Occupancy of avian foraging guilds in soybean fields and borders in Entre Ríos, Argentina: responses to vegetation structure and prey resources

Background Reconciling agriculture and biodiversity conservation is a challenge given the growing demand for agricultural products. In recent decades, Argentina has witnessed agricultural expansion and intensification affecting biodiversity and associated ecosystem services. Within agroecosystems, the level of habitat quality is critical for birds, and may depend on vegetation structure, availability of invertebrate prey, and the use of pesticides. Although the relationship between vegetation structure and avian occurrence has been widely studied, to our knowledge, there are no studies that also incorporate prey availability throughout the cycle of soybean crops in Argentina. We estimated and predicted the effects of land cover and temporal variation on the occurrence of avian foraging guilds in Entre Ríos, Argentina, in order to guide management related to potential ecosystem services provided by birds. We also estimated temporal effects of vegetation structure and insecticides on the main arthropod orders consumed by birds to evaluate prey availability. Methods We conducted bird and arthropod surveys for 2 years along transects located in 20 randomly selected soybean fields (N = 60) and their adjacent borders (N = 78) throughout the crop growing season, in four seasons. We estimated avian occupancy, accounting for imperfect detection, and arthropod counts fitting generalized linear mixed models. Results The number of native trees in field borders positively influenced the occurrence of most bird species, mainly insectivores. Granivore foliage gleaners, also were positively affected by grass height. Salliers and aerial foragers were weakly affected by distance to forest and native trees. In general, the availability of invertebrates to birds was highest during the third season. Arthropod counts in borders were greater during the last three crop stages than during the pre-sowing period. Conclusions We found that with 10 to 15 native tree species in borders, coupled with a complex vegetation structure with shrubs and grasses, we could conserve a wide spectrum of insectivorous birds, and may contribute to the invertebrate pest control service. Vegetated field borders function as a refuge for arthropods, especially agriculturally beneficial taxa such as Hymenopterans. Finally, several groups of birds use the interior of the fields and could help control pests.

Field Theory from a Transnational Perspective

This chapter provides a new reading of field theory from a transnational perspective in light of the criticism taking issue with its alleged “methodological nationalism.” The field is an abstract concept that allows for the methodological autonomization of a space of activity defined in relational terms, provided that this autonomization is historically and sociologically grounded. As a result, fields are not necessarily limited to the perimeters of the nation-state. After reviewing the process of differentiation of fields and the phenomena of dependence and embeddedness, the chapter addresses the phenomena of nationalization and the role of the state in the formation of fields, then analyzes different modes and strategies of internationalization in relation to the structure of international power struggles, and to the tensions between state, market, and field borders. Finally, indicators of the emergence of transnational fields are proposed. In conclusion, the chapter comes back to the question of comparativism.

Evaluation of an advanced practice radiation therapist role in palliative radiation therapy.

136 Background: To evaluate the impact a new Advanced Practice Palliative Radiation Therapist (APRT) role had on patients treated with palliative intent, with respect to reducing time from referral to treatment. To evaluate the technical ability of the APRT to delineate palliative field borders on digitally reconstructed radiographs (DRR) compared to the treating Radiation Oncologist (RO). Methods: The time in working days from referral to treatment and referral to planning was recorded for all palliative patients having 10 fractions or less. The patients were classified into two groups. Patients from G1 were referred to one of four selected ROs or directly to the APRT. All clinical and technical elements of their radiotherapy treatment were managed by the APRT. Patients from G2 were referred to one of the remaining four ROs in the department and had their radiation therapy treatment managed through the standard pathway. The APRT delineated field borders on all patients in G1, blinded to the ROs field delineation. The RO then deemed the APRTs field placement acceptable or unacceptable. If unacceptable the RO documented the reasons for rejection. Results: Over 5 months, data was collected on 150 palliative patients. The APRT managed 94 patients. The remaining 56 patients were processed through the standard pathway. The APRT delineated 90 palliative fields on patients blinded to the RO. Of these, 89% were deemed acceptable by the RO. Conclusions: There has been a positive impact with respect to reducing time from referral to treatment for patients receiving palliative radiotherapy with the introduction of the APRT role in palliative radiotherapy.[Table: see text]