Antarctic krill are obligate swarmers and the size and shape of the swarms they form can have a major influence on trophic interactions and biogeochemical fluxes. Parameterizing variability in size and shape is therefore a useful step toward understanding the operation of the Southern Ocean ecosystem. We analyse the relationships between the length L L, thickness T T, perimeter P P, and area A A of 4650 vertical cross-sections of open-ocean krill swarms obtained within the Atlantic sector of the Southern Ocean in summer 2003. Our data show that these parameters are tightly interrelated. The thickness TT increases on average as L 0.67 L0.67and has a log-normal distribution within each length class. The perimeter and area scale with L L and T T as P∼L 0.77 T P∼L0.77T and A∼L 0.86 T 0.48A∼L0.86T0.48. The swarm aspect ratio, T/L T/L, decreases approximately as L −0.32 L-0.32. The surface roughness (defined as P/A P/A) has a weak dependence on swarm length and decreases approximately as T −0.46T-0.46, which can be explained only by the appearance of indentations and cavities in the swarm shape. Overall, our study finds that there are distinct limits to the size and shape of swarms that Antarctic krill appear to be capable of forming and we explore the potential explanatory factors contributing to these limitations.
When somebody asks you, ’Do you like the taste of hospital food?’, it’s usually because you’ve spilt somebody’s pint in a packed Wetherspoon’s. Last month, British Baker had to ponder this question when we attended a taste test of baked goods, supplied into Southampton University Hospital. And it wasn’t without a similar sense of Friday night trepidation. This was a gluten-free taste test.”Go on, try the gluten-free baguette,” was the ominous dare that crept around the tasting table. On the surface, this curio seemed inviting enough: a dark crust, a slash down the centre, your standard bake-off quality baguette. But on the inside lurked something more akin to petrified loft insulation, with the mouth-feel of running your tongue up a brick wall.Such is the hit-but-mainly-miss nature of that unique niche: bakery products for people who cannot eat bakery products. “Do they actually taste this stuff?” piped up one member of the panel, held at the hospital, which was looking for something more palatable than this rogue baton.While there are, no doubt, a lot of stinkers out on the gluten-free market, product quality and availability has rocketed over the last five years. Dedicated free-from sections have sprung up in all the major multiples, while high street café chains stock gluten-free products as a staple.Why the shift? One reason is that consumers are increasingly shunning the GP for information on dietary matters in favour of Google, and self-diagnosing coeliac disease in greater numbers. For people under 44, the internet now ranks above GPs as a source of information on food sensitivity issues. Gluten is increasingly perceived as a “red flag” ingredient, like saturated fat. And coeliac disease has becomes that oddest of species: a disease it’s cool to have.A new report commissioned by Mrs Crimble’s – a free-from cake and biscuit brand – noted that most of the growth in the free-from market had not come from people who think they had a food intolerance, but from those who simply want less wheat and gluten in their diets, and that accounts for half the market. It stated the number of people who believed they had some food intolerance had grown by over a third between January 2007 and 2008, though from a small base.”The supermarkets are doing gluten-free more and more – partly because it’s quite fashionable to have allergies,” reflects Clea Pidgeon, paediatric dietician at the hospital. “You’ll read that some celebrity is on a wheat-free diet and that it’s the best thing ever, and people will have a go at it. That’s why it’s become a lot more available, but this helps the patients who really need it!”It was these genuine sufferers who tested the products with us in Southampton. Intriguingly, panellists said product quality was not as important as availability. Most attendees were grateful just to have something baked to eat. “I’ve not had a chocolate teacake for four years!” exclaimed one, joyfully. Price was the overwhelming sticking point for most coeliacs, who complained in chorus of the hefty premiums placed on standard products. When BB followed this up with suppliers, they said prices will only come down when scales increase and the category goes more mainstream.The market has changed considerably; while, five years ago, gluten-free bread would come in tins, you can now buy fresh bread, though often they have to be “refreshed” in the microwave – a drawback for everyday consumption. “People cannot regenerate their bread at school or work,” notes Pidgeon. “Bread, patients tell me, is the biggest area of concern, though there has certainly been real improvements.”But is it really possible to make gluten-free products that stand up next to regular ones? “We’re seeing more real bakers like ourselves in the market – and not just pharmaceutical companies – making the products,” says Paddy Cronin, sales and marketing director of United Central Bakeries, which is developing cakes alongside its existing gluten-free morning goods.== ==It’s apparent the expectations of some coeliacs are growing in tandem with product quality. I put it to one panellist that, surely, gluten-free is too niche to ever become mainstream. “Research suggests that 1% of the population are gluten-intolerant, but they don’t know it – that’s a huge market,” he replied. Of course, the remaining 99% that aren’t and do know it, is even more huge.Switching allegianceWould a coeliac really switch allegiance to, for example, Costa, if they found it stocked a gluten-free product, I ventured? “They already sell a couple of gluten-free products. But… they should be selling more than that!”The gripe is that, while gluten-free cakes are available in cafés, there are few gluten-free morning goods. But this may be down to the technical challenges in NPD. “It’s difficult to make them, because you don’t have the benefits of gluten, which gives structure – so you’re working more with a batter than a dough,” says UCB’s Cronin. “But anything is possible; we’ve made gluten-free pitta bread and crumpets when no-one else in the market was doing so.”But NPD for coeliacs is a tricky beast. It is very hard to find one ingredient that can replace gluten’s function in baking and still get a cake or biscuit that tastes good. “A careful mix of ingredients such as gluten-free flours – rice flour, maize flour and possibly starches, fibres and gums – I find can work well in baking,” says Angela Mumby, a technologist for consultant firm Food Ambitions.The other challenge for suppliers is that, while coeliacs are screaming out for more gluten-free, it can be hard to reach that audience. “I believe an increasing number of consumers are hoping that tasty gluten-free treats will make their way to mainstream stores. We receive many requests from the specialist stores, but I fear that mainstream venues are hesitant to stock gluten-free for fear that their conventional customers will not buy them,” says Lise Madsen, MD of Honeyrose Bakery.”Many gluten-free products taste pretty awful and yes, it’s difficult to overcome the inherent gritty, dry and heavy texture that characterises poor gluten-free products, but it’s definitely possible.”While coeliacs can source products directly, mainly through organisations such as Coeliac UK and Allergies UK, the difficulty, they say, is in trying to find much gluten-free on the high street. Unless, that is, you threaten to vomit in the shopkeeper’s face, as one panellist suggested: “They don’t take much notice if you say you’re coeliac. It’s not the same as nut allergies, where people are worried you’ll have a fit. But they’re more sympathetic if you threaten to throw up your stomach lining.”—-=== Labelling ===Coeliac disease is characterised by intolerance to gluten, but there is no legal definition of what gluten-free means. An international standard for gluten-free products that are produced from cereals containing gluten – The Codex Alimentarius – allows 200mg of gluten per kilogram in products, though manufacturers are not legally required to comply. In December 2007, it was announced that the Codex standard was to be cut to just 20mg/kg following pressure from campaigners. Those products between 20 and 200mg/kg will be referred to as “gluten-reduced”. The majority of coeliacs could tolerate between 20mg and 100mg of gluten per kg of product.”While in the grand scheme of things its impact will be low, apart from on those who follow a gluten-free diet, it will mean that coeliacs may lose faith in those brands that were once labelled as gluten-free, but will in future be labelled as gluten-reduced or reformulated and relaunched,” reported research firm Mintel.—-=== Street walking ===So how hard is it to get a gluten-free treat with your coffee? We’re not talking about soups, salads or jacket potatoes here – we want cakes, scones, the good stuff. Here’s what the streets of Southampton had to offer…? 1 John Lewis café: cherry and coconut slice, £1.95? 2 Morris Pasties: sells a variety of packaged traybakes and slices, but are any of them suitable for coeliacs? “How hungry are you?” says the assistant. “Our soups are gluten-free but our pasties and cakes aren’t.”? 3 Costa: Gluten-free round raspberry shortcake, £1.20? 4 Greggs and Subway: Dream on!? 5 Pret A Manger: The assistant guides us through a weighty ingredients book, and there are gluten-free salads, crisps and soups, but only one wheat-free orange cake finger, £1.99? 6 Bhs Coffee Shop: “We don’t have any information on what is or isn’t in the products, sorry…”? 7 M&S Café Revive: Rich fruit cake finger £1.50? 8 Druckers: none of their delightful treats were gluten-free—-=== Talking heads ===== Elianor Kea, dietician ==”A lot of the gluten-free breads are very dry, heavy and crumbly. But people generally don’t complain; they’re just pleased that they’ve got something that they can eat.”Once you’re on a gluten-free diet you’ve got the same health risks as everybody else. So most people will put up with the fact that the bread’s not as nice.”== Anna Brian, dietician and coeliac ==”With the sandwiches, you’ll find that the bread is very crumbly and dry. But if you have them as an open sandwich, you’ve only got one slice of bread to get through. If patients can’t find a bread they like, we urge them to get a breadmaker and try using seeds to make the bread more interesting. They tend to get the basics on prescription and buy the little luxuries from supermarkets.”== Karen Read, administrator, coeliac for four years ==”Gluten hides itself in a lot of products, so you don’t buy processed foods if you’re a coeliac. I tend to make everything like breads from scratch.”I don’t buy from supermarkets, because they’re a lot more expensive than normal foods, and you can make them yourself. I’ve lost the taste of what baked products used to taste like, and I’m used to it.”== Alan Noble, retired, coeliac for 11 years ==”The hardest thing for a coeliac is going out for a coffee or tea, because you’re very lucky to get something.”When you do find somewhere, you spread the word. It must be very difficult for a bakery to keep the separation in their production, but it would be nice to just be able to buy a gluten-free roll or scone from a baker in the high street.”