Search results for "Ester"
showing 10 items of 4273 documents
NO contributes to cadmium toxicity in Arabidopsis thaliana by mediating an iron deprivation response
2009
Nitric oxide (NO) functions as a cell-signaling molecule in plants. In particular, a role for NO in the regulation of iron homeostasis and in the plant response to toxic metals has been proposed. Here, we investigated the synthesis and the role of NO in plants exposed to cadmium (Cd(2+)), a nonessential and toxic metal. We demonstrate that Cd(2+) induces NO synthesis in roots and leaves of Arabidopsis (Arabidopsis thaliana) seedlings. This production, which is sensitive to NO synthase inhibitors, does not involve nitrate reductase and AtNOA1 but requires IRT1, encoding a major plasma membrane transporter for iron but also Cd(2+). By analyzing the incidence of NO scavenging or inhibition of …
Underwater high frequency noise: Biological responses in sea urchin Arbacia lixula (Linnaeus, 1758)
2020
Marine life is extremely sensitive to the effects of environmental noise due to its reliance on underwater sounds for basic life functions, such as searching for food and mating. However, the effects on invertebrate species are not yet fully understood. The aim of this study was to determine the biochemical responses of Arbacia lixula exposed to high-frequency noise. Protein concentration, enzyme activity (esterase, phosphatase and peroxidase) and cytotoxicity in coelomic fluid were compared in individuals exposed for three hours to consecutive linear sweeps of 100 to 200 kHz lasting 1 s, and control specimens. Sound pressure levels ranged between 145 and 160 dB re 1μPa. Coelomic fluid was …
Elicitins trap and transfer sterols from micelles, liposomes and plant plasma membranes
1999
Using elicitins, proteins secreted by some phytopathogenic Oomycetes (Phytophthora) known to be able to transfer sterols between phospholipid vesicles, the transfer of sterols between micelles, liposomes and biological membranes was studied. Firstly, a simple fluorometric method to screen the sterol-carrier capacity of proteins, avoiding the preparation of sterolcontaining phospholipidic vesicles, is proposed. The transfer of sterols between DHE micelles (donor) and stigmasterol or cholesterol micelles (acceptor) was directly measured, as the increase in DHE fluorescence signal. The results obtained with this rapid and easy method lead to the same conclusions as those previously reported, u…
Winter movement patterns of a globally endangered avian scavenger in south-western Europe
2020
AbstractPartial migration, whereby some individuals migrate and some do not, is relatively common and widespread among animals. Switching between migration tactics (from migratory to resident or vice versa) occurs at individual and population levels. Here, we describe for the first time the movement ecology of the largest wintering population of Egyptian Vultures (Neophron percnopterus) in south-west Europe. We combined field surveys and GPS tracking data from December to February during four wintering seasons (2014–2018). The wintering population consisted on average of 85 individuals (range 58–121; 76% adults and 24% subadults). Individuals were counted at five different roosting sites lo…
Late Cretaceous-Early Eocene origin of yams (Dioscorea, Dioscoreaceae) in the Laurasian Palaearctic and their subsequent Oligocene-Miocene diversific…
2015
Aim: Dioscorea (Dioscoreaceae) is a predominantly pantropical genus (< 600 species) that includes the third most important tropical tuber crop and species of pharmacological value. Fossil records from both the Northern and Southern Hemispheres were used to test hypotheses about the origin of the genus Dioscorea, and to examine potential macroevolutionary processes that led to its current distribution. Location: Pantropical distribution. Methods: Divergence times were estimated using the most comprehensive phylogeny of the group published to date based on plastid sequences and fossil calibrations, applying a relaxed-clock model approach. Ancestral areas and range shifts were reconstructed us…
Monitoring the reproductive activity in captive bred female ball pythons (P. regius) by ultrasound evaluation and noninvasive analysis of faecal repr…
2018
The royal python (Python regius) is commonly bred in captivity. To have a successful breeding season, accurate monitoring of the reproductive activity is necessary. The use of non-invasive monitoring methods in exotics is important in order to minimize stress. For this purpose ultrasound has been anecdotally used to monitor royal python reproductive activity. However, there is limited information regarding the reproductive cycle of this species. The aim of the present study is to monitor the female reproductive cycle of the royal python using ultrasonography and gonadal steroid metabolite measurements in the faeces. The reproductive activity of one hundred twenty-nine adult female P. regius…
Is it really you,Orthotrichum acuminatum? Ascertaining a new case of intercontinental disjunction in mosses
2015
Intercontinental disjunct distributions are a main issue in current biogeography. Bryophytes usually have broad distribution ranges and therefore constitute an interesting subject of study in this context. During recent fieldwork in western North America and eastern Africa, we found new populations of a moss morphologically similar to Orthotrichum acuminatum. So far this species has been considered to be one of the most typical epiphytic mosses of the Mediterranean Basin. The new findings raise some puzzling questions. Do these new populations belong to cryptic species or do they belong to O. acuminatum, a species which then has a multiple-continent disjunct range? In the latter case, how c…
Low fitness at low latitudes: Wintering in the tropics increases migratory delays and mortality rates in an Arctic breeding shorebird
2020
Publisher's version (útgefin grein)
First record of Tamarix macrocarpa (Tamaricaceae) for Europe
2017
AbstractTamarix macrocarpa, a species with distribution in Central and North Africa, in the countries bordering the Persian Gulf and in Central and western Asia is recorded for the first time for Europe. Pentamerous flowers and androecium diplostemonous characterize this small tree.
Epibiontes en juveniles de tortugas carey Eretmochelys imbricata varadas en la costa del Departamento de Rocha, Uruguay
2016
The hawksbill turtle (Eretmochelys imbricata) is the most threatened sea turtle species in the world. An important aspect of the biology of sea turtles is the study of colonizing fauna, i.e., their epibiota. The aim of this study is a taxonomic determination on the epibiota found on 4 hawksbills turtles stranded in 2009 and 2011 on the coast of Rocha Department, Uruguay. The epibiota was composed by algae from the class Phaeophyceae (Sphacelaria sp. and Hincksia mitchelliae) and invertebrates from the classes Cirripedia (Platylepas hexastylos, Chelonibia testudinaria and Amphibalanus improvisus) and Hirudinea (Ozobranchus margoi), with greater predominance of P. hexastylos cirripeds (n= 365…