| 1. |
- Kanai, M, et al.
(författare)
-
- 2023
-
swepub:Mat__t
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Lenton, S, et al.
(författare)
-
Dynamic footprint of sequestration in the molecular fluctuations of osteopontin.
- 2015
-
Ingår i: Journal of the Royal Society Interface. - : The Royal Society. - 1742-5662 .- 1742-5689. ; 12:110
-
Tidskriftsartikel (refereegranskat)abstract
- The sequestration of calcium phosphate by unfolded proteins is fundamental to the stabilization of biofluids supersaturated with respect to hydroxyapatite, such as milk, blood or urine. The unfolded state of osteopontin (OPN) is thought to be a prerequisite for this activity, which leads to the formation of core-shell calcium phosphate nanoclusters. We report on the structures and dynamics of a native OPN peptide from bovine milk, studied by neutron spectroscopy and small-angle X-ray and neutron scattering. The effects of sequestration are quantified on the nanosecond- ångström resolution by elastic incoherent neutron scattering. The molecular fluctuations of the free phosphopeptide are in agreement with a highly flexible protein. An increased resilience to diffusive motions of OPN is corroborated by molecular fluctuations similar to those observed for globular proteins, yet retaining conformational flexibilities. The results bring insight into the modulation of the activity of OPN and phosphopeptides with a role in the control of biomineralization. The quantification of such effects provides an important handle for the future design of new peptides based on the dynamics-activity relationship.
|
|
| 5. |
- Rockström, Johan, et al.
(författare)
-
A safe operating space for humanity
- 2013
-
Ingår i: The Future of Nature. - : Yale University Press. - 9780300184617 ; , s. 491-501
-
Bokkapitel (refereegranskat)
|
|
| 6. |
- Abrams, Jesse F., et al.
(författare)
-
Committed Global Warming Risks Triggering Multiple Climate Tipping Points
- 2023
-
Ingår i: Earth's Future. - 2328-4277. ; 11:11
-
Tidskriftsartikel (refereegranskat)abstract
- Many scenarios for limiting global warming to 1.5(degrees)C assume planetary-scale carbon dioxide removal sufficient to exceed anthropogenic emissions, resulting in radiative forcing falling and temperatures stabilizing. However, such removal technology may prove unfeasible for technical, environmental, political, or economic reasons, resulting in continuing greenhouse gas emissions from hard-to-mitigate sectors. This may lead to constant concentration scenarios, where net anthropogenic emissions remain non-zero but small, and are roughly balanced by natural carbon sinks. Such a situation would keep atmospheric radiative forcing roughly constant. Fixed radiative forcing creates an equilibrium committed warming, captured in the concept of equilibrium climate sensitivity. This scenario is rarely analyzed as a potential extension to transient climate scenarios. Here, we aim to understand the planetary response to such fixed concentration commitments, with an emphasis on assessing the resulting likelihood of exceeding temperature thresholds that trigger climate tipping points. We explore transients followed by respective equilibrium committed warming initiated under low to high emission scenarios. We find that the likelihood of crossing the 1.5(degrees)C threshold and the 2.0(degrees)C threshold is 83% and 55%, respectively, if today's radiative forcing is maintained until achieving equilibrium global warming. Under the scenario that best matches current national commitments (RCP4.5), we estimate that in the transient stage, two tipping points will be crossed. If radiative forcing is then held fixed after the year 2100, a further six tipping point thresholds are crossed. Achieving a trajectory similar to RCP2.6 requires reaching net-zero emissions rapidly, which would greatly reduce the likelihood of tipping events.
|
|
| 7. |
- Brovkin, Victor, et al.
(författare)
-
Past abrupt changes, tipping points and cascading impacts in the Earth system
- 2021
-
Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 14:8, s. 550-558
-
Forskningsöversikt (refereegranskat)abstract
- A synthesis of intervals of rapid climatic change evident in the geological record reveals some of the Earth system processes and tipping points that could lead to similar events in the future. The geological record shows that abrupt changes in the Earth system can occur on timescales short enough to challenge the capacity of human societies to adapt to environmental pressures. In many cases, abrupt changes arise from slow changes in one component of the Earth system that eventually pass a critical threshold, or tipping point, after which impacts cascade through coupled climate-ecological-social systems. The chance of detecting abrupt changes and tipping points increases with the length of observations. The geological record provides the only long-term information we have on the conditions and processes that can drive physical, ecological and social systems into new states or organizational structures that may be irreversible within human time frames. Here, we use well-documented abrupt changes of the past 30 kyr to illustrate how their impacts cascade through the Earth system. We review useful indicators of upcoming abrupt changes, or early warning signals, and provide a perspective on the contributions of palaeoclimate science to the understanding of abrupt changes in the Earth system.
|
|
| 8. |
- Fischer, B., et al.
(författare)
-
Cannabis Policy : Moving beyond Stalemate
- 2010
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- "Cannabis, marijuana, pot, ganja - it goes by many names -- is by far the most widely used illegal substance, and accounts for more arrests than any other drug. Barely a week goes by without this drug appearing in the newpapers, and politicians have famously tied themselve in knots, trying to decide just how to deal with this recreational drug. While there have been many drug policy books on other substances - both legal and illegal, few have focused on this drug. Cannabis Policy: Moving beyond Stalemate is unique in providing the materials needed for deciding on policy about cannabis in its various forms. It reviews the state of knowledge on the health and psychological effects of cannabis, and its dangerousness relative to other drugs. It considers patterns and trends in use, the size and character of illicit markets, and the administration of current policies, including arrests and diversion to treatment, under the global prohibition regime. It looks at the experience of a number of countries which have tried reforming their regimes and softening prohibition, exploring the kinds of changes or penalties for use for possession: including depenalization, decriminalization, medical control, and different types of legalization. It evaluates such changes and draws on them to assess the effects on levels and patterns of use, on the market, and on adverse consequences of prohibition. For policymakers willing to look outside the box of the global prohibition regime, the book examines the options and possibilities for a country or group of countries to bring about change in, or opt out of, the global control system. Throughout, the book examines cannabis within a global frame, and provides in accessible form information which anyone considering reform will need in order to make decisions on cannabis policy (much of which is new or has not been readily available). This book will be essential for those involved in policymaking and be of interest to a wide range of readers interested in drugs and drug policy, as well as being an excellent supplementary text for university courses in criminology, policy science, social science, or public health"
|
|
| 9. |
|
|
| 10. |
- Holt, Carl, et al.
(författare)
-
Mineralisation of soft and hard tissues and the stability of biofluids.
- 2014
-
Ingår i: Journal of Structural Biology. - : Elsevier BV. - 1095-8657 .- 1047-8477. ; 185:3, s. 383-396
-
Tidskriftsartikel (refereegranskat)abstract
- Evidence is provided from studies on natural and artificial biofluids that the sequestration of amorphous calcium phosphate by peptides or proteins to form nanocluster complexes is of general importance in the control of physiological calcification. A naturally occurring mixture of osteopontin peptides was shown, by light and neutron scattering, to form calcium phosphate nanoclusters with a core-shell structure. In blood serum and stimulated saliva, an invariant calcium phosphate ion activity product was found which corresponds closely in form and magnitude to the ion activity product observed in solutions of these osteopontin nanoclusters. This suggests that types of nanocluster complexes are present in these biofluids as well as in milk. Precipitation of amorphous calcium phosphate from artificial blood serum, urine and saliva was determined as a function of pH and the concentration of osteopontin or casein phosphopeptides. The position of the boundary between stability and precipitation was found to agree quantitatively with the theory of nanocluster formation. Artificial biofluids were prepared that closely matched their natural counterparts in calcium and phosphate concentrations, pH, saturation, ionic strength and osmolality. Such fluids, stabilised by a low concentration of sequestering phosphopeptides, were found to be highly stable and may have a number of beneficial applications in medicine.
|
|
