Hasil untuk "Environmental Science"

Daniel McDonald, Embriette R. Hyde, Justine W. Debelius et al.

We show that a citizen science, self-selected cohort shipping samples through the mail at room temperature recaptures many known microbiome results from clinically collected cohorts and reveals new ones. Of particular interest is integrating n = 1 study data with the population data, showing that the extent of microbiome change after events such as surgery can exceed differences between distinct environmental biomes, and the effect of diverse plants in the diet, which we confirm with untargeted metabolomics on hundreds of samples. ABSTRACT Although much work has linked the human microbiome to specific phenotypes and lifestyle variables, data from different projects have been challenging to integrate and the extent of microbial and molecular diversity in human stool remains unknown. Using standardized protocols from the Earth Microbiome Project and sample contributions from over 10,000 citizen-scientists, together with an open research network, we compare human microbiome specimens primarily from the United States, United Kingdom, and Australia to one another and to environmental samples. Our results show an unexpected range of beta-diversity in human stool microbiomes compared to environmental samples; demonstrate the utility of procedures for removing the effects of overgrowth during room-temperature shipping for revealing phenotype correlations; uncover new molecules and kinds of molecular communities in the human stool metabolome; and examine emergent associations among the microbiome, metabolome, and the diversity of plants that are consumed (rather than relying on reductive categorical variables such as veganism, which have little or no explanatory power). We also demonstrate the utility of the living data resource and cross-cohort comparison to confirm existing associations between the microbiome and psychiatric illness and to reveal the extent of microbiome change within one individual during surgery, providing a paradigm for open microbiome research and education. IMPORTANCE We show that a citizen science, self-selected cohort shipping samples through the mail at room temperature recaptures many known microbiome results from clinically collected cohorts and reveals new ones. Of particular interest is integrating n = 1 study data with the population data, showing that the extent of microbiome change after events such as surgery can exceed differences between distinct environmental biomes, and the effect of diverse plants in the diet, which we confirm with untargeted metabolomics on hundreds of samples.

K. Lewis

We are experiencing an antimicrobial resistance (AMR) crisis, brought on by the drying up of the antibiotic discovery pipeline and the resulting unchecked spread of resistant pathogens. Traditional methods of screening environmental isolates or compound libraries have not produced a new drug in over 30 years. Antibiotic discovery is uniquely difficult due to a highly restrictive penetration barrier and other mechanisms that allow bacteria to survive in the presence of toxic compounds. In this Perspective, we analyze the challenges facing discovery and discuss an emerging new platform for antibiotic discovery. The penetration barrier makes screening conventional synthetic compound libraries largely impractical, and actinomycetes, the main source of natural product compounds, have been overmined. The emerging platform is based on understanding the rules that guide the permeation of molecules into bacteria and on advances in microbiology, which enable us to identify and access attractive groups of secondary metabolite producers. Establishing this platform will enable reliable production of lead compounds to combat AMR.

Hao Tan, Jialing Li, M. He et al.

D. Kriebel, J. Tickner, P. Epstein et al.

Environmental scientists play a key role in society's responses to environmental problems, and many of the studies they perform are intended ultimately to affect policy. The precautionary principle, proposed as a new guideline in environmental decision making, has four central components: taking preventive action in the face of uncertainty; shifting the burden of proof to the proponents of an activity; exploring a wide range of alternatives to possibly harmful actions; and increasing public participation in decision making. In this paper we examine the implications of the precautionary principle for environmental scientists, whose work often involves studying highly complex, poorly understood systems, while at the same time facing conflicting pressures from those who seek to balance economic growth and environmental protection. In this complicated and contested terrain, it is useful to examine the methodologies of science and to consider ways that, without compromising integrity and objectivity, research can be more or less helpful to those who would act with precaution. We argue that a shift to more precautionary policies creates opportunities and challenges for scientists to think differently about the ways they conduct studies and communicate results. There is a complicated feedback relation between the discoveries of science and the setting of policy. While maintaining their objectivity and focus on understanding the world, environmental scientists should be aware of the policy uses of their work and of their social responsibility to do science that protects human health and the environment. The precautionary principle highlights this tight, challenging linkage between science and policy.

M. D. Schwartz

Xingcheng Lu, Yixin Luo, Yiang Chen et al.

Carbon monoxide (CO) is a major atmospheric pollutant with adverse health effects on humans. Moreover, CO can indirectly prolong the lifetime of methane and contribute to global warming. Therefore, understanding the spatial distribution of CO emissions is crucial for designing much-needed strategies to control this pollutant. In this work, a hybrid Weather Research & Forecasting–stochastic time-inverted Lagrangian transport (WRF-STILT)–Bayesian inversion framework was constructed to correct CO emissions over the Greater Bay Area (GBA) for February 2019 and February 2020. After adjusting CO emissions, the average root mean squared error (RMSE), normalized mean error (NME), and correlation coefficient (R) for the simulated CO concentrations in February 2019 and 2020 changed from 0.31 ppm to 0.12 ppm (a 61% reduction), 0.35 to 0.13 (a 63% reduction), and 0.47 to 0.87 (an 85% increase), respectively. The updated CO emissions were then used as input for the Comprehensive Air Quality Model with Extensions (CAMx), a Eulerian model, to further validate the method. The results again indicated that the simulation performance was improved substantially, with a 58% increase in the average R value, a 62% reduction in the RMSE, and a 68% reduction in the NME. This validates the effectiveness of the proposed method in correcting CO emissions. According to the updated emission data, CO emissions over the GBA during the Spring Festival and the COVID-19 lockdown period were 8.3% and 19.6% lower than during normal periods, respectively. These results highlight the importance of accounting for such atypical events in emission estimation and air quality modeling. Analysis of the source areas contributing to CO concentrations in population centers of major GBA cities showed that the average contributions from local emissions and emissions from other GBA cities were 45.5% and 38.8%, respectively. The method developed in this work can be further used for CO adjustment in other regions and contribute to a deeper understanding of the characteristics of this important pollutant.

Calum J. Pritchard, Nabeil K. G. Salama, Iain Berrill et al.

Abstract Minimum landing sizes are a fisheries management tool conventionally used to exclude juveniles from fisheries. Harvest slot limits (HSL) are an alternative fisheries management tool used to exclude both juveniles and larger individuals from a fishery through the implementation of both minimum and maximum landing sizes. However, fishery‐dependent data from HSL‐managed fisheries are only representative of a small portion of the population. These data do not meet the requirements for conventional stock assessments nor harvest control rules, so these fisheries cannot be assessed without additional and expensive fishery‐independent data. The objective of this research was to develop a novel harvest control rule able to produce catch advice for fisheries managed by HSL using fishery‐dependent data. The SlotLim method, and corresponding R package, were developed and applied to the data‐limited Scottish live ballan wrasse Labrus bergylta fishery. Within SlotLim, the advised catch is a product of the previous catch and two multipliers: the targeted biomass adjustment (TBA) and size adherence multiplier (SAM). The TBA assesses the rate of change in an abundance or biomass index, adjusted for the proportion of the population targeted by HSL. The SAM assesses fishers' compliance with HSL. The methodology follows a simple premise: the advised catch increases with increasing abundance/biomass indices and adherence to HSL. The minimum data requirements are two consecutive years of catch, length frequency and an abundance or biomass index (all from fishery‐dependent sources), species‐specific growth rate coefficients and the natural mortality rate. The SlotLim method advised catch for a reduction in catch by 17% for the Scottish ballan wrasse fishery due to an observed reduction in abundances indices and non‐adherence to maximum landing sizes. Solution. The SlotLim method allows HSL‐managed fisheries to be assessed at limited expense, contributing to the continued sustainable use of these resources. HSL may also be considered a viable strategy for other data‐limited fisheries upon the availability of this harvest control rule.

Tra Mai Ngo, Van Hung Hoang, Huu Tap Van et al.

This study examines the fly ash from Soc Son municipal waste power plant (SMPP) and suggests ways to repurpose it to reduce its environmental impact. Fly ash from the Soc Son waste power plant has a gray color, spherical particles with a 5–103 μ m diameter, and a high carbon and heavy metal content. Bermorite crystals can absorb and release heavy metals, making monitoring secondary pollutants during incineration crucial. The EDX analysis of fly ash from the Soc Son waste power plant revealed that it was predominantly contaminated with metal elements, with the highest percentage of calcium. The EDX was able to detect heavy metals in incinerator fly ash. The concentration of Zn in the fly ash exceeded QCVN 07:2009/BTNMT standards, indicating the high amounts of some elements that may be hazardous to the environment and human health. Using the SEM/EDX and XRF, the fly ash from the Soc Son landfill power plant was analyzed and discovered that it exceeds permissible limits for dangerous heavy elements. The most common inorganic elements are Ca, followed by Zn, Pb, Cd, and Ag. Fly ash is classed as hazardous waste due to its high concentration of heavy metals, which results from the combustion of municipal solid waste that has not been separated. Vietnam fights municipal solid waste incinerator fly ash production. Some nations stabilize fly ash to remove harmful components and use it in buildings. Stabilized fly ash makes unfired construction bricks and cement manufacturing components and combining fly ash with inorganic trash protects the environment.

LI Yexin, LYU Gang, WANG Daohan et al.

【Objective】 Restoring coal mining waste dumps is a way to alleviate their detrimental impact on environment. In this paper, we present the results of an experimental study on distribution and stability of soil aggregates in a reclaimed coal mining overburden dump. 【Method】 The experiment was carried out at a reclaimed coal mine dump site in a grassland region in northern China. We measured the development of fissures from Zone I (GF) to Zone three (GFIII) in the fissure zone. The composition and distribution soil aggregates in these zones were determined using dry-wet sieve method. Aggregate stability and its relationship with the fissures was analyzed. 【Result】 The content of the >0.25 mm air-dried aggregates over the fissure zones was 23.02%~42.70%, and content of the >0.25 mm water-stable soil aggregates was 16.9%~29.52%. There was no significant difference between air-dried aggregates and water-stable aggregates. The content of the >0.25 mm water-stable soil aggregates in the 0~60 cm soil layer in GF, GFⅡ and GF Ⅲ was 25.26%, 26.57%, 23.62%, respectively, while the percentage of aggregate destruction in the three fissure zones was 20.77%~36.17%, 20.52%~25.00%, and 26.58%~40.56%, respectively. The percentage of aggregate destruction in 0~10, 10~20, 20~30, 30~40, 40~50, and 50~60 cm soil layers was 28.81%, 29.96%, 26.19%, 23.50%, 24.91%, and 29.38%, respectively. The fractal dimension of air-dried and water-stable soil aggregates was 2.847~2.919 and 2.898~2.942, respectively. Small aggregates and fine particles are the dominant aggregates. The mean mass diameter (MWD) and geometric mean diameter (GMD) of the air-dried aggregates in three fissure zones were 1.11, 1.05, 1.28 mm, and 0.45, 0.44, 0.49 mm, respectively. The MWD and GMD of water-stable soil aggregates in the three fissure zones were 0.67, 0.73, 0.72 mm, and 0.36, 0.38, 0.37 mm, respectively. Soil in GFⅡ had good structure and aggregate stability. Most of water-stable soil aggregates in the fissure zones were unstable due to the formation and development of fissures. 【Conclusion】 The formation and development of fissures in the reclaimed coal mining overburden dump reduced the stability of soil aggregates, thereby resulting in aggregate segmentation. The larger and wider the fissures were, the less stable the soil aggregates were.

Kai-Huang Chen, Chien-Min Cheng, Na-Fu Wang et al.

Activation energy, bipolar resistance switching behavior, and the electrical conduction transport properties of ITO_X:SiO₂ thin film resistive random access memory (RRAM) devices were observed and discussed. The ITO_X:SiO₂ thin films were prepared using a co-sputtering deposition method on the TiN/Si substrate. For the RRAM device structure fabrication, an Al/ITO_X:SiO₂/TiN/Si structure was prepared by using aluminum for the top electrode and a TiN material for the bottom electrode. In addition, grain growth, defect reduction, and RRAM device performance of the ITO_X:SiO₂ thin film for the various oxygen gas flow conditions were observed and described. Based on the <i>I-V</i> curve measurements of the RRAM devices, the turn on-off ratio and the bipolar resistance switching properties of the Al/ITO_X:SiO₂/TiN/Si RRAM devices in the set and reset states were also obtained. At low operating voltages and high resistance values, the conductance mechanism exhibits hopping conduction mechanisms for set states. Moreover, at high operating voltages, the conductance mechanism behaves as an ohmic conduction current mechanism. Finally, the Al/ITO_X:SiO₂/TiN/Si RRAM devices demonstrated memory window properties, bipolar resistance switching behavior, and nonvolatile characteristics for next-generation nonvolatile memory applications.

Shivani Narwal, Rajesh Dhankhar, Savita Kalshan et al.

Presence of plastics in the surroundings is ubiquitous, as generation of plastics is booming globally and it gets accumulated in oceans leading to deleterious impacts on marine life, public health and the surrounding environment. Owing to its non-degradable nature, plastic particles remain in surroundings for extended periods which automatically facilitate its out spreading. Therefore, there is a need to shift to bio-based plastics, as bio-based green economy hinges on sustainable employment of bioresources for generating a broad spectrum of products, biofuels, chemicals and bioplastics. Typically bioplastics are synthesized from bio-based resources considered to contribute more to sustainable production of plastic as a part of the circular economy. Bioplastics are luring attention and growing as counterfeit material for petroleum-derived plastics owing to their biodegradability. Recently an engrossed interest has been burgeoning in producing drop-in polymers and new-fangled bioplastics by utilizing lignocellulosic feedstock. This paper reviews the enormous potential of lignocellulosic feedstock as a significant inedible substrate for bioplastic synthesis. Polyhydroxyalkanoates, polyurethanes, polylactic acid and starch-bioplastic are prevailing bio-based plastic comparably derived from lignocellulosic biomass. In forthcoming years bioplastic derived years’ bioplastic derived from lignocellulose will loom as valuable material in numerous fields for an extensive range of cutting-edge applications.

Zahid Mehmood, Zubair Ahmad, Asad Ullah et al.

Background: Understanding students' perception of the educational environment and their cognitive load in this context is crucial for optimizing the effectiveness of e-learning platforms. Objective: To compare educational environment perception and cognitive load in under-graduates Doctor of Physical Therapy (DPT) and post-graduate Master in Science of Physical Therapy (MSPT) students having online learning experiences. Methodology: In this comparative cross-sectional study, data was collected through non-probability convenient sampling from n=274 under-graduates DPT (n=225) and post-graduates MSPT(n=49) students of either gender having one-semester experience of online learning, Dundee Ready Education Environment Measure (DREEM) for measuring educational environmental perception and Rating Scale of Mental Effort (RSME) for measurement of cognitive load. Online self-structured was developed questionnaire and shared through communication media platform and data analysis was made through SPSS version 28. Results: There were n=225 under-graduates (DPT) and n=49 post-graduates (MSPT) students in which, there were n=208 females and n=66 males. The overall DREEM score showed that MSPT students are more significantly positive (p<0.001, Cohen’s d=1.01) than DPT students regarding the perception of the educational environment with a large effect size. While there was no significant difference (p=0.114) between MSP and DPT students regarding cognitive load. Conclusion: Post-graduates (MSPT) students have better educational environmental perception than undergraduate (DPT) students but there was no significant difference in cognitive load in undergraduate (DPT) and post-graduates (MSPT) students. Keywords: cognition; cognitive load; mental effort; e-learning; physiotherapist.

Peng Liu, Hugo Kyo Lee, Marco Casazza

D. J. Carlin, M. F. Naujokas, Karen D. Bradham et al.

Background: Exposure to inorganic and organic arsenic compounds is a major public health problem that affects hundreds of millions of people worldwide. Exposure to arsenic is associated with cancer and noncancer effects in nearly every organ in the body, and evidence is mounting for health effects at lower levels of arsenic exposure than previously thought. Building from a tremendous knowledge base with > 1,000 scientific papers published annually with “arsenic” in the title, the question becomes, what questions would best drive future research directions? Objectives: The objective is to discuss emerging issues in arsenic research and identify data gaps across disciplines. Methods: The National Institutes of Health’s National Institute of Environmental Health Sciences Superfund Research Program convened a workshop to identify emerging issues and research needs to address the multi-faceted challenges related to arsenic and environmental health. This review summarizes information captured during the workshop. Discussion: More information about aggregate exposure to arsenic is needed, including the amount and forms of arsenic found in foods. New strategies for mitigating arsenic exposures and related health effects range from engineered filtering systems to phytogenetics and nutritional interventions. Furthermore, integration of omics data with mechanistic and epidemiological data is a key step toward the goal of linking biomarkers of exposure and susceptibility to disease mechanisms and outcomes. Conclusions: Promising research strategies and technologies for arsenic exposure and adverse health effect mitigation are being pursued, and future research is moving toward deeper collaborations and integration of information across disciplines to address data gaps. Citation: Carlin DJ, Naujokas MF, Bradham KD, Cowden J, Heacock M, Henry HF, Lee JS, Thomas DJ, Thompson C, Tokar EJ, Waalkes MP, Birnbaum LS, Suk WA. 2016. Arsenic and environmental health: state of the science and future research opportunities. Environ Health Perspect 124:890–899; http://dx.doi.org/10.1289/ehp.1510209

Seiichi Okuno, Seiichi Okuno, Hirotaka Katahira et al.

This study aimed to identify the impact on spinal cord integrity and determine the electrophysiological safety level during surgery for thoracolumbar intervertebral disk herniation in dogs. A total of 52 dogs diagnosed with thoracolumbar intervertebral disk herniation were enrolled. The tibial nerve somatosensory evoked potential elicited on the scalp by stimulation of the tibial nerve was recorded before and during hemilaminectomy. Both the amplitude and latency of the somatosensory evoked potential were periodically registered, and the percentage changes from the pre-operative control values (amplitude rate and latency rate) were calculated. When the multifidus muscles were retracted after removal from the spinous processes and vertebrae, the somatosensory evoked potential amplitude rate decreased in all dogs, while the latency rate increased in 33 dogs examined. The amplitude rate remained unchanged during the halting procedure, loosening retraction, and hemilaminectomy. After removing the disc material from the spinal canal, the amplitude rate was increased. The somatosensory evoked potential latency increased when the multifidus muscles were retracted and shortened after multifidus muscles closure in four cases. The outcome of all cases showed improvement in clinical signs 7 days after operation. Spinal cord conduction is impaired by retraction of the multifidus muscles and improved by removal of disk materials. Maintaining intraoperative SEP amplitudes above 50% of control may help avoid additional spinal cord injury during surgery. Since we have no case that worsened after the surgery, however, further studies are necessary to confirm this proposal.

Yuan Zou, Wei Chen, Siliang Li et al.

In terrestrial ecosystems, vegetation is sensitive to climate change and human activities. Its spatial-temporal changes also affect the ecological and social environment. In this paper, we considered the Beijing–Tianjin–Hebei region to study the spatio-temporal vegetation patterns. The detailed analysis of a moderate-resolution imaging spectroradiometer (MODIS) data were carried out through the Google Earth Engine (GEE) platform. Our results show a slow and tortuous upward trend in the average leaf area index (LAI) in the study region for the periods 2001–2020. Specifically, Beijing had the highest LAI value, with an average of 1.64 over twenty years, followed by Hebei (1.30) and Tianjin (1.04). Among different vegetation types, forests had the highest normalized difference vegetation index (NDVI) with the range of 0.62–0.78, followed by shrubland (0.58–0.75), grassland (0.34–0.66), and cropland (0.38–0.54) over the years. Spatially, compared to the whole study area, index value in the northwestern part of the Beijing–Tianjin–Hebei region increased greatly in many areas, such as northwest Beijing, Chengde, and Zhangjiakou, indicating a significant ecological optimization. Meanwhile, there was ecological degradation in the middle and southeast regions, from Tangshan southeastward to Handan, crossing Tianjin, Langfang, the east part of Baoding, Shijiazhuang, and the west part of Cangzhou. Air temperature and precipitation were positively and significantly correlated with net primary production (NPP) and precipitation stood out as a key driver. Additionally, an intensification of the urbanization rate will negatively impact the vegetation NPP, with the shrubland and forest being affected most relative to the cropland.

Bo Wang, Hongxi Chen, Yibin Ao et al.

In order to support the green and low-carbon transformation of China’s construction industry and accomplish the dual carbon objective, it is vital to accelerate green technology innovation. Therefore, this paper takes the Chengdu–Chongqing urban agglomeration of China as the study area, using the super-efficiency slacks-based measure (SBM)model and the gravity model to assess the efficiency of green technology innovation in the construction industry, utilizing geographical detectors to investigate the drivers of green technology innovation in the construction industry further. Additionally, we consider each influencing factor’s level of impact on the efficiency of green technology innovation in the construction sector both under the single factor and double factor scenarios. The findings indicate that there is a considerable difference in the efficiency of green technology innovation in the Chengdu–Chongqing metropolitan agglomeration’s construction industry, and the trend is upward. In addition, the research area exhibited spatially heterogeneous characteristics in terms of the efficiency of green technology innovation in the construction industry, and the spatial spillover effect was significantly limited by distance. Further research revealed that environmental legislation, economic development, public environmental concern, urbanization level, and foreign direct investment were the primary driving factors of green technology innovation efficiency in the construction sector, and industrial size was the potential driving factor. The spatial and temporal differentiation of the green technology innovation efficiency in the construction industry was also more affected by the interaction between the dominating factor and the prospective factor than by either factor acting alone. The research’s findings are useful in advancing the green and low-carbon transformation of the construction sector in the Chengdu–Chongqing metropolitan agglomeration by offering theoretical support and decision-making reference.

W. Cunningham, B. W. Saigo

J. Adams