| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)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. |
- Dale, Virginia H., et al.
(författare)
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Status and prospects for renewable energy using wood pellets from the southeastern United States
- 2017
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Ingår i: Global Change Biology Bioenergy. - : Wiley-Blackwell. - 1757-1693 .- 1757-1707. ; 9:8, s. 1296-1305
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Tidskriftsartikel (refereegranskat)abstract
- The ongoing debate about costs and benefits of wood-pellet based bioenergy production in the southeastern United States (SE USA) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention as US exports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants. We ask, 'How is the production of wood pellets in the SE USA affecting forest systems and the ecosystem services they provide?' To address this question, we review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide evidence that wood pellets in the SE USA are a fraction of total forestry operations and can be produced while maintaining or improving forest ecosystem services. Ecosystem services are protected by the requirement to utilize loggers trained to apply scientifically based best management practices in planning and implementing harvest for the export market. Bioenergy markets supplement incomes to private rural landholders and provide an incentive for forest management practices that simultaneously benefit water quality and wildlife and reduce risk of fire and insect outbreaks. Bioenergy also increases the value of forest land to landowners, thereby decreasing likelihood of conversion to nonforest uses. Monitoring and evaluation are essential to verify that regulations and good practices are achieving goals and to enable timely responses if problems arise. Conducting rigorous research to understand how conditions change in response to management choices requires baseline data, monitoring, and appropriate reference scenarios. Long-term monitoring data on forest conditions should be publicly accessible and utilized to inform adaptive management.
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| 3. |
- Englund, Oskar, et al.
(författare)
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Multifunctional perennial production systems for bioenergy: performance and progress
- 2020
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Ingår i: Wiley Interdisciplinary Reviews. - : Wiley. - 2041-8396 .- 2041-840X.
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Tidskriftsartikel (refereegranskat)abstract
- As the global population increases and becomes more affluent, biomass demands for food and biomaterials will increase. Demand growth is further accelerated by the implementation of climate policies and strategies to replace fossil resources with biomass. There are, however, concerns about the size of the prospective biomass demand and the environmental and social consequences of the corresponding resource mobilization, especially concerning impacts from the associated land-use change. Strategically integrating perennials into landscapes dominated by intensive agriculture can, for example, improve biodiversity, reduce soil erosion and nutrient emissions to water, increase soil carbon, enhance pollination, and avoid or mitigate flooding events. Such ?multifunctional perennial production systems? can thus contribute to improving overall land-use sustainability, while maintaining or increasing overall biomass productivity in the landscape. Seven different cases in different world regions are here reviewed to exemplify and evaluate (a) multifunctional production systems that have been established to meet emerging bioenergy demands, and (b) efforts to identify locations where the establishment of perennial crops will be particularly beneficial. An important barrier towards wider implementation of multifunctional systems is the lack of markets, or policies, compensating producers for enhanced ecosystem services and other environmental benefits. This deficiency is particularly important since prices for fossil-based fuels are low relative to bioenergy production costs. Without such compensation, multifunctional perennial production systems will be unlikely to contribute to the development of a sustainable bioeconomy.
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| 4. |
- Nordborg, Maria, 1985, et al.
(författare)
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Energy analysis of poplar production for bioenergy in Sweden
- 2018
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 112, s. 110-120
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Tidskriftsartikel (refereegranskat)abstract
- Poplar (Populus spp.) species are currently not widely grown in Sweden but offer interesting options for future large-scale biomass production for bioenergy. This study assesses the average annual net energy yield and the ratio between the gross energy yield and the total primary energy input for well-managed current commercial poplar production systems in Sweden, with and without fertilization with mineral nitrogen (N). The two systems perform similarly, mainly because the yield response to fertilization is estimated to be small. The average annual net energy yields with and without fertilization are estimated at 190 and 179 GJ ha−1 yr−1, respectively. The corresponding energy ratios are 32 and 34, i.e., the total primary energy inputs correspond to only ca. 3% of the gross energy yield, in both cases. Therefore, improving the net energy yield by increasing the harvest level may be considered the most important objective from an energy performance point of view. To do this, more research is needed in order to develop poplar clones that are better adapted to the Swedish climate and identify in which situations poplar responds well to fertilization. At the same time, by reducing the energy inputs associated with the most fuel-intensive activities (wood-chip transportation, chipping, harvesting, forwarding, and stump lifting), greenhouse gas emissions can be reduced. The results should be interpreted with caution since several parameters, especially the yield response to fertilization and fuel consumption rates, are associated with considerable uncertainties.
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| 5. |
- Nordborg, Maria, 1985, et al.
(författare)
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Energy analysis of willow production for bioenergy in Sweden
- 2018
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Ingår i: Renewable and Sustainable Energy Reviews. - : Elsevier BV. - 1879-0690 .- 1364-0321. ; 93, s. 473-482
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Forskningsöversikt (refereegranskat)abstract
- Energy from biomass, including lignocellulosic crops such as willow (Salix spp.), is expected to increase in importance in Sweden. This study assesses the average annual net energy yield and the ratio between gross energy yield and total primary energy input for well-managed current commercial willow production systems in Sweden subject to three levels of fertilization with mineral nitrogen (N): N-high, N-medium, and N-zero. The average annual net energy yields are estimated at 175, 133, and 86 GJ ha −1 yr −1 , and the (dimensionless) energy ratios are estimated at 19, 32, and 47, for N-high, N-medium, and N-zero, respectively. Thus, there is a trade-off between achieving a high net energy yield and achieving a high energy ratio. Since the total primary energy input amounts to ≤ 5% of the gross energy yield in all cases, and the amount of arable land is limited, productivity increases may be considered more important than energy efficiency improvements. Substantial improvements in energy performance can be achieved by increasing harvest levels and improving energy efficiency in ammonia production and biomass transportation. The results should be interpreted with caution since several input parameters, especially energy use in ammonia production, fuel consumption rates, and the yield response to fertilization, are associated with considerable uncertainties.
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| 6. |
- Todisco, Gabriele, et al.
(författare)
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Integrated Genomic and Transcriptomic Analysis Improves Disease Classification and Risk Stratification of MDS with Ring Sideroblasts
- 2023
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 29:20, s. 4256-4267
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Ring sideroblasts (RS) define the low-risk myelodysplastic neoplasm (MDS) subgroup with RS but may also reflect erythroid dysplasia in higher risk myeloid neoplasm. The benign behavior of MDS with RS (MDSRSþ) is limited to SF3B1-mutated cases without additional high-risk genetic events, but one third of MDSRSþ carry no SF3B1 mutation, suggesting that different molecular mechanisms may underlie RS formation. We integrated genomic and transcriptomic analyses to evaluate whether transcriptome profiles may improve current risk stratification. Experimental Design: We studied a prospective cohort of MDSRSþ patients irrespective of World Health Organization (WHO) class with regard to somatic mutations, copy-number alterations, and bone marrow CD34þ cell transcriptomes to assess whether transcriptome profiles add to prognostication and provide input on disease classification. Results: SF3B1, SRSF2, or TP53 multihit mutations were found in 89% of MDSRSþ cases, and each mutation category was associated with distinct clinical outcome, gene expression, and alternative splicing profiles. Unsupervised clustering analysis identified three clusters with distinct hemopoietic stem and progenitor (HSPC) composition, which only partially overlapped with mutation groups. IPSS-M and the transcriptome-defined proportion of megakaryocyte/erythroid progenitors (MEP) independently predicted survival in multivariable analysis. Conclusions: These results provide essential input on the molecular basis of SF3B1-unmutated MDSRSþ and propose HSPC quantification as a prognostic marker in myeloid neoplasms with RS.
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