bluuebunny/crossref_metadata_2025 huggingface dataset:
Myosin‐dependent transport in neurons
Authors: Bridgman Paul C.
Published: December 2003

Axonal transport in neurons has been shown to be microtubule dependent, driven by the molecular motor proteins kinesin and dynein. However, organelles undergoing fast transport can often pause or rapidly change directions without apparent dissociation from their transport tracks. Cytoskeletal polymers such as neurofilaments and microtubules have also been shown to make infrequent but rapid movements in axons indicating that their transport is likely to involve molecular motors. In addition, neurons have multiple compartments that are devoid of microtubules where transport of organelles is still seen to occur. These areas are rich in other cytoskeletal polymers such as actin filaments. Transported organelles have been shown to associate with multiple motor proteins including myosins. This suggests that nonmicrotubule‐based transport may be myosin driven. In this review we will focus our attention on myosin motors known to be present in neurons and evaluate the evidence that they contribute to transport or other functions in the different compartments of the neuron. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 164–174, 2004
Thermal degradation kinetics and lifetime prediction of a luminescent conducting polymer
Authors: Wang Huimin , Tao Xiaoming , Newton Edward
Published: December 2003

The thermal stability, degradation kinetics and lifetime‐prediction of a luminescent conducting polymer, poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV), are investigated. The derivative thermogravimetry curves indicate a double‐stage decomposition process in a nitrogen atmosphere, and a multi‐stage decomposition process in an air atmosphere. The apparent activation energy values of MEH‐PPV are higher in nitrogen than in air. Activation energies slightly increase and are then approximately stable in nitrogen for the initial mass loss, while the activation energy changes differently with the percentage mass loss in air. The activation energy decreases for the initial mass loss and increases with mass loss when the mass loss is above 30%; beyond 70% it decreases again. The lifetime of MEH‐PPV decreases dramatically from 106 min to 0.03 min as the temperature increases from 25 °C to 300 °C in air. The lifetime is longer in nitrogen than in air and decreases from 1014 min to 2.34 min with increasing the temperature from 25 °C to 300 °C in nitrogen. These lifetime parameters indicate that the service/process temperature has a strong influence on the luminescence of MEH‐PPV. The maximum absorption and wavelength at maximum absorption of MEH‐PPV decrease with increasing temperature in the visible region. Copyright © 2003 Society of Chemical Industry
Improved high‐temperature performance of iron (II) complexes for ethylene polymerization by variation of aluminoxanes
Authors: Yang Huaxiang , Wang Qi , Fan Zhiqiang , Xu Hong
Published: December 2003

Modification of ethyl‐iso‐butylaluminoxanes (EBAOs) with alkyl boronic acid resulted in different co‐catalytic performances when combined with iron complexes for ethylene polymerization, in particular the preferred high‐temperature performance. The changes in polymerization activity and molecular weight distribution of the resulting polymer derived from the variation of aluminoxane were investigated. The varying performance of the iron complex with different aluminoxanes has proved that the interaction between the late transition metal complex and aluminoxane greatly affects the performance of such bicomponent catalyst systems Copyright © 2003 Society of Chemical Industry
Swelling behaviour of a new kind of polyampholyte hydrogel composed of dimethylaminoethyl methacrylate and acrylic acid
Authors: Zhai Maolin , Chen Yanfeng , Yi Min , Ha Hongfei
Published: December 2003

Poly[(dimethylaminoethyl methacrylate)‐co‐(acrylic acid)] [poly(DMAEMA‐co‐AAc)] hydrogels have been synthesized by UV‐induced copolymerization of dimethylaminoethyl methacrylate (DMAEMA) and acrylic acid monomer. The effects of pH and ionic strength on the swelling behaviour of poly(DMAEMA‐co‐AAc) hydrogels were investigated in detail. It was found that there is minimal equilibrium swelling ratio (ESR) for the hydrogels with the change of pH, and the pH at minimal ESR of the hydrogels was defined by the isoelectric points (IEP), similar to the situation with protein molecules. The IEP of the hydrogels shifted to higher values with increase in the DMAEMA content in the hydrogels. Antipolyelectrolyte behaviour of the hydrogels at a pH near the IEP was observed as well, and the ESR increased with increasing ionic strength. The study of swelling kinetics of the hydrogels showed that the swelling process was Fickian at the IEP and non‐Fickian when the pH deviated from the IEP. Copyright © 2003 Society of Chemical Industry
Synthesis and characterization of ethoxy‐terminated ladder‐like polymethylsilsesquioxane oligomer
Authors: Duan Qinghua , Zhang Yong , Jiang Jinqiang , Deng Kuilin , Zhang Taoyi , Xie Ping , Zhang Rongben , Fu Pengfei
Published: December 2003

A fully ethoxy‐terminated ladder‐like polymethylsilsesquioxane oligomer (EtO‐Me‐T) has been synthesized and characterized for the first time using an effective transient catalyst (tetramethylammonium hydroxide, TMAH) via the dehydration alcoholysis reaction of hydroxy‐terminated ladder‐like polymethylsilsesquioxane (HO‐Me‐T) prepared by a modified stepwise coupling polymerization approach. Compared with the common acidic or basic catalysts, use of the transient catalyst TMAH can not only make the HO‐Me‐T molecules fully ethoxy‐terminated but also enables the catalyst to be readily and thoroughly removed after completion of the alcoholysis reaction. It is noteworthy that the common acidic or basic catalysts widely used in the dehydration alcoholysis reaction are clearly unsuitable for the preparation of EtO‐Me‐T oligomer because the latter would be hydrolyzed unavoidably back to the parent HO‐Me‐T during the washing process. In addition, preliminary exploration indicates that, when compared with the tetraethyl orthosilicate (Si(OEt)4) generally used as a crosslinking agent for the room‐temperature vulcanization of silicone rubber (RTV‐SR), the oligomer EtO‐Me‐T is a promising replacement which can greatly improve the mechanical properties of RTV‐SR Copyright © 2003 Society of Chemical Industry
Solution structure of ADO1, a toxin extracted from the saliva of the assassin bug, Agriosphodrus dohrni
Authors: Bernard Cédric , Corzo Gerardo , Adachi‐Akahane Satomi , Foures Guillaume , Kanemaru Kazunori , Furukawa Yasuo , Nakajima Terumi , Darbon Hervé
Published: December 2003

ADO1 is a toxin purified from the saliva of the assassin bug, Agriosphodrus dohrni. Because of its similarity in sequence to Ptu1 from another assassin bug, we did not assess its pharmacologic target. Here, we demonstrate by electrophysiologic means that ADO1 targets the P/Q‐type voltage‐sensitive calcium channel. We also determine the solution structure of ADO1 using two‐dimensional NMR techniques, followed by distance geometry and molecular dynamics. The structure of ADO1 belongs to the inhibitory cystine knot (ICK) structural family (i.e., a compact disulfide‐bonded core from which four loops emerge). ADO1 contains a two‐stranded, antiparallel β‐sheet structure. We compare the structure of ADO1 with other voltage‐sensitive calcium‐channel blockers, analyze the topologic juxtaposition of key functional residues, and conclude that the recognition of voltage‐sensitive calcium channels by toxins belonging to the ICK structural family requires residues located on two distinct areas of the molecular surface of the toxins. Proteins 2003. © 2003 Wiley‐Liss, Inc.
Using evolutionary information for the query and target improves fold recognition
Authors: Wallner Björn , Fang Huisheng , Ohlson Tomas , Frey‐Skött Johannes , Elofsson Arne
Published: December 2003

In this study, we show that it is possible to increase the performance over PSI‐BLAST by using evolutionary information for both query and target sequences. This information can be used in three different ways: by sequence linking, profile–profile alignments, and by combining sequence–profile and profile–sequence searches. If only PSI‐BLAST is used, 16% of superfamily‐related protein domains can be detected at 90% specificity, but if a sequence–profile and a profile–sequence search are combined, this is increased to 20%, profile–profile searches detects 19%, whereas a linking procedure identifies 22% of these proteins. All three methods show equal performance, but the best combination of speed and accuracy seems to be obtained by the combined searches, because this method shows a good performance even at high specificity and the lowest computational cost. In addition, we show that the E‐values reported by all these methods, including PSI‐BLAST, underestimate the true rate of false positives. This behavior is seen even if a very strict E‐value cutoff and a limited number of iterations are used. However, the difference is more pronounced with a looser E‐value cutoff and more iterations. Proteins 2003;53:000–000. © 2003 Wiley‐Liss, Inc.
NH…O, OH…O, and CH…O hydrogen bonds in protein–ligand complexes: Strong and weak interactions in molecular recognition
Authors: Sarkhel Sanjay , Desiraju Gautam R.
Published: December 2003

The characteristics of NH…O, OH…O, and CH…O hydrogen bonds are examined in a group of 28 high‐resolution crystal structures of protein–ligand complexes from the Protein Data Bank and compared with interactions found in small‐molecule crystal structures from the Cambridge Structural Database. It is found that both strong and weak hydrogen bonds are involved in ligand binding. Because of the prevalence of multifurcation, the restrictive geometrical criteria set up for hydrogen bonds in small‐molecule crystal structures may need to be relaxed in macromolecular structures. For example, there are definite deviations from linearity for the hydrogen bonds in protein–ligand complexes. The formation of CH…O hydrogen bonds is influenced by the activation of the CαH atoms and by the flexibility of the side‐chain atoms. In contrast to small‐molecule structures, anticooperative geometries are common in the macromolecular structures studied here, and there is a gradual lengthening as the extent of furcation increases. CH…O bonds formed by Gly, Phe, and Tyr residues are noteworthy. The numbers of hydrogen bond donors and acceptors agree with Lipinski's “rule of five” that predicts drug‐like properties. Hydrogen bonds formed by water are also seen to be relevant in ligand binding. Ligand CH…Ow interactions are abundant when compared to NH…Ow and OH…Ow. This suggests that ligands prefer to use their stronger hydrogen bond capabilities for use with the protein residues, leaving the weaker interactions to bind with water. In summary, the interplay between strong and weak interactions in ligand binding possibly leads to a satisfactory enthalpy–entropy balance. The implications of these results to crystallographic refinement and molecular dynamics software are discussed. Proteins 2004. ©2003 Wiley‐Liss, Inc.
From “Try It and See” to strategic exploration: Characterizing young children's scientific reasoning
Authors: Tytler Russell , Peterson Suzanne
Published: December 2003

This article explores ways of characterizing different dimensions and levels of scientific reasoning in early elementary school children, in the context of open explorations. The article focuses on children's performance on three probes which involve using evidence to generate and evaluate knowledge claims. A number of dimensions have been used to characterize children's approaches to exploration and knowledge construction, which demonstrate the interrelationship between conceptual knowledge and scientific reasoning. Children differed markedly across these dimensions, yet individual children were relatively consistent in their approach to the tasks. The major differences in performance are linked to fundamental distinctions in the way ideas are viewed in relation to evidence. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 41: 94–118, 2004
Linear Approximation of Execution-Time Constraints
Authors: Lermer Karl , Fidge Colin J. , Hayes Ian J.
Published: December 2003

This paper defines an algorithm for predicting worst-case and best-case execution times, and determining execution-time constraints of control-flow paths through real-time programs using their partial correctness semantics. The algorithm produces a linear approximation of path traversal conditions, worst-case and best-case execution times and strongest postconditions for timed paths in abstract real-time programs. Also shown are techniques for determining the set of control-flow paths with decidable worst-case and best-case execution times. The approach is based on a weakest liberal precondition semantics and relies on supremum and infimum calculations similar to standard computations from linear programming and Presburger arithmetic. The methodology is applicable to any executable language with a predicate transformer semantics and hence provides a verification basis for both high-level language and assembly code execution-time analysis.
Late Quaternary stratigraphy and geochronology of the western Killpecker Dunes, Wyoming, USA
Authors: Mayer James H. , Mahan Shannon A.
Published: December 2003

New stratigraphic and geochronologic data from the Killpecker Dunes in southwestern Wyoming facilitate a more precise understanding of the dune field’s history. Prior investigations suggested that evidence for late Pleistocene eolian activity in the dune field was lacking. However, luminescence ages from eolian sand of ∼15,000 yr, as well as Folsom (12,950–11,950 cal yr B.P.) and Agate Basin (12,600–10,700 cal yr) artifacts overlying eolian sand, indicate the dune field existed at least during the latest Pleistocene, with initial eolian sedimentation probably occurring under a dry periglacial climate. The period between ∼13,000 and 8900 cal yr B.P. was characterized by relatively slow eolian sedimentation concomitant with soil formation. Erosion occurred between ∼8182 and 6600 cal yr B.P. on the upwind region of the dune field, followed by relative stability and soil formation between ∼5900 and 2700 cal yr B.P. The first of at least two latest Holocene episodes of eolian sedimentation occurred between ∼2000 and 1500 yr, followed by a brief (∼500 yr) episode of soil formation; a second episode of sedimentation, occurring by at least ∼700 yr, may coincide with a hypothesized Medieval warm period. Recent stabilization of the western Killpecker Dunes likely occurred during the Little Ice Age (∼350–100 yr B.P.). The eolian chronology of the western Killpecker Dunes correlates reasonably well with those of other major dune fields in the Wyoming Basin, suggesting that dune field reactivation resulted primarily due to departures toward aridity during the late Quaternary. Similar to dune fields on the central Great Plains, dune fields in the Wyoming Basin have been active under a periglacial climate during the late Pleistocene, as well as under near-modern conditions during the latest Holocene.
RORα1 and RORα4 suppress TNF‐α‐induced VCAM‐1 and ICAM‐1 expression in human endothelial cells
Authors: Migita Hideyuki , Satozawa Noboru , Lin Jiing-Huey , Morser John , Kawai Kohichi
Published: December 2003

Retinoic acid receptor‐related orphan receptor‐α (RORα) is a nuclear orphan receptor. Adenovirus‐mediated overexpression of RORα1 and RORα4 suppressed tumor necrosis factor‐α (TNF‐α)‐induced expression of vascular cell adhesion molecule‐1 (VCAM‐1) and intracellular adhesion molecule‐1 (ICAM‐1) in human umbilical vein endothelial cells. Overexpression of RORα1 and RORα4 also suppressed TNF‐α‐stimulated translocation of p50 and p65 to the nucleus. In contrast, dominant‐negative deletion mutants of RORα1 and RORα4 failed to suppress the induction of VCAM‐1 and ICAM‐1 and translocations of p50 and p65. These results suggest that RORα1 and RORα4 regulate the inflammatory responses via inhibition of the nuclear factor‐κB signaling pathway in endothelial cells.
Evolutional analysis of human influenza A virus N2 neuraminidase genes based on the transition of the low‐pH stability of sialidase activity1
Authors: Suzuki Takashi , Takahashi Tadanobu , Saito Takehiko , Guo Chao-Tan , Hidari Kazuya I.-P.Jwa , Miyamoto Daisei , Suzuki Yasuo
Published: December 2003

The 1957 and 1968 human pandemic influenza A virus strains as well as duck viruses possess sialidase activity under low‐pH conditions, but human H3N2 strains isolated after 1968 do not possess such activity. We investigated the transition of avian (duck)‐like low‐pH stability of sialidase activities with the evolution of N2 neuraminidase (NA) genes in human influenza A virus strains. We found that the NA genes of H3N2 viruses isolated from 1971 to 1982 had evolved from the side branches of NA genes of H2N2 epidemic strains isolated in 1968 that were characterized by the low‐pH‐unstable sialidase activities, though the NA genes of the 1968 pandemic strains preserved the low‐pH‐stable sialidase. These findings suggest that the prototype of the H3N2 epidemic influenza strains isolated after 1968 probably acquired the NA gene from the H2N2 low‐pH‐unstable sialidase strain by second genetic reassortment in humans.
THE INNOCENCE OF JACQUES-PIERRE BRISSOT
Authors: BURROWS SIMON
Published: December 2003

Even during his lifetime, the French revolutionary Girondin leader Jacques-Pierre Brissot de Warville's reputation was tarnished by allegations that, before 1789, he was a swindler, police spy, and political pornographer. These charges resurfaced in 1968 in a celebrated article by Robert Darnton, which found miscellaneous, fragmentary evidence to support them, above all in the papers of the pre-revolutionary police chief, Lenoir. Although Darnton's view has been challenged by several historians, no critic has supplied any substantive new evidence, and hence the Brissot debate remains mired in assertions and counter-assertions. This article finally offers such evidence, drawing both on Darnton's main source, the Lenoir papers, and on sources unavailable to him in 1968, notably records of Brissot's Licée de Londres and his embastillement, now on deposit in the Archives Nationales. While acquiting Brissot on all counts, it finds that Darnton's suspicions were not entirely unfounded. Brissot did have compromising links to both police and political pornographers. Nevertherless, allegations that he spied and wrote scandalous pamphlets appear malicious, despite Brissot's arrest on the latter charge in 1784. The article also attempts to explain Brissot's motivations and the lasting implications of his arrest and persecution in shaping Brissot and the French Revolution.
MOSCOW'S INTERWAR INFILTRATION OF BRITISH INTELLIGENCE, 1919–1929
Authors: MADEIRA VICTOR
Published: December 2003

The celebrated ‘Cambridge five’ have hitherto been believed to be the first long-term communist penetration agents in HM government, beginning with Donald Maclean in 1935. However, new research indicates that by 1919 another Cambridge man – like four of the ‘five’, a Trinity graduate – had already begun working for Moscow. This article is the first to examine how William Norman Ewer, known as ‘Trilby’ to his co-conspirators, organized networks in Great Britain and France to target the governments of those two powers. Under close Soviet supervision, Ewer's subordinates infiltrated half-a-dozen Whitehall departments, foremost among them Scotland Yard. Operating under the aegis of the home office, the Yard was a vital cog in the machinery of government set up to combat the ‘red menace’ in this country immediately after the First World War. By compromising the lead agency tasked with fighting them, the Bolsheviks thus created the requisite conditions for the metastasis in Great Britain of Soviet espionage in the 1920s.
‘Bawku is still volatile’: ethno-political conflict and state recognition in Northern Ghana
Authors: Lund Christian
Published: December 2003

This article analyses a longstanding ethno-political conflict between Kusasis and Mamprusis in Bawku in north-east Ghana. A double argument is pursued. First, while communal conflict and violence challenge the state and expose its incapacity, the conflicts (played out over chieftaincy, party politics, land, markets, names of places etc.) at the same time invoke a powerful idea of the state as the most significant institution to qualify claims as rights or discard them as illegitimate. Second, the broad variety of social conflicts has effectively been cut to fit an ethnic distinction. Thus, the various conflictual issues have ‘confirmed’ and structured each other. The antagonisms have been crystallised and a pattern entrenching conflict between the two groups has been perpetuated. The article draws historical lines from the 1930s to the present, linking national policy to local politics and political culture with a particular focus on the political manifestations vis-à-vis the state and the use of ‘history’ to justify claims.
From jambanja to planning: the reassertion of technocracy in land reform in south-eastern Zimbabwe?
Authors: Chaumba Joseph , Scoones Ian , Wolmer William
Published: December 2003

This paper examines the land occupations and fast-track resettlement process in Chiredzi district in Zimbabwe's southeast lowveld, and argues that their broad-brush representation as chaotic, violent and unplanned is misleading. In Zimbabwe the instruments and mechanisms of order assert themselves even in the midst of violent disorder. The on-going deployment of the formal and technical tools and discourses of land-use planning have been instrumental in securing the visibility and legitimacy of Zimbabwe's new settlers. The speed and short cuts of the fast-track land reform process and vagueness of policies to date have in the short term opened up a certain amount of space for negotiation and a degree of leeway and flexibility in land-use planning and allocation. But the danger for the settlers is that, by deploying a discourse rooted in long-held and institutionally embedded Rhodesian traditions of planning and control, they have played into a process that – as so often in Zimbabwe's history – will re-impose coercive land-use regulations that are at odds with their livelihood strategies and seek to vet settlers and so undermine populist claims of redressing inequalities and providing land to the landless and poor.
Private Lives, State Intervention: Cases of Runaway Marriage in Rural North India
Authors: Chowdhry Prem
Published: December 2003

The introduction of modern concepts like adulthood and sanctity given to individual rights has legally turned the individual settlement of marriage between two consenting adults to be legitimate. Under the Hindu Marriage Act 1955, except for certain incest taboos, the legal restrictions on marriage of two adult Hindus are almost non-existent. Briefly speaking, this means that under the law both sagotra (same gotra) and inter-caste marriages are permitted. Yet, the customary rules regulating marriages in most parts of north India are based upon caste endogamy, village and clan exogamy. While keeping within caste, they adopt the gotra or got, as is known in rural north India, rule of exogamy (gotra are an exogamous patrilineal clan whose members are thought to share patrilineal descent from a common ancestor). For marriage certain prohibited degrees of kinship have to be avoided. As a rule three or four got exogamy is followed by most caste groups upper or lower. Any break in this, though legally allowed, is not acceptable.
A Disguised Defeat: The Myanmar Campaign of the Qing Dynasty
Authors: Dai Yingcong
Published: December 2003

The Qing Myanmar campaign (1765-1770) was the most disastrous frontier war that the Qing dynasty had ever waged. In the beginning, the Qianlong emperor (r. 1735-1795) of the Qing dynasty had envisaged winning this war in one easy stroke, as he deemed Myanmar no more than a remote barbarian tribe without any power. But he was wrong. After the Green Standard troops in Yunnan failed to bring the Myanmar to their knees, Qianlong sent his elite Manchu troops in. A regional conflict was thus escalated into a major frontier war that involved military maneuvers nationwide. At the front, the Manchu Bannermen had to deal with the unfamiliar tropical jungles and swamps, and above all, the lethal endemic diseases. Not only did one after another commander-in-chief of the Qing dynasty fail to conquer Myanmar, but the Qing troops also suffered extremely heavy casualties. After a gruelling four-year campaign, a truce was reached by the field commanders of the two sides at the end of 1769 with the Qing invading expedition failing to conquer Myanmar and withdrawing in disarray. To rehabilitate itself, the Qing dynasty kept a heavy military lineup in the border areas of Yunnan for about one decade in an attempt to wage another war while imposing a ban on inter-border trade for two decades.
In Search of the British Indian in British India: White Orphans, Kipling's Kim,
and Class in Colonial India
Authors: Hubel Teresa
Published: December 2003

Contemporary scholars struggling to keep their work politically meaningful and efficacious often, with the best of intentions, invoke the triad of race, gender and class. But though this three-part mantra is persistently and even passionately recited, usually in the introductory paragraphs of a scholarly piece, ‘attentive listening,’ as historian Douglas M. Peers asserts, ‘reveals that class is sounded with little more than a whisper’ (825). Unlike the other two, class largely remains an under-explored and, consequently, little understood category of experience and inquiry. I can say with certainty that this is true in my own field of postcolonial studies, with its sub-discipline of colonial discourse analysis. In part because of the politically justifiable emphasis on race in postcolonial research and theory (and only later, through feminist insistence, was that emphasis broadened to include gender), we have yet to develop as sustained, various, and subtle a critique of class as that which now exists for race and gender.
Risk factors and the prevalence of leptospirosis infection in a rural community of Chiapas, Mexico
Authors: LEAL-CASTELLANOS C. B. , GARCÍA-SUÁREZ R. , GONZÁLEZ-FIGUEROA E. , FUENTES-ALLEN J. L. , ESCOBEDO-DE LA PEÑA J.
Published: December 2003

A cross-sectional study was conducted in Mapastepec, a rural community of the southern state of Chiapas, Mexico. The overall prevalence of leptospirosis infection in 1169 subjects was 37·7% [95% confidence intervals (95% CI) 34·9–40·5]. The main risk factors related to leptospirosis infection were flooding, mainly if subjects had a skin cut or abrasion [odds ratio (OR) 4·2; 95% CI 3·1–5·7], having domestic animals, either dogs and/or cats (OR 1·3; 95% CI 0·96–1·8) or cattle and/or pigs (OR 1·9; 95% CI 1·3–2·7), contact with animal excreta with no protection and with a skin cut or abrasion (OR 2·3; 95% CI 1·1–4·6). Those subjects with a dengue infection in the previous year had also an excess risk (OR 1·4; 95% CI 0·9–2·0). Mapastepec is a previously unknown area with high endemicity. Specific preventive measures should be adopted to prevent any contact with infected animals, and animal immunization should also be implemented. There is need of an epidemiological surveillance system to allow proper diagnosis.
Prognostic factors for the long-term development of ocular lesions in 327 children with congenital toxoplasmosis
Authors: BINQUET C. , WALLON M. , QUANTIN C. , KODJIKIAN L. , GARWEG J. , FLEURY J. , PEYRON F. , ABRAHAMOWICZ M.
Published: December 2003

The aim of this study was to identify the high-risk factors associated with the development of ocular lesions in a large cohort of children with congenital toxoplasmosis (CT), irrespective of their gestational age at the time of maternal infection. Children were managed according to a standardized protocol and monitored for up to 14 years at the Croix-Rousse Hospital, Lyon, France. Cox model and a flexible regression, spline-based method were used for the analysis. During a median follow-up time of 6 years, 79 of the 327 children (24%) had at least one retinochoroidal lesion. No bilateral impairment of visual acuity was observed. The risk of a child developing ocular disease was higher not only when mothers were infected early during pregnancy, which was expected, but also when CT was diagnosed prior to or at the time of birth, when non-ocular manifestations were present at baseline and when birth was premature.
Acarological risk of exposure to agents of tick-borne zoonoses in the first recognized Italian focus of Lyme borreliosis
Authors: MANNELLI A. , BOGGIATTO G. , GREGO E. , CINCO M. , MURGIA R. , STEFANELLI S. , DE MENEGHI D. , ROSATI S.
Published: December 2003

Acarological risk was calculated as the probability of encountering at least one host-seeking Ixodes ricinus tick infected by the pathogen Borrelia burgdorferi sensu lato, in 100 m transects in the province of Genoa, Italy. The seasonal pattern of I. ricinus was studied using generalized estimating equations (GEE) with negative binomial error, to consider overdispersion of tick counts and repeated sampling of the same dragging sites from April 1998 to March 1999. Prevalence of infection by B. burgdorferi s.l. was evaluated by PCR and hybridization with genospecies-specific probes. Acarological risk (R) peaked in April (R=0·2, 95% CI 0·13–0·26) and November (R=0·29, 95% CI 0·10–0·46). Borrelia garinii and B. valaisiana were the most common genospecies at our study site suggesting a major role of birds as reservoirs. DNA from Anaplasma phagocytophilum, the agent of granulocytic ehrlichiosis in humans and animals, was amplified from an adult I. ricinus.
A large infantile gastroenteritis outbreak in Albania caused by multiple emerging rotavirus genotypes
Authors: VILLENA C. , GABRIELI R. , PINTÓ R. M. , GUIX S. , DONIA D. , BUONOMO E. , PALOMBI L. , CENKO F. , BINO S. , BOSCH A. , DIVIZIA M.
Published: December 2003

By the end of December 2000, the epidemiological system ‘Alert’ of the Public Health Institute in Tirane reported an outbreak of acute gastroenteritis. The outbreak involved children in Tirane and in the rural area. In total, 2722 children were seen in Tirane Hospital and 982 (56·4%) were treated for acute gastroenteritis. The age group with the highest morbidity was 0–5 years (89·7%), followed by the 6–9 (6·2%) and 10–15 years age groups (4·1%). The distribution of acute gastroenteritis cases, which occurred along the same water distribution system, suggests a waterborne origin. The nucleic acid amplification confirmed the co-circulation of different genotypes of rotavirus, mainly P[8]G9 and P[8]G3, responsible for the outbreak. Other enteric viruses such as astrovirus serotype 1, adenovirus and Norovirus, genogroups I and II were detected. Co-infections with different rotavirus genotypes and even with different enteric viruses were detected in several samples.
European bat lyssaviruses: an emerging zoonosis
Authors: FOOKS A. R. , BROOKES S. M. , JOHNSON N. , McELHINNEY L. M. , HUTSON A. M.
Published: December 2003

In Europe, two bat lyssaviruses referred to as European bat lyssaviruses (EBLVs) types 1 and 2 (genotypes 5 and 6 respectively) which are closely related to classical rabies virus are responsible for an emerging zoonosis. EBLVs are host restricted to bats, and have been known to infect not only their primary hosts but also in rare circumstances, induce spillover infections to terrestrial mammals including domestic livestock, wildlife and man. Although spillover infections have occurred, there has been no evidence that the virus adapted to a new host. Since 1977, four human deaths from EBLVs have been reported. None of them had a record of prophylactic rabies immunization. Only fragmentary data exist about the effectiveness of current vaccines in cross-protection against EBLVs. It is clear that EBLV in bats cannot be eliminated using conventional strategies similar to the control programmes based on vaccine baits used for fox rabies in Europe during the 1980s. Due to the protected status of bats in Europe, our knowledge of EBLV prevalence and epidemiology is limited. It is possible that EBLV is under-reported and that the recorded cases of EBLV represent only a small proportion of the actual number of infected bats. For this reason, any interaction between man and bats in Europe must be considered as a possible exposure. Human exposure through biting incidents, especially unprovoked attacks, should be treated immediately with rabies post-exposure treatment and the bat, where possible, retained for laboratory analysis. Preventative measures include educating all bat handlers of the risks posed by rabies-infected animals and advising them to be immunized. This review provides a brief history of EBLVs, their distribution in host species and the public health risks.
Obsessional experiments for linear logic proof-nets
Authors: de FALCO LORENZO TORTORA
Published: December 2003

We address the question of injectivity of coherent semantics of linear logic proof-nets. Starting from Girard's definition of experiment, we introduce the key-notion of ‘injective obsessional experiment’, which allows us to give a positive answer to our question for certain fragments of linear logic, and to build counter-examples to the injectivity of coherent semantics in the general case.
Neonatal screening for cystic fibrosis: France rises to the challenge
Authors: Farriaux J. P. , Vidailhet M. , Briard M. L. , Belot V. , Dhondt J. L.
Published: December 2003

Summary: This paper describes the adjustments to the French neonatal screening programme required by the introduction of systematic screening for cystic fibrosis (CF), taking into account both the legal and statutory framework and the lessons of a pilot study carried out 10 years ago. The French association for the screening and prevention of infant handicaps (AFDPHE) has been mandated by its regulatory agencies to organize screening for CF in France (metropolitan and overseas territories). During the year 2001, expert groups (Technical Aspects, Information, Ethics and Genetics, Criteria for CF Centres, Protocol for the Care of a Newborn with CF) issued recommendations for the establishment of a national programme that would guarantee efficiency and adequate patient care from the time of diagnosis onward. The programme is based on a strategy combining immunoreactive trypsin (IRT) assay and the analysis of DNA mutations in dried blood samples obtained at 3 days of age. When an elevated IRT value is found, DNA analysis is performed on the same sample. Owing to the relative regional heterogeneity existing in France, 30 selected mutations are used, which provide 85% coverage. The Ethics and Genetics Committee recommended that, in order to avoid arousing anxiety by a recall, informed consent, according to the French legislation on bioethics, should be obtained for all neonates at birth by having the parents sign directly on the sampling paper. Information brochures for parents and health professionals have been designed. A new organization of patient care, involving the creation of CF centres recognized by the Ministry of Health, has been decided; all children diagnosed are to be referred to such centres, where they can be well cared for by a trained staff with sufficient means. The programme was implemented region by region in France, from the beginning of the year 2002 to early 2003. The expert groups still meet periodically to evaluate the implementation of the programme and to check that the terms of the agreement between the AFDPHE and the Social Security Agency are complied with.
Two novel mutations in the gene for human α‐mannosidase that cause α‐mannosidosis
Authors: Beccari T. , Bibi L. , Ricci R. , Antuzzi D. , Burgalossi A. , Costanzi E. , Orlacchio A.
Published: December 2003

Summary: Mutation analysis performed on two Italian patients with α‐mannosidosis allowed the identification of two new mutations, IVS20−2A>G and 322–323insA. The patients were both homozygous for these mutations. The first mutation causes skipping of exon 21, whereas the second causes a frameshift introducing a stop codon at position 160 of the amino acid sequence.
Magnetospheric disturbance induced equatorial plasma bubble development and dynamics: A case study in Brazilian sector
Authors: Abdu M. A. , Batista I. S. , Takahashi H. , MacDougall J. , Sobral J. H. , Medeiros A. F. , Trivedi N. B.
Published: December 2003

Equatorial ionospheric plasma bubble irregularity development and dynamics during the major magnetospheric storm of 26 August 1998 are investigated using the data collected by a multistation and multi‐instrument diagnostic network operated at equatorial and low latitude sites in Brazil, and auroral electrojet activity (AU/AL), IMF, and Dst indices. A magnetospheric disturbance onset in the morning of 26 August 1998 was initiated by a solar wind shock and associated IMF Bz polarity reversals and ssc that were soon followed by a succession of substorm‐like auroral electrojet (AE) intensifications and Dst development. An IMF Bz southward turning and associated AE intensifications in the Brazilian dusk sector produced intense prompt penetration eastward electric field that caused large F region vertical drift and consequently the developments of intense postsunset equatorial anomaly and a series of intense plasma bubbles, the latter event lasting the entire night, as observed by digital ionosondes at São Luís (2.33°S, 315.8°E, dip angle: −.5°) and Fortaleza (3.9°S, 321.55°W, dip angle: −9°) and an all‐sky imager, two scanning photometers, and a Digisonde at the low‐latitude site Cachoeira Paulista (22.6°S, 315°E; dip angle: −28°). A notable aspect of the dynamics of the bubbles was their initially very low eastward drift velocity which turned into steadily increasing westward velocity that lasted till early morning hours. The results show for the first time a relationship between the zonal drift velocities of optically observed large‐scale bubbles (tens to hundreds of kilometers) and that of the smaller scale (kilometer sizes) structures as observed by a digital ionosonde. The results point to the dominant role of a disturbance dynamo associated westward thermospheric wind to maintain the plasma irregularity drift increasingly westward going into postmidnight hours. As an important finding, the results further show that significant contribution to the westward plasma bubble irregularity drift, normally attributed to disturbance dynamo effect, could arise from prompt penetration disturbance zonal electric field, in the course of a disturbance sequence lasting several hours. Such effect is attributed to Hall electric field arising from the primary disturbance zonal electric field, under enhanced nighttime ionospheric conductivities produced possibly by storm associated particle precipitation, in the Brazilian longitude sector in agreement with recent evidences [Abdu et al., 1998b].
Lithospheric structure across oblique continental collision in New Zealand from wide‐angle P wave modeling
Authors: Scherwath Martin , Stern Tim , Davey Fred , Okaya David , Holbrook W. Steven , Davies Rob , Kleffmann Stefan
Published: December 2003

Oblique convergence between the Australian and Pacific plates in South Island, New Zealand, has resulted in crustal thickening and distributed deformation within both plates. We measure this thickening and image the deformation with seismic wide‐angle data along a 600 km long transect that spans the plate boundary. P wave arrival times from 34,000 rays are used to construct a two‐dimensional model for seismic velocity with depth. Crustal velocities average 6.1 and 6.2 (±0.23) km/s for the Australian and Pacific sides of the boundary, respectively. Upper mantle velocities average 8.1 (±0.25) km/s. Distributed deformation is indicated by the following observations: a reduction in upper crustal and midcrustal velocities by 4% west of the plate boundary, ascribed to flexural bending stresses; a velocity reduction of 8% immediately east of the Alpine fault, linked to high pore fluid pressures; 17 km of crustal thickening to form a 44(±1.4) km deep crustal root that is offset 10–20 km SE of the highest mountains; a velocity reversal below the midcrust in the eastern part of the crustal root, caused either by heating or an artifact from seismic anisotropy; strong thickening of a 7.0(±0.4) km/s fast lower crust within the crustal root; and a low‐velocity zone in the Australian upper mantle due to sampling the slow orientation of upper mantle anisotropy.
Detection of change in the Arctic using satellite and in situ data
Authors: Comiso Josefino C. , Yang Jiayan , Honjo Susumo , Krishfield Richard A.
Published: December 2003

The decade of the 1990s was the warmest decade of the last century, while the year 1998 was the warmest year ever observed by modern techniques, with 9 out of 12 months of the year being the warmest months. Satellite ice cover and surface temperature data, European Centre for Medium‐Range Weather Forecasts (wind), and ocean hydrographic data are examined to gain insights into this warming phenomenon. Areas of ice‐free water in both western and eastern regions of the Arctic are found to have followed a cyclical pattern with approximately decadal period but with a lag of about 3 years between the eastern and western regions. The pattern was interrupted by unusually large anomalies in 1993 and 1998 in the western region and in 1995 in the eastern region. The area of open water in 1998 was the largest ever observed in the western region and occurred concurrently with large surface temperature anomalies in the area and adjacent regions. This also occurred at a time when the atmospheric circulation changed from predominantly cyclonic in 1996 to anticyclonic in 1997 and 1998. Detailed hydrographic measurements over the same general area in April 1996 and April 1997 indicate a warming and significant freshening in the top layer of the ocean, suggesting increases in ice melt and/or river runoff. Continuous ocean temperature and salinity data from ocean buoys at depths of 8, 45, and 75 m confirm these results and show large interannual changes during the 1996–1998 period. Surface temperature data show a general warming in the region that is highly correlated with observed decline in summer sea ice, while hydrographic data suggest that in 1997 and 1998, the upper part of the ocean was unusually fresh and warm compared to available data between 1956 and 1996.
Toward a nonlinear ensemble filter for high‐dimensional systems
Authors: Bengtsson Thomas , Snyder Chris , Nychka Doug
Published: December 2003

Many geophysical problems are characterized by high‐dimensional, nonlinear systems and pose difficult challenges for real‐time data assimilation (updating) and forecasting. The present work builds on the ensemble Kalman filter (EnsKF), with the goal of producing ensemble filtering techniques applicable to non‐Gaussian densities and high‐dimensional systems. Three filtering algorithms, based on representing the prior density as a Gaussian mixture, are presented. The first, referred to as a mixture ensemble Kalman filter (XEnsF), models local covariance structures adaptively using nearest neighbors. The XEnsF is effective in a three‐dimensional system, but the required ensemble grows rapidly with the dimension and, even in a 40‐dimensional system, we find the XEnsF to be unstable and inferior to the EnsKF for all computationally feasible ensemble sizes. A second algorithm, the local‐local ensemble filter (LLEnsF), combines localizations in physical as well as phase space, allowing the update step in high‐dimensional systems to be decomposed into a sequence of lower‐dimensional updates tractable by the XEnsF. Given the same prior forecasts in a 40‐dimensional system, the LLEnsF update produces more accurate state estimates than the EnsKF if the forecast distributions are sufficiently non‐Gaussian. Cycling the LLEnsF for long times, however, produces results inferior to the EnsKF because the LLEnsF ignores spatial continuity or smoothness between local state estimates. To address this weakness of the LLEnsF, we consider ways of enforcing spatial smoothness by conditioning the local updates on the prior estimates outside the localization in physical space. These considerations yield a third algorithm, which is a hybrid of the LLEnsF and the EnsKF. The hybrid uses information from the EnsKF to ensure spatial continuity of local updates and outperforms the EnsKF by 5.7% in RMS error in the 40‐dimensional system.
Possible roles of pH, temperature, and partial dissolution in determining boron concentration and isotopic composition in planktonic foraminifera
Authors: Wara M. W. , Delaney M. L. , Bullen T. D. , Ravelo A. C.
Published: December 2003

We present the first continuous records from 0 to 5 Ma (in 0.333 m.y. integrated time steps) of paired boron/calcium (B/Ca) ratios and boron isotopes (δ11B) in the planktonic foraminifera Globogerinoides sacculifer (without sacc) from a site in the western equatorial Pacific Ocean (Ocean Drilling Program Site 806). These measurements, the first made in conjunction with calcification temperature (magnesium/calcium ratios) and average shell mass measurements, indicate that pH is not the sole environmental variable controlling B in planktonic foraminiferal calcite. Our data are consistent with calcification temperature exerting a primary control on B concentration and isotopic composition in planktonic foraminifera. If so, calcification temperature must be taken into account if pH for past oceans and atmospheric pCO2 are to be estimated from B isotope measurements in foraminiferal calcite. Doing so will substantially increase the uncertainty of pH estimates. Although this work was designed as a temporal study, its results define new aspects of calibrating the δ11B paleo‐pH tracer.
Sources of Asian dust and role of climate change versus desertification in Asian dust emission
Authors: Zhang X. Y. , Gong S. L. , Zhao T. L. , Arimoto R. , Wang Y. Q. , Zhou Z. J.
Published: December 2003

Simulations of Asian dust emissions over the past 43 years are presented based on a size‐dependent soil dust emission and transport model (NARCM) along with supporting data from a network of surface stations. The deserts in Mongolia and in western and northern China (mainly the Taklimakan and Badain Juran, respectively) contribute ∼70% of the total dust emissions; non‐Chinese sources account for ∼40% of this. Several areas, especially the Onqin Daga sandy land, Horqin sandy land, and Mu Us Desert, have increased in dust emissions over the past 20 years, but efforts to reduce desertification in these areas may have little effect on Asian dust emission amount because these are not key sources. The model simulations indicate that meteorology and climate have had a greater influence on the Asian dust emissions and associated Asian dust storm occurrences than desertification.
Tropical drought regions in global warming and El Niño teleconnections
Authors: Neelin J. D. , Chou C. , Su H.
Published: December 2003

Climate model global warming simulations predict large regional changes in tropical rainfall, including regions of drought. Qualitatively similar changes occur during El Niño interannual variability. Using an intermediate climate model, we have identified a mechanism that creates regional reductions in precipitation at the margins of convection zones during warming. In this “upped‐ante mechanism”, a warm troposphere increases the value of surface boundary layer moisture required for convection to occur. In regions of plentiful moisture supply, moisture simply rises to maintain precipitation, but this increases the moisture gradient relative to neighboring subsidence regions. Reductions in rainfall then result for those margins of convection zones that have strong inflow of air from the subsidence regions and less frequently meet the increased “ante” for convection. In simulations analyzed here, this new mechanism is the leading cause of tropical drought in the global warming case and is dominant in certain El Niño drought regions.