A review of current status of theoretical paradigm and results of direct and indirect experiments to study cosmic rays through the knee region are presented and discussed. There is general agreement that the knee is around a PeV and that it reflects a rigidity cutoff. The composition of cosmic rays in the knee region is mixed and changing with energy. The two direct experiments, JACEE and RUNJO...

Ecosystem resilience, i.e. an ecosystem’s ability to maintain its basic functions and controls under disturbances, is often interpreted as insurance: by decreasing the probability of future drops in the provision of ecosystem services, resilience insures risk-averse ecosystem users against potential welfare losses. Using a general and stringent definition of ‘insurance’ and a simple ecological-...

The TeV-emitting BL Lac object Mkn 421 was observed with very long baseline interferometry (VLBI) at three closely-spaced epochs one-month apart in March–April 1998. The source was also monitored at very-high γ-ray energies (TeV measurements) during the same period in an attempt to search for correlations between TeV variability and the evolution of the radio morphology on parsec scales. While ...

Scientists express concern about increasing levels of greenhouse gases mainly due to fossil fuel consumption and deforestation. In response to the latter, policy-makers have introduced a range of policy measures to conserve and enhance forest ecosystems for carbon sequestration. The costs for policy measures to maintain ecosystem services can be calculated easily, but especially non-market/non-...

pricing policies play an important role in water demand management and its optimal allocation. determining proper water price leads to optimal allocation of water especially in agricultural consumptions. applying new subsidy targeting law in iran which insists on pricing water based on its supply cost, will effects considerably on water resource management in agriculture sector. so, in this stu...

Non-thermal TeV γ-ray emission within multi-pc scale has been observed from the center region of our galaxy. We argue that these γ-rays are the result of a transient activity of the massive black hole Sgr A which resides at the Galactic center. About thousands of years ago, the black hole may have experienced an active phase by capturing a red giant star and forming an accretion disk, temporari...

Abstract We construct tree-level four-particle open-string amplitudes relevant to dilepton and diphoton production at hadron colliders. We expand the amplitudes into string resonance (SR) contributions and compare the total cross-section through the first SR with the Z ′ search at the Tevatron. We establish a current lower bound based on the CDF Run I results on the string scale to be about 1.1...

The Bialas-Bzdak model of elastic proton-proton scattering assumes a purely imaginary forward scattering amplitude, which consequently vanishes at the diffractive minima. We extended the model to arbitrarily large real parts in a way that constraints from unitarity are satisfied. The resulting model is able to describe elastic pp scattering not only at the lower ISR energies but also at √ s =7 ...

TeV gamma rays emitted by GRBs are converted into electron-positron pairs via interactions with the extragalactic infrared radiation fields. In turn the pairs produced, whose trajectories are randomized by magnetic fields, will inverse Compton scatter off the cosmic microwave background photons. The beamed TeV gamma ray flux from GRBs is thus transformed into a GeV isotropic gamma ray flux, whi...