Find Research Output

Research Output
  • All
  • Scholar Profiles
  • Research Units
  • Research Output
Department Publication Year Content Type Data Sources


Department of Health and Environmental Sciences
Clear all

1.Landscape effects on pollinator communities and pollination services in small-holder agroecosystems

Author:Zou, Y;Bianchi, FJJA;Jauker, F;Xiao, HJ;Chen, JH;Cresswell, J;Luo, SD;Huang, JK;Deng, XZ;Hou, LL;van der Werf, W


Abstract:Pollination by insects is key for the productivity of many fruit and non-graminous seed crops, but little is known about the response of pollinators to landscapes dominated by small-holder agriculture. Here we assess the relationships between landscape context, pollinator communities (density and diversity) and pollination of oilseed rape in 18 landscapes with proportions of small-holder farming ranging from 10%% to 70%% in southern China. To quantify the contribution of pollinators to oilseed rape yield, we manipulated pollinator access in a focal oilseed rape field in each landscape using open and closed cages. The pollinator communities in the focal fields were sampled using pan traps. The abundance of wild pollinators increased significantly with the proportion of cultivated land, but the diversity of the wild pollinator communities declined. The responses of pollinator abundance and diversity to cultivated land were best explained at scales of around 1000 m. The abundance of the unmanaged honey bee Apis cerana was positively associated with the proportion of cultivated land, whereas the abundance of the managed A. mellifera was not. A pollination services index (PSI) was calculated by comparing the reproductive investment in seeds between plants with or without pollinator access. PSI was positively correlated with wild pollinator abundance, but not with the abundance of honeybee species. PSI was also not significantly correlated with the area proportion of cultivated land. Our results indicate that crop dominated landscapes with numerous small fields supported an abundant, but relatively species poor bee community that delivered pollination services to oilseed rape. Conservation of (semi-)natural habitats, however, is important for maintaining the diversity of wild pollinators.

2.Elevational species richness gradients in a hyperdiverse insect taxon: a global meta-study on geometrid moths

Author:Beck, J;McCain, CM;Axmacher, JC;Ashton, LA;Bartschi, F;Brehm, G;Choi, SW;Cizek, O;Colwell, RK;Fiedler, K;Francois, CL;Highland, S;Holloway, JD;Intachat, J;Kadlec, T;Kitching, RL;Maunsell, SC;Merckx, T;Nakamura, A;Odell, E;Sang, W;Toko, PS;Zamecnik, J;Zou, Y;Novotny, V


Abstract:Aims We aim to document elevational richness patterns of geometrid moths in a globally replicated, multi-gradient setting, and to test general hypotheses on environmental and spatial effects (i. e. productivity, temperature, precipitation, area, mid-domain effect and human habitat disturbance) on these richness patterns. Location Twenty-six elevational gradients world-wide (latitudes 288 S to 518 N). Methods We compiled field datasets on elevational gradients for geometrid moths, a lepidopteran family, and documented richness patterns across each gradient while accounting for local undersampling of richness. Environmental and spatial predictor variables as well as habitat disturbance were used to test various hypotheses. Our analyses comprised two pathways: univariate correlations within gradients, and multivariate modelling on pooled data after correcting for overall variation in richness among different gradients. Results The majority of gradients showed midpeak patterns of richness, irrespective of climate and geographical location. The exclusion of humanaffected sampling plots did not change these patterns. Support for univariate main drivers of richness was generally low, although there was idiosyncratic support for particular predictors on single gradients. Multivariate models, in agreement with univariate results, provided the strongest support for an effect of area-integrated productivity, or alternatively for an elevational area effect. Temperature and the mid-domain effect received support as weaker, modulating covariates, while precipitation-related variables had no explanatory potential. Main conclusions Despite the predicted decreasing diversity-temperature relationship in ectotherms, geometrid moths are similar to ants and salamanders as well as small mammals and ferns in having predominantly their highest diversity at mid-elevations. As in those comparative analyses, single or clear sets of drivers are elusive, but both productivity and area appear to be influential. More comparative elevational studies for various insect taxa are necessary for a more comprehensive understanding of elevational diversity and productivity.



Source:China Scholars Abroad,2017,Vol.


4.Whole-cell bioreporters and risk assessment of environmental pollution: A proof-of-concept study using lead

Author:Zhang, XK;Qin, BQ;Deng, JM;Wells, M


Abstract:As the world burden of environmental contamination increases, it is of the utmost importance to develop streamlined approaches to environmental risk assessment in order to prioritize mitigation measures. Whole-cell biosensors or bioreporters and speciation modeling have both become of increasing interest to determine the bioavailability of pollutants, as bioavailability is increasingly in use as an indicator of risk. Herein, we examine whether bioreporter results are able to reflect expectations based on chemical reactivity and speciation modeling, with the hope to extend the research into a wider framework of risk assessment. We study a specific test case concerning the bioavailability of lead (Pb) in aqueous environments containing Pb-complexing ligands. Ligands studied include ethylene diamine tetra-acetic acid (EDTA), meso-2,3 dimercaptosuccinic acid (DMSA), leucine, methionine, cysteine, glutathione, and humic acid (HA), and we also performed experiments using natural water samples from Lake Tai (Taihu), the third largest lake in China. We find that EDTA, DMSA, cysteine, glutathione, and HA amendment significantly reduced Pb bioavailability with increasing ligand concentration according to a log-sigmoid trend. Increasing dissolved organic carbon in Taihu water also had the same effect, whereas leucine and methionine had no notable effect on bioavailability at the concentrations tested. We find that bioreporter results are in accord with the reduction of aqueous Pb2+ that we expect from the relative complexation affinities of the different ligands tested. For EDTA and HA, for which reasonably accurate ionization and complexation constants are known, speciation modeling is in agreement with bioreporter response to within the level of uncertainty recognised as reasonable by the United States Environmental Protection Agency for speciation-based risk assessment applications. These findings represent a first step toward using bioreporter technology to streamline the biological confirmation or validation of speciation modeling for use in environmental risk assessment. (C) 2017 Elsevier Ltd. All rights reserved,

5.Wild pollinators enhance oilseed rape yield in small-holder farming systems in China

Author:Zou, Y;Xiao, HJ;Bianchi, FJJA;Jauker, F;Luo, SD;van der Werf, W

Source:BMC ECOLOGY,2017,Vol.17

Abstract:Background: Insect pollinators play an important role in crop pollination, but the relative contribution of wild pollinators and honey bees to pollination is currently under debate. There is virtually no information available on the strength of pollination services and the identity of pollination service providers from Asian smallholder farming systems, where fields are small, and variation among fields is high. We established 18 winter oilseed rape (Brassica napus L.) fields along a large geographical gradient in Jiangxi province in China. In each field, oilseed rape plants were grown in closed cages that excluded pollinators and open cages that allowed pollinator access. The pollinator community was sampled by pan traps for the entire oilseed rape blooming period. Results: Oilseed rape plants from which insect pollinators were excluded had on average 38%% lower seed set, 17%% lower fruit set and 12%% lower yield per plant, but the seeds were 17%% heavier, and the caged plants had 28%% more flowers and 18%% higher aboveground vegetative biomass than plants with pollinator access. Oilseed rape plants thus compensate for pollination deficit by producing heavier seeds and more flowers. Regression analysis indicated that local abundance and diversity of wild pollinators were positively associated with seed set and yield/straw ratio, while honey bee abundance was not related to yield parameters. Conclusions: Wild pollinator abundance and diversity contribute to oilseed rape yield by enhancing plant resource allocation to seeds rather than to above-ground biomass. This study highlights the importance of the conservation of wild pollinators to support oilseed rape production in small-holder farming systems in China.

6.A copula-based model for air pollution portfolio risk and its efficient simulation

Author:Sak, H;Yang, GY;Li, BL;Li, WF


Abstract:This paper introduces a portfolio approach for quantifying pollution risk in the presence of PM concentration in cities. The model used is based on a copula dependence structure. For assessing model parameters, we analyze a limited data set of PM levels of Beijing, Tianjin, Chengde, Hengshui, and Xingtai. This process reveals a better fit for the t-copula dependence structure with generalized hyperbolic marginal distributions for the PM log-ratios of the cities. Furthermore, we show how to efficiently simulate risk measures clean-air-at-risk and conditional clean-air-at-risk using importance sampling and stratified importance sampling. Our numerical results show that clean-air-at-risk at 0.01 probability level reaches up to (initial PM concentrations of cities are assumed to be ) for the constructed sample portfolio, and that the proposed methods are much more efficient than a naive simulation for computing the exceeding probabilities and conditional excesses.

7.An extended Last Glacial Maximum in subtropical Australia

Author:Petherick, LM;Moss, PT;McGowan, HA


Abstract:A continuous, record encompassing the termination of the Last Glacial cycle (defined here as ca. 30 -18 cal. kyr BP) has been developed using multiple proxies (viz. clastic sediment flux, grain size, moisture content, pollen and charcoal) archived in lake sediments from Tortoise Lagoon, North Stradbroke Island, Australia. The record indicates an extended Last Glacial Maximum, with an onset at ca. 30 kyr BP. The presence of rainforest and arboreal taxa for the 30-18 kyr BP period indicate a positive moisture balance, while the presence of the now regionally extinct Asteraceae (Tubuliflorae) and Tubulifloridites pleistocenicus indicate relatively cool temperatures. Total clastic sediment flux and the vegetation assemblage suggest that, at least in subtropical Australia, the Last Glacial Maximum was characterized by two peaks in aridity at ca. 29-26 kyr BP and 24.5-20 kyr BP. (C) 2016 Elsevier Ltd and INQUA. All rights reserved.

8.Impacts of particulate matter (PM2.5) on the behavior of freshwater snail Parafossarulus striatulus

Author:Hartono, D;Lioe, B;Zhang, YX;Li, BL;Yu, JZ


Abstract:Fine particulate (PM2.5) is a severe problem of air pollution in the world. Although many studies were performed on examining effects of PM2.5 on human health, the understanding of PM2.5 influence on aquatic organisms is limited. Due to wet deposition, the pollutants in PM2.5 can enter aquatic ecosystems and affect aquatic organisms. This study tested the hypothesis that PM2.5 will negatively affect the behavior of freshwater snail Parafossarulus striatulus (Benson, 1842). Along with PM2.5, a number of components (Al, Pb, and Zn) that are commonly present in PM2.5 were also tested for their effects on the snail's behavior. The snail behavior was scored using the Behavioral State Score (BSS), ranging from 0 (no movement) to 5 (active locomotion and fully extended body). The result shows that high PM2.5 concentration dose (7.75 mg/L) induced a significant decrease in snails' movement behavior, and such reduced movement. The same behavior was also observed for treatments with chemical components related to PM2.5, including aluminum and acidity (pH 5.0). In contrast, a low concentration of PM2.5 (3.88 mg/L), lead, and zinc did not significantly affect snails' behavior. The results suggest that high PM2.5 deposition in water bodies, associated with acidification and some metals, can have an adverse effect on aquatic organisms.

9.A photovoltaic self-powered gas sensor based on a single-walled carbon nanotube/Si heterojunction

Author:Liu, L;Li, GH;Wang, Y;Wang, YY;Li, T;Zhang, T;Qin, SJ


Abstract:We present a novel photovoltaic self-powered gas sensor based on a p-type single-walled carbon nanotube (SWNT) and n-type silicon (n-Si) heterojunction. The energy from visible light suffices to drive the device owing to a built-in electric field (BEF) induced by the differences between the Fermi levels of SWNTs and n-Si.

10.Single CdS Nanorod for High Responsivity UV-Visible Photodetector

Author:Zhao, W;Liu, L;Xu, MZ;Wang, XW;Zhang, T;Wang, YN;Zhang, ZY;Qin, SJ;Liu, Z


Abstract:1D nanoscale photodetectors have been extensively investigated for the unique geometry structure and novel physical and chemical properties. The 1D CdS materials have received much attention in the field due to its high photosensitivity and fast response, while how to achieve high responsivity is still in development, despite it is the crucial target to the excellent photodetector. Single crystal CdS nanorods (NRs) are synthesized on SiO2/Si substrate over large scale via the chemical vapor deposition method. The individual single CdS nanorod photodetector have been fabricated by using photolithography process and the responsivity of the photodetector is investigated systematically. At a very low percentage of illumination intensity (2%%, 0.5 mW cm(-2)) under 450 nm, the photodetector exhibited a high responsivity and reached at 1.23 x 10(4) A W-1 with the bias voltages of 2 V. The good crystallinity and large surface of CdS nanorod are the reasons of this excellent performance of CdS based photodetector. The strategy proposed herein appears to hold great potential for a high responsivity with low illumination intensity.

11.Prevalence of Clostridium difficile infection and colonization in a tertiary hospital and elderly community of North-Eastern Peninsular Malaysia

Author:Zainul, NH;Ma, ZF;Besari, A;Asma, HS;Rahman, RA;Collins, DA;Hamid, N;Riley, TV;Lee, YY


Abstract:Little is known about Clostridium difficile infection (CDI) in Asia. The aims of our study were to explore (i) the prevalence, risk factors and molecular epidemiology of CDI and colonization in a tertiary academic hospital in North-Eastern Peninsular Malaysia; (ii) the rate of carriage of C. difficile among the elderly in the region; (iii) the awareness level of this infection among the hospital staffs and students. For stool samples collected from hospital inpatients with diarrhea (n = 76) and healthy community members (n = 138), C. difficile antigen and toxins were tested by enzyme immunoassay. Stool samples were subsequently analyzed by culture and molecular detection of toxin genes, and PCR ribotyping of isolates. To examine awareness among hospital staff and students, participants were asked to complete a self-administered questionnaire. For the hospital and community studies, the prevalence of non-toxigenic C. difficile colonization was 16%% and 2%%, respectively. The prevalence of CDI among hospital inpatients with diarrhea was 13%%. Out of 22 C. difficile strains from hospital inpatients, the toxigenic ribotypes 043 and 017 were most common (both 14%%). In univariate analysis, C. difficile colonization in hospital inpatients was significantly associated with greater duration of hospitalization and use of penicillin (both P < 0.05). Absence of these factors was a possible reason for low colonization in the community. Only 3%% of 154 respondents answered all questions correctly in the awareness survey. C. difficile colonization is prevalent in a Malaysian hospital setting but not in the elderly community with little or no contact with hospitals. Awareness of CDI is alarmingly poor.

12.Climatic Causes of the Selenium-deficient Soil Belt in China

Author:SUN Guoxin;LI Yuan;LI Gang;CHEN Zheng;ZHU Yongguan



13.Improvement in CH4/CO2 ratio and CH4 yield as related to biomass mix composition during anaerobic co-digestion

Author:Poulsen, TG;Adelard, L;Wells, M

Source:WASTE MANAGEMENT,2017,Vol.61

Abstract:Sixteen data sets (two of which were measured in this study) with a combined total of 145 measurements of ultimate methane yield (UMY) during mono- and co-digestion of ternary biomass mixtures were used to assess impact of co-digestion on the relative change in UMY (,UMY) as a function of biomass mix composition. The data involved 9 biomass materials (brewery spent grains, chicken manure, cow manure, fresh grass clippings, pig manure, primary sewage sludge, vegetable food waste, wheat straw, and rice straw). Results of the assessment shows that co-digestion in 85%% of yields positive values of Delta UMY regardless of the biomass materials used, however, a smaller fraction (15%%) resulted in negative Delta UMY during co-digestion. The data further indicate that for each set of ternary biomass material mixtures there exists an optimal biomass mix composition at which Delta UMY is at a maximum. Statistical analyses based on the data used here indicate that the maximum value of Delta UMY(Delta UMYmax) is always positive regardless of biomass materials being co-digested. (C) 2016 Elsevier Ltd. All rights reserved.

14.Meteorological driven factors of population growth in brown planthopper, Nilaparvata lugens Stal (Hemiptera: Delphacidae), in rice paddies

Author:Li, XZ;Zou, Y;Yang, HY;Xiao, HJ;Wang, JG


Abstract:Growth of brown planthopper (BPH) (Nilaparvata lugens Stal) in rice paddies is mainly driven by meteorological factors under similar management practices. By analyzing field investigation and meteorological data collected from 2008 to 2013 in Nanchang, China, we show that BPH population densities and monthly growth rates (BGR) changed greatly from May to October, and these changes were closely associated with meteorological factors. Stepwise regression and path analysis indicated average speed of winds (AW) in June and lowest temperature (LT) in July were the first factors entering analysis, which interpreted 46.20%% and 31.90%% of their influences on BGR. While highest temperature (HT) in August and average temperature (AT) in September were the most important factors affecting BGR, but their direct path coefficients were all smaller than their corresponding indirect path coefficients. In October, relative humidity (RH), AW and number of raining days (RD) had significant effects on BGR. According to the sum of each meteorological factor entering stepwise regression analysis sequences, we found AW had the utmost effect on BPH growth, followed by AT and RH, but LT and RD least. The work demonstrate dynamic meteorological factors driving BPH growth and outbreak in rice paddies, which would facilitate the development of durable approaches for forecasting and controlling this destructive rice pest.

15.Exposure to environmental microbiota explains persistent abdominal pain and irritable bowel syndrome after a major flood

Author:Yusof, N;Hamid, N;Ma, ZF;Lawenko, RM;Mohammad, WMZW;Collins, DA;Liong, MT;Odamaki, T;Xiao, JZ;Lee, YY

Source:GUT PATHOGENS,2017,Vol.9

Abstract:Background: After an environmental disaster, the affected community is at increased risk for persistent abdominal pain but mechanisms are unclear. Therefore, our study aimed to determine association between abdominal pain and poor water, sanitation and hygiene (WaSH) practices, and if small intestinal bacterial overgrowth (SIBO) and/or gut dysbiosis explain IBS, impaired quality of life (QOL), anxiety and/or depression after a major flood. Results: New onset abdominal pain, IBS based on the Rome III criteria, WaSH practices, QOL, anxiety and/or depression, SIBO (hydrogen breath testing) and stools for metagenomic sequencing were assessed in flood victims. Of 211 participants, 37.9%% (n = 80) had abdominal pain and 17%% (n = 36) with IBS subtyped diarrhea and/or mixed type (n = 27 or 12.8%%) being the most common. Poor WaSH practices and impaired quality of life during flood were significantly associated with IBS. Using linear discriminant analysis effect size method, gut dysbiosis was observed in those with anxiety (Bacteroidetes and Proteobacteria, effect size 4.8), abdominal pain (Fusobacteria, Staphylococcus, Megamonas and Plesiomonas, effect size 4.0) and IBS (Plesiomonas and Trabulsiella, effect size 3.0). Conclusion: Disturbed gut microbiota because of environmentally-derived organisms may explain persistent abdominal pain and IBS after a major environmental disaster in the presence of poor WaSH practices.



Source:World Education Information,2017,Vol.30

Abstract:美国威斯康星大学麦迪逊分校是一所美国顶尖的研究型大学。全校4万名学生中近1万名是研究生,全校共有159个硕士点,110个博士点,每年毕业的硕士生300余名,博士生200余名。作为顶尖研究型大学,丰富的图书馆资源是必不可少的。威斯康星大学麦迪逊分校一共有40多个专业图书馆,馆藏700万册图书、5万多份期刊杂志、600多万份微缩胶,是全美大学中的第11大图书馆。文章系笔者在健康科学图书馆工作期间对该馆馆长朱丽·施奈德(Julie Schneider)女士采访整理而成。

17.Metacognitive beliefs mediate the relationship between mind wandering and negative affect

Author:Carciofo, R;Song, N;Du, F;Wang, MM;Zhang, K


Abstract:Two studies (Ns = 254 and 130, aged 18-28) aimed to investigate associations between mind wandering and metacognitive beliefs, and whether these beliefs are involved in the relationship between mind wandering and negative affect. Participants completed questionnaire measures of metacognitive beliefs, mind wandering, daydreaming, negative affect, mindfulness, and sleep quality. Study 2 also included the Sustained Attention to Response Task, with thought-probe assessment of task-unrelated thought (mind wandering/daydreaming). The frequency of mind wandering/daydreaming/task-unrelated thought was found to positively correlate with the metacognitive dimensions of less cognitive confidence, more endorsement of belief in the uncontrollability/danger of thoughts, and more endorsement of belief in the need to control thoughts. Multiple-mediator analysis was undertaken with three main models where either mind wandering, daydreaming frequency, or task-unrelated thought was the predictor for negative affect. Metacognitive beliefs, mindfulness and sleep quality were simultaneously entered as potential mediators. Results showed that metacognitive belief in the uncontrollability/danger of thoughts was a consistently significant mediator, while mindfulness and sleep quality were less consistent. Overall, the current research indicates that metacognitive beliefs are an important consideration in the study of mind wandering/daydreaming, and a possibly key factor in understanding the association with negative affect. (C) 2016 Elsevier Ltd. All rights reserved.

18.LjMOT1, a high-affinity molybdate transporter from Lotus japonicus, is essential for molybdate uptake, but not for the delivery to nodules

Author:Duan, GL;Hakoyama, T;Kamiya, T;Miwa, H;Lombardo, F;Sato, S;Tabata, S;Chen, Z;Watanabe, T;Shinano, T;Fujiwara, T

Source:PLANT JOURNAL,2017,Vol.90

Abstract:Molybdenum (Mo) is an essential nutrient for plants, and is required for nitrogenase activity of legumes. However, the pathways of Mo uptake from soils and then delivery to the nodules have not been characterized in legumes. In this study, we characterized a high-affinity Mo transporter (LjMOT1) from Lotus japonicus. Mo concentrations in an ethyl methanesulfonate-mutagenized line (ljmot1) decreased by 70-95%% compared with wild-type (WT). By comparing the DNA sequences of four AtMOT1 homologs between mutant and WT lines, one point mutation was found in LjMOT1, which altered Trp(292) to a stop codon; no mutation was found in the other homologous genes. The phenotype of Mo concentrations in F-2 progeny from ljmot1 and WT crosses were associated with genotypes of LjMOT1. Introduction of endogenous LjMOT1 to ljmot1 restored Mo accumulation to approximately 60-70%% of the WT. Yeast expressing LjMOT1 exhibited high Mo uptake activity, and the K-m was 182 nM. LjMOT1 was expressed mainly in roots, and its expression was not affected by Mo supply or rhizobium inoculation. Although Mo accumulation in the nodules of ljmot1 was significantly lower than that of WT, it was still high enough for normal nodulation and nitrogenase activity, even for cotyledons-removed ljmot1 plants grown under low Mo conditions, in this case the plant growth was significantly inhibited by Mo deficiency. Our results suggest that LjMOT1 is an essential Mo transporter in L. japonicus for Mo uptake from the soil and growth, but is not for Mo delivery to the nodules.

19.Video monitoring of brown planthopper predation in rice shows flaws of sentinel methods

Author:Zou, Y;de Kraker, J;Bianchi, FJJA;van Telgen, MD;Xiao, HJ;van der Werf, W


Abstract:Immobilized preys are routinely used in agro-ecological exposure studies to quantify predation of pests under field conditions, but this method has not been validated. Our purpose was to determine the validity of using immobilized adults of the major rice pest Nilaparvata lugens, brown plant hopper (BPH), as sentinels. We used direct observation by video recording to determine the causal agents of removal of field exposed BPH sentinels with two experiments: 1) we recorded removal events of dead, immobilized BPH; and 2) we compared removal of (i) dead, immobilized BPH, (ii) live, immobilized BPH, and (iii) live, mobile BPH. Long-horned grasshoppers were responsible for most removals of dead, immobilized BPH, in both experiments. Predatory ground beetles removed most of the live, immobilized BPH, whereas frogs were the major predators of live, mobile BPH. Overall, we showed that removal of immobilized sentinel prey is not representative for predation of live, mobile prey, stressing the need for a critical assessment of commonly used sentinel methods. In addition, we found that frogs played the major role in predation of BPH in rice. As current strategies to enhance biocontrol of planthoppers in rice focus on arthropod natural enemies, this finding could have major implications.
Total 19 results found
Copyright 2006-2020 © Xi'an Jiaotong-Liverpool University 苏ICP备07016150号-1 京公网安备 11010102002019号