Ian Hopkinson

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Book review: Buried by Professor Alice Roberts

Continuing with my Alice Roberts binge, I now review Buried: An Alternative History of the First Millennium in Britain. Following the theme of the two other books in the series, Ancestors and Crypt, Buried looks at history through the lens of seven burials. It finishes with a final, more general chapter which looks at identity and the balance between migration and cultural diffusion.

The first millennium covers the Roman occupation of Britain followed by the period sometimes known as the “Dark Ages” or the “Anglo Saxon Period”.

The first three burials are in the Roman era, they cover a weird pipe burial where the ashes from a cremation are buried in a lead container with a pipe leading up to the surface. This is believed to be a a facility for enabling mourners to symbolically eat and drink with the deceased. This was a funeral practice known in the Roman period and continued for a long time in, for example, Russia where food and drink were left on the grave. To a degree this is a chapter about cremation, which was the favoured Roman practice – sky burials were more the preference in Iron Age Britain – they leave little trace. After the Romans left inhumation became the common practice.

The second chapter is a somewhat traumatic one on infant burials in the Roman period, focused on the 97 infant burials found at the Yewden Roman Villa near Hambledon. Infants were often buried close to homes rather than in cemeteries in the Roman period. Some of the bones at Yewden show signs of cutting, it isn’t entirely clear why there are such injuries but obstetric surgery is a possibility. It has been estimated that infant mortality was as high as 30% in this period. There are hints that infanticide was practiced more widely than today on those infants who might today survive with treatment. These infant burials highlight the difficulty of understanding what was happening, and how people felt from fragmentary remains.

The last of the Roman burials covers decapitation, burials where the corpse has clearly been decapitated – it focuses on the Whelnetham cemetery at Bury St Edmunds. One thing that is becoming clear is that there is no such thing as a typical cemetery from this period, each of the burials in this book illustrates another variation from the “norm” – whatever that may be. Perhaps that is the result of the selections made by the author but it may be that in an era before mass communication and a strong nation state or church, burial was much more a local affair. Ultimately why bodies were decapitated before burial is unclear, sometimes it was as the result of execution or a final punishment for criminals in other cases it may have been a superstitious measure to prevent ghosts or other apparitions.

The diversity of burial practices is again highlighted in the next burials at Breamore in Hampshire dating from around 600CE where the local style seems to have been burial with a bucket amongst many other grave goods! The site was discovered after a metal detectorist discovered a very elaborate bucket which appears to have come from a workshop many miles away in the Southern Türkiye. It is here that the theme of Anglo Saxons, and how they came to replace the Romans takes place. The term “Anglo Saxon” has its own postscript chapter since it is a problematic term. For archaeologists it has a precise meaning: the period from the end of the Roman occupation to the Norman invasion but more recently it has been co-opted as an ethnic term meaning “white, of Northern European origin”. Some (approximately one) historical records suggest the Anglo Saxon takeover of culture in Britain was the result of mass migration or invasion. However, the writer of this history – Gildas – certainly had an axe to grind. It seems more likely that the apparent Anglo Saxon invasion was a cultural shift that came from longstanding trade links across northern Europe. The Roman invasion of Britain was more a replacement / coalition of the ruling class than a mass migration, although soldiers and mercenaries came to Britain from around the Empire. The Anglo Saxon “invasion” appears to have been more of a re-instatement of the Iron Age status quo drawing on existing trade and cultural links.

The next chapter is not focussed on a burial as such but on the Staffordshire horde, and the intensive study of a single type of jewellery and how it changes over time. Although dramatic, discoveries such as the Staffordshire Horde are frustrating since they come with no context, they are typically found with no accompanying burial, building or even roadway.

The local interest for me is in the sixth chapter, where Roberts looks at burials near Benllech in Anglesey – where we have been on holiday a couple of times. The “burials” are basically bodies thrown into a ditch, and the key question is whether they are part of a battle against Viking invaders. This again touches on the movement of people around Northern Europe and the degree to which they assimilated locally.

Towards the end of the Roman Empire it became Christian, and in the subsequent years Roman burial practices, and those countries where the Church prevailed, changed. Cremations were replaced with burials, grave goods fell out of favour (to the chagrin of modern archaeologists), and churches and cemeteries combined – in the earlier Roman period there were temples in settlements and separate cemeteries on the outskirts. In some ways the Roman Empire seems not to have fallen but rather have been replaced with the Catholic Church, based in Rome.

As I finish my binge on Alice Roberts I find her books make engaging reading, as well as archaeological detail they also cover historiography and the broader questions of the period the burials address. Buried addresses more of the historical record than Ancestors which focussed on an earlier period (where there were no historical records), and less of the ancient DNA work which is found more in the recent Crypt. Ancient DNA is particularly relevant to understanding disease. The field of ancient DNA is evolving very rapidly, even in the couple of years between the writing of Buried and Crypt.

Book review: Crypt by Professor Alice Roberts

My next review is for Crypt by Professor Alice Roberts, this is one of a sequence of three books on archaeology and history centred around burials. I reviewed Ancestors a couple of years ago which covered the prehistoric period. Crypt covers the second millennium of the current era, the third book, Buried, covers the first millennium and is on my reading list.

In common with Ancestors, Crypt considers seven burials across a period of time – in this case the medieval period – from about 1000CE to 1500CE. The burials are a launch point for a wider discussion covering archaeology, genetics, disease pathology and history. It is the study of DNA from ancient bodies that has been the biggest innovation over the last 25 or so years, and it has been applied to a lot of existing archaeological collections as well as new digs. It can show how diseases have emerged and evolved over the period of human history.

“Crypt” is not a particularly accurate description of the burial sites, the chapters look at a mass grave in Oxford (in a ditch) whose members met violent ends, a leper colony near Winchester, Thomas Beckett’s (possible) burial at Canterbury Cathedral, burials at Norton Priory near Runcorn showing evidence of Paget’s disease, plague pits and evidence for the Black Death, the Mary Rose and the skeletons of otherwise healthy men, finishing with a burial at a church in York and syphilis.

In contrast to Ancestors this book has much more historical material, understandably since Ancestors covered prehistoric burials.

The book starts with the discovery of 35 skeletons in a ditch in Oxford, primarily young men who had met a violent end. Ultimately this was linked to Æthelred the Unready’s edict to kill Danes in England dated to 1002CE in the Anglo-Saxon Chronicles. Although the carbon dating initially indicated the skeletons were from a slightly earlier period, isotope analysis suggested they had a diet very high in fish, which is know to lead to systematically older carbon dating. It also suggest that the skeletons may have belonged to Danes, whose economy was very dependent on fishing. Contemporary reporting of the massacre was limited but picked up after the Norman invasion as some sort of justification for the invasion.

Leprosy was spreading in the 11th century – possibly as a result of the Crusades. The second chapter of Crypt concerns the hospital on Magdalene Hill on the outskirts of Winchester. 100 graves were excavated of which 85% had inhabitants afflicted by leprosy – this is very clear from skeletal evidence. The hospital was founded around 1000CE, in this period hospitals were starting to be founded but the line between hospital and monastery/abbey was blurred. In the modern era PCR analysis has shown that many have leprosy without symptoms.

In some senses the chapter on Thomas Beckett is anomalous, it is almost entirely historical. On his well-documented death he was quickly made a saint and his tomb at Canterbury Cathedral, featuring a special alcove for his severed scalp, became a site of pilgrimage. The archaeological interest is because none of the tomb of St Thomas remains, it was removed by Henry VIII during the Dissolution who also comprehensively clamped down on celebration of St Thomas. The chapter also talks about the politics between the local royalty and the Roman church.

The chapter on Norton Priory, near Runcorn, brings things home for me – I live just down the road in Chester. The new visitor centre looks rather fine. The focus here is on Paget’s Disease which is a disorder of the bone which is more common in north west England, and used to be more common generally. As a disease it is still a bit of a mystery. Norton Priory has a very high incidence of Paget’s in its graveyard – as many as 3 in 20 skeletons show evidence of the disease.

Paget’s disease and leprosy both show clear signs of disease on the bone, the Black Death on the other hand, does not since it kills its victims in days, or even hours giving little time for bone to be affected. This means that genetic methods are used to diagnose the disease in ancient remains. They were first applied to the Black Death around 2000 but the results were disputed with the identity of the disease micro-organism for the Black Death only confirmed as Yersinia pestis in 2011. It has been identified in victims of the earlier Justinian plague.

For Roberts the Mary Rose is a significant part of her childhood memories, as it is for me – many of us around the age of 50 will remember the raising of the Mary Rose shown on an old CRT TV in the school assembly hall. The interest in the Mary Rose is that the anaerobic silt of the Solent preserved the skeletons of its crew very well and nets to prevent boarders meant many men were trapped on the sinking ship. The primary interest here is in counting the dead, best estimates are rather below the historical figures suggesting that the ship may have been under-crewed. The skeletal pathologies are also of interest – what was the impact of the types of activities that sailors and fighting men undertook on their skeletons.? The Mary Rose is also the home of a large cache, over 100, of English long bows – very few of these famous weapons have been preserved – in fact the Wikipedia article cites only three other examples not from the Mary Rose.

Crypt finishes with an unusual burial in a York church, (All Saints on Fishergate) and syphilis. The burial is unusual because it is a pit burial in the apse of the church. The buried skeleton contains crater-like lesions characteristic of advanced syphilis. The origin of syphilis is still a mystery, there has long been a “Columbian Hypothesis” that Columbus brought syphilis back from the New World (in exchange for a wide range of diseases brought from the Old World) – however genetic analysis has failed to find the syphilis bacteria in remains prior to 1492 in either the New or Old World. The burial is thought to have been of an anchoress, possibly Lady Isabella Germann, buried around 1493.

The disease pathology sections are interesting but can be quite lengthy, I noticed this particularly in the chapter on the skeletons of the Mary Rose in the discussion on the skeletal features arising from archery – it all became clear when Roberts writes of this topic “…this had formed the backbone of my PhD”!

Reading this book it becomes clear that the various diseases mentioned, leprosy, syphilis, and Black Death went through periods of high prevalence across human history -this is covered in Peter Frankopan’s book The Earth Transformed. The bubonic plague – the disease responsible for the Black Death, is covered in Simon Schama’s book, Foreign Bodies, at least for the 19th century outbreak.

I enjoyed this book, so much so that I have just bought the last (for me) of the sequence.

Book review: An Immense World by Ed Yong

My next review is of An Immense World by Ed Yong, subtitled How Animal Senses Reveal the Hidden Realms Around Us. I reviewed Yong’s previous book, I Contain Multitudes a while back. Somewhat foolishly I was slightly reluctant to pick this one up since I felt I was clued up on the “five senses”. I was incredibly wrong about this quick judgement. First of all, “five senses” are a human-centric view promulgated by the ancient Greeks, secondly it turns out we have been learning a lot about animal senses in my lifetime and show no signs of letting up.

The book is divided into 12 reasonably long chapters, treating smells and tastes, light, colour, pain, heat, contact and flow, surface vibrations, sound, echoes, electric fields, and magnetic fields. Finishing with a chapter on how senses work together and one on the pollution of the senses in the natural environment with artificial light and sound. We can see here the traces of the original five senses but some are split (light and colour, sound and echoes), taste and smell are merged; magnetic fields and electric fields are new introductions.

A key concept which is found throughout the book is the idea of “umwelt”, the perceptual world of an organism, which was coined by Jakob von Uexküll in 1909. Touching on the penultimate chapter first, this “umwelt” is almost impossible for us to fully appreciate – we can’t even be sure how the senses we share are experienced by other animals. Let alone how they work together with other senses that we don’t have.

One comfort of this book is that it turns out that human senses are not that bad. Yong cautions though that absolute comparisons across species are often wrong, and don’t account for large variations between individuals. His goal is to talk about diversity rather than ranking. A general theme is that although some animals might exceed us in terms of acuity, often it is the speed at which a response can be made that is the critical factor.

All of the chapters involve Yong talking to scientists, not just about the science but how and where it is done, which is engaging.

For smell the key ability that animals have over humans is better sampling so that scent traces can be followed, snakes do this with their forked tongues whilst dogs do so with subtly designed airways. I was also interested to learn that sea birds are sensitive to dimethyl sulphoxide which is an indicator for a bountiful ocean, and whose concentration likely serves as a large scale map. Taste is covered in just a couple of pages, essentially it is used by animals as a final go/no go decision on eating stuff – smell is a much more subtle sense.

It turns out human vision is pretty good compared to other animals, at least in certain aspects. Only eagles and other raptors have better acuity, certain flies have vision which is up to 10 times faster than ours. Many animals can sense light outside the human visual range, in the ultra-violet and infra-red and use this ability for specific purposes. I think the key takeaway for me was that the human visual system is not a blueprint for all visual systems, mantis shrimps, for example have a ridiculous number of different types visual receptors but they are used in a very different way to ours – almost like a set of special purpose triggers for motion, colour, light direction rather then general receptors whose signals are processed by the brain. It also seems that the colour vision is just not that important for survival – many people get by with impaired colour vision, and although colour vision like ours is not rare amongst certain groups it is in no way necessary for survival.

Yong makes a point about how our own senses guide our view of the mental world of other animals, we see cows as passive because they are not always looking around at their environment, as we do but they have virtually panoramic vision so they don’t need to constantly move their heads to see what is going on around them.

The chapter on pain starts with the naked mole-rat, whose tolerance of very high levels of carbon dioxide in their burrows is enabled by their limited ability to sense the pain induced by acidic substances (carbon dioxide forms carbonic acid). Much of pain research seems to be about belatedly realising that all manner of animals feel pain, and perhaps we shouldn’t inflict it.

Heat is generally detected by the TRP channel proteins, with different variants responsible for for different temperatures including “dangerously hot” and “dangerously cold” the temperature at which they are triggered varies from animal to animal. Melanophila (fire) beetles have incredibly sensitive heat sensing organs that can detect fires by their infra-red emissions from miles away. Similarly snakes are able to detect the direction heat is coming from, with signals processed alongside sight.

It turns out that touch is quite a varied sense, we think in terms of our fingers touching solid surfaces but for many animals the feel of flow in water is more important. The feeling of flow of water helps predators catch their prey, and fish to school together. Related is sensitivity to surface vibrations, which insects and other invertebrates have developed to an incredible degree. The songs of certain insects in surface vibrations are as sophisticated as bird song.

My favourite fact from the chapter on sound is that owls have one ear higher than the other so that they can locate sounds vertical by arrival time. I also learned that zebrafinches have very high sensitivity to the fine structure of their songs but are less sensitive to the notes they sing, it made me think a little of “tone” in guitar playing.

We should see echolocation as touching with sound, it wasn’t until the 1930s that it was appreciated that bats echolocated, and rather later for dolphins. Echolocation can be remarkably sensitive, dolphins can not only identify different materials from echolocations but they can match an object “seen” with echolocation to one “seen” with their eyes. Military interest in echolocation is essentially a result of a recognition that human technology lags biology.

Another novel sense, as far as humans are concerned, is electric. It has long been known that some fish used electricity as a weapon, but only in the 1950s was it recognised that it was also used for sensing. There are two types of electrosensing, one is active – like echolocation but it is omnidirectional and there is no wait for a signal return. The second is passive, some animals can detect the weak electric fields of animals going about their normal business. In common with echolocation the animals that use it have exquisite control over the frequencies, and sequences, of the probe pulses they generate.

Sensitivity to magnetic fields is the most elusive of senses, it has only been recognised relatively recently and we still don’t know for sure exactly how animals are sensitive to magnetic fields – there has been no conclusive identification of the receptor cells.

Astronomers have long been concerned with light pollution but it has only been more recently that biologists have realised it is a significant threat to animals. Similarly with sound, we are sensitive to noise pollution close up but don’t appreciate the significant noise pollution in pristine-looking environments.

I thoroughly enjoyed this book, as I did I Contain Multitudes. The style is engaging, and the subject matter is fascinating.

Book review: A Philosophy of Software Design by John Ousterhout

Next for review is A Philosophy of Software Design by John Ousterhout. This a book about a big idea for software design. The big idea is that good software design is about managing complexity. In Ousterhout’s view complexity leads to a set of bad things: (1) change amplification – small changes in code lead to big effects, (2) cognitive load – complex software is difficult to understand, and (3) unknown unknowns – complex software can spring the unexpected on us.

Ousterhout covers this big idea in 20 short chapters with frequent reference to a projects that he has run with students repeatedly (including a GUI text editor and a HTTP server) – providing a testbed for reviewing many design choices. He also uses the RAMCloud project as an example, as well as features of Java and the UNIX operating system. This makes a refreshing change from artificial examples.

To decrease complexity requires developers to think strategically rather than tactically which goes against the flow of some development methodologies. Ousterhout suggests spending 10-20% of time on strategic thinking – this will pay off in the long term. He cites Facebook as a company who worked tactically and Google and VMWare as companies who worked more strategically.

At the core of reducing complexity is the idea of “deep modules”, that’s to say systems that have a relatively small interface (the width) which hides information about a potentially complex process (the depth). The Java garbage collector is the limiting case for this – having no user accessible interface. The aim of the deep modules is to hide implementation details (information) from users whilst presenting an interface that only takes what is required. This means deciding what matters to the user – and the best answer is as little as possible.

This goes somewhat against the ideas of the Agile development movement, as expressed in Clean Code by Robert C. Martin (which I read 10 years ago) – who was a big fan of very short functions. I noticed in my review Clean Code that I have some sympathy with Ousterhout’s view – small functions introduce a complexity overhead in function definitions.

Also on the theme of Agile development, Martin (in Clean Code) sees comments as a failing whilst Ousterhout is a fan of comments, covering them in four chapters. I recently worked on a project where the coding style was to rigorously exclude comments which I found unhelpful, that said I look at my code now and see orphaned comments – no longer accurate or relevant. The first of Ousterhout’s chapters on comments talks about four excuses to not provide comments, and his response to them:

  1. Good code is self-documenting – some things cannot be said in code (like motivations and quirks)
  2. I don’t have time to document – 10% of time on comments will pay off in future
  3. Comments get out of date and are misleading – see later chapter
  4. The comments I have seen are useless – do better!

The later chapters focus on the considered use of comments – thinking about where and what to comment rather than sprinkling comments around at a whim. The use of auto-documentation systems (like Sphinx for Python) is a large part of realising this since they force you to follow standard formats for comments – typically after the first line of a function definition. Comments on implementation details should be found through the body of a function (and definitely not in source control commit messages). He also introduces the idea of a central file for recording design decisions that don’t fit naturally into the code. I include the chapter on “Choosing names” under “comments” – Ousterhout observes that if you are struggling to find a good name for something there is a good chance that what you are trying to name is complex and needs simplification.

Certain types of code, Ousterhout cites event-driven programming, are not amenable to producing easy to understand code. He also dedicates a chapter to handling errors – arguing that errors should be defined out of existence (for example deleting a file that doesn’t exist shouldn’t cause an error, because the definition of such a function should be “make sure a file does not exist” rather than “delete a file”). Any remaining exceptions should be handled in one place, as far as possible.

There is a chapter on modern software development ideas and where they fit, or don’t, with the central theme. Object-orientation he sees as good in general, with information hidden inside classes but warns against over use of inheritance which leads to complexity (just where is this method defined?). He also comments that although design patterns are generally good their over-application is bad. He is in favour of unit tests but not test-driven development. This seems to be related to his central issue around Agile development – it encourages tactical coding in an effort to produce features rapidly (per sprint). He believes Agile can work if the “features” developed in sprints are replaced with “abstractions”. He doesn’t like Java’s getters and setters, nor its complex serialisation system which requires you to setup up buffering separately from opening a file as a stream – I remember finding this puzzling.

I enjoyed this book – it provides some support for continuing to do things I currently do although they are a little against the flow of Agile development and food for thought in improving further.

Book review: Her Space, Her Time by Shohini Ghose

My next review is of Her Space, Her Time by Shohini Ghose. I picked this book up as a result of a review in New Scientist. It is in the spirit of Broad Band which covered the contributions of women to computing over the years – contributions which have historically been ignored. Her Space, Her Time does the same for women in physics, generally on the astrophysics and cosmology side of the subject.

The book is divided into seven chapters each covering an area of physics and a group of women who worked in those areas. The chapters cover star cataloguing (and rather more), the big bang, the space programme, radioactivity, nuclear fission, particle physics and dark matter/ beta decay. This results in a coverage which is approximately chronological.

There are some recurring themes in the book: women not allowed entry to universities for undergraduate and graduate studies, women not allowed employment in university departments and facilities (often the pretext is the lack of toilets for women), women not allowed employment at the same institution as their spouse (this seemed common in the US and its effect on the recruitment and promotion of women was noted as far back as 1966), being ignored by the Nobel Prize committee and (sometimes) their male collaborators. These women were frequently the only women in the room. Fleeing Nazi Germany (and Austria) is a theme too but that applies equally to men.

On a more positive note their work was often recognised and rewarded during their lifetimes by their scientific communities. In at least the case of Ernest Rutherford and Ernest Lawrence they had the support of senior scientists throughout their lives.

The Harvard Observatory features heavily in the first couple of chapters. Women originally became involved as “computers” analysing the stars in the photographic plates. They included Williamina Fleming, Annie Jump Cannon, Antonia Maury and Cecilia Payne-Gaposchkin with Anna Draper providing funding to the observatory via a bequest in the late 19th century. In they first instance they were analysing stars for brightness and then later for spectral features. A group of women were responsible for compiling the “Harvard” stellar classification scheme which classifies stars by temperature using the letters O, B, A, F, G, K, M (typically remembered by a sexist mnemonic). One of the women, Henrietta Swan Leavitt, discovered the relationship between brightness and period for stars which is central to measuring intergalactic (and shorter distances) and was key to understanding the scale of the galaxy and the universe. Over a very long period Harvard Observatory allowed women to be employed as astronomers, and finally become professors in astronomy. The transitions usually being the result of a change in observatory or university management.

The third chapter is a bit of an oddity, looking at women’s contributions to the space programme on the project management and rocketry side of things rather than physics as such.

The final four chapters are then an extended collection on nuclear physics starting with Marie Skłodowska-Curie, and the less well known Harriet Brooks who worked on the new subject of radioactivity in the late 19th century. Brooks worked with Rutherford, publishing in 1904 in Nature on their discovery of radon. Rutherford and Frederick Soddy would earn the Nobel Prize for the transmutation of elements whilst Brooks was left out. Rutherford and Brooks clearly had a long personal relationship, ending in 1933 on her death at the age of 56. Brooks had left physics research in 1907 when she married Frank Pitcher.

Chapter 5 largely concerns Lise Meitner who was involved in the discovery of nuclear fission with Otto Hahn with whom she worked closely for many years. Hahn received the Nobel Prize for their work on nuclear fission, whilst she did not – this has been seen as one of the more egregious omissions of the Nobel Prize Committee – Meitner was nominated for a Nobel Prize 48 times and was widely recognised as an expert in her field. Her position was made more difficult because she was Jewish, worked in Austria and with Hahn who despite protestations was a Nazi sympathiser at the very least.

Chapter 6 concerns cosmic rays and the photographic detection thereof. It starts with Bibha Chowdhuri who is from Ghose’s home city of Kolkata and was later to discover cosmic ray muons using this method. The focus of the chapter though is Marietta Blau and her student Hertha Wambacher who developed the method of photographic detection of cosmic rays. The Meitner/Hahn story is reprised here with Jewish Blau forced to leave Vienna in 1938 with her student Wambacher, a Nazi sympathiser, remaining to take credit. Elisa Frota-Pessoa, a Brazilian physicist, is mentioned somewhat incidentally towards the end of the chapter with Ghose stumbling on one of her (very prescient) publications whilst researching other work.

The book finishes with the slightly odd pairing of Wu Chien Shiung who was instrumental in the discovery of parity violation which won her colleagues Tsung-Dao Lee and Chen-Ning Yang the 1957 Nobel Prize in Physics (they specifically mentioned her in their acceptance speech) and Vera Rubin who is credited with discovering dark matter by measuring the rotation curves of galaxies and observing that they flatten at large radii – an indicator of the presence of extra, unseen matter.

Reading back through my notes, women were at the heart of modern physics through the 20th century, often those women were the only ones in the room – it is clear they were exceedingly capable. The men around them collected a dozen Nobel Prizes whilst the only woman from this book to win the Nobel Prize for Physics was Marie Skłodowska-Curie. Maria Goeppert Mayer shared the Nobel Prize for Physics in 1963 she is the only other woman to win in the 20th century. She is not included in this book, perhaps because her Nobel Prize meant she was already well known.

In the past I thought the Nobel Prize committee were simply a bit careless in failing to award women but reading this book it seems they were rather purposeful – the physics community knew these women, and the significance of what they had done, and many were nominated for a Nobel Prize, often repeatedly.

As a result of this book I am now interested in a parallel volume of Indian scientists in the West!