The Forward Exchange Rate Bias Puzzle: Evidence from New Cointegration Tests

An important puzzle in international finance is the failure of the forward exchange rate to be a rational forecast of the future spot rate. It has often been suggested that this puzzle may be resolved by using better statistical procedures that correct for both non-stationarity and nonnormality in the data. We document that even after accounting for non-stationarity, nonnormality, and heteroscedasticity using parametric and non-parametric tests on data for over a quarter century, US dollar forward rates for horizons ranging from one to twelve months for the major currencies, the British pound, Japanese yen, Swiss franc, and the German mark, are generally not rational forecasts of future spot rates. These findings of non-rationality in forward exchange rates for the major currencies continue to be puzzling especially as these foreign exchange markets are some of the most liquid asset markets with very low trading costs.flight-to-quality, contagion, multivariate GARCH

Catalytic Hydrogenation of Benzoic Acid

Hydrogenation of benzoic acid using mono- and bimetallic catalyst of Ru, Pd, Co, and Re yielded different products. It was observed that 5% Ru/C was an active catalyst for hydrogenation of both aromatic ring and carboxylic group, while Pd/C catalyst hydrogenated only aromatic ring. Ru-Sn/Al2O3 is a chemoselective catalyst for hydrogenation of –COOH group of benzoic acid

Sweet Taste Signaling: The Core Pathways and Regulatory Mechanisms

Sweet taste, a proxy for sugar-derived calories, is an important driver of food intake, and animals have evolved robust molecular and cellular machinery for sweet taste signaling. The overconsumption of sugar-derived calories is a major driver of obesity and other metabolic diseases. A fine-grained appreciation of the dynamic regulation of sweet taste signaling mechanisms will be required for designing novel noncaloric sweeteners with better hedonic and metabolic profiles and improved consumer acceptance. Sweet taste receptor cells express at least two signaling pathways, one mediated by a heterodimeric G-protein coupled receptor encoded by taste 1 receptor members 2 and 3 (TAS1R2 + TAS1R3) genes and another by glucose transporters and the ATP-gated potassium (KATP) channel. Despite these important discoveries, we do not fully understand the mechanisms regulating sweet taste signaling. We will introduce the core components of the above sweet taste signaling pathways and the rationale for having multiple pathways for detecting sweet tastants. We will then highlight the roles of key regulators of the sweet taste signaling pathways, including downstream signal transduction pathway components expressed in sweet taste receptor cells and hormones and other signaling molecules such as leptin and endocannabinoids

Evaluation of the Efficacy of DNA Macro Chips in Early Detection of Septicemia in Children Receiving Cancer Chemotherapy

INTRODUCTION: Infection is a major cause of morbidity and mortality in pediatric oncology patients 1. Febrile episodes occur in approximately one‐third of neutropenic episodes in children with chemotherapy‐induced neutropenia 2. The possible infectious origin of fever is a central point in the management of neutropenic patients. A rapid microbiological diagnosis could therefore confirm an infectious cause of fever (thereby excluding non‐infectious causes) and help in the choice of a specific therapy.The current gold standard for the detection of bacterial pathogens in blood is blood culture. However, all blood culture systems suffer from several limitations, such as lack of rapidity and low sensitivity, especially when the patient has already received antibiotics and when fastidious micro‐organisms are involved 3. From this perspective, the diagnosis of bloodstream infections could prove really challenging in hemato‐ oncological patients, who routinely receive prophylactic antibiotics and whose blood cultures therefore often remain negative 4,5,6,7. Even after the detection of growth in cultured blood (usually not before 6–12 h of incubation), conventional blood cultures require at least a further 24–48 h for the definitive identification of the pathogen and the evaluation of its sensitivity to antibiotics 3,8. Other parallel approaches are therefore needed, and among them well‐designed molecular assays could prove really useful. Several molecular techniques have already been successfully used in routine microbiology laboratories for direct detection of viral, bacterial, mycotic and protozoan pathogens However, their use on whole blood samples for detection of sepsis has been hampered by several factors, including insufficient sensitivity, presence of PCR inhibitors in blood, and the difficulty of setting up an assay capable of detecting a wide range of potential pathogens 3. The DNA Macro Chip is a new concept, that allows for the simultaneous identification of multiple organisms like bacteria, viruses, fungi and parasites in a single test from a single sample. It involves the concept of syndrome based diagnosis, which allows for simultaneous detection of all probable causative agents which can cause sepsis, obviating multiple sequential tests and loss of time. AIMS AND OBJECTIVES: 1.To evaluate the efficacy of DNA Macrochips in early detection of septicaemia in children receiving cancer chemotherapy. OBJECTIVE OF THE STUDY: 1. To assess the sensitivity, specificity and predictive value of DNA Macrochips in the diagnosis of septicaemia 2. To compare the results of the DNA Macrochip with blood cultures in children with various malignancies during febrile episodes 3. To assess whether the DNA Macrochip can be used as an added / alternate modality in detecting bacteremia during febrile episodes in children undergoing cancer chemotherapy. DISCUSSION: In this study we aimed to evaluate the efficacy of DNA macrochip, a new PCR based technology, in early detection of septicaemia in children undergoing cancer chemotherapy in our centre. Blood culture and DNA macochip tests were done 121 children on 157 occasions. The incidence of septicaemia in our study was 9.6%. This is less than our previous observations44 and those published in the literature by Erten et al (20%)55 and Dubey et al (36%)56. The spectrum of organisms isolated in blood culture were Coagulase negative Staphylococcus(4), NFGNB(3), Pseudomonas aeruginosa(2), alpha hemolytic streptococci (1), E coli(1), Enterococci (1), Hemophilus influenzae (1), gram negative bacilli (1), aerobic spore forming organism (1), Klebsiella pneumonia (1) and Candida (1) with equal proportion of gram negative and gram positive infections. This observation was similar to that of Erten et al55, where the proportion of Gram positive and Gram negative bacteremia was similar. However, in the study conducted bt Dubey et al56, they found a higher proportion of Gram negative bacteremia in 83% of cases. An obvious focus of infection was present in 79 of 157 cases; these were lower respiratory tract infection in 31, oral mucositis 21, acute gastroenteritis 17 and local infections such as cellulitis, ear infection and throat infection in 11. This incidence is similar to that reported by Jimeno A et al57 in a study conducted on adult patients with febrile neutropenia, where the incidence of pneumonia was 23%, acute gastroenteritis 12.8% and ENT infections 7.7%. They found a higher incidence of oral mucositis (23%), in their group. DNA Macrochip test identified various microbes in 85 /157 samples (54.% ) The spectrum of organisms isolated were Acinetobacter baumanii (25), Candida (25) Pseudomanas aeruginosa (14), Streptococcus species (other than Streptococcus pneumonia)(12), Klebsiella pneumoniae (11), Staphylococcus aureus (9), Streptococcus pneumonia (8), Aspergillus species (8), Enterococcus(5), Bacteroides (2), Neisseria meningitides (1). This higher rate of isolation of organisms may be because of previous subclinical infections, cross reaction of the primer used in the technique for PCR amplification with the genome of other organisms, or due to contamination of the samples with organisms. However, when we compared the corresponding reports of the blood culture and DNA Macrochip on the same sample, in only four cases both tests was positive for the same organism. SUMMARY AND CONCLUSIONS: • We studied 157 febrile episodes in 121 febrile children undergoing chemotherapy for various malignancies and compared the results of blood culture and the DNA Macrochip in this group. 1. Blood culture was positive in 15 cases whereas DNA macrochip identified 120 organisms from 85 blood samples with multiple isolates in 28 cases. Both tests identified same organism only in 4 cases. 2. Sensitivity and specificity of the DNA Macrochip was calculated using blood culture as gold standard. The sensitivity was 26.7% and specificity was 47.37%, positive predictive value was 5.4% and negative predictive value was 85.13%. These were too low for a diagnostic test, therefore DNA Macrochip concept in it’s present stage is not an useful methodology for the detection of septicemia. 3. In the standardization study where 14 blood samples spiked with known organisms were sent to XCyton lab for DNA Macrochip analysis, it was found that the DNA Macrochip identified organisms in all 14 samples including 4 negative controls. In eight samples correct organism was detected, but in four samples additional organisms were isolated. The possibilities of the DNA primer used for PCR amplification cross reacting with the genome of other organisms, thereby giving false positive results as well as the contamination of the blood samples may explain this observation. 4. When we did a comparative analysis of the blood culture and DNA Macrochip against foci of infection and severity of illness, it was found that in 60% of cases with foci of infection was positive by DNA test and the organisms identified are known to cause these infections. Severity of illness was similar in both groups, suggesting equivalence between the two groups. However, sample sizes were too small to draw any conclusions from this

Classification Based Analysis on Cancer Datasets Using Predictor Measures

Cancer is a life-threatening disease. Probably the most effective way to reduce cancer deaths is to detect it earlier. Diagnosing the disease earlier needs an accurate and reliable procedure which could be used by physicians to distinguish between cancer from malignant ones without leaving for surgical biopsy. Data mining offers solution for such types of the problems where a large quantity of information about patients and their conditions are stored in clinical database. This paper focuses on prediction of some such diseases like Leukemia and Breast cancers. Naïve Bayes and SVM prediction models are built for the prediction and classification. The performance of the proposed models produced significant results of above 96% while compared with other models in terms of accuracy, computational time and convergence. Keywords: Prediction, Data Mining, Diagnosis, Cancer, Naïve Bayes, Supper Vector machine (SVM). DOI: 10.7176/CEIS/10-6-05 Publication date:July 31st 201

Comparison of home made and commercial rapid urease tests for detection of helicobacter pylori in patients with gastroduodenitis and peptic ulcer

Introductions: Helicobacter pylori is one of the common and medicallyprominent infections worldwide and an established etiological factor for pepticulcer disease. This study was conducted to compare the results of two types ofRapid Urease Tests (RUT) for H. pylori infection.Methods: This study was conducted in patients with gastro duodenal diseasesvisiting Kantipur Hospital from June to August 2010. Antral biopsies werecollected from sixty patients visiting endoscopy unit. The diagnosis was of H.pylori infection carried out using two types of rapid urease tests (commercialand homemade) as well as Histopathology.Results: H. pylori infection was detected in 34 (56.67%) of 60 by histologicaltest, 24 (40%) by homemade kit method and 28 (46.67%) by commercial RUTmethod. The sensitivity, specificity, positive predictive value (PPV) and negativepredictive value (NPV) for RUT (commercial kit) considering histology as goldstandard were 76.74%, 92.31%, 92.85% and 75% respectively. The sensitivity,specificity, PPV and NPV for RUT (homemade kit) were 58.82%, 84.62%, 83.3% and 61.11% respectively.Conclusions: Homemade rapid urease test was sensitive and specific fordetection of H. pylori infection than commercial test.Keywords: helicobacter pylori, peptic ulcer, rapid urease tes