Lethal and sublethal effects of fenitrothion and deltamethrin residues on the egg parasitoid Trissolcus grandis (Hymenoptera: Scelionidae)

Effects of fenitrothion and deltamethrin, the most commonly used insecticides in Iran for controlling Eurygaster integriceps Puton (Heteroptera: Scutelleridae), in wheat and barley were assessed on adults and preimaginal stages of egg parasitoid Trissolcus grandis Thompson (Hymenoptera: Scelionidae). Adult parasitoids exposed to field recommended concentrations of the insecticides suffered 100% mortality within 24 h. LC50 values of fenitrothion and deltamethrin for T. grandis were 8.1 and 3.9 microg (AI) /ml, respectively. Both insecticides and the preimaginal stage of exposure had a significant influence on the level of adult emergence from host eggs treated with field recommended rates. Fenitrothion and deltamethrin reduced the emergence rates by 18 and 34.4%, respectively, compared with the control. However, neither insecticide significantly affected the longevity or reproductive capacity of emerged females, or the sex ratio of their progeny. This study revealed that application of these insecticides should be avoided in early season to conserve natural or released populations of T. grandis. Both insecticides seemed to be detrimental to the parasitoid and need to be applied cautiously through season.     

Length‐weight and length–length relationships of three algae‐scraping cyprinid species from Iran

The study presents length–weight relationships (LWRs) and length–length relationships (LLRs) for three algae‐scraper species; Capoeta coadi from the Kouhrang River (Iran; 32°23′N, 50°08′E) a part of the Tigris drainage basin, Capoeta pyragyi from Cheshmeh Langan River (32°55′N, 50°10′E) a part of Zayanderud River basin and Capoeta umbla from Chooman River (35°57′N, 45°47′E). Fish were sampled by electro fishing (Samus1000; Power Out: 200 watts) in August, September and October 2017. Sampling was carried out each months in sites covering an area of about 100 m² including runs, riffles and pools at a water depth of 10–60 cm. The obtained LWRs and LLRs showed a high level of correlation (r² > 0.99).     

Localized Surface Plasmon Resonance (LSPR)-Based Nanobiosensor for Methamphetamin Measurement

Aptamers are DNA or RNA single-stranded molecules that bind specifically to target molecules with high affinity. Function of nucleic acid aptamers is based on organized tertiary structure of them that is related to primary sequence, length of nucleic acid molecule, and environmental conditions. Herein, a localized surface plasmon resonance (LSPR) nanobioprobe has been developed based on specific aptamer-conjugated gold nanoparticles for rapid detection of methamphetamine. Detection of methamphetamine was studied via monitoring the gold nanoparticles (GNPs) LSPR band alterations in the presence of different concentrations. The covalent conjugation has been confirmed with FT-IR spectroscopy, and size alterations of gold nanoparticles before and after the conjugation state were monitored using dynamic light scattering (DLS) technique. The results show high affinity of aptamer to methamphetamine. Moreover, the results show conjugated aptamer with GNP in different concentrations of methamphetamine that contribute to color changes that is visible with unaided eye. Also, 14 nm LSPR shift was seen after conjugation of aptamer with GNP. Nanoparticle diameter after conjugation with aptamer was increased from 30 to 91 nm and decreased after incubation with methamphetamine (due to folding) from 91 to 84 nm. Detection limit of this designed nanoprobe is 500 nM. Plasmonic nanoparticle-based nanobioprobe is a new field for development of sensitive detection systems.

     

Exogenously applied paclobutrazol modulates growth in salt-stressed wheat plants

Effect of paclobutrazol (PBZ) treatment on salinity tolerance of wheat (Triticum aestivum) was investigated on a salt-tolerant (Karchia-65) and salt-sensitive (Ghods) cultivars. Salinity significantly reduced the investigated growth parameters such as plant height, length and area of sixth leaf, root length, fresh and dry weight of shoot, roots and sixth leaf, water content (WC) of plant and seeds weight in the both cultivars. The negative effect of salinity in Ghods cultivar was more than Karchia cultivar. However, PBZ treatment reduced the growth in both cultivars, the differences in plant growth among various levels of NaCl decreased in PBZ-treated plants. Salt stress resulted in high accumulation of Na⁺ in the sixth leaf and roots in both cultivars, particularly in Ghods cultivar. Against Karchia cultivar, salt stress decreased the storage of K⁺, P and N in sixth leaf and roots in Ghods cultivar. In the both cultivars, PBZ treatment enhanced the K⁺, P and N contents in sixth leaf and roots by increasing salinity. Although PBZ treatment decreased the growth of plants, it improved the weight of seeds against stress damage. PBZ treatment reduced the accumulation of harmful Na⁺ ion in plant tissues while increased the K⁺, P and N contents. These observations suggest that PBZ treatment may increase tolerance by diminishing ionic imbalance caused by salt stress.     

Epigenetic marks in estrogen receptor alpha CpG island correlate with some reproductive risk factors in breast cancer

Reproductive backgrounds, such as age at menarche and menopause, age of first full-term pregnancy (FFTP), number of full-term deliveries and oral contraceptive use are main hormone-related risk factors of breast cancer. It seems that the mentioned factors may affect the risk of breast cancer by enhancing the duration of exposure to estrogen as a potent carcinogen for breast tissue, but the molecular mechanism which links each risk factor to breast cancer is unclear. Estrogen mainly works via its nuclear receptor (ERα). As epigenetic alterations such as CpG methylation are potential links between endogenous or exogenous exposures and genome, we hypothesized that hormone-related risk factors may correlate with the epigenetic marks of the ERα promoter in breast tumors. In the present study, the CpG methylation status of the ERα gene in 99 samples of breast tumors belonged to women with different reproductive histories was evaluated. The reproductive history data were collected from patients. ERα CpG methylation was investigated by methylation specific PCR in DNA samples were obtained from the breast tumors. We could show that some of the hormone-related risk factors (early FFTP and increased number of pregnancies) were inversely correlated with epigenetic marks in ERα gene in breast tumors. Other hormone-related risk factors such as age of menarche and menopause and oral contraceptive use did not show any association with ERα methylation. It seems that pregnancy-related risk factors in comparison with other hormone-related factors work via different mechanism. As ERα methylation is a poor prognosis marker in breast tumors, its association with some modifiable reproductive risk factors (FFTP age and numbers of pregnancies) reiterates the importance of programming reproductive life style not only for prevention of breast cancer but also in favoring the prognosis of the affected women. The exact molecular mechanisms of the observed correlation need more investigation in the future.     

<Emphasis Type="Italic">Barracudia australiensis</Emphasis> n. g., n. sp. (Nematoda: Philometridae) from the obtuse barracuda <Emphasis Type="Italic">Sphyraena obtusata</Emphasis> Cuvier (Perciformes: Sphyraenidae) off eastern Australia

Based on light and scanning electron microscopical studies, a new nematode parasite, Barracudia australiensis n. sp. (Philometridae), is described from the gall-bladder of the marine fish (obtuse barracuda) Sphyraena obtusata Cuvier (Sphyraenidae, Perciformes) from off the eastern Pacific coast of Australia, for which a new genus Barracudia n. g. is established. This new genus is mainly characterised by features found in the male: sickle-shaped, ventrally curved spicules, a gubernacum with a broad, dorsally bent distal portion and a markedly dorsoventrally elongated cloacal aperture. Based on these features, Barracudia spp. conspicuously differ from representatives of all other philometrid genera with known males. Philometra philippinensis Quiazon & Yoshinaga, 2013 is transferred to Barracudia as B. philippinensis (Quiazon & Yoshinaga, 2013) n. comb. Barracudia australiensis is the third nominal species of philometrids described from the Sphyraenidae and the 19th species of the Philometridae recorded from fishes in Australian waters.     

Evaluation of COVID-19 vaccination strategies with a delayed second dose

Two of the Coronavirus Disease 2019 (COVID-19) vaccines currently approved in the United States require 2 doses, administered 3 to 4 weeks apart. Constraints in vaccine supply and distribution capacity, together with a deadly wave of COVID-19 from November 2020 to January 2021 and the emergence of highly contagious Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants, sparked a policy debate on whether to vaccinate more individuals with the first dose of available vaccines and delay the second dose or to continue with the recommended 2-dose series as tested in clinical trials. We developed an agent-based model of COVID-19 transmission to compare the impact of these 2 vaccination strategies, while varying the temporal waning of vaccine efficacy following the first dose and the level of preexisting immunity in the population. Our results show that for Moderna vaccines, a delay of at least 9 weeks could maximize vaccination program effectiveness and avert at least an additional 17.3 (95% credible interval [CrI]: 7.8–29.7) infections, 0.69 (95% CrI: 0.52–0.97) hospitalizations, and 0.34 (95% CrI: 0.25–0.44) deaths per 10,000 population compared to the recommended 4-week interval between the 2 doses. Pfizer-BioNTech vaccines also averted an additional 0.60 (95% CrI: 0.37–0.89) hospitalizations and 0.32 (95% CrI: 0.23–0.45) deaths per 10,000 population in a 9-week delayed second dose (DSD) strategy compared to the 3-week recommended schedule between doses. However, there was no clear advantage of delaying the second dose with Pfizer-BioNTech vaccines in reducing infections, unless the efficacy of the first dose did not wane over time. Our findings underscore the importance of quantifying the characteristics and durability of vaccine-induced protection after the first dose in order to determine the optimal time interval between the 2 doses.

There are two widely used COVID-19 vaccination strategies; administering the two doses three to four weeks apart or delaying the administration of the second dose. A modelling study calibrated to COVID-19 spread and vaccination in the US shows that delaying the second dose can maximize the benefits of vaccination programs under certain conditions.     

The development of inducer and effector immune suppressor cell function in Xenopus laevis, the South African clawed toad: the effect of metamorphosis

Thymic capacity to induce suppression of antibody production by immunized Xenopus laevis toadlet spleen fragments was tested in co-cultures for different developmental stages (Nieuwkoop, P.D. and J. Faber: Normal Table of Xenopus laevis (Daudin) (North Holland, Amsterdam) 1967). While thymuses of stages 52-54 (premetamorphosis) induced suppression, those of stages 58-62 (metamorphosis) did not. This capacity returned in metamorphic climax (stages 63-65). Tests of lectin-induced suppressor function in spleens of different developmental stages exposed the same pattern of compromised activity during metamorphosis. To test whether larval thymuses could effect suppression, rather than just induce it, antigen-activated thymuses from the different stages were co-cultured with immunized toadlet spleen fragments which had been suppressor-depleted by cyclophosphamide. Only thymuses from premetamorphic larvae suppressed. Thus, when thymic capacity to induce suppression returned in metamorphic climax, it was adult-like: it lacked effector suppressor cells.