Impact of polarization pulling on optimal spectrometer design for stimulated Brillouin scattering microscopy.

Brillouin spectroscopy has become an important tool for mapping the mechanical properties of biological samples. Recently, stimulated Brillouin scattering () measurements have emerged in this field as a promising technology for lower noise and higher speed measurements. However, further improvements are fundamentally limited by constraints on the optical power level that can be used in biological samples, which effectively caps the gain and signal-to-noise ratio () of biological measurements.

Stimulated Brillouin scattering flow cytometry.

We present the use of stimulated Brillouin scattering spectroscopy to achieve rapid measurements of cell biomechanics in a flow cytometer setup. Specifically, our stimulated Brillouin scattering flow cytometry can acquire at a rate of 200 Hz, with a spectral acquisition time of 5 ms, which marks a 10x improvement compared to previous demonstrations of spontaneous Brillouin scattering flow cytometry. We experimentally validate our stimulated Brillouin scattering flow cytometer by measuring cell populations of normal breast epithelial cells and metastatic breast epithelial cancer cells.

Ice-inhabiting species of Bdelloidea Rotifera reveal a pre-Quaternary ancestry in the Arctic cryosphere.

Historical climate data indicate that the Earth has passed through multiple geological periods with much warmer-than-present climates, including epochs of the Miocene (23-5.3 mya BP) with temperatures 3-4°C above present, and more recent interglacial stages of the Quaternary, for example, Marine Isotope Stage 11c (approx. 425-395 ka BP) and Middle Holocene thermal maximum (7.

A palaeogenomic investigation of overharvest implications in an endemic wild reindeer subspecies.

Overharvest can severely reduce the abundance and distribution of a species and thereby impact its genetic diversity and threaten its future viability. Overharvest remains an ongoing issue for Arctic mammals, which due to climate change now also confront one of the fastest changing environments on Earth. The high-arctic Svalbard reindeer (Rangifer tarandus platyrhynchus), endemic to Svalbard, experienced a harvest-induced demographic bottleneck that occurred during the 17-20th centuries.

Contrasting genomic consequences of anthropogenic reintroduction and natural recolonization in high-arctic wild reindeer.

Anthropogenic reintroduction can supplement natural recolonization in reestablishing a species' distribution and abundance. However, both reintroductions and recolonizations can give rise to founder effects that reduce genetic diversity and increase inbreeding, potentially causing the accumulation of genetic load and reduced fitness. Most current populations of the endemic high-arctic Svalbard reindeer () originate from recent reintroductions or recolonizations following regional extirpations due to past overharvesting.