| 1. |
- Cederwall, Bo, et al.
(författare)
-
Evidence for a spin-aligned neutron-proton paired phase from the level structure of 92Pd
- 2011
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 469:7328, s. 68-71
-
Tidskriftsartikel (refereegranskat)abstract
- Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.
|
|
| 2. |
- Kehoe, Laura, et al.
(författare)
-
Make EU trade with Brazil sustainable
- 2019
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6438, s. 341-
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
|
|
| 3. |
- Tjernström, Michael, et al.
(författare)
-
The Arctic Summer Cloud Ocean Study (ASCOS) : overview and experimental design
- 2014
-
Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 14:6, s. 2823-2869
-
Tidskriftsartikel (refereegranskat)abstract
- The climate in the Arctic is changing faster than anywhere else on earth. Poorly understood feedback processes relating to Arctic clouds and aerosol-cloud interactions contribute to a poor understanding of the present changes in the Arctic climate system, and also to a large spread in projections of future climate in the Arctic. The problem is exacerbated by the paucity of research-quality observations in the central Arctic. Improved formulations in climate models require such observations, which can only come from measurements in situ in this difficult-to-reach region with logistically demanding environmental conditions. The Arctic Summer Cloud Ocean Study (ASCOS) was the most extensive central Arctic Ocean expedition with an atmospheric focus during the International Polar Year (IPY) 2007-2008. ASCOS focused on the study of the formation and life cycle of low-level Arctic clouds. ASCOS departed from Longyearbyen on Svalbard on 2 August and returned on 9 September 2008. In transit into and out of the pack ice, four short research stations were undertaken in the Fram Strait: two in open water and two in the marginal ice zone. After traversing the pack ice northward, an ice camp was set up on 12 August at 87 degrees 21' N, 01 degrees 29' W and remained in operation through 1 September, drifting with the ice. During this time, extensive measurements were taken of atmospheric gas and particle chemistry and physics, mesoscale and boundary-layer meteorology, marine biology and chemistry, and upper ocean physics. ASCOS provides a unique interdisciplinary data set for development and testing of new hypotheses on cloud processes, their interactions with the sea ice and ocean and associated physical, chemical, and biological processes and interactions. For example, the first-ever quantitative observation of bubbles in Arctic leads, combined with the unique discovery of marine organic material, polymer gels with an origin in the ocean, inside cloud droplets suggests the possibility of primary marine organically derived cloud condensation nuclei in Arctic stratocumulus clouds. Direct observations of surface fluxes of aerosols could, however, not explain observed variability in aerosol concentrations, and the balance between local and remote aerosols sources remains open. Lack of cloud condensation nuclei (CCN) was at times a controlling factor in low-level cloud formation, and hence for the impact of clouds on the surface energy budget. ASCOS provided detailed measurements of the surface energy balance from late summer melt into the initial autumn freeze-up, and documented the effects of clouds and storms on the surface energy balance during this transition. In addition to such process-level studies, the unique, independent ASCOS data set can and is being used for validation of satellite retrievals, operational models, and reanalysis data sets.
|
|
| 4. |
- De Palma, Adriana, et al.
(författare)
-
Predicting bee community responses to land-use changes : effects of geographic and taxonomic biases
- 2016
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 6, s. 1-14
-
Tidskriftsartikel (refereegranskat)abstract
- Land-use change and intensification threaten bee populations worldwide, imperilling pollination services. Global models are needed to better characterise, project, and mitigate bees' responses to these human impacts. The available data are, however, geographically and taxonomically unrepresentative; most data are from North America and Western Europe, overrepresenting bumblebees and raising concerns that model results may not be generalizable to other regions and taxa. To assess whether the geographic and taxonomic biases of data could undermine effectiveness of models for conservation policy, we have collated from the published literature a global dataset of bee diversity at sites facing land-use change and intensification, and assess whether bee responses to these pressures vary across 11 regions (Western, Northern, Eastern and Southern Europe; North, Central and South America; Australia and New Zealand; South East Asia; Middle and Southern Africa) and between bumblebees and other bees. Our analyses highlight strong regionally-based responses of total abundance, species richness and Simpson's diversity to land use, caused by variation in the sensitivity of species and potentially in the nature of threats. These results suggest that global extrapolation of models based on geographically and taxonomically restricted data may underestimate the true uncertainty, increasing the risk of ecological surprises.
|
|
| 5. |
- Kaufmann, Tobias, et al.
(författare)
-
Common brain disorders are associated with heritable patterns of apparent aging of the brain
- 2019
-
Ingår i: Nature Neuroscience. - : Nature Publishing Group. - 1097-6256 .- 1546-1726. ; 22:10, s. 1617-
-
Tidskriftsartikel (refereegranskat)abstract
- Common risk factors for psychiatric and other brain disorders are likely to converge on biological pathways influencing the development and maintenance of brain structure and function across life. Using structural MRI data from 45,615 individuals aged 3-96 years, we demonstrate distinct patterns of apparent brain aging in several brain disorders and reveal genetic pleiotropy between apparent brain aging in healthy individuals and common brain disorders.
|
|
| 6. |
- Carlström, Mattias, et al.
(författare)
-
L-arginine or tempol supplementation improves renal and cardiovascular function in rats with reduced renal mass and chronic high salt intake
- 2013
-
Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 207:4, s. 732-741
-
Tidskriftsartikel (refereegranskat)abstract
- Aim Early life reduction in nephron number and chronic high salt intake cause development of renal and cardiovascular disease, which has been associated with oxidative stress and nitric oxide (NO) deficiency. We investigated the hypothesis that interventions stimulating NO signalling or reducing oxidative stress may restore renal autoregulation, attenuate hypertension and reduce renal and cardiovascular injuries following reduction in renal mass and chronic high salt intake. Methods Male SpragueDawley rats were uninephrectomized (UNX) or sham-operated at 3weeks of age and given either a normal-salt (NS) or high-salt (HS) diet. Effects on renal and cardiovascular functions were assessed in rats supplemented with substrate for NO synthase (L-Arg) or a superoxide dismutase mimetic (Tempol). Results Rats with UNX+HS developed hypertension and displayed increased renal NADPH oxidase activity, elevated levels of oxidative stress markers in plasma and urine, and reduced cGMP in plasma. Histological analysis showed signs of cardiac and renal inflammation and fibrosis. These changes were linked with abnormal renal autoregulation, measured as a stronger tubuloglomerular feedback (TGF) response. Simultaneous treatment with L-Arg or Tempol restored cGMP levels in plasma and increased markers of NO signalling in the kidney. This was associated with normalized TGF responses, attenuated hypertension and reduced signs of histopathological changes in the kidney and in the heart. Conclusion Reduction in nephron number during early life followed by chronic HS intake is associated with oxidative stress, impaired renal autoregulation and development of hypertension. Treatment strategies that increase NO bioavailability, or reduce levels of reactive oxygen species, were proven beneficial in this model of renal and cardiovascular disease.
|
|
| 7. |
- Wilkinson, Mark D., et al.
(författare)
-
Comment : The FAIR Guiding Principles for scientific data management and stewardship
- 2016
-
Ingår i: Scientific Data. - : Springer Science and Business Media LLC. - 2052-4463. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- There is an urgent need to improve the infrastructure supporting the reuse of scholarly data. A diverse set of stakeholders-representing academia, industry, funding agencies, and scholarly publishers-have come together to design and jointly endorse a concise and measureable set of principles that we refer to as the FAIR Data Principles. The intent is that these may act as a guideline for those wishing to enhance the reusability of their data holdings. Distinct from peer initiatives that focus on the human scholar, the FAIR Principles put specific emphasis on enhancing the ability of machines to automatically find and use the data, in addition to supporting its reuse by individuals. This Comment is the first formal publication of the FAIR Principles, and includes the rationale behind them, and some exemplar implementations in the community.
|
|
| 8. |
- Yang, Ting, et al.
(författare)
-
Genetic Abrogation of Adenosine A(3) Receptor Prevents Uninephrectomy and High Salt-Induced Hypertension
- 2016
-
Ingår i: Journal of the American Heart Association. - 2047-9980 .- 2047-9980. ; 5:7
-
Tidskriftsartikel (refereegranskat)abstract
- Background - Early-life reduction in nephron number (uninephrectomy [UNX]) and chronic high salt (HS) intake increase the risk of hypertension and chronic kidney disease. Adenosine signaling via its different receptors has been implicated in modulating renal, cardiovascular, and metabolic functions as well as inflammatory processes; however, the specific role of the A(3) receptor in cardiovascular diseases is not clear. In this study, gene-modified mice were used to investigate the hypothesis that lack of A(3) signaling prevents the development of hypertension and attenuates renal and cardiovascular injuries following UNX in combination with HS (UNX-HS) in mice.Methods and Results - Wild-type (A(3)(+/+)) mice subjected to UNX-HS developed hypertension compared with controls (mean arterial pressure 106 +/- 3 versus 82 +/- 3 mm Hg; P<0.05) and displayed an impaired metabolic phenotype (eg, increased adiposity, reduced glucose tolerance, hyperinsulinemia). These changes were associated with both cardiac hypertrophy and fibrosis together with renal injuries and proteinuria. All of these pathological hallmarks were significantly attenuated in the A(3)(-/-) mice. Mechanistically, absence of A(3) receptors protected from UNX-HS-associated increase in renal NADPH oxidase activity and Nox2 expression. In addition, circulating cytokines including interleukins 1 beta, 6, 12, and 10 were increased in A(3)(+/+) following UNX-HS, but these cytokines were already elevated in naive A(3)(-/-) mice and did not change following UNX-HS.Conclusions - Reduction in nephron number combined with chronic HS intake is associated with oxidative stress, chronic inflammation, and development of hypertension in mice. Absence of adenosine A(3) receptor signaling was strongly protective in this novel mouse model of renal and cardiovascular disease.
|
|
| 9. |
|
|
| 10. |
- Gao, Xiang, et al.
(författare)
-
Adenosine A(1)-receptor deficiency diminishes afferent arteriolar and blood pressure responses during nitric oxide inhibition and angiotensin II treatment
- 2011
-
Ingår i: American Journal of Physiology. Regulatory Integrative and Comparative Physiology. - : American Physiological Society. - 0363-6119 .- 1522-1490. ; 301:6, s. R1669-R1681
-
Tidskriftsartikel (refereegranskat)abstract
- Adenosine mediates tubuloglomerular feedback responses via activation of A(1)-receptors on the renal afferent arteriole. Increased preglomerular reactivity, due to reduced nitric oxide (NO) production or increased levels of ANG II and reactive oxygen species (ROS), has been linked to hypertension. Using A(1)-receptor knockout (A(1)(-/-)) and wild-type (A(1)(+/+)) mice we investigated the hypothesis that A(1)-receptors modulate arteriolar and blood pressure responses during NO synthase (NOS) inhibition or ANG II treatment. Blood pressure and renal afferent arteriolar responses were measured in nontreated mice and in mice with prolonged N(omega)-nitro-L-arginine methyl ester hydrochloride (L-NAME) or ANG II treatment. The hypertensive responses to L-NAME and ANG II were clearly attenuated in A(1)(-/-) mice. Arteriolar contractions to L-NAME (10(-4) mol/l; 15 min) and cumulative ANG II application (10(-12) to 10(-6) mol/l) were lower in A(1)(-/-) mice. Simultaneous treatment with tempol (10(-4) mol/l; 15 min) attenuated arteriolar responses in A(1)(+/+) but not in A(1)(-/-) mice, suggesting differences in ROS formation. Chronic treatment with L-NAME or ANG II did not alter arteriolar responses in A(1)(-/-) mice, but enhanced maximal contractions in A(1)(+/+) mice. In addition, chronic treatments were associated with higher plasma levels of dimethylarginines (asymmetrical and symmetrical) and oxidative stress marker malondialdehyde in A(1)(+/+) mice, and gene expression analysis showed reduced upregulation of NOS-isoforms and greater upregulation of NADPH oxidases. In conclusion, adenosine A(1)-receptors enhance preglomerular responses during NO inhibition and ANG II treatment. Interruption of A(1)-receptor signaling blunts L-NAME and ANG II-induced hypertension and oxidative stress and is linked to reduced responsiveness of afferent arterioles.
|
|
