Risk-management of UAS robust autonomy for integration into civil aviation safety frameworks

This paper discusses a model of the civil aviation reg-ulation framework and shows how the current assess-ment of reliability and risk for piloted aircraft has a limited applicability for Unmanned Aircraft Systems (UAS) as technology moves towards higher levels of autonomous decision making. Then, a new frame-work for risk management of robust autonomy is pro-posed, which arises from combining quantified mea-sures of risk with normative decision making. The term Robust Autonomy describes the ability of an au-tonomous system to either continue or abort its oper-ation whilst not breaching a minimum level of accept-able safety in the presence of anomalous conditions. The term combines reliability, safety, and robust-ness. The decision making associated with risk man-agement requires quantifying probabilities associated with the measures of risk and also consequences of outcomes related to the behaviour of autonomy. The probabilities are computed from an assessment under both nominal and anomalous scenarios described by faults, which can be associated with the aircraft's ac-tuators, sensors, communication link, changes in dy-namics, and the presence of other aircraft in the op-erational space. The consequences of outcomes are characterised by a loss function quantifies the desir-ability of the outcome

A review of the concept of autonomy in the context of the safety regulation of civil unmanned aircraft systems.

Civil aviation safety regulations and guidance mate- rial classify Unmanned Aircraft Systems (UAS) as ei- ther Remotely-Piloted Aircraft Systems (RPAS) or Autonomous Aircraft Systems (AAS). This distinc- tion is based on the premise that the e ective safety risk management of UAS is dependent on the degree of autonomy of the system being operated. However, it is found that there is no consensus on the concept of autonomy, on how it can be measured, or on the na- ture of the relationship between Levels of Autonomy (LoA) and the safety-performance of UAS operations. An objective of this paper is to evaluate existing LoA assessment frameworks for application in avia- tion safety regulations for UAS. The results from a comprehensive review of existing concepts of auton- omy and frameworks for assessing LoA are presented. Six case study UAS were classi ed using the pub- lished LoA frameworks. The implied LoA of UAS for existing modes of operation (e.g., teleoperation, semi- autonomous) were also assessed using the published frameworks. It was found that the existing LoA assessment frameworks, when applied to the case study UAS, do not provide a consistent basis for distinguishing between the regulatory classes of RPAS and AAS. It was also found that the existing regulatory de ni- tion of an autonomous aircraft is too broad, covering UAS of signi cantly di erent levels of capability and system complexity. Within the context of aviation safety regulations, a new LoA assessment framework for UAS is required

ALARP and the risk management of civil unmanned aircraft systems

Key to the continued growth of the civil Unmanned Aircraft System (UAS) aviation sector is the devel- opment of a regulatory framework that will provide assurances in the management of the risks associated with their operation. Decisions in relation the evalu- ation and treatment of aviation risks need to be made in accordance with the As Low As Reasonably Prac- ticable (ALARP) framework. There are a number of concerns in relation to the application of the ALARP framework to new technologies. This paper explores these concerns with respect to the risk management of civil UAS. A review of the ALARP frameworks de ned by the International Civil Aviation Organization (ICAO), the Civil Aviation Safety Authority (Australia), the Civil Aviation Authority (United Kingdom) and by the UK Health and Safety Executive is presented. This review identi ed subtle di erences that can have a signi cant impact on how ALARP frameworks would be applied to UAS. A number of inconsistencies in the frameworks were also identi ed. These issues aside, it was found that a conceptual application of an ALARP framework can be made. However, sig- ni cant diculties were identi ed in the substantia- tion of a framework. In particular, the quanti cation of the decision criteria for UAS, the handling of un- certainty, and the identi cation, characterisation and representation of societal concerns within a frame- work. Guidance as to how the dimensions of societal concern and levels of risk can be jointly considered within an ALARP framework could not be identi ed within the literature. For new technologies such asUAS, these dimensions can be as signi cant a factor in decision-making as that of the quanti ed measures of the risk. Due to these de ciencies, there are signif- icant diculties in the application and substantiation of an ALARP framework to the risk management of new technologies such as UAS

Hydraulic Relations and Water Use of Mediterranean Ornamental Shrubs in Containers

A detailed, species-specific comprehension of plant water behavior can be a central tool to improve water management in nursery production and irrigated landscapes. Potted plants of Nerium oleander, Pittosporum tobira, and Ligustrum japonicum 'Texanum' were exposed to controlled increasing drought conditions in greenhouse. Water use, gas exchange, and foliar thermoregulation were monitored along the trial. N. oleander showed the most efficient response to increasing water stress, maintaining high levels of gas exchange and evapotranspiration rate during the whole trial, whereas L. japonicum emerged as the most sensitive species, with a significant drop in physiological performances already from the second day. The more aggressive water behavior of N. oleander can be compared to the one of anisohydric plants, whereas L. japonicum displays an isohydric strategy. P. tobira showed intermediate characteristics between the two other species. This work comes to provide useful tools for the management of irrigation in plant nursery and for decision making in the use of ornamental shrubs for landscape applications

Estimation of tulathromycin depletion in plasma and milk after subcutaneous injection in lactating goats using a nonlinear mixed-effects pharmacokinetic modeling approach

Citation: Lin, Z. M., Cuneo, M., Rowe, J. D., Li, M. J., Tell, L. A., Allison, S., . . . Gehring, R. (2016). Estimation of tulathromycin depletion in plasma and milk after subcutaneous injection in lactating goats using a nonlinear mixed-effects pharmacokinetic modeling approach. Bmc Veterinary Research, 12, 10. https://doi.org/10.1186/s12917-016-0884-4Background: Extra-label use of tulathromycin in lactating goats is common and may cause violative residues in milk. The objective of this study was to develop a nonlinear mixed-effects pharmacokinetic (NLME-PK) model to estimate tulathromycin depletion in plasma and milk of lactating goats. Eight lactating goats received two subcutaneous injections of 2.5 mg/kg tulathromycin 7 days apart; blood and milk samples were analyzed for concentrations of tulathromycin and the common fragment of tulathromycin (i.e., the marker residue CP-60,300), respectively, using liquid chromatography mass spectrometry. Based on these new data and related literature data, a NLME-PK compartmental model with first-order absorption and elimination was used to model plasma concentrations and cumulative excreted amount in milk. Monte Carlo simulations with 100 replicates were performed to predict the time when the upper limit of the 95% confidence interval of milk concentrations was below the tolerance. Results: All animals were healthy throughout the study with normal appetite and milk production levels, and with mild-moderate injection-site reactions that diminished by the end of the study. The measured data showed that milk concentrations of the marker residue of tulathromycin were below the limit of detection (LOD = 1.8 ng/ml) 39 days after the second injection. A 2-compartment model with milk as an excretory compartment best described tulathromycin plasma and CP-60,300 milk pharmacokinetic data. The model-predicted data correlated with the measured data very well. The NLME-PK model estimated that tulathromycin plasma concentrations were below LOD (1.2 ng/ml) 43 days after a single injection, and 62 days after the second injection with a 95% confidence. These estimated times are much longer than the current meat withdrawal time recommendation of 18 days for tulathromycin in non-lactating cattle. Conclusions: The results suggest that twice subcutaneous injections of 2.5 mg/kg tulathromycin are a clinically safe extra-label alternative approach for treating pulmonary infections in lactating goats, but a prolonged withdrawal time of at least 39 days after the second injection should be considered to prevent violative residues in milk and any dairy goat being used for meat should have an extended meat withdrawal time

Copper induces Cu-ATPase ATP7A mRNA in a fish cell line, SAF1

Copper transporting ATPase, ATP7A, is an ATP dependent copper pump present in all vertebrates, critical for the maintenance of intracellular and whole body copper homeostasis. Effects of copper treatment on ATP7A gene expression in fibroblast cells (SAF1) of the sea bream (Sparus aurata) were investigated by qRT-PCR and by a medium density microarray from a closely related species, striped sea bream (Lithognathus mormyrus). To discriminate between the effects of Cu and other metals, SAF1 cells were exposed to sub-toxic levels of Cu, Zn and Cd. Expression of Cu homeostasis genes copper transporter 1 (CTR1), Cu ATPase (ATP7A), Cu chaperone (ATOX1) and metallothionein (MT) together with the oxidative stress markers glutathione reductase (GR) and Cu/Zn superoxide dismutase (CuZn/SOD) were measured 0, 4 and 24 hours post-exposure by qRT-PCR. Microarray was conducted on samples from 4 hours post Cu exposure. Cu, Zn and Cd increased MT and GR mRNA levels, while only Cu increased ATP7A mRNA levels. Microarray results confirmed the effects of Cu on ATP7A and MT and in addition showed changes in the expression of genes involved in protein transport and secretion. Results suggest that ATP7A may be regulated at the transcriptional level directly by Cu and by a mechanism that is different from that exerteted by metals on MT genes