Effect of experimental therapeutic ultrasound on the distal antebrachial growth plates in one-month-old rabbits

The effect of therapeutic ultrasound (US) on the growth plates of growing bone was determined through fluorescence labelling and histopathological evaluation in one-month-old rabbits. Mean growth rates and mean heights of the growth plates of the US exposed radius vs. control radius, and US exposed ulna vs. control ulna showed no statistically significant differences at all intensities and time intervals. Mean growth rates and heights of the growth plates of the US exposed radius for 0.2 W/cm(2) (SATA) US vs. 0.5 W/cm(2) US showed the same type of pattern compared to those of the control radius for 0.2 W/cm(2)vs. 0.5 W/cm(2) at days 10, 15 and 20. Similar results were also found for the ulna. Effects of 0.5 W/cm(2) US on the mean growth rates and mean heights of the growth plates were superior to those of 0.2 W/cm(2) US at day 10. The results at day 10 were reversed for the same comparisons at days 15 and 20. No cavitation effect of US was observed on growth plate cells. There was no evidence of partial or complete premature closure of the growth plates or of angular deformity of the carpal region.     

Properties of a citrus isolate of olive latent virus 1, a new necrovirus

A virus was recovered by sap transmission from plants of several citrus species exhibiting or not symptoms of chlorotic dwarf (CCD), a disease recently reported from Eastern Mediterranean Turkey. The virus was identified as an isolate of olive latent virus 1 (OLV-1), originally described as a possible sobemovirus. The citrus isolate of OLV-1 (OLV-1/Tk) possesses biological, morphological, physico-chemical, and ultrastructural properties similar, if not identical to those of the OLV-1 type strain and is also serologically indistinguishable from it. In addition, OLV-1/Tk has many properties, especially physico-chemical, in common with serotypes A and D of tobacco necrosis necrovirus (TNV-A and TNV-D). However, OLV-1/Tk is only very distantly related serologically to both TNV-A and D, suggesting that it can be regarded as a distinct species in the genusNecrovirus. OLV-1/Tk could not be detected in citrus tissues by ELIS A or dot-blot molecular hybridization, probably because of the extremely low virus concentration. By contrast, limited virus recovery was obtained by sap inoculation and fair detection rates were afforded by PCR. OLV-1/Tk was identified in 54 of 92 (59%) citrus plants affected by CCD and in 14 of 49 (28%) symptomless plants. These results do not support the notion that there is a cause-effect relationship between OLV-1/Tk and CCD, even though the more frequent association of this virus with diseased plants remains intriguing.     

Studies on differential response of wheat cultivars to boron toxicity

Experiments were carried out to study the differential responses of different wheat cultivars to boron toxicity in field, greenhouse and growth chamber conditions. In field trials carried out at two locations, both of which are known to contain toxic amounts of water-extractable B, significant correlations were obtained between toxicity symptoms and grain yields. The only durum cultivar included in this group of experiments (Kunduru 1149) was the most sensitive of the 21 cultivars trialed. The most tolerant cultivars were of local origin. Genotype-environment interaction was considerably large. Twenty-nine bread wheat and three durum wheat cultivars were compared in a greenhouse experiment with and without the application of 40 mg L^-1 B. Again, the durums were the most sensitive cultivars. The most tolerant cultivars were either selections from local populations or had at least one parent of local origin. The detrimental effect of B on root dry matter production was much higher than on shoot dry matter (45 and 26%, respectively), but genotypical variation was greater in shoot growth retardation. While this implies the possible role of reduced translocation, high concentrations of B in the shoots of tolerant cultivars (though lower than in the sensitive cultivars) indicated the existence of other contributing mechanisms, such as tissue tolerance. Also, greater genotypical variation in older leaves showed that reduced uptake might be more important than reduced translocation in some cases. Due to the lack of correlation between results from the field and the controlled-environment studies, it was concluded that screenings should be undertaken in both situations as a means of verification. Another conclusion drawn was that symptom scoring for B tolerance was more reliable than measuring plant B concentrations. This revised version was published online in August 2006 with corrections to the Cover Date.     

Distribution and genetic diversity of Dothistroma septosporum in Pinus brutia forests of south-western Turkey

Dothistroma needle blight (DNB) is a serious disease of the Pinaceae, mainly Pinus species, caused by the fungi Dothistroma septosporum and D. pini. Both species are regarded as invasive forest pathogens worldwide, with rising incidence in central and northern Europe over the last three decades. In this work, 29 sites were investigated between 2013 and 2015 in south-western Turkey. Morphological examination of needles confirmed DNB infection (i.e., Dothistroma conidiospores observed) at 18 sites, and a total of 108 Dothistroma sp. isolates were obtained from 11 of the sites. Host age seemed to be an important factor in both occurrence and severity of DNB in Pinus brutia forests. Continuous rainy days, especially in December, may increase severity of disease; however, extreme rain events may reduce available conidiospores on plant tissues or in the air. Species-specific mating type primers showed that all isolates were D. septosporum; D. pini was not detected. The mating type ratio was close to 1:1, indicating sexual recombination was occurring. Eleven microsatellite markers revealed 59 unique multilocus haplotypes (MLHs) among the 73 isolates originating from different conidiomata. The majority of MLHs were represented by a single isolate (n = 52) and only one MLH was shared between two localities. Analyses showed high genetic diversity, isolation-by-distance, and clear population clusters. These findings suggest that D. septosporum is well established in south-western Turkey and is probably not a recent introduction.     

Radiological risk assessment of fish feed and feed raw materials

In this study, natural radioactivity concentrations of fish feed and feed raw materials were assessed. Several feeds and raw materials were provided from the suppliers who dominate the aquaculture sector. ²²⁶Ra, ²³²Th and ⁴⁰K concentrations were determined by using a high‐purity germanium detector. The measured activity concentrations of samples ranged from 3.28 ± 0.27 to 15.90 ± 1.36, from 1.27 ± 0.10 to 12.07 ± 1.21 and from 52.01 ± 2.60 to 1,158.96 ± 54.42 Bq/kg for ²²⁶Ra, ²³²Th and ⁴⁰K respectively. The gamma dose rate and annual effective dose rate of samples were calculated to be in the range of 1.99–50.47 nGy/h and 2.44–61.89 µSv/yr respectively. Since the calculated radiological risk parameters of the samples were lower than the world wide average values, the radiation hazard is insignificant for human handlers.     

Effects of sodium selenite on some biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss Walbaum, 1792) exposed to Pb2+ and Cu2+

This study was carried out to understand the preventive effect of selenium (Se⁴⁺) on heavy metal stress induced by lead and copper in rainbow trout (Oncorhynchus mykiss). Variation in glutathione peroxidase (Se-GSH-Px) and superoxide dismutase (SOD) activity, and in malondialdehyde (MDA) levels in liver, spleen, heart, and brain tissues of rainbow trout after 72 h of exposure to Pb²⁺ and Cu²⁺ were investigated in the presence and absence of Se⁴⁺. In the presence of Se⁴⁺, Se-GSH-Px activity and SOD activity were found to be higher and MDA levels were lower compared with in its absence. Hematological parameters were also determined and it has been observed that total leukocyte count (WBC), mean cell volume (MCV), and mean cell hemoglobin (MCH) were increased and erythrocyte number (RBC), hemoglobin (Hb), and hematocrit value (Hct; P < 0.05) were decreased in fish exposed to heavy metals in the absence of selenium. Selenium presence recovered hematological parameters to normal levels. In the light of our findings, it could be stated that Pb²⁺ and Cu²⁺ lead to dramatic changes in biochemical and hematological parameters and selenium caused these parameters to converge to control levels when it was administered concurrently with these heavy metals.     

Use of dispersed flow models in design of biofilm reactors

An attempt has been made to set up a relationship between the removal efficiency and the dispersion characteristics of biological filters. For granular-media trickling filters, effluent concentrations have been calculated with the equation of complete mixing at low flow rates and by means of a dispersed plug-flow model for large hydraulic loadings. For coarse media, the mixed flow zone disappears and the substrate removal is obtained using the equation of dispersed plug flow. The effect of temperature and substrate concentration on the filter efficiency has been investigated using the model developed and the application of this theory to the practical problems has been thus demonstrated.     

Kinetics Characteristics of Biofilm Reactors

A numerical model of biofilm reactors was tested using Monod typebiological kinetics in terms of the properties of feed solutionand dispersion. The model is based on computer techniques andthe numerical evaluation of the normalized biofilm mathematicalmodel. The effect of inlet parameters including concentration,flow rate, mass transfer coefficient and biofilm thickness wereinvestigated using the computer program developed. The numericalmodel was also applied to experimental data to demonstrate itsvalidity. In thin biofilms kinetic coefficients and otherparameters such as molecular diffusivity can be determinedbased upon experimental results. In thick biofilms, however, anadditional kinetic parameter or any other quantity related tomass transfer is a prerequisite in the evaluation ofexperimental data.