| 1. |
- Prusti, T., et al.
(författare)
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The Gaia mission
- 2016
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 595
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Tidskriftsartikel (refereegranskat)abstract
- Gaia is a cornerstone mission in the science programme of the European Space Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page.
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| 2. |
- Clementini, G., et al.
(författare)
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Testing parallaxes with local Cepheids and RR Lyrae stars
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 605
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Tidskriftsartikel (refereegranskat)abstract
- Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the HIPPARCOS and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (MV-[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS.Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with sigma(omega)/omega < 0 : 5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with sigma(omega)/omega 0 : 5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with sigma(omega)/omega < 0 : 5). The new relations were computed using multi- band (V; I; J; K-s) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL; PW; PLZ, and MV [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods.Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the HIPPARCOS measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive.Conclusions. TGAS parallaxes bring a significant added value to the previous HIPPARCOS estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018.
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| 3. |
- Brown, A. G. A., et al.
(författare)
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Gaia Data Release 1 Summary of the astrometric, photometric, and survey properties
- 2016
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 595
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Tidskriftsartikel (refereegranskat)abstract
- Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of similar to 3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr(-1) for the proper motions. A systematic component of similar to 0.3 mas should be added to the parallax uncertainties. For the subset of similar to 94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr(-1). For the secondary astrometric data set, the typical uncertainty of the positions is similar to 10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to similar to 0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data.
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| 4. |
- van Leeuwen, F., et al.
(författare)
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Gaia Data Release 1 : Open cluster astrometry: Performance, limitations, and future prospects
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 601
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Tidskriftsartikel (refereegranskat)abstract
- Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs.
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| 5. |
- Teixeira, J., et al.
(författare)
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Tropical and Subtropical Cloud Transitions in Weather and Climate Prediction Models : The GCSS/WGNE Pacific Cross-Section Intercomparison (GPCI)
- 2011
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Ingår i: Journal of Climate. - 0894-8755 .- 1520-0442. ; 24:20, s. 5223-5256
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Tidskriftsartikel (refereegranskat)abstract
- A model evaluation approach is proposed in which weather and climate prediction models are analyzed along a Pacific Ocean cross section, from the stratocumulus regions off the coast of California, across the shallow convection dominated trade winds, to the deep convection regions of the ITCZ-the Global Energy and Water Cycle Experiment Cloud System Study/Working Group on Numerical Experimentation (GCSS/WGNE) Pacific Cross-Section Intercomparison (GPCI). The main goal of GPCI is to evaluate and help understand and improve the representation of tropical and subtropical cloud processes in weather and climate prediction models. In this paper, a detailed analysis of cloud regime transitions along the cross section from the subtropics to the tropics for the season June-July-August of 1998 is presented. This GPCI study confirms many of the typical weather and climate prediction model problems in the representation of clouds: underestimation of clouds in the stratocumulus regime by most models with the corresponding consequences in terms of shortwave radiation biases; overestimation of clouds by the 40-yr ECMWF Re-Analysis (ERA-40) in the deep tropics (in particular) with the corresponding impact in the outgoing longwave radiation; large spread between the different models in terms of cloud cover, liquid water path and shortwave radiation; significant differences between the models in terms of vertical cross sections of cloud properties (in particular), vertical velocity, and relative humidity. An alternative analysis of cloud cover mean statistics is proposed where sharp gradients in cloud cover along the GPCI transect are taken into account. This analysis shows that the negative cloud bias of some models and ERA-40 in the stratocumulus regions [as compared to the first International Satellite Cloud Climatology Project (ISCCP)] is associated not only with lower values of cloud cover in these regimes, but also with a stratocumulus-to-cumulus transition that occurs too early along the trade wind Lagrangian trajectory. Histograms of cloud cover along the cross section differ significantly between models. Some models exhibit a quasi-bimodal structure with cloud cover being either very large (close to 100%) or very small, while other models show a more continuous transition. The ISCCP observations suggest that reality is in-between these two extreme examples. These different patterns reflect the diverse nature of the cloud, boundary layer, and convection parameterizations in the participating weather and climate prediction models.
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| 6. |
- Svensson, Gunilla, et al.
(författare)
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Evaluation of the Diurnal Cycle in the Atmospheric Boundary Layer Over Land as Represented by a Variety of Single-Column Models : The Second GABLS Experiment
- 2011
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Ingår i: Boundary-layer Meteorology. - : Springer Science and Business Media LLC. - 0006-8314 .- 1573-1472. ; 140:2, s. 177-206
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Tidskriftsartikel (refereegranskat)abstract
- We present the main results from the second model intercomparison within the GEWEX (Global Energy and Water cycle EXperiment) Atmospheric Boundary Layer Study (GABLS). The target is to examine the diurnal cycle over land in today's numerical weather prediction and climate models for operational and research purposes. The set-up of the case is based on observations taken during the Cooperative Atmosphere-Surface Exchange Study-1999 (CASES-99), which was held in Kansas, USA in the early autumn with a strong diurnal cycle with no clouds present. The models are forced with a constant geostrophic wind, prescribed surface temperature and large-scale divergence. Results from 30 different model simulations and one large-eddy simulation (LES) are analyzed and compared with observations. Even though the surface temperature is prescribed, the models give variable near-surface air temperatures. This, in turn, gives rise to differences in low-level stability affecting the turbulence and the turbulent heat fluxes. The increase in modelled upward sensible heat flux during the morning transition is typically too weak and the growth of the convective boundary layer before noon is too slow. This is related to weak modelled near-surface winds during the morning hours. The agreement between the models, the LES and observations is the best during the late afternoon. From this intercomparison study, we find that modelling the diurnal cycle is still a big challenge. For the convective part of the diurnal cycle, some of the first-order schemes perform somewhat better while the turbulent kinetic energy (TKE) schemes tend to be slightly better during nighttime conditions. Finer vertical resolution tends to improve results to some extent, but is certainly not the solution to all the deficiencies identified.
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| 7. |
- Lock, Nina, et al.
(författare)
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Scrutinizing negative thermal expansion in MOF-5 by scattering techniques and ab initio calculations
- 2013
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9234. ; 42:6, s. 1996-2007
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Tidskriftsartikel (refereegranskat)abstract
- Complementary experimental techniques and ab initio calculations were used to determine the origin and nature of negative thermal expansion (NTE) in the archetype metal-organic framework MOF-5 (Zn4O(1,4-benzenedicarboxylate) (3)). The organic linker was probed by inelastic neutron scattering under vacuum and at a gas pressure of 175 bar to distinguish between the pressure and temperature responses of the framework motions, and the local structure of the metal centers was studied by X-ray absorption spectroscopy. Multi-temperature powder-and single-crystal X-ray and neutron diffraction was used to characterize the polymeric nature of the sample and to quantify NTE over the large temperature range 4-400 K. Ab initio calculations complement the experimental data with detailed information on vibrational motions in the framework and their correlations. A uniform and comprehensive picture of NTE in MOF-5 has been drawn, and we provide direct evidence that the main contributor to NTE is translational transverse motion of the aromatic ring, which can be dampened by applying a gas pressure to the sample. The linker motion is highly correlated rather than local in nature. The relative energies of different framework vibrations populated in MOF-5 are suggested by analysis of neutron diffraction data. We note that the lowest-energy motion is a librational motion of the aromatic ring which does not contribute to NTE. The libration is followed by transverse motion of the linker and the carboxylate group. These motions result in unit-cell contraction with increasing temperature.
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| 8. |
- Garcia-Carreras, Luis, et al.
(författare)
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The Turbulent Structure and Diurnal Growth of the Saharan Atmospheric Boundary Layer
- 2015
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Ingår i: Journal of the Atmospheric Sciences. - 0022-4928 .- 1520-0469. ; 72:2, s. 693-713
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Tidskriftsartikel (refereegranskat)abstract
- The turbulent structure and growth of the remote Saharan atmospheric boundary layer (ABL) is described with in situ radiosonde and aircraft measurements and a large-eddy simulation model. A month of radiosonde data from June 2011 provides a mean profile of the midday Saharan ABL, which is characterized by a well-mixed convective boundary layer, capped by a small temperature inversion (<1K) and a deep, near-neutral residual layer. The boundary layer depth varies by up to 100% over horizontal distances of a few kilometers due to turbulent processes alone. The distinctive vertical structure also leads to unique boundary layer processes, such as detrainment of the warmest plumes across the weak temperature inversion, which slows down the warming and growth of the convective boundary layer. As the boundary layer grows, overshooting plumes can also entrain free-tropospheric air into the residual layer, forming a second entrainment zone that acts to maintain the inversion above the convective boundary layer, thus slowing down boundary layer growth further. A single-column model is unable to accurately reproduce the evolution of the Saharan boundary layer, highlighting the difficulty of representing such processes in large-scale models. These boundary layer processes are special to the Sahara, and possibly hot, dry, desert environments in general, and have implications for the large-scale structure of the Saharan heat low. The growth of the boundary layer influences the vertical redistribution of moisture and dust, and the spatial coverage and duration of clouds, with large-scale dynamical and radiative implications.
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| 9. |
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| 10. |
- Bravender, T., et al.
(författare)
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Classification of Eating Disturbance in Children and Adolescents: Proposed Changes for the DSM-V
- 2010
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Ingår i: European Eating Disorders Review. - : Wiley. - 1072-4133 .- 1099-0968. ; 18:2, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- Childhood and adolescence are critical periods of neural development and physical growth. The malnutrition and related medical complications resulting from eating disorders such as anorexia nervosa (AN), bulimia nervosa (BN) and eating disorder not otherwise specified may have more severe and potentially more protracted consequences during youth than during other age periods. The consensus opinion of an international workgroup of experts on the diagnosis and treatment of child and adolescent eating disorders is that (a) lower and more developmentally sensitive threshold's of symptom seventy (e.g lower frequency of purging behaviours, significant deviations from growth curves as indicators of clinical seventy) be used as diagnostic boundaries for children and adolescents, (b) behavioural indicators of psychological features of eating disorders be considered even in the absence of direct self-report of such symptoms and (C) multiple informants (e.g parents) be used to ascertain symptom profiles. Collectively, these recommendations will permit earlier identification and intervention to prevent the exacerbation of eating disorder symptoms. Copyright (C) 2010 John Wiley & Sons, Ltd and Eating Disorders Association
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| 11. |
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| 12. |
- Cheung, LC, et al.
(författare)
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Preclinical efficacy of azacitidine and venetoclax for infant KMT2A-rearranged acute lymphoblastic leukemia reveals a new therapeutic strategy
- 2023
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 37:1, s. 61-71
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Tidskriftsartikel (refereegranskat)abstract
- Infants with KMT2A-rearranged B-cell acute lymphoblastic leukemia (ALL) have a dismal prognosis. Survival outcomes have remained static in recent decades despite treatment intensification and novel therapies are urgently required. KMT2A-rearranged infant ALL cells are characterized by an abundance of promoter hypermethylation and exhibit high BCL-2 expression, highlighting potential for therapeutic targeting. Here, we show that hypomethylating agents exhibit in vitro additivity when combined with most conventional chemotherapeutic agents. However, in a subset of samples an antagonistic effect was seen between several agents. This was most evident when hypomethylating agents were combined with methotrexate, with upregulation of ATP-binding cassette transporters identified as a potential mechanism. Single agent treatment with azacitidine and decitabine significantly prolonged in vivo survival in KMT2A-rearranged infant ALL xenografts. Treatment of KMT2A-rearranged infant ALL cell lines with azacitidine and decitabine led to differential genome-wide DNA methylation, changes in gene expression and thermal proteome profiling revealed the target protein-binding landscape of these agents. The selective BCL-2 inhibitor, venetoclax, exhibited in vitro additivity in combination with hypomethylating or conventional chemotherapeutic agents. The addition of venetoclax to azacitidine resulted in a significant in vivo survival advantage indicating the therapeutic potential of this combination to improve outcome for infants with KMT2A-rearranged ALL.
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| 13. |
- Colo, GP, et al.
(författare)
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Focal adhesion disassembly is regulated by a RIAM to MEK-1 pathway
- 2012
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Ingår i: Journal of cell science. - : The Company of Biologists. - 1477-9137 .- 0021-9533. ; 125:22Pt 22, s. 5338-5352
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Tidskriftsartikel (refereegranskat)abstract
- Cell migration and invasion require regulated turnover of integrin-dependent adhesion complexes. RIAM is an adaptor protein mediating talin recruitment to the cell membrane, whose depletion leads to defective melanoma cell migration and invasion. Here we investigated the potential involvement of RIAM in focal adhesion (FA) dynamics. RIAM-depleted melanoma and breast carcinoma cells displayed an increased number, size and stability of FAs, which accumulated centrally located at the ventral cell surface, a phenotype caused by defective FA disassembly. Impairment in FA disassembly due to RIAM knocking down correlated with deficient integrin-dependent MEK-Erk1/2 activation, and importantly, overexpression of constitutively active MEK resulted in rescue of FA disassembly and recovery of cell invasion. Furthermore, RIAM-promoted RhoA activation following integrin engagement was needed for subsequent Erk1/2 activation, and RhoA overexpression partially rescued the FA phenotype in RIAM-depleted cells, suggesting a functional role also for RhoA downstream of RIAM, but upstream of Erk1/2. In addition, RIAM knock down led to enhanced phosphorylation of paxillin Tyr118 and Tyr31. However, expression of phosphomimetic and non-phosphorylatable mutants at these paxillin residues indicated that paxillin hyper-phosphorylation is a subsequent consequence of the blockade of FA disassembly, but does not cause the FA phenotype. RIAM depletion also weakened association between FA proteins, suggesting that it may play important adaptor roles for the correct assembly of adhesion complexes. Our data indicate that integrin-triggered, RIAM-dependent MEK activation may represent a key feed-back event required for efficient FA disassembly, which may contribute to explain the role of RIAM in cell migration and invasion.
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| 14. |
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| 15. |
- Miller, V., et al.
(författare)
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Availability, affordability, and consumption of fruits and vegetables in 18 countries across income levels: findings from the Prospective Urban Rural Epidemiology (PURE) study
- 2016
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Ingår i: Lancet Global Health. - : Elsevier BV. - 2214-109X. ; 4:10
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Tidskriftsartikel (refereegranskat)abstract
- Background Several international guidelines recommend the consumption of two servings of fruits and three servings of vegetables per day, but their intake is thought to be low worldwide. We aimed to determine the extent to which such low intake is related to availability and affordability. Methods We assessed fruit and vegetable consumption using data from country-specific, validated semi-quantitative food frequency questionnaires in the Prospective Urban Rural Epidemiology (PURE) study, which enrolled participants from communities in 18 countries between Jan 1, 2003, and Dec 31, 2013. We documented household income data from participants in these communities; we also recorded the diversity and non-sale prices of fruits and vegetables from grocery stores and market places between Jan 1, 2009, and Dec 31, 2013. We determined the cost of fruits and vegetables relative to income per household member. Linear random effects models, adjusting for the clustering of households within communities, were used to assess mean fruit and vegetable intake by their relative cost. Findings Of 143 305 participants who reported plausible energy intake in the food frequency questionnaire, mean fruit and vegetable intake was 3.76 servings (95% CI 3.66-3.86) per day. Mean daily consumption was 2.14 servings (1.93-2.36) in low-income countries (LICs), 3.17 servings (2.99-3.35) in lower-middle-income countries (LMICs), 4.31 servings (4.09-4.53) in upper-middle-income countries (UMICs), and 5.42 servings (5.13-5.71) in high-income countries (HICs). In 130 402 participants who had household income data available, the cost of two servings of fruits and three servings of vegetables per day per individual accounted for 51.97% (95% CI 46.06-57.88) of household income in LICs, 18.10% (14.53-21.68) in LMICs, 15.87% (11.51-20.23) in UMICs, and 1.85% (-3.90 to 7.59) in HICs (p(trend) = 0.0001). In all regions, a higher percentage of income to meet the guidelines was required in rural areas than in urban areas (p<0.0001 for each pairwise comparison). Fruit and vegetable consumption among individuals decreased as the relative cost increased (p(trend) = 0.00040). Interpretation The consumption of fruit and vegetables is low worldwide, particularly in LICs, and this is associated with low aff ordability. Policies worldwide should enhance the availability and aff ordability of fruits and vegetables.
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| 16. |
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| 17. |
- Birch, C. E., et al.
(författare)
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Modelling atmospheric structure, cloud and their response to CCN in the central Arctic : ASCOS case studies
- 2012
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 12:7, s. 3419-3435
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Tidskriftsartikel (refereegranskat)abstract
- Observations made during late summer in the central Arctic Ocean, as part of the Arctic Summer Cloud Ocean Study (ASCOS), are used to evaluate cloud and vertical temperature structure in the Met Office Unified Model (MetUM). The observation period can be split into 5 regimes; the first two regimes had a large number of frontal systems, which were associated with deep cloud. During the remainder of the campaign a layer of low-level cloud occurred, typical of central Arctic summer conditions, along with two periods of greatly reduced cloud cover. The short-range operational NWP forecasts could not accurately reproduce the observed variations in near-surface temperature. A major source of this error was found to be the temperature-dependant surface albedo parameterisation scheme. The model reproduced the low-level cloud layer, though it was too thin, too shallow, and in a boundary-layer that was too frequently well-mixed. The model was also unable to reproduce the observed periods of reduced cloud cover, which were associated with very low cloud condensation nuclei (CCN) concentrations (< 1 cm(-3)). As with most global NWP models, the MetUM does not have a prognostic aerosol/cloud scheme but uses a constant CCN concentration of 100 cm(-3) over all marine environments. It is therefore unable to represent the low CCN number concentrations and the rapid variations in concentration frequently observed in the central Arctic during late summer. Experiments with a single-column model configuration of the MetUM show that reducing model CCN number concentrations to observed values reduces the amount of cloud, increases the near-surface stability, and improves the representation of both the surface radiation fluxes and the surface temperature. The model is shown to be sensitive to CCN only when number concentrations are less than 10-20 cm(-3).
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| 18. |
- Chung, Ning Ning, et al.
(författare)
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Sex-linked genetic diversity originates from persistent sociocultural processes at microgeographic scales
- 2019
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 6:8
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Tidskriftsartikel (refereegranskat)abstract
- Population genetics has been successful at identifying the relationships between human groups and their interconnected histories. However, the link between genetic demography inferred at large scales and the individual human behaviours that ultimately generate that demography is not always clear. While anthropological and historical context are routinely presented as adjuncts in population genetic studies to help describe the past, determining how underlying patterns of human sociocultural behaviour impact genetics still remains challenging. Here, we analyse patterns of genetic variation in village-scale samples from two islands in eastern Indonesia, patrilocal Sumba and a matrilocal region of Timor. Adopting a ‘process modelling’ approach, we iteratively explore combinations of structurally different models as a thinking tool. We find interconnected socio-genetic interactions involving sex-biased migration, lineage-focused founder effects, and on Sumba, heritable social dominance. Strikingly, founder ideology, a cultural model derived from anthropological and archaeological studies at larger regional scales, has both its origins and impact at the scale of villages. Process modelling lets us explore these complex interactions, first by circumventing the complexity of formal inference when studying large datasets with many interacting parts, and then by explicitly testing complex anthropological hypotheses about sociocultural behaviour from a more familiar population genetic standpoint.
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| 19. |
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| 20. |
- Lansing, J. Stephen, et al.
(författare)
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Adaptive self-organization of Bali's ancient rice terraces
- 2017
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:25, s. 6504-6509
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Tidskriftsartikel (refereegranskat)abstract
- Spatial patterning often occurs in ecosystems as a result of a self-organizing process caused by feedback between organisms and the physical environment. Here, we show that the spatial patterns observable in centuries-old Balinese rice terraces are also created by feedback between farmers' decisions and the ecology of the paddies, which triggers a transition from local to global-scale control of water shortages and rice pests. We propose an evolutionary game, based on local farmers' decisions that predicts specific power laws in spatial patterning that are also seen in a multispectral image analysis of Balinese rice terraces. The model shows how feedbacks between human decisions and ecosystem processes can evolve toward an optimal state in which total harvests are maximized and the system approaches Pareto optimality. It helps explain how multiscale cooperation from the community to the watershed scale could persist for centuries, and why the disruption of this self-organizing system by the Green Revolution caused chaos in irrigation and devastating losses from pests. The model shows that adaptation in a coupled human-natural system can trigger self-organized criticality (SOC). In previous exogenously driven SOC models, adaptation plays no role, and no optimization occurs. In contrast, adaptive SOC is a self-organizing process where local adaptations drive the system toward local and global optima.
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| 21. |
- Lansing, J. Stephen, et al.
(författare)
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Kinship structures create persistent channels for language transmission
- 2017
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:49, s. 12910-12915
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Tidskriftsartikel (refereegranskat)abstract
- Languages are transmitted through channels created by kinship systems. Given sufficient time, these kinship channels can change the genetic and linguistic structure of populations. In traditional societies of eastern Indonesia, finely resolved cophylogenies of languages and genes reveal persistent movements between stable speech communities facilitated by kinship rules. When multiple languages are present in a region and post-marital residence rules encourage sustained directional movement between speech communities, then languages should be channeled along uniparental lines. We find strong evidence for this pattern in 982 individuals from 25 villages on two adjacent islands, where different kinship rules have been followed. Core groups of close relatives have stayed together for generations, while remaining in contact with, and marrying into, surrounding groups. Over time, these kinship systems shaped their gene and language phylogenies: Consistently following a postmarital residence rule turned social communities into speech communities.
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| 22. |
- Lock, John G, et al.
(författare)
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Reticular adhesions are a distinct class of cell-matrix adhesions that mediate attachment during mitosis
- 2018
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Ingår i: Nature Cell Biology. - Stockholm : Karolinska Institutet, Dept of Biosciences and Nutrition. - 1465-7392 .- 1476-4679.
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Tidskriftsartikel (refereegranskat)abstract
- Adhesion to the extracellular matrix persists during mitosis in most cell types. However, while classical adhesion complexes, such as focal adhesions, do and must disassemble to enable mitotic rounding, the mechanisms of residual mitotic cell-extracellular matrix adhesion remain undefined. Here, we identify 'reticular adhesions', a class of adhesion complex that is mediated by integrin alpha v beta 5, formed during interphase, and preserved at cell-extracellular matrix attachment sites throughout cell division. Consistent with this role, integrin beta 5 depletion perturbs mitosis and disrupts spatial memory transmission between cell generations. Reticular adhesions are morphologically and dynamically distinct from classical focal adhesions. Mass spectrometry defines their unique composition, enriched in phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P-2)-binding proteins but lacking virtually all consensus adhesome components. Indeed, reticular adhesions are promoted by PtdIns(4,5)P-2, and form independently of talin and F-actin. The distinct characteristics of reticular adhesions provide a solution to the problem of maintaining cell-extracellular matrix attachment during mitotic rounding and division.
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| 23. |
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| 24. |
- Plantard, L, et al.
(författare)
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PtdIns(3,4,5)P₃ is a regulator of myosin-X localization and filopodia formation
- 2010
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Ingår i: Journal of cell science. - : The Company of Biologists. - 1477-9137 .- 0021-9533. ; 123:20Pt 20, s. 3525-3534
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Tidskriftsartikel (refereegranskat)abstract
- Phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P3] is a key regulator of cell signaling that acts by recruiting proteins to the cell membrane, such as at the leading edge during cell migration. Here, we show that PtdIns (3,4,5)P3 plays a central role in filopodia formation via the binding of myosin-X (Myo10), a potent promoter of filopodia. We found that the second pleckstrin homology domain (Myo10-PH2) of Myo10 specifically binds to PtdIns(3,4,5)P3, and that disruption of this binding led to impairment of filopodia and partial re-localization of Myo10 to microtubule-associated Rab7-positive endosomal vesicles. Given that the localization of Myo10 was dynamically restored to filopodia upon reinstatement of PtdIns(3,4,5)P3-binding, our results indicate that PtdIns(3,4,5)P3 binding to the Myo10-PH2 domain is involved in Myo10 trafficking and regulation of filopodia dynamics.
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| 25. |
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| 26. |
- Vallurupalli, M., et al.
(författare)
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Students for global oncology: Building a movement for student education and engagement in an emerging field
- 2015
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Ingår i: Annals of Global Health. - : Ubiquity Press, Ltd.. - 2214-9996. ; 81:1, s. 56-56
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Program/Project Purpose: Increased recognition of the global cancer burden and inequalities in care and outcomes have led to the growing field of global oncology, focused on strengthening health systems to improve cancer prevention and care. Motivated students and trainees are in need of pathways to approach these challenges. In 2012, Harvard Medical students formed Students for Global Oncology (S4GO), an adjunct to the larger inter-professional organization Global Oncology. The group had three aims: 1) connect students with mentors in the field, 2) develop novel approaches in global oncology, and 3) disseminate global oncology knowledge. Structure/Method/Design: S4GO has created content and organized events to increase awareness about the global cancer burden, while promoting trainee opportunities in research and practical hands-on projects. Engagement was enhanced by mentorship from more senior students and faculty, to interface with existing global oncology projects. Outcomes & Evaluation: Since 2012, S4GO has grown from two to 68 students. Currently, new chapters at seven other institutions in the US and Canada are being developed. As of October 2014, S4GO has developed a case-based cancer care delivery curriculum with six case-based seminars, along with numerous blog entries and interviews of leading researchers in the field of global oncology, all available on the S4GO website. Students have completed projects in over nine countries and are actively involved in technological and on-the-ground efforts to develop creative solutions and collaborations aimed at easing the global cancer burden. Held in February 2014, the inaugural student-led global oncology symposium involved 200 individuals from across the world, including leaders in global health, pharmaceutical industry, public policy and cancer care. This symposium has been viewed by hundreds online and has fostered novel collaborations and projects focused on enhancing cancer care delivery. Going Forward: In the coming years, S4GO will continue efforts to build awareness and catalyze creative solutions for cancer care in resource-limited settings. These efforts will increase exposure for novel and successful student efforts as well as intra-institutional and intra-professional activity.
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| 27. |
- Willms, A. G., et al.
(författare)
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Factors influencing the fascial closure rate after open abdomen treatment : Results from the European Hernia Society (EuraHS) Registry Surgical technique matters
- 2022
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Ingår i: Hernia. - : Springer Nature. - 1265-4906 .- 1248-9204. ; 26:1, s. 61-73
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Tidskriftsartikel (refereegranskat)abstract
- Purpose Definitive fascial closure is an essential treatment objective after open abdomen treatment and mitigates morbidity and mortality. There is a paucity of evidence on factors that promote or prevent definitive fascial closure. Methods A multi-center multivariable analysis of data from the Open Abdomen Route of the European Hernia Society included all cases between 1 May 2015 and 31 December 2019. Different treatment elements, i.e. the use of a visceral protective layer, negative-pressure wound therapy and dynamic closure techniques, as well as patient characteristics were included in the multivariable analysis. The study was registered in the International Clinical Trials Registry Platform via the German Registry for Clinical Trials (DRK00021719). Results Data were included from 630 patients from eleven surgical departments in six European countries. Indications for OAT were peritonitis (46%), abdominal compartment syndrome (20.5%), burst abdomen (11.3%), abdominal trauma (9%), and other conditions (13.2%). The overall definitive fascial closure rate was 57.5% in the intention-to-treat analysis and 71% in the per-protocol analysis. The multivariable analysis showed a positive correlation of negative-pressure wound therapy (odds ratio: 2.496, p < 0.001) and dynamic closure techniques (odds ratio: 2.687, p < 0.001) with fascial closure and a negative correlation of intra-abdominal contamination (odds ratio: 0.630, p = 0.029) and the number of surgical procedures before OAT (odds ratio: 0.740, p = 0.005) with DFC. Conclusion The clinical course and prognosis of open abdomen treatment can significantly be improved by the use of treatment elements such as negative-pressure wound therapy and dynamic closure techniques, which are associated with definitive fascial closure.
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