Catalytic combustion control

A mathematical model representing the dynamic behaviour observed at the actual catalytic incineration plant at Perstorp was derived. The model equations for the two main process units, the heat exchanger and the incinerator, were based on the lumped systems approach in order to avoid using partial differential equations. The model was written in Matlab and implemented in Simulink using s-functions for the dynamic study. By analyzing the dynamic data from the actual plant, it was discovered that the possible source of the ocassional large temperature variations in the incinerator is the periodic variations in the inlet compositions, amplified the overly agressive air valve controller combined with a significant dead time. This results in oscillations due to overshooting. This behaviour was successfully reproduced using the derived model. Two possibilities for improving the control performance were investigated, both using already existing sensors and actuators. The first control improvement involved reducing the proportional gain according to the SIMC tuning rules for PI controllers. This resulted in a significant reduction in the amplitude of the oscillations in the temperatures throughout the reactor, and thus a more stable performance. Finally, cascade control was implemented using the faster-responding catalyst bed temperature for the inner loop, and the reactor outlet temperature for the outer loop. This provided the most optimal results with the best disturbance rejection as it is able to compensate for the disturbance before it is detected in the outlet temperature

Kognitive utfordringer i to norske lærebokserier fra ungdomsskolen – en mixed methods studie

I denne masteroppgaven i matematikkdidaktikk undersøker vi de kognitive utfordringene i oppgavene i to norske lærebokserier for ungdomsskolen. Norske matematikklærere benytter seg i stor grad av læreboka i undervisningen (Mullis, Martin, Foy & Arora, 2012), samt at en rekke studier hevder at det er læreboka og oppgavene i dem som i stor grad legger til rette for hva elevene lærer seg (Fan, Miao & Zhu, 2013; Hiebert m.fl., 1997; Hiebert & Wearne, 1997; Pepin & Haggarty, 2007; Robitaille & Travers, 1992). På bakgrunn av dette ønsker vi å undersøke denne problemstillingen: I hvilken grad får elevene kognitive utfordringer gjennom oppgavene som gis i de to mest brukte lærebøkene på ungdomskolen i Norge? 1. Hvilken grad av kognitive nivåkrav krever oppgavene? 2. Hvilke typer svar krever oppgavene? For å svare på denne problemstillingen har vi gjennomført en mixed methods studie. Analysen er delt inn i en horisontal del og en vertikal del. Den horisontale analysen har gitt oss oversikt over bakgrunnsinformasjonen og en generell oversikt over læreverkene vi har benyttet oss av. Denne analysen har blant annet gitt oss grunnlaget for å dele oppgavene inn i ulike tema. Den vertikale analysen gikk mer i dybden. Her benyttet vi oss av to ulike tilnærminger, en kvantitativ og en kvalitativ del. I den kvantitative analysen kodet vi oppgaver i forhold til vårt konseptuelle rammeverk. I tillegg gjennomførte vi en kvalitativ tilleggsanalyse av et utvalg av lærebøkenes grubleoppgaver. Den kvantitative analysen av oppgavene har hovedtyngden i denne masteroppgaven, mens hensikten med den kvalitative tilleggsanalysen var å ytterligere belyse elementer som vårt konseptuelle rammeverk ikke fanget opp. Funnene våre viser at oppgavene i begge lærebokseriene i stor grad er lavere kognitivt krevende. Særlig Faktor, men også Maximum gir elevene få muligheter til å møte på kognitivt utfordrende oppgaver. Oppgaver med lavere kognitive nivåkrav gir elevene minimal mulighet for å møte på kognitive utfordringer som igjen fører til svakere utvikling av matematisk kompetanse. Flesteparten av oppgavene vi har kategorisert krever kun at elevene gir et svar, i stedet for en forklaring eller en begrunnelse. I og med at en så stor andel av oppgavene kun krever et svar mener vi dette begrenser de kognitive utfordringene i oppgavene

Opportunity to learn in Norwegian and Finnish lower secondary mathematics textbooks

Source at https://ncm.gu.se/.Although both Finland and Norway are part of a common Nordic education culture, Finland have consistently outperformed the other Nordic countries in PISA studies. In this study, we compare Finnish and Norwegian textbook series. The results indicate that both textbook series largely facilitate skill efficiency, and most tasks are low cognitive demand. However, the Finnish textbook series facilitate conceptual understanding to a greater degree. The Finnish textbook series also introduce and develop connections between a greater number of mathematical ideas, and there is a greater number and proportion of high cognitive demand tasks in the Finnish textbooks

Genotyping of human papillomavirus in triaging of low-grade cervical cytology.

OBJECTIVE: The objective of the study was to evaluate whether typing of human papillomavirus (HPV) among women with low-grade cervical cytology can improve the ability to identify women with cervical cancer or cervical intraepithelial neoplasia grade III (CIN III or worse). STUDY DESIGN: A total of 1595 women with low-grade cervical cytology participating in a randomized implementation trial of HPV triaging using Hybrid Capture II were also HPV genotyped and CIN III or worse predictive values evaluated. RESULTS: HPV 16 was detected in 57% of cases with CIN III or worse but only among 24% of all tested women. Testing for the 3 HPV types with highest risk (HPV16/31/33) detected 77% of CIN III or worse, with 36% of women testing positive. Positivity for the other high-risk HPV types had a decreased risk for CIN III or worse. CONCLUSION: Different high-risk HPV types confer different risks for the presence of CIN III or worse, implying that HPV genotyping could be useful for the optimization of triaging strategies

Impact of an icy winter on the Pacific oyster (Crassostrea gigas Thunberg, 1793) populations in Scandinavia

The Pacific oyster (Crassostrea gigas) is an invasive species that has dispersed into Scandinavia during the last few decades. The objective of this study was to evaluate the effects of extreme winter conditions on the mortality of the Pacific oyster in Scandinavia. The study was done by compiling mortality data from independent surveys in Denmark, Sweden and Norway. Winter mortality of the oysters increased with latitude, which can be explained by the colder climate experienced at higher latitudes. Mortality was also found to be affected by site specific conditions such as water depth at the sampling sites of oyster populations. Despite the severe winter conditions of 2009/2010 causing high mortality, the Pacific oyster still exists in large numbers in Scandinavia. The present investigation indicates that extreme winter onditions may result in a temporary reduction of the density of the Pacific oyster, but that the species can be expected to continue its invasion of Scandinavian coastal areas.publishedVersio

Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function

Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes

Development and validation of a novel clinical risk score to predict hypoxaemia in children with pneumonia using the WHO PREPARE dataset

Background: Hypoxaemia predicts mortality at all levels of care, and appropriate management can reduce preventable deaths. However, pulse oximetry and oxygen therapy remain inaccessible in many primary care health facilities. We aimed to develop and validate a simple risk score comprising commonly evaluated clinical features to predict hypoxaemia in 2–59-month-old children with pneumonia. Methods: Data from seven studies conducted in five countries from the Pneumonia Research Partnership to Assess WHO Recommendations (PREPARE) dataset were included. Readily available clinical features and demographic variables were used to develop a multivariable logistic regression model to predict hypoxemia (oxygen saturation <90%) at presentation to care. The adjusted log coefficients were transformed to derive the PREPARE hypoxemia risk score and its diagnostic value was assessed in a held-out, temporal validation dataset. The model and risk score were analysed by evaluating the area under the receiver operating characteristic curve (AUC), sensitivity and specificity. Results: We included 14 509 children in the analysis; 9.8% (n=2515) were hypoxemic at presentation. The multivariable regression model to predict hypoxemia included age, sex, respiratory distress (nasal flaring, grunting and/or head nodding), lower chest indrawing, respiratory rate, body temperature and weight-for-age z-score. The model showed fair discrimination (AUC 0.70, 95% CI 0.67 to 0.73) and calibration in the validation dataset. The simplified PREPARE hypoxaemia risk score includes five variables: age, respiratory distress, lower chest indrawing, respiratory rate and weight-for-age z-score. Conclusion: The PREPARE hypoxemia risk score, comprising five easily available characteristics, has the potential to be used to identify hypoxemia in children with pneumonia with a fair degree of certainty for use in health facilities without pulse oximetry. Its implementation would require careful consideration to limit the burden of inappropriate referrals on patients and the health system. Further external validation in community settings in low- and middle-income countries is required

Gene expression profiling in primary breast cancer distinguishes patients developing local recurrence after breast-conservation surgery, with or without postoperative radiotherapy

Introduction Some patients with breast cancer develop local recurrence after breast-conservation surgery despite postoperative radiotherapy, whereas others remain free of local recurrence even in the absence of radiotherapy. As clinical parameters are insufficient for identifying these two groups of patients, we investigated whether gene expression profiling would add further information. Methods We performed gene expression analysis (oligonucleotide arrays, 26,824 reporters) on 143 patients with lymph node-negative disease and tumor-free margins. A support vector machine was employed to build classifiers using leave-one-out cross-validation. Results Within the estrogen receptor-positive (ER+) subgroup, the gene expression profile clearly distinguished patients with local recurrence after radiotherapy (n = 20) from those without local recurrence (n = 80 with or without radiotherapy). The receiver operating characteristic (ROC) area was 0.91, and 5,237 of 26,824 reporters had a P value of less than 0.001 (false discovery rate = 0.005). This gene expression profile provides substantially added value to conventional clinical markers (for example, age, histological grade, and tumor size) in predicting local recurrence despite radiotherapy. Within the ER- subgroup, a weaker, but still significant, signal was found (ROC area = 0.74). The ROC area for distinguishing patients who develop local recurrence from those who remain local recurrence-free in the absence of radiotherapy was 0.66 (combined ER+/ER-). Conclusion A highly distinct gene expression profile for patients developing local recurrence after breast-conservation surgery despite radiotherapy has been identified. If verified in further studies, this profile might be a most important tool in the decision making for surgery and adjuvant therapy

Khoe-San genomes reveal unique variation and confirm the deepest population divergence in Homo sapiens

Abstract: The southern African indigenous Khoe-San populations harbor the most divergent lineages of all living peoples. Exploring their genomes is key to understanding deep human history. We sequenced 25 full genomes from five Khoe-San populations, revealing many novel variants, that 25% of variants are unique to the Khoe-San, and that the Khoe-San group harbors the greatest level of diversity across the globe. In line with previous studies, we found several gene regions with extreme values in genome-wide scans for selection, potentially caused by natural selection in the lineage leading to Homo sapiens and more recent in time. These gene regions included immunity-, sperm-, brain-, diet-, and muscle-related genes. When accounting for recent admixture, all Khoe-San groups display genetic diversity approaching the levels in other African groups and a reduction in effective population size starting around 100,000 years ago. Hence, all human groups show a reduction in effective population size commencing around the time of the Out-of- Africa migrations, which coincides with changes in the paleoclimate records, changes that potentially impacted all humans at the time