bluuebunny/crossref_metadata_2025 huggingface dataset:
Severe falciparum malaria and acquired childhood language disorder
Authors: Carter Julie A , Lees Janet A , Gona Joseph K , Murira Gladys , Rimba Kenneth , Neville Brian G. R. , Newton Charles R J C
Published: December 2005

Language disorders have been reported after severe falciparum malaria but the deficits have not been described in detail. We assessed language outcome in three groups of children aged 6 to 9 years (n=487): those previously admitted to Kilifi District Hospital, Kenya, with cerebral malaria (CM; n=152; mean age 7y 4 mo [SD 1y 1mo]; 77 males, 75 females); or those with malaria and complicated seizures (M/S; n=156; mean age 7y 4mo [SD 1y 2mo]; 72 males, 84 females); and those unexposed to either condition (n=179; mean age 7y 6mo [SD 1y 1mo]; 93 males, 86 females). Median age at hospital admission was 28 months (interquartile range [IQR] 19 to 44 mo) among children with a history of CM and 23 months (IQR 12 to 35mo) among children with a history of M/S. A battery of eight assessments covering the major facets of speech and language was used to measure language performance. Cognitive performance, neurological/motor skills, behaviour, hearing, and vision were also measured. Eighteen (11.8%) of the CM group, 14 (9%) of the M/S group, and four (2.2%) of the unexposed group were found to have a language impairment. CM (odds ratio 3.68,95% confidence interval 1.09 to 12.4, p=0.04) was associated with significantly increased odds of an impairment‐level score relative to the unexposed group. The results suggest that falciparum malaria is one of the most common causes of acquired language disorders in the tropics.
Herpes simplex encephalitis: diagnostic problems and late relapse
Authors: De Tiège Xavier , Rozenberg Flore , Burlot Karine , Gaudelus Joël , Ponsot Gérard , Héron Bénédicte
Published: December 2005

A 5‐year‐old female presented with prolonged afebrile right‐sided focal seizures, right brachio‐facial paralysis, and dysarthria; consciousness was not altered. Fever appeared 20 hours after onset of neurological symptoms. At admission (day 1) cerebral computerized tomography and cerebrospinal fluid (CSF) analyses were normal including undetectable alpha‐interferon (α‐IFN) and negative herpes simplex virus (HSV) polymerase chain reaction (PCR). Acyclovir was started at a dosage of 60mg/kg/day for 21 days and neurological symptoms improved. Cerebral magnetic resonance imaging (MRI) showed lesions in the left thalamus and left parietal lobe. On day 8, CSF contained an elevated leukocyte count with a predominance of lymphocytes, but ?‐IFN and HSV DNA were still undetectable. Delayed intrathecal synthesis of specific anti‐HSV antibodies was found on day 26 and confirmed herpes simplex encephalitis (HSE) diagnosis. Twenty months after this episode, the patient presented with a febrile meningeal syndrome. PCR detected HSV DNA in CSF and cerebral imaging showed a new left temporal lesion. At relapse onset, intrathecal synthesis of specific anti‐HSV antibodies had disappeared. Acyclovir was started at a dosage of 60mg/kg/day for 21 days and neurological status improved. At discharge, neurological examination showed right hemiparesis and bucco‐facial dyspraxia. Diagnostic problems of HSE diagnosis in children are highlighted. It is suggested that the premature disappearance of intrathecal synthesis of a specific anti‐HSV antibody might play a permissive role in the resurgence of cerebral viral replication.
Balancing certainty and uncertainty in clinical medicine
Authors: Hayward Richard
Published: December 2005

Nothing in clinical medicine is one hundred per cent certain. Part of a doctor's education involves learning how to cope with the anxiety that uncertainty in decisions affecting life and death inevitably produces. This paper examines: (1) the role of anxiety ‐ both rational and irrational ‐ in the provision of health care; (2) the effects of uncertainty upon the doctor‐patient relationship; (3) the threat uncertainty poses to medical authority (and the assumption of infallibility that props it up); (4) the contribution of clinical uncertainty to the rising popularity of alternative therapies; and (5) the clash between the medical and the legal understanding of how certainty should be defined, particularly as it affects the paediatric community. It concludes by suggesting some strategies that might facilitate successful navigation between the opposing and ever‐present forces of certainty and uncertainty.
Extranasopharyngeal angiofibroma of the cheek
Authors: Dere Huseyin , Ozcan K Murat , Ergul Gulusan , Bahar Secil , Ozcan Ibrahim , Kulacoglu Sezer
Published: December 2005

Angiofibromas rarely localize in extranasopharyngeal sites. The most common site for extranasopharyngeal angiofibromas is the maxillary sinus. The ethmoid and sphenoid sinuses, nasal septum, middle and inferior turbinates, conjunctiva, molar and retromolar region, and larynx are other sites where extranasopharyngeal angiofibromas have been reported. Only one case of buccal extranasopharyngeal angiofibroma has been reported to date. We present a case of buccal extranasopharyngeal angiofibroma that was excised completely following embolization and we also review the literature.
Use of an intra-operative nerve stimulator in identifying the hypoglossal nerve
Authors: Walshe Peter , Shandilya Munish , Rowley Helena , Zahirovich Avdo , Walsh Rory McConn , Walsh Michael , Timon Conrad
Published: December 2005

Previously, the hypoglossal nerve has not undergone intra-operative monitoring during neck operations in which the nerve is at risk. As society becomes increasingly litigious, this may change. This study describes the technique and the microvoltages used in 10 patients for intra-operative stimulation of the hypoglossal nerve with the Magstim nerve stimulator. We confirm that the technique is possible, simple and safe, with minimal disturbance to the patient, anaesthetist and surgeon.
Driving and otolaryngology: do we know the rules?
Authors: Evans Andrew , Eng C Y
Published: December 2005

Certain medical conditions may affect one's ability to drive safely. In the United Kingdom, the Driver and Vehicle Licensing Agency (DVLA) issues guidelines outlining which medical conditions drivers must notify them of. In order to assess our knowledge of, and ability to apply, the current DVLA guidelines with regard to otolaryngological conditions, a postal survey was sent to all otolaryngologists in Scotland. The responses obtained suggest that the current DVLA guidelines are not well understood or easily applied, and it is recommended that all otolaryngologists familiarize themselves with these guidelines in order to better advise their patients with regard to driving.
Pannaria conoplea and P. tavaresii (Ascomycota: Pannariaceae) new to Chile
Authors: Galloway David J. , Quilhot Wanda , Jørgensen Per Magnus
Published: December 2005

A collection of lichens made in 1998 (by WQ) from the bark of Austrocedrus chilensis at a locality in southern Chile, disclosed two species of Pannaria not hitherto recorded from the Chilean lichen mycobiota (Galloway & Quilhot 1999): (1) the pantemperate taxon Pannaria conoplea (Ach.) Bory, which is widespread in the Northern Hemisphere as well as having rare outliers in East Africa, Venezuela, Ecuador and Australia (see Jørgensen 1978; Swinscow & Krog 1988; Jørgensen & Galloway 1992; Jørgensen & Arvidsson 2004), and (2) Pannaria tavaresii P. M. Jørg., known earlier from North America (including Mexico and Jamaica), Portugal, Macaronesia (Jørgensen 1978), Australia (Jørgensen & Galloway 1992), Sardinia and Italy (Nimis 1993) and previously collected in 1986 from near Valdivia in Chile. The discovery of Pannaria conoplea and P. tavaresii in Chile adds to the known Pannaria mycobiota of Chile (Galloway & Quilhot 1999), bringing the total number of species of this genus in Chile to 23. Eleven taxa formerly placed in Psoroma, are now correctly accommodated in Pannaria (see Jørgensen 2001b; Elvebakk & Galloway 2003; Jørgensen & Sipman 2004; Passo et al. 2004). Both Pannaria conoplea and P. tavaresii are within the currently accepted circumscription of Pannaria (Jørgensen 1994, 2004a, 2004b). Descriptions of the Chilean material are given below.
Two new species of Arthopyrenia from Italy
Authors: RAVERA Sonia
Published: December 2005

Arthopyrenia tuscanensis Coppins & S. Ravera and A. coppinsii S. Ravera are described as new to science. They share the characteristic tadpole-shaped ascospores with a conical lower cell, but are otherwise comparable to A. salicis A. Massal.
Photosynthetic performance of Xanthoria mawsonii C. W. Dodge in coastal habitats, Ross Sea region, continental Antarctica
Authors: PANNEWITZ Stefan , GREEN T. G. Allan , SCHLENSOG Mark , SEPPELT Rod , SANCHO Leopoldo G. , SCHROETER B.
Published: December 2005

Xanthoria mawsonii C. W. Dodge was found to perform well physiologically in a variety of habitats at high latitudes in continental Antarctica. The net photosynthetic rate of 7·5 μ mol CO2 kg−1 s−1 is exceptionally high for Antarctic lichens. Field and laboratory measurements proved the photosynthetic apparatus to be highly adapted to strong irradiance. The cold resistance of the photosystem II reaction centres is higher than the photosynthetic CO2 fixation process. Optimum temperature for net photosynthesis was c. 10°C. The lichen grows along water channels where it is frequently inundated and hydrated to maximum water content, although net photosynthesis is strongly depressed by super saturation. In these habitats the lichen is photosynthetically active for long periods of time. Xanthoria mawsonii also grows at sites where it depends entirely on the early spring snow melt and occasional snow fall for moisture. It has an exceptionally short reactivation phase and is able to utilize snow immediately. Recovery of activity by absorbing water vapour from air, though practically possible, seems to be of ecological importance only under snow at subzero temperatures.
A new taxonomy of the Caloplaca citrina group in the Nordic countries, except Iceland
Authors: ARUP Ulf
Published: December 2005

The Caloplaca citrina group in the Nordic countries, except Iceland, is analysed with regard to morphology, anatomy, ecology, and chemistry. Their genetic relationship is also analysed using the ITS ribosomal DNA gene. The results show that there are at least five species within what has been called C. citrina, of which four are closely related to one another and to several non-sorediate species. Three of these, C. citrina, C. flavocitrina and C. arcis have previously been recognized at specific or varietal level some time during the last two centuries, whereas the fourth species, C. dichroa, is described as new. The fifth species, C. phlogina, is not related to the other species but shows a close relationship to the Xanthoria candelaria group. The species are described and illustrated in colour. Distribution maps are given for the study area and a key to sorediate, yellow to orange species occurring in the Nordic countries, except Iceland, is also provided.
New species of Bactrospora, Enterographa, Graphidastra and Lecanographa from northern Thailand and Vietnam
Authors: SPARRIUS Laurens B. , SAIPUNKAEW Wanaruk , WOLSELEY Patricia A. , APTROOT André
Published: December 2005

Bactrospora perspiralis, B. subdryina, Enterographa mesomela, Graphidastra laii and Lecanographa atropunctata (Roccellaceae) are described as new to science based on specimens collected in the wet subtropical lowlands of northern Thailand and Vietnam. The new Graphidastra is the third species in the genus and was also found in Taiwan.
Detection of paralogous polyketide synthase genes in Parmeliaceae by specific primers
Authors: OPANOWICZ Magdalena , BLAHA Juliane , GRUBE Martin
Published: December 2005

A first assessment of paralogy in non-reducing polyketide synthases of Parmeliaceae is presented. Primers which are specific to the keto-acyl synthase domain were used to amplify gene fragments of putative non-reducing polyketide synthases from various representatives of the family. The corresponding sequences were analysed together with a selection of known polyketide synthase genes from other fungi, including lichenized fungi. The results suggest that genes from Parmeliaceae represent at least 6 paralogs. Their different positions in the tree partly correlate with the variable presence of spliceosomal introns at particular positions in the gene fragments. Because only one paralog could be unambiguously detected in each species by direct sequencing of PCR products with this approach, we tested the applicability of clade-specific primers, designed by using orthologous signature sequences. With these primers more paralogs could be detected from the same DNA extract in a number of species, but certain paralogs were consistently not amplified in these species. The paralog-specific primer approach can potentially be used for a rapid screening of PKS genes from a broader range of lichen fungi.
The lichen genus Topeliopsis, additions and corrections
Authors: FRISCH Andreas , KALB Klaus
Published: December 2005

Topeliopsis darlingtonii A. Frisch & Kalb and Topeliopsis elixii A. Frisch & Kalb from Australia and Topeliopsis meridensis Kalb & A. Frisch from Venezuela are described as new species. Thelotrema decorticans Müll. Arg. and Ocellularia subdenticulata Zahlbr. are transferred to Topeliopsis and are the correct names for T. corticola Kalb and T. vezdae Kalb, respectively. A revised key of the genus Topeliopsis is presented. Ascoconidia, produced in old ascospores of T. elixii, are described for the first time for the Thelotremataceae.
Foliicolous lichens and associated lichenicolous fungi in the north-eastern Iberian Peninsula: the effect of environmental factors on distribution
Authors: LLOP Esteve , GÓMEZ-BOLEA Antonio
Published: December 2005

The foliicolous lichens and the environmental factors at 14 stations in Catalonia were examined and the relationships between their foliicolous flora and climatic features analysed. This information could be used to predict potential sites with foliicolous lichens in areas with a Mediterranean climate. In addition, two species new to the European lichen flora (Bacidina canariensis and Fellhanera semecarpi) are recorded, and also 8 species new to the lichen and lichenicolous flora of the Iberian Peninsula (Arthonia leptosperma, Byssoloma diederichii, Chionosphaera apobasidialis, Cladosporium arthoniae, Fellhanera christiansenii, Fellhanera seroexspectata, Strigula smaragdula and Vezdaea dawsoniae).
REDUCING DEHN FILLINGS AND SMALL SURFACES
Authors: LEE SANGYOP , OH SEUNGSANG , TERAGAITO MASAKAZU
Published: December 2005

In this paper we investigate the distances between Dehn fillings on a hyperbolic 3-manifold that yield 3-manifolds containing essential small surfaces including non-orientable surfaces. In particular, we study the situations where one filling creates an essential sphere or projective plane, and the other creates an essential sphere, projective plane,
annulus, Möbius band, torus or Klein bottle, for all eleven pairs of such non-hyperbolic manifolds.
PROPERLY STRATIFIED ALGEBRAS AND TILTING
Authors: FRISK ANDERS , MAZORCHUK VOLODYMYR
Published: December 2005

We study the properties of tilting modules in the context of properly stratified algebras. In particular, we answer the question of when the Ringel dual of a properly stratified algebra is properly stratified itself, and show that the class of properly stratified algebras for which the characteristic tilting and cotilting modules coincide is closed under taking the Ringel dual. Studying stratified algebras whose Ringel dual is properly stratified, we discover a new Ringel-type duality for such algebras, which we call the two-step duality. This duality arises from the existence of a new (generalized) tilting module for stratified algebras with properly stratified Ringel dual. We show that this new tilting module has a lot of interesting properties; for instance, its projective dimension equals the projectively defined finitistic dimension of the original algebra, it guarantees that the category of modules of finite projective dimension is contravariantly finite, and, finally, it allows one to compute the finitistic dimension of the original algebra in terms of the projective dimension of the characteristic tilting module.
ON RATIONAL CUSPIDAL PROJECTIVE PLANE CURVES
Authors: DE BOBADILLA J. FERNÁNDEZ , LUENGO-VELASCO I. , MELLE-HERNÁNDEZ A. , NÉMETHI A.
Published: December 2005

In 2002, L. Nicolaescu and the fourth author formulated a very general conjecture which relates the geometric genus of a Gorenstein surface singularity with rational homology sphere link with the Seiberg--Witten invariant (or one of its candidates) of the link. Recently, the last three authors found some counterexamples using superisolated singularities. The theory of superisolated hypersurface singularities with rational homology sphere link is equivalent with the theory of rational cuspidal projective plane curves. In the case when the corresponding curve has only one singular point one knows no counterexample. In fact, in this case the above Seiberg--Witten conjecture led us to a very interesting and deep set of `compatibility properties' of these curves (generalising the Seiberg--Witten invariant conjecture, but sitting deeply in algebraic geometry) which seems to generalise some other famous conjectures and properties as well (for example, the Noether--Nagata or the log Bogomolov--Miyaoka--Yau inequalities). Namely, we provide a set of `compatibility conditions' which conjecturally is satisfied by a local embedded topological type of a germ of plane curve singularity and an integer $d$ if and only if the germ can be realized as the unique singular point of a rational unicuspidal projective plane curve of degree $d$. The conjectured compatibility properties have a weaker version too, valid for any rational cuspidal curve with more than one singular point. The goal of the present article is to formulate these conjectured properties, and to verify them in all the situations when the logarithmic Kodaira dimension of the complement of the corresponding plane curves is strictly less than 2.
QUASICONFORMAL DEFORMATIONS AND VOLUME GROWTH
Authors: HERRON DAVID A.
Published: December 2005

We determine when a metric measure space admits a uniformizing density which has Ahlfors regular volume growth. A characterization of uniformizing conformal densities in terms of doubling and a lifting procedure are the key ingredients in our presentation. We also furnish an application characterizing metric doubling measures.
BIHERMITIAN STRUCTURES ON COMPLEX SURFACES Proc. London Math. Soc. (3) 79 (1999) 414–428)
Authors: APOSTOLOV VESTISLAV , GAUDUCHON PAUL , GRANTCHAROV GUEO
Published: December 2005

We correct the statements of Theorem 1 and Corollary 2 of the above-mentioned paper and provide a new argument for Corollary 2. We also update some parts of the paper in the light of recent major developments in the theory of bihermitian structures, due to M. Gualtieri and N. Hitchin.
ON THE ABSOLUTELY CONTINUOUS SPECTRUM IN A MODEL OF AN IRREVERSIBLE QUANTUM GRAPH
Authors: NABOKO SERGEY N. , SOLOMYAK MICHAEL
Published: December 2005

A family $\mathbf{A}_\alpha$ of differential operators depending on a real parameter $\alpha \ge 0$ is considered. This family was suggested by Smilansky as a model of an irreversible quantum system. We find the absolutely continuous spectrum $\sigma_{a.c.}$ of the operator $\mathbf{A}_\alpha$ and its multiplicity for all values of the parameter. The spectrum of $\mathbf{A}_0$ is purely absolutely continuous and admits an explicit description. It turns out that for $\alpha < \sqrt 2$ one has $\sigma_{a.c.}(\mathbf{A}_\alpha) = \sigma_{a.c.}(\mathbf{A}_0)$, including the multiplicity. For $\alpha \ge \sqrt2$ an additional branch of the absolutely continuous spectrum arises; its source is an auxiliary Jacobi matrix which is related to the operator $\mathbf{A}_\alpha$. This birth of an extra branch of the absolutely continuous spectrum is the exact mathematical expression of the effect that was interpreted by Smilansky as irreversibility.
SMALL DEVIATIONS OF RIEMANN--LIOUVILLE PROCESSES IN ${L_{\lowercase{q}}}$ SPACES WITH RESPECT TO FRACTAL MEASURES
Authors: LIFSHITS MIKHAIL A. , LINDE WERNER , SHI ZHAN
Published: December 2005

We investigate Riemann--Liouville processes $R_H$, with $H > 0$, and fractional Brownian motions $B_H$, for $0 < H < 1$, and study their small deviation properties in the spaces $L_q([0, 1], \mu)$. Of special interest here are thin (fractal) measures $\mu$, that is, those that are singular with respect to the Lebesgue measure. We describe the behavior of small deviation probabilities by numerical quantities of $\mu$, called mixed entropy numbers, characterizing size and regularity of the underlying measure. For the particularly interesting case of self-similar measures, the asymptotic behavior of the mixed entropy is evaluated explicitly. We also provide two-sided estimates for this quantity in the case of random measures generated by subordinators.

While the upper asymptotic bound for the small deviation probability is proved by purely probabilistic methods, the lower bound is verified by analytic tools concerning entropy and Kolmogorov numbers of Riemann--Liouville operators.
T-cell signalling and immune system disorders
Authors: Wilkinson Beverley , Downey Jocelyn S. , Rudd Christopher E.
Published: December 2005

T-cell receptor (TCR) engagement initiates intracellular signalling cascades that lead to T-cell proliferation, cytokine production and differentiation into effector cells. These cascades comprise an array of protein-tyrosine kinases, phosphatases, GTP-binding proteins and adaptor proteins that regulate generic and specialised functions. The integration of these signals is essential for the normal development, homeostasis and function of T cells. Defects in a single mediator can produce T cells that are unable to participate fully in an immune response and/or that mount an inappropriate response, which leads to immunodeficiency, autoimmunity or leukaemia/lymphomas. This review highlights some of the key players in T-cell signalling and their involvement in the development of various clinical disease states. Some of these immune-specific signalling proteins are attractive potential targets in the development of therapies to augment T-cell responses to antigen or tumours, and to treat immune cell disorders.
Comparison of energetic ions in cusp and outer radiation belt
Authors: Chen Jiasheng , Fritz Theodore A. , Sheldon Robert B.
Published: December 2005

Recently, large diamagnetic cavities with a size of as large as 6 Re have been observed in the dayside high‐altitude cusp regions. Associated with these cavities are charged particles with energies from 20 keV up to 10 MeV. Their seed population is a mixture of ionospheric and solar wind particles. The energetic ion intensity, charge composition, energy spectrum, and phase space density observed in the high‐altitude dayside cusp have been compared with that measured in the outer radiation belt over an energy range of 1–200 keV/e for protons and He++ ions and of 41–200 keV/e for O+ ions. It is found that (1) the shape of ion energy spectra in the cusp is different from that in the outer radiation belt, (2) the ion phase space densities in the outer radiation belt are organized by magnetic moment, and (3) the ion phase space density of both He++ and O+ in the cusp are higher than that in the outer radiation belt at a given magnetic moment. These results suggest that (1) the measured cusp energetic ions cannot be explained by simple transport from an outer radiation belt (or ring current) source; rather, (2) a nonadiabatic energization process would be required to relate the cusp energetic ion population to the belt ion population, and (3) cusp energetic particles are potentially an additional independent source of the charged particles in the outer radiation belt.
Triple oxygen isotope composition of dissolved O2 in the equatorial Pacific: A tracer of mixing, production, and respiration
Authors: Hendricks Melissa B. , Bender Michael L. , Barnett Bruce A. , Strutton Peter , Chavez Francisco P.
Published: December 2005

As a contribution to the study of equatorial Pacific biogeochemistry, we measured the O2/Ar ratio and the triple isotope composition (18O, 17O, and 16O) of O2 along six meridional lines in the equatorial Pacific (8°N–8°S at 95°W, 110°W, 125°W, 140°W, 155°W, and 170°W). O2/Ar ratios and δ18O were close to equilibrium values within the mixed layer and followed the general trend of increasing δ18O with decreasing O2/Ar at greater depths. The 17Δ (≈δ17O–0.5δ18O) constrains the fraction of photosynthetic O2; 17Δ was slightly elevated with respect to equilibrium within the mixed layer due to local photosynthetic production. In aphotic zone waters above 250 m depth the average 17Δ values were higher than in the mixed layer. There are four sources of this photosynthetic signal in the dark ocean: production in the euphotic zone prior to subduction in the distant source regions, production below the mixed layer during travel to the equatorial zone, diapycnal mixing with shallower waters bearing photosynthetic O2, and accumulation of photosynthetic O2 produced at very low rates below the 1% light level. Our results also constrain biological production rates within the mixed layer at several locations along 95°W and 110°W. Our average rate of 14C production (53 ± 34 mmol C m−2 d−1) agreed well with other estimates in the equatorial Pacific, while our average rate of net C production (6.9 ± 6.2 mmol C m−2 d−1) and f ratio (0.12 ± 0.11) were somewhat lower than other estimates. Adding δ18O and 17Δ as tracers to three‐dimensional biogeochemical ocean GCMs and comparing results with observations will extend our understanding of metabolic rates in the study region.
Momentum flux budget analysis of wind‐driven air‐water interfaces
Authors: Kukulka Tobias , Hara Tetsu
Published: December 2005

Accurate knowledge of the air‐sea momentum flux plays a critical role in ocean‐atmosphere modeling. In this study we investigate the momentum flux budget at an air‐water interface in the presence of wind‐driven gravity‐capillary waves. At the air‐sea interface the total momentum flux (wind stress) partitions into viscous and wave‐induced stress; the latter transfers momentum into surface waves. We estimate the wave growth rate (momentum transfer rate into waves) to close the momentum flux budget, using previous laboratory measurements of total and viscous stress, as well as surface wave spectra. The wave‐induced stress is computed via a parameterized wave growth rate, which is proportional to the turbulent stress divided by the wave‐phase speed squared. The constant of proportionality is then determined under two different assumptions. The first assumption (nonsheltering assumption) is that the turbulent stress is equal to the total wind stress. In the second assumption (sheltering assumption) the wave growth rate is determined by the local turbulent stress, which is a reduced turbulent stress due to the presence of longer waves. Both assumptions yield simple closed form expressions for the stress‐partitioning ratio (ratio between the total stress and the viscous stress). With the sheltering assumption the growth rate agrees with previous theoretical and empirical estimates. Without sheltering, the growth rate is significantly lower than previous estimates. Therefore our results indicate that the growth rate of surface waves is determined by the local, reduced turbulent stress rather than the total wind stress.
An efficient two‐stage Markov chain Monte Carlo method for dynamic data integration
Authors: Efendiev Y. , Datta‐Gupta A. , Ginting V. , Ma X. , Mallick B.
Published: December 2005

In this paper, we use a two‐stage Markov chain Monte Carlo (MCMC) method for subsurface characterization that employs coarse‐scale models. The purpose of the proposed method is to increase the acceptance rate of MCMC by using inexpensive coarse‐scale runs based on single‐phase upscaling. Numerical results demonstrate that our approach leads to a severalfold increase in the acceptance rate and provides a practical approach to uncertainty quantification during subsurface characterization.
Support vector machines for nonlinear state space reconstruction: Application to the Great Salt Lake time series
Authors: Asefa Tirusew , Kemblowski Mariush , Lall Upmanu , Urroz Gilberto
Published: December 2005

The reconstruction of low‐order nonlinear dynamics from the time series of a state variable has been an active area of research in the last decade. The 154 year long, biweekly time series of the Great Salt Lake volume has been analyzed by many researchers from this perspective. In this study, we present the application of a powerful state space reconstruction methodology using the method of support vector machines (SVM) to this data set. SVM are machine learning systems that use a hypothesis space of linear functions in a kernel‐induced higher‐dimensional feature space. SVM are optimized by minimizing a bound on a generalized error (risk) measure rather than just the mean square error over a training set. Under Mercer's conditions on the kernels the corresponding optimization problems are convex; hence global optimal solutions can be readily computed. The SVM‐based reconstruction is used to develop time series forecasts for multiple lead times ranging from 2 weeks to several months. Unlike previously reported methodologies, SVM are able to extract the dynamics using only a few past observed data points out of the training examples. The reliability of the algorithm in learning and forecasting the dynamics is tested using split sample sensitivity analysis, with a particular interest in forecasting extreme states. Efforts are also made to assess variations in predictability as a function of initial conditions and as a function of the degree of extrapolation from the state space used for learning the model.
A numerical study of surface‐subsurface exchange processes at a riffle‐pool pair in the Lahn River, Germany
Authors: Saenger Nicole , Kitanidis Peter K. , Street Robert L.
Published: December 2005

Hyporheic exchange is an ecologically important process, controlling the nutrient supply in the upper sediments and thus benthic habitat quality. Hydraulic exchange at a riffle‐pool sequence in the Lahn River, Germany, was analyzed using HEC‐RAS to simulate the surface water flow as a boundary for the subsurface flow and MODFLOW, MODPATH, and MT3DMS to reproduce the transport in the subsurface. Solute transport and residence times of surface water in the subsurface were simulated after calibrating sediment properties to fit simulated hydraulic head to measured subsurface head from the riffle‐pool pair. Three surface water flow rates were considered. Results indicated that exchange increases with increasing surface water flow. However, the hydraulic conductivity of the riverbed sediments influences the mass transfer more than the surface water flow. The ratio of the infiltration rate to the surface water flow is of the same order of magnitude for all the considered flow conditions. Residence times of surface water in the subsurface varied inversely with the flow rates in the river.
Detailed structure within a tropical cyclone “eye”
Authors: Teshiba Michihiro , Fujita Hiroshi , Hashiguchi Hiroyuki , Shibagaki Yoshiaki , Yamanaka Manabu D. , Fukao Shoichiro
Published: December 2005

The characteristics of the “eye” and eyewall of a Tropical Cyclone (TC) are examined with a wind profiler and upper‐soundings around a small island belonging to Japan. There are few observations of wind behavior in the eye of a TC with high time and height resolutions. In the eye of the TC, weak cyclonic wind and updraft formed like a cylinder centered on the TC. The updraft did not form clouds and precipitation because stable and relatively dry air existed in the middle troposphere. There were dry layers above the middle troposphere in the eye, especially in the lower layers on the front side of the TC. Therefore, the rainfall associated with the eyewall was strengthened and developed. This is the first time that the detailed wind behavior in the eye of the TC in the developing and mature stage has been observed.
On the times of high and low tides
Authors: Longuet‐Higgins M. S.
Published: December 2005

The number N of low tides in a given 6‐hour interval of the day varies typically by a factor of order 2. A simple formula is derived relating Nmax/Nmin to the ratio R of the solar and lunar semi‐diurnal tidal constituents. This is shown to be quite accurate provided that the diurnal constituents are not large, and that the shallow‐water tides are negligible. Hence R could often be deduced from observations of Nmax/Nmin alone, with the aid of only a timepiece.
Duskside auroral undulations observed by IMAGE and their possible association with large‐scale structures on the inner edge of the electron plasma sheet
Authors: Lewis W. S. , Burch J. L. , Goldstein J. , Horton W. , Perez J. C. , Frey H. U. , Anderson P. C.
Published: December 2005

On February 6, 2002 large‐scale undulations along the equatorward edge of the afternoon/dusk auroral oval were observed with the IMAGE FUV/Wideband Imaging Camera (WIC) during the late expansion/recovery phase of a substorm. The undulations are similar to others previously reported, but occur at higher than usual latitudes and map to the outer duskside magnetosphere, 1 to 2 RE beyond a plasmaspheric drainage plume. The mapping suggests that the undulations result from large‐scale fluctuations on the inner edge of the electron plasma sheet. 2.5‐D simulations using representative plasma parameters for this region indicate that such large‐scale coherent structures can be created by a kinetic drift wave driven by the ion pressure gradient in the destabilizing curvature and grad B drift of the plasma sheet ions.
Rupture details of the 28 March 2005 Sumatra Mw 8.6 earthquake imaged with teleseismic P waves
Authors: Walker Kristoffer T. , Ishii Miaki , Shearer Peter M.
Published: December 2005

We image the rupture of the 28 March 2005 Sumatra Mw 8.6 earthquake by back‐projecting teleseismic P waves recorded by the Global Seismic Network and the Japanese Hi‐net to their source. The back‐projected energy suggests that the rupture started slowly, had a total duration of about 120 s, and propagated at 2.9 to 3.3 km/s from the hypocenter in two different directions: first toward the north for ∼100 km and then, after a ∼40 s delay, toward the southeast for ∼200 km. Our images are consistent with a rupture area of ∼40,000 km2, the locations of the first day of aftershocks, and the Harvard CMT Mw of 8.6, which implies an average slip of ∼6 m. The earthquake is similar in its location, size, and geometry to a Mw ∼8.5 event in 1861. Our estimated average slip is consistent with a partially coupled subduction interface, GPS forearc velocities, and the ∼59 mm/yr convergence rate if the 2005 earthquake released elastic strain that accumulated over many hundreds of years rather than just since the last 1861 event.
Central‐north China precipitation as reconstructed from the Qing dynasty: Signal of the Antarctic Atmospheric Oscillation
Authors: Wang Huijun , Fan Ke
Published: December 2005

Based on the long‐term Central‐north China precipitation (CNCP) time series reconstructed from the Qing Dynasty Official Document, the relationship between CNCP and the Antarctic Atmospheric Oscillation (AAO) in June‐July is examined. The analysis yields a (significant) negative correlation of −0.22. The signal of AAO in CNCP is further studied through analyses of the atmospheric general circulation variability related to AAO. It follows that AAO‐related variability of convergence and convection over the tropical western Pacific can exert impact on the circulation condition and precipitation in north China (actually, the precipitation in the Yangtze River Valley as well) through atmospheric teleconnection known as the East Asia‐Pacific (or Pacific–Japan) teleconnection wave pattern. There is also an AAO‐connected wave train in the vorticity field at high troposphere over Eurasia, providing an anti‐cyclonic circulation in central‐north China favorable to the decline of precipitation in positive phase of AAO.
Interannual persistence effects in vegetation dynamics of semi‐arid Africa
Authors: Martiny N. , Richard Y. , Camberlin P.
Published: December 2005

Over 15 years of Normalized Difference Vegetation Index (NDVI) data from the Advanced Very High Resolution Radiometers (AVHRR) are used to study the response of vegetation activity to rainfall in three semi‐arid regions of Africa. The relationships between annual NDVI and annual precipitation (PPT) time series are examined using statistical approaches (simple and partial correlations, linear multiple regressions). It appears that annual NDVI highly depends on PPT of the concurrent year and the previous year. An analysis of particularly dry and wet years enables to better diagnose two distinct responses of vegetation activity to rainfall. The “recovery” effect represents the difficulty of vegetation to recover from previous two‐year drought conditions. The “memory” effect represents the capacity of semi‐arid ecosystems to benefit from a water surplus at a one‐year time‐lag.
Stalagmite evidence for the onset of the Last Interglacial in southern Europe at 129 ± 1 ka
Authors: Drysdale Russell N. , Zanchetta Giovanni , Hellstrom John C. , Fallick Anthony E. , Zhao Jian‐xin
Published: December 2005

Multi‐proxy data from an Italian stalagmite constrain the commencement of full Last Interglacial conditions in southern Europe at 129 ± 1 ka, consistent with absolutely dated records currently available from both hemispheres. The post‐glacial transition towards warmer and wetter conditions commenced at 134 ± 2 ka. Oxygen isotope evidence suggests this was interrupted briefly at 130 ± 2 ka, an event probably related to the ‘Termination II pause’ associated with Heinrich Event 11. For most of the stalagmite, the pattern of δ18O variation mimics the air temperature record from the Vostok ice core, especially through marine isotope stage 5. There is no obvious evidence for substantial ‘early interglacial’ warming.
Global plasmasphere evolution 22–23 April 2001
Authors: Goldstein J. , Sandel B. R. , Forrester W. T. , Thomsen M. F. , Hairston M. R.
Published: December 2005

The evolution of the plasmasphere during the moderate 22–23 April 2001 storm is studied by comparing observed plasmasphere behavior to the predictions of a simulation. The plasmasphere observations include global images from IMAGE EUV and density and flow measurements from LANL MPA. The subjective uncertainty in the EUV plasmapause was found to be 0.2L. Inward plasmapause motion was correlated with southward interplanetary magnetic field (IMF), with a 27 min delay. The electric (E) field at the plasmapause was approximately 13% of the solar wind E‐field. The observations support the idea that plasmaspheric erosion begins with a partial plasmapause indentation which then gradually widens in magnetic local time (MLT) to encompass the entire nightside. In situ measurements confirm a dayside plume of sunward flowing plasma, and images show that the plume subsequently experienced phases of MLT narrowing and rotation/wrapping. To simulate the event, we employed a test particle representation of the plasmapause using a parametric E‐field model that includes corotation and convection from two sources: dayside magnetopause reconnection (DMR) and the subauroral polarization stream (SAPS). The model captures the phases of plume evolution, and it reproduces the observed plasmapause with maximum (mean) error <0.7L (0.24L). The model fails to reproduce important subglobal features (e.g., a predawn plasmaspheric shoulder) and grossly misplaces the inner edge of the rotating and wrapping plume. SAPS contributes significantly to the duskside flows, but the simulated flows are about 50% smaller than those seen by LANL MPA. The simulated plasmapause E‐field is about 70% of the EUV‐inferred value.
An algorithm to detect isolated anomalies in three‐dimensional stratified data fields with an application to density fields from four deep basins of the Baltic Sea
Authors: Reißmann Jan H.
Published: December 2005

A new approach to describe the mesoscale variability caused by eddies in terms of the integral properties of all eddies contained in a certain ocean volume is suggested. For this purpose a pattern recognition algorithm to detect isolated anomalies in three‐dimensional stratified data fields was developed and is introduced in detail. An application to 12 eddy‐resolving density fields acquired in the framework of the German‐Russian project MESODYN in four deep basins of the Baltic Sea, namely, the Arkona Basin, the Bornholm Basin, the Stolpe Furrow, and the Eastern Gotland Basin, demonstrates that the algorithm works properly. The most remarkable finding of this application is that the volume fraction occupied by the isolated anomalies or eddies is constant. It amounts to about 12% of the total volume for each data field no matter whether the stratification corresponds to a summer or a winter situation. Many possible applications of the pattern recognition are proposed to document its general usefulness. Finally, the main features of the algorithm and possible extensions are discussed extensively.
Canary Current and North Equatorial Current from an inverse box model
Authors: Hernández‐Guerra Alonso , Fraile‐Nuez Eugenio , López‐Laatzen Federico , Martínez Antonio , Parrilla Gregorio , Vélez‐Belchí Pedro
Published: December 2005

The large‐scale Canary Basin circulation is estimated from a box inverse model applied to hydrographic data from a quasi‐synoptic survey carried out in September 2003. The cruise consisted of 76 full depth CTD and oxygen stations. Circulation is required to nearly conserve mass and anomalies of salinity and heat within layers bounded by neutral surfaces. It permits advective and diffusive exchange between layers and an adjustment of the Ekman transport and the freshwater flux divergences. The Canary Current at the thermocline layer transports a net mass of 4.7 ± 0.8 Sv southward north of the Canary Islands from the African coast to 19°W. It is divided into a northward circulation at a rate of 1.1 ± 0.5 Sv between the African coast and Lanzarote Island and a southward transport of 5.8 ± 0.6 Sv. It transports North Atlantic Central Water and organic matters advected offshore by the filaments protruding from the upwelling system off northwest Africa. At 24°N, the Canary Current feeds the North Equatorial Current that transports a mixture of North and South Atlantic Central Waters westward. In the intermediate layer a southwestward flow of 1.2 ± 1.1 Sv transports Mediterranean Water to the Subtropical Gyre, though the highest salt flux is transported by a meddy. Oxygen distribution and mass transport suggest a northeastward deep flow of a water mass colder than 2.2°C consisting of diluted Antarctic Bottom Water. The heat and freshwater divergences and the average dianeutral velocity and diffusion between the sections and the African coast are negligible.
On minimum relative entropy concepts and prior compatibility issues in vadose zone inverse and forward modeling
Authors: Hou Zhangshuan , Rubin Yoram
Published: December 2005

A comprehensive stochastic approach for forward modeling of the state variables in the vadose zone as well as for inverse modeling of the hydraulic parameters is proposed and applied to a field site in Napa Valley, California. The approach combines the Richards equation and the van Genuchten–Mualem soil models, with initial and boundary conditions provided by geophysical and meteorological measurements, into a Bayesian formalism, which allows integration between different complementary information sources. A major challenge in such studies is the integration between different types of data, of different quality and resolution, and with prior information. Accurate modeling of prior information is challenging because of the need to avoid subjective judgment with regard to the quality of the prior information and its significance. To obtain minimally subjective prior probabilities required for the Bayesian approach, we employ the principle of minimum relative entropy (MRE). It can often be the case that information that is considered a suitable prior may, in fact, become incompatible with field observations as more observations become available. Our study considers this possibility and explores possible indications for prior incompatibility. We test our forward and inverse modeling approaches using field data. The results indicate that our approach is consistent, in the sense that as additional data are introduced, the simulated soil moisture content profile better matches the observed profile and the predictive intervals become much narrower. The narrower intervals of the soil moisture predictions indicate the reduction of uncertainties associated with the model parameters.
Ethiopia: between Sub‐Saharan Africa and Western Eurasia
Authors: Lovell A. , Moreau C. , Yotova V. , Xiao F. , Bourgeois S. , Gehl D. , Bertranpetit J. , Schurr E. , Labuda D.
Published: December 2005

Ethiopia is central to population genetic studies investigating the out of Africa expansion of modern humans, as shown by Y chromosome and mtDNA studies. To address the level of genetic differentiation within Ethiopia, and its relationship to Sub‐Saharan Africa and Eurasia, we studied an 8kb segment of the X‐chromosome from 72 chromosomes from the Amhara, Oromo and Ethiopian Jews, and compared these results with 804 chromosomes from Middle Eastern, African, Asian and European populations, and 22 newly typed Saharawi. Within Ethiopia the two largest ethnic groups, the Amhara and Oromo, were not found to be statistically distinct, based on an exact test of haplotype frequencies. The Ethiopian Jews appear as an admixed population, possibly of Jewish origin, though the data remain equivocal. There is evidence of a close relationship between Ethiopian and Yemenite Jews, likely a result of indirect gene flow. Within an African and Eurasian context, the distribution of alleles of a variable Tn repeat, and the spread of haplotypes containing Africa‐specific alleles, provide evidence of a genetic continuity from Sub‐Saharan Africa to the Near East, and furthermore suggest that a bottleneck occurred in Ethiopia associated with an out of Africa expansion. Ethiopian genetic heterogeneity, as evidenced by principal component analysis of haplotype frequencies, most likely resulted from periods of subsequent admixture. While these results are from the analysis of one locus, we feel that in association with data from other marker systems they add a complementary perspective on the history of Ethiopia.