bluuebunny/crossref_metadata_2025 huggingface dataset:
Cat‐scratch disease: Otolaryngologic manifestations and management
Authors: Ridder Gerd Jürgen , Boedeker Carsten Christof , Technau‐Ihling Katja , Sander Anna
Published: March 2005

OBJECTIVE

The bacteria Bartonella henselae has been known as the principal causative agent of cat‐scratch disease (CSD) since 1992. It is an important cause of infectious lymphadenopathies in the head and neck. Nevertheless, CSD often remains unrecognized in cases of cervicofacial lymph node enlargement.

STUDY DESIGN

Between January 1997 and May 2003, we conducted a prospective clinical study including 721 patients with primarily unclear masses in the head and neck.

RESULTS

CSD was diagnosed by serology and molecular investigations in 99 patients (13.7%; median age 33 years). Cervicofacial lymphadenopathy was the most common manifestation. Atypical manifestation of CSD including Parinaud's oculoglandular syndrome, swelling of the parotid gland and erythema nodosum were diagnosed in 8.1%, 8.1%, and 2.0% of cases, respectively.

CONCLUSIONS

Our results demonstrate that CSD is a major cause of enlarged cervicofacial lymph nodes and should therefore be included in the differential diagnosis of lymphadenopathy in the head and neck region.
Long‐term results of cochlear implantation in children
Authors: Haensel JAN , Engelke Jan‐Christian , Ottenjann Wiebke , Westhofen Martin
Published: March 2005

OBJECTIVES

Since the first implantation of a multichannel cochlear implant over 15 years ago there have been improvements in implant devices, surgical techniques, speech coding strategies and rehabilitation matters. There also have been concerns, whether the first implanted systems are stable and the benefit for the patients is constant over a long time. This study analyzes long‐term results of prelingually deaf children who were implanted at Aachen University Hospital.

STUDY DESIGN AND SETTING

We examined 16 prelingually deaf children, who underwent cochlear implantation at our department between 1990 and 1993 over a time period of 10 to 13 years. The indication, perioperative complications, technical parameters, speech test results as well as the psychosocial development of the children were analyzed. A questionnaire containing questions about the daily use, expectations and the personal evaluation of the procedure was sent to all patients.

RESULTS

The mean age of all patients was 9 years at time of implantation. In two cases we saw postoperative complications which needed an intervention. The speech test results remained stable after reaching a plateau after 5 years. Eighty‐eight percent of all patients would undergo the procedure again and 94% would recommend cochlear implantation to others.

CONCLUSION

Cochlear implantation in cases of prelingual deafness is feasible without severe complications and leads to an increasing quality of life demonstrated by long‐term observation.
Paragangliomas in patients with mutations of the SDHD gene
Authors: Boedeker Carsten Christof , Neumann Hartmut P. H. , Ridder Gerd Jürgen , Maier Wolfgang , Schipper Jörg
Published: March 2005

OBJECTIVE

Paragangliomas represent neoplasms of neural crest origin that arise from paraganglia. Mutations in the gene encoding succinate dehydrogenase subunit D (SDHD) are responsible for a percentage of hereditary paragangliomas. We previously described a group of 271 pheochromocytoma patients, 11 of whom had mutations of the SDHD gene. The objective of this study was to find out whether those 11 patients had additional paragangliomas.

STUDY DESIGN

Ten patients participated in our clinical screening program that included MRI of the skull base and neck, thorax, and abdomen, as well as an 18Fluoro‐DOPA positron emission tomography (DOPA‐PET).

RESULTS

Five patients presented with head and neck paragangliomas, 1 patient with a thoracic paraganglioma, and 2 patients with intraabdominal paragangliomas.

CONCLUSIONS

The screening for paragangliomas in patients with mutations of the SDHD gene offers the chance to diagnose those tumors in an early stage.

SIGNIFICANCE

Because morbidity after surgical resection increases with tumor size, early surgery will minimize the potential risks.
Elective neck dissection versus observation in primary parotid carcinoma
Authors: Zbären P. , Schüpbach J. , Nuyens M. , Stauffer E.
Published: March 2005

OBJECTIVE

To evaluate the efficacy of elective neck dissection in the clinically negative neck of patients with primary carcinoma of the parotid gland.

STUDY DESIGN AND SETTING

A retrospective analysis was undertaken at a university Department of Otorhinolaryngology‐Head and Neck Surgery on 83 previously untreated patients with primary carcinoma of the parotid gland and a clinically negative neck. The reliability of fine needle aspiration cytology, frozen section, and the clinico‐pathologic findings of patients with occult neck metastases were analyzed. The regional recurrence rate and the outcome were compared among 2 groups; one with elective neck dissection (N = 41) and one without elective neck dissection (N = 42).

RESULTS

The diagnosis of malignancy was known preoperatively in 59 (71%) cases, the exact histologic tumor type in 36 (43%) and the grade in 37 (44%) of 83 cases. Occult metastases were detected in 8 (20%) of 41 cNO patients, in 5 cases associated with a high‐grade and in 3 cases with a low‐grade carcinoma. Recurrence of disease developed in 5 (12%) patients in the elective neck dissection group and in 11 (26%) patients in the observation group. All of the 7 neck recurrences occurred in the observation group. The 5‐year actuarial and disease‐free survival rate was 80% and 86% for patients with elective neck dissection and 83% and 69% for patients without neck dissection.

CONCLUSION AND SIGNIFICANCE

A routine elective neck dissection is suggested in all patients with primary carcinoma of the parotid gland. The efficacy of elective neck dissection, nevertheless, has never been evaluated prospectively.
Idiopathic submandibular sialoceles in the neck
Authors: Ang Annette H. C. , Goh Yau‐Hong
Published: March 2005

A submandibular sialocele is a subcutaneous cavity containing saliva. The clinical and radiologic features of 3 patients with an idiopathic submandibular sialocele are presented. All 3 patients were males in their twenties. Submandibular sialocele presents as a soft cystic and compressible neck mass, with no history of previous trauma or diseases of the salivary gland. Computed tomography (CT) of the neck revealed a homogenous lesion with enhancing rim. The lesion appeared to be insinuating into the surrounding tissue. Excision of the sialocele, leaving the submandibular gland intact, was performed for the first patient. Recurrence of a neck mass occurred after 4 months. Complete excision of the sialocele with associated submandibular gland was subsequently performed. There was no recurrence after a follow‐up period of 3 years. Excision of gland and sialocele was performed for the other 2 patients. There was no recurrence after a follow‐up of 2 years and 10 months, respectively.
The influence of tracheotomy tubes on the swallowing frequency in neurogenic dysphagia
Authors: Seidl Rainer O. , Nusser‐Müller‐Busch Ricki , Ernst Arne
Published: March 2005

OBJECTIVES

To compare the swallowing frequency in patients with neurogenic dysphagia with or without tracheotomy tubes (TT) to assess the underlying mechanisms of dysphagia to improve rehabilitation strategies.

STUDY DESIGN AND SETTING

Prospective study, 10 patients (64 ± 7 years) with neurogenic dysphagia. Glasgow Coma Scale (GCS) less than 8 points, tracheotomy due to the dysphagia 2 weeks before the examination. The swallowing frequency (1 or less over 5 min) was assessed over 5 consecutive days with or without TT.

RESULTS

The swallowing frequency increased after removal of the TT. These findings did not influence the GCS or the Coma Remission Scale. Over a 5‐day period, the frequency of swallowing was increased.

CONCLUSION

TTs decisively influence the swallowing behavior of vegetative patients. This phenomenon could be based on an improved sensitivity under re‐established physiological expiration. We strongly favor removing the TT or deflating the cuff of the TT under therapeutic conditions in a rehabilitation therapy setting.
Overexpression of MMP‐2 in laryngeal squamous cell carcinoma: A potential indicator for poor prognosis
Authors: Liu Wei‐Wei , Zeng Zong‐Yuan , Wu Qiu‐Liang , Hou Jing‐Hui , Chen Yi‐Yong
Published: March 2005

OBJECTIVES

To investigate the expression and clinical significance of gelatinases (MMP‐2 and MMP‐9) in patients with laryngeal squamous cell carcinoma (LSCC).

STUDY DESIGN AND SETTING

In a retrospective study of 72 consecutive patients with LSCC hospitalized in a single cancer center, immunohisto‐chemistry was used to examine the expression of MMP‐2 and MMP‐9 in surgical samples. The results were compared to clinicopathological features and prognosis.

RESULTS

The positive expression of MMP‐2 and MMP‐9 in patients with LSCC was 50% (36/72) and 73.6% (53/72), respectively. According to the expression scale, there were 36 patients of ‐, 26 patients of +, 7 patients of + +, and 3 patients of + + + expression of MMP‐2; 19 patients of ‐, 26 patients of +,16 patients of ++, and 11 patients of + + + expression of MMP‐9. There was no significant relationship found between the expression of MMP‐2 or MMP‐9 and clinicopathological features of LSCC, such as histological grade, primary site, T stage, N stage, and clinical stage. The 5‐year overall survival (OS) and disease‐free survival (DFS) rate calculated by Kaplan‐Meier method in patients with negative and positive expression of MMP‐9 and MMP‐2 was 73.68%, 50.94%, 73.68%, and 49.06% in MMP‐9 and 72.22%, 41.67%, 72.22%, and 38.89% in MMP‐2, respectively. Significant 5‐year survival difference was found between patients with negative and positive expression of MMP‐2 (log rank = 6.74, P = 0.0094). There was significant lower survival rate in patients with higher positive expression of MMP‐2 (log rank = 11.77, P = 0.0028). In glottic laryngeal cancer, positive expression of MMP‐2 could predict poor survival and was more likely to present primary recurrence.

CONCLUSION

The expression of MMP‐2 could be used as a potential predictor for poor prognosis in patients with LSCC.
Can mobile phone emissions affect auditory functions of cochlea or brain stem?
Authors: Sievert UWE , Eggert Siegfried , Pau Hans Wilhelm
Published: March 2005

PROBLEMS ADDRESSED

Despite their abundant spread, mobile phones are suspected by a major share of the population to cause adverse effects on health and welfare. The ear as the sense organ next to the individual device has rarely been Investigated for short‐term effects in this regard. In a previous article, we could not prove any impact on the vestibular part of the inner ear. Our present examinations are concerned with the question whether mobile phone emissions could affect cochlear or auditory brain stem functions.

METHODS AND MEASURES

In 12 healthy test persons with normal hearing, auditory brain stem reflexes recordings were performed before, during, and after exposure to electromagnetic emissions by standardized mobile phone devices. Two modes of electromagnetic emissions fields were administered: pulsed and continuous. For acoustic stimulation simultaneous to field exposure, special “plug‐in” earphones had to be used.

RESULTS

No impact on auditory brain stem reflexes recordings in terms of absolute and interpeak latencies could be found.

CLINICAL SIGNIFICANCE

Together with the results of a previous article concerned with the vestibular part of the inner ear, we can state that there are no adverse effects of mobile phone emissions on the ear function, at least on a short‐term range. Of course, any long‐term effects cannot be excluded by our study.
Routine histopathology in uncomplicated sinus surgery: Is it necessary?
Authors: Romashko Alexander A. , Stankiewicz James A.
Published: March 2005

OBJECTIVE

To evaluate the incidence of occult pathology in routine, uncomplicated endoscopic sinus surgery, and to suggest guidelines for when to send specimens for histopathologic exam.

STUDY DESIGN AND SETTING

Retrospective analysis of case records of 790 patients who underwent 868 endoscopic sinus surgeries at a tertiary care center from 1986 to 2003. Indications were chronic sinusitis, recurrent acute sinusitis, nasal polyposis, or combinations of these diagnoses. All cases were considered routine and did not involve preoperative suspicion of neoplasm or other complicating factors. Charts were reviewed for surgical indication, patient age, laterality of disease, history of prior sinus surgery, intraoperative suspicion of tumor, and final histopathology.

RESULTS

In 868 cases of endoscopic sinus surgery, occult neoplasm was diagnosed in 2 patients (0.23%). In one patient, the initial surgery cured the lesion. Final histopathology of the remaining 866 (99.8%) specimens was consistent with inflammation and/or nasal polyposis. In 121 cases of unilateral sinusitis, none was positive for neoplasm. In 277 cases involving bilateral nasal polyposis and 13 involving unilateral polyposis, no neoplasms were found. Intraoperative suspicion of neoplasm occurred in 12 cases, with all specimens read as consistent with sinusitis and/or polyposis.

CONCLUSIONS

Histopathologic review of every specimen obtained in routine sinus surgery for sinusitis and/or nasal polyposis is not indicated. Submission of specimen is indicated in routine cases when: 1) there is intraoperative suspicion of tumor, 2) unilateral nasal polyposis is present, 3) unilateral sinus opacification is present, and 4) additional diagnostic information is needed (eg, presence of eosinophils, fungal forms, etc.).

SIGNIFICANCE

Establishes a safe and reasonable standard of care, with potential cost savings and medico‐legal ramifications.
Simulation of carbon isotope discrimination of the terrestrial biosphere
Authors: Suits N. S. , Denning A. S. , Berry J. A. , Still C. J. , Kaduk J. , Miller J. B. , Baker I. T.
Published: March 2005

We introduce a multistage model of carbon isotope discrimination during C3 photosynthesis and global maps of C3/C4 plant ratios to an ecophysiological model of the terrestrial biosphere (SiB2) in order to predict the carbon isotope ratios of terrestrial plant carbon globally at a 1° resolution. The model is driven by observed meteorology from the European Centre for Medium‐Range Weather Forecasts (ECMWF), constrained by satellite‐derived Normalized Difference Vegetation Index (NDVI) and run for the years 1983–1993. Modeled mean annual C3 discrimination during this period is 19.2‰; total mean annual discrimination by the terrestrial biosphere (C3 and C4 plants) is 15.9‰. We test simulation results in three ways. First, we compare the modeled response of C3 discrimination to changes in physiological stress, including daily variations in vapor pressure deficit (vpd) and monthly variations in precipitation, to observed changes in discrimination inferred from Keeling plot intercepts. Second, we compare mean δ13C ratios from selected biomes (Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal) to the observed values from Keeling plots at these biomes. Third, we compare simulated zonal δ13C ratios in the Northern Hemisphere (20°N to 60°N) to values predicted from high‐frequency variations in measured atmospheric CO2 and δ13C from terrestrially dominated sites within the NOAA‐Globalview flask network. The modeled response to changes in vapor pressure deficit compares favorably to observations. Simulated discrimination in tropical forests of the Amazon basin is less sensitive to changes in monthly precipitation than is suggested by some observations. Mean model δ13C ratios for Broadleaf, Temperate Broadleaf, Temperate Conifer, and Boreal biomes compare well with the few measurements available; however, there is more variability in observations than in the simulation, and modeled δ13C values for tropical forests are heavy relative to observations. Simulated zonal δ13C ratios in the Northern Hemisphere capture patterns of zonal δ13C inferred from atmospheric measurements better than previous investigations. Finally, there is still a need for additional constraints to verify that carbon isotope models behave as expected.
Stream temperature changes over Lena River Basin in Siberia
Authors: Yang Daqing , Liu Baozhong , Ye Baisheng
Published: March 2005

This study analyzes long‐term (1950–1992) stream temperature records over the Lena watershed, in order to understand water temperature regimes and changes induced by reservoir regulations, and by natural variations. Water temperature regimes are similar over the Aldan and Upper Lena regions. Stream temperatures at the Lena basin outlet are up to 8°C lower than the southern subbasins. Reservoir regulations strongly influence regional water temperature regime and change particularly in the regulated subbasins. Because of dam impact, stream temperatures increased (decreased) in the Vilui valley during the early (middle) open water season. Trend analyses show consistent warming across the entire Lena River basin in the early open water season, and mixed results in summer for the unregulated subbasins. For the regulated Vilui tributary, stream temperatures significantly increased in the early and late parts of the warm season due to combined effects of natural changes and reservoir regulations.
Impact of diabatic heating over the Tibetan Plateau on subsidence over northeast Asian arid region
Authors: Sato Tomonori , Kimura Fujio
Published: March 2005

The formation mechanism of the arid climate over northeast Asia is investigated by a series of regional climate model experiments. Precipitation there is suppressed by a prominent regional‐scale subsidence during summertime. An experiment without diabatic heating shows very gentle vertical motion there, whereas the subsidence is prominent when diabatic heating by solar radiation is included in the model. Additionally, the other experiments indicate that an artificial heating over the Tibetan Plateau enhances the subsidence over the arid area which is similar to the observed distribution. These results suggest that the thermal effects of the plateau induce the prominent subsidence. The mechanical effects of the topography, such as stationary mountain waves, are not a principal reason for the subsidence nor the arid climate. The stationary Rossby wave driven by the diabatic heating over the plateau tends to propagate northward during boreal summer, since subtropical westerly jet locates north of the plateau.
Some characteristics of intense geomagnetic storms and their energy budget
Authors: Vichare Geeta , Alex S. , Lakhina G. S.
Published: March 2005

The present study analyses nine intense geomagnetic storms (∣Dst∣ > 175 nT) with the aid of ACE satellite measurements and ground magnetic field values at Alibag Magnetic Observatory. The study confirms the crucial role of southward IMF in triggering the storm main phase as well as controlling the magnitude of the storm. The main phase interval shows clear dependence on the duration of southward IMF. An attempt is made to identify the multipeak signature in the ring current energy injection rate during main phase of the storm. In order to quantify the energy budget of magnetic storms, the present paper computes the solar wind energies, magnetospheric coupling energies, auroral and Joule heating energies, and the ring current energies for each storm under examination. Computation of the solar wind‐ magnetosphere coupling function considers the variation of the size of the magnetosphere by using the measured solar wind ram pressure. During the main phase of the storm, the solar wind kinetic energy ranges from 9 × 1017 to 72 × 1017 J with an average of 30 × 1017 J; the total energy dissipated in the auroral ionosphere varies between 2 × 1015 and 9 × 1015 J, whereas ring current energies range from 8 × 1015 to 19 × 1015 J. For the total storm period, about 3.5% of total solar wind kinetic energy is available for the redistribution in the magnetosphere, and around 20% of this goes into the inner magnetosphere and in the auroral ionosphere of both the hemispheres. It is found that during main phase of the storm, almost 5% of the total solar wind kinetic energy is available for the redistribution in the magnetosphere, whereas during the recovery phase the percentage becomes 2.3%.
A possible generation mechanism of temporal and spatial structures of flickering aurora
Authors: Sakanoi K. , Fukunishi H. , Kasahara Y.
Published: March 2005

Optical observations of flickering aurora by a high‐speed imaging photometer system were carried out at Syowa Station in 1998. A comparison between observed parameters of flickering aurora and theoretical values of dispersive Alfvén waves indicates that observed flickering aurora would be produced by electron flux modulations by electromagnetic ion cyclotron waves or inertial Alfvén waves in the auroral acceleration region located over the altitude range of ∼2000–5000 km. Interference wave patterns of two dispersive Alfvén waves in a resonance cone can explain the observed temporal and spatial structures of flickering aurora; flickering columns (or spots) remain in almost the same location during their lifetime and that their shapes become indistinguishable every half flickering period at the timing of the interchange of the bright and dark columns (or spots).
Simultaneous inversion of shear wave splitting observations from seismic arrays
Authors: Ryberg T. , Rümpker G. , Haberland C. , Stromeyer D. , Weber M.
Published: March 2005

Seismic waveforms recorded at high‐density receiver arrays facilitate the application of new inversion techniques, which take advantage of the coherent nature of the observations. We use measurements of shear wave splitting parameters from observed SKS waveforms along a dense receiver profile and compare them with splitting parameters obtained from numerical waveform modeling through anisotropic Earth models. We use two different iterative approaches for the inversion of the observed splitting parameters (1) a local optimization technique (the downhill simplex method) and (2) a global genetic algorithm search. In our forward modeling, we calculate SKS waveforms by a finite difference (FD) method solving the anisotropic wave equation, instead of deriving individual anisotropic models for each station and combining them into one model. By the comparison of FD modeling and observations we avoid a direct interpretation of the splitting parameters in terms of medium properties. We apply these techniques to the analysis of SKS phases recorded along a 100‐km profile located at the Dead Sea transform fault. The measured splitting parameters show gradual short‐scale variations along the profile which depend on frequency. Lateral and vertical variations of anisotropy are accounted for by two‐dimensional block structures. For the simplex method the complexity of the models (the number of anisotropic blocks) is increased gradually, whereas the number of anisotropic blocks is kept fixed for the genetic algorithm search. The anisotropic structures of the best fitting models derived from the two inversion approaches agree well. The results support earlier interpretations of the observations in terms of a narrow, approximately 20 km wide, vertical decoupling zone in the mantle that accommodates the transform motion between the African and Arabian plates.
A new class of microstructures which lead to transformation‐induced faulting in magnesium germanate
Authors: Riggs Eric M. , Green Harry W.
Published: March 2005

Transformation‐induced faulting has been studied extensively in natural olivine, ice, and a variety of other olivine analog systems over the last 15 years and remains a likely candidate mechanism for initiating deep focus earthquakes. The mechanism involves the formation of microscopic packets of fine‐grained denser materials from a metastable host, which then behave as mode I features that coalesce to allow bulk mode II shear failure. We present evidence for a new class of transformation microstructures that also allows shear failure at high pressures but which does not require the formation of widely distributed mode I features prior to shear failure. We have observed thin planar zones of transformation in coarse‐grained (∼150 μm) Mg2GeO4 olivine that form along crystallographic planes in deformed grains at temperatures cooler than those that allow significant development of anticracks. The development of these zones is rapid and only occurs after ∼25% bulk strain. Increasing strain leads to progressive development of these zones, in turn leading to bulk shear failure once a continuous pathway of fine‐grained spinel is formed that traverses the specimen. Transmission electron microscopy analysis shows that slip bands in olivine along (011) and (010) formed from dislocation pileups on these slip planes transform preferentially to a nanocrystalline aggregate of the denser spinel phase, aided by the high strain energy of these bands. This new, partially strain‐driven mechanism compliments shear failure by anticracks as described in previous studies and adds new possibilities for the triggering of bulk shear failure by rapid mineralogical transformations.
Soil moisture and predicted spells of extreme temperatures in Britain
Authors: Brabson B. B. , Lister D. H. , Jones P. D. , Palutikof J. P.
Published: March 2005

This paper reports on an analysis of the relationship of soil moisture to extreme temperatures in Britain, taken from the Hadley Centre general circulation model HadCM3 (1860–2099) and validated using the central England temperature extremes from the overlapping period 1878–2000. By 2100, HadCM3 predicts higher average temperatures and a greater variability, asymmetry, and persistence of warm extremes. A generalized extreme value analysis relates extremes to the periods of low soil moisture in the model. Longer spells of extreme temperature are seen to arise both from the statistical increase in the frequency of extremes and from the extended periods of low soil moisture. As an example, by 2060–2100 the probability of hot spells longer than 7 days with Tmax> 25°C is predicted to rise from its present value of 2%/summer to 10%/summer for high soil moisture summers and to 80%/summer when the low soil moisture summers are included.
Aerosol retrievals using rotating shadowband spectroradiometer data
Authors: Gianelli S. M. , Carlson B. E. , Lacis A. A.
Published: March 2005

The rotating shadowband spectroradiometer (RSS) is a high‐resolution device that measures the total, direct, and diffuse intensity of sunlight at 1016 different wavelengths. RSS data can be used to retrieve gas amounts and aerosol properties as well as to assess the accuracy of retrievals using data from lower‐spectral resolution instruments, such as the multifilter rotating shadowband radiometer (MFRSR). An algorithm to retrieve aerosol and gas amounts and the aerosol size distribution from RSS data, using the full resolution and using selected wavelengths, has been developed (Gianelli, 2004). The results of the retrievals, applied to RSS data from the southern Great Plains (SGP) site, indicate a number of things about the aerosol size distribution and our ability to retrieve aerosol information accurately. First, we show that the aerosol size distribution at SGP is at least bimodal. The notion that a more complex size distribution can be modeled with an appropriately selected monomodal distribution produces an unacceptable fit to the data once the separation of aerosol extinction from nitrogen dioxide absorption at short wavelengths is taken into consideration. Second, we find that the amount of retrievable aerosol information is limited by the wavelength range of the data. This is exemplified by the indeterminacy of the coarse‐mode effective radius and the interdependence in the retrievals of the fine‐mode effective radius and effective variance. Third, when the fine‐mode effective variance is constrained, an annual cycle in fine‐mode effective radius values emerges from the retrieval results, with a maximum in March and a minimum in September. Conceivably, changes in the effective variance could influence the observed pattern as well. The large margin of error in the coarse‐mode effective radius leads to relatively small error bars for the coarse‐ and fine‐mode optical depths, the fine‐mode effective radius, and ozone, except on those days when the coarse‐mode optical depth is high. Examining the retrieval results for different wavelength combinations of five RSS channels allows us to investigate whether or not the MFRSR channels are optimized to retrieve aerosol information or if a different filter set would increase the robustness of the retrievals. We show that replacing the 670 nm channel with one at either 375 or 1034 nm improves the retrieval accuracy. In particular, retrievals with the 1034 nm channel very closely reproduce the full RSS retrieval results, provided that the NO2 column amount can be determined by other means. The precision of the retrieved values of the fine‐mode effective radius is shown to be strongly sensitive to the precision of measured NO2 amounts; a margin of error in column NO2 of 0.3 Dobson units results in a corresponding margin of error of 0.04 μm in the fine‐mode effective radius. This confirms that aerosol sizes cannot be inferred accurately from optical depth spectra alone if either the amount of NO2 above a site is unknown or an inaccurate value is assumed.
Lithospheric structure under the western African‐European plate boundary: A transect across the Atlas Mountains and the Gulf of Cadiz
Authors: Zeyen Hermann , Ayarza Puy , Fernàndez Manel , Rimi Abdelkrim
Published: March 2005

We present a two‐dimensional lithospheric thermal and density model along a transect running from the southwestern Iberian Peninsula to the northwestern Sahara. The main goal is to investigate the lithosphere structure underneath the Gulf of Cadiz and the Atlas Mountains. The model is based on the assumption of topography in local isostatic equilibrium and is constrained by surface heat flow, gravity anomalies, geoid, and topography data. The crustal structure has been constrained by seismic and geological data where available. Mantle density is supposed to vary linearly with temperature, providing the link between thermal and density‐related data. The lithospheric thickness varies strongly along the profile, going from near 100 km under the Iberian Peninsula to at least 160–190 km under the Gulf of Cadiz and the Gharb foreland basin in Morocco and to 70 km underneath the Atlas Mountains, coinciding with a region of Neogene volcanism. The thickening of the lithosphere is interpreted as a SW trending lithospheric slab extending from the western Betics to the Gulf of Cadiz and the Gharb Basin, whereas the thin lithosphere underneath the Atlas may be interpreted as plume‐like asthenospheric upwelling similar to those observed in the west European Alpine foreland or as a side effect of a slab penetrating the less viscous asthenosphere.
Magnetic disconnection from the Sun: Observations of a reconnection exhaust in the solar wind at the heliospheric current sheet
Authors: Gosling J. T. , Skoug R. M. , McComas D. J. , Smith C. W.
Published: March 2005

We have identified an anti‐sunward‐directed, Petschek‐type, reconnection exhaust during a crossing of the heliospheric current sheet, HCS, by the ACE spacecraft. The exhaust in this relatively rare HCS event was a region of accelerated plasma flow filling the field reversal region and was bounded by Alfven waves propagating in opposite directions along recently merged field lines. Heliospheric magnetic field lines disconnected from the Sun by the reconnection process were identified in and surrounding the exhaust by the disappearance of the solar wind electron strahl there and by the interpenetration along the field of sunward‐streaming halo electrons from opposite sides of the exhaust. These observations demonstrate that strahl dropouts observed in the vicinity of the HCS at least at times are signatures of magnetic disconnection from the Sun.
Magnetic properties of (γ-Fe2O3)80Ag20 nanocomposites prepared in reverse micelles
Authors: Wiemann Joan A. , Dai Jianbiao , Tang Jinke , Long Gary J. , Spinu Leonard
Published: March 2005

The magnetic properties of nanoparticles of γ-Fe2O3 prepared by reverse micelles have been studied by dc magnetization, transverse ac susceptibility, and Mössbauer spectroscopy. The nanoparticles of γ-Fe2O3 in the nanocomposite (γ-Fe2O3)80Ag20 exhibit superparamagnetic behavior. The blocking temperatures determined by the three methods indicate the superparamagnetic nature of (γ-Fe2O3)80Ag20 above 70–80 K and show correlation with measuring time. The average particle diameter obtained by transmission electron microscopy of the γ-Fe2O3 particles is ∼10nm and that of the Ag particles is ∼20nm. The average particle size determined from the magnetic analyses for the γ-Fe2O3 particles is ∼12nm. Mössbauer spectra obtained between 4.2 and 295 K clearly reveal the presence of superparamagnetic relaxation at temperatures above ∼80K. The Mössbauer spectra reveal at most 1% of paramagnetic Fe2+ ions in the 295-K spectrum.
Fabrication of current-induced magnetization switching devices using etch-back planarization process
Authors: Ding Yunfei , Pakala Mahendra , Nguyen Paul , Meng Hao , Huai Yiming , Wang Jian-Ping
Published: March 2005

A patterning process for nanoscale current-perpendicular-to-plane magnetic devices was developed. Spin valve and magnetic tunnel junction (MTJ) pillars are patterned using electron-beam lithography and subsequent hard mask deposition and ion milling. Photoresist etch-back method is used to planarize the insulation layer, deposited on top of the spin valve/MTJ pillars, prior to top lead deposition. This method allows for a reduction of shadowing effect associated with the use of resist mask for ion milling. Critical switching current of ∼6×107A∕cm2 was observed for spin valve nanopillars with clear field dependence of the switching current, which is comparable to the reported value for metallic system.
Thermal expansion anomalies of R(Fe,M)12 (R=Y, Nd; M=Mo and Si)
Authors: Du Honglin , Cheng Benpei , Han Jingzhi , Liu Shunquan , Yang Jinbo , Yang Yingchang , Xue Yanjie , Chen Bo , Sun Guangai
Published: March 2005

Structural and thermal-expansion anomaly studies on R(Fe,M)12 (R=Nd and and Y, M=Mo and Si) compounds were performed by x-ray diffraction. Mo atoms occupy the 8i site. While Si atoms occupy the 8f and 8j sites but not the 8i site. Thermal-expansion anomaly shows only in ab plane in the Mo compounds, while becomes very weak and along with only the c axis in the Si compounds. The anomaly was attributed to the contribution of the interactions of short Fe–Fe distances similar to the previous explanation on other R–Fe intermetallics and that of other strongly positive interactions such as 8j-8j.
Zinc-blende-type MnAs nanoclusters embedded in GaAs
Authors: Yokoyama M. , Yamaguchi H. , Ogawa T. , Tanaka M.
Published: March 2005

Structural, magnetic, and magneto-optical properties of GaAs:MnAs granular thin films have been investigated. Zinc-blende(ZB)-type MnAs clusters were found to be formed by annealing GaAs:MnAs at 500°C with a ramp rate of 5°C∕min under a nitrogen atmosphere. Magnetic and magneto-optical properties of this GaAs:MnAs granular material with ZB-type MnAs clusters were different from those of the GaAs:MnAs with NiAs-type hexagonal MnAs clusters. The ferromagnetic transition temperature TC of the GaAs:MnAs of ZB type is estimated to be 360K, which is higher than TC(=313K) of the NiAs-type hexagonal MnAs.
Preparation of high moment CoFe films with controlled grain size and coercivity
Authors: Vopsaroiu M. , Georgieva M. , Grundy P. J. , Vallejo Fernandez G. , Manzoor S. , Thwaites M. J. , O’Grady K.
Published: March 2005

In this paper a preparation method for high moment CoFe thin films with soft magnetic properties is reported. A full control of coercivity in a series of 20-nm-thick CoFe films has been achieved without using seed layers, additives, or thermal annealing. The films were sputtered directly onto Si substrates and the coercivity was varied by changing the mean grain size in the sputtered films. The mean grain size was in turn controlled via the sputtering rate. A reduction in the coercivity has been observed from 120Oe for samples with a mean grain size larger than 17nm down to 12Oe for a sample with a mean grain size of 7.2nm. The results are in good agreement with the “random anisotropy model” relating the coercivity to the mean grain size in polycrystalline ferromagnetic films.
Microstructural control of microwave dielectric properties in CaTiO3–La(Mg1∕2Ti1∕2)O3 ceramics
Authors: Kipkoech Eric Rop , Azough Feridoon , Freer Robert
Published: March 2005

High-density xCaTiO3–(1−x)La(Mg1∕2Ti1∕2)O3 ceramics (x=0.0–1.0) were prepared by solid-state reaction. The products were characterized by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. CaTiO3–La(Mg1∕2Ti1∕2)O3 ceramics formed solid solutions throughout the compositional range with no evidence of a secondary phase. For most ceramics the symmetry was orthorhombic with Pbnm space group. The La(Mg1∕2Ti1∕2)O3 end member exhibited 1:1 ordering of Mg2+ and Ti4+ cations (in octahedral sites) superimposed on the perovskite distortions leading to monoclinic symmetry with P21∕n space group. Long-range 1:1 order of Mg2+ and Ti4+ cations was destroyed at x=0.3. The degree of distortion, unit-cell volume, and crystal lattice stress decreased with increasing CaTiO3 content. Twin and antiphase domains, generated by structural phase transitions on cooling, were observed in all the ceramics. Twin domain density increased with CaTiO3 content but the size of individual domains decreased. The twin domains were classified according to the symmetry elements at the twin boundaries as {112} and (110) twin types. The microwave dielectric properties (at 3.5–5.5 GHz) showed a strong dependence on composition. The relative permittivity (εr) and temperature coefficient of resonant frequency (TCf) increased nonlinearly with CaTiO3 content (εr29–170; TCf −50 to +710 ppm∕°C). In contrast Qf (GHz) values decreased approximately linearly with CaTiO3 content (48 000–5790). Near zero TCf (1.06 ppm∕°C) was attained at x=0.55, where εr=44.6 and Qf=32000GHz. The increase in relative permittivity and TCf with CaTiO3 content correlated with the reduction in composition-induced lattice stress in association with increasing macroscopic polarizability.
Magnetostatic interaction fields in first-order-reversal-curve diagrams
Authors: Muxworthy Adrian , Williams Wyn
Published: March 2005

The contribution of magnetostatic interaction fields in magnetic systems during first-order-reversal-curve (FORC) simulations has been systematically addressed using a dynamic micromagnetic algorithm. The interaction field distributions (IFD) display a nonlinear dependency on the field history and intergrain spacing, and are commonly asymmetric. The IFDs tend to be more Gaussian on average than Cauchian as predicted analytically for disordered systems, due to ordering during FORC diagram determination. The spreading of the FORC distribution in the vertical direction of the FORC diagram is shown to be directly related to the mean standard deviation of the IFD during the FORC measurement, with a small offset related to the smoothing factor.
Polarization anisotropy in the electroluminescence of m-plane InGaN–GaN multiple-quantum-well light-emitting diodes
Authors: Gardner N. F. , Kim J. C. , Wierer J. J. , Shen Y. C. , Krames M. R.
Published: March 2005

InGaN – GaN multiple-quantum-well light-emitting diodes were fabricated on (101¯0) m plane GaN films grown on (101¯0) m plane 4H–SiC substrates. The [0001] axis of the epitaxial film is parallel to the [0001] axis of the substrate. The surface is striated, with features running perpendicular to the c axis and a maximum surface height difference of 45nm. Electroluminescence shows strong polarization anisotropy, with 7× more light emitted with polarization perpendicular to the c axis compared to parallel to the c axis. An Ahrrenius fit of the polarization ratio indicates that there is a 49meV difference in the energy gap between the two polarization states. This suggests that a high polarization ratio can be maintained at the high temperatures (>150°C) and drive current densities required for high-power light-emitting diode applications.
Semiconductor quantum dot microcavity pillars with high-quality factors and enlarged dot dimensions
Authors: Löffler A. , Reithmaier J. P. , Sęk G. , Hofmann C. , Reitzenstein S. , Kamp M. , Forchel A.
Published: March 2005

Vertical-emitting AlAs∕GaAs microcavity pillars with a type of GaInAs quantum dots within a one λ cavity have been realized based on high reflectivity distributed Bragg reflectors. High-quality factors were achieved due to an improved fabrication technology with a maximum quality factor of 27 700 for a micropillar with a diameter of 4μm. The dot dimensions could be enlarged by one order of magnitude using a low strain Ga0.7In0.3As nucleation layer.
Hybrid solar cells with vertically aligned CdTe nanorods and a conjugated polymer
Authors: Kang Yoonmook , Park Nam-Gyu , Kim Donghwan
Published: March 2005

Vertically aligned CdTe nanorods were fabricated by electrodeposition and were applied for the active layer of solar cells after being combined with poly(3-octylthiophene) (P3OT), a conjugated polymer. The electrodeposited CdTe showed an n-type behavior with the electric resistivity and the electron density of 2×106Ωcm, 1.3×1010cm−3, respectively. Quantum efficiency curve of the hybrid solar cells exhibited a peak at the same wavelength as the optical absorption for CdTe nanorods. The hybrid solar cells demonstrated a power conversion efficiency of 1.06%, whereas the efficiency was only 0.0006% without the nanorods.
Unusual stress behavior in W-incorporated hydrogenated amorphous carbon films
Authors: Wang Ai-Ying , Ahn Hyo-Shin , Lee Kwang-Ryeol , Ahn Jae-Pyoung
Published: March 2005

Unusual stress behavior was observed in W-incorporated hydrogenated amorphous carbon films prepared by a hybrid process composed of ion-beam deposition and magnetron sputtering. As the tungsten concentration increased from 0 to 2.8at.%, the residual compressive stress decreased by 50%, without significant deterioration in the mechanical properties. This was followed by a rapid increase and a gradual decrease in the residual stress with increasing W concentration. High-resolution transmission electron microscopy analysis and first-principle calculations show that the reduced directionality of the W–C bonds in the W-incorporated amorphous carbon matrix relaxes the stress caused by the distorted bonds.
Physical limits to spatial resolution of optical recording: Clarifying the spatial structure of cortical hypercolumns
Authors: Polimeni Jonathan R. , Granquist-Fraser Domhnull , Wood Richard J. , Schwartz Eric L.
Published: March 2005

Neurons in macaque primary visual cortex are spatially arranged by their global topographic position and in at least three overlapping local modular systems: ocular dominance columns, orientation pinwheels, and cytochrome oxidase (CO) blobs. Individual neurons in the blobs are not tuned to orientation, and populations of neurons in the pinwheel center regions show weak orientation tuning, suggesting a close relation between pinwheel centers and CO blobs. However, this hypothesis has been challenged by a series of optical recording experiments. In this report, we show that the statistical error associated with photon scatter and absorption in brain tissue combined with the blurring introduced by the optics of the imaging system has typically been in the range of 250 μm. These physical limitations cause a systematic error in the location of pinwheel centers because of the vectorial nature of these patterns, such that the apparent location of a pinwheel center measured by optical recording is never (on average) in the correct
in vivo
location. The systematic positional offset is ≈116 μm, which is large enough to account for the claimed misalignment of CO blobs and pinwheel centers. Thus, optical recording, as it has been used to date, has insufficient spatial resolution to accurately locate pinwheel centers. The earlier hypothesis that CO blobs and pinwheel centers are coterminous remains the only hypothesis currently supported by reliable observation.
Employability and Enterprise: Evidence from the North East
Authors: Hartshorn Christina , Sear Leigh
Published: March 2005

The paper uses data gathered from both the demand and supply side in the North East. Insights are gained from two studies of owner-managers of small businesses and one study of the five universities in the North East of England, to characterise enterprising skills as a new employability skills set. Whilst there is a plethora of studies which consider different aspects of employability, such as employability representing the capabilities of being employed for a job, and a growing recognition of the difference between 'old' and 'new' employability skills sets required to compete with an increasingly flexible labour market, there is a lack of studies that have unpacked the key aspects of this new employability skills set. This paper addresses this gap. The paper concludes by presenting an employability policy outline that could be used by bodies such as Regional Development Agencies to ensure that individuals are equipped with the skills to cope with, and flourish in, the changing conditions of the labour market.
Young People, Job Search and Local Labour Markets: The Example of Belfast
Authors: Green Anne , Shuttleworth Ian , Lavery Stuart
Published: March 2005

In debates about employability, the role of area perceptions in shaping the labour market behaviour of individuals has been neglected. This paper sets out to gain an understanding of what relatively disadvantaged young people in Belfast know about the geography of labour market opportunities in the city and the locations where they are prepared to work. Using secondary data analysis and primary research methods, it is shown that most young people have a highly localised outlook. Factors of limited mobility, lack of confidence and religion intertwine in complex ways to limit perceived opportunities. It is concluded that geography does play a role in shaping access to employment and training opportunities.
Employability, Services for Unemployed Job Seekers and the Digital Divide
Authors: Lindsay Colin
Published: March 2005

Providing accurate and accessible labour market information is a key priority for policies targeted at improving the employability of unemployed people. In an attempt to develop the quality and reach of such services, policy-makers are increasingly turning to ICT, and particularly the Internet. However, there are concerns that the expansion of services delivered through ICT risks leaving behind the most disadvantaged. This paper investigates the current and potential role of ICT within the job-seeking activities of unemployed people in one urban labour market (the city of Glasgow). Deploying the concept of the 'digital divide' as an analytical framework, it examines differences between job seekers' access to, and use of, the Internet. The paper finds an association between higher levels of economic capital (income) and cultural capital (skills) and Internet access and job seeking. It is argued that a renewed commitment to the development of community-based technology centres and ICT training for the unemployed is required, if disadvantaged job seekers are to reap the potential employability gains associated with the expansion of on-line services.