Effects of ontogenetic stage and leaf age on leaf functional traits and the relationships between traits in Pinus koraiensis

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.

Cancer field surgery for locoregional tumor control of cervical carcinoma

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.