Effective,appropriate and simple culture,egg hatching and cryopreserving of the nematode Cheilospirura hamulosa

1. Successful invasion by nematode parasites is associated with several factors including egg hatching at the right time in their hosts. To determine a simple and appropriate medium for culture and egg hatching of the highly pathogenic species of the Acuariidae family, Cheilospirura hamulosa were cultured in three different media. In addition the viability of C. hamulosa eggs was determined after storage in frozen infected gizzards.

2. Eggs removed from the uteri of the female worms in infected gizzards were pooled and washed in distilled water and screened under a stereo dissecting microscope. Eggs were counted and cultured in three different media, nutrient agar, normal saline 0.9% and Bearman, at room temperature. Additionally, 10 infected gizzards were kept at ?20°C for 2 and 8 months.

3. After 4–5 d there had been no growth in the nutrient agar medium, whereas 11% of the cultured eggs in the Bearman medium contained larvae 2–3 d after culturing. In 0.9% normal saline medium the two polar knobs appeared on the two poles of the eggs at 2 d post cultivation, and 74% of the eggs contained a larva on the third day. Mature larvae gradually exited from the eggs.

4. Eggs collected from female worms in gizzards frozen at ?20°C were cultured in the same three culture media at room temperature. Larvae were visible in the eggs after 2–3 d in the Bearman and 0.9% normal saline media and hatched thereafter.

5. The 0.9% normal saline medium is recommended for egg hatching and cultivation of C. hamulosa due for simplicity, efficacy and cost effectiveness. Moreover, freezing of the infected gizzards at ?20°C is proposed for long-term storage of the eggs.     

Nitric oxide level in seminal plasma and its relation with sperm DNA damages

BACKGROUND: Evidence supports the involvement of nitric oxide (NO) in a variety of male reproductive processes such as spermatogenesis, spermiogenesis, sperm motion, sperm metabolism and sperm capacitation. However, low concentration of NO is essential in biology and physiology of spermatozoa, but high amounts of NO is toxic and has negative effects on sperm functions. On the other hand, it is established that high amounts of NO have detrimental effects on DNA. The integrity of sperm DNA is an important factor in successful fertility and embryo development. It is hypothesized that supra physiological concentrations of NO in seminal plasma cause sperm DNA damage. The aim of this study was to determine sperm DNA damage by comet assay and its correlation with NO level in seminal plasma of fertile and infertile men. METHODS: Semen samples were collected from 45 patients and 70 healthy donors. The stable metabolites of NO (nitrite and nitrate) in seminal plasma were measured by Griess assay and DNA damage was determined using single cell gel electrophoresis (comet) assay method. RESULTS: The NO concentration in the seminal plasma of infertile males was significantly higher than fertile males (5.74+/-1.01 microM/L vs. 3.88+/-0.53 microM/L). There was a significant positive correlation between the NO concentration and sperm DNA comet value in infertile males (P<0.01, R=0.598). CONCLUSION: These results indicate that the overproduction of NO in genital tract of infertile males has a potential pathogenetic role in the reduction of sperm DNA integrity.     

Olpidium bornovanus-mediated germination of ascospores of Monosporascus cannonballus: a host-specific rhizosphere interaction

Monosporascus cannonballus, a host-specific root-infecting ascomycete, is the causal agent of a destructive disease of melon (Cucumis melo L.) known as vine decline. Ascospores germinate only in the rhizosphere of melon plants growing in field soil. However, no germination occurs in the rhizosphere of melon plants if the field soil is heated to temperatures >50°C prior to infestation with ascospores. This observation suggested that germination is mediated by one or more heat-sensitive members of the soil microflora. Although bacteria or actinomycetes were heretofore suspected as the germination-inducing microbes, our data demonstrate that Olpidium bornovanus, an obligate, host-specific, root-infecting zoosporic fungus, is responsible. In four experiments conducted in autoclaved field soil amended with various population densities of culturally produced ascospores, significant ascospore germination was recorded only in the rhizosphere of cantaloupe seedlings colonized by O. bornovanus.     

Growth of Juvenile Synodontis petricola (Family: Mochokidae) Fed on a Formulated Diet, Artemia or Spirulina and Combinations Thereof

Two age groups of juvenile Synodontis petricola (Group I, 0.5 years and Group II, 1.5 years) were reared on each of five diets: formulated dry diet; Artemia; Spirulina; formulated diet plus Artemia; and formulated diet plus Spirulina. Fish were fed for 84 days and weighed and measured every 14 days. Growth of S. petricola averaged 0.06 mm/day for both age groups. There was no significant difference in percent survival between the fish fed on different diets within each of the two groups but the younger fish (0.5 years) had a significantly lower survival percentage (90.3%) than those in Group II (95.3%). Fish in Group I fed on Spirulina alone grew slower than those fed only on formulated dry feed, whereas the growth rates of fish fed on other diets, or diet combinations, did not differ from each other in both age groups. This revised version was published online in August 2006 with corrections to the Cover Date.     

Seroepidemiological survey of helminthic parasites of stray dogs in Sari City, northern Iran

The objective of this study was to determine the prevalence rate of helminthic parasites in stray dogs' population especially zoonotic infections and to identify potential risk factors in the different areas of Sari city in Caspian area, north of Iran. During the period from April to September 2007, 50 stray dogs were collected from urban areas of Sari city. Recovered parasites were fixed in alcohol and stained by carmine then observed by microscope. The taxonomic study was carried out by measuring different parts of the body of helminthes and statistical tests were performed using the Chi-square test. A total of 27 adult and 23 juvenile stray dogs were collected and the overall prevalence rate of infection was 90%. The three most common helminthes were Toxocara canis (60%), Ancylostoma caninum (46%) and Dipylidium caninum (36%). Other parasites were Uncinaria stenocephala (12%), Taenia hydatigena (6%), Spirocerca lupi (6%), Dirofilaria immitis (6%), Toxascaris leonina (2%), Rictularia sp. (2%), Taenia ovis (2%) and Taenia taeniformis (2%). Five species of zoonotic helminthes recovered were T. canis, A. caninum, U. stenocephala, D. caninum and D. immitis. Hookworm infections (58%) were more common significantly in the young stray dogs (p < 0.01). In regard to prevalence ofA. caninum, T. canis and U. stenocephala, there was significant difference between juvenile and adult dogs (p < 0.05). The results highlight the potential role of stray dogs for transmission of helminthic parasites particularly zoonotic parasites that are a significant risk to human health.     

Physiological changes in male and female pikeperch Sander lucioperca (Linnaeus, 1758) subjected to different photoperiods and handling stress during the reproductive season

Pikeperch broodstocks were exposed to different photoperiods: constant light (24L:0D), constant darkness (0L:24D), and 12 h light, 12 h darkness (12L:12D), for 40 days. Half of the broodstocks of each photoperiod were exposed to handling stress at a specific time of the day. Results showed that cortisol and lactate did not reveal any significant difference. However, glucose levels in females increased in the stress-free darkness period in comparison with stressful darkness photoperiods (0L:24D-s). Red blood cells in males and white blood cells in females showed a significant difference under different photoperiod regimes. Both sexes showed no significant difference in the differential count of leukocytes under different photoperiods and handling stress. Constant photoperiods and handling stress affected the hematological parameters, particularly, the number of lymphocytes and neutrophils in females. Our findings revealed that due to a long-term exposure to stressors, pikeperch brooders become adapted to stressful conditions.     

Plant selection method for urban landscapes of semi-arid cities (a case study of Tehran)

Choosing appropriate plants for urban landscapes is vital to avoid potential financial and environmental losses that may occur if all selection parameters are not taken into account. A methodology has been developed to assist landscape architects, planting designers, and urban horticulturists in the plant selection process. Tehran has been picked as a case study due to its arid and semi-arid climate which poses more challenges in front of an expert. After grouping plants, selection parameters have been defined for each plant group. Plant species were comparatively graded for each parameter by a group of eight specialists. Analytical hierarchy process (AHP) technique and hierarchical cluster analysis have been utilized to find the most adaptable plant species for the area according to the main selection parameters of zone tolerance, urban conditions, esthetics, maintenance, growth characteristics, and specific features. Several new plants were ranked high in the final tables suggesting that the urban landscape of Tehran has a great potential to become more attractive, less allergic, and less costly, as well as consuming less water. Before introducing new plants to the urban environment, they should be experimented on in small numbers for several years to confirm that they will not change the ecology of the whole region through invasion or posing a threat to any local plant species.     

Thematic Evolutionary Analysis of Core Agricultural and Natural Resource Academic Journals in Iran

ABSTRACT

For a core journal to be developed, fruitful research articles, diversity, and continuity of research topics are essential. The main goal of this study was to trace the thematic evolution (historical development) of agricultural and natural resource academic journals (ANAJs) published by public academic institutions in Iran. To this end, the study analyzed 2,961 articles published from 1905–2003 in all publicly-funded ANAJs in all contributing agricultural and natural resource academic majors (subfields), examining the scientific domain, research subject, research method, citations, impacts, and the aggregation level of journals on academic majors and academic majors on journals. Less than 5% of the articles were qualitative and cited theoretical frameworks. Over 95% were quantitative articles as their publications progressed. Thematically, agronomy and plant breeding, with 31.68%, had the highest aggregation level among academic majors; whereas, agricultural extension and education, with 2.08%, had the lowest.     

Antibacterial properties of Thymus pubescens and Thymus serpyllum essential oils

Antibacterial properties of essential oils of Thymus pubescens and Thymus serpyllum collected at pre and flowering stages were studied. The oils were found to possess bactericidal activities.