1,721,025 research outputs found
The effects of a neighbour and its identity on roots’ plastic growth
Full text linkPlant responses to the presence of neighbours and social interactions between them have the potential to alter fundamental aspects of plants' evolution, persistence, and coexistence. The present study employs a novel approach to investigate the three-dimensional movement of root tips in response to a neighbouring plant of the same or different species. We collected data from maize and pea plants in three experimental conditions: (i) individual condition, in which plants grew without neighbours; (ii) social growing condition with a conspecific neighbour, in which plants grew in the presence of another plant of the same species; and (iii) social growing with a heterospecific neighbour, in which plants grew in the presence of another plant of a different species. The results indicate that roots display a more pronounced 'exploratory' behaviour when growing under social conditions. For both maize and pea plants, a higher incidence of aggregative behaviour (primary root moving towards the neighbour) was observed when plants grew near a conspecific when compared with an heterospecific neighbour. According to our analyses, roots showing aggregative behaviour seem to detect the neighbouring root with a good level of geometrical precision as shown by the observed directional movement. We contend that this study provides for the first time quantitative information on the modulation of kinematic and oscillatory features of root movements, which are vital for a deeper understanding of plants' below-ground interactions
Asymmetrical distribution of supports affect pea plants movement and shape: Evidence of quantity discrimination?
Full text linkThe ability to discriminate more items from fewer items is an adaptive and innate cognitive feature of animals. Here, we found that this same capability is present in the plant kingdom. Pisum Sativum L. plants grew in the presence of supports that were distributed either equally (2 vs. 2; i.e., ED) or unequally (1 vs. 3; i.e., UD) on each side of a pot. Results showed that pea plants were able to sense the distribution of items in the environment, and to modulate the morphology and the kinematics of their tendrils on the basis of the support distribution. These findings indicate that processes such as quantity discrimination are present in plants, and are not restricted to the animal kingdom
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
‐19 vaccination willingness amongst healthcare students and professionals: Reveals generational patterns
Full text linkAims
To determine coronavirus disease 2019 (COVID-19) vaccination hesitancy in healthcare professionals and healthcare students in Italy across four generations (baby boomers, generations X, Y and Z).
Design
A cross-sectional descriptive study was performed through an online survey conducted from May to June 2021. The STROBE guidelines were adopted for reporting.
Methods
Data were collected by initially sending a survey link to a convenience sample of healthcare professionals and students, which was followed by snowball sampling. The VAX scale was validated and adopted. An ANOVA was performed to detect differences in vaccine-hesitancy beliefs between the four generational groups.
Results
The survey was completed by 1226 healthcare professionals and students. Worries about unforeseen future effects accounted for the higher vaccination hesitancy factor across generations. More positive attitudes towards COVID-19 vaccination were expressed by members of generation Z than by members of generation Y and baby boomers. Members of generation X had the highest vaccination hesitancy scores in the overall scale.
Conclusion
The results suggest that public health campaigns should take into account the generational differences in COVID-19 vaccination hesitancy to achieve higher levels of vaccine acceptance, including amongst healthcare professionals and students.
Impact
Vaccination is the most effective strategy to tackle the COVID-19 pandemic. The advice of health professionals strongly influences vaccination willingness in the general population. A consideration of the generational patterns in the COVID-19 vaccination hesitancy of healthcare workers and students may increase vaccination uptake in these populations, which in turn may lead to greater public acceptance of the vaccine
A system for the study of roots 3D kinematics in hydroponic culture: a study on the oscillatory features of root tip
Full text linkBackground. The root of a plant is a fundamental organ for the multisensory perception of the environment. Investigating root growth dynamics as a mean of their interaction with the environment is of key importance for improving knowledge in plant behaviour, plant biology and agriculture. To date, it is difficult to study roots movements from a dynamic perspective given that available technologies for root imaging focus mostly on static characterizations, lacking temporal and three-dimensional (3D) spatial information. This paper describes a new system based on time-lapse for the 3D reconstruction and analysis of roots growing in hydroponics.
Results. The system is based on infrared stereo-cameras acquiring time-lapse images of the roots for 3D reconstruction. The acquisition protocol guarantees the root growth in complete dark while the upper part of the plant grows in normal light conditions. The system extracts the 3D trajectory of the root tip and a set of descriptive features in both the temporal and frequency domains. The system has been used on Zea mays L. (B73) during the first week of growth and shows good inter-reliability between operators with an Intra Class Correlation Coefficient (ICC) > 0.9 for all features extracted. It also showed measurement accuracy with a median difference of < 1 mm between computed and manually measured root length.
Conclusions. The system and the protocol presented in this study enable accurate 3D analysis of primary root growth in hydroponics. It can serve as a valuable tool for analysing real-time root responses to environmental stimuli thus improving knowledge on the processes contributing to roots physiological and phenotypic plasticity
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
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