bluuebunny/crossref_metadata_2025 huggingface dataset:
Model studies of the interannual variability of the northern‐hemisphere stratospheric winter circulation: The role of the quasi‐biennial oscillation
Authors: Gray L. J. , Drysdale E. F. , Lawrence B. N. , Dunkerton T. J.
Published: February 2007

A series of experiments are described that examine the sensitivity of the northern‐hemisphere winter evolution to the equatorial quasi‐biennial oscillation (QBO). The prime tool for the experiments is a stratosphere‐mesosphere model. The model is integrated over many years with the modelled equatorial winds relaxed towards observed values in order to simulate a realistic QBO. In experiment A the equatorial winds are relaxed towards Singapore radiosonde observations in the height region 16‐32 km. In contrast to previous modelling studies, the Holton‐Tan relationship (warm/cold winters associated with easterly/westerly QBO winds in the lower stratosphere) is absent. However, in a second experiment (run B) in which the equatorial winds are relaxed towards rocketsonde data over the extended height range 16‐58 km, a realistic Holton‐Tan relationship is reproduced. A series of further studies are described that explore in more detail the sensitivity to various equatorial height regions and to the bottom‐boundary forcing. The experiments suggest that the evolution of the northern‐hemisphere winter circulation is sensitive to equatorial winds throughout the whole depth of the stratosphere and not just to the lower‐stratospheric wind direction as previously assumed.
The microphysical properties of tropical convective anvil cirrus: A comparison of models and observations
Authors: Brown P. R. A. , Heymsfield A. J.
Published: February 2007

This paper describes the use of two‐dimensional (2‐D) cloud‐resolving numerical model simulations of a period of active convection from the Tropical Ocean‐Global Atmosphere Coupled Ocean‐Atmosphere Response Experiment to generate statistics of the distribution of total ice water content (IWC) and of the relative contribution to IWC of small (sub‐200 μm) particles with temperature. The model data are sampled in a way which excludes contributions from active convective updraught regions, so that the model results may be compared with similar such distributions derived from in situ sampling of a number of tropical anvil ice clouds in the vicinity of Kwajalein in the west Pacific.

The model gives a good description of the mean and mode IWC in each of seven temperature ranges and, for temperatures warmer than –40°C, correctly predicts the dominant contribution of large particles to the IWC. At lower temperatures, the model retains an excessive fraction of its IWC in large particles. Estimates of the maximum crystal length (MCL) that would be sampled by a 2‐D Optical Array Probe exceed the observed values in this temperature range but are otherwise in good agreement. Tests of the sensitivity of model results to the cloud ice bulk density, and the absence of a homogeneous freezing source of ice crystals, suggest that the excessive MCL values are due in part to excessive rates of autoconversion and aggregation of cloud ice.
Parametrization of solar radiation in inhomogeneous stratocumulus: Albedo bias
Authors: Los Alexander , Duynkerke Peter G.
Published: February 2007

Low‐level cloud fields with typical albedos between 50% and 70% contribute significantly to short‐wave cloud radiative forcing. Consequently, the earth's radiative budget is sensitive to extended stratocumulus which typically occurs in sub‐tropical subsidence regions over the oceans. It is therefore vital to represent the cloud albedo of such cloud fields accurately in climate models. Nevertheless, cloud fields are modelled as homogeneous plane‐parallel clouds, which leads to an overestimation of the albedo by up to 15% compared with real inhomogeneous clouds, both types of cloud fields having the same mean cloud optical depth. This so‐called plane‐parallel cloud albedo bias has given rise to a number of studies that present methods for reducing the albedo bias for stratiform clouds in climate models.

Using Monte Carlo simulations and the Independent Pixel Approximation (IPA) the inhomogeneous cloud albedo is investigated with the aim of deriving a parametrization of the albedo bias. The new approach used here is that the variance of the cloud optical depth is parametrized as a function of grid size and mean cloud liquid‐water content. The variance of the cloud optical depth is derived from turbulence processes. For the determination of the albedo bias an analytical solution is presented which is based on a simplified distribution function of the cloud optical depth and the IPA method. When used in conjunction with the parametrized variance of the cloud optical depth, a box function, which replaces the distribution function, produces comparable results to Monte Carlo simulations within an acceptable accuracy of a few per cent.
The impact of new water vapour spectral line parameters on the calculation of atmospheric absorption
Authors: Zhong Wenyi , Haigh Joanna D. , Belmiloud Djedjiga , Schermaul Roland , Tennyson Jonathan
Published: February 2007

New laboratory measurements and theoretical calculations of integrated line intensities for water vapour bands in the near‐infrared and visible regions (8600–15 000 cm−1) show a systematic 6–26% increase in band intensities compared to the HITRAN96 database. We have used the GENLN2 line‐by‐line code to assess the effects of such changes in the water vapour spectral database on calculations of clear‐sky short‐wave fluxes and heating rates. Three standard atmospheres were used and it was found that, compared with HITRAN96 results, the absorbed downward solar fluxes increase (including the effects of theoretically predicted weak water lines in the region) by 5.5, 4.8 and 2.2 W m−2 (solar zenith angle = 30°) and by 2.4, 2.1 and 1.1 W m−2 (solar zenith angle = 75°) respectively. The maximum change in heating rate is about 4%. The effects are about five to eight times larger than those produced by using the Giver et al. corrections. The combined effects of the revised description of the spectroscopy of water vapour account for approximately 30–90% of the absorption currently ascribed to the water vapour continuum in this spectral region.
Teleconnections between the tropical Pacific and the Sahel
Authors: Rowell David P.
Published: February 2007

A greater understanding of equatorial teleconnections is a key aspect of research into seasonal prediction and future climate change for tropical regions. Here the impact of Pacific sea surface temperature (SST) anomalies on rainfall fluctuations over the semi‐arid Sahel is explored, using a combination of observed and model data.

The first key topic of this study is the identification of those aspects of anomalous Pacific SST variability that are most strongly linked to the Sahel. One of these, also illuminated by earlier studies, is similar to the classic El Niño Southern Oscillation pattern in the central and east Pacific, which in its El Niño phase increases the likelihood of Sahel drought. It is shown here that, although a part of this link is indirect (operating via Atlantic SSTs), its main effect appears to be through a direct atmospheric teleconnection. The other critical pattern, of equal importance and revealed here by a novel analysis technique, is the large‐scale zonal gradient of SSTs from the west Pacific to the east Indian Ocean. If weakened, this too enhances the likelihood of Sahel drought. Atmospheric general circulation model experiments, forced either by observed or idealized SSTs, are used to confirm these two influences on the Sahel. Crucially, their Sahelian impact is substantially reinforced when both are present and, additionally, further empirical analysis shows them to be largely independent.

The second key topic is an investigation of the mechanisms for this Pacific‐Sahel teleconnection. These appear to involve anomalous stationary equatorial waves, with communication occurring in both the eastward and westward directions. In El Niño years (for example), a Kelvin wave emanates across the Atlantic from east Pacific convective heating anomalies, and an equatorial Rossby wave appears over the Indian Ocean in response to the anomalous west Pacific‐Indian Ocean SST gradients via convective heating anomalies over the Indian Ocean. These interact over Africa to enhance large‐scale subsidence over the Sahel, thus reducing seasonal rainfall totals. Interannual changes in propagating equatorial waves or in the residence of subseasonal regimes appear not to play a substantial role.
Bispectral analysis of geopotential‐height anomalies for synoptic‐intraseasonal time‐scales
Authors: Efimov V. V. , Shokurov M. V.
Published: February 2007

Spectral decomposition of the third moment of geopotential‐height fluctuations, bispectral analysis, is considered as a convenient and straightforward method of studying the nonlinear three‐wave interactions between spectral constituencies of anomalies. The real part of the bispectrum directly indicates an asymmetry of the probability density function (PDF), and the imaginary part indicates lack of time reversability of the time series. NCEP reanalysis data for 1982–96 and NMC analysis data for 1946–89 are used. Different frequency domains of bispectra are considered, namely, the synoptic frequencies, 2–6 days, lower intraseasonal frequencies, 32–128 days, and joint synoptic‐intraseasonal frequency ranges.

The spatial distribution of the integral over all frequencies of the real part of the bispectra, characterizing asymmetry of the PDF, on the whole, is the same as that obtained earlier by Holtzer. A similar integral of the imaginary part essentially differs from zero and has more non‐zonal behaviour. The first of them, asymmetry, accounts for different contributions of nonlinear and linear terms in the balance equation for geopotential anomalies.

The spatial distribution of the bispectra in the low‐frequency intraseasonal domain is nearly the same as for their integrals, because of the predominant contribution of low frequencies in the spectra of geopotential oscillations. The distribution of the real and imaginary parts of the bispectra in the synoptic frequency range indicates an asymmetry between positive and negative deviations of high‐frequency transients, and a spatial asymmetry between the front and back slopes of the eastward‐moving synoptic cyclones. This behaviour is clearly evident in storm‐track regions.

Most interesting is the synoptic‐intraseasonal frequency domain. Non‐zero values of real and imaginary parts of the bispectra imply an existence of low‐frequency oscillations of geopotential heights bounded by envelopes of synoptic fluctuations. This phenomenon is seen for all regions in both hemispheres and during both seasons, but takes place especially clearly in the storm‐track regions over the Pacific and Atlantic oceans. Phase shifts between the low‐frequency component and the variance of synoptic transients in most regions are nearly out of phase, but in the regions of storm‐track activity the phase relationship changes regularly along the tracks. Meaningful treatment of many of the results of the bispectral analysis needs special consideration.
The effect of the island of Crete on the Etesian winds over the Aegean Sea
Authors: Kotroni Vassiljki , Lagouvardos Kostas , Lalas Dimitris
Published: February 2007

The Etesians (northern sector winds), which blow over the Aegean Sea during summer, affect human activities in the area. The numerous islands of the Aegean and especially Crete (a mountainous island in the southern Aegean oriented perpendicular to the surface flow) seem to play an important role in the modification of the wind field during the Etesians. The Crete mountain ranges, surrounded as they are by water, are an excellent example of a major isolated topographic feature which significantly modifies the regional airflow and pressure; however, this modification can hardly be defined due to the lack of observing stations over the sea. For this reason, the available land surface and ship synoptic observations are used, together with ERS scatterometer wind data in order to identify the regions over the Aegean where the wind reaches its maximum intensity, and to assess the influence of Crete on the wind field. Moreover, numerical modelling is used to provide some further insight on the orographically disturbed wind flow. Sensitivity tests performed with the hydrostatic model BOLAM show that the interaction of the Etesian wind flow with the mountains of Crete produces deceleration of the Etesians up to almost 120 km upstream, the leftward deflection of the air as it approaches the mountains, and the associated intensification of the flow east of the island.
Modelling the local surface exchange over a grass‐field site under stable conditions
Authors: Best M. J. , Hopwood W. P.
Published: February 2007

Observations of near‐surface variables are used with the Met Office Surface Exchange Scheme to calculate the exchange of heat and moisture between the surface and the atmosphere for a grass‐field site at the Met Office, Cardington, UK. Different methods for modelling the stability near the surface are investigated with the surface temperatures and turbulent heat fluxes compared with data collected from the site. The results show that, whilst using Monin‐Obukhov similarity theory can give good results in stable conditions, the form of the stability functions can significantly affect the accuracy in certain stability regimes. The use of log‐linear stability functions can cause the turbulent fluxes of heat and moisture to cut off at stabilities which are too close to neutral compared with the observations. The results also show that unrealistically high surface temperatures are obtained in clear‐sky nocturnal conditions with the standard surface energy balance. An alternative energy balance which includes a canopy of vegetation above the underlying soil gives better agreement with the observations in these conditions.
A strategy for high‐resolution ensemble prediction. II: Limited‐area experiments in four Alpine flood events
Authors: Marsigli C. , Montani A. , Nerozzi F. , Paccagnella T. , Tibaldi S. , Molteni F. , Buizza R.
Published: February 2007

A high‐resolution ensemble system, based on five runs of a limited‐area model (LAM), is described. The initial and boundary conditions for the LAM integrations are provided by the representative members (RMs) selected from the European Centre for Medium‐Range Weather Forecasts Ensemble Prediction System (EPS). EPS members are grouped in five clusters; then, from each cluster, an RM is selected, according to the methodology described in the companion paper. The ability of the high‐resolution ensemble system to predict the occurrence of heavy rainfall events (either five or six days ahead) is tested for four cases of floods over the Alpine region. Results show that, in two case‐studies, the LAM integration corresponding to the RM of the highly populated cluster predicts the observed rainfall with a very good degree of time and spatial accuracy. In the other two cases, the extreme events are captured by at least one of the runs nested on the members of the less populated clusters. Probability maps constructed from LAM integrations provide great detail on the location of the regions affected by heavy precipitation and the information gained with respect to EPS probability maps and LAM deterministic forecasts is highlighted. The probabilistic estimates based on the LAM ensembles are also shown to be of valuable assistance to forecasters in issuing early flood alerts, contributing to the definition of a flood‐risk alarm system.
A method for testing a prespecified subgroup in clinical trials
Authors: Song Yang , Chi George Y. H.
Published: February 2007

In clinical trials, investigators are often interested in the effect of a given study treatment on a subgroup of patients with certain clinical or biological attributes in addition to its effect on the overall study population. Such a subgroup analysis would become even more important to the study sponsor if an efficacy claim can be made for the subgroup when the test for the overall study population fails at a prespecified alpha level. In practice, such a claim is often dependent on prespecification of the subgroup and certain implicit or explicit requirements placed on the study results due to ethical or regulatory concerns. By carefully considering these requirements, we propose a general statistical methodology for testing both the overall and subgroup hypotheses, which has optimal power and strongly controls the familywise Type I error rate. Copyright © 2007 John Wiley & Sons, Ltd.
A comparison between acoustic output indices in 2D and 3D/4D ultrasound in obstetrics
Authors: Sheiner E. , Hackmon R. , Shoham‐Vardi I. , Pombar X. , Hussey M. J. , Strassner H. T. , Abramowicz J. S.
Published: February 2007

Objective

Three‐dimensional (3D) ultrasound is gaining popularity in prenatal diagnosis. While there are no studies regarding the safety of 3D ultrasound, it is now widely performed in non‐medical facilities, for non‐diagnostic purposes. The present study was aimed at comparing the acoustic output, as expressed by thermal index (TI) and mechanical index (MI), of conventional two‐dimensional (2D) and 3D/4D ultrasound during pregnancy.

Methods

A prospective, observational study was conducted, using three different commercially available machines (iU22, Philips Medical Systems; Prosound Alfa‐10, Aloka; and Voluson 730 Expert, General Electric). Patients undergoing additional 3D/4D ultrasound examinations were recruited from those scheduled for fetal anatomy and follow‐up exams. Fetuses with anomalies were excluded from the analysis. Data were collected regarding duration of the exam, and each MI and TI during 2D and 3D/4D ultrasound exams.

Results

A total of 40 ultrasound examinations were evaluated. Mean gestational age was 31.1 ± 5.8 weeks, and mean duration of the exam was 20.1 ± 9.9 min. Mean TIs during the 3D (0.27 ± 0.1) and 4D examinations (0.24 ± 0.1) were comparable with the TI during B‐mode scanning (0.28 ± 0.1, P = 0.343). The MIs during the 3D volume acquisitions were significantly lower than those in the 2D B‐mode ultrasound studies (0.89 ± 0.2 vs. 1.12 ± 0.1, P = 0.018). The 3D volume acquisitions added 2.0 ± 1.8 min of actual ultrasound scanning time (i.e. not including data processing and manipulation, or 3D displays, which are all post‐processing steps). The 4D added 2.2 ± 1.2 min.

Conclusions

Acoustic exposure levels during 3D/4D ultrasound examination, as expressed by TI, are comparable with those of 2D B‐mode ultrasound. However, it is very difficult to evaluate the additional scanning time needed to choose an adequate scanning plane and to acquire a diagnostic 3D volume. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Materialien für die Brillenbeschichtung in Aufdampfanlagen
Authors: Zültzke W. , Schraner E. , Stolze M.
Published: February 2007

Heutzutage können Beschichtungen für organische Brillengläser nicht mehr isoliert betrachtet werden. Es ist erforderlich, dass das Zusammenspiel zwischen Brillensubstrat, Hartlack und Schichtsystem genau untersucht wird um eine langlebige gute Qualität des Gesamtkomplexes Brille liefern zu können. Gerade im Substratbereich konnten in den letzten Jahren große Veränderungen beobachtet werden. Der Drang immer dünnere Brillengläser liefern zu können, hat dazu geführt, dass die Brechzahlen immer höher wurden. Die Problematik die sich daraus ergibt, ist weniger die Anpassung der Antireflexschichten auf die Substratbrechwerte als die Anpassung an die mechanischen und thermischen Eigenschaften der Substrate.

Für den Brillenbeschichter reduziert sich die Einflussnahme auf das System weitgehend auf die AR‐Beschichtung. Auf Substratmaterial und Hartlack haben nur die großen Brillenhersteller Einfluss. Die vielen mittleren und kleinen Beschichtungslabore weltweit jedoch müssen die Substrate und den Hartlack kaufen und die Qualitäten akzeptieren. Einzige Einflussnahme besteht bei der Auswahl der Schichtmaterialien für die AR und sowie der Prozesstechnik. Die richtige Wahl der Materialien in ihrer Qualität, Form und Preis ist ausschlaggebend für eine qualitativ hochwertige Beschichtung. Eine Vielzahl von Faktoren muss bei der Wahl für das geeignete Material berücksichtigt werden.
Überwachung von Niederdruck‐Plasmaanlagen
Authors: Michaeli Walter , Hegenbart Andreas , Binkowski Dirk , v. Fragstein Friederike
Published: February 2007

Die optische Emissionsspektroskopie (OES) stellt ein sehr vielfältiges und einfach einzusetzendes Verfahren für die Überwachung von industriellen Plasmaprozessen dar. Durch die direkte Überwachung des Plasmas können zahlreiche Einflussgrößen auf Niederdruck‐Plasmaprozesse erfasst werden, die bisher in der Regel noch nicht erfasst werden. Dabei spielen vor allem Randbedingungen, die nicht direkt beeinflussbar sind, eine wichtige Rolle. Beispiele dafür sind Verunreinigungen und Leckagen in der Plasmaanlage. Diese können sich negativ auf die Reproduzierbarkeit der Prozesse in der Produktion auswirken. Am Beispiel eines Beschichtungsprozesses wird der Einfluss eines Lecks auf die Beschichtung und das Plasma demonstriert. Darüber hinaus wird die Erfassung von Verunreinigungen und Dichtungsproblemen in einer Mikrowellen‐Plasmaquelle mittels OES gezeigt. Mit Hilfe der gezeigten Zusammenhänge lässt sich die OES zur kontnuierlichen Überwachung von Niederdruck‐Plasmaanlagen und damit zur Steigerung der Reproduzierbarkeit industrieller Niederdruck‐Plasmaprozesse einsetzen.
Surface Treatments of Automotive Parts – Research and Applications
Authors: Vetter J. , Crummenauer J. , Barbezat G. , Avissar J.
Published: February 2007

Surface treatments used in daily manufacturing of parts for the automotive industry are selected to serve functional and decorative requirements achieved of mass production. Increased loads (mechanical, thermal etc.), longer life time, weight reduction, friction reduction, and corrosion resistance are demanded for modern automotive systems. Within the last decade, improved and new deposition techniques were developed in PVD, PECVD, thermochemical heat treatment and thermal spraying. These new treatments are becoming more and more common in powertrain and engine applications. Generating optimized surfaces for different types of substrate materials (e.g. Al‐ alloys, case hardened steels etc.) and geometries (e.g. bores) also impacts the running costs. Due to the new developments within these competing surface treatments, it becomes more and more common to substitute traditional treatment‐substrate‐systems with advanced treatments. Both the application potential and selected examples of different surface treatments will be shown. Aspects of the internal coating of bores inside the engine by plasma spraying, features of the corrosion protection of parts for the powertrain by the IONITOX process and piston ring treatments are discussed in more detail.
Comparative food web structure of larval macrolepidoptera and their parasitoids on two riparian tree species
Authors: Barbosa Pedro , Caldas Astrid , Godfray H. Charles J.
Published: February 2007

Single species or groups of species can be subjected to differing levels of parasitism on different plants. Previous studies have reported that parasitism of larval macrolepidoptera in an assemblage on box elder (Acer negundoL.) was significantly greater than on black willow [Salix nigra(Marsh)]. In this study, quantitative food webs, parasitoid overlap diagrams and other food web attributes were used to identify and describe direct and indirect interactions, and to compare assemblages on each tree species. These comparisons helped identify possible mechanisms explaining the differential parasitism observed. Although links among numerically dominant species in each assemblage were not strong, links between numerically dominant and subdominant species were strong. That is, numerically dominant and subdominant species interacted via shared parasitoids. The degree of parasitoid sharing by numerically dominant and subdominant species differed in each tree. There was less sharing of parasitoids on black willow than on box elder. Further, on box elder, the majority of parasitoids affecting numerically subdominant species originated from numerically dominant species, unlike in willow. These results lead to a working hypothesis—the source/nursery hypothesis—that proposes that community‐wide levels of parasitism are highest in circumstances in which numerically subdominant species share parasitoid species in common with numerically dominant species, and most parasitoids attacking subdominant species originate from numerically dominant species. Thus, differences in degree of sharing and the types of herbivores sharing parasitoids may explain differential parasitism. Further, the source/nursery hypothesis may explain why the vast majority of species in most assemblages are numerically subdominant.
Synthesis of novel bleaching catalyst containing macrocyclic manganese complexes and potential applications in laundry detergent
Authors: Park Han Woong , Lee Sang Yun , Ahn Jae Bum , Suh Jeong‐Kwon , Kim Beom‐Sik , Lee Ki‐Moo , Kim Won Jong
Published: February 2007

A bleaching catalyst based on manganese complexes, consisting of meso‐5,5,7,12,12,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradecane and racemic‐5,5,7,12,12,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradecane ligands, was synthesized and applied at 25°C to cotton fabrics stained with tea, coffee, curry, and sugar beet to examine the bleaching properties. The bleaching performance of this novel catalyst was higher than that of the conventional activator, tetraacetyl ethylenediamine (TAED). Dye and fabric damage were also examined for six differently dyed test fabrics under stressed conditions over 30 wash cycles. The dye damage induced by the catalyst was significantly less than that induced by TAED in direct black 22, reactive blue 225, reactive red 158, and sulfur blue 19. Tensile strength loss measurement, which represents fabric damage, showed less damage for the catalyst in direct black 22, direct blue 71, reactive red 158, and sulfur blue 19. The results indicate that this new bleaching catalyst could potentially be employed for low‐temperature bleaching.
Mice raised on milk transgenically enriched with n−3 PUFA have increased brain docosahexaenoic acid
Authors: Kao Beth T. , DePeters Edward J. , Van Eenennaam Alison L.
Published: February 2007

The brain contains high levels of the long‐chain n−3 FA DHA(22∶6n−3), mainly in the gray matter and synaptosomes. Adequate intake of DHA is crucial for optimal nervous system function, particularly in infants. Supplementation of infant formulas with DHA at levels similar to human breast milk is recommended for biochemical and functional benefits to neonates. We generated transgenic mice that produce elevated levels of n−3 PUFA in their milk by expressing the Caenorhabditis elegans n−3 FA desaturase under the control of a lactation‐induced goat beta‐casein promoter. To examine the postnatal effects of consuming the n−3‐enriched milk, we compared the growth and brain and plasma FA composition of mouse pups raised on milk from transgenic dams with those observed for pups raised on milk from nontransgenic dams. A significant decrease in arachidonic acid (ARA, 20∶4n−6) and concomitant increases in n−3 PUFA were observed in the phospholipid fraction of transgenic mouse milk. The n−6∶n−3 FA ratios were 4.7 and 34.5 for the transgenic and control milk phospholipid fractions, respectively. DHA and DPA (22∶5n−6) comprised 15.1% and 2.8% of brain FA from weanling mice nursed on transgenic dams, as compared with 6.9% and 9.2% for weanling mice nursed on control dams, respectively. This transgenic mouse model offers a unique approach to disassociate the effects and fetal programming resulting from a high n−6∶n−3 FA ratio gestational environment from the postnatal nutritional effects of providing milk with differing n−6∶n−3 FA ratios.
Single‐Step analysis of individual conjugated bile acids in human bile using 1H NMR spectroscopy
Authors: Gowda G. A. Nagana , Ijare Omkar B. , Somashekar B. S. , Sharma Ajay , Kapoor V. K. , Khetrapal C. L.
Published: February 2007

1H and 13C NMR spectra of intact human bile were assigned using one‐dimensional (1H and 13C) and two‐dimensional (1H‐1H and 1H‐13C) experiments. Individual conjugated bile acids—glycocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid—were identified. The bile acids were quantified accurately and individually in a single step by using distinct and characteristic amide signals. Making use of 13C NMR, the study also suggests a way to analyze unconjugated bile acids separately, if present. Chemical shift assignments and rapid single‐step analysis of individual conjugated bile acids from intact bile presented herein may have immense utility in the study of bile acid metabolism and deeper understanding of hepatobiliary diseases.
The Rotational Effect of Pronation and Supination Osteotomies of the Forearm in a Cadaver Model: A Comparison of Osteotomy Sites on the Radius and the Ulna
Authors: SHIRAI H. , RYU J. , KISH V. , ABE M.
Published: February 2007

The purpose of this study was to investigate the effect on forearm rotation of rotation osteotomies at the distal and proximal levels of the radius and the ulna. Rotation osteotomies of 15° and 30° were made in the distal and proximal one-third of the radius and the ulna in ten cadaver specimens and changes of forearm arc of rotation were compared after osteotomy at the four sites. This study identifies the proximal ulna as the best of these sites for rotation osteotomy because of the high gain in the rotated direction and minimal loss in the opposite direction.
Treatment compliance in patients lost to follow‐up after polysomnography
Authors: Lin Ho‐Sheng , Zuliani Giancarlo , Amjad Esmael H. , Prasad Abhishek S. , Badr M. Safwan , Pan Chuan‐Ju G. , Rowley James A.
Published: February 2007

Objectives

Studies on positive airway pressure (PAP) compliance typically focus only on patients who returned for follow‐up. In this study, we examined patients who failed to follow‐up after their initial polysomnogram (PSG) and PAP titration to determine their treatment status in terms of PAP usage.

Study Design

On retrospective chart review, we identified 57 patients who, based on PSG findings and symptoms, required the use of PAP but failed to follow‐up after titration. Twenty‐five of these patients were successfully contacted and agreed to an interview.

Results

Only 7 (28%) patients were using PAP on a regular basis. The remaining 18 (72%) patients were noncompliant.

Conclusions

A significant proportion (24%) of OSA patients who required treatment with PAP were lost to follow‐up after polysomnography. This group of patients has previously been ignored in the literature. We showed in this study that majority (72%) of these patients were not being treated adequately for OSA.
Is routine inclusion of level IV necessary in neck dissection for clinically N0 supraglottic carcinoma?
Authors: Çagli Sedat , Yüce Imdat , Güney Ercihan
Published: February 2007

Objective

Elective level II to IV dissection has become a common practice for patients with N0 neck and supraglottic laryngeal carcinoma. Several authors have questioned the necessity of dissecting level IV and the possible risk of associated morbidities such as chyle leak and phrenic nerve injury.

Study Design and Setting

We reviewed 58 patients who underwent elective functional and lateral neck dissection for supraglottic carcinoma. Node levels were delineated just after the removal of the specimens. The patients were followed at least 3 years postoperatively or until the time of death; recurrence rates and levels were evaluated.

Results

Occult lymph node metastases were determined in 14 cases. Level II was the most involved zone (7 patients). Isolated level IV lymph node metastasis was not established.

Conclusion

We think that routine level IV dissection is not necessary in the management of clinically and radiologically N0 necks in patients with supraglottic laryngeal carcinoma.
Increased incidence of head and neck abscesses in children
Authors: Cabrera Cristina E. , Deutsch Ellen S. , Eppes Stephen , Lawless Stephen , Cook Steven , O'Reilly Robert C. , Reilly James S.
Published: February 2007

Objective

To describe increasing incidence and changing microbiology of head and neck abscesses in children admitted to the hospital during the first quarters of 2000 through 2003.

Study Design and Setting

Retrospective data warehouse review identified 89 children less than 19 years of age admitted to a tertiary care pediatric hospital during the first quarters of 2000 through 2003 for suspicion of head and neck abscess involving the neck, face, and peritonsillar, retropharyngeal, and parapharyngeal spaces; and for orbital and intracranial complications of acute sinusitis.

Outcome Measures

Outcome measures included the incidence of infection admissions and description of infection location and microbiology, calculated by χ2 technique.

Results

The incidence of infections increased in 2003. The greatest increase was in neck abscesses and complications of acute sinusitis.

Conclusions

The increase in group A strep infections may be related to its biologic properties.

Significance

Group A strep remains a significant cause of head and neck infections in children.
Current diagnosis and treatment of laryngocele in adults
Authors: Dursun Gursel , Ozgursoy Ozan B. , Beton Suha , Batikhan Hunkar
Published: February 2007

Objective

To evaluate the treatment outcome of a series of laryngoceles and to comment on the current diagnosis and management of laryngoceles.

Study Design and Setting

A retrospective review of charts, radiological and histopathological notes, videolaryngostroboscopic records, and acoustic voice analyses of patients with laryngocele treated over a 10‐year period was undertaken.

Results

Seven patients had internal laryngoceles; one had external; another one had combined laryngocele. Patients with internal laryngocele underwent endoscopic CO2 laser resection, while those with external or combined laryngocele were treated via external approach. Quality of voice was improved and no recurrences were encountered during the follow‐up. No evidence of laryngeal cancer was found on the histological examinations.

Conclusion

Endoscopic CO2 laser resection of internal laryngocele provides a reliable and cost‐effective method that minimizes hospitalization and the need for tracheotomy. We believe that advances in the applications of laser in microlaryngosurgery will alter the traditional management of all type of laryngoceles.
Individual rights and collective rights: Labor’s predicament in China
Authors: Chen Feng
Published: February 2007

Despite the government’s active legislation to protect workers, labor rights still remain widely ignored and poorly enforced in China. Structural constrains, such as the state’s development strategy biased on efficiency over equity, tight labor markets, and the lack of an effective safety net, cannot fully explain why Chinese workers have had so little impact on the environment in which they work and the violations of their rights often occur. Using Marshall’s theory of citizenship rights, this article explores the structure of China’s labor rights for an explanation. It argues that while Chinese labor legislation stipulates workers’ individual rights regarding contracts, wages, working conditions, pensions, and so on, it fails to provide them with collective rights, namely the rights to organize, to strike, and to bargain collectively in a meaningful sense. The lack of collective rights is one of the major factors that render workers’ individual rights vulnerable, hollow, unenforceable, or often disregarded. Labor legislation that enables workers to act collectively is crucial for safeguarding their individual rights.
CHAPTER 2 The epidemiology of human papillomavirus infection and its association with cervical cancer
Authors: Bosch F. Xavier , Qiao You‐Lin , Castellsagué Xavier
Published: February 2007

Cervical cancer has been recognized as a rare outcome of a common, sexually transmitted infection whose etiologic association is restricted to a few human papillomavirus (HPV) types. With optimal testing systems HPV DNA can be identified in nearly all specimens of invasive cervical cancer, and it is claimed that infection of the cervix with HPV is a necessary cause of cervical cancer. The evidence is consistent worldwide for squamous cell carcinomas (SCC), adenocarcinomas, and the vast majority (>95%) of the immediate cervical cancer precursors, namely high‐grade squamous intraepithelial lesions (HSILs)—also known as cervical intraepithelial neoplasia 3 (CIN 3) or carcinoma in situ. Cofactors that modify the risk for HPV DNA‐positive women include the use of oral contraceptives (OCs) for 5 or more years, smoking, high parity (5 or more full‐term pregnancies), and previ‐ous exposure to other sexually transmitted diseases such as Chlamydia trachomatis and herpes simplex virus type 2 (HSV‐2). Women exposed to the human immuno‐deficiency virus (HIV) are at high risk for HPV infection, HPV DNA persistence, and progression of HPV lesions to cervical cancer.
A2. Vulval intraepithelial neoplasia (VIN)
Authors: Hatch Kenneth D.
Published: February 2007

VIN 3 is most likely a cancer precursor and is induced by infection with high‐risk types of HPV. VIN 3 lesions may be asymptomatic or present with itching and/or burning or the appearance of a vulval lesion (often raised and hyperpig‐mented), which may be unifocal or multifocal. All vulval lesions should be biopsied to confirm the diagnosis. Treatment options include laser vaporization, excision or cautery. Long term follow up is essential.
A3. Vaginal intraepithelial neoplasia (VAIN)
Authors: Hatch Kenneth D.
Published: February 2007

VAIN is much rarer than the equivalent dysplastic changes found in the cervix but may accompany cervical intraepithelial neoplasia. VAIN is also HPV in‐duced and may be an extension of a cervical lesion or a satellite lesion. VAIN lesions are usually asymptomatic and detected by cytologic screening. Lesions can be ex‐cised, vaporized or treated locally with medical therapies. The incidence of vaginal cancer is very rare.
Section B: Malignant manifestations of HPV infection Carcinoma of the cervix, vulva, vagina, anus, and penis
Authors: Denny Lynette , Ngan Hextan Y.S.
Published: February 2007

Cervical cancer remains the commonest cancer among women in developing countries, affecting women at their peak of social and economic responsibility. In poor countries where access to diagnosis and treatment is extremely limited, most of the affected women present with late‐stage disease. Many do not even have access to palliative care. Outcome in women treated for cervical cancer is strongly influenced by the stage of diagnosis. The main treatment modalities remain surgical removal for early‐stage disease and chemoradiation for late‐stage disease.

Cancers of the vulva, vagina, penis, and anus are much less common than cervical cancer although, in most cases, they also are associated with human papillomavirus infection. Diagnosis and chief treatment modalities for cervical and these less common cancers are discussed.
CHAPTER 5 HPV infection and HPV‐associated neoplasia in immunocompromised women
Authors: Palefsky Joel
Published: February 2007

Human immunodeficiency virus (HIV)‐positive women and women with transplant‐associated immunocompromise are at increased risk for cervical intraepithelial neoplasia (CIN) and cervical cancer compared with healthy, immunocompetent women. HPV often manifests as a “field” effect in immunocompromised women who are also at increased risk for vaginal, vulval, and anal intraepithelial neoplasia. Immunocompromised women require careful follow‐up with regular cy‐tologic screening, and there should be a low threshold for performing colposcopic evaluation in these women. Once detected, CIN should be treated aggressively and the patient followed up closely for recurrence. Although treatment regimens are similar for immunocompromised and healthy women, the former may need multiple treatment modalities. Data on the ability of highly active antiretroviral therapy (HAART) to reduce the incidence of high‐grade CIN and on the regression of existing CIN are mixed, some studies showing no benefit and others a modest benefit from HAART. However, the incidence of cervical cancer has not declined since the introduction of HAART, and the use of HAART among HIV‐positive women has not changed the suggested approach to cervical cancer screening and treatment. Finally, prophylactic HPV vaccination offers the possibility of reducing the burden of disease among immunocompromised women, particularly if they are vaccinated before the onset of both sexual activity and immunocompromise. However, studies are needed to document safety and immunogenicity, and —given their high rate of prior HPV exposure —the effectiveness of the vaccine in these women.
Vaccines against the zoonotic trematodesSchistosoma japonicum,Fasciola hepaticaandFasciola gigantica
Authors: McMANUS D. P. , DALTON J. P.
Published: February 2007

Schistosoma japonicum,Fasciola hepaticaandF. giganticaare digenetic trematodes and, therefore, possess similar life cycles. While schistosomiasis japonica has for a long time been recognised as a major disease of both humans and animals, infection with fasciolids has only been considered of relevance to animals. However, a number of recent reports indicate that fasciolosis is becoming a serious public health problem, especially in South America, Egypt and Iran (sporadic cases are also on the increase throughout Europe). Vaccines targeted at animals could play an important role in controlling these three diseases in animals and, by blocking transmission of infection, have a concurrent beneficial effect on disease in humans. Approaches towards identifying and producing vaccines against these parasites are similar and are discussed in this reveiw.
Die gastroösophageale Refluxkrankheit – Update 2006
Authors: Gräter
Published: February 2007

Die gastroösophageale Refluxkrankheit (GERD) ist eine Befindlichkeitsstörung, welche die Lebensqualität beeinträchtigt, sie kann aber auch ohne anfängliche Beschwerden zu gravierenden Komplikationen führen. Typische Symptome wie Sodbrennen oder saures Aufstossen, aber auch Beschwerden extraösophagealer Manifestationen können auf eine GERD hinweisen. Junge Patienten mit typischen Refluxbeschwerden und ohne Alarmsymptome können zwar ohne weitere Diagnostik therapiert werden. In der Regel sollte aber primär eine Endoskopie durchgeführt werden, um die Therapie dem Stadium anpassen zu können und um eine Gefährdung durch Komplikationen zu erkennen. Für Akut- und Langzeitbehandlung eignen sich die gut verträglichen Protonenpumpeninhibitoren. Die laparoskopische Antirefluxoperation ist eine wirksame therapeutische Alternative, die Patientenselektion sollte aber gezielt und kritisch erfolgen. Dagegen haben sich Verfahren der interventionellen Endoskopie bisher nicht durchgesetzt. Das Entartungsrisiko des Barrett-Ösophagus wurde überschätzt, trotzdem ist eine endoskopisch-bioptische Überwachung anzuraten. Mit der Mukosaablation steht für hierbei entdeckte intraepitheliale Neoplasien und minimalinvasive Frühkarzinome eine wenig belastende interventionelle Therapieoption zur Verfügung.
Divertikulose – Divertikulitis
Authors: Maier
Published: February 2007

Die Divertikelerkrankung im Sinne einer meist asymptomatischen Divertikulose hat in den westlichen Ländern, bedingt durch die Ernährungsgewohnheiten und das zunehmende Lebensalter deutlich zugenommen. Der Verlauf der Erkrankung ist bei den meisten Patienten günstig. Lebenslang bleiben mindestens drei Viertel aller Patienten mit Kolondivertikeln asymptomatisch. 10–20% entwickeln klinische Symptome, vor allem eine Divertikulitis und selten Divertikelblutungen. Die Diagnostik beruht wesentlich auf der klinischen Untersuchung. Als bildgebendes Verfahren hat sich, neben der orientierenden Sonographie, die CT-Untersuchung bewährt. Der grösste Teil der Patienten mit Divertikelbeschwerden (und ohne Entzündungszeichen) profitiert von einer unspezifischen Behandlung (Bettruhe, flüssige Nahrung, Spasmolytika). Patienten mit Entzündungszeichen werden antibiotisch behandelt. Wichtig ist, dass der Arzt den Patienten regelmässig untersucht und spätestens dann, wenn nach 2–3 Tagen keine Verbesserung der Symptomatologie zu erkennen ist, die Differentialdiagnose nochmals überdacht, der Patient ggf. auch stationär eingewiesen wird. Patienten mit komplizierter Divertikulitis werden chirurgisch behandelt. Der Nutzen einer prophylaktischen Resektion zur Vermeidung von Komplikationen nach zwei Ereignissen einer akuten Divertikulitis wird zunehmend hinterfragt. Im Anschluss an eine durchgemachte Divertikulitis wird eine faserreiche Kost empfohlen – allerdings sind die Daten über ihren Nutzen widersprüchlich. Wichtig ist, nach jeder Divertikulitis das Colon hinsichtlich eines möglichen Karzinoms zu untersuchen.
Psychology as a Science
Authors: Drenth Pieter J.D.
Published: February 2007

This paper tries to demonstrate that the truthfulness and usefulness of psychology as a science, although clearly distinguishable, can and often do go together very well. The criteria for the two concepts are relevance and veracity, respectively. Each of these criteria is further analyzed and differentiated. Together they compose a three-dimensional Knowledge-Relevance (K-R) model. This model proves to be useful in addressing various classical epistemological questions, pertaining to both the theoretical and practical dimensions of psychology. It is argued that a proper balance between pure and applied research has to be kept so as to serve the various relevant objectives of psychology as a science.
Earthquake occurrence along the Java trench in front of the onset of the Wadati‐Benioff zone: Beginning of a new subduction cycle?
Authors: Špičák Aleš , Hanuš Václav , Vaněk Jiří
Published: February 2007

Spatial distribution of earthquake foci in the central part of the Sunda Arc was analyzed using global seismological data. The analysis revealed the existence of a distinct strip of earthquakes distributed along the Java trench, separated by a trench‐parallel, 50–150 km wide aseismic link from seismicity belonging to the Wadati‐Benioff zone of the recently subducting slab. The seismicity pattern at the plate margin corresponds well with the morphology of the seafloor: The along‐trench seismicity correlates with the position of the Java trench and the onset of the Wadati‐Benioff zone correlates with the Java trough. The GPS measurements performed in three analogous structural units of the neighboring Sumatran convergent margin point to substantial differences in velocities of movement of the respective units and correlate with the spatial distribution of earthquake foci. We interpret the distinct along‐trench seismicity as a consequence of the onset of a new subduction cycle due to the rapid convergent movement of the Indo‐Australian plate relative to the aseismic lithospheric link.
Ground based identification of dispersionless electron injections
Authors: Spanswick E. , Donovan E. , Friedel R. , Korth A.
Published: February 2007

Using data from an array of ground‐based single beam riometers and the CRRES Medium Energy B (MEB) particle detector we examine the signature of dispersionless electron injections. We find that it is possible to distinguish a dispersionless electron injection by it's integrated (>30 keV) flux signature at in situ satellites with a simple rise time criteria. If the total electron flux >30 keV exhibits a dramatic rise within 3 minutes then the signature is guaranteed to correspond to a dispersionless injection. Since the Kennel‐Petschek limit for strong pitch angle scattering is almost certainly met during substorm injections and riometers respond to the >30 keV energy range, this translates to an equivalent criteria for riometer absorption. We present results obtained using our selection criteria for the ground‐based identification of dispersionless electron injections including MLT dependence and initial spatial extent of the electron injection region.