Effect of cadmium,copper and chromium (VI) on the growth of nile water algae

The Algal Assay Procedure Bottle Test was used to investigate the effect of Cd, Cu, and Cr (VI) on the growth of Nile water algae. The results of this investigation indicated that Cd has slight inhibitory effects on algal growth at low concentration (0.05 mg L^?1), while it was inhibiting algal growth at higher concentration (> 1.0 mg L^?1). In contrast, Cu and Cr did not affect algal growth in all investigated concentrations. Combinations of Cd with Cu and Cr seemed to interact synergistically. The synergism between Cd and Cu was more pronounced than between Cd and Cr. Clear changes in the diversity and redundancy of algal structure took place after metal addition. The inhibitory effect of the studied metals was in the following order: Cd-Cu > Cd - Cr > Cd > Cu > Cr.     

Genetic polymorphism of plastid DNA in Tunisian date-palm germplasm (Phoenix dactylifera L.) detected with PCR-RFLP

Fifteen plastid fragments were amplified from a set of Tunisian date-palm accessions by PCR with consensus primers and analysed by RFLP. Polymorphic DNA bands were obtained as reliable molecular markers to estimate genetic distances among the accessions and to examine their phylogenetic relationships. The ctDNA PCR-RFLP method permitted the identification of two haplotypes that differ in the presence or absence of the HinfI restriction site. Phenetic groups composed of cultivars clustered together but does not constitute monophyletic groups. This typology agrees with the haplotypes' organization and provides a common genetic background within the implied varieties.     

Effect of in vitro exposure to Vibrio vulnificus on hydroelectrolytic transport and structural changes of sea bream (Sparus aurata L.) intestine

The everted gut sac technique has been used to investigate the effect of Vibrio vulnificus on water and electrolyte (Na⁺, K⁺, Cl⁻, HCO₃ ⁻) transport on the intestine of sea bream (Sparus aurata L.). Both the anterior and the posterior intestine were incubated in a medium containing 10⁸ V. vulnificus cells ml⁻¹ at 25°C for 2 h. The presence of V. vulnificus resulted in a significant reduction (P < 0.05) of water absorption in the anterior intestine, while sodium absorption in the anterior (P < 0.01) and posterior (P < 0.05) intestine was elevated. Chloride absorption was increased, but the changed was not significant, while potassium absorption decreased significantly (P < 0.05), but only in the posterior intestine. Incubation the sea bream intestine with V. vulnificus did not affect carbonate secretion in the anterior segment, whereas high secretion was stimulated in the posterior segment (P < 0.01). Histological evaluations demonstrated damage in the anterior intestine of sea bream that was characterized by the detachment of degenerative enterocytes, alterations in the microvilli, and the presence of a heterogenous cell population, indicating inflammation. Based on our results, we conclude that V. vulnificus caused cell damage to the intestine of sea bream and that the anterior intestine is more susceptible than the posterior part of the intestine. Several hypotheses are suggested to explain our observations, such as the presence of higher numbers of villosities in the anterior intestine than in the posterior one and/or the presence of endogenous bacteria in the posterior intestine which may have a protector role.     

Some morphological, biochemical and immunological blood parameters in European bison with or without lesions in the digestive, respiratory, urinary and reproductive tracts

Ninety-seven bison (39 males and 58 females) were culled out during three successive winter seasons. No infection with BHV-1 and BHV-5 or other viruses was detected by PCR and SN methods. Advanced pathological lesions observed in males exhibiting symptoms of posthitis/balanoposthitis are probably due to secondary infection by microorganisms present in the prepuce (Corynebacterium spp., Bacillus spp., Fusobacterium necrophorum, Staphylococcus spp. (coagulase negative) and Staphylococcus hyicus). Histopathological examinations of sections from prepuce and lips of pudendum showed the presence of Onchocercinae nematode (Onchocerca sp.). A comparison of biochemical and morphological blood parameters in the bison with or without lesions in the digestive (presence of parasites), respiratory, urinary and reproductive tracts revealed that the most variable parameter during reproductive organ disorder is the leukocyte count, while disorders in the urinary and digestive tracts coincided with the age of animals. In cases of digestive disorder most changes were observed in the number of neutrophils and concentration of urea. The number of red blood cells, monocytes, the level of alkaline phosphatase (AP) and hematocrit negatively correlated with age. Negative correlation was also observed between the number of neutrophils, level of creatinine and lymphocyte proliferation index. However, positive correlation was seen between erythrocyte sedimentation rate (Spearman's correlation coefficient), level of alanine aminotransferase (ALT) and protein, and age of the bison. Positive correlation was also observed between the lymphocyte count and lymphocyte proliferation index. The attempt to determine the reference values for blood biochemical and morphological parameters showed similarities to those of cattle.     

Tree species recognition system based on macroscopic image analysis

An automated wood texture recognition system of 48 tropical wood species is presented. For each wood species, 100 macroscopic texture images are captured from different timber logs where 70 images are used for training while 30 images are used for testing. In this work, a fuzzy pre-classifier is used to complement a set of support vector machines (SVM) to manage the large wood database and classify the wood species efficiently. Given a test image, a set of texture pore features is extracted from the image and used as inputs to a fuzzy pre-classifier which assigns it to one of the four broad categories. Then, another set of texture features is extracted from the image and used with the SVM dedicated to the selected category to further classify the test image to a particular wood species. The advantage of dividing the database into four smaller databases is that when a new wood species is added into the system, only the SVM classifier of one of the four databases needs to be retrained instead of those of the entire database. This shortens the training time and emulates the experts’ reasoning when expanding the wood database. The results show that the proposed model is more robust as the size of wood database is increased.     

Nutrient Stress,Ecophysiological, and Metabolic Aspects of Olive Tree Cultivars

This research, aimed at evaluating stress on the olive tree, utilized cultivars ‘Meski’ and ‘Chetoui’ in regards to the removal of major elements such as nitrogen (N), phosphorus (P), magnesium (Mg), and potassium (K). The experiment was conducted under greenhouse conditions in hydroponics culture. Measurements of leaf area showed a non-substantial and weak effect due to phosphorus, potassium, or magnesium deficiency compared to nitrogen. The growth analysis of dry matter showed an early depressive effect of nitrogen deficiency and a similar, but less important effect concerning phosphorus.

The induced nutritional stresses showed an important increase in stomata resistance, caused primarily by nitrogen or potassium deficiency, accompanied by a reduction of chlorophyll concentration, which resulted from the removal of phosphorus, magnesium, and mainly nitrogen supply. Remarkable starch synthesis and storage was also revealed following nitrogen deficiency, but it was very weak after the suppression of magnesium, which may provoke a weakening of growth and development of these plants.     

Toxic Effect of Certain Metals Mixture on Some Physiological and Morphological Characteristics of Freshwater Algae

The toxic effect of multi metals mixture which exist simultaneously in aquatic ecosystem on natural phytoplankton assemblages (green algae, blue-green algae and diatoms) was studied. For this purpose a laboratory scale unit was designed to evaluate the effect of continuous flow metals mixture in forms if triple and penta metals in Nile water algae. Clear changes in algal biomass in terms of chlorophyll a (chl a) took place when subjected to metals combination. The rise or decline in chl a was in relation with other algal pigments (chl b, chl c, carotenoides and phenophytin), protein and carbohydrate content of algal cells. Substantial changes in phytoplankton community structure was detected and the most tolerant group was blue-green algae followed by green algae while diatoms was the most sensitive group. The most dominant species in all cases were blue-green alga Oscillatoria mougeotii and green alga Scenedesmus quadricauda. In addition clear changes in morphological shape was observed for tolerant species belonging to the three algal groups. Nile water algae has ability to remove and accumulate metals in the following order therefore Zn > Cd > Ni > Cu > Cr. In addition, phytoplankton has ability to recovered from the stress of metals when eliminated from the media and the recovered biomass was nearly equivalent to that before exposing to metals stress. The overall effect of metals mixture depending on the type and number of metals, the algal community structure and ratio between different morphological forms of algae (unicellular, colonial and filamentous).     

Wild ostrich (<Emphasis Type="Italic">Struthio camelus</Emphasis>) ecology and physiology

This work discusses some of the important considerations of wild ostrich evolution, behaviour and ecology, as items included in ostrich production. In the process considerable research was conducted by collating information from peer-reviewed papers; textbooks; manuals; and PubMed and Agricola searches. Selected areas reviewed included activity of ostriches; feeding and water needs; sexual maturity; egg laying and natural incubation; selected physiological parameters; and predation. There is an immediate and urgent need to conserve and protect the rapidly declining populations of wild ostriches with the committed involvement of governments and funding bodies.     

Inter-Simple Sequence Repeat fingerprints to assess genetic diversity in Tunisian fig (Ficus carica L.) germplasm

The genetic diversity of 18 Tunisian fig cultivars was investigated at the DNA level using the Inter Simple Sequence Repeat (ISSR) associated with the Polymerase Chain Reaction (PCR). Using a set of primers, the most informative ones were selected that were characterized by an important Resolving power value of 29.6. A total of 47 discernible fragments were scored from samples, with a mean of 11.7 fragments per primer. The 90.4% of sample that were polymorphic were scored as molecular markers to examine the Tunisian fig germplasm polymorphism at DNA level. A large genetic diversity as related to ISSR patterns was found within the local Tunisian fig germplasm. An UPGMA dendrogram exhibits the unstructured variability in this crop. Moreover, the principal component analysis shows that the observed diversity was typically continuous. Our data provide a large number of ISSR markers that are useful in the fingerprinting of Ficus carica L. cultivars, and in the understanding of the genetic relationships among these accessions.     

The difference in N metabolism between NAD(P)H-specific NR-deficient mutant and wild-type barley (Hordeum vulgare L.)

Abstract

Barley (Hordeum vulgare L.) is an important crop for cereal research. In this study, two barley genotypes the wild-type (Steptoe) and the mutant (Az12) were used. An experiment was conducted using ¹⁵N-tracing method to NADH-specific nitrate reductase (NR)-deficient mutant seedling of barley. The N-depleted seedlings were exposed to a nutrient solution containing nitrate and nitrite, and were labeled with ¹⁵N for 38?h under (14?L/10D) cycles. The two genotypes utilized ¹⁵NO₃^? and accumulated it as reduced ¹⁵N, predominately in the shoots. However, nitrate reduction in the Az12 shoots was 9% lower than that in the Steptoe shoots at 38?h. As a result, in the Az12, nitrate accumulation in shoots was 78% higher than that in the Steptoe. Accumulation of reduced ¹⁵N in the Az12 roots was nearly similar to that of the Steptoe roots, but 8% lower in the Az12 shoots than in the Steptoe shoots at the end of the experiment. Also for both genotypes, root contribution increased during L/D cycles and decreased during the subsequent light cycle. Upward transport of reduced ¹⁵N via the xylem in the Az12 was nearly two times higher than that in Steptoe during the second light period (24–38?h). In both genotypes, xylem transport of reduced ¹⁵N was far exceeded the downward phloem transport. Abbreviations Anl accumulation of reduced ¹⁵N from ¹⁵NO₃^? in non-labeled roots of split roots

Ar accumulation in roots of reduced ¹⁵N from ¹⁵NO₃^?

As accumulation in shoots of reduced ¹⁵N from ¹⁵NO₃^?

Rr ¹⁵NO₃^? reduction in roots

Rs ¹⁵NO₃^? reduction in shoots

Tp translocation to root of shoot reduced ¹⁵N from ¹⁵NO₃^? in phloem

Tx translocation to shoot of root-reduced ¹⁵N from ¹⁵NO₃^? in xylem

FW fresh weight