Automating insect monitoring using unsupervised near-infrared sensors.

Insect monitoring is critical to improve our understanding and ability to preserve and restore biodiversity, sustainably produce crops, and reduce vectors of human and livestock disease. Conventional monitoring methods of trapping and identification are time consuming and thus expensive. Automation would significantly improve the state of the art. Here, we present a network of distributed wireless sensors that moves the field towards automation by recording backscattered near-infrared modulation signatures from insects. The instrument is a compact sensor based on dual-wavelength infrared light emitting diodes and is capable of unsupervised, autonomous long-term insect monitoring over weather and seasons. The sensor records the backscattered light at kHz pace from each insect transiting the measurement volume. Insect observations are automatically extracted and transmitted with environmental metadata over cellular connection to a cloud-based database. The recorded features include wing beat harmonics, melanisation and flight direction. To validate the sensor's capabilities, we tested the correlation between daily insect counts from an oil seed rape field measured with six yellow water traps and six sensors during a 4-week period. A comparison of the methods found a Spearman's rank correlation coefficient of 0.61 and a p-value = 0.0065, with the sensors recording approximately 19 times more insect observations and demonstrating a larger temporal dynamic than conventional yellow water trap monitoring.

The effec of triethylcitrate on the porosity and biocompatibility of poly (lactic acid) membranes

The aim of this study was to investigate stability and tissue response to poly (L-lactic acid) (PLLA) membranes implanted in sub-dermal tissue of rats. Membranes with and without plasticizer (triethylcitrate) were compared. Membranes without plasticizer were denser and more compact than those with triethylcitrate. Fifteen days and 30 days after implantation, the membranes with tissue adhered were removed and processed for light microscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). By 15 days post-implantation, membranes lacking plasticizer showed invasion of the pores by connective tissue. Thirty days after implantation, the pores of membranes with plasticizer were invaded by blood vessels, and multi-nucleated giant cells surrounded by globular units of the membranes. Membrane debris was also detected in the cytoplasm of multi-nucleated giant cells. These data show that the addition of plasticizer to PLLA results in a more porous membrane, therefore enabling them more suitable in tissue repair (than membranes without plasticizer).