Science and Photography
The Wellcome Trust — a London-based medical research charity — has just announced the winners of its 2012 image competition, and they are positively stunning.
1. Moth fly (Psychodidae)
This false-coloured scanning electron micrograph shows a moth fly (Psychodidae), also known as a drain fly. As its name suggests, the fly’s larvae commonly live and grow in domestic drains; the adult fly emerges near sinks, baths and lavatories. The moth flies’ bodies and wings are covered in hairs, which gives them a ‘fuzzy’, moth-like appearance. The fly is 4-5 mm long, and each eye is approximately 100 microns wide.
2. Lavender leaf
This false-coloured scanning electron micrograph (SEM) shows a lavender leaf (Lavandula) imaged at 200 microns. Lavender, which is native to the Mediterranean region, is an evergreen shrub that grows to about three feet high and has small blue or purple flowers and narrow grey leaves. Lavender yields an essential oil with sweet overtones, which can be used in balms, salves, perfumes, cosmetics and topical applications. It is also used to aid sleep, to relax and to alleviate anxiety.
3. Xenopus laevis oocytes
This confocal micrograph shows stage V-VI oocytes (800-1000 micron diameter) of an African clawed frog (Xenopus laevis), a model organism used in cell and developmental biology research. Each oocyte is surrounded by thousands of follicle cells, shown in the image by staining DNA blue. Blood vessels, which provide oxygen to the oocyte and follicle cells, are shown in red. The ovary of each adult female Xenopus laevis contains up to 20 000 oocytes. Mature oocytes are approximately 1.2 mm in diameter, much larger than the eggs of many other species.
4. Caffeine crystals
This false-coloured scanning electron micrograph shows caffeine crystals. Caffeine is a bitter, crystalline xanthine alkaloid that acts as a stimulant drug. In plants, caffeine functions as a defence mechanism. Found in varying quantities in the seeds, leaves and fruit of some plants, caffeine acts as a natural pesticide that paralyses and kills certain insects feeding on the plant. The main crystals of caffeine were 400-500 microns long; however, this crystal group formed on the end of the larger crystal and measures around 40 microns in length.