Comparison of plasma clearance of exogenous creatinine,exo-iohexol,and endo-iohexol over a range of glomerular filtration rates expected in cats     

Ingrid M. van Hoek  Hervé P. Lefebvre  Dominique Paepe  Siska Croubels  Vincent Biourge  Sylvie Daminet 《Journal of Feline Medicine and Surgery》2009,11(12):1028-1030

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Molecular analysis of the sex chromosomes of the platyfish Xiphophorus maculatus: Towards the identification of a new type of master sexual regulator in vertebrates     

ASTRID BÖHNE  Christina SCHULTHEIS  Delphine GALIANA‐ARNOUX  Alexander FROSCHAUER  Qingchun ZHOU  Cornelia SCHMIDT  Yvonne SELZ  Catherine OZOUF‐COSTAZ  Agnès DETTAI  Béatrice SEGURENS  Arnaud COULOUX  Sylvie BERNARD‐SAMAIN  Valérie BARBE  Stefan CHILMONCZYK  Frédéric BRUNET  Amandine DARRAS  Marta TOMASZKIEWICZ  Marie SEMON  Manfred SCHARTL  Jean‐Nicolas VOLFF 《Integrative zoology》2009,4(3):277-284

In contrast to mammals and birds, fish display an amazing diversity of genetic sex determination systems, with frequent changes during evolution possibly associated with the emergence of new sex chromosomes and sex‐determining genes. To better understand the molecular and evolutionary mechanisms driving this diversity, several fish models are studied in parallel. Besides the medaka (Oryzias latipes Temminck and Schlegel, 1846) for which the master sex‐determination gene has been identified, one of the most advanced models for studying sex determination is the Southern platyfish (Xiphophorus maculatus, Günther 1966). Xiphophorus maculatus belongs to the Poeciliids, a family of live‐bearing freshwater fish, including platyfish, swordtails and guppies that perfectly illustrates the diversity of genetic sex‐determination mechanisms observed in teleosts. For X. maculatus, bacterial artificial chromosome contigs covering the sex‐determination region of the X and Y sex chromosomes have been constructed. Initial molecular analysis demonstrated that the sex‐determination region is very unstable and frequently undergoes duplications, deletions, inversions and other rearrangements. Eleven gene candidates linked to the master sex‐determining gene have been identified, some of them corresponding to pseudogenes. All putative genes are present on both the X and the Y chromosomes, suggesting a poor degree of differentiation and a young evolutionary age for platyfish sex chromosomes. When compared with other fish and tetrapod genomes, syntenies were detected only with autosomes. This observation supports an independent origin of sex chromosomes, not only in different vertebrate lineages but also between different fish species.  相似文献   

Quercetin exhibits a specific fluorescence in cellular milieu: a valuable tool for the study of its intracellular distribution     

Nifli AP  Theodoropoulos PA  Munier S  Castagnino C  Roussakis E  Katerinopoulos HE  Vercauteren J  Castanas E 《Journal of agricultural and food chemistry》2007,55(8):2873-2878

The elaboration of novel techniques for flavonoid intracellular tracing would elucidate the compounds' absorption and bioavailability and assist molecular and pharmacological approaches, as they are promising candidates for drug development. This study exploited the properties of quercetin (3,3',4',5,7-pentahydroxyflavone), found in high concentrations in the majority of edible plants. Through the use of UV-vis spectroscopy, confocal microscopy, and HPLC-ESI-MS, native quercetin, at physiologically relevant concentrations, was found to exhibit a specific fluorescence (488 nmex/500-540 nmem) upon internalization. This fluorescence shift is due to a non-covalent binding to intracellular targets (probably proteins) and compatible with the settings applied in confocal microscopy. This property provides a valuable, selective alternative technique for quercetin tracing in cellular systems, permitting the quantitative evaluation of its transit at pharmacologically relevant concentrations and the validation of a number of already described molecular functions.  相似文献   

Assessment of anthocyanins in grape (Vitis vinifera L.) berries using a noninvasive chlorophyll fluorescence method     

Agati G  Meyer S  Matteini P  Cerovic ZG 《Journal of agricultural and food chemistry》2007,55(4):1053-1061

Anthocyanins (Anths) in grape (Vitis vinifera L.) berries harvested at véraison from Pinot Noir and Pinot Meunier cultivars were assessed nondestructively by measuring chlorophyll fluorescence (ChlF) excitation spectra. With increasing Anth content, less excitation light was transmitted to the deeper Chl layers, and thus the ChlF signal decreased proportionally. By applying Beer-Lambert's law, the logarithm of the ratio between the fluorescence excitation spectra (log FER) from a green and a red berry gave the in vivo absorption spectrum of Anths, which peaked at about 540 nm. Absolute quantitative nondestructive determination of Anths for each berry was obtained by the log FER calculated for two excitation wavelengths, 540 and 635 nm (absorbed and not-absorbed by Anths, respectively) of ChlF at 685 nm. Over a range of skin colors going from green to purple, the relationship between the log [ChlF(635)/ChlF(540)] and the Anth concentration of berry extracts was fairly well fitted (r 2 = 0.92) using a power function. Reflectance spectra on the same berry samples were also measured, and Anth reflectance indices, which were originally developed for apples and table grapes, were derived. The log FER Anth index was superior to the reflectance-ratio-based index, but was as good as the color index for red grapes (CIRG) calculated from the whole visible reflectance spectrum. The proposed log FER method, applied by means of suitable portable devices, may represent a new, rapid, and noninvasive tool for the assessment of grape phenolic maturity in vineyards.  相似文献   

Combined effects of temperature and salinity on development and survival of Atlantic halibut larvae     

Oddvar H. Ottesen  Sylvie Bolla 《Aquaculture International》1998,6(2):103-120

The effects of different combinations of temperature and salinity on development and survival of Atlantic halibut, Hippoglossus hippoglossus (L.), larvae were studied in two experiments. In the period from 57 to 120 d° post hatching, approximately 38% of the larvae died: in both experiments, mortality was significantly related to temperature, but there was no relationship to salinity.Cumulative, chronic mortality during the yolk-sac stage (until 210 d°) was related to salinity. High mortality was observed in both experiments when high salinity (>34%) was combined with incubation at either high (9 °C) or low (3 °C) temperature. The development of head lesions was significantly related to temperature, and for larvae kept at high salinity, increased mortality may have been a result of salinity stress in the injured larvae.Abnormal development of the caudal notochord, sometimes resulting in a 90-degree bend of the tail, occurred during incubation of early yolk-sac larvae in high-salinity water. The occurrence of larvae with locked jaws, and larvae with oedema in the yolk-sac sinus and pericardium, was significantly related to temperature. © Rapid Science Ltd. 1998  相似文献   

Temporal (1958–1993) and spatial patterns of land use changes in Haut-Saint-Laurent (Quebec, Canada) and their relation to landscape physical attributes     

Daiyuan Pan  Gérald Domon  Sylvie de Blois  André Bouchard 《Landscape Ecology》1999,14(1):35-52

In the last few years, landscape researchers have sought to understand temporal and spatial patterns of landscape changes in order to develop comprehensive models of land cover dynamics. To do so, most studies have used similar methods to quantify structural patterns, usually by comparing various landscape structural indices through time. Whereas the necessity for complementary approaches which might provide insights into landscape dynamics at some finer scale relevant to local managers has been expressed, few studies have proposed alternative methodologies. Moreover, the important relationship between the physical constraints of the landscape and land use dynamics has been seldom emphasized. Here we propose a methodological outline which was applied to the study of a rural landscape of Southern Quebec, Canada, to detect spatial and temporal (1958 to 1993) patterns of land cover changes at field, patch and landscape level. We then relate these patterns to the underlying physical structure of landscape elements using GIS and canonical correspondence analyses. We use the different geomorphological deposit types as stable discriminant factors which may constrain land use.Canonical correspondence analyses showed relations of land use and land use changes to the physical attributes of the landscape elements, whereas spatial analyses revealed very dynamic patterns at finer spatial and temporal scales. They highlighted the fact that not only the physical attributes of the landscape elements but also their spatial configuration were important determinants of land use dynamics in this area. Thus more land use changes occurred at the boundary between geomorphological deposit types than in any other locations. This trend is apparent for specific small-size changes (e.g. forest to crop), but not for the large-size ones (e.g. abandoned land to forest). Although land use changes are triggered by socioeconomic forces in this area, these changes are nevertheless constrained by the underlying physical landscape structure. A thorough comprehension of historical changes will enhance our capability to predict future landscape dynamics and devise more effective landscape management strategies.  相似文献   

The structure of boreal old-growth forests changes at multiple spatial scales over decades     

Kulha  Niko  Pasanen  Leena  Holmström  Lasse  De Grandpré  Louis  Gauthier  Sylvie  Kuuluvainen  Timo  Aakala  Tuomas 《Landscape Ecology》2020,35(4):843-858

Landscape Ecology - Changes in the structure of boreal old-growth forests are typically studied at a specific spatial scale. Consequently, little is known about forest development across different...  相似文献   

In situ roots decompose faster than shoots left on the soil surface under subtropical no-till conditions     

Majid Mahmood Tahir  Sylvie Recous  Celso Aita  Raquel Schmatz  Getúlio Elias Pilecco  Sandro José Giacomini 《Biology and Fertility of Soils》2016,52(6):853-865

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Preliminary evaluation of purified lignin and hemicellulose as prebiotics candidates for Atlantic Salmon,Salmo salar L.     

Rodrigue Yossa  Sylvie Levesque  David B. Groman  Jairo H. Lora 《Journal Of Applied Aquaculture》2018,30(3):256-271

A study was conducted to investigate the potential of purified lignin and hemicellulose as prebiotics in diets for Atlantic salmon, Salmo salar L., postsmolt in seawater (30 ppt) at 14.9 ± 1.2°C. Triplicate groups of fish (initial individual body mass of 101.6 ± 1.2 g) were fed either the fishmeal-dense (32% of fishmeal) control diet (A) or one of the nine diets (15% fishmeal) supplemented with lignin:hemicellulose ratios (% diet:% diet) of 0.05:0 (B), 0.25:0 (C), 0.50:0 (D), 1.00:0 (E), 0:0.05 (F), 0:0.25 (G), 0:0.50 (H), 0.05:0.25 (I), and 0.25:0.50 (J) for 12 weeks in a complete randomized experimental design. At the end of the experiment, the thermal-unit growth coefficient (TGC) was significantly lower in salmon fed diets with 0.50% and 1.00% purified lignin than those fed the control diet, while there was no significant difference between the other treatments and the control diet (P < 0.05). The feed efficiency (FE) was significantly lower in salmon fed diets with 0.50% and 1.00% purified lignin and 0.05% hemicellulose than those fed the control diet, while there was no significant difference between the other treatments and the control diet (P < 0.05). The hepatosomatic index (HSI), intestinal villus length, and apparent digestibility coefficient (ADC) of nutrients in diets were similar (P > 0.05) among all the diets. This study demonstrated that inclusions of up to 0.25% of dietary purified lignin alone, and 0.25%–0.50% of dietary hemicellulose alone or in combination with dietary lignin can be considered as candidate prebiotics in Atlantic salmon nutrition.  相似文献