bluuebunny/crossref_metadata_2025 huggingface dataset:
Late Foragers and First Farmers (8000–3700 BC)
Authors: Bradley Richard , Haselgrove Colin , Vander Linden Marc , Webley Leo
Published: November 2020

This chapter spans an important period division. It considers both the ‘Mesolithic’ hunter-gatherers of the study area, and the first ‘Neolithic’ farmers. The relationship between them is one of the most important issues to be investigated by prehistoric archaeology, but it is also one of the most contentious. The period between 8000 and 3700 BC saw the change from a reliance on wild resources to a new subsistence economy based on the ownership of domesticated plants and animals. It must have involved completely new forms of social organization. The transition between these phases occurred at different times in different parts of north-west Europe, but in all instances it is where two distinctive kinds of scholarship impinge on one another. To some extent the distinction between these kinds of research is determined by the kinds of evidence that are available. For the most part Mesolithic activity is characterized by hearths, scatters of stone tools, shell middens, and other food remains. In some regions there are graves, but traces of domestic buildings are comparatively rare. There is little sign of more monumental structures. The Neolithic period, on the other hand, is characterized by durable wooden houses, enclosures, mounds, and stone-built tombs, and by a much wider range of artefacts. This contrast has implications for the kinds of research that can be undertaken. With notable exceptions, students of the Mesolithic are most concerned with food production, settlement patterns, and lithic technology and place a particular emphasis on ecology and adaptation. Specialists on the Neolithic period do not neglect these fields, but they are also able to consider monumental architecture. Because they can draw on a wider range of data, their studies extend to ritual and social organization in a way that is more difficult to achieve in the archaeology of foragers. That contrast has become even wider with recent increases in the scale of fieldwork. Mesolithic sites contain comparatively few subsoil features and are difficult to detect by remote sensing or sample excavation.
The Expansion of Settlement (1100–250 BC)
Authors: Bradley Richard , Haselgrove Colin , Vander Linden Marc , Webley Leo
Published: November 2020

The previous chapter addressed an important period of change, but this would not have been apparent to the scholars who devised the Three Age Model. The most important developments between 1600 and 1100 BC were most clearly evidenced in the ancient landscape and registered to a smaller extent by the metalwork finds on which the traditional scheme depends. The same is true of the evidence considered in this chapter, for it cuts across the conventional distinction between the Bronze and Iron Ages. It begins in a period when bronze was still the main metal, but also considers a time when a new kind of raw material was employed. Similarly, it ends part way through the phase usually characterized as ‘Iron Age’, so that the drastic economic and political transformations that communities experienced in the late first millennium BC can be considered separately. These provide the subject of Chapter 7. By the late Bronze Age, evidence for settlements and houses is fairly abundant, and some sparsely used parts of the landscape were occupied for the first. This expansion—which continued into the Iron Age—is associated with new agricultural techniques and a wider range of crops. The nature of settlements suggests an emphasis on small household groups as the basic unit of society. New kinds of focal sites also appeared, which may have been used for assemblies and public ceremony. They include hillforts in upland regions, while other communal centres may have played the same role in lowland areas. Meanwhile, the trend towards less elaborate burial practices that had begun during the middle Bronze Age spread increasingly widely. Investment in funerary monuments was generally modest, and mortuary rituals displayed social distinctions in relatively subtle ways. While prestige objects were rarely placed with the dead, the deposition of metalwork in rivers and other places in the landscape increased. These metal artefacts have provided the basis for studies of long-distance interaction, and their styles have been used to define three geographically extensive traditions, in Atlantic, Nordic, and central Europe. Other ritual practices that developed during this time involved feasting and cooking.
Mr Khama is Coming to Dinner
Authors: Öhrström Lars
Published: November 2020

The temperature is approaching +38°C, and the highway between Botswana’s capital Gaborone and Francistown stretches out ahead in a straight line, heading north-east. It is the peak of the hot season, and here on the verge of the Kalahari Desert a dusty yellowish hue should colour the landscape, but instead rains have made everything a vibrant green. We stop and see hundreds of identical butterflies assembled in a small mud pool, and back on the well-paved and smooth road we are constantly vigilant to avoid the occasional cow, goat, or donkey feasting on the green grass beside the highway. At the big coal mine and power station in Palapye we turn left from the main road, and after another hour we pass a big modern shopping centre and then, without really noticing, we have entered Serowe, considered by some to be the largest traditional village in Africa—a settlement with a population of 90,000 or so spread out in mostly one- or two-storey houses in a very distinctive un-city-like manner. We see signs directing us to the museum, that we don’t find, and the kgotla, that we do. This large, very tidy, open space, surrounded by majestic trees and a wall at hip-height, is still the meeting place of the Bamangwato tribal councils (the word kgotla means ‘court’ in Setswana), but today it is completely deserted. But let’s now move back to 23 June 1949, when the situation was very different. Serowe, then the largest urban centre in the British Bechuanaland Protectorate, had just seen a massive invasion of South African and British journalists, in addition to the hundreds of tribesmen gathered in the kgotla. It was not as hot, as it was winter, but at that time this really was a remote place. There was not a metre of paved road in the Protectorate, the country was poor and austere, and the British preferred to conduct their fairly relaxed administration from the more comfortable Mafeking in the Union of South Africa.
Pardon My French: Captain Haddock and the Suff erings of the Savoyards
Authors: Öhrström Lars
Published: November 2020

Spending time in the European Alps means, especially in the tourist season, being constantly reminded of both the heroism and suffering brought about by this magnificent landscape. The bookshops of Grenoble all have prominent displays of the exploits and adventures of living and prematurely killed Alpinists, and on the radio you can but wait for the news of this year’s first deaths on the slopes of Mont Blanc—at 15,782 feet (4,810 metres) the highest mountain peak in Europe. But this landscape used to be cruel in a more sinister and hidden way, invisible to the naked eye. Not before certain experiments were made on seaweeds gathered on the Normandy beaches could we begin to understand and deal with the cause of the terrible sights and encounters Swiss Alpinist pioneer Horace-Bénédict de Saussure had in a small remote village near Aosta in the Piedmont in present-day Italy. Saussure, a young professor at the university of Geneva, was out on one of his numerous hikes in the western Alps, nowadays part of Switzerland, Italy, and France, but then largely under the jurisdiction of the Kingdom of Sardinia. On this summer’s day in 1768 he came upon a small village and naturally wanted to know where he was, so he asked the first man he met on the way into the village, but got no reply. With one person, that could have been a language problem, or a general distrust towards suspicious strangers (entering a small café in a remote village and registering everyone inside going completely silent does not mean they have all simultaneously developed a speech disorder). However, as he got further into the village and still got no more than inarticulate grunts from the second and third person as well, he began to wonder what was going on. Closer to the village centre he saw a disquieting number of men and women with enormous goitres, fat lips, perpetually halfopen mouths, and blank expressions, and was terrified. As he recalls in the second volume of the first serious description of this region, Voyage dans les Alpes, ‘It was as if an evil spirit had transformed every inhabitant into a dumb animal, leaving only the human form to show that they had once been men’.
Descriptive Psychopathology
Authors: Summerfield Julian , Yousif Michael
Published: November 2020

Psychopathology is ‘the systematic study of abnormal experience, cog­nition and behaviour; the study of the products of a disordered mind’ (Sims, 2002). Descriptive psychopathology refers to a particular approach to the assessment and understanding of the signs and symptoms of men­tal disorder and forms the basis of clinical psychiatry. The term descriptive in this context refers to a necessarily value- and theory-free interpreta­tion of the mental and behavioural phenomena a patient presents with. For students of medicine and psychiatry, it is essential to understand the significance of this and the rationale behind it. Psychiatry is unique among the medical specialties in that there are few objective clinical signs and no biomarkers (at least in vivo) which indicate the presence or otherwise of specific mental disorders. Contrast this with bodily disorders whose features are physical and objective; they lend themselves to being measurable, quantifiable, and therefore reliable to assess. Features of mental disorders present through behaviour and experience (thoughts, feelings, perceptions); they are internal and essen­tially subjective. This renders psychopathological phenomena elusive to clinical assessment in the way physical disorders are, leaving psychiatry in somewhat of a quandary; how to establish a reliable and valid system of assessing subjective phenomena? Furthermore, there needs to be a safeguard against the undue influence of bias caused by personal value judgements when interpreting subjective phenomenon. A chest X-ray showing a lobe consolidation or a blood test showing anaemia is open to far less interpretation than a person complaining of low mood or hearing voices. A further challenge in addition to that posed by the subjective nature of psychopathological phenomena is that of the absence of established aetiological mechanisms of mental disorders. Whether they are caused by physical changes in the brain or are social phenomena caused by experience (or some combination) remains contentious. Indeed, this debate continues to strike at the very concept of mental disorder. Therefore, clinical assessment of a person presenting with mental disorder must enable accessing and understanding the patient’s inner world; it must be based on a system that is value-free so as to avoid the undue influence of the personal beliefs of the clinician; and it obvi­ously cannot be reliant on thus-far absent aetiology.
Child and Adolescent Psychiatry
Authors: Morganstein Louise , Hill Jonathan
Published: November 2020

Child and adolescent psychiatry is the medical specialty that works with children, young people, and families with emotional and behavioural problems. As children and young people are still developing and grow­ing, their emotional wellbeing and functioning needs to be thought about in this context, making it different from adult psychiatry. Communication with people of all ages is vital within the specialty and information from a wide variety of sources, including parents or carers, school, and peers, is used to inform the clinical picture, in addition to history-taking and direct observations of the child’s behaviour. Play is often used to understand younger children’s thoughts and feelings. In theory, the specialty covers children and young people from birth up to the teenage years, although different services cover slightly different age ranges. The spectrum of difficulties covered within the specialty include psy­chiatric disorders also seen in adults (such as psychosis); problems spe­cific to the age group (such as separation anxiety); lifelong conditions which start in childhood (such as ADHD); and conditions that may pre­sent in different ways in childhood or adolescence (such as phobias). Approaches to treatment include psychopharmacological interven­tions, and numerous therapeutic modalities including family therapy and CBT, which can be modified for different age groups. Most work is community based, although there are specialist inpatient units which offer on-going educational opportunities to young people who need the intensive support and risk reduction of a hospital admission. Work tends to be done within MDTs using a range of knowledge and expertise to offer the most appropriate care.
Phasing in Crystallography
Authors: Giacovazzo Carmelo
Published: November 2020

Modern crystallographic methods originate from the synergy of two main research streams, the small-molecule and the macro-molecular streams. The first stream was able to definitively solve the phase problem for molecules up to 200 atoms in the asymmetric unit. The achievements obtained by the macromolecular stream are also impressive. A huge number of protein structures have been deposited in the Protein Data Bank. The solution of them is no longer reserved to an elite group of scientists, but may be attained in a large number of laboratories around the world, even by young scientists. New probabilistic approaches have been tailored to deal with larger structures, errors in the experimental data, and modest data resolution. Traditional phasing techniques like ab initio, molecular replacement, isomorphous replacement, and anomalous dispersion techniques have been revisited. The new approaches have been implemented in robust phasing programs, which have been organized in automatic pipelines usable even by non-experts. Protein structures, which 50 years ago could take months or even years to solve, can now be solved in a matter of hours, partly also due to technological advances in computer science. This book describes all modern crystallographic phasing methods, and introduces a new rational classification of them. A didactic approach is used, with the techniques described simply and logically in the main text, and further mathematical details confined to the Appendices for motivated readers. Numerous figures and applicative details illustrate the text.
Overview of the OSCE Station
Authors: Creed Fiona
Published: November 2020

Student health care practitioners are often apprehensive about simulated examinations as they have never undertaken an examination like this before and often do not know what to expect. The purpose of the chapter is to explore the OSCE process and help you to understand and plan for your own OSCE. OSCE examinations may be organized very differently depending upon the subject of the examination and your own university’s preference. Most simulated examinations are held in clinical skills rooms or simulation suites at the student’s university campus. Very occasionally they may be held off site at another location, e.g. a hospital teaching room. The examination structure may vary dramatically (Bloomfield et al. 2010) and may be: ● Multiple short stations, ● Complex single stations, ● Unmanned station. These are also known as ‘short case’ OSCE stations. A typical short station OSCE will involve the student health care practitioner ‘rotating’ around a number of different stations. It is likely that within each examination room several skills will be assessed at any one time and part of the assessment will involve moving from station to station to ensure that students complete all skills/knowledge assessments that are required. This format allows examiners to assess a range of skills during one simulated examination period (Ahuja 2009). The number of stations will depend upon the university’s examination structure but it may be that there are up to five stations to attend. Some universities ask students to rotate around more than this (in some occasions up to 20). This type of OSCE is very common in pre-registration nursing OSCEs (Bloomfield et al. 2010). Simulated examinations may be held in one room or students may be required to move from room to room to ensure all skills are assessed. This type of OSCE is usually used to examine the more complex skills and may be used in the final year to test more complicated skills such as assessment of the sick patient. You should be aware that you may also be asked to undertake OSCE in your post-registration nurse education.
Reactions
Authors: Atkins Peter
Published: November 2020

Illustrated with remarkable new full-color images--indeed, one or more on every page--and written by one of the world's leading authorities on the subject, Reactions offers a compact, pain-free tour of the inner workings of chemistry. Reactions begins with the chemical formula almost everyone knows--the formula for water, H2O--a molecule with an "almost laughably simple chemical composition." But Atkins shows that water is also rather miraculous--it is the only substance whose solid form is less dense than its liquid (hence ice floats in water)--and incredibly central to many chemical reactions, as it is an excellent solvent, being able to dissolve gases and many solids. Moreover, Atkins tells us that water is actually chemically aggressive, and can react with and destroy the compounds dissolved in it, and he shows us what happens at the molecular level when water turns to ice--and when it melts. Moving beyond water, Atkins slowly builds up a toolkit of basic chemical processes, including precipitation (perhaps the simplest of all chemical reactions), combustion, reduction, corrosion, electrolysis, and catalysis. He then shows how these fundamental tools can be brought together in more complex processes such as photosynthesis, radical polymerization, vision, enzyme control, and synthesis. Peter Atkins is the world-renowned author of numerous best-selling chemistry textbooks for students. In this crystal-clear, attractively illustrated, and insightful volume, he provides a fantastic introductory tour--in just a few hundred colorful and lively pages - for anyone with a passing or serious interest in chemistry.
Matter Falling Out: Precipitation
Authors: Atkins Peter
Published: November 2020

I shall now introduce you to one of the simplest kinds of chemical reaction: precipitation, the falling out from solution of newly formed solid, powdery matter when two solutions are mixed together. The process is really very simple and, I have to admit, not very interesting. However, I am treating it as your first encounter with creating a different form of matter from two starting materials, so please be patient as there are much more interesting processes to come. I would like you to regard it as a warming-up exercise for thinking about and visualizing chemical reactions at a molecular level. Not much is going on, so the steps of the reaction are reasonably easy to follow. There isn’t much to do to bring about a precipitation reaction. Two soluble substances are dissolved in water, one solution is poured into the other, and—providing the starting materials are well chosen—an insoluble powdery solid immediately forms and makes the solution cloudy. For instance, a white precipitate of insoluble silver chloride, looking a bit like curdled milk, is formed when a solution of sodium chloride (common salt) is poured into a solution of silver nitrate. Now, as we shall do many times in this book, let’s imagine shrinking to the size of a molecule and watch what happens when the sodium chloride solution is poured into the silver nitrate solution. As you saw in my Preliminary remark, when solid sodium chloride dissolves in water, Na+ ions and Cl– ions are seduced by water molecules into leaving the crystals of the original solid and spreading through the solution. Silver nitrate is AgNO3; Ag denotes a silver atom, which is present as the positive ion Ag+; NO3– is a negatively charged ‘nitrate ion’, 1. Silver nitrate is soluble because the negative charge of the nitrate ion is spread over its four atoms rather than concentrated on one, 2, as it is for the chloride ion, and as a result it has rather weak interactions with the neighbouring Ag+ ions in the solid.
Back to Basics: Reduction
Authors: Atkins Peter
Published: November 2020

In its original meaning, reduction was what was done to a metal ore to obtain the metal itself: the stony ore hacked from the land was reduced to the malleable, ductile, lustrous, useful metal. Ores are commonly oxides or sulfides, so the process of reduction typically involves the removal of oxygen or sulfur. In that sense, reduction is the opposite of oxidation, which I touched on in Reaction 3. In this chapter I shall stick with the metallurgical context and examine that hugely important industrial process, the reduction of iron ore to iron at what can be regarded as the head of the steel chain. However, like oxidation, the concept of reduction has acquired a much broader meaning, as I shall touch on fleetingly in this section and reveal fully in Reaction 5. A typical iron ore is haematite, an iron oxide of composition Fe2O3 and consisting of a stack of Fe3+ and O2– ions (Figure 4.1, over the page; Fe is the symbol for iron, from the Latin ferrum). In the industrial process for the production of iron, the ‘reducing agent’, the substance that brings about reduction, is essentially carbon in the form of coke. Early furnaces used charcoal, but coke is much harder and allows for much taller columns of ore, carbon, and limestone (the last to collect impurities as slag; see Reaction 9). Reduction on this huge scale is carried out in the great blast furnaces that epitomize heavy industry and the industrial revolution, but those furnaces are little more than sophistications of the fires that first led mankind from the Bronze Age to the Iron Age about 3000 years ago. The eponymous blast of a blast furnace is a blast of air. It may seem odd to use oxygen-rich air in a process designed to remove oxygen from an ore, but it is used to oxidize the carbon to carbon monoxide and also to help ensure that the contents of the furnace do not settle to the bottom.
Two Hands Clapping: Redox Reactions
Authors: Atkins Peter
Published: November 2020

I promised in Reactions 3 and 4 to lead you to the promised land of the modern understanding of oxidation and reduction reactions. This is the section where these two great chemical rivers flow together and acquire great explanatory power and wide applicability. I have already shown that one great class of reactions, those between acids and bases (Reaction 2), takes place by the transfer of one fundamental particle, the proton. I shall now show you that oxidation and reduction reactions all take place by the transfer of another fundamental particle, in this case the proton’s cousin, the electron. Don’t be put off by the thought that in this unification of two great rivers I am embarking on a highly abstract, distant-from-reality account. All I am doing is looking for and presenting the essential step that is involved in these reactions. This is a bit like looking for the core idea of many sports, which is to get a projectile to move into a particular location, be it soccer, baseball shooting, darts, archery, or billiards. I hope you will begin to appreciate in the course of this chapter that when chemists carry out their reactions by stirring, boiling, and mixing, all they are doing is encouraging fundamental particles, in this case electrons but in Reaction 2 protons, to migrate from where they are found to where the chemist wants them to be. Industry does the same coaxing on a massive scale. My aim here is to show you that everything I discussed in Reactions 3 and 4 boils down to the consequences of the transfer of electrons from one species to another. You have already caught a glimpse of that process as we stood together perilously deep inside the blast furnace in Reaction 4 and saw that O2– ions transfer electrons to Fe3+ ions to bring about the reduction of the ore to the metal. Tighten your intellectual seat belt. I intend to develop the very sparse view that oxidation is the loss of electrons and reduction is their gain. That is the austere message to take from this chapter, but I will cloak it in velvet.
Marriage Broking: Catalysis
Authors: Atkins Peter
Published: November 2020

A ‘catalyst’ is a substance that increases the rate of a chemical reaction without itself being consumed. The Chinese characters for catalyst, which translate as ‘marriage broker’, convey the sense exactly. For instance, a huge advance in industrial chemistry was achieved early in the twentieth century when the German chemist Fritz Haber (1868–1934) found that nitrogen and hydrogen could be induced to combine to form ammonia, NH3, if the two gases were heated under pressure in the presence of iron. They hardly react at all if iron is not present. Haber’s achievement has helped to save the world, as well as contributing not a little to its destruction. Ammonia is of prime importance for the production of fertilizers, and through that application catalysis has helped to feed the world. Ammonia is also of prime importance for the manufacture of explosives, and through that application catalysis has taken away with that hand some of what the other hand has provided. The chemical industry could not function without catalysts as they enable reactions to occur at economically viable rates. They also enable some reactions to occur which in their absence would not occur at all. Catalysts are used to refine fuels, thus enabling transport. They are used in the manufacture of polymers, thus enabling the fabrication of so many of the artefacts of everyday life as well as the fabrics of fashion and furnishings. Without catalysts there would be very little of what we recognize as the familiar modern world. Our bodies also function under the control of catalysts. Biological catalysts are called enzymes, and I describe their function in Reaction 27. There are two broad classes of catalyst. A ‘heterogeneous catalyst’ is typically a solid and the reagents are liquids or gases that flow over the solid and react as they come into contact with it; this is the case with Haber’s catalyst. A ‘homogeneous catalyst’ is a gas or a substance that dissolves in a liquid reaction mixture. Anthropogenic (human-made) chorine atoms, perhaps from aerosol gases that have travelled up into the stratosphere, are homogeneous catalysts for the destruction of ozone.
Snapping Together: Condensation Polymerization
Authors: Atkins Peter
Published: November 2020

One of the most famous of all plastics is nylon. I shall use it to represent how the second type of polymers is made. There are many varieties of nylon, but it will be enough to consider just one exemplar, the one known as ‘nylon-66’. It is so called because the repeating motif is a chain of six carbon atoms, then a group of atoms that provide a link, and then another chain of six carbon atoms. The pattern C6-link-C6 is repeated indefinitely to give the ‘66’ polymer. As you will see in more detail in Reaction 27, nylon is a very primitive version of a protein-like molecule, the molecules that control all bodily process and also form claws, nails, and hair. A protein molecule has the same links but more varied combinations of carbon atoms. It is, however, an interesting point that we clad our exteriors in material that emulates our interiors. One of the molecules used to build the polymer is 1 (on the next page; note the six C atoms). As it happens, this molecule is a close relative, with four and five C atoms respectively instead of six, of the two compounds cadaverine and putrescine, with names indicate their origin and odour. Thus, not only does nylon emulate the living, but we clad ourselves in molecules akin to the odour of death. The other molecule we need is 2 (note the six C atoms again). The task of the nylon manufacturer is to link the –NH2 end of one molecule to the –COOH end of the other molecule, then doing it over and over again to grow long spindly polymer molecules. You know from Reaction 2 that NH3 is a base (a proton acceptor), so you should be able to accept that the –NH2 business end of molecule 1 is also a base. Similarly, you saw in the same discussion that –COOH is a structural motif of acetic acid, an acid (a proton donor), so you should be able to see that the business end of molecule 2 is an acid.
Zippers: Base Catalysis
Authors: Atkins Peter
Published: November 2020

A base, you should recall from Reaction 2, is the second hand clapping to the acid’s first. That is, whereas an acid is a proton donor, a base is its beneficiary as a proton acceptor. The paradigm base is a hydroxide ion, OH–, which can accept a proton and thereby become H2O. However, in the context of catalysis, the topic of this section, its role is rather different: instead of using its electrons to accept the proton, it uses them to behave as a nucleophile (Reaction 15), a searcher out of positive charge. Instead of forming a hydrogen–oxygen bond with an incoming proton, it sets the electronic fox among the electronic geese of a molecule by forming a new carbon–oxygen bond and thereby loosening the bonds to neighbouring atoms so that they can undergo rearrangement. The OH– ion in effect unzips the molecule and renders it open to further attack. Base catalysis has a lot of important applications. An ancient one is the production of soap from animal fat. To set that scene, I shall consider a simple model system, the ‘hydrolysis’ (severing apart by water) of the two components of an ester, 1 (the same compound I used in Reaction 17, a combination of acetic acid and ethanol), and then turn to soap-making itself. You saw in Reaction 17 how esters can be broken down into their components, a carboxylic acid and an alcohol, by an acid; here we see the analogous reaction in the presence of a base. To be specific, the reagent is a solution of sodium hydroxide, which provides the OH– ions that catalyse the reaction. We watch what happens when a solution of sodium hydroxide is added to an ester and the mixture is boiled. The O oxygen atoms of the ester have already ripened the molecule for nucleophilic attack by drawing some of the electron cloud away from the C atom to which they are both attached, leaving it with a partial positive charge, 2. The negatively charged OH– ion sniffs out that positive charge and jostles in to do its business.
Adding Up: Addition
Authors: Atkins Peter
Published: November 2020

Adding up, or more formally ‘addition’, is just what it says: it is the attachment of atoms to a sensitive spot on a molecule. I need to stand back for a moment and explain what I mean by a ‘sensitive spot’. You already know (from Reaction 13) that some atoms are held to each other by an electron cloud (a ‘single bond’) and others by a doubly dense cloud (a ‘double bond’). There is a third type in which the atoms are held together by an even denser, triply dense cloud of electrons, forming a ‘triple bond’. Here I am concerned with the latter two types of bond, the so-called ‘multiple bonds’. These are the sensitive spots of organic molecules for it is quite easy to attack a multiple bond, rearrange the clouds, and attach other groups. For simplicity, I shall deal only with the more common type of multiply bonded molecule, one with a double bond. A double bond is a region rich in electrons, so you should suspect that any missile that will attack it will be an electrophile (a seeker-out of negative charge, of electron richness, Reaction 16). I shall consider a very simple case: the addition of bromine to cyclohexene, 1. As we have seen in Reaction 15, the presence of a bromine atom, Br, in a molecule is often the starting point for building on other groups of atoms, so this is an important reaction in a chain that might be used to construct something useful, such as a pharmaceutical. Bromine is a liquid composed of Br2 molecules. Cyclohexene is a liquid composed of hexagonal benzene-like molecules but with only one double bond in each molecule. Why I have chosen this slightly elaborate molecule rather than something simpler, such as ethylene (ethene, Reaction 13), will soon become clear. Let’s shrink together down to our normal molecular size and watch what happens as the bromine is poured into the cyclohexene. We already know from Reaction 16 that a bromine molecule has a nose for negative charge, so you should not be surprised to see one homing in on the electron-rich double bond of a nearby cyclohexene molecule.
Carbon Footprints: The Wittig Reaction
Authors: Atkins Peter
Published: November 2020

As a molecular architect working on an atomic construction site you need to be able to build up the carbon skeleton of your project, not merely decorate it with foreign atoms. There are dozens of different ways of doing that, and in this and the next section I shall introduce you to just two of them to give you a taste of what is available. A secondary point is that throughout chemistry you will find reactions denoted by proper nouns, recognizing the chemists who have invented or developed them. One example is that of the ‘Wittig reaction’, which is named after the German chemist Georg Wittig (1897–1987; Nobel Prize 1979). The reaction is used to replace the oxygen atom of a CO group in a molecule by a carbon atom, so that what starts out as decoration becomes part of a growing network of carbon atoms. You need to know that phosphine, PH3, 1, the phosphorus cousin of ammonia, NH3, is a base (Reaction 2). When it accepts a proton it becomes the ion PH4+. The H atoms in that ion can be replaced with other groups of atoms. A replacement that will be of interest is when three of the H atoms have been replaced by benzene rings and the remaining H atom has been replaced by –CH3. The resulting ion is 2. In the presence of a base, such as the hydroxide ion, OH–, the –CH3 group can be induced to release one of its protons, so the positive ion becomes the neutral molecule, 3. Note that there is a partial positive charge on the P atom and a partial negative charge on the C atom of the CH2 group. The presence of that partial negative charge suggests that the species could act as a nucleophile (Reaction 15), a seeker out of positive charge, with the CH2 group the charge-seeking head of the missile. Let’s watch what happens when 3 attacks a molecule with a CO group, specifically 4: perhaps you want to sprout a carbon chain out from the ring and intend to begin by replacing the O atom with a C atom.
Irritating Atmospheres: Atmospheric Photochemistry
Authors: Atkins Peter
Published: November 2020

The problem of photochemically generated smog begins inside internal combustion engines, where at the high temperatures within the combustion cylinders and the hot exhaust manifold nitrogen molecules and oxygen molecule combine to form nitric oxide, NO. Almost as soon as it is formed, and when the exhaust gases mingle with the atmosphere, some NO is oxidized to the pungent and chemically pugnacious brown gas nitrogen dioxide, NO2, 1. We need to watch what happens when one of these NO2 molecules is exposed to the energetic ultraviolet photons in sunlight. We see a photon strike the molecule and cause a convulsive tremor of its electron cloud. In the brief instant that the electron cloud has swarmed away from one of the bonding regions, an O atom makes its escape, leaving behind an NO molecule. We now continue to watch the liberated O atom. We see it collide with an oxygen molecule, O2, and stick to it to form ozone, O3, 2. This ozone is formed near ground level and is an irritant; ozone at stratospheric levels is a benign ultraviolet shield. Now keep your eye on the ozone molecule. In one instance we see it collide with an NO molecule, which plucks off one of ozone’s O atoms, forming NO2 and letting O3 revert to O2. Another fate awaiting NO2 is for it to react with oxygen and any unburned hydrocarbon fuel and its fragments that have escaped into the atmosphere. We can watch that happening too where the air includes surviving fragments of hydrocarbon fuel molecules. A lot of little steps are involved, and they occur at a wide range of rates. Let’s suppose that some unburned fuel escapes as ethane molecules, CH3CH3, 3. Although ethane is not present in gasoline, a CH3CH2· radical (Reaction 12) would have been formed in its combustion and then combined with an H atom in the tumult of reactions going on there. You already know that vicious little O atoms are lurking in the sunlit NO2-ridden air. We catch sight of one of their venomous acts: in a collision with an H2O molecule they extract an H atom, so forming two ·OH radicals.
Principles of surgery
Authors: Al-Alaak Asmaa
Published: November 2020

Modern surgery is possibly the most complete discipline in medicine today. It combines the need for understanding of the complete range of pathological processes that befall the human body from neoplasia and microbiological disease to degenerative and genetic related conditions. There is a need to be familiar with the latest concepts in how to monitor and manage the physiological processes of the body whilst still need­ing to understand when and how treatment, surgical and non-surgical, should be used. The modern student or trainee must be able to mas­ter all these disciplines. Integrating the understanding of basic body processes with the principles of how and when to support, prevent, or replace them forms the core of the principles of surgery. In the following sections, the questions will cover all these principles. This first chapter also covers the key points of the assessment of surgical disease by history and examination as well as how pathological processes in organ systems can affect patients coming to surgery. Lastly, every doctor needs to understand the basic facts about how surgical operations and procedures are conducted and how patients are kept safe during surgery.
Colorectal surgery
Authors: Wood James
Published: November 2020

Among the abdominal surgical specialities, colorectal surgery is, argu­ably, the most wide ranging. It spans a number of areas of practice each requiring many distinct knowledge bases. A large part of the speciality revolves around colorectal neoplasia which involves understanding of epidemiology, cell biology, and clinical genetics as well as appreciation of the major surgical presentations including some of the commoner abdominal emergencies, principles of surgical oncology, and pathology. Inflammatory bowel disease features a crossover area with medicine but all students of surgery need to understand the role of surgery in the context of advanced medical therapies including newer biological immu­nomodulatory treatments. On the other hand, functional pelvic floor dis­orders and diseases of the anal canal and rectum require understanding of anatomy and the wide range of local therapies available. This chapter will test all these areas from pathology to anatomy, prin­ciples of major surgery, and outpatient treatments.
Managing Infection
Authors: Prieto Jacqui , Kiernan Martin
Published: November 2020

This chapter addresses the fundamental nursing role and responsibility of preventing the risk of infection in all healthcare settings. Every nurse should possess the knowledge and skills to assess the risk of infection, to select and implement evidence-based strategies to prevention infection, and to review the effectiveness of these to inform any necessary changes in care. Healthcare-associated infection (HCAI) is the term used to describe an infection that arises as a result of some exposure to healthcare. Unlike the more traditional terms ‘hospital-acquired’ or ‘nosocomial’ infection, this updated term encompasses the range of settings in which healthcare is delivered and from which infections may arise. In recent years, much of the attention on HCAIs has focused on methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile (C. difficile), both of which are closely monitored in acute hospitals and in England as part of a programme of mandatory surveillance (National Audit Office, 2009). It is important to recognize that HCAIs are caused by a wide variety of microorganisms, for example Escherichia coli (E. coli), which require equal attention in clinical practice. Because the principles of infection prevention are applicable to all causes of HCAIs, this chapter focuses on these underpinning principles rather than on specific microorganisms of concern. As a nurse, you have a fundamental responsibility for minimizing the risk of infection in all healthcare settings and in the patient’s own home by understanding and applying these principles in practice. HCAI is a significant problem in all healthcare settings, although much more is known about its prevalence and incidence in hospitals than in other healthcare environments. Prevalence of HCAI is the total number of cases that occur either at a particular time (point prevalence) or over a defined period of time (period prevalence). The UK prevalence surveys, conducted in 2006, estimated that, at any one time, approximately one in eight hospital inpatients has a HCAI (Smyth et al., 2008; Reilly et al., 2008). This figure is comparable with data from inpatient populations in other countries, with reported rates ranging between 3.5% and 9.5% (e.g. European Centre for Disease Prevention and Control, 2008; Gravel et al., 2007; Wu et al., 2005).
Medicines management for nursing practice
Authors: Brack Graham , Franklin Penny , Caldwell Jill
Published: November 2020

Medicines Management for Nursing Practice: Pharmacology, Patient Safety, and Procedures is a friendly guide designed to equip pre-registration and newly qualified nurses with the medicines management knowledge and skills to provide safe patient-centred care. Balancing theory with practical advice, this accessible text covers basic pharmacology, drug calculations, key legislation and standards, and patient safety. Drawing from the most up-to-date sources of evidence and advice, including NMC and BNF guidelines, Medicines Management for Nursing Practice prepares nurses to promote their patients' safety, concordance, understanding of medicines, and wellbeing. This book takes a lively and straightforward approach to a vital set of nursing skills. Learning features such as reflection points, exercises, and further reading help readers to develop and consolidate their knowledge. Chapters on pharmacology and drug calculations take a step-by-step approach and are supported by diagrams and examples to aid understanding. Case studies relate guidelines and theories to the common practical scenarios that nurses encounter on a day-to-day basis.
Alternative Graphical Causal Models and the Identification of Direct Effects
Authors: Robins James M. , Richardson Thomas S.
Published: November 2020

The subject-specific data from either an observational or experimental study consist of a string of numbers. These numbers represent a series of empirical measurements. Calculations are performed on these strings and causal inferences are drawn. For example, an investigator might conclude that the analysis provides strong evidence for ‘‘both an indirect effect of cigarette smoking on coronary artery disease through its effect on blood pressure and a direct effect not mediated by blood pressure.’’ The nature of the relationship between the sentence expressing these causal conclusions and the statistical computer calculations performed on the strings of numbers has been obscure. Since the computer algorithms are well-defined mathematical objects, it is crucial to provide formal causal models for the English sentences expressing the investigator’s causal inferences. In this chapter we restrict ourselves to causal models that can be represented by a directed acyclic graph. There are two common approaches to the construction of causal models. The first approach posits unobserved fixed ‘potential’ or ‘counterfactual’ outcomes for each unit under different possible joint treatments or exposures. The second approach posits relationships between the population distribution of outcomes under experimental interventions (with full compliance) to the set of (conditional) distributions that would be observed under passive observation (i.e., from observational data). We will refer to the former as ‘counterfactual’ causal models and the latter as ‘agnostic’ causal models (Spirtes, Glymour, & Scheines, 1993) as the second approach is agnostic as to whether unit-specific counterfactual outcomes exist, be they fixed or stochastic. The primary difference between the two approaches is ontological: The counterfactual approach assumes that counterfactual variables exist, while the agnostic approach does not require this. In fact, the counterfactual theory logically subsumes the agnostic theory in the sense that the counterfactual approach is logically an extension of the latter approach. In particular, for a given graph the causal contrasts (i.e. parameters) that are well-defined under the agnostic approach are also well-defined under the counterfactual approach.
Statistical Methodology for a SMART Design in the Development of Adaptive Treatment Strategies
Authors: Oetting Alena I. , Levy Janet A
Published: November 2020

The past two decades have brought new pharmacotherapies as well as behavioral therapies to the field of drug-addiction treatment (Carroll & Onken, 2005; Carroll, 2005; Ling & Smith, 2002; Fiellin, Kleber, Trumble-Hejduk, McLellan, & Kosten, 2004). Despite this progress, the treatment of addiction in clinical practice often remains a matter of trial and error. Some reasons for this difficulty are as follows. First, to date, no one treatment has been found that works well for most patients; that is, patients are heterogeneous in response to any specific treatment. Second, as many authors have pointed out (McLellan, 2002; McLellan, Lewis, O’Brien, & Kleber, 2000), addiction is often a chronic condition, with symptoms waxing and waning over time. Third, relapse is common. Therefore, the clinician is faced with, first, finding a sequence of treatments that works initially to stabilize the patient and, next, deciding which types of treatments will prevent relapse in the longer term. To inform this sequential clinical decision making, adaptive treatment strategies, that is, treatment strategies shaped by individual patient characteristics or patient responses to prior treatments, have been proposed (Greenhouse, Stangl, Kupfer, & Prien, 1991; Murphy, 2003, 2005; Murphy, Lynch, Oslin, McKay, & Tenhave, 2006; Murphy, Oslin, Rush, & Zhu, 2007; Lavori & Dawson, 2000; Lavori, Dawson, & Rush, 2000; Dawson & Lavori, 2003). Here is an example of an adaptive treatment strategy for prescription opioid dependence, modeled with modifications after a trial currently in progress within the Clinical Trials Network of the National Institute on Drug Abuse (Weiss, Sharpe, & Ling, 2010). . . . Example . . . . . . First, provide all patients with a 4-week course of buprenorphine/naloxone (Bup/Nx) plus medical management (MM) plus individual drug counseling (IDC) (Fiellin, Pantalon, Schottenfeld, Gordon, & O’Connor, 1999), culminating in a taper of the Bup/Nx. If at any time during these 4 weeks the patient meets the criterion for nonresponse, a second, longer treatment with Bup/Nx (12 weeks) is provided, accompanied by MM and cognitive behavior therapy (CBT). However, if the patient remains abstinent from opioid use during those 4 weeks, that is, responds to initial treatment, provide 12 additional weeks of relapse prevention therapy (RPT). . . .