Slick science—impacts and remediation of oil spills
This photo shows an oil slick on a test lake. As Canada faces critical decisions on the use and distribution of energy resources, the need for strong scientific evidence is becoming clearer. We need to understand the impacts of oil spills and how to best clean them up. Whole ecosystem research on oil spills can help us understand how complex substances such as diluted bitumen, an unrefined crude oil from the Alberta oil sands, behaves in freshwater environments. We can also learn the risk bitumen poses to the fish and other organisms that live there. By adding oil to complex natural systems, like those at the Experimental Lakes Area in northwestern Ontario, we can test various methods of oil spill remediation under realistic conditions, to help efforts to respond to spills. Reflected in the water in this photo is the forest that surrounds the test lake. An oil sheen covers the surface as a result of the oil added experimentally.
A deadly hiding spot
Alex Smith
We recently discovered a new item on the menu for the carnivorous pitcher plant (Sarracenia purpurea). Previously, it was thought that the plant captured vertebrates accidentally. However, juvenile spotted salamanders (Ambystoma maculatum) are falling victim to the plant’s watery trap by the dozens and may be an important nutrient source for this population of pitcher plants in Algonquin Park, Ontario. Compared to the plants’ typical prey, each trapped salamander can contribute a substantial amount of nitrogen, equivalent to that found in over 400 ants. Why are these cup-shaped leaves so attractive to the salamanders? How important are these meat-eating plants as a cause of salamander death? How much nutrition do the plants gain from their salamander meals? These are the questions we continue to ask as we unravel this surprising source of salamander mortality and plant nutrition.
Neuro nova
This image shows dopamine neurons, which underlie many important processes in the brain. Losing them can impact movement, mood and addiction. Obtaining dopaminergic neurons from live animals to study is difficult, so we make these neurons by culturing them from stem cells. In this image, a sphere of dopaminergic neurons is shown one day after attaching to a coverslip. The neurons have been stained —a mature dopaminergic marker in red, and an immature dopaminergic marker in green. The more immature dopaminergic neurons, on the exterior of the sphere, have extended processes and have migrated away from the central sphere, giving the impression of a shining star. We use this process to produce highly pure cultures of dopaminergic neurons, allowing us to model how the human midbrain can be affected by environmental and genetic factors that may contribute to neurological disease.
Light above the fire
In the fire’s aftermath, the forest floor is covered by a layer of calcined organic matter. During the months that follow, ash washed by successive rains fertilizes the ground. The site is soon recolonized by species whose reproductive strategy is adapted to fire. This photograph, taken during a controlled burning in La Mauricie National Park, documents the immediate impacts of fire on forest soils. These observations help to identify sites favourable to the establishment of conifer seedlings planted to ensure reforestation. Digital photography.
Blooming minerals
These “flowers,” whose petals are formed of silver salt crystals, are cultivated on a microscopic scale. The process begins by submitting a field sown with nanoparticles of silver to the effects of a plasma, as if the lightning’s energy electrified the ambient air for several minutes. Rather than melting and merging into larger drops, miniscule silver beads incorporate nitrogen and oxygen from the air, forming micrometric crystals. The experiment had a fascinating result: the creation of a material never before seen in this world! Scanning electron microscopy Colourized image.
Desertification in the Yukon
Glacial melting caused by climate change is raising a multitude of environmental and social issues. These issues are even more significant when the glacier in question feeds a river’s main tributary. Such is the case in the Yukon with Ä’ą̈y Chù or Slim’s River. The riverbed of this waterway vital to Indigenous communities is gradually drying up. Dunes are formed by ever more frequent dust storms. Taken during one such storm, this photograph shows a member of the research team returning after installing a meteorological station. Digital photography.
Garlic galore! What’s the difference?
With so many cultivated varieties producing bulbs, bulbils, leaves and flower heads of various shapes and colours, Québec garlic has lots of flavours—several distinct flavours, in fact! Categorizing the diversity of garlic remains a challenge, however, since the plant adapts to variations in its environment. For example, one variety’s small white bulb can yield a large purple bulb the following season. To better commercialize the different varieties, their morphological characteristics and tastes need to be catalogued according to genetic identity. Digital photography stitching.
“Leaves” in the backyard
This image depicts the surface shapes of copper sulphide (chalcocite [Cu2S]) formed by corrosion of copper in an aqueous sulphide environment. Copper is one of the first metals used by humans and one of the fundamental materials of civilization. Today, it has been chosen for containers for used nuclear fuel because of its stability under the oxygen-free and cool conditions in deep geologic repositories. Current studies focus on determining corrosion mechanisms and rates, and on measuring the distribution of corrosion damage on containers with a copper coating or shell. In these containers, sulphate-reducing bacteria are expected to produce sulphide that will be transported to the container’s surface through the clays compacted around it.
A crab’s eye view
A symbiotic crab keeps a watchful eye on its home, a Pocillopora acuta colony in a heat stress experiment within a flow-through seawater experimental tank system at the National Museum of Marine Biology and Aquarium in Taiwan. Climate change-induced ocean warming is pushing coral beyond its temperature limits, resulting in mass bleaching events everywhere in the world. Under heat-stress conditions, corals expel their symbiotic algae and turn white. If conditions don’t improve, corals begin to starve, leading to high mortality and degradation of the reef. The current decline of coral reefs is putting millions of people and approximately one-third of marine organisms at risk due to a critical loss of ecosystem function and services. This experiment was designed to understand mechanisms of thermal tolerance in corals that allow for resilience in a warming ocean, and to test innovative active management techniques (assisted evolution) to enhance thermal tolerance.
A listeria flower of death
This image shows a fluorescent overlay of HeLa cells infected with the common foodborne pathogen Listeria monocytogenes, showing the bacteria spreading from cell to cell. The sample was stained with phalloidin to label filamentous actin (green) and DAPI to label the DNA in the host cell nuclei as well as the bacteria (blue). It was transfected with GFP-CD147 (pseudo-colourized magenta) in the cell initiating the spreading event.
Beauty is in the eye of the bee
This photo shows Ceratina calcarata, a tiny bee native to eastern North America that digs its nests into raspberry twigs. The mother’s chosen nesting site can have long-term consequences for developing bees. Sunny sites are hotter than shady sites. Insects cannot regulate their body temperature, so their physiological processes are influenced by their environmental temperature. Insects reared in cooler temperatures grow to a larger adult body size than those reared in warm temperatures. Developmental temperature also influences cell size in some insects. The relationship between temperature and body size in insects is known as the temperature-size rule (TSR). By measuring the width of the bee’s head and the size of the units of its compound eye (ommatidia), we can determine whether C. calcarata conforms to the TSR. In this view of a female’s head, you can see the compound eyes, the simple eyes (ocelli) on top of the bee’s head, and tiny sensory hairs on the face and antennae.
Cancer cartography
This image shows an ovarian tumour biopsy sample. State-of-the-art technology is now allowing researchers to map tumours in three dimensions with the resolution to see individual cells. This is helping scientists understand how tumours grow and how drugs are transported to cancer cells. As in this image, tumour biopsies are taken from patients and treated with chemicals that make them as transparent as glass. Key structures are then labelled with different colours, and high-speed microscopes take detailed three-dimensional images. Individual cells can be identified by their blue nuclei, and the bonds holding cells lining the tumour blood vessels show up in red. The information extracted from these images forms a detailed map that is unique to each individual tumour. By creating detailed tumour maps, scientists hope to engineer drug carriers that can navigate through the tumour to seek out and destroy cancer cells more effectively.
Conduits of life
This image shows a portion of a blood vessel that has been grown within a microfluidic device. Blood vessels are composed of many cells that have bonded to each other through membrane proteins (red). As blood flows past the cells, their cellular skeletons (green) align in the direction of blood flow. The blue dots are the nuclei of the cells, where DNA is stored. We stained the cells with DAPI, phalloidin, and antibodies that bind to vascular endothelial cadherin. Growing blood vessels inside microfluidic devices allows researchers to figure out what happens to medicines and nanoparticles once they are injected into the blood.
From sock to stream
Pictured are three silver-coated nylon fibres (centre) woven among a series of thinner polyester threads in clothing. This research aims to identify the release of silver nanomaterials from clothing into the environment. These silver-coated fibres are found in numerous types of athletic clothing for odour control but may pose a risk to the environment and humans, because of the toxicity of silver.
Human stem cells bridging the gap
Maryam Dadabhoy
This image shows human iPS-derived neural stem cells forming neurospheres. The neurospheres are on a 1% QL6 self-assembling peptide biomaterial matrix, which is providing a promising approach for treating spinal cord injury. After a traumatic spinal cord injury, the microenvironment around the lesion worsens, leading to high counts of neuronal cell death that leave behind cystic cavitations. QL6 can be used as a novel, extracellular matrix-like lattice that can fill in these cavities and support grafting transplanted neural stem cells. The processes growing from the large spherical cell clusters onto the fine biomaterial surrounding them provide future hope for an effective regenerative therapeutic strategy for spinal cord injury.
Merry X-Pus to one and all
The image shows cells from the head cartilages of a Xenopus tropicalis (western clawed frog) tadpole (red) and its surrounding tissues. These tissues, including muscle and epithelium (green), are made up of individual cells, each containing nuclei (light blue). Colours are produced by immunostaining of Col2 protein in the extracellular matrix secreted by chondrocytes. Here, cartilage is undergoing a process called “hypertrophy,” in which its cells are increasing in size.
Mighty magnetic marvels
This image shows magnetic cobalt ferrite crystals, ranging in size from about 50 nm to 600 nm, roughly 10,000 times smaller than a poppy seed. Nanomaterials research focuses on the unique optical, electronic and magnetic behaviour of nanostructure materials. Materials scientists aim to understand the phenomena behind these properties, finding applications to which the specialty materials are best suited. Despite all particles having the same chemical composition and the same atomic arrangement, three distinct shapes can be seen: spheres, disks and octahedra. These cobalt ferrite crystals are being used to investigate how shape and size play a role in enhancing electromagnetic fields for use in optical sensing devices.
Moments from freedom
Only two days after their hearts began beating and with newly formed eyes (the small black dots), these developing snail embryos are just hours away from heading out into the world for the first time. Freshwater snails represent an important part of aquatic ecosystems by acting as nutrient recyclers. They are also an excellent “canary in the coal mine” that helps us to understand the impacts of chemicals that find their way into our waterways and how we can better regulate these chemicals. We used time-lapse macrophotography to capture the entire development of freshwater snail embryos — from the first cell division to hatching — at five-minute intervals. This technique allows us to describe development in freshwater snails at a novel level of detail. By photographing this microscopic miracle of life, we are studying how pollution can cause multi-generational effects long after the exposure has ended.
Nuclear staircase
This image displays the grain structure of a uranium dioxide (UO2) pellet. Naturally stepped virgin surfaces of UO2 crystals were sintered together to form a nuclear fuel pellet. Such pellets fuel nuclear power reactors, which have been used commercially since the 1950s and currently generate approximately 10% of the world’s electricity. When used nuclear fuel is removed from a reactor, it is extremely radioactive. The radioactivity will decrease over time. However, the used fuel will remain a human health risk for hundreds of thousands of years. For the long-term safety of people and the environment, the used fuel is encapsulated within a robust, corrosion-resistant container engineered to prevent the release of radionuclides into the environment. To ensure safety in case a container is breached, the rate of radionuclide release from a breached container must be assessed. Using various corrosion experiments, the rate at which radionuclides would be released from the pellets can be determined.
Protein production in egg chambers
Egg chambers of the fly Drosophila melanogaster contain “nurse cells,” with the large cells on one half and a single oocyte ensheathed by many small epithelial cells on the other. Each cell nucleus is visualized by sequestering fluorescent proteins into the nucleus, and the different fluorescent intensities reflect the amount of protein being produced by each cell. Different colours of fluorescent proteins simultaneously track the maternal and paternal copies of a gene being translated into protein products. Tracking when, where, and how much protein is being produced by a cell is important for understanding cell biology. We use these flies to measure protein production over time in every single cell in the living animal. This allows us to examine how changes in the environment affect protein synthesis and influence which parental copy of a gene is being produced at any given time.
