Ontogeny of the shi drum Umbrina cirrosa (Linnaeus 1758), a candidate new species for aquaculture

The ontogeny of shi drum Umbrina cirrosa (Linnaeus 1758), a candidate new species for aquaculture, was studied throughout the entire larval phase. Geometric morphometric analysis revealed two clear inflection points (7.0 and 12.7 mm total length, TL) in the shape ontogeny of this species, separating the studied period into three phases of different allometric priorities. Spline graphs demonstrated that the major non‐uniform shape ontogeny correlated with the development of the fins, the anterior dorsal area of the body, the caudal peduncle, the eye and the mouth. Concerning the morphological features, shi drum larvae are characterized by an upward anterior bending of the notochord. The ontogeny of the fins began with the formation of the pectoral buds (2.9 mm TL), continued with the notochord flexion (4.3 mm TL, associated with the caudal fin development), the appearance of the pelvic buds, the first anal rays (4.5 mm TL) and the first dorsal rays (4.8 mm TL). Shi drum juveniles presented 25 vertebrae and the following dominant fin types: D XI,23, AII,6, VI,5, P17 and C17.     

Effects of atrazine on the viability and the formation of byssus of the mussel <Emphasis Type="Italic">Mytilus galloprovincialis</Emphasis>

Shellfish farming often takes place in areas subjected to various recurring pollutions. The intensive use of herbicides in agriculture leads to the presence of residues in the aquatic ecosystems. In the present study, the effects of atrazine on the viability of the mussel Mytilus galloprovincialis and the formation of their byssus were studied. A total of 720 mussels (mean length 24 mm ± 2.1 SD) were divided into six groups. The mussels from the first five groups were exposed to five concentrations of atrazine, 10, 8, 5, 2 and 1 ppm, while one group was used as control. The LC₅₀ was calculated after 48 h, while the long-term effect of atrazine on the viability and byssus formation of the mussels were studied for 21 days. The LC₅₀ was found to be 6.33 ppm. From all the concentrations of atrazine to which the mussels were exposed, only in two of them (2 and 1 ppm) some mussels survived up to the last day of the experiment. The survival rate in the control group was significantly higher than those of mussels that were exposed to atrazine. Regarding the byssus formation, the number of byssal threads was significant lower in the mussels that were exposed to 2 and 1 ppm atrazine compared to the control group, while no byssal threads were formed by the mussels exposed to 10, 8 and 5 ppm. All the mussels that survived on day 21 were then exposed to air. The LT₅₀ for the control group and the mussels which had been exposed to 1 and 2 ppm atrazine were 5.14, 2.77 and 1.98 days, respectively. The results of the present study indicate that atrazine has a significant effect on the viability of mussels both in the water and in air and on their ability to form byssus.     

Chronotypology and melatonin alterations in minimal hepatic encephalopathy

Background  

"Minimal (subclinical) hepatic encephalopathy" is a term that describes impairment of every day life activities in cirrhosis patients without clinical neurologic abnormalities. Melatonin diurnal pattern disruption and metabolic changes due to liver insufficiency can affect the human biologic clock. Our study was conducted to measure plasma melatonin levels in an attempt to correlate plasma melatonin abnormalities with liver insufficiency severity, and describe chronotypology in cirrhosis patients with minimal encephalopathy.     

Effects of age and frequency of cutting on productivity of Mediterranean deciduous fodder tree and shrub plantations

Deciduous fodder trees and shrubs are important feed resources for the critical summer period in semi-arid and sub-humid Mediterranean environments. Eleven such species were established in central Macedonia, Greece as 1-year old seedlings in 1987 and studied through 1994. Height and biomass were statistically different among species and tended to increase with the age of plants. Common Robinia pseudoacacia was the tallest and the most productive species, reaching more than 3 m height and 4 kg DM/plant 8 years since planting; it was followed by Ostrya carpinifolia, the variety monophylla of Robinia, Colutea arborescens and Amorpha fruticosa. Grazeable proportion of total biomass was about 50% and decreased as the age of plants increased. Repeated annual cutting resulted in significant reduction of both height and total biomass by 51% and 88%, respectively as compared with uncut plants at the end of the eighth year while frequent cutting tended to increase the grazeable proportion of biomass after the fourth year. To attain an optimum combination of quantity and quality of biomass in deciduous fodder tree and shrub plantations cutting or grazing should not start earlier than the third year since establishment.     

Effect of storage time on the urine protein: creatinine ratio in alkaline ovine urine

The urine protein:creatinine (UPC) ratio is considered the reference method to assess proteinuria. Its diagnostic value in ovine medicine needs further elucidation. In population monitoring and/or for research purposes, it is convenient to collect many samples simultaneously and store them for later analysis. However, analyte stability data are required to ensure reliable results. We used 15 of 90 urine samples collected from sheep to assess the effect of storage time on the UPC ratio. After centrifugation, the supernatant of each sample was divided into 6 aliquots. Urine protein and creatinine concentrations were determined immediately in one aliquot using the pyrogallol red and a modified Jaffè method, respectively. The other aliquots were stored at −18°C. Based on the absence of active sediment, alkaline urine pH, and UPC ratio ≥0.2, we included 15 samples in our study. The UPC ratio was determined in the stored aliquots 2, 7, 14, 21, and 60 d after collection. The data were analyzed with univariate ANOVA. No significant difference was observed in the urinary concentrations of protein, creatinine, and the UPC ratio (0.8 ± 0.84 in conventional units and 0.09 ± 0.095 in SI units) among different times (p > 0.05). The UPC ratio remained stable for 2 mo in ovine urine samples stored at −18°C.     

Response of ungrafted rootstocks and rootstocks grafted with wine grape varieties (Vitis sp.) to ‘lime-induced chlorosis’

The ungrafted rootstocks 41B, 1103P, 110R and 140Ru, the grafted combinations of 41B, 1103P and 110R with Xinomavro (one of the most important red wine grape varieties in Greece), as well as those of 1103P, 110R and 140Ru with Chardonnay, were evaluated for 'lime-induced chlorosis' tolerance by growing them with a) basic nutrient solution (BNS), b) BNS + 10 mM bicarbonate, c) BNS without iron (Fe) and d) BNS without zinc (Zn), in hydroponics. The ungrafted 140Ru followed by 41B under high bicarbonate presented the lowest degree of chlorosis; however only 41B presented non-differentiated biomass production and root/shoot ratio. Chlorotic symptoms in combination with plant growth parameters should be used as a tool for grapevine rootstock lime-tolerance screening whereas leaf Fe concentration and root ferric chelate reductase (FCR) activity should not. Lime-stress conditions affected plant mineral nutrition by depressing leaf nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg) and increasing potassium (K), and zinc (Zn).     

Grazing effects on the sustainability of an oak coppice forest

In Greece, deciduous oak forests usually provide both, wood production and grazing of understory vegetation. Grazing as a management tool was assayed in a deciduous oak coppice forest of 2000 ha under conversion during the management period of 1991–2005 in Central Macedonia, Greece. In this forest, 1340 cows and 3880 goats were grazing from May to October along the years. The impact of grazing pressure on forest growth was related to the difference of the overall wood stock in two sampling times conducted during the management period of 1991 and 2005. Three grazing pressures were distinguished in the forest: heavy, moderate and light. The moderate grazing improved tree growth and provided significant wood production during the management period. It has also resulted in a sustainable production of herbage and browse in the understory, supporting the maintenance of the livestock. It seems that the conversion of a deciduous oak coppice forest to a high forest along with livestock grazing in the understory is a very efficient management scheme for sustainable production in such a forest.     

A newly developed droplet digital PCR for Ehrlichia canis detection: comparisons to conventional PCR and blood smear techniques

Canine monocytic ehrlichiosis caused by Ehrlichia canis infection is a life-threatening vector-borne disease in dogs worldwide. Routine blood smear has very low sensitivity and cannot accurately provide a quantitative result. Conventional PCR (cPCR) and real-time PCR (qPCR) are widely used as molecular methods for E. canis detection. qPCR is quantitative but relies on standard curves of known samples. To overcome this difficulty, this study developed a new E. canis quantitative detection method, using droplet digital polymerase chain reaction (ddPCR). ddPCR was evaluated against cPCR and blood smears. PCR amplicons and genomic DNA (gDNA) from 12 microscopic positive samples were used to identify the limits of detection (LODs) in ddPCR and cPCR. Our ddPCR was assessed in 92 field samples, it was compared with cPCR and blood smears. ddPCR showed LOD=1.6 copies/reaction, or 78 times more sensitive than cPCR (LOD=126 copies/reaction), using PCR amplicons as a template, whereas both ddPCR and cPCR had equal LODs at 0.02 ng gDNA/reaction. In addition, ddPCR had 100% sensitivity and 75% specificity for E. canis detection compared to cPCR and no cross-reaction with other blood pathogens was observed. ddPCR identified more positive samples than cPCR and blood smear. ddPCR improved the overall performance of E. canis detection, with a better LOD and comparable sensitivity and specificity to cPCR. The technique might be helpful for diagnosis of E. canis in light infection, evaluating the number of E. canis and follow-up after treatment.     

Partial characterization of cobalamin deficiency in Chinese Shar Peis

A total of 22,462 serum sample results from dogs being evaluated for gastrointestinal disease at the Gastrointestinal Laboratory, College of Veterinary Medicine, Texas A&M University were evaluated retrospectively. The proportion of dogs with serum cobalamin concentrations below the reference interval and median serum concentrations were compared between Shar Peis and other dog breeds. Serum samples were also obtained prospectively from 22 healthy and 32 Shar Peis with chronic gastrointestinal disease and 59 healthy dogs of other breeds, and serum concentrations of cobalamin, folate, and methylmalonic acid were determined and compared. Overall, 64.0% (89/139) of serum samples from Shar Peis showed serum cobalamin concentrations below the limit of the reference interval and 38.1% (53/139) of these were below the detectable limit for the assay. The median serum cobalamin concentration in Shar Peis was significantly lower than in other breeds. Shar Peis with gastrointestinal disease had significantly lower serum cobalamin and higher serum methylmalonic acid concentrations compared to healthy Shar Peis. Healthy Shar Peis had significantly increased serum methylmalonic acid concentrations compared to healthy dogs of other breeds. There were no meaningful differences in folate concentrations between groups. In conclusion, Shar Peis have a high prevalence of cobalamin deficiency compared to other breeds and healthy Shar Peis may have subclinical cobalamin deficiency.     

Liver flukes promote cholelithiasis in sheep

The main objective of this study was to investigate whether cholelithiasis in sheep is related to parasitism or other commonly observed disorders such as liver abscesses. Additionally, the features of the observed biliary calculi are described. The livers of 254 randomly selected clinically healthy adult dairy sheep were used. All visible concretions in the bile were considered as stones. Based on the macroscopical examination, 60 livers were normal, 40 were parasitized with Fasciola hepatica, 42 were parasitized with Dicrocoelium dendriticum, 28 were parasitized with both D. dendriticum and F. hepatica, 40 livers had abscesses and 44 had hydatid cysts. Biliary calculi were detected in 40 livers. Twenty livers had pigment stones and 20 livers had cholesterol stones. The percentage of cholelithiasis was significantly higher in livers parasitized with flukes compared with the others (P<0.05) and the parasitoses with F. hepatica and D. dendriticum were proven to be significant risk factors (P<0.05) for the presence of cholelithiasis in sheep.