thought as a complex and diverse design through......Architectural freedom and industrialized architecture. Inge Vestergaard, Associate Professor, Cand. Arch. Aarhus School of Architecture, Denmark Noerreport 20, 8000 Aarhus C Telephone +45 89 36 0000 E-mai l inge.vestergaard@aarch.dk Based on the repetitive architecture from the "building boom" 1960...... to 1973 it is discussed how architects can handle these Danish element and montage buildings through the transformation to upgraded aesthetical, functional and energy efficient architecture. The method used is analysis of cases, parallels to literature studies and producer interviews. This analysis...

  12. Software architecture

    CERN Document Server

    Vogel, Oliver; Chughtai, Arif

    2011-01-01

    As a software architect you work in a wide-ranging and dynamic environment. You have to understand the needs of your customer, design architectures that satisfy both functional and non-functional requirements, and lead development teams in implementing the architecture. And it is an environment that is constantly changing: trends such as cloud computing, service orientation, and model-driven procedures open up new architectural possibilities. This book will help you to develop a holistic architectural awareness and knowledge base that extends beyond concrete methods, techniques, and technologi

  13. Green Architecture

    Science.gov (United States)

    Lee, Seung-Ho

    Today, the environment has become a main subject in lots of science disciplines and the industrial development due to the global warming. This paper presents the analysis of the tendency of Green Architecture in France on the threes axes: Regulations and Approach for the Sustainable Architecture (Certificate and Standard), Renewable Materials (Green Materials) and Strategies (Equipments) of Sustainable Technology. The definition of 'Green Architecture' will be cited in the introduction and the question of the interdisciplinary for the technological development in 'Green Architecture' will be raised up in the conclusion.

  14. Local architecture

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Local architecture refers to structures built in the countryside,such as temples,memorial halls,residences, stores,pavilions, bridges,decorated archways, and wells. Because these structures were all built by focal craftsmen and villagers in the traditional local style, they are generally called local architecture.

  15. Architecture Sustainability

    NARCIS (Netherlands)

    Avgeriou, Paris; Stal, Michael; Hilliard, Rich

    2013-01-01

    Software architecture is the foundation of software system development, encompassing a system's architects' and stakeholders' strategic decisions. A special issue of IEEE Software is intended to raise awareness of architecture sustainability issues and increase interest and work in the area. The fir

  16. Architectural Contestation

    NARCIS (Netherlands)

    Merle, J.

    2012-01-01

    This dissertation addresses the reductive reading of Georges Bataille's work done within the field of architectural criticism and theory which tends to set aside the fundamental ‘broken’ totality of Bataille's oeuvre and also to narrowly interpret it as a mere critique of architectural form, consequ

  17. Architectural geometry

    NARCIS (Netherlands)

    Pottmann, Helmut; Eigensatz, Michael; Vaxman, A.; Wallner, Johannes

    2015-01-01

    Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural

  18. Reticulate phylogeny of gastropod-shell-breeding cichlids from Lake Tanganyika – the result of repeated introgressive hybridization

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    Blanc Michel

    2007-01-01

    Full Text Available Abstract Background The tribe Lamprologini is the major substrate breeding lineage of Lake Tanganyika's cichlid species flock. Among several different life history strategies found in lamprologines, the adaptation to live and breed in empty gastropod shells is probably the most peculiar. Although shell-breeding arose several times in the evolutionary history of the lamprologines, all obligatory and most facultative shell-breeders belong to the so called "ossified group", a monophyletic lineage within the lamprologine cichlids. Since their distinctive life style enables these species to live and breed in closest vicinity, we hypothesized that these cichlids might be particularly prone to accidental hybridization, and that introgression might have affected the evolutionary history of this cichlid lineage. Results Our analyses revealed discrepancies between phylogenetic hypotheses based on mitochondrial and nuclear (AFLP data. While the nuclear phylogeny was congruent with morphological, behavioral and ecological characteristics, several species – usually highly specialized shell-breeders – were placed at contradicting positions in the mitochondrial phylogeny. The discordant phylogenies strongly suggest repeated incidents of introgressive hybridization between several distantly related shell-breeding species, which reticulated the phylogeny of this group of cichlids. Long interior branches and high bootstrap support for many interior nodes in the mitochondrial phylogeny argue against a major effect of ancient incomplete lineage sorting on the phylogenetic reconstruction. Moreover, we provide morphological and genetic (mtDNA and microsatellites evidence for ongoing hybridization among distantly related shell-breeders. In these cases, the territorial males of the inferred paternal species are too large to enter the shells of their mate, such that they have to release their sperm over the entrance of the shell to fertilize the eggs. With sperm

  19. Architectural Narratives

    DEFF Research Database (Denmark)

    Kiib, Hans

    2010-01-01

    and architectural heritage; another group tries to embed new performative technologies in expressive architectural representation. Finally, this essay provides a theoretical framework for the analysis of the political rationales of these projects and for the architectural representation bridges the gap between......In this essay, I focus on the combination of programs and the architecture of cultural projects that have emerged within the last few years. These projects are characterized as “hybrid cultural projects,” because they intend to combine experience with entertainment, play, and learning. This essay...... identifies new rationales related to this development, and it argues that “cultural planning” has increasingly shifted its focus from a cultural institutional approach to a more market-oriented strategy that integrates art and business. The role of architecture has changed, too. It not only provides...

  20. Architectural Theatricality

    DEFF Research Database (Denmark)

    Tvedebrink, Tenna Doktor Olsen

    This PhD thesis is motived by a personal interest in the theoretical, practical and creative qualities of architecture. But also a wonder and curiosity about the cultural and social relations architecture represents through its occupation with both the sciences and the arts. Inspired by present...... initiatives in Aalborg Hospital to overcome patient undernutrition by refurbishing eating environments, this thesis engages in an investigation of the interior architectural qualities of patient eating environments. The relevance for this holistic perspective, synthesizing health, food and architecture...... environments and a knowledge gap therefore exists in present hospital designs. Consequently, the purpose of this thesis has been to investigate if any research-based knowledge exist supporting the hypothesis that the interior architectural qualities of eating environments influence patient food intake, health...

  1. Architectural Theatricality

    DEFF Research Database (Denmark)

    Tvedebrink, Tenna Doktor Olsen

    and well-being, as well as outline a set of basic design principles ‘predicting’ the future interior architectural qualities of patient eating environments. Methodologically the thesis is based on an explorative study employing an abductive approach and hermeneutic-interpretative strategy utilizing tactics......This PhD thesis is motived by a personal interest in the theoretical, practical and creative qualities of architecture. But also a wonder and curiosity about the cultural and social relations architecture represents through its occupation with both the sciences and the arts. Inspired by present...... initiatives in Aalborg Hospital to overcome patient undernutrition by refurbishing eating environments, this thesis engages in an investigation of the interior architectural qualities of patient eating environments. The relevance for this holistic perspective, synthesizing health, food and architecture...

  2. A Three-Dimensional Stereotaxic MRI Brain Atlas of the Cichlid Fish Oreochromis mossambicus

    Science.gov (United States)

    Simões, José M.; Teles, Magda C.; Oliveira, Rui F.; Van der Linden, Annemie; Verhoye, Marleen

    2012-01-01

    The African cichlid Oreochromis mossambicus (Mozambique tilapia) has been used as a model system in a wide range of behavioural and neurobiological studies. The increasing number of genetic tools available for this species, together with the emerging interest in its use for neurobiological studies, increased the need for an accurate hodological mapping of the tilapia brain to supplement the available histological data. The goal of our study was to elaborate a three-dimensional, high-resolution digital atlas using magnetic resonance imaging, supported by Nissl staining. Resulting images were viewed and analysed in all orientations (transverse, sagittal, and horizontal) and manually labelled to reveal structures in the olfactory bulb, telencephalon, diencephalon, optic tectum, and cerebellum. This high resolution tilapia brain atlas is expected to become a very useful tool for neuroscientists using this fish model and will certainly expand their use in future studies regarding the central nervous system. PMID:22984463

  3. Genomic islands of speciation separate cichlid ecomorphs in an East African crater lake.

    Science.gov (United States)

    Malinsky, Milan; Challis, Richard J; Tyers, Alexandra M; Schiffels, Stephan; Terai, Yohey; Ngatunga, Benjamin P; Miska, Eric A; Durbin, Richard; Genner, Martin J; Turner, George F

    2015-12-18

    The genomic causes and effects of divergent ecological selection during speciation are still poorly understood. Here we report the discovery and detailed characterization of early-stage adaptive divergence of two cichlid fish ecomorphs in a small (700 meters in diameter) isolated crater lake in Tanzania. The ecomorphs differ in depth preference, male breeding color, body shape, diet, and trophic morphology. With whole-genome sequences of 146 fish, we identified 98 clearly demarcated genomic "islands" of high differentiation and demonstrated the association of genotypes across these islands with divergent mate preferences. The islands contain candidate adaptive genes enriched for functions in sensory perception (including rhodopsin and other twilight-vision-associated genes), hormone signaling, and morphogenesis. Our study suggests mechanisms and genomic regions that may play a role in the closely related mega-radiation of Lake Malawi.

  4. Nuclear markers reveal that inter-lake cichlids' similar morphologies do not reflect similar genealogy.

    Science.gov (United States)

    Kassam, Daud; Seki, Shingo; Horic, Michio; Yamaoka, Kosaku

    2006-08-01

    The apparent inter-lake morphological similarity among East African Great Lakes' cichlid species/genera has left evolutionary biologists asking whether such similarity is due to sharing of common ancestor or mere convergent evolution. In order to answer such question, we first used Geometric Morphometrics, GM, to quantify morphological similarity and then subsequently used Amplified Fragment Length Polymorphism, AFLP, to determine if similar morphologies imply shared ancestry or convergent evolution. GM revealed that not all presumed morphological similar pairs were indeed similar, and the dendrogram generated from AFLP data indicated distinct clusters corresponding to each lake and not inter-lake morphological similar pairs. Such results imply that the morphological similarity is due to convergent evolution and not shared ancestry. The congruency of GM and AFLP generated dendrograms imply that GM is capable of picking up phylogenetic signal, and thus GM can be potential tool in phylogenetic systematics.

  5. Redescription of Clinostomum phalacrocoracis metacercariae (Digenea: Clinostomidae in cichlids from Lake Kinneret, Israel

    Directory of Open Access Journals (Sweden)

    Caffara Monica

    2014-01-01

    Full Text Available Clinostomidae are digeneans characterized by a complex taxonomic history, continuously under revision based on both morphological and molecular analysis. Among the 14 species considered valid so far Clinostomum phalacrocoracis has been well described only at the adult stage, whereas the morphology of the metacercarial stage has been reported only once. During a parasitological survey carried out on 262 wild cichlids sampled from Lake Kinneret (Israel metacercariae referable to C. phalacrocoracis were found in 18 fingerlings. In this study, we report this clinostomid species for the first time in wild fish from Israel describing the metacercarial stage of Clinostomum phalacrocoracis, coupling its morphological description with molecular analysis carried out on ITS rDNA and COI mtDNA sequences.

  6. Genetic linkage of distinct adaptive traits in sympatrically speciating crater lake cichlid fish

    Science.gov (United States)

    Fruciano, Carmelo; Franchini, Paolo; Kovacova, Viera; Elmer, Kathryn R.; Henning, Frederico; Meyer, Axel

    2016-01-01

    Our understanding of how biological diversity arises is limited, especially in the case of speciation in the face of gene flow. Here we investigate the genomic basis of adaptive traits, focusing on a sympatrically diverging species pair of crater lake cichlid fishes. We identify the main quantitative trait loci (QTL) for two eco-morphological traits: body shape and pharyngeal jaw morphology. These traits diverge in parallel between benthic and limnetic species in the repeated adaptive radiations of this and other fish lineages. Remarkably, a single chromosomal region contains the highest effect size QTL for both traits. Transcriptomic data show that the QTL regions contain genes putatively under selection. Independent population genomic data corroborate QTL regions as areas of high differentiation between the sympatric sister species. Our results provide empirical support for current theoretical models that emphasize the importance of genetic linkage and pleiotropy in facilitating rapid divergence in sympatry. PMID:27597183

  7. Biogeographical implications of Zambezian Cichlidogyrus species (Platyhelminthes: Monogenea: Ancyrocephalidae) parasitizing Congolian cichlids.

    Science.gov (United States)

    Vanhove, Maarten P M; Van Steenberge, Maarten; Dessein, Steven; Volckaert, Filip A M; Snoeks, Jos; Huyse, Tine; Pariselle, Antoine

    2013-01-22

    Fishes normally restricted to inland waters are valuable model systems for historical biogeography, inter alia, because of their limited dispersal abilities and concordance with the distribution patterns of other freshwater taxa (Zogaris et al. 2009). The comparison of fish species assemblages has been the major biogeographical tool for delineating African aquatic ecoregions as the fossil record is often meagre and merely offers complementary information. This is, for example, the case for the Zambezian and Congolian ichthyofaunal provinces, which display substantial contemporary fish diversity (Stewart 2001). Between both regions lies the Bangweulu-Mweru ecoregion (sensu Scott 2005), known for its high percentage of endemicity. Although hydrographically belonging to the Congo Basin, the Bangweulu-Mweru ecoregion has a high affinity with the Zambezi province (Scott 2005), due to historical river connections (Tweddle 2010). Studies comparing the Zambezi and Congo ichthyofaunal provinces are rare and hampered by lack of data from the Congo Basin. The latter harbours more than 1250 fish species (Snoeks et al. 2011) while in the Zambezi, only 120 freshwater fishes are found (Tweddle 2010). Indeed, species richness declines in all major African teleost families from the Congo Basin southwards, riverine haplochromine cichlids forming a notable exception to this rule (Joyce et al. 2005). Although it was hypothesized by Tweddle (2010) that the origin of many Zambezian fish species is in the Congo Basin, the haplochromines Serranochromis Regan, Sargochromis Regan, Pharyngochromis Greenwood and Chetia Trewavas, together forming the serranochromines, have their centre of diversity in the rivers of the Zambezian ichthyofaunal province (Joyce et al. 2005). Therefore, the biogeographical history of Cichlidae across the Zambezi- Congo watershed is not only key to cichlid biogeography on an African scale, but also complementary to biogeography of all other teleosts in the region

  8. Architectural technology

    DEFF Research Database (Denmark)

    2005-01-01

    The booklet offers an overall introduction to the Institute of Architectural Technology and its projects and activities, and an invitation to the reader to contact the institute or the individual researcher for further information. The research, which takes place at the Institute of Architectural...... Technology at the Roayl Danish Academy of Fine Arts, School of Architecture, reflects a spread between strategic, goal-oriented pilot projects, commissioned by a ministry, a fund or a private company, and on the other hand projects which originate from strong personal interests and enthusiasm of individual...

  9. Humanizing Architecture

    DEFF Research Database (Denmark)

    Toft, Tanya Søndergaard

    2015-01-01

    The article proposes the urban digital gallery as an opportunity to explore the relationship between ‘human’ and ‘technology,’ through the programming of media architecture. It takes a curatorial perspective when proposing an ontological shift from considering media facades as visual spectacles...... agency and a sense of being by way of dematerializing architecture. This is achieved by way of programming the symbolic to provide new emotional realizations and situations of enlightenment in the public audience. This reflects a greater potential to humanize the digital in media architecture....

  10. Laboratory mating trials indicate incipient speciation by sexual selection among populations of the cichlid fish Pseudotropheus zebra from Lake Malawi.

    Science.gov (United States)

    Knight, Mairi E.; Turner, George F.

    2004-01-01

    It has been suggested that sexual selection may have played a major role in the rapid evolution of hundreds of species of cichlid fishes in Lake Malawi. We report the results of a laboratory test of assortative mating among Lake Malawi cichlid fishes from five closely related geographical populations differing in male courtship colour. Paternity of clutches was tested using microsatellite DNA typing of offspring. Out of 1955 offspring typed, 1296 (66.3%) were sired by the male from the same population as the female, which is more than three times the rate expected if females do not differentiate among males of the different populations (20%). This result indicates that mate preferences of geographical races are strongly differentiated, consistent with the races representing incipient geographical species diverging under sexual selection exerted by female preferences for different male courtship colours. PMID:15209099

  11. Phylogeography, colonization and population history of the Midas cichlid species complex (Amphilophus spp. in the Nicaraguan crater lakes

    Directory of Open Access Journals (Sweden)

    Meyer Axel

    2010-10-01

    Full Text Available Abstract Background Elucidation of the mechanisms driving speciation requires detailed knowledge about the phylogenetic relationships and phylogeography of the incipient species within their entire ranges as well as their colonization history. The Midas cichlid species complex Amphilophus spp. has been proven to be a powerful model system for the study of ecological specialization, sexual selection and the mechanisms of sympatric speciation. Here we present a comprehensive and integrative phylogeographic analysis of the complete Midas Cichlid species complex in Nicaragua (> 2000 individuals covering the entire distributional range, using two types of molecular markers (the mitochondrial DNA control region and 15 microsatellites. We investigated the majority of known lake populations of this species complex and reconstructed their colonization history in order to distinguish between alternative speciation scenarios. Results We found that the large lakes contain older and more diverse Midas Cichlid populations, while all crater lakes hold younger and genetically less variable species assemblages. The large lakes appear to have repeatedly acted as source populations for all crater lakes, and our data indicate that faunal exchange among crater lakes is extremely unlikely. Despite their very recent (often only a few thousand years old and common origin from the two large Nicaraguan lakes, all crater lake Midas Cichlid radiations underwent independent, but parallel, evolution, and comprise distinct genetic units. Indeed several of these crater lakes contain multiple genetically distinct incipient species that most likely arose through sympatric speciation. Several crater lake radiations can be traced back to a single ancestral line, but some appear to have more than one founding lineage. The timing of the colonization(s of each crater lake differs, although most of them occurred more (probably much more recently than 20,000 years ago. Conclusion The

  12. Antipredator responses by native mosquitofish to non-native cichlids: An examination of the role of prey naiveté

    Science.gov (United States)

    Rehage, Jennifer S.; Dunlop, Katherine L.; Loftus, William F.

    2009-01-01

    The strong impact of non-native predators in aquatic systems is thought to relate to the evolutionary naiveté of prey. Due to isolation and limited dispersal, this naiveté may be relatively high in freshwater systems. In this study, we tested this notion by examining the antipredator response of native mosquitofish, Gambusia holbrooki, to two non-native predators found in the Everglades, the African jewelfish,Hemichromis letourneuxi, and the Mayan cichlid, Cichlasoma urophthalmus. We manipulated prey naiveté by using two mosquitofish populations that varied in their experience with the recent invader, the African jewelfish, but had similar levels of experience with the longer-established Mayan cichlid. Specifically, we tested these predictions: (1) predator hunting modes differed between the two predators, (2) predation rates would be higher by the novel jewelfish predator, (3) particularly on the naive population living where jewelfish have not invaded yet, (4) antipredator responses would be stronger to Mayan cichlids due to greater experience and weaker and/or ineffective to jewelfish, and (5) especially weakest by the naive population. We assayed prey and predator behavior, and prey mortality in lab aquaria where both predators and prey were free-ranging. Predator hunting modes and habitat domains differed, with jewelfish being more active search predators that used slightly higher parts of the water column and less of the habitat structure relative to Mayan cichlids. In disagreement with our predictions, predation rates were similar between the two predators, antipredator responses were stronger to African jewelfish (except for predator inspections), and there was no difference in response between jewelfish-savvy and jewelfish-naive populations. These results suggest that despite the novelty of introduced predators, prey may be able to respond appropriately if non-native predator archetypes are similar enough to those of native predators, if prey rely

  13. The African cichlid fish Astatotilapia burtoni uses acoustic communication for reproduction: sound production, hearing, and behavioral significance.

    Science.gov (United States)

    Maruska, Karen P; Ung, Uyhun S; Fernald, Russell D

    2012-01-01

    Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2-5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the

  14. The use of multiple sources of social information in contest behavior: testing the social cognitive abilities of a cichlid fish

    OpenAIRE

    Takashi eHotta; Tomohiro eTakeyama; Dik eHeg; Satoshi eAwata; Lyndon Alexander Jordan; Masanori eKohda

    2015-01-01

    Theory suggests that living in large social groups with dynamic social interactions often favours the evolution of enhanced cognitive abilities. Studies of how animals assess their own contest ability commonly focus on a single cognitive task, and little is known about the diversity or co-occurrence of cognitive abilities in social species. We examined how a highly social cichlid fish Julidochromis transcriptus uses four major cognitive abilities in contest situations; direct experience, winn...

  15. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs.

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaëlle; Azzouzi, Naoual; Coutanceau, Jean-Pierre; Bonillo, Celine; D'Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D'Hont, Angélique; Conte, Matthew,; Van Bers, Nikkie; Penman, David,; Hitte, Christophe; Crooijmans, Richard

    2012-01-01

    International audience; ABSTRACT: BACKGROUND: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. Itis also an important model for studies of fish physiology, particularly because of its broadtolerance to an array of environments. It is a good model to study evolutionary mechanismsin vertebrates, because of its close relationship to haplochromine cichlids, which haveundergone rapid speciation in East Africa. The existing genomic resources for Nile tilapi...

  16. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs.

    OpenAIRE

    Guyon Richard; Rakotomanga Michaelle; Azzouzi Naoual; Coutanceau Jean Pierre; Bonillo Celine; D’Cotta Helena; Pepey Elodie; Soler Lucile; Rodier-Goud Marguerite; D’Hont Angelique; Conte Matthew A; van Bers Nikkie EM; Penman David J; Hitte Christophe; Crooijmans Richard PMA

    2012-01-01

    Abstract Background The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic ma...

  17. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaelle; Azzouzi, Naoual; Coutanceau, Jean Pierre; Bonillo, Celine; D’Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D’Hont, Angelique; Conte, Matthew A; van Bers, Nikkie EM; Penman, David J.; Hitte, Christophe; Crooijmans, Richard Pma

    2012-01-01

    Background The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC en...

  18. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    OpenAIRE

    Guyon, Richard; Rakotomanga, Michaëlle; Azzouzi, Naoual; Coutanceau, Jean-Pierre; Bonillo, Celine; D'Cotta, Helena; Pepey, Elodie; Soler, Lucile; Rodier-Goud, Marguerite; D'Hont, Angélique; Conte, Matthew,; Van Bers, Nikkie; Penman, David,; Hitte, Christophe; Crooijmans, Richard P M A

    2012-01-01

    BACKGROUND: The Nile tilapia (Oreochromis niloticus) is the second most farmed fish species worldwide. Itis also an important model for studies of fish physiology, particularly because of its broadtolerance to an array of environments. It is a good model to study evolutionary mechanismsin vertebrates, because of its close relationship to haplochromine cichlids, which haveundergone rapid speciation in East Africa. The existing genomic resources for Nile tilapiainclude a genetic map, BAC end se...

  19. Architectural Engineers

    DEFF Research Database (Denmark)

    Petersen, Rikke Premer

    engineering is addresses from two perspectives – as an educational response and an occupational constellation. Architecture and engineering are two of the traditional design professions and they frequently meet in the occupational setting, but at educational institutions they remain largely estranged......The design professions have always been an amorphous phenomena difficult to merge under one label. New constellations continually emerge, questioning, stretching, and reconfiguring the understanding of design and the professional practices linked to it. In this paper the idea of architectural....... The paper builds on a multi-sited study of an architectural engineering program at the Technical University of Denmark and an architectural engineering team within an international engineering consultancy based on Denmark. They are both responding to new tendencies within the building industry where...

  20. Architectural Mealscapes

    DEFF Research Database (Denmark)

    Tvedebrink, Tenna Doktor Olsen; Fisker, Anna Marie; Kirkegaard, Poul Henning

    2012-01-01

    the German architect Gottfried Semper developed a theory on the “four elements of Architecture” tracing the origin of architecture back to the rise of the early human settlement and the creation of fire. With the notion ‘hearth’ as the first motive in architecture and the definition of three enclosing...... motives; mounding, enclosure and roof, Semper linked the cultural and social values of the primordial fireplace with the order and shape of architecture. He claimed that any building ever made was nothing but a variation of the first primitive shelters erected around the fireplace, and that the three...... enclosing motives existed only as defenders of the “sacred flame”. In that way Semper developed the idea that any architectural scenery can be described, analyzed and explained by understanding the contextual, symbolic and social values of how the four basic motives of hearth, mounding, enclosure, and roof...

  1. Systemic Architecture

    DEFF Research Database (Denmark)

    Poletto, Marco; Pasquero, Claudia

    2012-01-01

    design protocols developed to describe the city as a territory of self-organization. Collecting together nearly a decade of design experiments by the authors and their practice, ecoLogicStudio, the book discusses key disciplinary definitions such as ecologic urbanism, algorithmic architecture, bottom......-up or tactical design, behavioural space and the boundary of the natural and the artificial realms within the city and architecture. A new kind of "real-time world-city" is illustrated in the form of an operational design manual for the assemblage of proto-architectures, the incubation of proto......-gardens and the coding of proto-interfaces. These prototypes of machinic architecture materialize as synthetic hybrids embedded with biological life (proto-gardens), computational power, behavioural responsiveness (cyber-gardens), spatial articulation (coMachines and fibrous structures), remote sensing (FUNclouds...

  2. Shaping development through mechanical strain: the transcriptional basis of diet-induced phenotypic plasticity in a cichlid fish.

    Science.gov (United States)

    Gunter, Helen M; Fan, Shaohua; Xiong, Fan; Franchini, Paolo; Fruciano, Carmelo; Meyer, Axel

    2013-09-01

    Adaptive phenotypic plasticity, the ability of an organism to change its phenotype to match local environments, is increasingly recognized for its contribution to evolution. However, few empirical studies have explored the molecular basis of plastic traits. The East African cichlid fish Astatoreochromis alluaudi displays adaptive phenotypic plasticity in its pharyngeal jaw apparatus, a structure that is widely seen as an evolutionary key innovation that has contributed to the remarkable diversity of cichlid fishes. It has previously been shown that in response to different diets, the pharyngeal jaws change their size, shape and dentition: hard diets induce an adaptive robust molariform tooth phenotype with short jaws and strong internal bone structures, while soft diets induce a gracile papilliform tooth phenotype with elongated jaws and slender internal bone structures. To gain insight into the molecular underpinnings of these adaptations and enable future investigations of the role that phenotypic plasticity plays during the formation of adaptive radiations, the transcriptomes of the two divergent jaw phenotypes were examined. Our study identified a total of 187 genes whose expression differs in response to hard and soft diets, including immediate early genes, extracellular matrix genes and inflammatory factors. Transcriptome results are interpreted in light of expression of candidate genes-markers for tooth size and shape, bone cells and mechanically sensitive pathways. This study opens up new avenues of research at new levels of biological organization into the roles of phenotypic plasticity during speciation and radiation of cichlid fishes.

  3. Male convict cichlid 11-ketotestosterone levels throughout the reproductive cycle: an exploratory profile study in laboratory and field populations

    Directory of Open Access Journals (Sweden)

    Natalie April van Breukelen

    2015-05-01

    Full Text Available The convict cichlid (Amatitlania nigrofasciata has been extensively examined in relation to many behavioral topics, such as courtship, pair-bonding, bi-parental care, and territoriality. Recently, this model species has been utilized in studies on genetics, endocrinology, and neuroanatomy, with an ultimate goal of connecting behavior with its underlying mechanisms. The goal of this study was two-fold: (1 profile the circulating levels of plasma 11KT in the male convict cichlid at multiple points during the reproductive cycle and (2 generally compare the hormonal profiles of the widely used laboratory populations and those of a free-living population in the streams of Costa Rica. The results of the field experiment showed that male convict cichlids had higher levels of circulating 11KT during courtship and lower during the parental care and non-breeding phases. The profile of the laboratory population was similar to the profile of the free-living individuals, with significantly higher levels of 11KT occurring during courtship than during parental care, though the level of 11KT during non-breeding phase was elevated in the laboratory. The high levels of 11KT during courtship and low levels of 11KT during parental care found in both the field and the laboratory is similar to what has been reported in other species of teleosts, and may suggest an important function of 11KT in the expression of courtship behavior and the subsequent onset of parental behaviors in this model species.

  4. Phylogenetic relationships of Middle American cichlids (Cichlidae, Heroini) based on combined evidence from nuclear genes, mtDNA, and morphology.

    Science.gov (United States)

    Rícan, Oldrich; Zardoya, Rafael; Doadrio, Ignacio

    2008-12-01

    Heroine cichlids are the second largest and very diverse tribe of Neotropical cichlids, and the only cichlid group that inhabits Mesoamerica. The taxonomy of heroines is complex because monophyly of most genera has never been demonstrated, and many species groups are without applicable generic names after their removal from the catch-all genus Cichlasoma (sensu Regan, 1905). Hence, a robust phylogeny for the group is largely wanting. A rather complete heroine phylogeny based on cytb sequence data is available [Concheiro Pérez, G.A., Rícan O., Ortí G., Bermingham, E., Doadrio, I., Zardoya, R. 2007. Phylogeny and biogeography of 91 species of heroine cichlids (Teleostei: Cichlidae) based on sequences of the cytochrome b gene. Mol. Phylogenet. Evol. 43, 91-110], and in the present study, we have added and analyzed independent data sets (nuclear and morphological) to further confirm and strengthen the cytb-phylogenetic hypothesis. We have analyzed a combined cytb-nuclear (RAG1 and two S7 introns) data set of 48 species representing main heroine lineages to achieve further resolution of heroine higher taxonomic levels and a combined cytb-morphological data set of 92 species to stabilize generic taxonomy. The recovered phylogenies supported the circumamazonian--CAM--Heroini (sensu Concheiro Peréz et al., 2007) as a monophyletic group, that could be divided into six main clades: (1) australoheroines (the southernmost heroine genus Australoheros), (2) nandopsines (the Antillean genus Nandopsis), (3) caquetaines (including the north western Amazonian genera Caquetaia and Heroina), (4) astatheroines (including Astatheros, Herotilapia and Rocio), (5) amphilophines (including Amphilophus and related genera), and (6) herichthyines (including Herichthyis and related genera). Nuclear and mitochondrial data partitions arrived at highly congruent topologies. Suprageneric relationships were influenced mainly by the nuclear signal, as well as the most basal phylogenetic position

  5. Architectural geometry

    KAUST Repository

    Pottmann, Helmut

    2014-11-26

    Around 2005 it became apparent in the geometry processing community that freeform architecture contains many problems of a geometric nature to be solved, and many opportunities for optimization which however require geometric understanding. This area of research, which has been called architectural geometry, meanwhile contains a great wealth of individual contributions which are relevant in various fields. For mathematicians, the relation to discrete differential geometry is significant, in particular the integrable system viewpoint. Besides, new application contexts have become available for quite some old-established concepts. Regarding graphics and geometry processing, architectural geometry yields interesting new questions but also new objects, e.g. replacing meshes by other combinatorial arrangements. Numerical optimization plays a major role but in itself would be powerless without geometric understanding. Summing up, architectural geometry has become a rewarding field of study. We here survey the main directions which have been pursued, we show real projects where geometric considerations have played a role, and we outline open problems which we think are significant for the future development of both theory and practice of architectural geometry.

  6. Architectural Anthropology

    DEFF Research Database (Denmark)

    Stender, Marie

    Architecture and anthropology have always had a common focus on dwelling, housing, urban life and spatial organisation. Current developments in both disciplines make it even more relevant to explore their boundaries and overlaps. Architects are inspired by anthropological insights and methods......, while recent material and spatial turns in anthropology have also brought an increasing interest in design, architecture and the built environment. Understanding the relationship between the social and the physical is at the heart of both disciplines, and they can obviously benefit from further...... collaboration: How can qualitative anthropological approaches contribute to contemporary architecture? And just as importantly: What can anthropologists learn from architects’ understanding of spatial and material surroundings? Recent theoretical developments in anthropology stress the role of materials...

  7. Multithreading architecture

    CERN Document Server

    Nemirovsky, Mario

    2013-01-01

    Multithreaded architectures now appear across the entire range of computing devices, from the highest-performing general purpose devices to low-end embedded processors. Multithreading enables a processor core to more effectively utilize its computational resources, as a stall in one thread need not cause execution resources to be idle. This enables the computer architect to maximize performance within area constraints, power constraints, or energy constraints. However, the architectural options for the processor designer or architect looking to implement multithreading are quite extensive and

  8. Architectural Anthropology

    DEFF Research Database (Denmark)

    Stender, Marie

    and other spaces that architects are preoccupied with. On the other hand, the distinction between architecture and design is not merely one of scale. Design and architecture represent – at least in Denmark – also quite different disciplinary traditions and methods. Where designers develop prototypes......, architects tend to work with models and plans that are not easily understood by lay people. Further, many architects are themselves sceptical towards notions of user-involvement and collaborative design. They fear that the imagination of citizens and users is restricted to what they are already familiar with...

  9. The function of anal fin egg-spots in the cichlid fish Astatotilapia burtoni.

    Directory of Open Access Journals (Sweden)

    Anya Theis

    Full Text Available Color and pigmentation patterns of animals are often targets of sexual selection because of their role in communication. Although conspicuous male traits are typically implicated with intersexual selection, there are examples where sex-specific displays play a role in an intrasexual context, e.g. when they serve as signals for aggression level and/or status. Here, we focus on the function of a conspicuous male ornament in the most species-rich tribe of cichlid fishes, the haplochromines. A characteristic feature of these ca. 1500 species are so-called egg-spots in form of ovoid markings on the anal fins of males, which are made up of carotenoid based pigment cells. It has long been assumed that these yellow, orange or reddish egg-spots play an important role in the courtship and spawning behavior of these maternal mouth-brooding fishes by mimicking the eggs of a conspecific female. The exact function of egg-spots remains unknown, however, and there are several hypotheses about their mode of action. To uncover the function of this cichlid-specific male ornament, we used female mate choice experiments and a male aggression test in the haplochromine species Astatotilapia burtoni. We manipulated the number and arrangement of egg-spots on the anal fins of males, or removed them entirely, and tested (1 female preference with visual contact only using egg-traps, (2 female preference with free contact using paternity testing with microsatellites and (3 male aggression. We found that females did not prefer males with many egg-spots over males with fewer egg-spots and that females tended to prefer males without egg-spots over males with egg-spots. Importantly, males without egg-spots sired clutches with the same fertilization rate as males with egg-spots. In male aggression trials, however, males with fewer egg-spots received significantly more attacks, suggesting that egg-spots are an important signal in intrasexual communication.

  10. Architectural Tops

    Science.gov (United States)

    Mahoney, Ellen

    2010-01-01

    The development of the skyscraper is an American story that combines architectural history, economic power, and technological achievement. Each city in the United States can be identified by the profile of its buildings. The design of the tops of skyscrapers was the inspiration for the students in the author's high-school ceramic class to develop…

  11. Religious Architecture

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The main religions of ancient China were Buddhism,Taoism and Islam, of which Buddhism was the most widespread. As a result, Buddhist temples and towers are found all over China, and have become important components of the country's ancient architecture.

  12. Architectural Illusion.

    Science.gov (United States)

    Doornek, Richard R.

    1990-01-01

    Presents a lesson plan developed around the work of architectural muralist Richard Haas. Discusses the significance of mural painting and gives key concepts for the lesson. Lists class activities for the elementary and secondary grades. Provides a photograph of the Haas mural on the Fountainbleau Hilton Hotel, 1986. (GG)

  13. Textile Architecture

    DEFF Research Database (Denmark)

    Heimdal, Elisabeth Jacobsen

    2010-01-01

    Textiles can be used as building skins, adding new aesthetic and functional qualities to architecture. Just like we as humans can put on a coat, buildings can also get dressed. Depending on our mood, or on the weather, we can change coat, and so can the building. But the idea of using textiles...

  14. Guanine-based structural coloration as an indicator of oxidative stress in a cichlid fish.

    Science.gov (United States)

    Cahn, Matthew D; Brown, Alexandria C; Clotfelter, Ethan D

    2015-07-01

    Vertebrate pigmentation is known to be influenced by oxidative stress, but few studies have tested the hypothesis that structural coloration can be similarly affected. We tested whether fish iridophores, which produce structural color using guanine stacks, might be affected by the prooxidant-antioxidant balance of the animal. Specifically, we hypothesized that convict cichlids (Amatitlania nigrofasciata) metabolize guanine present in iridophores to uric acid, an antioxidant, in response to oxidative damage. We used Hunter's contrast gloss and high performance liquid chromatography to determine whether dietary guanine supplementation allows fish to maintain their structural coloration despite oxidative stress induced via ultraviolet-B (UV-B) radiation. We found that dietary guanine was associated with greater skin gloss, and that exposure to UV-B light reduced glossiness. UV-B exposure did not increase oxidative damage (acrolein) or total antioxidant capacity in the skin or liver. Our experiment did not detect effects of dietary guanine or UV-B light on uric acid, but uric acid was positively related to antioxidant capacity. Our results support the hypothesis that structural color in fish may be altered by environmental stressors such as exposure to UV light, and highlight the need for future studies to consider the role of iridophores in condition-dependent visual signaling.

  15. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish

    Science.gov (United States)

    Magalhaes, I. S.; Smith, A. M.; Joyce, D. A.

    2017-01-01

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle “bowers” several times their size. We tested the idea that a less costly “sneaking” strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females’ mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders. PMID:28128313

  16. Reproductive-tactic-specific variation in sperm swimming speeds in a shell-brooding cichlid.

    Science.gov (United States)

    Fitzpatrick, J L; Desjardins, J K; Milligan, N; Montgomerie, R; Balshine, S

    2007-08-01

    Theory predicts that males experiencing elevated levels of sperm competition will invest more in gonads and produce faster-swimming sperm. Although there is ample evidence in support of the first prediction, few studies have examined sperm swimming speed in relation to sperm competition. In this study, we tested these predictions from sperm competition theory by examining sperm characteristics in Telmatochromis vittatus, a small shell-brooding cichlid fish endemic to Lake Tanganyika. Males exhibit four different reproductive tactics: pirate, territorial, satellite, and sneaker. Pirate males temporarily displace all other competing males from a shell nest, whereas sneaker males always release sperm in the presence of territorial and satellite males. Due to the fact that sneakers spawn in the presence of another male, sneakers face the highest levels of sperm competition and pirates the lowest, whereas satellites and territorials experience intermediate levels. In accordance with predictions, sperm from sneakers swam faster than sperm from males adopting the other reproductive tactics, whereas sperm from pirates was slowest. Interestingly, we were unable to detect any variation in sperm tail length among these reproductive tactics. Thus, sperm competition appears to have influenced sperm energetics in this species without having any influence on sperm size.

  17. Territorial males can sire more offspring in nests with smaller doors in the cichlid Lamprologus lemairii.

    Science.gov (United States)

    Ota, Kazutaka; Awata, Satoshi; Morita, Masaya; Yokoyama, Ryota; Kohda, Masanori

    2014-01-01

    To examine how territorial males counter reproductive parasites, we examined the paternity of broods guarded by territorial males using 5 microsatellite loci and factors that determine siring success in a wild population of the Lake Tanganyika cichlid Lamprologus lemairii. Females enter rock holes (nests) and spawn inside, and territorial males release milt over the nest openings. Sneakers attempt to dart into the nests, but territorial males often interrupt the attempt. The body size of territorial males (territorial defense ability) and the size of nest opening (the ability to prevent sneakers from nest intrusions) are predicted to be factors that affect paternity at the premating stage, whereas milt quality traits are factors that affect paternity at the postmating stage. Parentage analyses of 477 offspring revealed that most clutches have few or no cuckolders, and territorial males sired >80% of eggs in 7 of the 10 analyzed clutches. Larger territorial males that spawned in nests with narrower openings had greater siring success. In contrast, none of the milt traits affected the siring success. These suggest that territorial male L. lemairii adopt premating strategies whereby they effectively prevent reproductive parasitism.

  18. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish.

    Science.gov (United States)

    Magalhaes, I S; Smith, A M; Joyce, D A

    2017-01-27

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle "bowers" several times their size. We tested the idea that a less costly "sneaking" strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females' mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders.

  19. Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid.

    Science.gov (United States)

    Kohda, Masanori; Heg, Dik; Makino, Yoshimi; Takeyama, Tomohiro; Shibata, Jun-ya; Watanabe, Katsutoshi; Munehara, Hiroyuki; Hori, Michio; Awata, Satoshi

    2009-12-07

    Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result.

  20. As clear as mud: Turbidity induces behavioral changes in the African cichlid Pseudocrenilabrus multicolor

    Directory of Open Access Journals (Sweden)

    Suzanne M. GRAY, Laura H. McDONNELL, Fabio G. CINQUEMANI,Lauren J. CHAPMAN

    2012-02-01

    Full Text Available Aquatic biodiversity is being lost at an unprecedented rate. One factor driving this loss is increased turbidity, an environmental stressor that can impose behavioral, morphological, and/or physiological costs on fishes. Here we describe the behavioral response of a widespread African cichlid, Pseudocrenilabrus multicolor victoriae, to turbidity. We used a split-brood rearing design to test if F1 offspring reared in turbid water, originating from river (turbid and swamp (clear populations, behave differently than full-sibs reared in clear water. We examined two facets of behavior: (1 behaviors of fish in full sib groups, including activity level and social dynamics collected during the rearing period; and (2 male aggressive behavior directed at potential male competitors after fish had reached maturity; this was done in an experimental set-up independent of the rearing aquaria. Regardless of population of origin, fish reared in turbid water were marginally less active and performed fewer social behaviors than those reared in clear water. On the other hand, when tested against a competitor in turbid water, males performed more aggressive behaviors, regardless of population of origin or rearing environment. Our results suggest a plastic behavioral response to turbidity that may allow P. multicolor to persist over a range of turbidity levels in nature by decreasing activity and general social behaviors and intensifying reproductive behaviors to ensure reproductive success [Current Zoology 58 (1: 146–157, 2012].

  1. Male mate choice scales female ornament allometry in a cichlid fish

    Directory of Open Access Journals (Sweden)

    Kullmann Harald

    2010-10-01

    Full Text Available Abstract Background Studies addressing the adaptive significance of female ornamentation have gained ground recently. However, the expression of female ornaments in relation to body size, known as trait allometry, still remains unexplored. Here, we investigated the allometry of a conspicuous female ornament in Pelvicachromis taeniatus, a biparental cichlid that shows mutual mate choice and ornamentation. Females feature an eye-catching pelvic fin greatly differing from that of males. Results We show that allometry of the female pelvic fin is scaled more positively in comparison to other fins. The pelvic fin exhibits isometry, whereas the other fins (except the caudal fin show negative allometry. The size of the pelvic fin might be exaggerated by male choice because males prefer female stimuli that show a larger extension of the trait. Female pelvic fin size is correlated with individual condition, suggesting that males can assess direct and indirect benefits. Conclusions The absence of positive ornament allometry might be a result of sexual selection constricted by natural selection: fins are related to locomotion and thus may be subject to viability selection. Our study provides evidence that male mate choice might scale the expression of a female sexual ornament, and therefore has implications for the understanding of the relationship of female sexual traits with body size in species with conventional sex-roles.

  2. Unusual allometry for sexual size dimorphism in a cichlid where males are extremely larger than females

    Indian Academy of Sciences (India)

    Kazutaka Ota; Masanori Kohda; Tetsu Sato

    2010-06-01

    When males are the larger sex, a positive allometric relationship between male and female sizes is often found across populations of a single species (i.e. Rensch’s rule). This pattern is typically explained by a sexual selection pressure on males. Here, we report that the allometric relationship was negative across populations of a shell-brooding cichlid fish Lamprologus callipterus, although males are extremely larger than females. Male L. callipterus collect and defend empty snail shells in each of which a female breeds. We found that, across six populations, male and female sizes are positively correlated with not only sexual and fecundity selection indices, but also with shell sizes. Given their different reproductive behaviours, these correlations mean that males are required to be more powerful, and thus larger, to transport larger shells, while female bodies are reduced to the shell size to enable them to enter the shells. Among the three size selections (sexual selection, fecundity selection and shell size), shell size explained the allometry, suggesting that females are more strongly subject to size selection associated with shell size availability than males. However, the allometry was violated when considering an additional population where size-selection regimes of males differed from that of other populations. Therefore, sexual size allometry will be violated by body size divergence induced by multiple selection regimes.

  3. Chromosomal distribution of microsatellite repeats in Amazon cichlids genome (Pisces, Cichlidae).

    Science.gov (United States)

    Schneider, Carlos Henrique; Gross, Maria Claudia; Terencio, Maria Leandra; de Tavares, Édika Sabrina Girão Mitozo; Martins, Cesar; Feldberg, Eliana

    2015-01-01

    Fish of the family Cichlidae are recognized as an excellent model for evolutionary studies because of their morphological and behavioral adaptations to a wide diversity of explored ecological niches. In addition, the family has a dynamic genome with variable structure, composition and karyotype organization. Microsatellites represent the most dynamic genomic component and a better understanding of their organization may help clarify the role of repetitive DNA elements in the mechanisms of chromosomal evolution. Thus, in this study, microsatellite sequences were mapped in the chromosomes of Cichla monoculus Agassiz, 1831, Pterophyllum scalare Schultze, 1823, and Symphysodon discus Heckel, 1840. Four microsatellites demonstrated positive results in the genome of Cichla monoculus and Symphysodon discus, and five demonstrated positive results in the genome of Pterophyllum scalare. In most cases, the microsatellite was dispersed in the chromosome with conspicuous markings in the centromeric or telomeric regions, which suggests that sequences contribute to chromosome structure and may have played a role in the evolution of this fish family. The comparative genome mapping data presented here provide novel information on the structure and organization of the repetitive DNA region of the cichlid genome and contribute to a better understanding of this fish family's genome.

  4. As clear as mud: Turbidity induces behavioral changes in the African cichlid Pseudocrenilabrus multicolor

    Institute of Scientific and Technical Information of China (English)

    Suzanne M. GRAY; Laura H. McDONNELL; Fabio G. CINQUEMANI; Lauren J. CHAPMAN

    2012-01-01

    Aquatic biodiversity is being lost at an unprecedented rate.One factor driving this loss is increased turbidity,an environmental stressor that can impose behavioral,morphological,and/or physiological costs on fishes.Here we describe the behavioral response of a widespread African cichlid,Pseudocrenilabrus multicolor victoriae,to turbidity.We used a split-brood rearing design to test if F1 offspring reared in turbid water,originating from river (turbid) and swamp (clear) populations,behave differently than full-sibs reared in clear water.We examined two facets of behavior:(1) behaviors of fish in full sib groups,including activity level and social dynamics collected during the rearing period; and (2) male aggressive behavior directed at potential male competitors after fish had reached maturity; this was done in an experimental set-up independent of the rearing aquaria.Regardless of population of origin,fish reared in turbid water were marginally less active and performed fewer social behaviors than those reared in clear water.On the other hand,when tested against a competitor in turbid water,males performed more aggressive behaviors,regardless of population of origin or rearing environment.Our results suggest a plastic behavioral response to turbidity that may allow P multicolor to persist over a range of turbidity levels in nature by decreasing activity and general social behaviors and intensifying reproductive behaviors to ensure reproductive success [ Current Zoology 58 (1):146-157,2012].

  5. Effect of mate size on maternal reproductive effort in the convict cichlid Amatitlania siquia

    Institute of Scientific and Technical Information of China (English)

    Ashley R. ROBART

    2012-01-01

    The differential allocation hypothesis predicts individuals will increase their reproductive investment when mated to a high quality partner.In many species of fish with biparental care females prefer large males due to the males' greater ability to raise more offspring to independence.I examined the relationship between mate quality,parental care and number of offspring in a natural population of convict cichlids Amatitlania siquia.The frequency of frontal displays by females was positively correlated with male standard length.Additionally,as males increased in length relative to their mate,females increased the frequency of chases towards predators,while males decreased the number of displays towards brood predators.This trade-off in parental effort within a pair due to mate quality is a key prediction of differential allocation.The number of offspring was correlated with male,but not female,standard length.These results support the differential allocation hypothesis in that females offered more parental care to offspring of a larger male,while their mates decreased the amount of care they provided.Additionally,females benefited in terms of number of offspring by pairing with higher quality mates.Increased female investment may provide an incentive to ensure male care and maintain pair bonding,which could lead to greater reproductive success through increased offspring survival [Current Zoology 58 (1):66-72,2012].

  6. Symmetry perception in bamboo sharks (Chiloscyllium griseum) and Malawi cichlids (Pseudotropheus sp.).

    Science.gov (United States)

    Schluessel, V; Beil, O; Weber, T; Bleckmann, H

    2014-09-01

    Several species have been shown to perceive symmetry as a measure of superior genetic quality, useful for assessing potential mates or mediating other visual activities such as the selection of food sources. The current study assessed whether Pseudotropheus sp. and Chiloscyllium griseum, two fish species from distantly related groups, possess symmetry perception. In alternative two choice experiments, individuals were tested for spontaneous preferences and trained to discriminate between abstract symmetrical and asymmetrical stimulus pairs. Pair discriminations were followed by extensive categorization experiments. Transfer tests elucidated whether bilaterally symmetrical and rotationally symmetrical stimuli could be distinguished. Sharks were also tested for the degree of dissimilarity between two symbols that could still be detected. While sharks showed both a spontaneous preference for symmetry as well as remarkable discrimination abilities by succeeding in all of the presented tasks, cichlids showed no spontaneous preference, had difficulties in discriminating between symbols and performed poorly in the categorization experiments. Sharks distinguished between bilaterally and rotationally symmetrical stimuli and easily differentiated between a four-armed cross (all arms 90° apart) and a cross where one of the arms was only 45° spaced from the one next to it. Performance did not decline when the separation was extended to 70°, but was significantly reduced at an 80° separation. Results indicate that the ability for symmetry perception varies across fish species and individuals, whereby some can detect even subtle differences in this respect.

  7. Immunocytochemical characterisation of neural stem-progenitor cells from green terror cichlid Aequidens rivulatus.

    Science.gov (United States)

    Wen, C M; Chen, M M; Nan, F H; Wang, C S

    2017-01-01

    In this study, cultures of neural stem-progenitor cells (NSPC) from the brain of green terror cichlid Aequidens rivulatus were established and various NSPCs were demonstrated using immunocytochemistry. All of the NSPCs expressed brain lipid-binding protein, dopamine- and cAMP-regulated neuronal phosphoprotein 32 (DARPP-32), oligodendrocyte transcription factor 2, paired box 6 and sex determining region Y-box 2. The intensity and localisation of these proteins, however, varied among the different NSPCs. Despite being intermediate cells, NSPCs can be divided into radial glial cells, oligodendrocyte progenitor cells (OPC) and neuroblasts by expressing the astrocyte marker glial fibrillary acidic protein (GFAP), OPC marker A2B5 and neuronal markers, including acetyl-tubulin, βIII-tubulin, microtubule-associated protein 2 and neurofilament protein. Nevertheless, astrocytes were polymorphic and were the most dominant cells in the NSPC cultures. By using Matrigel, radial glia exhibiting a long GFAP(+) or DARPP-32(+) fibre and neurons exhibiting a significant acetyl-tubulin(+) process were obtained. The results confirmed that NSPCs obtained from A. rivulatus brains can proliferate and differentiate into neurons in vitro. Clonal culture can be useful for further studying the distinct NSPCs.

  8. Phylogeographic Diversity of the Lower Central American Cichlid Andinoacara coeruleopunctatus (Cichlidae

    Directory of Open Access Journals (Sweden)

    S. Shawn McCafferty

    2012-01-01

    Full Text Available It is well appreciated that historical and ecological processes are important determinates of freshwater biogeographic assemblages. Phylogeography can potentially lend important insights into the relative contribution of historical processes in biogeography. However, the extent that phylogeography reflects historical patterns of drainage connection may depend in large part on the dispersal capability of the species. Here, we test the hypothesis that due to their relatively greater dispersal capabilities, the neotropical cichlid species Andinoacara coeruleopunctatus will display a phylogeographic pattern that differs from previously described biogeographic assemblages in this important region. Based on an analysis of 318 individuals using mtDNA ATPase 6/8 sequence and restriction fragment length polymorphism data, we found eight distinct clades that are closely associated with biogeographic patterns. The branching patterns among the clades and a Bayesian clock analysis suggest a relatively rapid colonization and diversification among drainages in the emergent Isthmus of Panama followed by the coalescing of some drainages due to historical connections. We also present evidence for extensive cross-cordillera sharing of clades in central Panama and the Canal region. Our results suggest that contemporary phylogeographic patterns and diversification in Lower Central American fishes reflect an interaction of historical drainage connections, dispersal, and demographic processes.

  9. MUF architecture /art London

    DEFF Research Database (Denmark)

    Svenningsen Kajita, Heidi

    2009-01-01

    Om MUF architecture samt interview med Liza Fior og Katherine Clarke, partnere i muf architecture/art......Om MUF architecture samt interview med Liza Fior og Katherine Clarke, partnere i muf architecture/art...

  10. Kosmos = architecture

    Directory of Open Access Journals (Sweden)

    Tine Kurent

    1985-12-01

    Full Text Available The old Greek word "kosmos" means not only "cosmos", but also "the beautiful order", "the way of building", "building", "scenography", "mankind", and, in the time of the New Testament, also "pagans". The word "arhitekton", meaning first the "master of theatrical scenography", acquired the meaning of "builder", when the words "kosmos" and ~kosmetes" became pejorative. The fear that architecture was not considered one of the arts before Renaissance, since none of the Muses supervised the art of building, results from the misunderstanding of the word "kosmos". Urania was the Goddes of the activity implied in the verb "kosmein", meaning "to put in the beautiful order" - everything, from the universe to the man-made space, i. e. the architecture.

  11. Architectural Theatricality

    DEFF Research Database (Denmark)

    Tvedebrink, Tenna Doktor Olsen

    putting an emphasis on architecture as unified scenery guided by the four motives hearth, enclosure, dressing and context. This theoretical framework draws on the Gastronomic Analogy put forth by James Fergusson in 1862 and an interpretation of the writings of the 19th century architect Gottfried Semper...... with the material appearance of objects, but also the imaginary world of dreams and memories which are concealed with the communicative significance of intentions when designing the future super hospitals....

  12. Architectural Theatricality

    DEFF Research Database (Denmark)

    Tvedebrink, Tenna Doktor Olsen; Fisker, Anna Marie; Kirkegaard, Poul Henning

    2013-01-01

    is known for his writings on theatricality, understood as a holistic design approach emphasizing the contextual, cultural, ritual and social meanings rooted in architecture. Relative hereto, the International Food Design Society recently argued, in a similar holistic manner, that the methodology used......’ is an overlooked element in hospital eating environments today, and further point at how Semper’s discourse on theatricality can be used to add a more nuanced perspective to future hospitality studies....

  13. Multispecies Outcomes of Sympatric Speciation after Admixture with the Source Population in Two Radiations of Nicaraguan Crater Lake Cichlids.

    Science.gov (United States)

    Kautt, Andreas F; Machado-Schiaffino, Gonzalo; Meyer, Axel

    2016-06-01

    The formation of species in the absence of geographic barriers (i.e. sympatric speciation) remains one of the most controversial topics in evolutionary biology. While theoretical models have shown that this most extreme case of primary divergence-with-gene-flow is possible, only a handful of accepted empirical examples exist. And even for the most convincing examples uncertainties remain; complex histories of isolation and secondary contact can make species falsely appear to have originated by sympatric speciation. This alternative scenario is notoriously difficult to rule out. Midas cichlids inhabiting small and remote crater lakes in Nicaragua are traditionally considered to be one of the best examples of sympatric speciation and lend themselves to test the different evolutionary scenarios that could lead to apparent sympatric speciation since the system is relatively small and the source populations known. Here we reconstruct the evolutionary history of two small-scale radiations of Midas cichlids inhabiting crater lakes Apoyo and Xiloá through a comprehensive genomic data set. We find no signs of differential admixture of any of the sympatric species in the respective radiations. Together with coalescent simulations of different demographic models our results support a scenario of speciation that was initiated in sympatry and does not result from secondary contact of already partly diverged populations. Furthermore, several species seem to have diverged simultaneously, making Midas cichlids an empirical example of multispecies outcomes of sympatric speciation. Importantly, however, the demographic models strongly support an admixture event from the source population into both crater lakes shortly before the onset of the radiations within the lakes. This opens the possibility that the formation of reproductive barriers involved in sympatric speciation was facilitated by genetic variants that evolved in a period of isolation between the initial founding

  14. Feeding Your Newborn

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Feeding Your Newborn KidsHealth > For Parents > Feeding Your Newborn ... giving up the breast. previous continue About Formula Feeding Commercially prepared infant formula is a nutritious alternative ...

  15. Acquisition of Lateralized Predation Behavior Associated with Development of Mouth Asymmetry in a Lake Tanganyika Scale-Eating Cichlid Fish.

    Science.gov (United States)

    Takeuchi, Yuichi; Hori, Michio; Tada, Shinya; Oda, Yoichi

    2016-01-01

    The scale-eating cichlid Perissodus microlepis with asymmetric mouth is an attractive model of behavioral laterality: each adult tears off scales from prey fishes' left or right flanks according to the direction in which its mouth is skewed. To investigate the development of behavioral laterality and mouth asymmetry, we analyzed stomach contents and lower jaw-bone asymmetry of various-sized P. microlepis (22 ≤ SLLake Tanganyika. The shapes of the pored scales found in each specimen's stomach indicated its attack side preference. Early-juvenile specimens (SLphysical and behavioral literalities may contribute to efficient scale-eating.

  16. Haplochromis ushindi spec. nov., the largest piscivorous cichlid in the Mwanza Gulf area of Lake Victoria (East Africa) before the Nile perch upsurge

    NARCIS (Netherlands)

    Oijen, van M.J.P.

    2004-01-01

    A new species of a haplochromine cichlid (Pisces: Cichlidae: Haplochrominae) from Lake Victoria is described. It is the largest species known from the Mwanza gulf area before the Nile perch upsurge in 1986. Specimens have been collected between 1975 and 1985. Presumably, the species does not exist a

  17. From green architecture to architectural green

    DEFF Research Database (Denmark)

    Earon, Ofri

    2011-01-01

    they have overshadowed the architectural potential of green architecture. The paper questions how a green space should perform, look like and function. Two examples are chosen to demonstrate thorough integrations between green and space. The examples are public buildings categorized as pavilions. One....... Architectural green could signify green architecture with inclusive interrelations between green and space, built and unbuilt, inside and outside. The aim of the term is to reflect a new focus in green architecture – its architectural performance. Ecological issues are not underestimated or ignored, but so far......The paper investigates the topic of green architecture from an architectural point of view and not an energy point of view. The purpose of the paper is to establish a debate about the architectural language and spatial characteristics of green architecture. In this light, green becomes an adjective...

  18. Textile Architecture

    DEFF Research Database (Denmark)

    Heimdal, Elisabeth Jacobsen

    2010-01-01

    Textiles can be used as building skins, adding new aesthetic and functional qualities to architecture. Just like we as humans can put on a coat, buildings can also get dressed. Depending on our mood, or on the weather, we can change coat, and so can the building. But the idea of using textiles...... to create human habitation is not new. As Diether S. Hope phrases it, referring to tents: The history of development of humanity would be barely conceivable without free spanning textile membrane structures....

  19. Catalyst Architecture

    DEFF Research Database (Denmark)

    Kiib, Hans; Marling, Gitte; Hansen, Peter Mandal

    2014-01-01

    of programs, have a role in mediating positive social and/or cultural development. In this sense, we talk about architecture as a catalyst for: sustainable adaptation of the city’s infrastructure appropriate renovation of dilapidated urban districts strengthening of social cohesiveness in the city development...... meaningful for everyone. The exhibited works are designed by SANAA, Diller Scofidio + Renfro, James Corner Field Operation, JBMC Arquitetura e Urbanismo, Atelier Bow-Wow, Ateliers Jean Nouvel, COBE, Transform, BIG, Topotek1, Superflex, and by visual artist Jane Maria Petersen....

  20. Architectural dreaming

    Institute of Scientific and Technical Information of China (English)

    Mark Godfrey

    2004-01-01

    <正> For the first 800 years of its existence, Beijing retained essentially the same character: a walled palace city at its centre, organised on a strict north-south axis and contained within a sea of courtyard houses along lanes too narrow forcars. Today Beijing’s basic unit of architectural scale has become the skyscraper, erected a dozen at a time and facing massive highways. Ancient buildings are so small and unloved by comparison that they threaten to disappear from view. Fuelled by an economic boom, and propelled by banks flushed with mortgage cash, Beijing has embarked on the largest building campaign the world has ever seen.

  1. Two types of dominant male cichlid fish: behavioral and hormonal characteristics

    Directory of Open Access Journals (Sweden)

    Rosa M. Alcazar

    2016-08-01

    Full Text Available Male African cichlid fish, Astatotilapia burtoni, have been classified as dominant or subordinate, each with unique behavioral and endocrine profiles. Here we characterize two distinct subclasses of dominant males based on types of aggressive behavior: (1 males that display escalating levels of aggression and court females while they establish a territory, and (2 males that display a stable level of aggression and delay courting females until they have established a territory. To profile differences in their approach to a challenge, we used an intruder assay. In every case, there was a male-male confrontation between the resident dominant male and the intruder, with the intruder quickly taking a subordinate role. However, we found that dominant males with escalating aggression spent measurably more time attacking subordinates than did dominant males with stable aggression that instead increased their attention toward the females in their tank. There was no difference in the behavior of intruders exposed to either type of dominant male, suggesting that escalating aggression is an intrinsic characteristic of some dominant males and is not elicited by the behavior of their challengers. Male behavior during the first 15 min of establishing a territory predicts their aggressive class. These two types of dominant males also showed distinctive physiological characteristics. After the intruder assay, males with escalating aggression had elevated levels of 11-ketotestosterone (11-KT, testosterone, estradiol, and cortisol, while those with stable aggression did not. These observations show that the same stimulus can elicit different behavioral and endocrine responses among A. burtoni dominant males that characterize them as either escalating or stable aggressive types. Our ability to identify which individuals within a population have escalating levels of aggressive responses versus those which have stable levels of aggressive responses when exposed to

  2. Mechanism of action of endosulfan as disruptor of gonadal steroidogenesis in the cichlid fish Cichlasoma dimerus.

    Science.gov (United States)

    Da Cuña, Rodrigo H; Rey Vázquez, Graciela; Dorelle, Luciana; Rodríguez, Enrique M; Guimarães Moreira, Renata; Lo Nostro, Fabiana L

    2016-09-01

    The organochlorine pesticide endosulfan (ES) is used in several countries as a wide spectrum insecticide on crops with high commercial value. Due to its high toxicity to non-target animals, its persistence in the environment and its ability to act as an endocrine disrupting compound in fish, ES use is currently banned or restricted in many other countries. Previous studies on the cichlid fish Cichlasoma dimerus have shown that waterborne exposure to ES can lead to both decreased pituitary FSH content and histological alterations of testes. As gonadotropin-stimulated sex steroids release from gonads was inhibited by ES in vitro, the aim of the present study was to elucidate possible mechanisms of disruption of ES on gonadal steroidogenesis in C. dimerus, as well as compare the action of the active ingredient (AI) with that of currently used commercial formulations (CF). Testis and ovary fragments were incubated with ES (AI or CF) and/or steroidogenesis activators or precursors. Testosterone and estradiol levels were measured in the incubation media. By itself, ES did not affect hormone levels. Co-incubation with LH and the adenylate cyclase activator forskolin caused a decrease of the stimulated sex steroids release. When co-incubated with precursors dehydroandrostenedione and 17αhydroxyprogesterone, ES did not affect the increase caused by their addition alone. No differences were observed between the AI and CFs, suggesting that the effect on steroidogenesis disruption is mainly caused by the AI. Results indicate that action of ES takes place downstream of LH-receptor activation and upstream of the studied steroidogenic enzymes.

  3. Fish embryo and juvenile size under hypoxia in the mouth- brooding African cichlid Pseudocrenilabrus multicolor

    Directory of Open Access Journals (Sweden)

    E.E. REARDON, L.J. CHAPMAN

    2012-06-01

    Full Text Available We used a field survey and a laboratory rearing experiment to (a examine response (size and survival to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers and (b explore the degree to which developmental response can be environmentally-induced. Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO concentrations. In the laboratory, first generation (F1 broods of low-DO origin were reared under high or low DO. Brooding period was quantified for the mothers; and egg size, egg metabolic rate and juvenile size-at-release were quantified in their (F2 offspring. The F2 offspring were split and grown for 3 months post-release under high or low DO, and juvenile size and survival were quantified. In the field survey, across stages, embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations. In the laboratory experiment, F2 eggs and juveniles-at-release from mother’s mouth did not differ in mass, length, survival regardless of development DO environment. However, juveniles diverged in size after leaving mother’s mouth, exhibiting smaller size when grown under low DO. Size differences in embryo size across field populations and divergence in embryo size after release from the mother’s mouth support predictions for smaller body size under hypoxia. There was no evidence for negative effects on survival of juveniles after 3 months. Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development. This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes [Current Zoology 58 (3: 401-412, 2012].

  4. Fish embryo and juvenile size under hypoxia in the mouth-brooding African cichlid Pseudocrenilabrus multicolor

    Institute of Scientific and Technical Information of China (English)

    E.E.REARDON; L.J.CHAPMAN

    2012-01-01

    We used a field survey and a laboratory rearing experiment to (a) examine response (size and survival) to life-long hypoxia in offspring of the African maternal mouth-brooding cichlid Pseudocrenilabrus multicolor victoriae (Seegers) and (b) explore the degree to which developmental response can be environmentally-induced.Embryo size metrics were quantified in 9 field populations across a range of dissolved oxygen (DO) concentrations.In the laboratory,first generation (F1) broods of low-DO origin were reared under high or low DO.Brooding period was quantified for the mothers; and egg size,egg metabolic rate and juvenile size-at-release were quantified in their (F2) offspring.The F2 offspring were split and grown for 3 months post-release under high or low DO,and juvenile size and survival were quantified.In the field survey,across stages,embryos from low-DO field populations were shorter and weighed less than embryos from high-DO populations.In the laboratory experiment,F2 eggs and juveniles-at-release from mother's mouth did not differ in mass,length,survival regardless of development DO environment.However,juveniles diverged in size after leaving mother's mouth,exhibiting smaller size when grown under low DO.Size differences in embryo size across field populations and divergence in embryo size after release from the mother's mouthsupport predictions for smaller body size under hypoxia.There was no evidence for negative effects on survival of juveniles after 3 months.Brooding period was 16% shorter in females reared under low DO suggesting that hypoxia may accelerate embryo development.This work provides insights into how bearer fishes respond to hypoxic stress relative to fishes with no post-spawning parental care; a shorter brooding interval and smaller body size may provide an optimal solution to parent and embryo survival under hypoxia in brooding fishes.

  5. Effect of Hypergravity on Carbonanhydrase Reactivity in inner Ear Ioncytes of developing Cichlid Fish

    Science.gov (United States)

    Beier, M.; Anken, R.; Rahmann, H.

    It has been shown earlier that hypergravity slows down inner ear otolith growth in developing fish. Otolith growth in terms of mineralisation mainly depends on the enzyme carboanhydrase (CAH), which is responsible for the provision of the pH- value necessary for calcium carbonate deposition and thus also is presumed to play a prominent role in Ménière's disease (a sensory - motor disorder inducing vertigo and kinetosis). Larval siblings of cichlid fish (Oreochromis mossambicus) were subjected to hypergravity (3g; 6 hours) during development and separated into normally and kinetotically swimming individuals following the transfer to 1g (i.e., stopping the centrifuge; kinetotically behaving fish performed spinning movements). Subsequently, CAH was histochemically demonstrated in inner ear ionocytes (cells involved in the endolymphatic ion exchange) and enzyme reactivity was determined densitometrically. The results showed that CAH-reactivity was significantly increased in normally behaving hyper-g specimens as compared to controls kept at 1g, whereas no difference in enzyme reactivity was evident between the controls and kinetotically behaving fish. On the background of earlier studies, according to which (1) hypergravity induces a decrease of otolith growth and (2) the otolithic calcium incorporation (visualized using the calcium -tracer alizarin complexone) of kinetotically swimming hyper - g fish was lower as compared to normally behaving hyper - g animals, the present study strongly supports the concept that an increase in CAH-reactivity may result in a decrease of otolithic calcium deposition. The mechanism regulating CAH-activity hitherto remains to be determined. Acknowledgement: This work was financially supported by the German Aerospace Center (DLR) (FKZ: 50 WB 9997).

  6. The role of otolith size in hearing – Insights from cichlid fishes

    Directory of Open Access Journals (Sweden)

    Tanja Schulz-Mirbach

    2015-10-01

    Full Text Available Otolithic end organs in fishes function as accelerometers and are involved in the senses of balance and hearing (e.g. Popper et al. 2005. Otolith mass and shape are likely decisive factors influencing otolith motion, but while it is largely unknown how different shapes affect otolith movement relative to the sensory epithelium (Popper et al. 2005, greater otolith mass is predicted to result in enhanced stimulation of sensory hair cells and improved hearing (Lychakov and Rebane 2005. What few studies exist on this topic, however, yielded contradicting results in that they did or did not find a correlation between increased otolith mass and enhanced hearing (see Kéver et al. 2014. We investigated the relationship between otolith morphology (including 3D-models of otoliths based on high-resolution microCT imaging and otolith weight and hearing abilities in cichlids while comparing three species (Etroplus maculatus, Hemichromis guttatus, Steatocranus tinanti with different swimbladder morphology and hearing abilities (Schulz-Mirbach et al. 2014. We predicted Etroplus maculatus—the species that displays the best hearing sensitivities—to possess larger/heavier otoliths. As swimbladder extensions in this species are connected to the lagena, we further predicted to find heavier lagenar otoliths. Compared to H. guttatus and S. tinanti, E. maculatus showed the heaviest saccular otoliths, while lagenar otoliths were significantly thinner and lighter than in the former two species, apparently contradicting the hypothesis that the lagena and its otolith are primarily involved in improved hearing abilities. Our results support the idea that there is no ‘simple’ relationship between otolith weight, ancilliary auditory structures and hearing abilities. 3D-models of inner ears and otoliths may be ideally suited for future studies modeling complex otolith motion and thus, may provide a better understanding of how otolith morphology contributes to inner

  7. Sexual selection on color and behavior within and between cichlid populations: Implications for speciation

    Directory of Open Access Journals (Sweden)

    Michael J. PAUERS, Jeffrey S. MCKINNON

    2012-06-01

    Full Text Available Sexual selection is widely viewed as playing a central role in haplochromine cichlid speciation. Hypothetically, once divergent mate preferences evolve among populations of these fishes, reproductive isolation follows and the populations begin to behave as different species. Various studies have examined patterns of assortative mating among species and sometimes populations, but few have examined variation in directional preferences, especially among populations of the same species. We investigated mate choice behavior in two populations of Labeotropheus fuelleborni, a Lake Malawi endemic. We test whether mating preferences between populations are based on the same traits and in the same direction as preferences within populations. We examine the potential contributions of two classes of trait, color patterns and behaviors, to reproductive isolation. When females chose between either two males of their own population, or two from another, female preferences were generally similar (for the female population across the two contexts. Mate choice patterns differed between (female populations for a measure of color, but only modestly for male behavior. In a separate experiment we simultaneously offered females a male of their own population and a male from a different population. In these trials, females consistently preferred males from their own population, which were also the males that displayed more frequently than their opponents, but not necessarily those with color traits suggested to be most attractive in the previous experiment. Thus directional preferences for chroma and related aspects of color may be important when females are presented with males of otherwise similar phenotypes, but may play little role in mediating assortative mating among populations with substantially different color patterns. A preference for male behavior could play some role in speciation if males preferentially court same-population females, as we have observed

  8. Sexual selection on color and behavior within and between cichlid populations: Implications for speciation

    Institute of Scientific and Technical Information of China (English)

    Michael J.PAUERS; Jeffrey S.MCKINNON

    2012-01-01

    Sexual selection is widely viewed as playing a central role in hapiochromine cichlid speciation.Hypothetically,once divergent mate preferences evolve among populations of these fishes,reproductive isolation follows and the populations begin to behave as different species.Various studies have examined patterns of assortative mating among species and sometimes populations,but few have examined variation in directional preferences,especially among populations of the same species.We investigated mate choice behavior in two populations of Labeotropheus fuelleborni,a Lake Malawi endemic.We test whether mating.preferences between populations are based on the same traits and in the same direction as preferences within populations.We examine the potential contributions of two classes of trait,color patterns and behaviors,to reproductive isolation.When females chose between either two males of their own population,or two from another,female preferences were generally similar (for the female population) across the two contexts.Mate choice patterns differed between (female) populations for a measure of color,but only modestly for male behavior.In a separate experiment we simultaneously offered females a male of their own population and a male from a different population.In these trials,females consistently preferred males from their own population,which were also the males that displayed more frequently than their opponents,but not necessarily those with color traits suggested to be most attractive in the previous experiment.Thus directional preferences for chroma and related aspects of color may be important when females are presented with males of otherwise similar phenotypes,but may play little role in mediating assortative mating among populations with substantially different color patterns.A preference for male behavior could play some role in speciation if males preferentially court same-population females,as we have observed for the populations studied herein.

  9. Social regulation of male reproductive plasticity in an African cichlid fish.

    Science.gov (United States)

    Maruska, Karen P; Fernald, Russell D

    2013-12-01

    Social interactions with the outcome of a position in a dominance hierarchy can have profound effects on reproductive behavior and physiology, requiring animals to integrate environmental information with their internal physiological state; but how is salient information from the animal's dynamic social environment transformed into adaptive behavioral, physiological, and molecular-level changes? The African cichlid fish, Astatotilapia burtoni, is ideally suited to understand socially controlled reproductive plasticity because activity of the male reproductive (brain-pituitary-gonad) axis is tightly linked to social status. Males form hierarchies in which a small percentage of brightly colored dominant individuals have an active reproductive axis, defend territories, and spawn with females, while the remaining males are subordinate, drably colored, do not hold a territory, and have a suppressed reproductive system with minimal opportunities for spawning. These social phenotypes are plastic and quickly reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. Here, we review the rapid and remarkable plasticity that occurs along the entire reproductive axis when males rise in social rank, a transition that has important implications for the operational sex ratio of the population. When males rise in rank, transformations occur in the brain, pituitary, circulation, and testes over short time-scales (minutes to days). Changes are evident in overt behavior, as well as modifications at the physiological, cellular, and molecular levels that regulate reproductive capacity. Widespread changes triggered by a switch in rank highlight the significance of external social information in shaping internal physiology and reproductive competence.

  10. Discovery of the invasive Mayan Cichlid fish "Cichlasoma" urophthalmus (Günther 1862) in Thailand, with comments on other introductions and potential impacts

    Science.gov (United States)

    Nico, Leo G.; Beamish, William H.; Musikasinthorn, Prachya

    2007-01-01

    We report on the occurrence and possible establishment of a non-native cichlid fish in a brackish-water system in the lower Chao Phraya River delta region, Thailand. Although, the possibility of some degree of introgressive hybridization can not be ruled out, Thailand specimens agree best with Mayan Cichlid “Cichlasoma” urophthalmus (Günther 1862). Our collections represent the first records of this New World, highly-invasive, euryhaline fish from Thailand and coincides with recent collections from Singapore. Positive identification of specimens as “C.” urophthalmus requires caution due to the diversity of the Cichlidae (>1,300 species), widespread introduction of many family members, variation within species, extensive interspecific overlap in characters, and proliferation of artificial cichlid hybrids (e.g., Flowerhorns). We first became aware of the Thailand population in 2005 when “C.” urophthalmus began appearing in the catches of local fishermen. We visited the site in November 2006 and obtained and examined voucher specimens. The abundance and wide size range of juveniles and adults in local ponds and an adjacent canal is evidence of natural reproduction. Because water bodies throughout the Chao Phraya delta are interconnected and subject to flooding, it is likely that “C.” urophthalmus is already established and is dispersing, but surveys and monitoring are needed to determine their exact geographic range. The Thailand population is compared to “C.” urophthalmus introduced into Florida (USA). Based on what is known about Florida “C.” urophthalmus, it is predicted that this cichlid will further invade coastal and inland waters in Thailand and elsewhere in Southeast Asia. This cichlid has a long history in the aquarium trade in Europe. However, there are no records from the wild in European waters and, because of the colder climate, the possibility of establishment in that region is relatively low.

  11. Genetic Evidence for Multiple Sources of the Non-Native Fish Cichlasoma urophthalmus (Günther; Mayan Cichlids) in Southern Florida

    Science.gov (United States)

    Harrison, Elizabeth; Trexler, Joel C.; Collins, Timothy M.; Vazquez-Domínguez, Ella; Razo-Mendivil, Ulises; Matamoros, Wilfredo A.; Barrientos, Christian

    2014-01-01

    The number and diversity of source populations may influence the genetic diversity of newly introduced populations and affect the likelihood of their establishment and spread. We used the cytochrome b mitochondrial gene and nuclear microsatellite loci to identify the sources of a successful invader in southern Florida, USA, Cichlasoma urophthalmus (Mayan cichlid). Our cytochrome b data supported an introduction from Guatemala, while our microsatellite data suggested movement of Mayan Cichlids from the upper Yucatán Peninsula to Guatemala and introductions from Guatemala and Belize to Florida. The mismatch between mitochondrial and nuclear genomes suggests admixture of a female lineage from Guatemala, where all individuals were fixed for the mitochondrial haplotype found in the introduced population, and a more diverse but also relatively small number of individuals from Belize. The Florida cytochrome b haplotype appears to be absent from Belize (0 out of 136 fish screened from Belize had this haplotype). Genetic structure within the Florida population was minimal, indicating a panmictic population, while Mexican and Central American samples displayed more genetic subdivision. Individuals from the Upper Yucatán Peninsula and the Petén region of Guatemala were more genetically similar to each other than to fish from nearby sites and movement of Mayan Cichlids between these regions occurred thousands of generations ago, suggestive of pre-Columbian human transportation of Mayan Cichlids through this region. Mayan Cichlids present a rare example of cytonuclear disequilibrium and reduced genetic diversity in the introduced population that persists more than 30 years (at least 7–8 generations) after introduction. We suggest that hybridization occurred in ornamental fish farms in Florida and may contribute their establishment in the novel habitat. Hybridization prior to release may contribute to other successful invasions. PMID:25184569

  12. Genetic evidence for multiple sources of the non-native fish Cichlasoma urophthalmus (Günther; Mayan Cichlids) in southern Florida.

    Science.gov (United States)

    Harrison, Elizabeth; Trexler, Joel C; Collins, Timothy M; Vazquez-Domínguez, Ella; Razo-Mendivil, Ulises; Matamoros, Wilfredo A; Barrientos, Christian

    2014-01-01

    The number and diversity of source populations may influence the genetic diversity of newly introduced populations and affect the likelihood of their establishment and spread. We used the cytochrome b mitochondrial gene and nuclear microsatellite loci to identify the sources of a successful invader in southern Florida, USA, Cichlasoma urophthalmus (Mayan cichlid). Our cytochrome b data supported an introduction from Guatemala, while our microsatellite data suggested movement of Mayan Cichlids from the upper Yucatán Peninsula to Guatemala and introductions from Guatemala and Belize to Florida. The mismatch between mitochondrial and nuclear genomes suggests admixture of a female lineage from Guatemala, where all individuals were fixed for the mitochondrial haplotype found in the introduced population, and a more diverse but also relatively small number of individuals from Belize. The Florida cytochrome b haplotype appears to be absent from Belize (0 out of 136 fish screened from Belize had this haplotype). Genetic structure within the Florida population was minimal, indicating a panmictic population, while Mexican and Central American samples displayed more genetic subdivision. Individuals from the Upper Yucatán Peninsula and the Petén region of Guatemala were more genetically similar to each other than to fish from nearby sites and movement of Mayan Cichlids between these regions occurred thousands of generations ago, suggestive of pre-Columbian human transportation of Mayan Cichlids through this region. Mayan Cichlids present a rare example of cytonuclear disequilibrium and reduced genetic diversity in the introduced population that persists more than 30 years (at least 7-8 generations) after introduction. We suggest that hybridization occurred in ornamental fish farms in Florida and may contribute their establishment in the novel habitat. Hybridization prior to release may contribute to other successful invasions.

  13. Induced cytochrome P450 1A activity in cichlid fishes from Guandu River and Jacarepagua Lake, Rio de Janeiro, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Parente, Thiago E.M.; Oliveira, Ana C.A.X. de [Laboratorio de Toxicologia Ambiental, Escola Nacional de Saude Publica - FIOCRUZ, Av Brasil 4036, Predio de Expansao do Campus, Rio de Janeiro, RJ 21041-361 (Brazil); Paumgartten, Francisco J.R. [Laboratorio de Toxicologia Ambiental, Escola Nacional de Saude Publica - FIOCRUZ, Av Brasil 4036, Predio de Expansao do Campus, Rio de Janeiro, RJ 21041-361 (Brazil)], E-mail: paum@ensp.fiocruz.br

    2008-03-15

    The induction of cytochrome P4501A-mediated activity (e.g. ethoxyresorufin-O-deethylation, EROD) has been used as a biomarker for monitoring fish exposure to AhR-receptor ligands such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and polychlorinated dibenzo-dioxins/furans (PCDD/Fs). In this study we found that hepatic EROD is induced in fish ('Nile tilapia', Oreochromis niloticus and 'acara', Geophagus brasiliensis) from the Guandu River (7-17-fold) and Jacarepagua Lake (7-fold), Rio de Janeiro, Brazil. Since both cichlid fish are consumed by the local population and the Guandu River is the main source of the drinking water supply for the greater Rio de Janeiro metropolitan area, pollution by cytochrome P4501A-inducing chemicals is a cause for concern and should be further investigated in sediments, water and biota. We additionally showed that EROD activity in the fish liver post-mitochondrial supernatant-simpler, cheaper and less time consuming to prepare than the microsomal fraction-is sufficiently sensitive for monitoring purposes. - Increased EROD activity in the liver of cichlid fishes indicated that Guandu River, the source of drinking water supply for Rio de Janeiro is polluted by CYP1A-inducing chemicals.

  14. Male-male competition and nuptial-colour displacement as a diversifying force in Lake Victoria cichlid fishes.

    Science.gov (United States)

    Seehausen, Ole; Schluter, Dolph

    2004-07-01

    We propose a new mechanism for diversification of male nuptial-colour patterns in the rapidly speciating cichlid fishes of Lake Victoria. Sympatric closely related species often display nuptial colours at opposite ends of the spectrum with males either blue or yellow to red. Colour polymorphisms within single populations are common too. We propose that competition between males for breeding sites promotes such colour diversification, and thereby speciation. We hypothesize that male aggression is primarily directed towards males of the common colour, and that rare colour morphs enjoy a negatively frequency-dependent fitness advantage. We test our hypothesis with a large dataset on the distributions and nuptial colorations of 52 species on 47 habitat islands in Lake Victoria, and with a smaller dataset on the within-spawning-site distributions of males with different coloration. We report that territories of males of the same colour are negatively associated on the spawning site, and that the distribution of closely related species over habitat islands is determined by nuptial coloration in the fashion predicted by our hypothesis. Whereas among unrelated species those with similar nuptial colour are positively associated, among closely related species those with similar colour are negatively associated and those with different colour are positively associated. This implies that negatively frequency-dependent selection on nuptial coloration among closely related species is a sufficiently strong force to override other effects on species distributions. We suggest that male-male competition is an important and previously neglected agent of diversification among haplochromine cichlid fishes.

  15. POTENSI INVASIF IKAN ZEBRA CICHLID (Amatitlania nigrofasciata Günther, 1867DI DANAU BERATAN, BALI DITINJAU DARI ASPEK BIOLOGINYA

    Directory of Open Access Journals (Sweden)

    Agus Arifin Sentosa

    2016-03-01

    Full Text Available Danau Beratan yang terletak di kawasan Bedugul, Bali telah terintroduksiikan zebra cichlid (Amatitlania nigrofasciata Günther, 1867 secara tidak sengaja. Tujuan penelitian adalah untuk mengetahui potensi ikan zebra sebagai ikan asing invasif di Danau Beratan berdasarkan kajian pada beberapa aspek biologinya. Penelitian dilakukan dengan metode survei lapang di Danau Beratan, Bali pada bulan Mei, Juli dan Oktober 2011. Contoh ikan diperoleh menggunakan jaring insang percobaan dan jaring tarik. Analisis data meliputi hubungan panjang berat, faktor kondisi, parameter pertumbuhan, kebiasaan makanan dan aspek reproduksi ikan. Hasil penelitian menunjukkan ikan zebra mendominasi hasil penangkapan. Ikan tersebut memiliki faktor kondisi yang baik dengan nilai laju pertumbuhan tahunan (K yang tinggi, bersifat generalis dalam memanfaatkan sumber daya makanan dan matang gonad pada ukuran panjang yang kecil. Karakteristik biologi inimengindikasikan ikan tersebut memiliki potensi invasif yang cukup tinggi.  Lake Beratanislocated inBedugul, Balihas been an unintentional introduction ofzebracichlid(Amatitlania nigrofasciataGünther, 1867. The aim of this research was to determine thepotential ofzebra cichlid becomeinvasivealienfish speciesinLake Beratanbasedonseveralbiological aspects.The study was carried outby field surveymethods in Lake Beratan, Bali on May, JulyandOctober 2011. Fish samples was obtained usingexperimentalgillnetsandmodification ofseine nets. Data analysis included the lengthweightrelationship, conditionfactor, growth parameters, foodhabitsand its reproduction aspects. The results showedthat zebracichliddominatethe experimental catchin LakeBeratan. Analysis showedthese fishhavea goodconditionwith ahigh growth rate, have a generalist characteristic in exploitingthe natural food resourcesandmatureat small length size. A reviewforseveral biological aspects ofthe zebra cichlidshowedthatfishhavea highinvasivepotentialinLake Beratan.

  16. Origin and evolution of B chromosomes in the cichlid fish Astatotilapia latifasciata based on integrated genomic analyses.

    Science.gov (United States)

    Valente, Guilherme T; Conte, Matthew A; Fantinatti, Bruno E A; Cabral-de-Mello, Diogo C; Carvalho, Robson F; Vicari, Marcelo R; Kocher, Thomas D; Martins, Cesar

    2014-08-01

    Approximately 15% of eukaryotes contain supernumerary B chromosomes. When present, B chromosomes frequently represent as much as 5% of the genome. Despite thousands of reports describing the distribution of supernumeraries in various taxa, a comprehensive theory for the origin, maintenance, and evolution of B chromosomes has not emerged. Here, we sequence the complete genomes of individual cichlid fish (Astatotilapia latifasciata) with and without B chromosomes, as well as microdissected B chromosomes, to identify DNA sequences on the B. B sequences were further analyzed through quantitative polymerase chain reaction and in situ hybridization. We find that the B chromosome contains thousands of sequences duplicated from essentially every chromosome in the ancestral karyotype. Although most genes on the B chromosome are fragmented, a few are largely intact, and we detect evidence that at least three of them are transcriptionally active. We propose a model in which the B chromosome originated early in the evolutionary history of Lake Victoria cichlids from a small fragment of one autosome. DNA sequences originating from several autosomes, including protein-coding genes and transposable elements, subsequently inserted into this proto-B. We propose that intact B chromosome genes involved with microtubule organization, kinetochore structure, recombination and progression through the cell cycle may play a role in driving the transmission of the B chromosome. Furthermore, our work suggests that karyotyping is an essential step prior to genome sequencing to avoid problems in genome assembly and analytical biases created by the presence of high copy number sequences on the B chromosome.

  17. Allometric shape change of the lower pharyngeal jaw correlates with a dietary shift to piscivory in a cichlid fish

    Science.gov (United States)

    Hellig, Christoph J.; Kerschbaumer, Michaela; Sefc, Kristina M.; Koblmüller, Stephan

    2010-07-01

    The morphological versatility of the pharyngeal jaw of cichlid fishes is assumed to represent a key factor facilitating their unparalleled trophic diversification and explosive radiation. It is generally believed that the functional design of an organism relates to its ecology, and thus, specializations to different diets are typically associated with distinct morphological designs, especially manifested in the cichlids’ pharyngeal jaw apparatus. Thereby, the lower pharyngeal jaw (LPJ) incorporates some of the most predictive features for distinct diet-related morphotypes. Thus, considering that piscivorous cichlids experience an ontogenetic dietary shift from typically various kinds of invertebrates to fish, concomitant morphological changes in the LPJ are expected. Using Lepidiolamprologus elongatus, a top predator in the shallow rocky habitat of Lake Tanganyika, as model, and applying geometric and traditional morphometric techniques, we demonstrate an allometric change in ontogenetic LPJ shape development coinciding with the completion of the dietary shift toward piscivory. The piscivorous LPJ morphotype is initiated in juvenile fish by increasing elongation and narrowing of the LPJ and—when the fish reach a size of 80-90 mm standard length—further refined by the elongation of the posterior muscular processes, which serve as insertion for the fourth musculus levator externus. The enlarged muscular processes of the fully mature piscivorous morphotype provide for the construction of a powerful lever system, which allows the large individuals to process large prey fish and rely on exclusive piscivory.

  18. Lab architecture

    Science.gov (United States)

    Crease, Robert P.

    2008-04-01

    There are few more dramatic illustrations of the vicissitudes of laboratory architecturethan the contrast between Building 20 at the Massachusetts Institute of Technology (MIT) and its replacement, the Ray and Maria Stata Center. Building 20 was built hurriedly in 1943 as temporary housing for MIT's famous Rad Lab, the site of wartime radar research, and it remained a productive laboratory space for over half a century. A decade ago it was demolished to make way for the Stata Center, an architecturally striking building designed by Frank Gehry to house MIT's computer science and artificial intelligence labs (above). But in 2004 - just two years after the Stata Center officially opened - the building was criticized for being unsuitable for research and became the subject of still ongoing lawsuits alleging design and construction failures.

  19. Decoding the architectural theory

    Institute of Scientific and Technical Information of China (English)

    Gu Mengchao

    2008-01-01

    Starting from the illustration of the definition and concept of the architectural theory, the author established his unique understanding about the framework of the architectural theory and the innovation of the architectural theory underlined by Chinese characteristics.

  20. Feeding tube insertion - gastrostomy

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002937.htm Feeding tube insertion - gastrostomy To use the sharing features on this page, please enable JavaScript. A gastrostomy feeding tube insertion is the placement of a feeding ...

  1. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... 1- to 2-Year-Old Breastfeeding vs. Formula Feeding KidsHealth > For Parents > Breastfeeding vs. Formula Feeding Print ... a lactation specialist. previous continue All About Formula Feeding Commercially prepared infant formulas are a nutritious alternative ...

  2. Animal Feeding Operations

    Science.gov (United States)

    ... What's this? Submit Button Healthy Water Home Animal Feeding Operations Recommend on Facebook Tweet Share Compartir On ... Concentrated Animal Feeding Operations (CAFOs) What are Animal Feeding Operations (AFOs)? According to the United States Environmental ...

  3. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... A What's in this article? All About Breastfeeding Breastfeeding Challenges All About Formula Feeding Formula Feeding Challenges Making a Choice en español Lactancia materna versus lactancia artificial Choosing whether to breastfeed or formula feed their ...

  4. SUSTAINABLE ARCHITECTURE : WHAT ARCHITECTURE STUDENTS THINK

    OpenAIRE

    SATWIKO, PRASASTO

    2013-01-01

    Sustainable architecture has become a hot issue lately as the impacts of climate change become more intense. Architecture educations have responded by integrating knowledge of sustainable design in their curriculum. However, in the real life, new buildings keep coming with designs that completely ignore sustainable principles. This paper discusses the results of two national competitions on sustainable architecture targeted for architecture students (conducted in 2012 and 2013). The results a...

  5. Modeling Architectural Patterns Using Architectural Primitives

    NARCIS (Netherlands)

    Zdun, Uwe; Avgeriou, Paris

    2005-01-01

    Architectural patterns are a key point in architectural documentation. Regrettably, there is poor support for modeling architectural patterns, because the pattern elements are not directly matched by elements in modeling languages, and, at the same time, patterns support an inherent variability that

  6. Lightweight enterprise architectures

    CERN Document Server

    Theuerkorn, Fenix

    2004-01-01

    STATE OF ARCHITECTUREArchitectural ChaosRelation of Technology and Architecture The Many Faces of Architecture The Scope of Enterprise Architecture The Need for Enterprise ArchitectureThe History of Architecture The Current Environment Standardization Barriers The Need for Lightweight Architecture in the EnterpriseThe Cost of TechnologyThe Benefits of Enterprise Architecture The Domains of Architecture The Gap between Business and ITWhere Does LEA Fit? LEA's FrameworkFrameworks, Methodologies, and Approaches The Framework of LEATypes of Methodologies Types of ApproachesActual System Environmen

  7. Software architecture 2

    CERN Document Server

    Oussalah, Mourad Chabanne

    2014-01-01

    Over the past 20 years, software architectures have significantly contributed to the development of complex and distributed systems. Nowadays, it is recognized that one of the critical problems in the design and development of any complex software system is its architecture, i.e. the organization of its architectural elements. Software Architecture presents the software architecture paradigms based on objects, components, services and models, as well as the various architectural techniques and methods, the analysis of architectural qualities, models of representation of architectural templa

  8. Software architecture 1

    CERN Document Server

    Oussalah , Mourad Chabane

    2014-01-01

    Over the past 20 years, software architectures have significantly contributed to the development of complex and distributed systems. Nowadays, it is recognized that one of the critical problems in the design and development of any complex software system is its architecture, i.e. the organization of its architectural elements. Software Architecture presents the software architecture paradigms based on objects, components, services and models, as well as the various architectural techniques and methods, the analysis of architectural qualities, models of representation of architectural template

  9. Distribution of Endomorphin-like-immunoreactive neurones in the brain of the cichlid fish Oreochromis mossambicus.

    Science.gov (United States)

    Vijayalaxmi; Ganesh, C B

    2017-02-08

    Endomorphins are tetrapeptides involved in pain and neuroendocrine responses with high affinity for mu opioid receptors in mammals. In the present investigation, we studied the distribution of endomorphin-like-immunoreactive (EM-L-ir) neurones in the brain of the cichlid fish Oreochromis mossambicus. Application of antisera against endomorphin 1 and 2 (EM-1-2) revealed the presence of EM-L-ir somata and fibres throughout the different subdivisions of the olfactory bulb such as the olfactory nerve layer and the granule cell layer. While the extensions of EM-L-ir fibres were seen along the medial olfactory tract, intensely labeled EM-L-ir somata were found in different subdivisions of the telencephalon. In the diencephalon, intensely stained EM-L-ir neurones were noticed in the preoptic area, the nucleus preopticus pars magnocellularis, the suprachiasmatic nucleus, the nucleus lateralis tuberis pars lateralis (NLTl) and the nucleus lateralis tuberis pars medialis (NLTm) regions, whereas projections of EM-L-ir fibres were also seen along the hypothalamo-hypophyseal tract suggested a possible hypophysiotrophic role for these neurones. Intense to moderately stained EM-L-ir neurones were noticed in different subdivisions of thalamic nucleus such as the dorsal posterior thalamic nucleus, commissura posterior, ventromedial thalamic nucleus, nucleus posterior tuberis, ventrolateral thalamic nucleus and medial preglomerular nucleus. Numerous intensely stained perikarya and axonal fibres were also noticed throughout the inferior lobe, along the periventricular margin of the reccessus lateralis, and in the nucleus recesus lateralis regions. In addition, numerous moderately labeled EM-like neuronal populations were found in the secondary gustatory nucleus and rostral spinal cord. The widespread distribution of EM-L-ir neurones throughout the brain and spinal cord indicate diverse roles for these cells in neuroendocrine and neuromodulatory responses for the first time in fish

  10. Evidence of a specialized feeding niche in a Late Triassic ray-finned fish: evolution of multidenticulate teeth and benthic scraping in †Hemicalypterus.

    Science.gov (United States)

    Gibson, Sarah Z

    2015-04-01

    Fishes have evolved to exploit multiple ecological niches. Extant fishes in both marine (e.g., rabbitfishes, surgeonfishes) and freshwater systems (e.g., haplochromine cichlids, characiforms) have evolved specialized, scoop-like, multidenticulate teeth for benthic scraping, feeding primarily on algae. Here, I report evidence of the oldest example of specialized multidenticulate dentition in a ray-finned fish, †Hemicalypterus weiri, from the Upper Triassic Chinle Formation of southeastern Utah (∼210-205 Ma), USA. †H. weiri is a lower actinopterygian species that is phylogenetically remote from modern fishes, and has evolved specialized teeth that converge with those of several living teleost fishes (e.g., characiforms, cichlids, acanthurids, siganids), with a likely function of these teeth being to scrape algae off a rock substrate. This finding contradicts previously held notions that fishes with multicuspid, scoop-like dentition were restricted to teleosts, and indicates that ray-finned fishes were diversifying into different trophic niches and exploring different modes of feeding earlier in their history than previously thought, fundamentally altering our perceptions of the ecological roles of fishes during the Mesozoic.

  11. Sounds produced by the cichlid fish Metriaclima zebra allow reliable estimation of size and provide information on individual identity.

    Science.gov (United States)

    Bertucci, F; Attia, J; Beauchaud, M; Mathevon, N

    2012-04-01

    Sounds produced by male cichlids Metriaclima zebra during aggressive interactions were recorded to conduct a detailed analysis and to search for potential individual acoustic signatures. Fish from two different size groups (small and large individuals) were analysed. The two groups were significantly different for all acoustic variables considered; six of seven features demonstrated a significant interindividual variability and most of them were correlated with the size of the emitter. A cross-validated and permuted discriminant function analysis (pDFA) separated the two groups and correctly classified around 50% of the sounds to the correct individuals. Acoustic features that best distinguished among males were the instantaneous frequency of sounds and the modulation of pulse amplitude. These results suggest that acoustic signals could bear information about individual identity. The long-term stability of this signature is likely to be weak since the signature of a growing individual may change over time.

  12. Construction of bacterial artificial chromosome libraries for the Lake Malawi cichlid (Metriaclima zebra), and the blind cavefish (Astyanax mexicanus).

    Science.gov (United States)

    Di Palma, Federica; Kidd, Celeste; Borowsky, Richard; Kocher, Thomas D

    2007-01-01

    Teleost fishes have become important models for studying the evolution of the genetic mechanisms of development. A key resource for comparative genomics and positional cloning are large-insert libraries constructed in bacterial artificial chromosomes. We have constructed bacterial artificial chromosome libraries for two species of teleost fish that are important models for the study of developmental evolution. Metriaclima zebra is one of several hundred closely related, morphologically diverse, haplochromine cichlids which have evolved over the last one million years in Lake Malawi, East Africa. The Mexican tetra, Astyanax mexicanus, is well known for adaptations related to the recent evolution of blind cave-dwelling forms. Clones and high-density filters for each library are available to the scientific community through the Hubbard Center for Genome Studies.

  13. Architecture as Design Study.

    Science.gov (United States)

    Kauppinen, Heta

    1989-01-01

    Explores the use of analogies in architectural design, the importance of Gestalt theory and aesthetic cannons in understanding and being sensitive to architecture. Emphasizes the variation between public and professional appreciation of architecture. Notes that an understanding of architectural process enables students to improve the aesthetic…

  14. Functional analysis of the larval feeding circuit in Drosophila.

    Science.gov (United States)

    Bhatt, Parag K; Neckameyer, Wendi S

    2013-11-19

    The serotonergic feeding circuit in Drosophila melanogaster larvae can be used to investigate neuronal substrates of critical importance during the development of the circuit. Using the functional output of the circuit, feeding, changes in the neuronal architecture of the stomatogastric system can be visualized. Feeding behavior can be recorded by observing the rate of retraction of the mouth hooks, which receive innervation from the brain. Locomotor behavior is used as a physiological control for feeding, since larvae use their mouth hooks to traverse across an agar substrate. Changes in feeding behavior can be correlated with the axonal architecture of the neurites innervating the gut. Using immunohistochemistry it is possible to visualize and quantitate these changes. Improper handling of the larvae during behavior paradigms can alter data as they are very sensitive to manipulations. Proper imaging of the neurite architecture innervating the gut is critical for precise quantitation of number and size of varicosities as well as the extent of branch nodes. Analysis of most circuits allow only for visualization of neurite architecture or behavioral effects; however, this model allows one to correlate the functional output of the circuit with the impairments in neuronal architecture.

  15. Can You Hear Architecture

    DEFF Research Database (Denmark)

    Ryhl, Camilla

    2016-01-01

    Taking an off set in the understanding of architectural quality being based on multisensory architecture, the paper aims to discuss the current acoustic discourse in inclusive design and its implications to the integration of inclusive design in architectural discourse and practice as well...... design and architectural quality for people with a hearing disability and a newly conducted qualitative evaluation research in Denmark as well as architectural theories on multisensory aspects of architectural experiences, the paper uses examples of existing Nordic building cases to discuss the role...... of acoustics in both inclusive design and multisensory architecture....

  16. Disturbance cues in freshwater prey fishes: Does urea function as an‘early warning cue’in juvenile convict cichlids and rainbow trout?

    Institute of Scientific and Technical Information of China (English)

    Grant E. BROWN; Christopher D. JACKSON; Patrick H. MALKA; (E)lisa JACQUES; Marc-Andre COUTURIER

    2012-01-01

    Freshwater vertebrate and invertebrate prey species commonly rely on chemosensory information,including non-injury released disturbance cues,to assess local predation threats.We conducted laboratory studies to (1) determine if urea can function as a disturbance cue in juvenile convict cichlids and rainbow trout and (2) determine if the background level of urea influences the behavioral response to a subsequent pulse of urea ('background noise' hypothesis).In the first series of trials,juvenile cichlids and trout were exposed to urea at varying concentrations (0 to 0.5 mg L-1 for cichlids and 0 to 1.0 mg L-1 for trout).Our results suggest that both cichilds and trout exhibited functionally similar responses to urea and conspecific disturbance cues and that increasing the concentration of urea results in an increase intensity of antipredator behaviour.In the second series of trials,we pre-exposed cichlids or trout to intermediate or high concentrations of urea (or a distilled water control) and then tested for the response to a second pulse of urea at at intermediate or high concentrations (versus a distilled water control).Our results demonstrate that pre-exposure to urea reduces or eliminates the response to a second pulse of urea,supporting the background noise hypothesis.Together,our results suggest that pulses of urea,released by disturbed or stressed individuals,may function as an early warning signal in freshwater prey species [Current Zoology 58 (2):250-259,2012].

  17. A new fossil cichlid from the Middle Miocene in the East African Rift Valley (Tugen Hills, Central Kenya: First record of a putative Ectodini

    Directory of Open Access Journals (Sweden)

    Melanie Altner

    2015-11-01

    Full Text Available Identification of fossil cichlids is difficult, because the currently used diagnostic morphological characters for living cichlids are mostly soft tissue based and such characters are hardly preserved in fossils. During our recent fieldwork in the Central Kenya Rift (E-Africa, we discovered several exceptionally well-preserved fossil cichlids, which can be assigned to different lineages among the African Pseudocrenilabrinae. Here we present one of those new specimens. Its most conspicuous character is a lateral line divided into three segments. This specimen was found in the lacustrine sediments of the Middle Miocene site Waril, Tugen Hills, Kenya. The site represents the deposits of an ancient freshwater lake ca. 9-10 million years ago. Previous work on fossil leaves from the same site allow for the reconstruction of open vegetation surrounding the lake and pronounced dry seasons. Among the main further characteristics of the new fossil cichlid is a lachrimal with six lateral line canals, big cycloid scales and a low number of dorsal fin spines (XIII. The latter two characters are traceable in several members of tribes within the Pseudocrenilabrinae. However, a lachrimal with six lateral line canals is exclusively found in certain tribes of the EAR (East African Radiation within the Pseudocrenilabrinae. Moreover, the unique lateral line pattern is solely present in two genera of the EAR tribe Ectodini. However, the fossil shows cycloid scales, while modern Ectodini have ctenoid scales. Taken all evidence together, this fossil may perhaps represent an ancient lineage related to the Ectodini. Up to date, there is no definite fossil record of the members of the EAR. Our fossil may represent the first reliable calibration point for this group, which would be consistent with the previously reconstructed diversification time of the H-lineage (EAR tribes, except Boulengerochromini, Bathybatini, Trematocarini and Lamprologini and the Lamprologini ca

  18. Feeding tube - infants

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007235.htm Feeding tube - infants To use the sharing features on this page, please enable JavaScript. A feeding tube is a small, soft, plastic tube placed ...

  19. Jejunostomy feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000181.htm Jejunostomy feeding tube To use the sharing features on this ... vomiting Your child's stomach is bloated Alternate Names Feeding - jejunostomy tube; G-J tube; J-tube; Jejunum ...

  20. Nasogastric feeding tube

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000182.htm Nasogastric feeding tube To use the sharing features on this ... the nose. It can be used for all feedings or for giving a person extra calories. It ...

  1. Tube Feeding Troubleshooting Guide

    Science.gov (United States)

    Tube Feeding Troubleshoot ing Guide This guide is a tool to assist you, and should not replace your doctor’s ... everyone. table of contents Going Home with Tube Feedings....................................................2 Nausea and ... ...

  2. Breastfeeding vs. Formula Feeding

    Science.gov (United States)

    ... Parks EP, Shaikhkhalil A, Groleau V, Wendel D, Stallings VA. Feeding healthy infants, children, and adolescents. In: ... 2016:chap. Stettler N, Bhatia J, Parish A, Stallings VA. Feeding healthy infants, children, and adolescents. In: ...

  3. Feeding Your Newborn

    Science.gov (United States)

    ... for your child. These guidelines on breastfeeding and bottle feeding can help you make the decision that's right ... formula is a nutritious alternative to breast milk. Bottle feeding can offer more freedom and flexibility for moms, ...

  4. Exporting Humanist Architecture

    DEFF Research Database (Denmark)

    Nielsen, Tom

    2016-01-01

    values and ethical stands involved in the export of Danish Architecture. Abstract: Danish architecture has, in a sense, been driven by an unwritten contract between the architects and the democratic state and its institutions. This contract may be viewed as an ethos – an architectural tradition...... with inherent aesthetic and moral values. Today, however, Danish architecture is also an export commodity. That raises questions, which should be debated as openly as possible. What does it mean for architecture and architects to practice in cultures and under political systems that do not use architecture...... as a way of generating humanism, freedom or equality? The essay outlines the background story, identifies a number of positions in relation to architecture exports and discusses some of the dilemmas that arise when Danish architecture is seen in an export perspective....

  5. Religious architecture: anthropological perspectives

    NARCIS (Netherlands)

    O. Verkaaik

    2013-01-01

    Religious Architecture: Anthropological Perspectives develops an anthropological perspective on modern religious architecture, including mosques, churches and synagogues. Borrowing from a range of theoretical perspectives on space-making and material religion, this volume looks at how religious buil

  6. Rhein-Ruhr architecture

    DEFF Research Database (Denmark)

    2002-01-01

    katalog til udstillingen 'Rhein - Ruhr architecture' Meldahls smedie, 15. marts - 28. april 2002. 99 sider......katalog til udstillingen 'Rhein - Ruhr architecture' Meldahls smedie, 15. marts - 28. april 2002. 99 sider...

  7. Low-level waste feed staging plan

    Energy Technology Data Exchange (ETDEWEB)

    Certa, P.J.; Grams, W.H.; McConville, C.M.; L. W. Shelton, L.W.; Slaathaug, E.J., Westinghouse Hanford

    1996-08-12

    The `Preliminary Low-Level Waste Feed Staging Plan` was updated to reflect the latest requirement in the Tank Waste Remediation Privatization Request for Proposals (RFP) and amendments. The updated plan develops the sequence and transfer schedule for retrieval of DST supernate by the management and integration contractor and delivery of the staged supernate to the private low-activity waste contractors for treatment. Two DSTs are allocated as intermediate staging tanks. A transfer system conflict analysis provides part of the basis for determining transfer system upgrade requirements to support both low-activity and high-level waste feed delivery. The intermediate staging tank architecture and retrieval system equipment are provided as a planning basis until design requirements documents are prepared. The actions needed to successfully implement the plan are identified. These include resolution of safety issues and changes to the feed envelope limits, minimum order quantities, and desired batch sizes.

  8. Architectural Knitted Surfaces

    DEFF Research Database (Denmark)

    Mossé, Aurélie

    2010-01-01

    WGSN reports from the Architectural Knitted Surfaces workshop recently held at ShenkarCollege of Engineering and Design, Tel Aviv, which offered a cutting-edge insight into interactive knitted surfaces. With the increasing role of smart textiles in architecture, the Architectural Knitted Surfaces...

  9. A high-resolution map of the Nile tilapia genome: a resource for studying cichlids and other percomorphs

    Directory of Open Access Journals (Sweden)

    Guyon Richard

    2012-06-01

    Full Text Available Abstract Background The Nile tilapia (Oreochromis niloticus is the second most farmed fish species worldwide. It is also an important model for studies of fish physiology, particularly because of its broad tolerance to an array of environments. It is a good model to study evolutionary mechanisms in vertebrates, because of its close relationship to haplochromine cichlids, which have undergone rapid speciation in East Africa. The existing genomic resources for Nile tilapia include a genetic map, BAC end sequences and ESTs, but comparative genome analysis and maps of quantitative trait loci (QTL are still limited. Results We have constructed a high-resolution radiation hybrid (RH panel for the Nile tilapia and genotyped 1358 markers consisting of 850 genes, 82 markers corresponding to BAC end sequences, 154 microsatellites and 272 single nucleotide polymorphisms (SNPs. From these, 1296 markers could be associated in 81 RH groups, while 62 were not linked. The total size of the RH map is 34,084 cR3500 and 937,310 kb. It covers 88% of the entire genome with an estimated inter-marker distance of 742 Kb. Mapping of microsatellites enabled integration to the genetic map. We have merged LG8 and LG24 into a single linkage group, and confirmed that LG16-LG21 are also merged. The orientation and association of RH groups to each chromosome and LG was confirmed by chromosomal in situ hybridizations (FISH of 55 BACs. Fifty RH groups were localized on the 22 chromosomes while 31 remained small orphan groups. Synteny relationships were determined between Nile tilapia, stickleback, medaka and pufferfish. Conclusion The RH map and associated FISH map provide a valuable gene-ordered resource for gene mapping and QTL studies. All genetic linkage groups with their corresponding RH groups now have a corresponding chromosome which can be identified in the karyotype. Placement of conserved segments indicated that multiple inter-chromosomal rearrangements have occurred

  10. Breast-Feeding Twins: Making Feedings Manageable

    Science.gov (United States)

    ... more than one baby? Here's help breast-feeding twins or other multiples, from getting positioned and ensuring ... babies who are born prematurely, as are many twins and higher order multiples. Breast milk is easier ...

  11. Software architecture evolution

    DEFF Research Database (Denmark)

    Barais, Olivier; Le Meur, Anne-Francoise; Duchien, Laurence

    2008-01-01

    Software architectures must frequently evolve to cope with changing requirements, and this evolution often implies integrating new concerns. Unfortunately, when the new concerns are crosscutting, existing architecture description languages provide little or no support for this kind of evolution....... The software architect must modify multiple elements of the architecture manually, which risks introducing inconsistencies. This chapter provides an overview, comparison and detailed treatment of the various state-of-the-art approaches to describing and evolving software architectures. Furthermore, we discuss...... one particular framework named Tran SAT, which addresses the above problems of software architecture evolution. Tran SAT provides a new element in the software architecture descriptions language, called an architectural aspect, for describing new concerns and their integration into an existing...

  12. High frequency of multiple paternity in broods of a socially monogamous cichlid fish with biparental nest defence.

    Science.gov (United States)

    Sefc, Kristina M; Mattersdorfer, Karin; Sturmbauer, Christian; Koblmüller, Stephan

    2008-05-01

    In several animal taxa, genetic analyses have demonstrated that social monogamy and biparental brood care do not preclude polygamous reproduction. Few studies have been conducted in fish, but in fish species without alternative reproductive phenotypes, social monogamy was largely congruent with genetic parentage. In contrast to these findings, we report an exceptionally high level of multiple paternity in a socially monogamous cichlid fish with biparental nest defence (Variabilichromis moorii), inferred from microsatellite and mitochondrial data of 10 broods. Whereas all offspring in a nest shared a common mother, each brood was sired by 2 to > 10 males. None of the inferred sires was assigned a large proportion of the brood. Paternity was estimated as the minimum number of sires required to explain multilocus offspring genotypes, and as the maximum-likelihood number of sires given population allele frequencies. Analysis of simulated brood genotypes suggested that, although these two methods tend to under- and overestimate, respectively, the true number of sires, primary sires with many offspring in a brood would have been detected. Hence, the genetic data indicate that the nest tending males suffer substantial cuckoldry and provide alloparental care for a large number of unrelated fry. We have no data on the social status of the cuckolding males, but due to synchronous spawning of pairs and commitment to brood care of paired males, it is possible that most of the parasitic spawners are solitary males.

  13. High levels of interspecific gene flow in an endemic cichlid fish adaptive radiation from an extreme lake environment.

    Science.gov (United States)

    Ford, Antonia G P; Dasmahapatra, Kanchon K; Rüber, Lukas; Gharbi, Karim; Cezard, Timothee; Day, Julia J

    2015-07-01

    Studying recent adaptive radiations in isolated insular systems avoids complicating causal events and thus may offer clearer insight into mechanisms generating biological diversity. Here, we investigate evolutionary relationships and genomic differentiation within the recent radiation of Alcolapia cichlid fish that exhibit extensive phenotypic diversification, and which are confined to the extreme soda lakes Magadi and Natron in East Africa. We generated an extensive RAD data set of 96 individuals from multiple sampling sites and found evidence for genetic admixture between species within Lake Natron, with the highest levels of admixture between sympatric populations of the most recently diverged species. Despite considerable environmental separation, populations within Lake Natron do not exhibit isolation by distance, indicating panmixia within the lake, although individuals within lineages clustered by population in phylogenomic analysis. Our results indicate exceptionally low genetic differentiation across the radiation despite considerable phenotypic trophic variation, supporting previous findings from smaller data sets; however, with the increased power of densely sampled SNPs, we identify genomic peaks of differentiation (FST outliers) between Alcolapia species. While evidence of ongoing gene flow and interspecies hybridization in certain populations suggests that Alcolapia species are incompletely reproductively isolated, the identification of outlier SNPs under diversifying selection indicates the radiation is undergoing adaptive divergence.

  14. Indirect mate choice, direct mate choice and species recognition in a bower-building cichlid fish lek.

    Science.gov (United States)

    Genner, M J; Young, K A; Haesler, M P; Joyce, D A

    2008-09-01

    Sexual selection arising through female mate choice typically favours males with larger, brighter and louder signals. A critical challenge in sexual selection research is to determine the degree to which this pattern results from direct mate choice, where females select individual males based on variation in signalling traits, or indirect mate choice, where male competition governs access to reproductively active females. We investigated female mate choice in a lekking Lake Malawi cichlid fish, Hemitilapia oxyrhynchus, in which males build and aggressively defend sand 'bowers'. Similar to previous studies, we found that male reproductive success was positively associated with bower height and centrality on the lek. However, this pattern resulted from males holding these territories encountering more females, and thus their greater success was due to indirect mate choice. Following initial male courtship, an increase in the relative mating success of some males was observed, but this relative increase was unrelated to bower size or position. Crucially, experimentally manipulating bowers to resemble those of a co-occurring species had no appreciable effect on direct choice by females or male spawning success. Together, these results suggest indirect mate choice is the dominant force determining male-mating success in this species, and that bowers are not signals used in direct mate choice by females. We propose that, in this species, bowers have a primary function in intraspecific male competition, with the most competitive males maintaining larger and more central bowers that are favoured by sexual selection due to higher female encounter rates.

  15. Is gastric sham feeding really sham feeding?

    Science.gov (United States)

    Sclafani, A; Nissenbaum, J W

    1985-03-01

    Rats were fitted with gastric cannulas, food deprived, and allowed to drink a sugar solution that drained out of the opened cannula; i.e., the rats sham-fed. Although this procedure is thought to prevent absorption of ingested food, it was found that the sham feeding of a 32% glucose or sucrose solution significantly elevated blood glucose levels. The addition of acarbose, a drug that inhibits the digestion of sucrose, to the 32% sucrose solution blocked the blood glucose rise, as did closing the pylorus with an inflatable pyloric cuff. Neither the drug nor the cuff, however, reduced the amount of sucrose solution consumed. These findings indicate that gastric sham feeding does not necessarily prevent the digestion and absorption of food, although absorption is not essential for the appearance of a vigorous sham-feeding response. Nevertheless the possibility that neural or hormonal feedback from the stomach contributes to the sham-feeding response cannot be excluded, and until this issue is resolved the results of gastric sham-feeding studies should be interpreted with caution.

  16. Genetic mapping of horizontal stripes in Lake Victoria cichlid fishes: benefits and pitfalls of using RAD markers for dense linkage mapping.

    Science.gov (United States)

    Henning, Frederico; Lee, Hyuk Je; Franchini, Paolo; Meyer, Axel

    2014-11-01

    The genetic dissection of naturally occurring phenotypes sheds light on many fundamental and longstanding questions in speciation and adaptation and is a central research topic in evolutionary biology. Until recently, forward-genetic approaches were virtually impossible to apply to nonmodel organisms, but the development of next-generation sequencing techniques eases this difficulty. Here, we use the ddRAD-seq method to map a colour trait with a known adaptive function in cichlid fishes, well-known textbook examples for rapid rates of speciation and astonishing phenotypic diversification. A suite of phenotypic key innovations is related to speciation and adaptation in cichlids, among which body coloration features prominently. The focal trait of this study, horizontal stripes, evolved in parallel in several cichlid radiations and is associated with piscivorous foraging behaviour. We conducted interspecific crosses between Haplochromis sauvagei and H. nyererei and constructed a linkage map with 867 SNP markers distributed on 22 linkage groups and total size of 1130.63 cM. Lateral stripes are inherited as a Mendelian trait and map to a single genomic interval that harbours a paralog of a gene with known function in stripe patterning. Dorsolateral and mid-lateral stripes were always coinherited and are thus under the same genetic control. Additionally, we directly quantify the genotyping error rates in RAD markers and offer guidelines for identifying and dealing with errors. Uncritical marker selection was found to severely impact linkage map construction. Fortunately, by applying appropriate quality control steps, a genotyping accuracy of >99.9% can be reached, thus allowing for efficient linkage mapping of evolutionarily relevant traits.

  17. Complex Feeding Decisions

    Directory of Open Access Journals (Sweden)

    Anna Miles PhD

    2016-08-01

    Full Text Available Objective: Where swallowing difficulties are chronic or progressive, or a patient is palliative, tube feeding is often not deemed appropriate. Instead, patients continue to eat and drink despite the risks of pneumonia and death. There is currently little evidence to guide clinical practice in this field often termed “risk feeding.” This qualitative study investigated staff, patient, and family member perceptions of risk feeding practices in one New Zealand hospital. Method: Twenty-nine staff members and six patients and/or their family were interviewed. Results: Thematic analysis revealed four global themes: supporting practice, communication, complexity of feeding decisions, and patient and family-centered care. Staff described limited education and organizational policy around risk feeding decisions. Communication was considered a major factor in the success. Conclusion: Feeding decisions are complex in the hospital environment. The themes identified in this study provide a foundation for hospital guideline development and implementation.

  18. Post-pyloric feeding

    Institute of Scientific and Technical Information of China (English)

    Eva Niv; Zvi Fireman; Nachum Vaisman

    2009-01-01

    Postpyloric feeding is an important and promising alternative to parenteral nutrition. The indications for this kind of feeding are increasing and include a variety of clinical conditions, such as gastroparesis, acute pancreatitis, gastric outlet stenosis, hyperemesis (including gravida), recurrent aspiration, tracheoesophageal fistula and stenosis in gastroenterostomy. This review discusses the differences between pre- and postpyloric feeding, indications and contraindications, advantages and disadvantages, and provides an overview of the techniques of placement of various postpyloric devices.

  19. The effect of high rearing densities on the growth of juveniles of the cichlid, cichlasoma managuense (Günther, 1869 (ESP

    Directory of Open Access Journals (Sweden)

    Jorge Günther Nonell

    2016-03-01

    Full Text Available The effect of high density culture on the growth of juvenile jaguar cichlids was investigated. Mean growth rate decrease with density, while the growth rate of the largest fishes was not affected. Reduction in mean growth resulted from a greater number of stunted individuals as well as from a higher degree of stunting. Skewness appears to be a better indicator of competitive effects than the coefficient of variation. It is concluded that at least in stagnant waters, even high densities do not affect the strong dominance hierarchy which establishes among guapote juveniles.

  20. Danger of zooplankton feeding

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Jiang, H.; Colin, S.P.

    2010-01-01

    Zooplankton feed in any of three ways: they generate a feeding current while hovering, cruise through the water or are ambush feeders. Each mode generates different hydrodynamic disturbances and hence exposes the grazers differently to mechanosensory predators. Ambush feeders sink slowly and ther......Zooplankton feed in any of three ways: they generate a feeding current while hovering, cruise through the water or are ambush feeders. Each mode generates different hydrodynamic disturbances and hence exposes the grazers differently to mechanosensory predators. Ambush feeders sink slowly...

  1. Infant feeding: formula, solids.

    Science.gov (United States)

    Barness, L A

    1985-04-01

    This article discusses and evaluates current formulas, traces their continual improvement (based largely on new information on breast milk composition), and then discusses the question of supplemental feedings.

  2. Architecture humanitarian emergencies

    DEFF Research Database (Denmark)

    Gomez-Guillamon, Maria; Eskemose Andersen, Jørgen; Contreras, Jorge Lobos

    2013-01-01

    Introduced by scientific articles conserning architecture and human rights in light of cultures, emergencies, social equality and sustainability, democracy, economy, artistic development and science into architecture. Concluding in definition of needs for new roles, processes and education of arc......, Architettura di Alghero in Italy, Architecture and Design of Kocaeli University in Turkey, University of Aguascalientes in Mexico, Architectura y Urbanismo of University of Chile and Escuela de Architectura of Universidad Austral in Chile....

  3. IT Architecture For Dummies

    CERN Document Server

    Hausman, Kalani Kirk

    2010-01-01

    A solid introduction to the practices, plans, and skills required for developing a smart system architecture. Information architecture combines IT skills with business skills in order to align the IT structure of an organization with the mission, goals, and objectives of its business. This friendly introduction to IT architecture walks you through the myriad issues and complex decisions that many organizations face when setting up IT systems to work in sync with business procedures. Veteran IT professional and author Kirk Hausman explains the business value behind IT architecture and provides

  4. Towards a Media Architecture

    DEFF Research Database (Denmark)

    Ebsen, Tobias

    2010-01-01

    This text explores the concept of media architecture as a phenomenon of visual culture that describes the use of screen-technology in new spatial configurations in practices of architecture and art. I shall argue that this phenomenon is not necessarily a revolutionary new approach, but rather...... a result of conceptual changes in both modes visual representation and in expressions of architecture. These are changes the may be described as an evolution of ideas and consequent experiments that can be traced back to changes in the history of art and the various styles and ideologies of architecture....

  5. Grid Architecture 2

    Energy Technology Data Exchange (ETDEWEB)

    Taft, Jeffrey D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-01-01

    The report describes work done on Grid Architecture under the auspices of the Department of Electricity Office of Electricity Delivery and Reliability in 2015. As described in the first Grid Architecture report, the primary purpose of this work is to provide stakeholder insight about grid issues so as to enable superior decision making on their part. Doing this requires the creation of various work products, including oft-times complex diagrams, analyses, and explanations. This report provides architectural insights into several important grid topics and also describes work done to advance the science of Grid Architecture as well.

  6. Elements of Architecture

    DEFF Research Database (Denmark)

    Elements of Architecture explores new ways of engaging architecture in archaeology. It conceives of architecture both as the physical evidence of past societies and as existing beyond the physical environment, considering how people in the past have not just dwelled in buildings but have existed...... and affective impacts, of these material remains. The contributions in this volume investigate the way time, performance and movement, both physically and emotionally, are central aspects of understanding architectural assemblages. It is a book about the constellations of people, places and things that emerge...

  7. Selection of Feed Intake or Feed Efficiency

    DEFF Research Database (Denmark)

    Veerkamp, Roel F; Pryce, Jennie E; Spurlock, Diane

    2013-01-01

    . In February 2013, the co-authors discussed how information on DMI should be incorporated in the breeding decisions. The aim of this paper is to present the overall discussion and main positions taken by the group on four topics related to feed efficiency: i) breeding goal definition; ii) biological variation...

  8. Creep Feeding Beef Calves

    OpenAIRE

    2005-01-01

    Creep feeding is the managerial practice of supplying supplemental feed (usually concentrates) to the nursing calf. Milk from a lactating beef cow furnishes only about 50 percent of the nutrients that a 3-4 month-old calf needs for maximum growth.

  9. On Detailing in Contemporary Architecture

    DEFF Research Database (Denmark)

    Kristensen, Claus; Kirkegaard, Poul Henning

    2010-01-01

    / tactility can blur the meaning of the architecture and turn it into an empty statement. The present paper will outline detailing in contemporary architecture and discuss the issue with respect to architectural quality. Architectural cases considered as sublime piece of architecture will be presented...

  10. Transition feeding of sows

    DEFF Research Database (Denmark)

    Theil, Peter Kappel

    2015-01-01

    becomes catabolic due to the high priority of milk production and to current feeding practices. Indeed, feed is changed from a gestation to a lactation diet for most sows and the feed supply typically goes from a restricted supply to an ad libitum allowance. In addition, transition sows are often exposed...... the first few days of lactation, and milk yield increases throughout the transition period and becomes the most important determinant of nutrient requirements. Thus, nutrient requirements of transition sows are affected by many intrinsic factors and these requirements change rapidly, yet, sow feeding...... practices do not acknowledge these changes. Development of new feeding strategies specifically adapted for the transition sow is likely of importance to match the rapid changes in nutrient requirements....

  11. Workflow automation architecture standard

    Energy Technology Data Exchange (ETDEWEB)

    Moshofsky, R.P.; Rohen, W.T. [Boeing Computer Services Co., Richland, WA (United States)

    1994-11-14

    This document presents an architectural standard for application of workflow automation technology. The standard includes a functional architecture, process for developing an automated workflow system for a work group, functional and collateral specifications for workflow automation, and results of a proof of concept prototype.

  12. Architecture and Stages

    DEFF Research Database (Denmark)

    Kiib, Hans

    2009-01-01

    as "experiencescape" - a space between tourism, culture, learning and economy. Strategies related to these challenges involve new architectural concepts and art as ‘engines' for a change. New expressive architecture and old industrial buildings are often combined into hybrid narratives, linking the past...

  13. Aesthetics of sustainable architecture

    NARCIS (Netherlands)

    Lee, S.

    2011-01-01

    The purpose of this book is to reveal, explore and further the debate on the aesthetic potentials of sustainable architecture and its practice. This book opens a new area of scholarship and discourse in the design and production of sustainable architecture, one that is based in aesthetics. The chapt

  14. SMRF architecture concepts

    NARCIS (Netherlands)

    Rossum, W.L. van; Wit, J.J.M. de; Otten, M.P.G.; Huizing, A.G.

    2011-01-01

    This presents three valuable applications of scalable multifunction RF (SMRF) systems. These systems allow radar, ESM, and communication functionality using a single front-end architecture. With the use of a novel system design tool, concepts for SMRF architectures for airborne, ground-based and nav

  15. Architecture and energy

    DEFF Research Database (Denmark)

    Marsh, Rob; Lauring, Michael

    2011-01-01

    Traditional low-energy architecture has not necessarily led to reduced energy consumption. A paradigm shift is proposed promoting pluralistic energy-saving strategies.......Traditional low-energy architecture has not necessarily led to reduced energy consumption. A paradigm shift is proposed promoting pluralistic energy-saving strategies....

  16. Digitally-Driven Architecture

    Directory of Open Access Journals (Sweden)

    Henriette Bier

    2014-07-01

    Full Text Available The shift from mechanical to digital forces architects to reposition themselves: Architects generate digital information, which can be used not only in designing and fabricating building components but also in embedding behaviours into buildings. This implies that, similar to the way that industrial design and fabrication with its concepts of standardisation and serial production influenced modernist architecture, digital design and fabrication influences contemporary architecture. While standardisation focused on processes of rationalisation of form, mass-customisation as a new paradigm that replaces mass-production, addresses non-standard, complex, and flexible designs. Furthermore, knowledge about the designed object can be encoded in digital data pertaining not just to the geometry of a design but also to its physical or other behaviours within an environment. Digitally-driven architecture implies, therefore, not only digitally-designed and fabricated architecture, it also implies architecture – built form – that can be controlled, actuated, and animated by digital means.In this context, this sixth Footprint issue examines the influence of digital means as pragmatic and conceptual instruments for actuating architecture. The focus is not so much on computer-based systems for the development of architectural designs, but on architecture incorporating digital control, sens­ing, actuating, or other mechanisms that enable buildings to inter­act with their users and surroundings in real time in the real world through physical or sensory change and variation.

  17. Teaching American Indian Architecture.

    Science.gov (United States)

    Winchell, Dick

    1991-01-01

    Reviews "Native American Architecture," by Nabokov and Easton, an encyclopedic work that examines technology, climate, social structure, economics, religion, and history in relation to house design and the "meaning" of space among tribes of nine regions. Describes this book's use in a college course on Native American architecture. (SV)

  18. Software Architecture Evolution

    Science.gov (United States)

    Barnes, Jeffrey M.

    2013-01-01

    Many software systems eventually undergo changes to their basic architectural structure. Such changes may be prompted by new feature requests, new quality attribute requirements, changing technology, or other reasons. Whatever the causes, architecture evolution is commonplace in real-world software projects. Today's software architects, however,…

  19. Applying neuroscience to architecture.

    Science.gov (United States)

    Eberhard, John P

    2009-06-25

    Architectural practice and neuroscience research use our brains and minds in much the same way. However, the link between neuroscience knowledge and architectural design--with rare exceptions--has yet to be made. The concept of linking these two fields is a challenge worth considering.

  20. Variable light environments induce plastic spectral tuning by regional opsin coexpression in the African cichlid fish, Metriaclima zebra.

    Science.gov (United States)

    Dalton, Brian E; Lu, Jessica; Leips, Jeff; Cronin, Thomas W; Carleton, Karen L

    2015-08-01

    Critical behaviours such as predation and mate choice often depend on vision. Visual systems are sensitive to the spectrum of light in their environment, which can vary extensively both within and among habitats. Evolutionary changes in spectral sensitivity contribute to divergence and speciation. Spectral sensitivity of the retina is primarily determined by visual pigments, which are opsin proteins bound to a chromophore. We recently discovered that photoreceptors in different regions of the retina, which view objects against distinct environmental backgrounds, coexpress different pairs of opsins in an African cichlid fish, Metriaclima zebra. This coexpression tunes the sensitivity of the retinal regions to the corresponding backgrounds and may aid in detection of dark objects, such as predators. Although intraretinal regionalization of spectral sensitivity in many animals correlates with their light environments, it is unknown whether variation in the light environment induces developmentally plastic alterations of intraretinal sensitivity regions. Here, we demonstrate with fluorescent in situ hybridization and qPCR that the spectrum and angle of environmental light both influence the development of spectral sensitivity regions by altering the distribution and level of opsins across the retina. Normally, M. zebra coexpresses LWS opsin with RH2Aα opsin in double cones of the ventral but not the dorsal retina. However, when illuminated from below throughout development, adult M. zebra coexpressed LWS and RH2Aα in double cones both dorsally and ventrally. Thus, environmental background spectra alter the spectral sensitivity pattern that develops across the retina, potentially influencing behaviours and related evolutionary processes such as courtship and speciation.

  1. Fighting and assessment in male cichlid fish: the effects of asymmetries in gonadal state and body size.

    Science.gov (United States)

    Neat; Huntingford; Beveridge

    1998-04-01

    In fights between animals over limited resources, the larger contestant often wins. Game theoretical models of animal fighting predict that relative body size is assessed during the fight and thus determines fight duration and intensity. In addition, if the contestants differ in the value they place on the disputed resource, this can also influence the outcome, duration and intensity of the fight. We studied territorial fighting in a cichlid fish, Tilapia zillii, in relation to relative body size and gonad weight. Relative gonad weight was a much stronger predictor of fight outcome than relative body size, even when body weight asymmetries were as large as 30%. This suggested that males with large gonads were fighting harder to defend their territory, perhaps because the value of a territory correlates with the gonadal state of the individual. A detailed analysis of mouth wrestling observed during fighting suggested that relative body size is assessed. However, contestants smaller than their opponent often continued to fight in spite of their size disadvantage. Weight disadvantaged winners appeared to fight more fiercely as suggested by a negative correlation between weight asymmetry and the proportion of bites inflicted by the winner. During escalated fighting, winners and losers differed consistently with regard to a behaviour termed mouth locking. Although neither biting nor persistence in mouth locking was related to gonad weight, we propose that the fish may have been assessing asymmetries unrelated to relative body size and possibly more related to levels of cost and the motivation to persist. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.

  2. A new cichlid fish in the Sahara: The Ounianga Serir lakes (Chad), a biodiversity hotspot in the desert.

    Science.gov (United States)

    Trape, Sébastien

    In the rare perennial bodies of water of the Sahara desert, only a few fish species have survived to increasing aridification since the end of the last humid period at the Holocene, approximately 5000 years BP. Here, I report the occurrence of an undescribed haplochomine cichlid fish in Lake Boukou, one of the seven Ounianga Serir lakes (Chad). These lakes are located in one of the most arid areas of the Sahara desert, but they persist by virtue of subsurface inflow of fresh groundwater from a large fossil aquifer. Astatotilapia tchadensis sp. nov. is characterized by a black bar between eye and corner of mouth, rounded orange spots on anal fin, scales ctenoid, lower limb of first gill arch with 7-8 gill rackers, dorsal fin with 13-14 spines and 9-11 soft rays, anal fin with 3 spines and 8-9 soft rays, 29 or 30 lateral line scales, and lower pharyngeal dentition with enlarged molariform teeth. The new species is easily distinguished from A. desfontainii and A. flaviijosephii, the northernmost haplochromine species currently isolated from its other group members, and appears close to an unnamed species of Lake Chad basin. Ounianga Serir lakes and especially Lake Boukou present a remarkable diversity of fish, the highest known in the Sahara desert with a total of at least six fish species belonging to six genera and three families. They also constitute an exceptional natural landscape inscribed on the UNESCO world heritage list in 2012 and a biodiversity hotspot for desert vertebrate species.

  3. Evidence for the involvement of dopamine in stress-induced suppression of reproduction in the cichlid fish Oreochromis mossambicus.

    Science.gov (United States)

    Chabbi, A; Ganesh, C B

    2015-05-01

    In the present study, we examined whether stress-induced suppression of reproduction is mediated through the catecholaminergic neurotransmitter dopamine (DA) in the female cichlid fish Oreochromis mossambicus. In the first experiment, application of antibody against tyrosine hydroxylase (TH; a marker for DA) in brain sections revealed the presence of intensely stained TH immunoreactive cells in the preoptic area (POA) and nucleus preopticus (NPO) during the previtellogenic phase. These cells showed weak immunoreactivity during the vitellogenic and prespawning phases concomitant with darkly stained luteinising hormone (LH) immunoreactive content in the proximal pars distalis (PPD) of the pituitary gland and fully ripened follicles (stage V) in the ovary of control fish. However, in fish exposed to aquacultural stressors, TH secreting cells remained intensely stained in POA and NPO regions during the prespawning phase, indicating increased synthetic and secretory activity, which was reflected by a significantly higher DA content compared to controls. Increased DA activity as a result of stress was associated with a decrease in the LH immunoreactive content in the PPD and an absence of stage V follicles in the ovary. In the second experiment, administration of DA caused effects similar to those in stressed fish, whereas DA receptor antagonist domperidone (DOM) treatment significantly increased the LH content in the PPD and the number of stage V follicles in unstressed fish. On the other hand, treatment of stressed fish with DOM resulted in dark accumulations of LH immunoreactive content in the PPD accompanied by the presence of stage V follicles in the ovary. Taken together, these results suggest an additional pathway for the inhibitory effects of stress through dopaminergic neurones along the reproductive axis.

  4. Architecture as liminal Space

    Directory of Open Access Journals (Sweden)

    Nilly Harag

    2015-11-01

    Full Text Available The point of departure of the architectural project has to stem from the combination of inner and outer journeys in between the real or imagined limits. The pressing challenge is to destabilize the neat division of architecture into separate bodies of knowledge and pose the architect’s mode of action on the threshold between the concrete and the universal. Architecture is a lens, an instrument one looks through to bring new perspectives into focus, enabling the transformation of experience from a magnified self-concentrated space to a wide horizon. Architecture narrates relations between spaces and examines its validity through signifying practices of design. Design for itself becomes the language of the current, of the immediate fashion. Architecture can fulfill peoples’ dreams and miraculously can provide them tools to invent new ones: Curiosity is the first motive to act.

  5. Can architecture be barbaric?

    Science.gov (United States)

    Hürol, Yonca

    2009-06-01

    The title of this article is adapted from Theodor W. Adorno's famous dictum: 'To write poetry after Auschwitz is barbaric.' After the catastrophic earthquake in Kocaeli, Turkey on the 17th of August 1999, in which more than 40,000 people died or were lost, Necdet Teymur, who was then the dean of the Faculty of Architecture of the Middle East Technical University, referred to Adorno in one of his 'earthquake poems' and asked: 'Is architecture possible after 17th of August?' The main objective of this article is to interpret Teymur's question in respect of its connection to Adorno's philosophy with a view to make a contribution to the politics and ethics of architecture in Turkey. Teymur's question helps in providing a new interpretation of a critical approach to architecture and architectural technology through Adorno's philosophy. The paper also presents a discussion of Adorno's dictum, which serves for a better understanding of its universality/particularity.

  6. Product Architecture Modularity Strategies

    DEFF Research Database (Denmark)

    Mikkola, Juliana Hsuan

    2003-01-01

    The focus of this paper is to integrate various perspectives on product architecture modularity into a general framework, and also to propose a way to measure the degree of modularization embedded in product architectures. Various trade-offs between modular and integral product architectures...... and how components and interfaces influence the degree of modularization are considered. In order to gain a better understanding of product architecture modularity as a strategy, a theoretical framework and propositions are drawn from various academic literature sources. Based on the literature review......, the following key elements of product architecture are identified: components (standard and new-to-the-firm), interfaces (standardization and specification), degree of coupling, and substitutability. A mathematical function, termed modularization function, is introduced to measure the degree of modularization...

  7. Architecture as Ars Combinatoria

    Directory of Open Access Journals (Sweden)

    Francesco Cacciatore

    2015-11-01

    Full Text Available Architecture today, no longer reflects the limits of experimentation and innovation. An extremely low-tech art whose field of possibilities consists of choosing and using that which has already been done in the past. It is because of this that the key skill a designer should have is the ability to recognize the complexity in forms around them: cities have the widest programming opportunities for architecture, in the two-way relationship that is established from the city that takes form in architecture and an architecture that finds its place in the contemporary city. Thus, architecture has its foundation in hospitality, an element that differentiates it significantly from the design.

  8. Cytogenetic mapping of the retroelements Rex1, Rex3 and Rex6 among cichlid fish: new insights on the chromosomal distribution of transposable elements.

    Science.gov (United States)

    Valente, G T; Mazzuchelli, J; Ferreira, I A; Poletto, A B; Fantinatti, B E A; Martins, C

    2011-01-01

    To enhance our understanding of the organization of the genome and chromosome evolution of cichlid fish species, we have isolated and physically mapped onto the chromosomes the transposable elements (TEs) Rex1, Rex3 and Rex6, which are conserved in teleost fish, in the chromosomes of African and South American cichlid species. The physical mapping of different Rex elements showed that they are primarily compartmentalized in the pericentromeric heterochromatic regions, although dispersed or clustered signals in euchromatic regions were also observed. The presence of TEs in heterochromatin can be correlated with their role in the structure and organization of heterochromatic areas (such as centromeres) or with the lower selective pressure that act on these gene-poor regions. The Rex elements were also concentrated in the largest chromosome pair of the Nile tilapia, Oreochromis niloticus. This chromosome pair is supposed to have originated by fusions, demonstrating the possible involvement of TEs with chromosome rearrangements. Besides general patterns of chromosomal distribution, comparative analysis suggests that Rex elements could differ in their chromosomal distribution among different fish groups or species and that intrinsic aspects of the genomes could influence the spread, accumulation or elimination of TEs.

  9. Minimalism in architecture: Abstract conceptualization of architecture

    Directory of Open Access Journals (Sweden)

    Vasilski Dragana

    2015-01-01

    Full Text Available Minimalism in architecture contains the idea of the minimum as a leading creative tend to be considered and interpreted in working through phenomena of empathy and abstraction. In the Western culture, the root of this idea is found in empathy of Wilhelm Worringer and abstraction of Kasimir Malevich. In his dissertation, 'Abstraction and Empathy' Worringer presented his thesis on the psychology of style through which he explained the two opposing basic forms: abstraction and empathy. His conclusion on empathy as a psychological basis of observation expression is significant due to the verbal congruence with contemporary minimalist expression. His intuition was enhenced furthermore by figure of Malevich. Abstraction, as an expression of inner unfettered inspiration, has played a crucial role in the development of modern art and architecture of the twentieth century. Abstraction, which is one of the basic methods of learning in psychology (separating relevant from irrelevant features, Carl Jung is used to discover ideas. Minimalism in architecture emphasizes the level of abstraction to which the individual functions are reduced. Different types of abstraction are present: in the form as well as function of the basic elements: walls and windows. The case study is an example of Sou Fujimoto who is unequivocal in its commitment to the autonomy of abstract conceptualization of architecture.

  10. Data-Centric Enterprise Architecture

    OpenAIRE

    Zeinab Rajabi; Maryam Nooraei Abade

    2012-01-01

    Enterprises choose Enterprise Architecture (EA) solution, in order to overcome dynamic business challenges and in coordinate various enterprise elements. In this article, a solution is suggested for the Enterprise Architecture development. The solution focuses on architecture data in the Enterprise Architecture development process. Data-centric architecture approach is preferred product-centric architecture approach. We suggest using Enterprise Ontology (EO) as context for collecting architec...

  11. Hybrid architecture: object, landscape, infrastructure

    OpenAIRE

    Pinto de Freitas, Rita

    2011-01-01

    The concept of "hybrid architecture" developed in this study considers hybrid all architecture that is at once object, landscape and infrastructure. Hybrid architecture, pushed by the fact that it concentrates in a single architectural intervention a triple object-, landscape- and infrastructure-related nature, generates architectural answers with very specific features, and its study achieves following goals: 1: Clarify the term hybrid related to architectural intervention; 2: Tran...

  12. Fractal Geometry of Architecture

    Science.gov (United States)

    Lorenz, Wolfgang E.

    In Fractals smaller parts and the whole are linked together. Fractals are self-similar, as those parts are, at least approximately, scaled-down copies of the rough whole. In architecture, such a concept has also been known for a long time. Not only architects of the twentieth century called for an overall idea that is mirrored in every single detail, but also Gothic cathedrals and Indian temples offer self-similarity. This study mainly focuses upon the question whether this concept of self-similarity makes architecture with fractal properties more diverse and interesting than Euclidean Modern architecture. The first part gives an introduction and explains Fractal properties in various natural and architectural objects, presenting the underlying structure by computer programmed renderings. In this connection, differences between the fractal, architectural concept and true, mathematical Fractals are worked out to become aware of limits. This is the basis for dealing with the problem whether fractal-like architecture, particularly facades, can be measured so that different designs can be compared with each other under the aspect of fractal properties. Finally the usability of the Box-Counting Method, an easy-to-use measurement method of Fractal Dimension is analyzed with regard to architecture.

  13. Avionics Architecture for Exploration Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Avionics Architectures for Exploration Project team will develop a system level environment and architecture that will accommodate equipment from multiple...

  14. Integrated Data Assimilation Architecture Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Integrated Data Assimilation Architecture (IDAA) is a middleware architecture that facilitates the incorporation of heterogeneous sensing and control devices...

  15. Fermented liquid feed for pigs

    OpenAIRE

    Missotten, Joris; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël

    2010-01-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviat...

  16. RECONSTRUCTING DECONSTRUCTION IN ARCHITECTURE

    Directory of Open Access Journals (Sweden)

    IDHAM Noor Cholis

    2013-12-01

    Full Text Available This paper examines deconstruction in architecture and forms used, which triggered by dispute of form and its scientification claimed by deconstructivists. Deconstruction terminologyis studied in the first part related to architecture field as a base knowledge. Some sample works of known deconstructionist architects are assessed in order to understand how their building is deconstructed and what forms they used. Discussion about form and its relation to other fields is then pursued by discussing the involvement of terminology of science, aesthetic pattern, and human life. The results of this discussion give clear understanding how form related to deconstruction in architecture are used.

  17. ARCHITECTURE INFORMS HISTORY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Clusters of ancient architecture in central China have recently been entered on the world heritage list A group of ancient architecture in Dengfeng,central China’s Henan Province,was added to the world heritage list at the 34th session of the World Heritage Committee in Brazil on August 1 this year.The architectural collection is China’s 39th property inscribed on the list,and the third world heritage site in the province after the Longmen Grottoes and Yinxu in Anyang,site of the capital of the late Shang Dynasty(1600-1046 B.C.).

  18. Adaptive Architectural Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Kirkegaard, Poul Henning

    2010-01-01

    . The general scopes of this paper are to develop a new adaptive kinetic architectural structure, particularly a reconfigurable architectural structure which can transform body shape from planar geometries to hyper-surfaces using different control strategies, i.e. a transformation into more than one or two...... different shape alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock- up concept...

  19. Towards Adaptive Evolutionary Architecture

    DEFF Research Database (Denmark)

    Bak, Sebastian HOlt; Rask, Nina; Risi, Sebastian

    2016-01-01

    This paper presents first results from an interdisciplinary project, in which the fields of architecture, philosophy and artificial life are combined to explore possible futures of architecture. Through an interactive evolutionary installation, called EvoCurtain, we investigate aspects of how...... to the development of designs tailored to the individual preferences of inhabitants, changing the roles of architects and designers entirely. Architecture-as-it-could-be is a philosophical approach conducted through artistic methods to anticipate the technological futures of human-centered development within...

  20. Computer architecture technology trends

    CERN Document Server

    1991-01-01

    Please note this is a Short Discount publication. This year's edition of Computer Architecture Technology Trends analyses the trends which are taking place in the architecture of computing systems today. Due to the sheer number of different applications to which computers are being applied, there seems no end to the different adoptions which proliferate. There are, however, some underlying trends which appear. Decision makers should be aware of these trends when specifying architectures, particularly for future applications. This report is fully revised and updated and provides insight in

  1. Architectures of prototypes and architectural prototyping

    DEFF Research Database (Denmark)

    Hansen, Klaus Marius; Christensen, Michael; Sandvad, Elmer;

    1998-01-01

    together as a team, but developed a prototype that more than fulfilled the expectations of the shipping company. The prototype should: - complete the first major phase within 10 weeks, - be highly vertical illustrating future work practice, - continuously live up to new requirements from prototyping...... sessions with users, - evolve over a long period of time to contain more functionality - allow for 6-7 developers working intensively in parallel. Explicit focus on the software architecture and letting the architecture evolve with the prototype played a major role in resolving these conflicting......This paper reports from experience obtained through development of a prototype of a global customer service system in a project involving a large shipping company and a university research group. The research group had no previous knowledge of the complex business of shipping and had never worked...

  2. Analysis of Architecture Pattern Usage in Legacy System Architecture Documentation

    NARCIS (Netherlands)

    Harrison, Neil B.; Avgeriou, Paris

    2008-01-01

    Architecture patterns are an important tool in architectural design. However, while many architecture patterns have been identified, there is little in-depth understanding of their actual use in software architectures. For instance, there is no overview of how many patterns are used per system or wh

  3. Robot Electronics Architecture

    Science.gov (United States)

    Garrett, Michael; Magnone, Lee; Aghazarian, Hrand; Baumgartner, Eric; Kennedy, Brett

    2008-01-01

    An electronics architecture has been developed to enable the rapid construction and testing of prototypes of robotic systems. This architecture is designed to be a research vehicle of great stability, reliability, and versatility. A system according to this architecture can easily be reconfigured (including expanded or contracted) to satisfy a variety of needs with respect to input, output, processing of data, sensing, actuation, and power. The architecture affords a variety of expandable input/output options that enable ready integration of instruments, actuators, sensors, and other devices as independent modular units. The separation of different electrical functions onto independent circuit boards facilitates the development of corresponding simple and modular software interfaces. As a result, both hardware and software can be made to expand or contract in modular fashion while expending a minimum of time and effort.

  4. Architecture for the senses

    DEFF Research Database (Denmark)

    Ryhl, Camilla

    2009-01-01

    findings from the PhD thesis 'A House for the Senses' by the author, a study of architectural requirements in housing design implied by a sensory impairment. The empirical research project is based on qualitative interviews and 1:1 testing in existing housing with participants who were either blind, deaf......Accommodating sensory disabilities in architectural design requires specific design considerations. These are different from the ones included by the existing design concept 'accessibility', which primarily accommodates physical disabilites. Hence a new design concept 'sensory accessbility......' is presented as a parallel and complementary concept to the existing one. Sensory accessiblity accommodates sensory disabilities and describes architectural design requirements needed to ensure access to to the sensory experiences and architectural quality of a given space. The article is based on research...

  5. DSP Architecture Design Essentials

    CERN Document Server

    Marković, Dejan

    2012-01-01

    In DSP Architecture Design Essentials, authors Dejan Marković and Robert W. Brodersen cover a key subject for the successful realization of DSP algorithms for communications, multimedia, and healthcare applications. The book addresses the need for DSP architecture design that maps advanced DSP algorithms to hardware in the most power- and area-efficient way. The key feature of this text is a design methodology based on a high-level design model that leads to hardware implementation with minimum power and area. The methodology includes algorithm-level considerations such as automated word-length reduction and intrinsic data properties that can be leveraged to reduce hardware complexity. From a high-level data-flow graph model, an architecture exploration methodology based on linear programming is used to create an array of architectural solutions tailored to the underlying hardware technology. The book is supplemented with online material: bibliography, design examples, CAD tutorials and custom software.

  6. Analyzing architecture articles

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In the present study, we express the quality, function, and characteristics of architecture to help people comprehensively understand what architecture is. We also reveal the problems and conflict found in population, land, water resources, pollution, energy, and the organization systems in construction. China’s economy is transforming. We should focus on the cities, architectural environment, energy conservation, emission-reduction, and low-carbon output that will result in successful green development. We should macroscopically and microscopically analyze the development, from the natural environment to the artificial environment; from the relationship between human beings and nature to the combination of social ecology in cities, and farmlands. We must learn to develop and control them harmoniously and scientifically to provide a foundation for the methods used in architecture research.

  7. Ancient Chinese Architecture

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    CHINESE people have accu-mulated a great deal ofexperience in architecture,constantly improving building ma-terials and thus creating uniquebuilding styles.The history of ancient Chinesearchitechtural development can be

  8. ARCHITECTURE INFORMS HISTORY

    Institute of Scientific and Technical Information of China (English)

    ZAN JIFANG

    2010-01-01

    @@ Agroup of ancient architecture in Dengfeng, central China's Henan Province, was added to the world heritage list at the 34th session of the World Heritage Committee in Brazil on August 1 this year. The architectural col-lection is China's 39th property inscribed on the list, and the third world heritage site in the province after the Longmen Grottoes and Yinxu in Anyang, site of the capital of the late Shang Dynasty (1600-1046 B.C.).

  9. BioArchitecture

    OpenAIRE

    Gunning, Peter

    2012-01-01

    Volume 1 has defined the scope of BioArchitecture. From the outset we have strived to ensure that BioArchitecture is not limited to the three major polymer systems of the cytoplasm. I am happy to say that a cursory glance at the contents of volume 1 makes it clear that we are interested in all aspects of bioarchitecture from molecules to polymers to cells to tissue to the organism.

  10. Essential software architecture

    CERN Document Server

    Gorton, Ian

    2011-01-01

    Job titles like ""Technical Architect"" and ""Chief Architect"" nowadays abound in software industry, yet many people suspect that ""architecture"" is one of the most overused and least understood terms in professional software development. Gorton's book tries to resolve this dilemma. It concisely describes the essential elements of knowledge and key skills required to be a software architect. The explanations encompass the essentials of architecture thinking, practices, and supporting technologies. They range from a general understanding of structure and quality attributes through technical i

  11. Artificial cognition architectures

    CERN Document Server

    Crowder, James A; Friess, Shelli A

    2013-01-01

    The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

  12. Climate and architecture

    DEFF Research Database (Denmark)

    Tind Kristensen, Eva; Friis Møller, Winnie; Rotne, Georg

    2010-01-01

    Climate and Architecture analyserer klimaets rolle i arkitekturen. Intentionen med bogen er at pege på nogle af de mange muligheder for bygningers klimaregulering, som et mere detaljeret studie af de lokale klimatiske forhold og den stedlige byggeskik tilbyder.......Climate and Architecture analyserer klimaets rolle i arkitekturen. Intentionen med bogen er at pege på nogle af de mange muligheder for bygningers klimaregulering, som et mere detaljeret studie af de lokale klimatiske forhold og den stedlige byggeskik tilbyder....

  13. Greek architecture now

    DEFF Research Database (Denmark)

    Skousbøll, Karin Merete

    2006-01-01

    With the author's Scandinavian viewpoint the aim of this book has been an investigation into contemporary Greek architecture and at the same time providing an understanding for its essential characteristics based on the historic, cultural heritage of Hellas.......With the author's Scandinavian viewpoint the aim of this book has been an investigation into contemporary Greek architecture and at the same time providing an understanding for its essential characteristics based on the historic, cultural heritage of Hellas....

  14. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  15. Time · Space · Architecture

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In the 20th century a Swiss writer wrote a book titled Time, Space and Architecture, in which he discussed the relationship between architecture and the times. Fifty years after that, this paper adopts the same title, hoping to deepen the understanding of the space-time structure in architecture and contribute to the new exploration of architectural forms.

  16. Masculinización del cíclido nativo Tenhuayaca, Petenia splendida (Günther, 1862, usando nauplios de Artemia como vehículo del esteroide 17-α metiltestosterona Mazculinization of the native cichlid Tenhuayaca, Petenia splendida (Günther, 1862, using Artemia nauplii as vehicle of the steroid 17-α methyltestosterone

    Directory of Open Access Journals (Sweden)

    Juan Manuel Vidal-López

    2009-12-01

    Full Text Available El uso de esteroides para producir poblaciones monosexo en cíclidos, ha sido ampliamente utilizado con el objetivo de evitar el proceso de reproducción y sobrepoblación de los estanques de cultivo, por medio de su aplicación a través del alimento balanceado. Sin embargo, cíclidos como la tenhuayaca, la cual tiene un alto potencial acuícola en el sureste de México y Centroamérica, durante su fase larvaria no aceptan el alimento balanceado, por lo que el uso de Artemia como vehículo para la administración de esteroides sintéticos ha sido propuesto recientemente. En el presente estudio se evaluó la masculinización de crías de Petenia splendida mediante la utilización de nauplios de Artemia como vehículo del esteroide 17-α metiltestosterona (MT, para lo cual se utilizaron larvas de primera alimentación a las cuales se les suministraron nauplios de Artemia como vehículo de la MT durante 5, 10, 20, 28, 45 y 60 días de alimentación, respectivamente y un tratamiento sin MT. Se determinó que los mayores porcentajes de masculinización y supervivencia, (96% de machos, 85% respectivamente se presentaron cuando se alimentaron las larvas con nauplios por 60 días. En el tratamiento control solamente se obtuvo un 56% de machos con una supervivencia de 83%, por lo cual concluimos que el uso de presas vivas como vehículo de la MT es adecuado para la producción de crías de P. splendida.At world-wide level the use of steroids to obtain all-male population in cichlids, has been widely used with the objective to avoid the reproduction process and to canalize the energy of the food in weight gain. In this sense, the application of steroids has been commonly through the artificial diets. Nevertheless, for some cichlid such as tenhuayaca or bay snook Petenia splendida, which is considered an appropriate species for aquaculture in the Southeastern of Mexico and Central America, the use of artificial diets during the larval period is not

  17. New Energy Architecture. Myanmar

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-06-15

    A global transition towards a new energy architecture is under way, driven by countries' need to respond to the changing dynamics of economic growth, environmental sustainability and energy security. The World Economic Forum, in collaboration with Accenture, has created the New Energy Architecture Initiative to address and accelerate this transition. The Initiative supports the development of national strategies and policy frameworks as countries seek to achieve the combined goals of energy security and access, sustainability, and economic growth and development. The World Economic Forum has formed a partnership with the Ministry of Energy of Myanmar to help apply the Initiative's approach to this developing and resource-rich nation. The Asian Development Bank and the World Economic Forum's Project Adviser, Accenture, have collaborated with the Forum on this consultation process, and have been supported by relevant government, industry and civil society stakeholders. The consultation process aims to understand the nation's current energy architecture challenges and provide an overview of a path to a New Energy Architecture through a series of insights. These insights could form the basis for a long-term multistakeholder roadmap to build Myanmar's energy sector in a way that is secure and sustainable, and promotes economic growth as the country makes its democratic transition. While not all recommendations can be implemented in the near term, they do provide options for creating a prioritized roadmap for Myanmar's energy transition. This report is the culmination of a nine-month multistakeholder process investigating Myanmar's energy architecture. Over the course of many visits to the country, the team has conducted numerous interviews, multistakeholder workshops, and learning and data-gathering exercises to ensure a comprehensive range of information and views. The team has also engaged with a variety of stakeholders to better

  18. Enteral feeding without pancreatic stimulation

    DEFF Research Database (Denmark)

    Kaushik, Neeraj; Pietraszewski, Marie; Holst, Jens Juul

    2005-01-01

    OBJECTIVE: All forms of commonly practiced enteral feeding techniques stimulate pancreatic secretion, and only intravenous feeding avoids it. In this study, we explored the possibility of more distal enteral infusions of tube feeds to see whether activation of the ileal brake mechanism can result...... in enteral feeding without pancreatic stimulation, with particular reference to trypsin, because the avoidance of trypsin stimulation may optimize enteral feeding in acute pancreatitis. METHODS: The pancreatic secretory responses to feeding were studied in 36 healthy volunteers by standard double......-lumen duodenal perfusion/aspiration techniques over 6 hours. Subjects were assigned to no feeding (n = 7), duodenal feeding with a polymeric diet (n = 7) or low-fat elemental diet (n = 6), mid-distal jejunal feeding (n = 11), or intravenous feeding (n = 5). All diets provided 40 kcal/kg ideal body weight/d and 1...

  19. Influence of altered gravity on the cytochemical localization of cytochrome oxidase activity in central and peripheral gravisensory systems in developing cichlid fish

    Science.gov (United States)

    Paulus, U.; Nindl, G.; Körtje, K. H.; Slenzka, K.; Neubert, J.; Rahmann, H.

    Cichlid fish larvae were reared from hatching to active free swimming under different gravity conditions: natural environment, increased acceleration in a centrifuge, simulated weightlessness in a clinostat and near weightlessness during space flight. Cytochrome oxidase activity was analyzed semiquantitatively on the ultrastructural level as a marker of regional neuronal activity in a primary, vestibular brainstem nucleus and in gravity receptive epithelia in the inner ear. Our results show, that gravity seems to be positively correlated with cytochrome oxidase activity in the magnocellular nucleus of developing fish brain. In the inner ear the energy metabolism is decreased under microgravity concerning utricle but not saccule. Hypergravity has not effect on cytochrome oxidase activity in sensory inner ear epithelia.

  20. Globalization and Landscape Architecture

    Directory of Open Access Journals (Sweden)

    Robert R. Hewitt

    2014-02-01

    Full Text Available The literature review examines globalization and landscape architecture as discourse, samples its various meanings, and proposes methods to identify and contextualize its specific literature. Methodologically, the review surveys published articles and books by leading authors and within the WorldCat.org Database associated with landscape architecture and globalization, analyzing survey results for comprehensive conceptual and co-relational frameworks. Three “higher order” dimensions frame the review’s conceptual organization, facilitating the organization of subordinate/subtopical areas of interest useful for comparative analysis. Comparative analysis of the literature suggests an uneven clustering of discipline-related subject matter across the literature’s “higher order” dimensions, with a much smaller body of literature related to landscape architecture confined primarily to topics associated with the dispersion of global phenomena. A subcomponent of this smaller body of literature is associated with other fields of study, but inferentially related to landscape architecture. The review offers separate references and bibliographies for globalization literature in general and globalization and landscape architecture literature, specifically.

  1. Comparative feeding ecology and habitats use of Crenicichla species (Perciformes: Cichlidae in a Venezuelan floodplain river

    Directory of Open Access Journals (Sweden)

    Carmen G. Montaña

    2009-06-01

    Full Text Available Feeding behavior and habitat use of two species of pike cichlids, or mataguaros, (Crenicichla lugubris and C. aff. wallacii were studied in the río Cinaruco, a floodplain river in the Venezuelan llanos. We examined 309 individuals of C. lugubris and 270 individuals of C. aff. wallacii from both the main channel and lagoons throughout the falling-water phase of the annual hydrological cycle. Crenicichla lugubris was common within habitats that contained rocks or woody debris, whereas C. aff. wallacii was more abundant in lagoons than the main channel, especially within shallow areas containing leaf litter. Although we did not capture C. aff. wallacii in rocky shoals, they sometimes were observed in these habitats. Crenicichla lugubris was larger than C. aff. wallacii (198.4 mm and 44.6 mm, respectively. Analysis of stomach contents showed that larger specimens (> 100 mm SL C. lugubris fed mostly on small fishes (e. g. characids, cichlids, but juveniles (O comportamento alimentar e o uso de habitat de duas espécies de "joanas", ou "mataguaros", (Crenicichla lugubris e C. aff. wallacii foram estudados no río Cinaruco, uma planície de alagamento nos llanos Venezuelanos. Examinamos 309 indivíduos de C. lugubris e 270 de C. aff. wallacii do canal principal e lagoas ao longo da fase de vazante de um ciclo hidrológico anual. Crenicichla lugubris foi comum em ambientes que continham rochas, galhos e troncos, enquanto que C. aff. wallacii foi mais abundante em lagoas do que no canal principal, especialmente em áreas rasas contendo folhiço. Embora não tenhamos capturado C. aff. wallacii em cardumes em meio às rochas, em algumas ocasiões eles foram observados nestes ambientes. Crenicichla lugubris foi maior do que C. aff. wallacii (198,4 mm e 44,6 mm CP, respectivamente. Análise dos conteúdos estomacais de C. lugubris revelou que os indivíduos maiores (> 100 mm CP se alimentaram principalmente de peixes pequenos (e. g. caracídeos e cicl

  2. Towards an Architectural Anthropology

    DEFF Research Database (Denmark)

    Stender, Marie

    2016-01-01

    their overlaps and collaboration. However, there are also challenging differences to take into account regarding disciplinary traditions of, for example, communication, temporality, and normativity. This article explores the potentials and challenges of architectural anthropology as a distinct sub......Architecture and anthropology have always had overlapping interests regarding issues such as spatial organisation, forms of human dwellings, and the interplay between social life and physical surroundings. Recent developments in both disciplines make it even more relevant to explore and evolve......-discipline and outlines its possible theoretical, methodological, and applied contributions. It is proposed that the ambition to understand people in a different way than they understand themselves is key in both disciplines, and that architectural anthropology is consequently not only relevant in studies of vernacular...

  3. Persian architecture and mathematics

    CERN Document Server

    2012-01-01

    This volulme features eight original papers dedicated to the theme “Persian Architecture and Mathematics,” guest edited by Reza Sarhangi. All papers were approved through a rigorous process of blind peer review and edited by an interdisciplinary scientific editorial committee. Topics range from symmetry in ancient Persian architecture to the elaborate geometric patterns and complex three-dimensional structures of standing monuments of historical periods, from the expression of mathematical ideas to architectonic structures, and from decorative ornament to the representation of modern group theory and quasi-crystalline patterns. The articles discuss unique monuments Persia, including domed structures and two-dimensional patterns, which have received significant scholarly attention in recent years. This book is a unique contribution to studies of Persian architecture in relation to mathematics.

  4. Towards an Architectural Anthropology

    DEFF Research Database (Denmark)

    Stender, Marie

    2016-01-01

    Architecture and anthropology have always had overlapping interests regarding issues such as spatial organisation, forms of human dwellings, and the interplay between social life and physical surroundings. Recent developments in both disciplines make it even more relevant to explore and evolve...... their overlaps and collaboration. However, there are also challenging differences to take into account regarding disciplinary traditions of, for example, communication, temporality, and normativity. This article explores the potentials and challenges of architectural anthropology as a distinct sub......-discipline and outlines its possible theoretical, methodological, and applied contributions. It is proposed that the ambition to understand people in a different way than they understand themselves is key in both disciplines, and that architectural anthropology is consequently not only relevant in studies of vernacular...

  5. Agent Architectures for Compliance

    Science.gov (United States)

    Burgemeestre, Brigitte; Hulstijn, Joris; Tan, Yao-Hua

    A Normative Multi-Agent System consists of autonomous agents who must comply with social norms. Different kinds of norms make different assumptions about the cognitive architecture of the agents. For example, a principle-based norm assumes that agents can reflect upon the consequences of their actions; a rule-based formulation only assumes that agents can avoid violations. In this paper we present several cognitive agent architectures for self-monitoring and compliance. We show how different assumptions about the cognitive architecture lead to different information needs when assessing compliance. The approach is validated with a case study of horizontal monitoring, an approach to corporate tax auditing recently introduced by the Dutch Customs and Tax Authority.

  6. Ancient Chinese Landscape Architecture

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    IN the past decade,the worldhas suddenly discovered thewonders of Chinese landscapegardening and garden architecture,and places like New York,Singaporeand London have all built Chinese-style gardens.The architectural stylespecial to Chinese gardens has,infact,developed·a“school”of itsown.In China,the landscaped gardenhas long been a part of culture,andliterature,painting,philosophy,cal-ligraphy and folk customs have alldealt with it at one time or another.Two categories of garden architec-ture exist:the imperial garden andthe private garden.The former is,ofcourse,grand and palatial and occu-pies large tracts of land,while the

  7. Architecture of Environmental Engineering

    DEFF Research Database (Denmark)

    Wenzel, Henrik; Alting, Leo

    2006-01-01

    An architecture of Environmental Engineering has been developed comprising the various disciplines and tools involved. It identifies industry as the major actor and target group, and it builds on the concept of Eco-efficiency. To improve Eco-efficiency, there is a limited number of intervention......-efficiency is the aim of Environmental Engineering, the discipline of synthesis – design and creation of solutions – will form a core pillar of the architecture. Other disciplines of Environmental Engineering exist forming the necessary background and frame for the synthesis. Environmental Engineering, thus, in essence...... comprise the disciplines of: management, system description & inventory, analysis & assessment, prioritisation, synthesis, and communication, each existing at all levels of intervention. The developed architecture of Environmental Engineering, thus, consists of thirty individual disciplines, within each...

  8. Architecture of Environmental Engineering

    DEFF Research Database (Denmark)

    Wenzel, Henrik; Alting, Leo

    2004-01-01

    An architecture of Environmental Engineering has been developed comprising the various disciplines and tools involved. It identifies industry as the major actor and target group, and it builds on the concept of Eco-efficiency. To improve Eco-efficiency, there is a limited number of intervention...... of Eco-efficiency is the aim of Environmental Engineering, the discipline of synthesis – design and creation of solutions – will form a core pillar of the architecture. Other disciplines of Environmental Engineering exist forming the necessary background and frame for the synthesis. Environmental...... Engineering, thus, in essence comprise the disciplines of: management, system description & inventory, analysis & assessment, prioritisation, synthesis, and communication, each existing at all levels of intervention. The developed architecture of Environmental Engineering, thus, consists of thirty individual...

  9. Representing infant feeding: content analysis of British media portrayals of bottle feeding and breast feeding

    OpenAIRE

    Henderson, L.; KITZINGER, Jenny; Green, J.

    2001-01-01

    Objective: To examine how breast feeding and bottle feeding are represented by the British media.\\ud Design: Content analysis.\\ud Subjects: Television programmes and newspaper articles that made reference to infant feeding during March 1999.\\ud Setting: UK mass media.\\ud Main outcome measures: Visual and verbal references to breast or bottle feeding in newspapers and television programmes.\\ud Results: Overall, 235 references to infant feeding were identified in the television sample and 38 in...

  10. Information architecture. Volume 3: Guidance

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The purpose of this document, as presented in Volume 1, The Foundations, is to assist the Department of Energy (DOE) in developing and promulgating information architecture guidance. This guidance is aimed at increasing the development of information architecture as a Departmentwide management best practice. This document describes departmental information architecture principles and minimum design characteristics for systems and infrastructures within the DOE Information Architecture Conceptual Model, and establishes a Departmentwide standards-based architecture program. The publication of this document fulfills the commitment to address guiding principles, promote standard architectural practices, and provide technical guidance. This document guides the transition from the baseline or defacto Departmental architecture through approved information management program plans and budgets to the future vision architecture. This document also represents another major step toward establishing a well-organized, logical foundation for the DOE information architecture.

  11. Reframing information architecture

    CERN Document Server

    Resmini, Andrea

    2014-01-01

    Information architecture has changed dramatically since the mid-1990s and earlier conceptions of the world and the internet being different and separate have given way to a much more complex scenario in the present day. In the post-digital world that we now inhabit the digital and the physical blend easily and our activities and usage of information takes place through multiple contexts and via multiple devices and unstable, emergent choreographies. Information architecture now is steadily growing into a channel- or medium-specific multi-disciplinary framework, with contributions coming from a

  12. Architecture as Ars Combinatoria

    OpenAIRE

    Francesco Cacciatore

    2015-01-01

    Architecture today, no longer reflects the limits of experimentation and innovation. An extremely low-tech art whose field of possibilities consists of choosing and using that which has already been done in the past. It is because of this that the key skill a designer should have is the ability to recognize the complexity in forms around them: cities have the widest programming opportunities for architecture, in the two-way relationship that is established from the city that takes form in arc...

  13. IT Service Management Architectures

    DEFF Research Database (Denmark)

    Tambo, Torben; Filtenborg, Jacob

    2017-01-01

    IT service providers tend to view their services as quasi-embedded in the client organisations infrastructure. Therefore, IT service providers lack a full picture of being an organisation with its own enterprise archicture. By systematically developing an enterprise architecture using the unifica......IT service providers tend to view their services as quasi-embedded in the client organisations infrastructure. Therefore, IT service providers lack a full picture of being an organisation with its own enterprise archicture. By systematically developing an enterprise architecture using...

  14. Lunar architecture and urbanism

    Science.gov (United States)

    Sherwood, Brent

    1992-01-01

    Human civilization and architecture have defined each other for over 5000 years on Earth. Even in the novel environment of space, persistent issues of human urbanism will eclipse, within a historically short time, the technical challenges of space settlement that dominate our current view. By adding modern topics in space engineering, planetology, life support, human factors, material invention, and conservation to their already renaissance array of expertise, urban designers can responsibly apply ancient, proven standards to the exciting new opportunities afforded by space. Inescapable facts about the Moon set real boundaries within which tenable lunar urbanism and its component architecture must eventually develop.

  15. Low Emission Feed

    NARCIS (Netherlands)

    Klop, G.

    2016-01-01

    Research into manipulating methane (CH4) production as a result of enteric fermentation in ruminants currently receives global interest. Using feed additives may be a feasible strategy to mitigate CH4 as they are supplied in such amounts that the basal diet composition will not be largely affected.

  16. Feeding of Diarmis Proboscis

    Science.gov (United States)

    Young, Jocelyn

    2005-01-01

    The feeding of Diarmis proboscis is an exciting outdoor laboratory activity that demonstrates a single concept of adaptations--cryptic colorations. The students are "transformed" into D. proboscis (no Harry Potter magic needed) in order to learn how adaptations work in the natural world. Prior to beginning this activity, students should have a…

  17. Feed sources for livestock

    NARCIS (Netherlands)

    Zanten, van H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Cu

  18. American School & University Architectural Portfolio 2000 Awards: Landscape Architecture.

    Science.gov (United States)

    American School & University, 2000

    2000-01-01

    Presents photographs and basic information on architectural design, costs, square footage, and principle designers of the award winning school landscaping projects that competed in the American School & University Architectural Portfolio 2000. (GR)

  19. The Architectural Information Map: Semantic modeling in conceptual architectural design

    NARCIS (Netherlands)

    Tunçer, E.B.

    2009-01-01

    This research focuses on the acquisition, representation, sharing and reuse of design information and knowledge in the conceptual phase of architectural design, and targets the creation of situated digital environments where communities of architectural practice communicate and collaborate using thi

  20. Discrete optimization in architecture architectural & urban layout

    CERN Document Server

    Zawidzki, Machi

    2016-01-01

    This book presents three projects that demonstrate the fundamental problems of architectural design and urban composition – the layout design, evaluation and optimization. Part I describes the functional layout design of a residential building, and an evaluation of the quality of a town square (plaza). The algorithm for the functional layout design is based on backtracking using a constraint satisfaction approach combined with coarse grid discretization. The algorithm for the town square evaluation is based on geometrical properties derived directly from its plan. Part II introduces a crowd-simulation application for the analysis of escape routes on floor plans, and optimization of a floor plan for smooth crowd flow. The algorithms presented employ agent-based modeling and cellular automata.

  1. Cartography of Architectural Controversies

    DEFF Research Database (Denmark)

    Lotz, Katrine

    2010-01-01

    or the office. The paper consists of investigations into such a stance. It is based on empiric studies, readings in architectural theory and applied actor-network theory. Furthermore the paper draws on recent examples of teaching practices pursuing this theme at the Royal Academy of Fine Arts, School...

  2. Cartography of architectural controversies

    DEFF Research Database (Denmark)

    Lotz, Katrine

    2009-01-01

    that employing the visualising methods of the recent development of Actor-Network-Theory called ‘Cartography of Controversies' might contribute to trans-disciplinary efforts to develop analytic understanding of the conflicting human purposes and power-struggles at stake in the be-coming of architecture....

  3. Principles of landscape architecture

    NARCIS (Netherlands)

    Nijhuis, S.

    2013-01-01

    The Department of Urbanism at the Faculty of Architecture and Built Environment, TU Delft considers urbanism as a planning and design oriented activity towards urban and rural landscapes. It aims to enhance, restore or create landscapes from a perspective of sustainable development, so as to guide,

  4. IT Service Management Architectures

    DEFF Research Database (Denmark)

    Tambo, Torben; Filtenborg, Jacob

    2017-01-01

    IT service providers tend to view their services as quasi-embedded in the client organisations infrastructure. Therefore, IT service providers lack a full picture of being an organisation with its own enterprise archicture. By systematically developing an enterprise architecture using...

  5. Robustness via Diffractal Architectures

    CERN Document Server

    Moocarme, Matthew

    2015-01-01

    When plane waves diffract through fractal-patterned apertures, the resulting far-field profiles or diffractals also exhibit iterated, self-similar features. Here we show that this specific architecture enables robust signal processing and spatial multiplexing: arbitrary parts of a diffractal contain sufficient information to recreate the entire original sparse signal.

  6. Architecture and Nature

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Chinese-American architect Maya Lin has become renowned by people in China recently because of her latest work-"What is Missing?" The multi-site project aims to raise public awareness of the current crisis surrounding biodiversity and habitat loss. Lin recently talked about the project’s background and her understanding of the relation between architecture and nature with Beijing Review.

  7. Enriching software architecture documentation

    NARCIS (Netherlands)

    Jansen, Anton; Avgeriou, Paris; Ven, Jan Salvador van der

    2009-01-01

    The effective documentation of Architectural Knowledge (AK) is one of the key factors in leveraging the paradigm shift toward sharing and reusing AK. However, current documentation approaches have severe shortcomings in capturing the knowledge of large and complex systems and subsequently facilitati

  8. Paper relief architecture

    NARCIS (Netherlands)

    Latka, J.F.

    2014-01-01

    The article presents two contemporary projects of paper structures relief architecture designed and built by Shigeru Ban Architects and Voluntary Architect Network. Author of the article took part in design and construction process of one of the projects. The project of Yaan Nursery School, which wa

  9. Evolution Through Architectural Reconciliation

    NARCIS (Netherlands)

    Avgeriou, Paris; Guelfi, Nicolas; Perrouin, Gilles

    2005-01-01

    One of the possible scenarios in a system evolution cycle, is to translate an emergent set of new requirements into software architecture design and subsequently to update the system implementation. In this paper, we argue that this form of forward engineering, even though addresses the new system r

  10. The toolbus coordination architecture

    NARCIS (Netherlands)

    Bergstra, J.A.; Klint, P.

    1996-01-01

    Building large, heterogeneous, distributed software systems poses serious problems for the software engineer; achieving interoperability of software systems is still a major challenge. We describe an experiment in designing a generic software architecture for solving these problems. To get control o

  11. Architectural Creation of Light

    DEFF Research Database (Denmark)

    Bülow, Katja

    2015-01-01

    Bidraget "Architectural Creation of Light" indgår sammen med 108 andre bidrag i bogen "You Say Light, I Think Shadow". Bogens indhold undersøger: "Hvad er lys". I dette bidrag besvares spørgsmålet gennem iagttagelser af arkitektstuderendes undersøgelser af lyset i deres arbejdsmodeller i...

  12. Interactive Architecture #1

    NARCIS (Netherlands)

    Oosterhuis, K.; Xia, X.

    2007-01-01

    The iA bookzine series will consist of twelve issues, bi-annually published over a period of six years under the supervision of Prof. ir. Kas Oosterhuis, director of the Hperbody at the Delft University of Technology. Interactive Architecture - from here on abbreviated as iA - is NOT simply archite

  13. Architectural Guide of Jordan

    DEFF Research Database (Denmark)

    Hilberth, Thomas Roger

    2016-01-01

    Architectural and cultural guidebook for Jordan that also includes a view on the Syrian refugee situation, especially in the large UNHCR camp of Zaatari. The guide book is a preparatory study for a field trip our master studio undertook to the Hashemite Kingdom of Jordan in Fall 2016....

  14. Smart Grid Architectures

    DEFF Research Database (Denmark)

    Dondossola, Giovanna; Terruggia, Roberta; Bessler, Sandford

    2014-01-01

    The scope of this paper is to address the evolution of distribution grid architectures following the widespread introduction of renewable energy sources. The increasing connection of distributed resources has a strong impact on the topology and the control functionality of the current distributio...

  15. Future Network Architectures

    DEFF Research Database (Denmark)

    Wessing, Henrik; Bozorgebrahimi, Kurosh; Belter, Bartosz;

    2015-01-01

    This study identifies key requirements for NRENs towards future network architectures that become apparent as users become more mobile and have increased expectations in terms of availability of data. In addition, cost saving requirements call for federated use of, in particular, the optical spec...

  16. Tutorial on architectural acoustics

    Science.gov (United States)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio

    2002-11-01

    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  17. [Architecture and movement].

    Science.gov (United States)

    Rivallan, Armel

    2012-01-01

    Leading an architectural project means accompanying the movement which it induces within the teams. Between questioning, uncertainty and fear, the organisational changes inherent to the new facility must be subject to constructive and ongoing exchanges. Ethics, safety and training are revised and the unit projects are sometimes modified.

  18. [Architecture, budget and dignity].

    Science.gov (United States)

    Morel, Etienne

    2012-01-01

    Drawing on its dynamic strengths, a psychiatric unit develops various projects and care techniques. In this framework, the institute director must make a number of choices with regard to architecture. Why renovate the psychiatry building? What financial investments are required? What criteria should be followed? What if the major argument was based on the respect of the patient's dignity?

  19. Enterprise Architecture Evaluation

    DEFF Research Database (Denmark)

    Andersen, Peter; Carugati, Andrea

    2014-01-01

    By being holistically preoccupied with coherency among organizational elements such as organizational strategy, business needs and the IT functions role in supporting the business, enterprise architecture (EA) has grown to become a core competitive advantage. Though EA is a maturing research area...

  20. EMI Security Architecture

    CERN Document Server

    White, J.; Schuller, B.; Qiang, W.; Groep, D.; Koeroo, O.; Salle, M.; Sustr, Z.; Kouril, D.; Millar, P.; Benedyczak, K.; Ceccanti, A.; Leinen, S.; Tschopp, V.; Fuhrmann, P.; Heyman, E.; Konstantinov, A.

    2013-01-01

    This document describes the various architectures of the three middlewares that comprise the EMI software stack. It also outlines the common efforts in the security area that allow interoperability between these middlewares. The assessment of the EMI Security presented in this document was performed internally by members of the Security Area of the EMI project.

  1. Terra Harvest software architecture

    Science.gov (United States)

    Humeniuk, Dave; Klawon, Kevin

    2012-06-01

    Under the Terra Harvest Program, the DIA has the objective of developing a universal Controller for the Unattended Ground Sensor (UGS) community. The mission is to define, implement, and thoroughly document an open architecture that universally supports UGS missions, integrating disparate systems, peripherals, etc. The Controller's inherent interoperability with numerous systems enables the integration of both legacy and future UGS System (UGSS) components, while the design's open architecture supports rapid third-party development to ensure operational readiness. The successful accomplishment of these objectives by the program's Phase 3b contractors is demonstrated via integration of the companies' respective plug-'n'-play contributions that include controllers, various peripherals, such as sensors, cameras, etc., and their associated software drivers. In order to independently validate the Terra Harvest architecture, L-3 Nova Engineering, along with its partner, the University of Dayton Research Institute, is developing the Terra Harvest Open Source Environment (THOSE), a Java Virtual Machine (JVM) running on an embedded Linux Operating System. The Use Cases on which the software is developed support the full range of UGS operational scenarios such as remote sensor triggering, image capture, and data exfiltration. The Team is additionally developing an ARM microprocessor-based evaluation platform that is both energy-efficient and operationally flexible. The paper describes the overall THOSE architecture, as well as the design decisions for some of the key software components. Development process for THOSE is discussed as well.

  2. Phylogeny and biogeography of 91 species of heroine cichlids (Teleostei: Cichlidae) based on sequences of the cytochrome b gene.

    Science.gov (United States)

    Pérez, Gustavo A Concheiro; Rícan, Oldrich; Ortí, Guillermo; Bermingham, Eldredge; Doadrio, Ignacio; Zardoya, Rafael

    2007-04-01

    Heroini constitute the second largest tribe of Neotropical cichlids and show their greatest diversity in Mesoamerica. Although heroine species are morphologically and ecologically very diverse, they were all historically assigned to one single genus, Cichlasoma that was never formally revised from a phylogenetic point of view. Here, we present the most comprehensive molecular phylogeny of the tribe Heroini to date, based on the complete DNA sequence of the mitochondrial gene cytochrome b, and the analysis of 204 individuals representing 91 species. Phylogenetic analyses did not support the monophyly of heroines because the genus Pterophyllum was placed as the sister group of all remaining heroines plus cichlasomatines. However, the recovered relative position of Pterophyllum was without strong statistical support. Within the remaining heroines, Hyspelecara and Hoplarchus are recovered with low support in a basal position with respect to a clade that includes Heros, Uaru, Mesonauta, and Symphysodon, and the circumamazonian (CAM) heroines. The first clade is restricted to South America. The largest clade of heroines, the CAM heroines, include more than 85% of the species within the tribe. This clade is mostly Mesoamerican, but also contains four species found in the Greater Antilles (Nandopsis), and three genera found in South America (the 'Heros' festae group, Australoheros, and Caquetaia). Up to eight major lineages can be recovered within the CAM heroines, but the phylogenetic relationships among them remain unresolved. Two large suprageneric groups can be distinguished, the amphilophines and the herichthyines. The amphilophines include Amphilophus, Archocentrus, Hypsophrys, Neetroplus, Parachromis, Petenia, and five additional unnamed genera (the 'Heros' istlanus group, the 'Amphilophus' calobrensis group, the 'Heros' urophthalmus group, the 'Heros' wesseli group, and the 'Heros' sieboldii group). The herichthyines include the crown-group herichthyines

  3. An Experiment in Architectural Instruction.

    Science.gov (United States)

    Dvorak, Robert W.

    1978-01-01

    Discusses the application of the PLATO IV computer-based educational system to a one-semester basic drawing course for freshman architecture, landscape architecture, and interior design students and relates student reactions to the experience. (RAO)

  4. Enterprise architecture for business success

    CERN Document Server

    Wijegunaratne, Inji; Evans-Greenwood, Peter

    2014-01-01

    Enterprise Architecture (EA) has evolved to become a prominent presence in today's information systems and technology landscape. The EA discipline is rich in frameworks, methodologies, and the like. However, the question of 'value' for business ;professionals remains largely unanswered - that is, how best can Enterprise Architecture and Enterprise Architects deliver value to the enterprise? Enterprise Architecture for Business Success answers this question. Enterprise Architecture for Business Success is primarily intended for IT professionals working in the area of Enterprise Architectu

  5. Economics-driven software architecture

    CERN Document Server

    Mistrik, Ivan; Kazman, Rick; Zhang, Yuanyuan

    2014-01-01

    Economics-driven Software Architecture presents a guide for engineers and architects who need to understand the economic impact of architecture design decisions: the long term and strategic viability, cost-effectiveness, and sustainability of applications and systems. Economics-driven software development can increase quality, productivity, and profitability, but comprehensive knowledge is needed to understand the architectural challenges involved in dealing with the development of large, architecturally challenging systems in an economic way. This book covers how to apply economic consider

  6. Architectural Design Activities for JAS

    CERN Document Server

    Khaled, Lena

    2009-01-01

    The critical part for building any software system is its architecture. Architectural design is a design at a higher level of abstraction. A good architecture ensures that software will satisfy its requirement. This paper defines the most important activities of architectural design that used through building any software; also it applies these activities on one type of Electronic Commerce (EC) applications that is Job Agency System(JAS) to show how these activities can work through these types of applications.

  7. Feed sources for livestock

    OpenAIRE

    Zanten, van, H.H.E.

    2016-01-01

    Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Current levels of production of especially animal-source food (ASF), pose severe pressure on the environment via their emissions to air, water, and soil; and their use of scarce resources, such as la...

  8. Live feeds in aquaculture

    OpenAIRE

    Dhert, Ph.; Sorgeloos, P

    1995-01-01

    Over the past two decades intensive larviculture of several fish and shellfish species has expanded into a multimillion dollar industry. Although much progress has been made in identifying the dietary requirements of the larvae of various aquaculture species, the mass culture of their early larval stages still requires the use of live feeds. Selected either through trial and error approaches or because of their convenience in mass production and use, hatcheries are relying today on three grou...

  9. Architectural engineering of FRP bridges

    OpenAIRE

    Smits, J.E.P.

    2014-01-01

    This paper deals with the use of Fibre Reinforced Polymers (FRP's) in architectural and structural bridge design. The challenges and opportunities that come with this relatively new material are discussed. An inventory is made of recent engineers' solutions in FRP, followed by a discussion on architectural application of FRP's derived from the authors architectural practice.

  10. Synthesis - Based Software Architecture Design

    NARCIS (Netherlands)

    Tekinerdogan, Bedir; Aksit, Mehmet; Akşit, Mehmet

    2001-01-01

    During the last decade several architecture design approaches have been introduced. These approaches however have to cope with several obstacles and software architecture design remains a difficult problem. To cope with these obstacles this chapter introduces a novel architecture design approach. Th

  11. Meet French Architecture in China

    Institute of Scientific and Technical Information of China (English)

    Susan

    2005-01-01

    On April 5, a French architectural exhibition entitled ""French Visions: City, Architecture and Sustainable Development"" was unveiled in Beijing Urban Planning Center. As a key exhibition within the framework of French Year in China, the exhibition will also be displayed in Shanghai and Chongqing. The largest exhibition of its kind ever held in China, French Visions extensively showed accomplishments of contemporary French architectural design.

  12. Software Architecture Description and UML

    NARCIS (Netherlands)

    Avgeriou, Paris; Guelfi, Nicolas; Medvidovic, Nenad

    2005-01-01

    The description of software architectures has always been concerned with the definition of the appropriate languages for designing the various architectural artifacts. Over the past ten years, formal or less formal Architecture Description Languages (ADLs) and supporting methods and tools have been

  13. Food Safety Information RSS feed

    Data.gov (United States)

    U.S. Department of Health & Human Services — This is an RSS Feed of Food Safety information that’s produced in real-time by the CDC. This RSS feed is the integration of two other XML feeds, one from the USDA's...

  14. Coupling between crossed dipole feeds

    DEFF Research Database (Denmark)

    Andersen, J.; Schjær-Jacobsen, Hans; Lessow, H.

    1974-01-01

    as a function of orientation and feeding network properties. The antennas are used as feeds for a parabolic reflector, and the effect of coupling on the secondary fields is analyzed. Especially significant is the polarization loss and it may, to some extent, be reduced by a proper choice of feeding network....

  15. Highly scalable digital front end architectures for digital printing

    Science.gov (United States)

    Staas, David

    2011-01-01

    HP's digital printing presses consume a tremendous amount of data. The architectures of the Digital Front Ends (DFEs) that feed these large, very fast presses have evolved from basic, single-RIP (Raster Image Processor) systems to multirack, distributed systems that can take a PDF file and deliver data in excess of 3 Gigapixels per second to keep the presses printing at 2000+ pages per minute. This paper highlights some of the more interesting parallelism features of our DFE architectures. The high-performance architecture developed over the last 5+ years can scale up to HP's largest digital press, out to multiple mid-range presses, and down into a very low-cost single box deployment for low-end devices as appropriate. Principles of parallelism pervade every aspect of the architecture, from the lowest-level elements of jobs to parallel imaging pipelines that feed multiple presses. From cores to threads to arrays to network teams to distributed machines, we use a systematic approach to move bottlenecks. The ultimate goals of these efforts are: to take the best advantage of the prevailing hardware options at our disposal; to reduce power consumption and cooling requirements; and to ultimately reduce the cost of the solution to our customers.

  16. Architecture Descriptions. A Contribution to Modeling of Production System Architecture

    DEFF Research Database (Denmark)

    Jepsen, Allan Dam; Hvam, Lars

    on the underlying principles of a production system’s design; and despite the existence of established architecture and platform theories and practices within product design, there is still a need for a better understanding of the architecture phenomenon itself, and certainly how it applies within production system....... The viewpoints provide a set of model kinds to frame select architecture related concerns relating to the production capability and the design of the technical system. With the contribution to architecture description there follows a need to support exchange and processing of architecture information within......The subject of this PhD dissertation is architecture-centric design and the description of production system architecture. Companies are facing demands for the development and production of new products at an ever increasing rate, as the market life of products decreases and the rate at which...

  17. Architecture and communication

    Directory of Open Access Journals (Sweden)

    Špela Hudnik

    2003-01-01

    Full Text Available The article presents effects of technology, science and capital strategies on changes in traditional forms and definitions of space, architecture and bodies. It confronts us with new processes of thinking and living that are constantly being transformed into new dynamic time and spatial contexts. Space is becoming the information filter, communication network. A cross-section of three landscapes: landscape of megastructures, nomadic landscapes and psychedelic landscapes, theory contributes to understanding of media and space-age technology, information technology and electronical language. It offers designs of various megastructures, media surfaces and envelopes of contemporary information society: the anthropological module, hyper- and infra-bodies, bio-electronical bodies and population genetics bodies. It presents the architecture of communication.

  18. Visual expression in architecture

    Directory of Open Access Journals (Sweden)

    Alfirević Đorđe

    2011-01-01

    Full Text Available Relaying on standpoints of the renowned art critic Herbert Read, according to which realism, idealism and expressionism are not separate art movements, but represent permanent basic factors in all arts, this paper considers the possibility of existence of elementary creative orientation in architecture as well. Starting from basic aspects of perception and representation of the world around us, and through a comparative analysis and examples from other fields, a thesis is presented according to which notions of mimesis (mimicry, associativity and expression in architecture are adequate counterparts to Read's basic factors of art - realism, idealism and expressionism. Depending on sociopolitical, cultural and historical, as well as other circumstances, from time to time some of these factors come to the surface, wrapped up in time, and emerge in some new or old form which we can recognize as an art movement or style.

  19. Art and Architectural Space

    DEFF Research Database (Denmark)

    Unterrainer, Walter

    2014-01-01

    art and architectural space museums and other exhibition spaces or how artists learn to love architects Over the last two decades, innumerable new museums, art galleries and other exhibition spaces have been built and opened all over the globe. The most extreme growth happened in China, where...... historically considered even the mother of all arts) - but more relevant: what are appropriate architectural spaces for presenting, exhibiting, contemplating, reflecting, meditating, discussing, enjoying, dissenting, debating creations of art. Simplified, this is a question about the relation between package...... and its content. The urban and spatial question goes far beyond museums and other buildings for art: how in democratic societies should public spaces be supported by art and how can public art support ´cityness´ and meaning versus spaces of consumerism. Famous but egocentric buildings with the main...

  20. Heterogeneous network architectures

    DEFF Research Database (Denmark)

    Christiansen, Henrik Lehrmann

    2006-01-01

    Future networks will be heterogeneous! Due to the sheer size of networks (e.g., the Internet) upgrades cannot be instantaneous and thus heterogeneity appears. This means that instead of trying to find the olution, networks hould be designed as being heterogeneous. One of the key equirements here...... is flexibility. This thesis investigates such heterogeneous network architectures and how to make them flexible. A survey of algorithms for network design is presented, and it is described how using heuristics can increase the speed. A hierarchical, MPLS based network architecture is described...... and it is discussed that it is advantageous to heterogeneous networks and illustrated by a number of examples. Modeling and simulation is a well-known way of doing performance evaluation. An approach to event-driven simulation of communication networks is presented and mixed complexity modeling, which can simplify...

  1. Consistent model driven architecture

    Science.gov (United States)

    Niepostyn, Stanisław J.

    2015-09-01

    The goal of the MDA is to produce software systems from abstract models in a way where human interaction is restricted to a minimum. These abstract models are based on the UML language. However, the semantics of UML models is defined in a natural language. Subsequently the verification of consistency of these diagrams is needed in order to identify errors in requirements at the early stage of the development process. The verification of consistency is difficult due to a semi-formal nature of UML diagrams. We propose automatic verification of consistency of the series of UML diagrams originating from abstract models implemented with our consistency rules. This Consistent Model Driven Architecture approach enables us to generate automatically complete workflow applications from consistent and complete models developed from abstract models (e.g. Business Context Diagram). Therefore, our method can be used to check practicability (feasibility) of software architecture models.

  2. Architecture and Energy

    DEFF Research Database (Denmark)

    Lauring, Michael; Marsh, Rob

    2009-01-01

    Architecture and Energy. Strategies for a Changing Climate. By Michael Lauring and Rob Marsh INTENT AND PURPOSE. The paper aims to further integrated design of low energy buildings with high architectural quality. A precondition for qualified integrated design is a holistic approach...... that on the technical side covers all sorts of energy used to construct, run and use modern buildings, and on the humane side includes functional, social and aesthetic aspects of modern living. The paper shows how qualified integrated design up till now has not been achieved. It shows how a narrow focus on the solution...... of sub-problems may result in big problems elsewhere in the complex system of designing buildings. The paper concludes that future ambitious low energy building strategies cannot focus only on heat consumption but must include a stronger focus on the use of electricity for non-heating purposes...

  3. Performative Urban Architecture

    DEFF Research Database (Denmark)

    Thomsen, Bo Stjerne; Jensen, Ole B.

    The paper explores how performative urban architecture can enhance community-making and public domain using socio-technical systems and digital technologies to constitute an urban reality. Digital medias developed for the web are now increasingly occupying the urban realm as a tool for navigating...... the perspectives of using interactive technologies for performative objects, which are able to register the impulses of urban activity and reproduce the contexts of the city. In this way the performative environment is established as an event setting providing an embodied experience as a ‘quasi-object' that can...... couple relationships between architecture, humans and society. These performative relationships between digital and physical environments are seen as illustrative of the social production of space by performance and the creative production of identity. The paper reflects on the perspectives...

  4. Generic robot architecture

    Science.gov (United States)

    Bruemmer, David J [Idaho Falls, ID; Few, Douglas A [Idaho Falls, ID

    2010-09-21

    The present invention provides methods, computer readable media, and apparatuses for a generic robot architecture providing a framework that is easily portable to a variety of robot platforms and is configured to provide hardware abstractions, abstractions for generic robot attributes, environment abstractions, and robot behaviors. The generic robot architecture includes a hardware abstraction level and a robot abstraction level. The hardware abstraction level is configured for developing hardware abstractions that define, monitor, and control hardware modules available on a robot platform. The robot abstraction level is configured for defining robot attributes and provides a software framework for building robot behaviors from the robot attributes. Each of the robot attributes includes hardware information from at least one hardware abstraction. In addition, each robot attribute is configured to substantially isolate the robot behaviors from the at least one hardware abstraction.

  5. Sustainable Enterprise Architecture

    CERN Document Server

    Hausman, Kirk

    2011-01-01

    Providing guidance that can be applied to an enterprise of any scale, this book supplies IT practitioners with the tools needed to present enterprise architecture concepts to non-technical stakeholders. Rather than focusing on a single governance framework, the text explains how to develop successful and sustainable enterprise deployments in any setting. Coverage includes general security practices, common threats, storage mechanisms, and the impact of virtualization. The author presents functional considerations for developing and maintaining extended enterprise networks using practices teste

  6. Architecture of Trusted PC

    Institute of Scientific and Technical Information of China (English)

    WU Shuhua; ZHU Yuefei

    2006-01-01

    This paper, focusing on the trusted computing group's standards, explained the key concept of trusted computing and provided the architecture of trusted PC. It built trust bottom-up by starting with trusted hardware and adding layers of trusted software. It is a system-level solution available to all applications running on the member platforms. This solution reduces the security burden on applications and thus simplifies application programming.

  7. Avionics Architecture Modelling Language

    Science.gov (United States)

    Alana, Elena; Naranjo, Hector; Valencia, Raul; Medina, Alberto; Honvault, Christophe; Rugina, Ana; Panunzia, Marco; Dellandrea, Brice; Garcia, Gerald

    2014-08-01

    This paper presents the ESA AAML (Avionics Architecture Modelling Language) study, which aimed at advancing the avionics engineering practices towards a model-based approach by (i) identifying and prioritising the avionics-relevant analyses, (ii) specifying the modelling language features necessary to support the identified analyses, and (iii) recommending/prototyping software tooling to demonstrate the automation of the selected analyses based on a modelling language and compliant with the defined specification.

  8. Aerobot Autonomy Architecture

    Science.gov (United States)

    Elfes, Alberto; Hall, Jeffery L.; Kulczycki, Eric A.; Cameron, Jonathan M.; Morfopoulos, Arin C.; Clouse, Daniel S.; Montgomery, James F.; Ansar, Adnan I.; Machuzak, Richard J.

    2009-01-01

    An architecture for autonomous operation of an aerobot (i.e., a robotic blimp) to be used in scientific exploration of planets and moons in the Solar system with an atmosphere (such as Titan and Venus) is undergoing development. This architecture is also applicable to autonomous airships that could be flown in the terrestrial atmosphere for scientific exploration, military reconnaissance and surveillance, and as radio-communication relay stations in disaster areas. The architecture was conceived to satisfy requirements to perform the following functions: a) Vehicle safing, that is, ensuring the integrity of the aerobot during its entire mission, including during extended communication blackouts. b) Accurate and robust autonomous flight control during operation in diverse modes, including launch, deployment of scientific instruments, long traverses, hovering or station-keeping, and maneuvers for touch-and-go surface sampling. c) Mapping and self-localization in the absence of a global positioning system. d) Advanced recognition of hazards and targets in conjunction with tracking of, and visual servoing toward, targets, all to enable the aerobot to detect and avoid atmospheric and topographic hazards and to identify, home in on, and hover over predefined terrain features or other targets of scientific interest. The architecture is an integrated combination of systems for accurate and robust vehicle and flight trajectory control; estimation of the state of the aerobot; perception-based detection and avoidance of hazards; monitoring of the integrity and functionality ("health") of the aerobot; reflexive safing actions; multi-modal localization and mapping; autonomous planning and execution of scientific observations; and long-range planning and monitoring of the mission of the aerobot. The prototype JPL aerobot (see figure) has been tested extensively in various areas in the California Mojave desert.

  9. Urban architecture in urban renewal

    DEFF Research Database (Denmark)

    Holmgren, Steen; Svensson, Ole

    2001-01-01

    and without obvious architectural value. These issues raise pertinent questions: what urban architectural problems and qualities exist in the complex, inner suburbs? What differences exist between professionals' and residents' perceptions and assessments of urban architecture? How can a shared language...... of urban architecture be developed? This research project attempts to answer these questions through a discourse on theories and methods and the development of "dialogue methods" by which professionals can learn about residents' perception of the urban architecture of their area, thus achieving a better...

  10. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael

    2010-07-25

    The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, so-called panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects.

  11. Quantifying loopy network architectures.

    Directory of Open Access Journals (Sweden)

    Eleni Katifori

    Full Text Available Biology presents many examples of planar distribution and structural networks having dense sets of closed loops. An archetype of this form of network organization is the vasculature of dicotyledonous leaves, which showcases a hierarchically-nested architecture containing closed loops at many different levels. Although a number of approaches have been proposed to measure aspects of the structure of such networks, a robust metric to quantify their hierarchical organization is still lacking. We present an algorithmic framework, the hierarchical loop decomposition, that allows mapping loopy networks to binary trees, preserving in the connectivity of the trees the architecture of the original graph. We apply this framework to investigate computer generated graphs, such as artificial models and optimal distribution networks, as well as natural graphs extracted from digitized images of dicotyledonous leaves and vasculature of rat cerebral neocortex. We calculate various metrics based on the asymmetry, the cumulative size distribution and the Strahler bifurcation ratios of the corresponding trees and discuss the relationship of these quantities to the architectural organization of the original graphs. This algorithmic framework decouples the geometric information (exact location of edges and nodes from the metric topology (connectivity and edge weight and it ultimately allows us to perform a quantitative statistical comparison between predictions of theoretical models and naturally occurring loopy graphs.

  12. The TDAQ Baseline Architecture

    CERN Multimedia

    Wickens, F J

    The Trigger-DAQ community is currently busy preparing material for the DAQ, HLT and DCS TDR. Over the last few weeks a very important step has been a series of meetings to complete agreement on the baseline architecture. An overview of the architecture indicating some of the main parameters is shown in figure 1. As reported at the ATLAS Plenary during the February ATLAS week, the main area where the baseline had not yet been agreed was around the Read-Out System (ROS) and details in the DataFlow. The agreed architecture has: Read-Out Links (ROLs) from the RODs using S-Link; Read-Out Buffers (ROB) sited near the RODs, mounted in a chassis - today assumed to be a PC, using PCI bus at least for configuration, control and monitoring. The baseline assumes data aggregation, in the ROB and/or at the output (which could either be over a bus or in the network). Optimization of the data aggregation will be made in the coming months, but the current model has each ROB card receiving input from 4 ROLs, and 3 such c...

  13. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael

    2010-07-26

    The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, socalled panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects. © 2010 ACM.

  14. Conflict, Space and Architecture

    Directory of Open Access Journals (Sweden)

    Marc Schoonderbeek

    2017-02-01

    Full Text Available Footprint 19 focuses on the more recent roles of architecture in the contemporary spaces of conflict. Departing from a spatial understanding of geopolitical, climatological and economical conflicts, the various contributions highlight the large scale and phenomenal transitions in the physical world and in society by extrapolating, through examples, the abundance of relations that can be traced between conflict, territory and architecture. Conflict areas often prove to be fertile grounds for innovation and for the emergence of new spatial forms. The issue reports on the state of perpetual global unrest in architecture through a series of articles and case studies that highlight the consequences of conflicts in the places and spaces that we inhabit. In the introduction, these are discussed as an interlinked global reality rather than as isolated incidents. In doing so, the contemporary spaces of conflict are positioned in the context of emerging global trends, conditions, and discourses in the attempt to address their indicative symptoms while reflecting on their underlying causes.

  15. Fermented liquid feed for pigs.

    Science.gov (United States)

    Missotten, Joris A M; Michiels, Joris; Ovyn, Anneke; De Smet, Stefaan; Dierick, Noël A

    2010-12-01

    Since the announcement of the ban on the use of antibiotics as antimicrobial growth promoters in the feed of pigs in 2006 the investigation towards alternative feed additives has augmented considerably. Although fermented liquid feed is not an additive, but a feeding strategy, the experimental work examining its possible advantages also saw a rise. The use of fermented liquid feed (FLF) has two main advantages, namely that the simultaneous provision of feed and water may result in an alleviation of the transition from the sow milk to solid feed and may also reduce the time spent to find both sources of nutrients, and secondly, that offering FLF with a low pH may strengthen the potential of the stomach as a first line of defence against possible pathogenic infections. Because of these two advantages, FLF is often stated as an ideal feed for weaned piglets. The results obtained so far are rather variable, but in general they show a better body weight gain and worse feed/gain ratio for the piglets. However, for growing-finishing pigs on average a better feed/gain ratio is found compared to pigs fed dry feed. This better performance is mostly associated with less harmful microbiota and better gut morphology. This review provides an overview of the current knowledge of FLF for pigs,dealing with the FLF itself as well as its effect on the gastrointestinal tract and animal performance.

  16. First feeding of larval herring

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

    1985-01-01

    The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk......, visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage....... In the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower end...

  17. Analysis of self-feeding in children with feeding disorders.

    Science.gov (United States)

    Rivas, Kristi M; Piazza, Cathleen C; Roane, Henry S; Volkert, Valerie M; Stewart, Victoria; Kadey, Heather J; Groff, Rebecca A

    2014-01-01

    In the current investigation, we evaluated a method for increasing self-feeding with 3 children with a history of food refusal. The children never (2 children) or rarely (1 child) self-fed bites of food when the choice was between self-feeding and escape from eating. When the choice was between self-feeding 1 bite of food or being fed an identical bite of food, self-feeding was low (2 children) or variable (1 child). Levels of self-feeding increased for 2 children when the choice was between self-feeding 1 bite of food or being fed multiple bites of the same food. For the 3rd child, self-feeding increased when the choice was between self-feeding 1 bite of food or being fed multiple bites of a less preferred food. The results showed that altering the contingencies associated with being fed increased the probability of self-feeding, but the specific manipulations that produced self-feeding were unique to each child.

  18. Feeding and Swallowing Disorders (Dysphagia) in Children

    Science.gov (United States)

    ... for the Public / Speech, Language and Swallowing / Swallowing Feeding and Swallowing Disorders (Dysphagia) in Children What are ... children with feeding and swallowing disorders ? What are feeding and swallowing disorders? Feeding disorders include problems gathering ...

  19. Feeding Tips For Your Baby with CHD

    Science.gov (United States)

    ... How To Feed Your Baby Either breast- or bottle-feeding works well for babies with heart problems, but ... do best with a combination of breast- and bottle-feeding. Breast-Feeding Your Baby If your baby is ...

  20. Feeding the Beast

    DEFF Research Database (Denmark)

    Hellström, Anders; Hervik, Peter

    2014-01-01

    of fear, we argue, this predisposes people to vote for anti-immigration parties. Our analysis highlights the position of anti-immigration parties; hence, the Sweden Democrats (SD) in Sweden and the Danish People’s Party (DPP) in Denmark. We use frame analysis to detect recurrent frames in the media debate...... as such plays a similar role and provides the DPP with an identity. We conclude that we are confronted with a two-faced beast that feeds on perceptions of the people as ultimately afraid of what are not recognized as native goods....

  1. Re-feeding syndrome.

    Science.gov (United States)

    Shadaba, A; Paine, J; Adlard, R; Dilkes, M

    2001-09-01

    The effect of a therapeutically administered high calorie diet in a severely malnourished patient is discussed in this case report. In patients with advanced head and neck cancer prolonged periods of malnutrition prior to admission are frequently encountered. This case report highlights the need to constantly monitor the electrolyte and vitamin levels during the early stages of instituting enteral or parenteral nutrition. By vigilant monitoring and a high index of suspicion re-feeding syndrome or severe hypophosphataemia and its associated complications can be avoided.

  2. Sculpture Versus Architecture?

    Directory of Open Access Journals (Sweden)

    Alexander Rappaport

    2007-07-01

    Full Text Available Many critics consider Richard Serra the leading sculptor of the 20th century. He is famous not only for inventing something new in sculpture (abstract sculpture compositions existed before him, having been opened by constructivist vanguard of the beginning of the 20th century. Material selections by Vladimir Tatlin and sculptures by Osip Tsadkin, as well as compositions by Henry Moor appeared before Serra. Serra is famous for transferring his works' accent from the works as they are, which could be installed in any place, to their environment. That is he saw in the sculpture a key to understanding the urban space. His crude metal sheets and profiles, rectangular and curvilinear, exceeding regular scale of sculpture, come closer to architecture. Richard Serra places them near architectural constructions as checkpoints of intermediate scale category of space located between so-called «street furniture» – lamp posts, stalls, fountains and benches – and buildings, especially huge modern ones.But the matter is not only in the scale. Serra's sculptures are not only abstract compositions that harmoniously add to the space with their spacious scale. They have some mystery, some implicit sense appearing before a pedestrian as an enigma. Their mystique opposes both street furniture and architecture. But first of all it opposes the historical sculpture with its enigma always overshadowed by historical or biographical topic. Krylov's sculpture in the Summer Garden or Minin and Pozharsky's monument on the Red Square do not strike us, because we know that those monuments are erected IN COMMEMORATION of prominent people, as fellow citizens' tribute to their great contribution to the national history. But the crude metal sheets welded at different angles – what are they for? Who needs them?As an art critic, Edward Goldman, said, fame came to Richard Serra in 1989, when the sculpture composition Tilted Arc erected eight years before it was demolished by

  3. Architectural communication: Intra and extra activity of architecture

    Directory of Open Access Journals (Sweden)

    Stamatović-Vučković Slavica

    2013-01-01

    Full Text Available Apart from a brief overview of architectural communication viewed from the standpoint of theory of information and semiotics, this paper contains two forms of dualistically viewed architectural communication. The duality denotation/connotation (”primary” and ”secondary” architectural communication is one of semiotic postulates taken from Umberto Eco who viewed architectural communication as a semiotic phenomenon. In addition, architectural communication can be viewed as an intra and an extra activity of architecture where the overall activity of the edifice performed through its spatial manifestation may be understood as an act of communication. In that respect, the activity may be perceived as the ”behavior of architecture”, which corresponds to Lefebvre’s production of space.

  4. Oxytocin, feeding and satiety

    Directory of Open Access Journals (Sweden)

    Nancy eSabatier

    2013-03-01

    Full Text Available Oxytocin neurones have a physiological role in food intake and energy balance. Central administration of oxytocin is powerfully anorexigenic, reducing food intake and meal duration. The central mechanisms underlying this effect of oxytocin have become better understood in the past few years. Parvocellular neurones of the paraventricular nucleus project to the caudal brainstem to regulate feeding via autonomic functions including the gastrointestinal vago-vagal reflex. In contrast, magnocellular neurones of the supraoptic and paraventricular nuclei release oxytocin from their dendrites to diffuse to distant hypothalamic targets involved in satiety.The ventromedial hypothalamus, for example, expresses a high density of oxytocin receptors but does not contain detectable oxytocin nerve fibres. Magnocellular neurones represent targets for the anorexigenic neuropeptide α-melanocyte stimulating hormone. . In addition to homeostatic control, oxytocin may also have a role in reward-related feeding. Evidence suggests that oxytocin can selectively suppress sugar intake and that it may have a role in limiting the intake of palatable food by inhibiting the reward pathway.

  5. Advanced Liquid Feed Experiment

    Science.gov (United States)

    Distefano, E.; Noll, C.

    1993-06-01

    The Advanced Liquid Feed Experiment (ALFE) is a Hitchhiker experiment flown on board the Shuttle of STS-39 as part of the Space Test Payload-1 (STP-1). The purpose of ALFE is to evaluate new propellant management components and operations under the low gravity flight environment of the Space Shuttle for eventual use in an advanced spacecraft feed system. These components and operations include an electronic pressure regulator, an ultrasonic flowmeter, an ultrasonic point sensor gage, and on-orbit refill of an auxiliary propellant tank. The tests are performed with two transparent tanks with dyed Freon 113, observed by a camera and controlled by ground commands and an on-board computer. Results show that the electronic pressure regulator provides smooth pressure ramp-up, sustained pressure control, and the flexibility to change pressure settings in flight. The ultrasonic flowmeter accurately measures flow and detects gas ingestion. The ultrasonic point sensors function well in space, but not as a gage during sustained low-gravity conditions, as they, like other point gages, are subject to the uncertainties of propellant geometry in a given tank. Propellant transfer operations can be performed with liquid-free ullage equalization at a 20 percent fill level, gas-free liquid transfer from 20-65 percent fill level, minimal slosh, and can be automated.

  6. Analytical Assessment of the Reciprocating Feed System

    Science.gov (United States)

    Eddleman, David E.; Blackmon, James B.; Morton, Christopher D.

    2006-01-01

    A preliminary analysis tool has been created in Microsoft Excel to determine deliverable payload mass, total system mass, and performance of spacecraft systems using various types of propellant feed systems. These mass estimates are conducted by inserting into the user interface the basic mission parameters (e.g., thrust, burn time, specific impulse, mixture ratio, etc.), system architecture (e.g., propulsion system type and characteristics, propellants, pressurization system type, etc.), and design properties (e.g., material properties, safety factors, etc.). Different propellant feed and pressurization systems are available for comparison in the program. This gives the user the ability to compare conventional pressure fed, reciprocating feed system (RFS), autogenous pressurization thrust augmentation (APTA RFS), and turbopump systems with the deliverable payload, inert mass, and total system mass being the primary comparison metrics. Analyses of several types of missions and spacecraft were conducted and it was found that the RFS offers a performance improvement, especially in terms of delivered payload, over conventional pressure fed systems. Furthermore, it is competitive with a turbopump system at low to moderate chamber pressures, up to approximately 1,500 psi. Various example cases estimating the system mass and deliverable payload of several types of spacecraft are presented that illustrate the potential system performance advantages of the RFS. In addition, a reliability assessment of the RFS was conducted, comparing it to simplified conventional pressure fed and turbopump systems, based on MIL-STD 756B; these results showed that the RFS offers higher reliability, and thus substantially longer periods between system refurbishment, than turbopump systems, and is competitive with conventional pressure fed systems. This is primarily the result of the intrinsic RFS fail-operational capability with three run tanks, since the system can operate with just two run

  7. On the Architectural Engineering Competences in Architectural Design

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning

    2007-01-01

    In 1997 a new education in Architecture & Design at Department of Architecture and Design, Aalborg University was started with 50 students. During the recent years this number has increased to approximately 100 new students each year, i.e. approximately 500 students are following the 3 years bach...... competences related to the specialization in Architectural Design. A detailed presentation can be found at the homepage: www.aod.aau.dk....

  8. ARQUITECTURAS INVISIBLES / Invisible Architecture

    Directory of Open Access Journals (Sweden)

    Francisco Javier Montero Fernández

    2012-11-01

    questions that go beyond quality. Political or commercial interests tend to confuse the opportunity for promotion with the merit of the project. It would be possible to number many competitions which have supposed a significant advance in architecture in the last century; a certain nostalgia for those times of debate which, together with other similar formulas such as entries in biennials, triennials or exhibitions, were capable of making empirical research from direct practice. On the contrary, today the policy framework of the architectural project is often defined in a manner foreign to real architecture, administratively dominated by a process that prioritizes legal and technical compliance over the quality of the project itself, confusing the means with the end. Criticism always aims at the author; it forgets the notable procedures which armed a jury gratuitously exonerated of responsibility or that legal framework that asphyxiates both architecture and the spirit of inquiry which should always prevail.This issue of the journal considers the assimilation of the competition into a research process parallel to an architecture united with quality and progress, an advanced architecture.

  9. The EPOS ICT Architecture

    Science.gov (United States)

    Jeffery, Keith; Harrison, Matt; Bailo, Daniele

    2016-04-01

    The EPOS-PP Project 2010-2014 proposed an architecture and demonstrated feasibility with a prototype. Requirements based on use cases were collected and an inventory of assets (e.g. datasets, software, users, computing resources, equipment/detectors, laboratory services) (RIDE) was developed. The architecture evolved through three stages of refinement with much consultation both with the EPOS community representing EPOS users and participants in geoscience and with the overall ICT community especially those working on research such as the RDA (Research Data Alliance) community. The architecture consists of a central ICS (Integrated Core Services) consisting of a portal and catalog, the latter providing to end-users a 'map' of all EPOS resources (datasets, software, users, computing, equipment/detectors etc.). ICS is extended to ICS-d (distributed ICS) for certain services (such as visualisation software services or Cloud computing resources) and CES (Computational Earth Science) for specific simulation or analytical processing. ICS also communicates with TCS (Thematic Core Services) which represent European-wide portals to national and local assets, resources and services in the various specific domains (e.g. seismology, volcanology, geodesy) of EPOS. The EPOS-IP project 2015-2019 started October 2015. Two work-packages cover the ICT aspects; WP6 involves interaction with the TCS while WP7 concentrates on ICS including interoperation with ICS-d and CES offerings: in short the ICT architecture. Based on the experience and results of EPOS-PP the ICT team held a pre-meeting in July 2015 and set out a project plan. The first major activity involved requirements (re-)collection with use cases and also updating the inventory of assets held by the various TCS in EPOS. The RIDE database of assets is currently being converted to CERIF (Common European Research Information Format - an EU Recommendation to Member States) to provide the basis for the EPOS-IP ICS Catalog. In

  10. Enterprise architecture evaluation using architecture framework and UML stereotypes

    Directory of Open Access Journals (Sweden)

    Narges Shahi

    2014-08-01

    Full Text Available There is an increasing need for enterprise architecture in numerous organizations with complicated systems with various processes. Support for information technology, organizational units whose elements maintain complex relationships increases. Enterprise architecture is so effective that its non-use in organizations is regarded as their institutional inability in efficient information technology management. The enterprise architecture process generally consists of three phases including strategic programing of information technology, enterprise architecture programing and enterprise architecture implementation. Each phase must be implemented sequentially and one single flaw in each phase may result in a flaw in the whole architecture and, consequently, in extra costs and time. If a model is mapped for the issue and then it is evaluated before enterprise architecture implementation in the second phase, the possible flaws in implementation process are prevented. In this study, the processes of enterprise architecture are illustrated through UML diagrams, and the architecture is evaluated in programming phase through transforming the UML diagrams to Petri nets. The results indicate that the high costs of the implementation phase will be reduced.

  11. Chipless RFID reader architecture

    CERN Document Server

    Karmakar, Nemai Chandra; Kalansuriya, Prasanna

    2013-01-01

    In the era of information communication technology (ICT), radio frequency identification (RFID) has been going through tremendous development. RFID technology has the potential of replacing barcodes due to its large information carrying capacity, flexibility in operations, and applications. The deployment of RFID has been hindered by its cost. However, with the advent of low powered ICs, energy scavenging techniques, and low-cost chipless tags, RFID technology has achieved significant development. This book addresses the new reader architecture, presents fundamentals of chipless RFID systems,

  12. Die-stacking architecture

    CERN Document Server

    Xie, Yuan

    2015-01-01

    The emerging three-dimensional (3D) chip architectures, with their intrinsic capability of reducing the wire length, promise attractive solutions to reduce the delay of interconnects in future microprocessors. 3D memory stacking enables much higher memory bandwidth for future chip-multiprocessor design, mitigating the ""memory wall"" problem. In addition, heterogenous integration enabled by 3D technology can also result in innovative designs for future microprocessors. This book first provides a brief introduction to this emerging technology, and then presents a variety of approaches to design

  13. Game engine architecture

    CERN Document Server

    Gregory, Jason

    2014-01-01

    ""… this book is the best of its kind, and you're lucky to have found it. It covers the huge field of game engine architecture in a succinct, clear way, and expertly balances the breadth and depth of its coverage, offering enough detail that even a beginner can easily understand the concepts it presents. The author, Jason Gregory, is not only a world expert in his field; he's a working programmer with production-quality knowledge and many shipped game projects under his belt. … Jason is also an experienced educator who has taught in the top-ranked university game program in North America. …

  14. Architecture Building Sustainability

    Institute of Scientific and Technical Information of China (English)

    DAVID HENDRICKSON

    2006-01-01

    @@ Leading architectural design and engineering firm, Skidmore,Owings, & Merrill (SOM), is renowned for pushing the envelope, masterminding some of the world's most cutting edge and enduring structural masterpieces - America's tallest building, the Sears Tower,in the firm's home city of Chicago, the 88-story Jinmao Tower in Shanghai, and the Freedom Tower in New York City, successor to the fallen World Trade Center complex,are among the well known projects in its building portfolio. SOM's next high profile assignment, the Pearl River Tower, in Guangzhou is one no less worthy of this tradition.

  15. Mobile networks architecture

    CERN Document Server

    Perez, Andre

    2013-01-01

    This book explains the evolutions of architecture for mobiles and summarizes the different technologies:- 2G: the GSM (Global System for Mobile) network, the GPRS (General Packet Radio Service) network and the EDGE (Enhanced Data for Global Evolution) evolution;- 3G: the UMTS (Universal Mobile Telecommunications System) network and the HSPA (High Speed Packet Access) evolutions:- HSDPA (High Speed Downlink Packet Access),- HSUPA (High Speed Uplink Packet Access),- HSPA+;- 4G: the EPS (Evolved Packet System) network.The telephone service and data transmission are the

  16. Microgrids architectures and control

    CERN Document Server

    Hatziargyriou, Nikos

    2014-01-01

    Microgrids are the most innovative area in the electric power industry today. Future microgrids could exist as energy-balanced cells within existing power distribution grids or stand-alone power networks within small communities. A definitive presentation on all aspects of microgrids, this text examines the operation of microgrids - their control concepts and advanced architectures including multi-microgrids. It takes a logical approach to overview the purpose and the technical aspects of microgrids, discussing the social, economic and environmental benefits to power system operation. The bo

  17. Advanced router architectures

    CERN Document Server

    Kloth, Axel K

    2005-01-01

    Routers, switches, and transmission equipment form the backbone of the Internet, yet many users and service technicians do not understand how these nodes really work.Advanced Router Architectures addresses how components of advanced routers work together and how they are integrated with each other. This book provides the background behind why these building blocks perform certain functions, and how the function is implemented in general use. It offers an introduction to the subject matter that is intended to trigger deeper interest from the reader. The book explains, for example, why traffic m

  18. Light Rhythms in Architecture

    DEFF Research Database (Denmark)

    Bülow, Katja

    2013-01-01

    On one hand, urban lighting expresses itself in a complex visual environment made by the interplay by between many separate lighting schemes, as street lighting, shop lighting, luminous commercials etc. On the other, a noticeable order of patterns occurs, when lighting is observed as luminous...... formation and rhythm. When integrated into an architectural concept, electrical lighting non-intended for poetic composition has the ability to contribute to place, time, and function-telling aspects of places in urban contexts. Urban environments are information wise challenging to pre-historic human...... instincts, but they can be met by careful selection and adjustment of existing light situations....

  19. Between Organisation and Architecture

    DEFF Research Database (Denmark)

    Stang Våland, Marianne

    2011-01-01

    . In this process, the open-office layout was introduced as a premediated design condition, a format that the users initially resisted. The paper discusses how end-user participation as a method and spatial design as a perspective may inform change in organisations. Although the users' resistance toward the open......This paper contributes to our sparse knowledge on the relationship between organisational and architectural design. It is based on an ethnographic study of the process of designing a municipality town hall, in which end-user participation constituted an integrated part of the design process...

  20. Etruscan Divination and Architecture

    Science.gov (United States)

    Magli, Giulio

    The Etruscan religion was characterized by divination methods, aimed at interpreting the will of the gods. These methods were revealed by the gods themselves and written in the books of the Etrusca Disciplina. The books are lost, but parts of them are preserved in the accounts of later Latin sources. According to such traditions divination was tightly connected with the Etruscan cosmovision of a Pantheon distributed in equally spaced, specific sectors of the celestial realm. We explore here the possible reflections of such issues in the Etruscan architectural remains.

  1. Future of information architecture

    CERN Document Server

    Baofu, Peter

    2008-01-01

    The Future of Information Architecture examines issues surrounding why information is processed, stored and applied in the way that it has, since time immemorial. Contrary to the conventional wisdom held by many scholars in human history, the recurrent debate on the explanation of the most basic categories of information (eg space, time causation, quality, quantity) has been misconstrued, to the effect that there exists some deeper categories and principles behind these categories of information - with enormous implications for our understanding of reality in general. To understand this, the b

  2. Architectural Prototyping in Industrial Practice

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius

    2008-01-01

    Architectural prototyping is the process of using executable code to investigate stakeholders’ software architecture concerns with respect to a system under development. Previous work has established this as a useful and cost-effective way of exploration and learning of the design space of a system......, in addressing issues regarding quality attributes, in addressing architectural risks, and in addressing the problem of knowledge transfer and conformance. Little work has been reported so far on the actual industrial use of architectural prototyping. In this paper, we report from an ethnographical study...... prototypes include end-user or business related functionality rather than purely architectural functionality. Based on these observations we provide recommendations for effective industrial architectural prototyping....

  3. Using Hybrid Algorithm to Improve Intrusion Detection in Multi Layer Feed Forward Neural Networks

    Science.gov (United States)

    Ray, Loye Lynn

    2014-01-01

    The need for detecting malicious behavior on a computer networks continued to be important to maintaining a safe and secure environment. The purpose of this study was to determine the relationship of multilayer feed forward neural network architecture to the ability of detecting abnormal behavior in networks. This involved building, training, and…

  4. Architectural Theory: A Construction Site

    Directory of Open Access Journals (Sweden)

    Ákos Moravánszky

    2014-07-01

    Full Text Available Around 1968 we saw the birth of a new architectural theory as the conjunction of architectural history and politically engaged architectural criticism. Not the aesthetics of architecture, but architecture itself in its structural relations with social life became the focus of attention. As a result of this development, it is no longer possible to study architectural history without a critical reflection on the method of the study itself and without a grade of interdisciplinarity. Traditional methods of historiography and iconography have been replaced by new approaches configured by psychoanalysis, deconstruction, cultural studies etc. Appropriation has become the proof of criticality both in architectural theory and in design; however, the understanding of the concepts and methods of other disciplines is basically metaphorical. The problem for a school of architecture lies not in the ‘criticality’ of the kind of architectural theory we described as emerging from the spirit of 1968, but in its discursive nature. The disciplinary specificity of architecture resists a discursive approach, and architectural students frequently question the usefulness of theory which undermines the notion of the ‘project’, without articulating a constructive proposal. Projectivity does not seem to provide an answer; its claim of performativity lacks the program to regain its organising power over contributions from other specialised disciplines and practices. Theory should focus on the terms of our discipline, which are so close to our ‘core beliefs’ regarding architecture that we usually take their meaning for granted. It would be wrong to see this focus of theory as a withdrawal into the realm of language. Indeed, after a period of theory alienating architects and the general public, it could now create a rhetoric to influence our understanding of our environment, which is itself organised on the level of language. The requirement that theory should

  5. Architecture in the network society

    DEFF Research Database (Denmark)

    2004-01-01

    Under the theme Architecture in the Network Society, participants were invited to focus on the dialog and sharing of knowledge between architects and other disciplines and to reflect on, and propose, new methods in the design process, to enhance and improve the impact of information technology...... on architecture. This conference and the past history of eCAADe is an example on establishing a social network for the sharing of knowledge regarding the use of computers in architectural education and research....

  6. Contemporary earthen architecture in Mexico

    OpenAIRE

    Aguilar Prieto, Berenice

    2009-01-01

    The purpose of this study is to put forward an appraisal of current remarkable works of earthen architecture in Mexico, where raw earth architecture, particularly in adobe, has been built since ancient times, but has nevertheless, been substituted by industrial materials that bring poor living conditions for the inhabitants both in urban as in rural areas. Recently, rather than vernacular architecture built by its users, it is within architectonic design that a kind of revival ...

  7. Towards a networkArchitecture

    DEFF Research Database (Denmark)

    Rüdiger, Bjarne; Tournay, Bruno

    2001-01-01

    Planche, bidrag til DAL-konkurrencen. Hvor industrien har været inspirationen for udviklingen af den moderne arkitektur, er IT det tekniske og æstetiske grundlag for den spirende NetworkArchitecture. Computeren og netværker af computerne er således mere end en metafor for NetworkArchitecture....... NetworkArchitecture består af intelligente byggekomponenter forbundet med hinanden i et netværk og i interaktion med omgivelser....

  8. Parallel Architectures and Bioinspired Algorithms

    CERN Document Server

    Pérez, José; Lanchares, Juan

    2012-01-01

    This monograph presents examples of best practices when combining bioinspired algorithms with parallel architectures. The book includes recent work by leading researchers in the field and offers a map with the main paths already explored and new ways towards the future. Parallel Architectures and Bioinspired Algorithms will be of value to both specialists in Bioinspired Algorithms, Parallel and Distributed Computing, as well as computer science students trying to understand the present and the future of Parallel Architectures and Bioinspired Algorithms.

  9. The ALMA software architecture

    Science.gov (United States)

    Schwarz, Joseph; Farris, Allen; Sommer, Heiko

    2004-09-01

    The software for the Atacama Large Millimeter Array (ALMA) is being developed by many institutes on two continents. The software itself will function in a distributed environment, from the 0.5-14 kmbaselines that separate antennas to the larger distances that separate the array site at the Llano de Chajnantor in Chile from the operations and user support facilities in Chile, North America and Europe. Distributed development demands 1) interfaces that allow separated groups to work with minimal dependence on their counterparts at other locations; and 2) a common architecture to minimize duplication and ensure that developers can always perform similar tasks in a similar way. The Container/Component model provides a blueprint for the separation of functional from technical concerns: application developers concentrate on implementing functionality in Components, which depend on Containers to provide them with services such as access to remote resources, transparent serialization of entity objects to XML, logging, error handling and security. Early system integrations have verified that this architecture is sound and that developers can successfully exploit its features. The Containers and their services are provided by a system-orienteddevelopment team as part of the ALMA Common Software (ACS), middleware that is based on CORBA.

  10. The role Sustainable Architecture in Iranian Traditional Architecture

    Directory of Open Access Journals (Sweden)

    Shabnam Azadi

    2016-12-01

    Full Text Available Using local and continental materials, Sustainable architecture aims to design sustainable buildings, decrease its damages to the environment, sources of energy and nature. A deeper thought on the principles of traditional architecture indicates that the idea of constancy has its origins back in ancient human norms. On the one hand, solving the environmental, cultural-social and economic problems, and the intense integrity of such issues, direct us toward traditional architecture and constancy in comparison and evaluation in order to extract the required lessons for today’s architectural design. On the other hand, the historical architectural and urbanization evidence reveals that in the past, architecture and urbanization have taken place in line with the environment, traditional architecture with a tendency to environmental and social constancy and with respect to natural resources and preserving them for the future generations. Nowadays, unlimited destruction of the environment which is due to the malicious attitude toward nature in the recent centuries, threatens human life. The sudden stop in the creative process of past architecture, and the faster and easier solutions by modern architects have made forget the methods which were appropriate with the environment. In this article, traditional Iranian houses were studied in this sense in order to have looked at the traditional architecture with open eyes and to use its intellectual background in today’s architecture and building techniques. Finally, in this research the reasons for constancy of Iranian traditional houses were investigated with a descriptiveanalytic approach and strategies are suggested with respect to new technology with the purpose of preserving traditional local architecture which causes sustainable development of the houses.

  11. Same school, different conduct: rates of multiple paternity vary within a mixed-species breeding school of semi-pelagic cichlid fish (Cyprichromis spp.).

    Science.gov (United States)

    Anderson, Caleb; Werdenig, Alexandra; Koblmüller, Stephan; Sefc, Kristina M

    2016-01-01

    Mating system variability is known to exist between and within species, often due to environmental influences. An open question is whether, vice versa, similar environmental conditions entail congruent mating behavior, for example in terms of multiple paternity, in species or populations sharing largely comparable breeding modes. This study employed microsatellite markers to investigate the incidence of multiple paternity in Cyprichromis coloratus and Cyprichromis leptosoma, two sympatric, closely related, mouthbrooding Lake Tanganyika cichlids with similar ecological and behavioral characteristics including the formation of open-water schools. Mouthbrooding females of both species were collected from the same mixed-species breeding school at the same time, minimizing environmental variation during courtship and mating. In C. coloratus, four of 12 broods had more than one sire, with a mean of 1.33 reconstructed sires per brood. C. leptosoma exhibited multiple paternity in 18 of 22 broods, with a mean of 2.59 or 2.86 reconstructed sires per brood according to the programs gerud and colony, respectively. In addition, two broods were found to contain offspring transplanted from another brood. There was no significant difference in brood size between species, but mean sire number did differ significantly. Hence, substantial similarity in reproductive behavior along with shared environmental conditions during courtship and spawning did not lead to equal rates of polyandry or sneaking in the two species.

  12. Induced cytochrome P450 1A activity in cichlid fishes from Guandu River and Jacarepaguá Lake, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Parente, Thiago E M; De-Oliveira, Ana C A X; Paumgartten, Francisco J R

    2008-03-01

    The induction of cytochrome P4501A-mediated activity (e.g. ethoxyresorufin-O-deethylation, EROD) has been used as a biomarker for monitoring fish exposure to AhR-receptor ligands such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and polychlorinated dibenzo-dioxins/furans (PCDD/Fs). In this study we found that hepatic EROD is induced in fish ("Nile tilapia", Oreochromis niloticus and "acará", Geophagus brasiliensis) from the Guandu River (7-17-fold) and Jacarepaguá Lake (7-fold), Rio de Janeiro, Brazil. Since both cichlid fish are consumed by the local population and the Guandu River is the main source of the drinking water supply for the greater Rio de Janeiro metropolitan area, pollution by cytochrome P4501A-inducing chemicals is a cause for concern and should be further investigated in sediments, water and biota. We additionally showed that EROD activity in the fish liver post-mitochondrial supernatant-simpler, cheaper and less time consuming to prepare than the microsomal fraction-is sufficiently sensitive for monitoring purposes.

  13. Strong assortative mating by diet, color, size, and morphology but limited progress toward sympatric speciation in a classic example: Cameroon crater lake cichlids.

    Science.gov (United States)

    Martin, Christopher H

    2013-07-01

    Models predict that sympatric speciation depends on restrictive parameter ranges, such as sufficiently strong disruptive selection and assortative mating, but compelling examples in nature have rarely been used to test these predictions. I measured the strength of assortative mating within a species complex of Tilapia in Lake Ejagham, Cameroon, a celebrated example of incipient sympatric adaptive radiation. This species complex is in the earliest stages of speciation: morphological and ecological divergence are incomplete, species differ primarily in breeding coloration, and introgression is common. I captured 27 mated pairs in situ and measured the diet, color, size, and morphology of each individual. I found strong assortative mating by color, size, head depth, and dietary source of benthic or pelagic prey along two independent dimensions of assortment. Thus, Ejagham Tilapia showed strong assortative mating most conducive to sympatric speciation. Nonetheless, in contrast to a morphologically bimodal Sarotherodon cichlid species pair in the lake, Ejagham Tilapia show more limited progress toward speciation, likely due to insufficient strength of disruptive selection on morphology estimated in a previous study (γ = 0.16). This supports the predicted dependence of sympatric speciation on strong assortment and strong disruptive selection by examining a potentially stalled example in nature.

  14. Intermediate number of major histocompatibility complex class IIB length variants relates to enlarged perivisceral fat deposits in the blunt-head cichlid Tropheus moorii.

    Science.gov (United States)

    Hablützel, P I; Vanhove, M P M; Grégoir, A F; Hellemans, B; Volckaert, F A M; Raeymaekers, J A M

    2014-10-01

    Studying the genetic basis of host-parasite interactions represents an outstanding opportunity to observe eco-evolutionary processes. Established candidates for such studies in vertebrates are immunogenes of the major histocompatibility complex (MHC). The MHC has been reported to reach high intra- and interindividual diversity, and a diverse MHC might be advantageous when facing infections from multiple parasites. However, other studies indicated that individuals with an intermediate number of MHC alleles are less infected with parasites or have other fitness advantages. In this study, we assessed the optimal number of MHC alleles in the blunt-head cichlid Tropheus moorii from Lake Tanganyika. We investigated the influence of the interindividual variation in number of MHC length variants on parasite infection and body condition, measured by the amount of perivisceral fat reserves. Surprisingly, there was no correlation between parasite infection and number of MHC length variants or perivisceral fat deposits. However, the individual number of MHC length variants significantly correlated with the amount of perivisceral fat deposits in males, suggesting that male individuals with an intermediate number of alleles might be able to use their fat reserves more efficiently.

  15. Redescription of Neoechinorhynchus (Neoechinorhynchus) golvani Salgado-Maldonado, 1978 (Acanthocephala: Neoechinorhynchidae) and description of a new species from freshwater cichlids (Teleostei: Cichlidae) in Mexico.

    Science.gov (United States)

    Salgado-Maldonado, Guillermo

    2013-05-01

    A redescription of Neoechinorhynchus (Neoechinorhynchus) golvani Salgado-Maldonado (An Inst Biol Univ Nal Autón Méx, Ser Zool 49:35-47, 1978) is presented, based on adult specimens collected from the type host Paraneetroplus fenestratus from the type location, the Lago de Catemaco lake, Veracruz state, Mexico, and its presence is recorded in other cichlids. Detailed studies of N. (N.) golvani using light microscopy revealed some taxonomically important, previously unreported features, such as the size and shape of fully developed adult males and females, and the structure of the eggs. Morphological variability in N. (N.) golvani is described. Based on these data, the geographic distribution of this species is documented. Neoechinorhynchus (Neoechinorhynchus) panucensis n. sp. is described from Herichthys labridens (Pellegrin), Amatitlania nigrofasciata (Günther), and Herichthys cyanoguttatus Baird and Girard (all of them Cichlidae), collected in the Río Atlapexco, a tributary to the upper Río Panuco basin, Hidalgo State, Mexico. This new species stand up alone because of its minute proboscis (♂ 50 × 60, ♀ 42-55 (48.5) × 48-63 (57.7)) and anterior hooks (♂ 27-30 (28.8) × 3-5 (4), ♀ 28-32 (30) × 5 (5)). A key to the species of Neoechinorhynchus recorded from freshwater fishes in Central and South America is included.

  16. A sex-specific trade-off between mating preferences for genetic compatibility and body size in a cichlid fish with mutual mate choice.

    Science.gov (United States)

    Thünken, Timo; Meuthen, Denis; Bakker, Theo C M; Baldauf, Sebastian A

    2012-08-01

    Mating preferences for genetic compatibility strictly depend on the interplay of the genotypes of potential partners and are therein fundamentally different from directional preferences for ornamental secondary sexual traits. Thus, the most compatible partner is on average not the one with most pronounced ornaments and vice versa. Hence, mating preferences may often conflict. Here, we present a solution to this problem while investigating the interplay of mating preferences for relatedness (a compatibility criterion) and large body size (an ornamental or quality trait). In previous experiments, both sexes of Pelvicachromis taeniatus, a cichlid fish with mutual mate choice, showed preferences for kin and large partners when these criteria were tested separately. In the present study, test fish were given a conflicting choice between two potential mating partners differing in relatedness as well as in body size in such a way that preferences for both criteria could not simultaneously be satisfied. We show that a sex-specific trade-off occurs between mating preferences for body size and relatedness. For females, relatedness gained greater importance than body size, whereas the opposite was true for males. We discuss the potential role of the interplay between mating preferences for relatedness and body size for the evolution of inbreeding preference.

  17. Sustainability and the Architectural History

    Directory of Open Access Journals (Sweden)

    Vandana Baweja

    2014-12-01

    Full Text Available In this paper, I will address the challenges of incorporating the discourse of Sustainability into the architectural history curriculum and how Sustainability in the survey can be related to the Sustainability education the design studio. I argue that the inclusion of Sustainability into the architectural survey will necessitate the production of revisionist architectural histories that are written through an environmental paradigm and are able to establish a dialogue with Sustainability education in the design studio. These revisionist histories will occupy the disciplinary territory that is produced at the intersection of architectural and environmental histories

  18. Integrated Data Assimilation Architecture Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Integrated Data Assimilation Architecture (IDAA) addresses the fundamental problem of command, control, and communications systems interoperability....

  19. Prey perception in feeding-current feeding copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Goncalves, Rodrigo J.; Florian Couespel, Damien

    2016-01-01

    We reply to the comments of Paffenhöfer and Jiang () who argues that remote chemical prey perception is necessary for feeding-current feeding copepods to fulfill their nutritional requirements in a dilute ocean, that remote chemical prey detection may only be observed at very low prey concentrati...

  20. Aquaculture and feeding ecology: Feeding behaviour in turbot larvae

    DEFF Research Database (Denmark)

    Bruno, Eleonora

    challenging for larval rearing. After the start of exogenous feeding, another intense and likely critical period of change occurs in the early life stages of fish. This stage is the metamorphosis, during which the larvae transform organs and body morphology to become juveniles. Compared to other teleosts...... metamorphosis in flatfish species is often unsuccessful, resulting in different types of abnormal development. The objective of this thesis was to analyse the feeding behaviour of the flatfish species turbot (Psetta maxima L.) larvae during the two crucial life periods, 1) first feeding and 2) metamorphosis....... To analyse whether these two periods are critical for the correct development and survival of turbot, feeding behaviours of larvae during the period of first feeding and during the first stages of metamorphosis was studied using video recordings. This provided qualitative and quantitative descriptions...

  1. Architecture of Institution & Home. Architecture as Cultural Medium

    NARCIS (Netherlands)

    Robinson, J.W.

    2004-01-01

    This dissertation addresses how architecture functions as a cultural medium. It does so by by investigating how the architecture of institution and home each construct and support different cultural practices. By studying the design of ordinary settings in terms of how qualitative differences in arc

  2. Software architecture as a set of architectural design decisions

    NARCIS (Netherlands)

    Jansen, Anton; Bosch, Jan; Nord, R; Medvidovic, N; Krikhaar, R; Khrhaar, R; Stafford, J; Bosch, J

    2006-01-01

    Software architectures have high costs for change, are complex, and erode during evolution. We believe these problems are partially due to knowledge vaporization. Currently, almost all the knowledge and information about the design decisions the architecture is based on are implicitly embedded in th

  3. The Architecture of Exoplanets

    Science.gov (United States)

    Hatzes, Artie P.

    2016-05-01

    Prior to the discovery of exoplanets our expectations of their architecture were largely driven by the properties of our solar system. We expected giant planets to lie in the outer regions and rocky planets in the inner regions. Planets should probably only occupy orbital distances 0.3-30 AU from the star. Planetary orbits should be circular, prograde and in the same plane. The reality of exoplanets have shattered these expectations. Jupiter-mass, Neptune-mass, Superearths, and even Earth-mass planets can orbit within 0.05 AU of the stars, sometimes with orbital periods of less than one day. Exoplanetary orbits can be eccentric, misaligned, and even in retrograde orbits. Radial velocity surveys gave the first hints that the occurrence rate increases with decreasing mass. This was put on a firm statistical basis with the Kepler mission that clearly demonstrated that there were more Neptune- and Superearth-sized planets than Jupiter-sized planets. These are often in multiple, densely packed systems where the planets all orbit within 0.3 AU of the star, a result also suggested by radial velocity surveys. Exoplanets also exhibit diversity along the main sequence. Massive stars tend to have a higher frequency of planets ( ≈ 20-25 %) that tend to be more massive ( M≈ 5-10 M_{Jup}). Giant planets around low mass stars are rare, but these stars show an abundance of small (Neptune and Superearth) planets in multiple systems. Planet formation is also not restricted to single stars as the Kepler mission has discovered several circumbinary planets. Although we have learned much about the architecture of planets over the past 20 years, we know little about the census of small planets at relatively large ( a>1 AU) orbital distances. We have yet to find a planetary system that is analogous to our own solar system. The question of how unique are the properties of our own solar system remains unanswered. Advancements in the detection methods of small planets over a wide range

  4. The Architecture of Exoplanets

    Science.gov (United States)

    Hatzes, Artie P.

    2016-12-01

    Prior to the discovery of exoplanets our expectations of their architecture were largely driven by the properties of our solar system. We expected giant planets to lie in the outer regions and rocky planets in the inner regions. Planets should probably only occupy orbital distances 0.3-30 AU from the star. Planetary orbits should be circular, prograde and in the same plane. The reality of exoplanets have shattered these expectations. Jupiter-mass, Neptune-mass, Superearths, and even Earth-mass planets can orbit within 0.05 AU of the stars, sometimes with orbital periods of less than one day. Exoplanetary orbits can be eccentric, misaligned, and even in retrograde orbits. Radial velocity surveys gave the first hints that the occurrence rate increases with decreasing mass. This was put on a firm statistical basis with the Kepler mission that clearly demonstrated that there were more Neptune- and Superearth-sized planets than Jupiter-sized planets. These are often in multiple, densely packed systems where the planets all orbit within 0.3 AU of the star, a result also suggested by radial velocity surveys. Exoplanets also exhibit diversity along the main sequence. Massive stars tend to have a higher frequency of planets (≈ 20-25 %) that tend to be more massive (M≈ 5-10 M_{Jup}). Giant planets around low mass stars are rare, but these stars show an abundance of small (Neptune and Superearth) planets in multiple systems. Planet formation is also not restricted to single stars as the Kepler mission has discovered several circumbinary planets. Although we have learned much about the architecture of planets over the past 20 years, we know little about the census of small planets at relatively large (a>1 AU) orbital distances. We have yet to find a planetary system that is analogous to our own solar system. The question of how unique are the properties of our own solar system remains unanswered. Advancements in the detection methods of small planets over a wide range of

  5. Prediction of Genomic Breeding Values for feed efficiency and related traits in pigs

    DEFF Research Database (Denmark)

    Do, Duy Ngoc; Janss, Luc; Strathe, Anders Bjerring;

    previously identified significant SNPs on 30-31Mb and 60-61Mb on chromosome 1 (SSC 1) for RFI and DFI, respectively, and found several novel SNPs on SSC 14 for RFI. Estimated genomic variance varied according to the power parameters. Prediction accuracy for BLP models ranged from 0.33-0.34 and 0......Improvement of feed efficiency is essential in pig breeding and selection for reduced residual feed intake (RFI) is an option. Accuracy of genomic prediction (GP) relies on assumptions of genetic architecture of the traits. This study applied five different Bayesian Power LASSO (BPL) models...... with different power parameters to investigate genetic architecture of RFI, to predict genomic breeding values, and to partition genetic variances for different SNP groups. Data were 1272 Duroc pigs with both genotypic and phenotypic records for RFI as well as daily feed intake (DFI). The gene mapping confirmed...

  6. Enteral Tube Feeding and Pneumonia

    Science.gov (United States)

    Gray, David Sheridan; Kimmel, David

    2006-01-01

    To determine the effects of enteral tube feeding on the incidence of pneumonia, we performed a retrospective review of all clients at our institution who had gastrostomy or jejunostomy tubes placed over a 10-year period. Ninety-three subjects had a history of pneumonia before feeding tube insertion. Eighty had gastrostomy and 13, jejunostomy…

  7. High-Tech Architecture

    Directory of Open Access Journals (Sweden)

    Özlem Eşsiz

    1999-05-01

    Full Text Available The technological development in building and construction area, bring with the new construction systems and the new products. The aim of this study is to define the High Tech concept, and set the common and basic characteristics of High Tech applications. During 1970’s High Tech was born and developed in Britain. Especially British Architects Richard Rogers, Michael Hopkins, Norman Foster, Nicholas Grimshaw and Ian Ritchie are the leaders of this style. Their architecture show the machine aesthetic and use of industrial revoluation materials such as glass and steel. The reasons for wide usage of this technology in building constructions are; the ease of renewing the structural and installation systems by the changing technology and giving monumentality to the prestige buildings. High Tech building which we have many examples of give their occupants a lot of opportunities and also they can adapt itself to the time.

  8. Functional Biomimetic Architectures

    Science.gov (United States)

    Levine, Paul M.

    N-substituted glycine oligomers, or 'peptoids,' are a class of sequence--specific foldamers composed of tertiary amide linkages, engendering proteolytic stability and enhanced cellular permeability. Peptoids are notable for their facile synthesis, sequence diversity, and ability to fold into distinct secondary structures. In an effort to establish new functional peptoid architectures, we utilize the copper-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC) reaction to generate peptidomimetic assemblies bearing bioactive ligands that specifically target and modulate Androgen Receptor (AR) activity, a major therapeutic target for prostate cancer. Additionally, we explore chemical ligation protocols to generate semi-synthetic hybrid biomacromolecules capable of exhibiting novel structures and functions not accessible to fully biosynthesized proteins.

  9. Architecture for Teraflop Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Breckenridge, A.R.; Haynes, R.A.

    1999-04-09

    Sandia Laboratories' computational scientists are addressing a very important question: How do we get insight from the human combined with the computer-generated information? The answer inevitably leads to using scientific visualization. Going one technology leap further is teraflop visualization, where the computing model and interactive graphics are an integral whole to provide computing for insight. In order to implement our teraflop visualization architecture, all hardware installed or software coded will be based on open modules and dynamic extensibility principles. We will illustrate these concepts with examples in our three main research areas: (1) authoring content (the computer), (2) enhancing precision and resolution (the human), and (3) adding behaviors (the physics).

  10. Thermal Space in Architecture

    DEFF Research Database (Denmark)

    Petersen, Mads Dines

    buildings. However at the bottom of this lies an understanding of how we inhabit the space in our buildings and how we historically have adapted to the changing conditions of the seasons in our buildings. Through an increased understanding of this adaptability of and to our buildings, our work with spaces...... and understanding of spaces in buildings can change significantly and instead of the creation of frozen geometrical spaces, thermal spaces can be created as it is suggested in meteorological architecture where functions are distributed in relation to temperature gradients. This creates an interesting contrast...... to the current discussions about passive houses that today is starting to set the standards in a Scandinavian context, where the highly controlled indoor environment is in focus relying on mechanical ventilation, creating spaces with a narrow margin for comfort. One can raise the question if re...

  11. Mobile Remote Control Architecture

    Directory of Open Access Journals (Sweden)

    George Stefan Bogdan

    2012-03-01

    Full Text Available When mobile device become more and more popular the need to have a software bridge between them and the old fashioned computers became evident. Many different solutions have appeared to fill the void but few offer more than file sinking or remote SSH (secure shell connections. For computer professionals and other alike a tool that can do more regarding this connectivity and control gap became necessary. With this paper it is described an architecture and an implementation for creating such a system, underlining the difficulties, challenges and the many choices regarding overall system design, security and implementation that need to be made in order to provide the user with a secure, reliable and professional solution.

  12. Naval open systems architecture

    Science.gov (United States)

    Guertin, Nick; Womble, Brian; Haskell, Virginia

    2013-05-01

    For the past 8 years, the Navy has been working on transforming the acquisition practices of the Navy and Marine Corps toward Open Systems Architectures to open up our business, gain competitive advantage, improve warfighter performance, speed innovation to the fleet and deliver superior capability to the warfighter within a shrinking budget1. Why should Industry care? They should care because we in Government want the best Industry has to offer. Industry is in the business of pushing technology to greater and greater capabilities through innovation. Examples of innovations are on full display at this conference, such as exploring the impact of difficult environmental conditions on technical performance. Industry is creating the tools which will continue to give the Navy and Marine Corps important tactical advantages over our adversaries.

  13. Architectural Practice as Research

    DEFF Research Database (Denmark)

    Hougaard, Anna Katrine

    2015-01-01

    , qualitative and quantitative, scientific and artistic methods pollinate each other, and an attempt to set up a span for ‘research by design’ to unfold in, rather than a rigid definition. In mutual exploitation architectural writing, drawing and potentially the construction of objects with properties embodied......The paper discusses a kind of research which lies between ‘research by design’ and ‘artistic research’. The term ‘research by design’ is reconstructed to include artistic ways of working, and the paper is an exemplification of a research practice, which seeks to let subjective and objective...... in them, is the very research. This approach is framed by Deleuze’s reading of Bergson’s intuitive method and Peirce’s concept abduction, both methods which concern creative processes, material production and organisation, and the breakthrough of novelty....

  14. Architectural Competition and BIM

    DEFF Research Database (Denmark)

    Sørensen, Nils Lykke; Frandsen, Anne Kathrine; Øien, Turid Borgestrand

    2015-01-01

    put under pressure. Thus, the two central actors involved inarchitectural competitions, architects and building clients, are continually influenced by such developments, interpreting and adaptingto changes according to their interests and horizons. During a project reviewing Nordic research literature...... on architecturalcompetitions, a series of interviews was conducted with building clients as well as architects, focusing on the impact of the above-mentioned changes within the building sector on architectural competitions as an institution. In the interviews, ICT and notleast BIM was a recurring theme that both parties saw...... as having a positive impact on competitions. But when looking closely into the answers, these revealed diverse understandings of how and why the impact of BIM on competitions could be said to be positive. The paper sheds light on the interaction between the actors (building clients, architects and client...

  15. An Embodied Architecture

    Directory of Open Access Journals (Sweden)

    Frances Downing

    2012-10-01

    Full Text Available An architecture of the body is emerging out of theories of biology, complexity, and systems through the use of an evolving organism as its metaphor. Autopoiesis is the term used by biologists to describe the realm of existence for a living organism as it slides between the interchange of structure and information. Incoming information is filtered through the organism for its usefulness in the art of staying alive. Structural or organizational changes evolve as the organism adjusts to new information. To remain a viable organism—to survive—means that an entity must keep evolving without surrendering identity. Humans must maintain an embodied identity, often referred to as an organized self (Maturana & Varela, 1980, 1987, while viably exchanging information with other entities and the environment. This operation creates a topological boundary across which the communication takes place. Cognitive theorists and researchers have proposed that the animal condition is one of Embodied Realism; that is, animals such as we humans, are embodied, using our bodies to create basic metaphors, and, that we do this in a“real” world. The role of cognition in this equation is to allow humans the use of embodiment to explore abstract ideas through metaphor—such as “grasping an idea” (Lakoff &Johnson, 2003. In doing so, it allows the invention of an evolving language that refers to things “outside” our skin,like other entities and places. Autopoiesis describes the activities at the “edge” or boundary of an organism. The linguistic act can, therefore, be identified as fundamental medium for communication in the edge, between inside and outside, that assures the autopoiesis of place.In our own bodies, flesh is the biological manifest of the edge or boundary condition. Our understanding of flesh is that it is another of our organs; and at the same time, all organs are also bounded by flesh. It serves as a porous filter, delicate and complicated

  16. Architecture, energy and climate

    DEFF Research Database (Denmark)

    Lauring, Michael

    2010-01-01

    Architecture has always had to relate to climatic conditions while providing shelter from the sun, the rain, the winds or the cold. This is a main purpose of buildings: To establish an indoor climate different from the outdoor. In the Nordic countries fuels for heating buildings has been a vital...... necessity almost as basic as food and water, and lack of wood has caused illness and migration - scarcity of energy is not a new topic either [Kjærgaard]. The new aspects are that human civilization is in danger of causing severe global climate changes, secondly that we can foresee using up the global non......-renewable reserves of oil, gas and uranium, both aspects capable of pulling the carpet under human civilization itself as we know it. The huge energy consumption especially in the northern hemisphere is closely linked to industrialization, and the response from those aware of energy and climate problems has in some...

  17. Multimedia communications: architectural alternatives

    Science.gov (United States)

    McGarty, Terrence P.; Treves, S. T.

    1992-03-01

    Multimedia communications systems are a combination of human interfaces and end users interacting with multimedia data bases and highly disparate but interconnected communications networks. This paper discusses several architectural alternatives and system requirements that will assist in the design and development of MMCS in actual environments. The approaches taken in this paper are based upon the development of such systems in both medical and printing and publishing environments. This paper develops several key concepts as how best to define and structure data in a multimedia environment, how best to integrate the communications elements, and how best to permit the maximum flexibility to the end user to utilize the system's capabilities in the context of a fully conversational environment.

  18. Parental concerns about complementary feeding

    DEFF Research Database (Denmark)

    Nielsen, Annemette; Michaelsen, Kim F.; Holm, Lotte

    2013-01-01

    Background/objectives:To investigate and analyze differences in parental concerns during earlier and later phases of complementary feeding.Subject/methods:Eight focus group interviews were conducted with 45 mothers of children aged 7 or 13 months. Deductive and inductive coding procedures were...... applied in the analysis.Results:There were marked differences in mothers' health concerns in early and in later phases of complementary feeding. In the early phase, feeding a child healthy food was an unquestioned and self-evident practice. The child's food was a specific category, separated from the rest....... Contested and partly contradictory practices resulted, including conscious acceptance of some intake of sugar and unhealthy fats. Perceived relevance of nutritional guidelines on complementary feeding was high in the early phase but declined later.Conclusion:Mothers' concerns and practices in the feeding...

  19. Secure Storage Architectures

    Energy Technology Data Exchange (ETDEWEB)

    Aderholdt, Ferrol [Tennessee Technological University; Caldwell, Blake A [ORNL; Hicks, Susan Elaine [ORNL; Koch, Scott M [ORNL; Naughton, III, Thomas J [ORNL; Pogge, James R [Tennessee Technological University; Scott, Stephen L [Tennessee Technological University; Shipman, Galen M [ORNL; Sorrillo, Lawrence [ORNL

    2015-01-01

    The purpose of this report is to clarify the challenges associated with storage for secure enclaves. The major focus areas for the report are: - review of relevant parallel filesystem technologies to identify assets and gaps; - review of filesystem isolation/protection mechanisms, to include native filesystem capabilities and auxiliary/layered techniques; - definition of storage architectures that can be used for customizable compute enclaves (i.e., clarification of use-cases that must be supported for shared storage scenarios); - investigate vendor products related to secure storage. This study provides technical details on the storage and filesystem used for HPC with particular attention on elements that contribute to creating secure storage. We outline the pieces for a a shared storage architecture that balances protection and performance by leveraging the isolation capabilities available in filesystems and virtualization technologies to maintain the integrity of the data. Key Points: There are a few existing and in-progress protection features in Lustre related to secure storage, which are discussed in (Chapter 3.1). These include authentication capabilities like GSSAPI/Kerberos and the in-progress work for GSSAPI/Host-keys. The GPFS filesystem provides native support for encryption, which is not directly available in Lustre. Additionally, GPFS includes authentication/authorization mechanisms for inter-cluster sharing of filesystems (Chapter 3.2). The limitations of key importance for secure storage/filesystems are: (i) restricting sub-tree mounts for parallel filesystem (which is not directly supported in Lustre or GPFS), and (ii) segregation of hosts on the storage network and practical complications with dynamic additions to the storage network, e.g., LNET. A challenge for VM based use cases will be to provide efficient IO forwarding of the parallel filessytem from the host to the guest (VM). There are promising options like para-virtualized filesystems to

  20. Perceived benefits from enterprise architecture

    NARCIS (Netherlands)

    Plessius, Henk; Steenbergen, Marlies van; Slot, Raymond

    2014-01-01

    Enterprise Architecture has been developed in order to optimize the alignment between business needs and the (rapidly changing) possibilities of information technology. But do organizations indeed benefit from the application of Enterprise Architecture according to those who are in any way involved

  1. Dynamic Weather Routes Architecture Overview

    Science.gov (United States)

    Eslami, Hassan; Eshow, Michelle

    2014-01-01

    Dynamic Weather Routes Architecture Overview, presents the high level software architecture of DWR, based on the CTAS software framework and the Direct-To automation tool. The document also covers external and internal data flows, required dataset, changes to the Direct-To software for DWR, collection of software statistics, and the code structure.

  2. On Information System Security Architecture

    Institute of Scientific and Technical Information of China (English)

    ChunfangJiang; ChaoyuanYue; JianguoZuo

    2004-01-01

    The current studies on security architecture and information system security architecture (ISSA) are surveyed in this paper, and some types and their features of ISSA are discussed. Then, the structural elements of ISSA are analyzed, and the constructing steps for ISSA are proposed.

  3. Renewal of Postwar Housing Architecture

    DEFF Research Database (Denmark)

    Bech-Danielsen, Claus

    2015-01-01

    This paper assesses Danish postwar housing architecture in relation to the concept of ‘everyday tectonics’. It is argued that the extensive criticism of the architecture of the postwar housing developments is probably linked to their tectonic qualities, but that, to an even higher degree, it is a...

  4. THE PALACE'S ARCHITECTURE

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Different from the Palace Museum in Beijing, the buildings at Shenyang Palace have unique national and local characteristics. Dominated by the architectural style of the Man people, who lived in Northeast China, they included the architectural structure and decoration methods of the Mongolian, Tibetan, Han and other ethnic groups.

  5. Secure Architectures for Mobile Applications

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The paper presents security issues and architectures for mobile applications and GSM infrastructure. The article also introduces the idea of a new secure architecture for an inter-sector electronic wallet used in payments - STP4EW (Secure Transmission Protocol for Electronic Wallet

  6. Architectural Portfolio 2001: Main Winners.

    Science.gov (United States)

    American School & University, 2001

    2001-01-01

    Presents descriptions and photographs of the following two American School and University Architectural Portfolio main winners for 2001: Chesterton, Indiana's Chesterton High School and Lied Library at the University of Nevada, Las Vegas. Included are each project's vital statistics, the architectural firm involved, and a list of designers.(GR)

  7. Assessing optimal software architecture maintainability

    NARCIS (Netherlands)

    Bosch, Jan; Bengtsson, P.O.; Smedinga, Rein; Sousa, P; Ebert, J

    2000-01-01

    Over the last decade, several authors have studied the maintainability of software architectures. In particular, the assessment of maintainability has received attention. However, even when one has a quantitative assessment of the maintainability of a software architecture, one still does not have a

  8. China Chongqing Architectural Design Institute

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    China Chongqing Architectural Design Institute was founded in 1950 and is now an A-Class prospecting and architectural design unit.Since 1997, it has ranked among the top 100 national prospecting and design units each year and has won the Advanced Enterprise for the Quality and Benefit of Chongqing for the past threeyears.

  9. Corporate Architecture and Limited Liability

    NARCIS (Netherlands)

    Couwenberg, Oscar

    2007-01-01

    Abstract This paper studies the effect of limited liability on corporate architecture. Corporate architecture refers to the use of governance instruments within the firm to control the behavior of employees. Four general instruments are defined that form the basis of the firm as a governance arrange

  10. Interior Design in Architectural Education

    Science.gov (United States)

    Gurel, Meltem O.; Potthoff, Joy K.

    2006-01-01

    The domain of interiors constitutes a point of tension between practicing architects and interior designers. Design of interior spaces is a significant part of architectural profession. Yet, to what extent does architectural education keep pace with changing demands in rendering topics that are identified as pertinent to the design of interiors?…

  11. Approaching Environmental Issues in Architecture

    DEFF Research Database (Denmark)

    Petersen, Mads Dines; Knudstrup, Mary-Ann

    2013-01-01

    The research presented here takes its point of departure in the design process with a specific focus on how it is approached when designing energy efficient architecture. This is done through a case-study of a design process in a Danish architectural office. This study shows the importance of hav...

  12. E-Learning in Architecture

    DEFF Research Database (Denmark)

    Juvancic, Matevz; Mullins, Michael; Zupancic, Tadeja

    2012-01-01

    E-learning in architectural and spatially related fields can be examined from two different perspectives, each having quite specific and complex implications. By discussing e-learning in architecture we inspect the scope of e-learning tools and practices within the architectural domain, the visual...... nature of education and professional training of architects, and the state of the art of e-learning implementations, together with their practicality and limitations. While these are the first areas that come to mind when considering e-learning in relation to architecture, there is another also very...... relevant and sometimes overlooked aspect: that of e-learning about architecture. In the latter, we introduce not only the professional but also the broader, non-expert public into the process of acting within, and shaping of, their spatial environments. This aspect raises burning questions regarding...

  13. Architectural Drawing - an Animate Field

    DEFF Research Database (Denmark)

    Hougaard, Anna Katrine

    2015-01-01

    important affordance of architectural drawing as a ¬hybrid between the openness of hand-sketching and the rule-based-ness of diagramming, an affordance which might be useful in the migrational zone of current architectural drawing where traditional hand drawing techniques and computer drawing techniques......Architectural drawing is changing because architects today draw with computers. Due to this change digital diagrams employed by computational architectural practices are often emphasized as powerful structures of control and organisation in the design process. But there are also diagrams, which do...... ways of directing behaviour of artefacts and living things without controlling this behaviour completely. I analyse a musical composition by John Cage as an example of a sketch diagram, and then hypothesize that orthogonal, architectural drawing can work in similar ways. Thereby I hope to point out...

  14. Natural energy and vernacular architecture

    Energy Technology Data Exchange (ETDEWEB)

    Fathy, H.

    1986-01-01

    This volume presents insights into the indigenous architectural forms in hot arid climates. The author presents his extensive research on climate control, particularly in the Middle East, to demonstrate the advantages of many locally available building materials and traditional building methods. He suggests improved uses of natural energy that can bridge the gap between traditional achievements and modern needs. He argues that various architectural forms in these climates have evolved intuitively from scientifically valid concepts. Such forms combine comfort and beauty, social and physical functionality. He discusses that in substituting modern materials, architects sometimes have ignored the environmental context of traditional architecture. As a result, individuals may find themselves physically and psychologically uncomfortable in modern structures. His approach, informed by a sensitive humanism, demonstrates the ways in which traditional architectural forms can be of use in solving problems facing contemporary architecture, in particular the critical housing situation in the Third World.

  15. Architecture in the Experience City

    DEFF Research Database (Denmark)

    Kiib, Hans

    2009-01-01

    . The article identifies new rationales related to this development, and it argues that ‘cultural planning' has increasingly shifted its focus from a cultural institutional approach to a more market-oriented strategy that combines art and business in a close relationship. The role of architecture has changed......This article focuses on the combination of programs and the architecture of cultural projects that have emerged within the last few years. These projects are characterized in the article as ‘hybrid cultural projects', because they intend to combine experience with entertainment, play and learning...... narratives related to historical buildings and architectural heritage; another group tries to embed new performative technologies in expressive architectural representation. The article provides a theoretical framework for the analysis of the political rationales of these projects and for the architectural...

  16. Architecture Governance: The Importance of Architecture Governance for Achieving Operationally Responsive Ground Systems

    Science.gov (United States)

    Kolar, Mike; Estefan, Jeff; Giovannoni, Brian; Barkley, Erik

    2011-01-01

    Topics covered (1) Why Governance and Why Now? (2) Characteristics of Architecture Governance (3) Strategic Elements (3a) Architectural Principles (3b) Architecture Board (3c) Architecture Compliance (4) Architecture Governance Infusion Process. Governance is concerned with decision making (i.e., setting directions, establishing standards and principles, and prioritizing investments). Architecture governance is the practice and orientation by which enterprise architectures and other architectures are managed and controlled at an enterprise-wide level

  17. An architecture for implementation of multivariable controllers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    1999-01-01

    august 2002 Abstract An architecture for implementation of multivariable controllers is presented in this paper. The architecture is based on the Youla-Jabr-Bongiorno-Kucera parameterization of all stabilizing controllers. By using this architecture for implementation of multivariable controllers...

  18. Secure Storage Architectures

    Energy Technology Data Exchange (ETDEWEB)

    Aderholdt, Ferrol [Tennessee Technological University; Caldwell, Blake A [ORNL; Hicks, Susan Elaine [ORNL; Koch, Scott M [ORNL; Naughton, III, Thomas J [ORNL; Pogge, James R [Tennessee Technological University; Scott, Stephen L [Tennessee Technological University; Shipman, Galen M [ORNL; Sorrillo, Lawrence [ORNL

    2015-01-01

    The purpose of this report is to clarify the challenges associated with storage for secure enclaves. The major focus areas for the report are: - review of relevant parallel filesystem technologies to identify assets and gaps; - review of filesystem isolation/protection mechanisms, to include native filesystem capabilities and auxiliary/layered techniques; - definition of storage architectures that can be used for customizable compute enclaves (i.e., clarification of use-cases that must be supported for shared storage scenarios); - investigate vendor products related to secure storage. This study provides technical details on the storage and filesystem used for HPC with particular attention on elements that contribute to creating secure storage. We outline the pieces for a a shared storage architecture that balances protection and performance by leveraging the isolation capabilities available in filesystems and virtualization technologies to maintain the integrity of the data. Key Points: There are a few existing and in-progress protection features in Lustre related to secure storage, which are discussed in (Chapter 3.1). These include authentication capabilities like GSSAPI/Kerberos and the in-progress work for GSSAPI/Host-keys. The GPFS filesystem provides native support for encryption, which is not directly available in Lustre. Additionally, GPFS includes authentication/authorization mechanisms for inter-cluster sharing of filesystems (Chapter 3.2). The limitations of key importance for secure storage/filesystems are: (i) restricting sub-tree mounts for parallel filesystem (which is not directly supported in Lustre or GPFS), and (ii) segregation of hosts on the storage network and practical complications with dynamic additions to the storage network, e.g., LNET. A challenge for VM based use cases will be to provide efficient IO forwarding of the parallel filessytem from the host to the guest (VM). There are promising options like para-virtualized filesystems to

  19. Schistosome feeding and regurgitation.

    Directory of Open Access Journals (Sweden)

    Patrick J Skelly

    2014-08-01

    Full Text Available Schistosomes are parasitic flatworms that infect >200 million people worldwide, causing the chronic, debilitating disease schistosomiasis. Unusual among parasitic helminths, the long-lived adult worms, continuously bathed in blood, take up nutrients directly across the body surface and also by ingestion of blood into the gut. Recent proteomic analyses of the body surface revealed the presence of hydrolytic enzymes, solute, and ion transporters, thus emphasising its metabolic credentials. Furthermore, definition of the molecular mechanisms for the uptake of selected metabolites (glucose, certain amino acids, and water establishes it as a vital site of nutrient acquisition. Nevertheless, the amount of blood ingested into the gut per day is considerable: for males ∼100 nl; for the more actively feeding females ∼900 nl, >4 times body volume. Ingested erythrocytes are lysed as they pass through the specialized esophagus, while leucocytes become tethered and disabled there. Proteomics and transcriptomics have revealed, in addition to gut proteases, an amino acid transporter in gut tissue and other hydrolases, ion, and lipid transporters in the lumen, implicating the gut as the site for acquisition of essential lipids and inorganic ions. The surface is the principal entry route for glucose, whereas the gut dominates amino acid acquisition, especially in females. Heme, a potentially toxic hemoglobin degradation product, accumulates in the gut and, since schistosomes lack an anus, must be expelled by the poorly understood process of regurgitation. Here we place the new observations on the proteome of body surface and gut, and the entry of different nutrient classes into schistosomes, into the context of older studies on worm composition and metabolism. We suggest that the balance between surface and gut in nutrition is determined by the constraints of solute diffusion imposed by differences in male and female worm morphology. Our conclusions have

  20. Digital Architecture Planning Model

    Energy Technology Data Exchange (ETDEWEB)

    Oxstrand, Johanna Helene [Idaho National Lab. (INL), Idaho Falls, ID (United States). Light Water Reactor Sustainability Program (LWRS); Al Rashdan, Ahmad Yahya Mohammad [Idaho National Lab. (INL), Idaho Falls, ID (United States). Light Water Reactor Sustainability Program (LWRS); Bly, Aaron Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States). Light Water Reactor Sustainability Program (LWRS); Rice, Brandon Charles [Idaho National Lab. (INL), Idaho Falls, ID (United States). Light Water Reactor Sustainability Program (LWRS); Fitzgerald, Kirk [Idaho National Lab. (INL), Idaho Falls, ID (United States). Light Water Reactor Sustainability Program (LWRS); Wilson, Keith Leon [Idaho National Lab. (INL), Idaho Falls, ID (United States). Light Water Reactor Sustainability Program (LWRS)

    2016-03-01

    As part of the U.S. Department of Energy’s Light Water Reactor Sustainability Program, the Digital Architecture (DA) Project focuses on providing a model that nuclear utilities can refer to when planning deployment of advanced technologies. The digital architecture planning model (DAPM) is the methodology for mapping power plant operational and support activities into a DA that unifies all data sources needed by the utilities to operate their plants. The DA is defined as a collection of information technology capabilities needed to support and integrate a wide spectrum of real-time digital capabilities for performance improvements of nuclear power plants. DA can be thought of as integration of the separate instrumentation and control and information systems already in place in nuclear power plants, which are brought together for the purpose of creating new levels of automation in plant work activities. A major objective in DAPM development was to survey all key areas that needed to be reviewed in order for a utility to make knowledgeable decisions regarding needs and plans to implement a DA at the plant. The development was done in two steps. First, researchers surveyed the nuclear industry in order to learn their near-term plans for adopting new advanced capabilities and implementing a network (i.e., wireless and wire) infrastructure throughout the plant, including the power block. Secondly, a literature review covering regulatory documents, industry standards, and technical research reports and articles was conducted. The objective of the review was to identify key areas to be covered by the DAPM, which included the following: 1. The need for a DA and its benefits to the plant 2. Resources required to implement the DA 3. Challenges that need to be addressed and resolved to implement the DA 4. Roles and responsibilities of the DA implementation plan. The DAPM was developed based on results from the survey and the literature review. Model development, including

  1. Software Defined Radio Architecture Contributions to Next Generation Space Communications

    Science.gov (United States)

    Kacpura, Thomas J.; Eddy, Wesley M.; Smith, Carl R.; Liebetreu, John

    2015-01-01

    systems, as well as those communications and navigation systems operated by international space agencies and civilian and government agencies. In this paper, we review the philosophies, technologies, architectural attributes, mission services, and communications capabilities that form the structure of candidate next-generation integrated communication architectures for space communications and navigation. A key area that this paper explores is from the development and operation of the software defined radio for the NASA Space Communications and Navigation (SCaN) Testbed currently on the International Space Station (ISS). Evaluating the lessons learned from development and operation feed back into the communications architecture. Leveraging the reconfigurability provides a change in the way that operations are done and must be considered. Quantifying the impact on the NASA Space Telecommunications Radio System (STRS) software defined radio architecture provides feedback to keep the standard useful and up to date. NASA is not the only customer of these radios. Software defined radios are developed for other applications, and taking advantage of these developments promotes an architecture that is cost effective and sustainable. Developments in the following areas such as an updated operating environment, higher data rates, networking and security can be leveraged. The ability to sustain an architecture that uses radios for multiple markets can lower costs and keep new technology infused.

  2. Hijazi Architectural Object Library (haol)

    Science.gov (United States)

    Baik, A.; Boehm, J.

    2017-02-01

    As with many historical buildings around the world, building façades are of special interest; moreover, the details of such windows, stonework, and ornaments give each historic building its individual character. Each object of these buildings must be classified in an architectural object library. Recently, a number of researches have been focusing on this topic in Europe and Canada. From this standpoint, the Hijazi Architectural Objects Library (HAOL) has reproduced Hijazi elements as 3D computer models, which are modelled using a Revit Family (RFA). The HAOL will be dependent on the image survey and point cloud data. The Hijazi Object such as Roshan and Mashrabiyah, become as vocabulary of many Islamic cities in the Hijazi region such as Jeddah in Saudi Arabia, and even for a number of Islamic historic cities such as Istanbul and Cairo. These architectural vocabularies are the main cause of the beauty of these heritage. However, there is a big gap in both the Islamic architectural library and the Hijazi architectural library to provide these unique elements. Besides, both Islamic and Hijazi architecture contains a huge amount of information which has not yet been digitally classified according to period and styles. Due to this issue, this paper will be focusing on developing of Heritage BIM (HBIM) standards and the HAOL library to reduce the cost and the delivering time for heritage and new projects that involve in Hijazi architectural styles. Through this paper, the fundamentals of Hijazi architecture informatics will be provided via developing framework for HBIM models and standards. This framework will provide schema and critical information, for example, classifying the different shapes, models, and forms of structure, construction, and ornamentation of Hijazi architecture in order to digitalize parametric building identity.

  3. Feed palatability and the alternative protein sources in shrimp feed

    Directory of Open Access Journals (Sweden)

    Chutima Tantikitti

    2014-02-01

    Full Text Available Feed palatability in carnivorous aquaculture species, shrimps in particular, has been crucially related to the presence of compounds acting as attractants that are commonly associated with the prey components under wild conditions. Thus a nutritionally adequate and organoleptically-pleasing diet is essential to achieve satisfactory intake and growth in shrimps. Historically, fishmeal has been an essential dietary component of intensive shrimp cultures because of its nutrient composition and compounds of high attractability. However, in recent years the fishmeal supplies have been dwindling due to over hunting, a diminishing natural fish-stock, elevating prices and market volatility. This has led to search for cheaper sources of suitable protein as fishmeal substitutes. To improve the palatability of diets, various substances have been investigated for their effectiveness in aqua-feed including natural feed ingredients and synthetic flavor substances. For crustacean, attractants characteristically are of low molecular weight, water and ethanol soluble, and amphoteric or basic compounds that are released from potential prey items. Compounds such as free amino acids, especially taurine, hydroxyproline, glycine, arginine, glutamic acid and alanine have been identified to stimulate feeding in shrimps. The same has been identified with organic acids, nucleotides and nucleosides, betaine, and some small peptides. Palatability also has been associated with animal’s past experience with the feed. Understanding the factors that regulate feed palatability is therefore primary for successful shrimp culture.

  4. How architecture students gain and apply knowledge of sustainable architecture

    DEFF Research Database (Denmark)

    Donovan, Elizabeth; Holder, Anna

    2016-01-01

    This paper will reflect on understandings of architectural pedagogy and the integration of sustainability into architectural design education. This is framed within an understanding of the construction industry’s role in the production of waste. Despite the complexity of global environmental crises...... teaching is partially integrated within the design studio courses. We compare the institution’s philosophy for sustainability with pedagogical approaches as practiced within the school. An empirical study was made of 2nd year architecture student experiences of a one-month introduction course to ‘Reuse...... and materials’. Within this, the students’ baseline knowledge of sustainable architecture was compared with their subsequent understandings and the opinions they formed. Our findings emphasise the importance of students’ personal critical reflection and active engagement but also the need for students...

  5. From Architectural Acoustics to Acoustical Architecture Using Computer Simulation

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning

    2005-01-01

    Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in architectural acoustics and the emergence of room acoustic simulation programmes with considerable potential, it is now possible to subjectively analyse and evaluate acoustic...... properties prior to the actual construction of a building. With the right tools applied, acoustic design can become an integral part of the architectural design process. The aim of this paper is to investigate the field of application that an acoustic simulation programme can have during an architectural...... acoustic design process and to set up a strategy to develop future programmes. The emphasis is put on the first three out of four phases in the working process of the architect and a case study is carried out in which each phase is represented by typical results ? as exemplified with reference...

  6. The architectural design of networks of protein domain architectures.

    Science.gov (United States)

    Hsu, Chia-Hsin; Chen, Chien-Kuo; Hwang, Ming-Jing

    2013-08-23

    Protein domain architectures (PDAs), in which single domains are linked to form multiple-domain proteins, are a major molecular form used by evolution for the diversification of protein functions. However, the design principles of PDAs remain largely uninvestigated. In this study, we constructed networks to connect domain architectures that had grown out from the same single domain for every single domain in the Pfam-A database and found that there are three main distinctive types of these networks, which suggests that evolution can exploit PDAs in three different ways. Further analysis showed that these three different types of PDA networks are each adopted by different types of protein domains, although many networks exhibit the characteristics of more than one of the three types. Our results shed light on nature's blueprint for protein architecture and provide a framework for understanding architectural design from a network perspective.

  7. Planetary cubesats - mission architectures

    Science.gov (United States)

    Bousquet, Pierre W.; Ulamec, Stephan; Jaumann, Ralf; Vane, Gregg; Baker, John; Clark, Pamela; Komarek, Tomas; Lebreton, Jean-Pierre; Yano, Hajime

    2016-07-01

    Miniaturisation of technologies over the last decade has made cubesats a valid solution for deep space missions. For example, a spectacular set 13 cubesats will be delivered in 2018 to a high lunar orbit within the frame of SLS' first flight, referred to as Exploration Mission-1 (EM-1). Each of them will perform autonomously valuable scientific or technological investigations. Other situations are encountered, such as the auxiliary landers / rovers and autonomous camera that will be carried in 2018 to asteroid 1993 JU3 by JAXA's Hayabusas 2 probe, and will provide complementary scientific return to their mothership. In this case, cubesats depend on a larger spacecraft for deployment and other resources, such as telecommunication relay or propulsion. For both situations, we will describe in this paper how cubesats can be used as remote observatories (such as NEO detection missions), as technology demonstrators, and how they can perform or contribute to all steps in the Deep Space exploration sequence: Measurements during Deep Space cruise, Body Fly-bies, Body Orbiters, Atmospheric probes (Jupiter probe, Venus atmospheric probes, ..), Static Landers, Mobile landers (such as balloons, wheeled rovers, small body rovers, drones, penetrators, floating devices, …), Sample Return. We will elaborate on mission architectures for the most promising concepts where cubesat size devices offer an advantage in terms of affordability, feasibility, and increase of scientific return.

  8. Bioclimatic Architecture; Arquitectura Bioclimatica

    Energy Technology Data Exchange (ETDEWEB)

    Rubenak, Joseph C. [A.G.I.S.A., Mexico D.F. (Mexico)

    2005-07-01

    The idea of the Bioclimatic Architecture comes from the term used by the Olgyay brothers, to emphasize the relations and connections between life, the climate and the bonds of these natural factors with the design. These base a method so that the development of the design responds in terms of function and comfort to the climatic implications that give context to the architectonic projects. The central objective is the creation of expressive spaces and aesthetically harmonic whose characteristics privilege the function of the building with optimal conditions for physical and psychological comfort for those who live, operate or use the building. [Spanish] La idea de la arquitectura bioclimatica proviene del termino utilizado por los hermanos Olgyay, para resaltar las relaciones y enlaces entre la vida, el clima y los vinculos de estos factores naturales con el diseno. Estos fundamentan un metodo para que el desarrollo del diseno responda en terminos de funcion y confort a las implicaciones climaticas que dan contexto a los proyectos arquitectonicos. El objetivo central es la creacion de espacios expresivos y esteticamente armonicos cuyas caracteristicas privilegien la funcion del inmueble con optimas condiciones de comodidad fisica y psicologica para quienes viven, operan o utilizan el edificio.

  9. Secure Cloud Architecture

    Directory of Open Access Journals (Sweden)

    Kashif Munir

    2013-02-01

    Full Text Available Cloud computing is set of resources and services offered through the Internet. Cloud services are delivered from data centers located throughout the world. Cloud computing facilitates its consumers by providing virtual resources via internet. The biggest challenge in cloud computing is the security and privacy problems caused by its multi-tenancy nature and the outsourcing of infrastructure, sensitive data and critical applications. Enterprises are rapidly adopting cloud services for their businesses, measures need to be developed so that organizations can be assured of security in their businesses and can choose a suitable vendor for their computing needs. Cloud computing depends on the internet as a medium for users to access the required services at any time on pay-per-use pattern. However this technology is still in its initial stages of development, as it suffers from threats and vulnerabilities that prevent the users from trusting it. Various malicious activitiesfrom illegal users have threatened this technology such as data misuse, inflexible access control and limited monitoring. The occurrence of these threats may result into damaging or illegal access of critical and confidential data of users. In this paper we identify the most vulnerable security threats/attacks in cloud computing, which will enable both end users and vendors to know a bout the k ey security threats associated with cloud computing and propose relevant solution directives to strengthen security in the Cloud environment. We also propose secure cloud architecture for organizations to strengthen the security.

  10. Innovations in dynamic architecture

    Directory of Open Access Journals (Sweden)

    Abdulmajid Karanouh

    2015-11-01

    Full Text Available High performance adaptive solutions are capable of responding to the dynamic nature of users and context. These innovative and dynamic systems are steadily gaining ground over ubiquitous ‘best fit’ static models. These architectural elements often exist beyond the scope of mainstream building standards and traditional methods for data representation or communication. This presents major challenges to a highly standardized and compartmentalized industry in which ‘innovation’ is limited to a few signature practices that design iconic yet expensive structures, which often prioritize aesthetics over performance. This paper offers an overview of the benefits that integrated dynamic systems bring to buildings. Through an examination of an applied practice, this paper offers guidelines for communicating complex geometry in a clear design language across interdisciplinary collaborations. The use of diagrammatic grammar to translate underlying algorithmic rules into instructions for design allows complex, innovative solutions to be realized more effectively. The ideas presented here are based on the design principles of the competition-winning scheme of the Al-Bahr Towers. As lead consultant in Innovation Design & Research at AHR (former Aedas-UK, Abdulmajid Karanouh designed and spearheaded this project in close collaboration with Arup. The buildings won the Best Innovation Award 2012 by the Council for Tall Buildings and Urban Habitat (CTBUH. The pair of towers won recognition for its performance-driven form, and dynamic facade that operates following the movement of the sun.

  11. System architecture with XML

    CERN Document Server

    Daum, Berthold

    2002-01-01

    XML is bringing together some fairly disparate groups into a new cultural clash: document developers trying to understand what a transaction is, database analysts getting upset because the relational model doesn''t fit anymore, and web designers having to deal with schemata and rule based transformations. The key to rising above the confusion is to understand the different semantic structures that lie beneath the standards of XML, and how to model the semantics to achieve the goals of the organization. A pure architecture of XML doesn''t exist yet, and it may never exist as the underlying technologies are so diverse. Still, the key to understanding how to build the new web infrastructure for electronic business lies in understanding the landscape of these new standards.If your background is in document processing, this book will show how you can use conceptual modeling to model business scenarios consisting of business objects, relationships, processes, and transactions in a document-centric way. Database des...

  12. Marc Treib: Representing Landscape Architecture

    DEFF Research Database (Denmark)

    Braae, Ellen Marie

    2008-01-01

    The editor of Representing Landscape Architecture, Marc Treib, argues that there is good reason to evaluate the standard practices of representation that landscape architects have been using for so long. In the rush to the promised land of computer design these practices are now in danger of being...... left by the wayside. The 14 often both fitting and well crafted contributions of this publication offer an approach to how landscape architecture has been and is currently represented; in the design study, in presentation, in criticism, and in the creation of landscape architecture....

  13. Digital design and computer architecture

    CERN Document Server

    Harris, David

    2010-01-01

    Digital Design and Computer Architecture is designed for courses that combine digital logic design with computer organization/architecture or that teach these subjects as a two-course sequence. Digital Design and Computer Architecture begins with a modern approach by rigorously covering the fundamentals of digital logic design and then introducing Hardware Description Languages (HDLs). Featuring examples of the two most widely-used HDLs, VHDL and Verilog, the first half of the text prepares the reader for what follows in the second: the design of a MIPS Processor. By the end of D

  14. Software Support for LIRAC Architecture

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Memory limitations are always a focus of computer architecture. The live range aware cache(LIRAC) offers a way to reduce memory access using live range information. In the LIRAC system, scratch data need not be written back if the data will no longer be used. Three kinds of software support developed for LIRAC architecture use compiler analyses, binary analyses, and trace analyses. Trace analysis results show that LIRAC can eliminate 29% of cache write-backs on average and up to 83% in the best case for the SPEC CPU 2000 benchmark. These software techniques can show the feasibility and potential benefit of the LIRAC architecture.

  15. A test of genetic association among male nuptial coloration, female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    Directory of Open Access Journals (Sweden)

    Inke van der SLUIJS, Peter D. DIJKSTRA, Charlotte M. LINDEYER et al.

    2013-04-01

    Full Text Available Both inter- and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits. Simultaneous disruptive selection by female mate choice and male-male competition can, in theory, lead to speciation without geographical isolation if both act on the same male trait. Female mate choice can generate discontinuities in gene flow, while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism. Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on. We tested for genetic associations among female mating preference, male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia. We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red. Male offspring of a red sire were significantly redder than males of a blue sire, indicating that intra-population variation in male coloration is heritable. We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests. There was no evidence for associations at the family level between female mating preferences and coloration of sires, but dam identity had a significant effect on female mate preference. Sons of the red sire directed significantly more aggression to red than blue males, whereas sons of the blue sire did not show any bias. There was a positive correlation among individuals between male aggression bias and body coloration, possibly due to pleiotropy or physical linkage, which could facilitate the maintenance of color polymorphism [Current Zoology 59 (2: 221-229, 2013].

  16. A test of genetic association among male nuptial coloration,female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    Institute of Scientific and Technical Information of China (English)

    Inke van der SLUIJS; Peter D.DIJKSTRA; Charlotte M.LINDEYER; Bertanne VISSER; Alan M.SMITH; Ton G.G.GROOTHUIS; Jacques J.M.van ALPHEN

    2013-01-01

    Both inter-and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits.Simultaneous disruptive selection by female mate choice and male-male competition can,in theory,lead to speciation without geographical isolation if both act on the same male trait.Female mate choice can generate discontinuities in gene flow,while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism.Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on.We tested for genetic associations among female mating preference,male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia.We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red).Male offspring of a red sire were significantly redder than males of a blue sire,indicating that intra-population variation in male coloration is heritable.We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests.There was no evidence for associations at the family level between female mating preferences and coloration of sires,but dam identity had a significant effect on female mate preference.Sons of the red sire directed significantly more aggression to red than blue males,whereas sons of the blue sire did not show any bias.There was a positive correlation among individuals between male aggression bias and body coloration,possibly due to pleiotropy or physical linkage,which could facilitate the maintenance of color polymorphism.

  17. Telemedicine system interoperability architecture: concept description and architecture overview.

    Energy Technology Data Exchange (ETDEWEB)

    Craft, Richard Layne, II

    2004-05-01

    In order for telemedicine to realize the vision of anywhere, anytime access to care, it must address the question of how to create a fully interoperable infrastructure. This paper describes the reasons for pursuing interoperability, outlines operational requirements that any interoperability approach needs to consider, proposes an abstract architecture for meeting these needs, identifies candidate technologies that might be used for rendering this architecture, and suggests a path forward that the telemedicine community might follow.

  18. Feeding profiles of tame moose

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report is on the feeding profiles of tame moose. 3 moose were observed for 99 hours while in natural range, each bite plant species, browse conditions and size...

  19. Social theory and infant feeding

    Science.gov (United States)

    2011-01-01

    Clinicians, public health advisors, nutritionists and others have been attempting to increase breastfeeding rates for the last few decades, with varying degrees of success. We need social science researchers to help us understand the role of infant feeding in the family. Some researchers in the area of food and nutrition have found Pierre Bourdieu's theoretical framework helpful. In this editorial, I introduce some of Bourdieu's ideas and suggest researchers interested in infant feeding should consider testing these theories. PMID:21676218

  20. Feed quality in swine diet

    Directory of Open Access Journals (Sweden)

    Živković Branislav

    2002-01-01

    Full Text Available The paper will demonstrate the quality of some feed used in swine diet. The emphasis will be on feed whose incorporation into mixes could result in unfavorable effects on production, health and economic production of swine. Data will be presented on maize and its possible negative effects, having in mind toxins. Soybean meal, or genetically modified soybean meal, will also be observed. The next feed which will be discussed will be soybean whey obtained by different procedures and the potential dangers of its use in swine diet rations. Sunflower meal, feed of animal origin, with emphasis on fish flour and meat-bone flour will also be covered in the work. A feed which has been attracting particular attention lately is yeast imported from Italy. Its quality characteristics will be discussed, the so-called non-protein nitrogen. Analyses of mineral feed will include sources of phosphorus, phosphates (monocalciumphosphate, dicalcium phosphate phytases and resolving the problem of phosphorus in swine rations. Finally, an inevitable segment are synthetic amino acids, especially lysine and its role in swine diet.

  1. Network architecture as internet governance

    Directory of Open Access Journals (Sweden)

    Francesca Musiani

    2013-10-01

    Full Text Available The architecture of a networked system is its underlying technical and logical structure, including transmission equipment, communication protocols, infrastructure, and connectivity between its components or nodes. This article introduces the idea of network architecture as internet governance, and more specifically, it outlines the dialectic between centralised and distributed architectures, institutions and practices, and how they mutually affect each other. The article argues that network architecture is internet governance in the sense that, by changing the design of the networks subtending internet-based services and the global internet itself, its politics are affected – the balance of rights between users and providers, the capacity of online communities to engage in open and direct interaction, the fair competition between actors of the internet market.

  2. Renewal of Postwar Housing Architecture

    DEFF Research Database (Denmark)

    Bech-Danielsen, Claus

    2015-01-01

    , it is also linked to the normative changes and altered perceptions of ‘a good life’ which appeared after the buildings had been constructed. Three generations of renovation and redevelopment of the developments are described and analysed, and three different architectural strategies are mapped. The first two...... with the style nor with the tectonics of the buildings. Rather it insists on seeking out the potentials in the original architecture, which are supplemented by basic architectural qualities, for example daylight, a view, and user improvements. The results of the three strategies are discussed, however without...... leading to any conclusion as to which strategy gives the best results. Nevertheless, the paper does conclude that recent years have seen fine results from the third strategy, and that ‘reusing’ the existing architecture can be of special significance in the suburbs....

  3. Solar habitats: a transmodern architecture

    Energy Technology Data Exchange (ETDEWEB)

    Pajvanski, Victor [Skopje Univ., Faculty of Architecture, Skopje (Macedonia (The Former Yugoslav Republic of))

    2000-04-01

    Architecture is both a science and an art. The cities in Macedonia were built as an image inherited mainly from ancient civilisations of the Roman empire, until the XIXth century. During this period, the proportions used for designing places were to a human scale. Today we recapture these traditional architectural images for living as made 'in situ and natura'. Human scale implies that housing units are single, double and multi houses at every level, surrounded with gardens and water. Also environmentally-oriented housing units are employed for collecting solar energy. Transmodern architecture takes, as an inspirational source, traditional Macedonian architecture coupled with contemporary building technology employing solar harnessing and energy efficiency, including the use of conservatories (for heat gain), chimneys (for heat loss) and water. (Author)

  4. Transverse pumped laser amplifier architecture

    Science.gov (United States)

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  5. Architecture, eTrees, & Nature

    Directory of Open Access Journals (Sweden)

    Dennis Dollens

    2010-06-01

    Full Text Available One vision for grafting biological performance into buildings includes inventing, growing, and synthesizing biological attributes for architectural life—thinking of architecture as metabolically evolved nature/culture. This requires a parallel strategy fostering collaborations between design, biology, art, horticulture, e-plant simulation, synthetic life, bio-mineralization, and advanced fabrication. It encourages designers to integrate industrial and agricultural information as design research with the goal of embedding specific environmental-life responses in architecture. This text discusses and illustrates induced evolution in one emerging method for design realized through software simulation—in this case, plant-to-architecture generation based in naturally occurring algorithms, found for example, in botanic phyllotaxy and allometry.

  6. Project Integration Architecture

    Science.gov (United States)

    Jones, William Henry

    2008-01-01

    The Project Integration Architecture (PIA) is a distributed, object-oriented, conceptual, software framework for the generation, organization, publication, integration, and consumption of all information involved in any complex technological process in a manner that is intelligible to both computers and humans. In the development of PIA, it was recognized that in order to provide a single computational environment in which all information associated with any given complex technological process could be viewed, reviewed, manipulated, and shared, it is necessary to formulate all the elements of such a process on the most fundamental level. In this formulation, any such element is regarded as being composed of any or all of three parts: input information, some transformation of that input information, and some useful output information. Another fundamental principle of PIA is the assumption that no consumer of information, whether human or computer, can be assumed to have any useful foreknowledge of an element presented to it. Consequently, a PIA-compliant computing system is required to be ready to respond to any questions, posed by the consumer, concerning the nature of the proffered element. In colloquial terms, a PIA-compliant system must be prepared to provide all the information needed to place the element in context. To satisfy this requirement, PIA extends the previously established object-oriented- programming concept of self-revelation and applies it on a grand scale. To enable pervasive use of self-revelation, PIA exploits another previously established object-oriented-programming concept - that of semantic infusion through class derivation. By means of self-revelation and semantic infusion through class derivation, a consumer of information can inquire about the contents of all information entities (e.g., databases and software) and can interact appropriately with those entities. Other key features of PIA are listed.

  7. The Mothership Mission Architecture

    Science.gov (United States)

    Ernst, S. M.; DiCorcia, J. D.; Bonin, G.; Gump, D.; Lewis, J. S.; Foulds, C.; Faber, D.

    2015-12-01

    The Mothership is considered to be a dedicated deep space carrier spacecraft. It is currently being developed by Deep Space Industries (DSI) as a mission concept that enables a broad participation in the scientific exploration of small bodies - the Mothership mission architecture. A Mothership shall deliver third-party nano-sats, experiments and instruments to Near Earth Asteroids (NEOs), comets or moons. The Mothership service includes delivery of nano-sats, communication to Earth and visuals of the asteroid surface and surrounding area. The Mothership is designed to carry about 10 nano-sats, based upon a variation of the Cubesat standard, with some flexibility on the specific geometry. The Deep Space Nano-Sat reference design is a 14.5 cm cube, which accommodates the same volume as a traditional 3U CubeSat. To reduce cost, Mothership is designed as a secondary payload aboard launches to GTO. DSI is offering slots for nano-sats to individual customers. This enables organizations with relatively low operating budgets to closely examine an asteroid with highly specialized sensors of their own choosing and carry out experiments in the proximity of or on the surface of an asteroid, while the nano-sats can be built or commissioned by a variety of smaller institutions, companies, or agencies. While the overall Mothership mission will have a financial volume somewhere between a European Space Agencies' (ESA) S- and M-class mission for instance, it can be funded through a number of small and individual funding sources and programs, hence avoiding the processes associated with traditional space exploration missions. DSI has been able to identify a significant interest in the planetary science and nano-satellite communities.

  8. The IVOA Architecture

    Science.gov (United States)

    Arviset, C.; Gaudet, S.; IVOA Technical Coordination Group

    2012-09-01

    Astronomy produces large amounts of data of many kinds, coming from various sources: science space missions, ground based telescopes, theoretical models, compilation of results, etc. These data and associated processing services are made available via the Internet by "providers", usually large data centres or smaller teams (see Figure 1). The "consumers", be they individual researchers, research teams or computer systems, access these services to do their science. However, inter-connection amongst all these services and between providers and consumers is usually not trivial. The Virtual Observatory (VO) is the necessary "middle layer" framework enabling interoperability between all these providers and consumers in a seamless and transparent manner. Like the web which enables end users and machines to access transparently documents and services wherever and however they are stored, the VO enables the astronomy community to access data and service resources wherever and however they are provided. Over the last decade, the International Virtual Observatory Alliance (IVOA) has been defining various standards to build the VO technical framework for the providers to share their data and services ("Sharing"), and to allow users to find ("Finding") these resources, to get them ("Getting") and to use them ("Using"). To enable these functionalities, the definition of some core astronomically-oriented standards ("VO Core") has also been necessary. This paper will present the official and current IVOA Architecture[1], describing the various building blocks of the VO framework (see Figure 2) and their relation to all existing and in-progress IVOA standards. Additionally, it will show examples of these standards in action, connecting VO "consumers" to VO "providers".

  9. Landscape Architecture and Sustainable Development

    OpenAIRE

    Walker, Jason Brian

    2001-01-01

    The purpose of this thesis is to examine the role of sustainable development in Landscape Architecture. From reviewing the literature, a position is developed. The position is that Sustainable Development is an important issue for landscape architects and that there are reasons landscape architects have had limited success in sustainable development. The method of the thesis is derived from assessing a problem of sustainable development and landscape architecture and developing a solution t...

  10. Investigating sustainability through vernacular architecture

    DEFF Research Database (Denmark)

    Eybye, Birgitte Tanderup

    2015-01-01

    Teksten drøfter, hvordan bæredygtighed kan komme til udtryk i førindustriel vernacular architecture, og om fortidens bæredygtige aspekter kan anvendes fremadrettet.......Teksten drøfter, hvordan bæredygtighed kan komme til udtryk i førindustriel vernacular architecture, og om fortidens bæredygtige aspekter kan anvendes fremadrettet....

  11. Hegel's notion of Gothic architecture

    OpenAIRE

    Bianco, Lino

    1996-01-01

    In an effort to look at Hegel's thoughts about Gothic architecture and their limitations, this paper examines his aesthetic theory, his theory of art history and the fine arts, and ' romantic architecture' in the Aesthetics. The most important notion in Hegel's aesthetic theory is the idea. It 'gives art its subject matter and its meaningfulness'.' His philosophy of art history is based on the symbiotic relation between art and religion, intrinsic expressions of the spirit. A r...

  12. Architectural Adaptability in Parallel Programming

    Science.gov (United States)

    1991-05-01

    I AD-A247 516 Architectural Adaptability in Parallel Programming Lawrence Alan Crowl Technical Report 381 May 1991 92-06322 UNIVERSITY OF ROC R...COMPUTER SCIENCE Best Avai~lable Copy Architectural Adaptability in Parallel Programming by Lawrence Alan Crowl Submitted in Partial Fulfillment of the...in the development of their programs. In applying abstraction to parallel programming , we can use abstractions to represent potential parallelism

  13. CITAstudio: Computation in Architecture 2015

    DEFF Research Database (Denmark)

    Nicholas, Paul; Ayres, Phil

    2016-01-01

    CITAstudio yearbook. CITAstudio: Computation in Architecture is a two year International Master's Programme at The Royal Danish Academy of Fine Arts, School of Architecture. With a focus on digital design and material fabrication the programme questions how computation is changing our spatial......, representational and material cultures. Through hands-on experimentation and production the programme emphasises learning-through-doing as a principle method for exploring computation as a means to pursue speculative design, experimental fabrication, material actuation and complex modelling....

  14. Behavior models for software architecture

    OpenAIRE

    Auguston, Mikhail

    2014-01-01

    Approved for public release; distribution is unlimited. Approved for public release; distribution is unlimited Monterey Phoenix (MP) is an approach to formal software system architecture specification based on behavior models. Architecture modeling focuses not only on the activities and interactions within the system, but also on the interactions between the system and its environment, providing an abstraction for interaction specification. The behavior of the system is defined as a set...

  15. Architecture-driven requirements prioritization

    OpenAIRE

    2012-01-01

    Quality requirements are main drivers for architectural decisions of software systems. However, in practice they are often dismissed during development, because of initially unknown dependencies and consequences that complicate implementation. To decide for meaningful, feasible quality requirements and trade them off with functional requirements, tighter integration of software architecture evaluation and requirements prioritization is necessary. In this position paper, we propose a tool-supp...

  16. Software defined radio architectures evaluation

    OpenAIRE

    Palomo, Alvaro; Villing, Rudi; Farrell, Ronan

    2008-01-01

    This paper presents an performance evaluation of GNU Radio and OSSIE, two open source Software Defined Radio (SDR) architectures. The two architectures were compared by running implementations of a BPSK waveform utilising a software loopback channel on each. The upper bound full duplex throughput was found to be around 700kbps in both cases, though OSSIE was slightly faster than GNU Radio. CPU and memory loads did not differ significantly.

  17. Security for service oriented architectures

    CERN Document Server

    Williams, Walter

    2014-01-01

    Although integrating security into the design of applications has proven to deliver resilient products, there are few books available that provide guidance on how to incorporate security into the design of an application. Filling this need, Security for Service Oriented Architectures examines both application and security architectures and illustrates the relationship between the two. Supplying authoritative guidance on how to design distributed and resilient applications, the book provides an overview of the various standards that service oriented and distributed applications leverage, includ

  18. Newborn First Feed and Prelacteal Feeds in Mansoura, Egypt

    Directory of Open Access Journals (Sweden)

    Abdel-Hady El-Gilany

    2014-01-01

    Full Text Available Background. Prelacteal feed (feeding any other substance before first breastfeeding appears to be common despite its harmful effects. By definition a child provided with prelacteal feed (PLF is not exclusively breastfed and PLF has many implications for the success and early initiation of breastfeeding. Objectives. To describe the prevalence of, nature of, and reasons for and factors associated with PLF. Methods. 647 mother-infant dyads were studied. Data was collected about the sociodemographic features of the family and baby, maternity care, the type of first feed before suckling, and causes of PLF. Maternal weight and height were measured and body mass index was calculated. Results. About 58% of newborns received prelacteal feeds. The commonest PLF was sugar/glucose water (39.6%. The most frequent reasons for giving PLF are tradition (61.0% and mother’s/mother in law’s advice (58.3%. The logistic regression revealed that the independent predictors of PLF are urban residence; maternal education; father’s education; low, middle, and high social class; maternal obesity; receiving antenatal care at private clinics and no antenatal care; Caesarean section; female babies; low birth weight; and admission to neonatal intensive care. Conclusion. Indiscriminate use of PLF should be discouraged in medical education and in antenatal maternal health education.

  19. Evaluation of tool support for architectural evolution

    NARCIS (Netherlands)

    Jansen, A; Bosch, J

    2004-01-01

    Evolution of software architectures is, different from architectural design, an area that only few tools have covered. We claim this is due to the lack of support for an important concept of architectural evolution: the notion of architectural design decisions. The absence of this concept in archite

  20. Towards an Operational Framework for Architectural Prototyping

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    2005-01-01

    We use a case study in architectural prototyping as input for presenting a first, tentative, framework describing key concepts and their relationships in architectural prototyping processes.......We use a case study in architectural prototyping as input for presenting a first, tentative, framework describing key concepts and their relationships in architectural prototyping processes....