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The relationship between mistletoes and birds has been studied from the perspectives of mutualism and seed dispersal. Here, we emphasize the role that avian dispersers play as agents of mistletoe seed transmission to plant hosts. We describe the patterns of transmission of the seeds of Tristerix aphyllus, an endophytic Chilean mistletoe, on two of its columnar cacti hosts (Eulychnia acida and Echinopsis skottsbergii) by the Chilean Mockingbird Mimus thenca. In north-central Chile, these cacti grow in relatively discrete subpopulations on north-facing slopes. We measured variation in seed transmission within 10 subpopulations varying in species composition, host density, parasite density, parasite prevalence (defined as the percentage of hosts infested in a given population), and disperser abundance. Seed transmission was independent of species, but was strongly dependent on prior parasitism. Parasitized individuals received seeds much more frequently than expected from their relative abundance. We found no correlation between the density of hosts and seed transmission. We found strong positive correlations, however, between parasite prevalence and seed transmission to both parasitized and nonparasitized hosts. Seed transmission of T. aphyllus seeds by M. thenca appeared to be frequency-rather than density-dependent. Seed transmission was also tightly and positively correlated with the abundance of seed-dispersing birds at each site. Because bird abundance and parasite prevalence were correlated, we conducted path analysis to disentangle their relative effect on seed transmission. A model including only the direct effect of bird abundance and the indirect effect of parasite prevalence through bird abundance explained roughly the same variance as a full model including both the direct and indirect effects of bird abundance and prevalence on seed transmission. Apparently, variation in bird abundance was the main determinant of variation in transmission. We suggest that mistletoes, host plants, and the birds that disperse mistletoe seeds are systems well suited for studies of the ecological and evolutionary dynamics of disease transmission. Key words: cacti hosts; disease transmission; Echinopsis skottsbergii; Eulychnia acida; Mimus thenca; mistletoes; parasitism; seed dispersal; Tristerix aphyllus., INTRODUCTION The ecological and evolutionary dynamics of diseases are molded by the processes by which parasites and pathogens are transmitted (Ewald 1993). Disease transmission can be passive, as in water- [...]

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We conducted a systematic review of the scientific literature published on plant-pollinator interactions, from both the plant and pollinator perspective, in the Chilean Mediterranean-type ecosystem ( MTE hereafter). Our search identified 69 published papers on 235 native plant species from 62 families. Less than 7.9% of the flowering species inhabiting the Chilean Mediterranean have been studied, and most studies were restricted to only one locality and one reproductive season. The geographic location of the studies differed from a random pattern, showing two well-defined areas where most studies were conducted. Likewise, most studies in the Andes Range were performed above 2000 m a.s.l. The number of species of flower visitor per plant species was low (4.25 ± 0.22), which probably results from the historical and biogeographic isolation of Chile. This literature survey shows that studies relating floral traits with pollinator attraction and plant reproduction are the most frequent topics of research, reaching 37.6% of studies, followed by studies that examine pollination in relation to human impact (16.1%), micro- and macroevolution (14.0%), relationships between pollination and other ecological interactions (10.8%), community and network assessments (11.8%), and effects of abiotic variables on pollination interactions (9.7%). Our review highlights a lack of research on the effects of pollination for anthropogenic land use especially as agricultural practice is one of the most salient features of the Chilean MTE. Future directions to increase our understanding of the role of plant-pollinator relationships for biodiversity maintenance should include: to extend the taxonomic and geographic scope of research, to increase the number of spatial and temporal replicates, to increase the number of studies on pollination networks as they provide estimates of community complexity and putative stability, to develop studies that estimate the importance of pollination for plant demographic parameters and conservation, and to conduct studies that estimate the ecological service provided by Chilean native pollinators for crop yield and sustainable agriculture. [ABSTRACT FROM AUTHOR]

Study design:This is a prospective study.Objectives:Young individuals with spinal cord injury (SCI) need support to actively participate in the community after their injuries. The 'Back on Track' mentoring program was developed to match mentees with SCI with mentors to assist with post-injury adjustment. The objectives of this study were to improve the percentage of youth and young adults with SCI, who access post-secondary education or employment opportunities and to improve quality of life.Setting:This study had a community-based setting.Methods:Each mentee with SCI was matched with a community-based mentor, with or without a disability. The mentoring relationship was planned for 2 years. Participants were evaluated with standardized questionnaires at intake, at the time of post-secondary education or employment entry and 4 months post entry.Results:In total, 39 individuals with SCI, age 16-26 years, were enrolled. Average age of mentees was 19.8 years (s.d.=3.0). In total, 29 participants were matched with mentors, and 10 participants (34%) completed the program, with seven (24%) returning to school, two (6.9%) returning to work and one individual (3.4%) attending school part time.Conclusion:Although multiple barriers to success occurred, this program demonstrated that it could assist the youth and young adults with SCI to obtain post-secondary education and employment. This type of support system should be encouraged in order to improve the quality and satisfaction of life for young adults with disabilities. [ABSTRACT FROM AUTHOR]