Search results for "Season"

Direct measurement of NO3 radical reactivity in a boreal forest

2018

We present the first direct measurements of NO3 reactivity (or inverse lifetime, s−1) in the Finnish boreal forest. The data were obtained during the IBAIRN campaign (Influence of Biosphere-Atmosphere Interactions on the Reactive Nitrogen budget) which took place in Hyytiälä, Finland during the summer/autumn transition in September 2016. The NO3 reactivity was generally very high with a maximum value of 0.94 s−1 and displayed a strong diel variation with a campaign-averaged nighttime mean value of 0.11 s−1 compared to a daytime value of 0.04 s−1. The highest nighttime NO3 reactivity was accompanied by major depletion of canopy level ozone and was associated with strong temperature inversion…

Mate Sampling and Assessment Procedures in Female Pied Flycatchers (Ficedula hypoleuca)

2010

Models of mate sampling strategies predict that choosiness should decrease throughout the breeding season due to increasing costs of delaying mating. Therefore, individuals who start searching mates relatively late, should spend less time on sampling, and sample fewer candidates compared to early individuals. We observed mate searching behavior of female pied flycatchers (Ficedula hypoleuca) by radio-tracking in study areas with 6–12 unpaired males. Contrary to the prediction, the observed numbers of males sampled by the searching females increased with time, i.e. late arriving females visited more males than early arrivers. However, this seems to be due to more active sampling of males in …

The importance of environmental microbes for Drosophila melanogaster during seasonal macronutrient variability

2021

AbstractExperiments manipulating the nutritional environment and the associated microbiome of animals have demonstrated their importance for key fitness components. However, there is little information on how macronutrient composition and bacterial communities in natural food sources vary across seasons in nature and on how these factors affect the fitness components of insects. In this study, diet samples from an orchard compost heap, which is a natural habitat for many Drosophila species and other arthropods, were collected over 9 months covering all seasons in a temperate climate. We developed D. melanogaster on diet samples and investigated stress resistance and life-history traits as w…

Seasonal cardenolide production and Dop5βr gene expression in natural populations of Digitalis obscura

2004

Productivity variations and seasonal fluctuations of cardenolides have been studied in 10 natural populations of Digitalis obscura distributed in three bioclimatic belts. Main cardenolides in D. obscura plants are those of the series A and such predominance (ca. 80-85%) over the series B metabolites is independent of the population studied or the degree of maturity of the leaves. Primary glycosides represent ca. 50-60% of total cardenolides; this percentage did not vary among populations or with the leaf age but increased in summer and decreased in winter. A correlation analysis between plant biomass and cardenolide content showed a positive relationship of these parameters, which, accordin…

Long-term characterization of trihalomethane levels in drinking water

2010

Water chlorination leads to the formation of trihalomethanes (THM). In this case study, the levels of THM during the chlorination process of the drinking water in Valencia (Spain) were determined over a 12-year period. Different control areas and points were strategically sampled and samples were analyzed by gas chromatography. Temporal tendencies, as well as spatial and seasonal variations, were established. The individual distribution of THM was also evaluated. Factors such as distances from chlorination points and inter-month seasonal distribution, including ambient temperature effect, were assessed. The range of total THM concentrations measured in the water network goes from 4 to 184 µ…

Soil Water Content Diachronic Mapping: An FFT Frequency Analysis of a Temperature–Vegetation Index

2020

Among the indirect estimation approaches of soil water content in the upper layer of the soil, the &ldquo

Seasonal pattern and amplitude: a logical framework to analyse seasonality in tourism. An application to bed occupancy in Sicilian hotels

2011

Many studies have investigated seasonality in tourism in terms of its causes and impacts, from both theoretical and applied perspectives. However, the definition of seasonality and, most of all, its application and measurement have not received the same degree of attention. In recognizing that seasonality has two main facets – pattern and amplitude – this paper critically examines the main seasonality measures proposed in the tourism literature, classifying them according to their properties and their most appropriate use. The framework then proposed is used to analyse a standard and comparable efficiency measure, such as the bed occupancy rate of Sicilian accommodation establishments, pla…

Seasonality in tourism: measures and applications to overnight stays in Sicily

2012

The use of constructed wetlands for the treatment and reuse of urban wastewater for the irrigation of two warm-season turfgrass species under Mediter…

2017

Constructed wetlands (CWs) represent low-cost technology for the treatment and reuse of wastewater in urban areas. This study aimed to evaluate the pollutant removal efficiency of a CW system and to assess the effects of irrigation using treated urban wastewater on soil and on two warm-season turf species. The research was carried out in Sicily (Italy) on a pilot-scale horizontal subsurface flow system which was fed with treated urban wastewater following secondary treatment from an activated-sludge wastewater treatment plant. The pilot system was located in an open urban park and comprised two separate parallel planted units. Experimental fields of Cynodon dactylon (L.) Pers. and Paspalum …

SINGLE FACTOR STOCHASTIC MODELS WITH SEASONALITY APPLIED TO UNDERLYING WEATHER DERIVATIVES VARIABLES

2003

This paper estimates single factor stochastic models describing daily air temperature behaviour. We modify classical financial models to reflect temperature seasonality and fit them to a time series representing temperatures in Spain. The estimated models are used in Montecarlo simulations to obtain heating and cooling degree-days, which are used as an underlying reference in weather derivatives. The final goal of this work is to obtain an insight into weather derivative valuation, and so making it easier to manage economic activity risks closely related to temperature (i.e. oil, gas and electricity prices and volumes). En este trabajo se estiman modelos estocásticos unifactoriales que desc…