Search results for "sif"
showing 10 items of 30916 documents
Poverty, Consent, and Choice in Early Marriage : Ethnographic Perspectives from Urban Tanzania
2018
The assumed inability of adolescents to voluntarily consent to marriage is a key definition of child marriage. Using ethnography, this study approaches consent, self-determination, and fulfillment ...
L’habitat durable sans l’habiter ? Fabrique de la densité en Bourgogne
2017
In 2009 and 2010, in order to combat the urban sprawl, the Grenelle Environment sets out urban density as a public policy issue. This notion builds on a modus operandi of an urbanization regime that includes both the environmental and the participatory dimensions in its approach. This injunction of sustainability is there implemented through a range of standards, rules and procedures, while the stakeholders in urbanism strive to arrange the experience of inhabiting. But how does this apparatus take the test of reality into account? Based on a qualitative research carried out from 2012 to 2015 on urban planning projects intended to increase density in urban and suburban areas in Burgundy, th…
Didaktiskās spēles kā uzmanības veicināšanas sastāvdaļa sākumskolā
2022
Bakalaura darba tēma ir “ Didaktiskās spēles kā uzmanības veicināšanas sastāvdaļa sākumskolā”. Darba autore Annija Šembele. Darba mērķis ir izpētīt sākumskolas vecuma bērnu uzmanības veicināšanas iespējas mācību procesā izmantojot didaktiskās spēles, lai sekmētu uzmanības spēju koncentrēšanu. Darbs sastāv no trīs nodaļām ar vairākām apakšnodaļām. Pirmajā nodaļā iekļauta teorētiskā analīze par uzmanību. Ir apkopota informācija par uzmanības vispārīgo raksturojumu, klasifikāciju un tās īpašībām un funkciju. Otrajā nodaļā ir apkopota informācija par sākumskolas bērnu attīstības īpatnībām pētāmās problēmas kontekstā. Tiek atklāts sākumskolas bērnu raksturojums un ietekmējoši faktori uzmanības a…
Modelling the effect of ethanol on growth rate of food spoilage moulds
2005
The effect of ethanol (E) on the radial growth rate (mu) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium digitatum, Rhizopus oryzae and Trichoderma harzianum) was assessed in Potato Dextrose Agar (PDA) medium at a(w) 0.99, 25 degrees C. In order to model this effect, the Monod type equation described previously by Houtsma et al. (Houtsma, P.C., Kusters, B.J.M., de Wit, J.C., Rombouts, F.M., Zwietering, M.H., 1994. Modelling growth rates of Listeria monocytogenes as a function of lactate concentration. Int…
Aposematism in the burying beetle? Dual function of anal fluid in parental care and chemical defence
2017
Burying beetles (Nicrophorus vespilloides) bear distinctive and variable orange-black patterning on their elytra and produce an anal exudate from their abdomen when threatened. During breeding, the anal exudates contribute to the antimicrobial defence of the breeding resource. We investigated whether the anal exudates also provide a responsive chemical defence, which is advertised to potential avian predators by the beetle’s orange and black elytral markings. We found that that the orange-black elytral markings of the burying beetle are highly conspicuous for avian predators against range of backgrounds, by using computer simulations. Using bioassays with wood ants, we also showed that the …
Colour alone matters : no predator generalization among morphs of an aposematic moth
2018
Local warning colour polymorphism, frequently observed in aposematic organisms, is evolutionarily puzzling. This is because variation in aposematic signals is expected to be selected against due to predators' difficulties associating several signals with a given unprofitable prey. One possible explanation for the existence of such variation is predator generalization, which occurs when predators learn to avoid one form and consequently avoid other sufficiently similar forms, relaxing selection for monomorphic signals. We tested this hypothesis by exposing the three different colour morphs of the aposematic wood tiger moth, Arctia plantaginis, existing in Finland to local wild-caught predato…
An aposematic colour‐polymorphic moth seen through the eyes of conspecifics and predators – Sensitivity and colour discrimination in a tiger moth
2018
Although predation is commonly thought to exert the strongest selective pressure on coloration in aposematic species, sexual selection may also influence coloration. Specifically, polymorphism in aposematic species cannot be explained by natural selection alone. Males of the aposematic wood tiger moth (Arctia plantaginis) are polymorphic for hindwing coloration throughout most of their range. In Scandinavia, they display either white or yellow hindwings. Female hindwing coloration varies continuously from bright orange to red. Redder females and yellow males suffer least from bird predation. White males often have higher mating success than yellow males. Therefore, we ask whether females ca…
Multimodal Aposematic Defenses Through the Predation Sequence
2021
Aposematic organisms warn predators of their unprofitability using a combination of defenses, including visual warning signals, startling sounds, noxious odors, or aversive tastes. Using multiple lines of defense can help prey avoid predators by stimulating multiple senses and/or by acting at different stages of predation. We tested the efficacy of three lines of defense (color, smell, taste) during the predation sequence of aposematic wood tiger moths (Arctia plantaginis) using blue tit (Cyanistes caeruleus) predators. Moths with two hindwing phenotypes (genotypes: WW/Wy = white, yy = yellow) were manipulated to have defense fluid with aversive smell (methoxypyrazines), body tissues with a…
Transparency reduces predator detection in mimetic clearwing butterflies
2019
International audience; Predation is an important selective pressure and some prey have evolved conspicuous warning signals that advertise unpalatability (i.e. aposematism) as an antipredator defence. Conspicuous colour patterns have been shown effective as warning signals, by promoting predator learning and memory. Unexpectedly, some butterfly species from the unpalatable tribe Ithomiini possess transparent wings, a feature rare on land but common in water, known to reduce predator detection.We tested if transparency of butterfly wings was associated with decreased detectability by predators, by comparing four butterfly species exhibiting different degrees of transparency, ranging from ful…
Safety in Numbers: How Color Morph Frequency Affects Predation Risk in an Aposematic Moth
2021
Polymorphic warning signals in aposematic systems are enigmatic because predator learning should favor the most common form, creating positive frequency-dependent survival. However, many populations exhibit variation in warning signals. There are various selective mechanisms that can counter positive frequency-dependent selection and lead to temporal or spatial warning signal diversification. Examining these mechanisms and their effects requires first confirming whether the most common morphs are favored at both local and regional scales. Empirical examples of this are uncommon and often include potentially confounding factors, such as a lack of knowledge of predator identity and behavior. …