1,994 research outputs found

    Cohomology of osp(12)\frak {osp}(1|2) acting on the space of bilinear differential operators on the superspace R11\mathbb{R}^{1|1}

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    We compute the first cohomology of the ortosymplectic Lie superalgebra osp(12)\mathfrak{osp}(1|2) on the (1,1)-dimensional real superspace with coefficients in the superspace Dλ,ν;μ\frak{D}_{\lambda,\nu;\mu} of bilinear differential operators acting on weighted densities. This work is the simplest superization of a result by Bouarroudj [Cohomology of the vector fields Lie algebras on RP1\mathbb{R}\mathbb{P}^1 acting on bilinear differential operators, International Journal of Geometric Methods in Modern Physics (2005), {\bf 2}; N 1, 23-40]

    On the prevalence of hierarchies in social networks

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    In this paper, we introduce two novel evolutionary processes for hierarchical networks referred to as dominance- and prestige-based evolution models, i.e., DBEM and PBEM, respectively. Our models are deterministic in nature which allows for closed-form derivation of equilibrium points for such type of networks, for the special case of complete networks. After deriving these equilibrium points, we are somewhat surprised in recovering the exponential and power-law strength distribution as the shared property of the resulting hierarchal networks. Additionally, we compute the network properties, Geodesic distance distribution and centrality closeness, for each model in closed form. Interestingly, these results demonstrate very different roles of hubs for each model, shedding the light on the evolutionary advantages of hierarchies in social networks: in short, hierarchies can lead to efficient sharing of resources and robustness to random failures. For the general case of any hierarchical network, we compare the estimations of tie intensities and node strengths using the proposed models to open-source real-world data. The prediction results are statistically compared using the Kolmogorov–Smirnov test with the original data

    Effect of Deficit Irrigation and Root-Zone Drying Irrigation Technique under Different Nitrogen Rates on Water Use Efficiency for Potato (Solanum Tuberosum L.) in Semi-arid Conditions (I)

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    An investigation was carried out at the Technical Center of Potato and Artichoke CTPTA in the region of Saida, located in the lower valley of Medjerda river during the season of 2017. The objective was to evaluate the effects of deficit irrigation (DI) and the root-zone drying irrigation technique (PRD) under different nitrogen rates on total dry matter production (TDM), water consumption (WC) and water use efficiency of potato (Solanum Tuberosum L. VS. Spunta). Three water treatments (T1 = FI = 100% ETC, T2 = DI = 75% ETC and T3 = PRD50) and three nitrogen rates (F1 = N150: 150 kg N ha-1, F2 = N75: 75kg N ha-1, F3 = N0: 0kg N ha-1) were applied since the tuber initiation (55 days after planting) to maturity (100 days after planting). The results showed that the water regime affected negatively the total dry matter accumulation. A decline of 7 and 18.6% was registered in the two treatments T2 and T3 compared to the control T1. The WC decreased during water restriction respectively by 16; 33 and 29% for the T2 and T3 (PRD50 left) and T3 (PRD50 right) compared to T1. For the three nitrogen treatments (F1, F2 and F3) the water restriction has increased the WUE. The best values was recorded in the treatment T2 and then in the treatment T3 from where this increase compared to T1 was equal to (22.6% and 12.9%), (24.1% and 12, 4%) and (21.9% and 15.3%) respectively

    Impact of Deficit Irrigation (DI) and Root-Zone Drying Irrigation Technique (PRD) under Different Nitrogen Rates on Radiation Use Efficiency for Potato (Solanum Tuberosum L.) in Semi-arid Conditions (II)

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    The study was carried out at the Technical Center of Potato and Artichoke CTPTA located in the lower valley of Medjerda river of Tunisia during the season of 2017. The purpose was to estimate the impact of deficit irrigation (DI) and the root-zone drying irrigation technique (PRD) under different nitrogen rates on photo synthetically active radiation absorbed and radiation use efficiency for Potato (Solanum Tuberosum L. VS. Spunta). Three water treatments (T1= 100% ETC, T2 = DI = 75% ETC and T3 = PRD50) and three nitrogen rates (F1 = N150: 150 kg N ha-1, F2 = N75: 75kg N ha-1, F3 = N0: 0kg N ha-1) were applied since the tuber initiation (55 days after planting) to maturity (100 days after planting). The deficit irrigation T2 has no effect on PARabs. Besides, the PRD50 has led to a reduction in PARabs. This decrease compare to T1 was equal to (8.9; 9.9 and 7.9%) respectively for the three treatments (F1; F2 and F3). The nitrogen deficit affects negatively the PARabs. An improvement of 13.2%, 11.2% and 12.2% of the F1 compared to the F3, respectively for the three water treatments (T1, T2 and T3). The T2 has no effect on RUE TDM. Conversely, the PRD50 has led to a reduction in RUE TDM. This decline referee against T1 was equal to (12.7; 17.4 and 21.5%) respectively for the three treatments (F1; F2 and F3). For RUEGY statistical analysis showed significant (P < 0.05) difference between the three irrigation treatments (T0, T1 and T2) for the three nitrogen treatments (F1; F2 and F3). The T2 and the PRD50 has led to a reduction in RUE GY. This decrease judge against T1 respectively for the two treatments (F2 and F3) was equal to (14.9 and 21.5%) and (19.6 and 31.2%)

    Méningiome primitif ethmoïdonasal.

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    Introduction : Les méningiomes primitifs des fosses nasales et des sinus paranasaux sont des tumeurs bénignes rares, la sémiologie clinique et radiologique n’est pas spécifique. L’objectif de ce travail est de décrire les aspects épidémiologiques, diagnostiques et thérapeutiques de cette localisation ectopique des méningiomes.Observation : Patient âgé de 52 ans, présentant une obstruction nasale bilatérale avec hyposmie et épistaxis depuis 4 ans, l’examen endonasal a montré un processus tissulaire polypoïde occupant les deux fosses nasales, la TdM a montré un processus tumoral ethmoïdonasal étendu aux sphénoïdes et vers les deux fosses nasales sans extension endocrânienne. Le patient a été opéré par voie transfaciale, l’examen anatomopathologique était en faveur d’un méningiome méningothélial gradei. Les contrôles cliniques, endoscopiques et scannographiques n’ont pas montré de résidu tumoral ni de récidive avec un recul de 4ans.Conclusion : Les fosses nasales et les sinus paranasaux représentent une localisation ectopique exceptionnelle des méningiomes extra crâniens primitifs. Ces tumeurs se développent lentement et leur pronostic est généralement bon après exérèse chirurgicale.Mots clés : Méningiomes ectopiques, sinus paranasaux, anatomie pathologique, immunohistochimie, chirurgie.Introductione : Primary extracranial meningiomas of the nasal cavity and paranasal sinuses are rare benign tumors, the clinical and radiological presentations are not specific. The objective of this work is to describe the epidemiological, diagnostic and therapeutic aspects of this ectopic location of meningiomas.Case report : 52-year-old patient, presented a bilateral nasal obstuction with hyposmie and epistaxis for 4 years, the endonasal examination showed a polypoid process occupying both nasal cavity, the CT examination showed a ethmoïdonasal tumoral process extending to sphenoid bones and both nasal cavity without endocranial extension. The patient was operated by transnasal approach, histopathological examination was in favour of a méningothélial meningioma rank i.The clinical, endoscopic and CT controls did not show tumor residue or a local recurrence with a recession of 4years. Nasal cavity and paranasal sinuses represent an exceptional ectopic location of primary extracranial meningiomas , these tumors are slowly growing, and their prognosis is generally good after surgical excision.Keyswords : ectopic meningioma, paranasal sinuses, histopathology, immunohistochemistry, surgery

    Cohomology of the Lie Superalgebra of Contact Vector Fields on R11\mathbb{R}^{1|1} and Deformations of the Superspace of Symbols

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    Following Feigin and Fuchs, we compute the first cohomology of the Lie superalgebra K(1)\mathcal{K}(1) of contact vector fields on the (1,1)-dimensional real superspace with coefficients in the superspace of linear differential operators acting on the superspaces of weighted densities. We also compute the same, but osp(12)\mathfrak{osp}(1|2)-relative, cohomology. We explicitly give 1-cocycles spanning these cohomology. We classify generic formal osp(12)\mathfrak{osp}(1|2)-trivial deformations of the K(1)\mathcal{K}(1)-module structure on the superspaces of symbols of differential operators. We prove that any generic formal osp(12)\mathfrak{osp}(1|2)-trivial deformation of this K(1)\mathcal{K}(1)-module is equivalent to a polynomial one of degree 4\leq4. This work is the simplest superization of a result by Bouarroudj [On sl\mathfrak{sl}(2)-relative cohomology of the Lie algebra of vector fields and differential operators, J. Nonlinear Math. Phys., no.1, (2007), 112--127]. Further superizations correspond to osp(N2)\mathfrak{osp}(N|2)-relative cohomology of the Lie superalgebras of contact vector fields on 1N1|N-dimensional superspace

    Is the Top Quark Really Heavier than the WW Boson?

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    Scalar induced top decays may drastically suppress B(tν+jet)B(t\to \ell\nu + jet) and still hide the top below MWM_W. The ppˉp\bar p collider experiments should enlarge the scope and study the mtB(tνj)m_t - B(t\to\ell\nu j) plane. Specific model signatures such as tch0cbbˉt\to ch^0\to cb\bar b (multiple high pTp_T bb-jets) and tbH+bcsˉt\to bH^+\to bc\bar s, bτ+νb\tau^+\nu (with $B(t\to b\tau\nu) \ \raisebox{-.5ex}{\rlap{\sim}} \raisebox{.4ex}{<<}\ 1/3)shouldbeexplored.Withoutrulingoutthesepossibilities,isolatedleptonsignalsinthefuturemightactuallybeduetothe4thgeneration) should be explored. Without ruling out these possibilities, isolated lepton signals in the future might actually be due to the 4th generation t^\primeor or b^\prime$ quark, while top quark and toponium physics could still turn up at LEP-II.Comment: 11 pages (RevTex), 3 figures (not included), NTUTH-93-0

    Crystallographically oriented magnetic ZnFe2O4 nanoparticles synthesized by Fe implantation into ZnO

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    In this paper, a correlation between structural and magnetic properties of Fe implanted ZnO is presented. High fluence Fe^+ implantation into ZnO leads to the formation of superparamagnetic alpha-Fe nanoparticles. High vacuum annealing at 823 K results in the growth of alpha-Fe particles, but the annealing at 1073 K oxidized the majority of the Fe nanoparticles. After a long term annealing at 1073 K, crystallographically oriented ZnFe2O4 nanoparticles were formed inside ZnO with the orientation relationship of ZnFe2O4(111)[110]//ZnO(0001)[1120]. These ZnFe2O4 nanoparticles show a hysteretic behavior upon magnetization reversal at 5 K.Comment: 21 pages, 7 figures, accepted by J. Phys. D: Appl. Phy

    Artesunate plus sulfadoxine-pyrimethamine for treatment of uncomplicated Plasmodium falciparum malaria in Sudan

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    BACKGROUND: Early diagnosis and effective treatment with an appropriate drug form the main components of the World Health Organization's strategy to reduce malaria related mortality. The few available drugs might be safeguarded if combined with artesunate. The addition of artesunate to a standard antimalarial treatment substantially reduces treatment failure, recrudescence and gametocyte carriage. METHODS: During late 2004, the efficacy of artesunate (4 mg/kg. day, on days 0–2) plus sulfadoxine-pyrimethamine (25 mg/kg, on day 0) for the treatment of uncomplicated Plasmodium falciparum malaria was investigated in four sentinel areas in Sudan, with different malaria transmission (Damazin, Kassala, Kosti, and Malakal). RESULTS: Two hundreds and sixty-nine patients completed the 28-day follow-up. On day one, 60 (22.3%) patients were febrile and 15 (5.5%) patients were parasitaemic. On day three, all the patients were afebrile and aparasitaemic. While two patients (0.7%, Kassala) showed late Clinical and Parasitological Failures, the rest (99.3%) of the patients demonstrated Adequate Clinical and Parasitological Response. A gametocytaemia were detected during the follow-up in one patient (0.37%, Kassala). Adverse drug effects were detected in 32 (11.9%) patients CONCLUSION: The study showed that AS plus SP is an effective, safe drug in the treatment of uncomplicated P. falciparum malaria in Sudan

    Zeroing In On the Top Quark, LSP and Scalar Higgs Masses

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    We estimate the top quark, lightest sparticle (LSP) and scalar higgs masses within a supersymmetric grand unified framework in which tanβmt/mb\tan\beta \simeq m_t/m_b and the electroweak symmetry is radiatively broken. The requirement that the calculated bb quark mass lie close to its measured value, together with the cosmological constraint ΩLSP1\Omega_{LSP} \approx 1, fixes the top quark mass to be mt(mt)170±15 GeVm_t(m_t) \approx 170 \pm 15\ GeV. The LSP (of bino purity >98%)\stackrel{_>}{_\sim} 98\%) has mass 200350 GeV\sim 200 - 350\ GeV. In the scalar higgs sector the CP-odd scalar mass mA<220 GeVm_A \stackrel{_<}{_\sim} 220\ GeV. With mA>MZm_A \stackrel{_>}{_\sim} M_Z, as suggested by the decay bsγb \rightarrow s\gamma, we find MZ<mh0(mH0)<140(220) GeVM_Z \stackrel{_<}{_\sim} m_{h^0} (m_{H^0}) \stackrel{_<}{_\sim} 140 (220)\ GeV and 120 GeV<mH±<240 GeV120\ GeV \stackrel{_<}{_\sim} m_{H^\pm} \stackrel{_<}{_\sim} 240\ GeV.Comment: 14 pages in plain LaTeX, BA-93-25, PRL-TH-93/
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