Definable Envelopes of Nilpotent Subgroups of Groups with Chain Conditions on Centralizers

An $\mathfrak{M}_C$ group is a group in which all chains of centralizers have finite length. In this article, we show that every nilpotent subgroup of an $\mathfrak{M}_C$ group is contained in a definable subgroup which is nilpotent of the same nilpotence class. Definitions are uniform when the lengths of chains are bounded

On 2-groups of almost maximal class

Let G be a 2-group of order 2^n, n>5, and nilpotency class n-2. The invariants of such groups determined by their group algebras over the field of two elements are given in the paper.Comment: 25 page

Finite element simulation of thunderstorm electrodynamics in the proximity of the storm

Observations of electric fields, Maxwell current density, and air conductivity over thunderstorms were presented. The measurements were obtained using electric field mils and conductivity probes installed on a U2 aircraft as the aircraft passed approximately directly over an active thunderstorm at an altitude of 18 to 20 km. Accurate electrical observations of this type are rare and provide important information to those involved in numerically modeling a thunderstorm. A preliminary set of computer simulations based on this data were conducted and are described. The simulations show good agreement with measurements and are used to infer the thundercloud's charging current and amount of charge exchanged per flash

PARTICIPATORY FOREST MANAGEMENT IN ANDHRA PRADESH : A Review

This paper traces the recent emergence of the new participatory forest management regime in AP Joint Forest Management (JFM) and Community Forest Management (CFM). This paper is based on the existing literature on forest policies, the historical context (pre-colonial, colonial and post independent India), and impact studies. The paper considers the contemporary developments in India in shaping the forest policies in AP. At the same time it considers the significant role played by donors and civil society. The process and quality of implementation, and the impact of the programme on local communities and resources are also examined. AP ranks fifth in India in terms of geographical area (275,068 sq km), and third in terms of forestland (63,813 sq km or 6.38 mha (Million Hectares), which constitutes 23% of APs total land area. Some 65% of APs forest area is spread over 8 predominantly tribal districts in the northern part of the state. These tribal populations are particularly dependent on the forest for their livelihoods for forest product collection and cultivation on forestland. Historically the relationship between these tribals and the government agencies, particularly the Forest Department (FD), has been very poor, with numerous uprisings, including the Naxalite movement. Many of these lands are disputed due to inadequacies in the legal processes by which largely tribal lands were declared state forests. Legally podu has de jure status prior to 1980 Act. Post 1980 podu cultivation is illegal and considered as encroachment. De facto podu is considered as encroachment (prior to 1980) as there is no proper settlement, conceptually typical podu practice is seen only in a few pockets in the state, especially in Vishakhapatnam. In 1956, on the formation of AP from Telangana and parts of the Madras Presidency, the pre-existing forest management regimes from the two distinct areas were harmonised by the Law Commission, leading to the AP Forest Act, 1967. Initially the states FD continued with a policy of commercialisation and revenue generation. However, with a growing crisis of forest degradation participatory approaches were introduced. The Government Order (GO) for JFM in AP was issued in 1992, although implementation didnt start until 1994. JFM has built on the roles played by both local forest *Centre for Economic and Social Studies, Hyderabad, India. +Overseas Development Group, University of East Anglia, Norwich, UK. users and the FD staff. Funding to the FD to promote JFM has come from both the World Bank (WB) and from centrally funded schemes, such as the Employment Assurance Scheme (EAS). Formation of Vana Samrakshana Samithies (VSS) began slowly after the GO, although by 2004 the official number stands at 7,245 VSS, managing 1,886,764 ha, (or over 29% of state forest land) and involving 611,095 families. The largest numbers of VSS are concentrated in the tribal areas of Adilabad, Visakhapatnam, and Khammam. The pattern of implementation and the outcomes is extremely complex, partly because of the wide variety of local conditions, ethnic and caste composition and local livelihood uses of forestland. The limited devolution of power which has occurred through VSS formation have however certainly been popular in many areas, because they have given local people endorsement to protect their local forest resources, upon which they depend for their livelihoods. Some employment opportunities have also been provided and some shares of revenues from forest product marketing are promised. Evidence suggests that the VSS have been successful in many areas in terms of regenerating degraded forests between 1993 and 1999. However there have been many criticisms of the JFM programme so far, most fundamentally focussing on the issues of power and land tenure. Because the FD has held almost complete discretionary power over the scheme and its implementation, the JFM process has inevitably reflected their objectives. Whilst many foresters have espoused very progressive ideas and concepts, in practice the implementation of the scheme has often furthered forest management strategy according to silvicultural norms, rather than local livelihood-oriented practices. In the context of a fundamental power asymmetry between the FD and the VSS., there has been little empowerment of local communities to take their own decisions with respect to forest management. This is most obviously seen in forest management plans. Whilst local people would like to see livelihood oriented forest management regime (ie. regular product flows, shorter term rotations, multiple product mixes) the FD has tended to prioritise its conventional forest management practices, often involving long rotation timber stands. The micro-plans commonly fit within wider divisional working plans. Livelihoods security could be increased if the forest resource were under a management plan, which actually prioritised local needs and opportunities. Institutional sustainability is a major problem in AP with many VSS becoming defunct due to conflict, lack of interest, or lack of funds. Where participation has been based on substantial funding flows, when the funds stop the motivation to participate reduces drastically. The institutional linkage between the VSS and the panchayat raj institutions has not been developed, which could ensure not only long-term sustainability, but also empowerment and legal independence of the local institutions. Non-Government Organisations (NGOs) have been largely excluded from the implementation of JFM, despite the fact they have played a major role in formulating the PFM policies at the state level.Forest Management, Andhra Pradesh

Automated quantification and evaluation of motion artifact on coronary CT angiography images

Abstract Purpose This study developed and validated a Motion Artifact Quantification algorithm to automatically quantify the severity of motion artifacts on coronary computed tomography angiography (CCTA) images. The algorithm was then used to develop a Motion IQ Decision method to automatically identify whether a CCTA dataset is of sufficient diagnostic image quality or requires further correction. Method The developed Motion Artifact Quantification algorithm includes steps to identify the right coronary artery (RCA) regions of interest (ROIs), segment vessel and shading artifacts, and to calculate the motion artifact score (MAS) metric. The segmentation algorithms were verified against ground‐truth manual segmentations. The segmentation algorithms were also verified by comparing and analyzing the MAS calculated from ground‐truth segmentations and the algorithm‐generated segmentations. The Motion IQ Decision algorithm first identifies slices with unsatisfactory image quality using a MAS threshold. The algorithm then uses an artifact‐length threshold to determine whether the degraded vessel segment is large enough to cause the dataset to be nondiagnostic. An observer study on 30 clinical CCTA datasets was performed to obtain the ground‐truth decisions of whether the datasets were of sufficient image quality. A five‐fold cross‐validation was used to identify the thresholds and to evaluate the Motion IQ Decision algorithm. Results The automated segmentation algorithms in the Motion Artifact Quantification algorithm resulted in Dice coefficients of 0.84 for the segmented vessel regions and 0.75 for the segmented shading artifact regions. The MAS calculated using the automated algorithm was within 10% of the values obtained using ground‐truth segmentations. The MAS threshold and artifact‐length thresholds were determined by the ROC analysis to be 0.6 and 6.25 mm by all folds. The Motion IQ Decision algorithm demonstrated 100% sensitivity, 66.7% ± 27.9% specificity, and a total accuracy of 86.7% ± 12.5% for identifying datasets in which the RCA required correction. The Motion IQ Decision algorithm demonstrated 91.3% sensitivity, 71.4% specificity, and a total accuracy of 86.7% for identifying CCTA datasets that need correction for any of the three main vessels. Conclusion The Motion Artifact Quantification algorithm calculated accurate

State-of-the-art survey of dissimilar metal joining by solid state welding

State-of-the-art of dissimilar metal joining by solid state diffusion bonding and roll and press welding, emphasizing stainless steel and aluminum allo

The Effect of Macro Information Environment Change on the Quality of Management Earnings Forecasts

The 1990s were characterized by substantial increases in the performance of and investor reliance on financial analysts. Because managers possess superior private information and issue forecasts to align investors’ expectations with their own, we predict that managers increased the quality of their earnings forecasts during the 1990s in order to keep pace with the improved forward-looking information provided by financial analysts, upon which investors increasingly relied. Using a sample of 2,437 management earnings forecasts, we document an increase in management earnings forecast precision, management earnings forecast accuracy, and managers’ tendency to explain earnings forecasts in 1993-1996 relative to 1983-1986. Given that these forecast characteristics are linked to greater informativeness and credibility, we also document that the information content of management earnings forecasts, as measured by the strength of share price responses to forecast news, increased in 1993 -1996 relative to 1983-1986. As expected, the increased information content of management forecasts primarily occurred for firms covered by financial analysts

Paired Pulse Basis Functions for the Method of Moments EFIE Solution of Electromagnetic Problems Involving Arbitrarily-shaped, Three-dimensional Dielectric Scatterers

A pair of basis functions is presented for the surface integral, method of moment solution of scattering by arbitrarily-shaped, three-dimensional dielectric bodies. Equivalent surface currents are represented by orthogonal unit pulse vectors in conjunction with triangular patch modeling. The electric field integral equation is employed with closed geometries for dielectric bodies; the method may also be applied to conductors. Radar cross section results are shown for dielectric bodies having canonical spherical, cylindrical, and cubic shapes. Pulse basis function results are compared to results by other methods