Search results for "DAP"

The effect of spatial and temporal scale on camouflage in North African rodents

2022

Abstract Background matching, a common form of camouflage, is a widespread anti-predator adaptation that hinders detection or recognition by increasing the resemblance of prey to its environment. However, the natural environment is complex and both spatially and temporally variable, which constrains effective background matching as an anti-predator strategy. Here, using remote sensing data (publicly available satellite imagery), we investigated how variation of habitat parameters predicts background matching in 16 Sahara–Sahel rodent species across spatial and temporal scales. All fur colour parameters (hue, saturation and brightness) strongly matched the respective habitats of the differen…

Range expansion to novel environments : evolutionary physiology and genetics in Leptinotarsa decemlineata

2010

Eco-physiological aspects of adaptation to seasonal environments : the latitudinal range expansion of the Colorado potato beetle across Europe

2013

Putative sorting signals involved in PIN1 trafficking

2013

Las auxinas son hormonas vegetales involucradas en muchos procesos fisiológicos, tales como el crecimiento y diferenciación celular, la maduración de los frutos, la floración o los tropismos. Su transporte a través de la planta es polar, jugando un papel esencial en la regulación del crecimiento y el desarrollo y contribuyendo al mantenimiento de la polaridad global de la planta. La polaridad en el flujo de auxinas es debida, al menos en parte, a la distribución polar de los transportadores de salida de auxina de la familia PIN. En Arabidopsis thaliana se han identificado 8 transportadores PIN diferentes. Todos ellos presentan una estructura similar, con un dominio citosólico central que se…

Effect of Cycloplegia on Blur Perception Thresholds as Measured by Source Method

2017

Abstract One of the advantages of a source method over observer method in blur perception measurements is better control of a stimulus blur level, which is achieved with computerised image processing unlike the observer method that requires optical defocusing of the observer. The aim of this study was to determine if paralysation of accommodation has effect on blur perception thresholds, thereby evaluating its necessity in such experiments. Blur perception thresholds (just noticeable blur, clear image, recognition, and non-resolvable blur thresholds) were evaluated with (using cycloplegia) and without paralysed accommodation to determine effect on blur perception. A computerised low-pass sp…

ANCESTRALITY OR MORPHOLOGICAL CONVERGENCE IN THE MOLLISSIMA AND ITALICA GROUPS OF SILENE IN THE WESTERN MEDITERRANEAN BASIN

2010

Adaptation to stressful environments : invasion success of the Colorado potato beetle (Leptinotarsa decemlineata)

2018

Biological invasions, specifically human-induced dispersals, are one of the major threats to our biodiversity and are predicted to increase. Invasive pests provide an opportunity to study whether adaptation to human-induced environments could promote invasions to other human-induced environments. One major anthropogenic selection pressure is created by pesticides, and pests can be exposed to various pesticides in their native, as well as introduced, ranges. I investigated whether exposure to anthropogenic selection (i.e. insecticides and herbicides) and exposure to multiple anthropogenic stressors selects for higher stress tolerance. I also tested whether parental prolonged diapause or inse…

Impact of Structural, Photochemical and Instrumental Effects on Leaf and Canopy Reflectance Variability in the 500–600 nm Range

2021

Current rapid technological improvement in optical radiometric instrumentation provides an opportunity to develop innovative measurements protocols where the remote quantification of the plant physiological status can be determined with higher accuracy. In this study, the leaf and canopy reflectance variability in the PRI spectral region (i.e., 500–600 nm) is quantified using different laboratory protocols that consider both instrumental and experimental set-up aspects, as well as canopy structural effects and vegetation photoprotection dynamics. First, we studied how an incorrect characterization of the at-target incoming radiance translated into an erroneous vegetation reflectance spectru…

Can the adaptive Metropolis algorithm collapse without the covariance lower bound?

2011

The Adaptive Metropolis (AM) algorithm is based on the symmetric random-walk Metropolis algorithm. The proposal distribution has the following time-dependent covariance matrix at step $n+1$ \[ S_n = Cov(X_1,...,X_n) + \epsilon I, \] that is, the sample covariance matrix of the history of the chain plus a (small) constant $\epsilon>0$ multiple of the identity matrix $I$. The lower bound on the eigenvalues of $S_n$ induced by the factor $\epsilon I$ is theoretically convenient, but practically cumbersome, as a good value for the parameter $\epsilon$ may not always be easy to choose. This article considers variants of the AM algorithm that do not explicitly bound the eigenvalues of $S_n$ away …

Global climate policies, local institutions and food security in a pastoral society in Ethiopia

2011

This paper explores climate change adaptation within national policy priorities in a least developed country (LDC). The premise of the article is that when considering food security, climate is an exogenous trigger, while the deeper causes lie in social problems. Therefore, adaptation is subordinate to poverty alleviation. The paper examines how these two goals, climate adaptation and poverty alleviation, can be combined. Recent studies have shown that the most effective way to adapt to changing climate conditions in a poor country is to rely on local institutions that have established and sustainable mechanisms to deal with extreme climatic conditions. This research analyzes the stakeholde…