Interactions between the ant Tapinoma nigerrimum (Hymenoptera: Formicidae) and the main natural enemies of the vine and citrus mealybugs (Hemiptera: Pseudococcidae)

Honeydew-excreting hemipterans, such as mealybug pests, can be protected from their natural enemies by tending ants in return for honeydew, thereby compromising the aims of biological control. In this respect, antagonistic interactions between the ant Tapinoma nigerrimum, native to the Mediterranean basin, and the main natural enemies of both the vine mealybug (VMB), Planococcus ficus, and the citrus mealybug (CM), Planococcus citri, were assessed in laboratory conditions. Parasitism of vine and CMs by their respective parasitoids, Anagyrus sp. nr. pseudococci and Leptomastix dactylopii, was negatively affected by the ant T. nigerrimum. Similarly, T. nigerrimum was shown to significantly disrupt the predatory potential of ladybird larvae, Cryptolaemus montrouzieri, when foraging on host CMs. By contrast, the presence of the ant did not negatively influence the predatory activity of C. montrouzieri adults when feeding on CMs. Consequently, the encyrtid parasitoids A. sp. nr. pseudococci and L. dactylopii and the larval stage of the predator C. montrouzieri may be considered as T. nigerrimum-sensitive, whereas the adults of C. montrouzieri may be regarded as T. nigerrimum-resistant predators. Accordingly, the ant T. nigerrimum constitutes a threat to the biological control of mealybugs by either the encyrtids A. sp. nr. pseudococci and L. dactylopii or the larval stage of the ladybird C. montrouzieri. Hence, adequate control of T. nigerrimum is highly recommended before any release of these mealybugs' natural enemies.     

Taurine for EPR dosimetry

EPR dosimetry is characterized by its non-destructive read-out and the possibility of dose archival. Here, taurine is proposed as a radiation dosimeter using EPR spectroscopy. The EPR spectrum of taurine was studied and assigned, and changes in the taurine EPR spectrum as a result of the change in both modulation amplitude and microwave power were quantified. For gamma radiation, the energy absorption coefficient and the collision mass stopping power of taurine were compared to the corresponding values of soft tissue and alanine, in addition to calculation of effective atomic numbers. The response of taurine to gamma radiation doses in the range from 0.1 to 50 kGy was investigated, as well as that in the range from 1.0 to 20.0 Gy using numerically enhanced EPR taurine spectra. Both response curves showed a linear behavior. In addition, the time dependence of radiation-induced radicals was studied for short (during the first 6 h after irradiation) and long (during about 3 months after irradiation) time periods, and a reasonable degree of stability of the taurine radicals was observed. It is concluded that taurine is a promising dosimeter, which is characterized by its simple spectrum, radical stability, and wide range of linear response to gamma radiation.     

Radiation-induced double-strand breaks require ATM but not Artemis for homologous recombination during S-phase

Double-strand breaks (DSBs) are repaired by two distinct pathways, non-homologous end joining (NHEJ) and homologous recombination (HR). The endonuclease Artemis and the PIK kinase Ataxia-Telangiectasia Mutated (ATM), mutated in prominent human radiosensitivity syndromes, are essential for repairing a subset of DSBs via NHEJ in G1 and HR in G2. Both proteins have been implicated in DNA end resection, a mandatory step preceding homology search and strand pairing in HR. Here, we show that during S-phase Artemis but not ATM is dispensable for HR of radiation-induced DSBs. In replicating AT cells, numerous Rad51 foci form gradually, indicating a Rad51 recruitment process that is independent of ATM-mediated end resection. Those DSBs decorated with Rad51 persisted through S- and G2-phase indicating incomplete HR resulting in unrepaired DSBs and a pronounced G2 arrest. We demonstrate that in AT cells loading of Rad51 depends on functional ATR/Chk1. The ATR-dependent checkpoint response is most likely activated when the replication fork encounters radiation-induced single-strand breaks leading to generation of long stretches of single-stranded DNA. Together, these results provide new insight into the role of ATM for initiation and completion of HR during S- and G2-phase. The DSB repair defect during S-phase significantly contributes to the radiosensitivity of AT cells.     

Association between chemerin rs17173608 and vaspin rs2236242 gene polymorphisms and the metabolic syndrome,a preliminary report

Metabolic syndrome (MeS) is associated with increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease. There is some evidence indicating that adipokines play a role in the development of MeS. The present study was aimed to investigate the impact of chemerin rs17173608 and vaspin rs2236242 gene polymorphisms with the risk of MeS in a sample of Iranian population.     

The effect of temperature on sperm motility and enzymatic activity in brown trout Salmo trutta, burbot Lota lota and grayling Thymallus thymallus

The effect of temperature on sperm motility was investigated in brown trout Salmo trutta, burbot Lota lota and grayling Thymallus thymallus using water and sperm motility prolonging saline solution (SMPS) for motility activation. The effect of temperature (4-20° C) on spermatozoal enzymes for energy supply [malate dehydrogenase (MDH), pyruvate kinase (PK), adenylate kinase (AK)], flagellar movement [Mg(2+) adenosine triposphatase (ATPase)] and oxidative defence [peroxidase (POX)] were measured in S. trutta and L. lota. Temperatures yielding the highest initial sperm motility rates and swimming velocities were 4-6° C for S. trutta [investigated range (IR) = 4-12° C] and L. lota (IR = 2-8° C) and 8-16° C (IR = 4-16° C) for T. thymallus. Motility variables were re-measured after 30 s in S. trutta, after 45 s in T. thymallus and after 60 s in L. lota in water and after 2 min in all investigated species in SMPS. Motility variables were increased by low temperatures and the results differed between water and SMPS. In S. trutta and L. lota, the temperature resulting in highest activities of MDH, PK, AK and ATPase was 4° C. POX had a very narrow temperature optimum at 20° C in both species. This may indicate that the temperature optimum of enzymes of energy supply and flagellar movement are closely related to motility. The present data show that the variables are affected by temperatures in an ecologically relevant range. Too low, as well as too high temperatures affected sperm motility, and the winter spawners (S. trutta and L. lota) have a narrower temperature optimum than the spring spawner T. thymallus.     

The discovery of a novel series of compounds with single-dose efficacy against juvenile and adult Schistosoma species

Treatment and control of schistosomiasis depends on a single drug, praziquantel, but this is not ideal for several reasons including lack of potency against the juvenile stage of the parasite, dose size, and risk of resistance. We have optimised the properties of a series of compounds we discovered through high throughput screening and have designed candidates for clinical development. The best compounds demonstrate clearance of both juvenile and adult S. mansoni worms in a mouse model of infection from a single oral dose of < 10 mg/kg. Several compounds in the series are predicted to treat schistosomiasis in humans across a range of species with a single oral dose of less than 5 mg/kg.     

Health-risk assessment related to the fluoride,nitrate, and nitrite in the drinking water in the Sanandaj,Kurdistan County,Iran

The concentration of fluoride and nitrate in groundwater is usually higher than that of surface water. The main objective of this study was to estimate the health-risk assessment associated with fluoride, nitrate, and nitrite in drinking water in Sanandaj and its villages. The number of samples in the Sanandaj and its rural was 106. The average concentration of fluoride in urban and rural drinking water was 0.22 mg/l and 0.27 mg/l, respectively. Fluoride concentration was also close to urban and rural drinking water. The concentration of nitrate in urban and rural drinking water was in the range between 0.28–27.77 mg/l and 1.28–80 mg/l, respectively. The concentration of nitrate reported in rural samples was higher than that of urban samples. The maximum concentration of nitrate reported in this study was 80 mg/l. The mean CDI for nitrate in the men, women, and children was 0.4258, 0.5110, and 1.1454, respectively. The findings of this study indicated that all three groups studied were exposed to nitrate contact hazards (HQ > 1). Therefore, the HQ in each of the three groups was higher than 1, which should be carefully monitored and necessary measures should be performed.     

Health risk assessment of fluoride in water distribution network of Mashhad,Iran

High and low levels of fluoride in drinking waters have been considered as a major public health issue in recent years. This cross-sectional study was conducted over five consecutive years (from 2012 to 2016) in the water distribution network of Mashhad city, Iran with the objectives of determining levels of fluoride and to perform health risk assessment among residents in the study area. Water samples were taken from 30 stations and were analyzed using UV-visible spectrophotometer. The mean annual concentrations of fluoride in all stations during five years of consecutive study were lower than the respective maximum permissible limits (1.5 mg/L) in water as regulated by the WHO. The human health risk assessment was performed by calculating the chronic daily intake and hazard quotient (HQ) of fluoride through human oral intake for adults (men and women) and children for each year during a five-year study. Health risk analysis in this study presented that the non-carcinogenic risk associated with fluoride exposure through drinking water in Mashhad was mostly acceptable because the mean HQ values of fluoride were lower than 1.     

Isocostic Acid,a Promising Bioactive Agent from the Essential Oil of Inula viscosa (L.): Insights from Drug Likeness Properties,Molecular Docking and SAR Analysis

The chemical composition of the essential oil (LEO) and its volatile fractions (V₁–V₁₀) collected during the hydrodistillation process every 15 min from the fresh leaves of I. viscosa (L.), growing in Tunisia, were analyzed by GC‐FID and GC/MS. Eighty‐two compounds, representing 90.9–99.4 % of the total samples, were identified. The crude essential oil (LEO) and its fractions (V₁–V₁₀) were characterized by the presence of a high amount of oxygenated sesquiterpenes (82.7–95.8 %). Isocostic acid ( 1 ) was found to be the most abundant component (37.4–83.9 %) and was isolated from the same essential oil over silica gel column chromatography and identified by spectroscopic methods (¹H, ¹³C, DEPT 135 NMR and EI‐MS) and by comparison with literature data. Furthermore, the fresh leaves essential oil (LEO), its volatile fractions (V₁–V₁₀) as well as compound 1 were screened for their antibacterial, antityrosinase, anticholinesterase and anti‐5‐lipoxygenase activities. It was found that the isolated compound 1 exhibited an interesting antibacterial activity against Staphylococcus aureus ATCC 25923 (MIC=32 μg/mL) and Enterococcus faecalis ATCC 29212 (MIC=32 μg/mL) and the highest antityrosinase activity (IC₅₀=13.82±0.87 μg/mL). Compound 1 was also found to be able to strongly inhibit 5‐lipoxygenase with an IC₅₀ value of 59.21±0.85 μg/mL. The bioactivity and drug likeness scores of compound 1 were calculated using Molinspiration software and interpreted, and the structure‐activity relationship (SAR) was discussed with the help of molecular docking analysis.