Best science images in 2012

A caffeine crystal magnified, cancer cells dividing and a close-up of a hopping fly are among the winners of the Wellcome Image Awards 2012. The awards are drawn from science being carried out by researchers across a variety of fields. Wellcome says they’re meant to highlight the best of their image collection, which you can read about here. Sixteen best science images were selected by a judging panel, including the BBC’s Medical Correspondent Fergus Walsh, who said:

This was another year of diverse, fascinating and beautiful images.

Some of the best of the winning images are below, with captions provided by Wellcome.

This false-coloured scanning electron micrograph (SEM) shows a lavender leaf (Lavandula), imaged at 200 microns. 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. The surface of the leaf is covered with fine hair-like outgrowths made from specialised epidermal cells called non-glandular trichomes, which protect the plant against pests and reduce evaporation from the leaf. Glandular trichomes are also present, containing the oil produced by the plant.

This false-coloured scanning electron micrograph (SEM) shows caffeine crystals. Caffeine is a bitter, crystalline xanthine alkaloid that acts as a stimulant drug. Beverages containing caffeine – such as coffee, tea, soft drinks and energy drinks – are extremely popular, and 90 per cent of adults consume caffeine daily. 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 whole crystal group is 40 microns in length.

This false-coloured scanning electron micrograph (SEM) 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’ body 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.

This false-coloured scanning electron micrograph (SEM) shows loperamide crystals. Loperamide, an antimotility drug used to treat diarrhoea, works by slowing down the movement of the intestine and reducing the speed at which the contents of the gut pass through. Food remains in the intestines for longer and water can be more effectively absorbed back into the body. This results in firmer stools that are passed less often. The crystal group measures approximately 250 microns across.

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 Xenopus laevis oocytes are approximately 1.2 mm in diameter, much larger than the eggs of many other species.

This false-coloured scanning electron micrograph (SEM) shows connective tissue removed from a human knee during arthroscopic surgery. Individual fibres of collagen can be distinguished and have been highlighted by the creator using a variety of colours.

This fluorescence micrograph shows the vascular system of a developing chicken embryo (Gallus gallus), two days after fertilisation. Injecting fluorescent dextran revealed the entire vasculature used by the embryo to feed itself from the rich underlying yolk inside the egg. The image shows the central chicken embryo surrounded by veins and arteries. The head of the embryo, including the embryonic eye and brain, can be seen on the upper part of the embryo, just above the embryonic heart. The long lower part of the embryo is the future body of the chicken, from which legs and wings will develop. At this stage of development, the embryo and its surrounding vasculature are a little smaller than a 5p coin.

This confocal micrograph shows the tissue structures within the leaf of an Arabidopsis thaliana seedling. The sample was fixed and stained with propidium iodide, which labels DNA, but was imaged four years later. Over time, oxidation of the stain in different parts of the tissue provides differential fluorescent properties that can be excited with distinct wavelengths of light from a confocal microscope. The researchers are using these techniques to investigate cellular architecture in plants and gene activity.

Bottom line: Some of the best of the winners of the Wellcome Image Awards 2012.

Submit your own Earth or night sky photos at EarthSky Community Photos.