Identifying a gender-inclusive pedagogy from Maltese science teachers' personal practical knowledge

Teachers bring with them into the science classrooms their own gendered identitities and their views and perceptions about how boys and girls learn and achieve in science. This paper tries to explore the way in which fourteen Maltese science teachers use their own 'personal practical knowledge' to identify their views about gender and science and create their own individual gender-inclusive pedagogy. The study suggests that the science teachers focus more on the individuality of students and on the social and cultural background of the students in their classrooms rather than on gender. The teachers try to develop pedagogies and assessment practices which take into consideration the personal constructs of individual learners. The ideas for such a gender-inclusive pedagogy emerge from their common-sense experience in the classroom, their training as teachers and are closely interrelated to current ideas of social constructivism

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

MÖSSBAUER SPECTROSCOPIC STUDIES OF THE CHEMICAL STATE OF IRON IN SILICATE MINERALS

Pour la plupart des silicates, tels que les pyroxènes et les amphiboles ferromagnétiques, un type de structure ne conduit qu'à un seul doublet. Ces doublets ont été très utiles pour caractériser les états d'oxydation et la coordination du fer, ainsi que pour estimer la population des sites. Récemment, deux effets supplémentaires - l'influence des seconds voisins et les échanges électroniques - ont été étudiés en relation avec des pics supplémentaires qui apparaissent dans le spectre. L'influence des seconds voisins est illustrée par des spectres d'omphacites (Ca,Na)(Fe,Mg, Al)Si2O6 pour lesquels les trois doublets M1 proviennent de trois des quatre combinaisons Na-Ca dans M2 : 1Ca-2Na, 2Ca-1Na, 3Ca. L'aire relative des pics correspondant à Fe2+ est en accord raisonnable avec la variation du rapport Ca/(Ca+Na) aussi bien qu'avec les prévisions théoriques. L'emploi de la spectrométrie Mössbauer pour étudier la cristallochimie du fer et les processus d'échange électronique est illustré par des spectres de grenats de Ti. Le fer peut y être placé en sites octaédriques et tétraédriques pour Fe3+, en sites dodécaédriques et octaédriques pour Fe2+. Un autre doublet a été attribué à la fois à Fe2+ tétraédrique et à un processus d'échange Fe2+-Fe3+ dont les caractéristiques sont discutées.For most "simple" silicates, such as ferromagnesium pyroxenes and amphiboles, one structural type of Fe yields no more than one doublet. These doublets have been very useful for characterizing the oxidation state and coordination environment of Fe, and for estimating site populations. Recently, two effects have been studied which give rise to "extra" peaks in the spectra - next nearest neighbour effects and electron exchange. Next nearest neighbour effects are illustrated by the spectra of omphacites (Ca,Na) (Fe,Mg,Al)Si2O6 in which the three M1 doublets arise from three of the four Na, Ca combinations in M2 ; 1Ca 2Na, 2Ca 1Na and 3Ca. The trend in relative Fe2+ peak areas with Ca/(Ca+Na) ratios agrees with theoretical predictions and the observed and theoretical relative Fe2+ peak areas are in reasonable agreement. The uses of Mössbauer spectroscopy for studying both the crystal chemistry of Fe and electron exchange processes are illustrated by the spectra of Ti garnets. Iron can be assigned in these spectra to Fe3+ in octahedral and tetrahedral sites, and Fe2+ in dodecahedral and octahedral sites. Another doublet has been assigned both to tetrahedral Fe2+ and an electron exchange Fe2+-Fe3+ species. Characteristics of electron-exchange doublets are discussed

SUPPRESSION OF MOLECULAR IONS IN SECONDARY ION MASS SPECTRA

Des perfectionnements dans l'élimination des ions moléculaires dans les spectres SIMS ont été obtenus à l'aide d'un analyseur ionique : Cameca IMS-3F. Cette étude montre une diminution du nombre d'ions moléculaires d'un facteur 10 à 100 par rapport aux techniques classiques utilisant un décalage d'énergie.Improved suppression of molecular ions in SIMS spectra has been obtained using a Cameca IMS-3F ion microscope. The approach described results in the suppression of molecular ions by factors of 10-100 fold more than by classical "energy offset"

Spectral Resolution and Raman Q3 and Q2 cross sections in ~40 mol% Na2O glasses

International audienceThere are four 29 Si NMR experimental studies published for glasses containing ~40 mol% Na 2 O and the reported Q species abundances are remarkably consistent. These results have been used to determine accurate Raman Q 3 and Q 2 cross sections for a 40.1 mol% Na 2 O glass. The Q 3 and Q 2 cross sections are respectively 1.10 and 0.95 (±0.03). The Q 2 band of the Raman spectrum is dominantly Lorentzian in shape whereas the Q 3 band is asymmetric and based on other studies, the asymmetry increases with alkali content, due primarily to alkali-BO interactions. As explanation, increase in alkali content enhances preferentially electron density over Si atoms of tetrahedra, thereby weakening Si-O coulombic interactions (i.e., force constants), which shifts the symmetric stretch of the Q 3 species to lower frequencies, producing asymmetric Q 3 line shapes. With Q 2 and Q 3 cross sections established, the high resolution of Raman spectroscopy now can be used to provide highly accurate estimates of Q species in silicate glasses and melts

The Chemical Nature of Oxidized Sulphur in Asphaltenes from X-Ray Absorption Spectroscopy

Bitumen samples have been chosen either from natural oil seepages and outcropping oil-stained reservoirs or archaeological bitumens from excavations in Iraq and Pakistan. Asphaltenes have been extracted from the bitumens. X-ray absorption near edge fine structure (XANES) spectroscopy at the S L-edge and K-edge has been employed to follow the oxidation effects on various sulphur moieties of the asphaltene fractions. Among asphaltenes extracted from archeological bitumens, sulphoxide, sulphone and sulphate are the predominant oxidized forms of sulphur

Application of XAFS in Tribology : P and S L-Edge XANES Spectroscopy of Antiwear Films

Antiwear additives are added to engine oils in the form of Zinc dialkyl dithiophosphates (ZDDPs). They form an antiwear (tribochemical) film on the rubbing surfaces. High resolution P and S L-edge X-ray absorption near edge (XANES) spectroscopy has been used to characterize the chemical nature of the films formed under air and inert atmosphere. The total electron yield and fluorescence yield detection methods have been employed to investigate the near surface and bulk composition of the films