Search results for "spring"
showing 10 items of 600 documents
Antibody injection in the egg yolk: maternal antibodies affect humoral immune response of the offspring
2010
Summary 1. In vertebrate species, maternal antibodies specific for the pathogens to which mothers have been exposed can be transmitted to offspring before birth. This is assumed to be adaptive as these antibodies can be essential in protecting offspring early in life before their own immune system is fully developed. However, fitness consequences in natural conditions and the long-term effects of these mechanisms have yet to be fully examined. 2. Exploring the ecological and evolutionary implications of such maternal effects requires experimental manipulations to avoid potential confounding maternal effects. In birds, maternal antibodies are transmitted via the egg yolk – a self contained e…
BOTH MALE AND FEMALE SEXUAL ORNAMENTS REFLECT OFFSPRING PERFORMANCE IN A FISH
2010
Secondary sexual characters are often expressed in both sexes (mutual ornamentation), but are less often studied simultaneously. We studied the adaptive signaling function of male and female ornamentation in a mutually ornamented fish, the whitefish Coregonus lavaretus. In an experimental design in which nongenetic environmental effects were minimized, we found that highly ornamented females, males, and their parental combinations had offspring with better swimming performance and predator-avoidance ability than less ornamented individuals or combinations. Furthermore, highly ornamented females had larger offspring that also had higher yolk volume than less ornamented individuals. Offspring…
Veronico beccabungae-callitrichetum stagnalis (Oberd. 1957) Müller 1962, a plant association new to Poland - Quality of habitat
2011
The paper presents a community of water plants that is new to Poland, <em>Veronico beccabungae-Callitrichetum</em> stagnalis (Oberd. 1957) Müller 1962. This community belongs to the class <em>Potametea</em>. It was discovered in the village of Odrowąż near the town of Krapkowice in Silesia (SW Poland). <em>Veronico beccabungae-Callitrichetum stagnalis</em> in Poland occurs within an irregularly shaped shallow underwater spring, located in the distal part of the Oder River’s flood terrace. This plant community covered 0.2 ha in 2008. <em>Callitriche stagnalis</em> predominated in this community. Species such as <em>Callitriche hamulata<…
An explicit mechanical interpretation of Eringen non-local elasticity by means of fractional calculus
2009
If the attenuation function of strain is expressed as a power law, the formalism of fractional calculus may be used to handle Eringen non-local elastic model. Aim of the present paper is to provide a mechanical interpretation to this non-local fractional elastic model by showing that it is equivalent to a discrete, point-spring model. A one-dimensional geometry is considered; static, kinematic and constitutive equations as well as the proper boundary conditions are derived and discussed.
Fecundity determines the outcome of founding queen associations in ants
2021
AbstractAnimal cooperation evolved because of its benefits to the cooperators. Pleometrosis in ants - the cooperation of queens to found a colony - benefits colony growth, but also incurs costs for some of the cooperators because only one queen usually survives the association. While several traits are associated with queen survival, they tend to be confounded and it is unclear which factor specifically determines the outcome of pleometrosis. In this study, we used the ant Lasius niger to monitor offspring production in colonies founded by one or two queens. Then, we experimentally paired queens that differed in fecundity but not in size, and vice versa, to disentangle the effect of these f…
Some Climatic Indices for Pinot noir Maturation at a Meteorological Station in Burgundy
2017
This paper deals with relationships between climate and vineyard at a meteorological station in the wine-growing area of Burgundy. Statistical analyses were carried out on data for the 1975-1996 period. Climatic indices for Pinot noir grape harvests were developed for the 1975-1990 period using a composite analysis. These revealed that high spring temperatures, after a dry winter, led to an early date of Pinot noir harvest, whereas low spring temperatures, after a rainy winter, led to a late date of harvest. These indices proved to be accurate for the 1991-1996 period. The date of Pinot noir harvest could be estimated as early as May, before flowering, using these indices and linear regres…
Toxicity of waste dump leachates and sugar factory effluents and their impact on groundwater and surface water quality in the Opole Province in Poland
2000
A battery of Toxkit microbiotests with 4 aquatic species from different trophic levels has been used to evaluate the toxicity of 2 types of point source pollution in the Voivoidship of Opole in Poland: percolating waters from drainage systems of 4 municipal waste dumps and the effluents of a sugar factory. In addition, the toxicity of groundwaters from 2 wells near 2 waste dumps was also assessed. All the drainage waters of the waste dumps and the groundwaters near one dump (an unprotected landfill) showed toxic effects on all the test species, for samples taken in spring as well as in autumn. The well water of the (more recent) waste dump of the City of Opole in turn did not show any toxic…
THE BLACK GOLD THAT CAME FROM THE SEA. A REVIEW OF OBSIDIAN STUDIES AT THE ISLAND OF USTICA
2018
Volcanism has produced a natural glass called obsidian that during prehistoric times, from Neolithic to the Metal Ages, was considered a valuable raw material in order to produce efficient cutting tools. Ustica, a small and solitary island in the southwestern Tyrrhenian Sea, despite being volcanic, did not generate any obsidian. Yet the island's soils return large quantities of obsidian fragments, residues of prehistoric use. Where did this material, defined by some archaeologists as the Black Gold of prehistory, come from? This article reviews the archaeometric studies on Ustica’s obsidians, carried out since the middle o f the 1990s, to answer this question. The obsidians of Ustica have b…
Potential Impact of Global Climate Change on Species Richness of Long-Distance Migrants
2003
Little evidence exists demonstrating that global climate change leads to systematic changes in the struc- ture of ecological communities. For avian communities, one would expect warmer winters to lead to declines in numbers of long-distance migrants if resident birds benefit from warmer winters and impose increasing competi- tive pressure on migrants. To study the potential influence of global climate change on long-distance migrants, we correlated the number of all species of land birds and the number and proportion of long-distance migrants, short- distance migrants, and residents in 595 grid cells across Europe. We used mean temperature of the coldest month, mean spring temperature, and …
Analysis of Conflict Datasets and Indicators: The Case of the “Arab Spring”
2017
This chapter contains an analysis of selected indicators of legitimacy, human rights and inequality, as well as information about conflict events for eight African countries affected by the Arab Spring, namely Algeria, Egypt, Libya, Mali, Mauritania, Morocco, Sudan, and Tunisia. The analyses described in this chapter allowed the determination of plausible estimates for input parameters such as legitimacy and welfare inequality, as well as patterns of size, duration and recurrence of conflict events in these countries. These results were used for setting the values of the input parameters, and for analyzing the plausibility of the solutions in the exploration of the agent-based model describ…