Search results for " behavior"

Widespread contribution of methane-cycle bacteria to the diets of lake profundal chironomid larvae.

2008

Reports of unexpectedly 13C-depleted chironomid larvae in lakes have led to an hypothesis that significant transfer of detrital organic matter to chironomid larvae may occur via methane-cycle bacteria. However, to date little is known of how such transfer might vary across species and lakes. We gathered data from 87 lakes to determine how widespread this phenomenon might be and to define boundaries for its likely magnitude. Carbon stable isotope values of chironomid larvae varied greatly between taxa. Very marked 13C-depletion was evident only in certain taxa, especially Chironomus plumosus, C. anthracinus, and C. tenuistylus, all characteristic of eutrophic or dystrophic lakes and known to…

Flavonoid metabolism and gene expression in developing olive (Olea europaea L.) fruit.

2012

The expression pattern of six genes (phenylalanine-ammonia-lyase, PAL, chalcone synthase, CHS, flavanone 3-hydroxylase, F3H, dihydroflavonol 4-reductase, DFR, anthocyanidin synthase, ANS, UDP-gluco...

Chloramphenicol effects on adventitious root production by radish hypocotyls

1990

Abstract The excision of the root accelerates greatly the formation of adventitious roots in the hypocotyl of etiolated radish seedlings, but if the seedlings develop in CAP 1×10−4M, no adventitious root are induced after cutting. IAA either alone or associated with CAP, significantly increases the number of primordia in normal hypocotyls if given at the moment of cutting, while it has not stimulatory effect on the hypocotyls of seedlings grown in CAP. IAA has significant effect on both elongation and tickening of hypocotyl segments prepared from seedlings grown in CAP, and this could indicate a specific action of the inhibitor either on a particular process or on particular cells. The endo…

Changes in net photosynthesis, chlorophyll fluorescence and xanthophyll cycle interconversions during freeze-thaw cycles in the Mediterranean moss Le…

1999

The tolerance to freezing and thawing of Leucodon sciuroides, a moss growing in mountainous areas of the Mediterranean (south-east Spain), was investigated by means of CO2 gas exchange, modulated chlorophyll (Chl) a fluorescence and pigment analysis by high-performance liquid chromatography. Evidence is presented for freezing-induced decreases in CO2 fixation that enhance non-radiative dissipation of absorbed light energy, a process which protects the photosynthetic apparatus. The photosynthetic apparatus of L. sciuroides remained fully recuperable after freezing, as indicated by the recovery of photosynthetic CO2 fixation and Chl fluorescence parameters to pre-freezing values during thawin…

The relationship between feed intake behaviour with intramuscular fat, cholesterol and fatty acid composition in pork

2011

The aim of this study was to investigate the phenotypic relationship between feed intake (FI) characteristics with intramuscular fat, cholesterol and fatty acid composition in pork. Data were available on 202 Duroc barrows. Intramuscular fatness was positively correlated with a higher percentage of saturated (SFA) and monounsaturated fatty acids (MUFA), a lower percentage of polyunsaturated (PUFA), omega-3 (ω3) and omega-6 (ω6) fatty acids, and a lower ω6/ω3 and P:S ratio (p < 0.05). Faster growth resulted in a higher level of SFA and a lower level of ω3 fatty acids (p < 0.05). Increased FI, residual feed intake (RFI) and feed intake time (TIME) and a decreased feed intake frequency (FREQ) …

Historical and current progress in understanding the origin and structure of humic substances

2010

Research into humic substances (HS) has focused selectively on the search for aromatic structures. All aromatic compounds are regarded as eligible HS constituents, whereas aliphatic, polysaccharide structural constituents are considered non-HS. Wet chemical methods for analysing HS produce 2–5% aromatic compounds from the original starting material. Only those compounds in the hydrophobic extraction phases are studied carefully. Compounds in the hydrophilic extraction phases, containing mainly aliphatics, are discarded. Solid-state NMR spectra from HS show 30–40% of carbon–carbon unsaturation, which is selectively interpreted as ‘aromatic’. No recognition is given to the fact that NMR spect…

The nature of the chemical bond in (CH3)3N-BCl3 and (CH3)3N-AlCl3

1994

Molecular/chemical ecology in sponges. Evidence for an adaptive antibacterial response in Suberites domuncola

2004

Sponges (Porifera) represent the evolutionary oldest metazoan phylum still extant today. They have developed a complex Bauplan, based on the existence of structural and regulatory molecules; many of these have been cloned and analyzed in the past years. The demosponge Suberites domuncula has been used as a suitable model to demonstrate that these animals not only possess an adaptive immune response on the level of cytokines, but also, as pointed out here, on the level of synthesis of bioactive alkyl-lipid derivatives. From specimens of S. domuncula the two lyso-PAF (platelet-activating factor) compounds, 1-O-hexadecyl-sn-glycero-3-phosphocholine and 1-O-octadecyl-sn-glycero-3-phosphocholine…

Physiological, morphological and metabolic changes in Tetrahymena pyriformis for the in vivo cytotoxicity assessment of metallic pollution: Impact on…

2007

Abstract The individual cytotoxicity of cadmium chloride, iron sulphate and chromium nitrate has been investigated by using the freshwater ciliate Tetrahymena pyriformis. The metabolic enzymes and antioxidant defense biomarkers were assessed. The results obtained reveal that their metal salts have perturbed the physiology and morphology of T. pyriformis. Also, the biomarkers assessed were sensitive to the presence of metal salts and this sensitivity was metal salt and dose dependant. To estimate the impact of their metal salts on mitochondria, we studied their effects in vivo and in vitro on the d -β-hydroxybutyrate dehydrogenase (BDH) (EC 1.1.1.30) inner mitochondrial membrane enzyme. The …

Salt tolerance of Rana temporaria: spawning site selection and survival during embryonic development (Amphibia, Anura)

1999

AbstractSpawning site selection of Rana temporaria is dependent on the salinity of the water. In the nature reserve 'Salzwiesen von Münzenberg' (Germany) the frogs avoided increased conductivity values, Cl- ion concentrations and salinities and selected lower values for spawning. In the laboratory Gosner stages 20/21 to 22/23 were more sensitive to sodium than the earlier G stages 8 to 20/21 (exposition for 72 h) though they were exposed for the shorter time period of 24 h. The 'no observed effect concentration' (NOEC) between G stages 8/9 and 20/21 was 648 ppm (3350 μS, 2.2‰ salinity) for Na+ and 1872 ppm (6500 μS, 4.0‰ salinity) for K+. The NOEC between G stages 20/21 and 22/23 was 1490 p…