Relationships between solar activity and climate change

The relationship between recurrent droughts in the High Plains of the United States and the double sunspot cycle is discussed in detail. It is suggested that high solar activity is generally related to an increase in meridional circulation and blocking patterns at high and intermediate latitudes, especially in winter, and the effect is related to the sudden formation of cirrus clouds during strong geomagnetic activity that originates in the solar corpuscular emission

Tests of physical mechanisms linking solar activity and/or geomagnetic disturbances with the large-scale circulation of the lower stratosphere and upper troposphere

Empirical facts are presented to help in selecting the most probable physical mechanisms that are responsible for the sun-weather connections

Accelerating Parallel Tempering: Quantile Tempering Algorithm (QuanTA)

Using MCMC to sample from a target distribution, $\pi(x)$ on a $d$-dimensional state space can be a difficult and computationally expensive problem. Particularly when the target exhibits multimodality, then the traditional methods can fail to explore the entire state space and this results in a bias sample output. Methods to overcome this issue include the parallel tempering algorithm which utilises an augmented state space approach to help the Markov chain traverse regions of low probability density and reach other modes. This method suffers from the curse of dimensionality which dramatically slows the transfer of mixing information from the auxiliary targets to the target of interest as $d \rightarrow \infty$. This paper introduces a novel prototype algorithm, QuanTA, that uses a Gaussian motivated transformation in an attempt to accelerate the mixing through the temperature schedule of a parallel tempering algorithm. This new algorithm is accompanied by a comprehensive theoretical analysis quantifying the improved efficiency and scalability of the approach; concluding that under weak regularity conditions the new approach gives accelerated mixing through the temperature schedule. Empirical evidence of the effectiveness of this new algorithm is illustrated on canonical examples

Physician Assisted Dying: A Turning Point?

Physician Assisted Dying (PAD) has been lawful in some countries since the 1940s and in the United States since 1997. There is a body of social and scientific research that has focused on whether the practice has been misused and whether gaps exist in legislative safeguards. There are multiple concerns with physicians assisting patients to die: incompatibility with the physician’s role as a healer, devaluation of human life, coercion of vulnerable individuals (e.g., the poor and disabled), and the risk that PAD will be used beyond a narrow group of terminally ill individuals. Statutes in the United States have been drafted with these concerns in mind in an effort to mitigate the possible risks of PAD while still providing individuals with access. There seems to be a shift in attitudes towards PAD. Currently four states statutorily permit PAD and it is being discussed by multiple legislatures across the country. There also seems to be a shift in medical practice as demonstrated by a 2015 survey that showed for the first time that more than half of physicians surveyed favored medical assistance in dying. PAD is a deeply personal choice. The question is whether more states will authorize the practice and, if so, what safeguards will be put in place to ensure the practice is not misused and remains consistent with prevailing social and ethical thought

GPS monitoring of a steel box girder viaduct

Structural performance monitoring of bridges has increased as major infrastructure ages and is required to sustain loads that are significantly greater than those predicted during design. Structural stiffness and/or mass distribution can change over the lifespan of a bridge structure. Resulting changes in profile or resonant frequency provide key indicators of change, and may identify structural defects. Field tests using GPS for monitoring relatively small deformations were carried out on a steel box girder viaduct bridge in the UK. The configuration consisted of five GPS receivers located at key locations on the viaduct and two reference GPS receivers. GPS data was collected at either 10 Hz or 20 Hz and post-processed using proprietary software, along with appropriate filtering and spectral analysis. Three main frequencies were clearly detected by the GPS in the vertical component. A previously reported frequency of approximately 0.56 Hz was identified along with two other frequencies. The peak vertical deflections lie in the range of ± 50 mm, while lateral and longitudinal deflections of much smaller magnitude - in the order of a few mm - are also measured. The use of GPS leads to readily obtained and useful engineering data for continued monitoring of structures

Harris recurrence of Metropolis-within-Gibbs and trans-dimensional Markov chains

A $\phi$-irreducible and aperiodic Markov chain with stationary probability distribution will converge to its stationary distribution from almost all starting points. The property of Harris recurrence allows us to replace ``almost all'' by ``all,'' which is potentially important when running Markov chain Monte Carlo algorithms. Full-dimensional Metropolis--Hastings algorithms are known to be Harris recurrent. In this paper, we consider conditions under which Metropolis-within-Gibbs and trans-dimensional Markov chains are or are not Harris recurrent. We present a simple but natural two-dimensional counter-example showing how Harris recurrence can fail, and also a variety of positive results which guarantee Harris recurrence. We also present some open problems. We close with a discussion of the practical implications for MCMC algorithms.Comment: Published at http://dx.doi.org/10.1214/105051606000000510 in the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Forced Migration, The Human Face of a Health Crisis

Nearly 60 million refugees, asylum-seekers and internally displaced persons (IDPs) fled their homes in 2014, predominately from war-torn Syria, Afghanistan and Somalia. The global response to assisting this vulnerable group has been wholly incommensurate with the need given the profound health hazards faced by forced migrants at each stage of their journey. The majority of forced migrants are housed in lower-income countries that do not have the infrastructure to assist the significant numbers of individuals who are crossing their borders and the humanitarian organizations who seek to assist in the response are grossly underfunded and under-resourced. Countries have varying responsibilities to protect different classes of forced migrants based in international law, however there are significant gaps in existing agreements, leaving many individuals without protection or hope of assistance. There is a need to strengthen existing international agreements to ensure that all classes of forced migrants are entitled to protection and to ensure the enforceability of existing agreements where governments refuse to honor their existing obligations

Mind Your Calling

Mind Your Calling, a speach given for the Friends United Meeting in 1972.https://digitalcommons.georgefox.edu/arthur_roberts/1004/thumbnail.jp