Constraints on accelerating universe using ESSENCE and Gold supernovae data combined with other cosmological probes

We use recently observed data: the 192 ESSENCE type Ia supernovae (SNe Ia), the 182 Gold SNe Ia, the 3-year WMAP, the SDSS baryon acoustic peak, the X-ray gas mass fraction in clusters and the observational $H(z)$ data to constrain models of the accelerating universe. Combining the 192 ESSENCE data with the observational $H(z)$ data to constrain a parameterized deceleration parameter, we obtain the best fit values of transition redshift and current deceleration parameter $z_{T}=0.632^{+0.256}_{-0.127}$, $q_{0}=-0.788^{+0.182}_{-0.182}$. Furthermore, using $\Lambda$CDM model and two model-independent equation of state of dark energy, we find that the combined constraint from the 192 ESSENCE data and other four cosmological observations gives smaller values of $\Omega_{0m}$ and $q_{0}$, but a larger value of $z_{T}$ than the combined constraint from the 182 Gold data with other four observations. Finally, according to the Akaike information criterion it is shown that the recently observed data equally supports three dark energy models: $\Lambda$CDM, $w_{de}(z)=w_{0}$ and $w_{de}(z)=w_{0}+w_{1}\ln(1+z)$.Comment: 18 pages, 8 figure

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

Physical activity, diet and BMI in children aged 6–8 years : a cross-sectional analysis

Objective To assess relationships between current physical activity (PA), dietary intake and body mass index (BMI) in English children. Longitudinal birth cohort study in northeast England, cross-sectional analysis. Participants 425 children (41% of the original cohort) aged 6–8 years (49% boys). Main outcome measures PA over 7 days was measured objectively by an accelerometer; three categories of PA were created: ‘active’ ≥60 min/day moderate-to-vigorous-intensity PA (MVPA); ‘moderately active’ 30–59 min/day MVPA; ‘inactive’ <30 min/day MVPA. Dietary intake over 4 days was measured using a prospective dietary assessment tool which incorporated elements of the food diary and food frequency methods. Three diet categories were created: ‘healthy’, ‘unhealthy’ and ‘mixed’, according to the number of portions of different foods consumed. Adherence to the ‘5-a-day’ recommendations for portions of fruit and vegetables was also assessed. Children were classified as ‘healthy weight’ or ‘overweight or obese’ (OW/OB) according to International Obesity Taskforce cutpoints for BMI. Associations between weight status and PA/diet categories were analysed using logistic regression. Few children met the UK-recommended guidelines for either MVPA or fruit and vegetable intake, with just 7% meeting the recommended amount of MVPA of 60 min/day, and 3% meeting the 5-a-day fruit and vegetable recommendation. Higher PA was associated with a lower OR for OW/OB in boys only (0.20, 95% CI 0.04 to 0.88). There was no association detected between dietary intake and OW/OB in either sex. Increasing MVPA may help to reduce OW/OB in boys; however, more research is required to examine this relationship in girls. Children are not meeting the UK guidelines for diet and PA, and more needs to be done to improve this situation

Tetramic acid and imidazolidinone syntheses via unexpected base induced cyclisations of alanine derived Weinreb amides

Reactions of N-protected derivatives of Weinreb amides of alanine with strong base unexpectedly gave tetramic acid derivatives or an imidazolidinone. The tetramic acid derivatives were obtained by unusual cyclisation of N-acyl N-methoxy derivatives of alanine Weinreb amide upon treatment with potassium hexamethyldisilazide and benzyl bromide. In contrast, treatment of a bromobenzylidine alanine Weinreb amide with potassium hexamethyldisilazide gave rise to cyclisation to form an imidazolidinone

Magnesium aryloxides: synthesis, structure, solution behavior and magnesiate ion formation

The heteroleptic magnesium complexes [{Ar'OMgBu}(2)] 1 and [{Ar'OMgN(i-Pr)(2)}(2)] 2, where OAr' = 2,6-di-tertbutylphenoxy, have been prepared and found to be dimeric in the solid state, with tri-coordinate metal centers. Complex 1 utilizes the aryloxide anions as bridging groups whereas the amido anions connect the metals in 2. Addition of THF or TMEDA to hydrocarbon solutions containing 2 results in disproportionation and the exclusive precipitation of the homoleptic, solvated, complexes [Mg(OAr')(2).2THF] 3 or [Mg(OAr')(2).TMEDA] 4. Both 3 and 4 are monomeric in the solid state with tetra-coordinate magnesium centers. Solution NMR spectroscopic studies of 1 and 2 reveal that disproportionation to the homoleptic complexes is promoted in THF-d(8) but that the main component still appears to be the heteroleptic species. Dissolution of the unsolvated dimeric complex [Mg(OAr')(2)] 5 in THF-d(8) results in partial formation of the magnesiate complex [Ar'OMg](+)[(Ar'O)(3)Mg](-)10, along with the monomer 3. In contrast, no magnesiate is formed on dissolution of 3 in THF-d(8), indicating that magnesiate formation most likely proceeds via unsymmetrical cleavage of the dimer. Ab initio calculations (HF/6-31G*) have been used to investigate the possible structures of the magnesiate species

Synthesis of the mixed lithium-potassium-(bis)magnesium N-metallated / N, C-dimetallated amide [Li2K2Mg4 {But(Me3Si)N} 4{But[Me2(H2C)Si]N}4] : an inverse crown molecule with an atomless cavity

Unlike previous members of the inverse crown family, which are heterobimetallic and have cationic rings surrounding anionic cores, the title compound is heterotrimetallic and its "guest" anion is intramolecularly stitched into the complex fused-ring structure of its cationic "host"

When do mothers think their child is overweight?

Objective: To quantify how overweight children have to be for their mothers to classify them as overweight and to express concern about future overweight, and to investigate the adiposity cues in children that mothers respond to. Design: Cross-sectional. Subjects: A total of 531 children from the Gateshead Millennium Study cohort at 6-8 years and their mothers. Measurements: In the mother: responses to two questions concerning the child's adiposity; height; weight; educational qualifications; and economic status. In the child: height; weight; waist circumference; skinfold thicknesses; bioelectrical impedance; and bone frame measurements. Results: The body mass index (BMI) at which half the mothers classify their child as overweight was 21.3 (in the obese range for children of this age). The BMI at which half the mothers were concerned about their child becoming overweight in the future was 17.1 (below the overweight range). Waist circumference and skinfolds contributed most to mothers' responses. Although BMI and fat scores were important predictors individually, they did not contribute independently once waist circumference and skinfolds (their most visible manifestations) were included in the regression equations. Mothers were less likely to classify girls as overweight. Mothers with higher BMIs were less likely to classify their child as overweight, but were more likely to be concerned about future overweight. Conclusion: Health promotion efforts directed at parents of young primary school children might better capitalise on their concern about future overweight in their child than on current weight status, and focus on mothers' response to more visible characteristics than the BMI. International Journal of Obesity (2011) 35, 510-516; doi: 10.1038/ijo.2010.260; published online 11 January 201