scholarly journals Root Plasticity in the Pursuit of Water

Plants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 236 ◽  
Author(s):  
Hillel Fromm

One of the greatest challenges of terrestrial vegetation is to acquire water through soil-grown roots. Owing to the scarcity of high-quality water in the soil and the environment’s spatial heterogeneity and temporal variability, ranging from extreme flooding to drought, roots have evolutionarily acquired tremendous plasticity regarding their geometric arrangement of individual roots and their three-dimensional organization within the soil. Water deficiency has also become an increasing threat to agriculture and dryland ecosystems due to climate change. As a result, roots have become important targets for genetic selection and modification in an effort to improve crop resilience under water-limiting conditions. This review addresses root plasticity from different angles: Their structures and geometry in response to the environment, potential genetic control of root traits suitable for water-limiting conditions, and contemporary and future studies of the principles underlying root plasticity post-Darwin’s ‘root-brain’ hypothesis. Our increasing knowledge of different disciplines of plant sciences and agriculture should contribute to a sustainable management of natural and agricultural ecosystems for the future of mankind.

2018 ◽  
Author(s):  
Uri Korisky ◽  
Rony Hirschhorn ◽  
Liad Mudrik

Notice: a peer-reviewed version of this preprint has been published in Behavior Research Methods and is available freely at http://link.springer.com/article/10.3758/s13428-018-1162-0Continuous Flash Suppression (CFS) is a popular method for suppressing visual stimuli from awareness for relatively long periods. Thus far, it has only been used for suppressing two-dimensional images presented on-screen. We present a novel variant of CFS, termed ‘real-life CFS’, with which the actual immediate surroundings of an observer – including three-dimensional, real life objects – can be rendered unconscious. Real-life CFS uses augmented reality goggles to present subjects with CFS masks to their dominant eye, leaving their non-dominant eye exposed to the real world. In three experiments we demonstrate that real objects can indeed be suppressed from awareness using real-life CFS, and that duration suppression is comparable that obtained using the classic, on-screen CFS. We further provide an example for an experimental code, which can be modified for future studies using ‘real-life CFS’. This opens the gate for new questions in the study of consciousness and its functions.


2019 ◽  
Vol 24 (1) ◽  
pp. 43-54
Author(s):  
Shweta Sharma

The aim of this article is to provide a critical review of the theories and the model used in the field of geometry education research. The article critically discusses van Hiele’s theory, Fischbein’s theory of figural concepts, Duval’ s theory of figural apprehension, the Spatial Operational Capacity (SOC) model by Wessels and van Niekerk, and the Sfard’s commognition theory. The van Hiele’s theory proposed a sequential order of development through which the learners construct their understanding of geometry concepts. Fischbein’ s theory of figural concepts suggested that a geometric figure is always comprised of a visible representation and a concept. Duval’s theory of figural apprehension underscored the heuristic value of a geometry figure for solving geometry problems. The SOC model by Wessels and van Niekerk emphasised the importance of instructional design incorporating a variety of physical and mental objects to work with to develop geometry concepts. Finally, the article discusses Sfard’s commognition theory that emphasises the communicative function of language in developing geometry concepts. There are two major concerns highlighted with respect to these theories and the model. Firstly, these theories and model emphasise the development of the two-dimensional geometry concepts, neglecting the development of the concepts of three-dimensional geometry. Secondly, these theories and the model fail to acknowledge the multilingual context of geometry class. The article aims to highlight the dearth of studies that explore the multilingual context of geometry class and calls for future studies in this direction.  


Author(s):  
Johannes A. Postma ◽  
◽  
Christopher K. Black ◽  

Root architectural (RSA) models have become important tools in root research and plant phenotyping for studying root traits, processes, and interactions with the environment. The models have been used to simulate how various root traits and processes influence water and nutrient uptake. At a more technical level, they have been used to develop phenotyping technology, particularly for testing algorithms for segmenting roots. To compute these quantitative estimates regarding plant nutrition and root functioning, much development occurred in the last decade increasing the complexity of the models. This chapter describes first the application of the models to questions in plant biology, breeding, and agronomy, and second the development of the models. It concludes with a small outlook suggesting that models need benchmarking and validation and that new developments are likely to include better descriptions of root plasticity responses and focus on biological interactions among (soil) organisms, including mycorrhizal fungi.


2018 ◽  
Vol 5 (2) ◽  
pp. 171914 ◽  
Author(s):  
Axel H. Newton ◽  
Frantisek Spoutil ◽  
Jan Prochazka ◽  
Jay R. Black ◽  
Kathryn Medlock ◽  
...  

The Tasmanian tiger or thylacine ( Thylacinus cynocephalus ) was an iconic Australian marsupial predator that was hunted to extinction in the early 1900s. Despite sharing striking similarities with canids, they failed to evolve many of the specialized anatomical features that characterize carnivorous placental mammals. These evolutionary limitations are thought to arise from functional constraints associated with the marsupial mode of reproduction, in which otherwise highly altricial young use their well-developed forelimbs to climb to the pouch and mouth to suckle. Here we present the first three-dimensional digital developmental series of the thylacine throughout its pouch life using X-ray computed tomography on all known ethanol-preserved specimens. Based on detailed skeletal measurements, we refine the species growth curve to improve age estimates for the individuals. Comparison of allometric growth trends in the appendicular skeleton (fore- and hindlimbs) with that of other placental and marsupial mammals revealed that despite their unique adult morphologies, thylacines retained a generalized early marsupial ontogeny. Our approach also revealed mislabelled specimens that possessed large epipubic bones (vestigial in thylacine) and differing vertebral numbers. All of our generated CT models are publicly available, preserving their developmental morphology and providing a novel digital resource for future studies of this unique marsupial.


F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 1310 ◽  
Author(s):  
Steven W. Wingett ◽  
Philip Ewels ◽  
Mayra Furlan-Magaril ◽  
Takashi Nagano ◽  
Stefan Schoenfelder ◽  
...  

HiCUP is a pipeline for processing sequence data generated by Hi-C and Capture Hi-C (CHi-C) experiments, which are techniques used to investigate three-dimensional genomic organisation. The pipeline maps data to a specified reference genome and removes artefacts that would otherwise hinder subsequent analysis. HiCUP also produces an easy-to-interpret yet detailed quality control (QC) report that assists in refining experimental protocols for future studies. The software is freely available and has already been used for processing Hi-C and CHi-C data in several recently published peer-reviewed studies.


10.28945/4660 ◽  
2020 ◽  
Vol 19 ◽  
pp. 855-889
Author(s):  
Reza Ghanbarzadeh ◽  
Amir Hossein Ghapanchi

Aim/Purpose: The purpose of this study was to examine the impact of five factors on the user acceptance of Three-Dimensional Virtual Worlds (3DVWs) in higher education. Another objective of the study was to investigate the effects of the application of 3DVWs on five variables relevant to positive outcomes for higher education students. Background: Three-Dimensional Virtual Worlds (3DVW) are of considerable importance and potential for the creation of the next generation of teaching and learning environments. There has been a remarkable interest in the educational communities in applying virtual environments for teaching and learning, and this technology has been largely adopted to favour educational settings. With the increasing development of 3DVW technologies in the education sector, two uncertainties have emerged with respect to higher education that significantly influence the applicability of the technology in the field: user acceptance of the technology and educational benefits of the technology for both individuals and institutions. Thus, this study examined the relationship between various factors and the user acceptance of 3DVWs in higher education as well as the relationship between the application of 3DVWs in higher education and positive educational outcomes. Methodology: By conducting a quantitative study, an extensive research model was developed by which 21 hypotheses were examined to assess the relationships between 12 variables. In order to evaluate the hypotheses, an online survey with 32 questions was developed and distributed among the participants. The questionnaire was developed to analyse the relationship between independent and dependent constructs of the research model. By applying a purposive convenience sampling technique, 135 undergraduate students, who were enrolled in a first-year elective course, participated in the survey. The PLS-SEM method was used to analyse the relationships between variables based on the hypothesised hypotheses. Second Life was used as the primary 3DVW environment for the research experiment in this study. Contribution: This study is among the first to conduct a quantitative method by developing an extensive research model to examine both antecedents and consequences of the application of 3DVWs in higher education. The research model exam-ined several self-developed variables relevant to the antecedents and conse-quences of user acceptance of 3DVWs those had not been defined or exam-ined previously in this field. The study takes 3DVW engagement into account, which is a variable associated with not only use, but also with continuous use of the technology, and deeper involvement with the technology. This study contributes to the research and practitioner body of knowledge by introduc-ing various factors significant in preparing a distance learning environment and activities that can be adapted in higher education. Findings: The findings suggest the effectiveness of ease of use, usefulness, enjoyment, and visual attractiveness of a 3DVW-based learning environment on user acceptance of the technology. Findings also suggest that application of 3DVWs has a significant impact on student satisfaction, learning outcome, retention, course engagement, and students’ graduate outcome. The study confirms that computer self-efficacy of higher education students does not have a positive impact on the acceptance of 3DVWs. Recommendations for Practitioners: Curriculum designers and developers should consider designing easy-to-use and user-friendly virtual learning environments and should make aesthetic design decisions to create appealing learning environments to attract students’ attention. A 3DVW-based learning environment needs to be realistic to make students experience a sense of presence within the environment. Increased enjoyment, pleasure, and playfulness of the virtual learning environment contribute to a higher level of adoption of 3DVWs among students. For the higher education institutions, the costs of developing and maintaining a virtual learning environment and implementing a teaching and learning programme are very low in comparison with a traditional face-to-face education system. This technology provides great capabilities for collaboration, teamwork, and networking on a worldwide scale. Recommendation for Researchers: Further studies are required to investigate from different perspectives the various factors impacting on user acceptance and/or positive outcomes of user acceptance of the technology. Using the technology for different courses, implementing different teaching and learning methods, and developing creative activities in the virtual environment might contribute to new findings in the field. This study could be extended by applying the technology in educational settings other than higher education, such as K–12. New studies could also explore other aspects of 3DVWs which were not part of the case study, such as the implementation of the technology on virtual reality, augmented reality, and smartphones. Impact on Society: The study would be beneficial for higher education institutions worldwide to regulate the key factors that affect students’ entrancement of 3DVWs as well as the positive outcomes of user acceptance of this cutting-edge technology for students. Future Research: This study could be a starting point for future research focusing on various aspects of the application of 3DVW technology in education. Future studies could identify and investigate other variables that are associated with user acceptance of 3DVW in education as well as the positive outcomes of the application of the technology in this field. The four new variables presented in this study can also be examined in different contexts and/or with the application of various technologies. There have been some inconsistencies between the findings of the current study and some of the previous studies in the field. Future studies can investigate inconsistent relationships much more meticulously in a similar context. Future studies could also explore other aspects of 3DVWs which were not part of the case study.


2014 ◽  
Author(s):  
Kyle P Chadwick ◽  
Sophie Regnault ◽  
Vivian Allen ◽  
John R. Hutchinson

The three-dimensional anatomy of the ostrich (Struthio camelus) knee (femorotibial, femorofibular, and femoropatellar) joint has scarcely been studied, and could elucidate certain mechanobiological properties of sesamoid bones. The adult ostrich is unique in that it has double patellae, while another similar ratite bird, the emu, has none. Understanding why these patellae form and what purpose they may serve is dually important for future studies on ratites as well as understanding mechanobiological characteristics of sesamoid bone development. For this purpose, we present a three-dimensional anatomical study of the ostrich knee joint, detailing osteology, ligaments and menisci, and myology. We have identified seven muscles which connect to the two patellae and compare our findings to past descriptions. These descriptions can be used to further study the biomechanical loading and implications of the double patella in the ostrich.


2014 ◽  
Author(s):  
Kyle P Chadwick ◽  
Sophie Regnault ◽  
Vivian Allen ◽  
John R. Hutchinson

The three-dimensional anatomy of the ostrich (Struthio camelus) knee (femorotibial, femorofibular, and femoropatellar) joint has scarcely been studied, and could elucidate certain mechanobiological properties of sesamoid bones. The adult ostrich is unique in that it has double patellae, while another similar ratite bird, the emu, has none. Understanding why these patellae form and what purpose they may serve is dually important for future studies on ratites as well as understanding mechanobiological characteristics of sesamoid bone development. For this purpose, we present a three-dimensional anatomical study of the ostrich knee joint, detailing osteology, ligaments and menisci, and myology. We have identified seven muscles which connect to the two patellae and compare our findings to past descriptions. These descriptions can be used to further study the biomechanical loading and implications of the double patella in the ostrich.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tianyu Cui ◽  
Veena Chattaraman ◽  
Lushan Sun

PurposeThis study adopted the functional, expressive and aesthetic (FEA) consumer needs model, aimed to examine the influence of consumers' FEA perceptions of three-dimensional printing (3DP) integrated apparel products on their product satisfaction and purchase intention.Design/methodology/approachAn online survey was employed with a sample of 332 participants (165 female and 167 male) aged 19 to 76, mean age of 35 years. A gender-neutral, 3DP integrated hooded sweatshirt was developed for this study featuring flexible, white 3D printed insets fabricated with an FDM 3D printer and white TPU filament sewn with traditional gray knit fleece.FindingsThe findings of this study suggest that the FEA model is appropriate in predicting consumers' satisfaction with 3DP integrated apparel products. Specifically, aesthetic (perceived beauty) and expressive (perceived coolness) dimensions are more influential than functional factors, except for the positive influence of perceived fit, in predicting consumers' satisfaction and purchase intentions for 3DP integrated apparel products.Research limitations/implicationsFuture studies could consider data collection from participants' physical fit testing or try on evaluation to determine the importance of the functional dimension in consumer response to 3DP integrated apparel product. Future studies could also examine full 3D printed apparel, or other 3DP integrated wearable products to expand the understanding of consumer perception of the application of 3DP technology.Originality/valueDespite the increasing exploration of 3DP integrated apparel products and industry attempts to make this innovation in apparel more mainstream, research on how mainstream consumers perceive such 3DP integrated apparel products is limited. This study addresses this gap, providing critical implications for future research and design.


Author(s):  
M. Ryan Chipley ◽  
Todd Barlow

Executive dashboards have become popular in enterprise software applications. Consequently, much advice has been offered by private consulting firms on how best to design dashboards. This paper details a couple of studies testing the advice given by the dashboard experts. The results suggest that some of the notions about how dashboard widgets should be designed might be incorrect. The results indicate that colored widgets are not necessarily inferior to simpler, colorless widgets. Similarly, fancy widgets (i.e., those with three dimensional characteristics) were not demonstrated to be inferior to plainer widgets. While some methodological challenges must be overcome in similar future studies, the results of the described studies do not support some popular ideas about executive dashboards (and data visualization in general), and suggest that the area of interest is ripe for further investigation.


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