Remote Sensing Applications in Monitoring of Protected Areas：A Bibliometric Analysis

The development of remote sensing platforms and sensors and improvement in science and technology provide crucial support for the monitoring and management of protected areas. This paper presents an analysis of research publications, from a bibliometric perspective, on the remote sensing of protected areas. This analysis is focused on the period from 1991 to 2018. For data, a total of 4546 academic publications were retrieved from the Web of Science database. The VOSviewer software was adopted to evaluate the co-authorships among countries and institutions, as well as the co-occurrences of author keywords. The results indicate an increasing trend of annual publications in the remote sensing of protected areas. This analysis reveals the major topical subjects, leading countries, and most influential institutions around the world that have conducted relevant research in scientific publications; this study also reveals the journals that include the most publications, and the collaborative patterns related to the remote sensing of protected areas. Landsat, MODIS, and LiDAR are among the most commonly used satellites and sensors. Research topics related to protected area monitoring are mainly concentrated on change detection, biodiversity conservation, and climate change impact. This analysis can help researchers and scholars better understand the intellectual structure of the field and identify the future research directions

Spatiotemporal Correlations between Water Footprint and Agricultural Inputs: A Case Study of Maize Production in Northeast China

To effectively manage water resources in agricultural production, it is necessary to understand the spatiotemporal variation of the water footprint (WF) and the influences of agricultural inputs. Employing spatial autocorrelation analysis and a geographically weighted regression (GWR) model, we explored the spatial variations of the WF and their relationships with agricultural inputs from 1998 to 2012 in Northeast China. The results indicated that: (1) the spatial distribution of WFs for the 36 major maize production prefectures was heterogeneous in Northeast China; (2) a cluster of high WFs was found in southeast Liaoning Province, while a cluster of low WFs was found in central Jilin Province, and (3) spatial and temporal differentiation in the correlations between the WF of maize production and agricultural inputs existed according to the GWR model. These correlations increased over time. Our results suggested that localized strategies for reducing the WF should be formulated based on specific relationships between the WF and agricultural inputs

Silica nanoparticles enhance autophagic activity, disturb endothelial cell homeostasis and impair angiogenesis

BACKGROUND: Given that the effects of ultrafine fractions (<0.1 μm) on ischemic heart diseases (IHD) and other cardiovascular diseases are gaining attention, this study is aimed to explore the influence of silica nanoparticles (SiNPs)-induced autophagy on endothelial cell homeostasis and angiogenesis. METHODS AND RESULTS: Ultrastructural changes of autophagy were observed in both vascular endothelial cells and pericytes in the heart of ICR mice by TEM. Autophagic activity and impaired angiogenesis were further confirmed by the immunohistochemistry staining of LC3 and VEGFR2. In addition, the immunohistochemistry results showed that SiNPs had an inhibitory effect on ICAM-1 and VCAM-1, but no obvious effect on E-selectin in vivo. The disruption of F-actin cytoskeleton occurred as an initial event in SiNPs-treated endothelial cells. The depolarized mitochondria, autophagic vacuole accumulation, LC3-I/LC3-II conversion, and the down-regulation of cellular adhesion molecule expression were all involved in the disruption of endothelial cell homeostasis in vitro. Western blot analysis indicated that the VEGFR2/PI3K/Akt/mTOR and VEGFR2/MAPK/Erk1/2/mTOR signaling pathway was involved in the cardiovascular toxicity triggered by SiNPs. Moreover, there was a crosstalk between the VEGFR2-mediated autophagy signaling and angiogenesis signaling pathways. CONCLUSIONS: In summary, the results demonstrate that SiNPs induce autophagic activity in endothelial cells and pericytes, subsequently disturb the endothelial cell homeostasis and impair angiogenesis. The VEGFR2-mediated autophagy pathway may play a critical role in maintaining endothelium and vascular homeostasis. Our findings may provide experimental evidence and explanation for cardiovascular diseases triggered by nano-sized particles. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12989-014-0050-8) contains supplementary material, which is available to authorized users

Toxic Effects of Silica Nanoparticles on Zebrafish Embryos and Larvae

Silica nanoparticles (SiNPs) have been widely used in biomedical and biotechnological applications. Environmental exposure to nanomaterials is inevitable as they become part of our daily life. Therefore, it is necessary to investigate the possible toxic effects of SiNPs exposure. In this study, zebrafish embryos were treated with SiNPs (25, 50, 100, 200 μg/mL) during 4-96 hours post fertilization (hpf). Mortality, hatching rate, malformation and whole-embryo cellular death were detected. We also measured the larval behavior to analyze whether SiNPs had adverse effects on larvae locomotor activity. The results showed that as the exposure dosages increasing, the hatching rate of zebrafish embryos was decreased while the mortality and cell death were increased. Exposure to SiNPs caused embryonic malformations, including pericardial edema, yolk sac edema, tail and head malformation. The larval behavior testing showed that the total swimming distance was decreased in a dose-dependent manner. The lower dose (25 and 50 μg/mL SiNPs) produced substantial hyperactivity while the higher doses (100 and 200 μg/mL SiNPs) elicited remarkably hypoactivity in dark periods. In summary, our data indicated that SiNPs caused embryonic developmental toxicity, resulted in persistent effects on larval behavior. © 2013 Duan et al.published_or_final_versio

Detection of human influences on temperature seasonality from the 19th century

It has been widely reported that anthropogenic warming is detectable with high confidence after the 1950s. However, current palaeoclimate records suggest an earlier onset of industrial-era warming. Here, we combine observational data, multiproxy palaeo records and climate model simulations for a formal detection and attribution study. Instead of the traditional approach to the annual mean temperature change, we focus on changes in temperature seasonality (that is, the summer-minus-winter temperature difference) from the regional to whole Northern Hemisphere scales. We show that the detectable weakening of temperature seasonality, which started synchronously over the northern mid–high latitudes since the late nineteenth century, can be attributed to anthropogenic forcing. Increased greenhouse gas concentrations are the main contributors over northern high latitudes, while sulfate aerosols are the major contributors over northern mid-latitudes. A reduction in greenhouse gas emissions and air pollution is expected to mitigate the weakening of temperature seasonality and its potential ecological effects

DICCCOL: Dense Individualized and Common Connectivity-Based Cortical Landmarks

Is there a common structural and functional cortical architecture that can be quantitatively encoded and precisely reproduced across individuals and populations? This question is still largely unanswered due to the vast complexity, variability, and nonlinearity of the cerebral cortex. Here, we hypothesize that the common cortical architecture can be effectively represented by group-wise consistent structural fiber connections and take a novel data-driven approach to explore the cortical architecture. We report a dense and consistent map of 358 cortical landmarks, named Dense Individualized and Common Connectivity–based Cortical Landmarks (DICCCOLs). Each DICCCOL is defined by group-wise consistent white-matter fiber connection patterns derived from diffusion tensor imaging (DTI) data. Our results have shown that these 358 landmarks are remarkably reproducible over more than one hundred human brains and possess accurate intrinsically established structural and functional cross-subject correspondences validated by large-scale functional magnetic resonance imaging data. In particular, these 358 cortical landmarks can be accurately and efficiently predicted in a new single brain with DTI data. Thus, this set of 358 DICCCOL landmarks comprehensively encodes the common structural and functional cortical architectures, providing opportunities for many applications in brain science including mapping human brain connectomes, as demonstrated in this work

Reconciling the Discrepancy of Post-Volcanic Cooling Estimated from Tree-Ring Reconstructions and Model Simulations over the Tibetan Plateau

Volcanic eruptions are a major factor influencing global climate variability, usually with a cooling effect. The magnitudes of post-volcanic cooling from historical eruptions estimated by tree-ring reconstructions differ considerably with the current climate model simulations. It remains controversial on what is behind such a discrepancy. This study investigates the role of internal climate variability (i.e., El Ni&ntilde;o/Southern Oscillation (ENSO) warm phase) with a regional focus on the Tibetan Plateau (TP), using tree-ring density records and long historical climate simulations from the fifth Coupled Model Intercomparsion Project (CMIP5). We found that El Ni&ntilde;o plays an important role behind the inconsistencies between model simulations and reconstructions. Without associated El Ni&ntilde;o events, model simulations agree well with tree-ring records. Divergence appears when large tropical eruptions are followed by an El Ni&ntilde;o event. Model simulations, on average, tend to overestimate post-volcanic cooling during those periods as the occurrence of El Ni&ntilde;o is random as part of internal climate variability

Spatial pattern characteristics of water footprint for maize production in Northeast China

BACKGROUND: Water footprint (WF) methodology is essential for quantifying total water consumption of crop production and making efficient water management policies. This study calculated the green, blue, grey and total WFs of maize production in Northeast China from 1998 to 2012 and compared the values of the provinces. This study also analyzed the spatial variation and structure characteristics of the WFs at the prefecture level. RESULTS: The annual average WF of maize production was 1029m3 per ton, which was 51% green, 21% blue and 28% grey. The WF of maize production was highest in Liaoning Province, moderate in Heilongjiang Province and lowest in Jilin Province. The spatial differences of the WFs calculated for the 36 major maize production prefectures were significant in Northeast China. There was a moderate positive spatial autocorrelation among prefectures that had similar WFs. Local indicator of spatial autocorrelation index (LISA) analysis identified prefectures with higher WFs in the southeast region of Liaoning Province and the southwest region of Heilongjiang Province and prefectures with lower WFs in the middle of Jilin Province. CONCLUSION: Spatial differences in the WF of maize production were caused mainly by variations in climate conditions, soil quality, irrigation facilities and maize yield. The spatial distribution of WFs can help provide a scientific basis for optimizing maize production distribution and then formulate strategies to reduce the WF of maize production

Bibliometric Analysis of Coastal and Marine Tourism Research from 1990 to 2020

Coastal and marine tourism (CMT) has become a growing and important subsector of the tourism industry in recent years. To identify the state of and trends in the field, a bibliometric analysis of CMT was conducted to evaluate global productivity over the past 31 years (1990-2020). All relevant publications in the analysis were extracted from the Web of Science Core Collection database. As a result, the review found that the identified 6190 documents showed an upward trend during this time period. The most productive and influential countries, institutions, and authors were also identified in this analysis, and the distribution of subject categories and journals was analyzed. VOSviewer was used to analyze the coauthorships among countries, institutions, and authors. Based on an analysis of the high-frequency keyword co-occurrence network, four major CMT research topics were identified: (1) the sustainable development of CMT, (2) the impact of CMT on destinations, (3) CMT management and conservation, and (4) the impact of climate change on CMT. This analysis can help reveal and determine the research focus and trends in the CMT field