Long-term complications of continent catheterizable channels: a problem for transitional urologists.

A majority of the transitional urology patient population have neurogenic bladder and many of these patients have undergone creation of continent catheterizable channels (CCCs) to facilitate bladder emptying. Transitional urologists will be faced with revision of these channels due to a variety of possible complications. We performed a comprehensive literature review to the data regarding the incidence, timing, and predisposing factors that lead to complications of CCCs as well as surgical revision techniques and their outcomes. Long-term channel complications and related revisions are common (25-30%) and likely underestimated. While many predictors for revision have been posited, the only predictor that has been significant in robust multivariable analysis is channel type, with appendicovesicostomies having a lower chance of requiring revision compared to Monti channels. Channels created in adults have high likelihood of requiring revision, even within a relatively short follow-up period. We review techniques for management of channel complications and their outcomes. As patients with congenital urologic conditions requiring CCCs are gaining longer lifespans, transitional urologists will be faced with revision and/or replacement of these channels. While some of these patients may require supravesical diversion in the future, data show that revision is feasible with good outcomes. Longer-term follow-up data is needed to understand the life-span and best practices of new CCCs created among the transitional population

Community learning and development training for professionals engaged in community regeneration and community planning

The study was commissioned by the Scottish Executive Development Department to identify training needs and current provision of community learning and development (CLD) training for a range of professionals (other than those formally qualified in CLD) who are engaged in community regeneration and community planning (Local Government in Scotland Act 2003). It was one of a series of studies emanating from the Scottish Executive response to the review: „Empowered to Practice – the future of community learning and development training in Scotland‟. One of the themes of the report taken up by the Scottish Executive was the need for; „wider opportunities for joint training with other disciplines such as teachers, librarians, college lecturers, health workers and social workers‟

Impact glasses from the less than 20-micrometer fraction of Apollo 17 soils 72501 and 78221

The chemical compositions of microscopic glasses produced during meteoroid impacts on the lunar surface provide information regarding the various fractionation processes that accompany these events. To learn more about these fractionation processes, we studied the compositions of submicrometer glass spheres from two Apollo 17 sampling sites using electron microscopy. The majority of the analyzed glasses show evidence for varying degrees of impact-induced chemical fractionation. Among these are HASP glasses (high-Al, Si-poor), which are believed to represent the refractory residuum left after the loss of volatile elements (e.g., Si, Fe, Na) from the precursor material. In addition to HASP-type glasses, we also observed a group of volatile-rich, Al-poor (VRAP) glasses that represent condensates of vaporized volatile constituents, and are complementary to the HASP compositions. High-Ti glasses were also found during the course of this study, and are documented here for the first time

The use of historical accounts of species distribution to suggest restoration targets for UK upland mires within a ‘moorland’ landscape

Using contemporary accounts of vegetation in the South Pennine landscape of northern England from the late 18th Century to the present day, we describe the degradation and subsequent partial recovery of these upland mire systems in terms of their vegetation biodiversity. The historical sources highlight several species that were once common on these peatlands but which do not currently feature as positive indicator species in monitoring or restoration programmes. The use of archival sources may provide additional evidence that complements palaeoecological data when setting restoration targets. For example, the historical accounts support the palaeoecological timeline for the disappearance of Sphagnum from these landscapes. As a step toward a possible expanded set of targets for restoration works, we suggest an extended list of positive indicator species for the South Pennines which could also be applicable elsewhere in the UK. These include species such as lesser twayblade (Neottia cordata) and the club mosses (Lycopodiaceae), which were noted to be common in the 18th and 19th centuries, but which had become rare by the early 20th century. We highlight changes in land ownership and land use through the process of enclosure, as well as indirect effects from industrialisation, as the dominant interacting drivers of vegetation change

An iron(ii) spin-crossover metallacycle from a back-to-back bis-[dipyrazolylpyridine]

The syntheses of 4-mercapto-2,6-di(pyrazol-1-yl)pyridine (bppSH) and bis[2,6-di(pyrazol-1-yl)pyrid-4-yl]disulfide (bppSSbpp) are reported. In contrast to previously published “back-to-back” bis-[2,6-di(pyrazol-1-yl)pyridine] derivatives, which form coordination polymers with transition ions that are usually insoluble, bppSSbpp yields soluble oligomeric complexes with iron(II) and zinc(II). Mass spectrometry and DOSY data show that [{Fe(μ-bppSSbpp)}n]2n+ and [{Zn(μ-bppSSbpp)}n]2n+ form tetranuclear metallacycles in nitromethane solution (n = 4), although 1H NMR and conductivity measurements imply the iron compound may undergo more fragmentation than its zinc congener. Both [{Fe(bppSH)2]2+ and [{Fe(μ-bppSSbpp)}n]2n+ exhibit thermal spin-crossover in CD3NO2 solution, with midpoint temperatures near 245 K. The similarity of these equilibria implies there is little cooperativity between the iron centres in the metallacyclic structures

A discrete invitation to quantum filtering and feedback control

The engineering and control of devices at the quantum-mechanical level--such as those consisting of small numbers of atoms and photons--is a delicate business. The fundamental uncertainty that is inherently present at this scale manifests itself in the unavoidable presence of noise, making this a novel field of application for stochastic estimation and control theory. In this expository paper we demonstrate estimation and feedback control of quantum mechanical systems in what is essentially a noncommutative version of the binomial model that is popular in mathematical finance. The model is extremely rich and allows a full development of the theory, while remaining completely within the setting of finite-dimensional Hilbert spaces (thus avoiding the technical complications of the continuous theory). We introduce discretized models of an atom in interaction with the electromagnetic field, obtain filtering equations for photon counting and homodyne detection, and solve a stochastic control problem using dynamic programming and Lyapunov function methods.Comment: 76 pages, 12 figures. A PDF file with high resolution figures can be found at http://minty.caltech.edu/papers.ph

Smoothed Analysis of Tensor Decompositions

Low rank tensor decompositions are a powerful tool for learning generative models, and uniqueness results give them a significant advantage over matrix decomposition methods. However, tensors pose significant algorithmic challenges and tensors analogs of much of the matrix algebra toolkit are unlikely to exist because of hardness results. Efficient decomposition in the overcomplete case (where rank exceeds dimension) is particularly challenging. We introduce a smoothed analysis model for studying these questions and develop an efficient algorithm for tensor decomposition in the highly overcomplete case (rank polynomial in the dimension). In this setting, we show that our algorithm is robust to inverse polynomial error -- a crucial property for applications in learning since we are only allowed a polynomial number of samples. While algorithms are known for exact tensor decomposition in some overcomplete settings, our main contribution is in analyzing their stability in the framework of smoothed analysis. Our main technical contribution is to show that tensor products of perturbed vectors are linearly independent in a robust sense (i.e. the associated matrix has singular values that are at least an inverse polynomial). This key result paves the way for applying tensor methods to learning problems in the smoothed setting. In particular, we use it to obtain results for learning multi-view models and mixtures of axis-aligned Gaussians where there are many more "components" than dimensions. The assumption here is that the model is not adversarially chosen, formalized by a perturbation of model parameters. We believe this an appealing way to analyze realistic instances of learning problems, since this framework allows us to overcome many of the usual limitations of using tensor methods.Comment: 32 pages (including appendix