Crustaceans functional diversity in mangroves and adjacent mudflats of the Persian Gulf and Gulf of Oman.

The effects of mangrove vegetation on functional features of crustacean assemblages were investigated using the Biological Traits Analysis (BTA). The study was carried out at four major sites in the arid mangrove ecosystem of the Persian Gulf and Gulf of Oman. Samples of Crustacea and associated environmental variables were taken seasonally (February 2018 and June 2019) from two habitats: a vegetated area with both mangrove trees and pneumatophores, and an adjacent mudflat. In each site, functional traits for the species were assigned using seven categories based on bioturbation, adult mobility, feeding habits and life-strategy traits. The results showed that the crabs (i.e., Opusia indica, Nasima dotilliformis and Ilyoplax frater) were widely distributed across all sites and habitats. The vegetated habitats supported higher taxonomic diversity than the mudflats, which highlights the importance of mangrove structural complexity for crustacean assemblages. Species inhabiting vegetated habitats were characterized by stronger presence of conveyor building species, detritivore, predator, grazer, lecithotrophic larval development, body size of 50-100 mm, and swimmer trait modalities. While, mudflat habitat enhanced the occurrences of surface deposit feeder, planktotrophic larval development, body size of <5 mm, and life span of 2-5 years. The results of our study showed that taxonomic diversity increased from the mudflats to the mangrove vegetated habitats. However, functional diversity did not differ between habitats. The significant differences in species and functional trait composition were observed between vegetated habitats and adjacent mudflats, stressing that different habitats may harbor different species and trait sets, likely as a result of habitat complexity. The use of taxonomic and functional attributes generate complementary information that can helps us to reach more efficient conclusions in terms of biodiversity conservation and ecosystem functionality in mangrove ecosystems.

Measurement of neutron equivalent dose in the thyroid, chiasma, and lens for patients undergoing pelvic radiotherapy: A phantom study.

Radiotherapy is one of the most common methods for treating malignant diseases, whose ultimate goal is to deliver lethal doses to tumor cells. One of the unwanted consequences of radiotherapy is secondary radiation outside the treatment field, which imposes additional doses to healthy tissues and organs, specifically neutron doses, which we aim to evaluate. Therefore, this study aims to measure the fast neutron equivalent dose and the risk of secondary cancer in the thyroid, chiasm, and lenses in the treatment of the pelvic area. In this study, CR-39 detectors were used to measure the equivalent fast neutron dose in different sections of the RANDO Phantom (thyroid, chiasm, and lenses) and were irradiated by the energy of 18 MV on Varian Clinac 2100 C-D linear accelerator. CR-39 detectors were calibrated with predetermined doses by an Am-Be neutron source. Then, after etching and reading processes, the equivalent dose of fast neutrons was determined. According to the results, the fast neutron doses in the thyroid, right and left eye lenses, and chiasm were 0.613 ± 0.024, 0.835 ± 0.040, 0.866 ± 0.016, and 0.685 ± 0.045 mSv/Gy, respectively. Moreover, the secondary cancer risks in the unshielded organs are 0.004, 0.029, 0.030, and 0.025 for the thyroid, right and left eye lenses, and chiasm, respectively. In conclusion, the contribution of neutrons to the secondary doses in the out-of-field organs is significant and should not be ignored.

Gold-nanoparticle-enriched breast tissue in breast cancer treatment using the INTRABEAM® system: a Monte Carlo study.

Using a 50-kV INTRABEAM® system after breast-conserving surgery, breast skin injury and long treatment time remain the challenging problems when large-size spherical applicators are used. This study has aimed to address these problems using gold (Au) nanoparticles (NPs). For this, surface and isotropic doses were measured using a Gafchromic EBT3 film and a water phantom. The particle propagation code EGSnrc/Epp was used to score the corresponding doses using a geometry similar to that used in the measurements. The simulation was validated using a gamma index of 2%/2 mm acceptance criterion in the gamma analysis. After validation Au-NP-enriched breast tissue was simulated to quantify any breast skin dose reduction and shortening of treatment time. It turned out that the gamma value deduced for validation of the simulation was in an acceptable range (i.e., less than one). For 20 mg-Au/g-breast tissue, the calculated Dose Enhancement Ratio (DER) of the breast skin was 0.412 and 0.414 using applicators with diameters of 1.5 cm and 5 cm, respectively. The corresponding treatment times were shortened by 72.22% and 72.30% at 20 mg-Au/g-breast tissue concentration, respectively. It is concluded that Au-NP-enriched breast tissue shows significant advantages, such as reducing the radiation dose received by the breast skin as well as shortening the treatment time. Additionally, the DERs were not significantly dependent on the size of the applicators.

Food sources for camptandriid crabs in an arid mangrove ecosystem of the Persian Gulf: a stable isotope approach.

Crabs of the family Camptandriidae are the most dominant burrowing crabs inhabiting arid mangrove forests of the Persian Gulf. They play important roles in the structuring and functioning of mangrove ecosystems by modulating biogeochemical processes and cycling of nutrients, serving as important ecosystem engineers. We analysed stable carbon (13C) and nitrogen (15N) isotope values of three camptandriid crabs (Opusia indica, Nasima dotilliformis, and Manningis arabicum) and their potential food sources in the Hara Biosphere Reserve, northern Persian Gulf. A Bayesian mixing model was used to estimate the contribution of potential food sources for consumers. The results showed that to some degree, all the four sources selected contributed to the camptandriid diets, but microphytobenthos made the most important contributions to the diet of the consumers. Mangroves do not appear to be a significant source of carbon in the diet of camptandriid crabs in the arid mangrove system of the Persian Gulf. Rather, they offer favourable growing conditions, thus boosting microphytobenthos production and availability for consumers which prefer a high nutritional and palatable source.

Dosimetric effect of nanoparticles in the breast cancer treatment using INTRABEAM®system with spherical applicators in the presence of tissue heterogeneities: A Monte Carlo study.

Using the 50 kV INTRABEAM®IORT system after breast-conserving surgery: tumor recurrence and organs at risk (OARs), such as the lung and heart, long-term complications remain the challenging problems for breast cancer patients. So, the objective of this study was to address these two problems with the help of high atomic number nanoparticles (NPs). A Monte Carlo (MC) Simulation type EGSnrc C++ class library (egspp) with its Easy particle propagation (Epp) user code was used. The simulation was validated against the measured depth dose data found in our previous study (Tegaw,et al2020 Dosimetric characteristics of the INTRABEAM®system with spherical applicators in the presence of air gaps and tissue heterogeneities,Radiat. Environ. Biophys. (10.1007/s00411-020-00835-0)) using the gamma index and passed 2%/2 mm acceptance criteria in the gamma analysis. Gold (Au) NPs were selected after comparing Dose Enhancement Ratios (DERs) of bismuth (Bi), Au, and platinum (Pt) NPs which were calculated from the simulated results. As a result, 0.02, 0.2, 2, 10, and 20 mg-Au/g-breast tissue were used throughout this study. These particles were not distributed in discrete but in a uniform concentration. For 20 mg-Au/g-breast tissue, the DERs were 3.6, 0.420, and 0.323 for breast tissue, lung, heart, respectively, using the 1.5 cm-diameter applicator (AP) and 3.61, 0.428, and 0.335 forbreast tissue, lung, and heart using the 5 cm-diameter applicator, respectively. DER increased with the decrease in the depth of tissues and increase in the effective atomic number (Zeff) and concentration of Au NPs, however, there was no significant change as AP sizes increased. Therefore, Au NPs showed dual advantages such as dose enhancement within the tumor bed and reduction in the OARs (heart and lung).