Predicting load path and tensile forces during cable yarding operations on steep terrain     

Sylvain Dupire  Franck Bourrier  Frédéric Berger 《Journal of Forest Research》2016,21(1):1-14

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DNA Quantity and Quality in Remnants of Traffic-Killed Specimens of an Endangered Longhorn Beetle: A Comparison of Different Methods     

Hans-Peter Rusterholz  Sylvain Ursenbacher  Armin Coray  Urs Weibel  Bruno Baur 《Journal of insect science (Online)》2015,15(1)

The sampling of living insects should be avoided in highly endangered species when the sampling would further increase the risk of population extinction. Nonlethal sampling (wing clips or leg removals) can be an alternative to obtain DNA of individuals for population genetic studies. However, nonlethal sampling may not be possible for all insect species. We examined whether remnants of traffic-killed specimens of the endangered and protected flighless longhorn beetle Iberodorcadion fuliginator (L., 1758) can be used as a resource for population genetic analyses. Using insect fragments of traffic-killed specimens collected over 15 yr, we determined the most efficient DNA extraction method in relation to the state of the specimens (crushed, fragment, or intact), preservation (dried, airtight, or in ethanol), storage duration, and weight of the sample by assessing the quantity and quality of genomic DNA. A modified cetyltrimethyl ammonium bromide method provided the highest recovery rate of genomic DNA and the largest yield and highest quality of DNA. We further used traffic-killed specimens to evaluate two DNA amplification techniques (quantitative polymerase chain reaction [qPCR] and microsatellites). Both qPCR and microsatellites revealed successful DNA amplification in all degraded specimens or beetle fragments examined. However, relative qPCR concentration and peak height of microsatellites were affected by the state of specimen and storage duration but not by specimen weight. Our investigation demonstrates that degraded remnants of traffic-killed beetle specimens can serve as a source of high-quality genomic DNA, which allows to address conservation genetic issues.  相似文献   

The fate of condensed tannins during litter consumption by soil animals     

Mathieu Coulis  Sylvie Rapior  Sylvain Coq 《Soil biology & biochemistry》2009,41(12):2573-2578

Condensed tannins (CT) can strongly affect litter decomposition, but their fate during the decomposition process, in particular as influenced by detritivore consumption, is not well understood. We tested the hypothesis that litter CT are reduced by the gut passage of two functionally distinct detritivores of Mediterranean forests, the millipede Glomeris marginata, and the land snail Pomatias elegans, as a fixed proportion of initial litter CT, but more so in Pomatias since snails are known to have a more efficient enzymatic capacity. Contrary to our hypothesis, both detritivore species reduced litter CT to near zero in their faecal pellets irrespective of the wide range in initial leaf litter CT concentrations of 9-188 mg g⁻¹ d m among three Mediterranean tree species (Pistacia terebinthus, Quercus ilex, Alnus glutinosa) and different decomposition stages of their litter. The almost complete disappearance of CT even from some litter types highly concentrated in CT, due to either degradation by gut microorganism or complexation of CT into insoluble high molecular weight structures, suggests a high “de-tanning” efficiency across functionally distinct detritivore species. The transformation of CT-rich litter into virtually CT-free faecal pellets by detritivores might be highly relevant for the subsequent decomposition process in ecosystems with a high macrofauna abundance and CT-rich plant species such as Mediterranean forests.  相似文献   

Spatial distribution of sediments and transfer properties in soils in a stormwater infiltration basin   总被引：3，自引：2，他引：1  

Patrice Cannavo  Laure Vidal-Beaudet  Béatrice Béchet  Laurent Lassabatère  Sylvain Charpentier 《Journal of Soils and Sediments》2010,10(8):1499-1509

Purpose  

The aim of our study was to characterise the heterogeneity of sediment distribution in a stormwater retention/infiltration basin (Pont de Cheviré, Nantes, France) and to determine the impact of this distribution on water transfer properties in the soil.  相似文献   

In vivo and in situ rhizosphere respiration in Acer saccharum and Betula alleghaniensis seedlings grown in contrasting light regimes     

Delagrange S  Huc F  Messier C  Dizengremel P  Dreyer E 《Tree physiology》2006,26(7):925-934

A perfusive method combined with an open-system carbon dioxide measurement system was used to assess rhizosphere respiration of Acer saccharum Marsh. (sugar maple) and Betula alleghaniensis Britton (yellow birch) seedlings grown in 8-l pots filled with coarse sand. We compared in vivo and in situ rhizosphere respiration between species, among light regimes (40, 17 and 6% of full daylight) and at different times during the day. To compute specific rhizosphere respiration, temperature corrections were made with either species-specific coefficients (Q10) based on the observed change in respiration rate between 15 and 21 degrees C or an arbitrarily assigned Q10 of 2. Estimated, species-specific Q10 values were 3.0 and 3.4 for A. saccharum and B. alleghaniensis, respectively, and did not vary with light regime. Using either method of temperature correction, specific rhizosphere respiration did not differ either between A. saccharum and B. alleghaniensis, or among light regimes except in A. saccharum at 6% of full daylight. At this irradiance, seedlings were smaller than in the other light treatments, with a larger fine root fraction of total root dry mass, resulting in higher respiration rates. Specific rhizosphere respiration was significantly higher during the afternoon than at other times of day when temperature-corrected on the basis of an arbitrary Q10 of 2, suggesting the possibility of diurnal variation in a temperature-independent component of rhizosphere respiration.  相似文献   

Determination of annual reproductive cycle in male sterlet,Acipenser ruthenus using histology and ultrasound imaging     

Golpour  Amin  Broquard  Coralie  Milla  Sylvain  Dadras  Hadiseh  Baloch  Abdul Rasheed  Saito  Taiju  Pšenička  Martin 《Fish physiology and biochemistry》2021,47(3):703-711

Fish Physiology and Biochemistry - The aim of this study was to evaluate seasonal testicular development in the cultured sterlet, Acipenser ruthenus. During annual sexual cycle of male sterlet,...  相似文献   

Is the use of recombinant cGnRH may be a future alternative to control the fish spawning? Let us go with the goldfish example     

Mohammadzadeh  Sedigheh  Milla  Sylvain  Ahmadifar  Ehsan  Karimi  Masoumeh  Dawood  Mahmoud A. O. 《Fish physiology and biochemistry》2021,47(4):951-960

The use of recombinant gonadotropin-releasing hormone (rGnRH) has very rarely been tested in fish to promote spawning. This study evaluated the impact of recombinant chicken gonadotropin-releasing hormone (rcGnRH) with metoclopramide on the release of sex steroids and final maturation induction in goldfish (Carassius auratus) broodstock. For this purpose, goldfish broodstock was divided into four groups and treated with 0.9% NaCl with 20 mg/kg metoclopramide (Met) (C); 10 μg/kg body weight (BW) rcGnRH with 20 mg/kg metoclopramide (rcGn10); 15 μg/kg BW rcGnRH with 20 mg/kg metoclopramide (rcGn15); and 20 μg/kg BW rcGnRH with 20 mg/kg metoclopramide (rcGn20). The capability of the rcGnRH for eliciting biological response was tested in vivo by evaluating the changes of 17β estradiol (E2), testosterone (T), and 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) and the induced spawning. Blood samples were obtained at 0 h, 12 h, and 24 h after injection. The rcGn10, rcGn15, and rcGn20 treatments induced lower E2 concentration, especially 24 h post-injection. T levels were significantly higher in rcGn10, rcGn15, and rcGn20 treatments 12 h post-injection than at 0 h and then decreased at 24 h post-injection. Furthermore, the rcGnRH tested significantly enhanced DHP secretion in rcGn10, rcGn15, and rcGn20 treatments 12 h post-injection before a decline at 24 h post-injection. No significant difference between the sampling times was found in the C treatment for the 3 sex steroids tested. The results also displayed that rcGnRH at 10–20 µg/kg of body weight can trigger spawning with the highest speed and efficiency of spawning at 20 µg/kg. The obtained results represent a possible strategy for enhancing the artificial reproduction and ovulation of broodstock fish by rGnRH and further support the use of recombinant hormones to promote reproduction in aquaculture.

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Relationships involving several types of extractives of five native argentine wood species of genera Prosopis and Acacia   总被引：1，自引：0，他引：1  

Benedetto Pizzo  Carolina L. PomettiJean-Paul Charpentier  Nathalie BoizotBeatriz O. Saidman 《Industrial Crops and Products》2011,34(1):851-859

The relationships existing among the values obtained when extracting the wood of four Argentinean species of Prosopis (P. alba, P. kuntzei, P. nigra, and P. ruscifolia) and one of the Acacia (A. aroma) by several procedures were evaluated and discussed. The used methods were: extraction in toluene/ethanol and hot water; determination of tannic and non-tannic content; measurement of phenolic compounds. Additionally, liquid chromatography (HPLC) was also used in order to quantitatively evaluate the content of (−)-mesquitol, a relatively unusual flavonoid (flavanol type). The total amount of Oxidation Products was also measured. They result from oxidation and polymerization processes of phenolic compounds occurring during heartwood formation, and were not separated during chromatographic analysis. Data evidenced a linear trend (R² = 0.970) between organic and tannic extractives of all species, and a similar one (R² = 0.927) between total phenols and tannic (or organic) extractives in the case of heartwood of Prosopis species. Interestingly, for sapwood very different values of organic extracts, tannic content or Oxidation Products type compounds were measured in spite of a similar amount of phenolic substances. Moreover, the various species presented the same peaks in chromatograms, thus evidencing the chemical similarity of compounds but a different quantity between heartwood and sapwood and also among the various species. The observed similarity implied that the various methods of extraction did not really extract only a single class of substances, and that great care must be adopted when using some specific procedures for extractions.Furthermore, the existing relationships between extractives and selected technological properties, namely specific volumetric shrinkage coefficient (BSvol) and natural durability (evaluated in terms of mass loss after fungal attacks in laboratory conditions), were given. It appeared that in heartwood BSvol was well correlated to organic extractives (R² = 0.984), thus evidencing the microimpregnation of cell walls by extractives, but the fitting quality of the correlation was dependent on the type of extractives used. Analogously, a good relationship between mass loss and phenolic compounds existed (R² = 0.764), and in this case the value of R² was even more dependent on the considered extracts. Moreover, the availability of quantitative data on several Prosopis species allowed to consistently evaluate the bioactivity of (−)-mesquitol on the resistance against fungal attack, and the logarithmic form of the relationship between mass loss and (−)-mesquitol content suggested a direct fungicidal activity of this compound. On the other hand, data also evidenced that neither phenolic compounds nor (−)-mesquitol can be considered as the unique and definite factor able to determine the durability of the considered species.  相似文献   

Antioxidant activity and phenolic composition of the medicinal and edible halophyte Mesembryanthemum edule L.     

Hanen Falleh  Riadh KsouriFaten Medini  Sylvain GuyotChedly Abdelly  Christian Magné 《Industrial Crops and Products》2011,34(1):1066-1071

Mesembryanthemum edule L. (sourfig, Aizoaceae) has long been used as food and in traditional medicine. This study was intended to characterize the antioxidant properties and the phenolic compounds of M. edule leaf, stem and root. The approach consisted to evaluate these organs for their antioxidant activities through several in vitro tests, to determine tissue contents in total phenolics, flavonoids and proanthocyanidins and to establish the phenolic composition through RP-HPLC analysis. All studied organs showed a high antioxidant activity as compared to positive control BHT, with maximal efficiency for stems followed by leaves and roots. The highest polyphenolic levels were found in stems and leaves (86.5 and 68.7 mg GAE g⁻¹ DW, respectively), suggesting that their strong antioxidant activity could be attributed to these phytochemicals. The HPLC analysis revealed that the main phenolic compounds were quercitrin and avicularin (1.4 and 1.15 mg g⁻¹ DW, respectively) in the leaves, while catechin and procyanidin B2 (1.66 and 1.54 mg g⁻¹ DW, respectively) were the most abundant phenolics in the stems. Overall, the strong antioxidant activity and richness of M. edule aerial tissues suggest that it could be advantageously used as a functional or nutraceutical food, to prevent or moderate oxidative stress-related diseases.  相似文献   

An inconvenient truth about xylem resistance to embolism in the model species for refilling <Emphasis Type="Italic">Laurus nobilis</Emphasis> L.     

Laurent J. Lamarque  Déborah Corso  José M. Torres-Ruiz  Eric Badel  Timothy J. Brodribb  Régis Burlett  Guillaume Charrier  Brendan Choat  Hervé Cochard  Gregory A. Gambetta  Steven Jansen  Andrew King  Nicolas Lenoir  Nicolas Martin-StPaul  Kathy Steppe  Jan Van den Bulcke  Ya Zhang  Sylvain Delzon 《Annals of Forest Science》2018,75(3):88

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