Testing the nonlinearity of the BVIcJHKs period-luminosity relations for the Large Magellanic Cloud Cepheids

A number of recent works have suggested that the period-luminosity (PL) relation for the Large Magellanic Cloud (LMC) Cepheids exhibits a controversial nonlinear feature with a break period at 10 days. Therefore, the aim of this Research Note is to test the linearity/nonlinearity of the PL relations for the LMC Cepheids in BVIcJHKs band, as well as in the Wesenheit functions. We show that simply comparing the long and short period slopes, together with their associate d standard deviations, leads to a strictly larger error rate than applying rigorous statistical tests such as the F-test. We applied various statistical tests to the current published LMC Cepheid data. These statistical tests include the F-test, the testimator test, and the Schwarz information criterion (SIC) method. The results from these statistical tests strongly suggest that the LMC PL relation is nonlinear in BVIcJH band but linear in the Ks band and in the Wesenheit functions. Using the properties of period-color relations at maximum light and multi-phase relations, we believe that the nonlinear PL relation is not caused by extinction errors.Comment: 6 pages, 5 figures and 2 tables, A&A accepte

FISCAL ADJUSTMENT AND DYNAMIC ECONOMICS PERFORMANCE: THE CASE OF MALAYSIA

The main objective of this study is to identify the link between fiscal adjustment and dynamic economic performance in Malaysia using time series data for entire period of 1980-2009. To examine the long-run relationship between fiscal adjustment and economic performance, this has study employed the Gregory-Hansen cointegration approach to capture the endogenous structural breaks in long-run equilibrium relationship with three different specifications. The finding of this study indicates that there is long-run positive cointegration relationship between fiscal adjustment and economic performance in Malaysia. Therefore, the finding of this study clearly shows that the dynamic and continuous economics performance is a key element of the successful of the stability of Malaysia’s economic in Southeast Asian region, although have faced several economic crisis.Fiscal adjustment, Economic performance, Gregory-Hansen

A stochastic model for sero conversion times of HIV transmission

This paper focuses on the study of a Stochastic Model for predicting the seroconversion time of HIV transmission. As the immune capacities of an individual vary and also have its own resistance, the antigenic diversity threshold is different for different person. We propose a stochastic model to study the damage process acting on the immune system that is non- linear. The mean of seroconversion time of HIV and its variance are derived. A numerical example is given to illustrate the seroconversion times of HIV transmission

Does tourism sustain the economic growth? A wavelet based evidence from United States

This study explores the relationship between tourism development and economic growth in high tourist arrival country such as the United States of America (USA) by adopting the wavelet transform approach using monthly data over the period 1996M01-2015M08. Three innovative techniques that are continuous wavelet, wavelet coherence power spectrum and wavelet based Granger causality that consider the decomposition of time-series at different time frequencies, are utilized to conduct the study. The results of autoregressive distributed lag and combine cointegration tests show that there is a significant long-run relationship occurs between tourism development and economic growth in USA. Furthermore, the results indicate that there is a unidirectional causal influence of economic growth on tourism development in the short-run whereas, in the long-run the opposite causal relationship is evident in USA. Thus it can be recommended that government needs to increase and promote tourism demand and further providing and nurturing the expansion of tourism supply with the advancement of economic growth

Investigations of the Non-Linear LMC Cepheid Period-Luminosity Relation with Testimator and Schwarz Information Criterion Methods

In this paper, we investigate the linearity versus non-linearity of the Large Magellanic Cloud (LMC) Cepheid period-luminosity (P-L) relation using two statistical approaches not previously applied to this problem: the testimator method and the Schwarz Information Criterion (SIC). The testimator method is extended to multiple stages for the first time, shown to be unbiased and the variance of the estimated slope can be proved to be smaller than the standard slope estimated from linear regression theory. The Schwarz Information Criterion (also known as the Bayesian Information Criterion) is more conservative than the Akaike Information Criterion and tends to choose lower order models. By using simulated data sets, we verify that these statistical techniques can be used to detect intrinsically linear and/or non-linear P-L relations. These methods are then applied to independent LMC Cepheid data sets from the OGLE project and the MACHO project, respectively. Our results imply that there is a change of slope in longer period ranges for all of the data sets. This strongly supports previous results, obtained from independent statistical tests, that the observed LMC P-L relation is non-linear with a break period at/around 10 days.Comment: 9 pages, 5 figures and 3 tables, PASP accepte

Return of education and retirement age decision: a case study among management graduates from Malaysia

In this study we propose a simulation approach using Cost and Benefit Analysis (CBA) to evaluate effects of the increase in retirement age on education return among tertiary management graduates in Malaysia. All data are computed into CBA model using simulation approach to measure the Internal Rate of Return (IRR) once the retirement age is increased yearly. The overall findings of this study show that the IRR is not sensitive to the assumption made about the retirement age decisions; and the IRR does not change from the compulsory retirement age proposed by the Malaysian government. Therefore, the 56 years for retirement age for management graduates in Malaysia is still ideal in term of education return

Returns to investment on tertiary education: the case of non-conventional business and management graduates

This study provides estimates of the private returns of tertiary nonconventional education (NCE) for management graduates in Malaysia. The term 'non-conventional education' used in this research refers to distance learning and part-time management degree program graduates. We evaluate the private returns using the basic concept of educational cost and benefit analysis. The data used were derived from alumni dataset from Universiti Putra Malaysia (UPM) and National University of Malaysia (UKM) alumni division. Calculating the private returns of lifetime earnings, we find that the internal rates of return for NCE graduates are similar in both public and private sectors. Nevertheless, the results presented in this study are the first approximation ever of the private rate of returns to NCE in Malaysia, based on surveys on management NCE graduates in the Malaysian labor market. This study also seeks to contribute to the existing knowledge of economic analysis on lifelong learning in Malaysia

Exploration of a potent PI3 kinase/mTOR inhibitor as a novel anti-fibrotic agent in IPF

© 2016 BMJ Publishing Group Ltd & British Thoracic Society.Rationale Idiopathic pulmonary fibrosis (IPF) is the most rapidly progressive and fatal of all fibrotic conditions with no curative therapies. Common pathomechanisms between IPF and cancer are increasingly recognised, including dysfunctional pan-PI3 kinase (PI3K) signalling as a driver of aberrant proliferative responses. GSK2126458 is a novel, potent, PI3K/mammalian target of rapamycin (mTOR) inhibitor which has recently completed phase I trials in the oncology setting. Our aim was to establish a scientific and dosing framework for PI3K inhibition with this agent in IPF at a clinically developable dose. Methods We explored evidence for pathway signalling in IPF lung tissue and examined the potency of GSK2126458 in fibroblast functional assays and precision-cut IPF lung tissue. We further explored the potential of IPF patient-derived bronchoalveolar lavage (BAL) cells to serve as pharmacodynamic biosensors to monitor GSK2126458 target engagement within the lung. Results We provide evidence for PI3K pathway activation in fibrotic foci, the cardinal lesions in IPF. GSK2126458 inhibited PI3K signalling and functional responses in IPF-derived lung fibroblasts, inhibiting Akt phosphorylation in IPF lung tissue and BAL derived cells with comparable potency. Integration of these data with GSK2126458 pharmacokinetic data from clinical trials in cancer enabled modelling of an optimal dosing regimen for patients with IPF. Conclusions Our data define PI3K as a promising therapeutic target in IPF and provide a scientific and dosing framework for progressing GSK2126458 to clinical testing in this disease setting. A proof-ofmechanism trial of this agent is currently underway. Trial registration number NCT01725139, pre-clinical

Bipolar ablation for deep intra-myocardial circuits: human ex vivo development and in vivo experience.

To access publisher's full text version of this article click on the hyperlink at the bottom of the pageCurrent conventional ablation strategies for ventricular tachycardia (VT) aim to interrupt reentrant circuits by creating ablation lesions. However, the critical components of reentrant VT circuits may be located at deep intramural sites. We hypothesized that bipolar ablations would create deeper lesions than unipolar ablation in human hearts.Ablation was performed on nine explanted human hearts at the time of transplantation. Following explant, the hearts were perfused by using a Langendorff perfusion setup. For bipolar ablation, the endocardial catheter was connected to the generator as the active electrode and the epicardial catheter as the return electrode. Unipolar ablation was performed at 50 W with irrigation of 25 mL/min, with temperature limit of 50°C. Bipolar ablation was performed with the same settings. Subsequently, in a patient with an incessant septal VT, catheters were positioned on the septum from both the ventricles and radiofrequency was delivered with 40 W. In the explanted hearts, there were a total of nine unipolar ablations and four bipolar ablations. The lesion depth was greater with bipolar ablation, 14.8 vs. 6.1 mm (P < 0.01), but the width was not different (9.8 vs. 7.8 mm). All bipolar lesions achieved transmurality in contrast to the unipolar ablations. In the patient with a septal focus, bipolar ablation resulted in termination of VT with no inducible VTs.By using a bipolar ablation technique, we have demonstrated the creation of significantly deeper lesions without increasing the lesion width, compared with standard ablation. Further clinical trials are warranted to detail the risks of this technique

Perinatal characteristics and risk of polio among Swedish twins

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90577/1/j.1365-3016.2012.01268.x.pd