We study the Gauss-Bonnet (GB) term as the leading higher-curvature correction to pure Einstein gravity. Assuming a tree-level ultraviolet completion free of ghosts or tachyons, we prove that the GB term has a nonnegative coefficient in dimensions greater than 4. Our result follows from unitarity of the spectral representation for a general ultraviolet completion of the GB term.

Introduction: Duration of untreated periods (DUP) is one of the most important predictors of treatment outcome, prognosis of psychotic disorder. Also, most neuroimaging studies have investigated the gray matter changes and less attention has been paid to white matter. The object of this study is to focused on the microstructural integrity of more short DUP (<1000days) in a relatively large samp...

Introduction: Duration of untreated periods (DUP) is one of the most important predictors of treatment outcome, prognosis of psychotic disorder. Also, most neuroimaging studies have investigated the gray matter changes and less attention has been paid to white matter. The object of this study is to focused on the microstructural integrity of more short DUP (<1000days) in a relatively large samp...

for the first time, potentilla balansae sojak. and potentilla radiata lehm. are reported from north and northeast of iran. potentilla balansae pesmen is akin to p. anatolica and p. umbrosa but differs from both in its smaller petals, fewer tooted leaflets and usually subpinnate leaves. potentilla radiata lehm., is a hybrid species in origin, (p. argentea 㗠p. thuringiaca ). the photographs of ...

medicago spp. is the most important forage crop in many regions of the world.annual medics have distinct advantages over perennial medicago. these species have fastergrowth rate in cultivation year, higher crude protein percentage, tolerance to pests and morevigorous seedlings. morphological and physical aspects of pod and seeds of annual medicsplay a major role in the tolerance of the plants t...

Medicago spp. is the most important forage crop in many regions of the world.Annual medics have distinct advantages over perennial Medicago. These species have fastergrowth rate in cultivation year, higher crude protein percentage, tolerance to pests and morevigorous seedlings. Morphological and physical aspects of pod and seeds of annual medicsplay a major role in the tolerance of the plants t...

INTRODUCTION Treatment of osteoporosis, in addition to a specific antiresorptive or anabolic treatment, requires supplementation with calcium and vitamin D. Widespread cultivation of pearl shells has made pearls available for commercial use for a very reasonable price. The main chemical compound of pearls from shells Pinctada maxima is calcium-carbonate (CaCO3). Recently developed technologies ...

PURPOSE To determine whether corneal sensitivity is different between the two genders. METHODS Corneal sensitivity of 130 normal volunteers, including 77 women and 53 men aged 20-35 years, with no history of previous ocular surgery was measured using the Cochet-Bonnet esthesiometer. Measurements were done on five corneal regions: central, nasal, inferior, temporal and superior. The findings w...

Laplace operators perturbed by meromorphic potential on the Riemann and separated type Klein surfaces are constructed and their indices are calculated by two different ways. The topological expressions for the indices are obtained from the study of spectral properties of the operators. Analytical expressions are provided by the Heat Kernel approach in terms of the functional integrals. As a res...