scholarly journals Timing it right: The Measurement and Prediction of Flowering

2002 ◽  
pp. 17-22
Author(s):  
R. J. Summerfiled
Keyword(s):  
Photoperiod Sensitivity ◽  
Natural Environments ◽  
Considerable Evidence ◽  
Germplasm Collections ◽  
Physiological Stage ◽  
Wide Range ◽  
Flowering Behaviour ◽  
Controlled Environments ◽  
Biochemical Mechanisms ◽  
Temperature Responses

Although the model described here was developed from research in controlled environments, there is now considerable evidence that in can be applied to a very wide range of natural environments in several species. Multi-locational trials augmented by successional sowing and, if considered necessary, supplementary illumination in the field to increase daylength, can be used to estimate the values of the model coefficients: (1) to characterize germplasm collections and so predict flowering behaviour elsewhere; (2) for interpreting and understanding crop adaptation; and (3) for genetic analysis of photoperiod sensitivity. We do not yet know whether the model has any contribution to make to the understanding of the biochemical mechanisms of photoperiod and temperature responses, but at the very least, it should provide the basis for indicating the most appropriate environmental conditions, genotypes and physiological stage of the plants most suitable for such investigations.

scholarly journals Galactose metabolic genes in yeast respond to a ratio of galactose and glucose

2015 ◽  
Vol 112 (5) ◽  
pp. 1636-1641 ◽  
Author(s):  
Renan Escalante-Chong ◽  
Yonatan Savir ◽  
Sean M. Carroll ◽  
John B. Ingraham ◽  
Jue Wang ◽  
...  
Keyword(s):  
Classical Model ◽  
Nutrient Sensing ◽  
Natural Environments ◽  
Glucose Signaling ◽  
Glucose Levels ◽  
Metabolic Genes ◽  
Wide Range ◽  
Controlled Environments ◽  
Single Input ◽  
Gal Genes

Natural environments are filled with multiple, often competing, signals. In contrast, biological systems are often studied in “well-controlled” environments where only a single input is varied, potentially missing important interactions between signals. Catabolite repression of galactose by glucose is one of the best-studied eukaryotic signal integration systems. In this system, it is believed that galactose metabolic (GAL) genes are induced only when glucose levels drop below a threshold. In contrast, we show that GAL gene induction occurs at a constant external galactose:glucose ratio across a wide range of sugar concentrations. We systematically perturbed the components of the canonical galactose/glucose signaling pathways and found that these components do not account for ratio sensing. Instead we provide evidence that ratio sensing occurs upstream of the canonical signaling pathway and results from the competitive binding of the two sugars to hexose transporters. We show that a mutant that behaves as the classical model expects (i.e., cannot use galactose above a glucose threshold) has a fitness disadvantage compared with wild type. A number of common biological signaling motifs can give rise to ratio sensing, typically through negative interactions between opposing signaling molecules. We therefore suspect that this previously unidentified nutrient sensing paradigm may be common and overlooked in biology.

Novel Loci Control Variation in Reproductive Timing inArabidopsis thalianain Natural Environments

Genetics ◽  
2002 ◽  
Vol 162 (4) ◽  
pp. 1875-1884 ◽  
Author(s):  
Cynthia Weinig ◽  
Mark C Ungerer ◽  
Lisa A Dorn ◽  
Nolan C Kane ◽  
Yuko Toyonaga ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Allelic Variation ◽  
Developmental Pathways ◽  
Natural Environments ◽  
Reproductive Timing ◽  
Controlled Environments ◽  
Photoperiod Pathway ◽  
Differential Involvement ◽  
Short Days ◽  
Transition To Flowering

AbstractMolecular biologists are rapidly characterizing the genetic basis of flowering in model species such as Arabidopsis thaliana. However, it is not clear how the developmental pathways identified in controlled environments contribute to variation in reproductive timing in natural ecological settings. Here we report the first study of quantitative trait loci (QTL) for date of bolting (the transition from vegetative to reproductive growth) in A. thaliana in natural seasonal field environments and compare the results with those obtained under typical growth-chamber conditions. Two QTL specific to long days in the chamber were expressed only in spring-germinating cohorts in the field, and two loci specific to short days in the chamber were expressed only in fall-germinating cohorts, suggesting differential involvement of the photoperiod pathway in different seasonal environments. However, several other photoperiod-specific QTL with large effects in controlled conditions were undetectable in natural environments, indicating that expression of allelic variation at these loci was overridden by environmental factors specific to the field. Moreover, a substantial number of QTL with major effects on bolting date in one or more field environments were undetectable under controlled environment conditions. These novel loci suggest the involvement of additional genes in the transition to flowering under ecologically relevant conditions.

scholarly journals Breeding Strategies to Improve Miscanthus as a Sustainable Source of Biomass for Bioenergy and Biorenewable Products

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 673 ◽  
Author(s):  
John Clifton-Brown ◽  
Kai-Uwe Schwarz ◽  
Danny Awty-Carroll ◽  
Antonella Iurato ◽  
Heike Meyer ◽  
...  
Keyword(s):  
Significant Contribution ◽  
Perennial Grass ◽  
Time Frame ◽  
Eastern Asia ◽  
Germplasm Collections ◽  
Naturally Occurring ◽  
Wide Range ◽  
Yield Quality ◽  
Short Time ◽  
Commercial Expansion

Miscanthus, a C4 perennial grass native to Eastern Asia, is being bred to provide biomass for bioenergy and biorenewable products. Commercial expansion with the clonal hybrid M. × giganteus is limited by low multiplication rates, high establishment costs and drought sensitivity. These limitations can be overcome by breeding more resilient Miscanthus hybrids propagated by seed. Naturally occurring fast growing indigenous Miscanthus species are found in diverse environments across Eastern Asia. The natural diversity provides for plant breeders, the genetic resources to improve yield, quality, and resilience for a wide range of climates and adverse abiotic stresses. The challenge for Miscanthus breeding is to harness the diversity through selections of outstanding wild types, parents, and progenies over a short time frame to deploy hybrids that make a significant contribution to a world less dependent on fossil resources. Here are described the strategies taken by the Miscanthus breeding programme at Aberystwyth, UK and its partners. The programme built up one of the largest Miscanthus germplasm collections outside Asia. We describe the initial strategies to exploit the available genetic diversity to develop varieties. We illustrate the success of combining diverse Miscanthus germplasm and the selection criteria applied across different environments to identify promising hybrids and to develop these into commercial varieties. We discuss the potential for molecular selections to streamline the breeding process.

scholarly journals Real-time gaze estimation via pupil center tracking

2018 ◽  
Vol 9 (1) ◽  
pp. 6-18 ◽  
Author(s):  
Dario Cazzato ◽  
Fabio Dominio ◽  
Roberto Manduchi ◽  
Silvia M. Castro
Keyword(s):  
Real Time ◽  
Learning Algorithm ◽  
Natural Environments ◽  
Gaze Estimation ◽  
Head Pose ◽  
Data Set ◽  
Gaze Tracking ◽  
Illumination Changes ◽  
Wide Range ◽  
Estimation System

Abstract Automatic gaze estimation not based on commercial and expensive eye tracking hardware solutions can enable several applications in the fields of human computer interaction (HCI) and human behavior analysis. It is therefore not surprising that several related techniques and methods have been investigated in recent years. However, very few camera-based systems proposed in the literature are both real-time and robust. In this work, we propose a real-time user-calibration-free gaze estimation system that does not need person-dependent calibration, can deal with illumination changes and head pose variations, and can work with a wide range of distances from the camera. Our solution is based on a 3-D appearance-based method that processes the images from a built-in laptop camera. Real-time performance is obtained by combining head pose information with geometrical eye features to train a machine learning algorithm. Our method has been validated on a data set of images of users in natural environments, and shows promising results. The possibility of a real-time implementation, combined with the good quality of gaze tracking, make this system suitable for various HCI applications.

Bacterial extracellular polysaccharides

1988 ◽  
Vol 34 (4) ◽  
pp. 415-420 ◽  
Author(s):  
Chris Whitfield
Keyword(s):  
Pathogenic Bacteria ◽  
Structural Information ◽  
Extracellular Polysaccharides ◽  
Natural Environments ◽  
Chemical Structures ◽  
Technological Advances ◽  
Wide Range ◽  
Surface Polysaccharides ◽  
Surface Location ◽  
Commercial Applications

The synthesis of extracellular polysaccharides has been recognized in certain bacterial cultures since the 1880s. It is now apparent that a wide range of bacteria produce these polymers and an equally wide range of chemical structures are possible. Their surface location, together with the range of available monosaccharide combinations, noncarbohydrate substituents, and linkage types, make extracellular polysaccharides excellent agents of diversity. As a result, much effort has been directed towards elucidating their structure in pathogenic bacteria and in enteric organisms in particular. Commercial applications of microbial polysaccharides have now broadened the scope of structural information. Most recently, technological advances in molecular biology have created the possibility of manipulating desired polymer characteristics, and with these advances, our knowledge of the mechanisms of synthesis and regulation of cell surface polysaccharides has improved. Ultimately more information regarding the function of extracellular polysaccharides in natural environments may result.

Concluding Speculations

2019 ◽  
pp. 334-344
Author(s):  
Mari Riess Jones
Keyword(s):  
Natural Environments ◽  
Laboratory Studies ◽  
Control Stimulus ◽  
Wide Range ◽  
Stimulus Timing

This final chapter is speculative. It addresses the entrainment assumptions of universality and resonance by reviewing the natural environments of a range of different species, from crickets to whales. The idea is that sensitivity to both rate and rhythm across different species is support for assuming natural driving rhythms exist that facilitate entrainment in a wide range of other species. Also discussed are two artifactual environments experienced by humans: namely, that of laboratory studies that artificially control stimulus timing and the contemporary machine-driven environment of computers and iPhones. The latter are speculated to lead to a sporadic habitat based on fast irregular (artifactual) driving rhythms.

scholarly journals Optimization of Data Processing Minimizes Impact of Self-Absorption on Phosphorus Speciation Results by P K-Edge XANES

Soil Systems ◽  
2019 ◽  
Vol 3 (3) ◽  
pp. 61 ◽  
Author(s):  
Carlos ◽  
Francisco ◽  
Wedisson ◽  
Leonardus ◽  
Jörg ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Data Processing ◽  
Soil Sample ◽  
Soil Phosphorus ◽  
Fluorescence Yield ◽  
Natural Environments ◽  
Phosphorus Speciation ◽  
Soil P ◽  
Wide Range ◽  
Calcium Iron

Bulk soil phosphorus speciation by X-ray absorption spectroscopy (XAS) using fluorescence yield-mode measurements is an important tool for phosphorus research because of the low soil P contents. However, when measuring in fluorescence mode, increasing the concentration of the absorbing atom can dampen the XAS spectral features because of self-absorption and affect the linear combination (LC) fitting results. To reduce the self-absorption for samples of high P contents, thick boron nitride diluted samples are produced, yet the effects of self-absorption on P speciation results via LC fitting of P K-edge XANES spectroscopy, and the possible benefits of data processing optimization are unknown. Toward this end, we produced a series of ternary standard mixtures (calcium-iron-aluminum phosphates) and an example soil sample both diluted using boron nitride over a range from 1 to ~900 mmol kg−1 for the soil sample and up to ~6000 mmol kg−1 for the standard mixture. We show that by optimizing background subtraction and normalization values, consistent results with less than 10% error can be obtained for samples with up to 300 mmol kg−1 P. Our results highlight the applicability of optimized P K-edge XANES fitting across a wide range of concentrations encountered in natural environments.

Interactions between human behaviour and the built environment in terms of facility management

Facilities ◽  
2018 ◽  
Vol 36 (1/2) ◽  
pp. 2-12 ◽  
Author(s):  
Darja Kobal Grum
Keyword(s):  
Built Environment ◽  
Low Income ◽  
Well Being ◽  
Human Behaviour ◽  
Natural Environments ◽  
Psychological Well Being ◽  
Content Type ◽  
Sustainable Solutions ◽  
Wide Range ◽  
The Impact

Purpose In comparison with the relations between the human and natural environments that have been the central focus of environmental psychology for many years, the interactions between the psychological processes underlying human behaviour and the built environment have only recently regained the interest of researchers. In this paper, the author first discusses the reasons for the slower development of human – built environment relations. Afterwards, the author systematically examines the impact that the research of environmental stress, namely, poor housing and poor neighbourhood quality, had on the contemporary understanding of human – built environment relations. Design/methodology/approach The author focuses on social, biophilic and evidence-based design. The author proposes deeper psychological engagement in correlation with human behaviour, psychological well-being and society. The author highlights the inclusion of psychologists in interdisciplinary research teams addressing the development of sustainable solutions to the issues of residential environments. Findings It has been shown that substandard house quality, high noise, lack of natural light in houses, poorer physical quality of urban neighbourhoods, living in a low-income neighbourhood, etc. are linked to elevated physiological and psychological stress. Despite this evidence, there is still a gap between building designers and building users in modern industrialised societies, which could deepen tenants’ dissatisfaction due to specific behavioural needs and consequently lower their psychological well-being and health risk behaviour. Research limitations/implications These are potential risks of error arising from the use of assumptions, limited samples size and data from the secondary resources. Originality/value The major contributions of this paper are as follows. If the environment is understood as a dynamic, constantly changing and complex system of a wide range of players, the author can discern in this environment a dynamic that is otherwise characteristic of emotional dynamics. Expressed participants’ high satisfaction with residential status does not necessarily generate high expectations regarding real estate factors.

Situated Composition in Emerging Mobile Sound Production Technologies and Practices

2017 ◽  
Vol 22 (1) ◽  
pp. 73-82
Author(s):  
Samuel Thulin
Keyword(s):  
Mobile Devices ◽  
Sound Production ◽  
Ease Of Use ◽  
Mobile Interfaces ◽  
Wide Range ◽  
Controlled Environments ◽  
Production Technologies ◽  
Audio Production

This article introduces the concept of ‘situated composition’, examining it in relation to developments in mobile sound production technologies and practices. Situated composition draws attention to the specific circumstances in which sound production and compositional activity take place. With mobile devices and apps offering heightened mobility and ease-of-use, ways of working with sound increasingly may be undertaken in a wide range of contexts outside of controlled environments specifically designed for sound work such as studios. Situated composition emphasises the interconnections between the situation in which composition unfolds and the process of composition, approaching composition as inherently distributed and collaborative in multiple ways. This article begins by considering how to situate mobile audio production apps, then moves on to elaborate the concept of situated composition and investigate specific practices. Drawing primarily on interviews carried out with fourteen composers, sound artists, musicians and producers who use mobile devices and apps in their sound work, as well as on podcasts, forums and my own work as a sound artist, I identify seven approaches to using mobile interfaces, focusing particularly on practitioners’ relationships with the surroundings where compositional activity unfolds.

scholarly journals How drain flies manage to almost never get washed away

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nathan B. Speirs ◽  
Gauri A. Mahadik ◽  
Sigurdur T. Thoroddsen
Keyword(s):  
Fluid Dynamics ◽  
Behavioral Response ◽  
Natural Environments ◽  
Hierarchical Roughness ◽  
Wide Range ◽  
Over Time

Abstract Drain flies, Pshycoda spp. (Order Diptera, Family Psychodidae), commonly reside in our homes, annoying us in our bathrooms, kitchens, and laundry rooms. They like to stay near drains where they lay their eggs and feed on microorganisms and liquid carbohydrates found in the slime that builds up over time. Though they generally behave very sedately, they react quite quickly when threatened with water. A squirt from the sink induces them to fly away, seemingly unaffected, and flushing the toilet with flies inside does not necessarily whisk them down. We find that drain flies’ remarkable ability to evade such potentially lethal threats does not stem primarily from an evolved behavioral response, but rather from a unique hair covering with a hierarchical roughness. This covering, that has never been previously explored, imparts superhydrophobicity against large droplets and pools and antiwetting properties against micron-sized droplets and condensation. We examine how this hair covering equips them to take advantage of the relevant fluid dynamics and flee water threats in domestic and natural environments including: millimetric-sized droplets, mist, waves, and pools of water. Our findings elucidate drain flies’ astounding ability to cope with a wide range of water threats and almost never get washed down the drain.

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