Search results for "occurence"
showing 5 items of 5 documents
Lichen communities on Populus tremula are affected by the density of Picea abies
2021
Questions Aspen (Populus tremula) is declining in the old‐growth forests of boreal Fennoscandia. This threatens the numerous taxa that are dependent on old aspens, including many epiphytic lichens. Potential methods to aid epiphytic lichens on aspen are centered around treatments which affect the density of Norway spruce (Picea abies). In this study, we investigated how epiphytic lichen communities on aspen are affected by the variation of spruce density in the immediate vicinity of the focal aspen. Location Southern boreal forests in Finland. Methods We recorded the occurrence of lichens from 120 aspens in 12 semi‐natural forest sites. We used spruce basal area as the measure for spruce de…
Childhood aggression and the co-occurrence of behavioural and emotional problems: results across ages 3–16 years from multiple raters in six cohorts …
2018
Childhood aggression and its resulting consequences inflict a huge burden on affected children, their relatives, teachers, peers and society as a whole. Aggression during childhood rarely occurs in isolation and is correlated with other symptoms of childhood psychopathology. In this paper, we aim to describe and improve the understanding of the co-occurrence of aggression with other forms of childhood psychopathology. We focus on the co-occurrence of aggression and other childhood behavioural and emotional problems, including other externalising problems, attention problems and anxiety-depression. The data were brought together within the EU-ACTION (Aggression in Children: unravelling gene-…
A segmented regression model for event history data: an application to the fertility patterns in Italy
2009
We propose a segmented discrete-time model for the analysis of event history data in demographic research. Through a unified regression framework, the model provides estimates of the effects of explanatory variables and jointly accommodates flexibly non-proportional differences via segmented relationships. The main appeal relies on ready availability of parameters, changepoints, and slopes, which may provide meaningful and intuitive information on the topic. Furthermore, specific linear constraints on the slopes may also be set to investigate particular patterns. We investigate the intervals between cohabitation and first childbirth and from first to second childbirth using individual data …
Rzadkie i ginące zbiorowiska roślin wodnych z klasy Potametea Słowińskiego Parku Narodowego
2018
Słowiński Park Narodowy, o powierzchni 32 744 ha, został utworzony w 1967 roku, a do sieci Światowych Rezerwatów Biosfery włączony w 1977 roku. Ponad połowę obszaru parku zajmują ekosystemy wodne, w tym pobrzeże Bałtyku, jeziora Łebsko, Gardno, Dołgie Wielkie i Dołgie Małe oraz w mniejszym stopniu rzeki: Łeba, Łupawa i Pustynka. W trakcie badań prowadzonych w latach 2013–2014 stwierdzono stanowiska czterech rzadkich i ginących zbiorowisk roślin wodnych z klasy Potametea, nienotowanych dotąd na obszarze Słowińskiego PN. Są to zespoły: rdestnicy trawiastej Potametum graminei, rdestnicy alpejskiej Potametum alpini, rogatka krótkoszyjkowego Ceratophylletum submersi ze związku Potamion oraz zesp…
Development of Henneguya zschokkei (Myxozoa: Myxosporea) actinospores in oligochaetes and plasmodia in whitefish Coregonous lavaretus
2013
The aim of this study was to describe the life cycle of H. zschokkei by observing the development of actinospores in oligochaete and the morphological development of H. zschokkei cysts in whitefish. Laboratory observation of seasonal occurrence of actinospores sampled from oligochaetes from RTKL Tervo Fish Farm revealed 6 types of actinospores from collective groups of Triactinomyxon, Raabeia and Aurantiactinomyxon in 2010, and 3 types of actinospores in 2011. Both years showed similar patterns with the release of actinospores peaking in both summer (June and July) and winter (January and February) times. The infection experiment was not successful in infecting Coregonus lavaretus with myxo…