1,721,099 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
European soybean to benefit people and the environment
Full text linkEurope imports large amounts of soybean that are predominantly used for livestock feed, mainly sourced from Brazil, USA and Argentina. In addition, the demand for GM-free soybean for human consumption is project to increase. Soybean has higher protein quality and digestibility than other legumes, along with high concentrations of isoflavones, phytosterols and minerals that enhance the nutritional value as a human food ingredient. Here, we examine the potential to increase soybean production across Europe for livestock feed and direct human consumption, and review possible effects on the environment and human health. Simulations and field data indicate rainfed soybean yields of 3.1 +/- 1.2 t ha-1 from southern UK through to southern Europe (compared to a 3.5 t ha-1 average from North America). Drought-prone southern regions and cooler northern regions require breeding to incorporate stress-tolerance traits. Literature synthesized in this work evidenced soybean properties important to human nutrition, health, and traits related to food processing compared to alternative protein sources. While acknowledging the uncertainties inherent in any modelling exercise, our findings suggest that further integrating soybean into European agriculture could reduce GHG emissions by 37-291 Mt CO2e year-1 and fertiliser N use by 0.6-1.2 Mt year-1, concurrently improving human health and nutrition
Linking the Topics "Climate Change and Nutrition" by Discussing Sustainability in Chemistry Lessons at School
Full text linkAgricultural production in Europe is intensive, highly specialized, and responsible for some negative environmental impacts related to climate change and loss of biodiversity, raising questions about the sustainability of farming and the wider food system. The integration of legumes into agricultural systems could contribute to the transition to more sustainable food production and consumption. For example, for the production of 100 g of protein in beef, 49.89 kg of CO2 is emitted, whereas for 100 g of protein in pulses, it is only 0.84 kg. While the general benefits from legume cultivation and consumption are widely known in the scientific community, there is little evidence on how to inform next generations. Therefore, in this paper, the development of materials for discussing sustainability in chemistry lessons at school using a guided inquiry approach is described and discussed. Chickpea and lupin were identified as two contrasting legume species that allowed exploring the role of established and novel crops as an example in Germany. Chemistry experiments related to nutrition were further developed, using canned chickpeas and lupin yoghurt as examples for plant-based food products. All materials were made available using an interaction box to ensure that the students can plan their own learning process individually. After finishing the work with the box, the students can use their results for a discussion
Spatial arrangement of intercropping impacts natural enemy abundance and aphid predation in an intensive farming system
Full text linkCrop diversification is an increasingly recognized management strategy to support biodiversity and ecosystem services, like pest and disease control, in agricultural systems. However, a significant obstacle to its adoption is the potential trade-off between ecosystem services and optimizing yields. We used a two year, on-farm study in Eastern Germany to test how different spatial arrangements of soy (Glycine max L.) and winter wheat (Triticum aestivum L.) can affect pest abundance, aphid predation, and natural enemy biodiversity as well as yields. We compared conventional sole cropping to three types of spatially diversified cropping systems: relay intercropping, wide strip cropping, and patch cropping. Strip cropping generally supported some of the highest levels of carabid abundance both years and spider abundance in 2022 without any yield penalties. While the relay system failed due to insufficient precipitation, strip cropping produced similar or higher yields than sole cropping (124 % and 96 % of the sole wheat yield and 96 % and 109 % of sole soy yield in 2022 and 2023, respectively). Strip cropping supported significantly more carabid beetles compared to sole cropped soy both years and sole cropped wheat in 2022. We found significantly different carabid community composition between wheat strips and patches and the corresponding soy strips and patches. There were no differences in aphid abundance between systems. Nevertheless, we found 51 % and 36 % higher aphid predation rates in wheat strips compared to wheat patches in 2022 and 2023. Our results provide initial insights into the potential of strip cropping to support both natural enemies and yields while also being an approachable diversification strategy for farmers
Faba bean introduction makes protein production less dependent on nitrogen fertilization in Mediterranean no-till systems
Full text linkContext: Under Mediterranean rainfed areas, no-till cereal-based systems have been adopted to cope with water availability and increasing input costs. However, the increased risk of biotic stresses, high N-fertilizer dependence, and current EU policies warrant cropping systems re-design. Objective: Evaluate diversification and N fertilization as strategies to improve N use efficiency at the cropping system level and quantify its productivity. Methods: Four crop sequences combined with four levels of N fertilization were assessed in a three-year field experiment in semiarid rainfed north-eastern Spain. Crop sequences were continuous winter wheat (WCS) and three-year diversified rotations with pea (PCS), faba bean (FCS), or a multi-service cover crop (MSCS) and two years of cereals. Crop, pre-crop and cropping system levels were considered. Agronomic evaluation included crops above-ground biological N fixation (Ndfa), net N balance (Ndfa minus N removed by grain), soil N mineralisation productivity, energy to N tradeoff (ENT), and N use efficiency of protein (NUEp) production. Results: Pea yields ranged from 0 to 766 kg ha-1 and Ndfa from 24% to 54%. Faba bean yield ranged from 1378 to 4251 kg ha-1 and Ndfa from 32% to 72%. Net N balance was close to neutral for pea while in faba bean it ranged from 41 to -21 kg N ha-1. Alternative pre-crops led to greater soil N mineralisation (51 kg N ha-1, on average) and higher wheat yield (564 kg ha-1, on average) compared to wheat as the pre-crop. N fertilization increased protein yields, with FCS presenting the highest yields at all N fertilizer rates. This effect led to a stable NUEp (1.69 kg protein kg N supply-1), as the protein yield increased proportionally to N supply. Conclusions: Diversification improved the succeeding wheat performance and grain legumes N fixation exceeded grain N removal. Introducing legumes into cropping systems led to a decrease in energy productivity compared to the cereal-based system. However, protein production in the FCS was higher than in any other cropping system regardless of the N fertilizer rate. Implications or significance: Crop diversification adds challenges and risks in dry Mediterranean areas. However, the study shows that crop diversification with faba bean can decrease cropping system's N-fertilizer dependence and increase protein productivity, contributing to cropping systems' sustainability
Winter wheat-soybean relay intercropping in conjunction with a shift in sowing dates as a climate change adaptation and mitigation strategy for crop production in Germany
Full text linkContext: Given the negative impacts of climate change on crop production, it is vital to implement efficient adaptation and mitigation strategies. The diversification of cropping systems, particularly through intercropping combined with shifts in sowing times, could have the potential to offset such negative impacts. Yet, both experimental data and simulation studies are scarce to elucidate the intercropping performance under future climate change conditions, particularly for evaluating its potential to offset climate impacts on crop and protein yields in German wheat-based systems. Objective: This study aimed to simulate the grain yield and grain protein performance of winter wheat-soybean relay-row intercropping across Germany under future climate conditions, comparing it to sole cropping systems. Methods: We employed the MONICA agroecosystem model and its intercropping module to simulate the performance of an innovative winter wheat-soybean relay intercropping system. This was in combination with a wide range of shifts in sowing dates, and we compared it against standard sole cropping under low and high emission scenarios across Germany. Results: The model projected a 15% higher sole wheat yield under the future (2031-2060) high emission scenario than that of the historical period (1981-2020), while sole soybean yield increased by 8% in the same case. Although the simulation of winter wheat-soybean relay intercropping across Germany indicated a 9 % yield penalty compared to sole cropping in the future, with a transgressive overyielding index of 0.91, intercropping emerged as particularly advantageous in terms of land-use efficiency and protein production. It saved 17 % of land compared to sole cropping, thus produced equal amounts of grain yield, and produced 16% more protein than sole cropping in the high emission scenario. On top of that, shifting the sowing dates of the component crops to earlier times was found to substantially enhance the advantages of intercropping, resulting in a maximum of 44 % higher total yield production, and 47 % higher protein production than sole wheat without shifting sowing date in the future projection window. Conclusion: Our findings highlight the grain yield and protein production potential of intercropping versus sole cropping under futuristic high emission scenarios (RCP 8.5), and underscoring its potential to create a win-win situation of increased crop diversity and productivity. The results affirm the crucial importance of selecting optimal sowing dates for the component crops in intercropping, to maximize production and ensure resilience in the face of a changing climate
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