Recursive imaging with multiply scattered waves using partial image regularization: A North Sea case study

As more resources are directed toward reverse time migration, an accurate velocity model, including strong reflectors, is necessary to form a clear image of the subsurface. This is of particular importance in the vicinity of salt, where singly scattered waves are often not ideal for imaging the salt flanks. This has led to interest in processing doubly scattered waves (also called duplex or prismatic waves) for imaging salt flanks and thus improving the location of salt boundaries in a velocity model. We used doubly scattered waves in a two-pass, one-way method to image salt flanks in a North Sea data set. By working in the one-way framework we were able to separately construct images with singly, doubly, and triply scattered waves. We used a multistep imaging process that includes multiply scattered waves by using an imaged reflector to fix one (or more) of the scattering points, allowing for multiply scattered energy from several reflectors, potentially with poor continuity, to be included without picking each reflector individually. With this method we were able to image the flank of a North Sea salt body

The Responsibility of Farmers, Public Authorities and Consumers for Safeguarding Bees Against Harmful Pesticides

The worldwide decline in bees and other pollinating insects is a threat to biodiversity and food security, and urgent action must be taken to stop and then reverse this decline. An established cause of the insect decline is the use of harmful pesticides in agriculture. This case study focuses on the use of pesticides in Norwegian apple production and considers who among farmers, consumers and public authorities is most responsible for protecting bees against harmful pesticides. The extent to which these three different groups consider themselves responsible and the degree to which they are trusted by each of the other groups are also studied. This empirical study involves both qualitative interviews with Norwegian apple farmers, consumers and public authorities and survey data from consumers and farmers. The results show that consumers consider public authorities and farmers equally responsible for protecting bees, while farmers are inclined to consider themselves more responsible. Farmers, consumers and public authorities do not consider consumers significantly responsible for protecting bees, and consumers have a high level of trust in both farmers and public authorities regarding this matter. This study also finds that a low level of consumer trust in farmers or public authorities increases consumers’ propensity to purchase organic food, suggesting that those who do not trust that enough action is adopted to protect the environment take on more individual responsibility. This paper adds to the existing literature concerning the allocation of responsibility for environmental outcomes, with empirical evidence focusing specifically on pesticides and bees.The Responsibility of Farmers, Public Authorities and Consumers for Safeguarding Bees Against Harmful PesticidespublishedVersio

Seismic Imaging and Illumination with Internal Multiples

If singly scattered seismic waves illuminate the entirety of a subsurface structure of interest, standard methods can be applied to image it. It is generally the case, however, that with a combination of restricted acquisition geometry and imperfect velocity models, it is not possible to illuminate all structures with only singly scattered waves. We present an approach to use multiply scattered waves to illuminate structures not sensed by singly scattered waves. It can be viewed as a refinement of past work in which a method to predict artifacts in imaging with multiply scattered waves was developed. We propose an algorithm and carry out numerical experiments, representative of imaging of the bottom and flanks of salt, demonstrating the effectiveness of our approach.Dutch National Science Foundation (grant number NWO:VIVI865.03.007)StatoilHydroNorwegian Research Council (ROSE project)Geo-Mathematical Imaging Grou

Breast cancer mortality in participants of the Norwegian Breast Cancer Screening Program

BACKGROUND The Norwegian Breast Cancer Screening Program started in 1996. To the authors' knowledge, this is the first report using individual-based data on invitation and participation to analyze breast cancer mortality among screened and nonscreened women in the program. METHODS Information on dates of invitation, attendance, breast cancer diagnosis, emigration, death, and cause of death was linked by using unique 11-digit personal identification numbers assigned all inhabitants of Norway at birth or immigration. In total, 699,628 women ages 50 to 69 years without prior a diagnosis of breast cancer were invited to the program from 1996 to 2009 and were followed for breast cancer through 2009 and death through 2010. Incidence-based breast cancer mortality rate ratios (MRRs) were compared between the screened and nonscreened cohorts using a Poisson regression model. The MRRs were adjusted for calendar period, attained age, years since inclusion in the cohorts, and self-selection bias. RESULTS The crude breast cancer mortality rate was 20.7 per 100,000 women-years for the screened cohort compared with 39.7 per 100,000 women-years for the nonscreened cohort, resulting in an MRR of 0.52 (95% confidence interval, 0.47-0.59). The mortality reduction associated with attendance in the program was 43% (MRR, 0.57; 95% confidence interval, 0.51-0.64) after adjusting for calendar period, attained age, years after inclusion in the cohort, and self-selection bias. CONCLUSIONS After 15 years of follow-up, a 43% reduction in mortality was observed among women who attended the national mammographic screening program in Norway

Increased Health Risk in Subjects with High Self-Reported Seasonality

Background: Seasonal variations in mood and behaviour, termed seasonality, are commonly reported in the general population. As a part of a large cross-sectional health survey in Hordaland, Norway, we investigated the relationship between seasonality, objective health measurements and health behaviours. Methodology/Principal Findings: A total of 11,545 subjects between 40–44 years old participated, completing the Global Seasonality Score, measuring seasonality. Waist/hip circumference, BMI and blood pressure were measured, and blood samples were analyzed for total cholesterol, HDL cholesterol, triglycerides and glucose. Subjects also completed a questionnaire on miscellaneous health behaviours (exercise, smoking, alcohol consumption). Hierarchical linear regression analyses were used to investigate associations between seasonality and objective health measurements, while binary logistic regression was used for analysing associations between seasonality and health behaviours. Analyses were adjusted for sociodemographic factors, month of questionnaire completion and sleep duration. Seasonality was positively associated with high waist-hip-ratio, BMI, triglyceride levels, and in men high total cholesterol. Seasonality was negatively associated with HDL cholesterol. In women seasonality was negatively associated with prevalence of exercise and positively associated with daily cigarette smoking. Conclusions/Significance: High seasonality was associated with objective health risk factors and in women also with health behaviours associated with an increased risk for cardiovascular disease

Health problems and help-seeking in a nationwide sample of operational Norwegian ambulance personnel

Background To estimate the prevalence of anxiety and depression symptoms, and their association with professional help-seeking, among operational ambulance personnel and a general working population, and to study the symptoms of musculoskeletal pain and disturbed sleep among ambulance personnel. Methods The results of a comprehensive nationwide questionnaire survey of operational ambulance personnel (n = 1180) were compared with the findings of a population-based Norwegian health study of working people (n = 31,987). The questionnaire included measures of help-seeking, the Hospital Anxiety and Depression Scale, the Subjective Health Complaints Questionnaire, the Karolinska Sleep Questionnaire and the Need for Recovery after Work Scale. Results Compared with those in the reference population, the mean of level anxiety symptoms in the ambulance sample was lower for men (3.5 vs. 3.9, P < 0.001) and women (4.0 vs. 4.4, P < 0.05), and the mean level of depression symptoms in ambulance workers was lower for men (2.3 vs. 2.8, P < 0.05) but not for women (2.9 vs. 3.1, P = 0.22). A model adjusted for anxiety and depression symptoms indicated that ambulance personnel had lower levels of help-seeking except for seeing a chiropractor (12% vs. 5%, P < 0.01). In the ambulance sample, symptoms of musculoskeletal pain were most consistently associated with help-seeking. In the adjusted model, only symptoms of disturbed sleep were associated with help-seeking from a psychologist/psychiatrist (total sample = 2.3%). Help-seeking was more often reported by women but was largely unaffected by age. Conclusion The assumption that ambulance personnel have more anxiety and depression symptoms than the general working population was not supported. The level of musculoskeletal pain and, accordingly, the level of help-seeking from a chiropractor were higher for ambulance workers. More research should address the physical strains among ambulance personnel