A study on siting of emergency shelters for dam failure floods considering population distribution and weather effects.

In recent years, dam failures have occurred frequently because of extreme weather, posing a significant threat to downstream residents. The establishment of emergency shelters is crucial for reducing casualties. The selection of suitable shelters depends on key information such as the number and distribution of affected people, and the effective capacity and accessibility of the shelters. However, previous studies on siting shelters did not fully consider population distribution differences at a finer scale. This limitation hinders the accuracy of estimating the number of affected people. In addition, most studies ignored the impact of extreme rainfall on the effective capacity and accessibility of shelters, leading to a low applicability of the shelter selection results. Therefore, in this study, land-use and land-cover change (LUCC) and nighttime lighting data were used to simulate population distribution and determine the number and distribution of affected people. Qualified candidate shelters were obtained based on screening criteria, and their effective capacity and accessibility information under different weather conditions were quantified. Considering factors such as population transfer efficiency, construction cost and shelter capacity constraints, a multi-objective siting model was established and solved using the non-dominated sorting genetic algorithm II (NSGA- II) to obtain the final siting scheme. The method was applied to the Dafangying Reservoir, and the results showed the following: (1) The overall mean relative error (MRE) of the population in the 35 downstream streets was 11.16 %, with good fitting accuracy. The simulation results truly reflect the population distribution. (2) Normal weather screening generated 352 qualified candidate shelters, whereas extreme rainfall weather screening generated 266 candidate shelters. (3) Based on the population distribution and weather factors, four scenarios were set up, with 63, 106, 73, and 131 shelters selected. These two factors have a significant impact on the selection of shelters and the allocation of evacuees, and should be considered in the event of a dam-failure floods.

The usefulness of artificial intelligence for safety assessment of different transport modes.

Recent research in transport safety focuses on the processing of large amounts of available data by means of intelligent systems, in order to decrease the number of accidents for transportation users. Several Machine Learning (ML) and Artificial Intelligence (AI) applications have been developed to address safety problems and improve efficiency of transportation systems. However exchange of knowledge between transport modes has been limited. This paper reviews the ML and AI methods used in different transport modes (road, rail, maritime and aviation) to address safety problems, in order to identify good practices and experiences that can be transferable between transport modes. The methods examined include statistical and econometric methods, algorithmic approaches, classification and clustering methods, artificial neural networks (ANN) as well as optimization and dimension reduction techniques. Our research reveals the increasing interest of transportation researchers and practitioners in AI applications for crash prediction, incident/failure detection, pattern identification, driver/operator or route assistance, as well as optimization problems. The most popular and efficient methods used in all transport modes are ANN, SVM, Hidden Markov Models and Bayesian models. The type of the analytical technique is mainly driven by the purpose of the safety analysis performed. Finally, a wider variety of AI and ML methodologies is observed in road transport mode, which also appears to concentrate a higher, and constantly increasing, number of studies compared to the other modes.

SARS-CoV-2 Risk Quantification Model and Validation Based on Large-Scale Dutch Test Events.

In response to the outbreak of SARS-CoV-2, many governments decided in 2020 to impose lockdowns on societies. Although the package of measures that constitute such lockdowns differs between countries, it is a general rule that contact between people, especially in large groups of people, is avoided or prohibited. The main reasoning behind these measures is to prevent healthcare systems from becoming overloaded. As of 2021 vaccines against SARS-CoV-2 are available, but these do not guarantee 100% risk reduction and it will take a while for the world to reach a sufficient immune status. This raises the question of whether and under which conditions events like theater shows, conferences, professional sports events, concerts, and festivals can be organized. The current paper presents a COVID-19 risk quantification method for (large-scale) events. This method can be applied to events to define an alternative package of measures replacing generic social distancing.

Road-safety-II: Opportunities and barriers for an enhanced road safety vision.

Road safety research is largely focused on prediction and prevention of technical, human or organisational failures that may result in critical conflicts or crashes. Indicators of traffic risk aim to capture the passage to unsafe states. However, research in other industries has shown that it is meaningful to analyse safety along the whole spectrum of behaviours. Knowing the causes and patterns of "successful" interactions, rather than failures, could give new insights on the complexity of the system and the adaptability and resilience of its users in handling the inherent risks. The concept is known as Safety-II and has been extensively explored in the aviation, healthcare and process engineering domains. In this paper, we explore a new Safety-II paradigm for road safety research. We briefly review Safety-II applications in other sectors. We then present a Safety-II model for road safety, by means of an inverse version of Hyden's "safety pyramid". Furthermore, we discuss a number of key road safety goals, theories, analysis methods and data sources and map them into a tentative taxonomy of Safety-I and Safety-II applications. It is concluded that there can be opportunities and benefits from adopting this new mindset, in order to complement existing approaches.

Towards common ethical and safe 'behaviour' standards for automated vehicles.

Automated vehicles (AVs) aim to dramatically improve traffic safety by reducing or eliminating human error, which remains the leading cause of road crashes. However, commonly accepted standards for the 'safe driving behaviour of machines' are pending and urgently needed. Unless a common understanding of safety as a design value is achieved, different manufacturers' driving styles may emerge, resulting in inconsistent, unpredictable and potentially unsafe 'behaviour' of AVs in certain situations. This paper aims to explore the main gaps and challenges towards establishing shared safety standards for the 'behaviour' of AVs, and contribute to their responsible traffic integration, by reviewing the state-of-the-art on AV safety in the core relevant disciplines: ethics of technology, safety science (engineering & human factors), and standardisation. The ethical and safety aspects investigated include the users' perception of AV safety, the ethical trade-offs in critical decision-making contexts, the pertinence of data-driven approaches for AVs to mimic human behaviour, and the responsibilities of various actors. Moreover, the paper reviews the current safety patterns, metrics (surrogate measures of safety - SMoS) and their thresholds introduced in existing research for three use cases: mixed traffic of AV and conventional vehicles, AV interaction with pedestrians and cyclists, and transition of control from machine to human driver. The results reveal several knowledge gaps within each discipline and highlights the lack of common understanding of safety across disciplines. On the basis of the results, the paper proposes a framework for further research on AV safety, identifying concrete opportunities for interdisciplinary research, with common goals and methodologies, and explicitly indicating the path for transfer of knowledge between sectors.

Safe-by-Design in Engineering: An Overview and Comparative Analysis of Engineering Disciplines.

In this paper, we provide an overview of how Safe-by-Design is conceived and applied in practice in a large number of engineering disciplines. We discuss the differences, commonalities, and possibilities for mutual learning found in those practices and identify several ways of putting those disciplinary outlooks in perspective. The considered engineering disciplines in the order of historically grown technologies are construction engineering, chemical engineering, aerospace engineering, urban engineering, software engineering, bio-engineering, nano-engineering, and finally cyber space engineering. Each discipline is briefly introduced, the technology at issue is described, the relevant or dominant hazards are examined, the social challenge(s) are observed, and the relevant developments in the field are described. Within each discipline the risk management strategies, the design principles promoting safety or safety awareness, and associated methods or tools are discussed. Possible dilemmas that the designers in the discipline face are highlighted. Each discipline is concluded by discussing the opportunities and bottlenecks in addressing safety. Commonalities and differences between the engineering disciplines are investigated, specifically on the design strategies for which empirical data have been collected. We argue that Safe-by-Design is best considered as a specific elaboration of Responsible Research and Innovation, with an explicit focus on safety in relation to other important values in engineering such as well-being, sustainability, equity, and affordability. Safe-by-Design provides for an intellectual venue where social science and the humanities (SSH) collaborate on technological developments and innovation by helping to proactively incorporate safety considerations into engineering practices, while navigating between the extremes of technological optimism and disproportionate precaution. As such, Safe-by-Design is also a practical tool for policymakers and risk assessors that helps shape governance arrangements for accommodating and incentivizing safety, while fully acknowledging uncertainty.

Safe by Design Regulation for Academic Experimentation and Value Conflicts: An Exploration of Solution Directions.

In this paper, we explore solution directions for the implementation of Safe by Design (SbD) in safety regimes for academic experimentation. SbD is a dynamic and anticipatory strategy for safety regulation in academic research. In this strategy, safety is taken in a broader sense including not only issues of technical precaution of avoiding risks of experimentation but also the societal responsibility of researchers and research institutes of identifying possible future risks. In our research, we have interviewed academic researchers from different disciplines and university support personnel about the factors that enable and limit the possibilities of researchers to implement SbD in safety regimes for experimentation. We articulate our findings in terms of a core set of research values and in terms of conflicts between safety and these research values. And we argue that tools for resolving value conflicts as originating in design for values research can provide directions to solve the value conflicts, and thus help academic researchers to adopt SbD in their experimentation.

Getting the Perpetrator Incorporated and Prioritized in Homicide Investigations: The Development and Evaluation of a Case-Specific Element Library (C-SEL).

Homicide investigators in the digital era have access to an increasing amount of data and the processing of all persons of interest and pieces of evidence has become nearly impossible. This paper describes the development and evaluation of a case-specific element library (C-SEL) that can be used to incorporate and prioritize persons of interest in homicide investigations. In a survey, 107 experts in the field of criminal investigation assigned an initial score to the elements. Each element was extended with underlying factors that can be used to adjust the initial score based on the relevance and credibility of the source. A case study was conducted using three Dutch real-world cases to evaluate the methodology. The results look promising and are better than four methodologies currently used in practice.

Economic risk criteria for dams considering the relative level of economy and industrial economic contribution.

When a dam breaks, huge floods will be generated that may inundate urban areas, enterprises, farmlands, and infrastructure and cause giant economic losses. Economic risk criteria are a kind of basis for determining dam risk levels and to decide whether risk control measures should be taken or not. However, compared to loss-of-life risk criteria, much fewer economic risk criteria for dams have been proposed and implemented for two main reasons: (a) The ability of most areas to endure economic losses caused by dam breach changes over time because of the constant development of their economic levels; and (b) Economic development levels in an area are distinct from the levels in other areas, resulting in significant differences in the ability of different areas to endure economic losses caused by a dam breach. Therefore, an equivalent economic scale (EES) that indicates the relative economic level of an area to the whole country in a given period of time is a preferred measure. It was shown in this paper that EES has much more stable values than do ordinary economic measures; therefore, it was taken as the basic index for establishing economic risk criteria. Furthermore, due to the distinct economic loss rates of different industries, the index of industrial economic contribution (IEC) was introduced to determine the correction coefficient to modify the ESS to reflect the potential economic loss of the area to be evaluated. This is the first research that pays careful attention to the change of ability to endure economic losses, in which the established economic risk criteria are applicable over a relatively long time and for different areas based on the consideration of the relative level of the economy and the industrial economic contribution.

Distribution and source assessment of polycyclic aromatic hydrocarbons levels from Lake IJssel (the Netherlands) and their responses to hydrology.

Based on field efforts in Lake IJssel (the Netherlands) from 2000 to 2010, dynamics of 15 priority PAHs in suspended particulate matter (SPM) and in seawater were determined. This study examined time-varying changes in PAH concentration and composition, apportioned potential anthropogenic sources, and quantified their linkages to hydrological factors. The sum of individual PAHs (defined as ∑15 PAHs) varied widely throughout the study period in Lake IJssel, ranging from 0.76 to 9.66 mg/kg in SPM and from 0.014 to 0.136 µg/L in seawater. High molecular weight PAHs were the most abundant PAH compounds, responsible for 73%-97%. Seasonal variation in ∑15 PAHs level was distinguished, peaked in late winter and early spring, and reached a minimum in summer. Over site, the heavy contamination was found at the river mouth (e.g., Genemuiden). The driving factors of SPM and water temperature controlled the fate of PAHs. Principal component analysis and diagnostic ratios suggested that PAHs may have been derived from different input sources through various transport pathways, for example, coal combustion source and petroleum source. The findings are useful for filling the knowledge gap of PAH dynamics in Lake IJssel and Wadden Sea, which exerts significant influences on lake's environment. PRACTITIONER POINTS: HMW PAHs (4-6 rings) were the most abundant PAH compounds. Heavy contamination was found in the mouth of IJssel River. Time-varying change in PAHs level was significantly correlated with riverine input. PAHs sources were apportioned via principal component analysis and diagnostic ratios.

Field analysis of PAHs in surface sediments of the Pearl River Estuary and their environmental impacts.

Based on a monthly field survey in 2011 of the Pearl River Estuary, the dynamics of polycyclic aromatic hydrocarbons (PAHs) in surface sediments (depth < 5 cm) were explored. The seasonal variations in PAH level and composition were investigated in this study, as well as their environmental behaviors, the role of particles, and source apportionment. The concentration of the sum of 16 priority PAHs (defined as ∑16PAHs) ranged from 0.32 to 1.10 µg/g, while that of the sum of 62 PAHs (defined as ∑tPAHs) varied from 0.83 to 2.75 µg/g. The levels of both the ∑16PAHs and ∑tPAHs peaked in February, although the minimum levels appeared in different months-December and August, respectively. The seasonal difference in the ∑tPAHs was significant (flood season, 7.69 µg/g; dry season, 10.51 µg/g). The 5-ring PAH compound (e.g., perylene) was the most abundant and was responsible for 35% of the total, which implied a terrestrial input source via the Pearl River. Sediment particles were predominantly composed of clayed sand, and sediment PAHs showed a greater tendency to be adsorbed onto the large-sized particles rather than the fine fractions. Total organic carbon (TOC) could considerably facilitate the sediment PAHs. Principal component analysis revealed that vehicle emission sources, petroleum sources, and combustion sources were the major anthropogenic contamination sources. The diagnostic ratios of various individual PAHs were also explored. These findings are particularly useful for understanding the geochemistry of organic pollutants in the complex estuarine environment.

Spatial Vulnerability of Network Systems under Spatially Local Hazards.

A hazard is often spatially local in a network system, but its impact can spread out through network topology and become global. To qualitatively and quantitatively assess the impact of spatially local hazards on network systems, this article develops a new spatial vulnerability model by taking into account hazard location, area covered by hazard, and impact of hazard (including direct impact and indirect impact), and proposes an absolute spatial vulnerability index (ASVI) and a relative spatial vulnerability index (RSVI). The relationship between the new model and some relevant traditional network properties is also analyzed. A case study on the spatial vulnerability of the Chinese civil aviation network system is conducted to demonstrate the effectiveness of the model, and another case study on the Beijing subway network system to verify its relationship with traditional network properties.

Production of viral vaccines for veterinary use.

This review provides inside information on the production of vaccines for veterinary use. The vaccines against rinderpest as well as foot and mouth disease are considered milestones in the history of veterinary vaccine production. Modern vaccines are based on the scientific progress in virology, cell biology and immunology. While naturally occurring attenuated viruses or viruses obtained after passage in different animal species or cell culture were used as vaccine strains in the early vaccines, nowadays targeted mutagenesis can be applied to generate vaccine virus strains. In principle, the antigen production process is the same for live and inactivated vaccines. The vaccine virus is usually grown in cell culture, either in roller bottles or bioreactors. Most live vaccines are freeze-dried in order to enable storage in the refridgerator for a longer period. To this end, a so-called stabilizer is added to the culture medium. The inactivation of the vaccine virus for the production of killed vaccines is done by physical or chemical treatments that lead to denaturation of the proteins or damage of the nucleic acids. The inactivated antigen may be further purified and mixed with an adjuvant. The quality standards for vaccines are layed down in international regulations and laws. Numerous tests are performed during the different production steps and on the final product in order to warrant the quality of each batch.

A concise equation that captures the essential elements of one-way sensitivity analyses in health economic models.

OBJECTIVE: Sensitivity analyses are often performed on only a limited number of variables without justification of the choice of variables and range of each variable. External parties such as health authorities are increasingly requiring submission of the actual model, often in order to test the robustness of the outcomes of the model by performing additional sensitivity analyses. The objective of this work was to develop an alternative method to capture the critical issues of a sensitivity analysis in a health economic model, especially regarding the selection of variables and determining the range for each variable. Apart from external parties such as health authorities, journal readers who want to perform their own sensitivity analysis but do not have access to the model may find this useful. METHODS AND RESULTS: Statistical methods based on Markov chain modeling and regression analysis, using the framework of the Taylor series expansion around a point, are used to derive an equation for 1-way sensitivity analyses. In particular, equations for costs and effects are being developed, from which the cost-effectiveness ratio is built. The article shows the feasibility of such equations for the execution of 1-way sensitivity analyses. CONCLUSION: An equation that can be derived in the manner described in this article provides a substantial amount of information. The inclusion of such an equation in a report may increase transparency of the reporting of outcomes of health economic models.

Success of frozen embryo transfer: Does the type of gonadotropin influence the outcome?

OBJECTIVES: To determine whether there is a difference in outcome between different ovulation-induced cycles after frozen-thawed embryo transfer (FET). METHODS: We searched the Cochrane Menstrual Disorders and Subfertility Group's trials register in May 2009, the Cochrane Central Register of Controlled Trials (Cochrane Library, Issue 1, 2008), ISI Web of Knowledge (1985 to August 2009), and reference lists of articles. Relevant conference proceedings were hand-searched and researchers in the field were contacted. Randomized controlled trials and retrospective studies were included, comparing the various cycle regimens and different methods during FET in assisted reproductive technology, ie, in vitro fertilization and intracytoplasmic sperm injection. RESULTS: Using the agonist long protocol for downregulation, five trials provided extractable data for live-birth rates, ongoing pregnancy, and clinical pregnancy rates following FET. One trial provided extractable data for clinical pregnancy rate. There was no evidence of a significant difference in any outcome between the users of urinary gonadotropins versus recombinant follicle-stimulating hormone. Data on implantation and miscarriage rates following FET were not available for analysis. CONCLUSIONS: It seems that clinical pregnancy rate after FET is not influenced by the type of gonadotropins used. Research should be directed towards improving freezing and thawing techniques.

Effect of urinary versus recombinant FSH on clinical outcomes after frozen-thawed embryo transfers: a systematic review.

Recent randomized trials, systematic reviews and cost-effectiveness analyses have demonstrated the relative efficacy,and in some cases superiority, of urinary gonadotrophins (uFSH, human menopausal gonadotrophin) compared with recombinant FSH (rFSH). However, the effectiveness of frozen-embryo transfers (FET) following ovarian stimulation with uFSH versus rFSH in the fresh cycle has not been well investigated. The objective of this study was to determine whether there are differences in clinical outcomes in women undergoing FET according to the type of gonadotrophin used during ovarian stimulation. Following a meticulous search, all published comparative studies of FET using ovarian stimulation were reviewed. Data on clinical outcomes were extracted and systematically presented. Using the agonist long protocol for down-regulation, five trials provided extractable data for live-birth and ongoing pregnancy rates following FET, as well as the cumulative live-birth, ongoing pregnancy and clinical pregnancy rates following fresh-embryo transfer and FET from the same cycle. There was no evidence of significant effect difference between the uses of uFSH versus rFSH regarding any of the outcomes. In conclusion there is insufficient evidence to determine whether the use of a certain type of gonadotrophin during ovarian stimulation affects the clinical outcomes in subsequent FET.