A Two-Singlet Model for Light Cold Dark Matter

We extend the Standard Model by adding two gauge-singlet $\mathbb{Z}_{2}$% -symmetric scalar fields that interact with visible matter only through the Higgs particle. One is a stable dark matter WIMP, and the other one undergoes a spontaneous breaking of the symmetry that opens new channels for the dark matter annihilation, hence lowering the mass of the WIMP. We study the effects of the observed dark matter relic abundance on the annihilation cross section and find that in most regions of the parameters space, light dark matter is viable. We also compare the elastic scattering cross-section of our dark matter candidate off nucleus with existing (CDMSII and XENON100) and projected (SuperCDMS and XENON1T) experimental exclusion bounds. We find that most of the allowed mass range for light dark matter will be probed by the projected sensitivity of XENON1T experiment.Comment: 30 pages, 17 figure

Exact relativistic beta decay endpoint spectrum

The exact relativistic form for the beta decay endpoint spectrum is derived and presented in a simple factorized form. We show that our exact formula can be well approximated to yield the endpoint form used in the fit method of the KATRIN collaboration. We also discuss the three neutrino case and how information from neutrino oscillation experiments may be useful in analyzing future beta decay endpoint experiments.Comment: 12 pages, 3 figure

Perspectives on next steps in classification of oro-facial pain - Part 3: biomarkers of chronic oro-facial pain - from research to clinic

The purpose of this study was to review the current status of biomarkers used in oro-facial pain conditions. Specifically, we critically appraise their relative strengths and weaknesses for assessing mechanisms associated with the oro-facial pain conditions and interpret that information in the light of their current value for use in diagnosis. In the third section, we explore biomarkers through the perspective of ontological realism. We discuss ontological problems of biomarkers as currently widely conceptualised and implemented. This leads to recommendations for research practice aimed to a better understanding of the potential contribution that biomarkers might make to oro-facial pain diagnosis and thereby fulfil our goal for an expanded multidimensional framework for oro-facial pain conditions that would include a third axis

Low power GaAs digital and analog functionalities for microwave signal conditioning in AESA systems

A MMIC demonstrator for RF phase and amplitude control with on board 18-bit serial to parallel conversion (Multi-Functional Chip) is presented. Thanks to an alternative digital building block topology, the DC power consumption of the digital serial to parallel converter is noteworthy: less than 43 mW (2 mW/bit). The main RF performances are 0° - 360° phase coverage and 0 dB - 31.5 dB attenuation setting, in the 7.6 GHz - 9.1 GHz operating bandwidth. The circuit, whose area is 6 mm2, is realised in an industrial and commercially available GaAs technology. This component can be used in active electronically scanned arrays for beam steering

Tocotrienol-rich fraction supplementation modulates antioxidant enzymes activity and reduces DNA damage in APPswe/PS1dE9 Alzheimer’s Disease Mouse Model

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by deterioration of the brain functions that result in impairment of memory, cognition and behavioural functions. Oxidative stress is well known to be one of the causative factors for AD. Thus this disease is potentially modulated by natural antioxidants such as vitamin E. The aim of this study was to evaluate the effect of tocotrienol-rich fraction (TRF) supplementation on antioxidant enzymes and DNA damage using APPswe/PS1dE9 transgenic mouse model of AD. Animals were supplemented with TRF (200 mg/kg) or alpha-tocopherol (αT) (200 mg/kg) for six months starting from nine months old. We found that superoxide dismutase (SOD) activity in AD mouse was decreased by supplementation of TRF and αT as compared with AD control mouse with no significant differences in glutathione peroxidise (GPx) activity in all groups. TRF supplementation significantly increased catalase (CAT) activity. The level of DNA damage of AD mouse shows significant decrease with supplementation of TRF and αT. In conclusion, TRF was able to modulate antioxidant enzymes activity and decreased the level of DNA damage of AD transgenic mouse model

Salt effect on physiological, biochemical and anatomical structures of two Origanum majorana varieties (Tunisian and Canadian)

In this study, we evaluated the salt concentration effect on plant growth, mineral composition, antioxidant responses and anatomical structure of two varieties of Origanum majorana after exposure to NaCl treatment. Our results show an inclusive behaviour of the two varieties, since the majority of sodium was exported and accumulated in their aerial parts. The Canadian variety (CV) appeared relatively more tolerant to salt than the Tunisian one (TV). Transversal section of leaves showed a thickening of dorsal and ventral cuticle, more importantly in CV than in TV, in the presence and in absence of salt. This was accompanied by an increase in the length of palisade cells, and the width of spongy collenchyma lacuna. The stem had a subquadrangular shape in TV and quadrangular in the Canadian variety. At mature stage, the stem pit was reabsorbed in the TV and replaced by a large cavity, whereas it remained unchanged in CV. The relative salt tolerance of the CV was related to: (1) a good selectivity in favour of K+: (2) a strong peroxidase activity and (3) an increase in the lengthening of palisade cell accompanied with an increase of lacunae in spongy parenchyma in CV.Key words: Origanum majorana, salinity, growth, mineral nutrition, leaves, stems, anatomical, antioxidant

Lowering solar mixing angle in inverted hierarchy without charged lepton corrections

In the present work, the inverted hierarchical neutrino mass model which is characterised by opposite CP parity in the first two mass eigenvalues $(m_1,-m_2,m_3)$, is studied in order to lower the predicted value of solar mixing angle $\tan^2\theta_{12}$, from the tri-bimaximal mixing (TBM), without sacrificing the conditions of maximal atmospheric mixing angle and zero reactor angle. The present attempt is different from the earlier approach where the correction from the charged lepton mass matrix is included in the leptonic mixing matrix to lower the prediction on solar mixing angle. The lowering of the solar mixing angle without charged lepton correction, can be obtained through the variation of the input value of a flavour twister term present in the texture of neutrino mass matrix having a 2-3 symmetry. The present analysis agrees with the latest experimental bounds on neutrino mass parameters and also represents an important result on the survival of the inverted hierarchical neutrino mass models having opposite CP parity in the first two eigenvalues.Comment: 10 pages, two figures. Accepted for publication in Journal of Physics G:Nuclear and Particle Physic

Physiological and structural modifications in snail medic (Medicago scutellata L.) plants exposed to salinity

Seeds of snail medic (Medicago scutellata L.) were assessed for their response to salt at the germination and seedling stages. NaCl at concentrations 86 and 170 mM decreased the final germination percentage. Embryonic axis length, water content and dry weight of embryonic axis and cotyledons were also reduced by salt treatment. Furthermore, 28-d-old plants were grown hydroponically with different NaCl concentrations (0, 86 and 170 mM). After 7 days of treatment, growth, water content and development of the different organs of M. scutellata plant were affected especially at the highest NaCl concentration (170 mM). However, NaCl did not affect root length and the number of stem shoots but reduced stem length and total leaf area. Salt treatment increased markedly the concentration of Na+ in leaf and root tissues while reduced that of K+ only in root and stem tissues. Lipid peroxidation revealed the damage of the membranes of roots and leaves. Moreover, showed a more intense suberization and lignification at the cambial zone of roots of M. scutellata, were observed under the effect of NaCl

Anisotropic Inflation and the Origin of Four Large Dimensions

In the context of (4+d)-dimensional general relativity, we propose an inflationary scenario wherein 3 spatial dimensions grow large, while d extra dimensions remain small. Our model requires that a self-interacting d-form acquire a vacuum expectation value along the extra dimensions. This causes 3 spatial dimensions to inflate, whilst keeping the size of the extra dimensions nearly constant. We do not require an additional stabilization mechanism for the radion, as stable solutions exist for flat, and for negatively curved compact extra dimensions. From a four-dimensional perspective, the radion does not couple to the inflaton; and, the small amplitude of the CMB temperature anisotropies arises from an exponential suppression of fluctuations, due to the higher-dimensional origin of the inflaton. The mechanism triggering the end of inflation is responsible, both, for heating the universe, and for avoiding violations of the equivalence principle due to coupling between the radion and matter.Comment: 24 pages, 2 figures; uses RevTeX4. v2: Minor changes and added references. v3: Improved discussion of slow-rol

Bimaximal mixing from the leptonic new texture for triangular mass matrices

An analysis of the leptonic texture for the new triangular mass matrices has been carried out. In particular, it is shown that both bimaximal and nearly bimaximal solutions for solar and atmospheric neutrino anomalies can be generated within this pattern. We have also derived exact and compact parametrization of the leptonic mixing matrix in terms of the lepton masses and the parameters $\alpha, \beta'$ and $\delta$. A consistency with the CHOOZ reactor result for $V_m{_{13}}$ and a smallness of the Jarlskog's invariant parameter are obtained.Comment: 16 pages, late