Energy and land use in the Pamir-Alai Mountains

In a comparative study of energy resources and energy consumption patterns in the Pamir-Alai Mountains of Kyrgyzstan and Tajikistan, the relations between energy consumption, land use, and livelihoods were investigated. An approach that presents energy flow through an ecosystem was developed, in particular to highlight ecosystem services and the scope of action for human interventions in the energy-land management nexus. Qualitative data were collected during a field study in October 2009 through household interviews and group discussions. Based on the relationship between energy supply and ecosystem services, typical village profiles depicting the flows of energy and financial assets are presented that illustrate the relation between energy resources, land use, and livelihood assets. The household interviews reflect situations in the different villages and allow a distinction to be made between the energy consumption patterns of poor and wealthier families. This case study in the Pamir-Alai Mountains emphasizes that a reappraisal of energy as a central focus within mountain ecosystems and their services to the population is necessary for both ecosystem preservation and poverty reduction

Magnetoasymmetric transport in a mesoscopic interferometer: From the weak to the strong coupling regime

The microreversibility principle implies that the conductance of a two-terminal Aharonov-Bohm interferometer is an even function of the applied magnetic flux. Away from linear response, however, this symmetry is not fulfilled and the conductance phase of the interferometer when a quantum dot is inserted in one of its arms can be a continuous function of the bias voltage. Such magnetoasymmetries have been investigated in related mesoscopic systems and arise as a consequence of the asymetric response of the internal potential of the conductor out of equilibrium. Here we discuss magnetoasymmetries in quantum-dot Aharonov-Bohm interferometers when strong electron-electron interactions are taken into account beyond the mean-field approach. We find that at very low temperatures the asymmetric element of the differential conductance shows an abrupt change for voltages around the Fermi level. At higher temperatures we recover a smooth variation of the magnetoasymmetry as a function of the bias. We illustrate our results with the aid of the electron occupation at the dot, demonstrating that its nonequilibrium component is an asymmetric function of the flux even to lowest order in voltage. We also calculate the magnetoasymmetry of the current-current correlations (the noise) and find that it is given, to a good extent, by the magnetoasymmetry of the weakly nonlinear conductance term. Therefore, both magnetoasymmetries (noise and conductance) are related to each other via a higher-order fluctuation-dissipation relation. This result appears to be true even in the low temperature regime, where Kondo physics and many-body effects dominate the transport properties.Comment: 17 pages, 9 figure

Type IIP supernova light curves affected by the acceleration of red supergiant winds

We introduce the first synthetic light-curve model set of Type IIP supernovae exploded within circumstellar media in which the acceleration of the red supergiant winds is taken into account. Because wind acceleration makes the wind velocities near the progenitors low, the density of the immediate vicinity of the red supergiant supernova progenitors can be higher than that extrapolated by using a constant terminal wind velocity. Therefore, even if the mass-loss rate of the progenitor is relatively low, it can have a dense circumstellar medium at the immediate stellar vicinity and the early light curves of Type IIP supernovae are significantly affected by it. We adopt a simple beta velocity law to formulate the wind acceleration. We provide bolometric and multicolor light curves of Type IIP supernovae exploding within such accelerated winds from the combinations of three progenitors, 12 - 16 Msun; five beta, 1-5; seven mass-loss rates, 1e-5 - 1e-2 Msun/yr; and four explosion energies, 0.5e51 - 2e51 erg. All the light curve models are available at https://goo.gl/o5phYb. When the circumstellar density is sufficiently high, our models do not show a classical shock breakout as a consequence of the interaction with the dense and optically-thick circumstellar media. Instead, they show a delayed 'wind breakout', substantially affecting early light curves of Type IIP supernovae. We find that the mass-loss rates of the progenitors need to be 1e-3 - 1e-2 Msun/yr to explain typical rise times of 5 - 10 days in Type IIP supernovae assuming a dense circumstellar radius of 1e15 cm.Comment: 12 pages, 9 figures, 2 tables, accepted by Monthly Notices of the Royal Astronomical Societ

Current-voltage correlations in interferometers

We investigate correlations of current at contacts and voltage fluctuations at voltage probes coupled to interferometers. The results are compared with correlations of current and occupation number fluctuations at dephasing probes. We use a quantum Langevin approach for the average quantities and their fluctuations. For higher order correlations we develop a stochastic path integral approach and find the generating functions of voltage or occupation number fluctuations. We also derive a generating function for the joint distribution of voltage or occupation number at the probe and current fluctuations at a terminal of a conductor. For energy independent scattering we found earlier that the generating function of current cumulants in interferometers with a one-channel dephasing or voltage probe are identical. Nevertheless, the distribution function for voltage and the distribution function for occupation number fluctuations differ, the latter being broader than that of former in all examples considered here.Comment: 23 pages, 10 figures, minor changes, additional appendix, added reference

Precision preparation of strings of trapped neutral atoms

We have recently demonstrated the creation of regular strings of neutral caesium atoms in a standing wave optical dipole trap using optical tweezers [Y. Miroshnychenko et al., Nature, in press (2006)]. The rearrangement is realized atom-by-atom, extracting an atom and re-inserting it at the desired position with sub-micrometer resolution. We describe our experimental setup and present detailed measurements as well as simple analytical models for the resolution of the extraction process, for the precision of the insertion, and for heating processes. We compare two different methods of insertion, one of which permits the placement of two atoms into one optical micropotential. The theoretical models largely explain our experimental results and allow us to identify the main limiting factors for the precision and efficiency of the manipulations. Strategies for future improvements are discussed.Comment: 25 pages, 18 figure

Adiabatic Quantum State Manipulation of Single Trapped Atoms

We use microwave induced adiabatic passages for selective spin flips within a string of optically trapped individual neutral Cs atoms. We position-dependently shift the atomic transition frequency with a magnetic field gradient. To flip the spin of a selected atom, we optically measure its position and sweep the microwave frequency across its respective resonance frequency. We analyze the addressing resolution and the experimental robustness of this scheme. Furthermore, we show that adiabatic spin flips can also be induced with a fixed microwave frequency by deterministically transporting the atoms across the position of resonance.Comment: 4 pages, 4 figure

Difference Equations and Highest Weight Modules of U_q[sl(n)]

The quantized version of a discrete Knizhnik-Zamolodchikov system is solved by an extension of the generalized Bethe Ansatz. The solutions are constructed to be of highest weight which means they fully reflect the internal quantum group symmetry.Comment: 9 pages, LaTeX, no figure

The Computational Power of Beeps

In this paper, we study the quantity of computational resources (state machine states and/or probabilistic transition precision) needed to solve specific problems in a single hop network where nodes communicate using only beeps. We begin by focusing on randomized leader election. We prove a lower bound on the states required to solve this problem with a given error bound, probability precision, and (when relevant) network size lower bound. We then show the bound tight with a matching upper bound. Noting that our optimal upper bound is slow, we describe two faster algorithms that trade some state optimality to gain efficiency. We then turn our attention to more general classes of problems by proving that once you have enough states to solve leader election with a given error bound, you have (within constant factors) enough states to simulate correctly, with this same error bound, a logspace TM with a constant number of unary input tapes: allowing you to solve a large and expressive set of problems. These results identify a key simplicity threshold beyond which useful distributed computation is possible in the beeping model.Comment: Extended abstract to appear in the Proceedings of the International Symposium on Distributed Computing (DISC 2015

Influence of the season on the salicylate and phenolic glycoside contents in the bark of Salix daphnoides, Salix pentandra, and Salix purpurea

Due to the benefits of herbal medicine and their wide range of application for human health, the usage of natural drug products, such as willow bark extract, has increased in the last few years. The principle active compounds of the drugs comprised primarily of willow bark are phenolic glycosides like salicylates. Phenolic glycoside profiles of bark vary among species and between the seasons. To identify and preserve willow clones with high salicylate content for possible commercial usage at a later stage, we have screened three Salix sp. in respect to their chemical profiles. The willow species analysed were: Salix daphnoides, Salix pentandra, and Salix purpurea. These species had distinct phenolic glycoside profiles. The major salicylate of S. daphnoides and S. purpurea clones was salicortin, whereas the main compound of S. pentandra was 2’- O-acetylsalicortin. According to the chemical profiles of 140 clones, seven independent clones of S. daphnoides and S. purpurea as well as four clones of S. pentandra with high phenolic glycoside contents were picked to study seasonal changes in bark chemistry. Overall, the clones of S. daphnoides showed the highest mean salicylate and phenolic glycoside contents, followed by S. pupurea and S. pentandra. The secondary metabolite content of willow bark clones decreased during the vegetative season from March to June 2007 and further from June to July 2007. Our study revealed that for optimum yield of phenolic glycosides the species, the clone, and the time of harvest during the season have to be taken in consideration