Konzepte und Guidelines für Applikationen in Cinematic Virtual Reality

Die meisten Menschen, die zum ersten Mal einen omnidirektionalen Film über ein Head-Mounted Display (HMD) sehen, sind fasziniert von der neuen Erlebniswelt. Das Gefühl, an einem anderen Ort zu sein, weit weg von der Realität, beeindruckt und lässt sie in eine andere Welt eintauchen. Die über Jahrzehnte entwickelte Filmsprache lässt sich nicht ohne Weiteres auf dieses neue Medium - Cinematic Virtual Reality (CVR) - übertragen. Der Betrachter kann die Blickrichtung und damit den sichtbaren Ausschnitt des Bildes frei wählen, und es ist deshalb nicht immer möglich, dem Zuschauer zu zeigen, was für die Geschichte wichtig ist. Herkömmliche Methoden für die Lenkung der Aufmerksamkeit - wie Nahaufnahmen oder Zooms - sind nicht ohne Weiteres verwendbar, andere – wie Bewegung und Farben – benötigen eine Evaluation und Anpassung. Um neue Konzepte und Methoden für CVR zu finden, sind neben den Forschungsergebnissen aus dem Filmbereich auch die anderer Forschungsgebiete, wie Virtual und Augmented Reality (VR und AR), relevant. Um geeignete Techniken der Aufmerksamkeitslenkung in CVR zu ergründen, werden in dieser Arbeit bekannte Methoden aus Film, VR und AR analysiert und eine einheitliche Taxonomie präsentiert. Dadurch ist es möglich, die verschiedenen Aspekte detaillierter zu untersuchen. Auch die Positionierung der Kamera kann nicht ohne Weiteres vom traditionellen Film auf CVR übertragen werden. Der Zuschauer nimmt bei der Betrachtung einer CVR-Anwendung in der virtuellen Welt die Position der Kamera ein. Dies kann zu Problemen führen, wenn die Kamerahöhe nicht seiner eigenen Körpergröße entspricht. Außerdem ist eine Auflösung einer Szene durch verschiedene Einstellungsgrößen nicht ohne Weiteres möglich, da dies für den Zuschauer ein Umherspringen in der virtuellen Welt bedeuten würde. In dieser Arbeit werden die Auswirkungen verschiedener Kamerapositionen auf den Zuschauer untersucht und Guidelines zur Kamerapositionierung vorgestellt. Die dazugewonnene Raumkomponente bietet neue Möglichkeiten. Schnitte müssen nicht unbedingt von der verstrichenen Zeit abhängen, sondern können auch auf der Blickrichtung des Betrachters basieren. In Übereinstimmung mit dem Begriff Timeline führen wir das Konzept der Spaceline für diese Methode der Story-Konstruktion ein. Während die Schnitte auf der Timeline vom Filmemacher festgelegt werden, bestimmt der Betrachter die Spaceline - innerhalb eines vom Filmemacher festgelegten Konstrukts. Durch diese individuelle Zuschauerführung ist es möglich, dass jeder seine eigene Geschichte in seinem eigenen Tempo und mit seinen eigenen Prioritäten entdeckt. Das Spaceline-Konzept bietet neue Interaktionsmöglichkeiten, die durch verschiedene Selektionstechniken umgesetzt werden können. Um Techniken zu finden, die für CVR geeignet sind, werden in dieser Arbeit blick- und kopfbasierte Ansätze untersucht. Auch wenn deren Wirksamkeit stark von den gewählten Parametern und physiologischen Faktoren abhängen, konnten wertvolle Erkenntnisse gewonnen werden, die in einen Design-Space für CVR-Konstrukte einfließen. Dieser Design-Space ermöglicht es beim Entwerfen einer CVR-Anwendung, die Attribute zu finden, die für die Anwendung am besten geeignet sind. Aber nicht nur die Entwicklung von CVR-Anwendungen stellt neue Herausforderungen. Durch das HMD ist ein Zuschauer von der restlichen Welt isoliert, und es bedarf neuer Methoden, um CVR als soziale Erfahrung erlebbar zu machen. Einige davon werden in dieser Arbeit vorgestellt und analysiert. Aus den gewonnenen Erfahrungen werden Empfehlungen für einen CVR-Movie-Player abgeleitet. Um die vorgestellten Konzepte und Guidelines zu entwickeln, wurden eine Reihe von Nutzerstudien durchgeführt, zum Teil mit Aufzeichnung der Kopf- und Blickrichtungen. Um diese Daten analysieren zu können, wurde ein Tool entwickelt, welches die Visualisierung der Daten auf dem Film ermöglicht. In dieser Arbeit werden Konzepte und Guidelines für verschiedene Felder in Cinematic Virtual Reality vorgestellt: Aufmerksamkeitslenkung, Kamerapositionierung, Montage, Zuschauererlebnis und Datenanalyse. Auf jedem dieser Gebiete konnten Erkenntnisse gewonnen werden, die auch für die andere Bereiche von Interesse sind. Oft hängen die Ergebnisse der einzelnen Fachgebiete zusammen und ergänzen sich gegenseitig. Ziel der Arbeit ist es, die verschiedenen Aspekte als Ganzes zu präsentieren.Most people who watch an omnidirectional film for the first time on a head-mounted display (HMD) are fascinated by the new world of experience. The feeling of being in a different place, right in the middle of the action, far from reality, impresses and gives the opportunity to immerse in another world. The film language developed over decades cannot simply be transferred to this new media, Cinematic Virtual Reality (CVR). The viewer can freely choose the direction of view and thus the visible section of the picture and it is therefore not always possible to show the viewer what is important for the story. Traditional methods for directing attention - such as close-ups or zooms - are not easy to use, others - such as movement and colors - needs to be assessed and adjusted. For finding new concepts and methods for CVR, in addition to the research results from the film area, other areas in the field of virtual and augmented reality (VR and AR) are relevant. In order to find suitable methods to draw attention in CVR, known methods from film, VR, and AR are analyzed in this work and a uniform taxonomy is presented. This makes it possible to investigate the various aspects of the methods in more detail. The positioning of the camera cannot simply be transferred from traditional film to CVR. When viewing a CVR application in the virtual world, the viewer takes the place of the camera in the real world. This can lead to problems if the camera height does not match the viewer’s height. In addition, a resolution of a scene due different setting sizes is not possible as this would mean that the viewer would jump around in the virtual world. In this work, the effects of different camera positions on the viewer are examined and guidelines for camera positioning are presented. The additional space component offers new possibilities. Cuts do not necessarily have to depend on the elapsed time, but can also be based on the viewer's gaze. In accordance with the term timeline, we introduce the concept of the spaceline for this method of story plot construction. While the cuts on the timeline are determined by the filmmaker, the viewer determines the spaceline - within a construct determined by the filmmaker. Through this individual guided tour, everyone can discover their own story at their own pace and with their own priorities. The spaceline concept offers new interaction options that can be implemented using various selection techniques. In order to find methods that are suitable for CVR, this work examines eye and head-based techniques. Even if the effectiveness of them strongly depends on the chosen parameters and physiological factors, valuable insights are gained, which are included in a design space for spaceline constructs. This design space allows one to find the attributes that best suits for the application when designing a CVR application. But not only the creation of CVR applications presents new challenges. The HMD isolates a viewer from the rest of the world and requires new techniques to experience CVR in a social way. Some of these are presented and analyzed in this work. Recommendations for a CVR movie player are derived from the experience gained. Several user studies were conducted to develop the concepts and guidelines, some of them by recording of the head and gaze directions. To be able to analyze this data, a tool was developed which enables us to visualize the data on the film. In this work, concepts and guidelines for various fields in Cinematic Virtual Reality are presented: attention guiding, camera positioning, montage, audience experience, and data analysis. In each of these areas, knowledge was gained that is also of interest to the other fields. The findings of the individual fields are often related and complement each other. This work aims to present the various aspects as a whole

Konzepte und Guidelines für Applikationen in Cinematic Virtual Reality

Die meisten Menschen, die zum ersten Mal einen omnidirektionalen Film über ein Head-Mounted Display (HMD) sehen, sind fasziniert von der neuen Erlebniswelt. Das Gefühl, an einem anderen Ort zu sein, weit weg von der Realität, beeindruckt und lässt sie in eine andere Welt eintauchen. Die über Jahrzehnte entwickelte Filmsprache lässt sich nicht ohne Weiteres auf dieses neue Medium - Cinematic Virtual Reality (CVR) - übertragen. Der Betrachter kann die Blickrichtung und damit den sichtbaren Ausschnitt des Bildes frei wählen, und es ist deshalb nicht immer möglich, dem Zuschauer zu zeigen, was für die Geschichte wichtig ist. Herkömmliche Methoden für die Lenkung der Aufmerksamkeit - wie Nahaufnahmen oder Zooms - sind nicht ohne Weiteres verwendbar, andere – wie Bewegung und Farben – benötigen eine Evaluation und Anpassung. Um neue Konzepte und Methoden für CVR zu finden, sind neben den Forschungsergebnissen aus dem Filmbereich auch die anderer Forschungsgebiete, wie Virtual und Augmented Reality (VR und AR), relevant. Um geeignete Techniken der Aufmerksamkeitslenkung in CVR zu ergründen, werden in dieser Arbeit bekannte Methoden aus Film, VR und AR analysiert und eine einheitliche Taxonomie präsentiert. Dadurch ist es möglich, die verschiedenen Aspekte detaillierter zu untersuchen. Auch die Positionierung der Kamera kann nicht ohne Weiteres vom traditionellen Film auf CVR übertragen werden. Der Zuschauer nimmt bei der Betrachtung einer CVR-Anwendung in der virtuellen Welt die Position der Kamera ein. Dies kann zu Problemen führen, wenn die Kamerahöhe nicht seiner eigenen Körpergröße entspricht. Außerdem ist eine Auflösung einer Szene durch verschiedene Einstellungsgrößen nicht ohne Weiteres möglich, da dies für den Zuschauer ein Umherspringen in der virtuellen Welt bedeuten würde. In dieser Arbeit werden die Auswirkungen verschiedener Kamerapositionen auf den Zuschauer untersucht und Guidelines zur Kamerapositionierung vorgestellt. Die dazugewonnene Raumkomponente bietet neue Möglichkeiten. Schnitte müssen nicht unbedingt von der verstrichenen Zeit abhängen, sondern können auch auf der Blickrichtung des Betrachters basieren. In Übereinstimmung mit dem Begriff Timeline führen wir das Konzept der Spaceline für diese Methode der Story-Konstruktion ein. Während die Schnitte auf der Timeline vom Filmemacher festgelegt werden, bestimmt der Betrachter die Spaceline - innerhalb eines vom Filmemacher festgelegten Konstrukts. Durch diese individuelle Zuschauerführung ist es möglich, dass jeder seine eigene Geschichte in seinem eigenen Tempo und mit seinen eigenen Prioritäten entdeckt. Das Spaceline-Konzept bietet neue Interaktionsmöglichkeiten, die durch verschiedene Selektionstechniken umgesetzt werden können. Um Techniken zu finden, die für CVR geeignet sind, werden in dieser Arbeit blick- und kopfbasierte Ansätze untersucht. Auch wenn deren Wirksamkeit stark von den gewählten Parametern und physiologischen Faktoren abhängen, konnten wertvolle Erkenntnisse gewonnen werden, die in einen Design-Space für CVR-Konstrukte einfließen. Dieser Design-Space ermöglicht es beim Entwerfen einer CVR-Anwendung, die Attribute zu finden, die für die Anwendung am besten geeignet sind. Aber nicht nur die Entwicklung von CVR-Anwendungen stellt neue Herausforderungen. Durch das HMD ist ein Zuschauer von der restlichen Welt isoliert, und es bedarf neuer Methoden, um CVR als soziale Erfahrung erlebbar zu machen. Einige davon werden in dieser Arbeit vorgestellt und analysiert. Aus den gewonnenen Erfahrungen werden Empfehlungen für einen CVR-Movie-Player abgeleitet. Um die vorgestellten Konzepte und Guidelines zu entwickeln, wurden eine Reihe von Nutzerstudien durchgeführt, zum Teil mit Aufzeichnung der Kopf- und Blickrichtungen. Um diese Daten analysieren zu können, wurde ein Tool entwickelt, welches die Visualisierung der Daten auf dem Film ermöglicht. In dieser Arbeit werden Konzepte und Guidelines für verschiedene Felder in Cinematic Virtual Reality vorgestellt: Aufmerksamkeitslenkung, Kamerapositionierung, Montage, Zuschauererlebnis und Datenanalyse. Auf jedem dieser Gebiete konnten Erkenntnisse gewonnen werden, die auch für die andere Bereiche von Interesse sind. Oft hängen die Ergebnisse der einzelnen Fachgebiete zusammen und ergänzen sich gegenseitig. Ziel der Arbeit ist es, die verschiedenen Aspekte als Ganzes zu präsentieren.Most people who watch an omnidirectional film for the first time on a head-mounted display (HMD) are fascinated by the new world of experience. The feeling of being in a different place, right in the middle of the action, far from reality, impresses and gives the opportunity to immerse in another world. The film language developed over decades cannot simply be transferred to this new media, Cinematic Virtual Reality (CVR). The viewer can freely choose the direction of view and thus the visible section of the picture and it is therefore not always possible to show the viewer what is important for the story. Traditional methods for directing attention - such as close-ups or zooms - are not easy to use, others - such as movement and colors - needs to be assessed and adjusted. For finding new concepts and methods for CVR, in addition to the research results from the film area, other areas in the field of virtual and augmented reality (VR and AR) are relevant. In order to find suitable methods to draw attention in CVR, known methods from film, VR, and AR are analyzed in this work and a uniform taxonomy is presented. This makes it possible to investigate the various aspects of the methods in more detail. The positioning of the camera cannot simply be transferred from traditional film to CVR. When viewing a CVR application in the virtual world, the viewer takes the place of the camera in the real world. This can lead to problems if the camera height does not match the viewer’s height. In addition, a resolution of a scene due different setting sizes is not possible as this would mean that the viewer would jump around in the virtual world. In this work, the effects of different camera positions on the viewer are examined and guidelines for camera positioning are presented. The additional space component offers new possibilities. Cuts do not necessarily have to depend on the elapsed time, but can also be based on the viewer's gaze. In accordance with the term timeline, we introduce the concept of the spaceline for this method of story plot construction. While the cuts on the timeline are determined by the filmmaker, the viewer determines the spaceline - within a construct determined by the filmmaker. Through this individual guided tour, everyone can discover their own story at their own pace and with their own priorities. The spaceline concept offers new interaction options that can be implemented using various selection techniques. In order to find methods that are suitable for CVR, this work examines eye and head-based techniques. Even if the effectiveness of them strongly depends on the chosen parameters and physiological factors, valuable insights are gained, which are included in a design space for spaceline constructs. This design space allows one to find the attributes that best suits for the application when designing a CVR application. But not only the creation of CVR applications presents new challenges. The HMD isolates a viewer from the rest of the world and requires new techniques to experience CVR in a social way. Some of these are presented and analyzed in this work. Recommendations for a CVR movie player are derived from the experience gained. Several user studies were conducted to develop the concepts and guidelines, some of them by recording of the head and gaze directions. To be able to analyze this data, a tool was developed which enables us to visualize the data on the film. In this work, concepts and guidelines for various fields in Cinematic Virtual Reality are presented: attention guiding, camera positioning, montage, audience experience, and data analysis. In each of these areas, knowledge was gained that is also of interest to the other fields. The findings of the individual fields are often related and complement each other. This work aims to present the various aspects as a whole

Are homeopathics able to replace antibiotics in the therapy of bovine mastitis? A placebo controlled randomized double-blind trial

To evaluate the effects of homeopathics on clinical mastitis cows and herd udder health this investigation was conducted in a Brandenburg bio-dyn herd of about 300 cows in two phases using a randomized doubleblind control trial design. After the first part in July 2002 the results preliminarily were evaluated and then the whole concept due to unsatisfying results was adapted. In Phase 1 a number of 121 clinical mastitis cases with 137 affected quarters matched the including criteria, in Phase 2 the number was 126 cows with 148 quarters. These animals were allocated to a code number which classified the case to Verum (n=65 and n=60) or placebo group (n=56 and n=66). In case of clinical mastitis cows were treated either by the oral dilution contending the required combined homeopathics or placebo. Animals were treated twice a day for 5 to 14 days (Phase 2: 1 to 7 days) depending on development of disease. In case of therapy failure in Phase 1 all animals were treated by an not coded homeopathic preparation and in Phase 2 by antibiotics according to bacteriological findings. Milk samples (double samples) for bacteriological and cell count investigation were taken before treatment (M1), 4 to 5 weeks after treatment termination (M2) and 7 to 8 weeks after treatment termination (M3). To evaluate the herd situation additional samples were taken after calving and before dry off. Healing criteria on the cow level was the clinical cure without secondary therapy and release to production. On quarter level the cure was determined by bacterial findings (BCR) and additional by cytological findings. A quarter was determined as „completely cured“, if no bacteria were found AND the cell count was below 100.000/ml. To assess the reduction of antibiotics within the concept it was hypothetically assumed that the mastitis cows had an average milk yield of 20,5 kg per day, was treated under conventional conditions by antibiotics over 3 days with a mean withdrawal time of 5 days (organic conditions x2). Afterwards, these theoretical values were compared to the extrapolated antibiotics input within our concept. Results While there is no difference between the cows in phase 1, on quarter level the verum group showed a significant higher complete cure rate than placebo group in Phase 2. These results are balanced by additional antibiotics treatment in case of therapy failure in the placebo group. The complete cure rate in the verum group after 8 weeks was 32% compared to 13% in placebo group (p<0.05). The limited cure results in single cows did not lead to an udder health depression of the herd. During the study the mean of somatic cell count could decreased by 100.000 cells/ml while the milk yield increased slightly by 250 kg/cow to 6.500 kg/cow/year. The number of actual antibiotic treatments during observation time compared to the number of mastitis cases which would be treated by antibiotics under conventionel conditions showed a reduction by 75%. The extrapolated reduction of milk loss by withdrawal was 25.000kg and the reduction of contaminated milk during treatment time was 13.100 kg per year for the herd. Discussion and Conclusions The increasing cure rates in the second part of the study are influenced by the enhancement of environmental preconditions in combination with the simplified therapy scheme. The therapists seemed to be more familiar with the fixed combinations of homeopathics so that positive effects of the homeopathics can be seen in this phase. After additional antibiotic treatments in case of therapy failure in specific infections (i.e. streptococci and staph. aureus) the cure rates could be elevated to a satisfying level. This fact shows that the limited and controlled use of antibiotics in organic herds can be helpful in the mastitis control. Regardless the conceptual modification to an antibiotic emergency concept, the massive reduction of antibiotics in combination with an increase of herd udder health justifies the therapy protocol in the second phase of the study. Hypothetically, the self cure of the animals is higher than known. The interaction between farmer or therapist and the cow could be a crucial criterion for the positive development of disease. As a conclusion, the integrated system consisting of preventive herd measures and complementary therapy added by limited antibiotic therapy. The precondition for the success is the attendance to optimize environmental conditions. The therapy system should be transparent, simple and easy to use. However, it is necessary to reflect every single mastitis case as a special one

When the Elephant Trumps": A Comparative Study on Spatial Audio for Orientation in 360◦ Videos

Orientation is an emerging issue in cinematic Virtual Reality (VR), as viewers may fail in locating points of interest. Recent strategies to tackle this research problem have investigated the role of cues, specifically diegetic sound effects. In this paper, we examine the use of sound spatialization for orien tation purposes, namely by studying different spatialization conditions ("none", "partial", and "full" spatial manipulation) of multitrack soundtracks. We performed a between-subject mixed-methods study with 36 participants, aided by Cue Control, a tool we developed for dynamic spatial sound edit ing and data collection/analysis. Based on existing literature on orientation cues in 360◦ and theories on human listening, we discuss situations in which the spatialization was more ef fective (namely, "full" spatial manipulation both when using only music and when combining music and diegetic effects), and how this can be used by creators of 360◦ videos.info:eu-repo/semantics/publishedVersio

Ongoing strategies to improve the management of upper respiratory tract infections and reduce inappropriate antibiotic use particularly among lower and middle-income countries: findings and implications for the future

Introduction: Antibiotics are indispensable to maintaining human health; however, their overuse has resulted in resistant organisms, increasing morbidity, mortality and costs. Increasing antimicrobial resistance (AMR) is a major public health threat, resulting in multiple campaigns across countries to improve appropriate antimicrobial use. This includes addressing the overuse of antimicrobials for self-limiting infections, such as upper respiratory tract infections (URTIs), particularly in lower- and middle-income countries (LMICs) where there is the greatest inappropriate use and where antibiotic utilization has increased the most in recent years. Consequently, there is a need to document current practices and successful initiatives in LMICs to improve future antimicrobial use. Methodology: Documentation of current epidemiology and management of URTIs, particularly in LMICs, as well as campaigns to improve future antimicrobial use and their influence where known. Results: Much concern remains regarding the prescribing and dispensing of antibiotics for URTIs among LMICs. This includes considerable self-purchasing, up to 100% of pharmacies in some LMICs. However, multiple activities are now ongoing to improve future use. These incorporate educational initiatives among all key stakeholder groups, as well as legislation and other activities to reduce self-purchasing as part of National Action Plans (NAPs). Further activities are still needed however. These include increased physician and pharmacist education, starting in medical and pharmacy schools; greater monitoring of prescribing and dispensing practices, including the development of pertinent quality indicators; and targeted patient information and health education campaigns. It is recognized that such activities are more challenging in LMICs given more limited resources and a lack of healthcare professionals. Conclusion: Initiatives will grow across LMICs to reduce inappropriate prescribing and dispensing of antimicrobials for URTIs as part of NAPs and other activities, and these will be monitored

Guidance in Cinematic Virtual Reality-Taxonomy, Research Status and Challenges

In Cinematic Virtual Reality (CVR), the viewer of an omnidirectional movie can freely choose the viewing direction when watching a movie. Therefore, traditional techniques in filmmaking for guiding the viewers&rsquo; attention cannot be adapted directly to CVR. Practices such as panning or changing the frame are no longer defined by the filmmaker; rather it is the viewer who decides where to look. In some stories, it is necessary to show certain details to the viewer, which should not be missed. At the same time, the freedom of the viewer to look around in the scene should not be destroyed. Therefore, techniques are needed which guide the attention of the spectator to visual information in the scene. Attention guiding also has the potential to improve the general viewing experience, since viewers will be less afraid to miss something when watching an omnidirectional movie where attention-guiding techniques have been applied. In recent years, there has been a lot of research about attention guiding in images, movies, virtual reality, augmented reality and also in CVR. We classify these methods and offer a taxonomy for attention-guiding methods. Discussing the different characteristics, we elaborate the advantages and disadvantages, give recommendations for use cases and apply the taxonomy to several examples of guiding methods

GazeRecall: Using Gaze Direction to Increase Recall of Details in 360circ Videos

In this work, we show how the use of flickering in Cinematic Virtual Reality (CVR) content can not only guide the user's attention, but also significantly improve recall of details. The findings are particularly useful for practitioners who generate educational and corporate training content, as well as for directors of CVR videos who want to draw the user's attention to certain details in movies or virtual tours. We report on a between-subjects user study, in which we experimented with flickering methods to increase user's recall of certain details in CVR videos. Participants had to report details of objects on which the method was applied. In our experiments, the intensive flicker improved the recall of details significantly. We discuss how the studied methods can improve recall of details in different use cases

Chironomid larvae enhance phosphorus burial in lake sediments: Insights from long-term and short-term experiments

Tube-dwelling macrozoobenthos can affect lake ecosystems in myriad ways, including changes in nutrient fluxes across the sediment-water interface. The pumping activity of chironomid larvae reinforces the transport of solutes between sediment and water. The transport of oxygen into the area surrounding the burrows generates oxidized compounds such as iron(oxy)hydroxides, which results in an additional phosphorus (P) sorption capacity similar to that of oxidized sediment surfaces. In the present study, the effect of the oxidized burrow walls of Chironomus plumosus on P binding capacity and P binding forms was tested in the laboratory using sediments with differing iron contents and varying numbers of chironomid larvae. In an additional long-term experiment, lake sediment naturally rich in iron was incubated under oxic conditions for 165 days, followed by a 3.5-year anoxic period. These experiments showed that: (1) Under oxic conditions the cumulative P uptake by sediments was dependent on larval densities. (2) The P that accumulated both at the sediment-water interface and in the oxidized burrow walls was mainly present as reductive soluble P (iron-bound P). Surprisingly, the amount of P released during the anoxic period in the long-term experiment was independent of the amount of P previously taken up during the oxic period since a portion of P was permanently retained in the sediment. The increase in alkaline soluble metal-bound P (NaOH-SRP) in formerly colonized sediments is a strong indication that the excessive P fixation by reductive soluble iron triggers the subsequent formation of stable iron phosphate minerals such as vivianite. Our study shows that P fixation that is induced by chironomid larvae is not always a completely reversible phenomenon, even after the emergence of the larvae and the re-establishment of anoxic conditions in the sediment

Frequency of a positive family history of colorectal cancer in general practice: a cross-sectional study

Evidence on the frequency of a positive family history of colorectal cancer (CRC) among individuals aged &lt;55 years is lacking. General practice setting might be well suited for the identification of individuals in this above-average risk group.; To determine the frequency of a reported positive family history of CRC among patients aged 40 to 54 years in a general practice setting.; We conducted a cross-sectional study in 21 general practices in Germany. Patients aged 40 to 54 years were identified by means of the practice software and interviewed by health care assistants using a standardized four-item questionnaire. Outcome was occurrence of a positive family history of CRC, defined as at least one first-degree relative (FDR: parents, siblings, or children) with CRC. Further measurements were FDRs with CRC / colorectal polyps (adenomas) diagnosed before the age of 50 and occurrence of three or more relatives with colorectal, stomach, cervical, ovarian, urethel or renal pelvic cancer.; Out of 6723 participants, 7.2% (95% confidence interval [CI] 6.6% to 7.8%) reported at least one FDR with CRC and 1.2% (95% CI 0.9% to 1.5%) reported FDRs with CRC diagnosed before the age of 50. A further 2.6% (95% CI 2.3% to 3.0%) reported colorectal polyps in FDRs diagnosed before the age of 50 and 2.1% (95% CI 1.8% to 2.5%) reported three or more relatives with entities mentioned above.; One in 14 patients reported at least one FDR with CRC. General practice should be considered when defining requirements of risk-adapted CRC screening