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Evolutionarily conserved, “natural” (n)IgM is broadly reactive to both self and foreign antigens. Its selective deficiency leads to increases in autoimmune diseases and infections. In mice, nIgM is secreted independent of microbial exposure to bone marrow (BM) and spleen B-1 cell–derived plasma cells (B-1PC), generating the majority of nIgM, or by B-1 cells that remain non-terminally differentiated (B-1sec). Thus, it has been assumed that the nIgM repertoire is broadly reflective of the repertoire of body cavity B-1 cells. Studies here reveal, however, that B-1PC generate a distinct, oligoclonal nIgM repertoire, characterized by short CDR3 variable immunoglobulin heavy chain regions, 7–8 amino acids in length, some public, many arising from convergent rearrangements, while specificities previously associated with nIgM were generated by a population of IgM-secreting B-1 (B-1sec). BM, but not spleen B-1PC, or B-1sec also required the presence of TCRαβ CD4 T cells for their development from fetal precursors. Together, the studies identify important previously unknown characteristics of the nIgM pool.

Supercritical CO2 (scCO2) extraction of valuable chemicals from food, biomass, and residues thereof has recently been recognized as a sustainable process. In this study, we present a new design of an attenuated total reflection infrared (ATR-IR) spectroscopic cell for monitoring the extraction of fatty acid from almonds under scCO2 conditions. The newly designed ATR-IR cell allows in situ monitoring of changes of the composition of the almonds during the scCO2 extraction process at a pressure of up to 450 bar. Extracted components can be spectroscopically followed at a time resolution of 30 s. This allows fast and facile optimization of scCO2 conditions such as temperature, pressure, and extraction time.

We report the discovery of a rare close binary system, SMSS J160639.78-100010.7, comprised of a magnetic white dwarf with a field of about 30 MG and a brown dwarf. We measured an orbital period of 92 min which is consistent with the photometric period. Minimum and maximum light occur at the orbital quadratures Phi=0.25 and 0.75, respectively, and cannot be caused by reflection on the brown dwarf, but, instead, by a spot on the synchronously rotating magnetic white dwarf. The brown dwarf does not fill its Roche lobe and the system may be in a low-accretion state or, more likely, in a detached state following episodes of mass transfer. SMSS J160639.78-100010.7 is the nearest known magnetic white dwarf plus brown dwarf system., Comment: Accepted for publication in MNRAS Letters

When judging subject-specific aspects of students’ texts, teachers should assess various characteristics, e.g., spelling and content, independently of one another since these characteristics are indicators of different skills. Independent judgments enable teachers to adapt their classroom instruction according to students’ skills. It is still unclear how well teachers meet this challenge and which intervention could be helpful to them. In Study 1, N = 51 pre-service teachers assessed four authentic English as a Second Language (ESL) essays with different overall text qualities and different qualities of spelling using holistic and analytic rating scales. Results showed a negative influence of the experimentally manipulated spelling errors on the judgment of almost all textual characteristics. In Study 2, an experimental prompt was used to reduce this judgment error. Participants who were made aware of the judgment error caused by spelling errors formed their judgments in a less biased way, indicating a reduction of bias. The determinants of the observed effects and their practical implications are discussed.

Die psychologische Forschung zur Urteilsgenauigkeit, welche den Kern der diagnostischen Kompetenz darstellt, konzentrierte sich meist auf die Frage, wie gut Lehrkrafte in der Lage sind, Leistungen von Lernenden korrekt zu beurteilen. Oft werden dabei generische Merkmale analysiert und Fachspezifika vernachlassigt. In den vorliegenden Studien wird mit dem Schulerinventar ASSET ein digitales Instrument vorgestellt, mit dem die Beurteilung von englischsprachigen Lernertexten anhand fachdidaktisch begrundeter Kriterien untersucht werden kann. Es wurden drei Experimente durchgefuhrt, in denen Probanden jeweils vier argumentative Essays anhand holistischer und analytischer Skalen beurteilten. Die Qualitat der Texte wurde variiert und jedem Text ein Name zugeordnet, der das Geschlecht bzw. den Migrationshintergrund der Lernenden anzeigte. Unsere Ergebnisse zeigen, dass Probanden in ihren Urteilen klar zwischen Texten mit hoher und niedriger Qualitat unterscheiden. In keiner der Studien wurden Unterschiede in der Beurteilung aufgrund der Namen der Lernenden gefunden. Diskutiert werden die Einsatzmoglichkeiten des Schulerinventars ASSET in experimentellen Studien und zu Ausbildungs- und Trainingszwecken im Lehramtsstudium.

Numerous studies have examined the relationship between lexical features of students’ compositions and judgements of text quality. However, the degree to which teachers’ judgements are influenced by the quality of vocabulary in students’ essays with regard to their assessment of other textual characteristics is relatively unexplored. This experimental study investigates the influence of lexical features on teachers’ judgements of English as a second language (ESL) argumentative essays. Using analytic and holistic rating scales, English pre-service teachers (N = 37) in Switzerland assessed four essays of different proficiency levels in which the levels of lexical diversity and sophistication had been experimentally varied. Coh-Metrix software was used to manipulate the level of lexical diversity, as measured by MTLD and D, and the Tool for the Automatic Analysis of Lexical Sophistication (TAALES) software was used to obtain differing levels of lexical sophistication, as measured by word range. The results suggested that texts with greater lexical diversity and sophistication were assessed more positively concerning their overall quality as well as the analytic criteria ‘grammar’ and ‘frame of essay’. The implications of this study for classroom practice and teacher education are discussed.

This experimental study examined the influence of vocabulary and spelling on teachers’ perceptions of English as a second language (ESL) essays. Sixty-nine pre-service teachers from Switzerland and...

This article outlines an English lesson for secondary schools, bringing together perspectives from media studies, teaching methodology in foreign language acquisition and teaching practice. We describe how pupils of a secondary school (3rd year, Gymnasium) engaged in-depth with the topic of feminism in music videos. Working in collaboration, the pupils analysed music videos they selected themselves, and uncovered gendered representations in the video, song text and sound. For this inquiry they used the digital tool TRAVIS GO, a web app specifically designed for schools. We describe how the functions of TRAVIS GO support the critical engagement with modern media products in language teaching, supporting the aim of initiating critical discussions of important topics in society with authentic materials.

The particle number (PN) emissions of vehicles equipped with particulate filters are low. However, there are technologies that can have high PN levels, especially below the currently lower regulated particle size of 23 nm. Sub-23-nm particles are also considered at least as dangerous as the larger ultrafine particles. For this reason, the European Union (EU) is planning to regulate particles down to 10 nm. In this study we compared prototype portable emission measurement systems (PEMS) and reference laboratory systems measuring from 10 nm. The tests included cycles and constant speeds, using vehicles fuelled with diesel, gasoline or liquefied petroleum gas (LPG). The results showed that the PEMS were within ±40% of the reference systems connected to the tailpipe and the dilution tunnel. Based on the positive findings and the detection efficiencies of the prototype instruments, a proposal for the technical specifications for the future regulation was drafted.

Assessing student writing is a complex task and experimental studies have shown that textual determinants, such as spelling or vocabulary, affect teachers’ judgments of other analytic criteria in student essays. Among these elements, organisation has not been extensively explored. This experimental study examines how organisational quality influences teacher judgments of ESL student texts in order to obtain a comprehensive overview of important determinants in the assessment process. Pre-service English teachers (N = 53) in Switzerland and Germany assessed four argumentative essays of two different overall text qualities in which two organisational features had been manipulated in terms of cohesive devices and paragraphing. Findings show that texts with higher organisational quality were assessed more positively concerning all analytic scales than texts with low organisational quality, indicating halo effects. In addition, an interaction effect was found between overall text quality and organisational quality, suggesting that the effect of organisational quality was stronger when overall text quality was low. This study sheds new light on the interaction between individual text features in the assessment of complex learner texts. Practical implications regarding essay assessment in teacher education are discussed.

Our ability to understand and intervene on eating in the absence of hunger (EAH) as it occurs in peoples' natural environments is hindered by biased methods that lack ecological validity. One promising indicator of EAH that does not rely on self-report and is easily assessed in free-living individuals is glucose. Here, we hypothesize that elevated pre-prandial blood glucose concentrations (PPBG), which reflect a source of readily-available, short-term energy, are a biological indicator of EAH. This was a 7-day observational study of N = 41, 18-24 year old men and women with BMI

Teacher judgment accuracy (TJA) is a central part of diagnostic competence. Research has revealed heterogeneous results regarding teacher characteristics as determinants of TJA. In the present experimental study N = 36 experienced and N = 47 student teachers holistically and analytically assessed four student essays. We compared the judgments of teachers and student teachers to machine scores and expert ratings. Experienced teachers’ judgments were more negative than student teachers’, and both judgments were more negative than those made by experts, and the machine. The results remained stable, even after controlling for content knowledge. They are discussed in relation to the assumption of an expert-blind-spot.

Purpose White light cystoscopy (WLC) is the standard procedure for visualising non-muscle invasive bladder cancer (NMIBC). However, WLC can fail to detect all cancerous lesions, and outcomes with transurethral resection of the bladder differ between institutions, controlled trials, and possibly between trials and routine application. This noninterventional study assessed the benefit of hexaminolevulinate blue light cystoscopy (HALC; Hexvix®, Ipsen Pharma GmbH, Germany) plus WLC versus WLC alone in routine use. Methods From May 2013 to April 2014, 403 patients with suspected NMIBC were screened from 30 German centres to perform an unprecedented detailed assessment of the additional detection of cancer lesions with HALC versus WLC alone. Results Among the histological results for 929 biopsy samples, 94.3 % were obtained from suspected cancerous lesions under either WLC or HALC: 59.5 % were carcinoma tissue and 40.5 % were non-cancerous tissue. Of all cancer lesions, 62.2 % were staged as Ta, 20.1 % as T1, 9.3 % as T2, 7.3 % as carcinoma in situ (CIS), and 1.2 % were unknown. Additional cancer lesions (+6.8 %) and CIS lesions (+25 %, p

The first stars are predicted to have formed within 200 million years after the Big Bang, initiating the cosmic dawn. A true first star has not yet been discovered, although stars with tiny amounts of elements heavier than helium ('metals') have been found in the outer regions ('halo') of the Milky Way. The first stars and their immediate successors should, however, preferentially be found today in the central regions ('bulges') of galaxies, because they formed in the largest over-densities that grew gravitationally with time. The Milky Way bulge underwent a rapid chemical enrichment during the first 1-2 billion years, leading to a dearth of early, metal-poor stars. Here we report observations of extremely metal-poor stars in the Milky Way bulge, including one star with an iron abundance about 10,000 times lower than the solar value without noticeable carbon enhancement. We confirm that the most metal-poor bulge stars are on tight orbits around the Galactic Centre, rather than being halo stars passing through the bulge, as expected for stars formed at redshifts greater than 15. Their chemical compositions are in general similar to typical halo stars of the same metallicity although intriguing differences exist, including lower abundances of carbon., Published in Nature on 11/11/15, see http://dx.doi.org/10.1038/nature15747

This study investigates English writing skills of learners two years and one year before their baccalaureate exam in upper secondary schools (academic track, Gymnasium) in Germany and Switzerland. It focuses on level and development of EFL writing as well as differences between groups (country, gender, language background). A sample of n = 2847 students worked in a repeated measurement study on two different writing tasks from the Test of English as a Foreign Language (TOEFL iBT). Results showed that in both countries over 70% of tested students achieved level B2 according to the Common European Framework of Reference for Languages (CEFR), thus mastering target standards one year before graduation. There were small effects for the development of writing skills over the school year, which were similar in size to studies on receptive skills. Swiss students outperformed German students while gender and language background did not have significant effects. These findings are discussed with regard to implications for English writing curricula and teacher education in an international context.

The authors discovered a number of minor inaccuracies on pp. 58–59 of this article. However, they do not affect any of the main claims regarding the influence of lexical features on text assessment made in that study. In this note, we provide a corrected proof of the inaccuracies (marked in bold). The authors would like to apologize for any inconvenience caused.

Observations of the deposits, flow marks, and damages of three mixed-snow avalanches of widely different size were analyzed with regard to flow regimes, velocities, pressures, densities, flow depths, erosion modes, and mass balance. Three deposit types of different density and granulometry could be clearly discerned in these avalanches. They are attributed to dense, fluidized, and suspension flow regimes, respectively. Combining observations, we estimated the density in the fluidized layer as 35&ndash, 100 kg m - 3 , in good agreement with inferences from pressure measurements. Upper bounds for the suspension layer density, arising from the run-up height, velocity, and damage pattern, are about 5 kg m - 3 at the valley bottom. An approximate momentum balance of the dense layer suggests that the snow cover was eroded to considerable depth, but only partly entrained into the flow proper. The suspension layer had largely lost its erosive power at the point where it separated from the denser parts of the avalanche. Our estimates shed doubt on collisions between snow particles and aerodynamic forces at the head of the avalanche as sole mechanisms for creating and upholding the fluidized layer. We conjecture that the drag from air escaping from the snow cover as it is being compressed by the overriding avalanche could supply the missing lift force.

We report the discovery of an unusual stellar system, SMSS J130522.47-293113.0. The optical spectrum is dominated by a blue continuum together with emission lines of hydrogen, neutral and ionized helium, and the N III, C III blend at around 4640-4650 Angstrom. The emission line profiles vary in strength and position on timescales as short as 1 day, while optical photometry reveals fluctuations of as much as ~0.2 mag in g on timescales as short as 10-15 min. The system is a weak X-ray source (f_{0.3-10} = (1.2 +/- 0.1) x 10^{-13} ergs cm^{-2} s^{-1} in the 0.3-10 keV band) but is not detected at radio wavelengths (3-sigma upper limit of 50 microJy at 5.5 GHz). The most intriguing property of the system, however, is the existence of two "blobs", a few arcsec in size, that are symmetrically located 3.8 arcmin (2.2 pc for our preferred system distance of ~2 kpc) each side of the central object. The blobs are detected in optical and near-IR broadband images but do not show any excess emission in Halpha images. We discuss the interpretation of the system, suggesting that the central object is most likely a nova-like CV, and that the blobs are relics of a pc-scale accretion-powered collimated outflow., Comment: 15 pages, 8 figures. Accepted by MNRAS on 2018 March 13

Electrochemical impedance spectroscopy is used during operation of different polymer electrolyte membrane fuel cell (PEMFC) stack assemblies at various conditions with special interest given to the characteristic time constant tlow-f derived from the low-frequency arc of the spectra which is typically in the range of approximately 15-0.5 Hz. This was done by fitting an equivalent electrical circuit (EEC) consisting of one resistor and two RC-elements to the data. Parameter variation performed on a 90-cell stack assembly suggests that conditions leading to different air flow velocities in the flow channels affect tlow-f while other parameters like humidity influence the impedance spectrum, but not tlow-f. Comparison of the stoichiometry variation between short stack and locally resolved single cell shows similar results with the stack's time constant matching that of the cell's segments which are located off-center toward the outlet. However, a nonlinear dependency between gas flow velocity and tlow-f especially at low stoichiometric values is obvious. Results from stoichiometry variations at different pressure levels suggest that this could be attributed to the different steady-state oxygen partial pressures during the experiments. Comparison of the stoichiometry variation between different stack platforms result in similar dependencies of tlow-f on air flow rate with respect to a reference oxygen partial pressure regardless of size, flow field, geometry, or cell count of the stack. The time constant caused by oxygen diffusion through the gas diffusion layer (GDL), tGDL, was approximated and compared to tlow-f. While it was found that tlow-f ≫ tGDL at low stoichiometric values, tlow-f decreases toward tGDL at very high gas flow rates, suggesting that tGDL offsets tlow-f and becomes dominating if no oxygen concentration variation along the flow channel was present.

Within the project "Elektrischer Antriebsstrang fur Arbeits- und Nutzfahrzeuge" (ELAAN), fuel cell and battery modules are combined with an electric motor to power a utility vehicle LADOG T1250 which is often used in municipal applications. Conventionally, the vehicle is powered by a four cylinder diesel engine which feeds a hydraulic pump. As fuel cells, batteries and electric motor replace the diesel engine and hydraulic traction system, the fuel economy can be improved by a factor of approximately three. Hydrogen is stored at 350 bar and can be refilled within few minutes. This makes the use of the electric vehicle comparable with the conventional one in terms of operation and refill time.

In this paper we present the results of a search for members of the globular cluster Palomar 5 and its associated tidal tails. The analysis has been performed using intermediate and low resolution spectroscopy with the AAOmega spectrograph on the Anglo-Australian Telescope. Based on kinematics, line strength and photometric information, we identify 39 new red giant branch stars along $\sim$20$^{\circ}$ of the tails, a larger angular extent than has been previously studied. We also recover eight previously known tidal tail members. Within the cluster, we find seven new red giant and one blue horizontal branch members and confirm a further twelve known red giant members. In total, we provide velocity data for 67 stars in the cluster and the tidal tails. Using a maximum likelihood technique, we derive a radial velocity for Pal 5 of $-57.4 \pm 0.3$ km s$^{-1}$ and a velocity dispersion of $1.2\pm0.3$ km s$^{-1}$. We confirm and extend the linear velocity gradient along the tails of $1.0 \pm 0.1$ km s$^{-1}$ deg$^{-1}$, with an associated intrinsic velocity dispersion of $2.1\pm0.4$ km s$^{-1}$. Neither the velocity gradient nor the dispersion change in any significant way with angular distance from the cluster, although there is some indication that the gradient may be smaller at greater angular distances in the trailing tail. Our results verify the tails as kinematically cold structures and will allow further constraints to be placed on the orbit of Pal 5, ultimately permitting a greater understanding of the shape and extent of the Galaxy's dark matter halo., 14 pages, 9 figures, 4 tables; Accepted for publication in MNRAS

Die Berufsgenossenschaft Nahrungsmittel und Gastgewerbe (BGN) hat mit einer Langsschnittstudie die Ausbildungssituation im Gastgewerbe untersucht und Auszubildende zu zwei Erhebungszeitpunkten befragt. Das Ziel der Untersuchung war die Beantwortung der Frage, warum vergleichsweise viele Auszubildende im Gastgewerbe, wie Koche/Kochinnen oder Restaurantfachleute, ihre Ausbildung abbrechen. Die Studie leistet eine Merkmalsbeschreibung von Auszubildenden im Gastgewerbe und liefert wertvolle Erkenntnisse zur Abbruchneigung, zur subjektiven Bewertung der Ausbildungssituation und zu Berufs- und Lebenszielen von Auszubildenden aus der Generation Y.

We present a detailed analysis of high-resolution, high S/N spectra for 5 Aquarius stream stars observed with the MIKE spectrograph on the Magellan Clay telescope. Our sample represents one third of the 15 known members in the stream. We find the stream is not mono-metallic: the metallicity ranges from [Fe/H] = -0.63 to -1.58. No anti-correlation in Na-O abundances is present, and we find a strong positive Mg-Al relationship, similar to that observed in the thick disk. We find no evidence that the stream is a result of a disrupted classical globular cluster, contrary to a previously published claim. High [(Na, Ni, alpha)/Fe] and low [Ba/Y] abundance ratios in the stream suggests it is not a tidal tail from a disrupted dwarf galaxy, either. The stream is chemically indistinguishable from Milky Way field stars with the exception of one candidate, C222531-145437. From its position, velocity, and detailed chemical abundances, C222531-145437 is likely a star that was tidally disrupted from omega-Centauri. We propose the Aquarius stream is Galactic in origin, and could be the result from a disk-satellite perturbation in the Milky Way thick disk on the order of a few Gyr ago: derived orbits, UVW velocities, and angular momenta of the Aquarius members offer qualitative support for our hypothesis. Assuming C222531-145437 is a tidally disrupted member of omega-Centauri, this system is the most likely disk perturber. In the absence of compelling chemical and/or dynamical evidence that the Aquarius stream is the tidal tail of a disrupted satellite, we advocate the "Aquarius group" as a more appropriate description. Like the Canis Major over-density, as well as the Hercules and Monoceros groups, the Aquarius group joins the list of kinematically-identified substructures that are not actually accreted material: they are simply part of the rich complexity of the Milky Way structure., Comment: Accepted to MNRAS. Updated to journal version

We present results from an extensive spectroscopic survey of field stars in the Small Magellanic Cloud (SMC). 3037 sources, predominantly first-ascent red giants, spread across roughly 37.5 sq. deg, are analysed. The line of sight velocity field is dominated by the projection of the orbital motion of the SMC around the LMC/Milky Way. The residuals are inconsistent with both a non-rotating spheroid and a nearly face on disk system. The current sample and previous stellar and HI kinematics can be reconciled by rotating disk models with line of nodes position angle, theta, ~ 120-130 deg., moderate inclination (i ~ 25-70 deg.), and rotation curves rising at 20-40 km/s/kpc. The metal-poor stars exhibit a lower velocity gradient and higher velocity dispersion than the metal-rich stars. If our interpretation of the velocity patterns as bulk rotation is appropriate, then some revision to simulations of the SMC orbit is required since these are generally tuned to the SMC disk line-of-nodes lying in a NE-SW direction. Residuals show strong spatial structure indicative of non-circular motions that increase in importance with increasing distance from the SMC centre. Kinematic substructure in the north-west part of our survey area is associated with the tidal tail or Counter-Bridge predicted by simulations. Lower line-of-sight velocities towards the Wing and the larger velocities just beyond the SW end of the SMC Bar are probably associated with stellar components of the Magellanic Bridge and Counter-Bridge, respectively. Our results reinforce the notion that the intermediate-age stellar population of the SMC is subject to substantial stripping by external forces., Comment: To appear in MNRAS

An important aspect when Al sheets are to be used for visible outer car body panels is surface appearance. Some age-hardenable Al-Mg-Si alloys of the AA 6xxx series can suffer from a phenomenon called roping. Roping appears on a macroscopic scale and manifests itself as the development of ridges and valleys 90° to the original rolling direction with a wavelength ranging from 1 to 10 mm when the sheet is formed to typical parts like doors or hoods. In the past years Al industry has developed means to minimise roping by careful control of alloy composition and through appropriate thermo-mechanical processing schedule. The increasing use of aluminium for outer skin applications gives proof that these efforts were successful. However, the extent of roping, and further the judgment of the quality of the surface appearance has up to now been done on a qualitative basis with comparisons against reference samples, as there are no established experimental techniques and no established analysis procedures for the quantification of this phenomenon. The goal of such a methodologyis to be able to quantify the extent of roping in 6xxx automotive carbody sheet alloys andto correlate it to a visual appearance rankingof roping. In the present study, a novel combination of a characterisation technique with an evaluation method is used to characterize and evaluate the roping behavior in aluminum alloys. This approach combines these already individually existing methods to a powerful tool: the measurement of a 3D surface topography with a subsequent analysis by means of Fourier analysis. The analysis of various car body sheet grades by means of this technique for uniaxial and biaxial loading conditions is presented in this paper.

A modular ductile failure model is presented and applied to the forming of an AA5182 aluminium alloy sheet. A detailed description of the failure model and its calibration is provided. The final application of the calibrated failure model to the deep drawing of a cruciform cup reveals a good correlation with the experimental findings. Finally, a study on the influence of the r-value on formability is conducted.

HERMES is a new high-resolution multi-object spectrograph on the Anglo Australian Telescope. The primary science driver for HERMES is the GALAH survey, GALactic Archaeology with HERMES. We are planning a spectroscopic survey of about a million stars, aimed at using chemical tagging techniques to reconstruct the star-forming aggregates that built up the disk, the bulge and halo of the Galaxy. This project will benefit greatly from the stellar distances and transverse motions from the Gaia mission.

In the present work the recently introduced Joined Ductile Failure (JDF) model has been slightly improved and is applied to sheet forming of an AA5182 aluminium alloy. Despite its simplicity the validation examples documented in the present work reveal that the JDF model is able of accurately predicting the onset as well as the location of ductile failure.

Cosmological models predict the oldest stars in the Galaxy should be found closest to the centre of the potential well, in the bulge. The EMBLA Survey successfully searched for these old, metal-poor stars by making use of the distinctive SkyMapper photometric filters to discover candidate metal-poor stars in the bulge. Their metal-poor nature was then confirmed using the AAOmega spectrograph on the AAT. Here we present an abundance analysis of 10 bulge stars with -2.8, Comment: 20 pages, 16 figures. Accepted to Monthly Notices of the Royal Astronomical Society. Online tables can be found at http://www.astro.lu.se/~louise/data

Study design Cost-effectiveness analysis alongside a cluster randomized controlled trial. Objective To study the cost-effectiveness of 2 low back pain guideline implementation (GI) strategies. Summary of background data Several evidence-based guidelines on management of low back pain have been published. However, there is still no consensus on the effective implementation strategy. Especially studies on the economic impact of different implementation strategies are lacking. Methods This analysis was performed alongside a cluster randomized controlled trial on the effectiveness of 2 GI strategies (physician education alone [GI] or physician education in combination with motivational counseling [MC] by practice nurses)--both compared with the postal dissemination of the guideline (control group, C). Sociodemographic data, pain characteristics, and cost data were collected by interview at baseline and after 6 and 12 months. low back pain-related health care costs were valued for 2004 from the societal perspective. Results For the cost analysis, 1322 patients from 126 general practices were included. Both interventions showed lower direct and indirect costs as well as better patient outcomes during follow-up compared with controls. In addition, both intervention arms showed superiority of cost-effectiveness to C. The effects attenuated when adjusting for differences of health care utilization prior to patient recruitment and for clustering of data. Conclusion Trends in cost-effectiveness are visible but need to be confirmed in future studies. Researchers performing cost-evaluation studies should test for baseline imbalances of health care utilization data instead of judging on the randomization success by reviewing non-cost parameters like clinical data alone.