Vote buying or (Political) business (cycles) as usual?

We report robust evidence of a new short-run monetary election cycle: the monthly growth rate of the money supply (M1) around elections is higher than in other months in a sample of low- and middle-income countries. We hypothesize this is related to systemic vote buying. Consistent with this, we find no cycle in authoritarian countries and countries with strong political institutions and a pronounced cycle in elections where international election monitors reported vote buying or in close elections. Using survey data on daily consumer expenditures, we show that within-household consumption of food increases in the days before elections. </jats:p

Local density of states of chiral Hall edge states in gyrotropic photonic clusters

We have constructed the Green's tensor for two-dimensional gyrotropic photonic clusters and have calculated their optical local density of states (LDOS). For clusters that support the chiral Hall edge states we calculate the LDOS as a function of wavele

Modal Analysis Of Enhanced Absorption In Silicon Nanowire Arrays

We analyze the absorption of solar radiation by silicon nanowire arrays, which are being considered for photovoltaic applications. These structures have been shown to have enhanced absorption compared with thin films, however the mechanism responsible for this is not understood. Using a new, semi-analytic model, we show that the enhanced absorption can be attributed to a few modes of the array, which couple well to incident light, overlap well with the nanowires, and exhibit strong Fabry-Perot resonances. For some wavelengths the absorption is further enhanced by slow light effects. We study the evolution of these modes with wavelength to explain the various features of the absorption spectra, focusing first on a dilute array at normal incidence, before generalizing to a dense array and off-normal angles of incidence. The understanding developed will allow for optimization of simple SiNW arrays, as well as the development of more advanced designs

Absorption enhancing proximity effects in aperiodic nanowire arrays

Aperiodic Nanowire (NW) arrays have higher absorption than equivalent periodic arrays, making them of interest for photovoltaic applications. An inevitable property of aperiodic arrays is the clustering of some NWs into closer proximity than in the equi

Modes of random lasers

In conventional lasers, the optical cavity that confines the photons also determines essential characteristics of the lasing modes such as wavelength, emission pattern, directivity, and polarization. In random lasers, which do not have mirrors or a well-defined cavity, light is confined within the gain medium by means of multiple scattering. The sharp peaks in the emission spectra of semiconductor powders, first observed in 1999, has therefore lead to an intense debate about the nature of the lasing modes in these so-called lasers with resonant feedback. We review numerical and theoretical studies aimed at clarifying the nature of the lasing modes in disordered scattering systems with gain. The past decade has witnessed the emergence of the idea that even the low-Q resonances of such open systems could play a role similar to the cavity modes of a conventional laser and produce sharp lasing peaks. We focus here on the nearthreshold single-mode lasing regime where nonlinear effects associated with gain saturation and mode competition can be neglected.We discuss in particular the link between random laser modes near threshold and the resonances or quasi-bound (QB) states of the passive system without gain. For random lasers in the localized (strong scattering) regime, QB states and threshold lasing modes were found to be nearly identical within the scattering medium. These studies were later extended to the case of more lossy systems such as random systems in the diffusive regime, where it was observed that increasing the openness of such systems eventually resulted in measurable and increasing differences between quasi-bound states and lasing modes. Very recently, a theory able to treat lasers with arbitrarily complex and open cavities such as random lasers established that the threshold lasing modes are in fact distinct from QB states of the passive system and are better described in terms of a new class of states, the so-called constant-flux states. The correspondence between QB states and lasing modes is found to improve in the strong scattering limit, confirming the validity of initial work in the strong scattering limit. © 2010 Optical Society of America

Direct CP-asymmetry in Inclusive Rare B-decays in 2HDM

The direct CP-asymmetry in the inclusive $B \to X_d \gamma$ and $B \to X_d e^+ e^ -$ decays is investigated in the two-Higgs doublet extension of the Standard Model (2HDM). The investigation is performed in the lowest non-vanishing order of the perturbation theory using the existing restrictions on the 2HDM parameters space. It is shown that the direct CP-asymmetry in the $B \to X_d \gamma$ decay can deviate significantly from the Standard Model predictions. In the presence of only one source of CP-violation (the CKM matrix weak phase) $a_{CP}(B \to X_d \gamma)$ can have the sign opposite to that in the SM. The new source of CP-violation can make $|a_{CP}(B \to X_d \gamma)|$ arbitrary small (unlike the SM case) and hence unmeasurable. Quantitatively, the obtained results suffer from the uncertainty of the choice of renormalization scale. As for the $B \to X_d e^+ e^ -$ rate asymmetry, its renormalization scale dependence in the lowest non-vanishing order does not allow to conclude if this quantity is efficient for testing New Physics beyond the Standard Model.Comment: 16 pages including 2 figure

b→sγb \to s \gamma Decay in SU(2)L×SU(2)R×U(1)SU(2)_L \times SU(2)_R \times U(1) Extensions of the Standard Model

The rare radiative decay $b \to s \gamma$ is studied in $SU(2)_L \times SU(2)_R \times U(1)$ extensions of the Standard Model. Matching conditions for coefficients of operators appearing in the low energy effective Hamiltonian for this process are derived, and QCD corrections to these coefficients are analyzed. The $b \to s \gamma$ decay rate is then calculated and compared with the corresponding Standard Model result. We find that observable deviations from Standard Model predictions can occur in $SU(2)_L \times SU(2)_R \times U(1)$ theories for a reasonable range of parameter values.Comment: 17 pages with 5 figures not included but available upon request, CALT-68-1893, TUM-T31-52/9

Pharmacological insights into the role of P2X4 receptors in behavioural regulation: lessons from ivermectin

This is the publisher's version, also available electronically from http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8920271&fileId=S1461145712000909Purinergic ionotropic P2X receptors are a family of cation-permeable channels that bind extracellular adenosine 5′-triphosphate. In particular, convergent lines of evidence have recently highlighted P2X4 receptors as a potentially critical target in the regulation of multiple nervous and behavioural functions, including pain, neuroendocrine regulation and hippocampal plasticity. Nevertheless, the role of the P2X4 receptor in behavioural organization remains poorly investigated. To study the effects of P2X4 activation, we tested the acute effects of its potent positive allosteric modulator ivermectin (IVM, 2.5–10 mg/kg i.p.) on a broad set of paradigms capturing complementary aspects of perceptual, emotional and cognitive regulation in mice. In a novel open field, IVM did not induce significant changes in locomotor activity, but increased the time spent in the peripheral zone. In contrast, IVM produced anxiolytic-like effects in the elevated plus maze and marble burying tasks, as well as depression-like behaviours in the tail-suspension and forced swim tests. The agent induced no significant behavioural changes in the conditioned place preference test and in the novel object recognition task. Finally, the drug induced a dose-dependent decrease in sensorimotor gating, as assessed by pre-pulse inhibition (PPI) of the acoustic startle reflex. In P2X4 knockout mice, the effects of IVM in the open field and elevated plus maze were similar to those observed in wild type mice; conversely, the drug significantly increased startle amplitude and failed to reduce PPI. Taken together, these results suggest that P2X4 receptors may play a role in the regulation of sensorimotor gatin

How do organisms affect and respond to climate change?

Life on Earth is diverse at many levels, meaning there is a lot of variety within species and there are many different kinds of species. This biodiversity provides many of the resources that humans need and enhances our quality of life. All of Earth’s organisms are affected by Earth’s climate, but they also influence Earth’s climate. In this article, we show how research on plants, animals, and microbes helps us better understand how living things can both impact and respond to climate change. This research also gives us insight into what the future might be like for life on Earth. Such knowledge will help us to protect our planet—and the living things on it—from the harmful effects of future climate change