11 research outputs found

    Panta Rhei benchmark dataset: socio-hydrological data of paired events of floods and droughts

    Get PDF
    As the adverse impacts of hydrological extremes increase in many regions of the world, a better understanding of the drivers of changes in risk and impacts is essential for effective flood and drought risk management and climate adaptation. However, there is currently a lack of comprehensive, empirical data about the processes, interactions, and feedbacks in complex human–water systems leading to flood and drought impacts. Here we present a benchmark dataset containing socio-hydrological data of paired events, i.e. two floods or two droughts that occurred in the same area. The 45 paired events occurred in 42 different study areas and cover a wide range of socio-economic and hydro-climatic conditions. The dataset is unique in covering both floods and droughts, in the number of cases assessed and in the quantity of socio-hydrological data. The benchmark dataset comprises (1) detailed review-style reports about the events and key processes between the two events of a pair; (2) the key data table containing variables that assess the indicators which characterize management shortcomings, hazard, exposure, vulnerability, and impacts of all events; and (3) a table of the indicators of change that indicate the differences between the first and second event of a pair. The advantages of the dataset are that it enables comparative analyses across all the paired events based on the indicators of change and allows for detailed context- and location-specific assessments based on the extensive data and reports of the individual study areas. The dataset can be used by the scientific community for exploratory data analyses, e.g. focused on causal links between risk management; changes in hazard, exposure and vulnerability; and flood or drought impacts. The data can also be used for the development, calibration, and validation of sociohydrological models. The dataset is available to the public through the GFZ Data Services (Kreibich et al., 2023, https://doi.org/10.5880/GFZ.4.4.2023.001)

    Splenic CD11c(+) cells derived from semi-immune mice protect naive mice against experimental cerebral malaria

    Get PDF
    Background: Immunity to malaria requires innate, adaptive immune responses and Plasmodium-specific memory cells. Previously, mice semi-immune to malaria was developed. Three cycles of infection and cure (\u27three-cure\u27) were required to protect mice against Plasmodium berghei (ANKA strain) infection. Methods: C57BL/6 J mice underwent three cycles of P. berghei infection and drug-cure to become semi-immune. The spleens of infected semi-immune mice were collected for flow cytometry analysis. CD11c(+) cells of semiimmune mice were isolated and transferred into naive mice which were subsequently challenged and followed up by survival and parasitaemia. Results: The percentages of splenic CD4(+) and CD11c(+) cells were increased in semi-immune mice on day 7 post-infection. The proportion and number of B220(+)CD11c(+)low cells (plasmacytoid dendritic cells, DCs) was higher in semi-immune, three-cure mice than in their naive littermates on day 7 post-infection (2.6 vs 1.1% and 491,031 vs 149,699, respectively). In adoptive transfer experiment, three months after the third cured P. berghei infection, splenic CD11c(+) DCs of non-infected, semi-immune, three-cure mice slowed Plasmodium proliferation and decreased the death rate due to neurological pathology in recipient mice. In addition, anti-P. berghei IgG1 level was higher in mice transferred with CD11c(+) cells of semi-immune, three-cure mice than mice transferred with CD11c(+) cells of naive counterparts. Conclusion: CD11c(+) cells of semi-immune mice protect against experimental cerebral malaria three months after the third cured malaria, potentially through protective plasmacytoid DCs and enhanced production of malaria-specific antibody

    The risks of pregnancy in the 21st century

    No full text
    2 page(s

    A New Insight to Vibration Characteristics of Spans under Random Moving Load: Case Study of 38 Bridges in Ho Chi Minh City, Vietnam

    No full text
    We propose a novel representative power spectrum density as a specific characteristic for showing responses of spans during a long operational period. The idea behind this method is to use the representative power spectrum density as a powerful tool to evaluate the stiffness decline of spans during their operation period. In addition, a new measurement method has been introduced to replace the traditional method of monitoring the health conditions of bridges through a periodic measurement technique. This helps to reduce costs when carrying out testing bridges. Besides, the proposed approach can be widely applied not only in Vietnam but also in many other underprivileged countries around the world. Obtained results show that, during the operational process of spans, there is not only a pure vibration evaluation such as bending vibration and torsion vibration tests but also a combination of various vibration types including bending-torsion vibration or high-level vibrations like first-mode bending and first-mode torsion. Depending on each type of structure and material properties, different types of vibrations will appear more or less during the operational process of spans under a random moving load. Furthermore, the representative power spectrum density is also suitable for evaluating and determining many different fundamental vibrations through the same measurement time as well as various measurement times

    Fretting Fatigue Damage Nucleation and Propagation Lifetime Using a Central Point Movement of Power Spectral Density

    No full text
    This paper presents a new perception in evaluating fretting fatigue damage nucleation and propagation lifetime under periodically forced circulation. A new approach, which is proposed in this paper, is to measure the change of the central point of power spectral density (CP-PSD) in different structural stiffness degradation stages. A notable aspect of this study lies in the combination between vibration amplitude and forced frequency of the fatigue-causing factors in beam structures. Additionally, it is found that randomization of the first phase from 0 to 2π yields more accurate modelling of the fatigue phenomenon. Results show that the CP-PSD parameter is significantly more sensitive compared to the regularly damage-evaluating parameters such as natural frequency, eigenvalues, or stress value. This reflects different levels of fatigue cycle effect on the structure in the experiment. At the same time, CP-PSD also categorizes the degradation level on different points on the structure under the periodically forced circulation. In addition, this paper also quantifies the relation between the changes of CP-PSD and each fatigue state. Results of this research will be a reference source to evaluate the lifespan of the structure by experimental methods

    Choice Factors When Vietnamese High School Students Consider Universities: A Mixed Method Approach

    No full text
    Higher education around the world and especially in Vietnam is becoming increasingly competitive. Universities apply marketing strategies to student recruitment and get to know their students and prospective students more closely, just as businesses learn about consumer attitudes and behavior. Therefore, studying students’ behavior of choosing a university is necessary, but most research about this topic has been conducted by a single approach. In order to examine the choice factors such as characteristics of institutions and information sources students consider when selecting universities, this research applies a mixed method approach, including both quantitative and qualitative data. Data were collected from questionnaire surveys with 670 responses from final-year high school students, and from 20 interviews with freshmen university students. Findings indicate the rankings of characteristics of institutions and information sources and the qualitative analysis explained how students consider them during their decision-making process. The research results provide important findings to help universities understand more about the factors that students are interested in and search for during the decision-making process

    The challenge of unprecedented floods and droughts in risk management

    No full text
    Risk management has reduced vulnerability to floods and droughts globally1,2, yet their impacts are still increasing3. An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data4,5. On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change3

    The challenge of unprecedented floods and droughts in risk management

    No full text
    Risk management has reduced vulnerability to floods and droughts globally1,2, yet their impacts are still increasing3. An improved understanding of the causes of changing impacts is therefore needed, but has been hampered by a lack of empirical data4,5. On the basis of a global dataset of 45 pairs of events that occurred within the same area, we show that risk management generally reduces the impacts of floods and droughts but faces difficulties in reducing the impacts of unprecedented events of a magnitude not previously experienced. If the second event was much more hazardous than the first, its impact was almost always higher. This is because management was not designed to deal with such extreme events: for example, they exceeded the design levels of levees and reservoirs. In two success stories, the impact of the second, more hazardous, event was lower, as a result of improved risk management governance and high investment in integrated management. The observed difficulty of managing unprecedented events is alarming, given that more extreme hydrological events are projected owing to climate change3
    corecore