263 research outputs found

    Sex Hormones Changes in Blood and Their Effect on Fecundity of African Catfish (Clarias gariepinus Burchell, 1822) after Being Injected with Different Doses of Human Chorionic Gonadotropin (HCG) Hormone

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    This study was conducted to investigate the effect of different dosesinjection of human chorionic gonadotropin (HCG) hormone on fecundityand serum sex hormones (FSH, LH, estrogen (E2), progesterone (P4),testosterone (T)) of African catfish (Clarias gariepinus). African catfishspawners were intermuscularly injected with different doses of HCG(500, 1500, 3000, 6000 IU/kg female), and group is not injected as acontrol; males were injected at half the female dose. The results showedthat, fish group injected by 6000 IU HCG/ kg female had the highestgonadsomatic index, absolute fecundity and relative fecundity, while,the lowest value of absolute fecundity and relative fecundity wererecorded with 500 IU HCG/ kg female. The group injected with thehighest amount of HCG (6000 IU/ kg female) recorded the lowest valuefrom egg diameter, while the highest egg diameter was observed in 500IU HCG/ kg female. In females, the group injected with 6000 IU HCG/kg female reflected the lowest level of FSH and the highest level of LHand the highest level of P4 compared to other treatments. Level of Trecorded the highest level with 1500 IU HCG/ kg female. The controlgroup reflected the highest level of FSH and E2, while the control groupreflected the lowest level of T and P4 level. In males, serum FSH, LH,P4 and E2 in male groups injected with HCG were relatively higher thanthose recorded in the control group. The highest level of T was recordedin treatment injected with the highest dose of HCG and decreased inother treatments until recorded the lowest level of T in the controlgroup. It was observed, HCG hormone has successfully and accelerateinduced spawning in African catfish (Clarias gariepinus) and increasedin reproductive performance with the increase in HCG dosage and ascompared to group not injected

    Forest Degradation in Dryland Ecosystems of Sudan: Review of the Causes, Consequences, Assessment Methods, and Potential Solutions

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    Dryland forests are ecologically and socioeconomically important. They contribute to livelihood diversification, food security, animal feed and shelter, and environmental conservation in sub-Saharan Africa, particularly Sudan. Despite their importance, current findings show that multiple ecological, human, socio-economic, and policy factors have damaged these resources. As a result, undesirable consequences have been observed, such as food famine, land and water resource degradation, decline/loss of biodiversity, and contribution to global warming that affect the welfare of humans, plants, animals, and micro-organisms. This chapter briefly reviews the forest degradation in drylands Sudan with emphasis on its common causes, impacts, assessment methods, management intervention efforts, and potential future solutions. Given the current situation, there must be urgent combating efforts to manage Sudan’s dryland forest resources properly. On the one hand, following prevention measures to essentially deal with the current causes thus prevent any further degradation of forest resources in dryland Sudan. On the other hand, there is an urgent need to address current degradation following appropriate and timely rehabilitation interventions. We also recommend adopting a serious monitoring and evaluation system within these combating efforts by applying the five common indicators for measuring forest degradation: biodiversity, productive functions, carbon storage, forest health, and protective functions

    Assessment of energy credits for the enhancement of the Egyptian Green Pyramid Rating System

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    Energy is one of the most important categories in the Green Building Rating Systems all over the world. Green Building is a building that meets the energy requirements of the present with low energy consumption and investment costs without infringing on the rights of forthcoming generations to find their own needs. Despite having more than a qualified rating system, it is clear that each system has different priorities and needs on the other. Accordingly, this paper proposes a methodology using the Analytic Hierarchy Process (AHP) for assessment of the energy credits through studying and comparing four of the common global rating systems, the British Building Research Establishment Environmental Assessment Method (BREEAM), the American Leadership in Energy and Environmental Design (LEED), the Australian Green Stars (GS), and the PEARL assessment system of the United Arab Emirates, in order to contribute to the enhancement of the Egyptian Green Pyramid Rating System (GPRS). The results show the mandatory and optional energy credits that should be considered with their proposed weights according to the present and future needs of green Egypt. The results are compared to data gathered through desk studies and results extracted from recent questionnaires

    Variation in the attachment of Streptococcus pneumoniae to human pharyngeal epithelial cells after treatment with S-carboxymethylcysteine

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    S-carboxymethylcysteine (S-CMC) is a mucolytic agent that can prevent respiratory infection by decreasing the attachment of respiratory pathogens to human pharyngeal epithelial cells (HPECs). Streptococcus pneumoniae is a major cause of respiratory infections. A previous study revealed that treatment of S. pneumoniae with S-CMC caused a decrease in the attachment of this bacterium to HPECs. In the present study we found that the effect of S-CMC varied according to hosts and strains. S-CMC treatment altered the surface structure of S. pneumoniae, resulting in a decrease of attachment, without affecting the virulence of the bacteria. © 2008 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases

    Probing R-parity violating models of neutrino mass at the Tevatron via top Squark decays

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    We have estimated the limiting branching ratio of the R-parity violating (RPV) decay of the lighter top squark, \tilde t_1 \ar l^+ d (l=el=e or μ\mu and d is a down type quark of any flavor), as a function of top squark mass(\MST) for an observable signal in the di-lepton plus di-jet channel at the Tevatron RUN-II experiment with 2 fb−1^{-1} luminosity. Our simulations indicate that the lepton number violating nature of the underlying decay dynamics can be confirmed via the reconstruction of \MST. The above decay is interesting in the context of RPV models of neutrino mass where the RPV couplings (λi3j′\lambda'_{i3j}) driving the above decay are constrained to be small (\lsim 10^{-3} - 10^{-4} ). If t~1\tilde t_1 is the next lightest super particle - a theoretically well motivated scenario - then the RPV decay can naturally compete with the R-parity conserving (RPC) modes which also have suppressed widths. The model independent limiting BR can delineate the parameter space in specific supersymmetric models, where the dominating RPV decay is observable and predict the minimum magnitude of the RPV coupling that will be sensitive to Run-II data. We have found it to be in the same ballpark value required by models of neutrino mass, for a wide range of \MST. A comprehensive future strategy for linking top squark decays with models of neutrino mass is sketched.Comment: 28 pages, 14 Figure

    A Complete Theory of Grand Unification in Five Dimensions

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    A fully realistic unified theory is constructed, with SU(5) gauge symmetry and supersymmetry both broken by boundary conditions in a fifth dimension. Despite the local explicit breaking of SU(5) at a boundary of the dimension, the large size of the extra dimension allows precise predictions for gauge coupling unification, alpha_s(M_Z) = 0.118 \pm 0.003, and for Yukawa coupling unification, m_b(M_Z) = 3.3 \pm 0.2 GeV. A complete understanding of the MSSM Higgs sector is given; with explanations for why the Higgs triplets are heavy, why the Higgs doublets are protected from a large tree-level mass, and why the mu and B parameters are naturally generated to be of order the SUSY breaking scale. All sources of d=4,5 proton decay are forbidden, while a new origin for d=6 proton decay is found to be important. Several aspects of flavor follow from an essentially unique choice of matter location in the fifth dimension: only the third generation has an SU(5) mass relation, and the lighter two generations have small mixings with the heaviest generation. The entire superpartner spectrum is predicted in terms of only two free parameters. The squark and slepton masses are determined by their location in the fifth dimension, allowing a significant experimental test of the detailed structure of the extra dimension. Lepton flavor violation is found to be generically large in higher dimensional unified theories with high mediation scales of SUSY breaking. In our theory this forces a common location for all three neutrinos, predicting large neutrino mixing angles. Rates for mu -> e gamma, mu -> e e e, mu -> e conversion and tau -> mu gamma are larger in our theory than in conventional 4D supersymmetric GUTs. Proposed experiments probing mu -> e transitions will probe the entire interesting parameter space of our theory.Comment: 51 pages, late

    Decaying into the Hidden Sector

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    The existence of light hidden sectors is an exciting possibility that may be tested in the near future. If DM is allowed to decay into such a hidden sector through GUT suppressed operators, it can accommodate the recent cosmic ray observations without over-producing antiprotons or interfering with the attractive features of the thermal WIMP. Models of this kind are simple to construct, generic and evade all astrophysical bounds. We provide tools for constructing such models and present several distinct examples. The light hidden spectrum and DM couplings can be probed in the near future, by measuring astrophysical photon and neutrino fluxes. These indirect signatures are complimentary to the direct production signals, such as lepton jets, predicted by these models.Comment: 40 pages, 5 figure

    Lepton flavour violation in e^{\pm}e^{-}\to \ell^{\pm}e^{-} (\ell = \mu,\tau) induced by R-conserving supersymmetry

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    The lepton flavour violating signals e+e−→ℓ+e−e^{+}e^{-}\to \ell^{+}e^{-} and e−e−→ℓ−e−(ℓ=μ,τ)e^{-}e^{-}\to \ell^{-}e^- (\ell=\mu,\tau) are studied in the context of low energy R-parity conserving supersymmetry at center of mass energies of interest for the next generation of linear colliders. Loop level amplitudes receive contributions from electroweak penguin and box diagrams involving sleptons and gauginos. Lepton flavour violation is due to off diagonal elements in SU(2)LSU(2)_L doublet slepton mass matrix. These masses are treated as model independent free phenomenological parameters in order to discover regions in parameter space where the signal cross section may be observable. The results are compared with (a) the experimental bounds from the non-observation of rare radiative lepton decays μ,τ→eγ\mu, \tau \to e\gamma and (b) the general mSUGRA theoretical scenario with seesaw mechanism where off diagonal slepton matrix entries are generated by renormalization group evolution of neutrino Yukawa couplings induced by the presence of new energy scales set by the heavy SU(2)LSU(2)_L singlet neutrino masses. It is found that in e−e−e^- e^- collisions the (eτe\tau) signal can be observable with a total integrated luminosity of 100 fb−1^{-1} and the that the background can be easily suppressed. In e+e−e^+ e^- collisions the cross section is smaller and higher luminosities are needed. The experimental bound on the decay μ→eγ\mu \to e \gamma prevents the (eμe\mu) signal from being observable.Comment: 14 pages, 12 figures, Revtex
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