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ZusammenfassungZum sogenannten Mittelbau zählen Doktoranden und Doktorandinnen, Postdocs, Nachwuchsgruppenleiter und -leiterinnen, Junior- und Tenure-Track-Professoren und -Professorinnen. Insbesondere Promovierende sowie Postdoktoranden und Postdoktorandinnen sind, noch mehr als früher, von den komplexen strukturellen und finanziellen Problematiken des Wissenschafts- und Lehrbetriebs betroffen, und das in vielerlei Hinsicht über Fächer hinweg. Der Flaschenhals auf dem Weg zur Professur oder einer anderweitig verstetigten Forschungs- oder Lehrstelle führt in der akademischen Karriere zu prekären Beschäftigungsverhältnissen. Die schwierige Vereinbarkeit von Familie und akademischer Karriere erzeugt eine zusätzliche Benachteiligung, insbesondere von Wissenschaftlerinnen. Mangelnde Qualitätssicherung sowie fehlende zuverlässige und vertrauenswürdige Prozesse erschweren die Aufdeckung und Aufarbeitung von Konflikten während der Promotionsphase und der Zeit des Postdoktorats. Der Beirat des wissenschaftlichen Nachwuchses (GI-WiN) der Gesellschaft für Informatik e. V. (GI) fordert und empfiehlt in einem Positionspapier (https://doi.org/10.1007/s00287-020-01250-x) mehrere Maßnahmen zur Stabilisierung von Karriere- und Beschäftigungssituation des Mittelbaus. Der vorliegende Artikel fasst die Ergebnisse einer Umfrage zur Ergänzung und empirischen Untermauerung dieser Empfehlungen zusammen. Die vorliegende Umfrage wurde mit dem Anspruch erhoben, Daten aus allen Fachbereichen – nicht nur der Informatik – zu sammeln. In den Ergebnissen zeigte sich, dass diesen vielfältigen Herausforderungen begegnet werden muss, die in Nicht-MINT-Fächern und MINT-Fächern ähnlich empfunden werden. Die Schaffung von unbefristeten Stellen für die Phase nach der Promotion wurde im Rahmen der Umfrage als besonders wünschenswert angesehen. Vorgeschlagen wurde auch die Abschaffung von Lehrstühlen und die Einführung einer Departmentstruktur. Des Weiteren wurde die Trennung von Begutachtung und Betreuung vor allem bei der Promotion angeregt. Die letzten 2 Jahre im Zeichen der COVID-19-Pandemie waren für einen großen Teil der Betroffenen von fehlendem fachlichen Austausch und sowohl beruflichen als auch privaten Zusatzbelastungen geprägt. Diese Ergebnisse können über die genannten Fachbereiche hinaus eine Entscheidungsgrundlage für eine gerechtere Wissenschaftspolitik liefern und bessere Arbeits- und Karrierebedingungen für den wissenschaftlichen Nachwuchs erwirken.

ZusammenfassungMaschinelle Lernverfahren finden seit einigen Jahren in immer mehr Bereichen vielfältige Anwendung, wodurch die Relevanz der dabei verwendeten Techniken deutlich wird. Unter dem Begriff des maschinellen Lernens (ML, oft auch „künstliche Intelligenz“) existieren zahlreiche Algorithmen, die unterschiedliche Komplexität und verschiedene Eigenschaften mit sich bringen. Für das Training dieser Algorithmen sind meist große Mengen an Daten notwendig. Insbesondere bei der Verwendung von personenbezogenen Daten stellen sich hierbei Fragen rund um den Datenschutz und die Privatsphäre von Betroffenen.Dies ist der erste Teil eines zweiteiligen Artikels zum Thema privatsphärefreundliches ML. Dieser erste Teil bietet einen leicht verständlichen Einstieg in das Thema des ML und geht dabei auf die wichtigsten Grundbegriffe ein. Außerdem werden einige der meistverwendeten ML-Verfahren, wie Entscheidungsbäume und neuronale Netze, vorgestellt. Im zweiten Teil, der in der kommenden Ausgabe des Informatik Spektrums erscheint, werden Privatsphäreangriffe und datenschutzfördernde Maßnahmen im Kontext von ML behandelt.

Diffusion treatments offer possibilities to enhance the performance and the service lifetime of hot forging tools. In combination with coating after nitriding, the surface layer hardness can be further increased. Within the scope of this study, a surface layer hardness above 2,000 HV0.005 was determined for borided or DLC (diamond-like carbon) coated surface layers. An increased surface layer hardness improves the abrasive wear resistance of forging dies. Furthermore, the plastic deformation of thermally softened forging die areas can be reduced. Beside these desirable effects, the ductility of diffusion treated or coated near surface layers is reduced and thermomechanical cracks are promoted. Therefore, additional approaches were developed to improve the thermomechanical crack behaviour of forging dies. Patterned plasmanitriding by the use of coverages to prevent areas from nitrogen diffusion, new combination processes of plasmanitrocarburizing (PNC) followed by plasmanitriding (PN) and the innovative boriding were investigated on different abstraction levels. A system of several testing rigs was set up to enable the abstraction of the thermal shock conditions in different stages. The patterned nitriding, boriding and combination plasma process (PN + PNC) were evaluated in a series of industrial field tests to derive recommendations for suitable tool treatments.

STUDY DESIGN Prospective cohort study. OBJECTIVE The aims of this study were to evaluate the outcome of surgical and nonsurgical treatment for patients with lumbar herniated disc (LHD) or lumbar spinal stenosis (LSS) after 2 years and to identify predictors for nonsuccess. SUMMARY OF BACKGROUND DATA Studies regarding the clinician's ability to identify patients with a poor prognosis are not in concurrence and further studies are warranted. METHODS This study included 390 patients with LHD or LSS referred for surgical evaluation after unsuccessful conservative treatment. Nonsuccess was defined as a Roland-Morris Disability score above 4 (0-23) or a Numeric Rating Scale back and leg pain score above 20 (0-60). Uni- and multivariate logistic regression analyses were used to investigate potential predictive factors including sociodemographic characteristics, history findings, levels of pain and disability, and magnetic resonance imaging findings. RESULTS Rates of nonsuccess at 2 years were approximately 30% in surgically treated patients with LHD, approximately about 60% in patients with LSS for disability, and 30% and 40%, respectively for pain. For the main outcome variable, disability, in the final multiple logistic regression model, nonsuccess after surgery was associated with male sex (odds ratio [OR] 2.04, 95% confidence interval [CI]: 1.02-4.11, P = 0.04), low level of education (OR 2.60, 95% CI: 1.28-5.29, P = 0.01), high pain intensity (OR 3.06, 95% CI: 1.51-6.21, P

ZusammenfassungDer Beirat des Wissenschaftlichen Nachwuchses (GI-WiN) der Gesellschaft für Informatik (GI) fordert und empfiehlt Maßnahmen zur Verbesserung der Lage von Promovierenden sowie Postdoktoranden und Postdoktorandinnen in der Informatik und anderen Technikwissenschaften.Promovierende sowie Postdoktoranden und Postdoktorandinnen im Bereich der Informatik sind in zunehmendem Maß von den komplexen strukturellen und finanziellen Problematiken des Wissenschafts- und Lehrbetriebs betroffen. Der Flaschenhals auf dem Weg zur Professur führt in der akademischen Karriere zu prekären Beschäftigungsverhältnissen. Die schwierige Vereinbarkeit von Familie und akademischer Karriere erzeugt eine zusätzliche Benachteiligung, insbesondere von Wissenschaftlerinnen. Mangelnde Qualitätssicherung sowie fehlende zuverlässige und vertrauenswürdige Prozesse erschweren die Aufdeckung und Aufarbeitung von Konflikten während der Promotionsphase und der Zeit des Postdoktorats. Fehlanreize im akademischen System beeinträchtigen eine direkte, intensive und regelmäßige Betreuung der jungen Akademiker durch Professorinnen und Professoren. Eine zeitnahe Bewältigung der in diesem Beitrag skizzierten Herausforderungen ist für den zukünftigen Fortbestand von Forschungseinrichtungen an Hochschulen sowie für eine erfolgreiche Fortführung des Prinzips der Bestenauslese von zentraler Bedeutung. Vor dem Hintergrund von bereits geplanten und durchgeführten Maßnahmen zur Stärkung des wissenschaftlichen Nachwuchses skizziert dieser Beitrag konkrete Maßnahmen; einerseits zur Verbesserung der Betreuung während der Promotionsphase und andererseits zur Strukturierung und Schaffung weiterer Karrierewege.

Background Multidisciplinary rehabilitation is recommended to reduce sickness absence and disability in patients with subacute or chronic low back pain (LBP). This study aimed to investigate whether a 12-week coordinated work oriented multidisciplinary rehabilitation intervention was effective on return to work and number of days off work during one-year follow-up when compared to usual care. Methods This study is a randomized controlled trial comparing the effectiveness of a 12-week multidisciplinary vocational rehabilitation program in addition to usual treatment. 770 patients with LBP, who were sick-listed, or at risk of being sick-listed were included in the study. The primary outcome was number of days off work due to LBP. The secondary outcomes were disability, health-related quality of life, pain, psychological distress and fear avoidance behavior. Data were collected at baseline, at the end of treatment, and at 6- and 12-months follow-up. Analyses were carried out according to the “intention-to-treat” principles. Results A significant decrease in the number of patients who were on sick-leave was found in both groups at the end of treatment and at 6- and 12-months follow-up. Additionally, disability, pain, health related quality of life, psychological distress, and fear avoidance beliefs improved in both groups. No statistically significant differences were found between the groups on any of the outcomes. Conclusions The coordinated multidisciplinary intervention had no additional effect on sickness absence, disability, pain, or health related quality of life as compared with that of usual care. Trial registration This study was retrospectively registered in ClinicalTrials.gov (registration ID: NCT01690234). The study was approved by The Danish Regional Ethics Committee (file no: H-C-2008–112) as well as registered at and approved by the Danish Data Protection Agency.

Datengestutzte Verfahren werden in der medizinischen Versorgungsforschung und Qualitatsentwicklung immer haufiger eingesetzt, um Behandlungstrends zu erkennen und das Ergebnis der Behandlungen zu evaluieren. Die hierfur notwendigen, langfristig erfassten medizinischen Daten konnen in Datenbanken, sogenannten medizinischen Registern, gesammelt werden. Es handelt sich bei medizinischen Daten jedoch um besonders schutzenswerte Daten, die hohen Datenschutzanforderungen unterliegen. Um die Speicherung der Daten auf lokalen, separat zu wartenden (und daher oft unzureichend geschutzten) Systemen zu vermeiden, stellen wir in diesem Beitrag ein Konzept fur ein solches Register mit zentraler Datenhaltung vor. Zum Schutz der Patientendaten kommen dabei Konzepte aus den Bereichen Security und Privacy by Design zur Anwendung.

Recently, health insurance claims have regained the attention of the scientific community as a source of real-world evidence in health care research and quality improvement. To date, very few studies are available which investigate the validity of health insurance claims; these may be affected by bias from several sources, such as possible upcoding of co-morbidities and complications for reimbursement advantages. The IDOMENEO study investigates the inpatient treatment of peripheral arterial disease (PAD) comprehensively using various data sources with a consortium involving experts from health care research and data privacy, a large health insurance fund, biostatisticians, jurists, and computer scientists. Prospective registry data were collected from 30–40 vascular centres in Germany using the GermanVasc registry. In addition, health insurance claims data were prospectively collected from BARMER, the second largest health insurance fund in Germany. The consortium is currently developing a data privacy compliant method of health insurance claims data validation, the methodological foundations of which are described here.

Two main impediments are currenty discussed with respect to the industrial application of magnesium sheets. First, the low formability of magnesium sheets requires many rolling passes to roll cast slabs to final gauge, which leads, second, to high costs for the production of magnesium sheets. An alternative cost-saving process chain for magnesium sheets with enhanced properties is the feedstock production by twin roll casting (TRC). In the TRC process, liquid metal proceeds from a furnace over a pipe into a crucible and then flows between a pair of counter rotating, internally cooled rolls. The metal solidifies upon touch with the cooled rolls and gets rolled to a strip. This paper refers to the comparison of the two processing routes on the example of the aluminum-free magnesium alloy MX20 (2 wt% Mn and 0.5 wt% Ca). Both kinds of production processes like casting and twin roll casting have an influence on the microstructure and texture of the feedstock material for the subsequent rolling process. The paper reports on the results of casting and twin roll casting experiments of this alloy. Furthermore, rolling trials are conducted and the deformation behavior of the sheets are presented and discussed with respect to the developed microstructures and textures. The different morphology of precipitates in the cast and twin roll cast feedstock material is used to improve the ductility of the magnesium alloy MX20.

Multi-material solutions represent a promising approach for the production of load-optimised parts. The combination of material-specific advantages of different materials in a single component allows the fulfilment of conflicting requirements e.g. high performance and low weight. Fabrication of hybrid components is challenging due to the dissimilar properties of the individual materials and requires the development of suitable manufacturing technologies. The present paper deals with the simulation-based design of a forming process for the production of a suspension control arm consisting of steel and aluminium. With the focus on material flow, two forming concepts, open-die and closed-die forging, were investigated, in order to ensure the required material distribution similar to the final part. In addition, a tool analysis was carried out to avoid thermo-mechanical overload of the tool system. It was found that the required material distribution can be achieved with both forming concepts. However, a closed-die forging concept is not suitable because of the high stresses in the forging dies exceed the tool steel’s strength.

Due to high thermo-mechanical loads, tools used in hot forming operations need a high resistance to different damage phenomena, such as deformation, cracking and abrasion. They are exposed to cyclic thermo-mechanical stress conditions, which leads to tool failure and subsequent tool replacement during cost-intensive production interruptions. To increase wear resistance, forging tools can be produced in the metastable austenite area. Forming of steel below the recrystallisation temperature, also known as “ausforming”, offers the possibility to increase strength without affecting ductile properties. This is due to grain refinement during forming. In this study, the thermo-mechanical treatment ausforming will be used to form the final contour of forging dies. For this purpose, an analogy study was performed where a cup-preform is ausformed, which represents the inner contour of a highly mechanically loaded forging die. It is investigated to what extent a fine-grained microstructure generated in the last forming stage can be achieved and how it influences the tool’s performance. The hot-working tool steel X37CrMoV5-1 (AISI H11) was used as workpiece material. To achieve optimal properties, process routes with tempering temperatures from 300 °C to 500 °C and global true plastic strains of φ = 0.25 and φ = 0.45 were examined. The results were evaluated by pulsation tests, metallographic analysis and hardness measurements of the formed parts. Optimal ausforming parameters were derived to produce a high performance forging die.

The current study introduces a method for manufacturing steel–aluminum bearing bushings by compound forging. To study the process, cylindrical bimetal workpieces consisting of steel AISI 4820 (1.7147, 20MnCr5) in the internal diameter and aluminum 6082 (3.2315, AlSi1MgMn) in the external diameter were used. The forming of compounds consisting of dissimilar materials is challenging due to their different thermophysical and mechanical properties. The specific heating concept discussed in this article was developed in order to achieve sufficient formability for both materials simultaneously. By means of tailored heating, the bimetal workpieces were successfully formed to a bearing bushing geometry using two different strategies with different heating durations. A metallurgical bond without any forging defects, e.g., gaps and cracks, was observed in areas of high deformation. The steel–aluminum interface was subsequently examined by optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the examined forming process, which utilized steel–aluminum workpieces having no metallurgical bond prior to forming, led to the formation of insular intermetallic phases along the joining zone with a maximum thickness of approximately 5–7 µm. The results of the EDS analysis indicated a prevailing FexAly phase in the resulting intermetallic layer.

To improve the bond strength of hybrid components when joined by friction welding, specimens with various front end surface geometries were evaluated. Rods made of aluminum AA6082 (AlSi1MgMn/EN AW-6082) and the case-hardening steel 20MnCr5 (AISI 5120) with adapted joining surface geometries were investigated to create both a form-locked and material-bonded joint. Eight different geometries were selected and tested. Subsequently, the joined components were metallographically examined to analyze the bonding and the resulting microstructures. The mechanical properties were tested by means of tensile tests and hardness measurements. Three geometrical variants with different locking types were identified as the most promising for further processing in a forming process chain due to the observed material bond and tensile strengths above 220 MPa. The hardness tests revealed an increase in the steel&rsquo, s hardness and a softening of the aluminum near the transition area. Apparent intermetallic phases in the joining zone were analyzed by scanning electron microscopy (SEM) and an accumulation of silicon in the joining zone was detected by energy-dispersive X-ray spectroscopy (EDS).

From a metal forming perspective, warm forming technologies can be used to reclaim the shape and functionality of worn engineering steel parts such as case-hardened geared components. Since forming temperatures are beneath the material-transformation temperature, no loss in hardness is expected and a new heat treatment can be omitted. In order to determine a process window for reclaiming geared components, upsetting tests were carried out on case-hardened workpieces made of AISI 5115.

Pseudonymisation provides the means to reduce the privacy impact of monitoring, auditing, intrusion detection, and data collection in general on individual subjects. Its application on data records, especially in an environment with additional constraints, like re-identification in the course of incident response, implies assumptions and privacy issues, which contradict the achievement of the desirable privacy level. Proceeding from two real-world scenarios, where personal and identifying data needs to be processed, we identify requirements as well as a system model for pseudonymisation and explicitly state the sustained privacy threats, even when pseudonymisation is applied. With this system and threat model, we derive privacy protection goals together with possible technical realisations, which are implemented and integrated into our event pseudonymisation framework PEEPLL for the context of event processing, like monitoring and auditing of user, process, and network activities. Our framework provides privacy-friendly linkability in order to maintain the possibility for automatic event correlation and evaluation, while at the same time reduces the privacy impact on individuals. Additionally, the pseudonymisation framework is evaluated in order to provide some restrained insights on the impact of assigned paradigms and all necessary new mechanisms on the performance of monitoring and auditing. With this framework, privacy provided by event pseudonymisation can be enhanced by a more rigorous commitment to the concept of personal data minimisation, especially in the context of regulatory requirements like the European General Data Protection Regulation., 10 pages. Extended version, Dec. 2019. A shortened version has been accepted for publication in the proceedings of the 35th ACM/SIGAPP Symposium On Applied Computing 2020

Mit der partiellen Einbringung von keramischen Partikeln in der Pulvermatrix lassen sich die lokalen Eigenschaften gezielt einstellen. Der Einsatz unterschiedlicher und heterogen verteilter Materialien in einem Werkstück wirkt sich auf den induktiven Erwärmungsprozess aus. Dieser Fachbeitrag beschäftigt sich mit Erwärmungsuntersuchungen an partiell partikelverstärkten Pulverpresslingen aus Stahl in den thixotropen Temperaturbereich für den anschließenden Schmiedeprozess. Due to the partial incorporation of ceramic particles, locally improved properties can be achieved in powder metallurgy of metal matrix composites. The use of various and heterogeneous distributed materials in one workpiece has an effect on the inductive heating process. This article deals with investigations on heating at thixotropic temperature range of partially particle-reinforced powder compacts made of steel for the subsequent forging process.

Due to a complex load spectrum of mechanical, thermal and tribochemical loads, hot forging tools are subject to increased wear. This results in cost-intensive reworking and possibly unscheduled machine downtimes. To reduce wear, research is currently being carried out on combinations of cooling lubricants and adjusted surface topographies in addition to diffusion and coating treatments. The aim of this contribution is to influence the friction between the workpiece and the tool surface by means of adapted surface topographies including cooling lubricant and thus to reduce tool wear. For this approach, tools were manufactured whose surfaces were treated with different shot peening materials and finally used in cylinder and ring compression tests under forging conditions. In order to draw conclusions on a potential influence of the friction conditions depending on the surface topography, the friction factors with lubricant application were determined with the help of the geometric changes of the ring samples after the forging process. The surfaces were also measured 3-dimensionally and the results from the optical analyses and the friction factor determinations were compared with different shot peening materials. The knowledge gained provides information on the application potential of differently conditioned surfaces in the field of hot bulk metal forming.

Background Subgrouping patients with chronic low back pain is recommended prior to selecting treatment strategy, and fear avoidance beliefs is a commonly addressed psychological factor used to help this subgrouping. The results of the predictive value of fear avoidance beliefs in patients with chronic low back pain in prognostic studies are, however, not in concordance. Therefore, the objective of this study was to examine the association between fear avoidance beliefs at baseline and unsuccessful outcome on sick leave, disability and pain at 12-month follow-up in patients with entirely chronic low back pain. Methods A secondary analysis of data from a randomised controlled trial. Patients with chronic low back pain (n = 559) completed questionnaires at baseline and after 12 months. Multiple logistic regression analyses were conducted to examine the association between fear avoidance beliefs and the outcomes sick leave, disability and pain. Results Higher fear avoidance beliefs about work at baseline were found to be significantly associated with still being on sick leave (OR 1.11; 95% CI 1.02–1.20) and having no reduction in pain (OR 1.04; 95% CI 1.01–1.08) after 12 months and may be associated with having no reduction in disability (OR 1.03; 95% CI 1.00–1.06) after 12 months (lower limit of 95% CI close to 1.00). Fear avoidance beliefs about physical activity were not found to be associated with the three outcomes. Conclusions High fear avoidance beliefs about work are associated with continuous sick leave after 1 year in patients with chronic low back pain. This finding might assist clinicians in choosing targeted treatment strategies in subgroups of working patients with chronic low back pain. Electronic supplementary material The online version of this article (10.1186/s12891-018-2351-9) contains supplementary material, which is available to authorized users.

Objective Acupuncture is a low risk option in pain management following total knee replacement as an alternative to opioid analgesics. Therefore, the benefit of acupuncture as adjunct to an exercise program was investigated. Furthermore, the modifying effect of previous benefit from acupuncture was explored. Design Three weeks postoperatively, eligible patients were randomized to acupuncture and exercises or exercises alone. Setting An outpatient rehabilitation centre in the municipality of Copenhagen, Denmark. Subjects A total of 172 patients were included. Methods Main outcome was proportion of patients that reported a clinically important change in pain at night following each treatment. Secondary outcomes were change in disability measured after termination of the course of treatment and at three months follow-up. Also consumption of medication and walking distance after termination of the course of treatment were assessed. Results No additional benefit of acupuncture was found on any of the main outcomes. Between-group differences were non-significant in proportions of patients with a clinically important reduction of night pain (Relative Risk: 0.98; 95% Confidence Interval (CI): 0.86-1.11) or evening pain (Relative Risk: 0.94; 95% CI: 0.81-1.0. Conclusions Our results do not support the addition of acupuncture to routine rehabilitation. Previous benefit from acupuncture was not able to identify those likely to respond to acupuncture. Future studies to investigate whether subgroups of patients would benefit from acupuncture are needed.

Hot forging is an effective production method producing safety relevant parts with excellent mechanical properties. The economic efficiency directly depends on the occurring wear of the tools, which limits service lifetime. Several approaches of the presenting research group aim at minimizing the wear caused by interacting mechanical and thermal loads by using enhanced nitriding technology. Thus, by modifying the surface zone layer it is possible to create a resistance against thermal softening provoking plastic deformation and pronounced abrasive wear. As a disadvantage, intensely nitrided surfaces may possibly include the risk of increased crack sensitivity and therefore feature the chipping of material at the treated surface. Recent projects (evaluated in several industrial applications) show the high technological potential of adapted treatments: A first approach evaluated localized treatments by preventing areas from nitrogen diffusion with applied pastes or other coverages. Now, further ideas are to use this principle to structure the surface with differently designed patterns generating smaller ductile zones beneath nitrided ones. The selection of suitable designs is subject to certain geo-metrical requirements though. The intention of this approach is to prevent the formation and propagation of cracks under thermal shock conditions. Analytical characterization methods for crack sensitivity of surface zone layers and an accurate system of testing rigs for thermal shock conditions verified the treatment concepts. Additionally, serial forging tests using adapted testing geometries and finally, tests in the industrial production field were performed. Besides stabilizing the service lifetime and decreasing specific wear mechanisms caused by thermal influences, the crack behavior was influenced positively. This leads to a higher efficiency of the industrial production process and enables higher output in forging campaigns of industrial partners.

Background Clinical examination findings are used in primary care to give an initial diagnosis to patients with low back pain and related leg symptoms. The purpose of this study was to develop best evidence Clinical Diagnostic Rules (CDR] for the identification of the most common patho-anatomical disorders in the lumbar spine; i.e. intervertebral discs, sacroiliac joints, facet joints, bone, muscles, nerve roots, muscles, peripheral nerve tissue, and central nervous system sensitization. Methods A sensitive electronic search strategy using MEDLINE, EMBASE and CINAHL databases was combined with hand searching and citation tracking to identify eligible studies. Criteria for inclusion were: persons with low back pain with or without related leg symptoms, history or physical examination findings suitable for use in primary care, comparison with acceptable reference standards, and statistical reporting permitting calculation of diagnostic value. Quality assessments were made independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies tool. Clinical examination findings that were investigated by at least two studies were included and results that met our predefined threshold of positive likelihood ratio ≥ 2 or negative likelihood ratio ≤ 0.5 were considered for the CDR. Results Sixty-four studies satisfied our eligible criteria. We were able to construct promising CDRs for symptomatic intervertebral disc, sacroiliac joint, spondylolisthesis, disc herniation with nerve root involvement, and spinal stenosis. Single clinical test appear not to be as useful as clusters of tests that are more closely in line with clinical decision making. Conclusions This is the first comprehensive systematic review of diagnostic accuracy studies that evaluate clinical examination findings for their ability to identify the most common patho-anatomical disorders in the lumbar spine. In some diagnostic categories we have sufficient evidence to recommend a CDR. In others, we have only preliminary evidence that needs testing in future studies. Most findings were tested in secondary or tertiary care. Thus, the accuracy of the findings in a primary care setting has yet to be confirmed. Electronic supplementary material The online version of this article (doi:10.1186/s12891-017-1549-6) contains supplementary material, which is available to authorized users.

Die europäische Wasserrahmenrichtlinie fordert von den EU-Mitgliedstaaten, für einen guten Gewässerzustand zu garantieren. Allerdings stoßen die Staaten bei der Umsetzung an die Grenzen ihrer souveränen Durchsetzungsmacht, weil sie unter anderem auf die freiwillige Kooperation nichtstaatlicher Akteure angewiesen sind.

Study design A report on plenary presentations and discussions of an expert panel and workshop ("Exercise as a treatment for subacute low back pain") that was held at the Amsterdam Forum VIII on Low Back Pain Research in Primary Care. Objective To highlight important issues regarding the design, conduct, and reporting of exercise trials and to provide suggestions for improvement in each domain. Summary of background data Despite improvements in the methodologic quality of randomized clinical trials on low back pain (LBP), current trials on exercise therapy still show methodologic flaws in the design and reporting of studies. Methods Important issues in the design, conduct, and reporting of exercise trials for LBP were introduced by 4 presenters, and this was followed by a group discussion among 40 attendees. Conclusions and recommendations were extracted by the workshop panelists and summarized in this paper. RESULTS.: Workshop discussion led to the following recommendations: (1) specify a theoretical framework for exercise therapy for designing the intervention and selecting appropriate treatment efficacy measures; (2) to overcome blinding problems in exercise trials, include sham interventions and assess the success of blinding; (3) evaluate the role of patient-provider interactions through the use of self-report or observational measures; (4) to assure quality of treatment, use exercise interventions that reference existing exercise guidelines; (5) use subgroup analyses to identify subgroups of patients most likely to benefit; (6) in reporting exercise trials, include an extensive description of the study population, a detailed exercise protocol, and some measure of patient compliance; (7) further categorization of exercise interventions is needed, in terms of concept, mode, intensity, duration, frequency, and length; and (8) trial;1>registration and publication of detailed study protocols may help to strengthen the evidence-based concerning exercise therapy for LBP. Conclusion By paying proper attention to issues concerning the design and reporting of exercise protocols when conducting future exercise trials, research may provide a stronger evidence basis for recommending or not recommending various exercise therapies for LBP.

Background Reports vary considerably concerning characteristics of patients who will respond to mobilizing exercises or manipulation. The objective of this prospective cohort study was to identify characteristics of patients with a changeable lumbar condition, i.e. presenting with centralization or peripheralization, that were likely to benefit the most from either the McKenzie method or spinal manipulation. Methods 350 patients with chronic low back pain were randomized to either the McKenzie method or manipulation. The possible effect modifiers were age, severity of leg pain, pain-distribution, nerve root involvement, duration of symptoms, and centralization of symptoms. The primary outcome was the number of patients reporting success at two months follow-up. The values of the dichotomized predictors were tested according to the prespecified analysis plan. Results No predictors were found to produce a statistically significant interaction effect. The McKenzie method was superior to manipulation across all subgroups, thus the probability of success was consistently in favor of this treatment independent of predictor observed. When the two strongest predictors, nerve root involvement and peripheralization, were combined, the chance of success was relative risk 10.5 (95% CI 0.71-155.43) for the McKenzie method and 1.23 (95% CI 1.03-1.46) for manipulation (P = 0.11 for interaction effect). Conclusions We did not find any baseline variables which were statistically significant effect modifiers in predicting different response to either McKenzie treatment or spinal manipulation when compared to each other. However, we did identify nerve root involvement and peripheralization to produce differences in response to McKenzie treatment compared to manipulation that appear to be clinically important. These findings need testing in larger studies. Trial registration Clinicaltrials.gov: NCT00939107 Electronic supplementary material The online version of this article (doi:10.1186/s12891-015-0526-1) contains supplementary material, which is available to authorized users.

The reliability and vulnerability of critical infrastructures have attracted a lot of attention recently. In order to assess these issues quantitatively, operational measures are needed. Such measures can also be used as guidance to road administrations in their prioritisation of maintenance and repair of roads, as well as for avoiding causing unnecessary disturbances in the planning of roadwork. The concepts of link importance and site exposure are introduced. In this paper, several link importance indices and site exposure indices are derived, based on the increase in generalised travel cost when links are closed. These measures are divided into two groups: one reflecting an “equal opportunities perspective”, and the other a “social efficiency perspective”. The measures are calculated for the road network of northern Sweden. Results are collected in a GIS for visualisation, and are presented per link and municipality. In view of the recent great interest in complex networks, some topological measures of the road network are also presented.