The efficiency of between and within full-sib family selection in a recurrent selection programme in sugar beet (Beta vulgaris L.)

The efficiency of between and within family selection in a full-sib family recurrent selection programme was investigated using data from three cycles of recurrent selection. Correlations between mid-parent values and offspring were high for sugar content and juice purity characters, but low for root weight and sugar yield. This suggests that single root selection within full-sib families is effective in the improvement of sugar content and juice purity, but ineffective for root weight and sugar yield. Root weight and sugar yield will respond better to between full-sib family selection. This revised version was published online in July 2006 with corrections to the Cover Date.     

Jupiter's Radiation Belts: Can Pioneer 10 Survive?

Model calculations of Jupiter's electron and proton radiation belts indicate that the Galilean satellites can reduce particle fluxes in certain regions of the inner magnetosphere by as much as six orders of magnitude. Average fluxes should be reduced by a factor of 100 or more along the Pioneer 10 trajectory through the heart of Jupiter's radiation belts in early December. This may be enough to prevent serious radiation damage to the spacecraft.     

Quantifying inherent predictability and spatial synchrony in the aphid vector Myzus persicae: field-scale patterns of abundance and regional forecasting error in the UK

Background

Sugar beet is threatened by virus yellows, a disease complex vectored by aphids that reduces sugar content. We present an analysis of Myzus persicae population dynamics with and without neonicotinoid seed treatment. We use 6 years' yellow water trap and field-collected aphid data and two decades of 12.2 m suction-trap aphid migration data. We investigate both spatial synchrony and forecasting error to understand the structure and spatial scale of field counts and why forecasting aphid migrants lacks accuracy. Our aim is to derive statistical parameters to inform regionwide pest management strategies.

Results

Spatial synchrony, indicating the coincident change in counts across the region over time, is rarely present and is best described as stochastic. Uniquely, early season field populations in 2019 did show spatial synchrony to 90 km compared to the overall average weekly correlation length of 23 km. However, 70% of the time series were spatially heterogenous, indicating patchy between-field dynamics. Field counts lacked the same seasonal trend and did not peak in the same week. Forecasts tended to under-predict mid-season log₁₀ counts. A strongly negative correlation between forecasting error and the proportion of zeros was shown.

Conclusion

Field populations are unpredictable and stochastic, regardless of neonicotinoid seed treatment. This outcome presents a problem for decision-support that cannot usefully provide a single regionwide solution. Weighted permutation entropy inferred that M. persicae 12.2 m suction-trap time series had moderate to low intrinsic predictability. Early warning using a migration model tended to predict counts at lower levels than observed. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Tick Bite Prophylaxis: Results From a 2012 Survey of Healthcare Providers

In a recent national survey, over 30% of healthcare providers (HCPs) reported prescribing tick bite prophylaxis in the previous year. To clarify provider practices, we surveyed HCPs to determine how frequently and for what reasons they prescribed tick bite prophylaxis. We included four questions regarding tick bite prophylaxis in the DocStyles 2012 survey, a computer‐administered questionnaire of 2205 US primary care physicians, paediatricians and nurse practitioners. Responses in 14 states with high Lyme disease incidence (high LDI) were compared with responses from other states (low LDI). Overall, 56.4% of 1485 providers reported prescribing tick bite prophylaxis at least once in the previous year, including 73.9% of HCPs in high LDI and 48.2% in low LDI states. The reasons given were ‘to prevent Lyme disease’ (76.9%), ‘patients request it’ (40.4%) and ‘to prevent other tickborne diseases’ (29.4%). Among HCPs who provided prophylaxis, 45.2% did so despite feeling that it was not indicated. Given a hypothetical scenario involving a patient with an attached tick, 38.1% of HCPs from high LDI states and 15.1% from low LDI states would prescribe a single dose of doxycycline; 19.0% from high LDI states and 27.5% from low LDI states would prescribe a full course of doxycycline. HCPs prescribe tick bite prophylaxis frequently in areas where Lyme disease is rare and for tickborne diseases for which it has not been shown effective. HCPs may be unaware of current tick bite prophylaxis guidelines or find them difficult to implement. More information is needed regarding the efficacy of tick bite prophylaxis for diseases other than Lyme disease.     

Assessment of the Risk of White Sturgeon to become Infected and Potential Carriers of Infectious Pancreatic Necrosis Virus

Abstract

Little scientific information is available to assess whether White Sturgeon Acipenser transmontanus can become infected and potential carriers of infectious pancreatic necrosis virus (IPNV). To assess this risk, monitoring results of adult and progeny White Sturgeon were examined from waters historically stocked with salmonid fish known to be IPNV carriers. From 1999 through 2004 White Sturgeon from a total of 30 separate families whose parentage came from waters historically stocked with IPNV carrier fish were tested. Duplicate groups of 25 juvenile Snake River White Sturgeon were waterborne exposed to 1.0×10⁴ 50% tissue culture infective dose (TCID50)/mL of water for 1 h and an additional group was injected intraperitoneally with 1.0×10⁵ TCID50/fish. A negative control group was handled similarly but was not exposed to the virus. No morbidity was detected in any of the treatment groups or the negative control. At 34, 40, 47, and 54 d postexposure to IPNV, virus reisolation was attempted on five fish from each group, and an additional five fish from each group were examined for histological changes consistent with an IPNV infection. At 34 and 40 d postinjection with IPNV, 20% (one of five) of the fish tested positive for the virus per sample interval; however, fish from groups that were waterborne-exposed to IPNV were all negative. At 47 and 54 d after exposure or injection with IPNV an additional five fish from each group were tested at each sample interval and all results were negative. Histological analysis of target tissue obtained from five fish per group at 34 and 54 d postinfection also failed to detect any consistent change associated with an IPNV infection. These results suggest that the risk of White Sturgeon to become infected and develop into potential carriers of IPNV is negligible.

Received May 21, 2013; accepted July 8, 2013     

Cryopreservation of Zona‐Free Cloned Buffalo (Bubalus Bubalis) Embryos: Slow Freezing vs Open‐Pulled Straw Vitrification

This study was carried out to compare the post‐thaw cryosurvival rate and the level of apoptosis in vitro produced zona‐free cloned buffalo blastocysts subjected to slow freezing or vitrification in open‐pulled straws (OPS). Zona‐free cloned embryos produced by handmade cloning were divided into two groups and were cryopreserved either by slow freezing or by vitrification in OPS. Cryosurvival of blastocysts was determined by their re‐expansion rate following post‐thaw culture for 22–24 h. The post‐thaw re‐expansion rate was significantly (p < 0.05) higher following vitrification in OPS (71.2 ± 2.3%) compared with that after slow freezing (41.6 ± 4.8%). For examining embryo quality, the level of apoptosis in day 8 frozen‐thawed blastocysts was determined by TUNEL staining. The total cell number was not significantly different among the control non‐cryopreserved cloned embryos (422.6 ± 67.8) and those cryopreserved by slow freezing (376.4 ± 29.3) or vitrification in OPS (422.8 ± 36.2). However, the apoptotic index, which was similar for embryos subjected to slow freezing (14.8 ± 2.0) or OPS vitrification (13.3 ± 1.8), was significantly (p < 0.05) higher than that for the control non‐cryopreserved cloned embryos (3.4 ± 0.6). In conclusion, the results of this study demonstrate that vitrification in OPS is better than slow freezing for the cryopreservation of zona‐free cloned buffalo blastocysts because it offers a much higher cryosurvival rate.     

Book reviews

Proceedings of the Fourth European Symposium on Poultry Welfare, Edited by C. J. Savory and B. O. hughes, 1993. 318 pp. illustrated. Potters Bar, London, Universities Federation for Animal Welfare. £ 10.00 ISBN 0 900767 83 9.

Microbiology of the Avian Egg. Edited by R. G. Board AND R. Fuller, 1994. 181 pp., illustrated. London, Chapman and Hall. £45.00 ISBN 0–412–47570–7.

Handbook of Avian Anatomy: Nomina Anatomic Avium. Second edition, Edited by J. J. Baumel, 1993. XXIV + 229 pp illustrated. Nutall Ornithological Club, c/o Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138, USA. $65.00     

Will Culling White‐Tailed Deer Prevent Lyme Disease?

White‐tailed deer play an important role in the ecology of Lyme disease. In the United States, where the incidence and geographic range of Lyme disease continue to increase, reduction of white‐tailed deer populations has been proposed as a means of preventing human illness. The effectiveness of this politically sensitive prevention method is poorly understood. We summarize and evaluate available evidence regarding the effect of deer reduction on vector tick abundance and human disease incidence. Elimination of deer from islands and other isolated settings can have a substantial impact on the reproduction of blacklegged ticks, while reduction short of complete elimination has yielded mixed results. To date, most studies have been conducted in ecologic situations that are not representative to the vast majority of areas with high human Lyme disease risk. Robust evidence linking deer control to reduced human Lyme disease risk is lacking. Currently, there is insufficient evidence to recommend deer population reduction as a Lyme disease prevention measure, except in specific ecologic circumstances.