Search results for "seasonal"

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

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…

Bleeding Follicular Conjunctivitis due to Influenza H1N1 Virus

2010

Influenza H1N1 or A virus is a new virus serotype capable of human-to-human transmission. This infection causes a flu syndrome similar to that of seasonal influenza, with only one case of conjunctivitis described and no clinical details or microbiological confirmation. Its diagnosis is performed by PCR of pharyngeal smear of the patients affected. We report the first well-documented case in the medical literature of conjunctivitis by H1N1 virus.

Seasonal characterization of nutritional, technological and antioxidant properties of Opuntia ficus-indica Mill. mucilage

2022

Opuntia ficus-indica Mill. fruit and cladodes are a source of mucilage, a carbohydrate complex, as well as of phytochemicals and other nutrients, useful in the food industry. Despite the environmental-based composition variability studied, there is no information on its seasonal variability, which is particularly important for its industrial use. In this study, some technological, nutritional, and bioactive properties of O. ficus-indica Mill. cladodes mucilage were analysed during the seasonal growth period. Total proteins did not change during the whole period and the lipid content significantly decreased from winter to the onset of summer. The fatty acid profile showed high levels of palm…

Seagrass meadows at the extreme of environmental tolerance: the case ofPosidonia oceanicain a semi-enclosed coastal lagoon

2009

Atoll-like structures of the endemic Mediterranean seagrass Posidonia oceanica were encountered in the innermost area of the Stagnone di Marsala, a semi-enclosed coastal lagoon along the western coasts of Sicily. The area is characterized by limited water exchange with the open sea and by a marked seasonal variation of water salinity and temperature, reaching beyond the theoretical tolerance limits of the species. In the present study we determined the genetic composition of the atoll-like structures, as well as the growth performance and flowering rate of these stands. We also assessed whether and to what extent the atoll-like structures are genetically isolated from plants growing in mead…

δ13C and δ15N variability in Posidonia oceanica associated with seasonality and plant fraction

2003

The carbon and nitrogen isotopic compositions of fractions of the seagrass Posidonia oceanica (L.) Delile in a Mediterranean shallow environment (Stagnone di Marsala, western Sicily) were investigated seasonally throughout 1998. The stable isotope ratios of seagrass leaves (intermediate and adult), rhizomes, leaf litter and aegagropiles were compared over 1 year in order to distinguish between seasonal and plant part variability. Significant differences in the isotopic composition tested using ANOVA were observed as a function of both plant fraction and season. There was an overall trend towards less discrimination against 13C in summer (average δ13C ∼ -10‰) than in winter (average δ13C ∼ -…

Seasonal changes in size, sex-ratio and body condition of the damselfishChromis chromisin the central Mediterranean Sea

2014

Chromis chromisis one of the most abundant fish species on the Mediterranean rocky shores. Acting as a by-pass of nutrients from the pelagic to the rocky littoral system, it plays an important role as a resource provider and has a relevant function in the community assemblage.Chromis chromishas many of the characteristics required of an indicator species (e.g. it is easy to recognize in the field, small sized, widespread and abundant). In this study we focused on individual size, sex-ratio and body condition in a damselfish population occurring in a central Mediterranean marine protected area. Fishing trials on a monthly basis (April–November) allowed us to assess seasonal changes in popula…