Post-release Phase Research Articles

Radiological Surveillance Using a Fixed-Wing UAV Platform

A drone–detector system was designed, developed, and tested for radiological monitoring. The system was tailored to perform measurements during the threat, release, and post-release phases of a nuclear or radiological event. This allows the surveillance of large areas, with an autonomy of up to 12 h, in a large range of altitudes above ground level. The detector system was optimized for gamma spectroscopy, taking into account the available payload for maximum endurance and maximum detection efficiency using ‘PENELOPE (2018)’ Monte Carlo simulations. A generic methodology was used to derive quantitative information on radioactivity levels from the raw measured gamma-ray spectra at different altitudes. Based on the methodology, it was demonstrated that the drone–detector system can measure the concentration of potassium-40 (K-40) that is naturally present in the soil. These measurements complied within 30% of the soil sampling results taking into account the uncertainties. The functioning of the system was tested during test flights, which demonstrated that radionuclide identification and quantification of radioactivity concentrations are possible.

Testing the Plasticity of Reinforcement Learning-based Systems

The dataset available for pre-release training of a machine-learning based system is often not representative of all possible execution contexts that the system will encounter in the field. Reinforcement Learning (RL) is a prominent approach among those that support continual learning, i.e., learning continually in the field, in the post-release phase. No study has so far investigated any method to test the plasticity of RL-based systems, i.e., their capability to adapt to an execution context that may deviate from the training one. We propose an approach to test the plasticity of RL-based systems. The output of our approach is a quantification of the adaptation and anti-regression capabilities of the system, obtained by computing the adaptation frontier of the system in a changed environment. We visualize such frontier as an adaptation/anti-regression heatmap in two dimensions, or as a clustered projection when more than two dimensions are involved. In this way, we provide developers with information on the amount of changes that can be accommodated by the continual learning component of the system, which is key to decide if online, in-the-field learning can be safely enabled or not.

Transcatheter aortic valve implantation in pure aortic regurgitation: Hemodynamic and echocardiographic findings in bioprosthesis vs. native valve

The objective of this study is to compare hemodynamic and echocardiographic findings between valve-in-valve (VIV) and native-valve (NV) patients submitted to transcatheter aortic valve implantation (TAVI) due to pure aortic regurgitation (AR). Patients with severe AR are surgically treated with variable postinterventional left-ventricular (LV) "reverse remodeling."TAVI might be considered in selected AR patients. Twenty-eight patients with pure severe AR caused by either degenerated bioprosthesis or NV disease were successfully treated by TAVI at our institution. LV catheterization before and after TAVI and echocardiography before, after (24-72 h), and at follow-up (3-12 months) were performed. Baseline clinical, hemodynamic, and echocardiographic characteristics were comparable between the two study groups, except for a younger age, higher proto-diastolic LV pressure, and higher LV end-systolic diameter in the NV group.At catheterization, an immediate hemodynamic impact of TAVI in both groups was noticed, with a trend toward better postprocedural residual regurgitation index and significantly lower LV dP/dT values (666.0 ± 177.9 vs.883.5 ± 259.7 mmHg/s, p = 0.04) in VIV.At echocardiography, both NV and VIV patients showed favorable (early and sustained) post-TAVI echocardiographically detectable reverse remodeling. VIV patients also showed more pronounced early reduction in indexed LV end-diastolic volume (68.1 ± 27.4vs. 86.5 ± 28.9 ml/m2 in VIV, p < 0.001and 81.0 ± 29.0vs. 95.2 ± 37.8 ml/m2 in NV, p = 0.043). Successful TAVI induces a striking hemodynamic impact with major structural (reverse remodeling) consequences in patients with pure AR caused by both bioprosthesis degeneration or NV disease. In the immediate postrelease phase, VIV patients might exhibit a more pronounced early LV contractile and structural benefit.

Large-Scale Deployment and Establishment of Wolbachia Into the Aedes aegypti Population in Rio de Janeiro, Brazil.

Traditional methods of vector control have proven insufficient to reduce the alarming incidence of dengue, Zika, and chikungunya in endemic countries. The bacterium symbiont Wolbachia has emerged as an efficient pathogen-blocking and self-dispersing agent that reduces the vectorial potential of Aedes aegypti populations and potentially impairs arboviral disease transmission. In this work, we report the results of a large-scale Wolbachia intervention in Ilha do Governador, Rio de Janeiro, Brazil. wMel-infected adults were released across residential areas between August 2017 and March 2020. Over 131 weeks, including release and post-release phases, we monitored the wMel prevalence in field specimens and analyzed introgression profiles of two assigned intervention areas, RJ1 and RJ2. Our results revealed that wMel successfully invaded both areas, reaching overall infection rates of 50–70% in RJ1 and 30–60% in RJ2 by the end of the monitoring period. At the neighborhood-level, wMel introgression was heterogeneous in both RJ1 and RJ2, with some profiles sustaining a consistent increase in infection rates and others failing to elicit the same. Correlation analysis revealed a weak overall association between RJ1 and RJ2 (r = 0.2849, p = 0.0236), and an association at a higher degree when comparing different deployment strategies, vehicle or backpack-assisted, within RJ1 (r = 0.4676, p < 0.0001) or RJ2 (r = 0.6263, p < 0.0001). The frequency knockdown resistance (kdr) alleles in wMel-infected specimens from both areas were consistently high over this study. Altogether, these findings corroborate that wMel can be successfully deployed at large-scale as part of vector control intervention strategies and provide the basis for imminent disease impact studies in Southeastern Brazil.

Change‐points‐based software scheduling

AbstractSoftware reliability literature consists of various change‐point‐based software reliability growth models and related release time problems. The primary assumption of the existing models is the existence of change‐point before software release time only. This does not look practical as the testing team becomes more proficient in detecting the faults due to their continuous involvement in software development by the software release time. Hence the fault detection rate in the pre‐ and postrelease phase is not the same. To capture this change in fault detection rate in the pre‐ and postrelease testing phase, we propose a new software reliability modeling framework by considering two change‐points during the software lifecycle; that is, there exists a change‐point before release time and release time as a change‐point. Further, in the last one‐decade software firms have changed their strategy of stop testing the software after release and continue to test even after release to remove the number of faults to provide better user experiences. This phenomenon attracted academicians to develop theoretical as well empirical study on postrelease testing and formulation of related release time problem. In this paper, we propose a software cost model to determine optimal release and testing stop time considering under the assumption of two change‐points as mentioned above. The proposed model is validated on real‐life data set.

CONFIDENCE: project description and main results

The project CONFIDENCE (COping with uNcertainties For Improved modelling and DEcision making in Nuclear emergenCiEs) performed research on identifying and reducing uncertainties in the release and post-release phases of an emergency. The project started in January 2017 as part of the European Joint Programme CONCERT. It brought together 31 partners from 18 countries and involved members of five European Radiation Protection Platforms namely ALLIANCE, EURADOS, MELODI, NERIS and SHARE. The work program included research on early phase modelling and monitoring considering weather, source term and monitoring uncertainties. Consideration of social, ethical and communication aspects was a key part of our activities. This comprised strategy development in the transition phase together with stakeholder interaction, understanding of the population and which uncertainties are relevant for decision-making. Finally, formal decision aiding techniques were investigated and tested.

Generalized software release and testing stop time policy

PurposeAlmost everything around us is the output of software-driven machines or working with software. Software firms are working hard to meet the user’s requirements. But developing a fault-free software is not possible. Also due to market competition, firms do not want to delay their software release. But early release software comes with the problem of user reporting more failures during operations due to more number of faults lying in it. To overcome the above situation, software firms these days are releasing software with an adequate amount of testing instead of delaying the release to develop reliable software and releasing software patches post release to make the software more reliable. The paper aims to discuss these issues.Design/methodology/approachThe authors have developed a generalized framework by assuming that testing continues beyond software release to determine the time to release and stop testing of software. As the testing team is always not skilled, hence, the rate of detection correction of faults during testing may change over time. Also, they may commit an error during software development, hence increasing the number of faults. Therefore, the authors have to consider these two factors as well in our proposed model. Further, the authors have done sensitivity analysis based on the cost-modeling parameters to check and analyze their impact on the software testing and release policy.FindingsFrom the proposed model, the authors found that it is better to release early and continue testing in the post-release phase. By using this model, firms can get the benefits of early release, and at the same time, users get the benefit of post-release software reliability assurance.Originality/valueThe authors are proposing a generalized model for software scheduling.

Impact of capture and chemical immobilization on the spatial behaviour of red deer Cervus elaphus hinds

Research and management programs of wild animal populations often require intensive field actions, which make direct interventions on animals such as capture, immobilization and manipulation, frequently necessary. Such events, however, could induce a stress response causing physiological and behavioural alterations in the individuals. Knowing the impact of these practices in the post-release phase is of crucial importance when studying the spatial behaviour of wild species. Our study aimed to investigate the potential effect of narcosis and application of GPS collars on 17 red deer Cervus elaphus hinds living in a mountainous area in northern Apennine, Italy. We conducted the analysis at a temporal scale of 45 days after release, in order to assess the response of animals in terms of changes in movement rates, distance from the barycentre of their positions and distance from the capture sites. We then compared habitat selection between the period of disturbance and the following days. This work represents the first study of the behavioural responses of wild red deer to capture and handling procedures. We showed that these operations significantly affect the spatial behaviour of hinds by inducing a short-term increase in movement rates and by keeping the animals away from the centre of their activity, for a period no longer than 10 days. The habitat selection analysis remarked a tendency to escape from human disturbance, by avoiding hunting sites and anthropized locations in favour of forest cover. Red deer hinds thus, seem to cope with stressful events and disturbance by adopting a flight behaviour, which includes moving away from the capture area and seeking refuges. The differences highlighted between the ‘stressful’ period and the following one, showed that such modifications persist for a limited time frame and suggested that this capture method is unlikely to lead to permanent alterations of behaviour.

Effect of interruption of over‐flooding releases of transgenic mosquitoes over wild population of Aedes aegypti: two case studies in Brazil

AbstractThe number of mosquito populations resistant to insecticides is increasing along with the reemerging of vector‐borne diseases. New technologies are under evaluation to complement the strategies used against these mosquitoes. Transgenic mosquitoes are one approach that some countries are considering and they are being evaluated to control the wild population. Although they have achieved success in population suppression of Aedes aegypti (L.) (Diptera: Culicidae), these studies have not demonstrated what the outcomes are when releases are interrupted (ceased). In this study, after demonstrating suppression of Ae. aegypti using transgenic technology, changes in the spatial distribution of the infestation and the abundance of the vector Ae. aegypti were assessed in the post‐release period, along with fluctuation of transgenic mosquitoes in two areas of Brazil. In both pilot trials, there was an average suppression of ca. 70% of the wild population due to the release of transgenic males compared to the pre‐release period. In Juazeiro (Mandacaru), in the post‐release phase, the number of eggs per trap ranged between 0.06 and 14.41 (mean ± SE = 4.44 ± 0.44), and the ovitrap index (OI = number of ovitraps with eggs/total number of ovitraps recovered) ranged from 0.01 to 0.43 (0.13 ± 0.01). In Jacobina (Pedra Branca), during the post‐release phase, the number of eggs per trap ranged between 1 and 7.2 (1.72 ± 0.72), and the OI ranged from 1 to 0.83 (0.095 ± 0.032). The mosquito population in Juazeiro (Mandacaru) remained suppressed for 17 weeks after the release interruption, whereas in Jacobina (Pedra Branca) suppression lasted 32 weeks. In Juazeiro, transgenic larvae were detected up to 5 months after the interruption of the over‐flooding releases of transgenic males. In Jacobina, they were found up to 2 months after the release interruption. The number of eggs collected increased 4–5 months after the release interruption, which indicated that the Ae. aegypti population had been re‐established after the interruption of releases. The results demonstrate that the technique requires a continuous release in the treated areas, and after suppression, the release rate can be decreased and used as a barrier against external migration.

Testing effort based modeling to determine optimal release and patching time of software

In this era of information technology, our dependence on software systems is increasing day by day. This dependence on software systems has increased the pressure on software firms to fulfill the customer’s demand for highly reliable software. On the other hand, for ensuring high reliability of the software prolonged testing is required, which consumes large amount of resources hence not feasible in the current stiff market competition. Further delay in release can cost a lot in terms of market opportunity. Therefore, to sustain in the market, firms are releasing the software early and removing the remaining number of bugs by updating with patches. A patch is a piece of software designed to update a computer program or its supporting data, to fix or improve it. With such patches usually called bug fixes, firms improve the usability or performance of the software. Providing patches needs extra amount of effort and manpower which costs high. Also early patch release may result in improper removal of bugs and late release can increase the risk of more of failures in the operational phase To overcome the above issues we have proposed a testing effort based cost model to determine the optimal release and patch time of a software so that the total cost is minimized. In the proposed cost model developing team continues removing the faults even after software release. Further, we have taken different distribution function in pre and post release phase (before and after patching) to develop the proposed cost model. Numerical illustration is provided at the end of the paper for validation of the proposed cost model.

Shinzo Abe’s World War II Statement: Peace, Reflection and Global Contributions

This paper attempts to analyse Abe’s statement from two perspectives – pre-release and post-release. The approach offers an insight into how analysts were wrong/right and how different the Abe statement was from the report released by the Advisory Committee. The paper attempts to offer a balanced view of the statement while recognising the reservations from Japan’s neighbours. Comparisons between the pre-release and post-release phases would be made.

Descent and spread of negatively buoyant thermals

Results are presented from a numerical and analytical study of negatively buoyant thermals. The numerical study consists of large-eddy simulations of thermal descent and spread. The thermals are initiated by a spherical perturbation in the homogeneous background potential temperature. Simulations covering various release heights, thermal radii and thermal buoyancies are carried out. The analysis involves matching similarity models of a thermal and an axisymmetric gravity current, hence describing the flow evolution in terms of the initial conditions and flow coefficients only. The simulations demonstrate that the flow transition through the impingement region is relatively smooth, the main flow adjustment being in the initial post-release phase of the thermal. Comparison of the simulations and the model enables determination of the coefficients, and validation of the similarity approach to predict the radial speed, reduced gravity and depth of the spreading flow on the ground. The predictions of reduced gravity and depth also depend on quantification of the increase in gravity-current volume due to entrainment, which is obtained from the simulations.

Conspicuous genetic structure belies recent dispersal in an endangered beach mouse (Peromyscus polionotus trissyllepsis)

Habitat fragmentation can exacerbate the impacts on population persistence in species with rapid life histories and specialized habitat requirements. We investigated genetic structuring across the range of the federally endangered (USA) Perdido Key beach mouse (PKBM), Peromyscus polionotus trissyllepsis, using 16 microsatellite loci. Between 2010 and 2012 we sampled the three core habitat areas that are separated by 3–5 km of developed area. One location GSP was re-established in 2010 with a release of 48 captive bred mice. The other two parks had a reticulate recent history, including extirpations, translocations and, a recent (2009) natural re-colonization. Our objectives were to document the level of genetic drift associated with the post-release phase at GSP over a 2-year period, and to test the hypothesis that PKBM dispersal connectivity is restricted between the three parks. The three populations were significantly genetically differentiated in 2010 and 2012 (pairwise F ST ranged from 0.135 to 0.276). However, Bayesian clustering, assignment tests and hybridization analyses revealed inter-park dispersal and reproduction in 2012 that was absent in 2010. The detection of dispersal was an important step in understanding the regulation of connectivity in this fragmented system. We propose that a combination of recent apparent population increases across the island combined with the concurrent re-establishment of beachfront vegetated sand berms encouraged inter-park dispersal detected in 2012. These results provide important information for the future conservation of beach mice inhabiting northern Gulf of Mexico and Atlantic barrier islands in light of continued development pressure.

Predicting the altitudinal distribution of an introduced phytophagous insect against an invasive alien plant from laboratory controlled experiments: case of Cibdela janthina (Hymenoptera:Argidae) and Rubus alceifolius (Rosaceae) in La Réunion

The sawfly Cibdela janthina (Hymenoptera: Argidae) native to Sumatra was introduced on La Reunion (France, Indian Ocean) in 2007 to control the giant bramble Rubus alceifolius (Rosaceae), one of the most invasive plants on this island. We determined the influence of temperature on the development duration and survival of C. janthina preimaginal stages in controlled conditions in order to parameterize a survival model and to relate the predicted survival with observed patterns of defoliation of the host plant at different altitudes. We adjusted the Regniere model to survival data, combined with the Lactin-2 model on development rate of the three preimaginal stages of C. janthina. This model adequately predicts the observed defoliation and the altitudinal limit of the biological control agent. Our results also show that studies on temperature-related constraints on the biology of an agent introduced for weed control should be emphasized both in the pre-release and the post-release phases of a biological control program to evaluate the potential success of the control programme.

Evaluating the post-release efficacy of invasive plant biocontrol by insects: a comprehensive approach

We propose a comprehensive program to evaluate the post-release phase of biocontrol programs that use insect herbivores to control invasive plant species. We argue that any release should be done in randomized release and non-release sites and should be followed up by well-replicated sampling and experimental protocols that evaluate the degree of success or failure. These follow-up studies should include landscape scale monitoring across relevant habitat gradients of (1) the abundance of the biocontrol agent, (2) the impact of the biocontrol agent on the target plant species, (3) the potential for non-target effects, and (4) the response of native species and communities to a reduction in the invasive species. We also argue that (5) experimental reductions of the biocontrol agent are required to eliminate the chance that the putative impact of the biocontrol agent is not confounded with other causes. Finally, we describe six scenarios, informed largely by a community ecology perspective, in which a biocontrol agent may decrease the abundance or vigor of the target plant species but not lead to successful control where native communities re-establish. We classify these failure scenarios as either direct or indirect effects of the invasive plant species: Native Source Limitation, Static Competitive Hierarchies, Novel Weapons, Trophic Shifts, Invasive Engineering and Associated Invasives. Overall, we argue that well replicated and landscape-scale post release monitoring programs are required not only to evaluate critically the degree of success and failure of biocontrol programs worldwide but also to provide insights into improving future biocontrol efforts.

Post-release information privacy protection: A framework and next-generation privacy-enhanced operating system

In today's digital world, privacy issues have received widespread public attention. Current research on information privacy protection focuses on release control and subject identity obscurity. Little work has been done, however, to prevent a piece of private information from being misused after that information has been released to external entities. This paper focuses on information privacy protection in a post-release phase. Without entirely depending on the information collector, an information owner is provided with powerful means to control and audit how his/her released information will be used, by whom, and when. The goal is to minimize the asymmetry of information flow between an information owner and an information collector. A set of innovative owner-controlled privacy protection and violation detection techniques has been proposed: Self-destroying File, Mutation Engine System, Automatic Receipt Collection, and Honey Token-based Privacy Violation Detection. Next generation privacy-enhanced operating system, which supports the proposed mechanisms, is introduced. Such a privacy-enhanced operating system stands for a technical breakthrough, which offers new features to existing operating systems. We discuss the functionalities of such an operating system and the design guidelines. To our best knowledge, no similar technical work has been found to provide post-release information privacy protection.

An Empirical Investigation of Signaling in the Motion Picture Industry

The contribution of this research lies in the use of real-world data to test several hypotheses about the role of two signals—sequels and advertising expenditures—in the motion picture industry. The authors analyze the data with a dynamic simultaneous-equations model of the drivers and the interrelationships of the behaviors of movie audiences, studios, and exhibitors. Specifically, the authors test for the attenuating role of third-party information sources, such as critics' review consensus and cumulative word of mouth, on the strength of the two aforementioned signals. The authors find evidence of such an effect both at the release phase across movies and over the postrelease phase for any movie. Notably, they hypothesize and show that sequels and advertising expenditures have a positive interaction effect on box office revenues. This is an important finding because though most firms use multiple signals for their products, empirical work on the interaction of two or more signals is rare. This study offers several new and interesting empirical insights into the market dynamics of the motion picture industry.

Measuring genetic diversity in translocation programmes: principles and application to a chimpanzee release project

AbstractLogging and poaching have dramatically reduced chimpanzee density and distribution in the Republic of Congo. Most chimpanzee translocations attempted in the past failed because a number of biological and non‐biological factors can influence success. Biological considerations include knowledge of behaviour, disease, habitat requirements and genetics. We critically review genetic considerations in pre‐ and post‐release phases of translocations and apply them to a welfare‐based chimpanzee release project in the Republic of Congo which aimed to re‐establish orphan chimpanzees in the wild with a native chimpanzee population. We analyze genetic diversity and relatedness in released animals and devise a genotyping strategy for monitoring of released individuals and their future offspring. Fifty‐nine confiscated chimpanzees from different areas of the Republic of Congo were typed for 20 microsatellites using plucked hair as the DNA source. Genetic diversity was high, with an average expected heterozygosity of 81%, and three to 18 alleles per locus. Between 1996 and 1998, 19 individuals were released, and genetic analysis showed that these are unrelated (mean r± jack‐knifed SD =−0.014 ± 0.001). Using FST and population admixture analysis, we identified population structure in wild chimpanzees. For long‐term genetic monitoring of released and native chimpanzees, we identified a set of six informative markers, which are easy to score using basic techniques.

Deriving a Fault Architecture to Guide Testing

Defect analysis of software components can be used to guide testing, with the goal of focusing on parts of the software that were fault-prone in earlier releases or earlier life cycle phases, such as development. We replicate a study that adapted a reverse architecting technique using defect reports to derive fault architectures. A fault architecture determines and visualizes components that are fault-prone in their relationships with other components, as well as those that are locally fault-prone. Our case study uses defect data from three releases of a large medical record system to identify relationships among system components, based on whether they are involved in the same defect report. We investigate measures that assess the fault-proneness of components and component relationships. Component relationships are used to derive a fault architecture. The resulting fault architecture indicates what the most fault-prone relationships are in a release. We also apply the technique in a new way. Not only do we derive fault architectures for each release, we derive fault architectures for the development, system test and post release phases within each release. Comparing across releases, makes it possible to see whether some components are repeatedly in fault-prone relationships. Comparing across phases, makes it possible to see whether development fault architectures can be used to identify those parts of the software that need to be tested more. We validate our predictions using system test data from the same release. We also use the development and system test fault architectures to identify fault-prone components after release, and validate our predictions using post release data.

Status of a reintroduced population of mountain gazelles Gazella gazella in central Arabia: management lessons from an aridland reintroduction

AbstractMountain gazelles were reintroduced to central Arabia during 1991–95. Hawtah reserve was searched for gazelles during the 1998–99 winter. Gazelles were seen in one wadi system and their signs were found in several others and on the plateau. Sightings were used to calculate the minimum number of gazelles in the Matham wadi system, which previously held most of the population. During October–November 1998, the minimum number was 64 per cent less than 4 years earlier. Frequent observation of recent signs in areas where no gazelles were seen suggested that daytime sightings alone were no longer adequate for monitoring this population. The decline in the number of gazelles seen, an increase in their flight distance and an apparent change in their activity patterns were consistent with the rangers' claim that poaching had commonly occurred. Poaching started after reserve management built, without adequate consultation, a new fence that was intended to bar local people from part of the reserve. Management lessons include the need for the following: continued monitoring of reintroduced populations after the initial postrelease phase; long-term dialogue with local people; effective law enforcement; and the management of aridland domestic livestock in ways that prevent inter specific competition for food causing the elimination of wild ungulates.