Phosphorus limitation on CO_(2)fertilization effect in tropical forests informed by a coupled biogeochemical model

Tropical forests store more than half of the world's terrestrial carbon(C)pool and account for one-third of global net primary productivity(NPP).Many terrestrial biosphere models(TBMs)estimate increased productivity in tropical forests throughout the 21st century due to CO_(2)fertilization.However,phosphorus(P)liaitations on vegetation photosynthesis and productivity could significantly reduce the CO_(2)fertilization effect.Here,we used a carbon-nitrogen-phosphorus coupled model(Dynamic Land Ecosystem Model;DLEM-CNP)with heterogeneous maximum carboxylation rates to examine how P limitation has affected C fluxes in tropical forests during1860-2018.Our model results showed that the inclusion of the P processes enhanced model performance in simulating ecosystem productivity.We further compared the simulations from DLEM-CNP,DLEM-CN,and DLEMC and the results showed that the inclusion of P processes reduced the CO_(2)fertilization effect on gross primary production(GPP)by 25%and 45%,and net ecosystem production(NEP)by 28%and 41%,respectively,relative to CN-only and C-on ly models.From the 1860s to the 2010s,the DLEM-CNP estimated that in tropical forests GPP increased by 17%,plant respiration(Ra)increased by 18%,ecosystem respiration(Rh)increased by 13%,NEP increased by 121%per unit area,respectively.Additionally,factorial experiments with DLEM-CNP showed that the enhanced NPP benefiting from the CO_(2) fertilization effect had been offset by 135%due to deforestation from the 1860s to the 2010s.Our study highlights the importance of P limitation on the C cycle and the weakened CO_(2)fertilization effect resulting from P limitation in tropical forests.

Can we go beyond INDCs： Analysis of a future mitigation possibility in China, Japan, EU and the U.S.

The most important achievement in the Paris Agreement is to set up emission reduction target by commitment submitted by each country/ region with the form INDC. However the emission reduction target inside INDCs could not match with the emission pathway for the global to keep a global temperature rise this century well below 2 ℃ and to drive efforts to limit the temperature increase even further to 1.5 ℃ above pre- industrial levels. It is important for countries to do more than their commitment in INDCs, especially in near term. This paper looks at the near term trend for possibilities for further emission reduction compared with INDCs, and found there do have the possibility. It concludes there is space for the four countries/regions to do more than their INDCs submitted to UNFCCC, and see the light towards to a global 2 ℃ target.

Comprehensive evaluation of dioxins and dioxin-like compounds in surface soils and river sediments from e-waste-processing sites in a village in northern Vietnam:Heading towards the environmentally sound management of e-waste

The management of electronic waste(e-waste),which can be a source of both useful materials and toxic substances,depending on the processing method,is important for promoting material cycling.In this study,we used the dioxin-responsive chemical-activated luciferase gene expression(DR-CALUX)assay combined with gas chromatographyehigh-resolution mass spectrometry to evaluate the levels of dioxin-like compounds in surface soils and river sediments collected in and around an e-waste-processing village in northern Vietnam.The WHO-TEQs(Toxic equivalents)of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),coplanar polychlorinated biphenyls(Co-PCBs),and polybrominated dibenzo-pdioxins and dibenzofurans(PBDD/Fs)in soils collected in January 2012 ranged from 0.29 to 310 pg/g(median 2.9 pg/g,n=32),and the WHO-TEQs in sediments ranged from 0.96 to 58 pg/g(median 4.4 pg/g,n=8).Dioxin-like activities(CALUX-TEQs[2,3,7,8-TCDD equivalent])in soils collected in January 2012,2013,and 2014 ranged from<30 to 4300 pg/g(median<30 pg/g,n=96),and the activities in sediments ranged from<30 to 4000 pg/g(median 33 pg/g,n=24).Dioxin-like compounds accumulated in samples collected around e-waste-processing areas such as open-burning sites and e-waste-processing workshops,and the compounds may be transported from their sources to surrounding areas over the course of several years.Some of the CALUX-TEQs,but not WHO-TEQs,values were higher than the maximum acceptable WHO-TEQs promulgated by various authorities,indicating that all dioxin-like compounds should be evaluated in samples collected from e-waste-processing areas.Our findings suggest that open burning and open storage of e-waste should be prohibited and that wastewater treatment should be implemented at each workshop to reduce contamination by dioxin-like compounds from e-waste.

Phenolic constituents and anticancer properties of Morus alba(white mulberry) leaves

Flavonoids are by far the most dominant class of phenolic compounds isolated from Morus alba leaves(MAL). Other classes of compounds are benzofurans, phenolic acids, alkaloids, coumarins, chalcones and stilbenes. Major flavonoids are kuwanons, moracinflavans, moragrols and morkotins. Other major compounds include moracins(benzofurans), caffeoylquinic acids(phenolic acids) and morachalcones(chalcones). Research on the anticancer properties of MAL entailed in vitro and in vivo cytotoxicity of extracts or isolated compounds. Flavonoids, benzofurans, chalcones and alkaloids are classes of compounds from MAL that have been found to be cytotoxic towards human cancer cell lines. Further studies on the phytochemistry and anticancer of MAL are suggested. Sources of information were Pub Med,Pub Med Central, Science Direct, Google, Google Scholar, J-Stage, Pub Chem and China National Knowledge Infrastructure.

Phenolic constituents from the root bark of Morus alba with emphasis on morusin and its anti-cancer properties

The root bark of Morus alba L. or white mulberry is widely used as traditional medicine in China, Japan and Korea. Major classes and types of phenolic compounds isolated from the root bark are flavonoids(kuwanons, morusin, cyclomorusin and sanggenons), benzofurans(moracins and mulberrofurans), and stilbenoids(mulberrosides). Some of the flavonoids and benzofurans are products of Diel-Alder type adducts. Other classes of compounds include triterpenes, phenolic acids and coumarins. Morusin, a prenylated flavonoid, was first isolated from the root bark of M. alba, and later from the leaf, stem bark and twig of the plant. The potent anti-cancer properties of morusin have attracted much attention with research on-going and new findings being published. The compound inhibits angiogenesis, tumour progression and tumour migration, and triggers apoptosis, cell cycle arrest and autophagy in colorectal, cervical, prostate, breast, hepatoma, pancreatic, glioblastoma, gastric, ovarian and lung cancer cell lines. The anti-cancer activities of morusin are executed via various molecular targets and signalling pathways. It is anticipated that on-going in vitro studies will progress gradually to in vivo studies using animal models before efforts towards drug development can be initiated for clinical trials.

Global land mapping of satellite-observed CO_(2)total columns using spatio-temporal geostatistics

This study presents an approach for generating a global land mapping dataset of the satellite measurements of CO_(2)total column(XCO_(2))using spatio-temporal geostatistics,which makes full use of the joint spatial and temporal dependencies between observations.The mapping approach considers the latitude-zonal seasonal cycles and spatio-temporal correlation structure of XCO_(2),and obtains global land maps of XCO_(2),with a spatial grid resolution of 1°latitude by 1°longitude and temporal resolution of 3 days.We evaluate the accuracy and uncertainty of the mapping dataset in the following three ways:(1)in cross-validation,the mapping approach results in a high correlation coefficient of 0.94 between the predictions and observations,(2)in comparison with ground truth provided by the Total Carbon Column Observing Network(TCCON),the predicted XCO_(2)time series and those from TCCON sites are in good agreement,with an overall bias of 0.01 ppm and a standard deviation of the difference of 1.22 ppm and(3)in comparison with model simulations,the spatio-temporal variability of XCO_(2)between the mapping dataset and simulations from the CT2013 and GEOS-Chem are generally consistent.The generated mapping XCO_(2)data in this study provides a new global geospatial dataset in global understanding of greenhouse gases dynamics and global warming.

Occurrence of emerging flame retardants from e-waste recycling activities in the northern part of Vietnam

This study investigated the contamination status of 21 emerging flame retardants(FRs)in soils(n=32)and river sediments(n=8)from an e-waste recycling(EWR)site in the northern part of Vietnam.Among analyzed FRs,higher levels of decabromodiphenyl ethane(DBDPE)(NDe4200 ng/g dw),1,2-bis-(2,4,6-tribromophenoxy)ethane(BTBPE)(NDe350 ng/g dw)and Dechlorane Plus isomers(DPs)(NDe65 ng/g dw)were found in soils near EWR workshops and open burning places.The highest concentrations of DBDPE(20 ng/g dw),BTBPE(5.7 ng/g dw)and DPs(6.7 ng/g dw)were also detected in sediments collected from the middle of the EWR site.The levels decreased concomitantly with increasing distance from the EWR site.These results indicate that these FRs were released to the surrounding environment from improper recycling activities,such as manual dismantling of devices and open burning of e-wastes.Moreover,the estimated daily intakes of those FRs via soil ingestion were approximately ten times higher for children than adults.To our knowledge,this is a first comprehensive study on characterization of soil and sediment contamination by a series of emerging FRs at an EWR site in Vietnam.

A synopsis on flavonoids from the roots of Scutellaria baicalensis with some insights on baicalein and its anti-cancer properties

Flavones are the most dominant type of flavonoids isolated from the roots of Scutellaria baicalensis(Radix Scutellariae), which is a traditional medicinal plant in East Asian countries, including China, Japan and Korea.Most of the flavones are derivatives with methoxyl and hydroxyl groups, and they include baicalein, baicalin, chrysin, norwogonin, oroxylin A and wogonin.Baicalein possesses anti-cancer activities against a wide spectrum of human cancer cells by inducing apoptosis and cell cycle arrest, and by inhibiting angiogenesis, metastasis and inflammation.Some examples of the effects of baicalein on apoptosis, cell cycle arrest and metastasis are presented with discussion on the molecular targets and pathways.Studies on the structure-activity relationships of flavonoid cytotoxicity towards human cancer cells show that the potent cytotoxic activities of baicalein can be attributed to its-OH groupsat C5, C6 and C7(triple hydroxylation) of ring A, carbonyl group at C4 of ring C, and C2–C3 double bond of ring C.Studies on structural modifications of baicalein have shown that the configurations at C6 of ring A are critical factors influencing its anti-proliferative activity.Considering the remarkable anti-cancer properties, the future prospects for developing baicalein into an anti-cancer drug are promising.

Proliferation of district heating using local energy resources through strategic building-stock management： A case study in Fukushima, Japan

District heating systems using cogeneration technology and renewable resources are considered as an effective approach to resources conservation and reduction of greenhouse gas （GHG） emissions. However, wide- spread aging and depopulation problems, as well as the popularization of energy-saving technologies in buildings, are estimated to greatly decrease energy consumption, leading to inefficiency in district heating and barriers to technology proliferation. From a long-term perspective, land use changes, especially the progression of compact city plans, have the potential to offset the decrement in energy consumption that maintains the efficiency of district heating systems. An integrated model is developed in this paper based on building cohort analysis to evaluate the economic feasibility and environmental impact of introdu- cing district heating systems to a long-term compact city plan. As applied to a case in the Soma Region of Fukushima, Japan, potential migration from the suburbs to the central station districts is simulated, where district heating based on gas-fired cogeneration is expected to be introduced. The results indicate that guided migration to produce concentrated centers of population can substan- tially increase the heat demand density, which supports a wider application of district heating systems and better low-carbon performance. These results are further dis- cussed in relation to technology innovation and related policies. It is concluded that policies related to urban land use planning and energy management should be integrated and quantitatively evaluated over the long-term with the aim of supporting urban low-carbon sustainable develop- ment.

Analysis of monomeric and oligomeric organophosphorus flame retardants in fish muscle tissues using liquid chromatographyeelectrospray ionization tandem mass spectrometry:Application to Nile tilapia(Oreochromis niloticus)from an e-waste processing area in northern Vietnam

Using electrospray ionization tandem mass spectrometry combined with liquid chromatography(LC),a novel analytical method was developed to quantify eight monomeric organophosphorus flame retardants(m-PFRs)and three oligomeric organophosphorus flame retardants(o-PFRs)in fish muscle samples.The optimization and validation experiments indicate that the developed method can determine accurately the concentrations of analytes in fish muscle samples.The recoveries of analytes in fish muscle samples were in the range of 74-105%.The coefficients of variation of the concentrations of analytes in fish muscle samples were 0.6-8.9%.The concentrations of analytes in procedural blanks were below the limit of quantification(LOQ)values.Furthermore,the developed method was applied to the analysis of m-PFRs and o-PFRs in the muscle samples of tilapias collected from an electronic waste(ewaste)processing area in northern Vietnam.The concentrations of m-PFRs such as tris(2-chloroethyl)phosphate(TCEP),tris(2-chloroisopropyl)phosphate(TCIPP),and triphenyl phosphate(TPHP)were dominant among the investigated m-PFRs.The respective concentrations of TCEP,TCIPP,and TPHP were up to 160,300,and 230 ng g^-1 lipid weight,respectively,whereas those of o-PFRs were up to 10 ng g^-1 lipid weight.The results of this study indicate lower accumulation potential of o-PFRs compared with m-PFRs for the first time.

Hazardous metals emissions from e-waste-processing sites in a village in northern Vietnam

Inappropriate e-waste-processing operation is a serious issue in developing countries since the early 2000's.Field research was conducted to clarify its influences and diffuse toxic substances in the environment at e-waste-processing sites in a village in northern Vietnam from 2012 to 2014.We investigated surface soil samples collected from e-waste-processing sites,open burning sites,and rice paddy sites.Sediment samples and water samples were also collected from a river that runs through the village.The hazardous metal concentration in soil and river sediment samples indicated that 7 elements(Ca,Cu,Mo,Ni,Pb,Sn,and Zn)had high concentrations as a result of e-waste-processing.Most notably,Pb and Cu had high concentrations in soil samples(Pb:26e2200 mg/kg,Cu:22e3000 mg/kg).The results of a multivariate analysis indicated that these 7 elements were closely correlated with e-waste-processing.Concentrations of hazardous metals showed an upward trend where e-waste-processing occurred during the 3-year study period,although it was not significant statistically at present.Open burning activity had a great influence on Cu accumulation,and maximum Cu concentrations increased from 340 mg/kg in 2012e3000 mg/kg in 2014 in soil samples from open-burning sites.There were large differences in the dominant hazardous metal depending on the type of e-waste-processing workshop because hazardous metal composition was influenced by the types of e-waste and the processing procedures.It is necessary to avoid e-waste processing in open-air environment to control emissions of hazardous substances.Especially,open burning should be prohibited.