Weak-Field Gravity of Circular Cosmic Strings

A weak-field solution of Einstein's equations is constructed. It is generated by a circular cosmic string externally supported against collapse. The solution exhibits a conical singularity, and the corresponding deficit angle is the same as for a straight string of the same linear energy density. This confirms the deficit-angle assumption made in the Frolov-Israel-Unruh derivation of the metric describing a string loop at a moment of time symmetry.Comment: 15 page

Smart Tea Project

Conference poster. The lab book is a big block to publication@source, if it’s not digital, it’s difficult to share. Most experimental information is recorded in a lab book in a highly personal way. We have created a new analogy to fully understand the use of the lab book and successfully built and evaluated a working electronic replacement

A Survey of Classical and Recent Results in RLC Circuit Synthesis

This is the final version of the article. Available from the publisher via the link in this record.The motivation provided by mechanical network synthesis to make a fresh attack on certain questions in circuit synthesis will be briefly recalled. The classical early work on RLC synthesis, beginning with the works of Foster and Cauer and culminating in the Bott-Duffin construction, will be explained in a tutorial manner. Recent work on RLC synthesis by Jiang and Smith and Hughes and Smith will be introduced. The proof in T.H. Hughes and M.C. Smith, 2014, " On the minimality and uniqueness of the Bott-Duffin procedure " , IEEE Trans. Aut. Contr., (to appear), showing the surprising result that the Bott-Duffin construction for a biquadratic minimum function is the simplest possible among series-parallel circuits, will be explained.This work was supported by the Engineering and Physical Sciences Research Council under Grant EP/G066477/

Neurone and astrocyte response to Aβ25-35: Role in glutathione in neuroprotection

Amyloid beta (AP) is strongly implicated in the pathogenesis of Alzheimer's disease and has been shown to cause oxidative stress and neurone death in vivo and in cell culture models. Astrocytes in cell culture conditions and in vivo appear to be more resistant to A(3 mediated toxicity, but do undergo morphological changes to adopt a stellate "activated" morphology. The experiments presented in this thesis have used the aggregating Ap fragment AJ325-35 to model A(3 toxicity to study why neurones are more vulnerable than astrocytes. Neurones and astrocytes were both shown to generate reactive oxygen species (ROS) in the presence of A025-35 although astrocytes contained higher levels of the antioxidant glutathione (GSH). It was shown that both astrocyte conditioned medium, and the GSH precursor y-glutamylcysteine raised neurone intracellular GSH levels and protected against AP25-35 mediated neurotoxicity to the same degree. In the brain, astrocytes provide neurones with the precursors needed for GSH synthesis. To test whether astrocyte support of neurone GSH synthesis was maintained in the presence of A(325-35, intracellular GSH was measured in both cell types after A(325- 35 treatment. It was shown that intracellular GSH was lowered in neurones but was maintained in astrocytes. The ability of astrocytes to maintain their GSH levels appeared to be dependent on an increase in the activity of glutathione reductase, the enzyme that recycles oxidised glutathione (GSSG) to its reduced form GSH. Furthermore, the amount of GSH released by astrocytes was increased after treatment with AP25-35. Conditioned medium from Ap25-35 treated astrocytes raised neurone intracellular GSH to the same degree, and gave similar neuroprotection as conditioned medium from control astrocytes. A co-culture protocol was developed in which neurones could be treated with A 325-35 and then transferred to co-culture with astrocytes. Astrocytes co-cultured with Ap25-35 treated neurones showed a decrease in intracellular GSH. This suggests that although Ap25-35 does not affect the ability of astrocytes to protect neurones by releasing GSH, signals from damaged neurones could limit the amount of antioxidant support neuron

The pursuit of organizational impact: hits, misses, and bouncing back

Conducting impactful research is a cornerstone of good academic practice. It increases the likelihood that research outcomes are used to generate positive change, e.g., by improving working lives, and delivering improvements in the management, operation, and performance of organizations. This, in turn, makes research relevant, representative, and credible. However, undertaking impactful research is challenging, especially when considered alongside other competing academic pressures and research goals. The purpose of this paper is to consider different approaches to creating impactful research in organizational psychology, and to propose that each approach can help meet different research goals. In particular, we introduce and reflect on the value of building long-term partnerships with organizations to create research impact, and consider lessons that we have learned from doing so. To do this, we conceptualize impact delivery as a socio-technical challenge, and demonstrate this using examples from our collaborations. We conclude with recommendations for those who seek to deliver research impact while grappling with these competing pressures

Sclerites and possible mouthparts of Wiwaxia from the temperate palaeolatitudes of Colombia, South America

This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/let.12154The problematic mollusc Wiwaxia is perhaps the most widely distributed non-mineralized Cambrian metazoan, but has only been reported from palaeotropical latitudes. Here we describe mid Cambrian (Drumian, c. 504 Ma) sclerites and possible tooth arrays from the northern Llanos Basin, Colombia, recovered from drilled ditch cuttings by palynological processing – demonstrating that pristine material and low manipulation processing are not essential to the recovery of Small Carbonaceous Fossils. This, the first report of Wiwaxia from South America, substantially expands Wiwaxia’s geographic range into the high palaeolatitudes.We thank the two referees for their constructive comments, and Ecopetrol SA for permission to publish the wellbore material. Jean Bernard Caron, Peter Fenton, Doug Erwin and Mark Florence provided access to Burgess Shale material, which was funded in part by a Geological Society of America research grant to M.R.S. M.R.S. is supported by Clare College, Cambridge

The Physiological and Biochemical Outcomes Associated with a Reflexology Treatment: A Systematic Review

Background. Reflexology is one of the top forms of complementary and alternative medicine in the UK and is used for healthcare by a diverse range of people. However, it is offered by few healthcare providers as little scientific evidence is available explaining how it works or any health benefits it may confer. The aim of this review was to assess the current evidence available from reflexology randomised controlled trials (RCTs) that have investigated changes in physiological or biochemical outcomes. Methods. Guidelines from the Cochrane Handbook of Systematic Reviews of Interventions were followed: the following databases were searched from inception to December 2013: AMED, CAM Quest, CINAHL Plus, Cochrane Central Register of Controlled Trials, Embase, Medline Ovid, Proquest, and Pubmed. Risk of bias was assessed independently by two members of the review team and overall strength of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation guidelines. Results. Seventeen eligible RCTs met all inclusion criteria. A total of 34 objective outcome measures were analysed. Although twelve studies showed significant changes within the reflexology group, only three studies investigating blood pressure, cardiac index, and salivary amylase resulted in significant between group changes in favour of reflexology. The overall quality of the studies was low

Questions of minimality in RLC circuit synthesis

This is the final version of the article. Available from the publisher via the link in this record.It is well known that the impedance of a passive circuit is necessarily positive-real.The Bott-Duffin procedure shows that any positive-real function has an RLC realisation, possibly with the number of reactive elements (inductors and capacitors) greatly exceeding the McMillan degree. It was recently shown that, for series-parallel circuits, that the Bott-Duffin procedure is minimal in the number of reactive elements (six) for the biquadratic minimum function. For general circuits, the best available result is the Reza-Pantell-Fialkow-Gerst simplification, published simultaneously in the 1954 papers, which reduces the number of reactive elements to five for the general biquadratic minimum function. In this extended abstract, we present an additional class of equivalent circuits which have not appeared previously in the literature. In the accompanying talk, we will show the remarkable result that the Reza-Pantell-Fialkow-Gerst simplification produces circuits which contain the least possible number of reactive elements for the realisation of certain biquadratic minimum functions.This work was supported by the Engineering and Physical Sciences Research Council under Grant EP/G066477/