7 research outputs found
Estimation of net apparent erosion in the SW Barents Sea by applying velocity inversion analysis
The SW Barents Sea was subjected to significant uplift and erosion during the Cenozoic, processes that are believed
to have had a significant impact on hydrocarbon maturation and migration in the area. The current study uses compaction of
shale- and sand-dominated layers to make a map of net apparent erosion throughout the SW Barents Sea. The map shows
regional trends consistent with deep-seated isostatic uplift of the crust in combination with glacial erosion as a driving
mechanism for the erosion.We find increased erosion towards the north and decreased erosion towards the west, in the western
Barents Sea. The trend of highest erosion has an axis stretching in a SEâNW orientation towards Svalbard. This indicates a
major change in the crustal uplift pattern in the transition from the Norwegian mainland to the Barents Sea. The velocity
inversion method used in this study combined with a two-baseline normal compaction trend model demonstrates a reliable
procedure for accurate erosion estimations. It allows erosion estimates from layers with different lithologies to be integrated into a common interpretation and differences to be interpreted geologically: for example, an apparent facies change to a mixed sandâshale lithology, possibly with reservoir quality sands developed, in the Cretaceous on the Bjarmeland Platform
Subtypes of insomnia and the risk of chronic spinal pain: the HUNT study
Objective: To examine the association between subtypes of insomnia and the risk of chronic spinal pain. Methods:The study comprised 16,401 participants without chronic spinal pain at baseline who were followed for ~11 years. People were categorized into âno insomnia symptomsâ,âsubthreshold insomniaâ,and âinsomniaâ. Insomnia was defined according to the diagnostic classification system requiring both daytime and nighttime symptoms, and further categorized into subtypes based on nighttime symptoms(ie, sleep onset latency [SOL-insomnia], wake after sleep onset [WASO-insomnia], early morning awakening [EMA-insomnia], or combinations of these). Subthreshold insomnia comprised those with only daytime impairment or one or more nighttime symptoms. Chronic spinal pain was defined as pain in either âneckâ, âlow backâ, or âupper backâ, or a combination of these. Results: In multivariable regression analysis using people without insomnia as reference, people with subthreshold insomnia or insomnia had relative risks (RRs) of chronic spinal pain of 1.29 (95% confidence interval [CI] 1.21e1.38) and 1.50 (95% CI 1.34e1.68), respectively. The RRs for people with one nighttime symptom were 1.30 (95% CI 0.83e2.05) for WASO-insomnia, 1.32 (95% CI 1.06e1.65) for EMA-insomnia, and 1.70 (95% CI 1.32e2.18) for SOL-insomnia, respectively. Combinations of nighttime insomnia symptoms gave RRs from 1.45 (95% CI 1.08e1.94) for WASOĂžEMA-insomnia to 1.72 (95% CI 1.36e2.19)for all nighttime symptoms (SOLĂžWASOĂžEMA-insomnia). Conclusions: These findings suggest that the risk of chronic spinal pain is highest among persons with insomnia subtypes characterized by sleep onset latency or among those having insomnia symptoms in allparts of the sleep period
Quantification of the magnitude of net erosion in the southwest Barents Sea using sonic velocities and compaction trends in shales and sandstones
During specific intervals within Mesozoic and Cenozoic times, several areas of the
southwestern Barents Sea were subjected to uplift and erosion. Areas with missing shallow
stratigraphic interval sections and major erosion can be seen at several places along interpreted
regional profiles in the southwestern Barents Sea. A new Normal Compaction Trend (NCT) for
two selected shaleâ and sandstoneâdominated lithologies has been constructed based on sonic
logs in the southwestern Barents Sea. The shaleâ dominated NCT is calibrated to the
Cretaceous shales in the Northern North Sea and Norwegian Sea and applied to the Cretaceous shales of the Barents Sea. The sandstoneâdominated NCT is calibrated to the Lower Jurassic
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re Formation of the Norwegian Sea and applied to the Lower JurassicâUpper Triassic coastal
plain section in the Barents Sea. By utilising the NCT model, the study estimates net apparent
erosion in 28 selected Barents Sea wells based on comparison of sonic log velocities. A net
apparent erosion map of the study area was constructed by gridding of the well values. The
accuracy of the map is limited in areas with little well control, such as in the northwest, where
the eastâwest transition into the southwestern Barents Sea region is poorly constrained. With
that in mind, the map clearly shows two regional trends which dominate the erosion pattern in
the study area; an increasing amount of erosion towards the north and a sharp decrease of
erosion westwards of the hinge zone into the southwestern Barents Sea. The highest erosion
estimates are observed towards Svalbard, with values up to 2500 m. The results of this study
can be further utilized in petroleum system studies in the eroded areas
Prognostic ability of STarT Back Screening Tool combined with work-related factors in patients with low back pain in primary care: a prospective study
Objective Primary care screening tools for patients with low back pain may improve outcome by identifying modifiable obstacles for recovery. The STarT Back Screening Tool (SBST) consists of nine biological and psychological items, with less focus on work-related factors. We aimed at testing the prognostic ability of SBST and the effect of adding items for future and present work ability.
Methods Prospective observational study in patients (n=158) attending primary care physical therapy for low back pain. The prognostic ability of SBST and the added prognostic value of two work items; expectation for future work ability and current work ability, were calculated for disability, pain and quality of life outcome at 3âmonths follow-up. The medium and high-risk group in the SBST were collapsed in the analyses due to few patients in the high-risk group. The prognostic ability was assessed using the explained variance (R2) of the outcomes from univariable and multivariable linear regression and beta values with 95% CIs were used to assess the prognostic value of individual items.
Results The SBST classified 107 (67.7%) patients as low risk and 51 (32.3%) patients as medium/high risk. SBST provided prognostic ability for disability (R2=0.35), pain (R2=0.25) and quality of life (R2=0.28). Expectation for return to work predicted outcome in univariable analyses but provided limited additional prognostic ability when added to the SBST. Present work ability provided additional prognostic ability for disability (β=â2.5; 95% CI=â3.6âto â1.4), pain (β=â0.2; 95% CI=â0.5âto â0.002) and quality of life (β=0.02; 95% CI=0.001âto 0.04) in the multivariable analyses. The explained variance (R2) when work ability was added to the SBST was 0.60, 0.49 and 0.47 for disability, pain and quality of life, respectively.
Conclusions Adding one work ability item to the SBST gives additional prognostic information across core outcomes
Genetic variants related to physical activity or sedentary behaviour: a systematic review
Background
Research shows that part of the variation in physical activity and sedentary behaviour may be explained by genetic factors. Identifying genetic variants associated with physical activity and sedentary behaviour can improve causal inference in physical activity research. The aim of this systematic review was to provide an updated overview of the evidence of genetic variants associated with physical activity or sedentary behaviour.
Methods
We performed systematic literature searches in PubMed and Embase for studies published from 1990 to April 2020 using keywords relating to âphysical activityâ, âexerciseâ, âsedentarinessâ and âgeneticsâ. Physical activity phenotypes were either based on self-report (e.g., questionnaires, diaries) or objective measures (e.g., accelerometry, pedometer). We considered original studies aiming to i) identify new genetic variants associated with physical activity or sedentary behaviour (i.e., genome wide association studies [GWAS]), or ii) assess the association between known genetic variants and physical activity or sedentary behaviour (i.e., candidate gene studies). Study selection, data extraction, and critical appraisal were carried out by independent researchers, and risk of bias and methodological quality was assessed for all included studies.
Results
Fifty-four out of 5420 identified records met the inclusion criteria. Six of the included studies were GWAS, whereas 48 used a candidate gene approach. Only one GWAS and three candidate gene studies were considered high-quality. The six GWAS discovered up to 10 single nucleotide polymorphisms (SNPs) associated with physical activity or sedentariness that reached genome-wide significance. In total, the candidate gene studies reported 30 different genes that were associated (pâ<â0.05) with physical activity or sedentary behaviour. SNPs in or close to nine candidate genes were associated with physical activity or sedentary behaviour in more than one study.
Conclusion
GWAS have reported up to 10 loci associated with physical activity or sedentary behaviour. Candidate gene studies have pointed to some interesting genetic variants, but few have been replicated. Our review highlights the need for high-quality GWAS in large population-based samples, and with objectively assessed phenotypes, in order to establish robust genetic instruments for physical activity and sedentary behaviour. Furthermore, consistent replications in GWAS are needed to improve credibility of genetic variants