Honey bee colony performance affected by crop diversity and farmland structure: a modeling framework

This is the final version. Available on open access from Wiley via the DOI in this recordForage availability has been suggested as one driver of the observed decline in honey bees. However, little is known about the effects of its spatiotemporal variation on colony success. We present a modeling framework for assessing honey bee colony viability in cropping systems. Based on two real farmland structures, we developed a landscape generator to design cropping systems varying in crop species identity, diversity, and relative abundance. The landscape scenarios generated were evaluated using the existing honey bee colony model BEEHAVE, which links foraging to in-hive dynamics. We thereby explored how different cropping systems determine spatiotemporal forage availability and, in turn, honey bee colony viability (e.g., time to extinction, TTE) and resilience (indicated by, e.g., brood mortality). To assess overall colony viability, we developed metrics, PH and PP, which quantified how much nectar and pollen provided by a cropping system per year was converted into a colony's adult worker population. Both crop species identity and diversity determined the temporal continuity in nectar and pollen supply and thus colony viability. Overall farmland structure and relative crop abundance were less important, but details mattered. For monocultures and for four-crop species systems composed of cereals, oilseed rape, maize, and sunflower, PH and PP were below the viability threshold. Such cropping systems showed frequent, badly timed, and prolonged forage gaps leading to detrimental cascading effects on life stages and in-hive work force, which critically reduced colony resilience. Four-crop systems composed of rye-grass–dandelion pasture, trefoil–grass pasture, sunflower, and phacelia ensured continuous nectar and pollen supply resulting in TTE > 5 yr, and PH (269.5 kg) and PP (108 kg) being above viability thresholds for 5 yr. Overall, trefoil–grass pasture, oilseed rape, buckwheat, and phacelia improved the temporal continuity in forage supply and colony's viability. Our results are hypothetical as they are obtained from simplified landscape settings, but they nevertheless match empirical observations, in particular the viability threshold. Our framework can be used to assess the effects of cropping systems on honey bee viability and to develop land-use strategies that help maintain pollination services by avoiding prolonged and badly timed forage gaps.German Academic Exchange ServiceHelmholtz Interdisciplinary GRADuate School for Environmental ResearchBiotechnology and Biological Sciences Research Council (BBSRC

Acute intraocular inflammation after intravitreous injections of bevacizumab for treatment of neovascular age-related macular degeneration

Purpose: Bevacizumab is an inhibitor of vascular endothelial growth factor widely used as an “off-label” treatment of neovascular age-related macular degeneration (AMD), despite the lack of clinical trial data on efficacy or safety of this drug. We describe acute intraocular inflammation after intravitreous injection of bevacizumab for the treatment of neovascular AMD. Design: A retrospective case series. Participants: Patients with neovascular AMD treated with intravitreous injection of bevacizumab from clinical practices in 2 states (Victoria and South Australia) in Australia. Methods: We retrospectively reviewed cases of acute intraocular inflammation after intravitreous injection of bevacizumab for the treatment of neovascular AMD. Main Outcome Measures: The detection and description of inflammation in a large cohort of patients. Results: There were 14 cases (11 women and 3 men), from a total of 1278 injections given. The mean age of patients was 83.7 years (range, 74–98). The majority had a prior injection of bevacizumab, with a mean number of injections of 2.7 (range, 1–6). Most patients presented within 24 hours of intravitreous injection, with rapid reduction in vision, but minimal discomfort. There were associated signs of ocular inflammation in the anterior and posterior segments of the eye. Visual acuity at presentation was substantially reduced compared with the preinjection acuity, although the vision rapidly improved with treatment over a period of 7–25 days toward preinjection visual acuity. Conclusions: Intravitreous injection of bevacizumab for the treatment of neovascular AMD may be associated with acute intraocular inflammation. Differentiation from infectious endophthalmitis is important for appropriate management of this condition.Sanjeewa S. Wickremasinghe, Kira Michalova, Jagjit Gilhotra, Robyn H. Guymer, C. Alex Harper, Tien Y. Wong and Salmaan Qureshihttp://www.elsevier.com/wps/find/journaldescription.cws_home/620418/description#descriptio

Continuing Medical Education: Ranibizumab treatment for neovascular age-related macular degeneration: from randomized trials to clinical practice

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