n. hassanzadeh

The major disease of Persian walnut is walnut blight caused by the bacterium Xanthomonas arboricola pv. juglandis. This disease limits walnut production in many regions of the world in particular those with warm and humid springs. All succulent tissues including recent shoots, fruits and catkins may be attacked but their sensitivity decreases over time. Symptoms on leaves begin as small, water-soaked spot that can expand to form angular necrotic lesions surrounded by a yellow hallo. Infection on the hull of the unripe fruits is initiates as a dark spot, which rapidly creates dark sunken lesions. If fruit infection occurs before shell hardening, the kernels are usually destroyed, infection after shell hardening results in dark kernels and poor-quality nuts, while the kernel is until consumable. The main current strategy for walnut blight control is to protect succulent tissues by copper-based sprays from bud-burst. However, multiple copper sprays do not always control the disease and there is the risk of development of copper resistant bacterial strains. Cultivation of resistant cultivars is the most practical, environmental friendly and economical approach for controlling of this disease. So far, there have not been any cultivar completely resistant or immune to this disease. However, variation in susceptibility level has been shown to occur, worldwide. The objective of this study was to determine leaf and unripe fruit resistance of Iranian promising walnut genotypes in response to controlled inoculation with X. arboricola pv. juglandis in orchard and laboratory conditions.

In this research, the relative resistance of leaf and unripe fruits to bacterial blight were studied in a number of promising walnut genotypes replicated during two years of 2015 and 2016. The local genotypes have been selected through massive surveys of native orchards in different provinces of the country. The main selective criterion for walnut selection was late leafing trait. In addition, correlation between leaf blight and unripe fruit blight severities were studied. The material included H1-7, H2-1, SHK2, Vina, Round de montignac (RDM), Lara, G4, G5, B10 and K15 genotypes and cultivars. From this material, KZ3, 88-2, 88-1 and G3 were registered and released in year 2019. Also, Serr, Chandler and Hartley cvs. were used as controls. A mixture of four local bacterial isolates originated from Qazvin, Karaj, Zanjan and Urmie was used as inoculum. The bacterial strains have already been characterized using different phenotypical and molecular tests. They were cultured on Nutrient Agar (NA) plates at 28 ℃. After 72 hours of cultivation, the colonies were suspended in distilled water; the concentration of the suspensions was read by spectrophotometer and after equalization, mixed and used as inoculum. Assessing leaf resistance was performed by spraying one year old grafted seedlings in glasshouse condition and lesion area was recorded 21 days after inoculation. Three leaves (contacting leaflets) of three seedlings were used per genotype. Assessing unripe fruit resistance was achieved by inoculating 45 days old fruits in laboratory condition and lesion diameter data was read 15 days after inoculation. 15 fruits per genotype were used and three lesions were created in each fruit. Statistical analysis of data was performed by Duncan Multiple test range using SAS software.

Based on the results, leaf and unripe fruit blight severities were different among different cultivars and genotypes in both years of evaluation. Combined analysis of blight severity data indicated that G3 (Alvand) and 88-2 (Persian) genotypes had the most leaf blight severity and thus, rated as the most susceptible, while Hartley cultivar had the least leaf blight severity and thus, as the most resistant. Based on combined analysis of data, H1-1 and SHK2 genotypes had the most blight diameters of unripe fruits and thus rated as the most susceptible and resistant genotypes, respectively. Leaves of newly released cultivars of Persian, Caspian, Alvand and Chaldoran were rated as susceptible, relatively resistant, susceptible and relatively susceptible, respectively. On the other hand, unripe fruits of Persian, Caspian, Alvand and Chaldoran were classified as resistant, resistant, relatively resistant and susceptible, respectively. Mean leaf blight severities were not different between the two years of study and also there was no difference between unripe fruit severities between two years of the experiment. No significant correlation was found between leaf blight and unripe fruit blight severities.

LAS is a major component of household and industrial detergents, which has caused many problems in the biological and non-biological sectors during the last decade due to the discharge of raw urban sewage into aquatic ecosystems. Considering the importance of this issue, the present study examines the concentration, distribution and evaluation of the ecological risk of this pollutant in the Anzali International Wetland.

50 stations from Anzali wetland water were selected for sampling. After measuring some water qualitative factors such as temperature, acidity, electrical conductivity and dissolved oxygen at the sampling site, samples were transferred to the laboratory and analysis and extraction of samples was performed using Methylene Blue method. Statistical analysis was performed using SPSS-22 software, pollution concentration zoning map using the conventional kriging method in ArcGIS 10.3 software and LAS risk estimation calculations using RQ formula in Excel software.

Based on research findings, LAS concentration was in the range of 0.01-3.93 mg/L. The highest concentration of LAS was observed in stations of central and eastern part of the wetland and the lowest concentrations in western and Siyah Kashim stations. The results of calculating the risk assessment (RQ) and the zoning of this pollutant showed a higher risk in many areas of the wetlands.

Considering the high concentrations of LAS in most areas of Anzali Wetland, it is necessary to pay more attention to management of urban wastewaters discharge and treatment of municipal wastewater of Anzali port and its adjacent areas and to control the entry of raw wastes into the wetland.

Linear alkyl benzene Sulfonate (LAS) is a major anionic surfactant utilized in detergents around the world and is subsequently a ubiquitous water contaminant. This paper deals with assessing human health risk due to LAS in Anzali Wetland between different age groups. Water samples were collected from 50 stations in the wetland. LAS concentration was determined by spectrophotometry at 650 nm. The risk quotients (RQ) index was used to assess the human health risk assessment of LAS in the wetland. Based on the results, the health risk index was lower than 0.2 in all stations, indicating that there is no LAS contaminant risk for human health in this wetland. However, due to the presence of the different unregulated discharge of wastewater to the wetland, without strong policies to control and management, the risk of contamination may increase in the future.

In the past decades, due to population growth and industrial activities, important water resources around the world have been exposed to domestic, industrial and agricultural wastewater. One of the most important wastewater pollutants is linear alkylbenzene sulphonates (LASs). This study aimed to investigate the concentration and health risk assessment of these compounds in the Abbasabad River in Hamadan.

This descriptive study was conducted in the spring of 2019 from the water sample of Abbasabad River in 17 stations. In this study, the optimized and modified method of methylene blue was used to measure the amount of LAS. After preparing the samples using the methylene blue method, the organic phase of the sample was separated and the LAS absorption was read using a spectrophotometer at a wavelength of 650 nm, and the LAS concentration was calculated using the obtained absorption and calibration curve. LAS health risk assessment was performed by calculating the risk quotient (RQ) index.

The results showed LAS concentration ranged from 0.11 to 2.65 mg/L with a mean of 1.25 mg/L. Based on field observations, the entry of untreated wastewater into the Abbasabad River was the main cause of the high concentration of LAS. The results of the health risk assessment showed no risk in different age groups.

The results show that at this level of LAS concentration in the Abbasabad River of Hamadan, there is no significant concern for human health. However, it is worthwhile to prevent the entry of untreated or inadequately treated wastewater into valuable water resources.

The current study investigated the concentration of Cu, Pb, Zn, Cd, Ni, and Cr in shell and soft tissue of Saccostrea cucullata, water, and sediments of seven stations in Qeshm Island of Persian Gulf.

The samples were digested by a combination of nitric acid and perchloric acid and the concentration of elements was measured by atomic absorption spectroscopy.

The results indicated that the concentrations of Cu and Zn in all samples, Ni in the sediment and Cd in oyster were the highest bio-water accumulation factor were significantly higher than those of bio-sediment accumulation factor. Also, these factors in the soft tissue were higher than in the shell. Furthermore, the macro-concentrators of soft tissue were Cd, Cu, and Zn, while the macro-concentrator of shell was Cd.

The shell can be an appropriate monitoring tool for evaluating Cu and Zn in water and Cu in sediments. Also, the soft tissue can be practical for monitoring Cu and Zn in sediments.

Background and Objectives:

 Khuzestan is the only province with sugarcane cultivation. One of the limiting factors in the production of this crop is the occurrence of frost damages in some years. Since no comprehensive research has yet been conducted on detection and evaluation of bacteria with the potential to form nuclear ice in frostbite, this study was carried out to evaluate this subject.

 Materials and Methods:

 This study was carried out in the laboratory of Institute for Research and Training of Sugar and Auxiliary Industries. Endophytic and epiphytic strains of bacteria were isolated from sugarcane. To test the freezing potential of representative strains, four tests including, "determination of Ice nucleation activity by freezing in the tube", "freezing droplet test at -20 °C", "Ice nucleation test on sugarcane cut leaves in vitro" and "Ice nucleation test on sugarcane plant in greenhouse conditions" were performed. Also the genes of the nucleus were detected by 3076f / 3463r and 3308f / 3463r specific primers. 

Results:

 Results show that bacteria species B. gladioli, B. fungorum, B. cantaminans, M. huakuii, O. ciceri, M. proteolyticum, M. Foliorum, R. solanacearum , R. picketii and X. campestris had different degrees of symptoms. In addition, the genes of the nucleus were detected by 3076f / 3463r and 3308f / 3463r specific primers. For all of above mentioned bacterial strains, specifically strain X. campestris, no references have been reported of ice nucleation activity. To assess susceptibility or resistance of sugarcane, cultivar CP69-1062 were the most susceptible and highly damaged in the tests including "Ice nucleation test on sugarcane cut leaves in vitro" and "Ice nucleation test on sugarcane plant in greenhouse conditions". In addition, CP57-614 and CP48-103 cultivars showed minimum variation in frosting in compression to CP69-1062 cultivar. Two cultivars including CP73-21 and SP70-1143 exhibited a high degree of resistance to frostbite.

 Discussion:

 Due to the high variation among Ice-Nucleating bacteria and the sensitivity of commercial cultivars, our finding can be a suitable option for producers and encourage them to use resistant cultivars in the field.

Research has shown that assessing the toxicity and ecological risk of various types of pollutants, including heavy metals, using specific indicators, is indispensable in the ecological risk assessment of the ecosystem. Accordingly, the aim of this study was the assessment of the ecological effect of heavy metals presence (Pb, Zn, Cu, Cd and, As) in Anzali wetland using Heavy Metals Pollution Index (HPI). 43 water samples were collected from the eastern, western and central parts of Anzali wetland. The samples were transferred to the laboratory, and the preparation steps were carried out using the ASTM method. Concentration of the elements was determined by Inductively Coupled Plasma -Atomic Emission Spectroscopy (ICP-AES). According to the concentration of heavy metals in the water samples, the index (HPI) was calculated. The results of the HPI index were classified into three classes: low risk (<15), moderate (15-30), and high risk (> 30). The numerical value of the HPI index was 3.59-23.3 with an average of 27.97, indicating the average level of heavy metals pollution in Anzali wetland. Indicator (HPI) in the eastern part of Anzali wetland and ​​the Pirbazar area showed a severe contamination and ecological hazard of the heavy metals and in the Abkenar region showed an acceptable ecological status. Although the average of HPI in the whole Anzali wetland was modest, but at some stations, especially in the east of the wetland, the HPI indicates the occurrence of ecological hazards in the wetland in the event of uncontrolled entry of pollutants in future. Therefore, monitoring the sources of these pollutants entering to the wetland and controlling the ecological risks is necessary.

Nowadays linear alkyl benzene sulfanate (LAS) is widely used in the production of various detergents. The purpose of this study was to assess the health and ecological hazards of this pollutant on target organisms such as fish and daphnia in the Doroodzan Dam water. According to the research objective and given existing restrictions, 21 water samples were collected in September 2018 from 7 selected stations based on the source of contamination in Doroodzan dam.  Water quality parameters including pH, Dissolved Oxygen (DO), potential Redox (ORP), Total dissolve solid (TDS) and Electrical conductivity (EC) was measured at the site. The amount of linear alkyl benzenesulfonate (LAS) was measured using an optimized methylene blue method after transferring samples to the lab. Then ecological and health risk assessment was performed by calculating the RQ index (risk index). The results showed that the mean of  pH, EC, TDS, salinity and DO were 8.88, 732.19 µs/cm,  482.49, 366.16 and 6.87 mg/L, respectively. The highest and lowest concentrations of LAS were 0.039 and 0.055 mg/L, respectively. The results also showed that there is a significant relationship between LAS concentration and pH. The results of the risk assessment showed that the health risk index in all stations is less than 0.1, while the ecological risk index except at station 7, are in low risk level. In general, the results show that the RQ index in the Droodzan Dam water is in appropriate range and in the low risk level. Therefore, it is necessary to conduct long-term studies in this field to ensure the persistence of optimal water conditions in the dam ecologically and health-wise.

The aim of this study was to examine some potential effects of 4-Nonylphenol (4-NP), Bisphenol A (BPA), and mixture of them on common carp, Cyprinus carpio and demonstrate induction of vitellogenin (Vtg) as a biomarker for screening aquatic ecosystems. These compounds with other estrogenic chemicals may be responsible for disrupting effects observed in fish. A total of 100 juvenile carp were treated experimentally with 17β-estradiol (E2), and increasing doses of 4-NP, BPA and also mixture of them. Then the plasma Vtg levels were measured using indirect competitive ELISA. Results showed a significant (P<0.05) increase in Vtg levels of exposed carps with E2, maximum 4-NP, BPA and their mixture. The group treated with E2 showed high induction (490%) with respect to controls. The groups treated with maximum dose of 4-NP and BPA showed also induction of Vtg, whereas the group treated with their mixture (3 mg kg−1 b.w. 4-NP and 0.01 mg kg−1 b.w. BPA) showed the highest induction (2126%). Finally, results showed that mixture of 4-NP and BPA exhibited stronger (synergistic) effects. So that, large scale monitoring of estrogenic effects caused by contamination may be considered as a biomarker in urban and industrial effluents.

Marine sediments are the most important component of monitoring the health of aquatic ecosystems. The present study uses sediment quality indices to determine the contamination status in Qeshm ecosystems and to evaluate the toxicity of the elements studied for its organisms. Sampling of surface sediments of seven stations was carried out on Qeshm coastal areas. The samples were digested by a combination of nitric acid and perchloric acid, and the concentration of metals was measured by atomic absorption spectrometry. The results of modified Hazard Quotient indicated a high pollution rate for copper and nickel metals in most stations, which was consistent with the results of the Potential Contamination Index in relation to nickel metal. Additionally, the results of the Potential Contamination Index and Contamination Factor agreed with the amount of lead element. According to the results, the pollution index of Hamoon Lake and Zakeri pier was highly contaminated and Modified Pollution Index demonstrated a contamination in Romacha, Hamoon Lake, Zakeri pier and Nazes areas. The enrichment factor associated with contamination regarding most of the heavy metals confirmed the indices used to evaluate the comtamination in the study area. Due to the higher concentrations of the heavy metals in the sediments than that of the quality guidelines, the high toxicity of sediments for the aquatic ecosystems was confirmed. The Romachah, Hamoon, Zakeri stations showed higher pollution levels and sever toxicity for aquatic life. Copper, nickel and in some cases lead, were the main heavy metals that contaminated the sediments in the region.

Heavy metals contaminations are readily bioaccumulated in aquatic systems and lead to increased concentrations in food chains, posing a serious threat to human health, water-related organisms and aquatic ecosystems. The purpose of the present study was to determine the concentration of heavy metals in surface sediments of CheshmehKile River, to evaluate environmental and ecological risk and to determine the degree of contamination of the elements studied. In this study, 25 samples of surface sediment were collected from the CheshmehKile River. The heavy metals content of the samples was measured by inductively coupled plasma-optical emission spectrometry. According to the content of heavy metals in sediment samples, environmental and ecological risk indices were calculated. Also, river contamination was evaluated by comparing the elements studied values with the sediment quality guidelines values. The mean concentration of chromium, manganese, iron, cobalt, nickel, zinc and arsenic were 41.27, 356.35, 16756.32, 9.17, 11.87, 41.24 and 24.60 µg/g, respectively. Based on the values of the CF and Igeo indices, all of the elements, with the exception of arsenic, showed a low degree of contamination. The indices of Eir and RI also showed the lowest ecological risk at all stations. The results of this study showed that the surface sediments of CheshmeKile River in Mazandaran province were somewhat contaminated with arsenic. However, fortunately, the river sediments were of good quality from the point of view of the content of chromium, manganese, iron, cobalt, nickel and zinc.

Accidents and injuries are a cause for concern for all countries in the world. Cognitive failures can be defined as cognitive-based errors on simple tasks that a person should normally be able to complete without fault; these mistakes include problems with memory, attention or action. The present study was designed to investigation of relationships between occupational cognitive failures and safety performance among bus drivers.

In this descriptive analytical study, 129 bus drivers completed an occupational cognitive failure questionnaire (OCFQ) and the DBQ as well as answered questions on accident involvements. Correlation and regression analysis were used for data processing.

Occupational cognitive failures have a significant direct positive effect on all driving unsafe behaviors including intended and unintended violations, slips and mistakes.

For assessment of safety performance in occupational driving jobs, we must use a valid instrument. The cognitive failures can predict bus drivers’ engagement in safe or unsafe behaviors.

Root-lesion disease, which is caused by Pratylenchus loosi , is one of the most important diseases currently impacting Iran tea plantations. This disease causes great economic crop impacts. Northern provinces, which supply much of Iran’s tea production, have been especially hard impact by root-lesion disease.The purpose of this study was to biological control the nematodes as one of the main sections and sustainable agriculture in integrated management systems, allowing application of Bacillus subtilis in the rhizosphere of tea plants infected with the root lesion nematode. In order to study this disease, more than fifty bacterial strains were collected from the rhizosphere area of the tea plants and screened for their antagonistic activities on the reduction of the density population of the adult and juvenile of Pratylenchus loosi under in-vitro condition. Four selected isolates with nematicidal activities were characterized and identified. All belonged to the species Bacillus subtilis. Death percentage of juveniles ranged from 62.88% to 86.01% for Bacillus subtilis (Rh-14) and (Rh-18), respectively. All bacterial strains isolated in this study had the ability to produce protease. The information obtained was needed as the first step toward the search for control strategies of root-lesion disease in tea plantations in Iran.