A Case Where Barro Expectations Are Not Rational

This note generalizes Feldstein’s (1976) criticism of Barro’s(1974) analysis for the case that the interest rate exceeds the growth rate. This is done by considering an economy in steady state where all agents hold “Barro expectations”: they believe that government debt must necessarily be repaid and therefore leave the present value of their income streams unchanged. In this scenario, a change in the mode of taxation affects the present value of disposable income in the private sector. This violates their Barro expectations

The role of nitric oxide in the interaction of Arabidopsis thaliana with the biotrophic fungi, Golovinomyces orontii and Erysiphe pisi

Powdery mildews are a diverse group of pathogenic fungi that can infect a large number of plant species, including many economically important crops. However, basic and applied research on these devastating diseases has been hampered by the obligate biotrophic lifestyle of the pathogens, which require living host cells for growth and reproduction, and lacking genetic and molecular tools for important host plants. The establishment of Arabidopsis thaliana as a host of different powdery mildew species allowed pursuing new strategies to study the molecular mechanisms governing these complex plant–pathogen interactions. Nitric oxide (NO) has emerged as an important signaling molecule in plants, which is produced upon infection and involved in activation of plant immune responses. However, the source and pathway of NO production and its precise function in the regulatory network of reactions leading to resistance is still unknown. We studied the response of Arabidopsis thaliana to infection with the adapted powdery mildew, Golovinomyces orontii (compatible interaction) and the non-adapted, Erysiphe pisi (incompatible interaction). We observed that NO accumulated rapidly and transiently at infection sites and we established a correlation between the resistance phenotype and the amount and timing of NO production. Arabidopsis mutants with defective immune response accumulated lower NO levels compared to wild type. Conversely, increased NO levels, generated by treatment with chemicals or expression of a NO-synthesizing enzyme, resulted in enhanced resistance, but only sustained NO production prevented excessive leaf colonization by the fungus, which was not achieved by a short NO burst although this reduced the initial penetration success. By contrast, lowered NO levels did not impair the ultimate resistance phenotype. Although our results suggest a function of NO in mediating plant immune responses, a direct impact on pathogen growth and development cannot be excluded

The measure and significance of Bateman's principles

Bateman's principles explain sex roles and sexual dimorphism through sex-specific variance in mating success, reproductive success and their relationships within sexes (Bateman gradients). Empirical tests of these principles, however, have come under intense scrutiny. Here, we experimentally show that in replicate groups of red junglefowl, Gallus gallus, mating and reproductive successes were more variable in males than in females, resulting in a steeper male Bateman gradient, consistent with Bateman's principles. However, we use novel quantitative techniques to reveal that current methods typically overestimate Bateman's principles because they (i) infer mating success indirectly from offspring parentage, and thus miss matings that fail to result in fertilization, and (ii) measure Bateman gradients through the univariate regression of reproductive over mating success, without considering the substantial influence of other components of male reproductive success, namely female fecundity and paternity share. We also find a significant female Bateman gradient but show that this likely emerges as spurious consequences of male preference for fecund females, emphasizing the need for experimental approaches to establish the causal relationship between reproductive and mating success. While providing qualitative support for Bateman's principles, our study demonstrates how current approaches can generate a misleading view of sex differences and roles

Explaining Africa’s public consumption procyclicality : revisiting old evidence

This paper compiles a novel dataset of time-varying measures of government consumption cyclicality for a panel of 46 African economies between 1960 and 2014. Government consumption has, generally, been highly procyclical over time in this group of countries. However, sample averages hide serious heterogeneity across countries with the majority of them showing procyclical behavior despite some positive signs of graduation from the “procyclicality trap” in a few cases. By means of weighted least squares regressions, we find that more developed African economies tend to have a smaller degree of government consumption procyclicality. Countries with higher social fragmentation and those are more reliant on foreign aid inflows tend to have a more procyclical government consumption policy. Better governance promotes counter- cyclical fiscal policy whileincreased democracy dampens it. Finally, some fiscal rules are important in curbing the procyclical behavior of government consumption.info:eu-repo/semantics/publishedVersio

Excited by a quantum field: Does shape matter?

The instantaneous transition rate of an arbitrarily accelerated Unruh-DeWitt particle detector on four-dimensional Minkowski space is ill defined without regularisation. We show that Schlicht's regularisation as the zero-size limit of a Lorentz-function spatial profile yields a manifestly well-defined transition rate with physically reasonable asymptotic properties. In the special case of stationary trajectories, including uniform acceleration, we recover the results that have been previously obtained by a regularisation that relies on the stationarity. Finally, we discuss evidence for the conjecture that the zero-size limit of the transition rate is independent of the detector profile.Comment: 7 pages, uses jpconf. Talk given at NEB XII (Nafplio, Greece, 29 June - 2 July 2006

Localised projective measurement of a relativistic quantum field in non-inertial frames

We propose a scheme to study the effect of motion on measurements of a quantum field carried out by a finite-size detector. We introduce a model of projective detection of a localised field mode in an arbitrary reference frame. We apply it to extract vacuum entanglement by a pair of counter-accelerating detectors and to estimate the Unruh temperature of a single accelerated detector. The introduced method allows us to directly relate the observed effects with the instantaneous proper acceleration of the detector.Comment: 5 pages, 2 figures. v2 Significant increase in the detail level regarding the motivation of the detector mode

How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile

We analyse within first-order perturbation theory the instantaneous transition rate of an accelerated Unruh-DeWitt particle detector whose coupling to a massless scalar field on four-dimensional Minkowski space is regularised by a spatial profile. For the Lorentzian profile introduced by Schlicht, the zero size limit is computed explicitly and expressed as a manifestly finite integral formula that no longer involves regulators or limits. The same transition rate is obtained for an arbitrary profile of compact support under a modified definition of spatial smearing. Consequences for the asymptotic behaviour of the transition rate are discussed. A number of stationary and nonstationary trajectories are analysed, recovering in particular the Planckian spectrum for uniform acceleration.Comment: 30 pages, 1 figure. v3: Added references and minor clarification

Selection Wages and Discrimination

Applicants for any given job are more or less suited to fill it, and the firm will select the best among them. Increasing the wage offer attracts more applicants and makes it possible to raise the hiring standard and improve the productivity of the staff. Wages that optimize on the trade-off between the wage level and the productivity of the workforce are known as selection wages. As men react more strongly to wage differentials than females, the trade-off is more pronounced for men and a profit-maximizing firm will offer a higher wage for men than for women in equilibrium

Transition rate of the Unruh-DeWitt detector in curved spacetime

We examine the Unruh-DeWitt particle detector coupled to a scalar field in an arbitrary Hadamard state in four-dimensional curved spacetime. Using smooth switching functions to turn on and off the interaction, we obtain a regulator-free integral formula for the total excitation probability, and we show that an instantaneous transition rate can be recovered in a suitable limit. Previous results in Minkowski space are recovered as a special case. As applications, we consider an inertial detector in the Rindler vacuum and a detector at rest in a static Newtonian gravitational field. Gravitational corrections to decay rates in atomic physics laboratory experiments on the surface of the Earth are estimated to be suppressed by 42 orders of magnitude.Comment: 27 pages, 1 figure. v3: Typos corrected. Published versio

Mental health academics in rural and remote Australia

Context: The significant impact of mental ill health in rural and remote Australia has been well documented. Included among innovative approaches undertaken to address this issue has been the Mental Health Academic (MHA) project, established in 2007. Funded by the Australian Government (Department of Health), this project was established as a component of the University Departments of Rural Health (UDRH) program. All 11 UDRHs appointed an MHA. Although widely geographically dispersed, the MHAs have collaborated in various ways. The MHA project encompasses a range of activities addressing four key performance indicators. These activities, undertaken in rural and remote Australia, aimed to increase access to mental health services, promote awareness of mental health issues, support students undertaking mental health training and improve health professionals' capacity to recognise and address mental health issues. MHAs were strategically placed within the UDRHs across the country, ensuring an established academic base for the MHAs' work was available immediately. Close association with each local rural community was recognised as important. For most MHAs this was facilitated by having an established clinical role in their local community and actively engaging with the community in which they worked. In common with other rural health initiatives, some difficulties were experienced in the recruitment of suitable MHAs, especially in more remote locations. The genesis of this article was a national meeting of the MHAs in 2014, to identify and map the different types of activities MHAs had undertaken in their regions. These activities were analysed and categorised by the MHAs. These categories have been used as a guiding framework for this article. Issues: The challenge to increase community access to mental health services was addressed by (i) initiatives to address specific access barriers, (ii) supporting recruitment and retention of rural mental health staff, (iii) developing the skills of the existing workforce and (iv) developing innovative approaches to student placements. Strategies to promote awareness of mental health issues included workshops in rural and remote communities, specific suicide prevention initiatives and targeted initiatives to support the mental health needs of Indigenous Australians. The need for collaboration between the widely dispersed MHAs was identified as important to bridge the rural divide, to promote project cohesiveness and ensure new ideas in an emerging setting are readily shared and to provide professional support for one another as mental health academics are often isolated from academic colleagues with similar mental health interests. Lessons learned: The MHA project suggests that an integrated approach can be taken to address the common difficulties of community awareness raising of mental health issues, increasing access to mental health services, workforce recruitment and retention (access), and skill development of existing health professionals (access and awareness). To address the specific needs and circumstances of their community, MHAs have customised their activities. As in other rural initiatives, one size was found not to fit all. The triad of flexibility, diversity and connectedness (both to local community and other MHAs) describes the response identified as appropriate by the MHAs. The breadth of the MHA role to provide university sponsored educational activities outside traditional student teaching meant that the broader health workforce benefited from access to mental health training that would not otherwise have occurred. Provision of these additional educational opportunities addressed not only the need for increased education regarding mental health but also reduced the barriers commonly faced by rural health professionals in accessing quality professional development