Formation of misaligned second-generation discs through fly-by encounters

Observations reveal protoplanetary discs being perturbed by fly-by candidates. We simulate a scenario where an unbound perturber, i.e. a fly-by, undergoes an inclined grazing encounter, capturing material and forming a second-generation protoplanetary disc. We run N-body and three-dimensional hydrodynamical simulations of a parabolic fly-by grazing a particle disc and a gas-rich protoplanetary disc, respectively. In both our N-body and hydrodynamic simulations, we find that the captured, second-generation disc forms at a tilt twice the initial fly-by tilt. This relationship is robust to variations in the fly-by’s tilt, position angle, periastron, and mass. We extend this concept by also simulating the case where the fly-by has a disc of material prior to the encounter but we do not find the same trend. An inclined disc with respect to the primary disc around a misaligned fly-by is tilted by a few degrees, remaining close to its initial disc tilt. Therefore, if a disc is present around the fly-by before the encounter, the disc may not tilt up to twice the perturber tilt depending on the balance between the angular momentum of the circumsecondary disc and captured particles. In the case where the perturber has no initial disc, analysing the orientation of these second-generation discs can give information about the orbital properties of the fly-by encounter

Adaptive fertigation system using hybrid vision-based lettuce phenotyping and fuzzy logic valve controller towards sustainable aquaponics

Sustainability is a major challenge in any plant factory, particularly those involving precision agriculture. In this study, an adaptive fertigation system in a three-tier nutrient film technique aquaponic system was developed using a non-destructive vision-based lettuce phenotype (VIPHLET) model integrated with an 18-rule Mamdani fuzzy inference system for nutrient valve control. Four lettuce phenes, that is, fresh weight, chlorophylls a and b, and vitamin C concentrations as outputted by the genetic programming-based VIPHLET model were optimized for each growth stage by injecting NPK nutrients into the mixing tank, as determined based on leaf canopy signatures. This novel adaptive fertigation system resulted in higher nutrient use efficiency (99.678%) and lower chemical waste emission (14.108 mg L-1) than that by manual fertigation (92.468%, 178.88 mg L-1). Overall, it can improve agricultural malpractices in relation to sustainable agriculture. © Fuji Technology Press Ltd.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines—2016 revision

Background: Allergic rhinitis (AR) affects 10% to 40% of the population. It reduces quality of life and school and work performance and is a frequent reason for office visits in general practice. Medical costs are large, but avoidable costs associated with lost work productivity are even larger than those incurred by asthma. New evidence has accumulated since the last revision of the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines in 2010, prompting its update. Objective: We sought to provide a targeted update of the ARIA guidelines. Methods: The ARIA guideline panel identified new clinical questions and selected questions requiring an update. We performed systematic reviews of health effects and the evidence about patients’ values and preferences and resource requirements (up to June 2016). We followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) evidence-to-decision frameworks to develop recommendations. Results: The 2016 revision of the ARIA guidelines provides both updated and new recommendations about the pharmacologic treatment of AR. Specifically, it addresses the relative merits of using oral H1-antihistamines, intranasal H1-antihistamines, intranasal corticosteroids, and leukotriene receptor antagonists either alone or in combination. The ARIA guideline panel provides specific recommendations for the choice of treatment and the rationale for the choice and discusses specific considerations that clinicians and patients might want to review to choose the management most appropriate for an individual patient. Conclusions: Appropriate treatment of AR might improve patients’ quality of life and school and work productivity. ARIA recommendations support patients, their caregivers, and health care providers in choosing the optimal treatment. © 2017 American Academy of Allergy, Asthma & Immunolog