55 research outputs found

    A two-dimensional angular-resolved proton spectrometer

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    We present a novel design of two-dimensional (2D) angular-resolved spectrometer for full beam characterization of ultrashort intense laser driven proton sources. A rotated 2D pinhole array was employed, as selective entrance before a pair of parallel permanent magnets, to sample the full proton beam into discrete beamlets. The proton beamlets are subsequently dispersed without overlapping onto a planar detector. Representative experimental result of protons generated from femtosecond intense laser interaction with thin foil target is presented

    Consumption-based greenhouse gas emissions accounting with capital stock change highlights dynamics of fast-developing countries.

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    Traditional consumption-based greenhouse gas emissions accounting attributed the gap between consumption-based and production-based emissions to international trade. Yet few attempts have analyzed the temporal deviation between current emissions and future consumption, which can be explained through changes in capital stock. Here we develop a dynamic model to incorporate capital stock change in consumption-based accounting. The new model is applied using global data for 1995-2009. Our results show that global emissions embodied in consumption determined by the new model are smaller than those obtained from the traditional model. The emissions embodied in global capital stock increased steadily during the period. However, capital plays very different roles in shaping consumption-based emissions for economies with different development characteristics. As a result, the dynamic model yields similar consumption-based emissions estimation for many developed countries comparing with the traditional model, but it highlights the dynamics of fast-developing countries

    Economic development and coastal ecosystem change in China

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    Despite their value, coastal ecosystems are globally threatened by anthropogenic impacts, yet how these impacts are driven by economic development is not well understood. We compiled a multifaceted dataset to quantify coastal trends and examine the role of economic growth in China's coastal degradation since the 1950s. Although China's coastal population growth did not change following the 1978 economic reforms, its coastal economy increased by orders of magnitude. All 15 coastal human impacts examined increased over time, especially after the reforms. Econometric analysis revealed positive relationships between most impacts and GDP across temporal and spatial scales, often lacking dropping thresholds. These relationships generally held when influences of population growth were addressed by analyzing per capita impacts, and when population density was included as explanatory variables. Historical trends in physical and biotic indicators showed that China's coastal ecosystems changed little or slowly between the 1950s and 1978, but have degraded at accelerated rates since 1978. Thus economic growth has been the cause of accelerating human damage to China's coastal ecosystems. China's GDP per capita remains very low. Without strict conservation efforts, continuing economic growth will further degrade China's coastal ecosystems

    c-Myc Regulates Self-Renewal in Bronchoalveolar Stem Cells

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    BACKGROUND: Bronchoalveolar stem cells (BASCs) located in the bronchoalveolar duct junction are thought to regenerate both bronchiolar and alveolar epithelium during homeostatic turnover and in response to injury. The mechanisms directing self-renewal in BASCs are poorly understood. METHODS: BASCs (Sca-1(+), CD34(+), CD31(-) and, CD45(-)) were isolated from adult mouse lung using FACS, and their capacity for self-renewal and differentiation were demonstrated by immunostaining. A transcription factor network of 53 genes required for pluripotency in embryonic stem cells was assessed in BASCs, Kras-initiated lung tumor tissue, and lung organogenesis by real-time PCR. c-Myc was knocked down in BASCs by infection with c-Myc shRNA lentivirus. Comprehensive miRNA and mRNA profiling for BASCs was performed, and significant miRNAs and mRNAs potentially regulated by c-Myc were identified. We explored a c-Myc regulatory network in BASCs using a number of statistical and computational approaches through two different strategies; 1) c-Myc/Max binding sites within individual gene promoters, and 2) miRNA-regulated target genes. RESULTS: c-Myc expression was upregulated in BASCs and downregulated over the time course of lung organogenesis in vivo. The depletion of c-Myc in BASCs resulted in decreased proliferation and cell death. Multiple mRNAs and miRNAs were dynamically regulated in c-Myc depleted BASCs. Among a total of 250 dynamically regulated genes in c-Myc depleted BASCs, 57 genes were identified as potential targets of miRNAs through miRBase and TargetScan-based computational mapping. A further 88 genes were identified as potential downstream targets through their c-Myc binding motif. CONCLUSION: c-Myc plays a critical role in maintaining the self-renewal capacity of lung bronchoalveolar stem cells through a combination of miRNA and transcription factor regulatory networks

    Globalization of forest land use: Increasing threats on climate-vulnerable regions

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    Given the increasing influence of international trade on regional land use, this paper presents a comprehensive overview of forest land use across global supply chains by means of embodiment accounting based on EXIOBASE 3 database, with a specific focus on the climate vulnerability and adaptation readiness of supply chain agents. Globally, 2268.3 million hectares (Mha) of forest land was exploited for forestry in 2015, while 30% was associated with export production, mainly sourced from Russia, Canada, Africa, South America and tropical and subtropical Asia-Pacific and linked to the final consumption of developed (e.g. the EU, the USA and Japan) and emerging (e.g. China and India) economies. During 2000–2015, forest land exploited in climate-vulnerable regions rose to 689.4 Mha, contributing over 50% of the overall increase in global forest land exploitation. Forest land use displaced from China and India to these regions increased by 2.6 and 3.3 times, respectively, due to escalating imports from tropics and subtropics (especially Asia-Pacific), where the readiness to take adaptation actions was also low. For the EU and the USA, virtual forest land use sourced from these regions remained large in absolute magnitude despite decreasing import volume. Therefore, transnational mutual efforts are needed to secure local forestry of climate-vulnerable regions, improve the resilience of global supply chains and mitigate negative influence on other sustainable development goals supported by forest ecosystems

    Characterization of the complete chloroplast genome of Saussurea integrifolia (Compositae)

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    The complete chloroplast genome sequence of Saussurea integrifolia, a flowering plant occurring in Hengduan Mountains with high altitudes, is determined in this study. The plastome is 152,584 bp in length, with one large single-copy region of 83,497 bp, one small single-copy region of 18,646 bp, and two inverted repeat (IR) regions of 25,221 bp. It contains 123 genes, including 86 protein-coding genes, 8 ribosomal RNA, and 36 transfer RNA. Phylogenetic tree shows that this species is a sister to Arctium lappa. The published plastome within Saussurea provides significant insight for elucidating the phylogenetic relationship of taxa within tribe Compositae
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