1,720,968 research outputs found
The Convention on International Trade in Endangered Species (CITES) and the Conservation of Plant Diversity
No full textSeasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian coast
No full textPhlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These compounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins dif-fers within and between species, shows geographical variations but may be also affected by abiotic or biotic factors. Aims of this study were to evaluate: (i) the temporal variation of total phenolic content in two brown algae, Dictyopteris polypodioides and Cystoseira amentacea, living respec-tively in the upper infralittoral zone and in the infralittoral fringe, and (ii) its relationship with depth. Thalli of both algae were collected from the north-western coast of Sicily.
Results showed significant differences in total phenol content between D. polypodioides and C. amentacea with a higher value observed in the first one. Both species showed a seasonal pattern of total phenolic contents and differences in the period of their maximum production were also ob-served between the two species. In D. polypodioides the peak was observed during winter and au-tumn (0.95 and 0.81% DW) whereas during spring and summer in C. amentacea (0.17 and 0.57% DW). The phenol concentration resulted negatively correlated with the air temperature and the me-dium solar radiation in D. polypodioides whereas the correlation was positive in C. amentacea.
Even though seaweeds living on the rocky intertidal habitats, subjected to large variations of envi-ronmental conditions, should invest more energy in defences, D. polypodioides showed a phenolic content higher than C. amentacea. Our results suggest that phenol content and seaweed zonation are not interdependent and that sheet-like algae such as D. polypodioides, resulting more attractive than thick leathery ones to herbivores, produce larger concentrations of these compounds in order to deter feeding by herbivores
Risposte agli stress ambientali in CYSTOSEIRA (C. AGARDH): effetti della temperatura sul contenuto dei composti fenolici
No full textPhenolic compounds are secondary metabolites involved in different protection mechanisms as, for example, against grazers, epiphytes and UV radiation. Seasonal variations of phenolic content in C. amentacea were analysed and laboratory experiments, in which C. amentacea was exposed to an increase of temperature (258C and 308C), were performed. Total phenolic content (TPC) was determined colorimetrically with the Folin–Ciocalteu reagent. In C. amentacea, a seasonal pattern in TPC was observed, with a maximum value in winter-spring. C. amentacea responded significantly to the temperature treatments with a consistent decrease in TPC after 48 h
INTERSPECIFIC VARIATION IN TOTAL PHENOLIC CONTENT IN TEMPERATE BROWN ALGAE
No full textThe aim of this study was to focus on interspecific variation of total phenolic contents (TPC) in temperate brown algae also considering their relationship with environmental conditions. In particular, we compared the TPC of four species characterized by different thallus morphology, growth cycle and bathymetric level: Cystoseira amentacea (C. Agardh) Bory, Cystoseira compressa (Esper) Gerloff & Nizamuddin, Dictyopteris polypodioides (A.P. De Candolle) J.V. Lamouroux and Padina pavonica (Linnaeus) Thivy, collected in summer 2011 from the north-western coast of Sicily
CITES, wild plant, and opportunities for crime
No full textThe illegal trade in endangered plants damages both the environment and local communities by threatening and destroying numerous species and important natural resources. There is very little research which systematically addresses this issue by identifying specific opportunities for crime. This article presents the results of an interdisciplinary study which brings together criminological and conservation science expertise to identify criminal opportunities in the illegal wild plant trade and suggest strategies in order to prevent and mitigate the problem. Methodologically, the study adapts a crime proofing of legislation approach to the UN Convention on the International Trade in Endangered Species of Wild Fauna and Flora and is based on documentary and interview data. Situational crime prevention is used as a framework to provide points for effective intervention
Effects of temperature on total phenolic compounds in Cystoseira amentacea (C. Agardh) Bory (Fucales, Phaeophyceae) from southern Mediterranean Sea
No full textThe aim of this study was to test the effects of temperature on phenolic content of the brown seaweed Cystoseira amentacea. Phenolic compounds are secondary metabolites involved in different protection mechanisms as, for example, against grazers, epiphytes and UV radiation. Seasonal variations of phenolic content in C. amentacea were analysed and laboratory experiments, in which C. amentacea was exposed to an increase of temperature (25°C and 30°C), were performed. Total phenolic content (TPC) was determined colorimetrically with the Folin–Ciocalteu reagent. In C. amentacea, a seasonal
pattern in TPC was observed, with a maximum value in winter-spring. C. amentacea responded significantly to the temperature treatments with a consistent decrease in TPC after 48 h
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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