VAT notches, voluntary registration, and bunching : theory and UK evidence

Using adminstrative tax records for UK businesses, we document both bunching in annual turnover below the VAT registration threshold and persistent voluntary registration by almost half of the firms below the threshold. We develop a conceptual framework that can simultaneously explain these two apparently conflicting facts. The framework also predicts that higher intermediate input shares, lower product-market competition and a lower share of business to consumer (B2C) sales lead to voluntary registration. The predictions are exactly the opposite for bunching. We test the theory using linked VAT and corporation tax records from 2004-2014, finding empirical support for these predictions

Fusion of Face and Speech Data for Person Identity Verification

Multi-modal person identity authentication is gaining more and more attention in the biometrics area. Combining different modalities increases the performance and robustness of identity authentication systems. The authentication problem is a binary classification problem. The fusion of different modalities can be therefore performed by binary classifiers. We propose to evaluate different binary classification schemes (SVM, MLP, C4.5, Fisher's linear discriminant, Bayesian classifier) on a large database (295 subjects) containing audio and video data. The identity authentication is based on two modalities: face and speec

Lung analysis in children mechanically ventilated with atelectasis after cardiac surgery

El objetivo de este estudio es asociar la área sana del pulmón (evaluado mediante radiografía) a los datos de mecánica respiratoria en niños en el postoperatorio de cirugía cardiaca, con atelectasia en ventilación mecánica en el modo asistido controlado. En el total, fueron seleccionados 46 niños, de los cuales 16 fueron excluidos debido a las ondas respiratorias irregulares o a la falta de datos de la gasometria arterial. Se analizó un grupo de 30 niños en el modo asistido controlado, de los cuales 10 han desarrollado atelectasia. Los datos fueron analizados antes y después del inicio de la atelectasia, y la mecánica respiratoria se correlacionó a las medidas del área del pulmón. En los 30 niños inicialmente sin complicación pulmonar fueron analizados los datos de la gasometria arterial para comprobar posibles cambios debido a los ciclos asistidos. La atelectasia puede modificar algunos parámetros de la mecánica respiratoria. En la asociación del área saludable del pulmón con la mecánica respiratoria, los resultados de correlación de Spearman demostraron significancia estadística entre el área del pulmón con la resistencia de las vías aéreas (ρ=-0,648 y p=0,043). Los resultados mostraron que es posible el análisis de las ondas de mecánica respiratoria a través de la selección de los ciclos controlados, puesto que no hubo alteración significativa en el potencial de hidrógeno iónico. El análisis de la mecánica respiratoria permite comprobar la función pulmonar y las posibles lesiones pulmonares. Es posible utilizar el análisis de la mecánica respiratoria diariamente en estos niños, permitiendo obtener informaciones importantes de la función pulmonar. El estudio también mostró que en el modo de ventilación controlada es posible evaluar la mecánica respiratoria.The main objective of this study is to associate the healthy area of the lung (evaluated by radiography) with the data of respiratory mechanics in children with atelectasis after cardiac surgery, under mechanical ventilation in the assisted controlled mode. Altogether, 46 children were selected, but 16 were excluded due to irregular respiratory waves or lack of the data on arterial blood gases. A group of 30 children under assisted controlled mode were analyzed, and 10 from this group developed atelectasis. The data were analyzed before and after the onset of atelectasis, and respiratory mechanics was correlated to radiography. We also analyzed the data related to arterial blood gas of these children - who initially had no pulmonary complication - to verify possible changes due to assisted controlled cycles. Atelectasis may modify some parameters of respiratory mechanics. In the association of the healthy area of the lung with the respiratory mechanics, the Spearman correlation results showed statistical significance of the lung area with airway resistance (ρ=−0.648 and p=0.043). Our results show that it is possible to analyze respiratory mechanics waves by selecting controlled cycles in the assisted controlled mode, since we found insignificant changes in potential ionic hydrogen. The analysis of respiratory mechanics allows checking lung function and undesired lung injuries; the analysis of respiratory mechanics can be daily performed in these children to have important information on the pulmonary function. Our research also showed that under the assisted controlled mode is also possible to evaluate respiratory mechanics.O objetivo deste estudo é associar a área saudável do pulmão (avaliada pela radiografia) aos dados de mecânica respiratória em crianças no pós-operatório de cirurgia cardíaca, com atelectasia em ventilação mecânica no modo assistido controlado. No total, foram selecionadas 46 crianças, das quais 16 foram excluídas devido às ondas respiratórias irregulares ou à falta de dados da gasometria arterial. Foi analisado um grupo de 30 crianças em modo assistido controlado, sendo que 10 crianças desenvolveram atelectasia. Os dados foram analisados antes e após o início da atelectasia, e a mecânica respiratória foi correlacionada às medidas da área do pulmão. Nas 30 crianças, inicialmente sem complicação pulmonar, foram analisados os dados da gasometria arterial para verificar possíveis mudanças devido aos ciclos assistidos. A atelectasia pode modificar alguns parâmetros da mecânica respiratória. Na associação da área saudável do pulmão com a mecânica respiratória, os resultados da correlação de Spearman mostraram significância estatística entre a área do pulmão com a resistência das vias aéreas (ρ=-0,648 e p=0,043). Os resultados demonstraram que é possível a análise das ondas de mecânica respiratória através da seleção dos ciclos controlados, uma vez que não houve alteração significativa no potencial de hidrogênio iônico. A análise da mecânica respiratória permite verificar a função pulmonar e as possíveis lesões pulmonares. A análise da mecânica respiratória pode ser usada diariamente nessas crianças, permitindo obter informações importantes da função pulmonar. O estudo também mostrou que no modo ventilatório assistido controlado também é possível avaliar a mecânica respiratória

Tax and occupancy of business properties : theory and evidence from UK business rates

We study the impact of commercial property taxation on vacancy rates and rents in the UK, using a new data-set, and exploiting exogenous variations in property tax rates from reliefs in the UK system: small business rate relief (SBRR), retail relief and empty property relief. We estimate that the retail relief reduces vacancies by 85%, and SBRR relief by up to 49%, while empty property exemption increases them by up to 89%. The effect of retail relief on clusters of urban properties (the "High St") is no different to its overall effect. SBRR increases (decreases) the likelihood that a property is occupied by a small (large) business. We also use data on asking prices for rental properties to study the effect of reliefs on rental rates. Rental rates move in the opposite direction to vacancy rates, except in the case of empty property relief. All these findings are consistent with a novel model of directed search in the commercial property market, also presented in the paper

Robot-Assisted Partial Nephrectomy: Evolving Techniques

Robotic-assisted partial nephrectomy is now embraced in urology as a recommended treatment option for small localised renal tumours. There is an increasing trend towards setting up robotic-assisted services in urological centres across the world. Our aim is to review the available published common robotic-assisted partial nephrectomy techniques. We present our institutions’ established step-by-step technique for performing robotic-assisted partial nephrectomy, in order to guide aspiring urologists interested in performing robotic-assisted partial nephrectomies. The importance of pre-operative review of imaging in a multi-disciplinary approach is critical. We emphasise certain tips inperforming a safer procedure

Earnings Management and Board Structure: Evidence From Nigeria

The board structure of an organization gives an overview of the standard of such organization, which also influences its public image. This study attempts to evaluate the role board structure plays in curtailing earnings management practices in Nigerian companies. This study sampled the data of 137 quoted companies in Nigeria for a period of 8 years (2003-2010). Earnings management was measured using the magnitude of the discretionary accruals as estimated by the performance matched modified Jones model. The ordinary least squares (OLS) regression technique was used to measure the research model as well as the Pearson moment correlation coefficient. The study shows that there is a significant relationship between board structure and earnings management practices in Nigeria. The study shows that there is a negative significant relationship between board size, gender, and board composition with earnings management; also, there is a positive significant relationship between board meeting and earnings management practices in Nigeria. There is a positive nonsignificant relationship between the presence of a remuneration committee and the dualization of CEO and chairman positions with earnings management practices in Nigeria. This study recommends that regulators at all levels should enforce the preparation and publication of financial reports by companies operating in Nigeria

The ITS2 Database III—sequences and structures for phylogeny

The internal transcribed spacer 2 (ITS2) is a widely used phylogenetic marker. In the past, it has mainly been used for species level classifications. Nowadays, a wider applicability becomes apparent. Here, the conserved structure of the RNA molecule plays a vital role. We have developed the ITS2 Database (http://its2.bioapps.biozentrum.uni-wuerzburg.de) which holds information about sequence, structure and taxonomic classification of all ITS2 in GenBank. In the new version, we use Hidden Markov models (HMMs) for the identification and delineation of the ITS2 resulting in a major redesign of the annotation pipeline. This allowed the identification of more than 160 000 correct full length and more than 50 000 partial structures. In the web interface, these can now be searched with a modified BLAST considering both sequence and structure, enabling rapid taxon sampling. Novel sequences can be annotated using the HMM based approach and modelled according to multiple template structures. Sequences can be searched for known and newly identified motifs. Together, the database and the web server build an exhaustive resource for ITS2 based phylogenetic analyses

An Optically-Discovered Outburst from XTE J1859+226

Using the Zwicky Transient Facility, in 2021 February we identified the first known outburst of the Black Hole X-ray Transient XTE J1859+226 since its discovery in 1999. The outburst was visible at X-ray, UV, and optical wavelengths for less than 20 days, substantially shorter than its 320-day full outburst in 1999, and the observed peak luminosity was two orders of magnitude lower. Its peak bolometric luminosity was only $2\times 10^{35}$ erg s$^{-1}$, implying an Eddington fraction of about $3\times10^{-4}$. The source remained in the hard spectral state throughout the outburst. From optical spectroscopy measurements we estimate an outer disk radius of 10$^{11}$ cm. The low observed X-ray luminosity is not sufficient to irradiate the entire disk, but we observe a surprising exponential decline in the X-ray lightcurve. These observations highlight the potential of optical and infrared (O/IR) synoptic surveys to discover low-luminosity activity from X-ray transients.Comment: 12 pages, 6 figures, accepted for publication in Ap

Implementation of U.K. Earth system models for CMIP6

We describe the scientific and technical implementation of two models for a core set of experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data) and initial conditions.We outline the scientific rationale and assumptions made in specifying these. Notable details of the implementation include an ozone redistribution scheme for prescribed ozone simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in the simulation of background natural vegetation.We discuss the implications of these decisions for interpretation of the simulation results. These simulations are expensive in terms of human and CPU resources and will underpin many further experiments; we describe some of the technical steps taken to ensure their scientific robustness and reproducibility

Random Convex Hulls and Extreme Value Statistics

In this paper we study the statistical properties of convex hulls of $N$ random points in a plane chosen according to a given distribution. The points may be chosen independently or they may be correlated. After a non-exhaustive survey of the somewhat sporadic literature and diverse methods used in the random convex hull problem, we present a unifying approach, based on the notion of support function of a closed curve and the associated Cauchy's formulae, that allows us to compute exactly the mean perimeter and the mean area enclosed by the convex polygon both in case of independent as well as correlated points. Our method demonstrates a beautiful link between the random convex hull problem and the subject of extreme value statistics. As an example of correlated points, we study here in detail the case when the points represent the vertices of $n$ independent random walks. In the continuum time limit this reduces to $n$ independent planar Brownian trajectories for which we compute exactly, for all $n$, the mean perimeter and the mean area of their global convex hull. Our results have relevant applications in ecology in estimating the home range of a herd of animals. Some of these results were announced recently in a short communication [Phys. Rev. Lett. {\bf 103}, 140602 (2009)].Comment: 61 pages (pedagogical review); invited contribution to the special issue of J. Stat. Phys. celebrating the 50 years of Yeshiba/Rutgers meeting