The migration route of oceanic squid provides critical information for us to understand their spatial and temporal variations.Mark-recapture and electronic tags tend to be problematic during processing.Cephalopod hard...The migration route of oceanic squid provides critical information for us to understand their spatial and temporal variations.Mark-recapture and electronic tags tend to be problematic during processing.Cephalopod hard structures such as the beak,containing abundant ecological information with stable morphology and statolithlike sequences of growth increments,may provide information for studying spatio-temporal distribution.In this study,we developed a method,which is based on elemental concentration of beaks at different ontogenetic stages and sampling locations,to reconstruct the squid migration route.We applied this method to Ommastrephes bartramii in the North Pacific Ocean.Nine trace elements were detected in the rostrum sagittal sections(RSS)of the beak using laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).For those elements,significant differences were found between the different ontogenetic stages for phosphorus(P),copper(Cu)and zinc(Zn).Sodium(Na),P and Zn were chosen as indicators of sea surface temperature(SST)and a regression model was estimated.The high probability of occurrence in a particular area represented the possible optimal squid location based on a Bayesian model.A reconstructed migration route in this study,combining all the locations at different ontogenetic stages,was consistent with that hypothesized in previous studies.This study demonstrates that the beak can provide useful information for identifying the migration routes of oceanic squid.展开更多
Environmental variations and ontogeny may affect plant morphological traits and biomass allocation patterns that are related to the adjustments of plant ecological strategies. We selected 2-, 3-and 4-year-old Fritilla...Environmental variations and ontogeny may affect plant morphological traits and biomass allocation patterns that are related to the adjustments of plant ecological strategies. We selected 2-, 3-and 4-year-old Fritillaria unibracteata plants to explore the ontogenetic and altitudinal changes that impact their morphological traits(i.e., plant height, single leaf area,and specific leaf area) and biomass allocations [i.e.,biomass allocations of roots, bulbs, leaves, stems, and flowers] at relatively low altitudinal ranges(3400 m to 3600 m asl) and high altitudinal ranges(3600 m to4000 m asl). Our results indicated that plant height,root biomass allocation, and stem biomass allocation significantly increased during the process of individual growth and development, but single leaf area, specific leaf area, bulb biomass allocation, and leaf biomass allocation showed opposite trends.Furthermore, the impacts of altitudinal changes on morphological traits and biomass allocations had no significant differences at low altitude, except for single leaf area of 2-year-old plants. At high altitude,significantly reduced plant height, single leaf area and leaf biomass allocation for the 2-year-old plants,specific leaf area for the 2-and 4-year-old plants, and stem biomass allocation were found along altitudinal gradients. Significantly increased sexual reproductive allocation and relatively stable single leaf area and leaf biomass allocation were also observed for the 3-and 4-year-old plants. In addition, stable specific leaf area for the 3-year-old plants and root biomass allocation were recorded. These results suggested that the adaptive adjustments of alpine plants, in particular F. unibracteata were simultaneously influenced by altitudinal gradients and ontogeny.展开更多
Lagochilus proskorjakovii Ikram is a strict endemic in Nuratau ridge (north-western spurs of the mountain range of the Pamir-Alai). It grows as a part of Amygdalus bucharica and Perovskia scrophulariifolia formation, ...Lagochilus proskorjakovii Ikram is a strict endemic in Nuratau ridge (north-western spurs of the mountain range of the Pamir-Alai). It grows as a part of Amygdalus bucharica and Perovskia scrophulariifolia formation, where the total projective cover of grass does not exceed 20%. In natural conditions growth, ontogeny of L. proskorjakovii is simple and complete. The duration of ontogenesis in the condition of Nuratau is no more than 22 - 23 years. Studied coenopopulations are normal, but are not complete. Coenopopulation self-maintenance is carried out by the seed of renewal. The characteristic spectrum of coenopopulation centered, with a peak in the middle-generative individuals. In most cases, specific developmental spectrum of coenopopulation coincides with the characteristic ones. The absence or small proportion of the young fraction in surveyed of coenopopulation is related to the elimination of young fragile individuals. According to the classification of “delta-omega”, the most of coenopopulations are maturing which confirms the positive state of coenopopulation demography. Studied the ontogeny and structure of adult endemic Nuratau established that the species belongs to caudexum shrubs, perennial that forms the axis of the short multicipital caudex. Buds renewal is at a height of 2 - 3 cm above the substrate. Investigated coenopopulations L. proskorjakovii are successiveness conditions. In addition to the Artemisia juncea + Perovskia scrophulariifolia + Ferula ovina + Stipa hohenackeriana community 1<sup>st</sup> coenopopulation (CP) mature;the 2<sup>nd</sup> CP is mature which was a part of the Amygdalus bucharica + Perovskia scrophulariifolia + Prangos pobularia + Bromus scoparius community;3<sup>rd</sup> CP is maturing being a part of Lonicera nummulariifolia + Perovskia scrophulariifolia + Hypericum scabrum + Bromus danthoniae community and the 4<sup>th</sup> CP is mature which occurred in Amygdalus bucharica + Ferula varia + Acroptilon repens + Taeniatherum crinitum plant community.展开更多
Predicting species abundance is one of the most fundamental pursuits of ecology.Combining the information encoded in functional traits and metacommunities provides a new perspective to predict the abundance of species...Predicting species abundance is one of the most fundamental pursuits of ecology.Combining the information encoded in functional traits and metacommunities provides a new perspective to predict the abundance of species in communities.We applied a community assembly via trait selection model to predict quadrat-scale species abundances using functional trait variation on ontogenetic stages and metacommunity information for over 490 plant species in a subtropical forest and a lowland tropical forest in Yunnan,China.The relative importance of trait-based selection,mass effects,and stochasticity in shaping local species abundances is evaluated using different null models.We found both mass effects and trait selection contribute to local abundance patterns.Trait selection was detectable at all studied spatial scales(0.04e1 ha),with its strength stronger at larger scales and in the subtropical forest.In contrast,the importance of stochasticity decreased with spatial scale.A significant mass effect of the metacommunity was observed at small spatial scales.Our results indicate that tree community assembly is primarily driven by ontogenetic traits and metacommunity effects.Our findings also demonstrate that including ontogenetic trait variation into predictive frameworks allows ecologists to infer ecological mechanisms operating in community assembly at the individual level.展开更多
Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been cond...Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species.We divided 67 Pinus koraiensis Sieb.et Zucc.of various sizes(0.3-100 cm diameter at breast height,DBH)into four ontogenetic stages,i.e.,young trees,middle-aged trees,mature trees and over-mature trees,and measured the leaf mass per area(LMA),leaf dry matter content(LDMC),and mass-based leaf nitrogen content(N)and phosphorus content(P)of each leaf age group for each sampled tree.One-way analysis of variance(ANOVA)was used to describe the variation in leaf traits by ontogenetic stage and leaf age.The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships.We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age.Most trait-trait relationships were consistent with the leaf economic spectrum(LES)at a global scale.Among them,leaf N content and LDMC showed a significant negative correlation,leaf N and P contents showed a significant positive correlation,and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage.LMA and LDMC showed a significant positive correlation,and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age.Additionally,there were no significant relationships between leaf N content and LMA in most groups,which is contrary to the expectation of the LES.Overall,in the early ontogenetic stages and leaf ages,the leaf traits tend to be related to a"low investment-quick returns"resource strategy.In contrast,in the late ontogenetic stages and leaf ages,they tend to be related to a"high investment-slow returns"resource strategy.Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.展开更多
Ontogenetic structure of eight coenopopulations of Tulipa korolkowii Regel were studied in Uzbekistan.Resistance mechanisms of Tulipa korolkowii coenopopulations are shown:seed and vegetative methods of self-maintenan...Ontogenetic structure of eight coenopopulations of Tulipa korolkowii Regel were studied in Uzbekistan.Resistance mechanisms of Tulipa korolkowii coenopopulations are shown:seed and vegetative methods of self-maintenance of coenopopulations.Coenopopulations(CP)of T.korolkovii studied in normal.CP 1,2,6,7,8 complete,and the rest(3,4,5)are incomplete,no senile individuals.Absence of old specimens in coenopopulation connected with die-off great number plants in generative period of ontogenesis.展开更多
Body shape and metabolic rate can be important determinants of animal performance,yet often their effects on influential traits are evaluated in a non-integrated way.This creates an important gap because the integrati...Body shape and metabolic rate can be important determinants of animal performance,yet often their effects on influential traits are evaluated in a non-integrated way.This creates an important gap because the integration between shape and metabolism may be crucial to evaluate metabolic scaling theories.Here,we measured standard metabolic rate in 1-and 2-years old juvenile brown trout Salmo trutta,and used a geometric morphometrics approach to extricate the effects of ontogeny and size on the link between shape and metabolic scaling.We evidenced near-isometric ontogenetic scaling of metabolic rate with size,but also a biphasic pattern driven by a significant change in metabolic scaling,from positive to negative allometry.Moreover,the change in metabolic allometry parallels an ontogenetic change from elongate to deep-bodied shapes.This is consistent with the dynamic energy budget(DEB)and surface area(SA)theories,but not with the resource transport network theory which predicts increasing allometric exponents for trends towards more robust,three-dimensional bodies.In addition,we found a relationship between body shape and size independent metabolic rate,with a positive correlation between robustness and metabolic rate,which fits well within the view of Pace-of-Life Syndromes(POLS).Finally,our results align with previous studies that question the universality of metabolic scaling exponents and propose other mechanistic models explaining the diversity of metabolic scaling relationships or emphasizing the potential contribution of ecological factors.展开更多
Horseshoe crabs,the most well-known example of“living fossils”,are iconic and ecologically important macroinvertebrates in coastal and estuarine ecosystems.Their blood is a crucial resource for manufacturing Limulus...Horseshoe crabs,the most well-known example of“living fossils”,are iconic and ecologically important macroinvertebrates in coastal and estuarine ecosystems.Their blood is a crucial resource for manufacturing Limulus or Tachypleus amebocyte lysate to detect bacterial endotoxins or fungal contamination in drug and medical devices.An enhanced understanding of their ecological roles and trophic interactions in the food webs is fundamental to facilitate resource management for the declining populations in Asia.Foraging information of the Asian species,however,is mainly derived from preliminary,scattered reports from a limited number of study locations.In this study,resource utilization,trophic niche dynamics,and trophic interaction of the juvenile tri-spine horseshoe crab,Tachypleus tridentatus(instars 1–12,approximately 0.5–8 years old)across ontogeny was assessed in diversified nursery habitats along the northern Beibu Gulf,China,using carbon and nitrogen stable isotopes.Our results suggest that:(i)T.tridentatus are ecological generalists given the vast range of carbon isotopic values and trophic niche width estimates exhibited between multiple instar groups;(ii)juvenile T.tridentatus across most habitat types predominantly assimilated energy from a variety of basal production sources in the food web,but primarily depended on sedimentary organic matter and seagrass resource pools;(iii)ontogenetic shifts in juvenile dietary proportions were evident,with decreased reliance on sedimentary organic matter,coupled with increased reliance on benthic macroinvertebrate grazers,detritivores,and omnivores with age;and(iv)nearly all juvenile instars occupied similar trophic positions in the food web with slight shifts in trophic position present with increasing size.Our findings indicate that resource availability and ontogenetic diet shifts strongly influence horseshoe crab trophic dynamics,and age should be accounted when formulating habitat conservation measures based on resource use for Asian horseshoe crabs.展开更多
Age and body size can influence predation risk and hence habitat use. Many species undergo ontogenetic shifts in habitat use as individuals grow larger and have different age-specific predation pressures. On coral ree...Age and body size can influence predation risk and hence habitat use. Many species undergo ontogenetic shifts in habitat use as individuals grow larger and have different age-specific predation pressures. On coral reefs, a number of fish species are more tolerant of threats in structurally complex habitats that contain more refuges than in less structurally complex habitats. However, we do not know how risk perception varies with age, and whether age interacts with habitat complexity. Adults and juveniles, because of their size, may face different risks in structurally simple versus complex habitats. We used flight initiation distanee as a metric to analyze perceptions of risk in a species of damselfish Stegastes nigricans. All else being equal, fish fleeing at greater distances are inferred to perceive higher risk. We targeted juvenile and adult damselfish to assess whether there are ontogenetic shifts in perceptions of safety in relation to structural complexity, inferred based on percent coral cover and rugosity. We found that adult damselfish tolerated closer approach in more complex habitats as measured by percent coral cover, but not rugosity, whereas juvenile fish always allowed closer approach than adult fish regardless of complexity. This ontogenetic shift in habitat use may result from juvenile fish taking bigger risks to maximize growth, whereas older animals, who are closer to their maximum body size, can afford to take fewer risks and protect their assets.展开更多
When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life stage.Many caterpillars in the genus Papilio exhibi...When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life stage.Many caterpillars in the genus Papilio exhibit unique ontogenetic color sequences:for example,early instars that masquerade as bird feces,with later instars possessing eyespots.I hypothesize that larvae abandon feces masquerade in favor of eyespots due to ontogenetic changes in signaler size.This ontogenetic pattern also occurs within broader seasonal shifts in background color and predator activity.I conducted predation experiments with artificial prey to determine how potential signaling constraints(specifically size and season)shape predation risk,and consequently the expression of ontogenetic color change in Papilio larvae.Seasonally,both predation and background greenness declined significantly from July to September,though there was little evidence that these patterns impacted the effectiveness of either color strategy.Caterpillar size and color strongly affected the attack rate of avian predators:attacks increased with prey size regardless of color,and eyespotted prey were attacked more than masquerading prey overall.These results may reflect a key size-mediated tradeoff between conspicuousness and intimidation in eyespotted prey,and raise questions about how interwoven aspects of behavior and signal environment might maintain the prevalence of large,eyespotted larvae in nature.展开更多
Ontogenetic aging of tissues and the gradual decrease of adventitious rooting are known challenges for the clonal propagation of woody species,hampering clonal forestry programs.This study examined possible signatures...Ontogenetic aging of tissues and the gradual decrease of adventitious rooting are known challenges for the clonal propagation of woody species,hampering clonal forestry programs.This study examined possible signatures of tissue rejuvenation/reinvigoration in different propagated materials of Eucalyptus microcorys by analyzing the total protein profile,peroxidase activity,macro-and micronutrient contents,and adventitious rooting of mini cuttings.The analyses were performed on E.microcorys shoots which were successfully obtained by seminal and grafting propagation,micropropagation with epicormic shoots,and indirect organogenesis.Among four mature trees used in the propagation,tissues from the one with the best propagation results were investigated for signs of tissue rejuvenation and/or reinvigoration.Five individuals from each technique were randomly selected and transferred to a semi-hydroponic"channel"system.After four weeks in the seedbed,the total protein,peroxidase activity,nutrient content and rooting of the mini cuttings were evaluated.SDS-PAGE enabled the differentiation of leaf samples obtained by grafting from the other propagation techniques,as revealed by two distinct bands.Materials obtained by micropropagation with epicormic shoots showed the highest peroxidase activity,while those obtained by seminal propagation and from the selected mature tree showed the lowest peroxidase activity.A portable X-ray fluorescence spectroscope(pXRF)identified adequate nutrient content in most of the nutrients tested in materials obtained by seminal and grafting propagation,and by indirect organogenesis.The analysis of adventitious rooting showed that the highest rooting percentage was observed in mini cuttings from seminal propagation(75%)followed by indirect organogenesis(35%).Based on principal component analysis,it was concluded that rooting of mini cuttings from both seminal propagation and indirect organogenesis was associated with phosphorous,sulphur,and potassium contents,which suggests a higher level of tissue rejuvenation/reinvigoration in these propagated plants.Further studies are recommended to search for other methods that present similarities with the responses to adventitious rooting in forest species and thus optimize the rescue and propagation of plants with distinct ontogenetic stages.展开更多
The contradiction between the supply and demand of edible vegetable oil in China is prominent,and the self-sufficiency rate is less than 35%.Peanut has a very outstanding status in ensuring the security of edible oil ...The contradiction between the supply and demand of edible vegetable oil in China is prominent,and the self-sufficiency rate is less than 35%.Peanut has a very outstanding status in ensuring the security of edible oil and food.The emphasis of increasing peanut yield should be the improvement of pod yield per unit area,because the total yield of peanut has not increased as required.This is attributed to mainly two factors-low increase in the crop productivity and the competition for land for grain and cotton crops.For traditional double-seed sowing pattern,it is difficult to further increase the peanut yield due to the serious contradiction between populations and individuals and the declining population quality under high-yield conditions.Single-seed precision sowing was proven to be a new way to increase the economic coefficient(economic yield/biological yield)with the basic stability of the total biomass,which could make plants distribute evenly,reduce the competition among individuals and attain the full production potential of single plant.In order to reveal the mechanism of increasing peanut yield by single-seed precision sowing,the effects on the ontogenetic development(plant character,physiological characteristic and nutrient utilization)and population structure(population uniformity and photosynthesis,source-sink relationship and yield composition)were systematically expounded.This study reports establishment of the high-yield cultivation technology system with the key technology of single-seed precision sowing and the supporting technology of fertilizing and management.We anticipate its wider application for the improvement of peanut yield.展开更多
Rapid and accurate perception of threat information is a critical ability and a prerequisite to survive natural selection for humans.To investigate whether threatening stimuli,especially phylogenetic and ontogenetic t...Rapid and accurate perception of threat information is a critical ability and a prerequisite to survive natural selection for humans.To investigate whether threatening stimuli,especially phylogenetic and ontogenetic threats,are processed automatically,we analyzed the visual mismatch negativity(vMMN,an event-related potential component reflecting automatic processing)elicited by the threats with a cross-modal oddball paradigm,where participants were required to focus on the auditory stimuli and ignore the visual stimuli in each block.In this study,neutral(non-threatening)images served as standard stimuli(80%),and phylogenetic(10%)and ontogenetic(10%)threat stimuli served as deviant stimuli when testing a large sample(N=96)of healthy volunteers.Threat-related visual mismatch negativity(threat-vMMN)was obtained by subtracting the event-related potential(ERP)elicited by standard stimuli from that elicited by deviant stimuli.The results indicated that the vMMN can be elicited by threat information.More importantly,the phylogenetic threat information elicited larger threat-vMMN than ontogenetic threat information.These findings suggest that perception of threat information was automatic,providing an evidential basis for the attentional advantages of survival processing.That is,automatic perception of phylogenetic threats has a particular evolutionary origin.展开更多
The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, t...The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, the state of the cenotic populations of the species was assessed, during the 2012-2018 years studied 15 cenopopulations different ecological-phytocenotic conditions in Uzbekistan.展开更多
Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes...Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes of relict mountains. The ontogenetic structure of five coenotypical populations of this taxa growing in the Kuldzhuktau and Auminzatau mountains had been revealed. The ontogenesis duration is more than 20 years in natural habitats. All investigated coenopopulations can be assessed as normal and incomplete. The typical spectrum of coenopopulations is centralized with a peak in the middle-generative individuals. The ontogenetic spectrum of the most studied coenopopulations coincides with the characteristic ontogenetic structure that indicates a favorable environmental condition in region for self-maintenance of L. subcordatum coenopopulations.展开更多
The main goal of this work is to demonstrate the suitability of survival analysis for ontogenetic studies. The research material includes retrospective data of the age of the occurrence of ontogenetic events such as b...The main goal of this work is to demonstrate the suitability of survival analysis for ontogenetic studies. The research material includes retrospective data of the age of the occurrence of ontogenetic events such as birth (N = 487), menarche (N = 2016) and menopause (N = 3597). In order to study the time of occurrence of ontogenetic events and to indicate the impact of environmental factors the survival analysis was applied. First, the percentiles of functions established for studied events were calculated. Next, the Kaplan-Meier survival curves were derived. In the last step theinfluence of environmental factors was established and the comparison of groups determined based on the chosen factors was performed. The delivery time shows that 14% of infants were bornpreterm. The risk of preterm delivery increases with the severity of factors disrupting pregnancy (from none to coexisting maternal and fetal risk factors) (;p < 0.001). In the case of menarche percentile positions indicate that the menarche occurs between the 12thand the 14thyear of life as the period in which most girls exceed the puberty threshold. The Cox’s proportional hazard model indicates that the time of menarche occurrence is significantly depended (;p < 0.001) on the place of the mother’s residence and number of children in the family (respectively p < 0.03 and p < 0.001). The time interval established for 50% occurrence of this experience was designated between the 49th and the 52nd years of life. The time of menopause occurrence is significantly depended on both of considered factors: the educational level and smoking cigarettes (, p < 0.001). Survival analysis is suitable for studies of the distribution in time of developmental events. It can be used to indicate the factors which significantly influence the course of development by modifying the duration of developmental stages.展开更多
Understanding of resource requirements of vulnerable species is key for conservation planning.Here,we used sta-ble carbon(δ13C)and nitrogen isotopes(δ15N)of hair from giant armadillos(Priodontes maximus)to understan...Understanding of resource requirements of vulnerable species is key for conservation planning.Here,we used sta-ble carbon(δ13C)and nitrogen isotopes(δ15N)of hair from giant armadillos(Priodontes maximus)to understand individual resource use.We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pan-tanal and compared the resource use between sexes and age classes.We also assessed the relationship of isotopic values with individuals’body mass and the habitat type used.We observed a wide variation in resource use by giant armadillos,showing that individuals consume prey that feeds on distinct resources and occupies different habitat types,indicating that there is individual variation in foraging behavior.Most giant armadillos presented a mixed diet(C3/C4 resources,forests/open areas),but a quarter of individuals had strictly C4 diets(open areas).Males are more prone to forage on C4 resources,presenting an isotopic niche 2.6-times larger than that of females.Subadults presented diets more associated with habitats with high arboreal cover(C3 resources,forests),while adults foraged more in open areas(C4 resources).This result is mirrored by the positive relationship betweenδ13C values and body mass,suggesting that larger giant armadillos tend to feed more in open areas.We observed thatδ13C values decreased as individuals increased the use of habitats with high arboreal cover.We stress the importance of con-serving the natural mosaic in the Pantanal landscape for the species persistence,given that giant armadillos require all habitat types to fulfill their dietary,spatial,and developmental needs.展开更多
Labeo victorianus(Boulenger,1901)is one of the endemic fishes in Lake Victoria Basin(LVB)but is now threatened by multiple stressors caused by human activities.We investigated spatial and temporal variability in food ...Labeo victorianus(Boulenger,1901)is one of the endemic fishes in Lake Victoria Basin(LVB)but is now threatened by multiple stressors caused by human activities.We investigated spatial and temporal variability in food composition and condition of L.victorianus in influent rivers of Lake Victoria,Kenya.Sampling was done during the dry and wet seasons by electrofishing.Food composition analysis showed that L.victorianus is a benthophagus and omnivorous species whose diet is dominated by detritus,periphyton and insects.There were differences in food composition among rivers,with significant river X season interactions(PERMANOVA F=11.6,df=4,p=0.001),suggesting that the diet depended on prevailing environmental conditions.In turbid rivers,the diet was dominated by detritus while in less turbid rivers it was dominated by insects and periphyton.Sand and mud also formed a significant part of the diet,which was an indication of a limited occurrence of preferable food items.There were ontogenetic shifts in food composition(PERMANOVA F=4.6,df=3,p=0.001),but also with a spatial interaction(PERMANOVA F=5.6,df=7,p=0.001),further indicating the role of environmental conditions in determining the diet for different size classes.Interestingly,the fish condition did not differ among rivers.This study shows that turbidity and organic matter and nutrient loading determine the diet of L.victorianus in LVB rivers,and provides further justification for the maintenance of water quality as a conservation measure for threatened species.展开更多
As the current standard,surgery is applied to treat early-stage cervical cancer and selected post-irradiation pelvic relapses.Surgical therapy for local disease is based on a model of unlimited isotropic cancer cell p...As the current standard,surgery is applied to treat early-stage cervical cancer and selected post-irradiation pelvic relapses.Surgical therapy for local disease is based on a model of unlimited isotropic cancer cell propagation and dissection artifacts such as subperitoneal“ligaments”and“spaces”.For regional disease,the role of traditional surgery is diagnostic and eventually cytoreductive.However,the isotropic local tumor propagation model has to be rejected due to numerous inconsistencies with clinical facts.Likewise,the“ligament and space”approach to the subperitoneum is too crude and variable to accurately cover both local spread and intercalated lymph node metastases of cervical cancer.The ontogenetic cancer field model is fully in line with the locoregional spread patterns of carcinoma of the female genital tract.Developmentally derived(ontogenetic)anatomy enables unbiased and accurate dissection of the complex tissue structures within the subperitoneum.Cancer field surgery founded on these insights has a high potential to improve the treatment outcome of cervical carcinoma.展开更多
Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactio...Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic phases.Methods In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available nutrients.Here we report measurements of above-and belowground interactions during entire growing season.Correlation between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also performed.Important findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing season.However,both negative and positive shoot interactions occurred among the four species.Despite there being shoot facilitative effect for E.nutans and S.superba,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot interaction.The interaction between root and shoot effect varied as a function of species identity and growth phases.The weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.展开更多
基金The National Natural Science Foundation of China under contract No.NSFC4147129the China Postdoctoral Science Foundation under contract No.2017M610277+1 种基金the Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources(Shanghai Ocean University),Ministry of Education under contract No.A1-0203-00-2009-6the Fund of Key Laboratory of Open-Sea Fishery Development,Ministry of Agriculture,China under contract LOF 2018-02
文摘The migration route of oceanic squid provides critical information for us to understand their spatial and temporal variations.Mark-recapture and electronic tags tend to be problematic during processing.Cephalopod hard structures such as the beak,containing abundant ecological information with stable morphology and statolithlike sequences of growth increments,may provide information for studying spatio-temporal distribution.In this study,we developed a method,which is based on elemental concentration of beaks at different ontogenetic stages and sampling locations,to reconstruct the squid migration route.We applied this method to Ommastrephes bartramii in the North Pacific Ocean.Nine trace elements were detected in the rostrum sagittal sections(RSS)of the beak using laser ablation inductively coupled plasma mass spectrometry(LA-ICP-MS).For those elements,significant differences were found between the different ontogenetic stages for phosphorus(P),copper(Cu)and zinc(Zn).Sodium(Na),P and Zn were chosen as indicators of sea surface temperature(SST)and a regression model was estimated.The high probability of occurrence in a particular area represented the possible optimal squid location based on a Bayesian model.A reconstructed migration route in this study,combining all the locations at different ontogenetic stages,was consistent with that hypothesized in previous studies.This study demonstrates that the beak can provide useful information for identifying the migration routes of oceanic squid.
基金funded by the Natural Science Foundation Project of Sichuan Science and Technology Department (2018JY0305)Key Projects of the Natural Science Foundation of Sichuan Education Department (18ZA0002)
文摘Environmental variations and ontogeny may affect plant morphological traits and biomass allocation patterns that are related to the adjustments of plant ecological strategies. We selected 2-, 3-and 4-year-old Fritillaria unibracteata plants to explore the ontogenetic and altitudinal changes that impact their morphological traits(i.e., plant height, single leaf area,and specific leaf area) and biomass allocations [i.e.,biomass allocations of roots, bulbs, leaves, stems, and flowers] at relatively low altitudinal ranges(3400 m to 3600 m asl) and high altitudinal ranges(3600 m to4000 m asl). Our results indicated that plant height,root biomass allocation, and stem biomass allocation significantly increased during the process of individual growth and development, but single leaf area, specific leaf area, bulb biomass allocation, and leaf biomass allocation showed opposite trends.Furthermore, the impacts of altitudinal changes on morphological traits and biomass allocations had no significant differences at low altitude, except for single leaf area of 2-year-old plants. At high altitude,significantly reduced plant height, single leaf area and leaf biomass allocation for the 2-year-old plants,specific leaf area for the 2-and 4-year-old plants, and stem biomass allocation were found along altitudinal gradients. Significantly increased sexual reproductive allocation and relatively stable single leaf area and leaf biomass allocation were also observed for the 3-and 4-year-old plants. In addition, stable specific leaf area for the 3-year-old plants and root biomass allocation were recorded. These results suggested that the adaptive adjustments of alpine plants, in particular F. unibracteata were simultaneously influenced by altitudinal gradients and ontogeny.
文摘Lagochilus proskorjakovii Ikram is a strict endemic in Nuratau ridge (north-western spurs of the mountain range of the Pamir-Alai). It grows as a part of Amygdalus bucharica and Perovskia scrophulariifolia formation, where the total projective cover of grass does not exceed 20%. In natural conditions growth, ontogeny of L. proskorjakovii is simple and complete. The duration of ontogenesis in the condition of Nuratau is no more than 22 - 23 years. Studied coenopopulations are normal, but are not complete. Coenopopulation self-maintenance is carried out by the seed of renewal. The characteristic spectrum of coenopopulation centered, with a peak in the middle-generative individuals. In most cases, specific developmental spectrum of coenopopulation coincides with the characteristic ones. The absence or small proportion of the young fraction in surveyed of coenopopulation is related to the elimination of young fragile individuals. According to the classification of “delta-omega”, the most of coenopopulations are maturing which confirms the positive state of coenopopulation demography. Studied the ontogeny and structure of adult endemic Nuratau established that the species belongs to caudexum shrubs, perennial that forms the axis of the short multicipital caudex. Buds renewal is at a height of 2 - 3 cm above the substrate. Investigated coenopopulations L. proskorjakovii are successiveness conditions. In addition to the Artemisia juncea + Perovskia scrophulariifolia + Ferula ovina + Stipa hohenackeriana community 1<sup>st</sup> coenopopulation (CP) mature;the 2<sup>nd</sup> CP is mature which was a part of the Amygdalus bucharica + Perovskia scrophulariifolia + Prangos pobularia + Bromus scoparius community;3<sup>rd</sup> CP is maturing being a part of Lonicera nummulariifolia + Perovskia scrophulariifolia + Hypericum scabrum + Bromus danthoniae community and the 4<sup>th</sup> CP is mature which occurred in Amygdalus bucharica + Ferula varia + Acroptilon repens + Taeniatherum crinitum plant community.
基金supported by the National Natural Science Foundation of China (31800353)the Yunnan Fundamental Research Projects (202101AV070005)+4 种基金Yunnan High Level Talents Special Support Plan (YNWR-QNBJ-2018-309)Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Y202080)the West Light Foundation of the Chinese Academy of Sciencessupported by the National Science Foundation United States (NSF DEB-2029997)
文摘Predicting species abundance is one of the most fundamental pursuits of ecology.Combining the information encoded in functional traits and metacommunities provides a new perspective to predict the abundance of species in communities.We applied a community assembly via trait selection model to predict quadrat-scale species abundances using functional trait variation on ontogenetic stages and metacommunity information for over 490 plant species in a subtropical forest and a lowland tropical forest in Yunnan,China.The relative importance of trait-based selection,mass effects,and stochasticity in shaping local species abundances is evaluated using different null models.We found both mass effects and trait selection contribute to local abundance patterns.Trait selection was detectable at all studied spatial scales(0.04e1 ha),with its strength stronger at larger scales and in the subtropical forest.In contrast,the importance of stochasticity decreased with spatial scale.A significant mass effect of the metacommunity was observed at small spatial scales.Our results indicate that tree community assembly is primarily driven by ontogenetic traits and metacommunity effects.Our findings also demonstrate that including ontogenetic trait variation into predictive frameworks allows ecologists to infer ecological mechanisms operating in community assembly at the individual level.
基金The work was financially supported by the National Natural Science Foundation of China(No.31971636)Yong Elite Scientists Sponsorship Program by CAST(2018QNRC001)the Fundamental Research Fund for the Central Universities(2572018CG03).
文摘Investigating the effects of ontogenetic stage and leaf age on leaf traits is important for understanding the utilization and distribution of resources in the process of plant growth.However,few studies have been conducted to show how traits and trait-trait relationships change across a range of ontogenetic stage and leaf age for evergreen coniferous species.We divided 67 Pinus koraiensis Sieb.et Zucc.of various sizes(0.3-100 cm diameter at breast height,DBH)into four ontogenetic stages,i.e.,young trees,middle-aged trees,mature trees and over-mature trees,and measured the leaf mass per area(LMA),leaf dry matter content(LDMC),and mass-based leaf nitrogen content(N)and phosphorus content(P)of each leaf age group for each sampled tree.One-way analysis of variance(ANOVA)was used to describe the variation in leaf traits by ontogenetic stage and leaf age.The standardized major axis method was used to explore the effects of ontogenetic stage and leaf age on trait-trait relationships.We found that LMA and LDMC increased significantly and N and P decreased significantly with increases in the ontogenetic stage and leaf age.Most trait-trait relationships were consistent with the leaf economic spectrum(LES)at a global scale.Among them,leaf N content and LDMC showed a significant negative correlation,leaf N and P contents showed a significant positive correlation,and the absolute value of the slopes of the trait-trait relationships showed a gradually increasing trend with an increasing ontogenetic stage.LMA and LDMC showed a significant positive correlation,and the slopes of the trait-trait relationships showed a gradually decreasing trend with leaf age.Additionally,there were no significant relationships between leaf N content and LMA in most groups,which is contrary to the expectation of the LES.Overall,in the early ontogenetic stages and leaf ages,the leaf traits tend to be related to a"low investment-quick returns"resource strategy.In contrast,in the late ontogenetic stages and leaf ages,they tend to be related to a"high investment-slow returns"resource strategy.Our results reflect the optimal allocation of resources in Pinus koraiensis according to its functional needs during tree and leaf ontogeny.
基金The current research is done under the project PZ-20170919165 Inventory of rare and endangered species of vascular plants of Navoi and Bukhara regions.
文摘Ontogenetic structure of eight coenopopulations of Tulipa korolkowii Regel were studied in Uzbekistan.Resistance mechanisms of Tulipa korolkowii coenopopulations are shown:seed and vegetative methods of self-maintenance of coenopopulations.Coenopopulations(CP)of T.korolkovii studied in normal.CP 1,2,6,7,8 complete,and the rest(3,4,5)are incomplete,no senile individuals.Absence of old specimens in coenopopulation connected with die-off great number plants in generative period of ontogenesis.
基金This work was supported by the Principality of Asturias(grant no.CN-07-164)the Spanish Government(grants no.MEC-CGL2004-03239/BOS and MMA/86-2003-1)FICYT(predoctoral fellowship BPO4-147 to J.R.S.G.)。
文摘Body shape and metabolic rate can be important determinants of animal performance,yet often their effects on influential traits are evaluated in a non-integrated way.This creates an important gap because the integration between shape and metabolism may be crucial to evaluate metabolic scaling theories.Here,we measured standard metabolic rate in 1-and 2-years old juvenile brown trout Salmo trutta,and used a geometric morphometrics approach to extricate the effects of ontogeny and size on the link between shape and metabolic scaling.We evidenced near-isometric ontogenetic scaling of metabolic rate with size,but also a biphasic pattern driven by a significant change in metabolic scaling,from positive to negative allometry.Moreover,the change in metabolic allometry parallels an ontogenetic change from elongate to deep-bodied shapes.This is consistent with the dynamic energy budget(DEB)and surface area(SA)theories,but not with the resource transport network theory which predicts increasing allometric exponents for trends towards more robust,three-dimensional bodies.In addition,we found a relationship between body shape and size independent metabolic rate,with a positive correlation between robustness and metabolic rate,which fits well within the view of Pace-of-Life Syndromes(POLS).Finally,our results align with previous studies that question the universality of metabolic scaling exponents and propose other mechanistic models explaining the diversity of metabolic scaling relationships or emphasizing the potential contribution of ecological factors.
基金This research was supported by the National Natural Science Foundation of China(41706183,41901226)the Guangxi Natural Science Foundation(2017GXNSFBA198181)the Guangxi BaGui Youth Scholars Program,the Guangxi Recruitment Program of 100 Global Experts,and the Guangxi Postdoctoral Innovation Program.
文摘Horseshoe crabs,the most well-known example of“living fossils”,are iconic and ecologically important macroinvertebrates in coastal and estuarine ecosystems.Their blood is a crucial resource for manufacturing Limulus or Tachypleus amebocyte lysate to detect bacterial endotoxins or fungal contamination in drug and medical devices.An enhanced understanding of their ecological roles and trophic interactions in the food webs is fundamental to facilitate resource management for the declining populations in Asia.Foraging information of the Asian species,however,is mainly derived from preliminary,scattered reports from a limited number of study locations.In this study,resource utilization,trophic niche dynamics,and trophic interaction of the juvenile tri-spine horseshoe crab,Tachypleus tridentatus(instars 1–12,approximately 0.5–8 years old)across ontogeny was assessed in diversified nursery habitats along the northern Beibu Gulf,China,using carbon and nitrogen stable isotopes.Our results suggest that:(i)T.tridentatus are ecological generalists given the vast range of carbon isotopic values and trophic niche width estimates exhibited between multiple instar groups;(ii)juvenile T.tridentatus across most habitat types predominantly assimilated energy from a variety of basal production sources in the food web,but primarily depended on sedimentary organic matter and seagrass resource pools;(iii)ontogenetic shifts in juvenile dietary proportions were evident,with decreased reliance on sedimentary organic matter,coupled with increased reliance on benthic macroinvertebrate grazers,detritivores,and omnivores with age;and(iv)nearly all juvenile instars occupied similar trophic positions in the food web with slight shifts in trophic position present with increasing size.Our findings indicate that resource availability and ontogenetic diet shifts strongly influence horseshoe crab trophic dynamics,and age should be accounted when formulating habitat conservation measures based on resource use for Asian horseshoe crabs.
文摘Age and body size can influence predation risk and hence habitat use. Many species undergo ontogenetic shifts in habitat use as individuals grow larger and have different age-specific predation pressures. On coral reefs, a number of fish species are more tolerant of threats in structurally complex habitats that contain more refuges than in less structurally complex habitats. However, we do not know how risk perception varies with age, and whether age interacts with habitat complexity. Adults and juveniles, because of their size, may face different risks in structurally simple versus complex habitats. We used flight initiation distanee as a metric to analyze perceptions of risk in a species of damselfish Stegastes nigricans. All else being equal, fish fleeing at greater distances are inferred to perceive higher risk. We targeted juvenile and adult damselfish to assess whether there are ontogenetic shifts in perceptions of safety in relation to structural complexity, inferred based on percent coral cover and rugosity. We found that adult damselfish tolerated closer approach in more complex habitats as measured by percent coral cover, but not rugosity, whereas juvenile fish always allowed closer approach than adult fish regardless of complexity. This ontogenetic shift in habitat use may result from juvenile fish taking bigger risks to maximize growth, whereas older animals, who are closer to their maximum body size, can afford to take fewer risks and protect their assets.
文摘When constraints on antipredator coloration shift over the course of development,it can be advantageous for animals to adopt different color strategies for each life stage.Many caterpillars in the genus Papilio exhibit unique ontogenetic color sequences:for example,early instars that masquerade as bird feces,with later instars possessing eyespots.I hypothesize that larvae abandon feces masquerade in favor of eyespots due to ontogenetic changes in signaler size.This ontogenetic pattern also occurs within broader seasonal shifts in background color and predator activity.I conducted predation experiments with artificial prey to determine how potential signaling constraints(specifically size and season)shape predation risk,and consequently the expression of ontogenetic color change in Papilio larvae.Seasonally,both predation and background greenness declined significantly from July to September,though there was little evidence that these patterns impacted the effectiveness of either color strategy.Caterpillar size and color strongly affected the attack rate of avian predators:attacks increased with prey size regardless of color,and eyespotted prey were attacked more than masquerading prey overall.These results may reflect a key size-mediated tradeoff between conspicuousness and intimidation in eyespotted prey,and raise questions about how interwoven aspects of behavior and signal environment might maintain the prevalence of large,eyespotted larvae in nature.
基金supported by the Coordination for the Improvement of Higher Education Personnel–Brazil (CAPES)the National Council for Scientific and Technological Development (CNPq)the Research Support Foundation of the State of Minas (FAPEMIG)。
文摘Ontogenetic aging of tissues and the gradual decrease of adventitious rooting are known challenges for the clonal propagation of woody species,hampering clonal forestry programs.This study examined possible signatures of tissue rejuvenation/reinvigoration in different propagated materials of Eucalyptus microcorys by analyzing the total protein profile,peroxidase activity,macro-and micronutrient contents,and adventitious rooting of mini cuttings.The analyses were performed on E.microcorys shoots which were successfully obtained by seminal and grafting propagation,micropropagation with epicormic shoots,and indirect organogenesis.Among four mature trees used in the propagation,tissues from the one with the best propagation results were investigated for signs of tissue rejuvenation and/or reinvigoration.Five individuals from each technique were randomly selected and transferred to a semi-hydroponic"channel"system.After four weeks in the seedbed,the total protein,peroxidase activity,nutrient content and rooting of the mini cuttings were evaluated.SDS-PAGE enabled the differentiation of leaf samples obtained by grafting from the other propagation techniques,as revealed by two distinct bands.Materials obtained by micropropagation with epicormic shoots showed the highest peroxidase activity,while those obtained by seminal propagation and from the selected mature tree showed the lowest peroxidase activity.A portable X-ray fluorescence spectroscope(pXRF)identified adequate nutrient content in most of the nutrients tested in materials obtained by seminal and grafting propagation,and by indirect organogenesis.The analysis of adventitious rooting showed that the highest rooting percentage was observed in mini cuttings from seminal propagation(75%)followed by indirect organogenesis(35%).Based on principal component analysis,it was concluded that rooting of mini cuttings from both seminal propagation and indirect organogenesis was associated with phosphorous,sulphur,and potassium contents,which suggests a higher level of tissue rejuvenation/reinvigoration in these propagated plants.Further studies are recommended to search for other methods that present similarities with the responses to adventitious rooting in forest species and thus optimize the rescue and propagation of plants with distinct ontogenetic stages.
基金supported by the National Natural Science Foundation of China(31601252 and 31571605)the National Key R&D Program of China(2018YFD0201000)+1 种基金the Natural Science Foundation of Shandong Province,China(BS2015SW020)the earmarked fund for China Agriculture Research System(CARS-13)。
文摘The contradiction between the supply and demand of edible vegetable oil in China is prominent,and the self-sufficiency rate is less than 35%.Peanut has a very outstanding status in ensuring the security of edible oil and food.The emphasis of increasing peanut yield should be the improvement of pod yield per unit area,because the total yield of peanut has not increased as required.This is attributed to mainly two factors-low increase in the crop productivity and the competition for land for grain and cotton crops.For traditional double-seed sowing pattern,it is difficult to further increase the peanut yield due to the serious contradiction between populations and individuals and the declining population quality under high-yield conditions.Single-seed precision sowing was proven to be a new way to increase the economic coefficient(economic yield/biological yield)with the basic stability of the total biomass,which could make plants distribute evenly,reduce the competition among individuals and attain the full production potential of single plant.In order to reveal the mechanism of increasing peanut yield by single-seed precision sowing,the effects on the ontogenetic development(plant character,physiological characteristic and nutrient utilization)and population structure(population uniformity and photosynthesis,source-sink relationship and yield composition)were systematically expounded.This study reports establishment of the high-yield cultivation technology system with the key technology of single-seed precision sowing and the supporting technology of fertilizing and management.We anticipate its wider application for the improvement of peanut yield.
文摘Rapid and accurate perception of threat information is a critical ability and a prerequisite to survive natural selection for humans.To investigate whether threatening stimuli,especially phylogenetic and ontogenetic threats,are processed automatically,we analyzed the visual mismatch negativity(vMMN,an event-related potential component reflecting automatic processing)elicited by the threats with a cross-modal oddball paradigm,where participants were required to focus on the auditory stimuli and ignore the visual stimuli in each block.In this study,neutral(non-threatening)images served as standard stimuli(80%),and phylogenetic(10%)and ontogenetic(10%)threat stimuli served as deviant stimuli when testing a large sample(N=96)of healthy volunteers.Threat-related visual mismatch negativity(threat-vMMN)was obtained by subtracting the event-related potential(ERP)elicited by standard stimuli from that elicited by deviant stimuli.The results indicated that the vMMN can be elicited by threat information.More importantly,the phylogenetic threat information elicited larger threat-vMMN than ontogenetic threat information.These findings suggest that perception of threat information was automatic,providing an evidential basis for the attentional advantages of survival processing.That is,automatic perception of phylogenetic threats has a particular evolutionary origin.
文摘The current state of coenotic populations of rare and endangered species of Uzbekistan-Tulipa micheliana Hoog is given. Based on the analysis of demographic indicators and a number of organisms and population signs, the state of the cenotic populations of the species was assessed, during the 2012-2018 years studied 15 cenopopulations different ecological-phytocenotic conditions in Uzbekistan.
文摘Lepidium subcordatum Botsch. et Vved. (Brassicaceae) is a rare endemic species of relict mountains of the Kyzylkum desert. The plant is listed in the “Red Data Book of Uzbekistan”. It grows on stony and rocky slopes of relict mountains. The ontogenetic structure of five coenotypical populations of this taxa growing in the Kuldzhuktau and Auminzatau mountains had been revealed. The ontogenesis duration is more than 20 years in natural habitats. All investigated coenopopulations can be assessed as normal and incomplete. The typical spectrum of coenopopulations is centralized with a peak in the middle-generative individuals. The ontogenetic spectrum of the most studied coenopopulations coincides with the characteristic ontogenetic structure that indicates a favorable environmental condition in region for self-maintenance of L. subcordatum coenopopulations.
文摘The main goal of this work is to demonstrate the suitability of survival analysis for ontogenetic studies. The research material includes retrospective data of the age of the occurrence of ontogenetic events such as birth (N = 487), menarche (N = 2016) and menopause (N = 3597). In order to study the time of occurrence of ontogenetic events and to indicate the impact of environmental factors the survival analysis was applied. First, the percentiles of functions established for studied events were calculated. Next, the Kaplan-Meier survival curves were derived. In the last step theinfluence of environmental factors was established and the comparison of groups determined based on the chosen factors was performed. The delivery time shows that 14% of infants were bornpreterm. The risk of preterm delivery increases with the severity of factors disrupting pregnancy (from none to coexisting maternal and fetal risk factors) (;p < 0.001). In the case of menarche percentile positions indicate that the menarche occurs between the 12thand the 14thyear of life as the period in which most girls exceed the puberty threshold. The Cox’s proportional hazard model indicates that the time of menarche occurrence is significantly depended (;p < 0.001) on the place of the mother’s residence and number of children in the family (respectively p < 0.03 and p < 0.001). The time interval established for 50% occurrence of this experience was designated between the 49th and the 52nd years of life. The time of menopause occurrence is significantly depended on both of considered factors: the educational level and smoking cigarettes (, p < 0.001). Survival analysis is suitable for studies of the distribution in time of developmental events. It can be used to indicate the factors which significantly influence the course of development by modifying the duration of developmental stages.
基金the National Council of Technological and Scientific Development(CNPq)for the research productivity fellowship grant(#308632/2018-4).
文摘Understanding of resource requirements of vulnerable species is key for conservation planning.Here,we used sta-ble carbon(δ13C)and nitrogen isotopes(δ15N)of hair from giant armadillos(Priodontes maximus)to understand individual resource use.We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pan-tanal and compared the resource use between sexes and age classes.We also assessed the relationship of isotopic values with individuals’body mass and the habitat type used.We observed a wide variation in resource use by giant armadillos,showing that individuals consume prey that feeds on distinct resources and occupies different habitat types,indicating that there is individual variation in foraging behavior.Most giant armadillos presented a mixed diet(C3/C4 resources,forests/open areas),but a quarter of individuals had strictly C4 diets(open areas).Males are more prone to forage on C4 resources,presenting an isotopic niche 2.6-times larger than that of females.Subadults presented diets more associated with habitats with high arboreal cover(C3 resources,forests),while adults foraged more in open areas(C4 resources).This result is mirrored by the positive relationship betweenδ13C values and body mass,suggesting that larger giant armadillos tend to feed more in open areas.We observed thatδ13C values decreased as individuals increased the use of habitats with high arboreal cover.We stress the importance of con-serving the natural mosaic in the Pantanal landscape for the species persistence,given that giant armadillos require all habitat types to fulfill their dietary,spatial,and developmental needs.
基金support was provided by the National Research Fund(NRF),Kenya through the KISS Project.
文摘Labeo victorianus(Boulenger,1901)is one of the endemic fishes in Lake Victoria Basin(LVB)but is now threatened by multiple stressors caused by human activities.We investigated spatial and temporal variability in food composition and condition of L.victorianus in influent rivers of Lake Victoria,Kenya.Sampling was done during the dry and wet seasons by electrofishing.Food composition analysis showed that L.victorianus is a benthophagus and omnivorous species whose diet is dominated by detritus,periphyton and insects.There were differences in food composition among rivers,with significant river X season interactions(PERMANOVA F=11.6,df=4,p=0.001),suggesting that the diet depended on prevailing environmental conditions.In turbid rivers,the diet was dominated by detritus while in less turbid rivers it was dominated by insects and periphyton.Sand and mud also formed a significant part of the diet,which was an indication of a limited occurrence of preferable food items.There were ontogenetic shifts in food composition(PERMANOVA F=4.6,df=3,p=0.001),but also with a spatial interaction(PERMANOVA F=5.6,df=7,p=0.001),further indicating the role of environmental conditions in determining the diet for different size classes.Interestingly,the fish condition did not differ among rivers.This study shows that turbidity and organic matter and nutrient loading determine the diet of L.victorianus in LVB rivers,and provides further justification for the maintenance of water quality as a conservation measure for threatened species.
文摘As the current standard,surgery is applied to treat early-stage cervical cancer and selected post-irradiation pelvic relapses.Surgical therapy for local disease is based on a model of unlimited isotropic cancer cell propagation and dissection artifacts such as subperitoneal“ligaments”and“spaces”.For regional disease,the role of traditional surgery is diagnostic and eventually cytoreductive.However,the isotropic local tumor propagation model has to be rejected due to numerous inconsistencies with clinical facts.Likewise,the“ligament and space”approach to the subperitoneum is too crude and variable to accurately cover both local spread and intercalated lymph node metastases of cervical cancer.The ontogenetic cancer field model is fully in line with the locoregional spread patterns of carcinoma of the female genital tract.Developmentally derived(ontogenetic)anatomy enables unbiased and accurate dissection of the complex tissue structures within the subperitoneum.Cancer field surgery founded on these insights has a high potential to improve the treatment outcome of cervical carcinoma.
基金National Natural Science Foundation of China(grant no.30600070)the National Basic Research program of China(grant no.2005CB422005).
文摘Aims Numerous studies have showed that the balance between negative and positive plant–plant interactions shifted along environmental gradients.But little is known how the positive or negative plant–plant interactions varied with temporal fluctuating habitat conditions and plant ontogenetic phases.Methods In a 2-year experiment,the four perennial grasses(Kobresia humilis,Stipa aliena,Elymus nutans and Saussurea superba)were grown under four interaction treatments(no root or shoot interaction,only shoot interaction,only root interaction,root and shoot interaction).Intensity of above-and belowground interactions is proposed to vary with the fluctuation of seasonal climatic conditions and soil available nutrients.Here we report measurements of above-and belowground interactions during entire growing season.Correlation between plant interaction intensity and seasonal soil available N as well as habitat climate conditions was also performed.Important findings Our experiment found that root interactions had negative effect on plant growth for the four species during growing season.However,both negative and positive shoot interactions occurred among the four species.Despite there being shoot facilitative effect for E.nutans and S.superba,the full interaction was negative,suggested that root interaction take more important role on plant growth than that of shoot interaction.The interaction between root and shoot effect varied as a function of species identity and growth phases.The weak correlation of plant interaction intensity to habitat environmental factors suggested that plant ontogenetic characteristics may be primary factors causing temporal variation in plant interaction.