55 research outputs found

    Rapid Acoustic Survey for Biodiversity Appraisal

    Get PDF
    Biodiversity assessment remains one of the most difficult challenges encountered by ecologists and conservation biologists. This task is becoming even more urgent with the current increase of habitat loss. Many methods–from rapid biodiversity assessments (RBA) to all-taxa biodiversity inventories (ATBI)–have been developed for decades to estimate local species richness. However, these methods are costly and invasive. Several animals–birds, mammals, amphibians, fishes and arthropods–produce sounds when moving, communicating or sensing their environment. Here we propose a new concept and method to describe biodiversity. We suggest to forego species or morphospecies identification used by ATBI and RBA respectively but rather to tackle the problem at another evolutionary unit, the community level. We also propose that a part of diversity can be estimated and compared through a rapid acoustic analysis of the sound produced by animal communities. We produced α and ÎČ diversity indexes that we first tested with 540 simulated acoustic communities. The α index, which measures acoustic entropy, shows a logarithmic correlation with the number of species within the acoustic community. The ÎČ index, which estimates both temporal and spectral dissimilarities, is linearly linked to the number of unshared species between acoustic communities. We then applied both indexes to two closely spaced Tanzanian dry lowland coastal forests. Indexes reveal for this small sample a lower acoustic diversity for the most disturbed forest and acoustic dissimilarities between the two forests suggest that degradation could have significantly decreased and modified community composition. Our results demonstrate for the first time that an indicator of biological diversity can be reliably obtained in a non-invasive way and with a limited sampling effort. This new approach may facilitate the appraisal of animal diversity at large spatial and temporal scales

    Survival outcomes for Australian women receiving trastuzumab for HER2-positive metastatic breast cancer following (neo)adjuvant trastuzumab: a national population-based observational study (2006-2014)

    Get PDF
    Patients treated with (neo)adjuvant trastuzumab who relapse and receive trastuzumab for metastatic breast cancer (MBC) are a growing population with little outcome data given their exclusion from most clinical trials. We aim to estimate survival outcomes for this trastuzumab 'pre-treated' population.Population-based study of Australian women receiving trastuzumab for HER2-positive MBC between 2006 and 2014, who also received (neo)adjuvant trastuzumab. We used Kaplan-Meier methods to estimate the following: overall survival (OS) from initiation of trastuzumab for MBC; duration of trastuzumab for MBC; and time from last (neo)adjuvant trastuzumab to first trastuzumab for MBC.Of 3199 patients dispensed trastuzumab for MBC, 634 (20%) had received (neo)adjuvant traztuzumab. Pre-treated patients had a median (interquartile range) OS of 21.8 months (10.9-51.6), trastuzumab duration of 12.8 months (4.7-17.5), and time from last (neo)adjuvant trastuzumab to first trastuzumab for MBC of 15.6 months (6.5-28.6). Median OS for patients initiating trastuzuma
    • 

    corecore