Spectrum monitoring: Radio Frequency Interferences (RFI) profile for hydroxyl (OH) lines window

It was crucial to monitor the Radio Frequency Interference (RFI) in order to conduct the radio astronomical research with very minimum RFI. These RFI will be distorted the astronomical data. In this work, we have investigated the RFI strength (dBm) and presenting on how the nearby RFI affect to the OH lines window (1600 MHz-1800 MHz). Measurement of RFI spectrum was done in one minute interval in 24 hours observation at Kusza Observatory (KO) using spectrum analyzer. RFI analysis was done by identifying the RFI strength (dBm) in 3 separated OH lines window which is window A, window B and window C. Window C was found as the higher RFI strength compared other two window. Besides, interference peak (1575MHz) has found affected the OH lines window by spilling out untill 90MHz to the left and 180MHz to the right.Keywords: radio frequency interference; hydroxyl lines; RFI strengt

Structured linear quadratic control computations over 2D grids

In this paper, we present a structured solver based on the preconditioned conjugate gradient method (PCGM) for solving the linear quadratic (LQ) optimal control problem for $K \times N$ sub-systems connected in a two-dimensional (2D) grid structure. Our main contribution is the development of a structured preconditioner based on a fixed number of inner-outer iterations of the nested block Jacobi method. We establish that the proposed preconditioner is positive-definite. Moreover, the proposed approach retains structure in both spatial dimensions as well as in the temporal dimension of the problem. The arithmetic complexity of each PCGM step scales as $O(KNT)$, where $T$ is the length of the time horizon. The computations involved at each step of the proposed PCGM are decomposable and amenable to distributed implementation on parallel processors connected in a 2D grid structure with localized data exchange. We also provide results of numerical experiments performed on two example systems.Comment: Submitted to the 62nd IEEE Conference on Decision and Control for possible publicatio

The maintenance of elevated active chlorine levels in the Antarctic lower stratosphere through HCl null cycles

The Antarctic ozone hole arises from ozone destruction driven by elevated levels of ozone destroying ("active") chlorine in Antarctic spring. These elevated levels of active chlorine have to be formed first and then maintained throughout the period of ozone destruction. It is a matter of debate how this maintenance of active chlorine is brought about in Antarctic spring, when the rate of formation of HCl (considered to be the main chlorine deactivation mechanism in Antarctica) is extremely high. Here we show that in the heart of the ozone hole (16–18 km or 85–55 hPa, in the core of the vortex), high levels of active chlorine are maintained by effective chemical cycles (referred to as HCl null cycles hereafter). In these cycles, the formation of HCl is balanced by immediate reactivation, i.e. by immediate reformation of active chlorine. Under these conditions, polar stratospheric clouds sequester HNO3 and thereby cause NO2 concentrations to be low. These HCl null cycles allow active chlorine levels to be maintained in the Antarctic lower stratosphere and thus rapid ozone destruction to occur. For the observed almost complete activation of stratospheric chlorine in the lower stratosphere, the heterogeneous reaction HCl + HOCl is essential; the production of HOCl occurs via HO2 + ClO, with the HO2 resulting from CH2O photolysis. These results are important for assessing the impact of changes of the future stratospheric composition on the recovery of the ozone hole. Our simulations indicate that, in the lower stratosphere, future increased methane concentrations will not lead to enhanced chlorine deactivation (through the reaction CH4 + Cl  ⟶  HCl + CH3) and that extreme ozone destruction to levels below  ≈ 0.1 ppm will occur until mid-century

Increased isolation of vibrio cholerae O1 serotype inaba over serotype ogawa in Pakistan

Although the predominant Vibrio cholerae serotype in Pakistan is Ogawa and serotype Inaba is rare, there has been a significant increase in the isolation of Inaba in our referral laboratory in Karachi. This paper reports this observation and further analysis of previous cholera data from 1993 to 2005 to assess the trend of occurrence and resistance pattern of V. cholerae strains. From January to September 2005, 245/3292 (7.4%) specimens yielded growth of V. cholerae. Of these, 243 were serotype Inaba, outnumbering serotype Ogawa. This recent Inaba strain is 100% resistant to cotrimoxazole, 3% resistant to chloramphenicol and not resistant to ampicillin, tetracycline and ofloxacin. This sensitivity pattern is almost similar to that of the previous predominant serotype Ogawa

Indirect Rapid Molds for Prototype Lost-Foam Pattern Production 506

Lost-foam (also known as Expendable Pattern Casting, EPC) is an ever-growing metalmcasting technique, capable of producing complex metal components without parting lines. Mold preparation for lost-foam casting is typically accurate, but expensive and slow. The goal of this research was to develop a new approach for producing rapid lost-foam molds. With this new approach, patterns generated by SFF technology are used to form indirect composite lost-foam molds. Ultimately, our objective is to produce these molds quickly, accurately, and inexpensively. This new approach to lost-foam mold-making will be explained as well as the results of one trial.Mechanical Engineerin

Comparison of double disc and combined disc method for the detection of extended spectrum beta lactamases in enterobacteriaceae

Objective: To compare double disc approximation and combined disc method for their ability to detect extended spectrum b lactamase (ESBL) production in enterobacteriaceae and determine the percentage of isolates which are falsely reported as sensitive in absence of ESBL detection, in a clinical microbiology laboratory of a tertiary care hospital between September-October 2002. Methods: Selected isolates were identified according to standard biochemical tests. Disc susceptibility tests were performed according to NCCLS. ESBL detection by combined disc [cefotaxime (30 ug) versus cefotaxime plus clavulanate (30+10 ug)] was compared with detection using double discs [amoxy-clavulanic acid (20+10 ug) and aztreonam (30 ug) applied 10 mm apart]. Results were interpreted according to NCCLS and analysed on SPSS version 10. Results: ESBL production was detected in 140 (30%) isolates by combined disc method and 139 (29.5%) by double disc method. There was no significant difference between two methods. Of the ESBL positive isolates 41 (29%) gave zone diameters that were within the sensitivity range cutoff and would have been falsely reported as being beta lactam sensitive in absence of ESBL detection. Conculsion: ESBL detection should be routinely performed in clinical laboratories as false reporting would result in treatment failure despite in vitro sensitivity. No difference was found between the combined disc and double disc methods hence either of two could be used

Capecitabine in the management of colorectal cancer

5-Fluorouracil has been a mainstay in the treatment of colorectal cancer for nearly five decades; however, the use of oral formulations of the medication has been gaining increasing traction since capecitabine was approved for use in adjuvant settings by the US Food and Drug Administration in 2005. The use of capecitabine has since spread to a number of off-label indications, including the treatment of advanced or metastatic colorectal cancer and the neoadjuvant treatment of rectal cancer. In light of increasing utilization, it is critical that clinicians have a firm understanding of the literature supporting capecitabine across various settings as well as the attributes of the drug, such as its dosing recommendations, side-effect profile, and use in the elderly. The purpose of this review is to synthesize the literature in a fashion that can be used to help guide decisions. In a setting of increasing focus on cost, the pharmacoeconomic literature is also briefly reviewed