| 2671. |
|
|
| 2672. |
- Petkova, Maya, 1990, et al.
(författare)
-
The complex multiscale structure in simulated and observed emission maps of the proto-cluster cloud G0.253+0.016 ('the Brick')
- 2023
-
Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 520:2, s. 2245-2268
-
Tidskriftsartikel (refereegranskat)abstract
- The Central Molecular Zone (the central ∼500 pc of the Milky Way) hosts molecular clouds in an extreme environment of strong shear, high gas pressure and density, and complex chemistry. G0.253+0.016, also known as 'the Brick', is the densest, most compact, and quiescent of these clouds. High-resolution observations with the Atacama Large Millimetre/submillimetre Array (ALMA) have revealed its complex, hierarchical structure. In this paper we compare the properties of recent hydrodynamical simulations of the Brick to those of the ALMA observations. To facilitate the comparison, we post-process the simulations and create synthetic ALMA maps of molecular line emission from eight molecules. We correlate the line emission maps to each other and to the mass column density and find that HNCO is the best mass tracer of the eight emission lines within the simulations. Additionally, we characterize the spatial structure of the observed and simulated cloud using the density probability distribution function (PDF), spatial power spectrum, fractal dimension, and moments of inertia. While we find good agreement between the observed and simulated data in terms of power spectra and fractal dimensions, there are key differences in the density PDFs and moments of inertia, which we attribute to the omission of magnetic fields in the simulations. This demonstrates that the presence of the Galactic potential can reproduce many cloud properties, but additional physical processes are needed to fully explain the gas structure.
|
|
| 2673. |
- Petrovic, Natasa, et al.
(författare)
-
Chronic Perixosome Proliferator-activated Receptor gamma (PPARgamma) activation of epididymally derived white adipocyte cultures reveals a population of thermogenically competent, UCP1-containing adipocytes molecularly distinct from classical brown adipocytes.
- 2010
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 285:10, s. 7153-7164
-
Tidskriftsartikel (refereegranskat)abstract
- The recent insight that brown adipocytes and muscle cells share a common origin and in this respect are distinct from white adipocytes has spurred questions concerning the origin and molecular characteristics of the UCP1-expressing cells observed in classical white adipose tissue depots under certain physiological or pharmacological conditions. Examining precursors from the purest white adipose tissue depot (epididymal), we report here that chronic treatment with the PPARgamma agonist rosiglitazone promotes not only the expression of PGC-1alpha and mitochondriogenesis in these cells but also a norepinephrine-augmentable UCP1 gene expression in a significant subset of the cells, providing these cells with a genuine thermogenic capacity. However, although functional thermogenic genes are expressed, the cells are devoid of transcripts for the novel transcription factors now associated with classical brown adipocytes (Zic1, Lhx8, Meox2 and characteristically PRDM16) or for myocyte-associated genes (myogenin and myomirs (muscle-specific microRNAs)) and retain white-fat characteristics such as Hoxc9 expression. Co-culture experiments verify that the UCP1-expressing cells are not proliferating classical brown adipocytes (adipomyocytes) and these cells therefore constitute a subset of adipocytes (''brite'' adipocytes) with a developmental origin and molecular characteristics distinguishing them as a separate class of cells.
|
|
| 2674. |
|
|
| 2675. |
|
|
| 2676. |
- Pettersson-Rimgard, Belinda, et al.
(författare)
-
Proton-coupled energy transfer in molecular triads
- 2022
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 377:6607, s. 742-746
-
Tidskriftsartikel (refereegranskat)abstract
- We experimentally discovered and theoretically analyzed a photochemical mechanism, which we term proton-coupled energy transfer (PCEnT). A series of anthracene-phenol-pyridine triads formed a local excited anthracene state after light excitation at a wavelength of similar to 400 nanometers (nm), which led to fluorescence around 550 nm from the phenol-pyridine unit. Direct excitation of phenolpyridine would have required similar to 330-nm light, but the coupled proton transfer within the phenolpyridine unit lowered its excited-state energy so that it could accept excitation energy from anthracene. Singlet-singlet energy transfer thus occurred despite the lack of spectral overlap between the anthracene fluorescence and the phenol-pyridine absorption. Moreover, theoretical calculations indicated negligible charge transfer between the anthracene and phenol-pyridine units. We construe PCEnT as an elementary reaction of possible relevance to biological systems and future photonic devices.
|
|
| 2677. |
|
|
| 2678. |
- Pfeiffer, Thomas, et al.
(författare)
-
Predicting the replicability of social and behavioural science claims in a crisis: The COVID-19 Preprint Replication Project
- 2023
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Replications are important for assessing the reliability of published findings. However, they are costly, and it is infeasible to replicate everything. Accurate, fast, lower-cost alternatives such as eliciting predictions could accelerate assessment for rapid policy implementation in a crisis. We elicited judgments from participants on 100 claims from preprints about an emerging area of research (COVID-19 pandemic) using an interactive structured elicitation protocol, and we conducted 29 new high-powered replications. After interacting with their peers, participant groups with lower task expertise (‘beginners’) updated their estimates and confidence in their judgements significantly more than groups with greater task expertise (‘experienced’). For experienced individuals, the average accuracy was 0.57 (95% CI: [0.53, 0.61]) after interaction, and they correctly classified 61% of claims; beginners’ average accuracy was 0.58 (95% CI: [0.54, 0.62]), correctly classifying 69% of claims. The difference in accuracy between groups was not statistically significant, and their judgments on the full set of claims were correlated (r=.48). These results suggest that both beginners and more experienced participants using a structured process have some ability to make better-than-chance predictions about the reliability of ‘fast science’ under conditions of high uncertainty. However, given the importance of such assessments for making evidence-based critical decisions in a crisis, more research is required to understand who the right experts in forecasting replicability are and how their judgements ought to be elicited.
|
|
| 2679. |
- Pham, James P., et al.
(författare)
-
Full-body skin examination in screening for cutaneous malignancy: A focus on concealed sites and the practices of international dermatologists
- 2024
-
Ingår i: JEADV CLINICAL PRACTICE. - 2768-6566. ; 3:4, s. 1132-1139
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundFull-body skin examination (FSE) is fundamental to the diagnosis of cutaneous malignancy but may not always include concealed site examination (CSE).ObjectivesTo determine the approach of international dermatologists to CSE during FSE and examine influencing factors, barriers and attitudes toward CSE.MethodsMembers of the International Dermoscopy Society were surveyed using an online 12-question survey disseminated via email.ResultsThere were 706 completed responses among 1249 unique clicks to the survey, representing a completion rate of 56.5%. Fifty-four percent of respondents reported always examining the breasts, while 52.8%, 18.8%, and 11.8% always examined the scalp, oral, and anogenital mucosa, respectively. The most frequent reason for examining concealed sites was patient concern, whilst common reasons for not examining concealed sites included low incidence of pathology and concern regarding allegations of sexual misconduct.ConclusionsOur findings allude to the need for international consensus guidelines regarding the conduct and inclusion of concealed or sensitive sites in routine FSE. This is essential to define clinician responsibilities, inform patient expectations of care, and thereby mitigate potential medicolegal repercussions.
|
|
| 2680. |
- Pichler, Irene, et al.
(författare)
-
Fine-Mapping of Restless Legs Locus 4 (RLS4) Identifies a Haplotype over the SPATS2L and KCTD18 Genes
- 2013
-
Ingår i: Journal of Molecular Neuroscience. - : Springer Science and Business Media LLC. - 0895-8696 .- 1559-1166. ; 49:3, s. 600-605
-
Tidskriftsartikel (refereegranskat)abstract
- Restless legs syndrome (RLS) is a sleep-related movement disorder that affects up to 15 % of the population. Linkage studies have identified several genomic loci in single families (12q, 14q, 9p, 2q, 20p and 16p, respectively). However, confirmation of these loci has not always been achieved, and causative mutations have not yet been identified. The locus on chromosome 2q33 (RLS4) was identified in two South Tyrolean families who shared a haplotype of microsatellite marker alleles across an 8.2-cM region. To pinpoint the gene localisation within RLS4, additional families from the same geographic region were evaluated, and linkage was replicated in one family. Within the candidate region, we initially found a haplotype of 23 single nucleotide polymorphism markers spanning 131.6 Kb shared by all affected members of the three linked families. Using a next generation sequencing approach, we further restricted the shared candidate region to 46.9 Kb over the potassium channel-related gene KCTD18 and exons 10-13 of SPATS2L.
|
|
