| 1. |
- Sumaila, U. Rashid, et al.
(författare)
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WTO must ban harmful fisheries subsidies
- 2021
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 374:6567, s. 544-544
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Chuong, Nguyen Canh, et al.
(författare)
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Amniocentesis test uptake for congenital defects : Decision of pregnant women in Vietnam
- 2018
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Ingår i: Health Care for Women International. - : TAYLOR & FRANCIS INC. - 0739-9332 .- 1096-4665. ; 39:4, s. 493-504
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Tidskriftsartikel (refereegranskat)abstract
- Our study aimed to identify the knowledge, attitude, and factors associated with uptake of amniocentesis test amongst pregnant women of advanced maternal age (35+ years old). A cross-sectional survey was performed on 481 participants in 2016. Women with higher educational attainment, higher income level, having a baby with congenital defects, and women with better knowledge and/or attitude about amniocentesis test were more likely to accept the test. Our study suggested the importance of counseling for women and more time should be given for them to absorb information before they make their decision to uptake the amniocentesis test.
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| 3. |
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| 4. |
- Thanh Hoan, Nguyen, et al.
(författare)
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Novel Time Series Bagging Based Hybrid Models for Predicting Historical Water Levels in the Mekong Delta Region, Vietnam
- 2022
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Ingår i: CMES - Computer Modeling in Engineering & Sciences. - : Tech Science Press. - 1526-1492 .- 1526-1506. ; 131:3, s. 1431-1449
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Tidskriftsartikel (refereegranskat)abstract
- Water level predictions in the river, lake and delta play an important role in flood management. Every year Mekong River delta of Vietnam is experiencing flood due to heavy monsoon rains and high tides. Land subsidence may also aggravate flooding problems in this area. Therefore, accurate predictions of water levels in this region are very important to forewarn the people and authorities for taking timely adequate remedial measures to prevent losses of life and property. There are so many methods available to predict the water levels based on historical data but nowadays Machine Learning (ML) methods are considered the best tool for accurate prediction. In this study, we have used surface water level data of 18 water level measurement stations of the Mekong River delta from 2000 to 2018 to build novel time-series Bagging based hybrid ML models namely: Bagging (RF), Bagging (SOM) and Bagging (M5P) to predict historical water levels in the study area. Performances of the Bagging-based hybrid models were compared with Reduced Error Pruning Trees (REPT), which is a benchmark ML model. The data of 19 years period was divided into 70:30 ratio for the modeling. The data of the period 1/2000 to 5/2013 (which is about 70% of total data) was used for the training and for the period 5/2013 to 12/2018 (which is about 30% of total data) was used for testing (validating) the models. Performance of the models was evaluated using standard statistical measures: Coefficient of Determination (R2), Root Mean Square Error (RMSE) and Mean Absolute Error (MAE). Results show that the performance of all the developed models is good (R2 > 0.9) for the prediction of water levels in the study area. However, the Bagging-based hybrid models are slightly better than another model such as REPT. Thus, these Bagging-based hybrid time series models can be used for predicting water levels at Mekong data.
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| 5. |
- Thu Thao, Bui T., et al.
(författare)
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Enhancement of selective monoaromatic hydrocarbon and syngas products from fast pyrolysis of cassava stalks over Co, Mo promoted Ni catalysts
- 2024
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Ingår i: Journal of the Energy Institute. - 1743-9671. ; 115
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Tidskriftsartikel (refereegranskat)abstract
- Catalytic fast pyrolysis of cassava stalks has been intriguing as a promising, feasible chemical refinery method in terms of waste-to-energy conversion from cassava cultivation. This study aims to determine the synergetic influence of Mo and Co on Ni catalysts (Ni, Ni–Mo, and Ni–Co) prepared via ultrasonic-assisted incipient wetness impregnation method for catalytic pyrolysis vapor upgrading. The results indicated that Co and Mo enhance the reducibility of NiO and promote weak-to-medium acidity, thereby enhancing Ni's performance. Mono-Ni favors cracking deoxygenation, whereas oxophilicity promoters particularly enhance the oxygen absorbability efficiency to selective deoxygenated production. A fine Ni dispersion on CoNi/SiO2 catalyst was observed to positively affect the production of monoaromatic hydrocarbons (46.10 %), in contrast to those without promoters (21.63 %). This is attributed to an optimal Ni-metallic distribution with a small crystal size of 7.01 nm and a high surface area of 342.6 m2 g−1, highlighting the effectiveness of the promoter-assisted Ni catalyst. Additionally, a high yield of H2 (66.9 %) in non-condensable gas was recorded at 550 °C. The study suggests that a simplified approach to developing Ni-based catalysts could enhance the eco-friendliness of commercial catalysts, thereby facilitating the scale-up of biomass pyrolysis applications.
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| 6. |
- von Seidlein, Lorenz, et al.
(författare)
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The impact of targeted malaria elimination with mass drug administrations on falciparum malaria in Southeast Asia: A cluster randomised trial
- 2019
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Ingår i: PLoS Medicine. - : PUBLIC LIBRARY SCIENCE. - 1549-1277 .- 1549-1676. ; 16:2
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Tidskriftsartikel (refereegranskat)abstract
- Background The emergence and spread of multidrug-resistant Plasmodium falciparum in the Greater Mekong Subregion (GMS) threatens global malaria elimination efforts. Mass drug administration (MDA), the presumptive antimalarial treatment of an entire population to clear the subclinical parasite reservoir, is a strategy to accelerate malaria elimination. We report a cluster randomised trial to assess the effectiveness of dihydroartemisinin-piperaquine (DP) MDA in reducing falciparum malaria incidence and prevalence in 16 remote village populations in Myanmar, Vietnam, Cambodia, and the Lao Peoples Democratic Republic, where artemisinin resistance is prevalent. Methods and findings After establishing vector control and community-based case management and following intensive community engagement, we used restricted randomisation within village pairs to select 8 villages to receive early DP MDA and 8 villages as controls for 12 months, after which the control villages received deferred DP MDA. The MDA comprised 3 monthly rounds of 3 daily doses of DP and, except in Cambodia, a single low dose of primaquine. We conducted exhaustive cross-sectional surveys of the entire population of each village at quarterly intervals using ultrasensitive quantitative PCR to detect Plasmodium infections. The study was conducted between May 2013 and July 2017. The investigators randomised 16 villages that had a total of 8,445 residents at the start of the study. Of these 8,445 residents, 4,135 (49%) residents living in 8 villages, plus an additional 288 newcomers to the villages, were randomised to receive early MDA; 3,790 out of the 4,423 (86%) participated in at least 1 MDA round, and 2,520 out of the 4,423 (57%) participated in all 3 rounds. The primary outcome, P. falciparum prevalence by month 3 (M3), fell by 92% (from 5.1% [171/3,340] to 0.4% [12/2,828]) in early MDA villages and by 29% (from 7.2% [246/3,405] to 5.1% [155/3,057]) in control villages. Over the following 9 months, the P. falciparum prevalence increased to 3.3% (96/2,881) in early MDA villages and to 6.1% (128/2,101) in control villages (adjusted incidence rate ratio 0.41 [95% CI 0.20 to 0.84]; p = 0.015). Individual protection was proportional to the number of completed MDA rounds. Of 221 participants with subclinical P. falciparum infections who participated in MDA and could be followed up, 207 (94%) cleared their infections, including 9 of 10 with artemisinin-and piperaquine- resistant infections. The DP MDAs were well tolerated; 6 severe adverse events were detected during the follow-up period, but none was attributable to the intervention. Conclusions Added to community-based basic malaria control measures, 3 monthly rounds of DP MDA reduced the incidence and prevalence of falciparum malaria over a 1-year period in areas affected by artemisinin resistance. P. falciparum infections returned during the follow-up period as the remaining infections spread and malaria was reintroduced from surrounding areas. Limitations of this study include a relatively small sample of villages, heterogeneity between villages, and mobility of villagers that may have limited the impact of the intervention. These results suggest that, if used as part of a comprehensive, well-organised, and well-resourced elimination programme, DP MDA can be a useful additional tool to accelerate malaria elimination.
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| 7. |
- Axfors, Cathrine, et al.
(författare)
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Mortality outcomes with hydroxychloroquine and chloroquine in COVID-19 from an international collaborative meta-analysis of randomized trials
- 2021
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Substantial COVID-19 research investment has been allocated to randomized clinical trials (RCTs) on hydroxychloroquine/chloroquine, which currently face recruitment challenges or early discontinuation. We aim to estimate the effects of hydroxychloroquine and chloroquine on survival in COVID-19 from all currently available RCT evidence, published and unpublished. We present a rapid meta-analysis of ongoing, completed, or discontinued RCTs on hydroxychloroquine or chloroquine treatment for any COVID-19 patients (protocol: https://osf.io/QESV4/). We systematically identified unpublished RCTs (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Cochrane COVID-registry up to June 11, 2020), and published RCTs (PubMed, medRxiv and bioRxiv up to October 16, 2020). All-cause mortality has been extracted (publications/preprints) or requested from investigators and combined in random-effects meta-analyses, calculating odds ratios (ORs) with 95% confidence intervals (CIs), separately for hydroxychloroquine and chloroquine. Prespecified subgroup analyses include patient setting, diagnostic confirmation, control type, and publication status. Sixty-three trials were potentially eligible. We included 14 unpublished trials (1308 patients) and 14 publications/preprints (9011 patients). Results for hydroxychloroquine are dominated by RECOVERY and WHO SOLIDARITY, two highly pragmatic trials, which employed relatively high doses and included 4716 and 1853 patients, respectively (67% of the total sample size). The combined OR on all-cause mortality for hydroxychloroquine is 1.11 (95% CI: 1.02, 1.20; I-2=0%; 26 trials; 10,012 patients) and for chloroquine 1.77 (95%CI: 0.15, 21.13, I-2=0%; 4 trials; 307 patients). We identified no subgroup effects. We found that treatment with hydroxychloroquine is associated with increased mortality in COVID-19 patients, and there is no benefit of chloroquine. Findings have unclear generalizability to outpatients, children, pregnant women, and people with comorbidities. Hydroxychloroquine and chloroquine have been investigated as a potential treatment for Covid-19 in several clinical trials. Here the authors report a meta-analysis of published and unpublished trials, and show that treatment with hydroxychloroquine for patients with Covid-19 was associated with increased mortality, and there was no benefit from chloroquine.
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| 8. |
- Banda, Francesco, et al.
(författare)
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BIOMASS L2 Prototype Processor : Current Status
- 2019
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Ingår i: International Geoscience and Remote Sensing Symposium (IGARSS). - 9781538691540 ; , s. 5996-5999
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Konferensbidrag (refereegranskat)abstract
- The ESA BIOMASS mission will be the 7th Earth Explorer measuring the above-ground biomass (AGB) in the world's forests. The current ESA Level-2 (L2) implementation study focuses on defining and implementing the main algorithms for forest parameter retrieval from BIOMASS data. After the first year of L2 study innovative results were achieved: the development of ground cancellation, in particular, has proved to be huge value, since it removes from the data the effects of environmental variability and contributions unrelated to the forest carried in the ground scattering. In this paper the current processor implementation and validation activities of the L2 team will be described.
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| 9. |
- Banda, Francesco, et al.
(författare)
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The BIOMASS level 2 prototype processor: Design and experimental results of above-ground biomass estimation
- 2020
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Ingår i: Remote Sensing. - : MDPI AG. - 2072-4292. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- BIOMASS is ESA's seventh Earth Explorer mission, scheduled for launch in 2022. The satellite will be the first P-band SAR sensor in space and will be operated in fully polarimetric interferometric and tomographic modes. The mission aim is to map forest above-ground biomass (AGB), forest height (FH) and severe forest disturbance (FD) globally with a particular focus on tropical forests. This paper presents the algorithms developed to estimate these biophysical parameters from the BIOMASS level 1 SAR measurements and their implementation in the BIOMASS level 2 prototype processor with a focus on the AGB product. The AGB product retrieval uses a physically-based inversion model, using ground-canceled level 1 data as input. The FH product retrieval applies a classical PolInSAR inversion, based on the Random Volume over Ground Model (RVOG). The FD product will provide an indication of where significant changes occurred within the forest, based on the statistical properties of SAR data. We test the AGB retrieval using modified airborne P-Band data from the AfriSAR and TropiSAR campaigns together with reference data from LiDAR-based AGB maps and plot-based ground measurements. For AGB estimation based on data from a single heading, comparison with reference data yields relative Root Mean Square Difference (RMSD) values mostly between 20% and 30%. Combining different headings in the estimation process significantly improves the AGB retrieval to slightly less than 20%. The experimental results indicate that the implemented retrieval scheme provides robust results that are within mission requirements.
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| 10. |
- Bui, Ha Thi Thu, et al.
(författare)
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The Association Between Gender Inequalities and Women's Utilization of Maternal Health Services : A Cross-Sectional Survey in Eight South Central Coast Provinces, Vietnam
- 2018
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Ingår i: Journal of Public Health Management and Practice. - 1078-4659 .- 1550-5022. ; 24:2, s. S19-S27
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Tidskriftsartikel (refereegranskat)abstract
- Background: Gender inequalities influence the utilization of maternal health services in Vietnam, but little research has been published. This study, therefore, aimed to explore the association between gender inequalities and women's utilization of maternal health services in Vietnam.Methods: The study was conducted in 8 provinces in the South Central Coast region of Vietnam during August 2013 to May 2014. A total of 907 women who delivered a year prior to the date of interview participated in the study. A multiple logistic regression model was used to examine the association between gender inequalities (including sociodemographic determinants of health) and utilization of 4 or more antenatal care (ANC4+) services, institutional delivery, and ever used contraceptive methods.Results: The utilization rate of maternal health services was varied, from 53.9% for ANC4+ to 87.7% for ever used a contraceptive method and 97% for institutional delivery. Ethnicity was identified as the most influential variable out of all sociodemographic determinants of health. Regarding gender inequalities, couple communication was the only variable having significant association with women's utilization of maternal health services.Conclusion: Women's equal role within context of their daily life and relations with their husbands (discussing maternal care with husband and having equal income to husband) supported their use of maternal health services. Therefore, there should be concerted efforts from all relevant stakeholders including the health system to focus on disadvantaged women in planning and delivery of maternal health services, especially to ethnic minority women. Male involvement strategy should be implemented to promote maternal health care, especially during the prenatal and postpartum period. To provide more culturally sensitive and right-based approaches in delivery of maternal health services to disadvantaged women in Vietnam, interventions are recommended that promote male involvement, that is, to engage men in service delivery to adapt and ensure the most appropriate and effective maternal health care.
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| 11. |
- Burt, Tal, et al.
(författare)
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Phase 0, Including Microdosing Approaches : Applying the Three Rs and Increasing the Efficiency of Human Drug Development
- 2018
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Ingår i: ATLA (Alternatives to Laboratory Animals). - : FRAME. - 0261-1929. ; 46:6, s. 335-346
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Tidskriftsartikel (refereegranskat)abstract
- Phase 0 approaches, including microdosing, involve the use of sub-therapeutic exposures to the tested drugs, thus enabling safer, more-relevant, quicker and cheaper first-in-human (FIH) testing. These approaches also have considerable potential to limit the use of animals in human drug development. Recent years have witnessed progress in applications, methodology, operations, and drug development culture. Advances in applications saw an expansion in therapeutic areas, developmental scenarios and scientific objectives, in, for example, protein drug development and paediatric drug development. In the operational area, the increased sensitivity of Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS), expansion of the utility of Positron Emission Tomography (PET) imaging, and the introduction of Cavity Ring-Down Spectroscopy (CRDS), have led to the increased accessibility and utility of Phase 0 approaches, while reducing costs and exposure to radioactivity. PET has extended the application of microdosing, from its use as a predominant tool to record pharmacokinetics, to a method for recording target expression and target engagement, as well as cellular and tissue responses. Advances in methodology include adaptive Phase 0/Phase 1 designs, cassette and cocktail microdosing, and Intra-Target Microdosing (ITM), as well as novel modelling opportunities and simulations. Importantly, these methodologies increase the predictive power of extrapolation from microdose to therapeutic level exposures. However, possibly the most challenging domain in which progress has been made, is the culture of drug development. One of the main potential values of Phase 0 approaches is the opportunity to terminate development early, thus not only applying the principle of 'kill-early-kill-cheap' to enhance the efficiency of drug development, but also obviating the need for the full package of animal testing required for therapeutic level Phase 1 studies. Finally, we list developmental scenarios that utilised Phase 0 approaches in novel drug development.
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| 12. |
- Dai, Heng, et al.
(författare)
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Finned zeolite catalysts
- 2020
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Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-1122 .- 1476-4660. ; 19:10, s. 1074-1080
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Tidskriftsartikel (refereegranskat)abstract
- Nanosized zeolites enable better catalytic performance; however, their synthesis is non-trivial. Here, a simple treatment is presented that enables the growth of nanosized fins on zeolites that act as pseudo-nanoparticles, reducing deactivation rates for methanol-to-hydrocarbon catalysis. There is growing evidence for the advantages of synthesizing nanosized zeolites with markedly reduced internal diffusion limitations for enhanced performances in catalysis and adsorption. Producing zeolite crystals with sizes less than 100 nm, however, is non-trivial, often requires the use of complex organics and typically results in a small product yield. Here we present an alternative, facile approach to enhance the mass-transport properties of zeolites by the epitaxial growth of fin-like protrusions on seed crystals. We validate this generalizable methodology on two common zeolites and confirm that fins are in crystallographic registry with the underlying seeds, and that secondary growth does not impede access to the micropores. Molecular modelling and time-resolved titration experiments of finned zeolites probe internal diffusion and reveal substantial improvements in mass transport, consistent with catalytic tests of a model reaction, which show that these structures behave as pseudo-nanocrystals with sizes commensurate to that of the fin. This approach could be extended to the rational synthesis of other zeolite and aluminosilicate materials.
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| 13. |
- Duy, Nguyen Van, et al.
(författare)
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Enhancement of NH3 gas sensing with Ag-Pt co-catalyst on SnO2 nanofilm towards medical diagnosis
- 2023
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 767
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Tidskriftsartikel (refereegranskat)abstract
- Exhaled breath analysis is a noninvasive diagnostic method for fatal disease monitoring and screening, which is recently gained extensive interest of researchers worldwide emphasizing on the development of effective chemiresistive gas sensor for practical application. Here, the Ag-Pt bimetallic nanoparticles were used to deco-rate nanofilms of SnO2 making different gas sensors with high performance. We found that the bimetal alloy improved the sensor performance significantly with super sensitivity as compared with the separate Ag and Pt catalyst. The right ratio of the bimetal made the sensor very sensitive to NH3, so that it was able to quickly (12 s) detect 1 parts-per-million of NH3 with a response of 4.31 at a temperature of 250 degrees C. The sensor limit of detection for NH3 was less than 10 parts-per-billion. The response of the sensor was negligibly affected by humidity and interfering gases. The results showed that the tiny, robust, and inexpensive sensor developed in this work can be used in breath analysis for early diagnosis via NH3 monitoring.
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| 14. |
- Eriksson, Kimmo, et al.
(författare)
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Perceptions of the appropriate response to norm violation in 57 societies
- 2021
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Ingår i: Nature Communications. - : Nature Research. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Norm enforcement may be important for resolving conflicts and promoting cooperation. However, little is known about how preferred responses to norm violations vary across cultures and across domains. In a preregistered study of 57 countries (using convenience samples of 22,863 students and non-students), we measured perceptions of the appropriateness of various responses to a violation of a cooperative norm and to atypical social behaviors. Our findings highlight both cultural universals and cultural variation. We find a universal negative relation between appropriateness ratings of norm violations and appropriateness ratings of responses in the form of confrontation, social ostracism and gossip. Moreover, we find the country variation in the appropriateness of sanctions to be consistent across different norm violations but not across different sanctions. Specifically, in those countries where use of physical confrontation and social ostracism is rated as less appropriate, gossip is rated as more appropriate. Little is known about peoples preferred responses to norm violations across countries. Here, in a study of 57 countries, the authors highlight cultural similarities and differences in peoples perception of the appropriateness of norm violations.
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| 15. |
- Hammad Khaliq, Ahmad, et al.
(författare)
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Spatiotemporal landslide susceptibility mapping using machine learning models: A case study from district Hattian Bala, NW Himalaya, Pakistan
- 2023
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Ingår i: Ain Shams Engineering Journal. - : Elsevier. - 2090-4479 .- 2090-4495. ; 14:3
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Tidskriftsartikel (refereegranskat)abstract
- The Himalayan region, a rugged mountain zone is among the most susceptible zones to the landslide hazard due to its terrain, geography, and active tectonics. Machine learning (ML) techniques are most advanced and precise methods to develop landslide susceptibility model (LSM). The current study was designed to analyze and assess the landslide susceptibility using ML approaches for District Hattian Bala, NW Himalayas, Pakistan. The historical satellite imageries are used to generate spatiotemporal landslide inventories of year 2005, 2007 and 2012. A spatial database was created pertaining to topographic, environmental, geologic, and anthropogenic factors including slope, aspect, elevation, curvature, plane curvature, profile curvature, topographic wetness index (TWI), lithology, distance to faults, distance to streams, distance to roads, normalized difference vegetation index (NDVI) and land use/ land cover (LULC). These LCFs were selected to analyze periodic landslide susceptibility in the region. The experimental design utilized 349, 393, and 735 landslide inventory of 2005, 2007, and 2012 respectively. Two ML models, i.e., Random Forest (RF) and Logistic Regression (LR) were applied to assess landslide susceptibility determine by thirteen landslide causative factors (LCFs). The spatiotemporal landslide inventory was partitioned into training (70%) and testing (30%) landslides for respective years to check the prediction accuracies of selected ML models. Comparative analysis of different LSMs was performed by the Receiver Operator Curves – Area Under Curves (ROC-AUC). The resultant accuracy, MAE, RMSE, Kappa, Precision, Recall, F1 indicated that RF outperformed the LR model. The study aims to minimize losses to lives and potential economic damage linked with recurrent slope instabilities in the region. It is anticipated that use of ML algorithms would support concerned authorities and organizations to effectively plan and manage landslide hazard in the region.
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| 16. |
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| 17. |
- Hoang-Minh, Thao, et al.
(författare)
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Mineralogical Characterization of Di Linh Bentonite, Vietnam: A Methodological Approach of X-ray Diffraction and Transmission Electron Microscopy
- 2014
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Ingår i: Proceedings of 13th International Symposium on Mineral Exploration (ISME-XIII). - Hanoi : Vietnam National University Press, Hanoi. - 9786046215400 ; , s. 143-148
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Konferensbidrag (refereegranskat)abstract
- Vietnam has decided to establish nuclear power as further energy option. In order to develop a Vietnamese reference bentonite as potential barrier in a final repository for high radioactive waste, a detailed mineralogical investigation of Di Linh bentonite (Lam Dong province), lacustrine clay, was carried out by different methods especially transmission electron microscopy (TEM) linked with energy-dispersive X-ray (EDX). From a sample homogenized from 5 tones of the bentonite, mineral formulae of clay particles was calculated The calculation also focuses on randomly interstratifications of two and three members. The fraction <2 μm of Di Linh bentonite is composed mainly by montmorillonite (Ca0.06Mg0.03Na0.09K0.03Al1.39Fe0.25Mg0.26(OH)2 Si3.96Al0.04O10) and regular ordering (R1) illite-smectite interstratifications with K- and charge-deficiency (Ca0.04Mg0.07Na0.18K0.16Al1.76Fe0.08Mg0.16(OH)2Si3.62Al0.38O10). Additionally, Fe-poor kaolinite-smectite-vermiculite interstratifications and trace of Fe-rich chloritesmectite- vermiculite interstatifications were identified. TEM-investigations showed analytical proofs of the sedimentary character of smectite formation in the Di Linh deposit. Parent muscovite was weathered in several steps in two different environments: (i) K-leaching and layer-wise alteration into kaolinite; (ii) further edge- controlled alteration of mica into lathlike montmorillonite particles under dissolution of kaolinite layers from former kaolinite-mica intergrowths. Mineralogical composition of the Di Linh bentonite with mainly montmorillonite and illite-rich illite-smectite interstratifications shows that the Di Linh bentonite can be a suitable barrier candidate in final repositories.
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| 18. |
- Hoang-Minh, Thao, et al.
(författare)
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Use of TEM-EDX for structural formula identification of clay minerals : a case study of Di Linh bentonite, Vietnam
- 2019
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Ingår i: Journal of applied crystallography. - : International Union of Crystallography (IUCr). - 0021-8898 .- 1600-5767. ; 52:1, s. 133-147
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Tidskriftsartikel (refereegranskat)abstract
- Transmission electron microscopy linked with energy-dispersive X-ray spectroscopy (TEM-EDX) was applied to characterize mineralogical signals ofweathering processes in the Di Linh bentonite deposit (Vietnam) and to visualize the effects of Na activation on the smectitic phases. Modelling of X ray diffraction patterns (oriented mount) was applied in order to refine the computed structural formula. X-ray diffraction, X-ray fluorescence and Fouriertransform infrared spectroscopy (FT-IR) methods were also applied to verify the TEM-EDX results. An Excel-based routine has been developed in this research to allow fast computation of structural formulae and classification of the investigated clay particles. This routine supports the acquirement of 100 300 TEM-EDX analyses as a representative set of individual particles for each sample. The Excel-based routine involves end members of different clay mineral groups and interstratifications with two or three members (e.g. illite smectite interstratifications – IS-ml; dioctahedral vermiculite–smectite interstratifications – diVS-ml; and kaolinite–montmorillonite–dioctahedral vermiculite interstratifications – KSV-ml). The routine is now freely available. According to the identification procedure, the <2 mm fraction of the Di Linh bentonite (Vietnam) is composed mainly of K- and charge-deficient illite smectite interstratifications (or diVS-ml): montmorillonite-rich randomly ordered (R0) type and illite-rich regularly ordered (R1) type. Additionally, Fe-poor KSV-ml was identified.Industrial Na activation of the Di Linh bentonite resulted in an increase of theR1 diVS-ml portion and dissolution of a large part of the smectite-rich phases.The TEM-EDX approach also gave analytical proof of a sedimentary processfor Di Linh smectite. The parent muscovite was altered in two different environments: (i) K-leaching and layer-wise alteration into kaolinite (weathering), and (ii) further edge-controlled alteration of mica into lath-like montmorillonite particles associated with a dissolution of kaolinite layers from the former kaolinite–mica intergrowths by heat impact (basalt flow).
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| 19. |
- Le Toan, Thuy, et al.
(författare)
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THE BIOMASS MISSION: OBJECTIVES AND REQUIREMENTS
- 2018
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Ingår i: International Geoscience and Remote Sensing Symposium (IGARSS). ; , s. 8563-8566
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Konferensbidrag (refereegranskat)abstract
- The Earth Explorer Biomass mission will provide the scientific community with accurate maps of tropical, temperate and boreal forest biomass, including height and disturbance patterns. This information is urgently needed to improve our understanding of the global carbon cycle and to reduce uncertainties in the calculation of carbon stocks and fluxes associated to the terrestrial biosphere. It is also crucial for approaches to managing climate, such as the UNFCCC initiative known as Reducing Emissions through Degradation and Deforestation (REDD+), aimed at climate change mitigation through conservation and better management of tropical forests The required measurements are forest biomass and forest height at resolution of 200 m, and detection of deforestation at 50 m. Global maps of biomass are required with accuracy of 20% (or 10 t ha(-1) when above-ground biomass are less than 50 t ha(-1)). To achieve this Biomass will be implemented as a P-band SAR mission. It will exploit the unique sensitivity of P-band SAR together with advanced retrieval methods including polarimetric interferometry (Pol-InSAR) and SAR tomography to measure biomass, height and disturbances across the entire biomass range every 6 months. The mission will also support important secondary objectives, including sub-surface imaging in arid zones, production of a bare-earth DTM and ice applications.
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| 20. |
- Nguyen, Thuy Trinh, et al.
(författare)
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Multimodal machine learning for mental disorder detection : a scoping review
- 2023
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Ingår i: 27th international conference on knowledge based and intelligent information and engineering sytems (KES 2023). - : Elsevier. ; , s. 1458-1467
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Konferensbidrag (refereegranskat)abstract
- Recent advancements in machine learning and multimedia technologies have paved new ways for automatic medical diagnosis. In mental health, multimodal inputs such as visual and audible sensing data are promising to investigate the underlying mechanisms of many conditions, such as depression and bipolar disorders. With the increasing burden on healthcare systems, timely diagnosis of mental diseases using multiple modalities might benefit millions of people worldwide. This scoping review provides an exploratory overview of recent multimodal machine learning approaches for mental disorder screening. We also discuss a generalised end-to-end multimodal machine learning pipeline for future research and development of multimodal disease detection.
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| 21. |
- Pham, Binh Thai, et al.
(författare)
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Performance Evaluation of Machine Learning Methods for Forest Fire Modeling and Prediction
- 2020
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Ingår i: Symmetry. - Switzerland : MDPI. - 2073-8994. ; 12:6
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Tidskriftsartikel (refereegranskat)abstract
- Predicting and mapping fire susceptibility is a top research priority in fire-prone forests worldwide. This study evaluates the abilities of the Bayes Network (BN), Naïve Bayes (NB), Decision Tree (DT), and Multivariate Logistic Regression (MLP) machine learning methods for the prediction and mapping fire susceptibility across the Pu Mat National Park, Nghe An Province, Vietnam. The modeling methodology was formulated based on processing the information from the 57 historical fires and a set of nine spatially explicit explanatory variables, namely elevation, slope degree, aspect, average annual temperate, drought index, river density, land cover, and distance from roads and residential areas. Using the area under the receiver operating characteristic curve (AUC) and seven other performance metrics, the models were validated in terms of their abilities to elucidate the general fire behaviors in the Pu Mat National Park and to predict future fires. Despite a few differences between the AUC values, the BN model with an AUC value of 0.96 was dominant over the other models in predicting future fires. The second best was the DT model (AUC = 0.94), followed by the NB (AUC = 0.939), and MLR (AUC = 0.937) models. Our robust analysis demonstrated that these models are sufficiently robust in response to the training and validation datasets change. Further, the results revealed that moderate to high levels of fire susceptibilities are associated with ~19% of the Pu Mat National Park where human activities are numerous. This study and the resultant susceptibility maps provide a basis for developing more efficient fire-fighting strategies and reorganizing policies in favor of sustainable management of forest resources.
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| 22. |
- Pham-Thanh, Long, et al.
(författare)
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Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam
- 2021
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Ingår i: Viruses. - : MDPI. - 1999-4915. ; 13:3
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Tidskriftsartikel (refereegranskat)abstract
- Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4-74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.
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| 23. |
- Roskam, Isabelle, et al.
(författare)
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Parental Burnout Around the Globe : a 42-Country Study
- 2021
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Ingår i: Affective science. - : Springer Science and Business Media LLC. - 2662-205X .- 2662-2041. ; 2, s. 58-79
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Tidskriftsartikel (refereegranskat)abstract
- High levels of stress in the parenting domain can lead to parental burnout, a condition that has severe consequences for both parents and children. It is not yet clear, however, whether parental burnout varies by culture, and if so, why it might do so. In this study, we examined the prevalence of parental burnout in 42 countries (17,409 parents; 71% mothers; Mage = 39.20) and showed that the prevalence of parental burnout varies dramatically across countries. Analyses of cultural values revealed that individualistic cultures, in particular, displayed a noticeably higher prevalence and mean level of parental burnout. Indeed, individualism plays a larger role in parental burnout than either economic inequalities across countries, or any other individual and family characteristic examined so far, including the number and age of children and the number of hours spent with them. These results suggest that cultural values in Western countries may put parents under heightened levels of stress.Supplementary Information: The online version contains supplementary material available at 10.1007/s42761-020-00028-4.
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| 24. |
- Roskam, Isabelle, et al.
(författare)
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Three reasons why parental burnout is more prevalent in individualistic countries : a mediation study in 36 countries
- 2024
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Ingår i: Social Psychiatry and Psychiatric Epidemiology. - : Springer Nature. - 0933-7954 .- 1433-9285. ; 59, s. 681-694
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe prevalence of parental burnout, a condition that has severe consequences for both parents and children, varies dramatically across countries and is highest in Western countries characterized by high individualism.MethodIn this study, we examined the mediators of the relationship between individualism measured at the country level and parental burnout measured at the individual level in 36 countries (16,059 parents).ResultsThe results revealed three mediating mechanisms, that is, self-discrepancies between socially prescribed and actual parental selves, high agency and self-directed socialization goals, and low parental task sharing, by which individualism leads to an increased risk of burnout among parents.ConclusionThe results confrm that the three mediators under consideration are all involved, and that mediation was higher for self-discrepancies between socially prescribed and actual parental selves, then parental task sharing, and lastly selfdi-rected socialization goals. The results provide some important indications of how to prevent parental burnout at the societal level in Western countries.
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| 25. |
- Thi Thuy, Tran, et al.
(författare)
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Site-directed mutagenesis of an alkaline phytase: Influencing specificity, activity and stability in acidic milieu
- 2011
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Ingår i: Enzyme and Microbial Technology. - : Elsevier BV. - 0141-0229. ; 49:2, s. 177-182
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Tidskriftsartikel (refereegranskat)abstract
- Site-directed mutagenesis of a thermostable alkaline phytase from Bacillus sp. MD2 was performed with an aim to increase its specific activity and activity and stability in an acidic environment. The mutation sites are distributed on the catalytic surface of the enzyme (P257R, E180N, E229V and S283R) and in the active site (K77R, K179R and E227S). Selection of the residues was based on the idea that acid active phytases are more positively charged around their catalytic surfaces. Thus, a decrease in the content of negatively charged residues or an increase in the positive charges in the catalytic region of an alkaline phytase was assumed to influence the enzyme activity and stability at low pH. Moreover, widening of the substrate-binding pocket is expected to improve the hydrolysis of substrates that are not efficiently hydrolysed by wild type alkaline phytase. Analysis of the phytase variants revealed that E229V and S283R mutants increased the specific activity by about 19% and 13%, respectively. Mutation of the active site residues K77R and K179R led to severe reduction in the specific activity of the enzyme. Analysis of the phytase mutant-phytate complexes revealed increase in hydrogen bonding between the enzyme and the substrate, which might retard the release of the product, resulting in decreased activity. On the other hand, the double mutant (K77R-K179R) phytase showed higher stability at low pH (pH 2.6-3.0). The E227S variant was optimally active at pH 5.5 (in contrast to the wild type enzyme that had an optimum pH of 6) and it exhibited higher stability in acidic condition. This mutant phytase, displayed over 80% of its initial activity after 3 h incubation at pH 2.6 while the wild type phytase retained only about 40% of its original activity. Moreover, the relative activity of this mutant phytase on calcium phytate, sodium pyrophosphate and p-nitro phenyl phosphate was higher than that of the wild type phytase. (C) 2011 Elsevier Inc. All rights reserved.
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| 26. |
- Tran, Thi-Thuy-Quynh, et al.
(författare)
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Network Coding with Multimedia Transmission and Cognitive Networking: An Implementation based on Software-Defined Radio
- 2020
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Ingår i: REV Journal on Electronics and Communications. ; 10:3-4, s. 72-84
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Tidskriftsartikel (refereegranskat)abstract
- Network coding (NC) is considered a breakthrough to improve throughput, robustness, and security of wireless networks. Although the theoretical aspects of NC have been extensively investigated, there have been only few experiments with pure NC schematics. This paper presents an implementation of NC under a two-way relay model and extends it to two non-straightforward scenarios: (i) multimedia transmission with layered coding and multiple-description coding, and (ii) cognitive radio with Vandermonde frequency division multiplexing (VFDM). The implementation is in real time and based on software-defined radio (SDR). The experimental results show that, by combining NC and source coding, we can control the quality of the received multimedia content in an on-demand manner. Whereas in the VFDM-based cognitive radio, the quality of the received content in the primary receiver is low (due to imperfect channel estimation) yet retrievable. Our implementation results serve as a proof for the practicability of network coding in relevant applications.
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| 27. |
- Trinh, Duc Anh, et al.
(författare)
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Impact of terrestrial runoff on organic matter, trophic state, and phytoplankton in a tropical, upland reservoir
- 2016
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Ingår i: Aquatic Sciences. - : Springer Science and Business Media LLC. - 1015-1621 .- 1420-9055. ; 78:2, s. 367-379
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Tidskriftsartikel (refereegranskat)abstract
- The impact of organic matter inputs from agricultural, forest and domestic sources on aquatic processes has been considerably less studied in tropical reservoirs relative to temperate systems despite the high number of these small aquatic systems in the tropics. Here we present the results of an in situ mesocosm study that examined the impact of allochthonous organic matter on a headwater reservoir in Northern Vietnam. We examined the impact of wastewater and soils from floodplain paddies, Acacia mangium plantations and from upland slopes on the metabolic status of the reservoir. The addition of floodplain paddy soils to the reservoir water led to a rapid switch in metabolic status from net autotrophic to net heterotrophic. In contrast, the addition of wastewater in low concentrations had less impact on the metabolic status of the reservoir, reflecting the low population density in the area. The addition of floodplain paddy soils also increased phytoplankton diversity and evenness relative to the control. In summary, soils from floodplain paddies and from A. mangium plantations had the highest impact on the reservoir, with upland soils and wastewater having less of an impact. We also found that primary production in this reservoir was nitrogen limited. In order to avoid accelerating the impact of runoff on the reservoir, future management options should perhaps focus on minimizing water and sediment runoff from upstream paddy fields and from A. mangium plantations. These results also underline the importance of studying these upland tropical water bodies that can contribute an important but, on the whole, ignored part of the global carbon balance.
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| 28. |
- Xiang, Deliang, 1989-
(författare)
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Urban Area Information Extraction From Polarimetric SAR Data
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Polarimetric Synthetic Aperture Radar (PolSAR) has been used for various remote sensing applications since more information could be obtained in multiple polarizations. The overall objective of this thesis is to investigate urban area information extraction from PolSAR data with the following specific objectives: (1) to exploit polarimetric scattering model-based decomposition methods for urban areas, (2) to investigate effective methods for man-made target detection, (3) to develop edge detection and superpixel generation methods, and (4) to investigate urban area classification and segmentation.Paper 1 proposes a new scattering coherency matrix to model the cross-polarized scattering component from urban areas, which adaptively considers the polarization orientation angles of buildings. Thus, the HV scattering components from forests and oriented urban areas can be modelled respectively. Paper 2 presents two urban area decompositions using this scattering model. After the decomposition, urban scattering components can be effectively extracted.Paper 3 presents an improved man-made target detection method for PolSAR data based on nonstationarity and asymmetry. Reflection asymmetry was incorporate into the azimuth nonstationarity extraction method to improve the man-made target detection accuracy, i.e., removing the natural areas and detecting the small targets.In Paper 4, the edge detection of PolSAR data was investigated using SIRV model and Gauss-shaped filter. This detector can locate the edge pixels accurately with fewer omissions. This could be useful for speckle noise reduction, superpixel generation and others.Paper 5 investigates an unsupervised classification method for PolSAR data in urban areas. The ortho and oriented buildings can be discriminated very well. Paper 6 proposes an adaptive superpixel generation method for PolSAR images. The algorithm produces compact superpixels that can well adhere to image boundaries in both natural and urban areas.
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