Reducing Penguin Pollution

The most common decay used for measuring 2beta_s, the phase of Bs-Bsbar mixing, is Bs -> J/psi phi. This decay is dominated by the colour-suppressed tree diagram, but there are other contributions due to gluonic and electroweak penguin diagrams. These are often referred to as "penguin pollution" (PP) because their inclusion in the amplitude leads to a theoretical error in the extraction of 2beta_s from the data. In the standard model (SM), it is estimated that the PP is negligible, but there is some uncertainty as to its exact size. Now, phi_s^{c\bar{c}s} (the measured value of 2beta_s) is small, in agreement with the SM, but still has significant experimental errors. When these are reduced, if one hopes to be able to see clear evidence of new physics (NP), it is crucial to have the theoretical error under control. In this paper, we show that, using a modification of the angular analysis currently used to measure phi_s^{c\bar{c}s} in Bs -> J/psi phi, one can reduce the theoretical error due to PP. Theoretical input is still required, but it is much more modest than entirely neglecting the PP. If phi_s^{c\bar{c}s} differs from the SM prediction, this points to NP in the mixing. There is also enough information to test for NP in the decay. This method can be applied to all Bs/Bsbar -> V1 V2 decays.Comment: 17 pages, latex, extensive discussion of theoretical error added, reference added. Further revision: even more detailed discussion of theoretical error added, as well as an explanation of why the NP strong phase is negligibl

The response of middle atmospheric ozone to solar UV irradiance variations with a period of 27 days

A one-dimensional photochemical-dynamical-radiative time-dependent model was used to study the response of middle atmospheric temperature and ozone to solar UV irradiance variations with the period of 27 days. The model solar UV O(x), HO(x), NO(x), and CIO(x)families and modeled solar UV variations. The amplitude of the primary temperature response to the solar UV variation is plus 0.4 K at 85-90 km with a phase lag of about 6 days. A secondary maximum response of plus 0.3 K at 45-50 km appears with a phase lag of 1 day. There is a maximum positive ozone response to the 27-day solar UV oscillation of 2.5 percent at 80-90 km with a phase lag of about 10 days after the solar irradiance maximum. At 70 km the ozone response is about 1.2 percent and is out of phase with the solar variation. In the upper stratosphere (40-50 km) the relative ozone variation is small, about 0.2 percent to 0.3 percent, and there is a negative phase of about 4 days between the ozone and solar oscillations. These oscillations are in phase in the middle stratosphere (35-40 km) where there is again a maximum relative response of about 0.6 percent. The reasons for these ozone amplitude and phase variations are discussed

Adding value to laboratory medicine: a professional responsibility

Laboratory medicine is a medical specialty at the centre of healthcare. When used optimally laboratory medicine generates knowledge that can facilitate patient safety, improve patient outcomes, shorten patient journeys and lead to more cost-effective healthcare. Optimal use of laboratory medicine relies on dynamic and authoritative leadership outside as well as inside the laboratory. The first responsibility of the head of a clinical laboratory is to ensure the provision of a high quality service across a wide range of parameters culminating in laboratory accreditation against an international standard, such as ISO 15189. From that essential baseline the leadership of laboratory medicine at local, national and international level needs to ‘add value’ to ensure the optimal delivery, use, development and evaluation of the services provided for individuals and for groups of patients. A convenient tool to illustrate added value is use of the mnemonic ‘SCIENCE’. This tool allows added value to be considered in seven domains: standardisation and harmonisation; clinical effectiveness; innovation; evidence-based practice; novel applications; cost-effectiveness; and education of others. The assessment of added value in laboratory medicine may be considered against a framework that comprises three dimensions: operational efficiency; patient management; and patient behaviours. The profession and the patient will benefit from sharing examples of adding value to laboratory medicine

Weak phases from topological-amplitude parametrization

We propose a parametrization for two-body nonleptonic $B$ meson decays, in which the various topologies of amplitudes are counted in terms of powers of the Wolfenstein parameter $\lambda\sim 0.22$. The weak phases and the amplitudes are determined by comparing this parametrization with available measurements. It is possible to obtain the phase $\phi_3$ from the $B\to K\pi$ data up to theoretical uncertainty of $O(\lambda^3)\sim 1$. The recently measured $B_d^0\to\pi^0\pi^0$ branching ratio implies a large color-suppressed or penguin amplitude, and that the extraction of the phase $\phi_2$ from the $B\to\pi\pi$ data may suffer theoretical uncertainty more than the expected one of $O(\lambda^2)\sim 5$.Comment: 11 pages, 4 figure

Bilateral nerve conduction studies in the evaluation of distal symmetric polyneuropathy

IntroductionNerve conduction studies are used to aid in the diagnosis of distal symmetric polyneuropathy (DSP). It is unclear whether bilateral lower extremity nerve conduction studies (NCS) are needed when evaluating for suspected DSP.MethodsWe retrospectively analyzed NCS from patients who presented to the University of Michigan electromyography laboratory between July 1, 2016 and December 31, 2017 with symptoms of DSP to assess agreement and correlation between left and right lower extremity NCS parameters.ResultsWe found significant agreement between abnormalities in individual nerve parameters of the left and right lower extremities of 105 patients, most notably in the sural nerve. In the 53 patients with bilateral sural, peroneal, and tibial studies, there was also significant agreement between whether the left and right met electrodiagnostic criteria for DSP (κ = 0.77).DiscussionBilateral lower extremity NCS may have limited utility in the evaluation of suspected DSP. Muscle Nerve, 2019Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151276/1/mus26616.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151276/2/mus26616_am.pd

Uremic serum-induced calcification of human aortic smooth muscle cells is a regulated process involving Klotho and RUNX2

© 2019 The Author(s). This is an open access article published by Portland Press Limited on behalf of the Biochemical Society and distributed under the Creative Commons Attribution License 4.0 (CC BY).Vascular calcification (VC) is common in subjects with chronic kidney disease (CKD) and is associated with increased cardiovascular risk. It is an active process involving transdifferentiation of arterial smooth muscle cells (SMCs) into osteogenic phenotype. We investigated the ability of serum from CKD subjects to induce calcification in human SMCs in vitro (calcific potential of sera: CP), and associated changes in expression of Runt-related transcription factor 2 (RUNX2), SM22a, and Klotho. Sera from subjects with CKD (18 stage 3, 17 stage 4/5, and 29 stage 5D) and 20 controls were added to human cultured SMCs and CP quantified. The CP of CKD sera was greater (P>0.01) than that of controls, though not influenced by CKD stage. Modification of diet in renal disease estimated glomerular filtration rate (MDRD-4 eGFR) (P>0.001), serum phosphate (P=0.042), receptor activator of nuclear factor ?appa-B ligand (RANKL) (P=0.001), parathyroid hormone (PTH) (P=0.014), and high-density lipoprotein (HDL)/cholesterol ratio (P=0.026) were independent predictors of CP accounting for 45% of variation. Adding calcification buffer (CB: calcium chloride [7 mM] and β-glycerophosphate [7 mM]) increased the CP of control sera to approximate that of CKD sera. CP of CKD sera was unchanged. CKD sera increased RUNX2 expression (P>0.01) in human SMCs and decreased SM22a expression (P>0.05). Co-incubating control but not CKD serum with CB further increased RUNX2 expression (P>0.01). Both SM22a and Klotho expression decreased significantly (P>0.01) in the presence of CKD serum, and were virtually abolished with stage 5D sera. These findings support active regulation by CKD serum of in vitro VC by induction of RUNX2 and suppression of SM22a and Klotho.Peer reviewe

Branching dendrites with resonant membrane: a “sum-over-trips” approach

Dendrites form the major components of neurons. They are complex branching structures that receive and process thousands of synaptic inputs from other neurons. It is well known that dendritic morphology plays an important role in the function of dendrites. Another important contribution to the response characteristics of a single neuron comes from the intrinsic resonant properties of dendritic membrane. In this paper we combine the effects of dendritic branching and resonant membrane dynamics by generalising the “sum-over-trips” approach (Abbott et al. in Biol Cybernetics 66, 49–60 1991). To illustrate how this formalism can shed light on the role of architecture and resonances in determining neuronal output we consider dual recording and reconstruction data from a rat CA1 hippocampal pyramidal cell. Specifically we explore the way in which an Ih current contributes to a voltage overshoot at the soma

Having a direct look:analysis of DNA damage and repair mechanisms by next generation sequencing

AbstractGenetic information is under constant attack from endogenous and exogenous sources, and the use of model organisms has provided important frameworks to understand how genome stability is maintained and how various DNA lesions are repaired. The advance of high throughput next generation sequencing (NGS) provides new inroads for investigating mechanisms needed for genome maintenance. These emerging studies, which aim to link genetic toxicology and mechanistic analyses of DNA repair processes in vivo, rely on defining mutational signatures caused by faulty replication, endogenous DNA damaging metabolites, or exogenously applied genotoxins; the analysis of their nature, their frequency and distribution. In contrast to classical studies, where DNA repair deficiency is assessed by reduced cellular survival, the localization of DNA repair factors and their interdependence as well as limited analysis of single locus reporter assays, NGS based approaches reveal the direct, quantal imprint of mutagenesis genome-wide, at the DNA sequence level. As we will show, such investigations require the analysis of DNA derived from single genotoxin treated cells, or DNA from cell populations regularly passaged through single cell bottlenecks when naturally occurring mutation accumulation is investigated. We will argue that the life cycle of the nematode Caenorhabditis elegans, its genetic malleability combined with whole genome sequencing provides an exciting model system to conduct such analysis

Diagnostic for new physics in B→πKB \to \pi K decays

A recent analysis of $B \to \pi K$ decays concludes that present data do not clearly indicate whether (i) the standard model (or $\Delta I=0$ new physics) is sufficient, or (ii) $\Delta I=1$ new physics is needed. We show that these two possibilities can be distinguished by whether a sum rule relating the CP asymmetries of the four $B \to \pi K$ decays is valid. If case (i) is favored, the sum rule holds, and one predicts $A_{CP}(\pi^0 K^0) = -0.15$, while in case (ii) fits to new physics involving large values of a color-suppressed tree amplitude entail $A_{CP}(\pi^0 K^0) = -0.03$. The current experimental average $A_{CP}(\pi^0 K^0) = -0.01 \pm 0.10$ must be measured a factor of at least three times more precisely in order to distinguish between the two cases.Comment: 10 pages, no figures. Submitted to Physics Letters B. Slight clarification adde

Warrants in underwritten IPOs: The Alternative Investment Market (AIM) experience

We examine the use of warrants as a part of underwriter compensation in IPOs listed on the Alternative Investment Market (AIM) of the London Stock Exchange. Our results show that, though warrant-issuing IPO firms are riskier, they are usually underwritten by reputable underwriters. Firms that are cash constrained at the time of their IPO are more likely to use warrants. Both market volatility and hot issue markets increase the likelihood of firms issuing warrants. We also find that warrant issuers are able to minimise their total costs of going public, even under a very light regulatory setting with regards non-cash compensation. They incur actual costs of 29.1%, but would have incurred greater costs of 33.8% had they not issued warrants to their underwriters. Overall, our results support the cost minimisation explanation of the use of warrants by UK IPO firms