Thwarting Last-Minute Voter Coercion

Counter-strategies are key components of coercion-resistant voting schemes, allowing voters to submit votes that represent their own intentions in an environment controlled by a coercer. By deploying a counter-strategy a voter can prevent the coercer from learning if the voter followed the coercer’s instructions or not. Two effective counter-strategies have been proposed in the literature, one based on fake credentials and another on revoting. While fake-credential schemes assume that voters hide cryptographic keys away from the coercer, revoting schemes assume that voters can revote after being coerced. In this work, we present a new counter-strategy technique that enables flexible vote updating, that is, a revoting approach that provides protection against coercion even if the adversary is able to coerce a voter at the very last minute of the voting phase. We demonstrate that our technique is effective by implementing it in Loki, an Internet-based coercion-resistant voting scheme that allows revoting. We prove that Loki satisfies a game-based definition of coercion-resistance that accounts for flexible vote updating. To the best of our knowledge, we provide the first technique that enables deniable coercion- resistant voting and that can evade last-minute voter coercion

Susceptibility of different populations of Tribolium confusum (Coleoptera: Tenebrionidae) to malathion (EC 57%) in flour mills of Iran

The confused flour beetle, Tribolium confusum, is a key pest of stored products such as wheat and flour. For decades, organophosphorus compounds, such as malathion and pirimiphos-methyl, have been applied against stored-product pests. In this research, susceptibility of different populations of T. confusum, collected from silos at different locations of Iran, against malathion (EC 57%), was studied in the laboratory, based on a completely randomized design. Based on pre-tests, the Bioassay Index Dose was estimated as 2 g a.i./m2. Out of 23 populations, 2 populations from Bandar-Abbas region were resistant populations against malathion (9.72% and 67.2% mortality), while one population from Khomein region was moderately resistant (86.08% mortality), and the rest of the population were susceptible to malathion (95.71% to 100% mortality). Therefore, in warm locations of Iran, where this pest has evolved resistance against malathion, other control measures shall be considered

Supersingular Isogeny-Based Ring Signature

A ring signature is a digital signature scheme that allows identifying a group of possible signers without revealing the identity of the actual signer. In this paper, we first present a post-quantum sigma protocol for a ring that relies on the supersingular isogeny-based interactive zero-knowledge identification scheme proposed by De Feo, Jao, and Plût in 2014. Then, we construct a ring signature from the proposed sigma protocol for a ring by applying the Fiat-Shamir transform. In order to reduce the size of exchanges, we use Merkle trees and show that the signature size increases logarithmically in the size of the ring. The security proofs and complexity analyses of the proposed protocols are also provided

Effects of imidacloprid, dichlorvos, pymetrozine and abamectin, on life table parameters of the predatory bug, Orius albidipennis (Hemiptera: Anthocoridae)

Effects of four pesticides (imidacloprid, dichlorvos, pymetrozine and abamectin) were evaluated on life table parameters of Orius albidipennis (Reuter). Pesticides were used at the concentrations recommended by the manufacturers. The bioassays were carried out using drum-cell method, in a growth chamber at 27 ± 1ºC, R.H. of 65 ± 5% and 16 h photo phase. The net reproductive rate (R0) value for the populations treated with imidacloprid, dichlorvos, pymetrozine, abamectin and tap water as control was, 2.91 ± 0.48, 18.85 ± 2.55, 10.16 ± 1.21, 8.00 ± 1.05, 43.40 ± 7.64; the intrinsic rate of natural increase (rm) was 0.040 ± 0.005, 0.097 ± 0.018, 0.086 ± 0.012, 0.078 ± 0.010, 0.148 ± 0.006: the mean generation time (T) was 25.60 ± 1.12, 25.94 ± 1.85, 26.37 ± 0.25, 25.61 ± 0.21, 25.20 ± 1.16; the doubling time (DT) was 18.04 ± 2.76, 7.72 ± 1.60, 8.23 ± 1.11, 9.24 ± 1.37, 4.68 ± 0.18, and the finite rate of increase (λ) was 1.041 ± 0.006, 1.102 ± 0.019, 1.090 ± 0.013, 1.081 ± 0.011, 1.160 ± 0.007, respectively. Imidacloprid and dichlorvos, which revealed the most and the least effects on the life table parameters, were the most and the least harmful among the chemicals tested

Comparative toxicity of abamectin, cyromazine and spinosad against the leaf-miner fly, Liriomyza sativae (Dip.: Agromyzidae)

The leaf-miner fly, Liriomyza sativae (Blanchard), is one of the major insect pests of vegetable crops in Iran and other countries. To determine the toxicity (LC50) of bioinsecticides abamectin 1.8% EC, cyromazine 75% WP and spinosad 24% SC against L. sativae, bioassay was done on its larval and adult stages under 25 ± 1°C, 65 ± 5% R.H. and a photoperiod of 16: 8 (L: D). The LC50 values found to be 1.5, 1.8, 14.3 ppm for abamectin, 34.8, 38.4, 1295 ppm for cyromazine and 4.4, 12.1, 13.7 ppm for spinosad against the first and last larval stages as well as the adults of L. sativae, respectively. The toxicity of the insecticides on the larval stages was higher than on adults. Using a mixture of petroleum oil, as a synergist, and the insecticides significantly increased the mortality of the first instar larvae. The results indicated that cyromazine is ineffective for the control of adults, while it is proved to be effective against the leaf-miner's larval stages. It is found that abamectin and spinosad are more efficient insecticides than cyromazine for the control of all developmental and adult stages of L. sativae

Compatibility of the entomopathogenic fungus Beauveria bassiana with the insecticides fipronil, pyriproxyfen and hexaflumuron

The compatibility of Beauveria bassiana isolate DEBI 002 (Atashgah) with fipronil, pyriproxyfenand hexaflumuron insecticides was assayed. To determine the impact of the insecticides on thegermination of the fungal spore, different concentrations of the compounds were added to the culturemedium (malt agar). In order to calculate the mycelial growth in different treatments, each colonydiameter was measured and the spores were counted in the surface area to assess its sporulation. Theresults showed that pyriproxyfen at 1500 ppm and hexaflumuron at 80 ppm completely inhibited mycelialgrowth, while the inhibitory effect of fipronil at 1600 ppm remained at 76.6%. The inhibitory effect oflower concentrations of all three insecticides was between 10 and 20%. All tested insecticides inhibitedthe spore production between 80 to 100% at the highest concentrations without any significantdifferences. Pyriproxyfen at 400 ppm and hexaflumuron at all concentrations completely inhibited sporegermination, with significant difference, comparing with the rest of treatments. The results indicate thathexaflumuron has the highest inhibitory effect on the spore germination and is not recommended to beused simultaneously with B. bassiana against the insect pests

Accuracy and efficiency of conventional ground sprayers in Iran

Sunn pest, Eurygaster integriceps, is a key pest of wheat and barley in Iran. At present, infested areas are treated with ground sprayers. A survey was conducted to evaluate the efficiency and calibration accuracy of ground hydraulic sprayers in Iran. The results showed that the motorized lance sprayer and manually operated sprayer were the most conventional sprayers, and fenitrothion EC 50% and deltamethrin EC 2.5% were the conventional insecticides against sunn pest in Kermanshah province. The mean efficacy percentage was 88% and 35% against nymphs and overwintered adults, respectively. In motorized lance sprayers, there were 5% and 90% overdosage of fenitrothion and deltamethrin, respectively; while, in manually carried sprayers, there were 5% and 25% overdosage of fenitrothion and deltamethrin, respectively. Applied dosages were 5-20% and 25-90% more than recommended dosages of fenitrothion and deltamethrin, respectively. Errors in effectiveness and applied dosage were higher in motorized lance sprayer than manually carried sprayers

Susceptibility of Males and Females of Cucumber Fruit Fly, Dacus ciliatus, to Various Insecticides in the Laboratory Conditions

Abstract The cucumber fly, Dacus ciliatus Loew., is a destructive pest of cucurbit crops in some regions of Iran. Susceptibility of adults of D. ciliatus to various insecticides (deltamethrin, dimethoate, trichlorofon, spinosad, acetamiprid, and malathion) was investigated. The insecticide toxicity was tested through contact method in three stages (males only, females only, and a mixture of males and females). The results showed that the used insecticides excellently affected on males and females of D. ciliatus through contact toxicity. Also, their effect on the mixture of males and females was acceptable. In addition, dimethoate and deltamethrin were better than the others. The LC 50 values of these two were less than 1 mg L -1 . Also, except for acetamiprid, LC 50 vales of all other insecticides on males and females were close

Effect of sub lethal concentrations of thiocyclam insecticide on biological parameters of Liriomyza sativae (Diptera: Agromyzidae) under laboratory conditions

Liriomyza sativae Blanchard is considered as one of the most important pests of greenhouse and farm vegetables. According to the recommendation of using thiocyclam insecticide against the mentioned pest, in the present study the lethal and sub-lethal effects (LC10= 49.15, LC20= 87.1 and LC30= 131.5 a.i. mg/L) of thiocyclam insecticide (Evisect® SP50%) was evaluated on the biological parameters of this pest under laboratory conditions. The method used in the experiments was Leaf dip technique for leaves containing fly larva. Data analysis was performed using Age-stage two sex life table theory.  The results showed that adult lifespan/longevity was significantly reduced by sublethal concentration. Fecundity was also affected by the studied concentrations and the lowest amount of this parameter (34.23 eggs/female) was recorded in LC30 concentration. Accordingly, sublethal concentrations reduced the net reproductive rate (R0), and there were significant differences among the values of this parameter at all treatments tested when compared with control (control: 78.01, LC10: 63.76, LC20: 33.6 and LC30: 11.58 offspring/individual). Other parameters such as intrinsic rate of increase (r), finite rate of increase (l) were also significantly lower than the control. The highest estimated values for r and λ were recorded at control (0.19 and 1.21 day-1, respectively). Finally, with the reduced rate of development for individuals treated with sublethal concentrations, the mean generation time (T) was significantly higher in individuals exposed to any concentration tested, So that it was the lowest in the control with 22.49 days and the highest in LC30 with 26.25 days. The findings of the present research indicate that thiocyclam insecticide has a good potential in controlling the leaf miner in lethal and sublethal concentrations, and the importance of considering the role of sublethal effects when attempting to evaluate the total impacts of specific pesticide on an insect pest population and its natural enemy