Natural lenses …

The photograph above is as about as far from Andreas Gursky’s careful constructions, described in the previous post, as it is possible to get.  It is a close-up of a green algal floc Heather noticed whilst on a walk around a local nature reserve.   I guess it fits the general description of “decisive moment” except that it takes a special sort of observer to find any interest at all in such an unprepossessing habitat.

Under the microscope, the floc turned out to be composed of filaments of Spirogyra, with a single helical chloroplast.  Members of this genus (and related genera such as Mougeotia) produce copious mucilage so are always slimy to the touch.  However, this mucilage makes it difficult for the waste gases produced by photosynthesis to diffuse away, leading to the production of bubbles within the mucilage mass.   The interest, today, however, was that these air bubbles are acting as tiny lenses through which it is possible to make out the individual filaments of Spirogyra.

The green floc beside a footpath in Crowtrees local nature reserve from which the other images in this post were derived. 

I should add the caveat here that the photograph was taken with the “super macro” facility of our Olympus TG2 camera but the end-product is, nonetheless, impressive.   It also offers us an insight into the world of the very earliest microscopists.  Anton van Leuwenhoek’s microscopes consisted of a metal plate which held a tiny sphere of glass which acted as a convex-convex lens capable of up to 266x magnification to a resolution of little  more than a micron (1/1000th of a millimetre) (follow this link for more details).  To give an idea of what he might have seen with this, the right hand image below used 400x magnification.

That, however, only tells us part of the story of Anton van Leuwenhoek’s genius.   Whilst we should not underestimate the skill required to make the lenses and their mounts, the other essential element is curiosity.   Curiosity is, itself, multifaceted: in a few weeks we will probably make a trip out to an old quarry where we know we will find several species of orchids, and maybe some excursions to locations new to us but where others have reported interesting assemblages.  That’s one type of curiosity.  However, simply looking harder at the habitats all around us involves a different type of curiosity: a recognition that there is more to know even about things we think we already know about.   The former broadens our experiences, the latter deepens them …

The algal floc at Crowtrees local nature reserve in close-up: left: an extreme macro view of a single bubble from the image at the top of the post and, right: filaments of Spirogyra photographed under the microscope.  Scale bar: 20 micrometres (= 1/50th of a millimetre).

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Challenging art …

I took the opportunity of a trip to London to slip into the Hayward Gallery to have a look at the Andreas Gursky retrospective.   I’ve been interested in Gursky for some time as, like fellow German Anselm Kiefer, he is someone who uses his art to ask big questions (see “The fine art of asking big questions” and “Anselm Kiefer and the art of algae”).  Gursky is principally a photographer rather than painter or sculptor though, like Kiefer, he works at large scales.  The Rhine II, the picture at the top of this post, is 3.5 m long and 2 metres high, for example.   Taking a picture on a mobile phone doesn’t really do it justice, particularly as Gursky’s works, though they look naturalistic, are the result of extensive digital manipulation.   In this case, he has turned a landscape of the River Rhine near Dusseldorf into a near-abstract composition.   This involved digital manipulation to remove all evidence of buildings on the far side of the river.

The next picture I’ve included is the type of image for which Gursky is best-known: monumental images taken from a high viewpoint and teeming with activities associated with global capitalism.   In this case, he has photographed a factory in Vietnam that is making cane furniture for IKEA.   I look at this work as a descendent of Bruegel’s busy pictures from the sixteenth century except that Gursky’s narrative is very different to anything that Bruegel tried to portray.   Here, the sea of identically-attired individuals all performing variations of the same basic processes merge into a repetitive abstract pattern.   It is the antithesis of Cartier-Bresson’s “decisive moment” not just because there is no single “moment” that is being captured but also because the impression of spontaneity is also false: these large images are, in fact, composed from many different images.  It is not always apparent on first viewing but close examination reveals the images to be uniformly in focus from front to back and, in the case of the panoramic views, to have no issues with distortion at the edges.   So Gursky also takes us to that ambiguous territory where images look like they are depicting an actual point in space and time but they are not yet, at the same time, they are conveying truths about the modern world.   We approach his work with an expectation that photographs represent reality.  But they don’t.  Or do they?

Andreas Gursky, 2004, Nha Trang.   295 x 207 cm

Les Mées is another example of a superficially simple image of an enormous solar farm in southern France, with the Alps as a backdrop.  Once again, however, there is post-production manipulation of the image but also, in part a consequence of scale, the invitation for the viewer to contemplate and meditate on what is portrayed.  Here we have the juxtaposition between the regular, angular solar panels completely covering the hillsides in the foreground, and the natural beauty of the Alps behind.   The manmade looks that much more artificial through the juxtaposition with the grandeur of the mountains.   One of the ironies of the image is that solar panels represent a sustainable future yet are, in this location, as much of a visual pollutant as an oil refinery.   This solar farm covers 200 hectares and generates enough electricity to power 12,000 households.  How many more of these would be needed to break the West’s dependence on oil and how many more landscapes would be changed as a result?   Energy always has comes at a price.

Gursky’s talent is to simultaneously draw viewers in to inspect the details whilst forcing them to step back and absorb the whole.  As you realise from the details that the image may not be exactly what first impressions suggest, so your mind is opened to other readings.   We look at these images both as technical creations in their own right but also as commentaries on the state of the world.   Gursky manages to simultaneously challenge our eyes and our thinking.

Andreas Gursky (2016) Les Mées.  221 x 367 cm.

Coda: A week after visiting the Gursky retrospective, I saw The Square at the Tyneside cinema.  If you have not heard of this film, it is a film about a contemporary art gallery directed by Ruben Őstland.   The plot focuses on the curator of a contemporary art gallery who is trying to present high-minded conceptual art with a moral message relevant to our times so it was hard not to escape the parallels with the Gursky retrospective.   Much of the dark humour in the film arises from the curator’s inability to reconcile these high ideals with his own private life (one of the key sequences involves a one night stand with a journalist – played by Elisabeth Moss – whose name he subsequently cannot remember).   One gets a sense when seeing art in the hushed sepulchres that are contemporary art galleries that these have a quasi-spiritual role in a largely secular age.   I have no problem with this, especially if the art makes people think about their place in the modern world.  But that does place a great responsibility on the artists and curators, in turn creating the potential for storylines such as that in The Square.   Ruben Őstland has done for contemporary art what Graham Greene was so good at doing for the Roman Catholic church: highlighting the paradoxes that are inevitable when fallible humans struggle to address the biggest questions of all.

Desmid diversity …

Back in September, I wrote about a joint British Phycological Society and Quekett Microscopical Club field weekend looking at desmids in the Lake District (see “Desmid Masterclass”, “Lessons from School Knott Tarn” and “Different tarn, different desmids …”).  Dave John sent some of the samples that we collected to David Williamson, the UK’s leading expert on desmids but, at 92, too frail to join us, and he has now sent back some fine drawings illustrating the range of desmids that he encountered.

Two of the tarns (Long Moss Tarn, Kelly Hall Tarns) are already recognised as Internationally Important Plant Areas (IPAs) for desmids because of their desmid diversity and containing internationally very rare desmids (based largely on David Williamson’s records) so their diversity is not a complete surprise to us.  Nonetheless, David found a total of 129 desmid taxa in the three tarns, whilst another desmid specialist, Marien van Westen, identified almost 160 desmids in another set of samples from the same tarns.

The drawings are arranged in three plates, one for each tarn.   Desmids identified by David Williamson from the three tarns are illustrated.  The desmids have been numbered and the captions prepared by David John who is analysing the findings and comparing them with surveys dating back to the 1970s.   David Williamson has drawn the taxa at different scales to roughly balance the arrangement on the collage, and adjusted the sizes so important details are visible.   No details of the chloroplasts are given since all samples had been preserved in formalin.  A few of the desmids, particularly those that are very long, have not been included in the plates.

Desmids from Long Moss Tarn (SD 292 936), September 2017.   Long Moss Tarn is shown in the photograph at the top of this post.

Desmids from Kelly Hall Tarn (SD 289 933), September 2017.

Desmids from School Knott Tarn (SD 427 973), September 2017.

Key

1-Actinotaenium diplosporum; 2-Actinotaenium turgidum;  3-Bambusina borreri;  4-Closterium acerosum var. borgei; 5-Closterium angustatum;  6-Closterium archerianum var. pseudocynthia;  7-Closterium archerianum; 8-Closterium attenuatum;  9-Closterium baillyanum var. alpinum; 10-Closterium baillyanum; 11-Closterium closterioides; 12-Closterium costatum; 13-Closterium dianae var. arcuatum; 14-Closterium dianae var. minus;  15-Closterium didymotocum; 16-Closterium incurvum; 17-Closterium intermedium; 18-Closterium kuetzingii;  19-Closterium lunula; 20-Closterium navicula;  21- Closterium setaceum; 22-Closterium striolatum; 23-Cosmarium amoenum; 24-Cosmarium anceps; 25-Cosmarium binum; 26-Cosmarium brebissonii; 27-Cosmarium contractum;  28-Cosmarium davidsonii; 29-Cosmarium debaryi;  30-Cosmarium depressum; 31-Cosmarium formosulum; 32-Cosmarium hostensiense; 33-Cosmarium incrassatum var. schmidlei; 34-Cosmarium margaritatum; 35-Cosmarium margaritiferum; 36-Cosmarium monomazum var. polymazum;  37-Cosmarium obtusatum;  38-Cosmarium ornatum; 39-Cosmarium ovale;  40-Cosmarium pachydermum; 41-Cosmarium pachydermum var. aethiopicum; 42-Cosmarium perforatum var. skujae; 43-Cosmarium portianum; 44-Cosmarium punctulatum;  45-Cosmarium quadratum; 46-Cosmarium quadrum; 47-Cosmarium subochthodes var. majus; 48-Cosmarium subtumidum var. groenbladii;  49-Cosmarium subundulatum; 50-Cosmarium tetragonum var. ornatum ; 51-Cosmarium tetraophthalmum; 52-Cosmarium variolatum;  53-Cosmocladium tuberculatum; 54-Desmidium aptogonum; 55-Desmidium swartzii; 56-Docidium baculum; 57-Euastrum ampullaceum; 58-Euastrum ansatum;  59-Euastrum bidentatum var. speciosum; 60-Euastrum gemmatum; 61-Euastrum luetkemulleri; 62-Euastrum oblongum; 63-Euastrum pectinatum; 64-Euastrum pulchellum; 65-Euastrum verrucosum; 66-Gonatozygon aculeatum; 67-Gonatozygon brebissonii; 68-Groenbladia undulata; 69-Haplotaenium minutum;  70-Hyalotheca dissiliens;  71- Micrasterias americana var. boldtii; 72-Micrasterias compereana; 73-Micrasterias crux-melitensis; 74-Micrasterias denticulata; 75-Micrasterias furcata; 76-Micrasterias pinnatifida;  77-Micrasterias radiosa; 78-Micrasterias rotata; 79-Micrasterias thomasiana; 80-Micrasterias truncata; 81-Netrium digitus; 82-Netrium digitus var. latum; 83-Netrium interruptum;  84-Penium exiguum; 85-Penium margaritaceum; 86-Pleurotaenium coronatum var. robustum;  87-Pleurotaenium ehrenbergii; 88-Pleurotaenium truncatum; 89-Sphaerozosma filiforme; 90-Staurastrum arachne;  91-Staurastrum arctiscon; 92-Staurastrum bieneanum; 93-Staurastrum boreale var. robustum; 94-Staurastrum cristatum; 95-Staurastrum dilatatum; 96-Staurastrum inconspicuum; 97-Staurastrum kouwetsii; 98-Staurastrum lapponicum; 99-Staurastrum maamense; 100-Staurastrum polytrichum; 101-Staurastrum productum; 102-Staurastrum quadrangulare; 103-Staurastrum striolatum; 104-Staurastrum teliferum; 105-Staurastrum tetracerum; 106-Staurodesmus convergens; 107-Staurodesmus convergens var. wollei; 108-Staurodesmus cuspidatus var. curvatus; 109-Staurodesmus megacanthus; 110- Xanthidium antilopaeum; 111-Xanthidium antilopaeum var. laeve; 112-Xanthidium antilopaeum var. polymazum; 113-Xanthidium cristatum.

My name is Legion …

I promised to write a little more about Gomphonema subclavatum, one of the diatoms we encountered in the previous post.   I picked this one out for more attention because it is one of many diatoms that have changed names in recent years and it is sometimes interesting to scratch around to understand why this has happened.

Had I seen this particular species fifteen years ago I would have called it Gomphonema clavatum without hesitation.  Although G. subclavatum was recognised as a distinct species back in the nineteenth century, for most of the twentieth century it was treated as a variety of G. longiceps, which Krammer and Lange-Bertalot then subsumed into G. clavatum.  If you look at their plate of G. clavatum, you will see a huge range of sizes and shapes so it is perhaps no surprise that people subsequently realised that there was more than one species lurking under this name.

Gomphonema subclavatum from Cregduff spring, Co. Mayo, Ireland, September 2017.  Photographs: Bryan Kennedy.  Scale bar: 10 micrometres ( = 100th of a millimetre).

When this happens, taxonomists ask which of the various contenders was the Gomphonema clavatum seen by the person who originally described the species.  This involves going back to the museum collection where that person deposited the material that they examined and taking another look.  This process of “typification” helps determine which of the forms is the rightful inheritor of the name.   Erwin Reichardt decided to have a go at this process for G. clavatum and went to examine the samples, now in the Museum für Naturkunde in Berlin, on which Christian Gottfreid Ehrenberg had based his original description.  However, he could find nothing that resembled G. clavatum, with the closest match being G. olivaceum.

I’m reading a biography at the moment that contains the warning that “history is always a matter of trying to think into the minds of people who think differently from ourselves”.  That serves as a useful reminder that Ehrenberg knew far less about the biology of diatoms than we do today, but was also limited by the technology available.  Not only were his microscopes far less sophisticated than ours but also capturing the essence of the organisms he saw in print was far from straightforward (see “Picture this?”).  The idea of Gomphonema clavatum that we had until Reichardt re-examined the type material was the result of a 180-year game of “Chinese whispers”: each generation matching their specimens to inadequate images and descriptions, then making their own images which, in turn, became the basis for their successor’s identifications.  By the time Krammer and Lange-Bertalot wrote their Flora, it was finally possible to reproduce high quality micrographs, rather than line drawings but over a century of taxonomic drift meant that their images are no longer connected to the right name.  Their plate actually shows two species: the larger forms with undulate margins belong to G. longiceps Ehrenberg 1854) whilst the smaller specimens are G. subclavatum.   That assumes, of course, that there are no further twists to come.  As I alluded in my previous post, morphology might not be telling us the whole story for this genus.

The unfortunate twist, also mentioned in my previous post, is that the taxonomic confusion in the past means that we don’t actually get any sharper ecological insights in the present as a result of unravelling these names.   Anyone looking at ecological data associated with “Gomphonema clavatum” from twenty years ago needs to know that this could represent either G. longiceps or G. subclavatum or one of a number of other species that have been split away in recent years.  There is always a hope that this better understanding of taxonomy will yield fruits as we go forward but I’m always suspicious that someone else might come along and rearrange things yet again…

Reference

Krammer, K. & Lange-Bertalot, H. (1986).  Süsswasserflora von Mitteleuropa. 2/1 Bacillariophyceae 1: Naviculaceae. Spektrum Akademischer Verlag, Heidelberg.

Reichardt, E. (2015). The identity of Gomphonema clavatum Ehrenberg (Bacillariophyceae) and typification of five species of the genus Gomphonema described by C.G. Ehrenberg.  Diatom Research 30: 141-149.

The biography to which I refer is Tom Wright’s new book on Paul (SPCK, 2018).

 

Baffling biodiversity …

Few of the participants in the UK / Ireland diatom ring-test that I described in my previous post felt any need to thank me for my choice of slide for our 50th test.  The slide came from a spring in County Mayo, Ireland, which is part of the Agricultural Catchments Programme, a large study into the effect of farming on water quality. The sample itself came from the stems and leaves of the submerged water cress (Nasturtium officinale*) plants which fill the entire channel.  It was a real stinker, with a mess of Gomphonema forms, several of which did not neatly fit any species description that we could find.   A conservative reckoning is that there were at least eight different Gomphonema “species” and that raises a further question about what it was about this habitat that led to so much diversity within a single genus within a single sample.

First, a quick tour around some of the Gomphonema forms that we found.   There was general agreement that the most common type was close to G. micropus Kützing 1844 but not a perfect match to published descriptions (the stria density, in particular, was too low).   The situation was further complicated because the status of G. micropus was questioned at times, with it being treated as a variety of G. parvulum and placed in the G. angustatum complex by different authorities during the 20th century.  Then there were a number of valves with more rounded ends and a higher striae density than G. micropus but which, if you look closely, are not symmetrical around the long axis.   We thought that these were close to G. cymbelliclinum Reichardt & Lange-Bertalot 1999.   Unfortunately, there were also quite a lot of valves that had intermediate properties, making it hard, in many cases, to say whether it was one species or the other.

Gomphonema cf micropus from Cregduff spring, Co. Mayo, Ireland, September 2017.  Photographs: Bryan Kennedy.  Scale bar: 10 micrometres ( = 100th of a millimetre).  The image at the top of the post shows Cregduff spring (photo by Lauren Williams)

Gomphonema cf cymbelliclinum from Cregduff spring, Co. Mayo, Ireland, September 2017.  Photographs: Bryan Kennedy.  Scale bar: 10 micrometres ( = 100th of a millimetre).

We also found some valves that were close to descriptions of Gomphonema utae Lange-Bertalot & Reichardt 1999 and some that were close to G. parallelistriatum Lange-Bertalot & Reichardt 1991.  We also found representatives of the G. parvulum complex, G. tergestinum and G. subclavatum (more about this one in the next post).

Gomphonema cf utae from Cregduff spring, Co. Mayo, Ireland, September 2017.  Photographs: Bryan Kennedy.  Scale bar: 10 micrometres ( = 100th of a millimetre).

Gomphonema cf parallelistriatum from Cregduff spring, Co. Mayo, Ireland, September 2017.  Photographs: Bryan Kennedy.  Scale bar: 10 micrometres ( = 100th of a millimetre).

So what is going on here?   There are, I suspect, two key elements to the story that we need to explain.  The first is the limits of species within Gomphonema.  I’ve touched on this before (see “Diatoms and dinosaurs”) and some recent studies that combine morphological and molecular biological evidence also cast doubt on our ability to differentiate within this genus using classical approaches.   Whilst I was struggling to disentangle the species in this sample, I had a conversation with an eminent taxonomist and she hinted darkly that Gomphonema was “over-described”.  There is a readiness to “split” established taxa and describe new species that, in her opinion, runs ahead of the evidence.

The limitations of taxonomy cannot explain all of the variation that we observed in this sample, so the second question to ask is what it is about the conditions here that allow so many representatives of one genus to thrive.   I’ve touched on this subject before (see “Baffled by the benthos (1)” and “Baffled by the benthos(2)”).  In these posts I introduced G. Evelyn Hutchinson’s “paradox of the plankton” in which he suggested that environments that look uniform, to mortals six orders of magnitude larger than algae are, in fact, considerably more heterogeneous  and, so offer more opportunities for “variations on a theme” to thrive.   In the second post I went on to suggest that this type of diversity imparts resilience to an ecosystem and so should be looked upon as a positive feature of the ecosystem when doing ecological status assessments.

There is, however, one final possibility that, to my knowledge, has not yet been explored.  The presence of transitional forms in the diatom assemblage at Cregduff may be an artefact of our inability to differentiate biological species based on a limited range of morphological criteria on offer. However, it is also possible that we are looking at a situation where the Linnaean species are not reproductively isolated from one another, allowing hybridisation.   The concept of a “hybrid swarm” is well known in some other groups (e.g. orchids) but has never been formally demonstrated in diatoms.  However, the wide morphological diversity within a single genus in one sample alongo with, in some cases, apparent continua of variation, does raise questions about speciation within thi genus.

The final twist to this story is that, from the point of view of current ecological status assessments, all this diversity has little effect.  Though everyone grumbled about the difficulties in naming the Gomphonema species, the results, as the box-and-whisker plot in the previous post show – were less variable than in many of our other ring tests.  What I suspect happened is that the underlying taxonomic confusion means that many of these taxa have “mid-range” scores for the TDI (and other indices), so the final calculation cancels out the identification issues.  Bear in mind that this may not always be the case!

* I understand that this is the correct name now, rather than Rorippa nasturtium-aquaticum.  See Al-Shehbaz, A. & Price, R.A. (1998).  Delimitation of the genus Nasturtium (Brassicaceae).  Novon 8: 124-126.

References

The two papers that deal with variation within Gomphonema to which I refer are:

Abarca, N., Jahn, R., Zimmermann, J. & Enke, N. (2014).  Does the cosmopolitan diatom Gomphonema parvulum (Kützing) Kützing have a biogeography? PLOS One 9: 1-18.

Kermarrec, L., Bouchez, A., Rimet, F. & Humbert, J.-F. (2013).  First evidence of the existence of semi-cryptic species and of a phylogeographic structure in the Gomphonema parvulum (Kützing) Kützing complex (Bacillariophyta).  Protist 164: 686-705.

Reaching a half century …

Last week saw a small career achievement as I sent out the result of the 50th diatom ring-test that I organise for the diatom analysts in the UK and Ireland.  “Ring-test” is the informal term for an inter-laboratory comparison, when two or more laboratories analyse the same sample and compare their results.  We started out doing regular ring-tests in 2007 for all the people who were analysing diatom samples for assessments associated with the Water Framework Directive, sending out five slides each year to staff in the UK and Irish environment agencies and contractors who worked with them. Now, a decade later, the scheme is still going strong, with participants from Germany, Sweden and Estonia joining the British and Irish contingents.

There are a number of similar schemes around Europe with the same basic model: the organiser sends out copies of a slide made from the same sample, all participants then analyse the slide and send in their results, which the organiser collates.   There is usually one or more designated “expert” against whose results everyone else is judged.  Most of the other schemes then organise a workshop at which participants gather to discuss the finer points of diatom taxonomy.   We have had workshops in the past, but these are not directly linked to the ring-tests.  Instead, we send out a report that summarises results and provides notes on the identification of difficult or unusual taxa.   The money we save on workshops means that we can circulate more slides.  I’m a great believer in “little and often” for this type of quality control.

A second feature of our scheme (which some of the other European schemes have also now adopted) is to use a panel of experienced analysts to provide the benchmark that other participants should achieve.   This means that we have an idea of both the average result and the scale of the variation associated with this.  We learned early on that some samples gave much less variable results than others, even when the analyses were performed by experienced analysts.  We use this knowledge to adjust the size of the “target” that participants must achieve.   The graphs below show the results for our most recent test.  The horizontal blue lines on the left hand graph show two standard deviations around the mean of the “expert” analyses (expressed as TDI).  This is the “warning limit”; if an analyst exceeds this then he or she should be looking at their results to see if they have made any mistakes.  The red line is the “action limit”, seven TDI units either side of the expert mean.   We know from other studies (see lower graph, left) that it is very unlikely that two replicate analyses have a greater difference than this, so analysts who exceed this should definitely be checking their results.

The results of the 50th UK / Ireland diatom ring test showing (left) difference in TDI and (right) number of taxa (N taxa) between experts and other participants.  Blue lines: mean TDI ± two standard deviations of expert panel’s mean; red lines: mean TDI ± 7.   Note that it is unusual for the between-analyst variability to be quite as narrow as it was for this slide.

The reason why we need flexible “warning limits” is illustrated in the right hand graph below.   This shows the similarity between two counts as a function of the diversity of the samples.   The relationship has a wedge-shape (illustrated by the blue line – the regression line through the 90th percentile of the data).   There are a number of reasons why two analysts are unlikely to get identical results, one of which is that they disagree on the identities of the taxa that they encounter (the reason why we are doing the audits in the first place).  But what a wedge-shaped relationship is also telling us is that there seems to be an upper limit to the similarity that can be achieved at any given diversity.   This is an inherent stochastic quality of the data and has nothing to do with the competence of the analysts.

Left: some of the data from which the “action limit” for the ring-tests was established.   These are the results of audits of 67 samples from Northern Ireland in which the original (“primary”) analysis was checked against the result of an independent (“audit”) analysis.   Right: The effect of diversity on the similarity between primary and audit analyses for the same dataset.

A further way in which our scheme differs from others is that no-one “passes” or “fails”.  That might seem counter-intuitive as this is supposed to be a test of competency.   A regular reader of this blog, however, should understand that there absolute truth is often elusive when it comes to identifying diatoms and other algae.  The hard objectivity needed for a real test of competency always has to be moderated by the recognition of the limitations of our craft.   Moreover, turning this exercise into a calibration exercise runs the risk of turning the analysts into machines.  Rather, we use the term “reflective learning”, encouraging participants to use the reports to judge their own performance relative to the experts, and to take their own corrective action.

Some of the organisations whose analysts participate use the ring-test as part of their own quality control systems, and will take corrective action if results stray across the action limit.  That seems to be a sensible compromise: quality control should be the responsibility of individual laboratories, rather than delegated out to third parties.   At the same time, organisations need to understand that the people who perform ecological analyses are professionals, not treated as if they are one more machine in a laboratory that needs to be calibrated.

 

If you are interested in joining the UK / Diatom ring test scheme, or just want to learn a little more about it, get in touch with me and I’ll do my best to answer your questions.

Reference

Kelly, M.G. (2013).  Building capacity for ecological assessment using diatoms in UK rivers.  Journal of Ecology and the Environment 36: 89-94.

 

3 minutes 59.4 seconds …

Back in 1995 I interviewed a number of eminent people about their first academic publications as part of an occasional series for the Times Higher Education Supplement.  I wrote about one of the more daunting of these in “An encounter with Enoch Powell”.   The hour or so I spent with Sir Roger Bannister, who died a couple of days ago, could not have been more different.   He was best known for three minutes 59.4 seconds on a running track in Oxford in May 1954 but went on to have a successful career as a neurologist and eventually became master of Pembroke College, Oxford.  He was, despite this sporting and academic prowess, one of the most charming people I have met.

One of the secrets of his success on the running track was that he was, to all intents and purposes, a sports scientist before that term had been coined.  He took time out from his medical degree to do research on the physiology of breathing and, more particularly, how the point of exhaustion could be delayed by feeding his subjects with different concentrations of oxygen.   As a medical student working in straightened times just after the war, his first task was to build his own equipment, including the treadmill on which he and an assortment of colleagues and friends ran in order to generate the data he needed.  Building this kit involved trips to RAF bases to strip meters and other parts from decommissioned bombers (John Hapgood, former Archbishop of York and also a physiologist by training told me a very similar story).

Whilst his experiments were not directly relevant to his running (his actual training time amounted to less than an hour a day), there was, clearly, a benefit from understanding how his body worked.  However, whilst a runner cannot alter the concentration of oxygen that he breathes, a mountaineer can, and Bannister’s work was used by the team that conquered Everest the following year (he commented that he was surprised at how unfit some of the Everest team were by the standards of track runners).

Whatever his other achievements, however, it was that afternoon in Oxford in May 1954 that defined Roger Bannister.  Three minutes 59 seconds works out at just over a quarter of Andy Warhol’s quotient of fifteen minutes of fame and would have ensured Bannister’s place in the history books.   However, as the obituaries in the newspapers show, he achieved far more than that in his life.   And he was a gentleman too.

If you have the patience to battle with News International’s paywall, you can read my original article by following this link.