Conservation implications of isotopic variation in nails and blood with wetland quality in three species of Australian freshwater turtle

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Production of Lectins from Marine Algae: Current Status,Challenges, and Opportunities for Non-Destructive Extraction

Marine algae are an excellent source of novel lectins. The isolation of lectins from marine algae expands the diversity in structure and carbohydrate specificities of lectins isolated from other sources. Marine algal lectins have been reported to have antiviral, antitumor, and antibacterial activity. Lectins are typically isolated from marine algae by grinding the algal tissue with liquid nitrogen and extracting with buffer and alcohol. While this method produces higher yields, it may not be sustainable for large-scale production, because a large amount of biomass is required to produce a minute amount of compound, and a significant amount of waste is generated during the extraction process. Therefore, non-destructive extraction using algal culture water could be used to ensure a continuous supply of lectins without exclusively disrupting the marine algae. This review discusses the traditional and recent advancements in algal lectin extraction methods over the last decade, as well as the steps required for large-scale production. The challenges and prospects of various extraction methods (destructive and non-destructive) are also discussed.     

Cost minimization through the use of taungya system in pulpwood plantation establishment

The costs and benefits of the use of three labour alternatives: direct permanent, direct casual and taungya labour in Gmelina arborea pulpwood plantation establishment in Nigeria were investigated. Results show that cost per hectare is lowest with taungya labour and highest with permanent labour with savings in cost of as much as 30% and 47% by taungya labour over casual and permanent labour respectively. The net present value per hectare of investment is highest when taungya labour is used and lowest and negative with permanent labour. Also, the internal rate of return of investment is highest with taungya labour and lowest with permanent labour. The net present values and internal rates of return for Gmelina plantations calculated for the three pulp and paper mills in Nigeria show the same trend in favour of taungya labour.     

Crop loss and control of Pseudocercospora fruit and leaf spot of citrus in Ghana

Pseudocercospora fruit and leaf spot (PFLS) of citrus, caused by Pseudocercospora angolensis, was recently described in Ghana and has spread in most citrus-growing areas of the country. A survey of PFLS incidence was conducted in the Eastern Region. Orchards were georeferenced and data on altitude, annual mean temperature, and annual precipitation were obtained from the WorldClim database. Fruit drop due to PFLS and other pests and diseases was evaluated in three orchards. Field efficacies of 4-week, 6-week and 8-week schedules with carbendazim + mancozeb were evaluated in the major and minor fruit production seasons. Ordinal logistic regression and generalized linear models were fitted in each case according to the nature of the data and possible overdispersion. Disease incidence in the sweet orange orchards surveyed was 25–100 %, with higher values in higher altitude areas exposed to lower temperatures and higher rainfall. PFLS was the main problem causing yield losses, associated with 84–87 % of fruit dropped on the orchard floor. PFLS severity on shoots and incidence on fruit 12 weeks after full bloom was significantly reduced by all fungicide schedules evaluated. The effects of fungicides on PFLS severity in fruit at harvest were not substantial because of intense fruit drop. The 8-week schedule showed the lowest effectiveness in reducing fruit drop and thus the 6-week schedule is preferred. Further research is needed for an integrated management of PFLS in Ghana.     

Impact of reader antenna polarisation, distance, inlay design, conveyor speed, tag location and orientation on the coupling of UHF RFID as applied to modified atmosphere packaged meat

Undetected RFID tags make the potential benefits of RFID unattainable. This study aimed to determine the most significant factors that affect RFID and particularly its application to the traceability of meat. Experimental parameters included five RFID tag inlays, two levels of conveyor speeds, five variations of beef sample and an empty container, 12 tags per test sample, three distances and two types of reader antenna polarisations. Tag detection rates were determined in three replicates per combination of test parameters. A GLM ANOVA was carried out on tag detection rate. In decreasing order of significance in terms of the effect on mean tag detection rate were distance, sample, inlay design, conveyor speed and reader antenna polarisation. Interaction of these factors also proved significant, in decreasing order of importance were reader antenna * inlay, sample type * distance, inlay * distance, sample type * inlay, sample type * reader antenna, distance * speed, sample type * speed and finally sample type * distance * speed. Linearly polarised antenna preformed better overall at detecting tags, with 63% mean detection rate compared with circularly polarised antenna with 57% mean detection rate. Varying the tag inlay resulted in mean detection rates of between 62% and 88%. Ideal transponder location on package was reader antenna polarisation dependent, but generally tags facing reader antennas exhibited better detection rate. Results revealed that the under side of the package was the most un-detectable transponder location, considering the placement of reader antennas on top, left and right sides of the sample. Conveyor speed also proved significant with a variation from 0.5 to 1.0 m/s resulting in an average detection rate ranging from 62% to 57%, respectively. Circularly polarised antennas are believed to perform better in cases of random tag orientation on products. It can be concluded that RFID systems implementation in the meat supply chain requires a holistic approach where distances, polarisations, inlay type, meat composition and conveyor speed need to be considered.     

Genetic Effects and Estimates for the Heritability of Size in Fingerling Hybrid Striped Bass Reared Indoors

Hybrid striped bass fingerlings were grown in replicated indoor tanks for 42 days to evaluate progeny performance of two growth-related traits. Analysis of variance demonstrated significant differences in length and weight of fingerlings among paternal and maternal half-sib families and high estimates of heritability for dams and sires. Based on significant sire and dam effects and high heritabilities, a substantial portion of the selection differential could be expected to be gained in offspring from selected pure-line parents. As demonstrated by these results, a breeding program could be used to select parental lines that produce faster growing hybrid offspring.     

Oxidative Stress and Interaction of Endothelin Receptors in Airways of Clinically Healthy Horses

Endothelin-1 (ET-1), a physiological as well as an inflammatory mediator, causes contraction of airway smooth muscles by binding to endothelin-A (ETA) and endothelin-B (ETB) receptors. We investigated the interaction between endothelin receptors on contractions and oxidative stress of bronchial rings of clinically healthy horses. Rings for response studies were set in tissue chambers containing oxygenated Tyrode’s solution. Concentration-response relationships were determined for ET-1 on control rings, rings incubated with ETA antagonist (BQ123), rings incubated with ETB antagonists (IRL 1038 and BQ788), and rings incubated with all antagonists combined. For oxidative stress studies, rings were incubated for 30 minutes separately with ET-1, ETA antagonist + ET-1, ETB antagonists + ET-1, and all three antagonists + ET-1. The control rings were not treated with any agents. Electron paramagnetic resonance (EPR) method was used to measure total reactive oxygen species (ROS), superoxide, and peroxynitrite. Results showed that ET-1 caused dose-dependent contractions which were increased by ETA blockade and decreased by ETB blockade. Combined blockade significantly inhibited the response to ET-1. Regarding the oxidative stress, ET-1 and its antagonists significantly reduced the total ROS. Superoxide production was significantly decreased by ETA antagonist and completely abolished when ETA and ETB antagonists were combined. Peroxynitrite production was not changed significantly. The study suggested that an interaction between ET receptors exists in the expression of contractile responses and oxidative stress. ET-1 attenuated oxidative stress by decreasing total ROS. ETA receptors may be primarily responsible for superoxide production. It appears that ET-1 does not affect peroxynitrite production in normal equine tissues.