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51.
New Caledonia is well known as a hot spot of biodiversity whose origin as a land mass can be traced back to the Gondwanan supercontinent. The local flora and fauna, in addition to being remarkably rich and endemic, comprise many supposedly relictual groups. Does the New Caledonian biota date back to Gondwanan times, building up its richness and endemism over 100 Myr or does it result from recent diversifications after Tertiary geological catastrophic events? Here we use a molecular phylogenetic approach to answer this question with the study of the Neocaledonian cockroach genus Angustonicus belonging to the subfamily Tryonicinae from Australia and New Caledonia. Both geological and molecular dating show that the diversification of this group is less than two million years old, whatever the date of its origin itself. This dating is not consistent with hypotheses of Gondwanan richness and endemism in New Caledonian biota. In other terms, local richness and endemism at the specific level are not necessarily related to an old Gondwanan origin of the Neocaledonian groups. © The Willi Hennig Society 2005.  相似文献   
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The synthesis and evaluation as tryptase inhibitors of a library of 2,5-diketopiperazine derivatives containing guanidine or amidine functional groups is reported. Among the compounds evaluated, derivatives 6{CG4-CG8} and 6{CG4-CG9} are the most active compounds and have marked selectivity towards tryptase in front of trypsin.  相似文献   
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The synthesis and structure-activity relationships of piperidinylpyrrolopyridines as potent and selective H(1) antagonists are discussed. It was found that the nature of the acid chain bonded to piperidine was a key feature for maintaining both the duration of action in vivo and lack of sedative properties.  相似文献   
54.
Affordable and easy-to-use methods for assessing biomass and leaf area index (LAI) would be of interest in most breeding programs. Here, we describe the evaluation of a protocol for photographic sampling and image analysis aimed at providing low-labor yet robust indicators of biomass and LAI. In this trial, two genotypes of triticale, two of bread wheat, and four of tritordeum were studied. At six dates during the growing cycle, biomass and LAI were measured destructively, and digital photography was taken on the same dates. Several vegetation indices were calculated from each image. The results showed that repeatable and consistent values of the indices were obtained in consecutive photographic samplings on the same plots. The photographic indices were highly correlated with the destructive measure-ments, though the magnitude of the correlation was lower after anthesis. This work shows that photographic assess-ment of biomass and LAI can be fast, affordable, have good repeatability, and can be used under bright and overcast skies. A practical vegetation index derived from pictures is the fraction of green pixels over the total pixels of the image, and as it shows good correlations with all biomass variables, is the most robust to lighting conditions and has easy interpretation.  相似文献   
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The main objective of this study was to assess organic matter (OM) and methylmercury (MeHg) sources for freshwater littoral macroinvertebrate primary consumers. The carbon and nitrogen stable isotope ratios (δ13C, δ15N) of sources (epiphytes, macrophytes, suspended particulate matter _SPM) and of macroinvertebrate consumers were measured in a fluvial lake with extensive macrophyte beds (emergent and submerged). To determine the relative contribution of each OM source to macroinvertebrate diets we used the IsoSource model that examines all possible combinations of solutions for each source. Total and MeHg concentrations of consumers were also measured. Results show that epiphytes and macrophytes are dominant in the diet of macroinvertebrates, especially in early summer (July). In mid-summer (August), SPM constitutes a non-negligible OM source to the primary consumers. Hg concentrations were higher in epiphytes than in the other OM sources. The proportion of epiphytes in macroinvertebrate diet was positively correlated with the percentage of MeHg in their tissues. There was no relationship between SPM assimilation and Hg concentration in macroinvertebrate consumers. These results suggest that epiphytes and macrophytes constitute the main pathway of Hg bioaccumulation in littoral food webs.
Fabien CremonaEmail: Email:
  相似文献   
57.
This study aims to establish themathematical relationship between allergenicpollen in the air and clinical cases ofpollinosis (hay fever) in humans, and toevaluate the immediate effect of wind and rainon such cases. The pollen was collected inFigueres, Catalonia, Spain (42°30 Nand 3° E), through a filtration method,in the spring of 1998. Skin tests revealed thatthe antigenic taxa are Olea europaea,Plantago sp., Parietaria officinalisand Gramineae. A linear correlation –with the number of days with presence of pollenas the abscissa and the number of days withcoincidence of pollinosis as the ordinate – wasperformed. The linear correlation coefficientwas 0.9285, at the limit of a directcorrelation by two degrees of freedom.Furthermore, a negative relationship wasobserved between the number of days with rainand number of days with pollinosis, and apositive relationship between the number ofdays with fixed wind speed and number of dayswith pollinosis.  相似文献   
58.
C75 is a synthetic compound described as having antitumoral properties. It produces hypophagia and weight loss in rodents, limiting its use in cancer therapy but identifying it as a potential anti‐obesity drug. C75 is a fatty acid synthase (FAS) inhibitor and, through its coenzyme A (CoA) derivative, it acts as a carnitine palmitoyltransferase (CPT) 1 inhibitor. Racemic mixtures of C75 have been used in all the previous studies; however, the potential different biological activities of C75 enantiomers have not been examined yet. To address this question we synthesized the two C75 enantiomers separately. Our results showed that (?)‐C75 inhibits FAS activity in vitro and has a cytotoxic effect on tumor cell lines, without affecting food consumption. (+)‐C75 inhibits CPT1 and its administration produces anorexia, suggesting that central inhibition of CPT1 is essential for the anorectic effect of C75. The differential activity of C75 enantiomers may lead to the development of potential new specific drugs for cancer and obesity. Chirality 25:281–287, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
59.
We measured ingestion rates of Calanoides acutus on different microbial components of the Gerlache Strait (GE) and Bellingshausen Sea (BE) waters during December 2002. At the time of the study the abundance of both zooplankton (42–133 ind m−3) and phytoplankton (0.76–1.5 µg chlorophyll a l−1) were low, indicating that the spring phytoplankton bloom was still not fully developed. C. acutus showed high clearance rates along the study (up to 432 ml ind−1 day−1), selecting for large motile organisms such as ciliates and the dinoflagellate Gyrodinium spp., although their feeding impact was always <0.1% of the standing stock of any of their prey. The total daily rations were low (∼2% body carbon per day), mostly the result of phytoplankton consumption (except for station GE3 in which heterotrophic flagellates contributed to 73% of the diet), and barely enough to cover metabolic demands. Based on the relationship between oxygen (carbon) consumption and ammonia excretion (considered as indicative of the metabolic substrate) it seems that standard metabolic demands were supplied, apart from the diet, by the use of their own non-structural proteins, whereas the remaining reserve-lipids were used to produce eggs.  相似文献   
60.
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