Ecological niche measurement and high-quality development of "the Belt and Road" core area.

A new stage in promoting the construction of the Silk Road Economic Belt Core Area, and Xinjiang has been transformed from a relatively closed inland area into an open border. In order to promote the high-quality development of Southern Xinjiang and solve the imbalance contradiction between the development of the Northern Xinjiang and Southern Xinjiang, taking the four districts in Southern Xinjiang as the study area, constructing a high-quality development ecological niche index system of three levels, namely economic, social and ecological, adopting the entropy method to assign weights to the evaluation indexes, and measuring the ecological niche width and the degree of ecological niche overlap of this region in the period from 2011 to 2020. The results show that: Firstly, tourism has the greatest impact on the ecological niche of economic development in state N, with a weighting of 14.18%; Secondly, the ecological status width of economic development in state N demonstrates a structural characteristic of "low level and low gap". The average value of ecological niche width is at class III, indicating a low development status and weak regional influence; Thirdly, the ecological niche overlap of state N is significantly influenced by spatial factors. Regions Z and S are closer together, resulting in higher competition for resource utilization and an average ecological niche overlap at class II. The other two regions are at class III. According to the theory of ecological niche expansion and separation, a specialization separation strategy should be adopted for areas with "low width and high overlap", and a strengthening expansion strategy should be adopted for areas with "low width and low overlap", to optimize the structure of ecological niches and promote high-quality development of the region.

Perchlorate in honey from China: Levels, pollution characteristics and health risk assessment.

The release and accumulation of perchlorate into the environment have raised concerns about safety to food, however, the dietary risk of perchlorate in honey have not yet received attention. Herein, we investigated the pollution characteristics and assessed the human health risks of perchlorate in honey from China. A total of 151 honey samples collected from 20 provinces of China were analyzed, and overall detection frequencies was 95.4 %. The levels of perchlorate ranged from below limit of quantitation to 612 µg/kg, with a mean value of 34.5 µg/kg. Lychee honey samples had the highest mean perchlorate concentration (163 µg/kg). The mean concentration of perchlorate in the honey samples produced in South China was significantly higher than that in honey from Southwest China, East China and North China (P < 0.05). The health risk assessment showed that mean hazard quotient (HQ) values of different honey for children (ranged from 0.0108 to 0.400) and adults (ranged from 0.0123 to 0.453) were less than 1. This result indicated that mean pollution levels of perchlorate in various honey were unlikely to pose health risk. However, perchlorate concentrations in two lychee honey samples had associated HQ values were >1, suggesting potential health risks. This work not only offers valuable information for honey consumer, but also important reference for comparison of honey samples in the future. ENVIRONMENTAL IMPLICATION: Perchlorate contamination has become a hot environmental issue in connection with human health due to its potential thyroid toxicity and widespread occurrence in environment and foods. Honey not only was widely beloved by consumers worldwide but also considered a potential indicator of environmental pollution. Here, a national investigation and risk assessment of perchlorate levels in different types of honey from China was conducted. The results describe the perchlorate contamination were extensive in honey samples, mean levels of perchlorate in various honey were unlikely to cause health risks. However, significantly high level of contamination in lychee honey should be of concern.

Efficiency and equity of bed utilization in China's health institutions: based on the rank-sum ratio method.

OBJECTIVE: The study aimed to analyze the efficiency and equity of bed utilization in Please check if the section headings are assigned to appropriate levels.China's healthcare institutions and to compare and analyze the overall health resource utilization efficiency in recent years and some specific utilization conditions in 2021, to provide empirical experience for the allocation of health care resources in epidemic China. METHODS: To compare and analyze the overall health resource utilization efficiency of the whole country with that of the East, middle, and West in 2021, and to analyze the bed utilization efficiency of different types of healthcare institutions in China and the bed utilization efficiency of various types of specialist hospitals in the country in 2021 by using the rank-sum ratio method. RESULTS: In 2021, the bed utilization rate of China's health institutions was 69.82%, and the number of bed turnover times was 27.65 times; the bed utilization rate of hospitals was 74.6%, and the number of bed turnover times was 26.08 times. The number of hospital bed turnovers was highest in the western region, lowest in the central region, and close to the national average in the eastern region. The average length of stay for discharged patients was the highest in the central region, the lowest in the eastern region, and the same as the national average in the western region. The analysis of rank-sum ratio method shows that among different types of health institutions' bed utilization efficiency (r = 0.935, P = 0.000), general hospitals and traditional Chinese medicine hospitals have the best bed utilization rate, and the bed utilization rate of community health service centers (stations) needs to be improved; while among various types of specialized hospitals' bed utilization efficiency (r = 0.959, P = 0.000), oncology hospitals, thoracic hospitals, and hematology hospitals, children's hospitals have high bed utilization efficiency; leprosy hospitals, cosmetic hospitals, and stomatology hospitals have low bed utilization efficiency. Health technicians per 1,000 population are highest in the western region, lowest in the central region, and lower in the eastern region than in the western region but slightly higher than the national average. The number of beds in health institutions per 1,000 population is the highest in the central region, the lowest in the eastern region, and slightly lower in the northwest than in the central region but higher than the national average. CONCLUSION: China's investment in health funding in the field of health care has been on the rise in recent years. However, there still exists the situation of uneven investment in health expenses and inconsistent medical efficiency among regions. And change such a status quo can be further improved in terms of government, capital, human resources, technology, information system, and so on.

Micro-agents' perception of landscape services and their multi-level driving influences in the headwater area of the Qiantang River, China.

Landscape services are an important basis for maintaining regional ecological security patterns, environmental health, and sustainable socio-economic development. As an important link between regional ecosystems and socio-economic development, micro-agents' production and life as well as their cognition and perception of landscape services notably impact the maintenance of multi-functional landscape development. This paper examines 9 rural communities in different areas and different development types in the headwater area of the Qiantang River in China, China's national key ecological functional area, in a typical case study. Based on farmer interviews and household surveys, this paper explores the changes of micro-agents' diversification perception of landscape services from 2010 to 2020. A multiple linear regression method is used to construct an index model of agents' perception of diversification of landscape services and to analyze the driving factors influencing changes. The results showed that (1) from 2010 to 2020, the micro-agent perception index of the diversity of farmland, forest, garden, and grassland landscape services increased by 0.46, 0.43, 0.67, and 0.51, respectively. Among them, the micro-agents' diversified perception of forest, farmland, garden, and grassland landscape services decreased in sequence. (2) From 2010 to 2020, in regard to the importance and vulnerability of landscape services, the difference between the perception levels of farmland landscape support services and grassland landscape regulation services in the agricultural production core area was the largest. In management and rationality perception of landscape services, the difference in the perception between grassland landscape service ecological and economic development areas was the largest. (3) Individual and family characteristics are important factors affecting the diversification perception of landscape services, while the natural environment and resource endowment impose negligible influences. Environmental policies only affect the diversification of grassland perception. The research results can provide a reference for maintaining regional landscape services, improving the well-being of micro-agents, and promoting the enhancement in ecological services and regional collaborative development.

Low-cost Prussian blue analogues for sodium-ion batteries and other metal-ion batteries.

As a class of promising cathodes in the field of large-scale power storage systems especially for alkali-metal-ion batteries (MIBs), Prussian blue (PB) and its analogues (PBAs) have received wide research attention due to their open framework, high theoretical specific capacity, and simple synthesis method. For large-scale applications, cathode materials with low-cost and long cycle life are preferred. However, only a few of the review papers have concentrated on the detailed analysis of low-cost PBAs, including Fe-based and Mn-based PBAs, which also show excellent electrochemical performance. This review aims to first provide an all-sided understanding of low-cost PBAs in terms of their application and recent progress in MIBs. Then, the major challenges such as inferior electrochemical properties of low-cost PBAs are discussed. Meanwhile, we provide feasible strategies to prepare PBA electrodes with advanced electrochemical performance. Finally, we present some personal perspectives and guidance for future research, aiming to narrow the gap between laboratory investigation and practical application.

Multi-functional identification of social-ecological landscape in ecologically fragile areas under the background of regional transformation development.

To realize the coordinated development of regional economy, society, and ecosystem is the ultimate goal of economic development and ecological protection in ecologically fragile areas. The multi-functional identification of socio-ecological landscape in ecologically fragile areas is helpful to alleviate the practical contradictions and conflicts faced by the region, and to better realize the optimal allocation of regional resources and the formulation of rational regional land management and planning strategies. This study takes Mizhi County, the most prominent and representative area of the ecologically fragile areas of the Loess Plateau, as the research area. The three dimensions of the ecosystem, social system, and production system were used to construct a landscape multi-functionality identification and evaluation model. A comprehensive identification method for the landscape multi-functionality evaluation, dominant-secondary function recognition, and dominant-secondary obstacle function recognition were carried out to realize the recognition of the landscape multi-functionality. The results were the following: (1) The identification of the landscape multi-functionality through multi-objective optimal decision making with limited scheme for the determination of regional functions should follow the optimal decision rule. (2) The multi-function comprehensive identification method for the landscape could be used to scientifically identify the landscape multi-functions in the ecologically fragile areas. (3) The multi-functions of the social-ecological landscape were obvious. An area with an extreme value was prominent and presented a state of aggregation. The spatial difference between the dominant and secondary functions (obstacle functions) was strong, and the degree of interdependence between functions was high. This study provides a scientific reference for landscape optimization management in the ecologically fragile areas of the Loess Plateau.

Spatiotemporal Characteristics of Coupling and Coordination of Cultural Tourism and Objective Well-Being in Western China.

A supply of high-quality cultural tourism products effectively promotes people's happiness. This study takes the coupling and coordination relationship between cultural tourism (CT) and objective well-being (OWB) in western China as the research object and constructs an index evaluation system for the development levels of cultural tourism and objective welfare, which are divided into three development stages of dysfunctional, transitional, and coordinated development and 10 coordination levels, including high-quality coordination. The entropy weight method, coupled coordination model, Thiel index, standard deviation, and coefficient of variation were used to calculate the comprehensive development index and coupling coordination degree of the CT and OWB systems in western China from 2007 to 2020, and then their evolution characteristics were analyzed from the perspectives of time and space. The results show the following: (1) The comprehensive development capacity of the CT and OWB systems in the western region shows a relatively consistent growth trend except for 2020, the overall development capacity of objective welfare was relatively high, and the development capacity of cultural tourism was relatively low. (2) The CT and OWB systems were in a state of transition from high coupling and low coordination to high coupling and high coordination, which were divided into three development stages: imbalanced stage (2007-2008), transitional stage (2009-2011), and coordinated development (2012-2020). The coordination degree has developed steadily from moderate misalignment to good coordination over time, and the diversified characteristics of coupling coordination levels are obvious. (3) The spatial equilibrium of the CT and OWB systems is obvious, and the spatial difference in the western region is getting smaller, but the relative gap is widening significantly. (4) The comprehensive development capacity of the cultural tourism system should be enhanced, the spiritual needs of residents based on objective well-being should be met, and the sustainable development of the CT and OWB systems.

Task and Non-task Brain Activation Differences for Assessment of Depression and Anxiety by fNIRS.

Diagnosis and treatment of the patients with major depression (MD) or the combined anxiety and depression (A&D) depend on the questionnaire, sometimes accompanied by tasks such as verbal fluency task (VFT). Functional near infrared spectroscopy (fNIRS) is emerging as an auxiliary diagnostic tool to evaluate brain function, providing an objective criterion to judge psychoses. At present, the conclusions derived from VFT or rest (non-task) studies are controversial. The purpose of this study is to evaluate if task performs better than non-task in separating healthy people from psychiatric patients. In this study, healthy controls (HCs) as well as the patients with MD or A&D were recruited (n = 10 for each group) to participate in the non-task and VFT tasks, respectively, and the brain oxygenation was longitudinally evaluated by using fNIRS. An approach of spectral analysis is used to analyze cerebral hemoglobin parameters (i.e., Oxy and Deoxy), characterizing the physiological fluctuations in the non-task and task states with magnitude spectrum and average power. Moreover, the standard deviation of oxygenation responses during the non-task was compared with the peak amplitude during the task, with the aim to explore the sensitivity of the VFT task to brain activation. The results show that there is no significant difference (p > 0.05) among the three groups in average power during non-task. The VFT task greatly enhanced the magnitude spectrum, leading to significant difference (p < 0.05) in average power between any of two groups (HC, MD, and A&D). Moreover, 40% patients with A&D have an intermediate peak (around 0.05 Hz) in the magnitude spectrum when performing the VFT task, indicating its advantage in characterizing A&D. We defined a rate of the non-task standard variation to the task peak amplitude (namely, SD-to-peak rate) and found that this rate is larger than 20% in 90% of the MD subjects. By contrast, only 40% HC subjects have an SD-to-peak rate larger than 20%. These results indicate that the non-task may not be sufficient to separate MD or A&D from HC. The VFT task could enhance the characteristics of the magnitude spectrum, but its intensity needs to be elevated so as to properly explore brain functions related to psychoses.

Functional Polymers and Polymer-Dye Composites for Food Sensing.

The sensitive, safe, and portable detection of food spoilage is becoming unprecedentedly important because it is closely related to the public health and economic development, particularly given the globalization of food supply chain. However, the existing approaches for food monitoring are still limited to meet these requirements. To address this challenge, much research has been done to develop an ideal food sensor that can indicate food quality in real-time in a sensitive and reliable way. So far, many sensors such as time-temperature indicators, smart trademarks, colorimetric tags, electronic noses, and electronic tongues, have been developed and even commercialized. In this feature article, the recent progress of food sensors based on functional polymers, including the molecular design of polymer structures, sensing mechanisms, and relevant processing techniques to fabricate a variety of food sensor devices is reviewed.

Unveiling the Finite Temperature Physics of Hydrogen Chains via Auxiliary Field Quantum Monte Carlo.

The ability to accurately predict the finite temperature properties and phase diagrams of realistic quantum solids is central to uncovering new phases and engineering materials with novel properties ripe for device applications. Nonetheless, there remain comparatively few many-body techniques capable of elucidating the finite temperature physics of solids from first principles. In this work, we take a significant step toward developing such a technique by generalizing our previous, exact fully ab initio finite temperature Auxiliary Field Quantum Monte Carlo (FT-AFQMC) method to model periodic solids and employing it to uncover the finite temperature physics of periodic hydrogen chains. Our chains' unit cells consist of 10 hydrogen atoms modeled in a minimal basis, and we sample 5 k-points from the first Brillouin zone to arrive at a supercell consisting of 50 orbitals and 50 electrons. Based upon our calculations of these chains' many-body energies, free energies, entropies, heat capacities, double and natural occupancies, and charge and spin correlation functions, we outline their metal-insulator and magnetic ordering as a function of both H-H bond distance and temperature. At low temperatures approaching the ground state, we observe both metal-insulator and ferromagnetic-antiferromagnetic crossovers at bond lengths between 0.5 and 0.75 Å. We then demonstrate how this low-temperature ordering evolves into a metallic phase with decreasing magnetic order at higher temperatures. In order to contextualize our results, we compare the features we observe to those previously seen in one-dimensional, half-filled Hubbard models at finite temperature and in ground state hydrogen chains. Interestingly, we identify signatures of the Pomeranchuk effect in hydrogen chains for the first time and show that spin and charge excitations that typically arise at distinct temperatures in the Hubbard model are indistinguishably coupled in these systems. Beyond qualitatively revealing the many-body phase behavior of hydrogen chains in a numerically exact manner without invoking the phaseless approximation, our efforts shed light on the further theoretical developments that will be required to construct the phase diagrams of the more complex transition metal, lanthanide, and actinide solids of longstanding interest to physicists.

Evolutionary Characteristics and Trade-Offs' Development of Social-Ecological Production Landscapes in the Loess Plateau Region from a Resilience Point of View: A Case Study in Mizhi County, China.

Social-ecological production landscape resilience (SELPR) is a significant representation of the continuous supply capacity of landscape services. It is a quantitative assessment of the spatial-temporal evolution of SELPR under internal and external disturbances that provides a scientific basis for regional ecological environments and socio-economic development. Taking Mizhi County for the study of the Loess Plateau region, a three-dimensional (social system, ecosystem, and production system) SELPR evaluation framework was constructed. Data integration was performed using the watershed as the evaluation unit. This study quantitatively evaluated the spatial-temporal differentiation of the social-ecological production landscape (SELPs) subsystem's resilience and the total SELPR in the study area and classified the areas from the three-system resilience combination level to achieve regional development trade-offs. The results were as follows: (1) In 2009-2018, the change in the social-ecological production landscapes pattern in Mizhi County showed a significant reduction in agricultural production landscapes, relatively stable social living landscapes, and an increase in ecological landscapes; (2) in 2009-2018, the SELPR increased by 12.38%. The spatial distribution of resilience was significantly different, showing a distribution pattern of high central and low surrounding areas; (3) the county's watershed development zones were divided into five partitions: synergistic promotion areas, ecological restoration areas, social development areas, production optimization areas, and comprehensive remediation areas. The five types of zones have a certain agglomeration effect. In addition, the main obstacle factors affecting the SELPR of each zone are quite different. The key issues and development directions of different types of watersheds are also proposed in this paper.

Extreme-value sampling design is cost-beneficial only with a valid statistical approach for exposure-secondary outcome association analyses.

In epidemiology cohort studies, exposure data are collected in sub-studies based on a primary outcome (PO) of interest, as with the extreme-value sampling design (EVSD), to investigate their correlation. Secondary outcomes (SOs) data are also readily available, enabling researchers to assess the correlations between the exposure and the SOs. However, when the EVSD is used, the data for SOs are not representative samples of a general population; thus, many commonly used statistical methods, such as the generalized linear model (GLM), are not valid. A prospective likelihood method has been developed to associate SOs with single-nucleotide polymorphisms under an extreme phenotype sequencing design. In this paper, we describe the application of the prospective likelihood method (STEVSD) to exposure-SO association analysis under an EVSD. We undertook extensive simulations to assess the performance of the STEVSD method in associating binary and continuous exposures with SOs, comparing it to the simple GLM method that ignores the EVSD. To demonstrate the cost-benefit of the STEVSD method, we also mimicked the design of two new retrospective studies, as would be done in actual practice, based on the PO of interest, which was the same as the SO in the EVSD study. We then analyzed these data by using the GLM method and compared its power to that of the STEVSD method. We demonstrated the usefulness of the STEVSD method by applying it to a benign ethnic neutropenia dataset. Our results indicate that the STEVSD method can control type I error well, whereas the GLM method cannot do so owing to its ignorance of EVSD, and that the STEVSD method is cost-effective because it has statistical power similar to that of two new retrospective studies that require collecting new exposure data for selected individuals.

Autistic traits influence the strategic diversity of information sampling: Insights from two-stage decision models.

Information sampling can reduce uncertainty in future decisions but is often costly. To maximize reward, people need to balance sampling cost and information gain. Here we aimed to understand how autistic traits influence the optimality of information sampling and to identify the particularly affected cognitive processes. Healthy human adults with different levels of autistic traits performed a probabilistic inference task, where they could sequentially sample information to increase their likelihood of correct inference and may choose to stop at any moment. We manipulated the cost and evidence associated with each sample and compared participants' performance to strategies that maximize expected gain. We found that participants were overall close to optimal but also showed autistic-trait-related differences. Participants with higher autistic traits had a higher efficiency of winning rewards when the sampling cost was zero but a lower efficiency when the cost was high and the evidence was more ambiguous. Computational modeling of participants' sampling choices and decision times revealed a two-stage decision process, with the second stage being an optional second thought. Participants may consider cost in the first stage and evidence in the second stage, or in the reverse order. The probability of choosing to stop sampling at a specific stage increases with increasing cost or increasing evidence. Surprisingly, autistic traits did not influence the decision in either stage. However, participants with higher autistic traits inclined to consider cost first, while those with lower autistic traits considered cost or evidence first in a more balanced way. This would lead to the observed autistic-trait-related advantages or disadvantages in sampling optimality, depending on whether the optimal sampling strategy is determined only by cost or jointly by cost and evidence.

Traceable in-cell synthesis and cytoplasm-to-nucleus translocation of a zinc Schiff base complex as a simple and economical anticancer strategy.

We have proposed a facile and cheap cancer therapeutic strategy by in-cell synthesizing theranostic Zn Schiff base complexes with nuclear targeting and DNA damaging capability. The in-cell synthesis can be traced via a green-to-blue fluorescence shift, and the subsequent cytoplasm-to-nucleus translocation realizes cancer-specific therapy both in vitro and in vivo.

Human representation of multimodal distributions as clusters of samples.

Behavioral and neuroimaging evidence shows that human decisions are sensitive to the statistical regularities (mean, variance, skewness, etc.) of reward distributions. However, it is unclear what representations human observers form to approximate reward distributions, or probability distributions in general. When the possible values of a probability distribution are numerous, it is cognitively costly and perhaps unrealistic to maintain in mind the probability of each possible value. Here we propose a Clusters of Samples (CoS) representation model: The samples of the to-be-represented distribution are classified into a small number of clusters and only the centroids and relative weights of the clusters are retained for future use. We tested the behavioral relevance of CoS in four experiments. On each trial, human subjects reported the mean and mode of a sequentially presented multimodal distribution of spatial positions or orientations. By varying the global and local features of the distributions, we observed systematic errors in the reported mean and mode. We found that our CoS representation of probability distributions outperformed alternative models in accounting for subjects' response patterns. The ostensible influence of positive/negative skewness on the over/under estimation of the reported mean, analogous to the "skewness preference" phenomenon in decisions, could be well explained by models based on CoS.

Oxidation-Resistant, Cost-Effective Epoxide-Modified Polyamine Adsorbents for CO2 Capture from Various Sources Including Air.

CO2 adsorbents based on the reaction of pentaethylenehexamine (PEHA) or tetraethylenepentamine (TEPA) with propylene oxide (PO) were easily prepared in "one pot" by impregnation on a silica support in water. The starting materials were readily available and inexpensive, facilitating the production of the adsorbents on a large scale. The prepared polyamine/epoxide adsorbents were efficient in capturing CO2 and could be regenerated under mild conditions (50-85 °C). They displayed a much-improved stability compared with their unmodified amine counterparts, especially under oxidative conditions. Leaching of the active organic amine became minimal or nonexistent after treatment with the epoxide. The adsorption as well as desorption kinetics were also greatly improved. The polyamine/epoxide adsorbents were able to capture CO2 from various sources including ambient air and indoor air with CO2 concentrations of only 400-1000 ppm. The presence of water, far from being detrimental, increased the adsorption capacity. Their use for indoor air quality purposes was explored.

Single-operator cholangioscopy for the treatment of concomitant gallbladder stones and secondary common bile duct stones.

BACKGROUND AND AIM: This study aims to assess the clinical validity and safety of single-operator cholangioscopy system (SOCS) for the treatment of concomitant gallbladder stones and secondary common bile duct (CBD) stones. METHODS: This retrospective study included 10 consecutive patients who had small-sized stones (< 1 cm) in both the gallbladder and CBD; the patients underwent SOCS treatment from June 2016 to December 2016. The clinical validity of this minimally invasive surgery was determined by the operation success rate, stone removal rate, postoperative hospital stay, hospitalization cost, and contrast images before and after the operation. The clinical safety was evaluated by perioperative complications and outcomes, gallbladder stone recurrence, and gallbladder contractility function. RESULTS: Both the technique success rate and the stone removal rate when using SOCS was 100%. There were no serious complications that occurred during the operation; three patients developed acute cholecystitis, and four patients underwent hyperamylasemia after the surgery. The average postoperative hospital stay was 5.8 ± 1.32 days, and the average hospitalization cost was 7466 ± 566.1 dollars. In the follow-up period, which ranged from 3 to 8 months, there was no stone residuals or recurrences in the gallbladder and CBD, and no patient showed a recurrence of biliary colic. In addition, the gallbladder contractility function was proven to be normal within 3 to 6 months after the operation. CONCLUSIONS: SOCS could successfully manage concomitant gallbladder stones and secondary CBD stones and precisely protect normal biliary function.

[Sources, Distribution of Main Controlling Factors, and Potential Ecological Risk Assessment for Heavy Metals in the Surface Sediment of Hainan Island North Bay, South China].

The distribution characteristics of the content of As, Cr, Cu, Hg, Pb, Zn, and Cd were researched based on the geochemical analysis of 159 surface sediment samples in Haikou Bay, Puqian Bay, Dongzhai Harbor, and Mulan Bay Mathematical statistics methods were used to interpret the sources of heavy metals, and the main controlling factors for heavy metal distribution were confirmed, having been analyzed qualitatively and semi-quantitatively. The results showed that the average contents of As, Cd, Cr, Cu, Hg, Pb, and Zn were 8.40, 0.06, 32.50, 8.32, 0.02, 18.77, and 35.87 µg·g-1, respectively. High contents of Cr, Cu, Hg, Pb, and Zn are mainly distributed in estuaries and harbors. The content of As increased gradually from south to north in the research area, while Cd gathered mainly in Haikou Bay. The source of Cu, Zn, Hg, Pb, Cr, and Cd in sediment was terrestrial input, which was controlled by anthropogenic pollution and migration of weathered products from mother rock. The source of As could be overseas material input. The grain size of sediment was the main factor controlling the contents of Cu, Zn, Hg, Pb, and Cr, and it was found that sediments with a finer grain size have more heavy metals adsorbed. The high As content was controlled mainly by the natural geological background factor, while the content of Cd reflected the difference in regional pollution caused by differing development in cities. Three surface sediment samples were evaluated as class Ⅱ of the National Marine Sediment Standard due to the content of As, while six surface sediment samples were evaluated as class Ⅱ due to the content of Cr, of which the pollution degree was moderate. The concentrations of Cd, Cu, Hg, Pb, and Zn in all of the 159 sediment samples fall in the Ⅰ class, of which the pollution degree is low. The degree of pollution for seven heavy metals were arranged in the following order:As > Cr > Pb > Zn > Cu > Cd > Hg. The potential ecological risk assessment results indicated that all heavy metals in surface sediment caused low levels of pollution generally, and that each heavy metal element was at a low ecological risk level. The order for the ecological risk of the seven heavy metals was:As > Hg > Cd > Pb > Cu > Cr > Zn; therefore, As was the main ecological risk factor. In general, the potential ecological risk for heavy metals was low, which illustrated that the marine environment in the study area was excellent.

[Assessing environmental and economical benefits of integrated sewage treatment systems].

Sewage treatment, treated water treatment and sludge treatment are three basic units of an integrated sewage treatment system. This work assessed the influence of reusing or discharge of treated water and sludge landfill or compost on the sustainability of an integrated sewage treatment system using emergy analysis and newly proposed emergy indicators. This system's value included its environmental benefits and the products. Environmental benefits were the differences of the environmental service values before and after sewage treatment. Due to unavailability of data of the exchanged substance and energy in the internal system, products' values were attained by newly proposed substitution values. The results showed that the combination of sewage treatment, treated water reuse and sludge landfill had the strongest competitiveness, while the combination of sewage treatment, treated water reuse and earthworm compost was the most sustainable. Moreover, treated water reuse and earthworm compost were helpful for improving the sustainability of the integrated sewage treatment system. The quality of treated water and local conditions should be also considered when implementing the treated water reuse or discharge. The resources efficiency of earthworm compost unit needed to be further improved. Improved emergy indices were more suitable for integrated sewage treatment systems.

Planning multiple movements within a fixed time limit: the cost of constrained time allocation in a visuo-motor task.

S.-W. Wu, M. F. Dal Martello, and L. T. Maloney (2009) evaluated subjects' performance in a visuo-motor task where subjects were asked to hit two targets in sequence within a fixed time limit. Hitting targets earned rewards and Wu et al. varied rewards associated with targets. They found that subjects failed to maximize expected gain; they failed to invest more time in the movement to the more valuable target. What could explain this lack of response to reward? We first considered the possibility that subjects require training in allocating time between two movements. In Experiment 1, we found that, after extensive training, subjects still failed: They did not vary time allocation with changes in payoff. However, their actual gains equaled or exceeded the expected gain of an ideal time allocator, indicating that constraining time itself has a cost for motor accuracy. In a second experiment, we found that movements made under externally imposed time limits were less accurate than movements made with the same timing freely selected by the mover. Constrained time allocation cost about 17% in expected gain. These results suggest that there is no single speed-accuracy tradeoff for movement in our task and that subjects pursued different motor strategies with distinct speed-accuracy tradeoffs in different conditions.