Search results for "Rom"
showing 10 items of 37506 documents
Does an ant-dispersed plant, Viola reichenbachiana, suffer from reduced seed dispersal under inundation disturbances?
2008
Many plant species use ants as seed dispersers. This dispersal mode is considered to be susceptible to disturbances, but the effect of natural, small-scale disturbances is still unknown. We investigated how small-scale disturbances due to inundation affect seed dispersal in Viola reichenbachiana, a dominant myrmecochorous herb in riparian forests. Inundation disturbances were high in depressions and low on hillocks of the forest floor. We found that V reichenbachiana was similarly abundant at highly and less disturbed sites, contrary to other, non ant-dispersed species. We also found that the motivation of ants to disperse seeds was higher at highly disturbed sites. Nevertheless, the number…
Parasite-induced behavioral change: mechanisms.
2010
Animal behavior and parasitism are more tightly linked than commonly thought. One of the most astonishing phenomena in host–parasite antagonistic interactions is ‘host manipulation,’ that is, the ability of a parasite to alter the behavior of its host in ways that appear to increase parasite fitness at the expense of host fitness. The mechanisms by which a parasite hijacks the behavior of its host have been explored using ethopharmacological and immunocytochemical approaches or carrying out a large-scale proteomic study on manipulated host’s brain. These few mechanistic studies have confirmed both the complexity of host manipulation by parasites and the importance of understanding the molec…
A preliminary check list of macromycetes in northern Tunisia
2016
AbstractWithin the last decade, checklists of fungi of several countries have been published or updated. Nevertheless, no checklists of macromycetes have hitherto been published for Tunisia (North Africa) apart from a mycocoenological study reporting 34 listed species. This work presents a list of macromycetes collected from January 2014 to March 2015 in six governorates of northern Tunisia. One hundred and twenty-three species (117 basidiomycetes and six ascomycetes) belonging to 78 genera and 46 families were recorded.
Distribution of sea urchins living near shallow water CO2 vents is dependent upon species acid-base and ion-regulatory abilities.
2013
To reduce the negative effect of climate change on Biodiversity, the use of geological CO2 sequestration has been proposed; however leakage from underwater storages may represent a risk to marine life. As extracellular homeostasis is important in determining species' ability to cope with elevated CO2, we investigated the acid-base and ion regulatory responses, as well as the density, of sea urchins living around CO2 vents at Vulcano, Italy. We conducted in situ transplantation and field-based laboratory exposures to different pCO2/pH regimes. Our results confirm that sea urchins have some ability to regulate their extracellular fluid under elevated pCO2. Furthermore, we show that even in cl…
New and interesting Orthoptera from the Arabian Peninsula and Socotra.
2017
Abstract This paper reports on some interesting taxa recently found in the Arabian Peninsula and the island of Socotra. Among them is a new species of brachypterous grasshopper Sphodromerus carapezzanus sp. n. (Acrididae: Calliptaminae), described from an isolated area in Dhofar (Oman). A female Heteracris hemiptera (Uvarov, 1935) (Acrididae: Eyprepocnemidinae) is reported, with morphological characters which do not fully comply with those of any known subspecies. Two species, hitherto rarely documented, are also reported, Phaneroptila insularis Uvarov, 1957 (Tettigoniidae: Phaneropterinae) from Socotra and Cataloipus thomasi Uvarov, 1933 (Acrididae: Eyprepocnemidinae) from Oman. Pycnodicty…
Lung function assessment in the Pacific walrus (Odobenus rosmarus divergens) while resting on land and submerged in water
2020
In the present study, we examined lung function in healthy resting adult (born in 2003) Pacific walruses (Odobenus rosmarus divergens) by measuring respiratory flow ([Formula: see text]) using a custom-made pneumotachometer. Three female walruses (670-1025 kg) voluntarily participated in spirometry trials while spontaneously breathing on land (sitting and lying down in sternal recumbency) and floating in water. While sitting, two walruses performed active respiratory efforts, and one animal participated in lung compliance measurements. For spontaneous breaths, [Formula: see text] was lower when walruses were lying down (e.g. expiration: 7.1±1.2 l s-1) as compared with in water (9.9±1.4 l s-…
NMR structure determination of (11E)-trinervita-1(14),2,11-triene, a new diterpene from sexual glands of termites
2005
Graphical Abstract Full-size image; International audience; Female alates of Nasutitermes ephratae termites from Guadeloupe and Nasutitermes sp. from Brazil produce a diterpene hydrocarbon of the molecular formula C20H30 as the main component of their tergal gland secretion. Analysis of NMR, IR, and mass spectra of the diterpene led to a structure of (11E)-trinervita-1(14),2,11-triene. Based on a comparison with the published oxygenated trinervitane skeleton from termites we prefer the enantiomer with absolute configurations (4R,7S,8R,15S,16S). The suggested structure is supported by ab initio quantum chemical calculation of 1H and 13C chemical shifts for the optimized geometry of the molec…
The defensive secretion of Eurycotis floridana (Dictyoptera, Blattidae, Polyzosteriinae): chemical identification and evidence of an alarm function
1997
0965-1748 doi: DOI: 10.1016/S0965-1748(97)00033-7; The defensive secretion of the cockroach Eurycotis floridana was believed to contain only (E)-2-hexenal. However, we have shown it consists of 40 components, of which 30 were tentatively identified. (E)-2-Hexenal, (E)-2-hexenol and (E)-2-hexenoic acid represented approximately 98% of the organic phase. The other 2% included 10 aldehydes, 10 alcohols, four acids, two lactones and one ether. Four compounds are novel insect exudates: 3-ethoxyhexanal, 3-hydroxyhexanal, [(E)-1-pentenyl]-4-propyl-1,3-dioxane and 3-[(E)-2-hexenoxyl-hexanal. In addition to its well-known allomonal function, we have demonstrated that the defensive secretion also act…
Photoreceptors and respiratory electron flow involvement in the activity of acifluorfen-methyl and LS 82-556 on nonchlorophyllous soybean cells
1987
Abstract The diphenyl ether acifluorfen-methyl [AFM; methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate] and the pyridine derivative LS 82-556 [( S )-3- N -(methylbenzyl)carbamoyl-5-propionyl-2,6-lutidine] induce light-dependent polyunsaturated fatty acid peroxidation, leading to general membrane disruption. Although devoid of functional chloroplasts, cultured soybean cells are sensitive to AFM and LS 82-556 only in the light. The possible involvement of carotenoids and respiratory electron flow was examined by monitoring ethane evolution, fluorescein release, and dry weight/fresh weight ratio alteration. Herbicide effects on cells exposed to white light or blue light (380–540 n…
A new C12 alcohol identified as a sex pheromone and a trail-following pheromone in termites: the diene (Z,Z)-dodeca-3,6-dien-1-ol
2003
0028-1042 (Print) Journal Article; The diunsaturated C12 alcohol (Z,Z)-dodeca-3,6-dien-1-ol (dodecadienol) has been characterized by GC-MS and FTIR as a novel releaser pheromone in termites. This alcohol identified in Ancistrotermes pakistanicus (Termitidae, Macrotermitinae) possesses a double pheromonal function which again illustrates the chemical parsimony of termites compared with other social insects. In workers, dodecadienol elicits trail-following at a very low concentration (activity threshold at 0.1 pg/cm of trail); in male alates it induces trail-following at a low concentration (1-10 pg/cm) and sexual attraction at a higher concentration (about 1 ng). Traces of the monounsaturate…