Tag Archives: history

Laveran’s eye

The military hospital of Constantine, Algeria was a fitting place to view what must have seemed the Devil in microscopic form.

Stages of the malaria parasite drawn by Alphonse Laveran

Natural history books you should read before you die

I can’t say enough good things about The Natural Histories Project / Natural History Network, birthed out of a series of workshops to initiate dialogue between ecologists, geologists, educators, university presidents, and artists about the re-imaging of natural history. The audio and video clips of different perspectives on natural history are fantastic. But what really caught my eye was the Journal of Natural History and Experience, in particular the ongoing series of “101 Natural History Books That You Should Read Before You Die.”

So far, the (early) list includes the following.

The Log from the Sea of Cortez by John Steinbeck

A Naturalist on a Tropical Farm by Alexander Skutch

The Art of Falconry by Frederick von Hohenstaufen

Field Notes on Science and Nature by Michael Canfield

The Voyage of the Beagle by Charles Darwin

The Naturalist on the River Amazons by Henry Walter Bates

Personal Narrative of Travels to the Equinocital Regions of America by Alexander von Humboldt

It’s a great list so far (myself only having read, and only then in part, half of these). Having a community-agreed upon canon of works to read, or a reading list to guide you in general, is always welcome. Like having a steady professor-friend by your side to offer advice only an insider would harbor.

An interesting look at using skeletal remains and historical reports to reconstruct the geographic distribution of a vector-borne disease.

Contagions

England once looked very different. Much of southern Britain was marshland for most of the island’s occupied history. These bogs, fens, and marshes ensured that areas of virtual wilderness persisted  from before Roman Britain through the Norman period and beyond. Despite the difficulties of using fenlands, these areas were not only occupied throughout the Anglo-Saxon period, but important centers like Croyland, Bardney, and Ely eventually developed in the marsh.

The largest fenland region was known as ‘the Wash’.  This low-lying region drained four rivers into  a square bay of the North Sea that forms the corner between Lincolnshire and Norfolk. In Anglo-Saxon times, this tidal marsh and bog was a vast border region between the region of Lindsey and East Anglia.  Places like Croyland and Ely were islands in the wetlands.  The eighth century Life of Guthlac describes the environment of Croyland when Guthlac arrived:

There is…

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Metaphor of microglia: the maintenance amoeba of the brain’s neural network

[Here on out, eukaryography will have weekly or so examples and discussions of creative metaphors used by writers of scientific phenomena. Today’s imagery comes from Mo Costandi at Neurophilosophy]

It is said that the human brain contains roughly 10 billion neurons, each of which is connected to those other neurons through 10,000 synapses. This figure, massive as it may be, is also an understatement—Mo Costandi at The Guardian notes that in actuality the numbers come in closer at hundreds of billions of neurons and glial cells, those non-neuron cells—also known as neuroglia—that maintain homeostasis in the brain and provide support and protection of neurons. In turn, this quantity of cells produces more like  a quadrillion synapses.

To maintain some control over this complex information processing system, our brain generates more neurons and neuroglia than necessary, ensuring a surplus of connections. To reduce noise in this system, the brain relies on a process known as pruning. Also known as neuro-structural reassembly, pruning can occur through several interrelated scenarios. In one, the brain must replace simpler associations with a matured understanding of complex relationships—as we mature from childhood, our brain does as well, and needs reconsideration of the economy of neurons to do so. This process is part of the more general act of the network’s housekeeping. Neurons that have been damaged, are decaying, or are no longer necessary are removed to improve the overall functioning of the organ. Costandi writes that although neuroscience has know this process continues into and somewhat through our adult lives, the field has been in the dark in regards to the mechanisms—the how of X connecting to Y—of pruning. Costandi reports that now, a team of Italian researchers has been able to clarify this void in our understanding. Pruning, they have found, occurs through the actions of cells called microglia, which scour the developing human brain and engulf unnecessary synapses.

Microglial cell from the mouse brain expressing green fluorescent protein. Photograph by EMBL/ Rosa Paolicelli.

The microglia are related to the macrophages of the innate immune system, and functionally are very much the same. A variety of macrophages exist,  and their roles include ingesting foreign material, releasing cytokines to stimulate other macrophages, and presenting antigens. In the same way, microglia act as the initial defense against invading pathogens and substances and performing maintenance tasks. But Costandi doesn’t limit his definition of microglia to the vocabulary of immunology—he also draws on a personal favorite, that of protozoology. Microglia, he writes,

crawl, amoeba-like, through the spaces between neurons, using their protrusions to detect viruses and microbes that have infiltrated the brain and quickly engulf those they find.

Amoeba, members of the genus Amoeba, were discovered by early cell biology in 1757 by  entomologist August Johann Rösel von Rosenhof. In his Insecten-Belustigung (Recreation among the Insects),  Rösel described, sketched, and discovered that one species of these organisms, which he called “the little Proteus,” when touched, drew its octopus-like figure together.

Engraved colored figures of Volvox and amoeba, August Johann Rösel von Rosenhof (1757).

This form-changing ability, which became the characteristic of amoeba that gave the group its 18th century name, Proteus animalcule—after the Greek god Proteus, who could shift his shape—is an aspect that allows these organisms to feed. Amoeba have cytoplasmic extensions called pseudopodia that accout for this shape shifting–like imagery. This process is the prerequisite for phagocytosis, the act of engulfing other organisms or matter in the pseudopodia and bringing them into the amoeba’s body to be metabolized. This “cell eating” phenomenon is also exibited by the macrophages and microglia that Costandi notes in his article:

Phagocytosis means “cell-eating” and is the process by which microglia and other cells take up solid materials. First, the material is pulled towards the cell membrane, which then begins to invaginate, or fold in on itself, to envelop the material. As the in-folding continues, the outer edges of the membrane are drawn together until they eventually meet, producing a globule (the vesicle), which then buds off and moves into the cell. The contents of the vesicle are then processed appropriately—microbes are destroyed and membrane proteins and other cellular components recycled.

Below, an amoeba, Vannella sp., engulfs an unspecified cell through this meticulously described process.

And returning to the first part of the metaphor, that of the microglia-as-macrophage, in the following video a white blood cell chases bacteria through a maze of erythrocytes.

Through the experiment performed by Rosa Paolicelli et al.the details and methods of which are explained in full by Costandi at his Neurophilosophy blogmicroglia in the brain tissue of mice were found to be engulfing, in much the same way as an amoeba or macrophage, fragments of a protein known as PSD-95, which is major part of the protein network found in active synapses of the brain. In the following video from Nimmerjahn et al. (2005), we can visualize microglial cells patrolling synapses for functional deficits.

Therefore, Costandi writes, “the developing brain treats unwanted synapses as if they were unwanted invaders. It dispatches microglial cells to survey the state of synapses in their surroundings and to dispose of the ones that are wired incorrectly or superfluous.” To the microglia in our neural network, unnecessary and outdated synapses are akin to pathogens in the bloodstream, particles of algae to a grazing amoeba in a drop of lake water in Rösel’s German countryside.

Beetles, form, art

In Emerging Infectious Diseases, each issue of the peer-reviewed journal contains a short essay that connects and contextualizes the artwork of the cover to the content of the issue (for a brief but interesting discussion of cover art on scientific journals, take a look at a post by biocreativity, another blog exploring the nexus of art, biology, creativity, science, design, and nature). The Centers for Disease Control and Prevention, the producing body of the journal, writes that the cover art is selected on the basis of “artistic quality, technical reproducibility, stylistic continuity, communication effectiveness, and audience appeal.” The cover story, on the other hand,

has evolved by popular demand, literally out of the journal readers’ wish to know the art and how it relates to them and to what they do. A sketch of the artist, period, and work, provides contextual knowledge, and a brief interpretation offers a link between the art and the human elements and goals of public health. The reader becomes familiar with the work, and in the end is surprised and, we hope, enlightened.

A rather dry description of these clips, but the author, Cyprus-born Polyxeni Potter, is rather anything but. Potter’s contextualization of the art and artists of which she writes is lyrical and informative. For a 2005 issue of EID, containing research on Staphylococcus aureus infection in football teams, bed bug infestations, Lyssavirus prevalence in Scottish bats, and other outbreaks,  Potter chose a watercolor painting of a stag beetle, most likely the Europe-dominated member of the Lucanidae family, Lucanus cervus. Of her selection of this organism, this “tribute to the minutest in nature,” Potter writes:

Other critters, not so benign or visible, are also easy to ignore, their pestiferous history relegated to the past and quickly forgotten. Blood-thirsty ticks, bed bugs, and other insects, as if caught in some Gothic time machine, continue to torment humans, still claiming their lives, if not their souls. Renewed infestations of ticks causing meningoencephalitis in Germany and of bed bugs compromising health in Canada and elsewhere warn against ignorance and neglect regarding visible or invisible tiny creatures of nature.

Albrecht Dürer (1471–1528). Stag Beetle (1505).

L. cervus, most simply known as the stag beetle, was named as such—lucanus—by Publius Nigidius Figulus, a scholar of the Late Roman Republic and friend to Cicero, due to its ornamental use in the Lucania region of Italy. The latter end of the creature’s binomial nomenclature, cervus, the direct Latin for deer, the stag. The naming is gender-biased, typical of sexual dimorphism, as the reference to the stag—which itself refers to a male red deer—is more applicable to the males of the beetle, themselves characterized by the mammal’s antlers.

Stag beetle, Pavel Krasensky (2007).

It was in Italy, home of Nigidius, the lucanus label, and the Latin for stag, writes Potter, that Albrecht Dürer, the painter responsible for the above work, was drawn. But it was in Venice to the northeast, rather than the linguistic homeland of L. cervus, that the artist found inspiration and welcome. Of Venice, Dürer reflected, “In Venice, I am treated as a nobleman…. I really am somebody, whereas at home I am just a hack.” This home was Nürnberg, Germany, where Dürer had been trained in Gothic traditions, metallurgy, and mathematics. His move to Italy brought him to the Northern Renaissance, to the work of Leonardo da Vinci, to printmaking. Like other polymaths of his day, Dürer asserted that “art must be based upon science,” and, in agreement with da Vinci, on mathematics, on geometric form, on the golden ratio.

Ratios and antlers held a special place to mathematicians and artists of the day. Named by the Greeks—Dürer held a special reverence for Aristotle—the golden ratio has been considered the proportion of length to width of a rectangle most objectively pleasing to the eye.  The golden ratio draws from the Fibonacci sequence, introduced to the West by Leonardo Fibonacci in the 1100s and utilized to solve an issue of the growth of a population of rabbits . In the Fibonacci sequence, one produces a sequence of numbers by starting with 1 and 1 and adding the two together—the product is, of course, 2. Obtaining the subsequent number involves adding the latter two integers—the result is 3. Follow the natural pattern and the integers appear as 5, 8, 13, 21, 34, 55, etc. The role of the golden ratio is in taking from Fibonacci’s order of numbers and dividing each pair (2 by 1, 3 by 2, 5 by 3, 8 by 5, etc.). The resulting quotients are, respectively, 2.0, 1.5, 1.67, and 1.6. Continue making these divisions, and one number will begin to hold as a constant quotient—1.618. Continue reading

Alternative narratives to the discovery of Lyme disease

Borrelia burgdorferi, the bacterium that causes Lyme disease, was first isolated in 1982 by Willy Burgdorfer, Ph.D., a zoologist and microbiologist at NIAID’s Rocky Mountain Laboratories (RML) in Hamilton, MT. The following is a brief history of this groundbreaking discovery.

So begins the description of the medical discovery of Lyme disease from the National Institute of Allergy and Infectious Diseases (NIAID). An agency of the National Institutes of Health, NIAID conducts and supports basic and applied medical research on infectious and allergic diseases to increase scientific knowledge and advance methods of treatment and prevention. Set in the disciplines of microbiology and immunology, in recent years this work has focused on asthma, bioterrorism, and emerging infectious diseases. Lyme disease—in belonging to the latter category—has been a principal interest to the agency, the focus on which has been on understanding the mechanisms of the bacterial organism’s pathogenesis, its modes of transmission, and antibiotic therapy.

B. burgdorferi spirochete. Image courtesy of NUCEL International Integrative Medical Center

According to this state narrative, Lyme disease—a bacterial infection transmitted by Ixodes scapularis, the black-legged tick—was discovered in 1975 when a team of researchers led by Dr. Allen Steere investigated why unusually large numbers of children were being diagnosed with juvenile rheumatoid arthritis in Lyme, Connecticut. In an early epidemiological report, Steere’s group examined the health status of 51 residents with the illness, characterized by ongoing swelling and pain in large joints. Published in 1977, the study argued the causative agent of the disease to be an unrecognized pathogen, possibly transmitted by an arthropod vector. The researchers found the disease to be highly complex, variable, and confusing, with some members of the cohort suffering from a short weeklong bout of illness while others experienced symptoms for months. When initial research found that 25% of residents with the illness developed an expanding red rash known in the medical literature as erythema migrans and that the majority of the towns’ cases were found in children living alongside wooded areas in the summer months, the team suggested the new disease could be related to the life cycle of ticks, particularly those of the Ixodes genus. With the assistance and expertise of Willy Burgdorfer, a medical entomologist specializing in tick-borne bacterial transmission, the researchers pinpointed the black-legged tick as the previously mentioned vector. Then, in 1982, Burgdorfer successfully isolated Borrelia burgdorferi from patients with the illness, proving that the spirochete bacterium caused what came to be known in medical and lay circles as Lyme disease.

Adult female I. scapularis

This account of medical detection is not confined to only the NIAID and other government research agencies—it circulates as the most common narrative in the biological and medical literature (Reik Jr 1991; Christen 1994; Reid 1998; Steere 2001; Knisley & Johnson 2004; Meyerhoff 2009; Sterle & Stanek 2009). As part of an institutional narrative of biological science’s importance, the account not only mentions the actions of and exchanges between epidemiologists, physicians, entomologists, and bacteriologists, but also frames these actors as the sole and vital components of the discovery, recording the event within a certain framework of what is and is not important. What’s at stake in recording the past within a particular perspective is not a rejection of scientific materiality, but rather an illustration of how what is ignored in our records echoes what continues to remain absent in contemporary discussion. Anthropologist Ilana Feldman follows this notion with the comment,  “There is no doubt that memories of the past say a great deal about people’s attitude in and towards the present.” Particular to the institutional memories created through state documents, Julie Taylor also notes the tensions implicit in certain modes of narrating the past. She writes that such documents inherently contain a politics of information, of including some parts of the past and excluding others: Continue reading

A gallery and a drawing

A recent gallery review in the New York Times asked the following question: are killer viruses, rendered in glass, also things of beauty? The exhibit, by Britain’s Luke Jerram, is showing in Manhattan from June 4th to July 31st, 2010. In it, Jerram has produced several infectious microbes out of glass, a step that the reviewer, the science journalist Donald G. McNeil Jr., questions and feels troubled by. As someone who reports on the global impact of infectious diseases, McNeil Jr. and his review both find troublesome depicting death as art and attempt to reconcile this bias. From the view of the artist, Jerram’s work attempts to reconcile the arts and the sciences, to illuminate cultural biases in biology and medicine’s depiction of pathogens, and to showcase his own agenda and position. I found the exhibit a success. But to get there, I need to stop, reflect, and return to the work of Ernst Haeckel and others if I wish to problematize McNeil Jr.’s critique.

Can art and science meet? Robert Hooke’s Micrographia serves as one example of this merger, and I can think of no better progression of the kind of polymath Robert Hooke embodied than in Ernst Haeckel. If Hooke had begun bridging the arts (drawings and sketches) with scientific rigor (microscopy), then it was Haeckel who took this task to another level. His Kunstformen der Natur, images of which were shown in an earlier post, not only was popular, but also embodied what Haeckel saw as scientific truths. If anything else, the prints of various organisms embody Haeckel’s scientific beliefs, his view of the world, which was often contested by the wider scientific community. In line with other mergers of art and science in 16th to 19th century Europe, Haeckel’s prints are about symmetry, about perfection, about order. Much like Robert Hooke’s Micrographia, in Kunstformen der Natur, something Platonic, some higher ideal, perhaps unobtainable by humans, existed in the natural world.
Continue reading