Self-regulation sets standards in echocardiography accreditation

he British Society of Echocardiography (BSE) and the European Association of Echocardiography (EAE) run voluntary accreditation programmes both for individuals and echocardiography laboratories with the aim of elevating standards both ways. In this commentary John Chambers discusses the evolution of accreditation and the development of standards of care in echocardiography in the UK and Europe. As past president of the BSE he has been instrumental in the process of developing training programmes and accreditation in echocardiography

The instability of planetary systems in binaries: how the Kozai mechanism leads to strong planet-planet interactions

In this letter we consider the evolution of a planetary system around a star inside a wide binary. We simulate numerically the evolution of the planetary orbits for both co-planar and highly-inclined systems. We find that the Kozai mechanism operates in the latter case. This produces a highly eccentric outer planet whose orbit crosses those of some of the inner planets. Strong planet-planet interactions then follow resulting in the ejection of one or more planets. We note that planetary systems resembling our solar system, formed around single stars in stellar clusters may exchange into binaries and thus will be vulnerable to planet stripping. This process will reduce the number of solar-system like planetary systems, and may produce at least some of the observed extra-solar planets.Comment: 5 pages, 2 figures, accepted for publication in MNRAS Letter

The subcoronary Toronto stentless versus supra-annular Perimount stented replacement aortic valve: Early clinical and hemodynamic results of a randomized comparison in 160 patients

BackgroundA stentless valve is expected to be hemodynamically superior to a stented valve. The aim of this study was to compare early postoperative hemodynamic function and clinical events in a randomized, prospective series of 160 stentless and stented biological replacement aortic valves.MethodsWe randomized 160 consecutive patients on 1 surgeon’s list to receive either a Toronto stentless porcine valve (St Jude Medical, Inc, St Paul, Minn) or a Perimount stented bovine pericardial valve (Edwards Lifesciences, Irvine, Calif). Echocardiography was performed at discharge, between 3 and 6 months, and at 1 year after surgery. Statistical analysis was performed by both intention to treat and actual valves implanted.ResultsThe mean labeled size of both designs of valve was 24.7. There were no statistically significant differences in results at any time interval or whether analysis was performed by actual valves implanted or intention to treat. At 3 to 6 months for the Toronto versus the Perimount valve, the effective orifice area was 1.58 versus 1.66 cm2, the mean pressure difference was 7.54 versus 7.42 mm Hg, and the peak velocity was 2.07 versus 2.0.1 m/s. There was no difference in mortality, regression of left ventricular hypertrophy, or complications other than paraprosthetic regurgitation at 12 months or on follow-up for a proportion of the sample to 8 years. The incidence of regurgitation through the valves was similar for Toronto (10%) and Perimount (13.8%) at 1 year, but mild paraprosthetic regurgitation was found in 5 patients with the Perimount valve and none with Toronto valves.ConclusionsThere were no significant differences in hemodynamic function or clinical events between the stented and stentless biological valves chosen for comparison in the early postoperative period or in preliminary follow-up to 5 years

Herschel Survey of Galactic OH+, H2O+, and H3O+: Probing the Molecular Hydrogen Fraction and Cosmic-Ray Ionization Rate

In diffuse interstellar clouds the chemistry that leads to the formation of the oxygen bearing ions OH+, H2O+, and H3O+ begins with the ionization of atomic hydrogen by cosmic rays, and continues through subsequent hydrogen abstraction reactions involving H2. Given these reaction pathways, the observed abundances of these molecules are useful in constraining both the total cosmic-ray ionization rate of atomic hydrogen (zeta_H) and molecular hydrogen fraction, f(H2). We present observations targeting transitions of OH+, H2O+, and H3O+ made with the Herschel Space Observatory along 20 Galactic sight lines toward bright submillimeter continuum sources. Both OH+ and H2O+ are detected in absorption in multiple velocity components along every sight line, but H3O+ is only detected along 7 sight lines. From the molecular abundances we compute f(H2) in multiple distinct components along each line of sight, and find a Gaussian distribution with mean and standard deviation 0.042+-0.018. This confirms previous findings that OH+ and H2O+ primarily reside in gas with low H2 fractions. We also infer zeta_H throughout our sample, and find a log-normal distribution with mean log(zeta_H)=-15.75, (zeta_H=1.78x10^-16 s^-1), and standard deviation 0.29 for gas within the Galactic disk, but outside of the Galactic center. This is in good agreement with the mean and distribution of cosmic-ray ionization rates previously inferred from H3+ observations. Ionization rates in the Galactic center tend to be 10--100 times larger than found in the Galactic disk, also in accord with prior studies.Comment: 76 pages, 25 figures, 6 tables; accepted for publication in Ap

Indications for echocardiography of replacement heart valves: a joint statement from the British Heart Valve Society and British Society of Echocardiography

Echocardiography plays a vital role in the follow-up of patients with replacement heart valves. However, there is considerable variation in international guidelines regarding the recommended time points after implantation at which routine echocardiography should be performed. The purpose of routine echocardiography is to detect early structural valve deterioration in biological valves to improve the timing of redo interventions. However, the risk of valve deterioration depends on many valve-related factors (valve design and patient prosthesis mismatch) and patient-related factors (age, diabetes, systemic hypertension, renal dysfunction and smoking). In this statement, the British Heart Valve Society and the British Society of Echocardiography suggest practical guidance. A plan should be made soon after implantation, but this may need to be modified for individual patients and as circumstances change. It is important that patients are managed in a multidisciplinary valve clinic

The use of indigenous knowledge in development: problems and challenges

The use of indigenous knowledge has been seen by many as an alternative way of promoting development in poor rural communities in many parts of the world. By reviewing much of the recent work on indigenous knowledge, the paper suggests that a number of problems and tensions has resulted in indigenous knowledge not being as useful as hoped for or supposed. These include problems emanating from a focus on the (arte)factual; binary tensions between western science and indigenous knowledge systems; the problem of differentiation and power relations; the romanticization of indigenous knowledge; and the all too frequent decontextualization of indigenous knowledge

Speciation with gene flow in a narrow endemic West Virginia cave salamander (\u3ci\u3eGyrinophilus subterraneus\u3c/i\u3e)

Due to their limited geographic distributions and specialized ecologies, cave species are often highly endemic and can be especially vulnerable to habitat degradation within and surrounding the cave systems they inhabit. We investigated the evolutionary history of the West Virginia Spring Salamander (Gyrinophilus subterraneus), estimated the population trend from historic and current survey data, and assessed the current potential for water quality threats to the cave habitat. Our genomic data (mtDNA sequence and ddRADseq-derived SNPs) reveal two, distinct evolutionary lineages within General Davis Cave corresponding to G. subterraneus and its widely distributed sister species, Gyrinophilus porphyriticus, that are also differentiable based on morphological traits. Genomic models of evolutionary history strongly support asymmetric and continuous gene flow between the two lineages, and hybrid classification analyses identify only parental and first generation cross (F1) progeny. Collectively, these results point to a rare case of sympatric speciation occurring within the cave, leading to strong support for continuing to recognize G. subterraneus as a distinct and unique species. Due to its specialized habitat requirements, the complete distribution of G. subterraneus is unresolved, but using survey data in its type locality (and currently the only known occupied site), we find that the population within General Davis Cave has possibly declined over the last 45 years. Finally, our measures of cave and surface stream water quality did not reveal evidence of water quality impairment and provide important baselines for future monitoring. In addition, our unexpected finding of a hybrid zone and partial reproductive isolation between G. subterraneus and G. porphyriticus warrants further attention to better understand the evolutionary and conservation implications of occasional hybridization between the species

Cost-Effective Use of Silver Dressings for the Treatment of Hard-to-Heal Chronic Venous Leg Ulcers

Aim To estimate the cost-effectiveness of silver dressings using a health economic model based on time-to-wound-healing in hard-to-heal chronic venous leg ulcers (VLUs). Background Chronic venous ulceration affects 1–3% of the adult population and typically has a protracted course of healing, resulting in considerable costs to the healthcare system. The pathogenesis of VLUs includes excessive and prolonged inflammation which is often related to critical colonisation and early infection. The use of silver dressings to control this bioburden and improve wound healing rates remains controversial. Methods A decision tree was constructed to evaluate the cost-effectiveness of treatment with silver compared with non-silver dressings for four weeks in a primary care setting. The outcomes: ‘Healed ulcer’, ‘Healing ulcer’ or ‘No improvement’ were developed, reflecting the relative reduction in ulcer area from baseline to four weeks of treatment. A data set from a recent meta-analysis, based on four RCTs, was applied to the model. Results Treatment with silver dressings for an initial four weeks was found to give a total cost saving (£141.57) compared with treatment with non-silver dressings. In addition, patients treated with silver dressings had a faster wound closure compared with those who had been treated with non-silver dressings. Conclusion The use of silver dressings improves healing time and can lead to overall cost savings. These results can be used to guide healthcare decision makers in evaluating the economic aspects of treatment with silver dressings in hard-to-heal chronic VLUs