The Emerging Conflict of Common Ravens Roosting on Electric Power Transmission Line Towers in Montana, USA

Bird interactions with electric power lines can cause faults (e.g., disruption of electrical service). Faults on 500kV transmission lines in Montana, USA, which are integral to the Northwest USA power grid, became concerning during winter 2016–2017. In 2017 we found insulators contaminated with bird droppings and discovered a large nocturnal roost of common ravens (Corvus corax). To assess the potential magnitude of the impact of raven roosts on electric power transmission, we summarized fault data obtained from the Energy Management System and raven abundance data obtained from the Christmas Bird Count in central Montana from 2005 to 2020. We also conducted counts at 7 roosts in the study area in winter 2019–2020. We detected a positive relationship between the number of faults reported and raven abundance. The 3 largest roosts we surveyed peaked at 1,000–1,500 ravens on single evenings. The number of faults reported in winter 2019–2020 decreased after use of silicon-coated insulators, perch deterrents, and periodic washing of insulators. Increased raven populations throughout their range may cause similar conflicts for other electric utilities. Long-term management of ravens will need to integrate approaches at both local and landscape scales

Regulation of RPE phenotype by Annexin A8 and Wnt signalling

Purpose. Fenretinide (FR), a retinoic acid derivative, is capable of trans-differentiating retinal pigment epithelial (RPE) cells into a neuronal-like phenotype in culture. Microarray analysis pre- and post-FR treatment revealed down-regulation of Annexin (Anx) A8 and various proteins involved in Wnt signalling in trans-differentiated cells. AnxA8, a member of a superfamily of calcium-dependent phospholipid-binding proteins, is expressed in RPE cells and involved in membrane and cytoskeletal organisation and cell proliferation. The purpose of this study was to analyse the role of AnxA8 and its relationship with Wnt signalling in epithelial trans-differentiation. Methods. At 10% confluence, human RPE cells were treated with 3% charcoal dextran-treated foetal bovine serum (FBS) for 24 h. 3 µM FR or vehicle (0.1% dimethylsulfoxide) was added to the cells every day for 7 days. As a second approach, AnxA8 was suppressed in RPE cells using short interfering RNA (siRNA). Cells were then analysed for expression of AnxA8, neuronal markers (Calbindin, Calretinin) and Wnt signalling proteins (β-Catenin, Frizzled-1, Frizzled-4, Wnt2b, Wnt3a) using immunofluorescence staining, qPCR and western blot analysis. Results. FR and AnxA8 siRNA treatment both induced a decrease in AnxA8 expression and inhibited cell proliferation. FR also led to trans-differentiation of ARPE-19 cells into neuron-like cells and a concomitant up-regulation of neuronal markers. Additionally, expression of proteins involved in Wnt signalling was decreased. The effect of FR was partially reversible by activating Wnt signalling using recombinant Wnt3a or SB216763, a glycogen synthase kinase-3β inhibitor. Conclusions. These data imply an important role for AnxA8 in maintaining RPE phenotype. Down-regulation of AnxA8 appears to be sufficient for neuronal trans-differentiation of RPE cells and the expression of neuronal markers. Further, the interdependence of AnxA8 and Wnt proteins suggests that AnxA8 might be an important regulator in Wnt signalling

Effect of organic, low-input and conventional production systems on yield and diseases in winter barley

The effect of organic, low-input and conventional management practices on barley yield and disease incidence was assessed in field trials over two years. Conventional fertility management (based on mineral fertiliser applications) and conventional crop protection (based on chemosynthetic pesticides) significantly increased the yield of winter barley as compared to organic fertility and crop protection regimes. Severity of leaf blotch (Rhynchosporium secalis) was highest under organic fertility and crop protection management and was correlated inversely with yield. For mildew (Erysiphe graminis), an interaction between fertility management and crop protection was detected. Conventional crop protection reduced severity of the disease, only under conventional fertility management. Under organic fertility management, incidence of mildew was low and application of synthetic pesticides in “low input” production systems had no significant effect on disease severity

Effect of wheat production system components on food preference in rats

In the study presented the effects of two major system components - fertility management and crop protection - were tested in a rat preference test for the first time. Wheat samples produced under 4 combinations of these management factors: -a) organic fertility and crop protection management, b) organic fertility management and conventional crop protection c) conventional fertility management and organic crop protection and d) conventional fertility management and crop protection - generated in the Nafferton factorial systems comparison (NFSC) trial at Newcastle University, were used as experimental diets. Results showed that the organically fertilised wheat was preferred by rats (P = 0.001) while the organic crop protection resulted in reduced wheat consumption (not significant). This might indicate that the rats did not sense or did not select against possible traces of plant protection agents but responded more clearly to differences that were caused by the fertility management

Regulation of epithelial cell phenotype by annexin A8

Background The retinoic acid derivative Fenretinide (Fr) is capable of trans-differentiating retinal pigment epithelial (RPE) cells towards a neuron-like phenotype in culture. Microarray analysis of Fr-treated ARPE-19 cells revealed down-regulation of annexin (anx) A8 in trans-differentiated cells. AnxA8, a calcium-dependent phospholipid-binding protein, is expressed in RPE cells, where it may be involved in membrane and cytoskeletal organisation and cell proliferation. Objectives The purpose of this study was to analyse the role of anxA8 in maintaining the RPE cell phenotype. Methods RPE cells were seeded at 2,200 cells/cm2 and treated with 3% charcoal dextran-treated foetal bovine serum (FBS) for 24 h. 1µM Fr or vehicle (0.1% dimethylsulfoxide) was added every day for 7 days. As a second approach, anxA8 was suppressed in RPE cells using short interfering RNA (siRNA). Further, an anxA8-GFP construct was used to overexpress anxA8 and to restore the anxA8 loss derived from Fr or anxA8 suppression. Cells were analysed for anxA8 and the neuronal markers Calbindin and Calretinin using immunofluorescence staining and qPCR. Results Fr and anxA8 siRNA treatment both induced a decrease in anxA8 expression and inhibited cell proliferation. They also led to RPE trans-differentiation into neuron-like cells and a concomitant up-regulation of neuronal markers. Overexpression of anxA8 led to a recovery of the anxA8 loss-induced neuron-like cell phenotype. Conclusions These data reveal an important role for anxA8 in maintaining RPE phenotype. Down-regulation of anxA8 appears not only to be sufficient, but also to be necessary for neuronal trans-differentiation of RPE cells and the expression of neuronal markers. Sources of funding: BBSRC Conflicts of interest: none declare

Complement increases release of proinflammatory and proangiogenic mediators by retinal pigment epithelial cells

Objectives. A mutation in complement factor H (CFH) gene, leading to augmented complement activation, is correlated with development of age-related macular degeneration (AMD). Therefore, the influence of complement on retinal pigment epithelial (RPE) cells was examined concerning their production of proinflammatory and proangiogenic mediators relevant in AMD. Methods. ARPE-19 cells were cultured with human or fetal calf serum (FCS). Therefore, complement containing native serum as well as the heat-inactivated form with inoperable complement was used. Further, RPE cells were treated with zymosan, a complement activating yeast particle. Serum and zymosan in combination was also tested. Levels of interleukin (IL)-6, -8 and vascular endothelial growth factor (VEGF) in supernatants were examined by ELISA. Results. Untreated RPE cells produced IL-6, -8 and VEGF constitutively. FCS or human serum led to a concentration dependent release of all mediators. Thereby, FCS increased the cytokine production stronger than human serum, native serum stronger than heat-inactivated. Zymosan only intensified IL-6 and -8 secretion. Combined treatment with serum and zymosan resulted in an additive release of IL-8 and VEGF. In contrast, secretion of IL-6 was synergistic. Conclusion. The enhanced expression of IL-6, -8 and VEGF by RPE after exposure to complement might explain the correlation between augmented complement production and inflammatory processes accompanying AMD. IL-6 production was strongly increased due to activation of complement within the serum by zymosan. Thus, complement activation could stimulate inflammatory processes by activated RPE cells leading to AMD

Regulation of epithelial cell phenotype by annexin A8 and Wnt signalling

The retinoic acid derivative Fenretinide (FR) is capable of trans-differentiating retinal pigment epithelial (RPE) cells towards a neuron-like phenotype in culture. Microarray analysis of FR-treated ARPE-19 cells revealed down-regulation of Annexin (Anx)A8 and specific Wnt signalling proteins in transdifferentiated cells. AnxA8, a calcium-dependent phospholipid-binding protein, is expressed in the RPE cell cytosol, where it may be involved in membrane and cytoskeletal organisation and cell proliferation. The aim here was to analyse the role of AnxA8 and its interaction with Wnt signalling in RPE cell transdifferentiation. Human RPE cells were seeded at a concentration of 2,200/ml and treated with 3% charcoal dextran-treated foetal bovine serum (FBS) for 24h. 3µM FR or vehicle (0.1% dimethylsulfoxide) was added every day for 7 days. As a second approach, AnxA8 was suppressed in RPE cells using short interfering RNA (siRNA). FR and AnxA8 siRNA treatment both induced a decrease in AnxA8 expression and inhibited cell proliferation. It further led to transdifferentiation of ARPE-19 cells into neuron-like cells and a concomitant up-regulation of the neuronal markers Calbindin and Calretinin analysed by qPCR and immunofluorescence. Additionally, expression of Wnt signalling proteins such as β-Catenin, Frizzled-1, Frizzled-4, Wnt2b and Wnt3a was decreased. The reduction in AnxA8 and cell morphology changes induced by FR, were not reversible by inhibiting Wnt signalling using Dickkopf-1 and DAPT. Wnt signalling activators such as recombinant Wnt3a or SB216763 (glycogen synthase kinase-3β inhibitor) were able to partially reverse the FR effect. These data imply an important role for AnxA8 in maintaining RPE phenotype. Down-regulation of AnxA8 appears to be sufficient for neuronal transdifferentiation of RPE cells and the expression of neuronal markers. Further, the interdependence of AnxA8 and Wnt proteins suggests that AnxA8 might be an important regulator of Wnt signalling

Utilizing Proximity for Increasing Student Knowledge Retention: A Near-Peer Tutoring Program Needs Study

The purpose of this study was to demonstrate the desire and need for peer-to-peer tutoring programs at Division 1 Dell Medical School at the University of Texas. Materials and Methods. Two sets of surveys were created and sent to students at the Dell Medical School, University of Texas, USA. One survey asking about the need or desire to engage with a peer tutor was sent to first-year students, and another one asking about the desire to provide these services to underclassmen as a potential leadership course option was sent to third-year students. Results. For the first-year student survey, 52.9% of respondents disagreed or strongly disagreed of being aware of near-peer tutoring and 70.5% of respondents either agreed or strongly agreed that it would be an option utilized by students. For the third-year student survey, 75% of students either disagreed or felt neutral in being aware of near-peer tutoring as an option to serve underclassmen, whereas 65% of upperclassmen either agreed or strongly agreed that if near-peer tutoring had been offered, they would have chosen this leadership course option in the effort to teach their underclassmen peers. Conclusions. Numerous studies have demonstrated peer-to-peer tutorial options to be of high utility to students in the medical education space. This particular paper obtained results demonstrating students’ desire to engage in peer tutoring voluntarily for their own course success goals and upperclassmen’s desire to participate as near-peer tutors for the benefit of underclassmen

Retinal pigment epithelial cells respond to complement by an augmented production of vitronectin

Objectives: Genetic studies have demonstrated the role of activated complement on the alternative pathway during the development of age-related macular degeneration (AMD). The extracellular matrix component vitronectin can protect against activated complement. Drusen appear in the retina between the retinal pigment epithelial (RPE) cell layer and Bruch’s membrane. Drusen are hallmarks of early and late AMD and contain high amounts of vitronectin. Therefore this study addressed the influence of complement on the vitronectin production by RPE cells. Methods: ARPE-19 cells as model for RPE cells were cultivated with increasing amounts of human serum as complement source in its naïve and heat (and thereby complement) inactivated form. In another series of experiments zymosan as an activator of the alternative pathway of complement was tested alone and in combination with naïve human serum. Vitronectin was assayed in situ by immunohistochemistry, on protein level by western blot and by PCR after reverse transcription of total RNA. Results: A constitutive production of vitronectin by RPE cells was detected by all three tests. With naïve human serum increased vitronectin protein was found by immunohistochemistry and western blot while the number of mRNA transcripts was not significantly altered. The vitronectin production was further enhanced with the combination of zymosan and naïve human serum while heat inactivated serum showed lesser effect. Conclusion: Activated complement lead to an augmented vitronectin production by RPE cells on post-transcriptional level. Enhanced complement activation during AMD might also contribute in vivo to an enhanced production of vitronectin by RPE cells. On the one hand this can cause protection against activated complement but on the other hand the increased retinal vitronectin might contribute to thickening of Bruch’s membrane and may facilitate the development of drusen