Antimicrobial stewardship in the dairy industry: responding to the threat of antimicrobial resistance

Dairy Australia is the national service body for the Australian dairy industry. Its role is to help farmers adapt to a changing operating environment and achieve a profitable, sustainable dairy industry. Although the use of antibiotics in Australian agriculture is relatively low in global terms, Dairy Australia recognises important drivers for continuous improvement in antimicrobial stewardship (AMS). Dairy Australia’s first strategic priority is to support profitable farms. This priority has driven the development of a range of on‐farm change management programs in the animal health and welfare fields to optimise the unit cost of production and dairy cattle welfare. Dairy Australia’s third strategic priority is to further develop a ‘trusted dairy industry’. Previous and current work under these two strategies position the dairy industry favourably with respect to confronting the challenge of antimicrobial resistance (AMR) and supporting sound AMS with the guiding principle of ‘as little as possible, as much as necessary’. However, given an incomplete but ongoing threat of AMR, more work is needed. Supported by Dairy Australia, the dairy industry has developed an antimicrobial use strategy aligning with the Australian Animal Sector National AMR Plan 2018.     

Enhanced resistance to a lepidopteran pest in transgenic sugar beet plants expressing synthetic <Emphasis Type="Italic">cry1Ab</Emphasis> gene

Two diploid sugar beet genotypes of agronomical importance were transformed using Agrobactrium tumefaciens harboring pBI35Scry containing a synthetic cry1Ab gene. Leaf blade with attached shoot bases, a highly regenerative tissue, were used as explant substratum for transformation. PCR screening with cry1Ab-specific primers showed the presence of transgene in more than 50% of the regenerated kanamycin-resistant plants after treatment with the antibiotic. A transformation rate of 8.8–12.2% (depending on genotype) was achieved as revealed by genomic DNA dot blotting. The intact integration of transgene cassette into the genome was furthermore confirmed by Southern blot analysis. The expression of the cry1Ab gene encoding a truncated endotoxin (67 kDa) at about 0.1% of total soluble protein was achieved in the leaves of transgenic plants as shown by Western blot analysis. Bioassays under in vitro conditions with Spodoptera littoralis, one of the most important pests in sugar beet fields, demonstrated enhanced resistance against this pest. The inheritance of the inserted transgene was confirmed in F₁ plants obtained through crossing of T₀ plants with a cytoplasmic male sterile line. Transgenic plants are currently grown in a greenhouse and will be subjected to further bioassay analyses against other lepidopteran pests of sugar beet.     

Effects of light and temperature treatments on germination and physiological traits of stevia seedling (Stevia rebuadiana Bertoni)

Light and temperature are among the environmental factors affecting germination of seeds and seedling growth. Therefore, this experiment was carried out to evaluate the effect of light (light, dark, and combined light and dark) and temperature (15, 20, 25, and 30?°C) treatments on seed germination indices and physiological traits of stevia. With increasing temperature to 25?°C, percentage and rate of germination, seedling length, and vigor index increased. Also, dark and integrated treatments light and dark conditions caused increased all traits, except for the mean germination time. The highest proline and protein contents were achieved under light conditions at 15 and 30?°C, respectively. With increasing temperature, the activity of antioxidant enzymes catalase and superoxide dismutase increased. The highest activities of catalase and superoxide dismutase were observed under light condition. In contrary, the highest peroxidase activity was observed under dark condition. Overall, the results showed that dark and combined dark and light conditions at 25?°C improved the physiological characteristics of the plant that can increase germination indices.     

Effects of magnetized water on the distribution pattern of soil water with respect to time in trickle irrigation

In arid and semi‐arid regions, farmers use low quality groundwater because of limited availability of high quality irrigation water; instead, magnetized water can be used for irrigation given its better quality. Magnetized water is obtained by passing water through permanent magnets or through electro‐magnets installed in or on a feeding pipeline. This study at the Gorgan Agricultural and Natural Resources Research Center, Gorgan province, Iran, investigated soil moisture distribution from trickle irrigation. Treatments were magnetic and non‐magnetic water and sub‐treatments involved the addition of 200 mg/L calcium carbonate and 400 mg/L calcium carbonate with well water providing the control. The experiment was laid out with a complete randomized block design with three replications. Soil moisture around the drippers was measured for 1, 2 and 3 days after irrigation during the 3‐month irrigation period. The results show that the differences in soil moisture for days 1, 2 and 3 after irrigation with magnetized irrigation water were lesser than those for the non‐magnetized irrigation water treatments. Irrigation with magnetized irrigation water caused higher soil moisture compared with the non‐magnetized irrigation water for different irrigation water salinities. The use of magnetized water for irrigation is recommended to improve irrigation efficiency.     

Alleviation of Salinity Stress by Vermicompost Extract: A Comparative Study on Five Fennel Landraces

In the present study, interaction between salinity (0, 40, 80, 120 mM NaCl) and vermicompost extract (VCE) on five fennel landraces (Urmia, Mashhad, Shiraz, Boushehr, Isfahan) was investigated in a factorial experiment as completely randomized design to find the best salt-tolerant landrace and potential alleviating role of VCE. Results showed that Boushehr and Isfahan were the most tolerant and sensitive landrace to salinity, respectively. Application of VCE improved germination and growth of salt-treated fennels. The amylase activity of fennels was not affected by salinity and not improved by VCE. While sodium (Na⁺) content of root and shoot of all salt-treated fennels increased, their potassium (K) content decreased. Under salinity stress, root K content of VCE-amended landraces was more than that of not amended ones. VCE also caused an increase in calcium (Ca) content of root of salt-treated Shiraz and Urmia landraces. In conclusion, VCE can alleviate adverse effects of salinity stress on fennel.     

The Seismic Structure of the Sun

Global Oscillation Network Group data reveal that the internal structure of the sun can be well represented by a calibrated standard model. However, immediately beneath the convection zone and at the edge of the energy-generating core, the sound-speed variation is somewhat smoother in the sun than it is in the model. This could be a consequence of chemical inhomogeneity that is too severe in the model, perhaps owing to inaccurate modeling of gravitational settling or to neglected macroscopic motion that may be present in the sun. Accurate knowledge of the sun's structure enables inferences to be made about the physics that controls the sun; for example, through the opacity, the equation of state, or wave motion. Those inferences can then be used elsewhere in astrophysics.     

A tunable kondo effect in quantum dots

A tunable Kondo effect has been realized in small quantum dots. A dot can be switched from a Kondo system to a non-Kondo system as the number of electrons on the dot is changed from odd to even. The Kondo temperature can be tuned by means of a gate voltage as a single-particle energy state nears the Fermi energy. Measurements of the temperature and magnetic field dependence of a Coulomb-blockaded dot show good agreement with predictions of both equilibrium and nonequilibrium Kondo effects.     

Hydrogen radicals, nitrogen radicals, and the production of O3 in the upper troposphere

The concentrations of the hydrogen radicals OH and HO2 in the middle and upper troposphere were measured simultaneously with those of NO, O3, CO, H2O, CH4, non-methane hydrocarbons, and with the ultraviolet and visible radiation field. The data allow a direct examination of the processes that produce O3 in this region of the atmosphere. Comparison of the measured concentrations of OH and HO2 with calculations based on their production from water vapor, ozone, and methane demonstrate that these sources are insufficient to explain the observed radical concentrations in the upper troposphere. The photolysis of carbonyl and peroxide compounds transported to this region from the lower troposphere may provide the source of HOx required to sustain the measured abundances of these radical species. The mechanism by which NO affects the production of O3 is also illustrated by the measurements. In the upper tropospheric air masses sampled, the production rate for ozone (determined from the measured concentrations of HO2 and NO) is calculated to be about 1 part per billion by volume each day. This production rate is faster than previously thought and implies that anthropogenic activities that add NO to the upper troposphere, such as biomass burning and aviation, will lead to production of more O3 than expected.     

Biomimetic Pathways for Assembling Inorganic Thin Films

Living organisms construct various forms of laminated nanocomposites through directed nucleation and growth of inorganics at self-assembled organic templates at temperatures below 100°C and in aqueous solutions. Recent research has focused on the use of functionalized organic surfaces to form continuous thin films of single-phase ceramics. Continuous thin films of mesostructured silicates have also been formed on hydrophobic and hydrophilic surfaces through a two-step mechanism. First, under acidic conditions, surfactant micellar structures are self-assembled at the solid/liquid interface, and second, inorganic precursors condense to form an inorganic-organic nanocomposite. Epitaxial coordination of adsorbed surfactant tubules is observed on mica and graphite substrates, whereas a random arrangement is observed on amorphous silica. The ability to process ceramic-organic nanocomposite films by these methods provides new technological opportunities.