Genomics and metabolic characteristics of simultaneous heterotrophic nitrification aerobic denitrification and aerobic phosphorus removal by Acinetobacter indicus CZH-5.

This study provides for the first time a systematic understanding of Acinetobacter indicus CZH-5 performance, metabolic pathway and genomic characteristics for aerobic nitrogen (N) and phosphorus (P) removal. Acinetobacter indicus CZH-5 showed promising performance in heterotrophic nitrification aerobic denitrification and aerobic phosphorus removal. Under optimal conditions, the maximum ammonia-N, total nitrogen and orthophosphate-P removal efficiencies were 90.17%, 86.33%, and 99.89%, respectively. The wide tolerance range suggests the strong environmental adaptability of the bacteria. The complete genome of this strain was reconstructed. Whole genome annotation was used to re-construct the N and P metabolic pathways, and related intracellular substance metabolic pathways were proposed. The transcription levels of related functional genes and enzyme activities further confirmed these metabolic mechanisms. N removal was achieved via the nitrification-denitrification pathway. Furthermore, CZH-5 exhibited significant aerobic P uptake, with phosphate diesters as the main species of intracellular P.

Intraspecific variations of leaf hydraulic, economic, and anatomical traits in Cinnamomum camphora along an urban-rural gradient.

Urbanization brings numerous benefits to residents, but it also introduces complex, variable, and heterogeneous habitat conditions to urban plants, resulting in an arid and hot urban environment that decreases tree growth and the ecological service capacity of trees. In this study, we evaluated leaf hydraulic, economic, and anatomical traits and their covariations of Cinnamomum camphora along an urban-rural gradient in Hefei, Eastern China. We found that Cinnamomum camphora in urban adopted a conservative hydraulic strategy with low leaf turgor loss point (Tlp), leaf hydraulic conductance (Kleaf), and leaf water potential resulting in 50 % loss of hydraulic conductance (P50), as well as a quick investment-return economic strategy with low unit leaf dry matter content (LMA) and high leaf nitrogen content (Leaf N). P50, Kleaf and LMA were significantly positively correlated with the urban-rural gradient (PC1urban-rural gradient), while Leaf N exhibited a negative correlation with it. The results showed a trade-off between intraspecific safety and efficiency in leaf hydraulic traits along the urban-rural gradient and an intraspecific coordinated variation in leaf hydraulic and economic traits. In addition, based on the analysis of a trait coordination network, it was revealed that leaf mesophyll and stomata were key structures for trait adjustment and coordination. Furthermore, our findings offer a significant theoretical underpinning for the effective management of landscape trees and the strategic planning of urban tree species.

Inheritance and Innovation of Pottery Sculpture Technique in Shiwan, China: A Grounded Study from Cultural Ecology.

Ceramics play an important role in human daily life and production practice. Pottery sculpture technique is the core of ceramic making. However, the production process of traditional ceramics is accompanied by high pollution, which has a great impact on human health and the ecological environment. Rapid development of industrialization has exacerbated this consequence. As the "Pottery Capital of Southern China", Foshan has been involved in environmental crises while relying on the ceramic industry to develop. Since the 21st century, Foshan has gradually successfully driven to upgrade the city from industrial to culture-led by carrying out positive innovations in Shiwan pottery sculpture technique. Therefore, based on the theoretical perspective of cultural ecology, this paper selects Shiwan pottery sculpture technique as the object, uses Python (Octopus Collector) to obtain data, and applies grounded theory to generate the ecological evolution model. This study discussed how the Shiwan pottery sculpture technique promotes the harmonious coexistence of human beings, industries, and cities in the new cultural ecological environment of the 21st century by exploring and clarifying the interaction and function of different elements in different stages of evolution. Finally, this study not only makes up for the current lack of research on Shiwan's cultural ecology, but also provides meaningful reference for environmental reform in other industrialized cities.

Integrated Sustainable Development of Culture into Tourist Map Design: A Case from Foshan, China.

As the fourth pillar of sustainable development, culture is widely recognized as contributing to human wellbeing. The distinctive culture of cities is an important driving force for attracting visitors to destinations for tourism consumption. Since historical cities have important cultural and historical values, the design of their tourist maps needs not only geographic positioning and artistic aesthetics, but also a systematic design method to present the connotation of regional cultures, so as to enhance the local cultural identity of hosts and the cultural cognition of visitors, and to drive the local tourism economy, improve the regional environment, promote cultural transmission and inheritance with the help of tourist map design in terms of cultural sustainability, which ultimately achieves sustainable development of human wellbeing. Taking Foshan, a national historical city, as an example, combined with the cultural gene and the cultural hierarchy theory, this study analyzes and summarizes the regional culture of Foshan from three aspects: material cultural gene, intangible cultural gene and spiritual cultural gene. This study also comprehensively presents the geographical information and historical or humanistic characteristics of the city through direct translation, narrative translation, and metaphor translation, which provide theoretical support and practical guidance for the integration of regional cultures into tourist map design.

Coordination of leaf hydraulic and economic traits in Cinnamomum camphora under impervious pavement.

BACKGROUND: Paved urban environments can pose great threats to the physiological functioning and ecological services of street trees. In this context, assessment of leaf phenotypic plasticity is crucial for understanding the ecological strategy of tree species under impervious pavements. RESULTS: In this study, we measured a set of leaf economic traits, hydraulic traits of Cinnamomum camphora, and surrounding environmental factors in a street site (the soil was covered by the impervious pavement) and a park site (the soil was covered by grass) in Hefei, eastern China. Compared with the park site, trees in the street site had higher stomatal length (SL), leaf thickness (LT), maximum photochemical quantum yield of photosystem II (Y(II)), and lower stomatal density (SD), specific leaf area (SLA), the leaf water potential at 50% loss of hydraulic conductance (P50), and leaf turgor loss point (TLP). Redundancy analysis showed that air relative humidity and volumetric soil water content caused these traits to be altered. CONCLUSIONS: Our results showed that C. camphora adapted to the street pavement environment through the coordination of leaf economic and leaf hydraulic traits, and adopted the slow investment return type in the leaf economic spectrum and high drought resistance to meet its actual physiological needs. This finding provides a new perspective for understanding the physiological strategies of street trees to adapt to urban pavement environments.

Responses in Growth and Anatomical Traits of Two Subtropical Tree Species to Nitrogen Addition, Drought, and Their Interactions.

Nitrogen (N) deposition and drought are two major stressors that influence tree growth and propagation. However, few studies have investigated their interactions. In this study, saplings of the two co-occurring species Ormosia pinnata (leguminous) and Schima superba (non-leguminous) were cultivated under two N addition rates (0 and 80 kg N ha-1 year-1) with well-watered (WW, 80% of field capacity), moderate drought (MD, 60% of field capacity), and severe drought conditions (SD, 40% of field capacity). We examined their growth, as well as multiple anatomical and non-structural carbohydrate (NSC) responses, after 2 years. Results revealed that N addition significantly promoted the growth of MD-stressed S. superba, whereas no significant effect was detected in O. pinnata. Decreased leaf water potential (both Ψmd and Ψpd) was also observed with N addition for both species under MD, but not under SD. Furthermore, the application of N positively impacted drought adaptive responses in the stem xylem of S. superba, showing decreased stem xylem vessel diameter (D H), theoretical hydraulic conductivity (K th), and increased vessel frequency (VF) upon drought under N addition; such impacts were not observed in O. pinnata. Regarding leaf anatomy, N addition also caused drought-stressed S. superba to generate leaves with a lower density of veins (VD) and stomata (SD), which potentially contributed to an enhanced acclimation to drought. However, the same factors led to a decrease in the palisade mesophyll thickness (PMT) of SD-stressed O. pinnata. Moreover, N addition increased the xylem soluble sugar and starch of MD-stressed O. pinnata, and decreased the xylem soluble sugar under SD for both species. The results suggest that N addition does not consistently modify tree growth and anatomical traits under variable water availability. S. superba appeared to have a greater capacity to be more adaptable under the future interactive effects of N addition and drought due to major modifications in its anatomical traits.

Distribution and characteristics of microplastics in the basin of Chishui River in Renhuai, China.

As an emerging pollutant, microplastics widely exist in rivers all over the world. Due to the differences of economic development, economic structure and population in different regions, the abundance of microplastics in rivers is different. In those areas where agriculture is developed, the content of film microplastics is more, while in densely populated areas, the content of fibrous microplastics is more. Taking Renhuai Basin of Chishui River as the research object, the pollution characteristics and current situation of microplastics in the basin were analyzed, and the contamination risk of microplastics was evaluated. The abundance of microplastics in Renhuai basin of Chishui River ranges from 1.77 to 14.33 items/L. The main forms of microplastics were fibrous (59.4%), white (including transparent) (41.3%) and polychromatic (44.1%). The particle size of microplastics was mainly 500- 1000 µm (63.9%). According to the assessment, the risk of microplastics in the basin is 111.79, which is a secondary risk area. This study can provide a further reference for understanding the pollution characteristics of microplastics in rivers.

The occurrence and abundance of microplastics in surface water and sediment of the West River downstream, in the south of China.

Microplastic pollution has aroused great concern in inland waters. Freshwater is the transport routes and potential sources for plastic fragments to the oceans. However, information especially about the occurrence of microplastics in freshwater systems is unclear in certain key areas. This work studied the distribution and characteristics for microplastics in the downstream area of West River. Both sediment and surface water detected microplastics with abundance ranging from 2560 to 10,240 items/kg and 2.99 to 9.87 items/L, respectively. Small size (<0.5 mm) and fiber were the main size and type in both surface waters and sediments. Polypropylene, polyethylene, polyethylene, polyvinyl chloride and polyethylene terephthalate were the polymer types of microplastics, as identified using a Fourier transform infrared spectrometer. In addition, findings here might be in consideration of studying about the distribution of microplastics and the degree to which they were influenced by the use of land. In descending order, the highest microplastics abundance was observed in commercial/public/recreational > residential > industrial > natural areas. Our results indicate the occurrence of high abundance microplastics in river impacted by human activities, and suggest that spatial distribution of microplastics varies between different land use areas.

Effects of the Supplementation of Lysophospholipids through Pelleted Total Mixed Rations on Blood Biochemical Parameters and Milk Production and Composition of Mid-Lactation Dairy Cows.

Lysophospholipids (LPL), a new feed additive, were supplemented to a pelleted total mixed ration (TMR) of dairy cows to examine its effects on feed intake, production, and composition of milk and plasma biochemical parameters. Two dietary treatments included diets supplemented without (control diet; CON) or with LPL at a dose of 0.5 g/kg of pelleted TMR. Twelve multiparous, mid-lactation, Holstein cows (Bodyweight 730 ± 9.3 kg; 100 ± 6.0 days in milk) were randomly assigned to one of the two dietary treatments with a 42-day measurement period after a 14-day adaptation period. Feed and water were provided ad libitum. Feed intake and milk yields were recorded daily, blood samples were collected fortnightly, and milk samples weekly. The results showed that the supplementation of LPL did not change feed dry matter intake, milk yields, and milk composition. However, it increased total protein and globulin and the activity of alkaline phosphatase and decreased total cholesterol in plasma. This study suggests that LPL may have beneficent effects in animal health but might be not a feasible feed additive to increase production for dairy cows fed a pelleted TMR.

Dietary Supplementation of Lysophospholipids Affects Feed Digestion in Lambs.

Five experiments were conducted to examine effects of lysophospholipids (LPL) on live weight gain, nutrient digestibility, ruminal fermentation parameters, serum biochemical parameters and rumen bacterial community profile in fattening lambs. Two dietary treatments (pelleted complete feed supplemented without (control diet; CON) or with 0.05% LPL on dry matter basis) were tested in these experiments. Feed and water were provided ad libitum to lambs. The results showed that average daily gain (ADG) tended to increase or was not affected by LPL supplementation. Compared with CON, the supplementation of LPL resulted in an increase in dry matter, crude protein and organic matter digestibilities, and a decrease in neutral detergent fiber and acid detergent fiber digestibilities. Ruminal pH values did not change with LPL supplementation, but the concentrations of ammonia and total short chain fatty acids (SCFAs) were increased. The molar proportion of major individual SCFAs and the ratio of acetate to propionate were not affected by LPL supplementation. While the activity of lipase was decreased with LPL supplementation, all other serum biochemical parameters did not change. Rumen bacterial community was altered by LPL supplementation with the relative abundance of fibrolytic bacteria in the total bacterial population, such as Prevotella, decreased. In conclusion, LPL supplementation can alter feed digestion, but may not result in consistent positive responses in animal growth performance.

Dissolving organic matter from low-organic sewage sludge for shortening the anaerobic digestion time.

Pretreatments have been successfully used to shorten the HRT of anaerobic digestion (AD) of sewage sludge, but they become ineffective for low-organic sewage sludge, with HRT > 10 days. Herein, a new process using alkaline hydrolysis-anaerobic digestion has been developed to solve this problem. Firstly, maximum organic matter in the sludge was dissolved by strong alkaline hydrolysis (pH > 11) in a two-stage alkaline hydrolysis system (TSAHS). Secondly, only the supernatant of the sludge that contained most of the methane potential was applied for AD. The operational conditions were optimized and the process mechanism was also analyzed. The results showed that under optimum operational conditions, above 19% of the organic matter in the sludge was released into the supernatant after alkaline hydrolysis in TSAHS, and the supernatant for AD achieved a methane production of 392 mL CH4 per g COD. The process attained a methane production of 0.26 m3 CH4 per kg VS and a VS reduction of 43.5%, while the HRT was only 12 h. The advantage of the mechanism was that the alkaline neutralization capacity of the sludge maintained a proper pH value for the supernatant from TSAHS, which benefited subsequent AD. It is concluded that the new process based on the dissolution of organic matter can attain a short digestion time for low-organic sludge.

Different Growth and Physiological Responses of Six Subtropical Tree Species to Warming.

Quantifying changes in interspecific plant growth and physiology under climate warming will facilitate explanation of the shifts in community structure in subtropical forest. We evaluated the effects of 3 years climate warming (ca. 1°C, 2012-2015) on plant growth and physiological parameters of six subtropical tree species by translocating seedlings and soil from a higher to a lower elevation site. We found that an increase in soil/air temperature had divergent effects on six co-occurring species. Warming increased the biomass of Schima superba and Pinus massoniana, whereas it decreased their specific leaf area and intrinsic water use efficiency compared to other species. Warming decreased the foliar non-structural carbohydrates for all species. Our findings demonstrated that a warmer climate would have species-specific effects on the physiology and growth of subtropical trees, which may cause changes in the competitive balance and composition of these forests.

Investigation of the accumulation of ash, heavy metals, and polycyclic aromatic hydrocarbons to assess the stability of lysis-cryptic growth sludge reduction in sequencing batch reactor.

The accumulation of ash, heavy metals, and polycyclic aromatic hydrocarbons (collectively called potential accumulating substances, PAS) was evaluated to ascertain the stability of lysis-cryptic growth sludge reduction process (LSRP) for municipal sludge treatment. One sequencing batch reactor (SBR) incorporated with homogenization was run to test the LSRP and another SBR as a control. The continuous monitoring results for 2 months showed that the ash and heavy metals slightly increased, and the polycyclic aromatic hydrocarbons decreased by 18.0%, indicating that there may be negligible accumulations during the LSRP. Their accumulations met pattern I, as demonstrated by statistical analysis, proving no PAS accumulation for LSRP. This was further confirmed by sludge activity and system performance. Moreover, the mechanism for no PAS accumulation was discussed. It was concluded that the LSRP was stable with no worries about PAS accumulation under the operational conditions.

Phosphorus uptake in four tree species under nitrogen addition in subtropical China.

Atmospheric N deposition is a serious problem in subtropical China where N is present in large amounts but P is deficient. Several studies hypothesized that N2 fixers can overcome phosphorus limitation by trading fixed N2 for soil phosphorus. In order to know whether N2 fixers could invest fixed N2 in extracellular phosphatase production and could stimulate arbuscular mycorrhizal fungi (AMF) to acquire soil P in N-rich subtropical China, an open-air greenhouse experiment was carried out. Two N2 fixers (Acacia mangium and Ormosia pinnata) and two non-N2 fixers (Schima superba and Pinus massoniana) were exposed to three levels of N addition: 5.6 kg ha-1 a-1 (ambient N), 15.6 kg ha-1 a-1 (middle N), and 20.6 kg ha-1 a-1 (high N). We found that the capacity of plants to acquire soil P in N-rich subtropical China is species specific. The higher P uptake rates were found for N2 fixers than non-N2 fixers under N addition, which were related to the greater soil APA and higher AMF (p < 0.01) in the soil of N2 fixers. However, with time, high N addition decreased more significant quantities of soil microbial phospholipid fatty acids (PLFAs) in the soil of N2 fixers than that of non-N2 fixers (p < 0.05). We conclude that N2 fixers have higher P uptake capacity than non-N2 fixers under ambient N deposition in subtropical China. However, continuing N deposition in the future might affect P uptake ability of N2 fixers as high N addition would decrease soil microbial PLFAs of N2 fixers.

Warming effects on photosynthesis of subtropical tree species: a translocation experiment along an altitudinal gradient.

Ongoing climate warming induced by human activities may have great impacts on trees, yet it remains unresolved how subtropical tree species respond to rising temperature in the field. Here, we used downward translocation to investigate the effects of climate warming on leaf photosynthesis of six common tree species in subtropical China. During the experimental period between 2012 and 2014, the mean average photosynthetic rates (Asat) under saturating light for Schima superba, Machilus breviflora, Pinus massoniana and Ardisia lindleyana in the warm site were7%, 19%, 20% and 29% higher than those in the control site. In contrast, seasonal Asat for Castanopsis hystrix in the warm site were lower compared to the control site. Changes in Asat in response to translocation were mainly associated with those in leaf stomatal conductance (gs) and photosynthetic capacity (RuBP carboxylation, RuBP regeneration capacity). Our results imply that climate warming could have potential impacts on species composition and community structure in subtropical forests.

CO2 enrichment and N addition increase nutrient loss from decomposing leaf litter in subtropical model forest ecosystems.

As atmospheric CO2 concentration increases, many experiments have been carried out to study effects of CO2 enrichment on litter decomposition and nutrient release. However, the result is still uncertain. Meanwhile, the impact of CO2 enrichment on nutrients other than N and P are far less studied. Using open-top chambers, we examined effects of elevated CO2 and N addition on leaf litter decomposition and nutrient release in subtropical model forest ecosystems. We found that both elevated CO2 and N addition increased nutrient (C, N, P, K, Ca, Mg and Zn) loss from the decomposing litter. The N, P, Ca and Zn loss was more than tripled in the chambers exposed to both elevated CO2 and N addition than those in the control chambers after 21 months of treatment. The stimulation of nutrient loss under elevated CO2 was associated with the increased soil moisture, the higher leaf litter quality and the greater soil acidity. Accelerated nutrient release under N addition was related to the higher leaf litter quality, the increased soil microbial biomass and the greater soil acidity. Our results imply that elevated CO2 and N addition will increase nutrient cycling in subtropical China under the future global change.

Diagnosis of thyroid nodules using virtual touch tissue quantification value and anteroposterior/transverse diameter ratio.

This paper proposes an effective approach to differential diagnosis of thyroid nodules using a hierarchical classification model based on the Virtual Touch tissue quantification (VTQ) value and anteroposterior/transverse diameter (A/T) ratio. One hundred twenty nodules (92 benign, 28 malignant) were analyzed using this approach by combining the quantitative elastic characteristic with the conventional sonographic feature. First, nodules were classified as benign (VTQ values <2.27 m/s), malignant (VTQ values >2.73 m/s) and indeterminate (2.27 m/s ≤ VTQ values ≤2.73 m/s) using two cutoff points selected on the basis of receiver operating characteristic analysis. Second, the indeterminate nodules were separated into malignant and benign nodules using an A/T ratio ≥1. The advantage of this approach was that it could alleviate the limitation of an overlap in VTQ values between benign and malignant nodules. According to the pathologic results, the accuracy of this approach was 95%. The proposed approach may potentially improve diagnostic accuracy.

Recovery of phosphorus and nitrogen from alkaline hydrolysis supernatant of excess sludge by magnesium ammonium phosphate.

Magnesium ammonium phosphate (MAP) method was used to recover orthophosphate (PO4(3-)-P) and ammonium nitrogen (NH4(+)-N) from the alkaline hydrolysis supernatant of excess sludge. To reduce alkali consumption and decrease the pH of the supernatant, two-stage alkaline hydrolysis process (TSAHP) was designed. The results showed that the release efficiencies of PO4(3-)-P and NH4(+)-N were 41.96% and 7.78%, respectively, and the pH of the supernatant was below 10.5 under the running conditions with initial pH of 13, volume ratio (sludge dosage/water dosage) of 1.75 in second-stage alkaline hydrolysis reactor, 20 g/L of sludge concentration in first-stage alkaline hydrolysis reactor. The order of parameters influencing MAP reaction was analyzed and the optimized conditions of MAP reaction were predicted through the response surface methodology. The recovery rates of PO4(3-)-P and NH4(+)-N were 46.88% and 16.54%, respectively under the optimized conditions of Mg/P of 1.8, pH 9.7 and reaction time of 15 min.

Nitrogen to phosphorus ratios of tree species in response to elevated carbon dioxide and nitrogen addition in subtropical forests.

Increased atmospheric carbon dioxide (CO2 ) concentrations and nitrogen (N) deposition induced by human activities have greatly influenced the stoichiometry of N and phosphorus (P). We used model forest ecosystems in open-top chambers to study the effects of elevated CO2 (ca. 700 µmol mol(-1) ) alone and together with N addition (100 kg N ha(-1)  yr(-1) ) on N to P (N : P) ratios in leaves, stems and roots of five tree species, including four non-N2 fixers and one N2 fixer, in subtropical China from 2006 to 2009. Elevated CO2 decreased or had no effects on N : P ratios in plant tissues of tree species. N addition, especially under elevated CO2 , lowered N : P ratios in the N2 fixer, and this effect was significant in the stems and the roots. However, only one species of the non-N2 fixers showed significantly lower N : P ratios under N addition in 2009, and the others were not affected by N addition. The reductions of N : P ratios in response to elevated CO2 and N addition were mainly associated with the increases in P concentrations. Our results imply that elevated CO2 and N addition could facilitate tree species to mitigate P limitation by more strongly influencing P dynamics than N in the subtropical forests.

Reduction of excess sludge production in sequencing batch reactor (SBR) by lysis-cryptic growth using homogenization disruption.

A lysis-cryptic growth system, which combined high-pressure-homogenization (HPH) for sludge disruption, was proposed to reduce excess sludge production in SBR. Experimental data was analyzed with the aid of response surface models to determine the optimal HPH disruption pressure, which was 70 MPa. By combining a 5.4 m3/d pilot SBR with HPH disruption, the new system achieved a 42.4% sludge reduction rate over a 75 days operation. Based on measurement of oxygen uptake rate and activity of the dehydrogenase, the lysis-cryptic growth system resulted in negligible change of the sludge activity. However, an increase of 0.04 mg/L of total-phosphorus (TP) and 2.40 mg/L suspended-solids (SS) was observed in the effluent due to the process of lysis-cryptic growth. Except for above listed points, the new system demonstrated improved sludge reduction performance while the direct cost of pilot SBR lysis-cryptic growth was only 0.177US dollar per kilogram (dry sludge) according to estimation.