1. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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2. |
- Coria, Jessica, 1979, et al.
(author)
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On the Use of Market Based Instruments to Reduce Air Pollution in Asia
- 2019
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In: Sustainability. - : MDPI AG. - 2071-1050. ; 11:18
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Journal article (peer-reviewed)abstract
- The high rates of economic activity and environmental degradation in Asia demand the implementation of creative and cost-effective environmental policy instruments that provide polluters with more flexibility to find least-cost solutions to pollution reduction. Despite their many theoretical advantages, the use of market-based instruments (MBIs) is a relatively recent phenomenon in Asia, partly due to policymakers being unfamiliar with MBIs and countries lacking the institutional capacity to implement and enforce them. This paper reviews the Asian experience with MBIs intended to reduce air pollution emissions and synthetizes lessons to be drawn and areas for improvement.
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3. |
- Holden, Stein T., et al.
(author)
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Tenure Security and Investment Effects of Forest Tenure Reform in China
- 2013
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In: Land Tenure Reform in Asia and Africa: assessing impacts on poverty and natural resource management / edited by Stein T. Holden, Keijiro Otsuka and Klaus Deininger... - UK : Palgrave Macmillan. - 9781137343802 ; , s. 256-282
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Book chapter (peer-reviewed)abstract
- http://www.palgraveconnect.com/pc/doifinder/10.1057/9781137343819.0020
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4. |
- Huang, Yuanyuan, et al.
(author)
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Hidden spin polarization in the centrosymmetric Mo S2 crystal revealed via elliptically polarized terahertz emission
- 2020
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In: Physical Review B. - 2469-9950. ; 102:8
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Journal article (peer-reviewed)abstract
- The spin polarization in centrosymmetric molybdenum disulfide (MoS2) bulk crystal is recorded by helicity dependent photocurrent exposed as elliptically polarized terahertz (THz) emission. We assign this observation to hidden spin polarization due to the local Dresselhaus effect induced by the molybdenum atomic site asymmetry. This spin polarization induces ultrafast optically controlled circular photogalvanic current that results in elliptically polarized THz emission. Furthermore, this THz radiation exhibits a helicity dependent bleaching effect under opposite circularly polarized excitations due to the spin relaxation. Our results demonstrate the viability of all-optical control of hidden spin polarization in two-dimensional materials and propose the applicability of the THz emission spectroscopy as a sensitive and contactless method to study spintronic physics in two-dimensional materials.
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5. |
- Jiang, Xuemei, et al.
(author)
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Impacts of Policy Measures on the Development of State Owned Forests in Northeast China : Theoretical Results and Empirical Evidence
- 2014
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In: Environment and Development Economics. - : Cambridge University Press. - 1355-770X .- 1469-4395. ; 19, s. 74-91
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Journal article (peer-reviewed)abstract
- State-owned forest enterprises (SOFEs) in northeast China play important roles both in timber production and in the maintenance of ecological security. This paper examines the effects of a number of policy measures on the behavioral choices of the SOFEs. The results show that the extent to which SOFE supervising authorities emphasized the improvement of forest resources in their annual evaluation of the SOFEs had significant impacts on the harvest and investment decisions and the development of forest resources. Promotion of the management and utilization of non-timber resources, as well as reforms aiming to increase the efficiency of forest protection and management, reduced timber harvests and increased investment, which in turn led to improvements of forest resources, although the effects were small. In contrast, reforms aimed at timber harvest and afforestation activities actually contributed to increasing timber harvest, which affected the development of the forest resources negatively.
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6. |
- Jiang, Xuemei, et al.
(author)
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Impacts of policy measures on the development of state-owned forests in Northeast China : Theoretical results and empirical evidence
- 2011
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Reports (other academic/artistic)abstract
- State-owned forest enterprises (SOFEs) in northeast China and Inner Mongolia play important roles both in timber production and in the maintenance of ecological security. However, since the late 1970s, forest resource and economic crises have seriously restricted these functions. Based on a theoretical and an empirical analysis of the harvest and investment behavior of the SOFEs, we examined the effects of forest policies and the socioeconomic conditions on the behavioral choices of the SOFEs. Both the extent to which SOFE supervising authorities emphasized improvement of forest resources in their annual evaluations and the increases in expenses necessary to manage SOFEs had significant impacts on harvest and investment decisions as well as development of forest resources. Promoting the management and utilization of non-timber resources, as well as reforms to increase the efficiency of forest protection and management, have reduced timber harvests as intended, which in turn has increased investment and improved forest resources. The effects have been relatively small, however. In contrast, reforms aimed at timber harvest and afforestation activities actually contributed toincreasing the timber harvest, which affected the development of the forest resources negatively.
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7. |
- Liu, Jintao, et al.
(author)
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Grid parameterization of a conceptual distributed hydrological model through integration of a sub-grid topographic index : necessity and practicability
- 2012
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In: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 57:2, s. 282-297
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Journal article (peer-reviewed)abstract
- Grid-based distributed models have become popular for describing spatial hydrological processes. However, the influence of non-homogeneity within a grid on streamflow simulation was not adequately addressed in the literature. In this study, we investigated how the statistical characteristics of soil moisture storage within a grid impacts on streamflow simulations. The spatial variation of the topographic index, TI, within a grid was used to determine parameter B of the statistical curve of soil moisture storage in the Xinanjiang model. For comparison of influences of the non-homogeneity within a grid on streamflow simulation, two parameterization schemes of soil moisture storage capacity were developed: a grid-parameterization scheme for a distributed model and a catchment-averaged scheme for a semi-distributed model. The practicability and usefulness of the grid-parameterization method were evaluated through model comparisons. The two models were applied in Jiangwan experimental catchment Zhejiang Province, China. Streamflow discharge data at the catchment outlet from 1971 to 1986 at different temporal resolutions, e. g. 15 min and daily time step, were used for model calibration and validation. Statistical results for different grid scales demonstrated that the mean and variation of TI and B decline significantly as the grid scale increases. The simulated streamflow discharges of the two models were similar and the semi-distributed model outperformed the distributed model slightly when the streamflow at the outlet of the catchment was used as the only basis for comparison. In addition, a relatively larger bias in the predicted discharges between these two models was observed along with an abrupt increase of soil moisture saturation ratio. A further analysis of the simulated soil moisture content distribution revealed that the distributed model can provide a reasonable representation of the variable source area concept, which was justified to some extent by the field experiment data.
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8. |
- Nie, Jintao, et al.
(author)
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SignFind: A Synchronized Sign Language and Chinese Character Teaching Game for Chinese Deaf Children Using Gesture Recognition
- 2022
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In: CHI EA '22: Extended Abstracts of the 2022 CHI Conference on Human Factors in Computing Systems. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450391566 ; , s. 1-7
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Conference paper (peer-reviewed)abstract
- This paper presents a targeted system to help Chinese deaf children learn both sign language and Chinese characters in early language learning. The system combines sign recognition and in-air writing techniques with games so that children can practice sign language and Chinese character writing at the same time. Sign recognition is used to assess the accuracy of sign language and in-air writing records the process of writing Chinese characters. In addition, the game adds to the learning fun and makes children more willing to complete learning tasks. We have developed a prototype to evaluate the effectiveness of a simultaneous Chinese sign language and Chinese character teaching system based on gesture recognition and in-air writing. We expect that this system will increase children's willingness and efficiency to learn sign language and Chinese characters, and eventually be used to assist in early language education for deaf children in the Chinese region.
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9. |
- Ostwald, Madelene, 1966-, et al.
(author)
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The Chinese Grain for Green Program – assessing the sequestered carbon from the land reform
- 2011
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In: World renewable Energy Congress 2011. - Linköping : Linköping University Electronic Press. - 9789173930703 ; , s. 2517-2522
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Conference paper (peer-reviewed)abstract
- Grain for Green Program was launched in China as a national measure to control erosion and increase vegetation cover in 1999. With a budget of 40 billion US dollar, the program that targets cropland and barren land has today converted over 20 million hectares of land into primarily tree-based plantations. Even though the design of the program includes a category of energy forest only a negligible part is planted as such (0.61%). The majority of the land converted is for protection (78%). The use of these plantations in the future is however unclear and a hypothesis of energy substitution is valid.In this paper, we try to estimate the overall carbon that has been sequestered due to the program by using official statistics from the program and by calculating it according to mainly three different approaches; calculations made on I) net primary production, II) figures from IPCC’s greenhouse gas inventory guidelines, and III) mean annual increment. We also highlight several of the uncertainties that are associated with the program and the estimations.The result shows that conversion of cropland and barren land generated carbon sequestration over its 10 first years ranging from 222 to 468 million tonnes of carbon, with the IPCC approach yielding the highest estimate whereas the other two approaches had more similar outcome (around 250 million tonnes of carbon). Uncertainties associated with the assessment lies within the use of growth curves not designed for the particular species and their different locations, actual survival rate of the plantations, and discrepancies in figures concerning the program (e.g. area, type, survival rates) at different levels of authority (from national to local). The carbon sequestered in the biomass (above and below ground) from this program is equivalent to 14% (based on median of all three approaches) of China’s yearly carbon dioxide emissions due to fossil fuel use and cement production.
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10. |
- Persson, Martin, 1976, et al.
(author)
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The Chinese Grain for Green Programme: Assessing the carbon sequestered via land reform
- 2013
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In: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 126, s. 142-146
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Journal article (peer-reviewed)abstract
- The Grain for Green Programme (GGP) was launched in China in 1999 to control erosion and increase vegetation cover. Budgeted at USD 40 billion, GGP has converted over 20 million hectares of cropland and barren land into primarily tree-based plantations. Although GGP includes energy forests, only a negligible part (0.6%) is planted as such, most of the land (78%) being converted for protection. Future use of these plantations is unclear and an energy substitution hypothesis is valid. We estimate the overall carbon sequestration via GGP using official statistics and three approaches, based on i) net primary production, ii) IPCCs greenhouse gas inventory guidelines, and iii) mean annual increment. We highlight uncertainties associated with GGP and the estimates. Results indicate that crop- and barren-land conversion sequestered 222-468 Mt of carbon over GGPs first ten years, the IPCC approach yielding the highest estimate and the other two approaches yielding similar but lower estimates (approximately 250 Mt of carbon). The carbon stock in these plantation systems yields a mean of 12.3 t of carbon per hectare. Assessment uncertainties concern the use of growth curves not designed for particular species and locations, actual plantation survival rates, and discrepancies in GGP figures (e.g., area, type, and survival rate) at different authority levels (from national to local). The carbon sequestered in above- and below-ground biomass from GGP represents 14% (based on the median of the three approaches) of Chinas yearly (2009) carbon dioxide emissions from fossil fuel use and cement production.
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