Marginalized iterative ensemble smoothers for data assimilation

Data assimilation is an important tool in many geophysical applications. One of many key elements of data assimilation algorithms is the measurement error that determines the weighting of the data in the cost function to be minimized. Although the algorithms used for data assimilation treat the measurement uncertainty as known, it is in many cases estimated or set based on some expert opinion. Here we treat the measurement uncertainty as a hyperparameter in a fully Bayesian hierarchical model and derive a new class of iterative ensemble methods for data assimilation where the measurement uncertainty is integrated out. The proposed algorithms are compared with the standard iterative ensemble smoother on a 2D synthetic reservoir model.publishedVersio

Regnskapsanalyse i makroøkonomisk prognosearbeid : en empirisk studie av hvor godt aggregert finansiell informasjon egner seg til å forbedre makroøkonomiske prognoser av økonomisk vekst i Norge

Makroøkonomi og regnskap er to disipliner innenfor det økonomiske fagfeltet som i det store og hele har utviklet seg hver for seg. Nå er en ny strøm forskning i ferd med å etablere en sterkere link mellom de to disiplinene, men det gjenstår enda å se studier fra Norge. Denne utredningen adresserer informasjonsgapet ved å undersøke hvorvidt aggregerte regnskapsmessige lønnsomhetsdrivere kan brukes til å predikere fremtidig makroøkonomisk vekst (BNP) i Norge. For å undersøke dette benytter vi kvartalsregnskaper fra norske børsnoterte virksomheter, hentet fra Compustat Global, og BNP-data hentet fra Statistisk Sentralbyrå (SSB). Vi finner at DuPont lønnsomhetsdrivere ikke utviser en statistisk signifikant sammenheng med fremtidig BNP-vekst i Norge. Resultatene strider mot studier gjort på amerikanske data, som viser en betydelig og signifikant sammenheng. Dette avviket indikerer at det er mer utfordrende å modellere fremtidig makroøkonomisk vekst i Norge sammenlignet med USA, basert på regnskapsdata. Videre har vi utført en tilleggstest som viser at aggregert regnskapsmessig fortjeneste er en ledende indikator for BNP-vekst fire kvartaler frem i tid. Dette avviker fra studier på amerikanske data, som viser at regnskapsinformasjon er best egnet til å predikere BNP-vekst ett kvartal frem i tid. Denne utredningen belyser sammenhengen mellom finansregnskapet og makroøkonomien i Norge. Studien dokumenterer at finansregnskapet inneholder ledende informasjon om makroøkonomisk aktivitet. Den dokumenterer allikevel noen særnorske utfordringer ved å modellere denne sammenhengen. Dette gir opphav til en rekke nye spørsmål innenfor forskningen på sammenhengen mellom finansregnskapet og den overordnede økonomiske aktiviteten i Norge. Resultatene bør derfor være av interesse for akademikere og økonomer forøvrig.nhhma

Metabolic Activation of Intrahepatic CD8+ T Cells and NKT Cells Causes Nonalcoholic Steatohepatitis and Liver Cancer via Cross-Talk with Hepatocytes

SummaryHepatocellular carcinoma (HCC), the fastest rising cancer in the United States and increasing in Europe, often occurs with nonalcoholic steatohepatitis (NASH). Mechanisms underlying NASH and NASH-induced HCC are largely unknown. We developed a mouse model recapitulating key features of human metabolic syndrome, NASH, and HCC by long-term feeding of a choline-deficient high-fat diet. This induced activated intrahepatic CD8+ T cells, NKT cells, and inflammatory cytokines, similar to NASH patients. CD8+ T cells and NKT cells but not myeloid cells promote NASH and HCC through interactions with hepatocytes. NKT cells primarily cause steatosis via secreted LIGHT, while CD8+ and NKT cells cooperatively induce liver damage. Hepatocellular LTβR and canonical NF-κB signaling facilitate NASH-to-HCC transition, demonstrating that distinct molecular mechanisms determine NASH and HCC development

Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU)

Purpose Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients. Methods We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses. Results We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4–46.1) had thrombocytopenia; 23.4% (20–26) had thrombocytopenia at ICU admission, and 19.8% (17.6–22.2) developed thrombocytopenia during their ICU stay. Non-AIDS-, non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19–2.42). Conclusion Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.publishedVersio

Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU)

Purpose: Thrombocytopenia (platelet count &lt; 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients. Methods: We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses. Results: We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4–46.1) had thrombocytopenia; 23.4% (20–26) had thrombocytopenia at ICU admission, and 19.8% (17.6–22.2) developed thrombocytopenia during their ICU stay. Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19–2.42). Conclusion: Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic

Stroke genetics informs drug discovery and risk prediction across ancestries

Previous genome-wide association studies (GWASs) of stroke — the second leading cause of death worldwide — were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (P < 0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries

COVID-19 Vaccination-related Complex Regional Pain Syndrome Masquerading as Erythromelalgia: A Case Report

Abstract is missing (Short communication

Quality minus junk : predicting wealth generating stocks with quality minus junk

In this thesis, we investigate if the quality minus junk (QMJ) factor can be used to predict the stocks responsible for the excess wealth creation in the US. We find that quality has a low predictive power on next months wealth generating stocks. Our findings do suggest that investors can benefit in terms of risk-adjusted returns if they use quality to predict portfolios of wealth generating stocks and portfolios of wealth destroying stocks. A predicted QMJ factor that buys and sells these high and low portfolios does not provide any additional compensation for risk over the original QMJ factor, unless investors are willing to weight the stocks equally. We also find that quality portfolios of stocks that are considered wealth generating and wealth destroying differs in quality, and that this difference also increases over time

Regnskapsanalyse i makroøkonomisk prognosearbeid : en empirisk studie av hvor godt aggregert finansiell informasjon egner seg til å forbedre makroøkonomiske prognoser av økonomisk vekst i Norge

Makroøkonomi og regnskap er to disipliner innenfor det økonomiske fagfeltet som i det store og hele har utviklet seg hver for seg. Nå er en ny strøm forskning i ferd med å etablere en sterkere link mellom de to disiplinene, men det gjenstår enda å se studier fra Norge. Denne utredningen adresserer informasjonsgapet ved å undersøke hvorvidt aggregerte regnskapsmessige lønnsomhetsdrivere kan brukes til å predikere fremtidig makroøkonomisk vekst (BNP) i Norge. For å undersøke dette benytter vi kvartalsregnskaper fra norske børsnoterte virksomheter, hentet fra Compustat Global, og BNP-data hentet fra Statistisk Sentralbyrå (SSB). Vi finner at DuPont lønnsomhetsdrivere ikke utviser en statistisk signifikant sammenheng med fremtidig BNP-vekst i Norge. Resultatene strider mot studier gjort på amerikanske data, som viser en betydelig og signifikant sammenheng. Dette avviket indikerer at det er mer utfordrende å modellere fremtidig makroøkonomisk vekst i Norge sammenlignet med USA, basert på regnskapsdata. Videre har vi utført en tilleggstest som viser at aggregert regnskapsmessig fortjeneste er en ledende indikator for BNP-vekst fire kvartaler frem i tid. Dette avviker fra studier på amerikanske data, som viser at regnskapsinformasjon er best egnet til å predikere BNP-vekst ett kvartal frem i tid. Denne utredningen belyser sammenhengen mellom finansregnskapet og makroøkonomien i Norge. Studien dokumenterer at finansregnskapet inneholder ledende informasjon om makroøkonomisk aktivitet. Den dokumenterer allikevel noen særnorske utfordringer ved å modellere denne sammenhengen. Dette gir opphav til en rekke nye spørsmål innenfor forskningen på sammenhengen mellom finansregnskapet og den overordnede økonomiske aktiviteten i Norge. Resultatene bør derfor være av interesse for akademikere og økonomer forøvrig