Prevalence of QoI resistance and mtDNA diversity in the Irish Zymoseptoria tritici population

peer-reviewedThe emergence and spread of Quinone outside Inhibitor (QoI) fungicide resistance in the Irish Zymoseptoria tritici population in the early 2000s had immediate impacts on the efficacy of the entire group of fungicides for the control of septoria tritici blotch. As a result, a dramatic reduction in the quantities applied to winter wheat occurred in the following seasons. Even in the absence of these fungicides, the frequency of the resistance allele, G143A in the pathogens mtDNA has remained exceptionally high (>97%), and as such, it can be anticipated that continued poor efficacy of current QoI fungicides will be observed. Amongst the isolates with G143A, differences in sensitivity to the QoI pyraclostrobin were observed in vitro. The addition of the alternative oxidase (AOX) inhibitor salicylhydroxamic acid increased sensitivity in these isolates, suggesting some continued impairment of respiration by the QoI fungicides, albeit weak. Interestingly, amongst those tested, the strains from a site with a high frequency of inserts in the MFS1 transporter gene known to enhance QoI efflux did not exhibit this increase in sensitivity. A total of 19 mtDNA haplotypes were detected amongst the 2017 strain collection. Phylogenetic analysis confirmed the suggestion of a common ancestry of all the haplotypes, even though three of the haplotypes contained at least one sensitive strain

Emergence of foams from the breakdown of the phase field crystal model

The phase field crystal (PFC) model captures the elastic and topological properties of crystals with a single scalar field at small undercooling. At large undercooling, new foam-like behavior emerges. We characterize this foam phase of the PFC equation and propose a modified PFC equation that may be used for the simulation of foam dynamics. This minimal model reproduces von Neumann's rule for two-dimensional dry foams, and Lifshitz-Slyozov coarsening for wet foams. We also measure the coordination number distribution and find that its second moment is larger than previously-reported experimental and theoretical studies of soap froths, a finding that we attribute to the wetness of the foam increasing with time.Comment: 4 pages, 4 figure

Nonlinear Pauli Susceptibilities in Sr3_3Ru2_2O7_7 and Universal Features of Itinerant Metamagnetism

We report, for the first time, measurements of the third order, $\chi_3$ and fifth order, $\chi_5$, susceptibilities in an itinerant oxide metamagnet, Sr$_3$Ru$_2$O$_7$ for magnetic fields both parallel and perpendicular to the c-axis. These susceptibilities exhibit maxima in their temperature dependence such that $T_1 \approx 2T_3 \approx 4T_5$ where the $T_i$ are the position in temperature where a peak in the $i$-th order susceptibility occurs. These features taken together with the scaling of the critical field with the temperature $T_1$ observed in a diverse variety of itinerant metamagnets find a natural explanation in a single band model with one Van Hove singularity (VHS) and onsite repulsion $U$. The separation of the VHS from the Fermi energy $\Delta$, sets a single energy scale, which is the primary driver for the observed features of itinerant metamagnetism at low temperatures.Comment: 8 pages, 7 figure

Winter Housing and Feeding System for Small to Medium Sized Dairy Farms

End of Project ReportA survey of 190 dairy farms in a co-operative area in the south of Ireland served as the main source of data in the present study. Eight farms representative of the different types of dairy farms were chosen and their data were analysed using the Finpack financial analysis program. These eight case studies were analysed using alternative funding strategies to determine the effect of alternative funding strategies for farm buildings on net farm income. The data obtained were extrapolated to the national dairy herd. There are some 14,050 dairy farms with quotas of less than 15,000 gallons and 40% of these were classified as non viable. The corresponding figures for other quota categories are as follows: 8,150 farms with quotas of 15,000-25,000 gallons with 40% non-viable; 7780 farms with quotas of 25,000-40,000 gallons with 20% nonviable; and 8,535 farms with quotas >40,000 gallons with 10% nonviable. Non-viable dairy farms were those with low income, low contact with advisory services, low household dependence on farm income, a poor attitude to development and expansion and generally inadequate farm facilities. Non-viable dairy farms should consider changing from dairying into a suckler and/or beef enterprise and should be assisted to do so by the advisory service. They should be considered for a suckler quota unit for each 987 gallons of milk they had been producing. They should consider using income assistants, e.g., REPS, Early Retirement Scheme and/or unemployment benefits as relevant. Training schemes should be targeted at young farmers and their spouses who are not working so that they have a better chance of offfarm employment, when relevant. Potentially viable and viable dairy farms should be assisted on a sliding scale depending on their quota size, as follows: Grant aid for upgrading milking facilities, grant aid for milking and milk cooling equipment, interest subsidies on interest payment on money borrowed for agricultural development, the smallest milk quota farms should be considered the priority for milk quota reallocation, quota purchase should be subsidised if possible, quota leasing should be subsidised for the smallest quota category (<15,000 gallons), installation Aid should be introduced for all viable and potentially viable dairy farms.Dairy Farmer Levy Fund

High prevalence of scrapie in a dairy goat herd: tissue distribution of disease-associated PrP and effect of PRNP genotype and age

Following a severe outbreak of clinical scrapie in 2006–2007, a large dairy goat herd was culled and 200 animals were selected for post-mortem examinations in order to ascertain the prevalence of infection, the effect of age, breed and PRNP genotype on the susceptibility to scrapie, the tissue distribution of diseaseassociated PrP (PrP$^{\rm d}$), and the comparative efficiency of different diagnostic methods. As determined by immunohistochemical (IHC) examinations with Bar224 PrP antibody, the prevalence of preclinical infection was very high (72/200; 36.0%), with most infected animals being positive for PrP$^{\rm d}$ in lymphoreticular system (LRS) tissues (68/72; 94.4%) compared to those that were positive in brain samples (38/72; 52.8%). The retropharyngeal lymph node and the palatine tonsil showed the highest frequency of PrP$^{\rm d}$ accumulation (87.3% and 84.5%, respectively), while the recto-anal mucosa-associated lymphoid tissue (RAMALT) was positive in only 30 (41.7%) of the infected goats. However, the efficiency of rectal and palatine tonsil biopsies taken shortly before necropsy was similar. The probability of brain and RAMALT being positive directly correlated with the spread of PrP$^{\rm d}$ within the LRS. The prevalence of infection was influenced by PRNP genetics at codon 142 and by the age of the goats: methionine carriers older than 60 months showed a much lower prevalence of infection (12/78; 15.4%) than those younger than 60 months (20/42; 47.6%); these last showed prevalence values similar to isoleucine homozygotes of any age (40/80; 50.0%). Two of seven goats with definite signs of scrapie were negative for PrP$^{\rm d}$ in brain but positive in LRS tissues, and one goat showed biochemical and IHC features of PrP$^{\rm d}$ different from all other infected goats. The results of this study have implications for surveillance and control policies for scrapie in goats