The contribution of acorn and soil N to early development of Chinese cork oak (Quercus variabilis Blume) seedlings under contrasting soil fertility conditions

40 p.Several studies have addressed the role of soil fertility on acorn N remobilization during seedling growth, but have focused on very early development stages or have assessed remobilization at a coarse grain ontogenetic scale making it difficult to know the precise time when seedlings switch from acorn N to soil N use. We cultivated Quercus variabilis seedlings under two distinct soil N fertility and assessed their growth, acorn N remobilization, and absorption of soil N at five distinct development stages, spanning from the incipient shoot emergence to the completion of the second flush of growth. Acorn N contributed more to seedling N content than soil N at all development stages. Seedlings began to uptake substantial amounts of soil N after the completion of leaf expansion during the first shoot flush of growth, coinciding with a fine root area that reached 50% of the maximum value observed at the end of the study. Roots became less dependent on acorn N before shoots. Soil fertility, rather than seedling growth rate, determined soil N uptake after the completion of leaf expansion in the first shoot flush of growth. We conclude that the acorn is the primary N source for Q. variabilis seedlings until the completion of the first shoot flush of growth. Soil fertility does not significantly affect either the amount of N remobilized from acorns or the switch from acorn N to massive soil N use, suggesting a minimal effect of forest microhabitat fertility on acorn N utilization by Q. variabilis seedlings.Gobierno de EspañaComunidad de MadridNational Natural Science Foundation of ChinaChina Scholarship Counci

Acorn size is more important than nursery fertilization for outplanting performance of Quercus variabilis container seedlings

Small acorns are usually discarded for seedling cultivation because they reduce plant quality. This,however, can potentially reduce genetic diversity of plantations. The use of small acorns will result in the production ofa higher proportion of small seedlings containing low nutrient levels and having poor outplanting performance in oakcontainer seedlings. Nursery fertilization partially offsets the negative effect of small acorns on seedling attributes in thenursery but not on outplanting performance.Small acorns result in low-quality seedlings and so are usually discarded in artificial regeneration programs of oakspecies. This can potentially reduce genetic diversity of plantations. Nursery fertilization may compensate for the low quality of small-acorn seedlings.To assess whether nursery fertilization interacts with Quercus variabilis acorn size to determine seedling morphology and nutrition in the nursery and outplanting performance.Methods Acorns of three size classes were used to cultivate seedlings with or without fertilization. Seedling emergence, nursery morphology and nutrient status, and outplanting survival and growth were measured.National Natural Science Foundation of ChinaFundamental Research Funds for Central UniversitiesComunidad de Madri

Simulated predation of Quercus variabilis acorns impairs nutrient remobilization and seedling performance irrespective of soil fertility

Background and aims Predators may partially orcompletely consume Quercus spp. acorns, but effectson nutrient remobilization and seedling performance arepoorly understood. We investigated interactions betweensoil fertility and the removal of Quercus variabilisacorn cotyledons at different early developmental stageson seedling nutrition and development.Methods Seedlings were grown in two soils of contrastingfertility and the kinetics of acorn nitrogen, phosphorusand potassium remobilization, and seedling survival,growth and nutrient content were analyzed.Results Acorn mass and macronutrients decreased remarkably<2 weeks after emergence, with nitrogen andphosphorus remobilizing faster than potassium. Acornremoval at or 1 week after emergence inhibited seedlingsurvival, growth and fine root formation, whereas removalfrom 2 to 10 weeks after emergence had minor effects. Acorn macronutrient remobilization and effects of acorn removal on seedling performance were not reversed under high soil fertility. When acorns were removed &#8805; 2 weeks after emergence, fertilization increased root surface and seedling nitrogen content. Conclusions. Acorn nutrients are more important than soil nutrients during very early seedling development. Cotyledon damage at emergence impairs seedling performance despite no direct damage to the remainder of the seedling. This effect cannot be reverted by high soil fertility and has potential ecological and practical implications for oak regeneration.National Natural Science Foundation of ChinaComunidad de Madri

Treatment of Esophagogastric Anastomotic Leak with Perianastomotic Drain

IntroductionThe most efficient treatment of such anastomotic leaks after esophagectomy remains controversial. Our objective was to evaluate the effectiveness of perianastomotic drains in anastomotic leaks.MethodsFive patients with intrathoracic anastomotic leaks had placement of perianastomotic drains through remanet esophagus and fitula into infected area. The other conservative methods of treatment were also chosen simultaneously.ResultsThe perianastomotic drains were placed successfully in all five patients. None of the patients underwent rethoracotomy. They were all cured. The median period to clinical healing was 33 days. The median hospital stay after the perianastomotic drainage procedure was 37 days.ConclusionThis procedure proved to be safe and effective in the treatment of esophagogastric anastomotic leak with perianastomotic drain through fistula

Growth and nutrient dynamics of transplanted Quercus variabilis seedlings as influenced by pre-hardening and fall fertilization

Stored nutrient reserves are closely correlated with survival and growth of transplanted seedlings. Previous studies have proven that combining pre-hardening fertilization (PF) with fall fertilization (FF) built seedling nutrient reserves more effectively; however, their effect on transplanting performance is poorly documented. We investigated the independent and interacting effects of 2 levels of PF and 4 levels of FF on seedling growth, nutrient acquisition and accumulation during different growth phases 1 year after transplanting of Blume in a nursery. High PF benefited nutrient reserves and subsequent transplanted seedling growth and tissue nutrient storage at the end of the rapid growth and hardening phases. Fall fertilization with 36 mg N increased stem dry mass and tissue nutrient content at the end of the hardening phase. At the conclusion of establishment, PF and FF showed a significant interaction for N and K uptake from soil. At the end of the rapid growth and hardening phases, high PF consistently increased nutrient uptake. Enhanced N and K uptake occurred following application of 36 mg N of FF at the end of the hardening phase. Distinct roles for PF and FF on 3 phases of transplanted seedlings demonstrated the necessity to evaluate fertilization in terms of nutrient reserves and subsequent transplanting performance in consecutive phases. Combining 100 mg N seedling during pre-hardening with 36 mg N seedling during fall yielded ideal transplanting performance for seedlings.Quercus variabilis â1â1Quercus variabili

Current situation, bottlenecks, and path options for the development of capital flows and integration in the Yangtze River Delta region

IntroductionCapital plays a crucial role in the development of regional economies, especially in low-income regions where it acts as a primary driver of economic growth. Efficient capital flow is essential for optimizing resource allocation and facilitating the development of integrated capital markets. This passage introduces the topic of capital, capital flow, and capital market integration and highlights their significance in regional development.MethodsTo gain a comprehensive understanding of capital flow and integration in the Yangtze River Delta region, the researchers conducted a connotative analysis. They constructed indicators from various aspects, including social fixed asset investment, bank capital flow, government transfer payments, social financing structure, and foreign direct investment. By utilizing these indicators, the researchers aimed to assess the current situation and identify bottlenecks related to capital flow and integration. Additionally, they drew on experiences from foreign capital flow and integration development to enrich their analysis.ResultsThe analysis revealed several primary bottlenecks affecting capital flow and integration in the Yangtze River Delta region. These bottlenecks include an unsound banking management system, the presence of government competition and administrative barriers, and shortcomings within listed companies. The results highlight the specific challenges that hinder the smooth functioning and integration of capital in the region.DiscussionTo promote the development of capital flows and integration in the Yangtze River Delta region, the researchers propose various recommendations. These suggestions include promoting the development of listed companies, establishing a robust banking management model, improving relevant government policies, and optimizing the investment environment. These recommendations serve as important guidelines for policymakers to enhance capital flow and integration in the Yangtze River Delta city cluster. Furthermore, they emphasize the need to strengthen financial supervision and improve institutional mechanisms within the three provinces and one city comprising the region

Evaluation of an identification method for the SARS-CoV-2 Delta variant based on the amplification-refractory mutation system

The Delta variant of SARS-CoV-2 dominated the COVID-19 pandemic due to its high viral replication capacity and immune evasion, causing massive outbreaks of cases, hospitalizations, and deaths. Currently, variant identification is performed mainly by sequencing. However, the high requirements for equipment and operators as well as its high cost have limited its application in underdeveloped regions. To achieve an economical and rapid method of variant identification suitable for undeveloped areas, we applied an amplification-refractory mutation system (ARMS) based on PCR for the detection of novel coronavirus variants. The results showed that this method could be finished in 90 min and detect as few as 500 copies/mL and not react with SARS-Coronavirus, influenza A H1N1(2009), and other cross-pathogens or be influenced by fresh human blood, α- interferon, and other interfering substances. In a set of double-blind trials, tests of 262 samples obtained from patients confirmed with Delta variant infection revealed that our method was able to accurately identify the Delta variant with high sensitivity and specificity. In conclusion, the ARMS-PCR method applied in Delta variant identification is rapid, sensitive, specific, economical, and suitable for undeveloped areas. In our future study, ARMS-PCR will be further applied in the identification of other variants, such as Omicron

Research of influence law of water content in coal to gas adsorption and desorption characteristics

In order to verify the influence law of water content in coal to gas adsorption and desorption characteristics, gas adsorption and desorption experiments were carried out in different equilibrium pressure conditions with different water content in coal. The experiment results show that the gas adsorption capacity decreases with increasing of water content in coal, it could be corrected by use of water content influence coefficient in practical application. With the water content increasing, the gas desorption became slower and the amount of gas remaining was greater. The water filled in the coal gap has inhibitory effect to gas adsorption and desorption

Cloud Computing and Its Application in Big Data Processing of Distance Higher Education

In the development of information technology the development of scientific theory has brought the progress of science and technology. The progress of science and technology has an impact on the educational field, which changes the way of education. The arrival of the era of big data for the promotion and dissemination of educational resources has played an important role, it makes more and more people benefit. Modern distance education relies on the background of big data and cloud computing, which is composed of a series of tools to support a variety of teaching mode. Clustering algorithm can provide an effective evaluation method for students' personality characteristics and learning status in distance education. However, the traditional K-means clustering algorithm has the characteristics of randomness, uncertainty, high time complexity, and it does not meet the requirements of large data processing. In this paper, we study the parallel K-means clustering algorithm based on cloud computing platform Hadoop, and give the design and strategy of the algorithm. Then, we carry out experiments on several different sizes of data sets, and compare the performance of the proposed method with the general clustering method. Experimental results show that the proposed algorithm which is accelerated has good speed up and low cost. It is suitable for the analysis and mining of large data in the distance higher education