1,720,994 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Cascading Effects Within Soil Food Web Amplify Fungal Biomass and Necromass Production
No full textABSTRACT Soil food webs regulate microbial biomass and necromass production and are therefore critical for carbon sequestration. The mechanisms by which top predators regulate microbial necromass formation across multitrophic levels in the real‐world soil food web remain nearly unknown. This study investigates how top‐down forces—from omnivorous‐predaceous nematodes to microbivorous nematodes and microbes—affect the formation of microbial necromass within tritrophic food webs under contrasting tillage regimes (tillage (till) vs. no‐tillage (no‐till)) on black soils (Mollisols), using a 1‐year 13 C‐labeled straw in situ tracing experiment integrated with a long‐term (> 5 years) tillage trial. The fungal‐to‐bacterial necromass ratio increased strongly in the no‐till soil compared to the till soil, with omnivores‐predators being the key factor for these changes. In the no‐till soil, abundant and diverse omnivores‐predators (46% and 67% higher in abundance and richness than in the till soil) created a typical predator–prey relationship with fungivores. This relationship was characterized by heavy predation on fungivores (51% of omnivore‐predator diet) and opposite 1‐year dynamics of 13 C content between omnivores‐predators and fungivores. Such a predator–prey relationship substantially reduced fungivore activity (73% and 90% decrease in 13 C content and enrichment rate), while accompanied by increased fungal activity (64% and 50% increase in 13 C content and enrichment rate) in the no‐till soil compared to the till soil. This predator‐driven cascade down the food chain amplified the fungal contribution to the fungal‐to‐bacterial necromass ratio. Conversely, these interactions, disrupted by continuous tillage, weakened fungal functions by interrupting the trophic cascade. In conclusion, these tiny yet ubiquitous omnivorous‐predaceous nematodes exert a disproportionate impact on necromass formation by boosting fungal biomass and activity. Further manipulative experiments targeting multi‐trophic interactions are essential to disentangle the mechanisms of microbial necromass formation, given the inherent complexity of soil food webs and the observational nature of this study.National Natural Science Foundation of China https://doi.org/10.13039/501100001809Youth Innovation Promotion Association of the Chinese Academy of Sciences https://doi.org/10.13039/50110000473
Soil Organic Carbon Increases With Decreasing Microbial Carbon Use Efficiency During Vegetation Restoration
No full textABSTRACT Microbial carbon (C) use efficiency (CUE) describes the proportion of organic C used by microorganisms for anabolic processes, which increases with soil organic C (SOC) content on a global scale. However, it is unclear whether a similar relationship exists during natural vegetation restoration in terrestrial ecosystems. Here, we investigated the patterns of CUE along a 160‐year vegetation restoration chronosequence (from farmland to climax forest) estimated by stoichiometric modeling; additionally, we examined the relationship between CUE and SOC content and combined these results with a meta‐analysis. The combination indicated that vegetation restoration decreased CUE from 0.35 to 0.28. Surprisingly, SOC content increased with decreasing CUE during vegetation restoration because forest soils have low pH values and high microbial phosphorus limitations compared to early ecosystems, implying that climax forests may not sequester as much soil C as expected. The shift in soil pH was the most important predictor of CUE compared to climate, plant, and microbial factors. CUE changes were directly induced by soil pH and not by the pH‐induced microbial community. Alkaline soil acidification tended to decrease CUE. This first large‐scale estimate of the relationship between CUE and SOC during natural restoration highlights the need to strengthen C sink management in mature forests to sustain their C sequestration potential.National Natural Science Foundation of China https://doi.org/10.13039/50110000180
Climate Change Accelerates Microbial Biomass Accumulation in Soils
No full textAbstract Soil microbial biomass (SMB) and stoichiometric ratios of carbon and nutrients in microorganisms are crucial to predict biogeochemical and nutrient cycling in terrestrial ecosystems, particularly under global change. Using SMB data from 1,288 studies in China, we mapped the distribution of microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP) and their stoichiometric ratios using the random forest model. The stocks of MBC, MBN, and MBP in the topsoil (0–30 cm) were (mean with 25% and 75% quantiles), , and Tg, respectively; the corresponding stocks in the subsoil (30–100 cm) were Tg C, Tg N, and Tg P, respectively. The mean MBC/MBN, MBC/MBP, and MBN/MBP ratios in the topsoil were estimated to be 10, 29, and 3.9, respectively, and the corresponding ratios in the subsoil were 8.6, 19, and 2.5, respectively. Soil physico‐chemical properties (pH and moisture) are the main direct drivers of SMB and their stoichiometric ratios, while climate (temperature) indirectly affects SMB. Climate indirectly affects SMB by altering soil moisture and substrate availability, the physico‐chemical properties directly shape SMB content through habitat and resource constraints. The Coupled Model Intercomparison Project Phase 6 demonstrated that SMB stocks will increase until 2,100. Under the Shared Socioeconomic Pathway 5–8.5, SMB stocks increased, especially in the topsoil. Our study clarified SMB stocks and microbial stoichiometric ratios for soils up to 1.0 m depth and revealed the main drivers. We assessed SMB density and microbial stoichiometric ratios, compiled databases across climatic regions, and provided recommendations for regional C, N, and P management.Plain Language Summary Soil microbes are vital for nutrient cycling and climate regulation. By analyzing 1,200+ studies across China, we mapped microbial carbon (C), nitrogen (N), and phosphorus (P) stocks in soils down to 1 m. Topsoil (0–30 cm) holds 970 trillion grams (Tg) of microbial C, 150 Tg N, and 60 Tg P, while the depth of 30–100 cm stores 650 Tg C, 120 Tg N, and 65 Tg P. Microbial nutrient ratios decrease with depth: topsoil microbes have higher C/N (10:1) and C/P (29:1) ratios than subsoil microbes (8.6:1 and 19:1). Soil pH and moisture directly control microbial activity, while climate (e.g., temperature) indirectly affects it by altering moisture and food resources. Climate models predict rising microbial biomass by 2,100, especially in the topsoil under high emissions, which could accelerate nutrient turnover and CO 2 release into the atmosphere. These insights aid soil health management and climate strategies, emphasizing the hidden role of microbes in sustaining ecosystems and food security.Key Points For the first time, we synthesized soil microbial biomass density data at a depth of 0–100 cm across China Soil moisture and pH are the primary direct drivers of microbial biomass, while the effects of temperature are indirect Projected warming and humidifying climates are expected to increase microbial biomass stocks in soilAbstract Soil microbial biomass (SMB) and stoichiometric ratios of carbon and nutrients in microorganisms are crucial to predict biogeochemical and nutrient cycling in terrestrial ecosystems, particularly under global change. Using SMB data from 1,288 studies in China, we mapped the distribution of microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP) and their stoichiometric ratios using the random forest model. The stocks of MBC, MBN, and MBP in the topsoil (0–30 cm) were (mean with 25% and 75% quantiles), , and Tg, respectively; the corresponding stocks in the subsoil (30–100 cm) were Tg C, Tg N, and Tg P, respectively. The mean MBC/MBN, MBC/MBP, and MBN/MBP ratios in the topsoil were estimated to be 10, 29, and 3.9, respectively, and the corresponding ratios in the subsoil were 8.6, 19, and 2.5, respectively. Soil physico‐chemical properties (pH and moisture) are the main direct drivers of SMB and their stoichiometric ratios, while climate (temperature) indirectly affects SMB. Climate indirectly affects SMB by altering soil moisture and substrate availability, the physico‐chemical properties directly shape SMB content through habitat and resource constraints. The Coupled Model Intercomparison Project Phase 6 demonstrated that SMB stocks will increase until 2,100. Under the Shared Socioeconomic Pathway 5–8.5, SMB stocks increased, especially in the topsoil. Our study clarified SMB stocks and microbial stoichiometric ratios for soils up to 1.0 m depth and revealed the main drivers. We assessed SMB density and microbial stoichiometric ratios, compiled databases across climatic regions, and provided recommendations for regional C, N, and P management.Plain Language Summary Soil microbes are vital for nutrient cycling and climate regulation. By analyzing 1,200+ studies across China, we mapped microbial carbon (C), nitrogen (N), and phosphorus (P) stocks in soils down to 1 m. Topsoil (0–30 cm) holds 970 trillion grams (Tg) of microbial C, 150 Tg N, and 60 Tg P, while the depth of 30–100 cm stores 650 Tg C, 120 Tg N, and 65 Tg P. Microbial nutrient ratios decrease with depth: topsoil microbes have higher C/N (10:1) and C/P (29:1) ratios than subsoil microbes (8.6:1 and 19:1). Soil pH and moisture directly control microbial activity, while climate (e.g., temperature) indirectly affects it by altering moisture and food resources. Climate models predict rising microbial biomass by 2,100, especially in the topsoil under high emissions, which could accelerate nutrient turnover and CO 2 release into the atmosphere. These insights aid soil health management and climate strategies, emphasizing the hidden role of microbes in sustaining ecosystems and food security.Key Points For the first time, we synthesized soil microbial biomass density data at a depth of 0–100 cm across China Soil moisture and pH are the primary direct drivers of microbial biomass, while the effects of temperature are indirect Projected warming and humidifying climates are expected to increase microbial biomass stocks in soilAbstract Soil microbial biomass (SMB) and stoichiometric ratios of carbon and nutrients in microorganisms are crucial to predict biogeochemical and nutrient cycling in terrestrial ecosystems, particularly under global change. Using SMB data from 1,288 studies in China, we mapped the distribution of microbial biomass carbon (MBC), nitrogen (MBN), and phosphorus (MBP) and their stoichiometric ratios using the random forest model. The stocks of MBC, MBN, and MBP in the topsoil (0–30 cm) were (mean with 25% and 75% quantiles), , and Tg, respectively; the corresponding stocks in the subsoil (30–100 cm) were Tg C, Tg N, and Tg P, respectively. The mean MBC/MBN, MBC/MBP, and MBN/MBP ratios in the topsoil were estimated to be 10, 29, and 3.9, respectively, and the corresponding ratios in the subsoil were 8.6, 19, and 2.5, respectively. Soil physico‐chemical properties (pH and moisture) are the main direct drivers of SMB and their stoichiometric ratios, while climate (temperature) indirectly affects SMB. Climate indirectly affects SMB by altering soil moisture and substrate availability, the physico‐chemical properties directly shape SMB content through habitat and resource constraints. The Coupled Model Intercomparison Project Phase 6 demonstrated that SMB stocks will increase until 2,100. Under the Shared Socioeconomic Pathway 5–8.5, SMB stocks increased, especially in the topsoil. Our study clarified SMB stocks and microbial stoichiometric ratios for soils up to 1.0 m depth and revealed the main drivers. We assessed SMB density and microbial stoichiometric ratios, compiled databases across climatic regions, and provided recommendations for regional C, N, and P management.Plain Language Summary Soil microbes are vital for nutrient cycling and climate regulation. By analyzing 1,200+ studies across China, we mapped microbial carbon (C), nitrogen (N), and phosphorus (P) stocks in soils down to 1 m. Topsoil (0–30 cm) holds 970 trillion grams (Tg) of microbial C, 150 Tg N, and 60 Tg P, while the depth of 30–100 cm stores 650 Tg C, 120 Tg N, and 65 Tg P. Microbial nutrient ratios decrease with depth: topsoil microbes have higher C/N (10:1) and C/P (29:1) ratios than subsoil microbes (8.6:1 and 19:1). Soil pH and moisture directly control microbial activity, while climate (e.g., temperature) indirectly affects it by altering moisture and food resources. Climate models predict rising microbial biomass by 2,100, especially in the topsoil under high emissions, which could accelerate nutrient turnover and CO 2 release into the atmosphere. These insights aid soil health management and climate strategies, emphasizing the hidden role of microbes in sustaining ecosystems and food security.Key Points For the first time, we synthesized soil microbial biomass density data at a depth of 0–100 cm across China Soil moisture and pH are the primary direct drivers of microbial biomass, while the effects of temperature are indirect Projected warming and humidifying climates are expected to increase microbial biomass stocks in soi
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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