Search results for "Climatic variables"
showing 10 items of 13 documents
Multiple paths to cold tolerance: the role of environmental cues, morphological traits and the circadian clock gene vrille
2021
AbstractBackgroundTracing the association between insect cold tolerance and latitudinally and locally varying environmental conditions, as well as key morphological traits and molecular mechanisms, is essential for understanding the processes involved in adaptation. We explored these issues in two closely-related species, Drosophila montana and Drosophila flavomontana, originating from diverse climatic locations across several latitudes on the coastal and mountainous regions of North America. We also investigated the association between sequence variation in one of the key circadian clock genes, vrille, and cold tolerance in both species. Finally, we studied the impact of vrille on fly cold…
Wind speed and temperature trends impacts on reference evapotranspiration in Southern Italy
2014
In this study, the impacts of both temperature and wind speed trends on reference evapotranspiration have been assessed using as a case study the Southern Italy, which present a wide variety of combination of such climatic variables trends in terms of direction and magnitude. The existence of statistically significant trends in wind speed and temperature from observational datasets, measured in ten stations over Southern Italy during the period 1968–2004, has been investigated. Time series have been examined using the Mann–Kendall nonparametric statistical test in order to detect possible evidences of wind speed and temperature trends at different temporal resolution and significance level.…
Improvement of Temperature Based ANN Models for ETo Prediction in Coastal Locations by Means of Preliminary Models and Exogenous Data
2008
This paper reports the application of artificial neural networks for estimating reference evapotranspiration (ETo) as a function of local maximum and minimum air temperatures and exogenous relative humidity and evapotranspiration in twelve coastal locations of the autonomous Valencia region, Spain. The Penman-Monteith model for ETo prediction, as been proposed by the Food and Agriculture Organization of the United Nations (FAO) as the standard method for ETo forecast, has been used to provide the ANN targets. The number of stations where reliable climatic data are available for the application of the Penman-Monteith equation is limited. Thus, the development of more precise predicting tools…
Risk factors for Lyme disease : A scale-dependent effect of host species diversity and a consistent negative effect of host phylogenetic diversity
2021
Biodiversity can influence disease risk. One example of a diversity-disease relationship is the dilution effect, which suggests higher host species diversity (often indexed by species richness) reduces disease risk. While numerous studies support the dilution effect, its generality remains controversial. Most studies of diversity-disease relationships have overlooked the potential importance of phylogenetic diversity. Furthermore, most studies have tested diversity-disease relationships at one spatial scale, even though such relationships are likely scale dependent. Using Lyme disease as a model system, we investigated the effects of host species richness and phylogenetic relatedness on the…
Climate variability and agricultural production efficiency: evidence from Ethiopian farmers
2020
It is known that climate and weather variability have negative impacts on agricultural production efficiency. The aim of this study is to analyse the impact of climatic variables on farms’ efficiency in Ethiopia making use of nationally representative datasets from Living Standards Measurement Study–Integrated Surveys on Agriculture (LSMS-ISA) 2011/2012. By using the Stochastic Frontier Approach, we estimate simultaneously the farmers’ optimal production function and technical inefficiency equations, taking into account unobserved heterogeneity of farmers. Our main findings show that climate change variables have a positive effect on households’ efficiency but the impact depends on the diff…
Winter “weekend effect” in southern Europe and its connections with periodicities in atmospheric dynamics
2008
[1] Winter weekly cycles of different climatic variables have been detected over Spain during the 1961–2004 period. The 13 analyzed series come from stations placed on different climatological and geographical areas with different level of urban influence. Therefore, the weekly cycles can hardly be related with local effects. Contrarily, we suggest that the weekly cycles may be related with changes in the atmospheric circulation over Western Europe, which may be due to some indirect effect of anthropogenic aerosols. Particularly interesting is the observed increase in Sea Level Pressure over Southern Europe during the weekends and consequently a decrease of anticyclonic conditions during th…
Bryophytes of Europe Traits (BET) dataset
2023
The Bryophytes of Europe Traits (BET) dataset includes values for 65 biological and ecological traits and 25 bioclimatic variables for all 1816 bryophytes included in the European Red List (Hodgetts et al. 2019). The traits are compiled from several regional trait datasets and manually complemented using Floras, species-specific literature and expert knowledge. The bioclimatic variables are calculated using the European range of each species. Details regarding the trait compilation and extraction of bioclimatic variables can be found in the corresponding data paper (Van Zuijlen et al. 2023).
Influence of climatic variables on acute myocardial infarction hospital admissions
2009
BACKGROUND: Seasonal peaks in acute myocardial infarction (AMI) incidence have been widely reported. Weather has been postulated to be one of the elements at the basis of this association. The aim of our study was to determine the influence of seasonal variations and weather on AMI hospital admissions. METHODS: We correlated the daily number of AMI cases admitted to a western Sicily hospital over twelve years and weather conditions on a day-to-day basis. Information on temperature, humidity, wind force and direction, precipitation, sunny hours and atmospheric pressure was obtained from the local Birgi Air Force base. A total of 3918 consecutive patients were admitted with AMI over the perio…
Climatic variables in Takotsubo cardiomyopathy: role of temperature
2017
Background Recent studies documented a seasonal (summer) and circadian (morning) temporal distribution of takotsubo cardiomyopathy (TTC). Aim The aim of our study was to investigate whether there is a relationship among season, temperature and the occurrence of TTC. A second aim of our study was the comparison of climatic variables in Takotsubo cardiomyopathy versus acute myocardial infarction (AMI). Methods We enrolled consecutive patients with TTC in three Italian centres and, for comparison consecutive patients with AMI. The frequency of TTC and AMI patients according to month, season and quartiles of temperature (I quartile: 9.8–15-, II quartile: 15–19-, III quartile: 19–25- and IV quar…
Genetic and morphologic diversity of European fan palm (Chamaerops humilisL.) populations from different environments from Sicily
2014
Chamaerops humilis is decreasing in abundance in Mediterranean Europe, which has induced the European community to call for its protection in Special Areas of Conservation. However, information about its genetic and morphological variability, which is crucial to the development of any conservation strategies, is insufficient. The present study aimed to investigate the genetic and morphological variability of C. humilis in Sicily, which was selected as a model because of the high number of dense populations. The relationships between morphological traits and climatic variables were studied to highlight patterns of adaptation to the environment, along with the genetic similarity among the pop…