Natural secondary forest has a strong capacity to regrow naturally and recover biodiversity rapidly on abandoned lands.However,at the neighborhood scale,which can truly reflect the facilitative or competitive interact...Natural secondary forest has a strong capacity to regrow naturally and recover biodiversity rapidly on abandoned lands.However,at the neighborhood scale,which can truly reflect the facilitative or competitive interactions among individual plants,the local diversity spatial structure in secondary forest and the feedback effects of neighborhood diversity on natural regeneration remain unclear,and this may be the key to properly understand the mechanisms of natural secondary forest species diversity recovery.To this end,this study established a dynamic plot in a rehabilitated secondary forest after disturbance and conducted a comprehensive survey of 68,336 individual plants with repeated measurements at 5-year interval to assess the characteristics of neighborhood diversity structure across life history stages and link the neighborhood species richness(NSR)effect translated by species interactions at species diversity structure with individual trees recruitment/mortality in secondary forest regeneration.The results showed that,compared with tropical and temperate natural forests,a higher proportion of diversity accumulators and a lower proportion of repellers in subtropical secondary forests resulted in neighborhood diversity structures characterized by heterospecific or high-diversity patches,which are beneficial to the maintenance or restoration of biodiversity.As an important supplement to the research on the relationship between diversity and productivity,our findings show a positive diversity-survival relationship in subtropical secondary forests.Importantly,we observed that the neighborhood diversity structure exhibited a trend of accumulator-dominated to neutral-dominant changes with life stage from sapling to adult,which,in turn,determined the direction and strength of NSR effects on recruitment/mortality.Specifically,diverse local neighborhoods at a later successional stage characterized with‘neutral’species-species interactions can act as a‘welfare net’by offering favorable microhabitats for the most vulnerable recruitments or saplings,i.e.,the NSR effects that promoted individual recruitment/survival in our study.These results not only enrich our understanding of the biodiversity-productivity-survival relationship but also highlight the importance of retaining latesuccessional species of native trees in intensive forest production or in situ conservation policies.展开更多
Tree interactions are essential for the structure,dynamics,and function of forest ecosystems,but variations in the architecture of life-stage interaction networks(LSINs)across forests is unclear.Here,we constructed 16...Tree interactions are essential for the structure,dynamics,and function of forest ecosystems,but variations in the architecture of life-stage interaction networks(LSINs)across forests is unclear.Here,we constructed 16 LSINs in the mountainous forests of northwest Hebei,China based on crown overlap from four mixed forests with two dominant tree species.Our results show that LSINs decrease the complexity of stand densities and basal areas due to the interaction cluster differentiation.In addition,we found that mature trees and saplings play different roles,the first acting as“hub”life stages with high connectivity and the second,as“bridges”controlling information flow with high centrality.Across the forests,life stages with higher importance showed better parameter stability within LSINs.These results reveal that the structure of tree interactions among life stages is highly related to stand variables.Our efforts contribute to the understanding of LSIN complexity and provide a basis for further research on tree interactions in complex forest communities.展开更多
AIM: To investigate and evaluate the change in healthrelated quality of life (HRQoL) by tumor node metastasis (TNM) staging system in patients with hepatocellular carcinoma (HCC). METHODS: A total of 140 patients diag...AIM: To investigate and evaluate the change in healthrelated quality of life (HRQoL) by tumor node metastasis (TNM) staging system in patients with hepatocellular carcinoma (HCC). METHODS: A total of 140 patients diagnosed with HCC between June 2008 and April 2009 in our department were enrolled to this study. One hundred and thirty-five (96.5%) patients had liver cirrhosis secondary to hepatitis B virus (HBV) infection, 73 (54.07%) of them being HBV DNA positive; the other etiologies of liver cirrhosis were alcoholic liver disease (1.4%), hepatitis C (1.4%) or cryptogenic (0.7%). All subjects were fully aware of their diagnosis and provided informed consent. HRQoL was assessed before treatment using the functional assessment of cancer therapy-hepatobiliary (FACT-Hep) questionnaire. Descriptive statistics were used to evaluate demographics and disease-specific characteristics of the patients. One-way analysis of variance and independent samples t tests were used to compare the overall FACT-Hep scores and clinically distinct TNM stages. Scores for all FACT-Hep items were analyzed by frequency analyses. The mean scores obtained from the FACT-Hep in different Child-Pugh classes were also evaluated. RESULTS: The mean FACT-Hep scores were reduced significantly from TNM StageⅠto Stage Ⅱ, Stage ⅢA, Stage ⅢB group (687 ± 39.69 vs 547 ± 42.57 vs 387 ± 51.24 vs 177 ± 71.44, P = 0.001). Regarding the physical and emotional well-being subscales, scores decreased gradually from Stage Ⅰ to Stage ⅢB (P = 0.002 vs Stage Ⅰ; P = 0.032 vs Stage Ⅱ; P = 0.033 vs Stage ⅢA). Mean FACT-Hep scores varied by Child-Pugh class, especially in the subscales of physical well-being, functional well-being and the hepatobiliary cancer (P = 0.001 vs Stage I; P = 0.036 vs Stage Ⅱ; P = 0.032 vs Stage ⅢA). For the social and family well-being subscale, only Stage ⅢB scores were significantly lower as compared with Stage Ⅰ scores (P = 0.035). For the subscales of functional well-being and hepatobiliary cancer, there were significant differences for Stages ⅡΙ, ⅢA and ⅢB (P = 0.002vs StageⅠ). CONCLUSION: HRQoL of patients with HCC worsens gradually with progression of TNM stages. The most impaired subscales of HRQoL, as measured by FACT-Hep, were physical and emotional well-being.展开更多
The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power ...The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power model was estimated for the length-weight relationship during the early life stages. Positive allometric growth for the head segment, trunk length, tail length and eye diameter was also found in the early life stages, while body depth, tail depth, tail fi n length, pectoral fi n length and barbel length displayed a negative coeffi cient. During the subsequent early developmental stage, the growth coeffi cients showed a clear and common tendency towards isometry for all measured body ratios. The allometric growth changes in Chinese loach during the early stage are possibly the result of selective organogenesis directed towards survival priorities.展开更多
Species-habitat association analysis is useful to detect spatial arrangement of individual plants, to discover rules about the distribution of species and to generate hypotheses about the possible underlying process c...Species-habitat association analysis is useful to detect spatial arrangement of individual plants, to discover rules about the distribution of species and to generate hypotheses about the possible underlying process controlling observed structures. Quantifying methods were used to classify habitats in terms of topographical variables in a mixed temperate broad-leaved Korean pine forest of the Changbai mountains in northeastern China. All of the 625 20 m × 20 m quadrats of the plot could be unambiguously assigned to one of three habitat categories (low-plateau, high-plateau and slope). Torus-translation tests were used to estimate species-habitat associations. Many species are clearly distributed in a biased fashion with respect to habitats. Fifteen (55.6%) out of 27 species showed strong positive or negative association with specific habitats. We compared species-habitat associations at the sapling and adult stages. Adjusted density values indicated few species exhibit extremely strong habitat associations. Only 9 out of 26 species had adjusted densities 〉 3 in the habitat for which they had strong positive affinity. Few species show the same associations at the small tree and large tree stages. Only 3 out of 22 occurring associations with a specific habitat appeared to have a consistent habitat association at the two stages. These results suggest that species-habitat associations exist in the 25-ha plot of the temperate forest of the Chang- bai mountains. Owing to limitations in our statistical methodology, we partly underestimated associations by ignoring rare species. Regeneration niches can contribute to co-existence, but regeneration niches due to habitat associations play a limited role in species co-existence, since most species show a similar trend in habitat associations at the sapling and adult stages. We should pay more attention to shifts in habitat associations, i.e. niche shifts at different stages of existence.展开更多
Systematics is traditionally based on morphological characters to both define species and establish classifications. In the past decades, partly due to the advent of molecular biology, traditional systematics has decl...Systematics is traditionally based on morphological characters to both define species and establish classifications. In the past decades, partly due to the advent of molecular biology, traditional systematics has declined while molecular systematics has tremendously increased. This results in that fewer funding are generally provided to traditional systematics, particularly for searching new morphological characters. Aquaculture, the farming of aquatic animals, has increased exponentially in the past decades, providing today more than half of fish consumed worldwide, and is expected to continue to rise. Aquaculture requires controlling the life cycle of the farmed fish in captivity, including the rearing of early life stages. Therefore, by coupling systematics and aquaculture, it could be possible to bring new funds and facilities to the former to study the early life stages of numerous fish species and to the latter it would offer a conceptual framework to perform comparative ontogeny. Together, this could help improving our knowledge on the early life stages that could be useful for both taxonomists and zootechnicians.展开更多
This paper considers the real value of unpaid work. Actual living satisfaction depends not only on market income measured using the current concept of GDP, but also on unpaid household production. We try to estimate b...This paper considers the real value of unpaid work. Actual living satisfaction depends not only on market income measured using the current concept of GDP, but also on unpaid household production. We try to estimate broad household income in Japan based on 2011 government estimates. We assume three household life stages, each of which consists of three cases categorized by the spouse's type of work. The results show that income differences between the three cases were very small and women worked longer hours than men in all household life stages. This reveals a different possible view of income distribution and poverty, in which women are overburdened.展开更多
Authors conducted pollination experiments and genetic analyses using microsatellite loci for a natural population of a shrub species,Magnolia salicifolia,in a secondary Japanese beech forest in Hakkoda mountains,north...Authors conducted pollination experiments and genetic analyses using microsatellite loci for a natural population of a shrub species,Magnolia salicifolia,in a secondary Japanese beech forest in Hakkoda mountains,northern Japan,to analyze inbreeding and inbreeding depression that involve sexual reproduction and population genetic structure of the species.The pollination experiments revealed that self-fertilization through geitonogamy is possible and that the magnitude of inbreeding depression(δ)at the embryonic stage is substantial(δ=0.42),suggesting that the inbreeding depression due to self-fertilization decreases seed production of the natural population.The genetic analyses showed discrepancy in the level of inbreeding between life history stages:the inbreeding coefficient for the juvenile and adult stage was 0.17 and 0.01,respectively,implying that most of inbred progenies cannot grow to the adult stage in the population,since the cumulative inbreeding depression is severe.These results are consistent with the hypothesis that explains mechanisms causing stable maintenance of severe inbreeding depression in partially inbred populations by focusing on the selective interference among deleterious mutations.It is suggested that some reproductive traits facilitating outcrossing in the species would be attributed to the severe cumulative inbreeding depression.展开更多
Toxicity of wastewater treatment plant (WWTP) effluents is usually assessed with standardized bioassays, as e.g. the Fish Embryo Toxicity test (FET), but assessment of sub-lethal toxic effects requires to develop more...Toxicity of wastewater treatment plant (WWTP) effluents is usually assessed with standardized bioassays, as e.g. the Fish Embryo Toxicity test (FET), but assessment of sub-lethal toxic effects requires to develop more adapted tests. The present work aimed to add the recording of several sub-lethal endpoints in exposed zebrafish embryo-larval stages in order to increase the sensitivity of residual toxicity evaluation of WWTP effluents using a semi-quantitative method (iFET score). This approach was complemented with the genotoxicity assessment on the exposed embryos, a sub-acute hazard particularly relevant to evaluate a potential chronic toxicity risk of low and multi-contaminated environmental matrices. Additionally, endocrine activities of effluents were quantified using human reporter cell lines. This test battery was applied to the assessment of the residual toxicity of five biological treatment effluents, further treated or not using various ozonation treatments intended to improve pharmaceutical compounds removal. Acute toxicity towards zebrafish embryos was very low. However, iFET score approach proposed was able to reveal residual toxicity through the presence of developmental abnormalities in all samples tested. Additionally, a low residual genotoxicity was measured in embryos exposed to two of the WWTP effluents when all excepted one exhibited a residual endocrine activity potential in the ng/L range providing complementary information on the occurrence of endocrine active chemicals and their reduction by different processes. To sum up, such a simplified and ecologically relevant test battery was found sensitive enough to characterize and differentiate various residual effluent’s ecotoxicity at contaminant levels of environmental concern.展开更多
The bio-control potential of rhizospere bacteria Pseudomonas fluorescens against plant-parasite nematode had been demonstrated. P. fluorescens had shown the effect to enhance tobacco resistance to root-knot nematode M...The bio-control potential of rhizospere bacteria Pseudomonas fluorescens against plant-parasite nematode had been demonstrated. P. fluorescens had shown the effect to enhance tobacco resistance to root-knot nematode Meloidogyne incognita. Inoculation with P. fluorescens in tobacco could lead to significant reductions in the number of juveniles that penetrated tobacco root and further life stage development of the juveniles. The number of juveniles penetrated into tobacco root in treatment with P. fluorescens is significantly different from CK at 2DAI,6DAI,8DAI and 10 DAI. Significant reduction and delayed development of juveniles that penetrated into tobacco root and treated were observed in treatment at14 DAI,21DAI,28 DAI and 35 DAI. In addition,P. fluorescens treatment leads to a significant reduction in the number of eggs per egg-mass at 35 DAI. The results show P. fluorescens induced a continuously suppression on root-knot nematode M. incognita throughout their entire early infection phase of root penetration,subsequent life stage development and reproduction.展开更多
Effects of river water from the Yangtze River (Nanjing section) on fish development, vitellogenin (VTG) induction, gonado-somatic index (GSI) and sex ratio were investigated by exposing goldfish (Carassius aura...Effects of river water from the Yangtze River (Nanjing section) on fish development, vitellogenin (VTG) induction, gonado-somatic index (GSI) and sex ratio were investigated by exposing goldfish (Carassius auratus) in the early life stage (from fertilization to 28 days post-hatch) to water samples (25%, 50% and 100%) collected from three representative sections. The results showed that there was no significant effect on hatching success for any of the exposure groups, but survival was significantly reduced when compared with the control (P 0.05). Body lengths, weights of all treated fish did not differ significantly from those of the control. Condition factors (CF) of larval fish exposed to 50% and 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section were significantly lower than that of the control (P 0.05). VTG inductions were significant in larval fish exposed to all the dilution series of river water. No significant difference in CF value was observed in any exposure group after 150 days of depuration. VTG was fully eliminated after 75 days of depuration. For both female and male, GSI did not significantly differ between exposure groups and the control after 150 days of convalescence. The highest female:male ratios were observed in response to the treatment with 50% or 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section (53:47, 56:44 and 54:46, respectively), but no significant difference in sex ratio was observed in any treated group when compared to the control. The results showed that early life stage exposure of river water from the Yangtze River (Nanjing section) had adverse effects on goldfish development and reproductive health, and the effects on CF and VTG were reversible after depuration in clean water.展开更多
Aims The evolutionary history and functional traits of species can illumi-nate ecological processes supporting coexistence in diverse forest communities.However,little has been done in decoupling the rela-tive importa...Aims The evolutionary history and functional traits of species can illumi-nate ecological processes supporting coexistence in diverse forest communities.However,little has been done in decoupling the rela-tive importance of these mechanisms on the turnover of phylogenetic and functional characteristics across life stages and spatial scales.Therefore,this study aims to estimate the contribution of environment and dispersal on the turnover of phylogenetic and functional diversity across life stages and spatial scales,in order to build a coherent pic-ture of the processes responsible for species coexistence.Methods We conducted the study in Xishuangbanna Forest Dynamics Plot in Yunnan Province,southwest China.We used four different spatial point process models to estimate the relative importance of disper-sal limitation and environmental filtering.The functional traits and phylogenetic relationships of all individual trees were incorporated in the analyses to generate measures of dissimilarity in terms of pair-wise and nearest-neighbor phylogenetic and functional characteris-tics across life stages and spatial scales.Important Findings We found non-random patterns of phylogenetic and functional turnover across life stages and spatial scales.Environmental filtering structured pairwise phylogenetic and functional beta diversity across spatial scales,while dispersal limitation alone,and in combination with environment filtering,shaped nearest neighbor phylogenetic and functional beta diversity.The relative importance of dispersal limitation and environmental filtering appeared to change with life stage but not with spatial scale.Our findings suggest that phylogenetic and functional beta diversity help to reveal the ecological processes responsible for evolu-tionary and functional assembly and highlight the importance of using a range of different metrics to gain full insights into these processes.展开更多
The current research elucidates the advertising scheme of automotive innovation by incorporating the various stages of the product life cycle.The study proposes an empirical model for the automotive industry to evalua...The current research elucidates the advertising scheme of automotive innovation by incorporating the various stages of the product life cycle.The study proposes an empirical model for the automotive industry to evaluate a time-point known as a switch-point or a take-off point at which firms should modify the advertising and sales promotion strategies to boost sales volume.The problem applies a time-series innovation diffusion model wherein adoption rate changes when a product enters a growth stage and then again when the company stops the advertising campaign in the maturity stage.The present paper develops a profit maximization problem,which optimizes the overall advertising duration and advertising take-off point.A numerical illustration is provided using the actual sales data of automobile industries,and sensitivity analysis is further performed to validate the effect of critical parameters on the optimization problem.展开更多
Northern Fulmars(Fulmarus glacialis)are a pelagic seabird species distributed at northern and polar latitudes.They are often used as an indicator of plastic pollution in the North Sea region,but data are lacking from ...Northern Fulmars(Fulmarus glacialis)are a pelagic seabird species distributed at northern and polar latitudes.They are often used as an indicator of plastic pollution in the North Sea region,but data are lacking from higher latitudes,especially when it comes to chicks.Here,we investigated amounts of ingested plastic and their characteristics in fulmar chicks from the Faroe Islands.Plastic particles(≥1 mm)in chicks of two age classes were searched using a digestion method with KOH.In addition,to evaluate if additive tissue burden reflects plastic ingestion,we measured liver tissue concentrations of two pollutant classes associated with plastic materials:polybrominated diphenyl ethers(PBDEs)and several dechloranes,using gas chromatography with high-resolution mass spectrometry.The most common shape was hard fragment(81%)and the most common polymer was polyethylene(73%).Plastic contamination did not differ between either age class,and we found no correlation between neither the amount and mass of plastic particles and the concentration of additives.After comparison with previous studies on adult fulmars,we do not recommend using chicks for biomonitoring adults because chicks seem to ingest more plastics than adults.展开更多
基金supported by the Innovative Team Project of Nanjing Institute of Environmental Sciences,MEECentral Public Welfare Scientific Institution Basal Research Fund,Ministry of Finance and Ministry of Ecology and Environment of China(Nos.GYZX210302,GYZX200203):Biodiversity Survey,Observation and Assessment Program of Ministry of Ecology and Environment of China+2 种基金The National Environmental Protection Public Welfare Industry Targeted Research Fund:Research and demonstration of key technologies for dynamic supervision of nature reserves(No.201509042)The Special Foundation for National Science and Technology Basic Resources Investigation of China(No.2019FY202300)The Jiangsu Postdoctoral Research Funding Program(No.2021K038A)。
文摘Natural secondary forest has a strong capacity to regrow naturally and recover biodiversity rapidly on abandoned lands.However,at the neighborhood scale,which can truly reflect the facilitative or competitive interactions among individual plants,the local diversity spatial structure in secondary forest and the feedback effects of neighborhood diversity on natural regeneration remain unclear,and this may be the key to properly understand the mechanisms of natural secondary forest species diversity recovery.To this end,this study established a dynamic plot in a rehabilitated secondary forest after disturbance and conducted a comprehensive survey of 68,336 individual plants with repeated measurements at 5-year interval to assess the characteristics of neighborhood diversity structure across life history stages and link the neighborhood species richness(NSR)effect translated by species interactions at species diversity structure with individual trees recruitment/mortality in secondary forest regeneration.The results showed that,compared with tropical and temperate natural forests,a higher proportion of diversity accumulators and a lower proportion of repellers in subtropical secondary forests resulted in neighborhood diversity structures characterized by heterospecific or high-diversity patches,which are beneficial to the maintenance or restoration of biodiversity.As an important supplement to the research on the relationship between diversity and productivity,our findings show a positive diversity-survival relationship in subtropical secondary forests.Importantly,we observed that the neighborhood diversity structure exhibited a trend of accumulator-dominated to neutral-dominant changes with life stage from sapling to adult,which,in turn,determined the direction and strength of NSR effects on recruitment/mortality.Specifically,diverse local neighborhoods at a later successional stage characterized with‘neutral’species-species interactions can act as a‘welfare net’by offering favorable microhabitats for the most vulnerable recruitments or saplings,i.e.,the NSR effects that promoted individual recruitment/survival in our study.These results not only enrich our understanding of the biodiversity-productivity-survival relationship but also highlight the importance of retaining latesuccessional species of native trees in intensive forest production or in situ conservation policies.
基金This study was supported by the National Water Pollution Control and Treatment Science and Technology Major Project(2017ZX07101-002).
文摘Tree interactions are essential for the structure,dynamics,and function of forest ecosystems,but variations in the architecture of life-stage interaction networks(LSINs)across forests is unclear.Here,we constructed 16 LSINs in the mountainous forests of northwest Hebei,China based on crown overlap from four mixed forests with two dominant tree species.Our results show that LSINs decrease the complexity of stand densities and basal areas due to the interaction cluster differentiation.In addition,we found that mature trees and saplings play different roles,the first acting as“hub”life stages with high connectivity and the second,as“bridges”controlling information flow with high centrality.Across the forests,life stages with higher importance showed better parameter stability within LSINs.These results reveal that the structure of tree interactions among life stages is highly related to stand variables.Our efforts contribute to the understanding of LSIN complexity and provide a basis for further research on tree interactions in complex forest communities.
基金Supported by Grants from the E-Institute of Shanghai Municipal Education Commission, No. E03008Shanghai Municipal Health Bureau of Traditional Chinese Medicine Research Project Fund 2010-2011, No. 2010L052B
文摘AIM: To investigate and evaluate the change in healthrelated quality of life (HRQoL) by tumor node metastasis (TNM) staging system in patients with hepatocellular carcinoma (HCC). METHODS: A total of 140 patients diagnosed with HCC between June 2008 and April 2009 in our department were enrolled to this study. One hundred and thirty-five (96.5%) patients had liver cirrhosis secondary to hepatitis B virus (HBV) infection, 73 (54.07%) of them being HBV DNA positive; the other etiologies of liver cirrhosis were alcoholic liver disease (1.4%), hepatitis C (1.4%) or cryptogenic (0.7%). All subjects were fully aware of their diagnosis and provided informed consent. HRQoL was assessed before treatment using the functional assessment of cancer therapy-hepatobiliary (FACT-Hep) questionnaire. Descriptive statistics were used to evaluate demographics and disease-specific characteristics of the patients. One-way analysis of variance and independent samples t tests were used to compare the overall FACT-Hep scores and clinically distinct TNM stages. Scores for all FACT-Hep items were analyzed by frequency analyses. The mean scores obtained from the FACT-Hep in different Child-Pugh classes were also evaluated. RESULTS: The mean FACT-Hep scores were reduced significantly from TNM StageⅠto Stage Ⅱ, Stage ⅢA, Stage ⅢB group (687 ± 39.69 vs 547 ± 42.57 vs 387 ± 51.24 vs 177 ± 71.44, P = 0.001). Regarding the physical and emotional well-being subscales, scores decreased gradually from Stage Ⅰ to Stage ⅢB (P = 0.002 vs Stage Ⅰ; P = 0.032 vs Stage Ⅱ; P = 0.033 vs Stage ⅢA). Mean FACT-Hep scores varied by Child-Pugh class, especially in the subscales of physical well-being, functional well-being and the hepatobiliary cancer (P = 0.001 vs Stage I; P = 0.036 vs Stage Ⅱ; P = 0.032 vs Stage ⅢA). For the social and family well-being subscale, only Stage ⅢB scores were significantly lower as compared with Stage Ⅰ scores (P = 0.035). For the subscales of functional well-being and hepatobiliary cancer, there were significant differences for Stages ⅡΙ, ⅢA and ⅢB (P = 0.002vs StageⅠ). CONCLUSION: HRQoL of patients with HCC worsens gradually with progression of TNM stages. The most impaired subscales of HRQoL, as measured by FACT-Hep, were physical and emotional well-being.
基金Supported by the National Key Technology Research and Development Program of China(Nos.2012BAD25B08,2012BAD25B00)
文摘The length-weight relationship and allometric growth patterns of hatchery-reared Chinese loach, Paramisgurnus dabryanus(Dabry de Thiersant, 1872), were determined from hatching to 60 days after hatching. A best power model was estimated for the length-weight relationship during the early life stages. Positive allometric growth for the head segment, trunk length, tail length and eye diameter was also found in the early life stages, while body depth, tail depth, tail fi n length, pectoral fi n length and barbel length displayed a negative coeffi cient. During the subsequent early developmental stage, the growth coeffi cients showed a clear and common tendency towards isometry for all measured body ratios. The allometric growth changes in Chinese loach during the early stage are possibly the result of selective organogenesis directed towards survival priorities.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30570306, 30870400 and 40971286)the Public Benefit Research Foun- dation of State Forestry Administration, China (No. 201104040)
文摘Species-habitat association analysis is useful to detect spatial arrangement of individual plants, to discover rules about the distribution of species and to generate hypotheses about the possible underlying process controlling observed structures. Quantifying methods were used to classify habitats in terms of topographical variables in a mixed temperate broad-leaved Korean pine forest of the Changbai mountains in northeastern China. All of the 625 20 m × 20 m quadrats of the plot could be unambiguously assigned to one of three habitat categories (low-plateau, high-plateau and slope). Torus-translation tests were used to estimate species-habitat associations. Many species are clearly distributed in a biased fashion with respect to habitats. Fifteen (55.6%) out of 27 species showed strong positive or negative association with specific habitats. We compared species-habitat associations at the sapling and adult stages. Adjusted density values indicated few species exhibit extremely strong habitat associations. Only 9 out of 26 species had adjusted densities 〉 3 in the habitat for which they had strong positive affinity. Few species show the same associations at the small tree and large tree stages. Only 3 out of 22 occurring associations with a specific habitat appeared to have a consistent habitat association at the two stages. These results suggest that species-habitat associations exist in the 25-ha plot of the temperate forest of the Chang- bai mountains. Owing to limitations in our statistical methodology, we partly underestimated associations by ignoring rare species. Regeneration niches can contribute to co-existence, but regeneration niches due to habitat associations play a limited role in species co-existence, since most species show a similar trend in habitat associations at the sapling and adult stages. We should pay more attention to shifts in habitat associations, i.e. niche shifts at different stages of existence.
文摘Systematics is traditionally based on morphological characters to both define species and establish classifications. In the past decades, partly due to the advent of molecular biology, traditional systematics has declined while molecular systematics has tremendously increased. This results in that fewer funding are generally provided to traditional systematics, particularly for searching new morphological characters. Aquaculture, the farming of aquatic animals, has increased exponentially in the past decades, providing today more than half of fish consumed worldwide, and is expected to continue to rise. Aquaculture requires controlling the life cycle of the farmed fish in captivity, including the rearing of early life stages. Therefore, by coupling systematics and aquaculture, it could be possible to bring new funds and facilities to the former to study the early life stages of numerous fish species and to the latter it would offer a conceptual framework to perform comparative ontogeny. Together, this could help improving our knowledge on the early life stages that could be useful for both taxonomists and zootechnicians.
文摘This paper considers the real value of unpaid work. Actual living satisfaction depends not only on market income measured using the current concept of GDP, but also on unpaid household production. We try to estimate broad household income in Japan based on 2011 government estimates. We assume three household life stages, each of which consists of three cases categorized by the spouse's type of work. The results show that income differences between the three cases were very small and women worked longer hours than men in all household life stages. This reveals a different possible view of income distribution and poverty, in which women are overburdened.
基金supported by JSPS KAKENHI(Grant number 18380099).
文摘Authors conducted pollination experiments and genetic analyses using microsatellite loci for a natural population of a shrub species,Magnolia salicifolia,in a secondary Japanese beech forest in Hakkoda mountains,northern Japan,to analyze inbreeding and inbreeding depression that involve sexual reproduction and population genetic structure of the species.The pollination experiments revealed that self-fertilization through geitonogamy is possible and that the magnitude of inbreeding depression(δ)at the embryonic stage is substantial(δ=0.42),suggesting that the inbreeding depression due to self-fertilization decreases seed production of the natural population.The genetic analyses showed discrepancy in the level of inbreeding between life history stages:the inbreeding coefficient for the juvenile and adult stage was 0.17 and 0.01,respectively,implying that most of inbred progenies cannot grow to the adult stage in the population,since the cumulative inbreeding depression is severe.These results are consistent with the hypothesis that explains mechanisms causing stable maintenance of severe inbreeding depression in partially inbred populations by focusing on the selective interference among deleterious mutations.It is suggested that some reproductive traits facilitating outcrossing in the species would be attributed to the severe cumulative inbreeding depression.
基金financially supported by the French Ministry of Economy,Industry and Digital within the framework of the Project TRIUMPH(TReatIng Urban Micropollutants and Pharmaceuticals in wastewaters)labelled and managed by the European Eureka Cluster ACQUEAU.Laurent Simon(LEHNA,UMR 5023)is deeply acknowledge for the total and dissolved organic carbon analysis.
文摘Toxicity of wastewater treatment plant (WWTP) effluents is usually assessed with standardized bioassays, as e.g. the Fish Embryo Toxicity test (FET), but assessment of sub-lethal toxic effects requires to develop more adapted tests. The present work aimed to add the recording of several sub-lethal endpoints in exposed zebrafish embryo-larval stages in order to increase the sensitivity of residual toxicity evaluation of WWTP effluents using a semi-quantitative method (iFET score). This approach was complemented with the genotoxicity assessment on the exposed embryos, a sub-acute hazard particularly relevant to evaluate a potential chronic toxicity risk of low and multi-contaminated environmental matrices. Additionally, endocrine activities of effluents were quantified using human reporter cell lines. This test battery was applied to the assessment of the residual toxicity of five biological treatment effluents, further treated or not using various ozonation treatments intended to improve pharmaceutical compounds removal. Acute toxicity towards zebrafish embryos was very low. However, iFET score approach proposed was able to reveal residual toxicity through the presence of developmental abnormalities in all samples tested. Additionally, a low residual genotoxicity was measured in embryos exposed to two of the WWTP effluents when all excepted one exhibited a residual endocrine activity potential in the ng/L range providing complementary information on the occurrence of endocrine active chemicals and their reduction by different processes. To sum up, such a simplified and ecologically relevant test battery was found sensitive enough to characterize and differentiate various residual effluent’s ecotoxicity at contaminant levels of environmental concern.
文摘The bio-control potential of rhizospere bacteria Pseudomonas fluorescens against plant-parasite nematode had been demonstrated. P. fluorescens had shown the effect to enhance tobacco resistance to root-knot nematode Meloidogyne incognita. Inoculation with P. fluorescens in tobacco could lead to significant reductions in the number of juveniles that penetrated tobacco root and further life stage development of the juveniles. The number of juveniles penetrated into tobacco root in treatment with P. fluorescens is significantly different from CK at 2DAI,6DAI,8DAI and 10 DAI. Significant reduction and delayed development of juveniles that penetrated into tobacco root and treated were observed in treatment at14 DAI,21DAI,28 DAI and 35 DAI. In addition,P. fluorescens treatment leads to a significant reduction in the number of eggs per egg-mass at 35 DAI. The results show P. fluorescens induced a continuously suppression on root-knot nematode M. incognita throughout their entire early infection phase of root penetration,subsequent life stage development and reproduction.
基金supported by the National Natural Science Foundation of China (No. 51079049)the National Basic Research Program (973) of China (No. 2010CB429006)
文摘Effects of river water from the Yangtze River (Nanjing section) on fish development, vitellogenin (VTG) induction, gonado-somatic index (GSI) and sex ratio were investigated by exposing goldfish (Carassius auratus) in the early life stage (from fertilization to 28 days post-hatch) to water samples (25%, 50% and 100%) collected from three representative sections. The results showed that there was no significant effect on hatching success for any of the exposure groups, but survival was significantly reduced when compared with the control (P 0.05). Body lengths, weights of all treated fish did not differ significantly from those of the control. Condition factors (CF) of larval fish exposed to 50% and 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section were significantly lower than that of the control (P 0.05). VTG inductions were significant in larval fish exposed to all the dilution series of river water. No significant difference in CF value was observed in any exposure group after 150 days of depuration. VTG was fully eliminated after 75 days of depuration. For both female and male, GSI did not significantly differ between exposure groups and the control after 150 days of convalescence. The highest female:male ratios were observed in response to the treatment with 50% or 100% river water from the Jiangxinzhou section and 100% river water from the Daqiao section (53:47, 56:44 and 54:46, respectively), but no significant difference in sex ratio was observed in any treated group when compared to the control. The results showed that early life stage exposure of river water from the Yangtze River (Nanjing section) had adverse effects on goldfish development and reproductive health, and the effects on CF and VTG were reversible after depuration in clean water.
基金National Natural Science Foundation of China(31400362 and 31670442)the National Key Basic Research Program of China(2014CB954100)+1 种基金the West Light Foundation of the Chinese Academy of Sciences and the Chinese Academy of Sciences Youth Innovation Promotion Association(2016352)the Applied Fundamental Research Foundation of Yunnan Province(2014GA003).
文摘Aims The evolutionary history and functional traits of species can illumi-nate ecological processes supporting coexistence in diverse forest communities.However,little has been done in decoupling the rela-tive importance of these mechanisms on the turnover of phylogenetic and functional characteristics across life stages and spatial scales.Therefore,this study aims to estimate the contribution of environment and dispersal on the turnover of phylogenetic and functional diversity across life stages and spatial scales,in order to build a coherent pic-ture of the processes responsible for species coexistence.Methods We conducted the study in Xishuangbanna Forest Dynamics Plot in Yunnan Province,southwest China.We used four different spatial point process models to estimate the relative importance of disper-sal limitation and environmental filtering.The functional traits and phylogenetic relationships of all individual trees were incorporated in the analyses to generate measures of dissimilarity in terms of pair-wise and nearest-neighbor phylogenetic and functional characteris-tics across life stages and spatial scales.Important Findings We found non-random patterns of phylogenetic and functional turnover across life stages and spatial scales.Environmental filtering structured pairwise phylogenetic and functional beta diversity across spatial scales,while dispersal limitation alone,and in combination with environment filtering,shaped nearest neighbor phylogenetic and functional beta diversity.The relative importance of dispersal limitation and environmental filtering appeared to change with life stage but not with spatial scale.Our findings suggest that phylogenetic and functional beta diversity help to reveal the ecological processes responsible for evolu-tionary and functional assembly and highlight the importance of using a range of different metrics to gain full insights into these processes.
基金The research work presented in this paper is supported by the grants to the first and third authors from DST,via DST PURSE phase II,India.
文摘The current research elucidates the advertising scheme of automotive innovation by incorporating the various stages of the product life cycle.The study proposes an empirical model for the automotive industry to evaluate a time-point known as a switch-point or a take-off point at which firms should modify the advertising and sales promotion strategies to boost sales volume.The problem applies a time-series innovation diffusion model wherein adoption rate changes when a product enters a growth stage and then again when the company stops the advertising campaign in the maturity stage.The present paper develops a profit maximization problem,which optimizes the overall advertising duration and advertising take-off point.A numerical illustration is provided using the actual sales data of automobile industries,and sensitivity analysis is further performed to validate the effect of critical parameters on the optimization problem.
基金funded by the Fram Centre Research Programme“Plastic in the Arctic”through the PlastFul project(PA072018)supported by the Norwegian Polar Institute and the PlastPoll project funded by the Research Council of Norway(#275172)This research was partly financed by The Research Council of Norway,project no.160022/F40 NINA basic funding。
文摘Northern Fulmars(Fulmarus glacialis)are a pelagic seabird species distributed at northern and polar latitudes.They are often used as an indicator of plastic pollution in the North Sea region,but data are lacking from higher latitudes,especially when it comes to chicks.Here,we investigated amounts of ingested plastic and their characteristics in fulmar chicks from the Faroe Islands.Plastic particles(≥1 mm)in chicks of two age classes were searched using a digestion method with KOH.In addition,to evaluate if additive tissue burden reflects plastic ingestion,we measured liver tissue concentrations of two pollutant classes associated with plastic materials:polybrominated diphenyl ethers(PBDEs)and several dechloranes,using gas chromatography with high-resolution mass spectrometry.The most common shape was hard fragment(81%)and the most common polymer was polyethylene(73%).Plastic contamination did not differ between either age class,and we found no correlation between neither the amount and mass of plastic particles and the concentration of additives.After comparison with previous studies on adult fulmars,we do not recommend using chicks for biomonitoring adults because chicks seem to ingest more plastics than adults.