bluuebunny/crossref_metadata_2025 huggingface dataset:
Relativistic Cosmology
Authors: Ellis George F. R. , Maartens Roy , MacCallum Malcolm A. H.
Published: April 2012

Cosmology has been transformed by dramatic progress in high-precision observations and theoretical modelling. This book surveys key developments and open issues for graduate students and researchers. Using a relativistic geometric approach, it focuses on the general concepts and relations that underpin the standard model of the Universe. Part I covers foundations of relativistic cosmology whilst Part II develops the dynamical and observational relations for all models of the Universe based on general relativity. Part III focuses on the standard model of cosmology, including inflation, dark matter, dark energy, perturbation theory, the cosmic microwave background, structure formation and gravitational lensing. It also examines modified gravity and inhomogeneity as possible alternatives to dark energy. Anisotropic and inhomogeneous models are described in Part IV, and Part V reviews deeper issues, such as quantum cosmology, the start of the universe and the multiverse proposal. Colour versions of some figures are available at www.cambridge.org/9780521381154.
Reading the Letters of Pliny the Younger
Authors: Gibson Roy K. , Morello Ruth
Published: April 2012

This is the first general introduction to Pliny's Letters published in any language, combining close readings with broader context and adopting a fresh and innovative approach to reading the letters as an artistically structured collection. Chapter 1 traces Pliny's autobiographical narrative throughout the Letters; Chapter 2 undertakes detailed study of Book 6 as an artistic entity; while Chapter 3 sets Pliny's letters within a Roman epistolographical tradition dominated by Cicero and Seneca. Chapters 4 to 7 study thematic letter cycles within the collection, including those on Pliny's famous country villas and his relationships with Pliny the Elder and Tacitus. The final chapter focuses on the 'grand design' which unifies and structures the collection. Four detailed appendices give invaluable historical and scholarly context, including a helpful timeline for Pliny's life and career, detailed bibliographical help on over 30 popular topics in Pliny's letters and a summary of the main characters mentioned in the Letters.
Socrates' Daimonic Art
Authors: Belfiore Elizabeth S.
Published: April 2012

Despite increasing interest in the figure of Socrates and in love in ancient Greece, no recent monograph studies these topics in all four of Plato's dialogues on love and friendship. This book provides important new insights into these subjects by examining Plato's characterization of Socrates in Symposium, Phaedrus, Lysis and the often neglected Alcibiades I. It focuses on the specific ways in which the philosopher searches for wisdom together with his young interlocutors, using an art that is 'erotic', not in a narrowly sexual sense, but because it shares characteristics attributed to the daimon Eros in Symposium. In all four dialogues, Socrates' art enables him, like Eros, to search for the beauty and wisdom he recognizes that he lacks and to help others seek these same objects of erôs. Belfiore examines the dialogues as both philosophical and dramatic works, and considers many connections with Greek culture, including poetry and theater.
Journal Kept by David Douglas during his Travels in North America 1823–1827
Authors: Douglas David
Published: April 2012

David Douglas (1799–1834), the influential Scottish botanist and plant collector, trained as a gardener before attending Perth College and Glasgow University. His genius for botany flourished and his talents came to the attention of the Royal Horticultural Society. With the society's backing he went to North America in 1823, beginning his life-long fascination with the region's flora. He discovered thousands of new species and introduced 240 of them to Britain, including the Douglas fir. Douglas continued to explore and discover plant species until his death in the Sandwich Islands (present-day Hawaii) in 1834. This remarkable journal, which remained unpublished until 1914, describes his adventures in North America during 1823–7. It also includes extracts from his journal of his explorations of Hawaii during 1833–4. The appendices include a listing of the plants Douglas introduced to Britain, and contemporary accounts of investigations into the mysterious circumstances of his death.
Cours d'histoire moderne
Authors: Guizot François
Published: April 2012

French politician François-Pierre-Guillaume Guizot (1787–1874) is well-known for establishing 'Guizot's law', which implemented primary education for all French citizens. As well as occupying various political offices during some of the most turbulent years in his nation's political history, Guizot was also an historian and was appointed to the chair of modern history at the Sorbonne in 1812. First published between 1829 and 1832, this five-volume history of 'civilisation in France' is based on a series of lectures delivered in 1828. The books are described as covering the period from the end of the Roman Empire to 1789, but the main focus is on the medieval period, to the death of St Louis (1270). Volume 3 discusses France from the death of Charlemagne in 814 to the reign of Hugh Capet (939–96), including relations with the papacy, and ends with a review of the narrative so far.
The History of the French Revolution
Authors: Thiers Adolphe
Published: April 2012

Marie-Louis-Adolphe Thiers (1797–1877) was a prominent figure in a turbulent period in French history. Described by Karl Marx as a 'monstrous gnome' and condemned by the left for suppressing the Paris Commune of 1871, he enjoyed a controversial political career, but it is for his epic Histoire de la Révolution Française that he is chiefly remembered today. It was first published in French in ten volumes between 1823 and 1827, and in 1838 Frederic Shoberl's English translation made it a staple of British bookshelves. Consolidated into five volumes and illustrated with an array of engravings, this edition presents readers with a history of events spanning more than a decade of revolution and war, and remains one of the most comprehensive accounts of the French Revolution. Volume 5 concludes the narrative with accounts of military campaigns abroad, political in-fighting at home, and Napoleon's coup d'état of November 1799.
Diplomata et Chartae Merovingicae Aetatis in Archivo Franciae Asservata
Authors: Anonymous
Published: April 2012

This collection of 48 Latin documents dating from the sixth to the ninth centuries was published anonymously in Paris in 1848, when its focus on St Denis, the burial place of the French kings, would have been highly politically sensitive. Many of the charters relate to land, revenues or rights given by Merovingian and Carolingian kings to religious institutions near Paris closely connected to their dynasty. Subjects include Childebert I's foundation of the abbey of St Vincent in 558, donating fields, meadows, forests, fisheries and mills on the River Seine, and grants to St Denis from benefactors including Chlotharus II in 527, Dagobert I in 637, Childebert III in 710 (the taxes on a market) and Chilperichus II in 716–7 (100 cows and a forest). Writings by Pope Nicholas I and a Byzantine emperor also appear. The book provides valuable information about land and power in early medieval France.
Servii Grammatici Qui Feruntur in Vergilii Carmina Commentarii
Authors: Servius
Published: April 2012

Servius Grammaticus is believed to have been active in the later part of the fourth century CE. Little is known about him (not even the correct form of his name) but he was traditionally thought to have been a pupil of the great grammarian Donatus. The most important work ascribed to him is this commentary on the Aeneid, Eclogues and Georgics of Vergil, which clarifies the content and language of Vergil's poems by citing other Latin authors, some of whose works are now lost and may be known only from Servius' references to them. This three-volume Latin edition (in four parts), begun by Georg Thilo (1831–93) and completed after Thilo's death by Hermann Hagen (1844–98), was published in Germany between 1878 and 1902, and is still regularly consulted by scholars of Vergil and of Latin literature. Volume 1 contains Servius' commentary on Aeneid Books 1–5.
Servii Grammatici Qui Feruntur in Vergilii Carmina Commentarii
Authors: Servius
Published: April 2012

Servius Grammaticus is believed to have been active in the later part of the fourth century CE. Little is known about him (not even the correct form of his name) but he was traditionally thought to have been a pupil of the great grammarian Donatus. The most important work ascribed to him is this commentary on the Aeneid, Eclogues and Georgics of Vergil, which clarifies the content and language of Vergil's poems by citing other Latin authors, some of whose works are now lost and may be known only from Servius' references to them. This three-volume Latin edition (in four parts), begun by Georg Thilo (1831–93) and completed after Thilo's death by Hermann Hagen (1844–98), was published in Germany between 1878 and 1902, and is still regularly consulted by scholars of Vergil and of Latin literature. Volume 3 Part 2 contains other classical commentaries and glosses on Vergil.
History of England from the Fall of Wolsey to the Death of Elizabeth
Authors: Froude James Anthony
Published: April 2012

James Anthony Froude (1818–94), historian and disciple of Carlyle, published this twelve-volume history of the English Reformation between 1858 and 1870. The work is shaped by Froude's firm belief that the Reformation enabled the development of modernity and the rise of 'progressive intelligence' in England. His polemical stance was criticised by some historians, but his engaging narrative style and elegant prose made his work extremely popular with the general public, and the books were highly influential. The first six volumes consider the course of the Reformation from the break with Rome until the accession of Elizabeth I in 1558, and the remaining six recount the reign of Elizabeth I, ending with the defeat of the Spanish Armada. Volume 1 recounts the last years of Wolsey's influence, the changing relationship between Church and State, and the marriage of Henry VIII and Anne Boleyn.
The History of England from the Accession of James II
Authors: Macaulay Thomas Babington
Published: April 2012

Thomas Babington Macaulay (1800–59) was one of the foremost nineteenth-century historians in the Whig tradition, which saw history as a series of developments towards enlightenment and democracy. He believed that the 'Glorious Revolution' of 1688 had preserved England from the constitutional upheavals suffered by much of Europe in 1848. Using a wider range of sources, including popular literature, than was then usual, and written in an accessible, novelistic rather than academic style, this five-volume work proved hugely influential upon contemporary historians and phenomenally successful with the public, although it was not without its critics. Volume 3, published in 1855, examines the succession of William and Mary, and the constitutional arrangements made for their coronation. It deals with the wars in Ireland and Scotland, and resistance to William in England, particularly among the dissenting clergy.
Working Men's Social Clubs and Educational Institutes
Authors: Solly Henry
Published: April 2012

Social reformer, Chartist sympathiser, advocate of universal suffrage, and opponent of slavery, Henry Solly (1813–1903) was a man driven by the desire to stamp out inequality. As part of his mission to improve the lives of working-class people, he founded the Working Men's Club and Institute Union, becoming its first paid secretary in 1863. The Union encouraged the formation of social and educational clubs where working men could 'meet for conversation, business, and mental improvement, with the means of recreation and refreshment, free from intoxicating drinks'. His tireless campaigning led directly to the formation of the Charity Organization Society, which advocated the principle of aiding those prepared to help themselves. Published in 1867, this is Solly's vigorous manifesto for social reform based around temperance and the formation of social clubs and educational institutes for working men.
Alan M. Turing
Authors: Turing Sara , Turing John F. , Irvine Lyn , Davis Martin
Published: April 2012

'In a short life he accomplished much, and to the roll of great names in the history of his particular studies added his own.' So is described one of the greatest figures of the twentieth century, yet Alan Turing's name was not widely recognised until his contribution to the breaking of the German Enigma code became public in the 1970s. The story of Turing's life fascinates and in the years since his suicide, Turing's reputation has only grown, as his contributions to logic, mathematics, computing, artificial intelligence and computational biology have become better appreciated. To commemorate the centenary of Turing's birth, this republication of his mother's biography is enriched by a new foreword by Martin Davis and a never-before-published memoir by Alan's older brother. The contrast between this memoir and the original biography reveals tensions and sheds new light on Turing's relationship with his family, and on the man himself.
Getting and Staying Productive
Authors: Schmenner Roger W.
Published: April 2012

All kinds of processes – those that make things or deliver services or operate companies – can be made more productive, and society's continued well-being requires it. This book is for all those with a stake in improving how companies run. It introduces the concept of 'swift, even flow' and explains how that concept stands behind popular business tools such as 'lean' principles and Six Sigma. More than that, it shows how swift, even flow can lead to deep, strategic insights and fresh ideas. The book uses many examples, both contemporary and historic, and 16 case studies from all sorts of business situations to demonstrate how swift, even flow can be applied. Services and manufacturing, supply chains and individual operations, product development and outsourcing, strategy and tactics, hourly workers and top level executives – all benefit from this fundamental re-thinking of what it takes to become productive.
The Maori King
Authors: Gorst J. E.
Published: April 2012

The British politician and lawyer Sir John Eldon Gorst (1835–1916) arrived in New Zealand in 1860, shortly after the outbreak of the Taranaki Wars (from 1860 onwards), with idealistic intentions of working with Bishop Selwyn and the Maori. He took on various governmental roles that required contact with the Maori, including those of school inspector, magistrate and, later, Civil Commissioner for the Waikato region, whose powerful chiefs had not signed the 1840 Treaty of Waitangi. In 1864 he published this book analysing the social and economic situation in New Zealand, the rapid deterioration of relations between Maori and Europeans (which he ascribes largely to errors and neglect on the part of the British administration) and Maori demands for self-government. He describes, often as an eye-witness, the complex political wrangling that took place, and sets out his own views about the past and future relations between the two ethnic groups.
First- and second-order forcing expansions in a lattice Boltzmann method reproducing isothermal hydrodynamics in artificial compressibility form
Authors: Silva Goncalo , Semiao Viriato
Published: April 2012

The isothermal Navier–Stokes equations are determined by the leading three velocity moments of the lattice Boltzmann method (LBM). Necessary conditions establishing the hydrodynamic consistency of these moments are provided by multiscale asymptotic techniques, such as the second-order Chapman–Enskog expansion. However, for simulating incompressible hydrodynamics the structure of the forcing term in the LBM is still a discordant issue as far as its correct velocity expansion order is concerned. This work uses the traditional second-order Chapman–Enskog expansion analysis to demonstrate that the truncation order of the forcing term may depend on the time regime in this case. This is due to the fact that LBM does not reproduce exactly the incompressibility condition. It rather approximates it through a weakly compressible or an artificial compressible system. The present study shows that for the artificial compressible setup, as the incompressibility flow condition is singularly perturbed by the time variable, such a connection will also affect the LBM forcing formulation. As a result, for time-independent incompressible flows the LBM forcing must be truncated to first order whereas for a time-dependent case it is convenient to include the second-order term. The theoretical findings are confirmed by numerical tests carried out in several distinct benchmark flows driven by space- and/or time-varying body forces and possessing known analytical solutions. These results are verified for the single relaxation time, the multiple relaxation time and the regularized collision models.
Protein restriction in early life is associated with changes in insulin sensitivity and pancreatic β-cell function during pregnancy
Authors: Ignácio-Souza Letícia Martins , Reis Sílvia Regina , Arantes Vanessa Cristina , Botosso Bárbara Laet , Veloso Roberto Vilela , Ferreira Fabiano , Boschero Antonio Carlos , Carneiro Everardo Magalhães , de Barros Reis Marise Auxiliadora , Latorraca Márcia Queiroz
Published: April 2012

Malnutrition in early life impairs glucose-stimulated insulin secretion in adulthood. Conversely, pregnancy is associated with a significant increase in glucose-stimulated insulin secretion under conditions of normoglycaemia. A failure in β-cell adaptive changes may contribute to the onset of diabetes. Thus, glucose homeostasis and β-cell function were evaluated in control-fed pregnant (CP) and non-pregnant (CNP) or protein-restricted pregnant (LPP) and non-pregnant (LPNP) rats, from fetal to adult life, and in protein-restricted rats that were recovered after weaning (RP and RNP). The typical insulin resistance of pregnancy was not observed in the RP rats, nor did pregnancy increase the insulin content/islet in the LPP group. The glucose dose–response curves from pregnant rats were shifted to the left in relation to the non-pregnant rats, except in the recovered group. Glucose utilisation but not oxidation in islets from the RP and LPP groups was reduced at a concentration of 8·3 mm-glucose compared with islets from the CP group. Cyclic AMP content and the potentiation of glucose-stimulated insulin secretion by isobutylmethylxanthine at a concentration of 2·8 mm-glucose indicated increased adenylyl cyclase 3 activity but reduced protein kinase A-α activity in islets from the RP and LPP rats. Protein kinase C (PKC)-α but not phospholipase C (PLC)-β1 expression was reduced in islets from the RP group. Phorbol-12-myristate 13-acetate produced a less potent stimulation of glucose-stimulated insulin secretion in the RP group. Thus, the alterations exhibited by islets from the LPP group appeared to be due to reduced islet mass and/or insulin biosynthesis. In the RP group the loss of the adaptive capacity apparently resulted from uncoupling between glucose metabolism and the amplifying signals of the secretory process, as well as a severe attenuation of the PLC/PKC pathway.
Norms and Social Hierarchies: Understanding International Policy Diffusion “From Below”
Authors: Towns Ann E.
Published: April 2012

This article aims to rethink the operation of norms in international policy diffusion. Norms do not simply standardize state behaviors, as is conventionally argued; norms also draw on and set up hierarchical social orders among states. Through a conceptual rethinking we gain a better understanding of where—among which states—new policies may first emerge: social hierarchies create incentives for new policies to develop at the margins of international society so that policies may diffuse “from below.” We also get a better grasp of how policy advocates frame the appropriateness or benefits of a new state practice: they must frame policy demands in terms of the international standing and rank of the targeted state. This article's empirical aspiration is to use these insights to help account for the international policy diffusion of legal sex quotas, a policy to increase the level of female legislators that developed first among “developing” states rather than among the so-called core of international society. By pointing to the link between norms and social hierarchy, the article helps account for policy diffusion “from below.”
How Can Economic Interests Influence Support for Free Trade?
Authors: Fordham Benjamin O. , Kleinberg Katja B.
Published: April 2012

Recent research on the sources of individual attitudes toward trade policy comes to very different conclusions about the role of economic self-interest. The skeptical view suggests that long-standing symbolic predispositions and sociotropic perceptions shape trade policy opinions more than one's own material well-being. We believe this conclusion is premature for two reasons. First, the practice of using one attitude to predict another raises questions about direction of causation that cannot be answered with the data at hand. This problem is most obvious when questions about the expected impact of trade are used to predict opinions about trade policy. Second, the understanding of self-interest employed in most studies of trade policy attitudes is unrealistically narrow. In reality, the close relationship between individual economic interests and the interests of the groups in which individuals are embedded creates indirect pathways through which one's position in the economy can shape individual trade policy preferences. We use the data employed by Mansfield and Mutz to support our argument that a more complete account of trade attitude formation is needed and that in such an account economic interests may yet play an important role.1
How dieting makes some fatter: from a perspective of human body composition autoregulation
Authors: Dulloo Abdul G. , Jacquet Jean , Montani Jean-Pierre
Published: April 2012

Dieting makes you fat – the title of a book published in 1983 – embodies the notion that dieting to control body weight predisposes the individual to acquire even more body fat. While this notion is controversial, its debate underscores the large gap that exists in our understanding of basic physiological laws that govern the regulation of human body composition. A striking example is the key role attributed to adipokines as feedback signals between adipose tissue depletion and compensatory increases in food intake. Yet, the relative importance of fat depletion per se as a determinant of post-dieting hyperphagia is unknown. On the other hand, the question of whether the depletion of lean tissues can provide feedback signals on the hunger–appetite drive is rarely invoked, despite evidence that food intake during growth is dominated by the impetus for lean tissue deposition, amidst proposals for the existence of protein–static mechanisms for the regulation of growth and maintenance of lean body mass. In fact, a feedback loop between fat depletion and food intake cannot explain why human subjects recovering from starvation continue to overeat well after body fat has been restored to pre-starvation values, thereby contributing to ‘fat overshooting’. In addressing the plausibility and mechanistic basis by which dieting may predispose to increased fatness, this paper integrates the results derived from re-analysis of classic longitudinal studies of human starvation and refeeding. These suggest that feedback signals from both fat and lean tissues contribute to recovering body weight through effects on energy intake and thermogenesis, and that a faster rate of fat recovery relative to lean tissue recovery is a central outcome of body composition autoregulation that drives fat overshooting. A main implication of these findings is that the risk of becoming fatter in response to dieting is greater in lean than in obese individuals.
WHEN BROADWAY CAME TO SWEDEN: THE EUROPEAN PREMIERE OF TENNESSEE WILLIAMS'SCAT ON A HOT TIN ROOF
Authors: Gindt Dirk
Published: April 2012

Returning fresh from her summer vacation, the suntanned managing director of Gothenburg City Theatre, Karin Kavli (1906–90), proudly announced at a press conference in early August 1955 that she had secured the rights to produce the European premiere of Tennessee Williams's acclaimed playCat on a Hot Tin Roof.1Well aware of the importance of creating a balanced repertoire that would satisfy the more artistically and literally minded audience and those who wanted some lighter forms of entertainment, Kavli understood that hosting the premiere of Williams's latest drama was quite a coup, especially in an age when television had begun to pose a great threat to theatre.
Adaptation of a trap door technique for the recovery of ovarian cortical biopsies from Cebus apella (capuchin monkey)
Authors: Santana Luana N. , Brito Adriel B. , Brito Danielle C. , Lima Julianne S. , Domingues Sheyla F.S. , Santos Regiane R.
Published: April 2012

There is a paucity of efficient cryopreservation protocols for primordial follicles enclosed in the ovarian tissue from non-human primates (NHP), in special New World primates. Our objective was to establish an optimal procedure for the recovery of ovarian biopsies from capuchin monkeys. To this end, we adapted a trap door biopsy method. Follicular density and quality of the biopsies were evaluated and ultrasound analysis was performed before and continuously after surgery to assess ovarian structure. Ovarian tissue biopsies recovered by the trap door technique allowed the successful harvesting of primordial follicles from capuchin monkeys, and no complication was recorded. The female cycle was not affected by surgery and no adherence was found thereafter. In conclusion, the adaptation of a trap door biopsy method is a safe procedure and allows recovery of healthy primordial follicles.
Glycerol decreases the integrity of the perinuclear theca in boar sperm
Authors: Arenas Núñez Marco Antonio , Juárez-Mosqueda María de Lourdes , Gutiérrez-Pérez Oscar , Anzaldúa Arce Santiago René , Izquierdo Alejandro Córdova , Rodríguez Roberto Martínez , Trujillo Ortega María Elena
Published: April 2012

We evaluated the effect of glycerol on the perinuclear theca (PT) of boar sperm. Samples from six ejaculates obtained from three different boars were incubated in the detergent Brij 36-T. Spermatozoa were treated with a glycerol concentration of either 2 or 4%, and incubated for 10 or 30 min; two other samples were treated with protease inhibitors (PI; leupeptin or an inhibitor commercial cocktail), mixed with 4% glycerol, and incubated for 30 min. A third glycerol-free group was used as the control. The samples were processed for electron microscopy evaluation. The PT remained intact in 78% of the control samples while, after addition of glycerol for 30 min, the proportion of spermatozoa with disrupted or absent PT increased (P < 0.05). PT was preserved in PI samples, but PT changes increased (P < 0.05). Differences due to treatment with glycerol (2 or 4%) at 10 or 30 min were not observed. These results show, to our knowledge for the first time, the adverse effect of glycerol on the integrity of the PT.
Foetal echocardiographic assessment of borderline small left ventricles can predict the need for postnatal intervention
Authors: Weber Roland W. , Ayala-Arnez Ricardo , Atiyah Merna , Etoom Yousef , Manlhiot Cedric , McCrindle Brian W. , Hickey Edward J. , Jaeggi Edgar T. , Nield Lynne E.
Published: April 2012

Background

We sought to prospectively determine foetal echocardiographic factors associated with neonatal interventions in borderline hypoplastic left ventricles.

Methods

Foetuses were included who had a left ventricle that was 2–4 standard deviations below normal for length or diameter and had forward flow across the mitral and aortic valves. Factors associated with an intervention in the first month of life or no need for intervention were sought using univariate and multivariate logistic regression models.

Results

From 2005 to 2008, 47 foetuses meeting the criteria had an additional diagnosis (+foetal coarctation/+transverse arch hypoplasia): atrioventricular septal defect 7 (+2/+0), double outlet right ventricle 2 (+0/+0), Shone's complex 19 (+9/+4), and ventricular disproportion 19 (+13/+11; 4 both). There were seven pregnancies terminated, three foetal demises, and five had compassionate care. There were 32 livebirths that either had a biventricular repair (n = 20, n = 2 dead), univentricular palliation (n = 2, both alive), or no intervention (n = 9). Overall survival of livebirths to 6 months of age was 79%. Factors associated with early intervention on first foetal echocardiogram were: obstructed or retrograde arch flow (p = 0.08, odds ratio 3.3), coarctation (p = 0.05, odds ratio 11.4), and left ventricle outflow obstruction (p = 0.05, odds ratio 12.5). Neonatal factors included: Shone's diagnosis (p = 0.02, odds ratio 4.9), bicuspid aortic valve (p = 0.005, odds ratio 11.7), and larger tricuspid valve z-score (p = 0.05, odds ratio 3.6). A neonatal factor associated with no intervention was a larger mitral valve z-score (mean −3.8 versus −4.2 intervention group, p = 0.04, odds ratio 2.8).

Discussion

The need for early intervention in foetuses with borderline hypoplastic left ventricle can be predicted by foetal echocardiography.
EFFECTS OF PREDATOR DIET BREADTH ON STABILITY OF SIZE SPECTRA
Authors: PLANK M. J.
Published: April 2012

Many marine ecosystems have the remarkable property that the abundance of organisms of a given body size is approximately proportional to the inverse square of that size. Size-structured models have been developed for which this “invariance-of-biomass” state is an equilibrium solution. These models are built on the coupling of predator growth to prey abundance, where prey suitability is determined by a size-based function referred to as a feeding kernel. In this paper, the local stability of the equilibrium state is investigated in a limiting case where predators only consume prey of a preferred size. In this special case, it is shown analytically that the equilibrium state is always unstable. It is concluded that some degree of diet breadth, in terms of the range of prey sizes consumed by a predator, is an essential prerequisite for the invariance-of-biomass state to be stable, as widely observed in the field.
Radiocarbon in the Northern Indian Ocean two decades after GEOSECS
Authors: Dutta Koushik , Bhushan Ravi
Published: April 2012

The 14C measurements in the Arabian Sea and the Bay of Bengal during the late 1990s offer a way to assess the temporal changes in the inventories of bomb‐14C and its penetration into the ocean, in two decades since GEOSECS expeditions (1977–1978). The mean penetration depth of bomb radiocarbon during GEOSECS (1977–1978) was 270 m, which increased by ∼40% to 381 m in 1994–1998. The small changes in bomb‐14C inventories, significant increase in the mean penetration depths and lowering of the surface Δ14C values in the northern Indian Ocean indicate the temporal variation of bomb‐14C in two decades is mainly through downward transfer through mixing with deeper waters. The observed bomb‐14C inventory in the northern Indian Ocean agrees with numerical model simulated values, except at the equatorial Indian Ocean. The high bomb‐14C inventory at the equator can be attributed to lateral advection of 14C‐enriched waters from the Pacific Ocean through the Indonesian archipelago. The air‐sea CO2exchange rates in the northern Indian Ocean calculated from the bomb‐14C inventories range from ∼7 mol m−2 yr−1 (in the northern Bay of Bengal) to 20 mol m−2 yr−1(in the equatorial Indian Ocean). Net sea‐air flux of CO2 estimated for the northern Indian Ocean between 0° and 25°N is ∼104 ± 30 TgC yr−1. The Bay of Bengal is a net sink of atmospheric CO2 (∼−1 ± 0.4 TgC yr−1), while the Arabian Sea is a source of CO2 (∼69 ± 21 TgC yr−1).
The source of the steep plasma density gradient in middle latitudes during the 11–12 April 2001 storm
Authors: Park S. , Kim K.‐H. , Kil H. , Jee G. , Lee D.‐H. , Goldstein J.
Published: April 2012

A steep plasma density gradient has been observed in the middle‐latitude F region during large geomagnetic storms. This phenomenon can be understood as a special form of the middle‐latitude ionization trough (hereafter trough), but its causal linkage has not yet been clarified. We investigate the association of the steep density gradient and the trough by comparing their morphologies and occurrence locations using the satellite and ground observation data during the 11–12 April 2001 storm. Steep density gradients are detected in the dusk sector at the equatorward edges of the aurora by the Defense Meteorological Satellite Program (DMSP) F13 spacecraft. The locations of the steep density gradients coincide with the locations of the ionospheric footprints of the plasmapause identified by the Imager for Magnetopause‐to‐Aurora Global Exploration satellite. These observations demonstrate that the steep density gradient is created at the typical location of the trough. However, the steep density gradient is not produced by the formation of an intense trough during the storm. The temporal evolution of the total electron content maps shows that the steep density gradient observed at dusk by DMSP is associated with the plasma density enhancement in the dayside and its corotation into the dusk sector. The severe plasma density enhancement in middle latitudes, in combination with the trough and presumably the plasma depletion in high latitudes by the neutral composition change, produces the steep density gradient in the subauroral region during the storm.
Deformation experiments of bubble‐ and crystal‐bearing magmas: Rheological and microstructural analysis
Authors: Pistone Mattia , Caricchi Luca , Ulmer Peter , Burlini Luigi , Ardia Paola , Reusser Eric , Marone Federica , Arbaret Laurent
Published: April 2012

Simple shear deformation experiments on three‐phase, hydrous, haplogranitic magmas, composed of quartz crystals (24–65 vol.%), CO2‐rich gas bubbles (9–12 vol.%) and melt in different proportions, were performed with a Paterson‐type rock deformation apparatus. Strain rates from 5 · 10−6 s−1 to 4 · 10−3 s−1 were applied at temperatures between 723 and 1023 K and at pressure of 200 MPa. The results show that the three‐phase suspension rheology is strongly strain rate dependent (non‐Newtonian behavior). Two non‐Newtonian regimes were observed: shear thinning (viscosity decreases with increasing strain rate) and shear thickening (viscosity increases with increasing strain rate). Shear thinning occurs in crystal‐rich magmas (55–65 vol.% crystals; 9–10 vol.% bubbles) as a result of crystal size reduction and shear zoning. Shear thickening prevails in dilute suspensions (24 vol.% crystals; 12 vol.% bubbles), where bubble coalescence and outgassing dominate. At intermediate crystallinity (44 vol.% crystals; 12 vol.% bubbles) both shear thickening and thinning occur. Based on the microstructural observations using synchrotron radiation X‐ray tomographic microscopy, bubbles can develop two different shapes: oblate at low temperature (<873 K) and prolate at high temperature (>873 K). These differences in shape are caused by different conditions of flow: unsteady flow, where the relaxation time of the bubbles is much longer than the timescale of deformation (oblate shapes); steady flow, where bubbles are in their equilibrium deformation state (prolate shapes). Three‐phase magmas are characterized by a rheological behavior that is substantially different with respect to suspensions containing only crystals or only gas bubbles.
A description of the Ross Ice Shelf air stream (RAS) through the use of self‐organizing maps (SOMs)
Authors: Seefeldt Mark W. , Cassano John J.
Published: April 2012

The low‐level wind field across the Ross Ice Shelf region, Antarctica is studied through the method of self‐organizing maps (SOMs). Emphasis is placed on identifying and characterizing the Ross Ice Shelf air stream (RAS). The RAS is a dominant northward stream of air resulting in significant transport of atmospheric mass from the interior of Antarctica. Two SOMs are created for the lowest model level (∼13 m) and the 5th lowest model level (∼150 m), from archived real‐time numerical weather prediction output of the Antarctic Mesoscale Prediction System (AMPS). A verification of the SOM for the lowest model level is completed by comparing select nodes to automatic weather station wind rose plots. The winds depicted in the lowest model level SOM are dominated by the position of the cyclone in the Ross Sea and the changes in wind speeds on the Antarctic plateau. The 5th lowest model level provides a better depiction of the RAS. The RAS is found to be present primarily when associated with a cyclone in the Ross Sea. There is a strong seasonality to the RAS with the RAS occurring frequently during the winter months and rarely during the summer months. The structure and position of the RAS is strongly dependent on the position of the Ross Sea cyclone.
Changes in ozone over Europe: Analysis of ozone measurements from sondes, regular aircraft (MOZAIC) and alpine surface sites
Authors: Logan J. A. , Staehelin J. , Megretskaia I. A. , Cammas J.‐P. , Thouret V. , Claude H. , De Backer H. , Steinbacher M. , Scheel H.‐E. , Stübi R. , Fröhlich M. , Derwent R.
Published: April 2012

We use ozone observations from sondes, regular aircraft, and alpine surface sites in a self‐consistent analysis to determine robust changes in the time evolution of ozone over Europe. The data are most coherent since 1998, with similar interannual variability and trends. Ozone has decreased slowly since 1998, with an annual mean trend of −0.15 ppb yr−1 at ∼3 km and the largest decrease in summer. There are some substantial differences between the sondes and other data, particularly in the early 1990s. The alpine and aircraft data show that ozone increased from late 1994 until 1998, but the sonde data do not. Time series of differences in ozone between pairs of locations reveal inconsistencies in various data sets. Differences as small as few ppb for 2–3 years lead to different trends for 1995–2008, when all data sets overlap. Sonde data from Hohenpeissenberg and in situ data from nearby Zugspitze show ozone increased by ∼1 ppb yr−1 during 1978–1989. We construct a mean alpine time series using data for Jungfraujoch, Zugspitze, and Sonnblick. Using Zugspitze data for 1978–1989, and the mean time series since 1990, we find that the ozone increased by 6.5–10 ppb in 1978–1989 and 2.5–4.5 ppb in the 1990s and decreased by 4 ppb in the 2000s in summer with no significant changes in other seasons. It is hard to reconcile all these changes with trends in emissions of ozone precursors, and in ozone in the lowermost stratosphere. We recommend data sets that are suitable for evaluation of model hindcasts.
A field proof‐of‐concept of aquifer imaging using 3‐D transient hydraulic tomography with modular, temporarily‐emplaced equipment
Authors: Cardiff M. , Barrash W. , Kitanidis P. K.
Published: April 2012

Hydraulic tomography is a field scale aquifer characterization method capable of estimating 3‐D heterogeneous parameter distributions, and is directly sensitive to hydraulic conductivity (K), thus providing a useful data source for improving flow and transport models. We present results from a proof‐of‐concept field and modeling study in which we apply 3‐D transient hydraulic tomography (3DTHT) to the relatively high‐K and moderately heterogeneous unconfined aquifer at the Boise Hydrogeophysical Research Site. Short‐duration (20 min) partially penetrating pumping tests, for which observed responses do not reach steady state, are used as the aquifer stimulation. To collect field data, we utilize a system of temporarily emplaced packer equipment to isolate multiple discrete intervals in boreholes. To analyze the data, we utilize MODFLOW combined with geostatistical inversion code based on the quasilinear approach of Kitanidis (1995). This combination of practical software allows inversion of large datasets (>250 drawdown curves, and almost 1000 individual data points) and estimation of K at >100,000 locations; reasonable runtimes are obtained using a single multicore computer with 12 GB of RAM. The K heterogeneity results from 3DTHT are cross‐validated against K characterization from a large set of partially penetrating slug tests, and found to be quite consistent. The use of portable, modular equipment for field implementation means that 3DTHT data collection can be performed (including mobilization/demobilization) within a matter of days. Likewise, use of a practical, efficient and scalable numerical modeling and inversion strategy means that computational effort is drastically reduced, such that 3‐D aquifer property distributions can be estimated quickly.
Quantification of mineral behavior in four dimensions: Grain boundary and substructure dynamics in salt
Authors: Borthwick V. E. , Schmidt S. , Piazolo S. , Gundlach C.
Published: April 2012

Here we present the first four dimensional (time and three dimensional space resolved) experiment on a strongly deformed geological material. Results show that even complicated microstructures with large continuous and discontinuous changes in crystallographic orientation can be resolved quantitatively. The details that can be resolved are unprecedented and therefore the presented technique promises to become influential in a wide range of geoscientific investigations. Grain and subgrain scale processes are fundamental to mineral deformation and associated Earth Dynamics, and time resolved observation of these processes is vital for establishing an in‐depth understanding of the latter. However, until recently, in situ experiments were restricted to observations of two dimensional surfaces. We compared experimental results from two dynamic, in situ annealing experiments on a single halite crystal; a 2D experiment conducted inside the scanning electron microscope and a 3D X‐ray diffraction experiment. This allowed us to evaluate the possible effects of the free surface on grain and subgrain processes. The extent to which surface effects cause experimental artifacts in 2D studies has long been questioned. Our study shows that, although the nature of recovery processes are the same, the area swept by subgrain boundaries is up to 5 times larger in the volume than observed on the surface. We suggest this discrepancy is due to enhanced drag force on subgrain boundaries by thermal surface grooving. Our results show that while it is problematic to derive absolute mobilities from 2D experiments, derived relative mobilities between boundaries with different misorientation angles can be used.
Tracking the magmatic evolution of island arc volcanism: Insights from a high‐precision Pb isotope record of Montserrat, Lesser Antilles
Authors: Cassidy M. , Taylor R. N. , Palmer M. R. , Cooper R. J. , Stenlake C. , Trofimovs J.
Published: April 2012

The volcanic succession on Montserrat provides an opportunity to examine the magmatic evolution of island arc volcanism over a ∼2.5 Ma period, extending from the andesites of the Silver Hills center, to the currently active Soufrière Hills volcano (February 2010). Here we present high‐precision double‐spike Pb isotope data, combined with trace element and Sr‐Nd isotope data throughout this period of Montserrat's volcanic evolution. We demonstrate that each volcanic center; South Soufrière Hills, Soufrière Hills, Centre Hills and Silver Hills, can be clearly discriminated using trace element and isotopic parameters. Variations in these parameters suggest there have been systematic and episodic changes in the subduction input. The SSH center, in particular, has a greater slab fluid signature, as indicated by low Ce/Pb, but less sediment addition than the other volcanic centers, which have higher Th/Ce. Pb isotope data from Montserrat fall along two trends, the Silver Hills, Centre Hills and Soufrière Hills lie on a general trend of the Lesser Antilles volcanics, whereas SSH volcanics define a separate trend. The Soufrière Hills and SSH volcanic centers were erupted at approximately the same time, but retain distinctive isotopic signatures, suggesting that the SSH magmas have a different source to the other volcanic centers. We hypothesize that this rapid magmatic source change is controlled by the regional transtensional regime, which allowed the SSH magma to be extracted from a shallower source. The Pb isotopes indicate an interplay between subduction derived components and a MORB‐like mantle wedge influenced by a Galapagos plume‐like source.
Little Ice Age cold interval in West Antarctica: Evidence from borehole temperature at the West Antarctic Ice Sheet (WAIS) Divide
Authors: Orsi Anais J. , Cornuelle Bruce D. , Severinghaus Jeffrey P.
Published: April 2012

The largest climate anomaly of the last 1000 years in the Northern Hemisphere was the Little Ice Age (LIA) from 1400–1850 C.E., but little is known about the signature of this event in the Southern Hemisphere, especially in Antarctica. We present temperature data from a 300 m borehole at the West Antarctic Ice Sheet (WAIS) Divide. Results show that WAIS Divide was colder than the last 1000‐year average from 1300 to 1800 C.E. The temperature in the time period 1400–1800 C.E. was on average 0.52 ± 0.28°C colder than the last 100‐year average. This amplitude is about half of that seen at Greenland Summit (GRIP). This result is consistent with the idea that the LIA was a global event, probably caused by a change in solar and volcanic forcing, and was not simply a seesaw‐type redistribution of heat between the hemispheres as would be predicted by some ocean‐circulation hypotheses. The difference in the magnitude of the LIA between Greenland and West Antarctica suggests that the feedbacks amplifying the radiative forcing may not operate in the same way in both regions.
Terrestrial gamma ray flashes with energies up to 100 MeV produced by nonequilibrium acceleration of electrons in lightning
Authors: Celestin Sebastien , Xu Wei , Pasko V. P.
Published: April 2012

Using Monte Carlo models simulating energetic electrons in inhomogeneous electric field and the transport of energetic photons in the Earth's atmosphere, we show that the spectrum of bremsstrahlung photons generated by nonequilibrium energetic electrons produced during stepping of lightning leaders can deviate from the typical spectrum of relativistic runaway electron avalanches (RREA) developing in weak homogeneous electric fields. This deviation is especially pronounced in the high‐energy tail of the electron energy distribution for lightning leaders possessing high voltages (several hundreds of megavolts) and extremely high fields around their tips. The photon spectrum obtained accurately reproduces the recently discovered high‐energy tail (up to 100 MeV) of terrestrial gamma‐ray flashes (TGFs). This analysis provides the first direct evidence that TGFs are produced by lightning and not over large distances in weak thunderstorm electric fields.