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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Diferentes densidades de gaiola e suas implicações no comportamento de galinhas poedeiras e na qualidade dos ovos produzidos / Different cage densities and their implications on the behavior of laying hens and the quality of eggs

Maria Amelia Flandres Cabrelon 26 January 2016 (has links)
Objetivou-se com esta pesquisa avaliar o efeito de diferentes densidades de galinhas poedeiras alojadas em gaiolas convencionais (50x45x40 cm) nos índices produtivos, na viabilidade, qualidade dos ovos e comportamento das aves. A pesquisa foi realizada na cidade de Bastos (SP) com duração de 18 semanas. Foram utilizadas 500 aves, da linhagem ISA Brown, distribuídas em 5 tratamentos com 25 repetições cada. Os tratamentos foram: tratamento 1: 6 aves/ gaiola (375,0 cm²), tratamento 2: 5 aves/gaiola (450,0 cm²); tratamento 3: 4 aves/gaiola (562,5 cm²); tratamento 4: 3 aves/ gaiola (750,0 cm²) e tratamento 5: 2 aves/gaiola (1.125,0 cm²). Adotou-se o delineamento inteiramente aleatorizado, este contendo cinco tratamentos e 25 repetições. De acordo com os resultados, verificou-se que o tratamento 1 apresentou as menores médias percentuais de produção quando relacionado aos demais tratamentos, diferindo-se estatisticamente. A viabilidade e qualidade dos ovos, não apresentaram diferença estatística entre os tratamentos. Já com relação ao comportamento das aves foi possível observar que o tratamento 5 (menor densidade) foi o que expressou diferentes comportamentos e diferiu-se estatisticamente dos demais. Observou-se também que, quanto à atividade, o tratamento 5 passou menor parte do tempo \"parado\". De acordo com esses resultados, conclui-se que com o aumento da densidade, ocorreu uma significativa redução na produção e na viabilidade, porém, quanto a qualidade dos ovos, não sofreu influência significativa, em relação aos comportamentos das aves, observouse que os animais expressaram melhor o seu comportamento natural quando estavam em menor densidade, ou seja, maior espaço. / The objective of this research was to evaluate the effect of different densities of laying hens housed in conventional cages (50x45x40 cm) in production rates, viability, quality of eggs and bird behavior. The survey was conducted in the city of Bastos (SP) lasting 18 weeks. They were used 500 birds, ISA Brown hens, distributed in 5 treatments with 25 repetitions each. The treatments were: Treatment 1: 6 / Bird Cage (375.0 cm²), treatment 2: 5 birds / cage (450.0 cm²); treatment 3: 4 birds / cage (562.5 cm²); Treatment 4: 3 birds / cage (750.0 cm²) and treatment 5: 2 / Bird Cage (1125.0 cm²). Adopted a completely randomized design, this containing five treatments and 25 repetitions. According to the results, it was found that the treatment 1 had the lowest average percentage of production when related to other treatments, differing statistically. The viability and quality of eggs, there was no statistical difference between treatments. In relation to the behavior of birds was observed that the treatment 5 (lower density) was expressed that the different behaviors and differed statistically from the others. It was also observed that, as the activity, treatment 5 spent less of their time \"stopped\". According to these results, we conclude that with the consolidation of the cages, it was noticeable that the production and mortality has a significant worsening, as the quality of eggs, there was no influence of the different densities of the conduct of the birds, it is observed that the animals best express their natural behavior when they are in lower density, or larger space.
12

Self-Assembled Coordination Cages for Catalysis and Proton Conduction

Samanta, Dipak January 2014 (has links) (PDF)
Biological systems construct varieties of self-assembled architectures with incredible elegance and precession utilizing proteins as subunits to accomplish widespread functions. Inspired by natural systems, construction of artificial model systems with such sophistication and delicacy has become an intriguing field of research over the last two decades using so-called self-assembly process. Judiciously selected complementary building units encoded with specific chemical and structural information can be self-assembled into pre-programmed abiological architectures in a manner similar to biological self-assembly. In this regard, kinetically labile metal-ligand coordination has become an efficient and powerful protocol for the construction of highly intricate structures with specific topology and functionality due to its simple design principle, high bond enthalpy, and predictable directionality. Two-component self-assembly is very widely used methodology and easy to monitor. Recently, multi-component self-assembly has come up as an alternative and effective pathway to achieve complex architectures connecting more than two components in a single step. However, formation of selective single product from multicomponents is entropically unfavorable. Only a very few 3D architectures have been known, that are obtained from a mixture of ditopic and tri- or tetratopic donors with metal acceptors with or without employing templates. Development of template-free multicomponent architectures is still in its infancy. Strong tendency of Pd(II)/Pt(II) to attain square-planar geometry around the metal center and kinetically labile nature of Pd(II)/Pd(II)-N(pyridine) bonds made them chemists’ favourite to engineer desired supramolecular coordination architectures with structural resemblance to Platonic or Archimedean solids by employing symmetrical pyridyl donors due to their predictable directionality. In case of poly-imidazole donors, free rotation of C-N bond connecting imidazole and phenyl ring allows various dispositions of the donating nitrogen with respect to the aromatic backbone, and therefore, the structural topology of the architectures, made of poly-imidazole ligands becomes much more interesting as compared to symmetrical Platonic or Archimedean solids. The physico-chemical properties of self-assembled coordination cages depend on the structures of the complexes. Presence of large internal cavity surrounded by aromatic core, provides an excellent environment for the encapsulation of varieties of guest molecule or as nano-reactors for different organic transformations. Structural investigation in terms of packing interactions, solvent molecules, intermolecular channels can sometimes determine the property of such self-assembled materials as well. Presence of acidic water as well as H-bonded 3D-networks of water molecules in molecular pockets make them potential material for proton conduction. In addition, metal-ligand coordination offers opportunity to introduce new functionality through pre-synthetic modification of the building constituents to influence the property of the supramolecular systems. Incorporation of unsaturated ethynyl functionality attached to the heavy transition metal is expected to exhibit efficient luminescence due to the facile metal to ligand charge transfer (MLCT). Hence, the final assemblies can be employed as chemosensors for electron-deficient nitroaromatics, which are the chemical signature of many of the commercially available explosives. The present investigation is focused on design and construction of discrete, nanoscopic coordination cages with unusual structural topology employing mainly imidazole-based donors with Pd(II)/Pt(II) acceptors and their applications in catalysis, chemosensing, and proton conduction. CHAPTER 1 of the thesis provides a general introduction to self-assembly focusing on the importance and advantages of metal-ligand directional bonding approach towards the construction of supramolecular architectures with various structural topologies. This chapter also includes a brief review on the applications of such coordination cages in various fields especially as ‘molecular flask’ for the observation of unique chemical phenomena and unusual reactions. Part A of CHAPTER 2 describes the synthesis of a new hollow Pd6 water soluble cage [{(tmen)Pd}6(timb)4](NO3)12 (1) via two-component self-assembly of a triimidazole donor and 90° Pd(II) acceptor [tmen = N,N,N’,N’-tetramethylethylenediamine, timb = 1,3,5-tris(1-imidazolyl)benzene]. The assembly was successfully crystallized with a hydrophilic dianionic benzoquinone derivative (formed in situ by the decomposition of DDQ) as [{(tmen)Pd}6(timb)4](NO3)10()2(H2O)18 (3), and a hydrophobic sterically demanding aromatic aldehyde as [{(tmen)Pd}6(timb)4](NO3)12{()4a}2(H2O)27 (5a) [where 2H2 = 2,3-dichloro-5,6-dihydroxycyclohexa-2,5diene-1,4-dione, 4a = 1-pyrenecarboxaldehyde,  = exohedral and  = endohedral] to confirm the hydrophobic nature of the cavity. Experiments were carried out to show that the hydrophobic confined nanospace of the cage (1) catalyses the Knoevenagel condensation of a series of different aromatic monoaldehydes with active methylene compounds in ‘green’ aqueous medium. The Knoevenagel condensation reaction is basically a dehydration reaction because water is a by-product. So the presence of water should, in principle, promote the backward reaction as per Le Chatelier’s principle. In general, these reactions with organic substrates are not performed in water. However, difficulty has been overcome using hydrophobic cavity of the cage. It has also been established that the cavity of the cage also enhances the rate of Diels-Alder reaction of 9-hydroxymethylanthracene with N-phenylmaleimide/N-cyclohexylmaleimide. Figure 1. Catalytic Knoevenagel condensation and Diels-Alder reaction using hydrophobic cavity of the cage (1) in aqueous medium. Part B of CHAPTER 2 reports unique three-component self-assembly incorporating both tri- and tetra-topic donors. Until now, a very few 3D-architectures have been known that are obtained from self-assembly of ditopic and tri- or tetratopic donors with metal acceptors. Scheme 1. Three-component self-assembly of a Pd7 cage (1) from cis-blocked Pd(II) 90° acceptor (M), tri-imidazole (timb) and tetra-imidazole (tim) donors. Self-assembled multicomponent discrete architecture composed of both tri- and tetra-topic donors is yet to be reported due to difficulty in prediction of the final structure from the mixture of ligands having multiple donor sites. The first example of self-sorted Pd7 molecular boat [{(tmen)Pd}7(timb)2(tim)2](NO3)14(H2O)20 (1) [tmen = N,N,N’,N’-tetramethylethylenediamine, timb = 1,3,5-tris(1-imidazolyl)-benzene, tim = 1,2,4,5-tetrakis(1-imidazolyl)benzene] was synthesized via three-component self-assembly of cis-(tmen)Pd(NO3)2, tetra- (tim) and tri-topic donors (timb) in a 7:2:2 ratio. The cavity of this cage was also utilized as a nanoreactor for catalytic Knoevenagel condensations of a series of aromatic aldehydes with 1,3-dimethylbarbituric acid (e) and Meldrum’s acid (f) in aqueous media. CHAPTER 3 presents the results of an investigation on how simple variation of length and coordination mode of linear donors can self-discriminate into markedly different complex architectures, from Pd8 molecular swing [{(tmen)Pd}8(tim)2(bpy)4](NO3)16 (1) or [{(tmen)Pd}8(tim)2(stt)5](NO3)6 (2) to Pd6 molecular boat [{(tmen)Pd}6(tim)2(bpe/dpe/pin/dpb)2](NO3)12, (3/4/5/6). Also by enhancing denticity [bidentate to tridentate (ptp)] as well as introducing asymmetry, they self-sort into Pd7 molecular tent [{(tmen)Pd}7(tim)2(ptp)2](NO3)14 (7) by employing it in a self-assembly of cis-(tmen)Pd(NO3)2 and tetraimidazole (tim) donor [where tmen = N,N,N’,N’-tetramethylethylenediamine, bpy = 4,4’-bipyridyl, stt = sodium terephthalate, bpe = trans-1,2-bis(4-pyridyl)ethylene, dpe = 1,2-di(pyridin-4-yl)ethane, pin = N-(pyridin-4-yl)isonicotinamide, dpb = 1,4-di(pyridin-4-yl)benzene, ptp = 6'-(pyridin-4-yl)-3,4':2',4''-terpyridine, and tim = 1,2,4,5-tetrakis(1- imidazolyl)benzene]. In these cases, control of the geometrical principles and stereo-electronic preferences of the building units allowed the formation of such intricate architectures. Some of these assemblies represent first examples of such types of structures, and their formation would not be anticipated by taking into account only the geometry of the donor and acceptor building units. In addition to their direct structural confirmation using single crystal X-ray diffraction analysis, propensity of the assemblies (1 and 3) to form inclusion complexes with large guest like C60 in solution was also demonstrated by fluorescence quenching experiment. The high KSV values for both the assemblies 1 (1.0 × 10-5 M-1) and 2 (1.6 × 10-6 M-1) with C60 indicated the propensity of these assemblies to form complexes with C60 in solution. Furthermore, inspection of crystal packing of other five complexes (2 and 4 - 7) revealed the presence of water molecules H-bonded with NO3– (O-H···O=N) and 3D H-bonded networks of water in the intermolecular pockets. Interestingly, the present complexes (2 and 4 - 7) show high conductivity across low-humidity range at ambient temperature and achieve a conductivity of ~10-3 Scm-1 at 75% relative humidity and 296 K. These supra-molecular architectures represent a new generation of discrete materials that display high proton conductivity under ambient conditions with activation energy comparable to that of Nafion. Scheme 2. Exclusive formation of Pd8 molecular swings (1 and 2), Pd6 molecular boats (3-6), and Pd7 molecular tent (7) via self-sorting. CHAPTER 4 presents self-selection by synergistic effect of morphological information and coordination ability of the ligands through specific coordination interactional algorithms within dynamic supramolecular systems involving a tetratopic Pd(II) acceptor and three different pyridine- and imidazole-based donors (La - Lc) [La = 1,3-bis((E)-2-(pyridin-3-yl)vinyl)benzene, Lb = 1,3-di(1H-imidazol-1-yl)benzene, and Lc = tris(4-(1H-imidazol-1-yl)phenyl)amine]. Three different cages, ‘paddle wheel’ cluster Pd2(La)4(NO3)4 (2a), molecular barrel Pd3(Lb)6(NO3)6 (2b) and molecular sphere Pd6(Lc)8(NO3)12 (2c) were first synthesized via two-component self-assembly of a tetratopic Pd(II) acceptor (1) and individual pyridine- and imidazole-based donors (La - Lc). When all the four components were allowed to interact in a complex reaction mixture, only one out of three cages was isolated. The inherent dynamic nature of the kinetically labile coordination bond allows constitutional adaptation through component exchange in the competition experiment involving multiple constituents to self-organize into specific combination and thereby, achieve the thermodynamically most stable assembly. The preferential binding affinity towards a particular partner was also established by transforming a non-preferred cage to a preferred cage by the interaction with the appropriate ligand and thus, this represents the first examples of two-step cage-to-cage transformation through constitutional evolution of Figure 2. Cage-to-cage transformation from non-preferred cage to preferred cage upon treatment with appropriate ligand; and Nyquist plots of the complexes (2b and 2c) under 98% RH condition and ambient temparature. dynamic systems induced by both coordination ability and geometry of the ligand. Moreover, computational study further supported the fact that coordination interaction of imidazole moiety to Pd(II) is enthalpically more preferred compared to pyridine which drives the selection process. In addition, analysis of crystal packing of both the complexes (2b and 2c) indicated the presence of strong H-bonds between NO3- and water molecules; as well as H-bonded 3D-networks of water. Interestingly, both the complexes exhibit promising proton conductivity (10-5 to ca. 10-3 S cm-1) at ambient temperature under relative humidity of ~98% with low activation energy. CHAPTER 5 covers design and synthesis of new organometallic building block 1,3,5-tris(4-trans-Pt(PEt3)2I(ethynyl)phenyl)benzene (1) incorporating Pt-ethynyl functionality and [2 + 3] self-assembly of its nitrate analogue 1,3,5-tris(4-trans-Pt(PEt3)2(ONO2)(ethynyl)phenyl)benzene (2) with “clip” type bidentate donors (L1 – L3) separately afforded three trigonal prismatic architectures (3a – 3c), respectively (Scheme 3), Scheme 3. Schematic presentation of three different donors (L1 – L3) and a new planar tritopic acceptor (2) and their [3 + 2] self-assembly into trigonal prismatic architectures (3a - 3c). [L1 = N1,N3-di(pyridin-3-yl)isophthalamide; L2 = 1,3-bis((E)-2-(pyridin-3-yl)vinyl)benzene; L3 = 1,3-bis(pyridin-3-ylethynyl)benzene]. All these prisms were characterized and their shapes/sizes are predicted through geometry optimization employing molecular mechanics universal force field (MMUFF) simulation. The extended -conjugation including the presence of Pt-ethynyl functionality make them electron rich as well as luminescent in nature. As expected, cages 3b and 3c exhibit fluorescent quenching in solution upon addition of picric acid [PA], which is a common constituent of many explosives. Interestingly, the non-responsive nature of fluorescent intensity towards other electron-deficient nitro-aromatic explosives (NAEs) makes them promising selective sensors for PA with a detection limit deep down to ppb. Complexes 3b – c represent the first examples of molecular metallocages as selective sensors for picric acid. Furthermore, solid-state quenching of fluorescent intensity of the thin film of 3b upon exposure to saturated vapor of picric acid draws special attention for infield application.
13

Vergleichende radiologische Untersuchungen zum Einheilungsverhalten intervertebraler Cages mit unterschiedlichem Design im Fusionsmodell der Schafshalswirbelsäule

Scholz, Matti 05 September 2005 (has links)
Einleitung: Experimentelle Daten zu Designparametern von Cages fehlen weitgehend. Ziel dieser Untersuchung war es, am Modell der Schafshalswirbelsäule den Effekt von Designparametern (Auflagefläche/Porengröße) auf das Einheilungsverhalten von Cages radiologisch zu untersuchen. Material und Methode: Bei 24 Merino-Schafen wurde eine intervertebrale zervikale Fusion C3/C4 mit 3 verschiedenen Stabilisierungsverfahren (n=8) durchgeführt. Gruppe1: autologer Beckenkammspan; Gruppe2: Syncage-C + autologe Spongiosa; Gruppe3: Harmscage + autologe Spongiosa. Während der Standzeit wurden radiologische Verlaufsuntersuchungen durchgeführt. Nach der 12-wöchigen Standzeit erfolgten funktionsradiologische Untersuchungen sowie computertomographische Untersuchungen am Präparat. Der Status der Fusion wurde anhand eines Fusionsscores bestimmt. Ergebnisse: Im Vergleich zum Beckenkammspan waren beide Cages in der Lage, die Höhe des Bandscheibenraums und den Intervertebralwinkel signifikant besser zu erhalten. Bezüglich der Sinterungsparameter, der radiologischen Funktionsuntersuchungen und des Fusionsscores waren bis auf den Zeitpunkt Woche 1 (Cage im Box-Design mit geringster Sinterung) keine signifikanten Unterschiede zwischen beiden Cages nachweisbar. Bei der Evaluation des Kallusvolumens zeigte sich für den Cage im Zylinder-Design eine größere Kallusformation, als für den Cage im Box-Design. Schlussfolgerung: Innerhalb der ersten 12 Wochen lassen sich nur in der frühen postoperativen Phase designspezifische Unterschiede zwischen beiden Cages nachweisen. Die Ergebnisse dieser Studie zeigen, dass die Auflagefläche für das Sinterungsverhalten eines Cage in vivo nur von untergeordneter Bedeutung ist. Ein signifikanter Einfluss der Porengröße der Cages auf das Einheilungsverhalten konnte radiologisch nicht nachgewiesen werden. Ein Einfluss der Primärstabilität des Implantats auf die Kallusformation kann postuliert werden. / Introduction: Experimental data of design parameters of cages are lacking. The purpose of this study was to compare the effect of design parameters (endplate-implant contact area/maximum contiguous pore) on interbody fusion in a sheep cervical spine model by radiological methods. Material and Method: Twenty-four sheep underwent C3-4 discectomy and fusion in which the following were used: Group 1, autologous tricortical iliac crest bone graft (n=8); Group 2, titanium cylinder-design cage + autologous bone graft (n=8); and Group 3, titanium box-design cage filled with autologous bone graft (n=8). During the evaluation period radiography was performed. After the 12 weeks' evaluation period, functional radiographs and quantitative computerized tomography scans were acquired. Status of fusion has been evaluated by means of a fusion score. Results: Over a 12 weeks' period significantly higher values for disc space height and intervertebral angle were shown in cage-treated sheep than in those that received bone graft. Comparing the cage-groups no significant difference could be found in disk-space height, functional radiographic assessment and fusion score except week one. At this time the box-design cage showed significantly better distractive properties. The cylinder-design cage showed significantly higher values for bone callus volume in comparison to the box-design cage. Conclusion: In the 12 weeks' period, no significant design specific differences between both cages could be stated except during the early post-operative period. This study shows that the parameter endplate-implant contact-area was not able to determine subsidence of cages. An influence of maximum contiguous pore on the fusion's result could not be shown by radiological data. Primary stiffness must have an influence on bone callus formation.
14

Supramolecular coordination cages based on bispyridyl-ligands with redox properties

Versäumer, Marina 27 June 2016 (has links)
No description available.
15

Allosteric interactions in coordination cages

Rizzuto, Felix January 2018 (has links)
Biomolecular receptors can catalyse reactions, alter their geometry, and inhibit their activity in response to molecules binding around their periphery. Synthetic receptors that can mimic this allosteric binding behaviour extend the potential applications of host-guest chemistry to programmable molecular systems. Modulating the degree and magnitude of interaction between components within these systems enables the design of chemical behaviour akin to biological complexity. With a view to developing artificial guest-binding regulation systems, a series of metal-organic cages capable of both the peripheral and internal encapsulation of guests are presented: octahedra capable of accommodating two guests in different locations simultaneously; cuboctahedral receptors that bind fullerenes with all-or-nothing positive cooperativity and assemble supramolecular entities internally; a heteroleptic triangular prism capable of recognising steroids and enantiopure natural products; and a tetrahedron that binds fullerene clusters. Each of these architectures employs one or more binding site to either: a) template specific products; b) regulate the cooperativity of binding of large anionic guests; c) assemble coordination complexes and interlocked species inside their cavities; d) alter their morphology in well-defined ways; or e) form assemblies with new electronic and electrochemical functionality. In all cases, chemical systems that respond to multiple stimuli simultaneously are explored, and new applications for bringing multiple species into proximity are detailed. The allosteric binding motifs described herein can be extended to sort reaction mixtures, generate specific isomeric forms, stabilise labile species and promote tuneable modes of intermolecular cooperativity.
16

Produção intensiva de surubins híbridos em gaiolas: estudos de caso / Cage production of hybrid surubins: Case studies

Coelho, Silvio Roméro de Carvalho 06 December 2005 (has links)
A utilização do sistema de tanques-rede na criação intensiva de peixes é uma alternativa para o aproveitamento racional dos corpos de água existentes no Brasil, impróprios para a prática da piscicultura convencional. Diversas espécies nativas apresentam potencial para a aqüicultura, como é o caso dos pintados e surubins. O presente estudo teve como objetivo identificar os fatores limitantes à produção comercial de surubins híbridos(Pseudoplatystoma fasciatum × P. coruscans) em gaiolas. Foi estudado o caso de um empreendimento na região de Santa Maria do Itabira, MG (19o26’58" S; 43o06’45" W; altitude 750 m). Em uma primeira avaliação, de abril a outubro de 2.000, vinte e sete gaiolas foram utilizadas para verificar efeitos do volume da gaiola (27,0 m3; 22,5 m3 e 13,5 m3) e densidade de estocagem (25 peixes m-3, 50 peixes m-3 e 75 peixes m-3) sobre o desempenho zootécnico dos animais e econômico dos nove arranjos produtivos (APn). As características da água permaneceram entre limites aceitáveis para a criação da espécie. A melhor sobrevivência, o melhor índice de conversão alimentar, o maior ganho de peso médio, o maior ganho de peso médio diário e o maior crescimento específico foram medidos no AP1, que usou gaiolas de menor volume (13,5 m3) povoadas com a maior densidade de estocagem (75 peixes m-3). A melhor avaliação econômica foi do AP9 (27,0 m3, 75 peixes m-3) que obteve uma taxa interna de retorno (TIR) de 122,95%, com um custo de produção de R$ 6.56 kg-1 de peixe. A segunda avaliação foi realizada variando a densidade de estocagem de 50, 75, 100 ou 125 peixes m-3 em gaiolas com volume de 10,8 m3, no período de outubro de 2.000 a março de 2.001. O maior índice de crescimento específico, o maior ganho de peso médio, o maior ganho de peso médio diário e o melhor índice de conversão alimentar aparente foram obtidos com o arranjo produtivo de 50 peixes m-3. Já o maior ganho de biomassa e o maior ganho de biomassa por unidade de volume foram conseguidos com o arranjo produtivo 125 peixes m-3. O menor custo unitário por quilo de peixe do arranjo produtivo 75 animais m-3 não significou que ele fosse a melhor decisão de investimento, já que ele apresentou a menor taxa interna de retorno e o pior prazo para a recuperação do capital investido. A taxa interna de retorno de 87,21% foi calculada para o investimento feito para 28 gaiolas com o arranjo produtivo que usou 100 animais m-3. / Intensive cage fish culture is an excellent alternative for the rational use of several Brazilian reservoirs. Several indigenous species, like the flat-head catfish, locally called "pintado" or "surubim", have demonstrated potential for intensive farming. The present study aimed to identify major factors limiting the commercial production of the flat-head catfish hybrid (Pseudoplatystoma fasciatum × P. coruscans) in cages. The study was carried out at Gororó farm, Santa Maria do Itabira, MG, Brazil (19o26’58" S; 43o06’45" W; altitude 750 m). The first evaluation was done from April to October, 2000. Twenty-seven cages were used to verify the effects of cage volume (27.0; 22.5 and 13.5 m3) and stocking density (25, 50 and 75 fish m-3), in triplicate, on growth performance and investment evaluation of the nine production sets obtained (APn). Water quality was within acceptable limits for the species. Best growth performance was registered for the AP1 (13,5 m3; 75 fish m-3). The first ranked investment choice was recorded for the AP9, with an internal rate of return (IRR) of 122.95 %, and total production cost of R$ 6.56 kg-1. The second evaluation was done from October, 2000 to March, 2001. Flat-head catfish hybrids were stocked at four different densities (25, 50, 100 and 125 fish m-3), with seven replicates, using twenty-eight, 10,8 m3 cages. The best specific growth rate, individual average weight gain, daily weight gain and feed conversion was registered for the 75 fish m-3 stocking density. The largest final biomass and biomass per unit of volume was obtained for the 125 fish m-3 density. Even though stocking 50 fish m-3 elicited the lowest production cost (R$ 6.93 kg-1), the best investment choice was the stocking rate of 100 fish m-3 production set, with IRR=87.21%.
17

Evaluation du probiotique bactérien Pediococcus acidilactici MA18/5M chez la crevette pénéide Litopenaeus stylirostris en Nouvelle-Calédonie

Castex, Mathieu 08 April 2009 (has links) (PDF)
Pediococcus acidilacticii MA18/5M est un probiotique bactérien (BACTOCELL®) qui a démontré son efficacité chez plusieurs espèces d'animaux terrestres et aquatiques. Cette thèse avait pour objectif d'investiguer plus en détails les effets de ce probiotique chez les crevettes pénéides d'élevage. Pour cette étude, nous avons choisi une approche globale replaçant la problématique dans un modèle d'interactions entre trois compartiments : la crevette, sa microflore intestinale et le probiotique. Après avoir défini les modalités d'administration, l'effet de P. acicilactici a été étudié, en conditions de laboratoire, chez la crevette Litopenaeus stylirostris, à différents niveaux: (i) statut nutritionnel et croissance, (ii) microflore bactérienne associée, et (iii) santé de l'animal à travers son statut antioxydant et son niveau de stress oxydant. Ainsi, le probiotique améliore la croissance des crevettes et l'indice de conversion de l'aliment. Notre étude montre que ces effets sont en partie liés à une meilleure utilisation de l'aliment, notamment des carbohydrates alimentaires, mais suggèrent aussi une action surle métabolisme, et/ou sur la croissance via un apport de nutriments essentiels. D'autre part, bien que les communautés bactériennes intestinales semblent peu affectées, un effet d'antagonisme du probiotique vis-à-vis de la flore intestinale totale et vibrionacée a été montré, ainsi qu'une réduction du niveau d'infection des crevettes au cours de challenge avec le pathogène V. nigripulchritudo. Par ailleurs, nous mettons en évidence que l'infection par ce pathogène, conduit à un abaissement des défenses antioxydantes, à une élévation des dégâts oxydatifs, et au déclenchement de mortalités dans les 48 heures. Le probiotique atténue le niveau de ce stress oxydant, et améliore significativement la résistance des crevettes à l'infection. Une hypothèse nutritionnelle est proposée afin d'expliquer ce résultat, hypothèse reposant sur un lien entre le métabolisme des carbohydrates et le statut antioxydant. A l'issue de ces travaux, nous pouvons alors proposer un premier scénario explicatif des effets de P. acidilactici chez une crevette pénéide. Finalement le probiotique a été éprouvé à l'échelle pilote sur une ferme commerciale de Nouvelle-Calédonie affectée par le « syndrome d'été ». Nous confirmons les améliorations apportées en terme de résultats zootechniques, avec notamment une meilleure résistance au syndrome. Ce travail a été réalisé grâce une méthode d'élevage en cages flottantes, mis au point au cours de cette thèse, et qui a dés lors été transférée, comme outil expérimental, à la filière crevetticole Calédonienne
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Production and behaviour of four strains of laying hens kept in conventional cages and a free run system

Singh, Renu 05 1900 (has links)
Production, egg quality, behaviour, and physical condition were compared from Wk 20 to Wk 50 among three beak- trimmed commercial laying strains, Lohmann White (LW), H & N White (HN), Lohmann Brown (LB), and a non-commercial Cross between Rhode Island Red (male) and Barred Plymouth Rock (female) in conventional cages and in floor pens. All chicks were reared in their respective environments, and 450 and 432 pullets were housed at 18 and 7 weeks of age in cages and floor pens respectively. Hens in cages were provided with 688 cm2/bird and those in pens with over 6,000 cm2/bird, both of which are more than provided by commercial standards. Body weights and eggshell weights were higher for birds in floor pens than those in cages, and although they increased with age, body weight of hens in cages decreased at Wk 50. White-egg layers (LW, HN) used perches and nest boxes more than Brown-egg layers (LB, Cross). During the laying period, mortality was higher for all strains in cages and during the rearing period mortality was higher in floor pens for LB hens but not other strains. No aggressive behaviours were found, but the frequency of gentle feather pecking and pecking at the enclosure was higher in cages than in floor pens. Feather condition deteriorated over time in cages mainly because of contact with the cage wires whereas in floor pens, feather condition of birds at Wk 20 was not different from that at Wk 50. The frequency of keel bone deformities was higher for White-egg layers than for Brown-egg layers in cages and was higher for Cross hens than other strains in floor pens. Claws were longer in cages than in the floor pens. Foot condition was worse in floor pens than in cages. The welfare indicators used in this study showed that cages restricted the hens' behaviour compared to floor pens and resulted in higher laying period mortality, reduced body weight and deteriorated feather condition than floor pens. Both systems had advantages and disadvantages in regard to the hens’ health and welfare. The use of environmental complexities was strain specific in floor pens. The environment by genotype interactions suggests that the strain should be considered when considering alternative housing systems.
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Engineering Behavior Artificial Benthic Habitats And Analysis and Design Anchoring Design Devices for Farming Cages

Ou, Rong-Chang 23 March 2002 (has links)
The purpose of this investigation was to integrate the knowledge and techniques of marine geotechnical engineering, underwater acoustic and optical observation into studying the engineering problems of artificial reefs off south-western coast of Taiwan (Fang-Liau ,Lin-Yang, Yung-An artificial reefs etc.) and the destruction of mooring system on farming cages caused by the interaction of wave-current system. The ultimate goal of this investigation was to understand the scouring activities of loosely and closely spaced artificial reefs; as well as, to evaluate the feasibility of using artificial reefs as deadweight anchoring devices for farming cages at Fang-Liau reef site. The results of this research were as follows: Fang-Liau artificial reef site: The maximum scouring depth can reach as deep as 2.2m around closely distributed reefs at this site. Only a few loosely deployed reefs were buried there, and the scouring depressions around these buried reefs had been filled up completely. To sum up, the behavior of scouring produced by the action of wave, current and typhoon around this site, merely limited to loosely distributed reefs, and the rim of closely distributed reefs. With the scouring time increasing, there were no obvious evidences for the burial of artificial reefs at this site. Lin-Yang artificial reef site: The scouring depressions around part of loosely deployed reefs expand as typhoons attacking at this site. The horizontal range of the scouring depressions can reach 92.3m in length, and parts of the reefs were buried during the process of scouring. Besides, as time went on, part of closely distributed reefs illustrated periodic variations of being buried by sediments with ripple marks, then shown up with evident height, and then buried again. To sum up, the behavior of scouring produced by the action of wave, current and typhoon around this site could cause the complete burial of the reefs. The possible procedures for the burial of reefs in the scouring depression were the actions of backfill of sandy sediments at this site. Yung-An artificial reef site: During summer time, especially with typhoons passed by, surficial sediments at this site were evident with mega ripple marks. The effects of scouring at this site were prominent than those at Fang-Liau reef site. The textures of surficial sediments were the major factor which induced this difference. Based on the considerations of safety of sliding, bearing capacity and overturning, the usage of artificial reefs as anchoring devices for farming cages could not satisfy the basic engineering requirements under the action of extreme wave and current. This research suggested the usage of cubical concrete block with shear keys for anchoring devices on farming cages. The minimum buoyant weight of this block should reach 28.8 to 38.7ton. The problem regarding construction and deployment techniques of this block need further considerations.
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Production and behaviour of four strains of laying hens kept in conventional cages and a free run system

Singh, Renu 05 1900 (has links)
Production, egg quality, behaviour, and physical condition were compared from Wk 20 to Wk 50 among three beak- trimmed commercial laying strains, Lohmann White (LW), H & N White (HN), Lohmann Brown (LB), and a non-commercial Cross between Rhode Island Red (male) and Barred Plymouth Rock (female) in conventional cages and in floor pens. All chicks were reared in their respective environments, and 450 and 432 pullets were housed at 18 and 7 weeks of age in cages and floor pens respectively. Hens in cages were provided with 688 cm2/bird and those in pens with over 6,000 cm2/bird, both of which are more than provided by commercial standards. Body weights and eggshell weights were higher for birds in floor pens than those in cages, and although they increased with age, body weight of hens in cages decreased at Wk 50. White-egg layers (LW, HN) used perches and nest boxes more than Brown-egg layers (LB, Cross). During the laying period, mortality was higher for all strains in cages and during the rearing period mortality was higher in floor pens for LB hens but not other strains. No aggressive behaviours were found, but the frequency of gentle feather pecking and pecking at the enclosure was higher in cages than in floor pens. Feather condition deteriorated over time in cages mainly because of contact with the cage wires whereas in floor pens, feather condition of birds at Wk 20 was not different from that at Wk 50. The frequency of keel bone deformities was higher for White-egg layers than for Brown-egg layers in cages and was higher for Cross hens than other strains in floor pens. Claws were longer in cages than in the floor pens. Foot condition was worse in floor pens than in cages. The welfare indicators used in this study showed that cages restricted the hens' behaviour compared to floor pens and resulted in higher laying period mortality, reduced body weight and deteriorated feather condition than floor pens. Both systems had advantages and disadvantages in regard to the hens’ health and welfare. The use of environmental complexities was strain specific in floor pens. The environment by genotype interactions suggests that the strain should be considered when considering alternative housing systems.

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