bluuebunny/crossref_metadata_2025 huggingface dataset:
Seroprevalence of human Taenia solium cysticercosis in Haiti
Authors: Raccurt C.P. , Agnamey P. , Boncy J. , Henrys J.-H. , Totet A.
Published: February 2009

Human Taenia solium cysticercosis is common in developing countries due to poor sanitary conditions and economics based on breeding livestock, especially pigs, with low hygiene standards. Neurocysticercosis, caused by migration of the larvae of the tapeworm in the nervous system, is the leading cause of acquired epilepsy in adults in Central and South America, sub-Saharan Africa, and East and South Asia. This makes neurocysticercosis a large public health problem in developing countries. Two clinical cases of neurocysticercosis have been observed recently in Haiti. In order to evaluate the prevalence of human T. solium cysticercosis in this country, in 2007 we conducted a cross-sectional serological retrospective survey using a Western blotting test (LDBIO Diagnostics®) in Port-au-Prince, where sewage systems are rare and swine usually roam freely throughout the area. A total of 216 serum samples, obtained from healthy adults seen in the work setting of periodical medical visits, were tested after storage at − 20°C. The frequency of antibodies in serum samples of the study population was 2.8% (6/216). The immunodominant bands recognized in Western blots were 23–26 kDa (100%), 39 kDa (67%), 45 kDa and 6–8 kDa (50%), 50–55 kDa (33%). These results confirm for the first time an endemic situation of cysticercosis in humans in Haiti, with similar prevalence as that reported in other Latin American and African countries. It reinforces the urgent need for control and prevention measures to be taken by local public health services.
Lost in Translation: Interpreting the Failure of Privatisation in the Brazilian Electric Power Industry
Authors: TANKHA SUNIL
Published: February 2009

Did Latin American privatisation policies fail because of flawed implementation of fundamentally sound policies or because privatisation policies were themselves seriously flawed? Using the Brazilian electric power reforms as a narrative tool, this paper examines the causal chain assumed by large-scale privatisation policies that were implemented as part of structural reform and adjustment programmes. The paper concludes that many privatisation policies and the economic stabilisation programmes within which they were embedded were not mutually reinforcing in the way that policymakers had expected, and that in their application much of what privatisation theories had claimed was lost in translation.
Sentencing the Social Question: Court-Made Labour Law in Cases of Occupational Accidents in Argentina, 1900–1915
Authors: SCHJOLDEN LINE
Published: February 2009

This article shows how Argentine judges effectively came to make labour law when ruling in occupational accident cases between 1900 and 1915. During this period, in the absence of a specific occupational accident law, a number of Argentine workers who had been victims of occupational accidents sued their employers for damages according to the Civil Code. By reinterpreting the principles of the Civil Code in these cases, Argentine judges attempted to accommodate aspects of a new social and economic reality to an increasingly outdated legal framework. The article argues that, in doing so, these judges articulated their own solution to one of the central issues of the time: the ‘social question’. Furthermore, the article shows how the judiciary's particular solution to the social question effectively defined the kind of citizenship rights workers were able to claim in court.
The Future of Christianity in Latin America
Authors: LEVINE DANIEL H.
Published: February 2009

The Christianity of the future in Latin America will remain dominant but now plural and competitive. The decline of Catholic monopoly and the surge of Protestant and Pentecostal churches, visible since the 1980s but with deeper roots, are explained in the context of social, cultural and political changes that have drawn churches into public space in new ways. The impact of democracy, violence, and a newly open civil society on churches and religious life is visible in new ideas about rights and associational life and in the withdrawal of the institutional churches from political confrontation, diversification of political positions and multiplication of voices in all churches.
Does promoter methylation of the SLC30A5 (ZnT5) zinc transporter gene contribute to the ageing-related decline in zinc status?
Authors: Coneyworth L. J. , Mathers J. C. , Ford D.
Published: February 2009

A decline in Zn status with ageing may contribute to the development of frailty, including impaired immune function, and increased incidence of age-related degenerative diseases. This decline may be a result of reduced dietary Zn intake and/or impaired Zn absorption in the gut. The Zn transporter ZnT5 may play a key role in the absorption of dietary Zn. The corresponding gene (SLC30A5) has a CpG island in its promoter region, so could be regulated by epigenetic mechanisms. It is hypothesised that methylation of the SLC30A5 promoter region is increased with age and that a resulting reduction in ZnT5 expression contributes to the decline in Zn status observed with ageing. This hypothesis has been addressed through (1) studies of effects of SLC30A5 promoter methylation on gene expression in vitro and (2) in vivo measurements of the DNA methylation status of this gene domain. It has been established in vitro that methylation of the human SLC30A5 promoter region results in reduced expression of an associated reporter gene. Second, this gene region shows variable levels of methylation in vivo. Correlation between the level of methylation at this locus and age would support the hypothesis that age-related hypermethylation of this region has the potential to modulate dietary Zn absorption. This premise is being investigated by analysis of additional samples from a human adult cohort to test the hypothesis that methylation of the SLC30A5 promoter region contributes to the age-related decline in Zn status.
Nutrigenetics and personalised nutrition: how far have we progressed and are we likely to get there?
Authors: Rimbach Gerald , Minihane Anne M.
Published: February 2009

Nutrigenetics and personalised nutrition are components of the concept that in the future genotyping will be used as a means of defining dietary recommendations to suit the individual. Over the last two decades there has been an explosion of research in this area, with often conflicting findings reported in the literature. Reviews of the literature in the area of apoE genotype and cardiovascular health, apoA5 genotype and postprandial lipaemia and perilipin and adiposity are used to demonstrate the complexities of genotype–phenotype associations and the aetiology of apparent between-study inconsistencies in the significance and size of effects. Furthermore, genetic research currently often takes a very reductionist approach, examining the interactions between individual genotypes and individual disease biomarkers and how they are modified by isolated dietary components or foods. Each individual possesses potentially hundreds of ‘at-risk’ gene variants and consumes a highly-complex diet. In order for nutrigenetics to become a useful public health tool, there is a great need to use mathematical and bioinformatic tools to develop strategies to examine the combined impact of multiple gene variants on a range of health outcomes and establish how these associations can be modified using combined dietary strategies.
Intervening to change the diets of low-income women
Authors: Davies Jennifer A. , Damani P. , Margetts Barrie M.
Published: February 2009

Diet-related sources of ill health, including Fe-deficiency anaemia, are prevalent in the local South Asian population. This population also has a high prevalence of low-birth-weight babies. A need for preventative measures that take a holistic view to dietary change was identified in a South Asian community in Southampton, UK. A peer-led approach was used, training and developing a local workforce to become community food assistants. This workforce, drawn from local black and minority ethnic communities, ran practical ‘hands-on’ culturally-appropriate food-related activities within their communities that were successful in achieving long-term change in the diets of local women and their families. This model has the potential for achieving sustained behaviour change and is able to engage key target groups that can often be difficult to reach through more traditional routes.
Hannah Arendt, 1906–1975
Authors: Villa Dana
Published: February 2009

This essay provides an overview of the life and theoretical concerns of Hannah Arendt. It traces the way her experience as a German Jew in the 1930s informed her analysis of totalitarianism in The Origins of Totalitarianism and her idea of the “banality of evil” in Eichmann in Jerusalem. The essay takes issue with those of Arendt's critics who detect a lack of “love of the Jewish people” in her writing. It also traces the way Arendt's encounter with totalitarian evil led to a deeper questioning of the anti-democratic impulses in the Western tradition of political thought—a questioning that finds its fullest articulation in The Human Condition and On Revolution. Throughout, my concern is to highlight Arendt's contribution to thinking “the political” in a way friendly to the basic phenomenon of human plurality. I also highlight her recovery and extension of the main themes of the civic republican tradition.
Philosophy as a Way of Life: The Case of Leo Strauss
Authors: Smith Steven B.
Published: February 2009

In this paper I consider Strauss's case for philosophy as a “way of life.” Strauss's case rests, I believe, on a view of philosophy first as a quest—an erotic aspiration—for knowledge of the whole and second as committed to a skeptical view of our ability ever to attain to such knowledge. Moreover, can the philosophic life defend itself against its most powerful alternative, namely, the case for revealed religion or does philosophy itself rest upon an act of faith of its own? I argue that philosophy has the resources to defend itself but only once it is understood as an open-ended (“zetetic”) search for truth. Only by returning to a conception of philosophy as “skeptic in the original sense of the term” can philosophy avoid the twin dogmatisms of faith and unbelief.
Moral Pluralism and Liberal Democracy: Isaiah Berlin's Heterodox Liberalism
Authors: Galston William A.
Published: February 2009

While Isaiah Berlin considered himself principally as a political theorist in the liberal tradition, his was an unorthodox liberalism in both method and substance, rooted in the confluence of three traditions—British, Russian, and Jewish. Unlike many liberals, he wrestled with the tension between universalism and particularism, and also between individualism and communalities. He rejected all monistic approaches to morality (including liberal monism) but repudiated as well the moral relativism of much modern thought, espousing instead value pluralism. While we cannot arrive at a universally valid conception of the summum bonum, we can specify the summun malum—the great evils of the human condition. Berlin saw political theory as a branch of moral philosophy but drew political morality from political life rather than imposing it on politics. The range of goods and principles that human beings rightly prize cannot be combined into harmonious wholes in either our individual or collective existence. Some goods exclude others, and we must choose among them.
Michael Oakeshott, 1901–1990
Authors: Fuller Timothy
Published: February 2009

Michael Oakeshott, one of the most important political thinkers in the second half of the twentieth century, has been understood to be a skeptical conservative, a romantic, a liberal individualist, an historian of political thought, a philosopher, a charismatic teacher. Each of these characterizations conveys something to be found in his life and work. This essay offers an intellectual portrait of his life's work from early to late through consideration of his major works from Experience and its Modes (1933) to Rationalism in Politics (1962; 1991), to the culmination in On Human Conduct (1975). His understanding of political philosophy is examined. The usefulness of the aforementioned characterizations is assessed.
Kinematic analysis of a fully decoupled translational parallel manipulator
Authors: Ruggiu M.
Published: February 2009

The paper describes the kinematic analysis of a new translational parallel manipulator (TPM). The manipulator consists of a fixed base, with a moving platform connected to the base by three identical legs with PUPR chains. The axes of the actuated motions are orthogonal. This configuration provides a very simplified kinematic analysis with fully decoupled input–output linear equations, absence of translational singularities, isotropy and ease of determining the workspace for the moving platform.
Undue Fear of Inducements in Research in Developing Countries
Authors: ARNASON GARDAR , VAN NIEKERK ANTON
Published: February 2009

Prematurely born children who have underdeveloped lungs may suffer a potentially fatal condition called respiratory distress syndrome. A U.S. company developed a drug, called Surfaxin, to treat such poorly functioning lungs. A placebo-controlled study was planned in four Latin American countries (Mexico, Ecuador, Bolivia, and Peru). At the time, in 2001, four treatments were already on the market, although not available to the research populations used in the study. This case is usually discussed as part of the standard of care debate or offered as an example of exploitation. However, what concerns us in this case is rather the choice given to the parents of a prematurely born child under these circumstances: “You can give consent for your child's participation in this study. Half of the babies enrolled will receive sham air and are as likely to die as if they had not enrolled. The other half will receive an active treatment and are more likely to survive.” The parents can vastly increase their baby's chances of survival by participating in the study. Can the consent be voluntary? Do the parents have any meaningful choice?
Vulnerability and Indigenous Communities: Are the San of South Africa a Vulnerable People?
Authors: CHENNELLS ROGER
Published: February 2009

In recent years, healthcare ethics, international law, and political philosophy have been moving closer together. The previously missing links are considerations of justice and their recognition through legal instruments. The most obvious example to date is the topic of benefit sharing.
The Ethics of Bioethics: Mapping the Moral Landscape, edited by Lisa A. Eckenwiler and Felicia G. Cohn. Baltimore, MD: Johns Hopkins University Press, 2007. 328 pp.
Authors: Parsi Kayhan
Published: February 2009

Readers are invited to contact Greg S. Loeben in writing at Midwestern University, Glendale Campus, Bioethics Program, 19555 N. 59th Ave., Glendale, AZ 85308 (gloebe@midwestern.edu) regarding books they would like to see reviewed or books they are interested in reviewing.
Commercial Organ Transplantation in the Philippines
Authors: TURNER LEIGH
Published: February 2009

Countries throughout Asia promote themselves as leading destinations for international travelers seeking inexpensive healthcare. India, Indonesia, Malaysia, Singapore, the Philippines, and Thailand are all trying to attract greater numbers of what their promotional campaigns call “medical tourists.” Government tourism initiatives, hospital associations, medical tourism companies, and individual hospitals advertise hip and knee replacements, spinal surgery, cosmetic surgery, and other medical procedures. In contrast to most nations marketing treatments to international patients, the Philippines differentiates itself by selling “all inclusive” kidney transplant packages. Patients from other countries travel to the Philippines and receive kidneys purchased from poor individuals.
Scholarly Communication in High-Energy Physics: Past, Present and Future Innovations
Authors: Aymar Robert
Published: February 2009

Unprecedented technological advancements have radically changed the way we communicate and, at the same time, are effectively transforming science into e-science. In turn, this transformation calls for an evolution in scholarly communication. This review describes several innovations, spanning the last decades of scholarly communication in High Energy Physics: the first repositories, their interaction with peer-reviewed journals, a proposed model for Open Access publishing and a next-generation repository for the field. We hope that some of these innovations, which are deeply rooted in the highly-interconnected and worldwide flavour of the High-Energy Physics community, can serve as an inspiration to other communities.
New Wine in Old Bottles: Current Developments in Digital Delivery and Dissemination
Authors: Ayris Paul
Published: February 2009

The purpose of this paper is to identify and assess current developments in scholarly publishing in Europe. Current models for disseminating content have limitations and Open Access models of publishing have been endorsed by the European Universities Association. The Harvard mandate for the deposit of materials in Open Access repositories is a bold new development, and the community is watching it with interest. It is possible that e-books may be the next large form of content to be made available to the user. Users certainly express interest in using this form of material. However, current library systems need to be developed in order to cope with this mass of new content. E-theses, available in Open Access from institutional repositories, are a form of content that is made much more visible than the paper equivalents. The DART-Europe portal, supported by LIBER (Association of European Research Libraries) currently provides access to 100,000 research theses in 150 European Universities. At an institutional and academic level, however, much remains to be done to embed Open Access into the landscape: the current situation is described in a new report for UCL (University College London), produced by RAND Europe.
Changing Historical Perspectives on the Nazi Dictatorship
Authors: Mommsen Hans
Published: February 2009

This paper discusses the change of the leading paradigms in the field of contemporary history in the Federal Republic of Germany. While, during the early post-Second World War period, the study of the interwar period was dominated by the theory of totalitarian dictatorship and the discussion of the deficiencies of the Paris peace treaty system, thereby focusing on the charismatic leadership of Adolf Hitler, the post-war generation of German historians analysed the emerging political system of the Third Reich from a more systematic perspective, depicting behind the Hitlerian façade the antagonistic political structure that resulted in an accelerating cumulative radicalisation of the Nazi regime. This functionalist approach, however, has recently been attacked for indirectly exculpating the Nazi crimes by underlining the systemic factors leading to the accumulation of terror and violence and is about to be replaced by a rather moralist interpretation of Nazi politics, accentuating the function of the ‘Volksgemeinschaft’ and the impact of Hitler’s charismatic leadership.
European Literature: Simply a Higher Degree of Universality?
Authors: Casanova Pascale
Published: February 2009

One of the most difficult and uncertain areas of research offered the historian of literature today is the attempt to define ‘European literature’ as a corpus and an object of literary and/or historical analysis. The various efforts of the past few years – in the form of anthologies as well as histories of literature – usually remain torn between a unitary presupposition that seems to be the only acceptable political-historical way of justifying the body of European literature and an irreducibly composite – not to say heterogeneous – reality that is not amenable to the representations of Europe as reduced to this superficial unity. If we are to reflect on the modalities and specificities of such a historical undertaking – which has so few equivalents in the world that it is all the harder to model – and shake off political models and representations, it seems to me that we need to work from another hypothesis. One of the few trans-historical features that constitutes Europe, in effect, one of the only forms of both political and cultural unity – one that is paradoxical but genuine – that makes of Europe a coherent whole, is none other than the conflicts3 and competitions that pitted Europe’s national literary spaces against one another in relentless and ongoing rivalry. Starting from this hypothesis, we would then have to postulate that, contrary to commonly accepted political representations, the only possible literary history of Europe would be the story of the rivalries, struggles and power relations between these national literatures. As a consequence, rather than a unity that remains if not problematic at least far from being achieved, it would no doubt be better to speak of an ongoing literary unification of Europe, in other words a process that occurs, occurred and is still occurring – paradoxically – through these struggles. This upside-down history would trace the models and counter-models, the powers and dependences, the impositions and the resistances, the linguistic rivalries, the literary devices and genres regarded as weapons in these specific, perpetual and merciless struggles. It would be the history of literary antagonisms, battles and revolts.
Voices from Exile: A Literature for Europe?
Authors: Neubauer John
Published: February 2009

Exile, for all of its pain and suffering, has offered European writers a way to step out of their national linguistic and cultural environment. Did exiled writers make use of this opportunity, and start writing a ‘literature for Europe’? By no means all did; many of them sealed themselves off in order to maintain the purity of their mother tongue, while others ‘opened up’ and adjusted to the culture of their host country, often even by adopting its language for their writing. Considering these questions, Pascale Casanova’sLa République mondiale des lettres1is of great help, although her models are Joyce, Beckett, and other writers, who were not exiles in a literal sense. Many ‘genuine’ exiles retained the national mentality of their youth.
Literature and the Symbolic Engineering of the European Self
Authors: Spiridon Monica
Published: February 2009

My study draws on the construction of a pro-European identity in modern Romania, a process set in motion by two main engines: a political one (the export around 1848 of the Great French Revolution, in a ‘tamed’ version, to Eastern Europe) and a cultural one (the emergence of Paris as the capital-city of European modernism). Born at the periphery of the continent, the Romanian identity project puts on display a series of insightful dimensions: a logic of homogenization, a centripetal pull towards centralization, linguistic standardization and unity, against any centrifugal forces of cultural difference, a top-down dynamics and, finally, an imaginary self-colonizing drive. As illustrated by the Romanian case, the paradigm of European nationalism opened up new ways of linking nation-building to the needs of modern societies and the interests of professional elites.
Spanish Literature and the Recovery of Historical Memory
Authors: González José M.
Published: February 2009

This article analyses the recovery of the historical memory of the Spanish Civil War in the last decade, after so many years of silence, forgetfulness and oblivion. Four points are developed: first, how this recovery is achieved by the civil society in general and by the Association for the Recovery of Historical Memory in particular. Secondly, there is a brief allusion to the quarrel between historians and philosophers about the place of memory and remembrance for the construction of the history of Spain. Thirdly, a reference to the recent Historical Memory Law is made, and finally there is a point about the important role played by literature in recovering the memory of many painful facts of the Civil War and Franco’s dictatorship from the point of view of the victims.
English and the Language of Others
Authors: Young Robert J.C.
Published: February 2009

Any consideration of English in the context of a literature for Europe prompts the question of whether English can be contained within the paradigm of Europe, whether it could or should ever be restrained from overflowing its edges and boundaries. While English was created from the crucible of European languages, its filiations have long since stretched far beyond the borders of the continent. Close observation of the dynamics of English, and of English Literature, it could be argued, illustrates one reason why contemporary Britain finds it difficult to limit itself to an exclusively European dimension.
Shape-shifting, sound-change and the genesis of prodigal writing systems
Authors: LAING MARGARET , LASS ROGER
Published: February 2009

In a series of articles we have looked at individual early Middle English writing systems and explored aspects of multivocal sound/symbol and symbol/sound relationships. This article combines previous observations with new material, and provides insights into the genesis of these relations and how they may interconnect. Since many early Middle English texts survive as copies, not originals, they may give clues to the orthographic systems of their exemplars too.

We investigate the ‘extensibility’ of Litteral and Potestatic Substitution Sets. Writing systems may be economical or prodigal. The ‘ideal’ economical system would map into a broad phonetic or a phonemic transcription: that is, one ‘sound’, one symbol. In early Middle English there is no one standard written norm, so there is potentially less restraint on diversity than in standard systems. Further extensibility is built into the system. We show that much of what tends to be dismissed as ‘scribal error’ rather represents writing praxis no longer familiar to us – flexible matrices of substitution and variation.
On the syntactic differences between OE dialects: evidence from the Gospels
Authors: SUÁREZ-GÓMEZ CRISTINA
Published: February 2009

Old English has traditionally been considered a period of linguistic homogeneity, since most available recorded texts are generally written in the West Saxon dialect. There are, however, isolated texts which have been ascribed to other varieties, in particular Northumbrian and Mercian. In fact, recent research on syntactic dialectology in early English (Kroch & Taylor 1997; Ogura 1999; Hogg 2004, 2006a; Ingham 2006) shows that linguistic variation has been present in the English language from the earliest times. This study reassesses the existence of variation in the syntax of texts belonging to different dialectal varieties in Old English, in particular in relative constructions. Based on an analysis of relative clauses in three versions of the Gospels from late Old English, representing West Saxon, Northumbrian and Mercian dialects, we will observe differences in the texts, regarding both the paradigm of relativizers and the position adopted by the relative clause within the main clause. I relate these differences to the existence of linguistic differences in northern and southern dialects.
Structural persistence: a case based on the grammaticalization of English adjectives of difference
Authors: BREBAN TINE
Published: February 2009

In this article, it is proposed that processes of grammaticalization are determined and constrained not only by the source semantics of the grammaticalizing item, i.e.lexicalpersistence in the sense of Hopper (1991), but also by the original structure the item occurs in. This previously unrecognized feature of grammaticalization is referred to asstructural persistence. The need to distinguish a structural equivalent to lexical persistence is argued on the basis of a particularly exemplary case, viz. the grammaticalization processes found with one lexically specific set of grammaticalizing elements in English, adjectives of difference such asother,different,various, etc. Before their grammaticalization, these adjectives occur in two different structural configurations, viz. (1) external comparison, in which the adjective describes a relation of difference between the referent of the noun phrase and a second, separately coded, entity, and (2) internal comparison, in which the entities that are said to be different are all denoted by the noun phrase containing the adjective. Even though they undergo the same general semantic process of grammaticalization and delexicalization in both structures, the adjectives acquire a different grammatical function in each of them. The different outcomes of the grammaticalization process can only be explained by relating them to the specific properties of the two source structures.
Astrocytes process synaptic information
Authors: Araque Alfonso
Published: February 2009

Astrocytes were classically considered as simple supportive cells for neurons without a significant role in information processing by the nervous system. However, considerable amounts of evidence obtained by several groups during the past years demonstrated the existence of a bidirectional communication between astrocytes and neurons, which prompted a re-examination of the role of astrocytes in the physiology of the nervous system. While neurons base their excitability on electrical signals generated across the membrane, astrocytes base their cellular excitability on variations of the Ca2+ concentration in the cytosol. This article discusses our current knowledge of the properties of the synaptically evoked astrocyte Ca2+ signal, which reveals that astrocytes display integrative properties for synaptic information processing. Astrocytes respond selectively to different axon pathways, discriminate between the activity of different synapses and their Ca2+ signal is non-linearly modulated by the simultaneous activity of different synaptic inputs. Furthermore, this Ca2+ signal modulation depends on astrocyte cellular intrinsic properties and is bidirectionally regulated by the level of synaptic activity. Finally, astrocyte Ca2+ elevations can trigger the release of gliotransmitters, which modulate neuronal activity as well as synaptic transmission and plasticity, hence granting the bidirectional communication with neurons. Consequently, astrocytes can be considered as cellular elements involved in information processing by the nervous system.
Transient thermal regimes in the Sierra Nevada and Baja California extinct outer arcs following the cessation of Farallon subduction
Authors: Erkan Kamil , Blackwell David
Published: February 2009

We examine the thermal relaxation of the Sierra Nevada and Baja California extinct outer arc blocks following the progressive cessation of Farallon subduction under western North America beginning at ∼30 Ma. Being parts of the same outer arc until the inland jump of the San Andreas transform fault at ∼5 Ma, these two regions show many similarities in their geology, geomorphology, rigid body behavior, and their relatively low seismicity. In the thermal model, we combine results of different geophysical and geophysical studies to constrain the thermal state and geometry of the outer arcs before the cessation of subduction and then model the postsubduction temperature responses in these regions using the results of the tectonic reconstructions. A well‐constrained regional thermal model of these blocks using the results of many earlier studies in these regions confirms that the present low heat flow values in these regions are the remnants of the very cold outer arc thermal regime of the subduction zone even as long as 30 Ma after cessation of subduction. Thus the entire Pacific boundary of the North American plate is still in a transient thermal state. The calculated low lithospheric temperatures in the Sierra Nevada and Peninsular blocks correlate very well with their rigid body behavior obtained from geodetic studies, and seismogenic layer thicknesses obtained from seismological studies. This is in contrast with the fact that both regions are surrounded by intense deformation associated with the western North America intraplate and extraplate motions. These low‐temperature islands play important roles in the present interaction of the North American and Pacific plates and contribute to the broad deformation of the transform boundary. The thermal relaxation of the extinct outer arcs includes both vertical heating from the underlying asthenosphere and the lateral heating from the extinct back arc (Basin and Range), which has remained as a high heat flow region after the cessation of the subduction. We suggest that the significant lateral heat transfer from the Basin and Range in the Sierra Nevada (and from the Gulf of California spreading center in the Peninsular block since ∼5 Ma) may be the main driving mechanism of the postsubduction volcanism/magmatism along the extinct volcanic arc and the recent tilted uplift of the Sierra Nevada block. The low lithospheric temperatures in Sierra Nevada region may also explain the observation of the high seismic velocities in the mantle beneath the southern Sierra Nevada where the downwelling of the mantle lithosphere proposed.
Channel stability in bed load–dominated streams with nonerodible banks: Inferences from experiments in a sinuous flume
Authors: Eaton Brett C. , Church Michael
Published: February 2009

Experimental and computational evidence shows that bed state adjustments can accommodate a twofold to fourfold change in sediment supply without otherwise affecting the morphology of a sinuous gravel bed stream channel with nonerodible banks. In contrast, previously published experiments of the same kind but with erodible channel banks suggest that changes in sediment supply are taken up almost exclusively by changes in channel sinuosity and hence the reach‐average water surface gradient. It appears that stream channel response to changes in sediment supply is strongly conditioned by the nature of the stream boundary, and that determines which of several potential adjustments are possible.
Linking two consecutive nonmerging magnetic clouds with their solar sources
Authors: Dasso S. , Mandrini C. H. , Schmieder B. , Cremades H. , Cid C. , Cerrato Y. , Saiz E. , Démoulin P. , Zhukov A. N. , Rodriguez L. , Aran A. , Menvielle M. , Poedts S.
Published: February 2009

On 15 May 2005, a huge interplanetary coronal mass ejection (ICME) was observed near Earth. It triggered one of the most intense geomagnetic storms of solar cycle 23 (Dstpeak = −263 nT). This structure has been associated with the two‐ribbon flare, filament eruption, and coronal mass ejection originating in active region 10759 (NOAA number). We analyze here the sequence of events, from solar wind measurements (at 1 AU) and back to the Sun, to understand the origin and evolution of this geoeffective ICME. From a detailed observational study of in situ magnetic field observations and plasma parameters in the interplanetary (IP) medium and the use of appropriate models we propose an alternative interpretation of the IP observations, different to those discussed in previous studies. In our view, the IP structure is formed by two extremely close consecutive magnetic clouds (MCs) that preserve their identity during their propagation through the interplanetary medium. Consequently, we identify two solar events in Hα and EUV which occurred in the source region of the MCs. The timing between solar and IP events, as well as the orientation of the MC axes and their associated solar arcades are in good agreement. Additionally, interplanetary radio type II observations allow the tracking of the multiple structures through inner heliosphere and pin down the interaction region to be located midway between the Sun and the Earth. The chain of observations from the photosphere to interplanetary space is in agreement with this scenario. Our analysis allows the detection of the solar sources of the transients and explains the extremely fast changes of the solar wind due to the transport of two attached (though nonmerging) MCs which affect the magnetosphere.
Pressure‐driven and ionosphere‐driven modes of magnetospheric interchange instability
Authors: Miura Akira
Published: February 2009

A general stability criterion for magnetospheric interchange instability, which includes an ionospheric destabilizing contribution, is derived for an arbitrary finite‐β magnetospheric model satisfying the magnetohydrostatic force balance. The derivation is based on the magnetospheric energy principle. Unperturbed field‐aligned currents in finite‐β nonaxisymmetric magnetospheric models are assumed to close via diamagnetic currents in the magnetosphere or in the ionosphere. By exploiting the limit of a very large perpendicular wave number and the eikonal representation for the perpendicular plasma displacement, the magnetospheric interchange mode is shown to be compressible. In this limit the kink mode makes no contribution to the change in the magnetospheric potential energy. By using magnetospheric flux coordinates, the explicit form of the magnetospheric potential energy change is calculated for interchange perturbations, which do not bend magnetospheric magnetic fields. For a nonaxisymmetric finite‐β magnetospheric model, a combined effect of the pressure gradient and field line curvature, not only in the meridional plane but also in the plane parallel to the longitudinal direction, is responsible for pressure‐driven interchange instability. For an axisymmetric, north‐south symmetric and low‐β magnetospheric model, in which the magnetic field is approximated by a dipole field, the m = 1 or m = 2 ionosphere‐driven mode, where m is the azimuthal mode number, has an upper critical equatorial β value for instability in the order of 1. Thus a substantial region of the inner magnetosphere or the near‐Earth magnetosphere may be unstable against ionosphere‐driven interchange instability caused by a horizontal plasma displacement on the spherical ionospheric surface.
Polarization and phase of planetary‐period magnetic field oscillations on high‐latitude field lines in Saturn's magnetosphere
Authors: Provan G. , Andrews D. J. , Arridge C. S. , Coates A. J. , Cowley S. W. H. , Milan S. E. , Dougherty M. K. , Wright D. M.
Published: February 2009

We examine magnetic field data obtained by the Cassini spacecraft on a sequence of high‐latitude orbits in Saturn's magnetosphere spanning October 2006 to May 2007 to determine whether planetary‐period oscillations are present on polar open field lines, such as have been found previously in near‐equatorial magnetic field data. Such oscillations are found generally to be present with amplitudes ∼0.5–1 nT, somewhat smaller than the few nT amplitudes typical of the quasi‐dipolar equatorial region. The polarization characteristics in the northern and southern polar regions are determined and found to differ significantly from those in the equatorial region. The phases of the oscillations in the northern and southern hemispheres are also determined relative to the equatorial oscillations, and hence relative to each other, requiring extension of the equatorial oscillation phase model to the end of 2007, spanning the interval of high‐latitude orbits. The results show that the overall pattern of field oscillations is not consistent with a rotating external current system that mimics a rotating transverse dipole in the outer regions. Rather, we suggest that the overall field perturbations are associated with a rotating partial ring current and its field‐aligned closure currents, the latter favoring the southern ionosphere during the southern summer conditions examined. A physical picture is presented that links together observed planetary‐period modulations in the middle and outer magnetospheric field, plasma, and radio emissions that may be subject to further test and makes predictions as to how these phenomena will evolve during future Saturn equinox and northern summer conditions.
Critical humidities of homogeneous and heterogeneous ice nucleation: Inferences from extended classical nucleation theory
Authors: Khvorostyanov Vitaly I. , Curry Judith A.
Published: February 2009

A generalization of classical ice nucleation theory is used to derive analytical expressions for the critical (threshold) humidities of homogeneous and heterogeneous freezing. The critical radius and energy of an ice embryo and nucleation rates were derived previously by the authors as functions of temperature, pressure, water saturation ratio, and radii of freezing particles. Here we invert the analytical expressions for the nucleation rates and solve them relative to the critical water and ice saturation ratios (or critical relative humidities). The critical humidities are expressed as analytical functions of temperature, pressure, nucleation or cooling rates, radius of freezing particles and their physico‐chemical properties, misfit strain, and activation energy. Calculations of critical ice relative humidities are made using these equations over an extended temperature range down to −75°C and are compared with previous empirical parameterizations and experimental data, and differences are interpreted in the context of variation of the other parameters. It is shown that the critical humidities for heterogeneous ice nucleation are lower than those for homogeneous nucleation; however, this difference is not constant but depends substantially on the temperature and properties of freezing aerosol. Some simple parameterizations for cloud and climate models are suggested.
Simultaneous observation on electric field changes at 60 m and 550 m from altitude‐triggered lightning flashes
Authors: Zhang Qilin , Qie Xiushu , Wang Zhenhui , Zhang Tinglong , Yang Jing
Published: February 2009

This paper reports the vertical electric field changes measured at 60 m and 550 m for two altitude‐triggered lightning discharges and analyzes the data with two leader models. The results show that the field change waveform produced by bidirectional leader/return stroke at 60 m is asymmetrical V‐shaped with the half‐peak width of about 100 μs. The field waveform of the following dart leader/return stroke sequences at 60 m and 550 m also appear asymmetrical V‐shaped, and the half‐peak widths of the V‐shaped for these two sites are 14 μs and 103 μs, respectively. The difference in the width of field waveforms can be explained by using the source charge leader model. The electric field changes of the dart leaders at 60 m and 550 m are 17.9 kV/m and 1.3 kV/m, respectively, yielding a horizontal distance dependence of d−1.18. At very close ranges (a few tens to hundreds of meters or less), the magnitude of the dart leader field change is not different from that of the following return stroke.
Evaluation of EM‐wave propagation in fully three‐dimensional atmospheric refractive index distributions
Authors: Chaubell Julian , Bruno Oscar P. , Ao Chi O.
Published: February 2009

We present a novel numerical method, based on high‐frequency localization, for evaluation of electromagnetic‐wave propagation through atmospheres exhibiting fully three‐dimensional (height, range and cross‐range) refractive index variations. This methodology, which is based on localization of Rytov‐integration domains to small tubes around geometrical optics paths, can accurately solve three‐dimensional propagation problems in orders‐of‐magnitude shorter computing times than other algorithms available presently. For example, the proposed approach can accurately produce solutions for propagation of ≈20 cm GPS signals across hundreds of kilometers of realistic, three‐dimensional atmospheres in computing times on the order of 1 hour in a present‐day single‐processor workstation, a task for which other algorithms would require, in such single‐processor computers, computing times on the order of several months.
Explicit solutions to two problems of steady groundwater flow with a threshold gradient
Authors: Anderson E. I.
Published: February 2009

We present explicit analytic solutions to two problems of steady, two‐dimensional groundwater flow, where Darcy's law is modified to incorporate a threshold gradient. The presence of a drain or well in both examples generates a free boundary, the stagnation zone boundary, separating flowing groundwater from stagnant groundwater. We use complex analysis, the hodograph, and the Milne‐Thomson circle theorem to evaluate the position of the free boundary directly, without resorting to conformal mapping.
Depth‐averaging errors in reactive transport modeling
Authors: Simpson M. J.
Published: February 2009

Depth‐averaged reactive transport models are commonly used to represent field‐scale contamination in groundwater aquifers. These models rely on simplifying the governing equations through defining a depth‐averaged variable and vertically integrating the full reactive transport equation. This approach is exact provided that the governing equation is linear; however, vertically averaging a nonlinear conservation equation can introduce an error into the simplified model. We present a framework for analyzing this error so that the suitability of a depth‐averaged reactive transport model can be assessed quantitatively before the model is implemented. This framework shows how the error introduced by depth‐averaging reactive transport equations is governed by the parameters in the kinetic model and the geometry of the reactive transport problem.
miR‐29a suppresses tristetraprolin, which is a regulator of epithelial polarity and metastasis
Authors: Gebeshuber Christoph A , Zatloukal Kurt , Martinez Javier
Published: February 2009

Several microRNAs (miRNAs) have recently been described as crucial regulators of epithelial‐to‐mesenchymal transition (EMT) and metastasis. By comparing the expression profiles of miRNAs, we found upregulation of miR‐29a in mesenchymal, metastatic RasXT cells relative to epithelial EpRas cells. Overexpression of miR‐29a suppressed the expression of tristetraprolin (TTP), a protein involved in the degradation of messenger RNAs with AU‐rich 3′‐untranslated regions, and led to EMT and metastasis in cooperation with oncogenic Ras signalling. We also observed enhanced miR‐29a and reduced TTP levels in breast cancer patient samples, indicating relevance for human disease. Previously, miR‐29 family members were shown to have tumour‐suppressive effects in haematopoietic, cholangiocytic and lung tumours. Therefore, miRNAs can act as either oncogenes or tumour suppressors, depending on the context.