Improving the Efficiency and Resolution of Time of Flight (TOF) Mass Spectrometer for Magnetospheric Applications.

The Earth magnetosphere is the volume of space formed by the Earth magnetic field in response to the flow of plasma from the solar wind. Although the magnetopause shields us from the solar wind there are far more particles that penetrate with energy, and momentum to the Earths magnetosphere and interacts with the Earth’s magnetic field to create various plasmas and currents which shape and couple different regions of magnetosphere. The study of the dynamics of ions in and outside of the magnetosphere is done through mass spectrometer. Over the years, CODIF Ion TOF spectrometer have been used to understand the composition of the ions. However, the total ion detection efficiency has been decreased by a factor of 50. Thus, the scope of this project is to improve the mass resolution of the detector by understanding the scattering of the ions within the instrument. Using SRIM and SIMION simulations, we model the interaction of ions with Micro-Channel Plates (MCP) and carbon foils, which are vital components in time-of-flight detectors

Understanding Thermometry at Low Temperature

Cryogenics play a vital role in building a Dynamic Nuclear Polarization (DNP) target for electron scattering experiments. The target material temperature was monitored using thermometry in order to evaluate their stability for use in the low temperature cryogenic bath of a DNP target. In this project, I investigated there solutions and accuracies of carbon ceramic, Cernox, Allen-Bradley, and thermocouple sensors at five known temperatures

Analyzing Compton Telescope (COMPTEL) Measurements of the Atmospheric Albedo Neutron Flux Using Neutron Capture

All orbiting spacecraft are susceptible to space radiation that can cause permanent damage to spacecraft electronics. The atmospheric neutron flux is one of the potential candidates that give rise to space radiation. To extend the atmospheric neutron study as a function of various geophysical and observational parameters (like magnetic rigidity, altitude, and phase of the solar cycle), the NASA COMPTEL (Compton Telescope) instrument on-board the CGRO (Compton Gamma Ray Observatory) spacecraft had been used to measure the spatial and temporal variation of neutrons. We used gamma-ray telescopic mode to measure the instrumental 2.2 MeV line that arose from the thermal neutron being captured by a proton in the D1 module. Hence, the 2.2 MeV line served as a surrogate for the albedo neutron flux. To support the CRAND (Cosmic Ray Albedo Neutron Decay) theory, systematic measurements of the 2.2 MeV line rate were done as a function of various parameters primarily geomagnetic rigidity ranging from 4-18 GV, geocentric elevation 0-180, and spacecraft altitude ranging from 325-525 km. Using the Morris et al. neutron fit function, the estimated line rate was calibrated to obtain measured neutron flux. To evaluate our findings, the measured neutron flux data was compared with Claret et al. simulated neutron data at solar minimum and solar maximum and also. Our neutron measurements follow the same trend as the simulated data

Analyzing Compton Telescope (COMPTEL) Measurements of the Atmospheric Albedo Neutron Flux Using Neutron Capture

All orbiting spacecraft are susceptible to space radiation that can cause permanent damage to spacecraft electronics. The atmospheric neutron flux is one of the potential candidates that give rise to space radiation. To extend the atmospheric neutron study as a function of various geophysical and observational parameters (like magnetic rigidity, altitude, and phase of the solar cycle), the NASA COMPTEL (Compton Telescope) instrument on-board the CGRO (Compton Gamma Ray Observatory) spacecraft had been used to measure the spatial and temporal variation of neutrons. We used gamma-ray telescopic mode to measure the instrumental 2.2 MeV line that arose from the thermal neutron being captured by a proton in the D1 module. Hence, the 2.2 MeV line served as a surrogate for the albedo neutron flux. To support the CRAND (Cosmic Ray Albedo Neutron Decay) theory, systematic measurements of the 2.2 MeV line rate were done as a function of various parameters primarily geomagnetic rigidity ranging from 4-18 GV, geocentric elevation 0-180, and spacecraft altitude ranging from 325-525 km. Using the Morris et al. neutron fit function, the estimated line rate was calibrated to obtain measured neutron flux. To evaluate our findings, the measured neutron flux data was compared with Claret et al. simulated neutron data at solar minimum and solar maximum and also. Our neutron measurements follow the same trend as the simulated data

Frequency Analysis of Annual One Day Maximum Rainfall at Amman Zarqa Basin, Jordan

Water management and design of irrigation and drainage projects are based on extreme values rather than on average values. Annual daily maximum rainfall corresponding to return periods varying from 2 to 100 years is used by design engineers and hydrologists for economic planning, and design of minor and major hydraulic structures. This research aims at performing frequency analysis of annual daily maximum rainfall in Amman-Zarqa Basin (AZB) which is an important basin in Jordan.  Daily rainfall data at 22 stations distributed in Amman-Zarqa Basin with long time series (more than 40 years) were used for this purpose. For each station, the annual 1- day maximum rainfall data were extracted. Daily maximum values have then been statistically analyzed by RAINBOW software using two probability distribution functions, namely: Linear and log normal distributions. The goodness of fit for the selected distributions is tested using the Chi-square and the Kolmogorov–Simrnov tests at three significant levels (?=5%, 10% and 20%). The results of the goodness of fit indicate that the Log normal distribution provides a good fit to the rainfall data in the basin. Frequency analysis is then conducted to extract the magnitude of 1 day annual maximum rainfall corresponding to 2, 5, 10, 25, 50 and 100 yr return periods for the 22 stations in AZB. Analysis of rainfall regime would enhance the management of water to prevent floods and droughts as well as an effective design of drainage structures especially in relation to their required hydraulic capacity. Keywords: Amman-Zarqa Basin, Extreme Events, Frequency Analysis, Probability Distribution, RAINBOW Software, Return Perio

Frequency of macroprolactin in hyperprolactinemia

Objective: To determine the frequency of Macroprolactin (MaPRL) in patients with increased total prolactin and its clinical and financial impact. Study Design: Cross-sectional study. Place and Duration of Study: Section of Clinical Chemistry, Department of Pathology and Laboratory Medicine, The Aga Khan University Hospital, Karachi, from March to May 2015. Methodology: Patients with high total prolactin were screened by polyethylene glycol (PEG) precipitation for determination of MaPRL. Clinical history, imaging work-ups, and cost incurred in further investigations were collected by telephonic interview after verbal consent. Patients were stratified into true hyperprolactinemia and macroprolactinemia after PEG treatment, based on monomeric prolactin levels. Medical records of cases registered with AKUH were reviewed to confirm the diagnosis. Results: Two hundred and thirty-nine patients were identified with high prolactin levels. Macroprolactinemia was identified in 145 (60.7%) and true hyperprolactinemia in 94 (39.3%) patients. Galactorrhea was significantly more in true hyperprolactinemic females (p=0.022), followed by visual disturbances (p=0.01) and headache (p=0.006). Moreover, as majority of population were females, the clinical features in the macroprolactinemia group as compared to true hyperprolactinemic group were mostly related to non-pituitary causes like drug intake [42.5% (54) vs. 37% (30)], heat intolerance due to thyroidal illness [41.7% (53) vs. 38.3% (31)] and surgery [26.8% (34) vs 22.2% (18)] in females. Further radiological workup (MRI, CT) were conducted in 35 (37.2%) patients with true hyperprolactinemia. Twenty-one (60%) of the patients were confirmed to have pituitary adenomas. In eight (5.5%) patients with MaPRL, only one had pituitary microadenoma on radiological workup. Total cost impact on the basis of investigations, was significantly higher in the group undergone imaging, despite 7 out of 8 individuals found to have normal imaging results. The median total cost in true hyperprolactinemic group undergone imaging was Rs. 4370 (IQR=2412.5, 22850) as compared to macroprolactinemic groups; Rs. 3,250 (IQR=2150, 4278). There was significant difference in the cost burden of both the groups (p \u3c0.001).Conclusion: High frequency of MaPRL was identified in patients with hyperprolactinemia. Screening with PEG precipitation in hyperprolactinemic sera is simple and cost-effective

Role of Social Commerce Forums in Establishing Purchase Intention: A Nexus Between Credibility, Trust and E-Commerce Satisfaction

Social media is persuading to consumers in field of social commerce (S-Commerce) by providing goods or services and fulfill their demands in a very short period of time. Electronic-satisfaction (e-satisfaction) and credibility have distinctive activities of social media that motivate and successively build the trust at various stages of purchase intentions. For better understanding it is necessary to recognize the factors of social commerce such as referrals, reviews & ratings because they have a strong influence on buying behaviour of ecommerce consumers. A quantitative and descriptive approach has been projected through simple random sampling. A cross-sectional data of 250 participants were collected by a survey questionnaire from social commerce users examined through Partial Least Square- Structural Educational Modeling-3 (PLS-SEM-3). A social support theory has supported relationship on trust through social media activities, surface credibility, and presumedcredibility as well as e-commerce satisfaction. Interestingly trust, surface and presumed credibility considerably significant impact on e-commerce and social commerce satisfaction that leads to develop purchase intention. The current study theoretically contributes novel indicator, presumed credibility in the social commerce industry and practically it promotes specific websites that triggers trust

Antisense PNA accumulates in Escherichia coli and mediates a long post-antibiotic effect

Antisense agents that target growth-essential genes display surprisingly potent bactericidal properties. In particular, peptide nucleic acid (PNA) and phosphorodiamidate morpholino oligomers linked to cationic carrier peptides are effective in time kill assays and as inhibitors of bacterial peritonitis in mice. It is unclear how these relatively large antimicrobials overcome stringent bacterial barriers and mediate killing. Here we determined the transit kinetics of peptide-PNAs and observed an accumulation of cell-associated PNA in Escherichia coli and slow efflux. An inhibitor of drug efflux pumps did not alter peptide-PNA potency, indicating a lack of active efflux from cells. Consistent with cell retention, the post-antibiotic effect (PAE) of the anti-acyl carrier protein (acpP) peptide-PNA was greater than 11 hours. Bacterial cell accumulation and a long PAE are properties of significant interest for antimicrobial development.Peer reviewe