Search results for " Introduction"
showing 10 items of 39 documents
Using invertebrate remains and pigments in the sediment to infer changes in trophic structure after fish introduction in Lake Fogo: a crater lake in …
2010
Generalist invasion in a complex lake food web
2023
Invasive species constitute a threat not only to native populations but also to the structure and functioning of entire food webs. Despite being considered as a global problem, only a small number of studies have quantitatively predicted the food web-level consequences of invasions. Here, we use an allometric trophic network model parameterized using empirical data on species body masses and feeding interactions to predict the effects of a possible invasion of Amur sleeper (Perccottus glenii), on a well-studied lake ecosystem. We show that the modeled establishment of Amur sleeper decreased the biomasses o ftop predator fishes by about 10%–19%. These reductions were largely explained by inc…
The spreading of the invasive italian wall lizard on Vulcano, the last island inhabited by the critically endangered aeolian wall lizard
2018
[EN] The Aeolian Wall Lizard (Podarcis raffoneae) is an endemic species of the Aeolian Archipelago of Italy (Mediterranean Sea). Its distribution is limited to three islets and two relict populations on a relatively large island: Vulcano (a population on the summit of Gran Cratere volcano and another on Capo Grosso promontory). The critically endangered Aeolian Wall Lizard is threatened by the introduction of the Italian Wall Lizard (Podarcis siculus), which successfully competes and hybridizes with the endemic lizard. The invasive lizard is widespread on Vulcano, although the literature does not provide the exact distribution. Our first aim was updating the distribution of the Italian Wall…
Possibile origine e consistenza di un popolamento di Quercus trojana Webb subsp. trojana (Fagaceae) nel Bosco della Ficuzza (Palermo, Sicilia
2014
Possible origin and demographic asset of a population of Quercus trojana Webb subsp. trojana (Fagaceae) in the wood of Ficuzza (Palermo, Sicily). The first record of Macedonian oak in Sicily is reported. The finding consists of 73 adult and 4 young individuals. A morphometric analysis of all of them, along with an assessment of their phytosanitary status was carried out. They all grow between 700 and 850 m a.s.l. on a 2,30 ha area, characterized by a land mosaic of shrubland and forest patches. Notwithstanding two years of researches, no ultimate proof has been found on their alien status. On this purpose, several alternative hypothesis are formulated and their strengths and weaknesses are …
Latvijas Universitātes Botāniskais dārzs, 80
2002
Teksts paralēli latviešu un angļu valodā
Introduction
2021
Introduction to the contributions of the edited book
Chapter 14: HPV vaccine introduction in industrialized countries.
2006
Introduction of a vaccine requires the achievement of three initial milestones. These are licensure by a national control authority that determines the vaccine is safe and effective, development of recommendations for use by expert advisory bodies on immunization, and obtaining funding for vaccination. Once these milestones have been achieved, a successful vaccination program requires that a number of interlinked programmatic components be brought together in a coordinated fashion. These include vaccine purchase and supply, vaccination service delivery, high coverage rates, surveillance of the vaccination program, immunization finance policies and practices, and political will. Human papill…
A Revised Short Form of the Extended Class Play Among Italian Early Adolescents
2019
Among the measures assessing peer reputation, the Extended Class Play (ECP) is now used extensively in North American settings. Little information is available in other cultural contexts. Furthermore, practical considerations suggest developing a shorter form of the ECP to be used in socio-educational environments. This study examined the ECP dimensions of peer assessment in Italy as well as developed a shorter form of the measure. We revised the ECP using factor analyses according to an explorative-confirmatory approach. The original 37-item ECP was shortened to a 22-item version and, subsequently, the properties of the revised measure were evaluated. We performed two studies comprising, r…
Too Little, Too Early: Introduction Timing and New Product Performance in the Personal Digital Assistant Industry
1997
The authors address the following key questions: (1) When should a firm introduce a new product? (2) What should its performance level be? and (3) How do the decisions of a competing firm affect a firm's timing and product performance decisions? The authors present a detailed case study of the initial competitors in the personal digital assistant (PDA) industry on the basis of which they construct a stylized game-theoretic model of entry timing and product performance level decisions in a duopoly. Situations in which the duopolists are symmetric as well as asymmetric in terms of their estimates of market size and product development capabilities are considered. When firms are symmetric, th…
Note di Abū Naṣr al-Fārābī sulla verità e falsità dell’astrologia
2020
Il presente contributo propone l’introduzione, la traduzione italiana e il commento delle Note sulla verità e falsità dell’astrologia (Nukat fī mā yaṣiḥḥu wa-mā lā yaṣiḥḥu min aḥkām al-nuǧūm) di Abū Naṣr al-Fārābī (m. 950). Tale scritto non è stato trasmesso direttamente dal suo autore né ci è giunto nella sua redazione definitiva, bensì in forma di appunti ricopiati da un grammatico di nome Abū Isḥāq al-Baġdādī. In trenta brevi capitoli al-Fārābī spiega ciò che è accessibile e ciò che è inaccessibile alle predizioni astrologiche e quali aspetti di tale scienza sia opportuno accogliere o respingere.