$^{12}CO(J=1 \to 0)$ observations of 34 blue compact and star burst galaxies are presented. Although these galaxies are experiencing vigorous star formation at the current epoch, CO has been detected in only five of them. The five detections reported in this paper are all in galaxies with relatively red colours, (B-V)_0 > 0.4. The new observations, when combined with previously published data on CO in BCGs, indicate that CO luminosity decreases with absolute luminosity of BCGs. Since the absolute luminosity of a galaxy is correlated with its metallicity, these results confirm that low metallicity BCGs have low abundances of CO gas. We also show that the star formation rate determined from the $H_β$ luminosity is lower than that determined from the far infrared luminosity.
A method for attenuation and scatter correction of brain single photon emission computed tomography (SPECT) is described where computed tomography (CT) images of the brain are used for the calculation of attenuation maps. The method is evaluated for the substance 99mTc hexamethylpropylene amine oxime. A transmission dependent scatter correction is utilized and is based on ray sums calculated through the attenuation map. A method based on external markers is used to align the SPECT and CT image volumes. The markers need only to be present during the SPECT acquisition since the corresponding landmarks can be found without markers on the CT images. The mismatching has been investigated for five patients who have undergone both a CT examination and a SPECT examination with markers. Twelve individuals from the staff have pointed out the landmarks on the CT images, with an average standard deviation of 3.4 mm. Reconstructions with an attenuation map shifted the corresponding 95% confidence interval have been performed to obtain an estimation of the quantitative uncertainty caused by the mismatching, and quantitative errors of up to 6.3% have been measured. At present the method is probably most useful when groups of patients are studied.
Obesity adversely affects frontal lobe brain structure and function. Here we sought to show that people who are obese versus those who are of normal weight over a 5-year period have differential global and regional brain volumes. Using voxel-based morphometry, contrasts were done between those who were recorded as being either obese or of normal weight over two time points in the 5 years prior to the brain scan. In a post-hoc preliminary analysis, we compared scores for obese and normal weight people who completed the trail-making task. A total of 292 subjects were examined following exclusions (for example, owing to dementia, stroke and cortical infarcts) from the Prospective Investigation of the Vasculature in Uppsala Seniors cohort with a body mass index of normal weight (<25 kg m−2) or obese (⩾30 kg m−2). People who were obese had significantly smaller total brain volumes and specifically, significantly reduced total gray matter (GM) volume (GMV) (with no difference in white matter or cerebrospinal fluid). Initial exploratory whole brain uncorrected analysis revealed that people who were obese had significantly smaller GMV in the bilateral supplementary motor area, bilateral dorsolateral prefrontal cortex (DLPFC), left inferior frontal gyrus and left postcentral gyrus. Secondary more stringent corrected analyses revealed a surviving cluster of GMV difference in the left DLPFC. Finally, post-hoc contrasts of scores on the trail-making task, which is linked to DLPFC function, revealed that obese people were significantly slower than those of normal weight. These findings suggest that in comparison with normal weight, people who are obese have smaller GMV, particularly in the left DLPFC. Our results may provide evidence for a potential working memory mechanism for the cognitive suppression of appetite that may lower the risk of developing obesity in later life.
We have observed the J=1-0 transitions of 12 CO and 13 CO in 21 galaxies. We measure unusually large 12 CO/ 13 CO (1-0) intensity ratios, R>20, in four merging galaxies NGC 3256, NGC 1614, Arp 220 (IC 4553) and Arp 299 (IC 694 and NGC 3690). All four are warm (fluxes at 60 and 100 μm, f 60 /f 100 ≥0.78) and luminous in the infrared (L IR ≥3×10 11 L ⊙ ). The ratio in the rest of the objects, which display a variety of morphologies, is well concentrated around a mean value of 11. We suggest that the large 12 CO/ 13 CO intensity ratios reflect a decrease in mean optical depth of molecular clouds that have been disturbed by powerful tidal forces or by a starburst triggered in the merging process
Background and Aims: Cotadutide, a dual receptor agonist with glucagon-like peptide-1 (GLP-1) and glucagon activity, is being researched for the potential treatment of nonalcoholic steatohepatitis. Given the known effects of glucagon on hepatic glycogen and lipid metabolism, the aim of this phase 2a study was to investigate the effect of cotadutide on hepatic glycogen. Methods: In this double-blind, placebo-controlled study, 21 overweight or obese adults with type 2 diabetes mellitus (HbA1c ≤ 8%) were randomized to receive once-daily subcutaneous cotadutide (n = 12) or placebo (n = 9) for 28 days. Following 48 hours of standardized meals, serial magnetic resonance spectroscopy scans relying on signals from naturally abundant 13C were performed to measure glycogen, and liver fat was also estimated. Fasting amino acid and ketone levels were also assessed. Results: Significant reductions from baseline in postprandial hepatic glycogen content were observed with cotadutide (-100.2 mmol/L; 90% CI: -150.2, -50.1) vs. placebo (+5.5 mmol/L; 90% CI: -47.2, 58.3; P = 0.023). Statistically significant reductions in hepatic glycogen content were observed across serial measures and after a 14-hour fast (P < 0.05), with an overall change in glycogen AUC24h of -27.3% (P = 0.003) vs. placebo. In addition, a relative reduction in liver fat of 33.2% vs. placebo was reported (P = 0.006), and significant reductions in fasting alanine, glutamate, glycine, lysine, and threonine levels were also observed with cotadutide vs. placebo (all P ≤ 0.05). Beta-hydroxybutyrate and acetoacetate levels were not significantly different between the two arms. Conclusions: Cotadutide promoted a generalized reduction in hepatic glycogen and selected amino acid levels. Substantial reductions in liver fat were also observed with cotadutide, suggesting glucagon receptor engagement. Disclosure D. Robertson: Employee; Self; AstraZeneca. Stock/Shareholder; Self; AstraZeneca. L. Hansen: Employee; Self; AstraZeneca. P. Ambery: Employee; Self; AstraZeneca. R.L. Esterline: Employee; Self; AstraZeneca. L. Jermutus: Employee; Self; AstraZeneca. Stock/Shareholder; Self; AstraZeneca. Y. Chang: None. M. Petrone: Employee; Self; AstraZeneca. E. Johansson: None. L. Johansson: Employee; Self; Antaros Medical AB. Stock/Shareholder; Self; Antaros Medical AB. F.B. Sjöberg: None. V. Parker: None. Funding AstraZeneca
