Background: The Cambodian Tailorbird(Orthotomus chaktomuk) was one of the most recent major ornithological discoveries in South-east Asia as it originated from lowland seasonally flooded scrub within the densely inhab...Background: The Cambodian Tailorbird(Orthotomus chaktomuk) was one of the most recent major ornithological discoveries in South-east Asia as it originated from lowland seasonally flooded scrub within the densely inhabited floodplain around the Tonle Sap, Mekong and Bassac rivers(Cambodia). The Cambodian Tailorbird is sister to the Dark-necked Tailorbird(O. atrogularis) with very limited genetics and biometric differentiation. Between 2004 and 2012, evidences of a new population of Ashy Tailorbird(O. ruficeps) in SE Cambodia/Vietnam accumulated but no museum specimens were ever reported. The Ashy Tailorbird currently consists of eight subspecies among which the closest geographical populations, O. r. cineraceus(SE Burma to Malay Peninsula, Sumatra, Bangka and Belitung) and O. r. borneoensis(Borneo), are allopatric. Subspecific identification of the Cambodian Ashy Tailorbirds individuals was not possible because of the limited differences in plumage among subspecies.Methods: We inspected the Orthotomus ruficeps specimens housed at the Museum National d'Histoire Naturelle(Paris) and discovered five specimens of O. ruficeps collected by Louis Rodolphe Germain in ‘Cochinchina'(corresponding to southern Vietnam) during the nineteenth century. We sequenced one mitochondrial locus and gathered biometric data from these specimens and compared them with other Orthotomus lineages.Results: The Ashy Tailord population from SE Cambodia and Vietnam is distinct from the two geographically close subspecies O. r. borneoensis(1.7%) and O. r. cineraceus(1.3%). O. chaktomuk is nested within O. atrogularis in the mitochondrial gene tree. The SE Cambodia/Vietnam population of O. ruficeps is distinct from the two other subspecies in bill shape.Conclusion: Our study described the biometric and molecular distinctiveness of a recently re-discovered population of Ashy Tailord in SE Cambodia and Vietnam and suggests that this population constitutes an independent evolutionary lineage that we describe here as a new subspecies. The newly described Cambodian Tailorbird is nested within the Dark-necked Tailorbird and the genetic divergence is much lower than initially described(0.4-0.7% vs 1.1-1.4%).展开更多
Dear Editor,Johannes Lehmann and Markus Kleber,in a controversial paper entitled"The contentious nature of soil organic matter"(Lehmann and Kleber,2015),suggested the abandonment of the term"humus"...Dear Editor,Johannes Lehmann and Markus Kleber,in a controversial paper entitled"The contentious nature of soil organic matter"(Lehmann and Kleber,2015),suggested the abandonment of the term"humus"and other associated terms such as"humic","humir","humified","humification".The first reason they cited was that these labels are only instrumental in outdated soil analytical methods,which are based on alkaline extraction of soil organic matter(SOM).展开更多
BACKGROUND Metastatic colorectal cancer(mCRC)is a global health challenge with a poor prognosis.Prognostic markers are critical for survival prediction.METHODS This multicenter,retrospective study measured baseline ca...BACKGROUND Metastatic colorectal cancer(mCRC)is a global health challenge with a poor prognosis.Prognostic markers are critical for survival prediction.METHODS This multicenter,retrospective study measured baseline carcinoembryonic antigen and carbohydrate antigen 19-9 levels to calculate a TMI as the geometric mean of values normalized to their upper limits of normal.Receiver operating characteristic curve analysis assessed TMI’s prognostic accuracy,and patients were stratified into high-TMI(≥1.39)and low-TMI(<1.39)groups.The primary endpoint was overall survival(OS),with progression-free survival and treatment response as secondary endpoints.RESULTS The study included 305 mCRC patients with a median follow-up of 22.9 months.The median OS for high-TMI patients was 29.5 months,significantly lower than the 45.6 months observed in the low-TMI group(P=0.02).The 2-year OS rates for the high-and low-TMI groups were 59.4%and 72.9%,respectively.Median progression-free survival was also shorter for the high-TMI group(14.0 vs 16.0 months,P=0.84).High TMI is an independent prognostic factor for worse OS.CONCLUSION TMI is a simple,cost-effective prognostic tool for mCRC,with high TMI associated with poorer survival outcomes.展开更多
The all-vanadium redox flow battery(VRFB)plays an important role in the energy transition toward renewable technologies by providing grid-scale energy storage.Their deployment,however,is limited by the lack of membran...The all-vanadium redox flow battery(VRFB)plays an important role in the energy transition toward renewable technologies by providing grid-scale energy storage.Their deployment,however,is limited by the lack of membranes that provide both a high energy efficiency and capacity retention.Typically,the improvement of the battery’s energy efficiency comes at the cost of its capacity retention.Herein,novel N-alkylated and N-benzylated meta-polybenzimidazole(m-PBI)membranes are used to understand the molecular requirements of the polymer electrolyte in a vanadium redox flow battery,providing an important toolbox for future research toward next-generation membrane materials in energy storage devices.The addition of an ethyl side chain to the m-PBI backbone increases its affinity toward the acidic electrolyte,thereby increasing its ionic conductivity and the corresponding energy efficiency of the VRFB cell from 70%to 78%at a current density of 200 mA cm^(-2).In addition,cells equipped with ethylated m-PBI showed better capacity retention than their pristine counterpart,respectively 91%versus 87%,over 200 cycles at 200 mA cm^(-2).The outstanding VRFB cycling performance,together with the low-cost and fluorine-free chemistry of the N-alkylated m-PBI polymer,makes this material a promising membrane to be used in next-generation VRFB systems.展开更多
Despite continuous progress made on the taxonomy of the genus Tropidophorus, the Lao Water Skink, T. laotus, is only known from brief descriptions of its syntypes in historical literature. Here we designate a lectotyp...Despite continuous progress made on the taxonomy of the genus Tropidophorus, the Lao Water Skink, T. laotus, is only known from brief descriptions of its syntypes in historical literature. Here we designate a lectotype and paralectotype of the species, redescribe the species based on the type series and newly collected topotypes, provide the first colored photographs of taxonomically-verified individuals, and estimate its phylogenetic position using mitochondrial DNA data for the first time.Using these comparable data, we confirm that the previously identified “T. berdmorei” population from southern Yunnan Province, China, represents a distinct new species that is closely related and morphologically similar to T. laotus, but differs from true T. laotus by having considerable genetic divergence(4.7%–4.8% for 12S, 3.2%–4.2% for 16S)and distinct morphological characters(e.g., undivided frontonasal scales and a distinct color pattern of the throat). The southern Yunnan population is therefore described as a new species. With the above newly acquired data, we update the checklist and the provincial-level distribution of the genus Tropidophorus in China and compile an updated key to all recognized species of the genus from China and Indochina.展开更多
The National Natural History Museum plays a key role in the implementation of the GSPC through its botanical gardens,the Conservatoire Botanique National du Bassin Parisien,the Herbarium,and also by providing expertis...The National Natural History Museum plays a key role in the implementation of the GSPC through its botanical gardens,the Conservatoire Botanique National du Bassin Parisien,the Herbarium,and also by providing expertise on all areas of the Strategy(botany,conservation,ethonobotany,article 8j,substainable use),etc.For 2 of the goals of GSPC(conserving plant diversity,Understanding and Documenting Plant Diversity),the Muséum has developed activities all over the world,including compilation of various flora and description of new species,as well as establishment of plant conservation schemes and habitat protection policies.It also conserves endangered species in the botanical garden.展开更多
BACKGROUND： Hepatocellular carcinoma （HCC） is a com- plex and heterogeneous malignancy, frequently occurs in the setting of a chronically diseased organ, with multiple con- founding factors making its management ch...BACKGROUND： Hepatocellular carcinoma （HCC） is a com- plex and heterogeneous malignancy, frequently occurs in the setting of a chronically diseased organ, with multiple con- founding factors making its management challenging. HCC represents one of the leading causes of cancer-related mortal- ity globally with a rising trend of incidence in some of the de- veloped countries, which indicates the need for better surgical and nonsurgical management strategies.展开更多
Meligethes （Meligethes） pallidoelytrorum, Chen et Kirejtshuk sp. nov. is described and illustrated from Sichuan, China. It can be readily distinguished from related species by the smoothed dorsal integument, diffuse...Meligethes （Meligethes） pallidoelytrorum, Chen et Kirejtshuk sp. nov. is described and illustrated from Sichuan, China. It can be readily distinguished from related species by the smoothed dorsal integument, diffused and sparse punctations on elytra and the very distinct tooth at base of the claw. Meligethes （Meligethes） lutra Solsky, 1876, syn. nov. and M. （M.） melleus Grouvelle, 1908, syn. nov. are proposed as the synonymies of M. （3l.）vulpes Solsky, 1876.展开更多
This work aims at characterizing organic matter produced by an alga Euglena gracil~ and a cyanobacteria Microcystis aeruginosa and assessing the evolution of its characteristics during growth. A culture medium was opt...This work aims at characterizing organic matter produced by an alga Euglena gracil~ and a cyanobacteria Microcystis aeruginosa and assessing the evolution of its characteristics during growth. A culture medium was optimized. The species growth phases were monitored using both visible spectrophotometry and flow cytometry cell counting. Organic matter fractionation according to hydrophobicity and specific UV absorbance （SUVA） index were used to specifically characterize the produced algal organic matter （AOM）. The AOM characteristics were both growth phase and species dependent. However, a similar evolution was observed. The hydrophilic fraction （HPI） was the major fraction whatever the growth phases and was almost the only one produced during lag and exponential phases. It represented around 75% of AOM during exponential phase and then decreased when the stationary phase appeared. It represented 46% and 60% of the AOM during late decline phase for the cyanobacteria and the alga respectively. The hydrophobic （HPO） and transphilic （TPH） fractions started to appear from the beginning of the stationary phase with more hydrophobic compounds coming from intracellular organic material of dying cells. HPO and TPH percentages still increased during the decline phase probably because of two additional processes： photo-dissolution and leaching of particulate organic matter from cells fragments. A comparison of AOM during late decline phase and natural organic matter （NOM） from Glane River （France） underlined that AOM was more fiydrophilic and presented a lower SUVA for each fractions than NOM. However, the difference between NOM and AOM hydrophobicity narrowed during decline phase.展开更多
Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese wa...Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese water deer Hydropotes inermis,a relatively small species of cervid,was investigated over 3 years. Except during the lactation period,reproductive females spent about 2-fold more time resting than feeding. During lactation,the amount of time spent feeding increased highly (25.3 min/h during lactation vs 17.3 min/h during the gestation period). Females spent less than 30% of time in communal behaviours with offspring. They did not reject alien fawns during this care period. Frequency and duration of suckling events decreased exponentially from the second week onwards. More than 10% of suckling bouts were non-filial. Prenatal investment leads to a mean litter mass (about 12% of maternal mass) higher than in most cervid species. Postnatal investment in fawns represents a daily mass gain of ca. 85 g/d during the first 2 weeks,without any sexual difference. Female production,timing and synchrony of births and survival of fawns characterized reproductive success. Seventy percent of mature females gave birth,with a mean of 1.9 offspring per female. The sex ratio was even. Births were synchronous,80% of births occurring in 25 days. In this herd,0.74 fawn per female was successfully weaned and 0.56 fawn per female survived through their first year. Based on these results we conclude that reproductive strategy of Chinese water deer was efficient and characterized by mother-offspring relationships typical of hiders and high levels of pre-and postnatal investments. This strategy seems typical of small species of cervids without marked sexual dimorphism.展开更多
Background:Since the overuse of antibiotics in animal production has led to a selection of antibiotic-resistant pathogens that affect humans and animals as well.Scientists are therefore searching for novel natural alt...Background:Since the overuse of antibiotics in animal production has led to a selection of antibiotic-resistant pathogens that affect humans and animals as well.Scientists are therefore searching for novel natural alternatives to antibiotics.In this study Lactobacillus reuteri and a combination of reuterin and microcin J25(RJ)were evaluated as promoters of growth and modulators of the cecal microbiota and metabolite profiles in broiler chickens.Oneday-old Cobb 500 male broilers were distributed to 8 treatments:negative control(without antibiotic),positive control(bacitracin),three concentrations of RJ and three doses of L.reuteri plus glycerol.The birds(2176,34 per pen,8 pens per treatment)were reared for 35 d.Results:The body weight of the bacitracin and 5 mmol/L reuterin combined with 0.08μmol/L microcin J25(10RJ)treatment group was significantly higher than that of the negative control group(P<0.05).L.reuteri had no significant effect on broiler growth.MiSeq high-throughput sequencing of 16S rRNA showed clustering of cecal microbial operational taxonomic unit diversity according to treatment.The influence of bacitracin and 10RJ on bacterial community overall structure was similar.They promoted Ruminococcaceae,Lachnospiraceae and Lactobacillaceae,increased the relative abundance of Faecalibacterium and decreased the abundance of Bacteroides and Alistipes,while the negative control condition favored Bacteroidaceae and Rikenellaceae.Furthermore,10RJ increased the concentration of short-chain fatty acid in the cecum and changed the metabolome overall.Conclusions:These overall suggest that 10RJ can promote a host-friendly gut environment by changing the cecal microbiome and metabolome.This combination of natural antimicrobial agents in the drinking water had a positive effect on broiler growth and may be suitable as an alternative to antibiotic growth promoters.展开更多
Moderate grazing by cattle increases the heterogeneity of soil and vegetation. This has been suggested as an ecologically sustainable mean of managing natural environments endangered by tree encroachment, such as heat...Moderate grazing by cattle increases the heterogeneity of soil and vegetation. This has been suggested as an ecologically sustainable mean of managing natural environments endangered by tree encroachment, such as heathlands. Our study was performed to test the impact of grazing intensity on soil macroinvertebrate communities in heterogeneous landscapes in a private property eligible to the Natura 2000 European Network of Special Protection Areas within the Brenne Natural Regional Park （Indre, ~rance）. We sampled macroinvertebrates along a broken line crossing 5 different land-use types, from pasture to pine forest, passing through a besom heath （Erica scoparia） heathland at 3 levels of cattle pressure. We hypothesized that： i） litter-dwelling （mostly arthropods and mollusks） and soil-dwelling macroinvertebrates （mostly earthworms） would respond in an opposite manner to various grazing intensities, and ii） intermediate cattle pressure （pastured heath） would increase soil and community heterogeneity. The results supported the first hypothesis, which was explained by land-use impacts mediated by soil properties. However, our results supported only partly the second hypothesis since maximum dissimilarity （whether in the composition of soil macroinvertebrate communities or in soil features） was observed in only one out of the two pastured heaths where cattle pressure was intermediate.展开更多
In the present study, a statistical investigation is carried out to explore whether there is a relationship between the critical frequency （foEs） of the sporadic-E layer that is occasionally seen on the E region of ...In the present study, a statistical investigation is carried out to explore whether there is a relationship between the critical frequency （foEs） of the sporadic-E layer that is occasionally seen on the E region of the ionosphere and the quasi- biennial oscillation （QBO） that flows in the east-west direction in the equatorial stratosphere. Multiple regression model as a statistical tool was used to determine the relationship between variables. In this model, the stationarity of the variables （foEs and QBO） was firstly analyzed for each station （Cocos Island, Gibilmanna, Niue Island, and Tahiti）. Then, a co- integration test was made to determine the existence of a long-term relationship between QBO and foes. After verifying the presence of a long-term relationship between the variables, the magnitude of the relationship between variables was further determined using the multiple regression model. As a result, it is concluded that the variations in foEs were explainable with QBO measured at 10 hPa altitude at the rate of 69%, 94%, 79%, and 58% for Cocos Island, Gibilmanna, Niue Island, and Tahiti stations, respectively. It is observed that the variations in foes were explainable with QBO measured at 70 hPa altitude at the rate of 66%, 69%, 53%, and 47% for Cocos Island, Gibilmanna, Niue Island, and Tahiti stations, respectively.展开更多
基金support by a Synthesys grant made available to J.Fuchs by the European Community-Research Infrastructure Action under the FP6 Structuring the European Research Area Program(SE-TAF-7153)
文摘Background: The Cambodian Tailorbird(Orthotomus chaktomuk) was one of the most recent major ornithological discoveries in South-east Asia as it originated from lowland seasonally flooded scrub within the densely inhabited floodplain around the Tonle Sap, Mekong and Bassac rivers(Cambodia). The Cambodian Tailorbird is sister to the Dark-necked Tailorbird(O. atrogularis) with very limited genetics and biometric differentiation. Between 2004 and 2012, evidences of a new population of Ashy Tailorbird(O. ruficeps) in SE Cambodia/Vietnam accumulated but no museum specimens were ever reported. The Ashy Tailorbird currently consists of eight subspecies among which the closest geographical populations, O. r. cineraceus(SE Burma to Malay Peninsula, Sumatra, Bangka and Belitung) and O. r. borneoensis(Borneo), are allopatric. Subspecific identification of the Cambodian Ashy Tailorbirds individuals was not possible because of the limited differences in plumage among subspecies.Methods: We inspected the Orthotomus ruficeps specimens housed at the Museum National d'Histoire Naturelle(Paris) and discovered five specimens of O. ruficeps collected by Louis Rodolphe Germain in ‘Cochinchina'(corresponding to southern Vietnam) during the nineteenth century. We sequenced one mitochondrial locus and gathered biometric data from these specimens and compared them with other Orthotomus lineages.Results: The Ashy Tailord population from SE Cambodia and Vietnam is distinct from the two geographically close subspecies O. r. borneoensis(1.7%) and O. r. cineraceus(1.3%). O. chaktomuk is nested within O. atrogularis in the mitochondrial gene tree. The SE Cambodia/Vietnam population of O. ruficeps is distinct from the two other subspecies in bill shape.Conclusion: Our study described the biometric and molecular distinctiveness of a recently re-discovered population of Ashy Tailord in SE Cambodia and Vietnam and suggests that this population constitutes an independent evolutionary lineage that we describe here as a new subspecies. The newly described Cambodian Tailorbird is nested within the Dark-necked Tailorbird and the genetic divergence is much lower than initially described(0.4-0.7% vs 1.1-1.4%).
文摘Dear Editor,Johannes Lehmann and Markus Kleber,in a controversial paper entitled"The contentious nature of soil organic matter"(Lehmann and Kleber,2015),suggested the abandonment of the term"humus"and other associated terms such as"humic","humir","humified","humification".The first reason they cited was that these labels are only instrumental in outdated soil analytical methods,which are based on alkaline extraction of soil organic matter(SOM).
文摘BACKGROUND Metastatic colorectal cancer(mCRC)is a global health challenge with a poor prognosis.Prognostic markers are critical for survival prediction.METHODS This multicenter,retrospective study measured baseline carcinoembryonic antigen and carbohydrate antigen 19-9 levels to calculate a TMI as the geometric mean of values normalized to their upper limits of normal.Receiver operating characteristic curve analysis assessed TMI’s prognostic accuracy,and patients were stratified into high-TMI(≥1.39)and low-TMI(<1.39)groups.The primary endpoint was overall survival(OS),with progression-free survival and treatment response as secondary endpoints.RESULTS The study included 305 mCRC patients with a median follow-up of 22.9 months.The median OS for high-TMI patients was 29.5 months,significantly lower than the 45.6 months observed in the low-TMI group(P=0.02).The 2-year OS rates for the high-and low-TMI groups were 59.4%and 72.9%,respectively.Median progression-free survival was also shorter for the high-TMI group(14.0 vs 16.0 months,P=0.84).High TMI is an independent prognostic factor for worse OS.CONCLUSION TMI is a simple,cost-effective prognostic tool for mCRC,with high TMI associated with poorer survival outcomes.
基金supported by the Swiss National Science Foundation(grant number 188631).
文摘The all-vanadium redox flow battery(VRFB)plays an important role in the energy transition toward renewable technologies by providing grid-scale energy storage.Their deployment,however,is limited by the lack of membranes that provide both a high energy efficiency and capacity retention.Typically,the improvement of the battery’s energy efficiency comes at the cost of its capacity retention.Herein,novel N-alkylated and N-benzylated meta-polybenzimidazole(m-PBI)membranes are used to understand the molecular requirements of the polymer electrolyte in a vanadium redox flow battery,providing an important toolbox for future research toward next-generation membrane materials in energy storage devices.The addition of an ethyl side chain to the m-PBI backbone increases its affinity toward the acidic electrolyte,thereby increasing its ionic conductivity and the corresponding energy efficiency of the VRFB cell from 70%to 78%at a current density of 200 mA cm^(-2).In addition,cells equipped with ethylated m-PBI showed better capacity retention than their pristine counterpart,respectively 91%versus 87%,over 200 cycles at 200 mA cm^(-2).The outstanding VRFB cycling performance,together with the low-cost and fluorine-free chemistry of the N-alkylated m-PBI polymer,makes this material a promising membrane to be used in next-generation VRFB systems.
基金support by the National Science Foundation of China (32130015)Yunnan Revitalization Talent Support Program Yunling Scholar Project+7 种基金the Animal Branch of the Germplasm Bank of Wild Species, Chinese Academy of Sciences (the Large Research Infrastructure Funding) to Jing CHE,Biological Resources Programme, Chinese Academy of SciencesYunnan Revitalization Talent Support Program Young Talent ProjectCAS Special Research Assistant (SRA) ProgramProgram of Yunnan Forestry and Grassland Administration (2022GF258D-10)Small Grant Program for New Records and Rediscoveries of Rare Species by Tencent FoundationShanshui Conservation Center to Kai WANGU.S. National Science Foundation (grant DEB1145922)the Partnerships for Enhanced Engagement in Research (PEER) Science program (grant PGA-2000003545), which is a partnership between the U.S. Agency for International Development (USAID) and the U.S. National Science Foundation to Bryan L. STUART。
文摘Despite continuous progress made on the taxonomy of the genus Tropidophorus, the Lao Water Skink, T. laotus, is only known from brief descriptions of its syntypes in historical literature. Here we designate a lectotype and paralectotype of the species, redescribe the species based on the type series and newly collected topotypes, provide the first colored photographs of taxonomically-verified individuals, and estimate its phylogenetic position using mitochondrial DNA data for the first time.Using these comparable data, we confirm that the previously identified “T. berdmorei” population from southern Yunnan Province, China, represents a distinct new species that is closely related and morphologically similar to T. laotus, but differs from true T. laotus by having considerable genetic divergence(4.7%–4.8% for 12S, 3.2%–4.2% for 16S)and distinct morphological characters(e.g., undivided frontonasal scales and a distinct color pattern of the throat). The southern Yunnan population is therefore described as a new species. With the above newly acquired data, we update the checklist and the provincial-level distribution of the genus Tropidophorus in China and compile an updated key to all recognized species of the genus from China and Indochina.
文摘The National Natural History Museum plays a key role in the implementation of the GSPC through its botanical gardens,the Conservatoire Botanique National du Bassin Parisien,the Herbarium,and also by providing expertise on all areas of the Strategy(botany,conservation,ethonobotany,article 8j,substainable use),etc.For 2 of the goals of GSPC(conserving plant diversity,Understanding and Documenting Plant Diversity),the Muséum has developed activities all over the world,including compilation of various flora and description of new species,as well as establishment of plant conservation schemes and habitat protection policies.It also conserves endangered species in the botanical garden.
文摘BACKGROUND： Hepatocellular carcinoma （HCC） is a com- plex and heterogeneous malignancy, frequently occurs in the setting of a chronically diseased organ, with multiple con- founding factors making its management challenging. HCC represents one of the leading causes of cancer-related mortal- ity globally with a rising trend of incidence in some of the de- veloped countries, which indicates the need for better surgical and nonsurgical management strategies.
基金supported by the National Natural Science Foundation of China(31010103913)Fundamental Research Funds for Chinese Central Universities
文摘Meligethes （Meligethes） pallidoelytrorum, Chen et Kirejtshuk sp. nov. is described and illustrated from Sichuan, China. It can be readily distinguished from related species by the smoothed dorsal integument, diffused and sparse punctations on elytra and the very distinct tooth at base of the claw. Meligethes （Meligethes） lutra Solsky, 1876, syn. nov. and M. （M.） melleus Grouvelle, 1908, syn. nov. are proposed as the synonymies of M. （3l.）vulpes Solsky, 1876.
基金the FEDER (European Found forRegional Development)the Regional Council of Limousin for their financial supportnt
文摘This work aims at characterizing organic matter produced by an alga Euglena gracil~ and a cyanobacteria Microcystis aeruginosa and assessing the evolution of its characteristics during growth. A culture medium was optimized. The species growth phases were monitored using both visible spectrophotometry and flow cytometry cell counting. Organic matter fractionation according to hydrophobicity and specific UV absorbance （SUVA） index were used to specifically characterize the produced algal organic matter （AOM）. The AOM characteristics were both growth phase and species dependent. However, a similar evolution was observed. The hydrophilic fraction （HPI） was the major fraction whatever the growth phases and was almost the only one produced during lag and exponential phases. It represented around 75% of AOM during exponential phase and then decreased when the stationary phase appeared. It represented 46% and 60% of the AOM during late decline phase for the cyanobacteria and the alga respectively. The hydrophobic （HPO） and transphilic （TPH） fractions started to appear from the beginning of the stationary phase with more hydrophobic compounds coming from intracellular organic material of dying cells. HPO and TPH percentages still increased during the decline phase probably because of two additional processes： photo-dissolution and leaching of particulate organic matter from cells fragments. A comparison of AOM during late decline phase and natural organic matter （NOM） from Glane River （France） underlined that AOM was more fiydrophilic and presented a lower SUVA for each fractions than NOM. However, the difference between NOM and AOM hydrophobicity narrowed during decline phase.
文摘Among cervids,maternal investment,estimated as the amount of resources and care allocated to the offspring,was expected to be related to species body size. Therefore,maternal investment in a herd of captive Chinese water deer Hydropotes inermis,a relatively small species of cervid,was investigated over 3 years. Except during the lactation period,reproductive females spent about 2-fold more time resting than feeding. During lactation,the amount of time spent feeding increased highly (25.3 min/h during lactation vs 17.3 min/h during the gestation period). Females spent less than 30% of time in communal behaviours with offspring. They did not reject alien fawns during this care period. Frequency and duration of suckling events decreased exponentially from the second week onwards. More than 10% of suckling bouts were non-filial. Prenatal investment leads to a mean litter mass (about 12% of maternal mass) higher than in most cervid species. Postnatal investment in fawns represents a daily mass gain of ca. 85 g/d during the first 2 weeks,without any sexual difference. Female production,timing and synchrony of births and survival of fawns characterized reproductive success. Seventy percent of mature females gave birth,with a mean of 1.9 offspring per female. The sex ratio was even. Births were synchronous,80% of births occurring in 25 days. In this herd,0.74 fawn per female was successfully weaned and 0.56 fawn per female survived through their first year. Based on these results we conclude that reproductive strategy of Chinese water deer was efficient and characterized by mother-offspring relationships typical of hiders and high levels of pre-and postnatal investments. This strategy seems typical of small species of cervids without marked sexual dimorphism.
基金the Natural Sciences and Engineering Research Council (NSERC) of Canada industrial research chair METABIOLAC (grant number IRCPJ 499946–15)from Agriculture and Agri-Food Canada (project PSS#1781, J-002308)
文摘Background:Since the overuse of antibiotics in animal production has led to a selection of antibiotic-resistant pathogens that affect humans and animals as well.Scientists are therefore searching for novel natural alternatives to antibiotics.In this study Lactobacillus reuteri and a combination of reuterin and microcin J25(RJ)were evaluated as promoters of growth and modulators of the cecal microbiota and metabolite profiles in broiler chickens.Oneday-old Cobb 500 male broilers were distributed to 8 treatments:negative control(without antibiotic),positive control(bacitracin),three concentrations of RJ and three doses of L.reuteri plus glycerol.The birds(2176,34 per pen,8 pens per treatment)were reared for 35 d.Results:The body weight of the bacitracin and 5 mmol/L reuterin combined with 0.08μmol/L microcin J25(10RJ)treatment group was significantly higher than that of the negative control group(P<0.05).L.reuteri had no significant effect on broiler growth.MiSeq high-throughput sequencing of 16S rRNA showed clustering of cecal microbial operational taxonomic unit diversity according to treatment.The influence of bacitracin and 10RJ on bacterial community overall structure was similar.They promoted Ruminococcaceae,Lachnospiraceae and Lactobacillaceae,increased the relative abundance of Faecalibacterium and decreased the abundance of Bacteroides and Alistipes,while the negative control condition favored Bacteroidaceae and Rikenellaceae.Furthermore,10RJ increased the concentration of short-chain fatty acid in the cecum and changed the metabolome overall.Conclusions:These overall suggest that 10RJ can promote a host-friendly gut environment by changing the cecal microbiome and metabolome.This combination of natural antimicrobial agents in the drinking water had a positive effect on broiler growth and may be suitable as an alternative to antibiotic growth promoters.
基金supported by the Institut Fédératif de Recherches, France (No.101)
文摘Moderate grazing by cattle increases the heterogeneity of soil and vegetation. This has been suggested as an ecologically sustainable mean of managing natural environments endangered by tree encroachment, such as heathlands. Our study was performed to test the impact of grazing intensity on soil macroinvertebrate communities in heterogeneous landscapes in a private property eligible to the Natura 2000 European Network of Special Protection Areas within the Brenne Natural Regional Park （Indre, ~rance）. We sampled macroinvertebrates along a broken line crossing 5 different land-use types, from pasture to pine forest, passing through a besom heath （Erica scoparia） heathland at 3 levels of cattle pressure. We hypothesized that： i） litter-dwelling （mostly arthropods and mollusks） and soil-dwelling macroinvertebrates （mostly earthworms） would respond in an opposite manner to various grazing intensities, and ii） intermediate cattle pressure （pastured heath） would increase soil and community heterogeneity. The results supported the first hypothesis, which was explained by land-use impacts mediated by soil properties. However, our results supported only partly the second hypothesis since maximum dissimilarity （whether in the composition of soil macroinvertebrate communities or in soil features） was observed in only one out of the two pastured heaths where cattle pressure was intermediate.
文摘In the present study, a statistical investigation is carried out to explore whether there is a relationship between the critical frequency （foEs） of the sporadic-E layer that is occasionally seen on the E region of the ionosphere and the quasi- biennial oscillation （QBO） that flows in the east-west direction in the equatorial stratosphere. Multiple regression model as a statistical tool was used to determine the relationship between variables. In this model, the stationarity of the variables （foEs and QBO） was firstly analyzed for each station （Cocos Island, Gibilmanna, Niue Island, and Tahiti）. Then, a co- integration test was made to determine the existence of a long-term relationship between QBO and foes. After verifying the presence of a long-term relationship between the variables, the magnitude of the relationship between variables was further determined using the multiple regression model. As a result, it is concluded that the variations in foEs were explainable with QBO measured at 10 hPa altitude at the rate of 69%, 94%, 79%, and 58% for Cocos Island, Gibilmanna, Niue Island, and Tahiti stations, respectively. It is observed that the variations in foes were explainable with QBO measured at 70 hPa altitude at the rate of 66%, 69%, 53%, and 47% for Cocos Island, Gibilmanna, Niue Island, and Tahiti stations, respectively.
