Transmission of Cyprinid herpesvirus-3 (CyHV-3) from goldfish to naïve common carp by cohabitation

Cyprinid herpesvirus-3 (CyHV-3) has spread worldwide and has had a major impact on koi and common carp production. Previous studies on the host range of the CyHV-3 found that fish species other than koi and common carp are fully resistant to natural virus exposure. Recently, CyHV-3 was detected in goldfish (Carassius auratus auratus) that were in contact with CyHV-3 infected koi. In the present study, a specific RT-PCR product was amplified from the viral thymidine kinase gene in gills, intestine and brain tissues of CyHV-3 infected goldfish. This implied that CyHV-3 replicated in these goldfish. Also, in the presence of a stress factor such as temperature fluctuation, the CyHV-3 infected goldfish transmitted the virus to cohabitated naïve SPF common carp. CyHV-3 DNA was detected in the cohabitated naïve carp tissues by PCR. The results of this study demonstrate that goldfish is a carrier for CyHV-3, permit virus propagation, and disseminate the virus to susceptible carp causing the disease.     

Effects of doxycycline on early infections of Dirofilaria immitis in dogs

The antifilarial effects of tetracycline drugs were first demonstrated when they were found to be highly effective against L(3) and L(4) of Brugia pahangi and Litomosoides sigmodontis in rodent models. Tetracyclines are also now known to have activity against microfilariae and adult Dirofilaria immitis, but assessment of their activity against larval and juvenile heartworms has not been reported previously. This study assessed the effects of doxycycline administered orally at 10mg/kg twice daily for 30-day periods at selected times during the early part of the life cycle of D. immitis in dogs with dual infections of D. immitis and B. pahangi. Twenty beagles were randomly allocated by weight to four groups of five dogs each. On Day 0, each dog was given 50 D. immitis L(3) and 200 B. pahangi L(3) by SC injection. Dogs received doxycycline on Days 0-29 (Group 1); Days 40-69 (Group 2); or Days 65-94 (Group 3). Group 4 served as untreated controls. Blood samples were collected for microfilariae counting and antigen testing. Necropsy for collection of adult heartworms and selected tissues were performed Days 218-222. Heartworms recovered were examined by immunohistology, conventional microscopy/transmission electron microscopy, and molecular biology techniques. No live heartworms were recovered from dogs in Group 1; dogs in Group 2 had 0 to 2 live worms (98.4% efficacy), and dogs in Group 3 had 0-36 live worms (69.6% efficacy). All control dogs had live adult heartworms (25-41). The live worms recovered from dogs in Groups 2 and 3 were less developed and smaller that worms from control dogs. Microfilariae were not detected in any dogs in Groups 1 and 2; one dog in Group 3 had 1 microfilariae/ml at necropsy. All control dogs had microfilariae at necropsy. One dog in Group 1 was antigen positive at one sampling (Day 166). One dog in Group 2 was antigen positive Days 196 and 218-222 and three dogs in Group 3 were antigen positive at one or more samplings All five control dogs were antigen positive at all three sampling times. These findings suggest that doxycycline at 10mg/kg orally twice daily for 30 days has efficacy against migrating tissue-phase larvae and juvenile worms and will delay or restrict microfilarial production.     

Risk factors for <Emphasis Type="Italic">Mycobacterium avium</Emphasis> subspecies <Emphasis Type="Italic">paratuberculosis</Emphasis> in Fars province (Southern Iran) dairy herds

A cross-sectional study was conducted from March to August 2006 in dairy herds in Fars province, southern Iran to determine the herd-level risk factors for infection with Mycobacterium avium subspecies paratuberculosis (MAP). Statistical analysis using multivariable logistic regression showed that contamination of udders of periparturient cows with manure (OR = 6.4, P = 0.02) and history of having suspected cases of Johne's disease in the herd (OR = 6.7, P = 0.04) were significantly associated with the herd infection status. No relationship between breed, herd size and other management practices with the infection status of the herd were found in this study. Implementing high sanitary measures in the farm, particularly with respect to manure handling and cleaning could be considered as one of the important aspects in controlling disease in the region as well as in the future educational effort.     

Picric Acid Degradation in Sediments from the Louisiana Army Ammunition Plant

Picric acid is an explosive historically produced and disposed at the Louisiana Army Ammunition Plant (LAAP) in northern Louisiana. The potential for natural degradation of picric acid was investigated by creating picric-acid slurries with four LAAP sediments of variable composition and monitoring for up to 98 days. The concentrations of picric acid decreased rapidly in all slurries during the first day, attributed to adsorption, followed by slower decreases in some samples due to degradation. Degradation in unsterilized slurries was nearly complete within 80 days for two of the four sediments. Increases in nitrite and nitrate concentration over time were proportional to the loss of picric acid and indicate that at least two of the three nitrite groups were removed from the picric acid molecule. The absence of significant concentrations of compounds with a mass greater than 100 amu in the final solutions suggests that all three nitrite groups were removed. No correlation was found between the degree of degradation and grain size, clay content, organic content, carbonate content, or a suite of element concentrations in the sediment. Degradation in sterilized samples was minimal for all sediment slurries, indicating microbial activity as the primary mechanism of degradation.     

Contact herbicidal activity optimization of methyl capped polyethylene glycol ester of pelargonic acid

Journal of Plant Diseases and Protection - The loss of important contact herbicides like paraquat opens opportunities for more potentially sustainable solutions demanded by consumers and...     

Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules

The solvent dependence of the second hyperpolarizability, gamma, of a variety of unsaturated organic compounds has been measured by third harmonic generation at 1907 nanometers. It is seen that the measured gamma is a function of solvent polarity. These solvent-dependent hyperpolarizabilities are associated with changes in molecular geometry from a highly bond-length alternated, polyene-like structure for a formyl-substituted compound in non-polar solvents, to a cyanine-like structure, with little bond-length alternation, for a dicyanovinyl-substituted compound in polar solvents. By tuning bond-length alternation, gamma can be optimized in either a positive or negative sense for polymethine dyes of a given conjugation length.     

Differences in viability and reactivity of actinospores of three myxozoan species upon ageing

Little is known about the viability of myxozoan actinospore stages after harvest from laboratory cultures of infected oligochaete worms. The viability and reactivity of actinospores of three myxozoan species was evaluated after short-term storage at 4 degrees C and 12 degrees C. Two methods of determining actinospore viability were compared: differential fluorescent staining and direct microscopic observation of morphological indicators of spore integrity. Spore reactivity was quantified by measuring polar filament discharge rates in a micro-assay with fish mucus substrate and mechanical stimulation by vibration. The age-dependent viability of the three species showed clear differences. Myxobolus cerebralis actinospores had the shortest effective life span whereas Henneguya nuesslini actinospores survived significantly longer. Storage at lower temperatures yielded higher viability in all species. Myxobolus pseudodispar actinospores were significantly robust up to 12 degrees C when assessed by staining, but showed similar viability characteristics as H. nuesslini when analyzed morphologically. Evaluation of spore viability by fluorescent staining correlated with morphological assessment, although fewer viable actinospores were usually detected microscopically. Polar filament discharge activity of morphologically intact actinospores did not significantly decrease until the third day of storage compared to freshly harvested samples. The results indicate that durability and reactivity trends during storage of actinospores differ among myxozoan species.     

Response of Manzanillo olive transplants to different nitrogen and cobalt applications

A pot experiment was carried on ‘Manzanillo’ olives transplants included three levels of nitrogen (N) (N₁=25, N₂=50 and N₃=75 g N plant^?1 year^?1) and four levels of cobalt (Co) (B₁=zero, B₂=10, B₃=20 and B₄=30 ppm Co). Generally, fertilizing with 50 g N plant^?1 year^?1 gave the highest significant value than those of other treatments in all vegetative growth characters. Vegetative growth was gradually increased by increasing cobalt up to 20 ppm and 30 ppm levels. Regarding the combination between nitrogen and cobalt levels in most cases, the best treatment was N₂ x B₃, which gave the highest values of vegetative growth characters. The combinations of nitrogen and cobalt created slightly more variable and increased effects on the macro and micronutrient contents of ‘Manzanillo’ olives transplants.     

Soil substrate as a cascade of capillary barriers for conserving water in a desert environment:lessons learned from arid nature

Interaction between soil pedogenesis, subsurface water dynamics, climate, vegetation and human ingenuity in a desert environment has been found to result in a unique ecohydrological system with an essentially three dimensional sedimentation structure in the bed of a recharge dam in Oman. A 3-D array of silt blocks sandwiched by dry sand-filled horizontal and vertical fractures was studied in pot experiments as a model of a natural prototype. Pots are filled with a homogenous sand-silt mixture(control) or artificially structured(smart design, SD) soil substrates. Rhodes grass and ivy(Ipomea, Convolvulaceae) were grown in the pots during the hottest season in Oman. Soil moisture content(SMC) was measured at different depths over a period of 20 days without irrigation. SD preserved the SMC of the root zone for both ivy and grass(SMC of around 25%–30% compared to 10% for control, 3 days after the last irrigation). Even after 20 days, SMC was around 18% in the SD and 7% in the control. This, similar to the case of a natural prototype, is attributed to the higher upward capillary movement of water in control pots and intensive evaporation. The capillary barrier of sand sheaths causes discontinuity in moisture migration from the micro-pores in the silt blocks to sand pores. The blocks serve as capillarity-locked water buffers, which are depleted at a slow rate by transpiration rather than evaporation from the soil surface. This creates a unique ecosystem with a dramatic difference in vegetation between SD-pots and control pots. Consequently, the Noy-Meir edaphic factor, conceptualizing the ecological impact of 1-D vertical heterogeneity of desert soils, should be generalized to incorporate 3-D soil heterogeneity patterns. This agro-engineering control of the soil substrate and soil moisture distribution and dynamics(SMDaD) can be widely used by desert farmers as a cheap technique, with significant savings of irrigation water.