Metal concentrations in razor clam Solen dactylus (Von Cosel, 1989) (Bivalvia: Solenidae), sediments and water in Golshahr coast of Bandar Abbas, Persian Gulf

In a complementary field study, the concentrations of some metals (Cu, Ag, Pb, Zn, Ni, Co, Mn, Fe, As, Cd, Cr, Mg and Ba) were measured in clam Solen dactylus, sediments and water collected at two stations (Park-e-Qadir, 56° 20/ E, 27° 11/ and Nakhl-e-Nakhoda, 56° 23/ E, 27° 10/ N) of Bandar Abbas coastal waters of the Persian Gulf in November 2008 and February 2009 showing different contamination levels. Although there is little information on metal concentrations in macro-benthic animals in this area, this study, for the first time, reports the accumulation of some metals in S. dactylus in order to introduce this species as a bioindicator for this area. Results indicated that Mg and Fe were the two most abundant metals in clams and sediments. The maximum and minimum metal concentrations in clams belonged to Mg (3850-5040 µgg-1 dry wt) and Ag (0.30-0.40-0.58 µgg-1 dry wt), respectively. There was a significant relationship between the accumulation of metals in clams, sediment and water samples. A significant relationship between clam lengths and concentrations of Cu (positive) and Mg (negative) were observed. Our study also showed that variable metal concentrations were related to different sampling stations, seasons and their interactions as well. Bioaccumulation of metals in clams was significantly different for eight metal elements between start of the gametogenesis and ripeness stages. Our investigation indicated that the clam S. dactylus could be a useful bioindicator for Zinc

Sniffer dogs as a screening/diagnostic tool for COVID-19: a proof of concept study

Background: Sniffer dogs are able to detect certain chemical particles and are suggest to be capable of helping diagnose some medical conditions and complications, such as colorectal cancer, melanoma, bladder cancer, and even critical states such as hypoglycemia in diabetic patients. With the global spread of COVID-19 throughout the world and the need to have a real-time screening of the population, especially in crowded places, this study aimed to investigate the applicability of sniffer dogs to carry out such a task. Methods: Firstly, three male and female dogs from German shepherd (Saray), German black (Kuzhi) and Labrador (Marco) breeds had been intensively trained throughout the classical conditioning method for 7 weeks. They were introduced to human specimens obtained from the throat and pharyngeal secretions of participants who were already reported positive or negative for SARS-COV-2 infection be RT-PCR. Each dog underwent the conditioning process for almost 1000 times. In the meantime another similar condition process was conducted on clothes and masks of COVID-19 patient using another three male and female dogs from Labrador (Lexi), Border gypsy (Sami), and Golden retriever (Zhico) breeds. In verification test for the first three dogs, 80 pharyngeal secretion samples consisting of 26 positive and 54 negative samples from different medical centers who underwent RT-PCR test were in a single-blind method. In the second verification test for the other three dogs, masks and clothes of 50 RT-PCR positive and 70 RT-PCR negative cases from different medical center were used. Results: In verification test using pharyngeal secretion, the sniffer dogs� detection capability was associated with a 65 of sensitivity and 89 of specificity and they amanged to identify 17 out of the 26 positive and 48 out of the 54 true negative samples. In the next verification test using patients� face masks and clothes, 43 out of the 50 positive samples were correctly identified by the dogs. Moreover, out of the 70 negative samples, 65 samples were correctly found to be negative. The sensitivity of this test was as high as 86 and its specificity was 92.9. In addition, the positive and negative predictive values were 89.6 and 90.3, respectively. Conclusion: Dogs are capable of being trained to identify COVID-19 cases by sniffing their odour, so they can be used as a reliable tool in limited screening. © 2021, The Author(s)