bluuebunny/crossref_metadata_2025 huggingface dataset:
Cochlear implantation in a patient with profound hearing loss with the A1555G mitochondrial DNA mutation and no history of aminoglycoside exposure
Authors: Ulubil S Arif , Furze Alexis D , Angeli Simon I
Published: November 2005

The A1555G mitochondrial deoxyribonucleic acid (mtDNA) point mutation has classically been associated with sensorineural hearing loss in patients following aminoglycoside exposure. More recently, the mutation has been implicated in sensorineural hearing loss in patients without previous aminoglycoside use. In addition, cochlear implantation has been shown to be effective in the group of patients with prior aminoglycoside exposure but, to date, no case of cochlear implantation in a patient with the A1555G mutation and no prior exposure to aminoglycosides has been explicitly described in the literature.

We report the case of an 80-year-old woman with the A1555G mtDNA mutation, a 35-year history of bilateral progressive hearing loss and no history of aminoglycoside exposure who underwent successful implantation of a Nucleus 24 Contour device at our institution. Post-operatively, the patient exhibited marked improvement in tests of auditory performance.

We conclude that cochlear implantation can be an effective method to restore some sense of hearing in patients with the A1555G mtDNA mutation and sensorineural hearing loss.
Sarcomatoid salivary duct carcinoma of the larynx
Authors: Jeong Han-Sin , Son Young-Ik , Ko Young-Hyeh , Kim Sang Yoon
Published: November 2005

The sarcomatoid variant is a rare subtype of salivary duct carcinoma that comprises epithelial and sarcomatoid components. The authors present the first reported case of sarcomatoid salivary duct carcinoma occurring in the larynx, which was successfully treated by partial laryngectomy with ipsilateral neck dissection, with no evidence of recurrence after five years.

Microscopic analysis revealed a composite epithelial and sarcomatoid tumour. The epithelial component was characterized by papillary proliferation of glandular and ductal structures lined with multilayered epithelial tumour cells. The sarcomatoid component was characterized by pleomorphic spindle cells with cytologic atypia, accompanied by small lymphoid cells, extensive proliferation of blood vessels and focal myxoid changes.

To the best of our knowledge, only one case of sarcomatoid salivary duct carcinoma outside a major salivary gland has been reported previously in the literature, and this is the first report of sarcomatoid salivary duct carcinoma arising from the larynx.
CO2 laser myringotomy in children with otitis media with effusion
Authors: Lin Shih-Hsiang , Lai Chien-Chung , Shiao An-Suey
Published: November 2005

Background: The study aimed to evaluate the clinical application of CO2 laser myringotomy in children with otitis media with effusion (OME) under topical anaesthesia in an office setting.

Methods: Laser myringotomy was performed with the CO2 laser Otoscan (OtoLAM) in 54 children (73 ears) with OME. The procedure on the tympanic membrane was performed under topical anaesthesia using Bonain's solution or 10 per cent Xylocaine (lidocaine) solution for 30 minutes before surgery. A circular perforation was created with a power of 15 W, single pulse duration of 200 msec and a scanned area of 1.9 mm in diameter.

Results: The mean healing time was 2.51 weeks (range 1–5 weeks). Effusion content was not a predictive prognostic factor for perforation healing time. Perforation location over anterior inferior or posterior inferior quadrants was not a predictive factor for perforation healing time. Xylocaine was the more effective anaesthestic. The OME resolution rate was 73 per cent.

Conclusion: Laser myringotomy provides intermediate duration middle-ear ventilation. It could be beneficial in selected children with OME.
Neck dissection: past, present and future?
Authors: Ferlito Alfio , Rinaldo Alessandra , Robbins K Thomas , Silver Carl E
Published: November 2005

With the exception of distant metastasis, the presence of cervical lymph node metastasis is the single most adverse independent prognostic factor in head and neck squamous cell carcinoma. Surgical removal of metastatic cervical lymph nodes had been attempted during the late nineteenth century, with varying techniques and poor results. A systematic approach to en bloc removal of cervical lymph node disease, described in detail by Jawdyński at the end of the nineteenth century and popularized and illustrated by Crile in the early twentieth century, provided consistent and more effective treatment and forms the basis of our current techniques. The concepts of radical neck dissection, employed extensively by Martin, were followed with almost religious consistency by most head and neck surgeons until the late twentieth century, when the principles of ‘functional’ neck dissection, developed by Suárez and popularized by Bocca, Gavilán, Ballantyne, Byers and others, led to the acceptance of modified radical neck dissection as treatment for lymph node disease in various stages. More recently, selective neck dissection, involving removal of nodes confined to the levels at greatest risk of metastasis from primary tumours at various sites, has become accepted practice for elective and, in some instances, therapeutic treatment of the neck. In the future, sentinel lymph node biopsy and the use of molecular pathological analyses may be employed to predict the presence of occult cervical disease, thus directing therapy to patients at greatest risk and sparing those without regional metastasis.
Chondrodysplasia punctata: case report and review of audiological and ENT features
Authors: Murdin L , Sirimanna T , Hartley B E , Holder S E
Published: November 2005

Chondrodysplasia punctata is a term referring to a clinically heterogeneous group of bone and cartilage dysplasias which cause characteristic epiphyseal stippling. The condition can involve the ear, nose and throat in diverse ways at many levels. We present a case of X-linked brachytelephalangic chondrodysplasia punctata, which illustrates the features of this condition particularly relevant to the audiological physician, otolaryngologist and neonatologist.
Otoacoustic emissions in young adults with a history of otitis media
Authors: Yilmaz Sule , Karasalihoglu Ahmet Rifat , Tas Abdullah , Yagiz Recep , Tas Memduha
Published: November 2005

The aim of this study was to investigate otoacoustic emissions in young adults who had a history of otitis media (OM) in childhood and to assess whether a history of OM had an irreversible effect on hearing. We studied 116 cases between 15 and 25 years of age, divided into three groups. Each subject underwent a single examination comprising otoscopy, pure-tone audiometry (PTA), tympanometry, and transient evoked otoacoustic emission (TEOAE) and distortion product otoacoustic emission (DPOAE) testing. Subjects in the first and second groups had normal audiometric hearing thresholds and type A tympanograms. The only difference between the first and second group was the presence or absence of a history of OM. The third group consisted of patients diagnosed as having active OM; these patients had poorer hearing thresholds and type B or C tympanograms. After statistical analysis of TEOAE and DPOAE results (one-way analysis of variance test), significant differences were noted between groups. Otoacoustic emission levels were, unsurprisingly, lowest in the third group, as expected. However, the most striking result in the study was that significantly fewer otoacoustic emissions were detected in subjects with a history of OM than in subjects without a history of OM. These findings suggest that OM in childhood may cause minor but irreversible damage to the middle ear or cochlea. Otoacoustic emissions testing can be used to detect this sub-clinical damage.
Congenital epulis
Authors: Kanotra Sonika , Kanotra Sohit Paul , Paul J
Published: November 2005

Congenital epulis or gingival granular cell tumour is a rare lesion occurring in the newborn, affecting females eight times more than males and arising more commonly from the maxillary than the mandibular alveolar ridge. We report the case of a five-day-old girl who presented to us with a large mass arising from the gingival mucosa of the mandible, causing feeding difficulty. Immediate surgical excision was followed by an uneventful recovery. The case is reported to make clinicians aware of this uncommon but easily treatable condition.
Steroids in rhinoplasty: a survey of current UK otolaryngologists' practice
Authors: Ofo E , Singh A , Marais J
Published: November 2005

The use of steroids during rhinoplasty to reduce post-operative periorbital oedema and ecchymosis has been advocated. A number of randomized controlled trials have demonstrated the benefit of steroids in rhinoplasty. The aim of this study was to determine current UK practice in the use of steroids during rhinoplasty performed by otolaryngologists.

A postal survey of consultant otolaryngologists in the UK was conducted. We received 203 responses, with 115 consultants performing 12 or more rhinoplasties per year. Only 28 consultants (24 per cent) used steroids routinely in patients undergoing rhinoplasty and of these 11 used a protocol, although this was unpublished. Dexamethasone was the most common steroid used (82 per cent), being administered as a single intravenous dose of 8 mg in the majority of cases (54 per cent). There was no correlation between the use of steroids and the number of rhinoplasties performed by individual consultants.

Despite the evidence supporting the use of steroids to reduce post-operative sequelae following rhinoplasty, only a minority of consultants in the UK appear to use them as part of their practice.
Laryngeal tuberculosis following laryngeal carcinoma
Authors: Nishiike Suetaka , Nagai Miki , Nakagawa Aya , Konishi Masaki , Sakata Yoshiharu , Aihara Teruhito , Harada Tamotsu
Published: November 2005

Laryngeal tuberculosis is a rare entity and the disease related to laryngeal cancer is extremely rare. We describe a case of laryngeal tuberculosis in a 74-year-old man with a history of radiotherapy for laryngeal carcinoma four months earlier. Laryngoscopy demonstrated a white mass on the right vocal fold at the site carcinoma had previously occupied. Recurrence of the cancer was suspected, but the biopsy result showed histological features of tuberculosis. We discuss the derangement of the host's mucosal barrier by the malignancy as a contributing factor in secondary tuberculous infection. Tubercular bacilli may be reactivated due to the immunosuppression associated with the therapy.
Is there an association ofPneumocystisinfection with the presence of arena-, hanta-, and poxvirus antibodies in wild mice and shrews in Finland?
Authors: LAAKKONEN J. , KALLIO E. R. , KALLIO-KOKKO H. , VAPALAHTI O. , VAHERI A. , HENTTONEN H.
Published: November 2005

As part of studies on the nature of the endemic virus infections in natural rodent hosts, the possible association of cyst forms ofPneumocystisspp. with the presence of hanta-, cowpox-, and arenavirus antibodies in wild mice (Apodemus flavicollis,N=105;Apodemus agrarius,N=63;Micromys minutus,N=50) and the common shrew (Sorex araneus,N=101) was studied in south-central Finland. One hantavirus (Saaremaa virus, SAAV) seropositiveA. agrarius, and 2 cowpoxvirus (CPXV) seropositiveS. araneuswere detected, and antibodies against an arenavirus (Lymphocytic choriomeningitis virus, LCMV) were found in all 3 mouse species but not in shrews. Cyst forms ofPneumocystisspp. were detected in all species exceptA. agrarius. There was no significant association between virus antibodies (LCMV in mice, and CPXV in shrews) and cyst forms ofPneumocystisin any of the species. Concurrent presence of virus antibodies (LCMV) and cyst forms ofPneumocystiswere detected only in 1M. minutus. In conclusion, we found no evidence of any association betweenPneumocystisand antibodies to any of the viruses tested.
Nitric oxide radicals in leucocytes and vaginal washes ofTrichomonas vaginalis-infected symptomatic and asymptomatic women
Authors: YADAV M. , DUBEY M. L. , GUPTA I. , MALLA N.
Published: November 2005

The clinical spectrum ofTrichomonas vaginalisinfection varies from asymptomatic to mild, moderate or severe vaginitis. Nitric oxide and other reactive nitrogen radicals produced by immune effector cells are important cytotoxic and cytostatic mediators against several microorganisms including parasites. In the present study, inducible nitric oxide synthase (iNOS) and reactive nitrogen intermediates (RNI) were determined in leucocyte cultures (stimulated withT. vaginalis in vitro) and vaginal washes (VWs) of 22 symptomatic and 20 asymptomaticT. vaginalis-infected and 20 healthy women by immunoblotting and Griess method respectively. The iNOS protein was detected in leucocytes and VWs of all the symptomatic and asymptomatic women, but was not detected in any of the samples from healthy women. Mean iNOS protein band intensity was significantly higher in leucocytes as compared to VWs (P<0·001) of both symptomatic and asymptomatic women and was also higher in leucocytes of asymptomatic as compared to symptomatic women (P<0·05). Mean RNI concentration was also significantly higher in leucocytes (P<0·01) and VWs (P<0·05) of asymptomatic as compared to symptomatic women, and was also higher in samples of infected as compared to healthy women (P<0·001). These results suggest that reactive nitrogen radicals may have a role in limitingT. vaginalisinfection in asymptomatic women.
Praziquantel and liposomized glucan-treatment modulated liver fibrogenesis and mastocytosis in mice infected withMesocestoides vogae(M. corti, Cestoda) tetrathyridia
Authors: HRČKOVA G. , VELEBNÝ S. , DAXNEROVÁ Z. , SOLÁR P.
Published: November 2005

β–glucans are immunomodulators able to activate innate immunity and to potentiate acquired immune reactions. We investigated the impact of co-administration of liposomized β-glucan on the larvicidal effect of the anthelmintic praziquantel (PZQ) in the livers and peritoneal cavities in mice infected withMesocestoides vogae(M. corti). Also, within 2 weeks following therapy (up to day 29 p.i.) we examined collagen synthesis in the livers of mice by means of biochemical determination of hydroxyprolin concentration, total mast cell counts and cell proliferative capacity using immunohistochemical and radiometrical methods. After co-administration of liposomized glucan (LG) and PZQ efficacy (%) was significantly higher than after treatment with either compond alone, particularly in the peritoneal cavity compared to the liver. In comparison with the control, more intense collagenesis was found in the B-liver parts (high intensity of infection) and lowering of collagen content in the A-parts (very weak infection). This effect was strongest after LG treatment and co-administration of PZQ abolished the pro-fibrotic effect of LG. In all groups, mast cell counts were higher in the B-liver parts than in the A-parts and the dynamics of mastocytosis was profoundly modulated following therapy. Whereas the effect of PZQ was only moderate, early and very strong onset was seen after LG treatment. Administration of PZQ supressed LG induced-elevation of mast cells counts in both liver parts. Using DNA S-phase markers (BrdU and3H-thymidine) the proliferative capacity was shown to be associated with several kinds of liver cells. Therapy significantly stimulated [3H]-thymidine incorporation (cell proliferation) only in the A-parts over that in control, the most after LG administration. In summary (i) the anthelmintic effect of PZQ could be enhanced after simultaneous administration of the immunomodulator β-glucan entrapped in a liposomal carrier, (ii) intense mastocytosis seen after treatment with LG seems to have a direct role in the glucan′s pro-fibrotic activity and can be abolished after co-administration of PZQ in a time-dependent manner, (iii) the pattern of cell proliferation indicates that in the case of PZQ treatment, the reparative processes of liver parenchyma are enhanced in an inverse correlation with the intensity of infection.
Psychiatric morbidity is related to parental age: a national cohort study
Authors: EKÉUS CECILIA , OTTERBLAD OLAUSSON PETRA , HJERN ANDERS
Published: November 2005

Background. The median age at first childbirth has increased dramatically in many high-income countries during the past decades. The psychiatric consequences of this demographic change are insufficiently described on a population level. This study aimed to investigate whether parental age at childbearing is related to psychiatric morbidity among Swedish youths.

Method. This was a cohort study based on Swedish national registers. A national cohort of 292129 children born to primiparas women during 1973–1979 was followed prospectively from 1987 to 2002 in registers. Multivariate Cox analyses of proportional hazards were used to estimate the relative risk of hospital admission for schizophrenia, alcohol and illicit drug abuse, suicide attempts and deaths.

Results. Youths born of teenage mothers had a high risk for suicide death [relative risk (RR) 1·9, 95% confidence interval (CI) 1·3–2·7] and hospital admissions because of suicide attempt (RR 2·0, 95% CI 1·7–2·3) and substance abuse (alcohol: RR 1·6, 95% CI 1·4–1·8; illicit drug: RR 2·2, 95% CI 1·9–2·5) after adjustments for major sociodemographic confounders, compared with children of mothers aged 25–29 years. Offspring of older parents (>34 years) had the highest risk for schizophrenia (RR 1·8, 95% CI 1·0–3·0).

Conclusions. Parental age is related to psychiatric morbidity.
Linguistic notes on magic bowls in the Moussaieff Collection
Authors: MORGENSTERN MATTHEW
Published: November 2005

The study of Babylonian Aramaic magic bowls has undergone something of a renaissance in recent years owing to a wave of new publications which have considerably enriched the corpus of texts now at the reader's disposal. In parallel, significant progress has been made in the identification, publication and study of accurate manuscripts of Babylonian Rabbinic literature. Based upon a close reading of recently published magic bowls from the Moussaieff Collection, this article seeks to indicate how the two corpora are mutually enlightening and dependent. An accurate reading and interpretation of the bowls depends upon an intimate knowledge of Babylonian Aramaic grammar, for which much is to be learnt from the best rabbinic manuscripts. At the same time, the magic bowls confirm the antiquity of many linguistic traits found in these rabbinic sources, and accordingly confirm their status as reliable witnesses to the Talmudic language.
Enantiodrama: Enantiosemia in Arabic and beyond
Authors: FINKIN JORDAN
Published: November 2005

Words which designate both themselves and their opposites can be found in many languages around the world. For the Arabic grammarians of the eighth and ninth centuries the existence of such a class of words was a concern as it was a potential hindrance to intelligibility and clarity of semantic interpretation. This paper seeks to engage one thread of that tradition, to reposition it in the context of more modern linguistic scholarship, and to expand on it implications for an understanding of language, all the while hopefully dispelling some of the more wanton psychological misconceptions it has engendered.
How did the quranic pagans make a living?
Authors: CRONE PATRICIA
Published: November 2005

This article examines the information given in the Quran, as distinct from the exegetical tradition, on the livelihoods pursued by the mushriku¯n to whom the Messenger was preaching. It finds them to be uniformly described as agriculturalists and seafarers. The purpose of their maritime activity is not usually specified, but on one occasion it is said to be for fishing. The believers, too, are agriculturalists in some passages, but they are more commonly described as traders. There is a wealth of passages depicting them as such, and preaching to them in commercial imagery, in the suras classified by the tradition as Medinese.
From practice to polemic: shared saints and festivals as ‘women's religion’ in the medieval Mediterranean
Authors: CUFFEL ALEXANDRA
Published: November 2005

In this article I examini two problems regarding women's participation in shared saint veneration and festivals in the eastern Mediterranean and Iberia. First, I ascertain what women's practices were, whether women participated in or assigned meanings to rituals that were separate from those of men, and finally, whether these shared practices were enough to break down religious barriers between women so that we may speak of ‘women's piety’ or ‘women's religious culture’ as a category that extends beyond the confines of individual religious affiliations. Secondly, I explore the meanings that certain male writers assigned in these practices and their emphasis on the fact that it was women, according to them, who engaged in the rituals. I show that, in contrast to Christian or Jewish authors, many Muslim legalists focused on women as the primary participants in certain types of piety as a polemical strategy to denigrate religious practices of which they disapproved.
Irano-Tocharica et Tocharo-Iranica
Authors: TREMBLAY XAVIER
Published: November 2005

This paper attempts a periodization and dialectal attribution of Iranian loan words found in Tocharian A and B, two Indo-European languages attested in c. 10,000 fragments unearthed in Chinese Turkestan since 1892. More than 100 loan words are scritinized and classified in eight sections, according to their origin: Old Iranian (probably issued from the common ancestry of the ‘Sakan’ languages, Khotanese, Tumshuqese and Waxi), three different stages of Khotanese, ‘Śaka’, (the language of the Iranian invaders of northern India), Parthian, Bactrian and Sogdian. Tocharians had dealings with all neighbouring Iranian peoples, but Khotanese and its ancestors clearly exerted the most durable influence. No loan word from more remote dialects (e.g. Persian and Ossetic) can be evidenced. The predominance of war-related and political vocabulary among the loan words and the direction of borrowing, overwhelmingly from Iranian to Tocharian, both point to a political ascendancy of Sakan-speaking tribes, and later of Bactria, on Tocharians.
Was there an imperial distribution of Buddha relics in ninth-century China?
Authors: BARRETT T. H.
Published: November 2005

To judge from one recorded case, the Huichang persecution of Buddhism in China of 840–44 could have brought a number of relics of the Buddha into the hands of the government, and this might further have allowed the succeeding, more pro-Buddhist, emperor to carry out a redistribution of these sacred objects to enhance his own prestige, as had already been done twice by earlier rulers. But while it is clear that he was prepared to send a relic to Korea as part of a diplomatic mission, there would appear to be no surviving records confirming that any systematic large-scale distribution was carried out at this time. We must provisionally conclude therefore that a later systematic distribution in the tenth century was influenced—perhaps indirectly—by the earlier examples, not by any event of the mid ninth century.
Religion and the first recorded print run: Luoyang, July, 855
Authors: BARRETT T. H.
Published: November 2005

The Xuanjie lu has long been recognized as an early recorded example of a printed text. The date of printing given in its preface suggests that its author, Hegan Ji, was about to be or had just been demoted from the governorship of Canton on the grounds of corruption, from where he was sent to Luoyang. This article argues for the latter place of publication, and suggests that the printing of ‘several thousand’ copies of this short work, while a notable achievement in itself, was perhaps primarily intended to recover the author's political fortunes—a goal in which the evidence suggests that he succeeded, to judge from a recently published inscription by one of his sons.
Situated creation of multimedia activities for distance learners:
motivational and cultural issues
Authors: DEVELOTTE CHRISTINE , MANGENOT FRANÇOIS , ZOUROU KATERINA
Published: November 2005

This paper discusses the design and implementation of a task-oriented collaborative learning (and training)
experimental project that was carried out with future language teachers. More specifically, a class of sixteen French students
enrolled in a Masters of Education course were asked to create multimedia resources for a group of Australian students with no prior
knowledge of French. This paper deals only with issues concerning French
students’ multimedia creations, not with the second phase of interactions with the Australian target group.
The theoretical background is situated and collaborative learning and training: the French students worked in pairs,
creating multimedia activities based on their culture for real students in a different location. They communicated with each
other during weekly classes and via a groupware tool. A triangulated data method
was used incorporating the students’ multimedia outcome, questionnaires and semi-directive interviews. The following
issues are discussed: what is the effect of such situated learning settings on motivation, commitment and computer literacy?
What image did the French students have of the Australian students and which cultural aspects did they try to convey?
Quasi‐monochromatic ULF foreshock waves as observed by the four‐spacecraft Cluster mission: 1. Statistical properties
Authors: Eastwood J. P. , Balogh A. , Lucek E. A. , Mazelle C. , Dandouras I.
Published: November 2005

Cluster data are used to study the statistics of a particular type of foreshock wave: quasi‐monochromatic ultra‐low‐frequency (ULF) waves with characteristic periods of 30 s in the spacecraft frame. On the basis of a large set of foreshock observations made in 2001 with spacecraft separations ∼600 km, the intrinsic properties of the waves are found using a cross‐correlation timing analysis. This method, which allows the solar wind rest frame properties of the waves to be calculated with fewer assumptions when compared to previous dual spacecraft analysis, is described in detail. The performance of minimum variance analysis (MVA) as a wave analysis tool is investigated experimentally using this multispacecraft analysis. MVA estimates of propagation direction are shown to diverge from the multispacecraft estimate in the limit of linear wave polarization. Theoretical estimates of MVA error are also compared to the observations. Previously established wave properties derived from ISEE are independently tested; it is found that statistically, the waves propagate at frequencies an order of magnitude below the ion cyclotron frequency in the solar wind rest frame and have wavelengths of the order of an Earth radius. However, these statements mask the fact that there is significant variation about these average values that is physical in nature. The data are plotted in the ω − k plane and the average frequency and wave number are used to experimentally identify the “average” resonant beam speed. This beam speed is an order of magnitude greater than the local Alfvén speed in the solar wind rest frame. Furthermore, histograms of the inferred beam speed normalized to the solar wind speed are presented and compared to previously published plasma data. Finally, the spacecraft frame wave period is found to be proportional to the magnetic field strength in a manner consistent with previous analyses.
Quasi‐monochromatic ULF foreshock waves as observed by the four‐spacecraft Cluster mission: 2. Oblique propagation
Authors: Eastwood J. P. , Balogh A. , Lucek E. A. , Mazelle C. , Dandouras I.
Published: November 2005

This paper presents the results of a statistical investigation into the nature of oblique wave propagation in the foreshock. Observations have shown that foreshock ULF waves tend to propagate obliquely to the background magnetic field. This is in contrast to theoretical work, which predicts that the growth rate of the mechanism responsible for the waves is maximized for parallel propagation, at least in the linear regime in homogenous plasma. Here we use data from the Cluster mission to study in detail the oblique propagation of a particular class of foreshock ULF wave, the 30 s quasi‐monochromatic wave. We find that these waves persistently propagate at oblique angles to the magnetic field. Over the whole data set, the average value of θkB was found to be 21 ± 14°. Oblique propagation is observed even when the interplanetary magnetic field (IMF) cone angle is small, such that the convective component of the solar wind velocity, vE×B, is comparable to the wave speed. In this subset of the data, the mean value of θkB was 12.9 ± 7.1°. In the subset of data for which the IMF cone angle exceeded 45°, the mean value of θkB was 19.5 ± 10.7°. When the angle between the IMF and the x geocentric solar ecliptic (GSE) direction (i.e., the solar wind vector) is large, the wave k vectors tend to be confined in the plane defined by the x GSE direction and the magnetic field and a systematic deflection is observed. The dependence of θkB on vE×B is also studied.
First coupled Sr and Pb isotopic measurements in volcanic gas condensates and groundwaters of Vulcano Island (Italy)
Authors: Nonell Anthony , Toutain Jean‐Paul , Polvé Mireille , Munoz Marguerite , Berger Gilles
Published: November 2005

For the first time, coupled Sr‐Pb concentrations and isotopic compositions have been measured on four crater fumaroles and six groundwaters sampled between 1999 and 2001 at Vulcano Island, southern Italy. Sr concentrations and isotopic compositions of groundwaters show that the Sr budget results mainly from the leaching of volcanic rock by groundwaters. Leaching intensity is controlled by the variable dissolution of volcanic gases into shallow aquifers. The data do not reveal any influence of seawater except at one coastal site. Low Pb concentrations together with calculated saturation indexes with respect to mineral phases indicate that Pb content in groundwaters is strongly influenced by adsorption and/or precipitation processes. Pb isotopic ratios of two steam‐heated waters display a clear anthropized meteoric water signature, suggesting gas dissolution or wall rock alteration to be a negligible process for this element in this particular context. Low (≈0.5) and high (102–103) enrichment factors were calculated for Sr and Pb, respectively, indicating their refractory and volatile behavior in volcanic gases. Most of the gas samples display Sr and Pb isotopic ratios similar to parent rocks. These data suggest that Sr is mainly derived from wall rock or particle contamination during gas ascent, whereas Pb results mainly from magma degassing. However, two gas condensates collected from two different fumarolic vents and at different periods show a dramatic Pb and Sr isotopic shift with a clear atmospheric/anthropogenic signature. Episodic permeability variations of the volcanic structure, probably arising from microseismicity swarms, changes of local stress field, and migration of self‐sealing processes lead to changing interactions between freshly infiltrated meteoric water and volcanic gases that temporarily modify the trace metal signature of the fumarolic gas.
Sr, Nd isotopic evidence of terrigenous flux variations in the Bay of Bengal: Implications of monsoons during the last ∼34,000 years
Authors: Ahmad S. M. , Anil Babu G. , Padmakumari V. M. , Dayal A. M. , Sukhija B. S. , Nagabhushanam P.
Published: November 2005

Sr and Nd isotopic compositions of a sediment core from the Bay of Bengal are used to constrain the provenance and transport pathways of their terrigenous component during the ∼3 to 34 14C kyr BP. The results clearly demonstrate a distinctly different source for detrital fluxes on the Ninetyeast Ridge from that of distal and western Fan sediments. There is a systematic pattern of climate‐related variability in 87Sr/86Sr and ɛNd(o) values at the studied location. Pulses of low 87Sr/86Sr, higher radiogenic Nd and high silt content occurring at ∼5–7 kyr intervals suggest significant changes in the detrital source. Increased supply of Irrawaddy‐derived sediments appears to be the dominant source for these pulses. Our results support the hypothesis that rapid cold events of North Atlantic (Heinrich events) are characterized by the intensified northeast monsoon.
Impact of 1998–2002 midlatitude drought and warming on terrestrial ecosystem and the global carbon cycle
Authors: Zeng Ning , Qian Haifeng , Roedenbeck Christian , Heimann Martin
Published: November 2005

A rare drought occurred from 1998 to 2002 across much of the Northern Hemisphere midlatitude regions. Using observational data and numerical models, we analyze the impact of this event on terrestrial ecosystem and the global carbon cycle. The biological productivity in these regions was found to decrease by 0.9 PgC yr−1 or 5% compared to the average of the previous two decades, in conjunction with significantly reduced vegetation greenness. The drought led to a land carbon release that is large enough to significantly modify the canonical tropically dominated ENSO response. An atmospheric inversion reveals that during the 1998–2002 drought period, Northern Hemisphere midlatitude changed from a 1980–1998 average of 0.7 PgC yr−1 carbon sink to nearly neutral to the atmosphere, while a forward model suggests a change of 1.3 PgC yr−1 in the same direction. This large CO2 source may explain the consecutive large increase in atmospheric CO2 growth rate of about 2 ppmv yr−1 in recent years, as well as the anomalous timing of events. This Northern Hemisphere CO2 anomaly was largely caused by reduced vegetation growth due to less precipitation, but also with significant contribution from higher temperature that directly increases respiration loss and indirectly further reduces soil moisture. Since the Northern Hemisphere midlatitude landscape has been significantly modified by agriculture, grazing, irrigation and fire suppression, the strong signature in the global carbon cycle of a drought initiated by changes in tropical oceanic temperatures is a remarkable manifestation of climate variability, with implications for carbon cycle response and feedback to future climate change.
Lightning sferics and stroke‐delayed pulses measured in the stratosphere: Implications for mesospheric currents
Authors: Thomas Jeremy N. , Holzworth Robert H. , McCarthy Michael P. , Pinto Osmar
Published: November 2005

During the Brazil Sprite Balloon Campaign 2002–03, the vector ELF to VLF (25 Hz–8 kHz) electric and magnetic fields driven by cloud‐to‐ground (CG) lightning strokes at horizontal distances of 75–600 km were measured at altitudes of 30–35 km. Electric field changes were measured for each of the 2467 CG strokes detected by the Brazilian Integrated Lightning Network. ELF pulses that occur 4–12 ms after the retarded time of the lightning sferic, which have been previously attributed to sprites, were found for 1.4% of 934 strokes examined. Thus, lightning‐driven electric and magnetic field changes were common and stroke‐delayed ELF pulses were rare, which disagrees with results from the Sprites99 Balloon Campaign.
Initial results of high‐latitude magnetopause and low‐latitude flank flux transfer events from 3 years of Cluster observations
Authors: Wang Y. L. , Elphic R. C. , Lavraud B. , Taylor M. G. G. T. , Birn J. , Raeder J. , Russell C. T. , Kawano H. , Zong Q.‐G. , Zhang H. , Zhang X. X. , Friedel R. H.
Published: November 2005

We present initial results from a statistical study of Cluster multispacecraft flux transfer event (FTE) observations at the high‐latitude magnetopause and low‐latitude flanks from February 2001 to June 2003. Cluster FTEs are observed at both the high‐latitude magnetopause and low‐latitude flanks for both southward and northward IMF. Among the 1222 FTEs, 36%, 20%, 14%, and 30% are seen by one, two, three, and four Cluster satellites, respectively. There are 73% (27%) of the FTEs observed outside (inside) the magnetopause, which might be caused by the motion of FTEs toward the magnetosheath when they propagate from subsolar magnetopause to the midlatitude and high‐latitude magnetopause and low‐latitude flanks. We obtain an average FTE separation time of 7.09 min, which is at the lower end of the previous results. The mean BN peak‐peak magnitude of Cluster FTEs is significantly larger than that from low‐latitude FTE studies. FTE BN peak‐peak magnitude clearly increases with increasing absolute magnetic latitude (MLAT), it has a weaker dependence on magnetic local time (MLT) with a peak near the magnetic local noon, and it has a complex dependence on Earth dipole tilt with a peak at around zero. FTE periodic behavior is found to be controlled by MLT, with a general increase of FTE separation time with increasing MLT, and by Earth dipole tilt, with a peak FTE separation time at around zero Earth dipole tilt. There is no clear dependence of FTE separation time on MLAT. There is a weak increase of FTE BN peak‐peak magnitude with increasing FTE separation time, and we see no clear dependence of it on FTE BN peak‐peak time. When no FTE identification thresholds are used, more accurate calculations of some FTE statistical parameters, including the mean BN peak‐peak time, can be obtained. Further, comparing results with different thresholds can help obtain useful information about FTEs.
Long‐duration penetration of the interplanetary electric field to the low‐latitude ionosphere during the main phase of magnetic storms
Authors: Huang Chao‐Song , Foster John C. , Kelley Michael C.
Published: November 2005

It is well known that the interplanetary electric field can penetrate to the low‐latitude ionosphere. It is generally believed that the penetration of electric fields can last only for ∼30 min because of the shielding effect in the ring current. In this paper we present the observations of the dayside ionospheric electric field enhancements at middle and low latitudes in association with reorientations of the interplanetary magnetic field (IMF). In six cases, the eastward electric field in the dayside equatorial ionosphere, measured by the Jicamarca incoherent scatter radar, was enhanced for 2–3 hours after the IMF turned southward and remained continuously southward. In one case the eastward electric field in the dayside midlatitude ionosphere, measured by the Millstone Hill incoherent scatter radar, was continuously enhanced for ∼10 hours during southward IMF. Since Millstone Hill is close to the equatorward boundary of the auroral zone during magnetic storms, the penetration electric field there may be different from that at the equatorial ionosphere. The most striking feature of the measurements is that the enhancements of the ionospheric electric field can last for many hours without significant decay. The electric field enhancements in the middle‐ and low‐latitude ionosphere are closely related to magnetic activity and occur during the main phase of magnetic storms. The observations show that the interplanetary electric field can continuously penetrate to the low‐latitude ionosphere without shielding for many hours as long as the strengthening of the magnetic activity is going on under storm conditions.
Ionospheric response to wave‐accelerated electrons at the poleward auroral boundary
Authors: Semeter J. , Heinselman C. J. , Sivjee G. G. , Frey H. U. , Bonnell J. W.
Published: November 2005

The local ionospheric response to an auroral intensification at the poleward auroral boundary has been investigated using the incoherent scatter radar (ISR) and optical instrumentation at Sondrestrom, Greenland, in conjunction with space‐borne measurements by the IMAGE and FAST satellites. ISR elevation scans through the illuminated region revealed filamentary columns of enhanced plasma density, ∼5 km in latitude by ∼200 km in altitude. Column densities were typically 5 × 1011/m3 above background and often constant over a broad range of altitudes. The brightness of the O+ 732–733 nm multiplet, monitored simultaneously by a near‐infrared spectrometer, exceeded 1.2 kR during one 4‐min period (a factor of ∼4 brighter than previously reported auroral measurements). A time‐dependent model was developed to relate O+ emission intensities to O+ column densities for a given illumination time. The results suggested that the electron source was composed of kilometer‐scale flux tubes locked in the E × B flow for several minutes whose average energy varied temporally between <100 eV and >1 keV over their illumination lifetime. Conjugate electrons measured by the FAST satellite at 1700 km showed evidence for energization by inertial Alfvén waves. Ionization rates computed from these spectra were sufficient to account for the observed filamentary ionospheric structure. The implications of such ionization patterns for electrodynamic coupling with the magnetosphere are discussed.
In situ thermal conductivity of gas‐hydrate‐bearing sediments of the Mallik 5L‐38 well
Authors: Henninges J. , Huenges E. , Burkhardt H.
Published: November 2005

Detailed knowledge about thermal properties of rocks containing gas hydrate is required in order to quantify processes involving gas hydrate formation and decomposition in nature. In the framework of the Mallik 2002 program, three wells penetrating a continental gas hydrate occurrence under permafrost were successfully equipped with permanent fiber‐optic distributed temperature sensing cables. Temperature data were collected over a 21‐month period after completing the wells. Thermal conductivity profiles were calculated from the geothermal data as well as from a petrophysical model derived from the available logging data and application of mixing law models. Results indicate that thermal conductivity variations are mainly lithologically controlled with a minor influence from hydrate saturation. Average thermal conductivity values of the hydrate‐bearing sediments range between 2.35 and 2.77 W m−1 K−1. Maximum gas hydrate saturations can reach up to about 90% at an average porosity of 0.3.
Geophysical Fluid Dynamics Laboratory general circulation model investigation of the indirect radiative effects of anthropogenic sulfate aerosol
Authors: Ming Yi , Ramaswamy V. , Ginoux Paul A. , Horowitz Larry W. , Russell Lynn M.
Published: November 2005

The Geophysical Fluid Dynamics Laboratory (GFDL) atmosphere general circulation model, with its new cloud scheme, is employed to study the indirect radiative effect of anthropogenic sulfate aerosol during the industrial period. The preindustrial and present‐day monthly mean aerosol climatologies are generated from running the Model for Ozone And Related chemical Tracers (MOZART) chemistry‐transport model. The respective global annual mean sulfate burdens are 0.22 and 0.81 Tg S. Cloud droplet number concentrations are related to sulfate mass concentrations using an empirical relationship (Boucher and Lohmann, 1995). A distinction is made between “forcing” and flux change at the top of the atmosphere in this study. The simulations, performed with prescribed sea surface temperature, show that the first indirect “forcing” (“Twomey” effect) amounts to an annual mean of −1.5 W m−2, concentrated largely over the oceans in the Northern Hemisphere (NH). The annual mean flux change owing to the response of the model to the first indirect effect is −1.4 W m−2, similar to the annual mean forcing. However, the model's response causes a rearrangement of cloud distribution as well as changes in longwave flux (smaller than solar flux changes). There is thus a differing geographical nature of the radiation field than for the forcing even though the global means are similar. The second indirect effect, which is necessarily an estimate made in terms of the model's response, amounts to −0.9 W m−2, but the statistical significance of the simulated geographical distribution of this effect is relatively low owing to the model's natural variability. Both the first and second effects are approximately linearly additive, giving rise to a combined annual mean flux change of −2.3 W m−2, with the NH responsible for 77% of the total flux change. Statistically significant model responses are obtained for the zonal mean total indirect effect in the entire NH and in the Southern Hemisphere low latitudes and midlatitudes (north of 45°S). The area of significance extends more than for the first and second effects considered separately. A comparison with a number of previous studies based on the same sulfate‐droplet relationship shows that, after distinguishing between forcing and flux change, the global mean change in watts per square meter for the total effect computed in this study is comparable to existing studies in spite of the differences in cloud schemes.
Evolutionary trends in volatiles of the nakhlite source region of Mars
Authors: Mathew K. J. , Marti K.
Published: November 2005

We report new data on isotopic systematics in nitrogen, Ar, and Xe of nakhlite NWA998 and discuss the implications of nakhlite signatures on the sources, evolution, and closed system properties of the nakhlite magma in the Martian mantle. The isotopic signatures of xenon in nakhlites are consistent and reveal a source region with the Chass‐S xenon signature, but which had assimilated fission gas starting with the initial early differentiation of Mars to the time of magma eruption 1.3 Gyr ago. We note a trend of correlated enrichments of the fission gas and of trace elements (REE) in the source. Nakhlite NWA817, which contains abundant mesostasis and a hydrous phase, shows a distinct nitrogen component as well as a fission gas excess in low‐temperature steps. Radiogenic 129Xe in nakhlites is associated with neither the fission gas nor the indigenous components and indicates a later incorporation, possibly during magma ascent. Indigenous nitrogen isotopic signatures of δ15N = 13‰ as observed in nakhlites (except NWA817) attest to very limited exchanges of modern atmospheric gases with the solid planet. This nakhlite nitrogen signature corresponds to the heavier of two indigenous signatures in Chassigny and supports other evidence for an origin in similar source regions.
Finite element modeling of short‐wavelength folding on Venus: Implications for the plume hypothesis for crustal plateau formation
Authors: Ghent Rebecca R. , Phillips Roger J. , Hansen Vicki L. , Nunes Daniel C.
Published: November 2005

The key geological observations and structural interpretations associated with the current plume hypothesis for Venusian crustal plateau formation are that (1) short‐wavelength, spatially periodic tectonic structures originated as mechanical instabilities in a regionally extensive surface brittle layer whose basal boundary was thermally generated and controlled; (2) characteristic wavelengths of spatially periodic structures record the brittle layer thickness at the time of deformation; and (3) structural wavelengths increased with time, driven by brittle layer thickening in response to cooling. The plume hypothesis accommodates these constraints by proposing that crustal plateaus formed above mantle plumes impinging on thin lithosphere; it further suggests that surface temperatures temporarily elevated to ∼1000 K may have been required to maintain a sufficiently thin brittle layer for formation of the shortest‐wavelength structures. We report here on finite element simulations designed to test the feasibility of the proposed thermal conditions. Specifically, we model formation of short‐wavelength folds thought to have initiated as contractional layer instabilities early in the plateau formation process. Under high surface temperatures, the finite element meshes develop semibrittle zones in which short‐wavelength folds can form, but development of even modest structural relief requires unrealistically high total mesh shortening. Thus elevated surface temperatures inhibit development of short‐wavelength folds because the models' effective integrated mechanical strength under such hot conditions is excessively low. Decreasing the surface temperature increases structural relief but produces tectonic wavelengths that are larger than those observed. We conclude that a model with solely thermal control of mechanical properties cannot explain the observed structures.