Bone has photoluminescent characteristics that can aid the analysis of thermally altered human skeletal remains as part of the forensic anthropological investigation. Photoluminescence stands collectively for fluorescence and phosphorescence. Because the difference in lifetime between fluorescence and phosphorescence is usually in the range of nano- to microseconds, it is only possible to visually determine whether bone phosphoresces when the lifetime is long enough to be observed. For this study, a distinction was made between long-decay and short-decay phosphorescence. So far, it was unknown whether (thermally altered) human bone emits long-decay phosphorescence after being illuminated and, thus, whether phosphorescence contributes to the observed photoluminescence. If so, whether the observable phosphorescence is dependent on temperature, exposure duration, surrounding medium, bone type, skeletal element, and excitation light and could aid the temperature estimation of heated bone fragments. In this study, bone samples were subjected to heat in the range of from room temperature to 900 °C for various durations in either air or adipose as surrounding medium. In addition, different skeletal elements of a human cadaver were recollected after cremation in a crematorium. Both sample collections were illuminated with light of different bandwidths and visually inspected for phosphorescence and photoluminescence. The samples were scored by means of a scoring index for the intensity of long-decay phosphorescence and photographically documented. The results show that thermally altered human bone fragments do phosphoresce. The observed phosphorescence is more dependent on temperature than on exposure duration, surrounding medium or skeletal element. Of the used wavelength bands, ultraviolet light provided the most temperature-related information, showing changes in both phosphorescence intensity and emission spectrum. Long-decay phosphorescence and fluorescence with short-decay phosphorescence coincide; however, there are also temperature-dependent differences. It is therefore concluded that phosphorescence contributes to the observable photoluminescence and that the visibly observable phosphorescent characteristics can aid the temperature estimation of cremated human skeletal fragments.

Massively Parallel Sequencing (MPS) enables simultaneous analysis of a much larger number of forensic markers compared to conventional capillary electrophoresis (CE) sizing-based genotyping. Since both methods rely on amplified STR fragments, stutter products will occur that can complicate the detection of minor contributors in mixed samples. Sequence variation observed in STRs and their flanking regions can help to distinguish genuine alleles from stutter artefacts and noise correction can be applied to filter stutter artefacts. Using data from 545 samples analysed with the Forenseq™ DNA Signature Prep kit, a training set was used to obtain FDSTools noise profiles and a test set to analyse the impact of FDSTools noise correction for different analysis thresholds. Noise correction enabled a substantial reduction of analysis thresholds with limited drop-in down to 1.5%. However, occasional noise outliers (after correction) of up to 5% of the corresponding allele do occur and may complicate analysis. Data analysis Initial calling of allelesUsing the FDSTools tssv, stuttermark and allelefinder, samples were selected and alleles were called for the FDSTools training set.

Assessing mosquito biodiversity is important for disease surveillance and ecosystem health assessments. Such studies are particularly needed in regions like the Caribbean, which have experienced a series of recent mosquito borne disease outbreaks but received little attention regarding its invertebrate biodiversity. Here, we report on results from a mosquito survey on the Dutch Leeward Islands (Sint Eustatius, Sint Maarten and Saba), carried out in April and October 2018, which is the first integrative survey since those conducted by Van der Kuyp (1947) and Wagenaar Hummelinck (1949). Moreover, we present a novel key for adults and fourth instar larvae of the mosquitoes of the Dutch Leeward Islands. Overall, eleven species were recorded, eight on Sint Maarten, five on Saba and two on Sint Eustatius. Two new potential disease vectors, Culex nigripalpus and Aedes taeniorhynchus, were recorded on Sint Maarten. One previously recorded species, Cx. habilitator, was not retrieved from any of the islands, which is further discussed in the paper. Species indicative of natural forest which previously occurred on all three islands were absent from Sint Eustatius and Sint Maarten but still present on Saba. In contrast, species indicative of human inhabitation, Ae. aegypti and Cx. quinquefasciatus, were highly abundant on Sint Maarten and Sint Eustatius and present in low numbers on Saba. Overall, the results of this study emphasize the importance of biodiversity surveys and indicate that frequent mosquito inventories may contribute to a better understanding of mosquito community composition and distribution of potential vector species.

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