114 research outputs found
Contribution of higher meson resonances to the electromagnetic -meson mass difference
Modifications of the DGMLY relation for calculation of electromagnetic
-meson mass difference based on the Chiral Symmetry Restoration phenomenon
at high energies as well as the Operator Product Expansion of quark densities
for vector () and axial-vector () meson fields difference are
proposed. In the calculations higher meson resonances in vector and
axial-vector channels are taken into account. It is shown that the inclusion of
the first and radial excitations improves the results for
electromagnetic -meson mass difference as compared with the previous ones.
Estimations on the electromagnetic and -meson decay constants and
the constant of effective chiral Lagrangian are obtained from the
generalized Weinberg sum rules.Comment: Latex2e, 10 pages, submitted to Yad. Phy
Climate Engineering Responses to Climate Emergencies
Despite efforts to stabilize CO_2 concentrations, it is possible that the
climate system could respond abruptly with catastrophic consequences.
Intentional intervention in the climate system to avoid or ameliorate such
consequences has been proposed as one possible response, should such a scenario
arise. In a one-week study, the authors of this report conducted a technical
review and evaluation of proposed climate engineering concepts that might serve
as a rapid palliative response to such climate emergency scenarios.
Because of their potential to induce a prompt (less than one year) global
cooling, this study concentrated on Shortwave Climate Engineering (SWCE)
methods for moderately reducing the amount of shortwave solar radiation
reaching the Earth. The study's main objective was to outline a decade-long
agenda of technical research that would maximally reduce the uncertainty
surrounding the benefits and risks associated with SWCE. For rigor of technical
analysis, the study focused the research agenda on one particular SWCE
concept--stratospheric aerosol injection--and in doing so developed several
conceptual frameworks and methods valuable for assessing any SWCE proposal.Comment: 66 pp., 5 figs., published by Novim, Santa Barbara, Cal., revised
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Mindfulness-Based Stress Reduction in Women with Overweight or Obesity: A Randomized Clinical Trial.
OBJECTIVE: To evaluate the feasibility and cardiometabolic effects of mindfulness-based stress reduction (MBSR) in women with overweight or obesity.
METHODS: Eighty-six women with BMI ≥ 25 kg/m
RESULTS: Compared to health education, the MBSR group demonstrated significantly improved mindfulness at 8 weeks (mean change from baseline, 4.5 vs. -1.0; P = 0.03) and significantly decreased perceived stress at 16 weeks (-3.6 vs. -1.3, P = 0.01). In the MBSR group, there were significant reductions in fasting glucose at 8 weeks (-8.9 mg/dL, P = 0.02) and at 16 weeks (-9.3 mg/dL, P = 0.02) compared to baseline. Fasting glucose did not significantly improve in the health education group. There were no significant changes in blood pressure, weight, or insulin resistance in the MBSR group.
CONCLUSIONS: In women with overweight or obesity, MBSR significantly reduces stress and may have beneficial effects on glucose. Future studies demonstrating long-term cardiometabolic benefits of MBSR will be key for establishing MBSR as an effective tool in the management of obesity
Safe vs. Fair: A formidable trade-off in tackling climate change
Global warming requires a response characterized by forward-looking management of atmospheric carbon and respect for ethical principles. Both safety and fairness must be pursued, and there are severe trade-offs as these are intertwined by the limited headroom for additional atmospheric CO2 emissions. This paper provides a simple numerical mapping at the aggregated level of developed vs. developing countries in which safety and fairness are formulated in terms of cumulative emissions and cumulative per capita emissions respectively. It becomes evident that safety and fairness cannot be achieved simultaneously for strict definitions of both. The paper further posits potential global trading in future cumulative emissions budgets in a world where financial transactions compensate for physical emissions: the safe vs. fair tradeoff is less severe but remains formidable. Finally, we explore very large deployment of engineered carbon sinks and show that roughly 1,000 Gt CO2 of cumulative negative emissions over the century are required to have a significant effect, a remarkable scale of deployment. We also identify the unexplored issue of how such sinks might be treated in sub-global carbon accounting
Post-construction thermal testing: Some recent measurements
In the UK, it has become apparent in recent years that there is often a discrepancy between the steady-state predicted and the measured in situ thermal performance of the building fabric, with the measured in situ performance being greater than that predicted. This discrepancy or gap in the thermal performance of the building fabric is commonly referred to as the building fabric 'performance gap'. This paper presents the results and key messages obtained from undertaking a whole-building heat loss test (a coheating test) on seven new-build dwellings as part of the Technology Strategy Board's Building Performance Evaluation Programme. While the total number of dwellings involved in the work reported here is small, the results illustrate that a wide range of discrepancies in thermal performance was measured for the tested dwellings. Despite this, the results also indicate that it is possible to construct dwellings where the building fabric performs thermally more or less as predicted, thus effectively bridging the traditional building fabric performance gap that exists in mainstream housing in the UK
Normative productivity of the global vegetation
<p>Abstract</p> <p>Background</p> <p>The biosphere models of terrestrial productivity are essential for projecting climate change and assessing mitigation and adaptation options. Many of them have been developed in connection to the International Geosphere-Biosphere Program (IGBP) that backs the work of the Intergovernmental Panel on Climate Change (IPCC). In the end of 1990s, IGBP sponsored release of a data set summarizing the model outputs and setting certain norms for estimates of terrestrial productivity. Since a number of new models and new versions of old models were developed during the past decade, these normative data require updating.</p> <p>Results</p> <p>Here, we provide the series of updates that reflects evolution of biosphere models and demonstrates evolutional stability of the global and regional estimates of terrestrial productivity. Most of them fit well the long-living Miami model. At the same time we call attention to the emerging alternative: the global potential for net primary production of biomass may be as high as 70 PgC y<sup>-1</sup>, the productivity of larch forest zone may be comparable to the productivity of taiga zone, and the productivity of rain-green forest zone may be comparable to the productivity of tropical rainforest zone.</p> <p>Conclusion</p> <p>The departure from Miami model's worldview mentioned above cannot be simply ignored. It requires thorough examination using modern observational tools and techniques for model-data fusion. Stability of normative knowledge is not its ultimate goal – the norms for estimates of terrestrial productivity must be evidence-based.</p
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