bluuebunny/crossref_metadata_2025 huggingface dataset:
Looking Ahead While Glancing Back
Authors: Marschark Marc , Lang Harry G. , Albertini John A.
Published: November 2020

In the preceding chapters, we have seen that a remarkable amount of progress has been made over the past 30 years toward understanding the impact of deafness on learning and development. Bringing together educational and research findings from diverse disciplines, we have endeavored to explain the current state of the art with regard to raising and educating deaf children, as well as some historical bases for contemporary approaches to deaf education. In describing research relating to educational foundations and teaching-learning processes, we have seen that providing parents with balanced and accurate information, continued research efforts, and professional development for teachers are vital parts of the educational futures of deaf students. At the end of each chapter, we have summarized significant findings and developments. Rather than attempting to provide an additional summary here, we reiterate some of the general themes of this book and the major implications for parents, teachers, and others involved in educating deaf students. Probably the most general and salient theme of this book is that the deaf learner should not be viewed as a hearing learner who cannot hear. It is often tempting, for reasons of either perceived equity or for expedience in the classroom, to assume that deaf and hearing children are the same. As we have seen, deaf and hearing children have different backgrounds, experiences, communication histories, and knowledge. To optimize the educational opportunities of deaf learners, we need to develop instructional materials, teaching strategies, and learning environments that take advantage of their strengths while compensating for their special needs. This means that treating deaf children the same as hearing children may be doing them a great disservice. At a minimum, we should resist superficial modifications to educational settings so that deaf children can share classrooms with hearing children when the fundamental needs of all involved have not been considered. A recurring finding across language, social, and academic domains is that early intervention for deaf children and their families is critical. Such programs do more than just support the development of communication and language—they provide deaf children with similar peers, role models, and contexts that promote early development.
Zoogeography
Authors: Meserve Peter L.
Published: November 2020

South America forms the greater part of the Neotropical faunal realm, which extends northward through Central America to tropical southern Mexico. Although making up only 12% of the world’s land area, South America is the richest continent for virtually all organismal groups, including vertebrates. For example, of the known 23,250 species of fish (Eschmeyer, 1998), 41% or 9,530 species are freshwater, and of these, more than 2,800 species (29%) are in South America (Moyle and Cech, 2000). A comparable level of diversity exists for amphibians and birds. Of Earth’s 5,900 species of amphibians, at least 1,749 or 30% occur in South America (Duellman, 1999a, 1999b; Köhler et al., 2005; www.amphibiaweb.org). More than 3,200 (or nearly 32%) of Earth’s 9,900 species of birds occur in South America (Sibley and Monroe, 1990). For reptiles and mammals, diversity is only slightly lower; at least 1,560 (19%) of 8,240 reptile species (Uetz and Etzold, 1996; www.reptiledatabase. org), and 1,037 (19%) of 5,416 mammal species (Nowak, 1999; Wilson and Reeder, 2005) are found in South America. Four major geological events or features are important to understanding South America’s contemporary zoogeography. The first was the breakup of Pangea, and then of Gondwana. South America and Africa remained close for an extended period of the Mesozoic, and thus share important similarities in their faunas, including groups not fully evolved at the time of separation. South America also maintained connections to other Gondwanan continents, directly with Antarctica, indirectly with Australia, until the early Cenozoic. The second major feature was South America’s long period of isolation in the Cenozoic, particularly from North America pending establishment of the late Pliocene land bridge after 3 Ma (million years before present). The latter resulted in “The Great American Interchange” (Webb, 1976; Marshall et al., 1982), which had profound consequences for the fauna. The third major feature of South America has been the Andes, which, in addition to modifying climate, have been a center of speciation, a dispersal route, and a barrier. The cordillera has had an overriding effect on distributions and histories of both past and current biotas on the continent.
Pre-European Human Impacts on Tropical Lowland Environments
Authors: Denevan William M.
Published: November 2020

The topic of early human impacts on New World environments, including Amazonia, is controversial as to degree and extent (Balée, 1989; Cleary, 2001; Denevan, 1992b; Gómez-Pompa and Kaus, 1992; Hayashida, 2005; Krech, 1999; Stahl, 1996; Vale, 2002). Certainly, whenever and wherever people were present, even sparse populations, there was some change in the landscape. People cannot live on the land and use plants and animals for subsistence and other needs without changing that land and the plants and animals present. Human-induced changes may involve equilibrium in which the natural ecosystem basically recovers, even though composition is changed, or in which the human ecosystem is sustainable; or the changes may involve disequilibrium in which the regenerative capacities (i.e., biological diversity and productivity) of either system are retarded or destroyed (i.e., degradation) (Sponsel, 1992). These changes may have been intentional or not, ephemeral or long lasting, localized or regional, onetime events or cumulative, highly visible or not readily apparent. Vegetation is the most widespread focus of change; other impacts have been on wildlife, soil, river patterns, microclimate, and the land surface itself. The forces of change are settlement, cultivation, grazing, hunting and gathering (foraging), burning, and various earthworks and river works. All of these impacts and forces were present in pre- European South America. Furthermore, native people “recognize that human beings, past and present . . . have affected the distribution of the biota and the formation of the landscape” (Balée, 2003: 285–286). “Far from being a wild world . . . the forest is perceived as a superhuman garden” by the Achuar in Ecuador (Descola, 1994: 324). Lacking written records, it is difficult to reconstruct early indigenous impacts, and any attempt to do so involves speculation and inference. Some alterations have persisted to the present, but most have been masked by either landscape recovery or by human destruction. Furthermore, nature and culture merge, the dichotomy being artificial, conceptual (Descola, 1994: 1–6). And some human disturbances that seem old are actually recent, but the reverse is also true. The distinction may be difficult to ascertain.
Agriculture and Soil Erosion
Authors: Harden Carol P. , Hyman Glenn G.
Published: November 2020

People have manipulated the natural environments of South America for agricultural purposes for several millennia. While agriculture is strongly affected by the physical attributes of a place—soil, water, climate, biota, and topography—agriculture changes a landscape’s physical and biological characteristics and processes. Agriculture may involve short- and long-term conversion of forest to cropland and pasture, modification of topography and drainage, and the introduction and propagation of exotic species. Soil erosion, much of which is caused by agriculture, is a major concern in South America. This chapter introduces the patterns of agriculture in South America and examines agricultural trends. It then reviews the causes and consequences of soil erosion at continental to local scales, providing examples from research conducted across the continent. As population grows and demand for agricultural production increases, knowledge of the physical geography of soil erosion will be even more critical for the sustainability of agriculture in South America. Agriculture is broadly defined here to encompass annual and permanent crops, tree crops, and livestock. Agricultural patterns of South America today reflect great differences in the continent’s natural environments. They also reflect the influence of international and global markets, the impacts of national policies, and the imprints of preand post-colonial settlement patterns, preferred species, and cultural preferences. The wide range of climates in South America allows a great variety of temperate and tropical fruits, vegetables, and grains to flourish. Historically, the diverse agricultural capabilities of different parts of the continent have been fundamental influences in the development of pre- and post-colonial human habitation and economic patterns (U.S. Agency for International Development, 1993; see chapters 16 and 17). At the continental scale, agriculture occurs across almost all regions of South America. It is notably absent only in the Gran Chaco, rugged portions of the high Andes, and desert landscapes along the Pacific coast of northern Chile and southern Perú. In practice, there is little cropland in sparsely populated regions, especially in the Amazon basin, and in densely populated urban areas, even where the lands and climates of those places are capable of supporting agriculture.
Impacts of El Niño-Southern Oscillation on Natural and Human Systems
Authors: Caviedes César N.
Published: November 2020

Off the coasts of northern Perú and southern Ecuador, warm equatorial waters meet the cold Humboldt Current. Variations in sea temperatures and associated fauna have been known to fishing folk since colonial times. They noticed that toward the end of every year tepid waters appeared between the Gulf of Guayaquil (Ecuador) and Point Pariñas (Perú) and persisted until late February, causing tropical species to be added to the fish they commonly caught. Coupled with the arrival of warm waters was a surge in air humidity and an increase in summer showers. Since this environmental phenomenon occurred around Christmas, the local fishermen called it El Niño, or Child Jesus. Early scientific observations on the nature and extent of these phenomena revealed that they were not regionally restricted to coastal Perú and Ecuador, but extended over the whole tropical Pacific, involving pressure fields and wind flows across the basin. Thus, when referring to this coupled ocean-atmospheric system, both variations of sea temperature across the tropical Pacific and changes of the atmosphere in contact with the ocean must be considered (Neelin et al., 1998). Normally, the tropical Pacific Ocean, from the coast of Ecuador and Perú to longitude 120°W, is dominated by westward- flowing cold waters, which are the prolongation of the Humboldt Current. Near longitude 120°W, sea surface temperatures approach normal equatorial values of ~28°C. When the flow reaches the western Pacific, it creates a sealevel rise of nearly 40 cm, which is maintained by the wind shear of the equatorial easterlies. The thermocline, which marks the lower boundary of the sun-heated water layer, runs at a depth of 40 m between Perú and the Galápagos Islands, but on the Asian side of the Pacific it dips to 120 m, revealing a marked asymmetry in the thickness of the sunheated layer across the Pacific. During El Niño years, the westward flow of cooler waters is weak because there is less wind shear from the easterly winds, and the thermocline plunges to 80 m in the eastern equatorial Pacific.
The Great Sea
Authors: Abulafia David
Published: November 2020

Connecting Europe, Asia, and Africa, the Mediterranean Sea has been for millennia the place where religions, economies, and political systems met, clashed, influenced and absorbed one another. In this brilliant and expansive book, David Abulafia offers a fresh perspective by focusing on the sea itself: its practical importance for transport and sustenance; its dynamic role in the rise and fall of empires; and the remarkable cast of characters-sailors, merchants, migrants, pirates, pilgrims-who have crossed and re-crossed it. Ranging from prehistory to the 21st century, The Great Sea is above all a history of human interaction. Interweaving major political and naval developments with the ebb and flow of trade, Abulafia explores how commercial competition in the Mediterranean created both rivalries and partnerships, with merchants acting as intermediaries between cultures, trading goods that were as exotic on one side of the sea as they were commonplace on the other. He stresses the remarkable ability of Mediterranean cultures to uphold the civilizing ideal of convivencia, "living together." Now available in paperback, The Great Sea is the definitive account of perhaps the most vibrant theater of human interaction in history.
Dis-integration, 400–600
Authors: Abulafia David
Published: November 2020

Ever since Edward Gibbon wrote his Decline and Fall of the Roman Empire the question why, when and indeed whether this great Roman Empire fell has been vigorously pursued by historians. It has been observed that at least 210 explanations have been offered, some frankly ridiculous (‘Semitization’, homosexuality, decline in manliness). The argument that it was the barbarian invasions that destroyed Rome – both the city and its empire – lost favour and has returned to favour. Some historians have insisted that the whole concept of the ‘fall of Rome’ is a misconception, and have emphasized the continuity of the Roman inheritance. Yet from a Mediterranean perspective, it is abundantly clear that the unity of the Great Sea had been shattered by 800. That leaves several centuries in which to place the process of disintegration, and several suspects: the Germanic barbarians in the fifth century and after, the Arab conquerors in the seventh century, Charlemagne and his Frankish armies in the eighth century, not to mention internal strife as Roman generals competed for power, either seeking regional dominions or the crown of the empire itself. Evidently there was no single ‘cause’ for the decline of Rome, and it was precisely the accumulation of dozens of problems that brought the old order to an end, rupturing the ‘Second Mediterranean’. During the long period from 400 to 800, the Mediterranean split apart economically and also politically: the Roman emperors saw that the task of governing the Mediterranean lands and vast tracts of Europe west of the Rhine and south of the Danube exceeded the capacity of one man. Diocletian, ruling from 284 onwards, based himself in the east at Nikomedeia, and entrusted the government of the empire to a team of co-emperors, first another ‘Augustus’ in the west, and then, from 293 to 305, two deputies or ‘Caesars’ as well, a system known as the Tetrarchy.
The Fall and Rise of Empires, 1130–1260
Authors: Abulafia David
Published: November 2020

The fleets of Pisa, Genoa and Venice were not the only navies that plied Italian waters. The conquest of Sicily by Roger I, the ‘Great Count’, was complete by 1091. Under Norman rule, the island flourished: Messina attracted Latin merchants, acting as a staging-post on the trade routes linking Genoa and Pisa to Acre and Alexandria; ibn Jubayr called it ‘the mart of the merchant infidels, the focus of ships from the world over’, and noted that it was a great arsenal, where the Sicilian fleet was constructed. The ruler reserved to his own use much of the pitch, iron and steel produced in his lands, for it was vital to control the raw materials required for ship construction. Roger I’s ruthless and talented son Roger II gained control of large tracts of southern Italy ruled by his cousins; no less importantly, he obtained the newly created crown of Sicily from the pope in 1130. He was a man of Mediterranean ambitions, seeing himself as the successor to the Greek tyrants and arguing that he was not a usurper but the reviver of an ancient kingdom. He appeared in public in Byzantine imperial costume or in the robes of an Arab emir. He decorated his palace chapel with the finest Greek mosaics and a superb wooden roof, the work of Arab craftsmen. He commissioned from Idrisi, a refugee prince from Ceuta, a geography of the world that enabled him (with its accompanying map) to contemplate the Mediterranean and the world beyond in extraordinary detail. Propaganda was matched by action. In 1147–8, at the time of the Second Crusade, he turned his attention to the Byzantine Empire. The crusade was summoned by the pope in 1147, following the fall to the Muslims of the crusader principality of Edessa in northern Syria; Roger offered his fleet, but under pressure from his enemy the German ruler, Conrad III, the offer was rejected. Roger had other uses for his fleet. In 1148 he took advantage of the fact that Manuel Komnenos, the Byzantine emperor, was distracted by the passage of the armies of the Second Crusade through his lands.
Merchants, Mercenaries and Missionaries, 1220–1300
Authors: Abulafia David
Published: November 2020

The collapse of empires in the central and eastern Mediterranean was matched in the far west by the disintegration of Almohad power. The caliphs lost their enthusiasm for the extremist doctrines of Almohadism, and were accused of betraying the principles of their movement. Following military defeat at the hands of Christian kings of Spain at Las Navas de Tolosa in 1212 the caliph is said to have been strangled by one of his slaves. The Almohad territories in Spain and Tunisia fell into the hands of a new generation of local kings who only paid lip-service to Almohadism. The Hafsid rulers who gained control of Tunis proclaimed themselves successors to the Almohad caliphate, though more as a way of asserting their legitimacy than out of deep commitment to Almohad beliefs. The Berber Marinids broke Almohad power in Morocco in the mid-thirteenth century, after a long struggle. At the same time the Nasrid dynasty established itself in Granada, where it would last until 1492; it adhered strictly to Sunni Islam, not Almohadism. The thirteenth century also saw a major transformation in the Christian western Mediterranean: Pisa’s rivalry with Genoa for mastery over the waters around Corsica and Sardinia culminated in Pisan defeat at the battle of Meloria and the loss of iron-rich Elba in 1284. Although the Pisans did not yet lose control of the large areas of Sardinia they ruled, and even recovered Elba, a new rival to both Pisa and Genoa emerged, not a maritime republic but a group of cities led by Barcelona and backed by the growing power of the king of Aragon and count of Catalonia, James I ‘the Conqueror’. The Mediterranean vocation of the kings of Aragon was not obvious before the thirteenth century. Lords of a small, mountainous kingdom that only toppled the Muslim emirate of Saragossa in 1118, they dissipated much of their energy in attempts to interfere in Christian Castile and Navarre. But in 1134 King Alfonso ‘the Battler’ of Aragon died, having failed to produce an heir; his brother, a monk, was forced out of his convent in order to breed.
Mare Nostrum – Again, 1918–1945
Authors: Abulafia David
Published: November 2020

While most naval action within the Mediterranean during the First World War took place in the east and in the Adriatic, in waters that lapped the shores of the disintegrating empires of the Ottomans and the Habsburgs, the entire Mediterranean became the setting for rivalry between 1918 and 1939. At the centre of the struggle for mastery of the Mediterranean lay the ambitions of Benito Mussolini, after he won control of Italy in 1922. His attitude to the Mediterranean wavered. At some moments he dreamed of an Italian empire that would stretch to ‘the Oceans’ and offer Italy ‘a place in the sun’; he attempted to make this dream real with the invasion of Abyssinia in 1935, which, apart from its sheer difficulty as a military campaign, was a political disaster because it lost him whatever consideration Britain and France had shown for him until then. At other times his focus was on the Mediterranean itself: Italy, he said, is ‘an island which juts into the Mediterranean’, and yet, the Fascist Grand Council ominously agreed, it was an imprisoned island: ‘the bars of this prison are Corsica, Tunisia, Malta and Cyprus. The guards of this prison are Gibraltar and Suez.’ Italian ambitions had been fed by the peace treaties at the end of the First World War. Not merely did Italy retain the Dodecanese, but the Austrians were pushed back in north-eastern Italy, and Italy acquired much of Italia irredenta, ‘unredeemed Italy’, in the form of Trieste, Istria and, along the Dalmatian coast, Zara (Zadar), which became famous for the excellent cherry brandy produced by the Luxardo family. Fiume (Rijeka) in Istria was seized by the rag-tag private army of the nationalist poet d’Annunzio in 1919, who declared it the seat of the ‘Italian Regency of Carnaro’; despite international opposition, by 1924 Fascist Italy had incorporated it into the fatherland. One strange manifestation, which reveals how important the past was to the Fascist dream, was the creation of institutes to promote the serious study (and italianità, ‘Italianness’) of Corsican, Maltese and Dalmatian history.
A Fragmented Mediterranean, 1945–1990
Authors: Abulafia David
Published: November 2020

The Allied victory over Germany in the Second World War, like that in the First, left the Mediterranean unsettled. After Greece emerged from its civil war with a pro-western government, there were ever louder rumbles in Cyprus, where the movement calling for enôsis, union with Greece, was gathering pace again. Precisely because the Greeks sided with the West, and because Turkey had kept out of the war, during the late 1940s the United States began to see the Mediterranean as an advance position in the new struggle against the expanding power of the Soviet Union. The explicit theme was the defence of democracy against Communist tyranny. Stalin’s realism had prevented him from supporting Communist insurgency in Greece, but he was keen to find ways of gaining free access to the Mediterranean through the Dardanelles. In London and Washington, the fear that Soviet allies would establish themselves on the shores of the Mediterranean remained real, since the partisan leader in Yugoslavia, Tito, had played the right cards during the last stages of the war, even winning support from the British. Moreover, the Italians had lost Zadar along with the naval base at Kotor and chunks of Dalmatia they had greedily acquired during the war, while Albania, after an agonizing period of first Italian and then German occupation, had recovered its independence under the Paris-educated Communist leader Enver Hoxha, whose uncompromising stance was to bring his country into ever-greater isolation. When he took power, Hoxha imagined that his country would form part of a brotherly band of socialist nations, alongside Tito’s renascent Yugoslavia and the Soviet Union. Close ties with the Yugoslavs were sealed by economic pacts which reveal Tito’s hope of drawing Albania into the Yugoslav federation. Hoxha had other aspirations, and in his view Albania’s right to defend every square inch of the national territory extended into the waters off the Albanian coast: the Corfu Channel, long used as a waterway linking Greece to the Adriatic, was mined to prevent foreign incursions. Britain decided to send warships through the channel, asserting its right to police the Mediterranean on behalf of the nations of the world.
Eye Movement Disorders
Authors: Wong Agnes
Published: November 2020

Eye Movement Disorders, by Dr. Agnes Wong, fills a great void in the Ophthalmology and Neurology literature by presenting eye movement disorders in a full-color, highly illustrative format. This text explains eye movement disorders in a concise yet comprehensive manner, which makes it an excellent reference book and an outstanding learning text for anyone trying to master the intricate relationship between eye movement disorders, and their underlying neuroanatomy and pathophysiology. Its easy-to-read and user-friendly approach will appeal to specialists in Ophthalmology, Neurology, and Neurosurgery who need a rapid reference on less familiar clinical problems. Key features include: Provides a coherent, concise, and easy to assimilate description and explanation of different eye movement disorders Presents over 100 full-color clinical photographs, radiographs, and color illustrations highlighting pertinent anatomy and brain pathways Highlights key information and important features through boxes, tables, and algorithms
Introduction
Authors: Crane Hewitt , Kinderman Edwin , Malhotra Ripudaman
Published: November 2020

Energy is central to our existence and our way of life. We use it in virtually all aspects of life: manufacturing the myriads of goods that we have come to depend on, growing our food, transporting goods and people, controlling our environment, communicating with one another, entertaining ourselves, and the list goes on. By and large, the standard of living of a society is directly linked to its energy consumption. Indeed, today’s technological society can be described, quite literally, as “turning oil into everything else that we eat or use.” Energy use is so pervasive that we often fail to recognize its role and are only reminded of our dependence on it when for some reason or another there is a shortage. To be sure, such reminders have occurred and will occur every so often. However, the shortages we have overcome thus far are very minor compared with what may lie ahead. With ever increasing numbers of people and nations striving to improve their standard of living, the demand for energy is soaring. At the same time, traditional sources of energy are being depleted, and even their current level of use poses a serious threat of global climate change. How are we going to provide the vast amounts of energy that we will need or desire in the future? That is the central question that this book addresses. Effective resolution of any major societal issue requires easy access to reliable and relevant information. When an issue is not only complex and multifaceted but also essential to maintaining the very fabric of the society, a lack of comprehensible information makes the public’s role and government leadership less effective, and appropriate solutions become more difficult to implement. This is the situation today with global energy—arguably the world’s largest industry and one central to all our lives. On the one hand, the public is generally unaware that a pervasive, long-term problem exists and that the world is facing a complex and potentially perilous, perhaps even revolutionary, future.
Ophthalmoscopy
Authors: Brinton Daniel A. , Wilkinson Charles P.
Published: November 2020

Indirect viewing systems, including the binocular indirect ophthalmoscope and slit lamp biomicroscopy through an indirect lens, have become the standard of care for management of retinal detachments. Comparison with direct ophthalmoscopy illustrates the capabilities of indirect systems. The technique of indirect ophthalmoscopy with scleral depression is presente The characteristics of direct and indirect ophthalmoscopy are compared in Table 3–1. Figure 3–1A shows the optical principles of direct ophthalmoscopy, and Figure 3–1B illustrates the optics of the indirect method. Substantial clinical differences between the two methods are due to the differences in optical characteristics. The direct ophthalmoscope offers 14X magnification compared with 3X with the indirect using the usual +20 diopter lens. However, this does not mean the direct device has an equal advantage in resolution. Resolution is a function of how close together two points can be and remain distinguished as separate when viewed through an optical system. The visualization of detail that an optical system permits is a function of its resolving power and not its magnifi cation. Resolution is a function of the light available at the points to be resolved and of the quality of the optical components of the system. Magnification plays a role only if the resolution of the optical system exceeds the resolution of the observing human eye at a given level of magnification. Too much magnification of a poorly resolved image results in a loss of detail, such as if one were to examine a halftone newspaper photograph under a microscope. With the direct method, the greater the degree of myopia, the higher the magnification of the fundus image and the smaller the field of view. In very high myopes, the field of view with the direct instrument becomes very limited. High cylindric errors strongly and adversely affect the image of direct ophthalmoscopy because the high magnification of the system also magnifies the effects of refractive errors on the image. With the indirect method, the lower magnification minimizes this effect. Furthermore, the condensing lens can be tilted slightly to overcome astigmatic aberrations. Examination of the retinal periphery entails the travel of light obliquely through the cornea and lens, introducing cylindrical aberrations that are likewise problematic with the direct ophthalmoscope and easily overcome with the indirect.
Prevention of Retinal Detachment
Authors: Brinton Daniel A. , Wilkinson Charles P.
Published: November 2020

Retinal detachment is an uncommon disease, affecting approximately 1 in 10,000 people in the general population per year. However, the incidence of retinal breaks is relatively high, affecting 5% to 7% of the population. Obviously, many retinal breaks have minimal, if any, risk for the possible development of a retinal detachment. This includes macular holes that occur as a degenerative process, and asymptomatic, small, round atrophic holes near the ora serrata. However, equatorial horseshoe tears with relevant symptoms progress to retinal detachment in most cases. Probably all surgeons would agree that a large horseshoe tear near the equator in the superior temporal quadrant, with new-onset symptoms of fl ashes and fl oaters and associated vitreous hemorrhage, should be treated prophylactically to avoid retinal detachment. In contrast, most would not advise treatment of a small, round atrophic hole near the inferior ora serrata in an asymptomatic patient with no history of prior detachment. Between these two obvious examples lies a broad spectrum of retinal breaks for which the surgeon must exercise judgment about instituting prophylactic treatment. Most of the breaks reported in surveys of asymptomatic patients or in autopsy series are of the atrophic type, and only a small proportion are horseshoe tears. Although there are no specific rules for the selection of patients for treatment, and each case has to be judged on its own characteristics, the application of evidencebased medicine to this topic has modified the opinions of many regarding the genuine value of prophylactic therapy for most retinal breaks. The American Academy of Ophthalmology has used this approach in developing a Preferred Practice Pattern (PPP) entitled “Posterior Vitreous Detachment, Retinal Breaks, and Lattice Degeneration,” the latest version of which was published in 2008. The evidence base described in this PPP will be employed in the following discussion. Characteristics associated with a relatively high risk of retinal detachment in an eye with visible retinal breaks are listed in Table 6–1. Symptoms and signs of PVD place an eye at particularly high risk. Additional factors include a variety of hereditary, congenital, acquired, and iatrogenic problems.
Concluding Remarks
Authors: Lee P.J.
Published: November 2020

The procedure and steps of petroleum resource assessment involve a learning process that is characterized by an interactive loop between geological and statistical models and their feedback mechanisms. Geological models represent natural populations and are the basic units for petroleum resource evaluation. Statistical models include the superpopulation, finite population, and discovery process models that may be used for estimating the distributions for pool size and number of pools, and can be estimated from somewhat biased exploration data. Methods for assessing petroleum resources have been developed using different geological perspectives. Each of them can be applied to a specific case. When we consider using a particular method, the following aspects should be examined: • Types of data required—Some methods can only incorporate certain types of data; others can incorporate all data that are available. • Assumptions required—We must study what specific assumptions should be made and what role they play in the process of estimation. • Types of estimates—What types of estimates does the method provide (aggregate estimates vs. pool-size estimates)? Do the types of estimates fulfill our needs for economic analysis? • Feedback mechanisms—What types of feedback mechanism does the method offer? PETRIMES is based on a probabilistic framework that uses superpopulation and finite population concepts, discovery process models, and the optional use of lognormal distributions. The reasoning behind the application of discovery process models is that they offer the only known way to incorporate petroleum assessment fundamentals (i.e., realism) into the estimates. PETRIMES requires an exploration time series as basic input and can be applied to both mature and frontier petroleum resource evaluations.
Introduction
Authors: Marks II Robert J
Published: November 2020

Jean Baptiste Joseph Fourier’s powerful idea of decomposition of a signal into sinusoidal components has found application in almost every engineering and science field. An incomplete list includes acoustics [1497], array imaging [1304], audio [1290], biology [826], biomedical engineering [1109], chemistry [438, 925], chromatography [1481], communications engineering [968], control theory [764], crystallography [316, 498, 499, 716], electromagnetics [250], imaging [151], image processing [1239] including segmentation [1448], nuclear magnetic resonance (NMR) [436, 1009], optics [492, 514, 517, 1344], polymer characterization [647], physics [262], radar [154, 1510], remote sensing [84], signal processing [41, 154], structural analysis [384], spectroscopy [84, 267, 724, 1220, 1293, 1481, 1496], time series [124], velocity measurement [1448], tomography [93, 1241, 1242, 1327, 1330, 1325, 1331], weather analysis [456], and X-ray diffraction [1378], Jean Baptiste Joseph Fourier’s last name has become an adjective in the terms like Fourier series [395], Fourier transform [41, 51, 149, 154, 160, 437, 447, 926, 968, 1009, 1496], Fourier analysis [151, 379, 606, 796, 1472, 1591], Fourier theory [1485], the Fourier integral [395, 187, 1399], Fourier inversion [1325], Fourier descriptors [826], Fourier coefficients [134], Fourier spectra [624, 625] Fourier reconstruction [1330], Fourier spectrometry [84, 355], Fourier spectroscopy [1220, 1293, 1438], Fourier array imaging [1304], Fourier transform nuclear magnetic resonance (NMR) [429, 1004], Fourier vision [1448], Fourier optics [419, 517, 1343], and Fourier acoustics [1496]. Applied Fourier analysis is ubiquitous simply because of the utility of its descriptive power. It is second only to the differential equation in the modelling of physical phenomena. In contrast with other linear transforms, the Fourier transform has a number of physical manifestations. Here is a short list of everyday occurrences as seen through the lens of the Fourier paradigm. • Diffracting coherent waves in sonar and optics in the far field are given by the two dimensional Fourier transform of the diffracting aperture. Remarkably, in free space, the physics of spreading light naturally forms a two dimensional Fourier transform. • The sampling theorem, born of Fourier analysis, tells us how fast to sample an audio waveform to make a discrete time CD or an image to make a DVD.
Multidimensional Signal Analysis
Authors: Marks II Robert J
Published: November 2020

N dimensional signals are characterized as values in an N dimensional space. Each point in the space is assigned a value, possibly complex. Each dimension in the space can be discrete, continuous, or on a time scale. A black and white movie can be modelled as a three dimensional signal.Acolor picture can be modelled as three signals in two dimensions, one each, for example, for red, green and blue. This chapter explores Fourier characterization of different types of multidimensional signals and corresponding applications. Some signal characterizations are straightforward extensions of their one dimensional counterparts. Others, even in two dimensions, have properties not found in one dimensional signals. We are fortunate to be able to visualize structures in two, three, and sometimes four dimensions. It assists in the intuitive generalization of properties to higher dimensions. Fourier characterization of multidimensional signals allows straightforward modelling of reconstruction of images from their tomographic projections. Doing so is the foundation of certain medical and industrial imaging, including CAT (for computed axial tomography) scans. Multidimensional Fourier series are based on models found in nature in periodically replicated crystal Bravais lattices [987, 1188]. As is one dimension, the Fourier series components can be found from sampling the Fourier transform of a single period of the periodic signal. The multidimensional cosine transform, a relative of the Fourier transform, is used in image compression such as JPG images. Multidimensional signals can be filtered. The McClellan transform is a powerful method for the design of multidimensional filters, including generalization of the large catalog of zero phase one dimensional FIR filters into higher dimensions. As in one dimension, the multidimensional sampling theorem is the Fourier dual of the Fourier series. Unlike one dimension, sampling can be performed at the Nyquist density with a resulting dependency among sample values. This property can be used to reduce the sampling density of certain images below that of Nyquist, or to restore lost samples from those remaining. Multidimensional signal and image analysis is also the topic of Chapter 9 on time frequency representations, and Chapter 11 where POCS is applied signals in higher dimensions.
Signal Recovery
Authors: Marks II Robert J
Published: November 2020

The literature on the recovery of signals and images is vast (e.g., [23, 110, 112, 257, 391, 439, 791, 795, 933, 934, 937, 945, 956, 1104, 1324, 1494, 1495, 1551]). In this Chapter, the specific problem of recovering lost signal intervals from the remaining known portion of the signal is considered. Signal recovery is also a topic of Chapter 11 on POCS. To this point, sampling has been discrete. Bandlimited signals, we will show, can also be recovered from continuous samples. Our definition of continuous sampling is best presented by illustration.Asignal, f (t), is shown in Figure 10.1a, along with some possible continuous samples. Regaining f (t) from knowledge of ge(t) = f (t)Π(t/T) in Figure 10.1b is the extrapolation problem which has applications in a number of fields. In optics, for example, extrapolation in the frequency domain is termed super resolution [2, 40, 367, 444, 500, 523, 641, 720, 864, 1016, 1099, 1117]. Reconstructing f (t) from its tails [i.e., gi(t) = f (t){1 − Π(t/T)}] is the interval interpolation problem. Prediction, shown in Figure 10.1d, is the problem of recovering a signal with knowledge of that signal only for negative time. Lastly, illustrated in Figure 10.1e, is periodic continuous sampling. Here, the signal is known in sections periodically spaced at intervals of T. The duty cycle is α. Reconstruction of f (t) from this data includes a number of important reconstruction problems as special cases. (a) By keeping αT constant, we can approach the extrapolation problem by letting T go to ∞. (b) Redefine the origin in Figure 10.1e to be centered in a zero interval. Under the same assumption as (a), we can similarly approach the interpolation problem. (c) Redefine the origin as in (b). Then the interpolation problem can be solved by discarding data to make it periodically sampled. (d) Keep T constant and let α → 0. The result is reconstructing f (t) from discrete samples as discussed in Chapter 5. Indeed, this model has been used to derive the sampling theorem [246]. Figures 10.1b-e all illustrate continuously sampled versions of f (t).
Signal and Image Synthesis: Alternating Projections Onto Convex Sets
Authors: Marks II Robert J
Published: November 2020

Alternating projections onto convex sets (POCS) [319, 918, 1324, 1333] is a powerful tool for signal and image restoration and synthesis. The desirable properties of a reconstructed signal may be defined by a convex set of constraint parameters. Iteratively projecting onto these convex constraint sets can result in a signal which contains all desired properties. Convex signal sets are frequently encountered in practice and include the sets of bandlimited signals, duration limited signals, causal signals, signals that are the same (e.g., zero) on some given interval, bounded signals, signals of a given area and complex signals with a specified phase. POCS was initially introduced by Bregman [156] and Gubin et al. [558] and was later popularized by Youla & Webb [1550] and Sezan & Stark [1253]. POCS has been applied to such topics as acoustics [300, 1381], beamforming [426], bioinformatics [484], cellular radio control [1148], communications systems [29, 769, 1433], deconvolution and extrapolation [718, 907, 1216], diffraction [421], geophysics [4], image compression [1091, 1473], image processing [311, 321, 470, 471, 672, 736, 834, 1065, 1069, 1093, 1473, 1535, 1547, 1596], holography [880, 1381], interpolation [358, 559, 1266], neural networks [1254, 1543, 909, 913, 1039], pattern recognition [1444, 1588], optimization [598, 1359, 1435], radiotherapy [298, 814, 1385], remote sensing [1223], robotics [740], sampling theory [399, 1334, 1542], signal recovery [320, 737, 1104, 1428, 1594], speech processing [1450], superresolution [399, 633, 654, 834, 1393, 1521], television [736, 786], time-frequency analysis [1037, 1043], tomography [1103, 713, 1212, 1213, 1275, 916, 1322, 1060, 1040], video processing [560, 786, 1092], and watermarking [19, 1470]. Although signal processing applications ofPOCS use sets of signals,POCSis best visualized viewing the operations on sets of points. In this section, POCS is introduced geometrically in two and three dimensions. Such visualization of POCS is invaluable in application of the theory.
Reconstruction of the Upper Eyelid
Authors: Harold Lee H.B. , Nunery William R.
Published: November 2020

Normal physiologic mechanisms of the upper eyelid are essential for preservation of the eye. Normal function and good cosmesis usually go hand in hand, but preservation of function is the more important of the two priorities. The general considerations in choosing a reconstruction technique include the restoration of: 1. A smooth conjunctival surface to line the eyelid and protect the cornea 2. Structural support of the tarsal plate 3. A smooth, nonabrasive lid margin 4. Normal vertical eyelid movement without ptosis or lagophthalmos 5. Normal horizontal tension with normal medial and lateral canthal tendon positions To cover small defects, the conjunctival lining may be rotated or advanced. For larger defects, the lining may be replaced with a buccal mucous membrane graft or a contralateral conjunctival graft. The tarsal plate usually requires 4 mm of vertical height to provide adequate eyelid support. If the 4 mm is unavailable, it may be replaced with lower lid tarsus, a free tarsal graft from the opposite lid, a free cartilage graft, a polytetrafluoroethylene graft, or a preserved sclera graft. The eyelid margin must be free of trichiasis or surface epithelium, which might abrade the cornea. When levator function is preserved following traumatic or surgical defects of the eyelid, ptosis can usually be avoided or corrected. The levator aponeurosis separates the orbital and palpebral portions of the lacrimal gland, and lacrimal tissue should be preserved when dissecting in the lateral canthal, lateral levator, and lateral anterior orbital areas. Lagophthalmos of the upper eyelid is usually due either to adhesion of the orbital septum to the tarsal plate or to external vertical skin shortage. Proper horizontal tension can be achieved by measuring full-thickness defects while gently pulling the edges of the defect toward each other. Careful measurement reduces the risk of excessive or deficient horizontal length following reconstruction. Skin grafts in the upper eyelids should be covered with a moderate pressure dressing for 4 to 6 days to prevent buckling or subgraft hematoma. Full-thickness skin grafts are preferred to split-thickness grafts for optimal tissue match and coloration. Upper eyelid sutures may be permanent or absorbable. Most external permanent sutures are 7-0 caliber.
Management of Blepharospasm and Hemifacial Spasm
Authors: Shah Heeral , Yen Michael T.
Published: November 2020

Benign essential blepharospasm and hemifacial spasm are chronic and disabling medical conditions. Both disorders can result in uncontrollable blinking or frank spasms of the eyelids and face, which may interfere with the activities of daily living and may even render a patient functionally blind and occupationally handicapped. Often, when untreated, the eyelid and facial spasms are so emotionally unsettling that the patients become withdrawn, frustrated, and desperate. Essential blepharospasm is the most common manifestation of orofacial movement disorders. The term is used to describe a movement disorder limited to the eyelid protractors without a secondary inciting cause, and is characterized by spontaneous, repetitive, forceful eyelid closure. Benign essential blepharospasm is caused by forceful contraction of the eyelid protractors, which include the orbicularis oculi, corrugator supercilii, and procerus muscles. The prevalence is 32 in 100,000 and women are more commonly affected than men (3:2). The peak onset is in the fifth to sixth decades, and symptoms peak 3 years after onset. When contractions are limited to the orbital and periorbital muscles, the term “benign essential blepharospasm” is used. Often, subsequent contractions of lower face and neck occur concurrently. This is termed Meige syndrome, orofacial dystonia, or oromandibular dystonia (Brueghel syndrome). Furthermore, dystonia outside of the facial nerve distribution is called segmental cranial dystonia or craniocervical dystonia. Initially, benign essential blepharospasm can manifest as increased frequency in blinking in response to several stimuli, including wind, air pollution, sunlight, noise, and movements of the head or eyes. It can significantly impair quality of life by causing difficulty in reading, writing, and driving. In severe cases, patients may be functionally blind. Several eyelid changes have been noted with longstanding blepharospasm including dermatochalasis, eyelid and brow ptosis, entropion, and canthal tendon abnormalities. Common symptoms that precede the official diagnosis of benign essential blepharospasm include eye irritation, photophobia, tearing, and ocular pain. Early symptoms include an increase in blink rate (77%), lid spasms (66%), ocular irritation (55%), midfacial or lower facial spasm (59%), brow spasm (24%), and eyelid tic (22%). Several conditions relieve blepharospasm; these include sleep, relaxation, inferior gaze, artificial tears, traction on eyelids, and humming.