3 resultados para maternally-mediated genotype effect

em Universitätsbibliothek Kassel, Universität Kassel, Germany


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This study aimed at evaluating the effects of different levels of rosemary (Rosmarinus officinalis) extract on growth rate, hematology and cell-mediated immune response in Markhoz newborn goat kids. Twenty four goat kids (aged 7 +/- 3 days) were randomly allotted to four groups with six replicates. The groups included: control, T1, T2 and T3 groups which received supplemented-milk with 0, 100, 200 and 400mg aqueous rosemary extract per kg of live body weight per day for 42 days. Body weights of kids were measured weekly until the end of the experiment. On day 42, 10 ml blood samples were collected from each kid through the jugular vein. Cell-mediated immune response was assessed through the double skin thickness after intradermal injection of phyto-hematoglutinin (PHA) at day 21 and 42. No significant differences were seen in initial body weight, average daily gain (ADG) and total gain. However, significant differences in globulin (P <0.05), and white blood cells (WBC) (P <0.001) were observed. There were no significant differences in haemoglobin (Hb), packed cell volume (PCV), red blood cells (RBC), lymphocytes and neutrophils between the treatments. Skin thickness in response to intra dermal injection of PHA significantly increased in the treated groups as compared to the control group at day 42 (P< 0.01) with the T3 group showing the highest response to PHA injection. In conclusion, the results indicated that aqueous rosemary extract supplemented-milk had a positive effect on immunity and skin thickness of newborn goat kids.

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The present study was carried out to evaluate the effect of different levels of garlic extract supplemented in milk on growth rate, haematology and cell–mediated immune response of Markhoz newborn goat kids. Twenty four newborn goat kids (aged 7+/-3days) were randomly assigned to four groups. The groups consisted of control (received milk without garlic extract), T1, T2 and T3 which received milk supplemented with 62.5, 125 and 250 mg aqueous garlic extract per kg live weight per day for 42 days, respectively. Body weights were measured weekly throughout the experimental period. At day 42, about 10 ml blood samples were collected from each kid via the jugular vein for haematological study. Cell–mediated immune response was evaluated through double skin thickness after intradermal injection of phyto-hematogglutinin (PHA) at day 21 and 42. Total gain was significantly higher for kids in T3 (P<0.05) compared with the control group. Average daily gain (ADG) in T3 group in week 4–5 was higher (P<0.05). Significant differences in globulin (P<0.01), hemoglobin (Hb; P<0.001), hematocrit (PCV; P<0.001), erythrocyte (RBC; P<0.001), neutrophil (P<0.001), lymphocyte (P<0.001) and leukocyte (WBC; P<0.001) were observed among groups. Hb, PCV, RBC, lymphocytes and WBC were higher in kids given garlic extract supplementation. There was a significant difference of double skin thickness among the groups at day 42 (P<0.01). In conclusion, this study indicated that milk supplemented with aqueous garlic extract improved growth rate and immunity of newborn goat kids.

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The magnetic properties and interactions between transition metal (TM) impurities and clusters in low-dimensional metallic hosts are studied using a first principles theoretical method. In the first part of this work, the effect of magnetic order in 3d-5d systems is addressed from the perspective of its influence on the enhancement of the magnetic anisotropy energy (MAE). In the second part, the possibility of using external electric fields (EFs) to control the magnetic properties and interactions between nanoparticles deposited at noble metal surfaces is investigated. The influence of 3d composition and magnetic order on the spin polarization of the substrate and its consequences on the MAE are analyzed for the case of 3d impurities in one- and two-dimensional polarizable hosts. It is shown that the MAE and easy- axis of monoatomic free standing 3d-Pt wires is mainly determined by the atomic spin-orbit (SO) coupling contributions. The competition between ferromagnetic (FM) and antiferromagnetic (AF) order in FePtn wires is studied in detail for n=1-4 as a function of the relative position between Fe atoms. Our results show an oscillatory behavior of the magnetic polarization of Pt atoms as a function of their distance from the magnetic impurities, which can be correlated to a long-ranged magnetic coupling of the Fe atoms. Exceptionally large variations of the induced spin and orbital moments at the Pt atoms are found as a function of concentration and magnetic order. Along with a violation of the third Hund’s rule at the Fe sites, these variations result in a non trivial behavior of the MAE. In the case of TM impurities and dimers at the Cu(111), the effects of surface charging and applied EFs on the magnetic properties and substrate-mediated magnetic interactions have been investigated. The modifications of the surface electronic structure, impurity local moments and magnetic exchange coupling as a result of the EF-induced metallic screening and charge rearrangements are analysed. In a first study, the properties of surface substitutional Co and Fe impurities are investigated as a function of the external charge per surface atom q. At large inter-impurity distances the effective magnetic exchange coupling ∆E between impurities shows RKKY-like oscillations as a function of the distance which are not significantly affected by the considered values of q. For distances r < 10 Å, important modifications in the magnitude of ∆E, involving changes from FM to AF coupling, are found depending non-monotonously on the value and polarity of q. The interaction energies are analysed from a local perspective. In a second study, the interplay between external EF effects, internal magnetic order and substrate-mediated magnetic coupling has been investigated for Mn dimers on Cu(111). Our calculations show that EF (∼ 1eV/Å) can induce a switching from AF to FM ground-state magnetic order within single Mn dimers. The relative coupling between a pair of dimers also shows RKKY-like oscillations as a function of the inter-dimer distance. Their effective magnetic exchange interaction is found to depend significantly on the magnetic order within the Mn dimers and on their relative orientation on the surface. The dependence of the substrate-mediated interaction on the magnetic state of the dimers is qualitatively explained in terms of the differences in the scattering of surface electrons. At short inter-dimer distances, the ground-state configuration is determined by an interplay between exchange interactions and EF effects. These results demonstrate that external surface charging and applied EFs offer remarkable possibilities of manipulating the sign and strength of the magnetic coupling of surface supported nanoparticles.