Structural studies of two solid steroid compounds

Polymorphism (including solvated solid forms) is relatively common among steroids.Understanding the physical properties of each polymorph/ solvate is important for evaluating their relative stability and dissolution rates (related to bioavailability). In pharmaceutical industry powder X-ray Diffraction (XRPD), complemented by thermal methods, is the most widely used technique for characterising solid forms. However, these methods do not directly provide molecular-level information. Solid-state NMR here plays an important leading role. A number of polymorphs and solvates of two steroids (androsterone and finasteride) have been studied. Solid-state NMR and XRPD were used to characterise the hemihydrate form and the anhydrous form 1 of androsterone. XRPD was also used to study the transformation between the hemihydrate and the anhydrous form at room temperature as a function of time. Furthermore, the 13C CPMAS spectra of the two forms were assigned by applying specialised NMR pulse sequences. A number of solid forms of finasteride have been described in the scientific and patent literature. Combined characterisation by solid-state NMR and X-ray diffraction has identified deficiencies in the patent literature, reflecting the limitations of characterisation based on XRPD alone. For instance, one of the patented finasteride "polymorphs" was proved to be a dioxane solvate hydrate. Solid-state NMR and single-crystal XRD have been used to define the structure in a number of newly prepared finasteride solvates. The solvates were found to be all isomorphous with each other as well as with another solvate reported in the literature. They appear to be bis (finasteride) monosolvate monohydrates. Preliminary proton spin-lattice relaxation measurements were done on the solvates and on form 11 (anhydrous). It is suggested that the relaxation is driven by reorientation of the methyl groups rather than by solvent dynamics. A new form X was characterised by solid-state NMR though the sample is of unknown origin. TGA and DSC experiments were also carried out on the various forms

Exploring the business benefits of regulatory compliance: the case of AML/CFT systems for banking institutions in Malaysia

It has been widely accepted that the banking industry is highly dependent on information technology (IT). Due to its pervasiveness and intertwining nature in most aspects of banking business, IT has also significantly become one of the critical components that facilitate the ability of banking institutions to meet regulatory requirements in an efficient and a cost-effective way. For instance, in the effort to mitigate the activities of money laundering and terrorism financing (ML/TF), various information on banking customers are timely and accurately gathered and analysed through automation. Furthermore, in many instances, IT systems exclusively built to achieve a similar objective are frequently established, and comparable to most IT implementations in the banking institutions, they are often can be equally regarded as a significant investment as well. Viewed from the longstanding debate on the value of IT investments to organisations, empirical research within the IS domain seemed to have placed less emphasis on the possible contribution of regulatory IT implementations. While it is easy to conceive that these IT deployments were never intended to directly benefit banking business from the outset, a study from this perspective should not be disregarded, but instead, warrant to be equally explored. The rationale for this statement can be attributed to the aforementioned assertion regarding the potentially substantial monetary investments required. In addition to this, it may also be due to the high tendency of stringent regulations being enforced in the future, and hence, could inevitably place a significant demand on organisational resources, and further influence their associated opportunity costs. For that reason, this study has attempted to fill the identified research gaps by conducting an investigation from the standpoint of a topical issue regarding anti-money laundering and counter terrorism financing (AML/CFT) implementation efforts within banking institutions. Utilising a conceptual framework that leverages the resource-based view (RBV) to structurally analyse a list of research objectives, empirical evidence of business benefits and the associated capabilities through organisational AML/CFT efforts have indeed been discovered. The benefits are particularly in the form of having the opportunity to leverage various information and infrastructure that were established for regulatory purposes. Further evidence has also suggested that selected AML/CFT alerts have the potential of providing unique opportunity for the organisation to trigger time-critical event-based marketing activities, resulting in a possible improved competitive positioning (ICP). Importantly, by appreciating the insights obtained through the research, a conceptual framework is proposed, which may aid to structurally assess the possible benefits of any organisational regulatory IT implementations

Performance modelling of fairness in IEEE 802.11 wireless LAN protocols

PhD ThesisWireless communication has become a key technology in the modern world, allowing network services to be delivered in almost any environment, without the need for potentially expensive and invasive fixed cable solutions. However, the level of performance experienced by wireless devices varies tremendously on location and time. Understanding the factors which can cause variability of service is therefore of clear practical and theoretical interest. In this thesis we explore the performance of the IEEE 802.11 family of wireless protocols, which have become the de facto standard for Wireless Local Area Networks (WLANs). The specific performance issue which is investigated is the unfairness which can arise due to the spatial position of nodes in the network. In this work we characterise unfairness in terms of the difference in performance (e.g. throughput) experienced by different pairs of communicating nodes within a network. Models are presented using the Markovian process algebra PEPA which depict different scenarios with three of the main protocols, IEEE 802.11b, IEEE 802.11g and IEEE 802.11n. The analysis shows that performance is affected by the presence of other nodes (including in the well-known hidden node case), by the speed of data and the size of the frames being transmitted. The collection of models and analysis in this thesis collectively provides not only an insight into fairness in IEEE 802.11 networks, but it also represents a significant use case in modelling network protocols using PEPA. PEPA and other stochastic process algebra are extremely powerful tools for efficiently specifying models which might be very complex to study using conventional simulation approaches. Furthermore the tool support for PEPA facilitates the rapid solution of models to derive key metrics which enable the modeller to gain an understanding of the network behaviour across a wide range of operating conditions. From the results we can see that short frames promote a greater fairness due to the more frequent spaces between frames allowing other senders to transmit. An interesting consequence of these findings is the observation that varying frame length can play a role in addressing topological unfairness, which leads to the analysis of a novel model of IEEE 802.11g with variable frame lengths. While varying frame lengths might not always be practically possible, as frames need to be long enough for collisions to be detected, IEEE 802.11n supports a number of mechanisms for frame aggregation, where successive frames may be sent in series with little or no delay between them. We therefore present a novel model of IEEE 802.11n with frame aggregation to explore how this approach affects fairness and, potentially, can be used to address unfairness by allowing affected nodes to transmit longer frame bursts.Kurdistan Region Government of Iraq (KRG) sponso

A simulative study on the performance evaluation for simultaneous and successive mobility for mobile IPv6

Mobile Internet Protocol (MIP) is the forms of the backbone for next generation wireless internet technology to provide uninterrupted network service while a node on the move. The original MIP use Home Agent to forward the traffic. Thus, it does not have problem with simultaneous mobility, i.e., the special case when both end nodes are mobile and move at about the same time. However, MIPv6 uses location binding updates which sent directly to a correspondent node to complete its registration. Thus, MIPv6 is vulnerable to the simultaneous mobility problem which leads to the interruption of communication and cause messages lost, especially protocol messages. Approach: This articleanalyzed the simultaneous and successive fast mobility problems and handover latency. Then propose a mechanism by adopting technique to the mobile node's Home Agent. Results: We simulated the proposed scheme using ns-2 and we present and analyze the performance testing for the proposed scheme by comparing it with the conventional MIPv6. Conclusion: Simulation results showed this scheme can effectively resolve simultaneous and successive mobility problems and reduce the handover latency which is affected by long registration time

Scheduling divisible jobs to optimize the computation and energy costs

The important challenge in cloud computing environment is to design a scheduling strategy to handle jobs, and to process them in a heterogeneous environment with shared data centers. In this paper, we attempt to investigate a new analytical framework model that enables an existing private cloud data-center for scheduling jobs and minimizing the overall computation and energy cost together. Our model is based on Divisible Load Theory (DLT) model to derive closed-form solution for the load fractions to be assigned to each machines considering computation and energy cost. Our analysis also attempts to schedule the jobs such a way that cloud provider can gain maximum benefit for his service and Quality of Service (QoS) requirement user’s job. Finally, we quantify the performance of the strategies via rigorous simulation studies

MRI brain classification using support vector machine

The field of medical imaging gains its importance with increase in the need of automated and efficient diagnosis in a short period of time. Other than that, medical image retrieval system is to provide a tool for radiologists to retrieve the images similar to query image in content. Magnetic resonance imaging (MRI) is an imaging technique that has played an important role in neuroscience research for studying brain images. Classification is an important part in retrieval system in order to distinguish between normal patients and those who have the possibility of having abnormalities or tumor. In this paper, we have obtained the feature related to MRI images using discrete wavelet transformation. An advanced kernel based techniques such as Support Vector Machine (SVM) for the classification of volume of MRI data as normal and abnormal will be deployed

A long-run relationship between the trade and its determinants for a group of selected Arab Maghreb Union Countries

The Arab Maghreb Union (AMU) comprising Algeria, Libya, Mauritania, Morocco, and Tunisia has established a framework to enhance regional cooperation on trade facilitation. It is doubtful whether the Arab Maghreb countries could achieve the goals of this regional cooperation or not. The objective of this study is to examine a long-run relationship between the trade and its determinants for a group of selected Arab Maghreb Union Countries.Using a data set consisting of a panel observation for the AMU countries for the period of 1989-2009; a panel unit root test was done to investigate the possibility of panel cointegration.Overall, the results are consistent with those found in Pedroni approach in all cases, parameters for the variables are found to be correctly signed and highly significant. In terms of trade openness, the results show that the trade barriers are found to be positively and significantly correlated with openness where their relationships within the AMU trade intensity ratios show a strong correlation.In other words, the trade barriers are fairly effective for increasing trade

An Efficient Parallel Quarter-sweep Point Iterative Algorithm for Solving Poisson Equation on SMP Parallel Computer

A new point iterative algorithm which uses the quarter-sweep approach was shown to be much faster than the full-and half- sweep point iterative algorithms for solving two dimensional Poison equation (Othman el at. 1998». However, the last two algorithms were found to be suitable for parallel implementation (Evans 1984) and Ali el at. (1997». In this paper, the parallel implementation of the new algorithm with the chessboard (CB) strategy on Symmetry Multi Processors (SMP) parallel computer was presented. The experimental results of a test problem were compared with the later two parallel algorithms

The halfsweeps multigrid method as a fast multigrid Poisson solver

The idea of halfsweeps iterative method (introduced by A. R. Abdullah, 1991) is used to develop the halfsweeps multigrid method to solve the 2-D elliptic partial differential equation with the Dirichlet boundary conditions. The method is shown to be very much faster compared with the fullsweeps multigrid method due to M. M. Gupta et al, 1995. Some numerical experiments are included to confirm our recommendation