We present results from multiple comprehensive models used to simulate an aggressive mitigation scenario based on detailed results of an Integrated Assessment Model. The experiment employs ten global ...climate and Earth System models (GCMs and ESMs) and pioneers elements of the long-term experimental design for the forthcoming 5th Intergovernmental Panel on Climate Change assessment. Atmospheric carbon-dioxide concentrations pathways rather than carbon emissions are specified in all models, including five ESMs that contain interactive carbon cycles. Specified forcings also include minor greenhouse gas concentration pathways, ozone concentration, aerosols (via concentrations or precursor emissions) and land use change (in five models). The new aggressive mitigation scenario (E1), constructed using an integrated assessment model (IMAGE 2.4) with reduced fossil fuel use for energy production aimed at stabilizing global warming below 2 K, is studied alongside the medium-high non-mitigation scenario SRES A1B. Resulting twenty-first century global mean warming and precipitation changes for A1B are broadly consistent with previous studies. In E1 twenty-first century global warming remains below 2 K in most models, but global mean precipitation changes are higher than in A1B up to 2065 and consistently higher per degree of warming. The spread in global temperature and precipitation responses is partly attributable to inter-model variations in aerosol loading and representations of aerosol-related radiative forcing effects. Our study illustrates that the benefits of mitigation will not be realised in temperature terms until several decades after emissions reductions begin, and may vary considerably between regions. A subset of the models containing integrated carbon cycles agree that land and ocean sinks remove roughly half of present day anthropogenic carbon emissions from the atmosphere, and that anthropogenic carbon emissions must decrease by at least 50% by 2050 relative to 1990, with further large reductions needed beyond that to achieve the E1 concentrations pathway. Negative allowable anthropogenic carbon emissions at and beyond 2100 cannot be ruled out for the E1 scenario. There is self-consistency between the multi-model ensemble of allowable anthropogenic carbon emissions and the E1 scenario emissions from IMAGE 2.4.
With an increasing political focus on limiting global warming to less than 2 °C above pre-industrial levels it is vital to understand the consequences of these targets on key parts of the climate ...system. Here, we focus on changes in sea level and sea ice, comparing twenty-first century projections with increased greenhouse gas concentrations (using the mid-range IPCC A1B emissions scenario) with those under a mitigation scenario with large reductions in emissions (the E1 scenario). At the end of the twenty-first century, the global mean steric sea level rise is reduced by about a third in the mitigation scenario compared with the A1B scenario. Changes in surface air temperature are found to be poorly correlated with steric sea level changes. While the projected decreases in sea ice extent during the first half of the twenty-first century are independent of the season or scenario, especially in the Arctic, the seasonal cycle of sea ice extent is amplified. By the end of the century the Arctic becomes sea ice free in September in the A1B scenario in most models. In the mitigation scenario the ice does not disappear in the majority of models, but is reduced by 42 % of the present September extent. Results for Antarctic sea ice changes reveal large initial biases in the models and a significant correlation between projected changes and the initial extent. This latter result highlights the necessity for further refinements in Antarctic sea ice modelling for more reliable projections of future sea ice.
Climate change impacts on the regional hydrological cycle are compared for model projections following an ambitious emissions-reduction scenario (E1) and a medium-high emissions scenario with no ...mitigation policy (A1B). The E1 scenario is designed to limit global annual mean warming to 2 °C or less above pre-industrial levels. A multi-model ensemble consisting of ten coupled atmosphere–ocean general circulation models is analyzed, which includes five Earth System Models containing interactive carbon cycles. The aim of the study is to assess the changes that could be mitigated under the E1 scenario and to identify regions where even small climate change may lead to strong changes in precipitation, cloud cover and evapotranspiration. In these regions the hydrological cycle is considered particularly vulnerable to climate change, highlighting the need for adaptation measures even if strong mitigation of climate change would be achieved. In the A1B projections, there are significant drying trends in sub-tropical regions, precipitation increases in high latitudes and some monsoon regions, as well as changes in cloudiness and evapotranspiration. These signals are reduced in E1 scenario projections. However, even under the E1 scenario, significant precipitation decrease in the subtropics and increase in high latitudes are projected. Particularly the Amazon region shows strong drying tendencies in some models, most probably related to vegetation interaction. Where climate change is relatively small, the E1 scenario tends to keep the average magnitude of potential changes at a level comparable to current intra-seasonal to inter-annual variability at that location. Such regions are mainly located in the mid-latitudes.
Unfortunately, in the aforementioned contribution, Fig. 5 (Monthly multi-model (mean and range) precipitation change (mm/day) for 2080–2099 minus 1980–1999 averaged over the 26 regions, E1 (black) ...and A1B (grey) scenarios) contains an error. For two of the contributing models (ECHAM5-C and INGVCE) the evapotranspiration data had the wrong sign, leading to an opposing annual cycle in these models compared to the other models. The corrected Fig. 5 is presented here. It can be seen that the annual cycles of the climate change signals in evapotranspiration in the two scenarios agree much better between the different models than previously estimated. The general picture clearly underscores the findings from the preceding Figs. 3 and 4 that the climate change signals are much reduced under the E1 scenario compared to the A1B scenario. This is true for the ensemble properties (means, percentiles, ...
Abstract Mechanisms behind the phenomenon of Arctic amplification are widely discussed. To contribute to this debate, the (AC) 3 project was established in 2016 ( www.ac3-tr.de/ ). It comprises ...modeling and data analysis efforts as well as observational elements. The project has assembled a wealth of ground-based, airborne, shipborne, and satellite data of physical, chemical, and meteorological properties of the Arctic atmosphere, cryosphere, and upper ocean that are available for the Arctic climate research community. Short-term changes and indications of long-term trends in Arctic climate parameters have been detected using existing and new data. For example, a distinct atmospheric moistening, an increase of regional storm activities, an amplified winter warming in the Svalbard and North Pole regions, and a decrease of sea ice thickness in the Fram Strait and of snow depth on sea ice have been identified. A positive trend of tropospheric bromine monoxide (BrO) column densities during polar spring was verified. Local marine/biogenic sources for cloud condensation nuclei and ice nucleating particles were found. Atmospheric–ocean and radiative transfer models were advanced by applying new parameterizations of surface albedo, cloud droplet activation, convective plumes and related processes over leads, and turbulent transfer coefficients for stable surface layers. Four modes of the surface radiative energy budget were explored and reproduced by simulations. To advance the future synthesis of the results, cross-cutting activities are being developed aiming to answer key questions in four focus areas: lapse rate feedback, surface processes, Arctic mixed-phase clouds, and airmass transport and transformation.
Unfortunately, in the aforementioned contribution, Table 2 of this paper erroneously reported two separate rows of data for the BCM-C model for both the A1B and E1 scenarios, only one of which was ...correct in each case. The lower of the two rows of data for each scenario (i.e. those corresponding to T changes of 2.44 K for A1B and 1.18 K for E1) contained correct data. The upper rows of data reported (i.e. those corresponding to T changes of 2.65 K for A1B and 1.38 for E1) contained some errors and should not have appeared. A corrected version of Table 2 appears below.
Twenty-three schizophrenia subjects were compared with healthy and clinical control subjects on an emotional priming task. Positive and negative emotional facial expressions were presented as primes, ...followed by a neutral pattern mask, then an emotionally neutral face as target. The prime-mask-target sequence was arranged to allow conscious perception of only the targets. Subjects had to judge if they had seen a pleasant or an unpleasant facial expression. All subjects judged the neutral target as significantly more unpleasant when negative emotional facial expressions were presented as primes as compared with positive or neutral facial expressions as primes. This judgment shift was significantly stronger in schizophrenia subjects than in control subjects. The stronger priming of schizophrenia subjects may reflect a stronger influence of automatically processed emotional stimuli on judgments. We suggest that increased spreading activation of emotional information might be related to low social/emotional functioning of the individual with schizophrenia.
PURPOSE
To investigate the effects of low‐load exercise with blood flow restriction on expression of genes related to hypoxia.
METHODS
Twenty‐four male (mean ± SD: age 21.3 ± 1.9 years, height 1.74 ± ...0.8 m, body mass 73 ± 1.8 kg) were divided into three groups: low‐load exercise (LL, n=9), low‐load exercise with blood flow restriction (LL‐BFR, n=8), and high‐load exercise (HL, n=7). For LL‐BFR group a pneumatic cuff was placed on the proximal portion of the thigh and inflated at 80% of the resting arterial occlusion pressure. All subjects performed bilateral knee extension, 2x/week, during 8 weeks. LL and LL‐BFR groups performed 3–4 sets of 15 reps at 20% 1RM whereas HL performed 3–4 sets of 8–10 reps at 80% 1RM with 60s rest interval between sets. Regulated in development and DNA damage response 1 (REDD1), hypoxia‐inducible factor‐1‐alpha (HIF‐1‐alpha), vascular endothelial growth factor (VEGF), and neuronal nitric oxide synthase (nNOS) mRNA gene expression were assessed before and after training. Mixed model for repeated measures was performed for each dependent variable, and statistical significance was set at p≤ 0.05.
RESULTS
REDD1 expression decreased in all groups from pre‐ to post‐training (p<.0001), and significantly lower REDD1 expression was found in both LL‐BFR and HL groups when compared with LL group at post‐training (p<0.05) Figure 1A). HIF‐1α mRNA expression increased in all groups from pre‐ to post‐training (p<.0001), and significantly greater values were observed in LL‐BFR and HL groups when compared with LL group at post‐training (p<.0001) Figure 1B. VEGF mRNA expression increased in both LL‐BFR and HL groups from pre‐ to post‐training (p<.0001); however, only LL‐BFR showed greater expression than LL group at post‐training (p=0.001) Figure 1C). nNOS mRNA expression increased in all groups from preto post‐training (p<.0001), and greater expression values were observed in LL‐BFR when compared with both LL and HL groups at post‐training (p<.0001) Figure 1D.
CONCLUSION
Low‐load resistance exercise with blood flow restriction induced changes in selected genes expression related to hypoxia following training. These results may contribute with the skeletal muscle hypertrophy responses and increased muscular angiogenesis after training period.
Support or Funding Information
This study was not supported by any funding
This is from the Experimental Biology 2018 Meeting. There is no full text article associated with this published in The FASEB Journal.
Genetic algorithms (GAs) have a long history of over four decades. GAs are adaptive heuristic search algorithms that provide solutions for optimization and search problems. The GA derives expression ...from the biological terminology of natural selection, crossover, and mutation. In fact, GAs simulate the processes of natural evolution. Due to their unique simplicity, GAs are applied to the search space to find optimal solutions for various problems in science and engineering. Using GAs for lens design was investigated mostly in the 1990s, but were not fully exploited. But in the past few years, there have been a number of newer studies exploring the application of GAs or hybrid GAs in optical design. In this paper, we discuss the basic ideas behind GAs and demonstrate their application in optical lens design.
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