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Smeti S.,University of Carthage | Hajji H.,University of Carthage | Bouzid K.,Tunis el Manar University | Abdelmoula J.,Tunis el Manar University | And 3 more authors.
Tropical Animal Health and Production | Year: 2014

The effects of rosemary supply in form of essential oils (REO) or leaves (RL) on performances of goats were investigated. Thirty goats were allocated into three equal groups, which were fed oat-hay ad libitum and 400 g of concentrate during the two last weeks of pregnancy and 600 g during the first 8 weeks of lactation. Three-control diet (C) was a mixture of barley, soybean meal and mineral vitamin supplement. The experimental concentrates contained the same mixture of the control diet plus 0.6 g/kg of REO or its equivalent supply RL (60 g/kg). Rosemary supply did not affect dry matter (DM), organic matter (OM), crude protein (CP) and neutral detergent fiber (NDF) digestibility. While urinary nitrogen loss was higher for experimental groups than the C (P = 0.03). Daily milk production was significantly higher (P = 0.007) for rosemary groups (694 and 582 ml for RL and REO, respectively) than C group (442 ml). Rosemary decreased numerically (P > 0.05) the fat content (23, 25 and 26.5 g/l for REO, RL and C groups, respectively) but significantly increased the fat (P = 0.003) and protein content (P = 0.008). The growth rate of kids was significantly higher (P = 0.008) for RL (111 g) than that for REO and C (97 and 83 g, respectively). However, rosemary has not shown significant effect on the plasma metabolite concentrations. Given the facility to obtain the rosemary leaves, this form of rosemary use is recommended as natural alternative to improve the performances of goats. © 2014, Springer Science+Business Media Dordrecht. Source

Zimmerman A.,CITA | Mark Z.,California Institute of Technology
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2016

Despite recent progress, the complete understanding of the perturbations of charged, rotating black holes as described by the Kerr-Newman metric remains an open and fundamental problem in relativity. In this study, we explore the existence of families of quasinormal modes of Kerr-Newman black holes whose decay rates limit to zero at extremality, called zero-damped modes in past studies. We review the nearly extremal and WKB approximation methods for spin-weighted scalar fields (governed by the Dudley-Finley equation) and give an accounting of the regimes where scalar zero-damped and damped modes exist. Using Leaver's continued fraction method, we verify that these approximations give accurate predictions for the frequencies in their regimes of validity. In the nonrotating limit, we argue that gravito-electromagnetic perturbations of nearly extremal Reissner-Nordström black holes have zero-damped modes in addition to the well-known spectrum of damped modes. We provide an analytic formula for the frequencies of these modes, verify their existence using a numerical search, and demonstrate the accuracy of our formula. These results, along with recent numerical studies, point to the existence of a simple universal equation for the frequencies of zero-damped gravito-electromagnetic modes of Kerr-Newman black holes, whose precise form remains an open question. © 2016 American Physical Society. Source

Godfroid J.,University of Pretoria | Scholz H.C.,University of Federal Defense Munich | Barbier T.,University of Namur | Nicolas C.,University of Namur | And 12 more authors.
Preventive Veterinary Medicine | Year: 2011

Following the recent discovery of new Brucella strains from different animal species and from the environment, ten Brucella species are nowadays included in the genus Brucella. Although the intracellular trafficking of Brucella is well described, the strategies developed by Brucella to survive and multiply in phagocytic and non-phagocytic cells, particularly to access nutriments during its intracellular journey, are still largely unknown. Metabolism and virulence of Brucella are now considered to be two sides of the same coin. Mechanisms presiding to the colonization of the pregnant uterus in different animal species are not known. Vaccination is the cornerstone of control programs in livestock and although the S19, RB51 (both in cattle) and Rev 1 (in sheep and goats) vaccines have been successfully used worldwide, they have drawbacks and thus the ideal brucellosis vaccine is still very much awaited. There is no vaccine available for pigs and wildlife. Animal brucellosis control strategies differ in the developed and the developing world. Most emphasis is put on eradication and on risk analysis to avoid the re-introduction of Brucella in the developed world. Information related to the prevalence of brucellosis is still scarce in the developing world and control programs are rarely implemented. Since there is no vaccine available for humans, prevention of human brucellosis relies on its control in the animal reservoir. Brucella is also considered to be an agent to be used in bio- and agroterrorism attacks. At the animal/ecosystem/human interface it is critical to reduce opportunities for Brucella to jump host species as already seen in livestock, wildlife and humans. This task is a challenge for the future in terms of veterinary public health, as for wildlife and ecosystem managers and will need a "One Health" approach to be successful. © 2011 Elsevier B.V. Source

Levine R.,CITA | Gnedin N.Y.,Fermi National Accelerator Laboratory | Gnedin N.Y.,University of Chicago | Hamilton A.J.S.,University of Colorado at Boulder
Astrophysical Journal | Year: 2010

Using cosmological simulations with a dynamic range in excess of 10 7, we study the transport of gas mass and angular momentum through the circumnuclear region of a disk galaxy containing a supermassive black hole (SMBH). The simulations follow fueling over relatively quiescent phases of the galaxy's evolution (no mergers) and without feedback from active galactic nuclei (AGNs), as part of the first stage of using state-of-the-art, high-resolution cosmological simulations to model galaxy and black hole co-evolution. We present results from simulations at different redshifts (z = 6, 4, and 3) and three different black hole masses (3 × 107, 9 × 107, and 3 × 108 M ⊙; at z = 4), as well as a simulation including a prescription that approximates optically thick cooling in the densest regions. The interior gas mass throughout the circumnuclear disk shows transient and chaotic behavior as a function of time. The Fourier transform of the interior gas mass follows a power law with slope -1 throughout the region, indicating that, in the absence of the effects of galaxy mergers and AGN feedback, mass fluctuations are stochastic with no preferred timescale for accretion over the duration of each simulation (∼1-2 Myr). The angular momentum of the gas disk changes direction relative to the disk on kiloparsec scales over timescales less than 1 Myr, reflecting the chaotic and transient gas dynamics of the circumnuclear region. Infalling clumps of gas, which are driven inward as a result of the dynamical state of the circumnuclear disk, may play an important role in determining the spin evolution of an SMBH, as has been suggested in stochastic accretion scenarios. © 2010. The American Astronomical Society. Source

Smeti S.,Laboratoire Of Productions Animales Et Fourrageres | Smeti S.,University of Carthage | Atti N.,Laboratoire Of Productions Animales Et Fourrageres | Mahouachi M.,ESA Kef | Munoz F.,CITA
Small Ruminant Research | Year: 2013

The aim of the present study was to determine the increase in shelf life of fresh Barbarine lamb's meat due to the effect of rosemary essential oils (RE) dietary. Thirty-two Barbarine lambs (19.9. kg body weight (BW)) were divided into 2 homogeneous groups receiving 50% dried alfalfa and 50% concentrate. Two types of concentrate were used, the Control (C) and the experimental, which corresponds to C with 0.06% of RE. At the end of the experiment (60 days), all animals were slaughtered. Lipid oxidation (TBARS) and color coordinates of longissimus dorsi (LD) of fresh lamb meat were analyzed on days 1, 3, 7 and 9.The RE incorporation has not affected the ultimate pH and cooking losses. TBARS values significantly increased for both treatments with storage time without any significant effect of regimen. At the ninth day of storage, meat of RE group tended to have higher redness (a*) and lower yellowness (b*) values (11.49 and 5.35 for RE vs. 10.30 and 5.58 for C). Lightness (L*) of meat from both treatments was in the range of acceptability (42-38) throughout the storage period. Panelists reported no significant effect of RE addition on the eating quality of lamb meat which was generally acceptable. The results showed that the dose rate of RE used in the present study did not affect lipid oxidation and had no significant effect against lamb meat discoloration across the storage period. © 2013 Elsevier B.V. Source

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