Fitted HBT radii versus space-time variances in flow-dominated models

The inability of otherwise successful dynamical models to reproduce the ``HBT radii'' extracted from two-particle correlations measured at the Relativistic Heavy Ion Collider (RHIC) is known as the ``RHIC HBT Puzzle.'' Most comparisons between models and experiment exploit the fact that for Gaussian sources the HBT radii agree with certain combinations of the space-time widths of the source which can be directly computed from the emission function, without having to evaluate, at significant expense, the two-particle correlation function. We here study the validity of this approach for realistic emission function models some of which exhibit significant deviations from simple Gaussian behaviour. By Fourier transforming the emission function we compute the 2-particle correlation function and fit it with a Gaussian to partially mimic the procedure used for measured correlation functions. We describe a novel algorithm to perform this Gaussian fit analytically. We find that for realistic hydrodynamic models the HBT radii extracted from this procedure agree better with the data than the values previously extracted from the space-time widths of the emission function. Although serious discrepancies between the calculated and measured HBT radii remain, we show that a more ``apples-to-apples'' comparison of models with data can play an important role in any eventually successful theoretical description of RHIC HBT data.Comment: 12 pages, 16 color figure

Credit Rating Prediction Using Different Machine Learning Techniques. International

Credit rating prediction is a crucial task in the banking and financial industry. Financial firms want to identify the likelihood of customers repaying loans or credit. With the advent of machine learning algorithms and big data analytics, it is now possible to automate and improve the accuracy of credit rating prediction. In this research, we aim to develop a machine learning-based approach for customer credit rating prediction. Machine learning algorithms, including decision trees, random forests, support vector machines, and logistic regression, were evaluated and compared in terms of accuracy, precision, and AUC. Feature selection was also performed to analyze the importance of different features in predicting credit ratings. Findings suggested that status, duration, credit history, amount, savings, other debtors, property, and employment duration are the most important features in predicting credit ratings. Results showed that the support vector machine algorithm did best in predicting bad credits. This research demonstrates the potential of machine learning algorithms for customer credit rating prediction and could have significant implications for the banking and financial industry by enabling more accurate and efficient credit rating predictions and reducing the risk of defaults and financial losses

Friedelin: A bacterial resistance modulator from Paulinia Pinnata L.

As part of the project to identify plant natural products which modulate bacterial multidrug resistance (MDR), bioassay-guided isolation of the methanol extract of Paullinia pinnata L. roots yielded four known compounds namely friedelin, â-sitosterol, â-sitosterol acetate and â-sitosterol Dglucoside. The structures were established by spectroscopic methods and comparison with published data. These compounds were tested for in vitro antibacterial and resistance modifying activities against strains of Staphylococcus aureus; SA1199B, RN4220 and XU212 possessing the Tet(K), Msr(A), and Nor(A) multidrug resistance efflux mechanisms respectively. At 10ìg/ml, none of the compounds displayed any antibacterial action but in combination with tetracycline, erythromycin andnorfloxacin, friedelin displayed a 2-fold, 4-fold and 16-fold potentiation of activities of these antibiotics against XU212, SA1199B and RN4220 possessing the Tet(K) [tetracycline resistant], Nor(A)[norfloxacin resistant] and Msr(A) [macrolide resistant] transporters respectively

Embedding the concept of ecosystems services:The utilisation of ecological knowledge in different policy venues

The concept of ecosystem services is increasingly being promoted by academics and policy makers as a means to protect ecological systems through more informed decision making. A basic premise of this approach is that strengthening the ecological knowledge base will significantly enhance ecosystem health through more sensitive decision making. However, the existing literature on knowledge utilisation, and many previous attempts to improve decision making through better knowledge integration, suggest that producing ‘more knowledge’ is only ever a necessary but insufficient condition for greater policy success. We begin this paper by reviewing what is already known about the relationship between ecological knowledge development and utilisation, before introducing a set of theme issue papers that examine—for the very first time—how this politically and scientifically salient relationship plays out across a number of vital policy venues such as land-use planning, policy-level impact assessment, and cost–benefit analysis. Following a detailed synthesis of the key findings of all the papers, this paper identifies and explores new research and policy challenges in this important and dynamic area of environmental governance

Grain quality characteristics of imported rice in Ghana: Implications for breeding for consumer-preferred varieties

ABSTRACTRice is the fastest growing food source in Ghana. The country, however, imports about 70 per cent of its rice requirement due to low volumes of production and poor grain quality of domestic rice compared to imported ones.  In the study, 10 popular imported rice brands on the Ghanaian market were characterised for grain quality traits including grain dimensions, apparent amylose content, gelatinisation temperature, paste viscosity properties, and aroma using physiochemical properties and DNA markers. The rice brands came from Asia and the USA. The rice type from Asia was found to be Jasmine-styled aromatic long grained with low amylose content and gelatinisation temperature, whereas those of USA were conventional long grain with intermediate amylose content and gelatinisation temperature.  These findings were confirmed through DNA marker analyses, with the rice types from Asia and the USA revealing the presence of the TAC and GCC of the waxy gene SNP haplotypes, respectively. The implication for rice breeding in Ghana is discussed.Original scientific paper. Received 29 Oct. 14; revised 03 Aug 15

Missed Opportunities for the Diagnosis of Pulmonary Tuberculosis in Ashanti and Western Regions of Ghana; Polymerase Chain Reaction, A Better Tool

The diagnosis of Pulmonary Tuberculosis (PTB) has mainly relied on sputum microscopy and culture. The use of molecular techniques such as the Polymerase Chain Reaction (PCR) and its overwhelming advantages compared with conventional diagnostic methodologies cannot be overemphasized. The main aim of this work was to compare the diagnostic sensitivities of microscopy, culture and PCR. Suspected PTB sputum samples were prospectively collected from six hospitals in the Ashanti and Western regions of Ghana. Microscopy was carried out on all samples at the field sites. Apart from culture and PCR, repeat sputum microscopy was carried out in the laboratories of the Kumasi Centre for Collaborative Research (KCCR). Out of the total 425 cases recruited for the study, 123 (29.0%) were smear positive on site in contrast to 275 (64.7%) positivity rate at KCCR. Regarding culture, 254 (59.9%) samples were culture positive whilst PCR technique using INS 1&2 and PR 8&9 primers were positive in 59.9 % and 56% of cases respectively. The proportion of missed positive cases of microscopy were 131 (51%) compared with culture and 1.1% missed cases when compared with PCR. The sensitivity and specificity of microscopy were 123/254 (48.4%) and 154/302 (50.99%). The study confirms the superiority of PCR in the diagnosis of PTB and indicates that a substantial proportion of PTB cases are missed when microscopy alone is used. In areas where the incidence of PTB is high and at referral hospitals, PCR can be done to augment the diagnosis of TB.Keywords: Pulmonary Tuberculosis, Sputum Microscopy, Culture, Polymerase Chain Reactio

Exploring Perceptions of Customer Value: The Role of Corporate Social Responsibility Initiatives in the European Telecommunications Industry

Purpose - This paper develops a framework that describes and explains how corporate social responsibility (CSR) initiatives are perceived by customers and links customer perception to the notion of customer value perception. In order to explore customer value conception firstly, the perception of CSR initiatives is investigated; secondly, indications for the value enhancing effects of CSR initiatives are studied, and finally, the varying effects which different value categories can have on customer attitudes and behaviour are extracted. Design/methodology/approach - The data consists of twelve semi-structured interviews with customers of European telecommunication companies. Findings - The results suggest that CSR initiatives, when communicated efficiently and considered as relevant by customers, will in the main enhance two customer value categories: (1) the extrinsic self-oriented value defined as efficiency and excellence and (2) the intrinsic other-oriented value pertaining to ethics or spirituality. Enhancement of extrinsic selforiented value imbeds the potential of CSR initiatives to affect customers’ purchase behaviour and thus strengthen ethical consumerism within the telecommunications industry. Research limitations/implications – The main implication for research is a better understanding of the relationship between customer perception and customer value perception in the field of ethical consumerism. Focusing on one industry for the study can be named as a limitation. Practical implications – As indicated by the research results by customers prioritised CSR initiative can affect the customer value perception, mainly the extrinsic/self-oriented value. If the company is aiming to change customer behaviour and to strengthen ethical consumerism, it is important that the customer experience of CSR initiatives improve excellence (quality) and/or efficiency of the product/service. Originality/value – This paper fulfils an identified need of research on how CSR initiatives can influence consumer behaviour

Stylet Penetration Activities by Aphis craccivora (Homoptera: Aphididae) on Plants and Excised Plant Parts of Resistant and Susceptible Cultivars of Cowpea (Leguminosae)

Direct current electrical penetration graphs (DC-EPGs) were used to analyze the stylet penetration activities of cowpea aphid, Aphis craccivora Koch, on plants of aphid-resistant (ICV-12) and aphid-susceptible (ICV-1) cultivars of cowpea, Vigna unguiculata (L.) Walpers. Aphid stylet penetration on whole plants at seedling, flowering, and podding stages were studied in one experiment, and in another experiment excised leaves from seedling plants, excised flowers, and excised pods were tested. Electrical signals depicting the aphid stylet penetration activities on their host plants were amplified, recorded onto a paper chart recorder, and scored for specific waveform patterns. Compared with similar tissues of ICV-1, intact leaves and excised seedling foliage of ICV-12 plants caused severe disruption of aphid stylet penetration activities. This was manifested in frequent penetration attempts that were abruptly terminated or unsustained, and in shorter penetration times, signifying antixenosis resistance in ICV-12. There was reduced occurrence of E waveforms, which represent stylet activity in plant vascular tissues. Also, prior exposure of test aphids to plants of one cultivar did not significantly influence the expected stylet penetration activities on plants of the other cultivar. Overall, ICV-12 exhibited high levels of resistance against A. craccivor

Observable implications of geometrical and dynamical aspects of freeze-out in heavy ion collisions

Using an analytical parameterization of hadronic freeze-out in relativistic heavy ion collisions, we present a detailed study of the connections between features of the freeze-out configuration and physical observables. We focus especially on anisotropic freeze-out configurations (expected in general for collisions at finite impact parameter), azimuthally-sensitive HBT interferometry, and final-state interactions between non-identical particles. Model calculations are compared with data taken in the first year of running at RHIC; while not perfect, good agreement is found, raising the hope that a consistent understanding of the full freeze-out scenario at RHIC is possible, an important first step towards understanding the physics of the system prior to freeze-out.Comment: 36 pages, 56 figures, 2 tables; version accepted for publication in PRC: some figures, references and discussion added; now also discusses classical versus quantum statistic

Truly reconciled? A dyadic analysis of post-conflict social reintegration in Northern Uganda

In the aftermath of civil war or violent internal conflict, one of the key peacebuilding challenges is the reconciliation of former enemies who are members of the same small-scale societies. A failure of social reintegration may contribute to what is known as a conflict trap. To detect lingering hostile attitudes among a community’s various factions is crucial, but the approaches adopted in previous studies tend to focus on the impact of conflict on one or other aggregated indicator of social cohesion rather than on how violence-affected individuals regard and act towards their fellow community members. Here we demonstrate the value of concentrating on this latter dyadic component of social interactions and we use behavioural experiments and a social tie survey to assess, in an appropriately disaggregated manner, social cohesion in a post-conflict setting in northern Uganda. Whereas in self-reported surveys, ex-combatants appear to be well-connected, active members of their communities, the experiments unveil the continued reluctance of other community members to share or cooperate with them; fewer resources are committed to ex-combatants than to others, which is statistically significant. The dyadic nature of our analysis allows us to detect which groups are more prone to discriminate against ex-combatants, which may help facilitate targeted interventions