470 research outputs found

    Formalizing space and place

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    International audienceThe space/place dichotomy has long been recognized in geography, and more broadly in the social sciences. The geographic information technologies that have emerged in the past few decades are almost exclusively spatial, however. The concepts, principles, and tools of the spatial perspective are reviewed, along with their importance in facilitating multidisciplinary social science. Arguments for a comparable placial perspective are presented and discussed

    Impacts of sea-land and mountain-valley circulations on the air pollution in Beijing-Tianjin-Hebei (BTH): A case study

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    In the study, observational data analyses and the WRF-CHEM model simulations are used to investigate the role of sea-land and mountain-valley breeze circulations in a severe air pollution event occurred in Beijing-Tianjin-Hebei (BTH) during August 9-10, 2013. Both the wind observations and the model simulations have clearly indicated the evolution of the sea-land and mountain-valley breeze circulations during the event. The WRF-CHEM model generally reproduces the local meteorological circulations and also performs well in simulating temporal variations and spatial distributions of fine particulate matters (PM2.5) and ozone (O-3) concentrations compared to observations in BTH. The model results have shown that the offshore land breeze transports the pollutants formed in Shandong province to the Bohai Gulf in the morning, causing the formation of high O-3 and PM2.5 concentrations over the gulf. The onshore sea breeze not only causes the formation of a convergence zone to induce upward movement, mitigating the surface pollution to some degree, also recirculates the pollutants over the gulf to deteriorate the air quality in the coastal area. The upward valley breeze brings the pollutants in the urban area of Beijing to the mountain area in the afternoon, and the downward mountain breeze transports the pollutants back during nighttime. The intensity of the mountain-valley breeze circulation is weak compared to the land-sea breeze circulation in BTH. It is worth noting that the local circulations play an important role when the large-scale meteorological conditions are relatively weak. (C) 2017 Elsevier Ltd. All rights reserved

    Cultivation of Artificial Algal Crust and Its Effect on Soil Improvement in Sandy Area

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    Algae are the pioneer species of biological soil crusts. Cyanobacteria, microschwannophyta and pseudocladophyta can form fixed quicksand algae crusts on the surface of sand surface. Through artificial culture, soil crusts can be formed in a short time. The development and succession of algeal-sand crust promoted the enrichment of nutrients in the sand surface layer, and created conditions for the reproduction of micro-soil organisms and the colonization of herbaceous plants, thus promoting the desert ecosystem to enter a virtuous cycle. This chapter will focus on the cultivation process of artificial soil crust and its effect on soil improvement (soil organic matter and nitrogen) in sandy areas. In conclusion, the application of algal solution can rapidly form algal crusts, and according to the research results, the formation of algal crusts can significantly improve the chemical and biological properties of soil

    Food safety analysis and management of Shiga toxin-producing Escherichia coli in edible agricultural products and kitchen

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    The sources and transmission routes of Shiga toxin-producing Escherichia coli (STEC) in edible agricultural products are analyzed. And the relationship between STEC contamination and food safety in home kitchen is discussed. The current supervision of STEC in edible agricultural products around the world is introduced. The solution and suggestion for the control of STEC in the home kitchen of China are proposed

    Thickness of Extraocular Muscle and Orbital Fat in MRI Predicts Response to Glucocorticoid Therapy in Graves’ Ophthalmopathy

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    33 patients with active, moderate-severe Graves’ ophthalmopathy (GO) received 4.5 g methylprednisolone for 12 weeks and were divided by efficacy into two groups (responsive and unresponsive). All patients and 10 controls underwent orbital MRI examination at baseline. No significant difference was seen in baseline clinical characteristics between the two GO groups. The values of exophthalmos were higher in both GO groups than in the control and were higher in the responsive group versus the unresponsive group. Compared to the unresponsive group, the responsive group had a thicker inferior rectus as well as thinner orbital fat. The inferior rectus/fat ratio was significantly higher in the responsive group versus the unresponsive group. Multivariate logistic regression analysis showed that the exophthalmos value and inferior rectus/fat ratio were significantly associated with the response to glucocorticoid (GC). ROC analysis revealed that the cut-off points of the inferior rectus/fat ratio combined with the exophthalmos value to indicate efficacy were 1.42 and 20.78. For moderate-severe GO patients with CAS > 3, the combined inferior rectus/fat ratio and exophthalmos value in MRI may be a valuable indicator to predict the response to GC therapy

    TOD typologies for metro stations based on the butterfly model

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    As a promising planning strategy for urban sustainability, transit-oriented development (TOD) has been widely encouraged and adopted to integrate land use and transport systems. Because of the different applications in form, function and impact, it is necessary to explore context-based TOD typologies to better map the TOD specificities and focus on strategic planning. As the best-known method, the node-place model provides a useful analytical framework to evaluate TOD typologies. However, by using two indexes to aggregate the node and place value, details of some important TOD characteristics are disregarded in this model. Proposing a multi-axial indexes system, the butterfly model can perform a more detailed evaluation of node and place. In this research, we have revised and optimized the butterfly model and taken Tianjin Metro Line 1 as a case study. We find that all stations can be divided into five TOD types with significant spatial variations. TOD principles have already been implemented in Tianjin with good integration between metro system and land use. The method demonstrated in this paper equips urban planners with a useful tool for evaluating TOD performance and adopting more targeted strategies

    Metagenomic insights into the abundance and composition of resistance genes in aquatic environments:Influence of stratification and geography

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    A global survey was performed with 122 aquatic metagenomic DNA datasets (92 lake water and 30 seawater) obtained from the Sequence Read Archive (SRA). Antibiotic resistance genes (ARGs) and metal resistance genes (MRGs) were derived from the dataset sequences via bioinformatic analysis. The relative abundances of ARGs and MRGs in lake samples were in the ranges ND (not detected)-1.34x10(0) and 1.22x10(-3) -1.98x10(-1) copies per 16S rRNA, which were higher than those in seawater samples. Among ARGs, multidrug resistance genes and bacitracin resistance genes had high relative abundances in both lake and sea water samples. Multimetal resistance genes, mercury resistance genes and copper resistance genes had the greatest relative abundance for MRGs. No significant difference was found between epilimnion and hypolimnion in abundance or the Shannon diversity index for ARGs and MRGs. Principal coordinates analysis and permutational multivariate analysis of variance (PERMANOVA) test showed that stratification and geography had significant influence on the composition of ARGs and MRGs in lakes (p < 0.05, PERMANOVA). Coastal seawater samples had significantly greater relative abundance and a higher Shannon index for both ARGs and MRGs than deep ocean and Antarctic seawater samples (p < 0.05, Kruskal-Wallis one-way ANOVA), suggesting that human activity may exert more selective pressure on ARGs and MRGs in coastal areas than those in deep ocean and Antarctic seawater

    Fetuin-B, a potential link of liver-adipose tissue cross talk during diet-induced weight loss–weight maintenance

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    BACKGROUND/OBJECTIVES: Numerous hepatokines are involved in inter-organ cross talk regulating tissue-specific insulin sensitivity. Adipose tissue lipolysis represents a crucial element of adipose insulin sensitivity and is substantially involved in long-term body weight regulation after dietary weight loss. Thus, we aimed to analyze the impact of the hepatokine Fetuin-B in the context of weight loss induced short- and long-term modulation of adipose insulin sensitivity. SUBJECTS/METHODS: 143 subjects (age > 18; BMI >= 27 kg/m(2)) were analyzed before (T-3) and after (T0) a standardized 12-week dietary weight reduction program. Afterward, subjects were randomized to a 12-month lifestyle intervention or a control group. After 12 months (T12) no further intervention was performed until 6 months later (T18) (Maintain-Adults trial). Tissue-specific insulin sensitivity was estimated by HOMA-IR (predominantly liver), ISIClamp (predominantly skeletal muscle), and free fatty acid suppression during hyperinsulinemic-euglycemic clamp (FFA(Supp)) (predominantly adipose tissue). Fetuin-B was measured at all concomitant time points. RESULTS: Circulating Fetuin-B levels correlated significantly with estimates of obesity, hepatic steatosis as well as HOMA-IR, ISIClamp, FFA(Supp) at baseline. Fetuin-B decreased during dietary weight loss (4.2 (3.5-4.9) vs. 3.8 (3.2-4.6) mu g/ml; p = 2.1 x 10(-5)). This change was associated with concomitant improvement of HOMA-IR (r = 0.222; p = 0.008) and FFA(Supp) (r = -0.210; p = 0.013), suggesting a particular relationship to hepatic and adipose tissue insulin sensitivity. Weight loss induced improvements of insulin resistance were almost completely preserved until months 12 and 18 and most interestingly, the short and long-term improvement of FFA(Supp) was partially predicted by baseline level of Fetuin-B. CONCLUSIONS: Our data suggest that Fetuin-B might be a potential mediator of liver-adipose cross talk involved in short- and long-term regulation of adipose insulin sensitivity, especially in the context of diet-induced weight changes
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