Search results for "GLMM"
showing 6 items of 16 documents
Reference growth charts for Posidonia oceanica seagrass: An effective tool for assessing growth performance by age and depth
2016
Abstract Growth performance of rhizomes has become among the most used descriptors for monitoring Posidonia oceanica seagrass dynamics and population status. However, ability to detect any change of growth in space or in time is often confounded by natural age-induced decline. To overcome this problem, we have produced reference growth charts, which in other areas are universally recognized as a very powerful tool for comparing growth of living beings during their ontogeny. Reference growth charts involving different P. oceanica growth performance measures (speed of growth and primary production of rhizomes) have been built using proper statistical frameworks (GLMM, Segmented and Quantile R…
Modeling Ordinal Item Responses via Binary GLMMs and Alternative Link Functions: An Application to Measurement of a Perceived Service Quality
2010
Evaluation of a service on the basis of consumer opinion is a widespread practice in many fields. The assessment of perceived quality [7] of a service is generally carried out through administration of a questionnaire, composed of several items with responses posed on an ordinal scale, whereby each item represents an important feature of the evaluated service [3, 7]. In this context, the aim is to evaluate something similar to the external effectiveness, that is the part of efficacy related to the satisfaction expressed by the service users for the provided service. A particular and important example of service users is represented by students’ responses measuring the perceived quality of s…
Effect of different substrata on rhizome growth, leaf biometry and shoot density of Posidonia oceanica
2013
The effects of different substratum typologies on Posidonia oceanica growth and morphology were estimated in four Sicilian meadows using Generalized and Linear Mixed Models combined with retrodating and biometric analyses. Substratum exerted a multiple effect, resulting in different biometric features for P. oceanica shoots settled on rock from those growing on sand and matte. On rock, values for growth rate, leaf length and shoot surface were lower than those on other substrata, with 42%, 23% and 32% the highest degree of difference respectively. The present study may have interesting methodological consequences for the comprehensive understanding of the causative variables potentially aff…
“You look at it, but will you choose it”: Is there a link between the foods consumers look at and what they ultimately choose in a virtual supermarke…
2022
Most of the studies that showed a link between gaze allocation and consumer's food choices were performed on food products belonging to a same category. However, consumers usually make food choices in more complex environments, between many different products, and different factors can influence their choices. Therefore, our study aimed to understand the link between gaze behavior and food choices in a complex and realistic situation of choice. Participants (n=99) performed a food choice task in a virtual supermarket. They had to choose three food products to create a dish in four scenarios evoking different motivations (focus on health, environment, food pleasure, and daily scenario as con…
Saistība starp briofītu funkcionālajām grupām, substrātu īpašībām un mežau augu sabiedrībām Moricsalas dabas rezervātā
2013
Anotācija Darba mērķis ir noskaidrot substrāta parametru ietekmi uz briofītu sugu bagātību, sugu sastopamību un sugu sadalījumu pa funkcionālajām grupām (dzīves formu un dzīves stratēģiju) dažādās meža augu sabiedrībās, kā arī izpētīt sūnu sugu sastāva mainību Moricsalā pēdējo 100 gadu laikā. Par pētāmo teritoriju izvēlēts Moricsalas dabas rezervātā, kas ir senākā aizsargājamā dabas teritorija Latvijā un ilgstoši neskartās dabas dēļ īpaši piemērota sūnu ekoloģijas izpētei. Pašlaik bagātīgu sūnu sugu sastopamību uz pētītajiem substrātiem nodrošina koku sugas ar atšķirīgu mizas reakciju, dažāda garuma un apkārtmēra kritalas, heterogēns koku sugu sastāvs. Pēdējo 100 gadu laikā Moricsalas meža …
Data from: Predator mimicry, not conspicuousness, explains the efficacy of butterfly eyespots
2015
Large conspicuous eyespots on butterfly wings have been shown to deter predators. This has been traditionally explained by mimicry of vertebrate eyes, but recently the classic eye-mimicry hypothesis has been challenged. It is proposed that the conspicuousness of the eyespot, not mimicry, is what causes aversion due to sensory biases, neophobia or sensory overloads. We conducted an experiment to directly test whether the eye-mimicry or the conspicuousness hypothesis better explain eyespot efficacy. We used great tits (Parus major) as model predator, and tested their reaction towards animated images on a computer display. Birds were tested against images of butterflies without eyespots, with …