Flood-prone area mapping using machine learning techniques: a case study of Quang Binh province, Vietnam

Vietnam’s central coastal region is the most vulnerable and always at flood risk, severely affecting people’s livelihoods and socio-economic development. In particular, Quang Binh province is often affected by floods and storms over the year. However, it still lacks studies on flood hazard estimation and prediction tools in this area. This study aims to develop a flooding susceptibility assessment tool using various machine learning (ML) techniques namely alternating decision tree (AD Tree), logistic model tree (LM Tree), reduced-error pruning tree (REP Tree), J48 decision tree (J48) and Naïve Bayes tree (NB Tree); historical flood marks; and available data of topography, hydrology, geology, and environment considering Quang Binh province as a study area. We used flood mark locations of major flooding events in the years 2007, 2010, and 2016; and ten flood conditioning factors to construct and validate the ML models. Various validation methods, including area under the ROC curve (AUC), were used to validate and compare the models. The result of the models’ validation suggests that all models have good performance: AD Tree (AUC = 0.968), LM Tree (AUC = 0.967), REP Tree (AUC = 0.897), J48 (AUC = 0.953), and NB Tree (AUC = 0.986). Out of these, NB Tree managed to achieve the best performance in terms of flood prediction with an accuracy higher than 92 %. The final flood susceptibility map highlights 6,265 km2 (78.8 % area) with a very low flooding hazard, 391 km2 (4.9 % area) with a low flooding hazard, 224 km2 (2.8 % area) with a moderate flooding hazard, 243 km2 (3.1 %) with a high flooding hazard, and 829 km2 (10.4 % area) with very high flooding hazard. The final flooding susceptibility assessment map could add a valuable source for flood risk reduction and management activities of Quang Binh province

Meloidogyne-SP4 effector gene silencing reduces reproduction of root-knot nematodes in rice (Oryza sativa)

International audienceThe root-knot nematodes (RKN) Meloidogyne graminicola and M. incognita are responsible for rice yield losses worldwide, particularly in Asia and Africa. Previous studies demonstrated that nematode-secreted proteins are crucial for root invasion and establishment in the host. We present some characteristics of a pioneer effector, M. incognita- secreted protein 4 (Mi-SP4), which is conserved in RKN and required for infection in compatible rice-RKN interactions. In situ hybridisation assays revealed Mi-SP4 expression in the dorsal pharyngeal gland of M. incognita second-stage juveniles (J2). Meloidogyne - SP4 transcripts strongly accumulated in pre-parasitic J2 and decreased in later parasitic stages of M. incognita and M. graminicola . Transient expression of the nematode effector gene in Nicotiana benthamiana leaves and onion cells indicated that GFP-tagged Mi-SP4 was present in the cytoplasm and accumulated in the nucleus of the plant cells. In vitro RNA interference (RNAi) gene silencing, obtained by soaking J2 with small-interfering (si)RNA si4-1, decreased Mi - SP4 expression in J2 by 35% and significantly reduced M. incognita reproduction in rice by at least 30%. Similarly, host-mediated gene silencing of the nematode SP4 effector candidate gene in transgenic rice plants significantly reduced M. graminicola reproduction by 26% to 47%. The data obtained demonstrate that Mi -SP4 is a pioneer virulence effector, which plays an essential role in both M. incognita and M. graminicola pathogenicity on rice

A Generic Framework for Accountable Optimistic Fair Exchange Protocol

Optimistic Fair Exchange protocol was designed for two parties to exchange in a fair way where an arbitrator always remains offline and will be referred only if any dispute happens. There are various optimistic fair exchange protocols with different security properties in the literature. Most of the optimistic fair exchange protocols satisfy resolution ambiguity where a signature signed by the signer is computational indistinguishable from the one resolved by the arbitrator. Huang et al. proposed the first generic framework for accountable optimistic fair exchange protocol in the random oracle model where it possesses resolution ambiguity and is able to reveal the actual signer when needed. Ganjavi et al. later proposed the first generic framework in the standard model. In this paper, we propose a new generic framework for accountable optimistic fair exchange protocol in the standard model using ordinary signature, convertible undeniable signature, and ring signature scheme as the underlying building blocks. We also provide an instantiation using our proposed generic framework to obtain an efficient pairing-based accountable optimistic fair exchange protocol with short signature

High-Precision Privacy-Preserving Real-Valued Function Evaluation

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Intensified antituberculosis therapy in adults with tuberculous meningitis

BACKGROUND: Tuberculous meningitis is often lethal. Early antituberculosis treatment and adjunctive treatment with glucocorticoids improve survival, but nearly one third of patients with the condition still die. We hypothesized that intensified antituberculosis treatment would enhance the killing of intracerebral Mycobacterium tuberculosis organisms and decrease the rate of death among patients. METHODS: We performed a randomized, double-blind, placebo-controlled trial involving human immunodeficiency virus (HIV)–infected adults and HIV-uninfected adults with a clinical diagnosis of tuberculous meningitis who were admitted to one of two Vietnamese hospitals. We compared a standard, 9-month antituberculosis regimen (which included 10 mg of rifampin per kilogram of body weight per day) with an intensified regimen that included higher-dose rifampin (15 mg per kilogram per day) and levofloxacin (20 mg per kilogram per day) for the first 8 weeks of treatment. The primary outcome was death by 9 months after randomization. RESULTS: A total of 817 patients (349 of whom were HIV-infected) were enrolled; 409 were randomly assigned to receive the standard regimen, and 408 were assigned to receive intensified treatment. During the 9 months of follow-up, 113 patients in the intensified-treatment group and 114 patients in the standard-treatment group died (hazard ratio, 0.94; 95% confidence interval, 0.73 to 1.22; P=0.66). There was no evidence of a significant differential effect of intensified treatment in the overall population or in any of the subgroups, with the possible exception of patients infected with isoniazid-resistant M. tuberculosis. There were also no significant differences in secondary outcomes between the treatment groups. The overall number of adverse events leading to treatment interruption did not differ significantly between the treatment groups (64 events in the standard-treatment group and 95 events in the intensified-treatment group, P=0.08). CONCLUSIONS: Intensified antituberculosis treatment was not associated with a higher rate of survival among patients with tuberculous meningitis than standard treatment. (Funded by the Wellcome Trust and the Li Ka Shing Foundation; Current Controlled Trials number, ISRCTN61649292. opens in new tab.)</p

A Note on the Invisibility and Anonymity of Undeniable Signature Schemes

Undeniable signature is a special featured digital signature which can only be verified with the help of the signer. Undeniable signature should satisfy invisibility which implies the inability of a user to determine the validity of a message and signature pair as introduced by Chaum et al. Galbraith and Mao later proposed the notion of anonymity which implies the infeasibility to determine which user has issued the signature. They also proved that the notions of invisibility and anonymity are equivalent when the signers possess the same signature space, such that if an undeniable signature possesses invisibility, then it also possesses anonymity, and vice versa. In this paper, we show that in contradiction to the equivalency result established by Galbraith and Mao, there exist some undeniable signature schemes that possess invisibility but not anonymity. This motivates us to find out whether there is a limitation on Galbraith and Mao’s equivalency result or the schemes are actually flawed. Our analysis shows that the anonymity property requires all signers to possess the same signature space but the invisibility property does not. This conforms to the equivalency result and implies that an undeniable signature scheme can be invisible but not anonymous if the signers possess the different signature spaces. Our result invalidates two past cryptanalysis on undeniable signature schemes