bluuebunny/crossref_metadata_2025 huggingface dataset:
A Holocene pollen record of persistent droughts from Pyramid Lake, Nevada, USA
Authors: Mensing Scott A , Benson Larry V , Kashgarian Michaele , Lund Steve
Published: July 2004

Pollen and algae microfossils preserved in sediments from Pyramid Lake, Nevada, provide evidence for periods of persistent drought during the Holocene age. We analyzed one hundred nineteen 1-cm-thick samples for pollen and algae from a set of cores that span the past 7630 years. The early middle Holocene, 7600 to 6300 cal yr B.P., was found to be the driest period, although it included one short but intense wet phase. We suggest that Lake Tahoe was below its rim for most of this period, greatly reducing the volume and depth of Pyramid Lake. Middle Holocene aridity eased between 5000 and 3500 cal yr B.P. and climate became variable with distinct wet and dry phases. Lake Tahoe probably spilled intermittently during this time. No core was recovered that represented the period between 3500 and 2600 cal yr B.P. The past 2500 years appear to have had recurrent persistent droughts. The timing and magnitude of droughts identified in the pollen record compares favorably with previously published δ18O data from Pyramid Lake. The timing of these droughts also agrees with the ages of submerged rooted stumps in the Eastern Sierra Nevada and woodrat midden data from central Nevada. Prolonged drought episodes appear to correspond with the timing of ice drift minima (solar maxima) identified from North Atlantic marine sediments, suggesting that changes in solar irradiance may be a possible mechanism influencing century-scale drought in the western Great Basin.
High-resolution evidence from southern China of an early holocene optimum and a mid-Holocene dry event during the Past 18,000 Years
Authors: Zhou Weijian , Yu Xuefeng , Jull A.J. Timothy , Burr G. , Xiao J.Y. , Lu Xuefeng , Xian Feng
Published: July 2004

Computer models suggest that the Holocene Optimum for East Asian summer monsoon precipitation occurred at different times in different regions of China. Previous studies indicate that this time-transgressive Holocene Optimum should have been experienced about 3000 yr ago in southern China. In this study we describe a section which allows us to test this timing directly. We have closely examined high-resolution eutrophic peat/mud sequences covering the past 18,000 cal yr at Dahu, Jiangxi, on the southern boundary of the mid subtropical zone in China. Late Pleistocene successions in the Dahu record indicate cooler and much wetter conditions relative to synchronous events in north-central China. Our results indicate that the Holocene Optimum occurred between ca. 10,000 and 6000 cal yr ago in southern China, consistent with the global pattern. Conditions were relatively dry and cold from 6000 to 4000 cal yr ago. Our data also support the conclusion that the last deglaciation to early Holocene in the south was much wetter, resulting in the formation of dense broad-leaved forests, which could have acted to moderate land temperature ∼10,000 to 6000 cal yr ago, yielding a stable early-Holocene climate. After 6000 cal yr, forest reduction led to unstable land temperatures, and possibly to a northerly shift of the subtropical high-pressure system. Whatever the mechanism, these changes resulted in decreased precipitation between 6000 and 4000 cal yr B.P. in southern China.
Household Crimes and Domestic Order: Keeping the Peace in Colonial Calcutta, c. 1770–c. 1840
Authors: GHOSH DURBA
Published: July 2004

During the early years of British expansion in Bengal, from the 1770s to the 1840s, British courts ruled on at least three dozen domestic violence cases. In the process of ruling on crimes in which native women were victims of burglary, rape, and murder at the hands of European men, judges on the Supreme Court of Calcutta became intimately involved with enforcing domestic peace and containing the social threat posed by interracial conjugal relationships between lower-class European soldiers and merchants and the native women with whom they cohabited or married. While high-ranking, upper-class men may have also physically abused native women with whom they were intimate, these relationships were rarely the subject of judicial scrutiny. Through criminal trials of domestic crimes or ‘intimate violence’, British judges and magistrates, who were among the highest status positions in the civil service, managed the sexual and familial transgressions of lower-ranking European soldiers, merchants and civil employees, thereby ‘making empire respectable,’ while simultaneously enabling lower-ranking men to enjoy continued sexual access to local women.
Early British Rule and Social Classification in Lanka
Authors: ROGERS JOHN D.
Published: July 2004

Recent scholarship has put forward two distinct interpretations of the origins of modern national and communal identity in South Asia. One sees colonial modernity as a radical epistemological break and judges the content of pre-colonial pasts irrelevant for understanding modern politics. According to this view, modern identities are responses to colonial constructions of Asian ‘tradition’. The other approach sees continuities between the late pre-colonial and early colonial periods. For these writers, the origins of modern national and communal identities lie not only in colonial interventions, but also in non-colonial eighteenth-century social formations and in early colonial interaction between the British and South Asians.
‘The Real Value of the Lands’: The Nawabs, the British and the Land Tax in Eighteenth-Century Bengal
Authors: TRAVERS T. R.
Published: July 2004

Ever since the late eighteenth century, no subject has been more prominent in histories of ‘the transition to colonialism’ in south Asia, than the issue of taxation. In particular, the complex system of agrarian taxation that was developed under the Mughal empire, and further elaborated by various post-Mughal regimes, has often been seen as the defining institution of both the pre-colonial and colonial states. What the British called ‘land revenues’, which included taxes on land proper (mal) and taxes on trade and markets (sair), were the main source of income for both Indian and British rulers. Assessments of the impact of colonial rule have often depended on supposed changes in the tax regime. Since the nineteenth century historians have tended to focus their attention on the relationship between the land tax and structures of agrarian property. They have generally argued that British rule both substantially increased the tax burden, and modified structures of agrarian tenure by splicing together rights of revenue collection and private property in land. But they have focused much more on early colonial policies with regard to private landed property, and less on the issue of the actual tax assessment. This paper takes up the issue of the land tax demand (known as jama in the terminology of Mughal and post-Mughal administration) tracing British debates about tax assessments through the first three decades of colonial rule in Bengal.
Indian Political Representations in Britain during the Transition to Colonialism
Authors: FISHER MICHAEL H.
Published: July 2004

During the transition to colonialism, over thirty Indian political missions ventured to London. Representing the interests of Indian royalty directly in British public discourse, these Indian diplomats strove to reshape colonial policies. They also gathered first-hand intelligence, unmediated by Britons, for their Indian audiences; some later Indian diplomats evidently learned from their precursors. Nonetheless, they increasingly struggled against spreading British colonialism, with its expanding surveillance and control over political communication, growing colonial archives, ever more dominant military force, and cultural assertions. Nor did their relatively isolated efforts accumulate into unified Indian policies. The dynamics of these unequal contests reveal how multi-centered, conflicted, and contingent was political intercourse over this period, in Britain and in India. This article analyzes these Indian missions, concentrating on two: one from early in the transition to colonialism when all parties were exploring the nature of such interactions, and the other late in that process when some Indian diplomats and, even more so, the Company's Directors, had learned to deploy more sophisticated tactics against each other. The 1857 conflict, which ended the Company's rule and established British royal authority over India, altered imperial relations with India's ‘princes’ profoundly, ushering in high colonial rule.
South India 1770–1840: The Colonial Transition
Authors: WASHBROOK DAVID
Published: July 2004

Readers in the historiography of colonial south India have every reason to feel puzzled by the answers available to even the most straightforward of questions. Was the colonial conquest achieved through the imposition of ‘superior’ European arms, technology and ideology or was it more in the nature of an internal subversion of the pre-existing Indian state system? Did British rule fundamentally alter the structures of South Indian society or did it rest lightly on top of pre-existing structures and serve to sustain established elites? Did it undermine the hold of ‘indigenous’ cultures on society or did it merely scratch their surface or even did it promote their revival?
Imagining ‘Greater India’: French and Indian Visions of Colonialism in the Indic Mode
Authors: BAYLY SUSAN
Published: July 2004

This article explores both Western and Asian imaginings of national histories beyond the boundaries of the nation. It seeks to contribute to the history of Asian modernities, and to the anthropological study of nationalism. Its focus is on thinkers and political actors whose visions of both the colonising and decolonising processes were translocal, rather than narrowly territorial in scope.
The lower deck on Aurora: H.V. Goddard's diary, 1913–14
Authors: Quilty Patrick G. , Goddard Peter H.
Published: July 2004

Herbert Victor Goddard was second steward on the voyage of SY Aurora under Captain John King Davis, to retrieve Douglas Mawson and the remaining members of the Australasian Antarctic Expedition (AAE) from Commonwealth Bay in the summer of 1913–14. He kept a previously unpublished diary in pencil. He was on his first and only voyage working at sea and the diary records observations by an optimistic newcomer to the region. It gives the view of the voyage from eyes different from those of the leaders of the expedition, records the daily routine on-board, and documents a few incidents not covered in the formal reports of the expedition.
Incineration of waste at Casey Station, Australian Antarctic Territory
Authors: O'Brien Joanna S. , Todd John J. , Kriwoken Lorne K.
Published: July 2004

The Australian Antarctic Division manages four permanent stations in the sub-Antarctic and Antarctic. At each station a municipal waste incinerator is used to dispose of putrescible waste, wood, paper, cardboard, and plastics. Incineration significantly reduces the volume of waste but this combustion also emits toxic compounds. This study examined the waste incineration stream at Casey Station, Australian Antarctic Territory. The waste stream was sorted, burnt, and the incinerator emissions monitored. Twelve chemical compounds in gaseous emissions and heavy metals in the ash were measured. Results indicate that emissions of carbon monoxide are higher than one might expect from a small incinerator, and hydrocarbon emissions from the incinerator exceed combined hydrocarbon emissions from other sources on station. Arsenic and copper concentrations in ash, which is returned to Australia for disposal, exceed limits for hazardous waste disposal and so treatment would be required. Recommendations are provided on controlling source material in order to reduce or eliminate toxic emissions and undertaking incinerator maintenance to optimise combustion.
Equilibrium distribution of petroleum hydrocarbons in freezing ground
Authors: Barnes David L. , Wolfe Sarah M. , Filler Dennis M.
Published: July 2004

Past documented laboratory measurements have shown movement of petroleum hydrocarbons to the freezing front in contaminated freezing soils. The mechanisms that are, in part, responsible for the increased contaminant concentration at the freezing front are illustrated in this study with a mass-balance model. Results from this quantitative analysis show that this concentration increase is due to exclusion of petroleum hydrocarbon from the crystalline ice structure and from physical displacement of liquid petroleum hydrocarbon from the pore space as water freezes and expands into ice. Consequences of this process in relation to contaminant migration in freezing soils through time are discussed.
Responses to global transformations: gender and ethnicity in resource-based localities in Iceland
Authors: Skaptadóttir Unnur Dís
Published: July 2004

This article examines the impacts of burgeoning globalisation on small fishery-based villages in Iceland. With economic restructuring, new technologies in production, and changing labour migration, the inhabitants are not uniformly able to take advantage of current changes, and some have lost while others have gained. The paper examines the effects on people's lives and experiences and how they cope with these changes locally. The discussion is based on ethnographic field research in the 1990s. It takes a particular look at aspects of local identities that are related to gender and nationality. Since gender and ethnic differences are embedded in social institutions, they are integral parts of individuals' strategies to make better lives for themselves. Gender and nationality are constructed in the process of societal transformations. The primary goal of this paper is to shed light on gender in relation to current transformation. However, nationality is a new marker of difference within the localities — with the growing number of immigrants — that is important to consider. Combining attention to gender and ethnic constructions gives a broad picture of life in fishery villages in the Arctic and the various strategies applied by the inhabitants.
To be different from or to be different than in present-day American English?
Authors: IYEIRI YOKO , YAGUCHI MICHIKO , OKABE HIROKO
Published: July 2004

The present paper discusses the use of the prepositions after different in present-day spoken American English, using the Corpus of Spoken Professional American-English [sic] (CSPAE), which includes transcriptions of conversations recorded between 1994 and 1998. As the corpus consists of four different professional settings (i.e. press conferences held at the White House and other locations, faculty meetings of the University of North Carolina, national meetings on mathematics tests, and national meetings on reading tests), it provides useful data for stylistic analyses. It is also useful for gender analyses of English, since it provides some personal data for most speakers and indicates whether they are male or female.
Code-mixing with a difference
Authors: VISWAMOHAN AYSHA
Published: July 2004

In recent years, the sociolinguistic theory of code-switching and code-mixing has been a source of great interest among scholars worldwide. The phenomenon is common in such multilingual societies as India. Most known cases of code-switching are, however, restricted to the spoken form, in which English is liberally interspersed with such regional languages as Hindi, Marathi, and Telugu. What has not yet significantly caught the attention of scholars is the notion of such switching and mixing in print. This practice is however particularly prevalent among writers in popular magazines, who resort to written code-switching for a variety of reasons. The present paper endeavours to examine the causes of the popularity of this style of writing in the light of some accepted theories of multilingualism.
Wailaici and English borrowings in Chinese
Authors: CHENGGANG ZHOU , YAJUN JIANG
Published: July 2004

We read with interest Hongyuan Wang's article ‘Loans to the Middle Kingdom revisited’ (ET77 Jan 04). This is a response to, and continuation of, Elizabeth Malischewski's 1987 article ‘Loan words to the Middle Kingdom’ in ET12, the author expresses the hope that this description ‘might serve as a useful addition to’ it (Wang 2004:47). We are as delighted to see the topic revisited after sixteen years as the editor, who states that Wang's article is ‘a valued addition to our series on English, China, China English, and Chinglish, and to Malischewski's original piece’ (McArthur 2004:2). However, we found that quite a number of words listed in the article are not loanwords, because of misunderstandings regarding loan word and loan translation in English and wailaici and wailaiyu, equivalents of loanword in a broader sense in Chinese, as a result of which his classification of the borrowings is confusing. The article has also tended to over-simplify the complex situation of such borrowings in Chinese and as such is misleading. We would like in this paper to clarify some of the misunderstandings and offer a brief introduction to the study of English borrowings in Chinese, a field which began c.1913 with the publication of Evan Morgan's Chinese New Terms & Expressions in Shanghai.
Folk etymology: alive and kicking in the 21st century
Authors: KAYE ALAN S.
Published: July 2004

The author focuses on the approach to word origins widely known as ‘folk etymology’, which he regards as ‘alive and kicking in America's leading daily newspapers, duping many a gullible reader’. To do this, he considers the etymology of the phrase ‘so long’ when used to mean ‘good-bye’.
On the bare genitive
Authors: Kaye Alan S.
Published: July 2004

A review of The Cambridge Grammar of the English Language (CGEL) by Rodney Huddleston and Geoffrey K. Pullum.
Consonantal beginnings
Authors: BULLEY MICHAEL
Published: July 2004

The writer discusses possible pairings of consonants at the beginnings of English words.
Talk shows
Authors: BLAISDELL BOB
Published: July 2004

The third in a series of true tales from a city university following on from ‘The jockey and his horse’ in ET75 (Jul 03) and ‘Shame’ in ET76 (Oct 03).
‘Dormez donc, mes chers amours’: Hérold's La Somnambule (1827) and dream phenomena on the Parisian lyric stage
Authors: HIBBERD SARAH
Published: July 2004

Ferdinand Hérold's 1827 ballet-pantomime La Somnambule, written for the Paris Opéra, is generally remembered today only as a source for Bellini's 1831 opera La sonnambula. However, Hérold's work – which also inspired a series of popular vaudevilles on the same theme – illustrates the strong, voyeuristic appeal of the trance phenomenon at the end of the Bourbon Restoration. It can be viewed as encapsulating wide-ranging contemporary ideas about the relationship between sleepwalking, mesmerism, madness and the supernatural. The aims of this article are twofold. First, it seeks to introduce important nuances into the received and often generalised claims usually made about the containing nature of trance scenes in nineteenth-century theatre, positing an alternative model to that of the unhinged heroine of Italian opera familiar from recent feminist writing on opera. Second, it illuminates the musical practices specific to late Restoration Paris that were so crucial to the aesthetic – and the success – of these sleepwalking heroines. A web of visual and musical allusions conjured up an entranced figure who, although related to the Italian operatic madwoman, has a personality and social implications all her own.
Editorial: changing views on Empire and Imperialism
Authors: WESSELING H. L.
Published: July 2004

Words can be confusing and titles can be misleading, particularly if titles consist of one simple word. Two titles suffice to illustrate this phenomenon. In 2000, a book appeared with the title Empire and in 2002 another book appeared with exactly the same title. In the first Empire, Michael Hardt, an American literary theorist, and Antonio Negri, an Italian political philosopher, argued that although classical imperialism is over, Empire is alive and well, albeit in a new form. For them ‘Empire’ means the following: ‘Our basic hypothesis is that sovereignty has taken a new form, composed of a series of national and supranational organisms united under a single logic of rule. This new global form of sovereignty is what we call Empire.’ This is a rather special definition of Empire because what one usually has in mind when using that word is something very different. It is the Empire that the other book, written by the British historian Niall Ferguson, is about. This book describes, as the subtitle indicates, The Rise and Demise of the British World Order. But it is also about something more, as is apparent from the rest of the subtitle: and the Lessons for Global Power. These lessons are intended for the rulers of the Empire of today, the Americans. While the first Empire is the Bible for anti-globalists, Ferguson's book can be considered as the New Testament of the advocates of America's imperial ambitions.
Man and the future environment
Authors: HEAP BRIAN
Published: July 2004

The future is notoriously difficult to predict, but it can be invented. One option would be to develop a strategy directed towards sustainable consumption because, while the patterns of consumption of food, energy and materials, including water, differ greatly in various parts of the world, if business continues as usual, rates of consumption threaten to become a serious source of conflict. Among the challenges of the new century are a better understanding of what is meant by the transition towards sustainable consumption and how science and technology could be used to improve the efficiency with which resources are utilized, new products and processes invented, and the environmental cost of modern lifestyles best evaluated. Efforts to influence the phenomenon of over-consumption in nations that are more developed economically, and address under-consumption in nations that are less developed, are not topics that can be resolved by scientists and technologists alone. Interdisciplinary studies have become increasingly important to elucidate best methods of production, benefits, threats and consumer behaviour. Implementation of new remedies from science and technology, however, requires dialogue with the public on a case-by-case basis and should begin at the earliest stages of innovation. Sustainable consumption as a strategy lies at the heart of sustainable development; it provides the basis of social equity currently undermined by the rich–poor divide and a route to conflict avoidance.
Calvinist and Catholic cities – urban architecture and ritual in confessional Europe
Authors: SCHILLING HEINZ
Published: July 2004

Urban history, at least in Germany, has mainly concentrated on the Medieval and Reformation cities on the one hand and Industrial and Contemporary cities on the other. However, recent debates among Early Modernists have produced the view that ‘confessionalization’, that is the formation of three or four modern church systems based on specific confessions of faith, was one of the most influential factors in producing the fundamental changes that occurred between 1550 and 1650 in Europe. This had a huge effect on the cities of Europe and their inhabitants. This paper compares Catholic and Protestant cities in Europe around 1600 with regard to their specific architecture and their religious and civic rituals. Rites and other religious functions or institutions have always been an important part of urban life. Lewis Mumford refers to religious funeral rites in his magisterial analysis of urban life in a universal perspective: ‘The city of the dead antedates the city of the living. In one sense, indeed the city of the dead is the forerunner, almost the core, of every living city.’ In Europe, the relationship between the Church and the towns or cities was especially close and, in a sense, fundamental because of the medieval history of the European towns and the structure and profile of pre-modern European societies in general. We start with a brief overview of these preconditions for urban life during Europe's confessional period, and then go on to take a closer look at the confessional city itself.
Free and coerced migrations: the Atlantic in global perspective
Authors: ELTIS DAVID
Published: July 2004

What distinguished the mass transatlantic migration that occurred between Columbian contact and the early nineteenth century from the movements of peoples around the globe that occurred both before and after this phenomenon? Two central distinguishing features were the large element of coercion in the movements across the early modern Atlantic world, and the central importance of identity in shaping both the direction of migration and its composition. On the first of these, coercion was a sine qua non, not only of the well-known slave trade, but also of the much smaller migrations of convicts and – given the temporary, if voluntary, signing away of the migrants' freedom – indentured servants and contract labourers. On the second, the question of who became slaves was determined by the refusal of Europeans to enslave other Europeans.
Europe and the immigration debate
Authors: EMMER P. C.
Published: July 2004

The European debate on immigration is marred by stereotypes, such as the supposition that Europe is full, that asylum seekers can be separated from economic immigrants, that the sending countries suffer from brain drain and that immigrants take jobs away from the population in the receiving countries. Many of these arguments can be reversed, but recently immigrants have indeed been costly to the EU taxpayer. However, demographic decline will force Europe to devise a system by which labour immigration can be profitable again for the host countries.
The Olympic Games in antiquity
Authors: PLEKET H. W.
Published: July 2004

The Olympic Games are an invention of the ancient Greeks. They were held in Olympia in a quadrennial rhythm, without interruption for ca. 1200 years. Compared with the modern Olympics, the ancient programme was small: running events (over several distances), the pentathlon, and the so-called ‘heavy’ events: wrestling, boxing and pankration. Various equestrian events (with and without chariots) completed the programme. This programme is discussed with the athletes, their social background and ideology. Although in ancient Olympia a wreath of olive-leaves – a forerunner of our modern gold medal – was the first and only prize, there was no amateurism in Greek athletics. Olympic athletes happily participated in highly rewarding money games both before and after the Olympics. Money was not despised; abuse of money, in the form of Wine, Women and Song was criticized, but some athletes, then as now, were unable to resist the temptations of life.
The predecessors of the Olympic movement, and Pierre de Coubertin
Authors: WEILER INGOMAR
Published: July 2004

Coubertin's contribution to the revival of the Olympic Games and the widespread opinion that the modern Games were ‘a French invention’ should be placed in their broad historical context. There are several arguments for and against the assumption that he was the founder, or ‘father’, of the modern Olympics and the Olympic movement. The historical development of the Olympic ideas since the time of Humanism will be discussed, along with the Renaissance and the various attempts to organize Olympic Games before 1896, with a further emphasis on the importance of Neo-Humanism and classical scholarship in Europe in the 18th and 19th centuries, in order better to understand ancient Greek athletics. Finally Pierre de Coubertin's concept of the Olympic Games and the contributions of the young Greek nation for the rebirth of the famous ancient games after the War of Independence will be analysed.
PD-L1-deficient mice show that PD-L1 on T cells, antigen-presenting cells, and host tissues negatively regulates T cells
Authors: Latchman Yvette E. , Liang Spencer C. , Wu Yin , Chernova Tatyana , Sobel Raymond A. , Klemm Martina , Kuchroo Vijay K. , Freeman Gordon J. , Sharpe Arlene H.
Published: July 2004

Both positive and negative regulatory roles have been suggested for the B7 family member PD-L1(B7-H1). PD-L1 is expressed on antigen-presenting cells (APCs), activated T cells, and a variety of tissues, but the functional significance of PD-L1 on each cell type is not yet clear. To dissect the functions of PD-L1
in vivo
, we generated PD-L1-deficient (PD-L1
–/–
) mice. CD4
+
and CD8
+
T cell responses were markedly enhanced in PD-L1
–/–
mice compared with wild-type mice
in vitro
and
in vivo
. PD-L1
–/–
dendritic cells stimulated greater wild-type CD4
+
T cell responses than wild-type dendritic cells, and PD-L1
–/–
CD4
+
T cells produced more cytokines than wild-type CD4
+
T cells
in vitro
, demonstrating an inhibitory role for PD-L1 on APCs and T cells.
In vivo
CD8
+
T cell responses also were significantly enhanced, indicating that PD-L1 has a role in limiting the expansion or survival of CD8
+
T cells. Studies using the myelin oligodendrocyte model of experimental autoimmune encephalomyelitis showed that PD-L1 on T cells and in host tissues limits responses of self-reactive CD4
+
T cells
in vivo
. PD-L1 deficiency converted the 129S4/SvJae strain from a resistant to experimental autoimmune encephalomyelitis-susceptible strain. Transfer of encephalitogenic T cells from wild-type mice into PD-L1
–/–
recipients led to exacerbated disease. Disease was even more severe in PD-L1
–/–
recipients of PD-L1
–/–
T cells. These results demonstrate that PD-L1 on T cells, APCs, and host tissue inhibits naïve and effector T cell responses and plays a critical role in T cell tolerance.
Snow conditions may create an invisible barrier for lynx
Authors: Stenseth Nils Chr. , Shabbar Amir , Chan Kung-Sik , Boutin Stan , Rueness Eli Knispel , Ehrich Dorothee , Hurrell James W. , Lingjærde Ole Chr. , Jakobsen Kjetill S.
Published: July 2004

The dynamics of Canadian lynx (Lynx canadensis) abundance are geographically structured according to the influence of large-scale climatic regimes. Here we demonstrate that this structuring matches zones of differential snow conditions, in particular surface hardness, as determined by the frequency of winter warm spells. Through a modified functional response curve, we show that various features of the snow may influence lynx interaction with its main prey species, the snowshoe hare (Lepus americanus). This study highlights the importance of snow, and exemplifies how large-scale climatic fluctuations can mechanistically influence population biological patterns.
O-GlcNAcylation regulates phosphorylation of tau: A mechanism involved in Alzheimer's disease
Authors: Liu Fei , Iqbal Khalid , Grundke-Iqbal Inge , Hart Gerald W. , Gong Cheng-Xin
Published: July 2004

Microtubule-associated protein tau is abnormally hyperphosphorylated and aggregated into neurofibrillary tangles in brains of individuals with Alzheimer's disease (AD) and other tauopathies. Tau pathology is critical to pathogenesis and correlates to the severity of dementia. However, the mechanisms leading to abnormal hyperphosphorylation are unknown. Here, we demonstrate that human brain tau was modified by O-GlcNAcylation, a type of protein O-glycosylation by which the monosaccharide β-N-acetylglucosamine (GlcNAc) attaches to serine/threonine residues via an O-linked glycosidic bond. O-GlcNAcylation regulated phosphorylation of tau in a site-specific manner bothin vitroandin vivo. At most of the phosphorylation sites, O-GlcNAcylation negatively regulated tau phosphorylation. In an animal model of starved mice, low glucose uptake/metabolism that mimicked those observed in AD brain produced a decrease in O-GlcNAcylation and consequent hyperphosphorylation of tau at the majority of the phosphorylation sites. The O-GlcNAcylation level in AD brain extracts was decreased as compared to that in controls. These results reveal a mechanism of regulation of tau phosphorylation and suggest that abnormal hyperphosphorylation of tau could result from decreased tau O-GlcNAcylation, which probably is induced by deficient brain glucose uptake/metabolism in AD and other tauopathies.
Somatolactin selectively regulates proliferation and morphogenesis of neural-crest derived pigment cells in medaka
Authors: Fukamachi Shoji , Sugimoto Masazumi , Mitani Hiroshi , Shima Akihiro
Published: July 2004

Species-specific colors and patterns on animal body surfaces are determined primarily by neural-crest-derived pigment cells in the skin (chromatophores). However, even closely related species display widely differing patterns. These contrasting aspects of chromatophores (i.e., the fixed developmental control within species and extreme diversity among species) seem to be a curious and suitable subject for understanding evolution and diversity of organisms. Here we identify a gene responsible for medaka “
color interfere
” mutants by positional cloning. These mutants do not show any obvious morphological and physiological defects other than defects in chromatophore proliferation and morphogenesis. The mutation has been identified as an 11-base deletion in
somatolactin
, which causes truncation 91 aa upstream of the C terminus of the protein's 230 aa.
Somatolactin
transcription changed dramatically during morphological body color adaptation to different backgrounds. This genetic evidence explains
somatolactin
function. Studying this mutant will provide further insights into the development and regulation of chromatophores and clues for reassessing other functions of
somatolactin
suggested in other fish.
Surviving the ice: Northern refugia and postglacial colonization
Authors: Rowe Kevin C. , Heske Edward J. , Brown Patrick W. , Paige Ken N.
Published: July 2004

The contemporary distribution of biological diversity cannot be understood without knowledge of how organisms responded to the geological and climatic history of Earth. In particular, Quaternary expansions and contractions of glacial ice sheets are thought to have played an important role in shaping the distribution of biodiversity among current populations in the north-temperate region. In the central U.S., fossil and palynological data provide support for the maintenance of a large southeastern refuge during the last glacial maximum, and many temperate organisms are believed to have responded to glacial expansion by shifting their ranges to southern refugia and recolonizing northward to track the receding ice sheets. Thus, organisms are assumed to track favorable climates, and species ranges are expected to have shifted significantly. Here we present data from a deciduous forest vertebrate, the eastern chipmunk (
Tamias striatus
) in the central U.S., indicating the maintenance of multiple refugial sources as well as a southward expansion from a northern refugium. These results challenge the view that, during glacial maxima, organisms must have migrated south out of their ranges to track favorable climates.
Pattern of polymorphism after strong artificial selection in a domestication event
Authors: Innan Hideki , Kim Yuseob
Published: July 2004

The process of strong artificial selection during a domestication event is modeled, and its effect on the pattern of DNA polymorphism is investigated. The model also considers population bottleneck during domestication. Artificial selection during domestication is different from a regular selective sweep because artificial selection acts on alleles that may have been neutral variants before domestication. Therefore, the fixation of such a beneficial allele does not always wipe out DNA variation in the surrounding region. The amount by which variation is reduced largely depends on the initial frequency of the beneficial allele,
p
. As a consequence,
p
has a strong effect on the likelihood of detecting the signature of selection during domestication from patterns of polymorphism. These theoretical results are discussed in light of data collected from maize. Although the main focus of this article is on domestication, this model can also be generalized to describe selective sweeps from standing genetic variation.
Essential role of brain-derived neurotrophic factor in adult hippocampal function
Authors: Monteggia Lisa M. , Barrot Michel , Powell Craig M. , Berton Olivier , Galanis Victor , Gemelli Terry , Meuth Sven , Nagy Andreas , Greene Robert W. , Nestler Eric J.
Published: July 2004

Brain-derived neurotrophic factor (BDNF) regulates neuronal development and function. However, it has been difficult to discern its role in the adult brain in influencing complex behavior. Here, we use a recently developed inducible knockout system to show that deleting BDNF in broad forebrain regions of adult mice impairs hippocampal-dependent learning and long-term potentiation. We use the inducible nature of this system to show that the loss of BDNF during earlier stages of development causes hyperactivity and more pronounced hippocampal-dependent learning deficits. We also demonstrate that the loss of forebrain BDNF attenuates the actions of desipramine, an antidepressant, in the forced swim test, suggesting the involvement of BDNF in antidepressant efficacy. These results establish roles for BDNF in the adult, and demonstrate the strength of this inducible knockout system in studying gene function in the adult brain.
Retrovirus resistance factors Ref1 and Lv1 are species-specific variants of TRIM5α
Authors: Hatziioannou Theodora , Perez-Caballero David , Yang Annie , Cowan Simone , Bieniasz Paul D.
Published: July 2004

Mammalian cells express several factors that act in a cell-autonomous manner to inhibit retrovirus replication. Among these are the Friend virus susceptibility factor 1/lentivirus susceptibility factor 1/restriction factor 1 (Ref1) class of restriction factors, which block infection by targeting the capsids of diverse retroviruses. Here we show that lentivirus susceptibility factor 1 and Ref1 are species-specific variants of tripartite interaction motif 5α (TRIM5α), a cytoplasmic body component recently shown to block HIV-1 infection in rhesus macaque cells, and can indeed block infection by widely divergent retroviruses. Depletion of TRIM5α from human cells relieved restriction of N-tropic murine leukemia virus (N-MLV), and expression of human TRIM5α in otherwise nonrestricting cells conferred specific resistance to N-MLV infection, indicating that TRIM5α is Ref1 or an essential component of Ref1. TRIM5α variants from humans, rhesus monkeys, and African green monkeys displayed different but overlapping restriction specificities that were quite accurately predicted by the restriction properties of the cells from which they were derived. All TRIM5α variants could inhibit infection by at least two different retroviruses, and African green monkey TRIM5α was able to inhibit infection by no less than four divergent retroviruses of human, non-human primate, equine, and murine origin. However, each TRIM5α variant was unable to restrict retroviruses isolated from the same species. These data indicate that TRIM5α can confer broad innate immunity to retrovirus infection in primate cells and is likely to be an important natural barrier to cross-species retrovirus transmission.
Unique modifications with phosphocholine and phosphoethanolamine define alternate antigenic forms ofNeisseria gonorrhoeaetype IV pili
Authors: Hegge Finn Terje , Hitchen Paul G. , Aas Finn Erik , Kristiansen Heidi , Løvold Cecilia , Egge-Jacobsen Wolfgang , Panico Maria , Leong Weng Yee , Bull Victoria , Virji Mumtaz , Morris Howard R. , Dell Anne , Koomey Michael
Published: July 2004

Several major bacterial pathogens and related commensal species colonizing the human mucosa express phosphocholine (PC) at their cell surfaces. PC appears to impact host–microbe biology by serving as a ligand for both C-reactive protein and the receptor for platelet-activating factor. Type IV pili ofNeisseria gonorrhoeae(Ng) andNeisseria meningitidis, filamentous protein structures critical to the colonization of their human hosts, are known to react variably with monoclonal antibodies recognizing a PC epitope. However, the structural basis for this reactivity has remained elusive. To address this matter, we exploited the finding that the PilE pilin subunit in Ng mutants lacking the PilV protein acquired the PC epitope independent of changes in pilin primary structure. Specifically, we show by using mass spectrometry that PilE derived from thepilVbackground is composed of a mixture of subunits bearing O-linked forms of either phosphoethanolamine (PE) or PC at the same residue, whereas the wild-type background carries only PE at that same site. Therefore, PilV can influence pilin structure and antigenicity by modulating the incorporation of these alternative modifications. The disaccharide covalently linked to Ng pilin was also characterized because it is present on the same peptides bearing the PE and PC modifications and, contrary to previous reports, was found to be linked by means of 2,4-diacetamido-2,4,6-trideoxyhexose. Taken together, these findings provide new insights into Ng type IV pilus structure and antigenicity and resolve long-standing issues regarding the nature of both the PC epitope and the pilin glycan.
The human and African green monkey TRIM5α genes encode Ref1 and Lv1 retroviral restriction factor activities
Authors: Keckesova Zuzana , Ylinen Laura M. J. , Towers Greg J.
Published: July 2004

The rhesus macaque tripartite motif containing protein TRIM5α specifically restricts HIV-1 infection at an early post-entry step before reverse transcription [Stremlau, M., Owens, C. M., Perron, M. J., Kiessling, M., Autissier, P. & Sodroski, J. (2004)
Nature
427, 848–853]. Here, we show that the human and African green monkey (AGM) TRIM5α genes encode Ref1 and Lv1 antiretroviral activities, respectively. Expression of TRIM5α in permissive cat cells renders them resistant to restriction-sensitive murine leukemia virus but not closely related insensitive virus. Disruption of TRIM5α expression in human and AGM cells with small interfering RNA rescues infectivity of restricted virus without affecting unrestricted virus. We also demonstrate that the activity of the murine restriction factor Fv1 depends on TRIM5α expression when Fv1 is expressed in human cells. Furthermore, a drug that modifies the behavior of the related promyelocytic leukemia protein PML specifically rescues infection by viruses restricted by human TRIM5α. Alignment of the TRIM5α proteins from rhesus macaque and AGM indicates an 18-aa insertion. We speculate that this insertion may contribute to the broader specificity of the AGM TRIM5α restriction as compared with the human and rhesus macaque proteins.
Chaotic microlasers based on dynamical localization
Authors: Podolskiy Viktor A. , Narimanov Evgenii , Fang Wei , Cao Hui
Published: July 2004

We report the direct observation of lasing action from a dynamically localized mode in a microdisk resonator with rough boundary. In contrast to microlasers based on stable ray trajectories, the performance of our device is robust with respect to the boundary roughness and corresponding ray chaos, taking advantage of Anderson localization in angular momentum. The resonator design, although demonstrated here in GaAs-InAs microdisk laser, should be applicable to any lasers and sensors based on semiconductor or polymer materials.
Magnetic circular dichroism of peralkylated tetrasilane conformers
Authors: Fogarty Heather A. , Imhof Roman , Michl Josef
Published: July 2004

Magnetic circular dichroism (MCD) of five peralkylated tetrasilanes (
1
–
5
) conformationally constrained to angles ranging from nearly 0° to 180° and of the open chain tetrasilane Si
4
Me
10
(
6
) shows a clear conformational dependence and permits the detection of previously hidden transitions. In the tetrasilane CH
2
Si
4
Me
8
(
1
), with the smallest dihedral angle, comparison of MCD with absorption spectra reveals four low-energy electronic transitions. In the tetrasilanes 2–4, three distinct transitions are apparent. In tetrasilanes 5 and 6, MCD reveals the very weak transition that has been predicted to be buried under the first intense peak and to which the anomalous thermochromism of 6 and other short-chain oligosilanes has been attributed.
An amyloid-forming segment of β2-microglobulin suggests a molecular model for the fibril
Authors: Ivanova Magdalena I. , Sawaya Michael R. , Gingery Mari , Attinger Antoine , Eisenberg David
Published: July 2004

In humans suffering from dialysis-related amyloidosis, the protein β2-microglobulin (β2M) is deposited as an amyloid; however, an amyloid of β2M is unknown in mice. β2M sequences from human and mouse are 70% identical, but there is a seven-residue peptide in which six residues differ. This peptide from human β2M forms amyloid
in vitro
, whereas the mouse peptide does not. Substitution of the human peptide for its counterpart in the mouse sequence results in the formation of amyloid
in vitro
. These results show that a seven-residue segment of human β2M is sufficient to convert β2M to the amyloid state, and that specific residue interactions are crucial to the conversion. These observations are consistent with a proposed Zipper-spine model for β2M amyloid, in which the spine of the fibril consists of an anhydrous β-sheet.
Development of a cancer DNA phenotype prior to tumor formation
Authors: Malins Donald C. , Anderson Katie M. , Gilman Naomi K. , Green Virginia M. , Barker Edward A. , Hellström Karl Erik
Published: July 2004

Using the carcinogen 3-methylcholanthrene (MCA), we demonstrate with Fourier transform-infrared spectroscopy that a cancer DNA phenotype is produced well in advance of palpable tumors. We further demonstrate that the administration of cyclophosphamide markedly inhibits the development of the cancer phenotype and concomitantly delays tumor formation. MCA, injected into the hind legs of mice, produced a variety of significant structural changes in the nucleotide bases and phosphodiester-deoxyribose backbone, as reflected in a substantial (34%) difference between the mean DNA spectra of the control and the MCA-injected mice. Strikingly, 57 days before the mean appearance of tumors, we could not distinguish the DNA structure of the histologically normal tissues of the MCA-injected mice from the DNA structure of the tumor tissues. This finding indicates the early development of a cancer phenotype. Confirmatory evidence was obtained when tissues from a group of mice injected with both MCA and cyclophosphamide did not manifest the cancer phenotype, and their mean DNA structure closely resembled that of the control mice. Accordingly, we propose that the cancer DNA phenotype, as evinced by Fourier transform-infrared spectroscopy, is a promising early indicator of tumor formation, and we postulate that agents capable of inhibiting this phenotype may delay or prevent carcinogenesis.
A rare-cell detector for cancer
Authors: Krivacic Robert T. , Ladanyi Andras , Curry Douglas N. , Hsieh H. B. , Kuhn Peter , Bergsrud Danielle E. , Kepros Jane F. , Barbera Todd , Ho Michael Y. , Chen Lan Bo , Lerner Richard A. , Bruce Richard H.
Published: July 2004

Although a reliable method for detection of cancer cells in blood would be an important tool for diagnosis and monitoring of solid tumors in early stages, current technologies cannot reliably detect the extremely low concentrations of these rare cells. The preferred method of detection, automated digital microscopy (ADM), is too slow to scan the large substrate areas. Here we report an approach that uses fiber-optic array scanning technology (FAST), which applies laser-printing techniques to the rare-cell detection problem. With FAST cytometry, laser-printing optics are used to excite 300,000 cells per sec, and emission is collected in an extremely wide field of view, enabling a 500-fold speed-up over ADM with comparable sensitivity and superior specificity. The combination of FAST enrichment and ADM imaging has the performance required for reliable detection of early-stage cancer in blood.