A simple design method for the cosine-modulated filter banks using weighted constrained least square technique

This paper presents a simple and efficient design method for cosine-modulated filter banks with prescribed stopband attenuation, passband ripple, and channel overlap. The method casts the design problem as a linear minimization of filter coefficients such that their value at ω=π/2M is 0.707, which results in a simpler, more direct design procedure. The weighted constrained least squares technique is exploited for designing the prototype filter for cosine modulation (CM) filter banks. Several design examples are included to show the increased efficiency and flexibility of the proposed method over the exiting methods. An application of the proposed method is considered in the area of sub-band coding of the ECG and speech signals.     

VDR,RXR, Coronin-1 and Interferonγ Levels in PBMCs of Type-2 Diabetes Patients: Molecular Link between Diabetes and Tuberculosis

Diabetes and tuberculosis are world’s most deadly epidemics. People suffering from diabetes are susceptible to tuberculosis. Molecular link between the two is largely unknown. It is known that Vitamin A receptor (RXR) heterodimerizes with Vitamin D receptor (VDR) and Peroxisome proliferator-activator receptor-γ (PPARγ) to regulate Tryptophan-aspartate containing coat protein (TACO) expression and fatty acid metabolism respectively, so it would be interesting to check the expression of these genes in diabetes mellitus (DM) patients which might explain the susceptibility of diabetics to tuberculosis. In this study, we checked the expression of RXR, VDR, TACO and Interferon-γ (IFNγ) genes in type-2 DM patients for understanding the link between the two diseases. We observed down regulation of RXR gene and corresponding up regulation of TACO gene expression. We have not observed significant change in expression of VDR and IFNγ genes in type-2 DM patients. Repression of RXR gene could hamper VDR-RXR heterodimer formation and thus would up regulate TACO gene expression which may predispose the type-2 DM patients to tuberculosis. Also, decrease in RXR-PPARγ heterodimer could be involved in DM.     

Myeloperoxidase in Chronic Kidney Disease

Numerous lines of evidence implicate a role of myeloperoxidase (MPO) in the pathogenesis of cardiovascular disease (CVD). It is a well accepted fact that patients with chronic kidney disease (CKD) are at an increased risk for CVD. MPO is a pro-oxidant enzyme which could be involved in the increased susceptibility of these patients to CVD. Hence, the levels of plasma MPO was determined in healthy controls as well as in patients with CKD [stratified with the level of their kidney failure as CKD stages II–V (end stage renal disease)]. Plasma MPO was assayed by a spectrophotometric method. Serum urea and creatinine were estimated on a clinical chemistry analyzer using standard laboratory procedures. The mean plasma MPO levels were significantly lower with advancing stages of renal failure (P < 0.001). There was a positive correlation between MPO and GFR (r = +0.89, P < 0.001) and a negative correlation with urea (r = −0.85, P < 0.001) and creatinine (r = −0.82, P < 0.001). While an inverse association was observed between plasma MPO and urea in CKD patients, such an association was not observed in control subjects (P = 0.43). In conclusion, the decline in plasma MPO levels may be due to the inhibitory effect of uraemic toxins on the enzyme.     

Dynamic optimal control model for profit maximization of software product under the influence of promotional effort

In this paper, a decision model is presented for the sales of software product to determine the profit and marketing policy under the influence of promotional efforts. The paper focuses on dependence of the optimal profit on the promotional efforts when there is diffusion effect of demand on the sales function. An elaborate optimization policy considering the dynamic nature of production cost function is proposed and numerical example is illustrated. The paper also studies the behavior of the future profit and its impact on profit maximization model by considering the constant price during the entire planning horizon. The experimental results greatly help us to identify the contributions of each selected parameter and its weight. Some conclusions, limitations of this study and future direction are also discussed.     

The major players in adaptive immunity

How do we remain healthy, for the most parts, in the midst of an environment teeming with opportunistic and infectious microbes, potential carcinogens and allergens? The fact is that our immune system, by and large, does a fine job in protecting us. It is therefore important to understand the organization of the immune network, which is broadly categorized into two groups: innate and adaptive. Cells involved in innate immunity are the first to come into contact with invading microbes, similar to the border security force, and respond rapidly but in a non-specific manner. On the other hand, the cells involved in adaptive immunity are slower to respond but act in a very specific manner. Though the primary response is slow, the secondary response is much faster and demonstrates memory. This article will focus on some important features and key players involved in the adaptive immune response. The first part deals with the humoral immune response mediated mainly by immunoglobulins produced by the B cells. The second part deals with T cells, the Major Histocompatibility Complex (MHC)-encoded molecules, and Recombination Activating Genes (RAG) responsible for generating diverse B-cell receptors (BCR) and T-cell receptors (TCR). With the advent of newer and smarter infectious agents, it is important to understand the working of the immune network as more research in this area may facilitate the development of better protective strategies.     

Understanding,embracing and reflecting upon the messiness of doctoral fieldwork

This Forum issue discusses the centrality of the fieldwork in doctoral research. The inevitability of researchers’ influence and of their values apparent during and after their fieldwork calls for a high degree of reflexivity. Since the standard methodology textbooks do not sufficiently guide on addressing such challenges, doctoral researchers go through stressful phases, at times revising various decisions they made before starting fieldwork. By drawing upon four case studies from varied contexts, this forum highlights some of these challenges including: going beyond signing the consent form and building rapport to elicit student voices; the ethical implications of White privilege of researchers turning consent into an obligatory contract with participants; unanticipated delays in the fieldwork opening up new possibilities; and tensions resulting from negotiating between insider and outsider identities while researching in two hostile contexts.     

Transformative learning in designing algorithms for reporting information systems

This paper describes a teaching method that enables students to design efficient and effective algorithms for reporting information systems applications. Adopting the general principles of transformative learning, students are immersed in a series of activities and interventions to enable learning. The activities provided opportunities for students to design algorithms, also using knowledge gained during the interventions. The interventions allowed students to gain knowledge about the output data structures such as list, table, and cube; the sequence control structures that may take different execution times; and the assumptions such as source data tables and mapping rules—all of which can contribute to the design of efficient and effective algorithms. 88 undergraduate business students in an advanced information systems course learn the principles of designing algorithms through critical reflection and reinterpretation consistent with the principles of transformative learning. The algorithms designed by students reveal that attention to the output data structures, sequence control structures, and assumptions enables the design of efficient and effective algorithms.     

Improved closed loop identification of transfer function model for unstable systems

The method of identifying first order plus time delay transfer function model proposed for unstable systems by Ananth and Chidambaram [Closed loop identification to transfer function model for unstable systems, J. Franklin Inst. 336 (1999) 1055-1061] is modified to avoid the stability problems [Cheres, Parameter estimation of an unstable system with a PID controller in a closed loop configuration, J. Franklin Inst., 2005, accepted for publication] of the method. Two modifications are proposed. In the first modification of the method, the under-determined algebraic equations problem is converted into an optimization problem for calculation of the three parameters of the first order plus time delay (FOPTD) model. A simple method is given for the initial guess values of the model parameters. In the second approach, from the definition of Laplace transform of the output response, a third equation is formulated. The resulted three equations, in terms of the three parameters of the transfer function model, are then numerically solved. Simulation results are given for the second order plus time delay transfer function considered by Cheres 2005 [Parameter estimation of an unstable system with a PID controller in a closed loop configuration, J. Franklin Inst., 2005, accepted for publication]. The responses of the identified models with the same PID controllers are compared with that of the actual system. PID controllers are designed based on the identified models. The closed loop responses of the controllers on the original system are evaluated and compared. The present methods give better control performances.     

Effect of oral antioxidant supplementation on lipid peroxidation during radiotherapy in head and neck malignancies

The objectives of the present study were to ascertain the variations in the serum levels of malondialdehyde and total antioxidant status, in head and neck malignancies with different stages, with and without oral antioxidant supplementation, before and after radiotherapy, and to validate the protective effects of an antioxidant supplementation during radiotherapy. The pretreatment values of serum malondialdehyde were significantly raised, while that of serum total antioxidant status were significantly declined in all the stages of head and neck malignancies, when compared with the healthy controls values (P<0.001). A significant correlation was observed related to the studied parameters and different stages of the disease. The study suggests that an oral antioxidant supplementation during radiotherapy is an effective mode in reducing oxidative stress. Antioxidant supplementation during radiotherapy may serve as an adjuvant therapy in malignancies offering a protection to normal cells that may further reduce the risk of developing secondary cancers.     

Urinary enzymes in nephrotic syndrome

Tubular damage is a complication associated with nephrotic syndrome and increased levels of urinary enzymes are of significant value in detection of the same. The aim of our study was to evaluate the use of urinary lysozyme and trehalase as markers of tubular dysfunction in nephrotic syndrome. This study assessed 35 nephrotic syndrome patients and 30 healthy controls matched for age and sex. Urine samples were examined at pretreatment and post treatment (8 weeks) stages for proteinuria, lysozyme and trehalase. At pretreatmant stage there was significant increase in urinary lysozyme and trehalase as compared to controls (p<0.001). A good correlation was observed between degree of proteinuria and urinary lysozyme (p<0.001;r=0.80) and trehalase (p<0.001; r=0.74). At the end of 8 weeks of treatment, the patients showed significant decrease in their urinary lysozyme and trehalase activity (p<0.001) but no correlation with degree of proteinuria was observed. Our results indicate that enzymes like lysozyme and trehalase can be used as markers of tubular dysfunction.