Emergent constraints for the climate system as effective parameters of bulk differential equations

Planning for the impacts of climate change requires accurate projections by Earth system models (ESMs). ESMs, as developed by many research centres, estimate changes to weather and climate as atmospheric greenhouse gases (GHGs) rise, and they inform the influential Intergovernmental Panel on Climate Change (IPCC) reports. ESMs are advancing the understanding of key climate system attributes. However, there remain substantial inter-ESM differences in their estimates of future meteorological change, even for a common GHG trajectory, and such differences make adaptation planning difficult. Until recently, the primary approach to reducing projection uncertainty has been to place an emphasis on simulations that best describe the contemporary climate. Yet a model that performs well for present-day atmospheric GHG levels may not necessarily be accurate for higher GHG levels and vice versa. A relatively new approach of emergent constraints (ECs) is gaining much attention as a technique to remove uncertainty between climate models. This method involves searching for an inter-ESM link between a quantity that we can also measure now and a second quantity of major importance for describing future climate. Combining the contemporary measurement with this relationship refines the future projection. Identified ECs exist for thermal, hydrological and geochemical cycles of the climate system. As ECs grow in influence on climate policy, the method is under intense scrutiny, creating a requirement to understand them better. We hypothesise that as many Earth system components vary in both space and time, their behaviours often satisfy large-scale differential equations (DEs). Such DEs are valid at coarser scales than the equations coded in ESMs which capture finer high-resolution grid-box-scale effects. We suggest that many ECs link to such effective hidden DEs implicit in ESMs and that aggregate small-scale features. An EC may exist because its two quantities depend similarly on an ESM-specific internal bulk parameter in such a DE, with measurements constraining and revealing its (implicit) value. Alternatively, well-established process understanding coded at the ESM grid box scale, when aggregated, may generate a bulk parameter with a common “emergent” value across all ESMs. This single emerging parameter may link uncertainties in a contemporary climate driver to those of a climate-related property of interest. In these circumstances, the EC combined with a measurement of the driver that is uncertain constrains the estimate of the climate-related quantity. We offer simple illustrative examples of these concepts with generic DEs but with their solutions placed in a conceptual EC framework.</p

The development of service user-led recommendations for health and social care services on leaving hospital with memory loss or dementia – the SHARED study

YesBackground Health and social care services are under strain providing care in the community particularly at hospital discharge. Patient and carer experiences can inform and shape services. Objective To develop service user-led recommendations enabling smooth transition for people living with memory loss from acute hospital to community. Design Lead and co-researchers conducted semi-structured interviews with 15 pairs of carers and patients with memory loss at discharge, 6 and 12 weeks post-discharge and one semi-structured interview with health and social care professionals and Admiral Nurses. Framework analysis was guided by co-researchers. Two focus groups of study participants, facilitated by co-researchers, met to shape and finalize recommendations. Setting and participants Recruitment took place in acute hospitals in two National Health Service (NHS) Trusts in England. Patients were aged 65 and over, with memory loss, an in-patient for at least 1 week returning to the community, who had a carer consenting to be in the study. Results Poor delivery of services caused considerable stress to some study families living with memory loss. Three key recommendations included a need for a written, mutually agreed discharge plan, a named coordinator of services, and improved domiciliary care services. Discussion and conclusions Vulnerable patients with memory loss find coming out of hospital after an extended period a stressful experience. The SHARED study contributes to understanding the hospital discharge process through the eyes of the patient and carer living with memory loss and has the potential to contribute to more efficient use of resources and to improving health outcomes in communities.National Institute for Health Research. Grant Number: PB-PG-1112-2906

Endoplasmic reticulum stress signalling induces casein kinase 1-dependent formation of cytosolic TDP-43 Inclusions in motor neuron-like cells

YesMotor neuron disease (MND) is a progressive neurodegenerative disease with no effective treatment. One of the principal pathological hallmarks is the deposition of TAR DNA binding protein 43 (TDP-43) in cytoplasmic inclusions. TDP-43 aggregation occurs in both familial and sporadic MND; however, the mechanism of endogenous TDP-43 aggregation in disease is incompletely understood. This study focused on the induction of cytoplasmic accumulation of endogenous TDP-43 in the motor neuronal cell line NSC-34. The endoplasmic reticulum (ER) stressor tunicamycin induced casein kinase 1 (CK1)-dependent cytoplasmic accumulation of endogenous TDP-43 in differentiated NSC-34 cells, as seen by immunocytochemistry. Immunoblotting showed that induction of ER stress had no effect on abundance of TDP-43 or phosphorylated TDP-43 in the NP-40/RIPA soluble fraction. However, there were significant increases in abundance of TDP-43 and phosphorylated TDP-43 in the NP-40/RIPA-insoluble, urea-soluble fraction, including high molecular weight species. In all cases, these increases were lowered by CK1 inhibition. Thus ER stress signalling, as induced by tunicamycin, causes CK1-dependent phosphorylation of TDP-43 and its consequent cytosolic accumulation.Funded by a biomedical research grant from the Motor Neurone Disease Association (ref Rattray/Apr15/837-791). The Bioimaging Facility microscopes used in this study were purchased with grants from BBSRC, Wellcome Trust and the University of Manchester Strategic Fund

Sortase-mediated labelling of lipid nanodiscs for cellular tracing

Lipid nanodiscs have broad applications in membrane protein assays, biotechnology and materials science. Chemical modification of the nanodiscs to expand their functional attributes is generally desirable for all of these uses. We present a method for site-selective labelling of the N-terminus of the nanodisc’s membrane scaffold protein (MSP) using the Sortase A protein. Labelling of the MSP was achieved when assembled within the lipid nanodisc architecture, demonstrating that this method can be used as a retrofit approach to modification of preformed nanodiscs before or during application. We label the MSP with a fluorescent fluorescein moiety and use them to image nanodisc uptake into HeLa cells. The Sortase A labelling method could be employed as a general approach to labelling nanodiscs with application-specific functionalities

Coulomb Charging Effects in an Open Quantum Dot

Low-temperature transport properties of a lateral quantum dot formed by overlaying finger gates in a clean one-dimensional channel are investigated. Continuous and periodic oscillations superimposed upon ballistic conductance steps are observed, when the conductance G of the dot changes within a wide range 0<G<6e^2/h. Calculations of the electrostatics confirm that the measured periodic conductance oscillations correspond to successive change of the total charge of the dot by $e$. By modelling the transport it is shown that the progression of the Coulomb oscillations into the region G>2e^2/h may be due to suppression of inter-1D-subband scattering. Fully transmitted subbands contribute to coherent background of conductance, while sequential tunneling via weakly transmitted subbands leads to Coulomb charging of the dot.Comment: 12 pages, RevTeX, 15 eps figures included, submitted to Phys. Rev.

Rotated Versions of the Jablonowski Steady‐State and Baroclinic Wave Test Cases: A Dynamical Core Intercomparison

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95316/1/jame31.pd

High CO2 decreases the long-term resilience of the free-living coralline algae Phymatolithon lusitanicum

Maerl/rhodolith beds are protected habitats that may be affected by ocean acidification (OA), but it is still unclear how the availability of CO2 will affect the metabolism of these organisms. Some of the inconsistencies found among OA experimental studies may be related to experimental exposure time and synergetic effects with other stressors. Here, we investigated the long-term (up to 20months) effects of OA on the production and calcification of the most common maerl species of southern Portugal, Phymatolithon lusitanicum. Both the photosynthetic and calcification rates increased with CO2 after the first 11months of the experiment, whereas respiration slightly decreased with CO2. After 20months, the pattern was reversed. Acidified algae showed lower photosynthetic and calcification rates, as well as lower accumulated growth than control algae, suggesting that a metabolic threshold was exceeded. Our results indicate that long-term exposure to high CO2 will decrease the resilience of Phymatolithon lusitanicum. Our results also show that shallow communities of these rhodoliths may be particularly at risk, while deeper rhodolith beds may become ocean acidification refuges for this biological community.Fundacao para a Ciencia e a Tecnologia [PTDC/MAR/115789/2009, SFRH/BD/76762/2011

Emergent constraints for the climate system as effective parameters of bulk differential equations

Planning for the impacts of climate change requires accurate projections by Earth system models (ESMs). ESMs, as developed by many research centres, estimate changes to weather and climate as atmospheric greenhouse gases (GHGs) rise, and they inform the influential Intergovernmental Panel on Climate Change (IPCC) reports. ESMs are advancing the understanding of key climate system attributes. However, there remain substantial inter-ESM differences in their estimates of future meteorological change, even for a common GHG trajectory, and such differences make adaptation planning difficult. Until recently, the primary approach to reducing projection uncertainty has been to place an emphasis on simulations that best describe the contemporary climate. Yet a model that performs well for present-day atmospheric GHG levels may not necessarily be accurate for higher GHG levels and vice versa. A relatively new approach of emergent constraints (ECs) is gaining much attention as a technique to remove uncertainty between climate models. This method involves searching for an inter-ESM link between a quantity that we can also measure now and a second quantity of major importance for describing future climate. Combining the contemporary measurement with this relationship refines the future projection. Identified ECs exist for thermal, hydrological and geochemical cycles of the climate system. As ECs grow in influence on climate policy, the method is under intense scrutiny, creating a requirement to understand them better. We hypothesise that as many Earth system components vary in both space and time, their behaviours often satisfy large-scale differential equations (DEs). Such DEs are valid at coarser scales than the equations coded in ESMs which capture finer high-resolution grid-box-scale effects. We suggest that many ECs link to such effective hidden DEs implicit in ESMs and that aggregate small-scale features. An EC may exist because its two quantities depend similarly on an ESM-specific internal bulk parameter in such a DE, with measurements constraining and revealing its (implicit) value. Alternatively, well-established process understanding coded at the ESM grid box scale, when aggregated, may generate a bulk parameter with a common “emergent” value across all ESMs. This single emerging parameter may link uncertainties in a contemporary climate driver to those of a climate-related property of interest. In these circumstances, the EC combined with a measurement of the driver that is uncertain constrains the estimate of the climate-related quantity. We offer simple illustrative examples of these concepts with generic DEs but with their solutions placed in a conceptual EC framework.</p

Experimental Evidence for Coulomb Charging Effects in an Open Quantum Dot at Zero Magnetic Field

We have measured the low-temperature transport properties of an open quantum dot formed in a clean one-dimensional channel. For the first time, at zero magnetic field, continuous and periodic oscillations superimposed upon ballistic conductance steps are observed when the conductance through the dot $G$ exceeds $2e^2/h$. We ascribe the observed conductance oscillations to evidence for Coulomb charging effects in an open dot. This is supported by the evolution of the oscillating features for $G>2e^2/h$ as a function of both temperature and barrier transparency. Our results strongly suggest that at zero magnetic field, current theoretical and experimental understanding of Coulomb charging effects overlooks charging in the presence of fully transmitted 1D channels.Comment: To appear in Phys. Rev. Lett. 81 (Oct 19 issue