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Species Capable (species + capable)
Selected AbstractsTreatment of PCB-contaminated soils: I. Evaluation of in situ reductive dechlorination of PCBsENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2001Robert C. Ahlert PhD PE Soil samples were obtained from a site contaminated with PCBs. PCB contamination is not uniform at the source of the samples. Some may be present as isolated "hot spots." The anaerobic phase of a two-stage bioremediation process was evaluated. Populations of native organisms were very low. Species capable of dechlorination of PCBs did not proliferate under anaerobic conditions in the laboratory. Reductive dechlorination did not occur. In-situ reductive dechlorination of heavily substituted PCB congeners is not likely to make a useful contribution to elimination at the site represented by the soil samples. [source] Multiple-brooding in birds of prey: South African Black Sparrowhawks Accipiter melanoleucus extend the boundariesIBIS, Issue 1 2005ODETTE CURTIS Multiple-brooding (raising more than one brood of young in quick succession) occurs infrequently in raptors and is generally restricted to either smaller species with shorter nesting periods, co-operative breeders or species capable of capitalizing on conditions of prolonged food abundance whenever they occur. This paper presents the first recorded cases of multiple-brooding in the Black Sparrowhawk Accipiter melanoleucus from two distinct locales in South Africa. In the Western Cape (Cape Peninsula), four attempts to multiple-brood were recorded in four different years, involving three distinct pairs of birds, and in KwaZulu,Natal (Eshowe), three distinct pairs of Sparrowhawks successfully multiple-brooded on several occasions over a 5-year study period. These results establish the Black Sparrowhawk as one of only two relatively large, monogamous raptor species, and the only specialist bird-eating raptor, in which multiple-brooding has been recorded with any frequency. The species' capacity to thrive in human-modified environments (i.e. alien plantations) and particularly to exploit associated foraging opportunities (e.g. high densities of doves and pigeons in suburban areas) may, at least partly, account for the instances of multiple-brooding reported here. We suggest that biologists be more vigilant for cases of multiple-brooding in raptors, as it is possible that this trait is more common than originally thought and has previously been overlooked. [source] Abundance and clonal replication in the tropical corallimorpharian Rhodactis rhodostomaINVERTEBRATE BIOLOGY, Issue 4 2000Nanette E. Chadwick-Furman Abstract. The corallimorpharian Rhodactis rhodostoma appears to be an opportunistic species capable of rapidly monopolizing patches of unoccupied shallow substrate on tropical reefs. On a fringing coral reef at Eilat, Israel, northern Red Sea, we examined patterns of abundance and clonal replication in R. rhodostoma in order to understand the modes and rates of spread of polyps across the reef flat. Polyps were abundant on the inner reef flat (maximum 1510 polyps m,2 and 69% cover), rare on the outer reef flat, and completely absent on the outer reef slope at >3 m depth. Individuals cloned throughout the year via 3 distinct modes: longitudinal fission, inverse budding, and marginal budding. Marginal budding is a replicative mode not previously described. Cloning mode varied significantly with polyp size. Approximately 9% of polyps cloned each month, leading to a clonal doubling time of about 1 year. The rate of cloning varied seasonally and depended on day length and seawater temperature, except for a brief reduction in cloning during midsummer when polyps spawned gametes. Polyps of R. rhodostoma appear to have replicated extensively following a catastrophic low-tide disturbance in 1970, and have become an alternate dominant to stony corals on parts of the reef flat. [source] Acceleration of nitric oxide autoxidation and nitrosation by membranesIUBMB LIFE, Issue 4-5 2007Matias N. Möller Abstract The reaction between nitric oxide (,NO) and oxygen yields reactive species capable of oxidizing and nitrosating proteins, as well as deaminating DNA bases. Although this reaction is considered too slow to be biologically relevant, it has been shown that membranes, lipoproteins, mitochondria and possibly proteins can accelerate this reaction. This effect stems from the higher solubility of both ,NO and O2in the hydrophobic phase of these biological particles, leading to a concentration of both reagents and so a higher rate of reaction. It has been determined that this reaction occurs from 30 to 300 times more rapidly within the membrane, while even higher values have been suggested for proteins. The autoxidation of ,NO in membranes is not the main route for cellular ,NO consumption but an important consequence of this phenomenon is to focus the generation of significant amounts of oxidizing and nitrosating molecules (nitrogen dioxide and dinitrogen trioxide) in the small volume comprised by cellular membranes. Even so, these reactive species are diffusible and their ultimate fate will depend on the reactivity towards available substrates rather than on physical barriers. The acceleration of ,NO autoxidation by biological hydrophobic phases may thus be a general phenomenon that increases in importance in cases of ,NO overproduction. IUBMB Life, 59: 243-248, 2007 [source] MOLECULAR AND PHYLOGENETIC CHARACTERIZATION OF PHORMIDIUM SPECIES (CYANOPROKARYOTA) USING THE CPCB-IGS-CPCA LOCUS,JOURNAL OF PHYCOLOGY, Issue 1 2005Ivanka Teneva The accurate determination of species of Cyanoprokaryota/Cyanophyceae has many important applications. These include the assessment of risk with regard to blooms in water reservoirs as well as the identification of species capable of producing valuable bioactive compounds. Commonly, Cyanoprokaryota are classified based on their morphology. However, morphological criteria are not always reliable because they may change, for example, due to environmental factors. Thus, genetic and molecular analyses are a promising additional approach, but their application has so far been limited to relatively few genera. In light of this, we present here the first characterization of species and strains of the genus Phormidium Kütz. based on the cpcB-IGS-cpcA locus of the phycocyanin operon. In phylogenetic analyses using deduced amino acid sequences of the cpcB-cpcA regions, Phormidium was found to be polyphyletic. This analysis appeared to be dominated by the cpcB region, which is characterized by a relatively high percentage of informative substitutions. The percentage of variable positions within the cpcB-IGS-cpcA locus overall was 16.5%, thereby indicating a level of divergence remarkably higher than that reported for Nodularia and Arthrospira in previous studies relying on cpcB-IGS-cpcA. Further, alignment of informative nucleotide substitutions in the cpcB-IGS-cpcA sequences revealed a mosaic distribution, which may be indicative of genetic recombination events. Finally, the length and sequences of the IGS region alone proved useful as markers to differentiate the cyanobacterial genus Phormidium. However, whether the IGS region per se is sufficiently discriminatory to differentiate between Phormidium species or even strains requires further investigation using newly identified Phormidium sequence data. [source] Ease and effectiveness of costly autotomy vary with predation intensity among lizard populationsJOURNAL OF ZOOLOGY, Issue 3 2004William E. Cooper Jr Abstract Costly anti-predatory defences are used in ecological time and maintained in evolutionary time by natural selection favouring individuals that survive through their use. Autotomy of expendable body parts is a striking example of a defence having multiple substantial costs, including loss of ability to use the same defence, loss of energy, and decreased growth, reproductive success and survival following autotomy, plus the energetic cost of replacing the lost body part in species capable of regenerating them. Our study shows that autotomy in the lacertid lizard Podarcis lilfordi reduces sprint speed, indicating decreased capacity to escape as well as the loss of energy. Autotomy carries substantial cost, and thus should be avoided except as a last resort. Ease of autotomy and post-autotomic movements were studied in three populations of lacertid lizards. Two were islet populations of P. lilfordi from Aire (lowest predation pressure) and Colom (intermediate predation pressure) off Minorca. The third was a mainland population of Podarcis hispanica, a closely related species from the mainland of the Iberian Peninsula where predation pressure is higher than on the islets. As predicted, a suite of autotomic traits increases the effectiveness of autotomy as a defence as predation pressure increases. With increasing predation pressure, the frequency of voluntary autotomy increases, latency to autotomy decreases, pressure on the tail needed to induce autotomy decreases, vigour of post-autotomic tail movements increases, and distance moved by the shed tail increases. Additional changes that might be related to predation pressure, but could have other causes, are the presence of tail coloration contrasting with body coloration except under the lowest predation pressure (Aire) and longer tails in the mainland species P. hispanica. Correspondence between predation pressure and the suite of autotomic traits suggests that autotomy is an important defence that responds to natural selection. Comparative data are needed to establish the generality of relationships suggested in our study of only three populations. [source] Biogenic amine production by lactic acid bacteria isolated from ciderLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2007G. Garai Abstract Aims:, To study the occurrence of histidine, tyrosine and ornithine decarboxylase activity in lactic acid bacteria (LAB) isolated from natural ciders and to examine their potential to produce detrimental levels of biogenic amines. Methods and Results:, The presence of biogenic amines in a decarboxylase synthetic broth and in cider was determined by reversed-phase high-performance liquid chromatography (RP-HPLC). Among the 54 LAB strains tested, six (five lactobacilli and one oenococci) were biogenic amine producers in both media. Histamine and tyramine were the amines formed by the LAB strains investigated. Lactobacillus diolivorans were the most intensive histamine producers. This species together with Lactobacillus collinoides and Oenococcus oeni also seemed to produce tyramine. No ability to form histamine, tyramine or putrescine by Pediococus parvulus was observed, although it is a known biogenic amine producer in wines and beers. Conclusions:, This study demonstrated that LAB microbiota growing in ciders had the ability to produce biogenic amines, particularly histamine and tyramine, and suggests that this capability might be strain-dependent rather than being related to a particular bacterial species. Significance and Impact of the Study:, Production of biogenic amines by food micro-organisms has continued to be the focus of intensive study because of their potential toxicity. The main goal was to identify the microbial species capable of producing these compounds in order to control their presence and metabolic activity in foods. [source] The role of pre- and post- alighting detection mechanisms in the responses to patch size by specialist herbivoresOIKOS, Issue 3 2005Tibor Bukovinszky Experimental data on the relationship between plant patch size and population density of herbivores within fields often deviates from predictions of the theory of island biogeography and the resource concentration hypothesis. Here we argue that basic features of foraging behaviour can explain different responses of specialist herbivores to habitat heterogeneity. In a combination of field and simulation studies, we applied basic knowledge on the foraging strategies of three specialist herbivores: the cabbage aphid (Brevicoryne brassicae), the cabbage butterfly (Pieris rapae L.) and the diamondback moth (Plutella xylostella L.), to explain differences in their responses to small scale fragmentation of their habitat. In our field study, populations of the three species responded to different sizes of host plant patches (9 plants and 100 plants) in different ways. Densities of winged cabbage aphids were independent of patch size. Egg-densities of the cabbage butterfly were higher in small than in large patches. Densities of diamondback moth adults were higher in large patches than in small patches. When patches in a background of barley were compared with those in grass, densities of the cabbage aphid and the diamondback moth were reduced, but not cabbage butterfly densities. To explore the role of foraging behaviour of herbivores on their response to patch size, a spatially explicit individual-based simulation framework was used. The sensory abilities of the insects to detect and respond to contact, olfactory or visual cues were varied. Species with a post-alighting host recognition behaviour (cabbage aphid) could only use contact cues from host plants encountered after landing. In contrast, species capable with a pre-alighting recognition behaviour, based on visual (cabbage butterfly) or olfactory (diamondback moth) cues, were able to recognise a preferred host plant whilst in flight. These three searching modalities were studied by varying the in flight detection abilities, the displacement speed and the arrestment response to host plants by individuals. Simulated patch size , density relationships were similar to those observed in the field. The importance of pre- and post- alighting detection in the responses of herbivores to spatial heterogeneity of the habitat is discussed. [source] Improved detection of reactive metabolites with a bromine-containing glutathione analog using mass defect and isotope pattern matchingRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 9 2010André LeBlanc Drug bioactivation leading to the formation of reactive species capable of covalent binding to proteins represents an important cause of drug-induced toxicity. Reactive metabolite detection using invitro microsomal incubations is a crucial step in assessing potential toxicity of pharmaceutical compounds. The most common method for screening the formation of these unstable, electrophilic species is by trapping them with glutathione (GSH) followed by liquid chromatography/mass spectrometry (LC/MS) analysis. The present work describes the use of a brominated analog of glutathione, N -(2-bromocarbobenzyloxy)-GSH (GSH-Br), for the invitro screening of reactive metabolites by LC/MS. This novel trapping agent was tested with four drug compounds known to form reactive metabolites, acetaminophen, fipexide, trimethoprim and clozapine. Invitro rat microsomal incubations were performed with GSH and GSH-Br for each drug with subsequent analysis by liquid chromatography/high-resolution mass spectrometry on an electrospray time-of-flight (ESI-TOF) instrument. A generic LC/MS method was used for data acquisition, followed by drug-specific processing of accurate mass data based on mass defect filtering and isotope pattern matching. GSH and GSH-Br incubations were compared to control samples using differential analysis (Mass Profiler) software to identify adducts formed via the formation of reactive metabolites. In all four cases, GSH-Br yielded improved results, with a decreased false positive rate, increased sensitivity and new adducts being identified in contrast to GSH alone. The combination of using this novel trapping agent with powerful processing routines for filtering accurate mass data and differential analysis represents a very reliable method for the identification of reactive metabolites formed in microsomal incubations. Copyright © 2010 John Wiley & Sons, Ltd. [source] Artificial molecular-level machinesTHE CHEMICAL RECORD, Issue 6 2001Vincenzo Balzani Abstract The concept of "machine" can be extended to the molecular level by designing supramolecular species capable of performing mechanical-like movements as a consequence of an appropriate energy supply. Molecular-level machines operate via electronic and nuclear rearrangements, for example, through some kind of chemical reaction. Like macroscopic machines, they are characterized by: (i) the kind of energy input supplied to make them work, (ii) the kind of movement performed by their components, (iii) the way in which their operation can be controlled and monitored, (iv) the possibility to repeat the operation at will and establish a cyclic process, (v) the time scale needed to complete a cycle of operation, and (vi) the function performed. A crucial issue is that concerning energy supply. Artificial machines powered by chemical energy ("fuels") produce waste products whose accumulation compromises the operation of the machine unless they are removed from the system. Photochemical and electrochemical energy inputs, however, can be used to make a machine work without formation of waste products. Examples of chemically, electrochemically, and photochemically powered machines investigated in our laboratory are reviewed, and future directions for the construction of novel machines are illustrated. The two most interesting kinds of applications of molecular-level machines are related to the mechanical aspect, which can be exploited, for example, for molecular-level transportation purposes, and the logic aspect, which can be exploited for information processing at the molecular level and, in the long run, for the construction of molecular level (chemical) computers. © 2001 John Wiley & Sons, Inc. and The Japan Chemical Journal Forum Chem Rec 1:422,435, 2001 [source] Sexual dimorphism of vocal control nuclei in budgerigars (Melopsittacus undulatus) revealed with Nissl and NADPH-d stainingTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2005Steven E. Brauth Abstract Nissl staining and nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) histochemistry were used to explore the existence of sexual dimorphism in vocal control nuclei of adult budgerigars (Melopsittacus undulatus), a parrot species capable of lifelong vocal learning. Behavioral studies indicate that adult males possess larger vocal repertoires than adult females and learn new calls more quickly. The results of the present study show that the volumes of all vocal nuclei, as measured using both Nissl-stained and NADPH-d-stained material, as well as the total numbers of NADPH-d neurons, were 35,110% greater in males. Furthermore, all vocal nuclei exhibit conspicuous NADPH-d staining compared to surrounding fields in both adult males and females. Nevertheless, there were no significant gender differences in either the intensity of neuropil staining or the densities of NADPH-d neurons in vocal nuclei. Moreover NADPH-d neuron somal shapes were similar in males and females. Diameters of NADPH-d neurons in vocal nuclei were 8.5,32% larger in males than in females. Greater size of NADPH-d neuronal somata in males may be a general property of this cell type in budgerigars because a similar gender difference was found in a visual nucleus, the entopallium, which is not directly associated with the vocal control system and does not exhibit sexual dimorphism in total volume or total NADPH-d neuron numbers. Taken together, the results of the present study favor the hypothesis that superior lifelong vocal learning ability in male budgerigars rests largely on larger volumes of vocal control nuclei in males rather than on sexual dimorphism in the internal composition of vocal nuclei. J. Comp. Neurol. 484:15,27, 2005. © 2005 Wiley-Liss, Inc. [source] | |||||||||||||