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21.
Supercapacitors: Design and Performance of Rechargeable Sodium Ion Batteries,and Symmetrical Li‐Ion Batteries with Supercapacitor‐Like Power Density Based upon Polyoxovanadates (Adv. Energy Mater. 6/2018)
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George Olah Stuart H. M. Butchart Andy Symes Iliana Medina Guzmán Ross Cunningham Donald J. Brightsmith Robert Heinsohn 《Biodiversity and Conservation》2016,25(2):205-223
Parrots (Psittaciformes) are among the most threatened bird orders with 28 % (111 of 398) of extant species classified as threatened under IUCN criteria. We confirmed that parrots have a lower Red List Index (higher aggregate extinction risk) than other comparable bird groups, and modeled the factors associated with extinction risk. Our analyses included intrinsic biological, life history and ecological attributes, external anthropogenic threats, and socio-economic variables associated with the countries where the parrot species occur, while we controlled for phylogenetic dependence among species. We found that the likelihood of parrot species being classified as threatened was less for species with larger historical distribution size, but was greater for species with high forest dependency, large body size, long generation time, and greater proportion of the human population living in urban areas in the countries encompassing the parrots’ home ranges. The severity of extinction risk (from vulnerable to critically endangered) was positively related to the per capita gross domestic product (GDP) of the countries of occurrence, endemism to a single country, and lower for species used as pets. A disproportionate number of 16 extinct parrot species were endemic to islands and single countries, and were large bodied, habitat specialists. Agriculture, hunting, trapping, and logging are the most frequent threats to parrots worldwide, with variation in importance among regions. We use multiple methods to rank countries with disproportionately high numbers of threatened parrot species. Our results promote understanding of global and regional factors associated with endangerment in this highly threatened taxonomic group, and will enhance the prioritization of conservation actions. 相似文献
24.
P G Farlie R Kerr P Thomas T Symes J Minichiello C J Hearn D Newgreen 《Developmental biology》1999,213(1):70-84
Cranial neural crest cell migration is patterned, with neural crest cell-free zones adjacent to rhombomere (R) 3 and R5. These zones have been suggested to result from death of premigratory neural crest cells via upregulation of BMP-4 and Msx-2 in R3 and R5, consequent to R2-, R4-, and R6-derived signals. We reinvestigated this model and found that cell death detected by acridine orange staining in avian embryos varied widely numerically and in pattern, but with a tendency for an elevated zone centered at the R2/3 boundary. In situ hybridization of BMP-4 mRNA resolved to centers at R3 and R5 but Msx-2 resolved to the R2/3 border with only a faint smear from R5 to R6. Outgrowth of neural crest cells was less in isolated R3 cultures than in R1+2, R2, and R4 cultures, but R3 showed neither a decrease in outgrowth of neural crest cells nor an increase in cell death when cocultured with R1+2, R2, or R4. In addition, in serum-free culture, exogenous BMP-4 strikingly reduced neural crest cell outgrowth from R1+2 and R4 as well as R3. Thus we cannot confirm the role of intraneural cell death in patterning rhombomeric neural crest outgrowth. However, grafting quail R2 or R4 adjacent to the chick hindbrain demonstrated a neural crest cell exclusion zone next to R3 and R5. We suggest that one important pattern determinant for rhombomeric neural crest cell migration involves the microenvironment next to the neural tube. 相似文献
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Dukka B KC 《BMC structural biology》2009,9(1):12-9
Background
Common structural biology methods (i.e., NMR and molecular dynamics) often produce ensembles of molecular structures. Consequently, averaging of 3D coordinates of molecular structures (proteins and RNA) is a frequent approach to obtain a consensus structure that is representative of the ensemble. However, when the structures are averaged, artifacts can result in unrealistic local geometries, including unphysical bond lengths and angles. 相似文献26.
Global indicators of biological invasion: species numbers, biodiversity impact and policy responses 总被引:1,自引:0,他引:1
Melodie A. McGeoch Stuart H. M. Butchart Dian Spear Elrike Marais Elizabeth J. Kleynhans y Symes Janice Chanson Michael Hoffmann 《Diversity & distributions》2010,16(1):95-108
Aim Invasive alien species (IAS) pose a significant threat to biodiversity. The Convention on Biological Diversity’s 2010 Biodiversity Target, and the associated indicator for IAS, has stimulated globally coordinated efforts to quantify patterns in the extent of biological invasion, its impact on biodiversity and policy responses. Here, we report on the outcome of indicators of alien invasion at a global scale. Location Global. Methods We developed four indicators in a pressure‐state‐response framework, i.e. number of documented IAS (pressure), trends in the impact of IAS on biodiversity (state) and trends in international agreements and national policy adoption relevant to reducing IAS threats to biodiversity (response). These measures were considered best suited to providing globally representative, standardized and sustainable indicators by 2010. Results We show that the number of documented IAS is a significant underestimate, because its value is negatively affected by country development status and positively by research effort and information availability. The Red List Index demonstrates that IAS pressure is driving declines in species diversity, with the overall impact apparently increasing. The policy response trend has nonetheless been positive for the last several decades, although only half of countries that are signatory to the Convention on Biological Diversity (CBD) have IAS‐relevant national legislation. Although IAS pressure has apparently driven the policy response, this has clearly not been sufficient and/or adequately implemented to reduce biodiversity impact. Main conclusions For this indicator of threat to biodiversity, the 2010 Biodiversity Target has thus not been achieved. The results nonetheless provide clear direction for bridging the current divide between information available on IAS and that needed for policy and management for the prevention and control of IAS. It further highlights the need for measures to ensure that policy is effectively implemented, such that it translates into reduced IAS pressure and impact on biodiversity beyond 2010. 相似文献
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Mark A. McPeek Laurel B. Symes Denise M. Zong Curtis L. McPeek 《Evolution; international journal of organic evolution》2011,65(2):419-428
The selection pressures imposed by mate choice for species identity should impose strong stabilizing selection on traits that confer species identity to mates. Thus, we expect that such traits should show nonoverlapping distributions among closely related species, but show little to no variance among populations within a species. We tested these predictions by comparing levels of population differentiation in the sizes and shapes of male cerci (i.e., the clasper structures used for species identity during mating) of six Enallagma damselfly species. Cerci shapes were nonoverlapping among Enallagma species, and five of six Enallagma species showed no population variation across their entire species ranges. In contrast, cerci sizes overlapped among species and varied substantially among populations within species. These results, taken with previous studies, suggest that cerci shape is a primary feature used in species recognition used to discriminate conspecific from heterospecifics during mating. 相似文献
28.
Kimberly Robertson Malcolm Garnham Wymond Symes 《The International Journal of Life Cycle Assessment》2014,19(10):1693-1704
Purpose
The aim of this study is to assess the life cycle carbon footprint of the New Zealand kiwifruit packaging and transport supply chain to retailers in two major markets (Japan and Germany). Results of this study have been used to identify areas of the New Zealand kiwifruit packaging and transport supply chain that contribute significantly to the carbon footprint and to identify options for reduction.Methods
This study is based on the ISO standards for life cycle assessment (namely, ISO 14040:2006 and ISO 14044:2006). The PAS 2050 also provided further methodological guidance. Primary packaging data were sourced from Zespri’s suppliers. End-of-life data were sourced from the market and waste statistics of the relevant countries. Gabi 4.4 was used for upstream material information and modelling.Results and discussion
The carbon footprint of the packaging and transport of kiwifruit ranged from 0.33 to 0.67 kg CO2e per kilogram of fruit delivered to a store depending on pack type and market. Shipping accounted for the majority of these emissions (58–82 %), and Zespri is actively working with shipping companies to reduce this. There are also opportunities to reduce the carbon footprint through reducing the amount of fruit repacked in the market, using trains for long-distance transport and increasing packaging recycling rates.Conclusions
There is a range of options for reducing the carbon footprint of the New Zealand kiwifruit packaging and transport supply chain. These will tend to be incremental (i.e. a number of small gains) and would involve working closely with partners in the supply chain. Options include increased efficiency in shipping, use of trains for land transport, reductions in the addition of structural packaging in the market, managing the product mix to minimize those supply chains with a higher carbon footprint, identifying alternative material for components of the packaging, replacing the use of polystyrene clamshells with alternative materials or plastic bags and maximizing recycling rates along all stages of the supply chain. 相似文献29.
Mijia Lu Yuexiu Zhang Piyush Dravid Anzhong Li Cong Zeng Mahesh KC Sheetal Trivedi Himanshu Sharma Supranee Chaiwatpongsakorn Ashley Zani Adam Kenney Chuanxi Cai Chengjin Ye Xueya Liang Jianming Qiu Luis Martinez-Sobrido Jacob S. Yount Prosper N. Boyaka Shan-Lu Liu Mark E. Peeples Amit Kapoor Jianrong Li 《Journal of virology》2021,95(20)
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