Study of Genetic Variability of Fatty Acid Profile in Bovine Milk and Fat Using Mid-Infrared SpectrometrySoyeurt, Hélène ![]() Doctoral thesis (2008) Changes in milk fat composition influence its nutritional quality as well as the technological properties of butter. The impact of feed on fat composition is well known; however, limited information is ... [more ▼] Changes in milk fat composition influence its nutritional quality as well as the technological properties of butter. The impact of feed on fat composition is well known; however, limited information is available on the genetic variability of fatty acids in bovine milk. The overall aim of this PhD thesis was to study the genetic variability of fatty acid profile in bovine milk and fat. This type of research needs a large amount of data. Expensive reference analysis is used to measure the fatty acid contents in fat. The first objective of this thesis was to develop an alternative method that could be faster and cheaper than traditional methods. Calibration equations predicting the contents of fatty acid from mid-infrared spectrum were established. The contents of saturated and monounsaturated fatty acids, omega-9, fatty acids with short, medium and long chain were the best predicted. Thanks to the implementation of this method in the Walloon routine milk recording, more than 20,000 milk samples were analyzed. This database permitted to model the variation of fatty acid contents in milk and fat. From these models, the genetic variability of fatty acid profile was shown. The complexity of models increased throughout this project due to the increase of new available data. Differences across 7 dairy breeds were estimated using single and multi-trait mixed models. Milk fat and delta-9 desaturase activity of Jersey and dual purpose Belgian Blue differed significantly from Holsteins. Therefore, the choice of a given breed could modify the fat composition. Heritability values obtained for studied fatty acids with multi-trait mixed model ranged from 0.05 to 0.42. Higher values were observed for saturated compared to unsaturated fatty acids. Moderate heritability estimates were observed for the activity of delta-9 desaturase (0.20) and the hardness of butter (0.27). These two traits were estimated by specific fatty acid ratios. The heritability observed using a multi-trait random regressions test day model for the content of saturated fatty acids (0.42) was similar to the one observed for the percentage of fat (0.37). Considering the impact of selection on fat content, the selection could have a great impact on fat composition. High genetic correlations were observed between some fatty acids having similarities in their synthesis. Heritability and correlations varied through the duration of the lactation. Due to the large number of fatty acids, the estimation of an index, which includes the proper fatty acid profile, could be interesting for a future selection program. This PhD thesis provides the background required by future studies to estimate the impact of animal selection on milkfat composition. [less ▲] Detailed reference viewed: 53 (13 ULg) Study of glass transition and fusion point of inulin by DSC and MDSCBlecker, Christophe ; ; et alPoster (2001, October) Detailed reference viewed: 17 (4 ULg) Study of graphite precipitation during heat treatment in chromium cast ironLecomte-Beckers, Jacqueline ; in Proceeding of the Annual Meeting of the SBM/NMVS (1997) Detailed reference viewed: 6 (1 ULg) Study of HCV and HIV infections in Mali: Comparative Epidemiology and Risk Factors; VAIRA, Dolorès ; GOTHOT, André et alPoster (2012) Detailed reference viewed: 9 (4 ULg) Study of heat and mass transfer in porous media: application to packed-bed dryingBennamoun, Lyes ; in Fluid Dynamics and Materials Processing (2008), 4(4), 221-230 Detailed reference viewed: 6 (3 ULg) Study of Highly Ionized Neon by Beam-Foil SpectroscopyBastin, Thierry ; Biémont, Emile ; Dumont, Paul-Dominique et alPoster (1995) Detailed reference viewed: 4 (2 ULg) Study of Human Error in complex systemsNyssen, Anne-Sophie ![]() Scientific conference (2003, May) Detailed reference viewed: 23 (3 ULg) Study of hypotonic polyuria after trans-sphenoidal pituitary adenomectomy.HANS, Pol ; Stevenaert, Achille ; Albert, Adelin ![]() in Intensive Care Medicine (1986), 12(2), 95-9 We have studied the postoperative diuresis patterns in 116 patients following the removal of a pituitary adenoma using the trans-sphenoidal approach. We observed a normal diuresis (ND) in 55 patients and ... [more ▼] We have studied the postoperative diuresis patterns in 116 patients following the removal of a pituitary adenoma using the trans-sphenoidal approach. We observed a normal diuresis (ND) in 55 patients and a hypotonic polyuria (HP) in 61 patients, consisting of water elimination (WE = 45 cases) and transient diabetes insipidus (DI = 16 cases). We investigated the problem of predicting these patterns from eight pre-operative factors by applying stepwise logistic discriminant analysis. We demonstrated that DI was significantly associated with a posterior localization of the adenoma in the pituitary gland and that WE was more frequently observed in cases of suprasellar expansion, in young patients, and in prolactin secreting tumors. Finally, we discuss the pathogenic role of these factors in the occurrence of HP, taking into account inhibition of vasopressin secretion and possible fluid overload. [less ▲] Detailed reference viewed: 2 (0 ULg) Study of interface trap density in a GeSn MOS structure by numerical simulation of the electrical characteristicsBaert, Bruno ; ; Schmeits, Marcel et alPoster (2013, June) Detailed reference viewed: 10 (3 ULg)![]() Study of interface trap density in a GeSn MOS structure by numerical simulation of the electrical characteristicsBaert, Bruno ; Schmeits, Marcel ; Nguyen, Ngoc Duy ![]() Conference (2013, May) The semiconducting alloy germanium tin (GeSn) is expected to play an important role in the development of high mobility channel materials for next generation CMOS and optoelectronic devices. The two most ... [more ▼] The semiconducting alloy germanium tin (GeSn) is expected to play an important role in the development of high mobility channel materials for next generation CMOS and optoelectronic devices. The two most interesting features of this material, which is compatible with mainstream Si technology, are its tunable direct band-gap and the possibility to induce strain due to the lattice mismatch with Ge and Si, thereby increasing the holes and electrons mobilities. It has been shown that the interface trap density can be under- or overestimated in Ge-channel MOSFETs when applying conventional measurement techniques such as the conductance method. As this effect is common in low band-gap materials, we expect that it also occurs for GeSn. Following our previous work on metal/GeSn/Ge structures, we have therefore applied our home-built numerical simulation software to a metal/oxide/GeSn MOS structure in order to investigate the result of the presence of such interface states. We discuss possible effects of the interface trap density, interface trap energy and temperature on the electrical characteristics. Successive simulations of both the steady-state and ac small-signal regimes give access to measurable quantities such as the admittance spectrum and the C-V curves. A physical interpretation can be attributed to their variations and an overall comparison can be made with results obtained from equivalent electrical circuit analysis. [less ▲] Detailed reference viewed: 36 (3 ULg)![]() Study of late Roman period gilded and patinated artifacts at the new external beam set-up of Liege cyclotronChene, Grégoire ; Mathis, François ; et alConference (2011, April) Detailed reference viewed: 11 (1 ULg) Study of lipase production by yeast Yarrowia lipolytica; Destain, Jacqueline ; Thonart, Philippe ![]() Poster (2000, September) Detailed reference viewed: 9 (1 ULg) Study of lipoxygenase activity during storage of potato tubers (Solanum tuberosum L.) in relation with membrane integrity.Fauconnier, Marie-Laure ; ; et alPoster (2001, June 06) Detailed reference viewed: 14 (0 ULg) Study of liquid fraction evolution of semi-solid steels for thixoformingLecomte-Beckers, Jacqueline ; Rassili, Ahmed ; Carton, Marc et alin Proceedings of the 8th ESAFORM Conference on Material Forming (2005) Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is ... [more ▼] Major challenge for semi-solid processing includes broadening the range of alloys that can be successfully thixoformed and developing alloys specifically for thixoforming. One important parameter is appropriate solidus-liquidus interval. The wider the solidification interval, the wider the processing window. This study is related to the experimental determination of this critical parameter on eight different steel compositions. This parameter was obtained using Differential Scanning Calorimetry. This technique allows to obtain the solid fraction versus temperature. [less ▲] Detailed reference viewed: 11 (0 ULg) Study of liquid fraction of semi-solids steels for thixoformingCarton, Marc ; Lecomte-Beckers, Jacqueline ![]() Report (2005) Detailed reference viewed: 3 (0 ULg) A study of low-energy guest phonon modes in clathrate-II NaxSi136 (x = 3, 23, and 24); Hermann, Raphaël ; Möchel, Anne et alin Journal of Physics : Condensed Matter (2010) Single-crystal x-ray diffraction from clathrate-II NaxSi136 (x = 24) prepared by a new technique reveals the exceptionally large Na@Si-28 atomic displacement parameter (U-eq) is strongly temperature ... [more ▼] Single-crystal x-ray diffraction from clathrate-II NaxSi136 (x = 24) prepared by a new technique reveals the exceptionally large Na@Si-28 atomic displacement parameter (U-eq) is strongly temperature dependent, and can be attributed to low-energy rattling modes associated with the Na guest. Inelastic neutron scattering (INS) spectra collected from NaxSi136 powder specimens (x = 3, 23) confirm the presence of low-energy guest-derived phonon modes for Na@Si-28 and Na@Si-20. The lower energy Na@Si-28 rattler mode falls in the frequency range of the silicon host acoustic phonons, indicating the possibility for interaction with these phonons. The presence of these low-energy modes combined with the ability to controllably vary the guest content presents a unique opportunity for exploring the influence of guest-framework interactions on the lattice dynamics in intermetallic clathrates. [less ▲] Detailed reference viewed: 9 (2 ULg) Study of Major Fungal Diseases Control on Postharvest Apples with Integrated Use of two Antagonistic Yeasts and ThermothrapyJijakli, Haissam ; Lepoivre, Philippe ![]() Poster (1997) Detailed reference viewed: 5 (0 ULg)![]() Study of mechanical, physical and chemical properties of a-C:H films deposited by reactive magnetron sputtering in DC pulsed mode; ; et al Poster (2010) Detailed reference viewed: 7 (1 ULg) Study of medieval glass fragments originating from Savona (Italy) and their relation with the glass produced in Altare; ; Mathis, François et alin Journal of Archaeological Science (2012), 39(7), 2191-2197 Altare was in the medieval and post-medieval period an important glassmaking center in the Liguria region in Northern Italy. The first historical evidence of glassmaking in Altare is dated to the twelfth ... [more ▼] Altare was in the medieval and post-medieval period an important glassmaking center in the Liguria region in Northern Italy. The first historical evidence of glassmaking in Altare is dated to the twelfth century. In spite of that, due to the continuity of glassmaking up to the present time and the contemporaneous intensive urbanization of the territory, no medieval glass from Altare or its immediate vicinity has been analyzed up to now. In this work, glass from archaeological excavations in the center of Savona, city with close ties with the glassmaking center, was studied. Glass fragments, dated from the tenth to the sixteenth century were selected from the collections of the Archaeological Museum in Savona and non-destructively analyzed with quantitative PIXE-PIGE. The resulting compositions, compared with known glass productions of the same time and evaluated on the basis of historical documents, offer an interesting panorama on the variety of glass circulation in Liguria. [less ▲] Detailed reference viewed: 31 (17 ULg) Study of metal regulation in Arabidopsis halleriHanikenne, Marc ![]() Conference (2004, January 22) Detailed reference viewed: 4 (1 ULg) |
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