Bubble Free Energy in Cosmological Phase Transitions

Free energy as a function of temperature and the bubble radius is determined for spherical bubbles created in cosmological first order phase transitions. The phase transition is assumed to be driven by an order parameter (e.g. a Higgs field) with quartic potential. The definition of the bubble radius and the corresponding generalized, curvature-dependent surface tensions are discussed. In the free energy expansion in powers of the inverse radius, the coefficients of the curvature term and the constant term are also calculated.Comment: 9 pages ( + 7 figures, available on request as a 130 kB Postscript file or by fax or mail), plain Latex, HU-TFT-92-5

Compressive linear network coding for efficient data collection in wireless sensor networks

International audienceWe address the problem of data collection in a wireless sensor network. Network coding is used for data delivery. The correlation between the measurements is exploited to recover the data at the sink, even in case of rank-deficient network matrix. The network coding operations are seen as lossy source compression, achieved by a finite-field random code generated during transmission. Decoding is performed using belief propagation on a factor graph which accounts for the correlation between the sensor measurements. Experimental results illustrate the performance of this technique for various field sizes and correlation levels

A systematic investigation of the development and implementation of activity-based budgeting systems in the UK : three case studies

Literature describes Activity-Based Budgeting (ABB) as an extended and advanced use of Activity-Based Costing (ABC) in a budgeting process. Despite some potential benefits of an ABB approach being suggested by a few academics and management consultants(Brimson & Antos, 1994/1999; Brimson & Fraser, 1991; Kaplan & Cooper, 1998; Sharman, 1996), very limited published literature has reported the actual ABB experience in practice. Empirical evidence from this research suggests that ABB development and implementation processes tend to encounter problems in practice which hinder the progress and even the successful completion of these processes. In the light of a general lack of published literature on ABB, it is thus necessary to explore some fundamental issues on the applications of ABB, investigate factors that may determine the success or otherwise of an ABB implementation, and gain an in-depth understanding of generic and specific attributes of an ABB process within an organisational context. This study examines the development and implementation of ABB systems in three UK organisations: Scottish Courage Brewing Limited -(SCB) (which is a wholly owned subsidiary of a multinational brewer, Scottish and Newcastle p1c), BG Transco plc (Transco) (which is a public listed organisation and operates in the regulated gas supply market), and Crown Prosecution Services (CPS) (which is one of the governmental agencies). In particular, this study examines the relationships between design specification of ABB systems, budgetary purposes and organisational objectives for system implementations on the basis of the ABB experiences gathered from SCB, Transco and CPS. Four basic themes emerge from this study. First, it is rather difficult to implement the ABB model into a computer system based purely on the concept of 'ABB as a reverse ABC process'. Such difficulty arises due to the fundamental difference in data processing requirements, namely data aggregation in an ABC process and data dissemination in an ABB process. This difference can create major permutation problems and render an ABB system significantly less cost-effective. Second, ABB information can enhance a strategic planning process by providing a clearer cross-functional view of an organisation's activities/processes and highlighting a causal link between performance and resource. In that sense, ABB information is perceived to be useful by top and middle line managers who want to see organisational performance and processes in a holistic manner. The existence of limited cost variability, which has been suggested in the literature as being unsuitable for the application of activity-based systems, does not prevent managers from using activity-based information to support decision making. Third, the success of an ABB implementation is attributed to a combination of internal and external factors. The internal factors are mainly related to technical, behavioural, organisational and cultural perspectives. For example, budgets and budgeting processes can help to form a particular set of norms (culture). The implementation of an ABB system may be perceived as an attempt to break the existing culture by introducing a new set of norms. Organisational restructuring, which destabilises the existing culture, may have some positive impacts on the ABB implementation. Furthermore, supportive administrative arrangements (e.g. standardised procedures and formalised goal/sub-goal development processes) and budgetary devolution can also help to define the precise role of an ABB system relating to organisational objectives, and thus pave the way for a smooth ABB implementation. Evidence of this research suggests that an ABB implementation can also be substantially influenced by some external factors, such as political concerns, regulator's pressure, and market competition. Fourth, some generic issues relating to the implementation of ABC/M and budgeting systems, such as top management's commitment, simplicity, compatibility and resistance to changes are also relevant to the implementation of an ABB system

The diagnostic potential of oxidative stress biomarkers for preeclampsia : systematic review and meta-analysis

Background: Preeclampsia is a multifactorial cardiovascular disorder of pregnancy. If left untreated, it can lead to severe maternal and fetal outcomes. Hence, timely diagnosis and management of preeclampsia are extremely important. Biomarkers of oxidative stress are associated with the pathogenesis of preeclampsia and therefore could be indicative of evolving preeclampsia and utilized for timely diagnosis. In this study, we conducted a systematic review and meta-analysis to determine the most reliable oxidative stress biomarkers in preeclampsia, based on their diagnostic sensitivities and specificities as well as their positive and negative predictive values. Methods: A systematic search using PubMed, ScienceDirect, ResearchGate, and PLOS databases (1900 to March 2021) identified nine relevant studies including a total of 343 women with preeclampsia and 354 normotensive controls. Results: Ischemia-modified albumin (IMA), uric acid (UA), and malondialdehyde (MDA) were associated with 3.38 (95% CI 2.23, 4.53), 3.05 (95% CI 2.39, 3.71), and 2.37 (95% CI 1.03, 3.70) odds ratios for preeclampsia diagnosis, respectively. The IMA showed the most promising diagnostic potential with the positive predictive ratio (PPV) of 0.852 (95% CI 0.728, 0.929) and negative predictive ratio (NPV) of 0.811 (95% CI 0.683, 0.890) for preeclampsia. Minor between-study heterogeneity was reported for these biomarkers (Higgins’ I2 = 0–15.879%). Conclusions: This systematic review and meta-analysis identified IMA, UA, and MDA as the most promising oxidative stress biomarkers associated with established preeclampsia. IMA as a biomarker of tissue damage exhibited the best diagnostic test accuracy. Thus, these oxidative stress biomarkers should be further explored in larger cohorts for preeclampsia diagnosis

A longitudinal study of the adoption of an activity-based planning system in the crown prosecution service of England and Wales, United Kingdom

Purpose – The purpose of this paper is to explore the adoption of a time-based activity-based costing (ABC) information system in resource planning (ABP) in the Crown Prosecution Service (CPS) of England and Wales, a public service organisation in the United Kingdom, for the period of 2000-2005. The aims of the study are to provide a technical review of the ABP application and to explore roles of the ABP system in achieving a “fairer” internal resource allocation and an improved understanding of business processes. Design/methodology/approach – The CPS's experience of adopting an ABP system is explained through the use of a case study involving interviews, observations, work shadowing and archival data over a period of six years, 2000-2005. The longitudinal nature of the study has enabled the researchers to align the outcome of ABP adoption with concurrent organisational changes. Findings – The study reveals that the growing understanding of the intrinsic links between business processes and the ABP information and its rationale, which remains unchanged throughout various phases of organisational changes, has promoted a sense of stability amongst CPS staff members. Practical implications – This study provides an in-depth understanding of the practical use of ABP and its evolving roles in the face of the changing organisational environment. Originality/value – This research discusses the prerequisite of the ABP system, a time-based ABC system, and the evolving roles of ABP from a cost-effective planning tool to a stability mechanism in face of constant organisational changes. This experience is invaluable to companies and practitioners seeking to implement a cost-effective planning tool

Craniofacial dysmorphology in Down syndrome is caused by increased dosage of Dyrk1a and at least three other genes

Down syndrome (DS), trisomy of human chromosome 21 (Hsa21), occurs in 1 in 800 live births and is the most common human aneuploidy. DS results in multiple phenotypes, including craniofacial dysmorphology, which is characterised by midfacial hypoplasia, brachycephaly and micrognathia. The genetic and developmental causes of this are poorly understood. Using morphometric analysis of the Dp1Tyb mouse model of DS and an associated mouse genetic mapping panel, we demonstrate that four Hsa21-orthologous regions of mouse chromosome 16 contain dosage-sensitive genes that cause the DS craniofacial phenotype, and identify one of these causative genes as Dyrk1a. We show that the earliest and most severe defects in Dp1Tyb skulls are in bones of neural crest (NC) origin, and that mineralisation of the Dp1Tyb skull base synchondroses is aberrant. Furthermore, we show that increased dosage of Dyrk1a results in decreased NC cell proliferation and a decrease in size and cellularity of the NC-derived frontal bone primordia. Thus, DS craniofacial dysmorphology is caused by an increased dosage of Dyrk1a and at least three other genes

A Systematic Literature Review on Performance Evaluation of Power System From the Perspective of Sustainability

Sustainability is a comprehensive concept that integrates at least three dimensions of environment, economy and society. The power system is the primary source of greenhouse gas emissions, adversely impacting environmental sustainability. It also generates necessary energy supplies, which promote economic and social sustainable development. Based on the sustainability nature of power system, this study puts forward an improved methodology, namely “Planning-Searching-Screening-Reporting-Reflecting” (PSSRR Cycle) to review the literature systematically on power system performance evaluation from a sustainability perspective over the past 20 years, with the aim of describing the current state of the whole performance evaluation system including the evaluation framework, evaluation indicators and evaluation methods, and providing research suggestions for future research. This study finds in the current literature that the Triple Bottom Line theory is the most commonly used theoretical evaluation framework; environmental and economic sustainability indicators are more emphasized; the DEA and MCDM methods are the more common evaluation methods. This study presents some future research notes, including improving the Sustainable Balanced Scorecard as a sustainable performance evaluation framework, emphasizing more social sustainability indicators, and using a combination of existing evaluation methods to make performance evaluation more efficient and accurate

Tract-specific white matter hyperintensities disrupt neural network function in Alzheimer's disease

Introduction: White matter hyperintensities (WMHs) increase the risk of Alzheimer's disease (AD). Whether WMHs are associated with the decline of functional neural networks in AD is debated. Method: Resting-state functional magnetic resonance imaging and WMH were assessed in 78 subjects with increased amyloid levels on AV-45 positron emission tomography (PET) in different clinical stages of AD. We tested the association between WMH volume in major atlas-based fiber tract regions of interest (ROIs) and changes in functional connectivity (FC) between the tracts' projection areas within the default mode network (DMN). Results: WMH volume within the inferior fronto-occipital fasciculus (IFOF) was the highest among all tract ROIs and associated with reduced FC in IFOF-connected DMN areas, independently of global AV-45 PET. Higher AV-45 PET contributed to reduced FC in IFOF-connected, temporal, and parietal DMN areas. Conclusions: High fiber tract WMH burden is associated with reduced FC in connected areas, thus adding to the effects of amyloid pathology on neuronal network function

Application of the quick scan audit methodology in an industrial filter production process

The quick scan audit methodology (QSAM) is an established investigative tool to assess the health of business processes and supply chains within short schedules. This study extends the standard QSAM procedure to include the simulation step. It also extends the QSAM to a wider industry platform by applying it into the precision mechanical engineering industry, where managers have been under competitive pressure to reduce an industrial filter production lead time. Following a review of the relevant literature, this paper presents the research design adopted in the study. The QSAM has been conducted using various data collection techniques (such as observations, process activity mapping, interviews, questionnaires, brainstorming and access to company documents) and data analysis methods (including cause and effect analysis, Pareto analysis and time series plot). This is followed by the development of a set of improvement strategies, namely, direct information sharing, priority planning, and additional data recording and analysis. In addition to testing the potential benefits of changing scheduling approaches for the paint plant, simulation has been utilized in this study as a communication means to increase employee participation in the QSAM process and enhance the audit accuracy. It has also provided the case company with a better understanding of the behaviour and characteristics of the system under study, thus facilitating more thoughtful decisions to improve the system. The paper concludes with further research opportunities derived from this study