Simultaneous Confidence Intervals for Risk Ratios in the Many-to-One Comparisons of Proportions

For many-to-one comparisons of independent binomial proportions using their ratios, we propose the MOVER approach generalizing Fieller\u27s theorem to a ratio of proportions by obtaining variance estimates in the neighbourhood of confidence limits for each proportion. We review two existing methods of inverting Wald and score test statistics and compare their performance with the proposed MOVER approach with score limits and Jeffreys limits for single proportions. As an appropriate multiplicity adjustment incorporating correlations between risk ratios, a Dunnett critical value is computed assuming a common, constant correlation of 0.5 instead of plugging in sample correlation coefficients. The simulation results suggest that the MOVER approach has desirable operating characteristics comparable to those of the method of inverting score test statistics. The MOVER with Jeffreys limits yields the median joint coverage percentage closest to the nominal level but its intervals may be wider than the other intervals in some parameter settings

Highly tunable repetition-rate multiplication of mode-locked lasers using all-fibre harmonic injection locking

Higher repetition-rate optical pulse trains have been desired for various applications such as high-bit-rate optical communication, photonic analogue-to-digital conversion, and multi- photon imaging. Generation of multi GHz and higher repetition-rate optical pulse trains directly from mode-locked oscillators is often challenging. As an alternative, harmonic injection locking can be applied for extra-cavity repetition-rate multiplication (RRM). Here we have investigated the operation conditions and achievable performances of all-fibre, highly tunable harmonic injection locking-based pulse RRM. We show that, with slight tuning of slave laser length, highly tunable RRM is possible from a multiplication factor of 2 to >100. The resulting maximum SMSR is 41 dB when multiplied by a factor of two. We further characterize the noise properties of the multiplied signal in terms of phase noise and relative intensity noise. The resulting absolute rms timing jitter of the multiplied signal is in the range of 20 fs to 60 fs (10 kHz - 1 MHz) for different multiplication factors. With its high tunability, simple and robust all-fibre implementation, and low excess noise, the demonstrated RRM system may find diverse applications in microwave photonics, optical communications, photonic analogue-to-digital conversion, and clock distribution networks.Comment: 25 pages, 9 figure

Defective Localization With Impaired Tumor Cytotoxicity Contributes to the Immune Escape of NK Cells in Pancreatic Cancer Patients

Tumor-infiltrating lymphocytes (TILs), found in patients with advanced pancreatic ductal adenocarcinoma (PDAC), are shown to correlate with overall survival (OS) rate. Although majority of TILs consist of CD8+/CD4+ T cells, the presence of NK cells and their role in the pathogenesis of PDAC remains elusive. We performed comprehensive analyses of TIL, PBMC, and autologous tumor cells from 80 enrolled resectable PDAC patients to comprehend the NK cell defects within PDAC. Extremely low frequencies of NK cells (<0.5%) were found within PDAC tumors, which was attributable not to the low expression of tumor chemokines, but to the lack of chemokine receptor, CXCR2. Forced expression of CXCR2 in patients' NK cells rendered them capable of trafficking into PDAC. Furthermore, NK cells exhibited impaired cell-mediated killing of autologous PDAC cells, primarily due to insufficient ligation of NKG2D and DNAM-1, and failed to proliferate within the hypoxic tumor microenvironment. Importantly, these defects could be overcome by ex-vivo stimulation of NK cells from such patients. Importantly, when the proliferative capacity of NK cells in vitro was used to stratify patients on the basis of cell expansion, patients whose NK cells proliferated <250-fold experienced significantly lower DFS and OS than those with ≥250-fold. Ex-vivo activation of NK cells restored tumor trafficking and reactivity, hence provided a therapeutic modality while their fold expansion could be a potentially significant prognostic indicator of OS and DFS in such patients

Electrochemical oxidation of organic molecules at smooth and stepped surface planes of platinum single crystal electrodes as studied by in situ infrared spectroscopy.

This dissertation explored pathways in the electrochemical oxidation of small organic molecules at atomically well-defined platinum single crystal surfaces. The compounds studied were methanol, ethanol, ethylene glycol and formic acid, which are candidate fuels for electrochemical fuel cells. Studies probed the influence of low coordination step sites on competing reaction pathways in experiments with Pt(111) and Pt(335) = Pt(s) $-$ (4(111) $\times$ (100)) electrodes. These reactions progressed through adsorbed carbon monoxide (CO) en route to the final oxidation product, carbon dioxide CO\sb2. Methanol oxidation was inhibited in the hydrogen adsorption potential region on smooth Pt(111), but progressed to adsorbed CO and CO\sb2 at more positive potentials, in the classical double-layer region. In contrast, methanol dissociative chemisorption occurred to a limited extent in the hydrogen adsorption potential region on Pt(335). Independent vibrational bands for CO adsorbed at step sites and on terrace planes of Pt(335)/H were detected with infrared spectroscopy. In the oxidation of ethanol, isotope labeling was used to track the fate of carbon atoms through the C-C bond cleavage pathway. Adsorbed CO originating from the alcohol group formed almost exclusively at potentials in the hydrogen adsorption region, while more positive potentials were required to oxidize the methyl group carbon atom. The acetic acid by-product was detected in an adsorbed state for the first time, and a correlation was shown between acetic acid adsorption and reaction inhibition. Chromatographic methods were used in combination with electrochemical and infrared spectroscopic techniques to probe the complex pathways associated with ethylene glycol oxidation. Products of C-C bond cleavage were prevalent on the stepped surface, while more two carbon carboxylic acids were produced at Pt(111). In concluding experiments, formic acid and ethanol oxidation were probed at Pt(111) and Pt(335) electrodes modified by bismuth (Bi) adatoms. At Bi treated surfaces, the rate of oxidation increased for formic acid but decreased for ethanol. At Bi coverages near saturation, the presence of the foreign metal affected reactions to a greater extent than the surface step density. Overall, reactions of these small organic molecules on the clean Pt surfaces progressed to a greater extent on Pt(335) than at the smooth Pt(111) surface.Ph.D.Analytical chemistryPure SciencesUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/130123/2/9712087.pd

DFT study of carbazole derivatives dehydrogenation on Pd(111) catalyst

The carbazole derivatives such as 9-ethylcarbazole have been studied as a potential hydrogen storage candidate. It is found that these materials can store hydrogen under moderate-to-ambient conditions in liquid state so that the transportation of hydrogen would be convenient. Besides, the reversibility of hydro/dehydrogenation is much better than the existing solid type of hydrogen storage carriers. However, the major problem for carbazole derivatives which contain ethyl and acetyl group is the cleavage between functional group and carbazole. Therefore, the hydrogen carrier must be regenerated cyclically, which lead to an increase in operational cost. In this work, the Density Functional Theory calculations are performed to understand the dehydrogenation reaction mechanism and decomposition of 9-ethy/acetylcarbazole on Pd(111). The secondary alcohol hydrogenated acetyl group distort the hydrogenated form of 9-acetylcarbazole on Pd(111), which lead to reducing activation energy. With respect to decomposition of functional group, 9-ethylcarbazole is slightly more stable than 9-acetylcarbazole. These results suggest the direction of molecular design for hydrogen storage materials

The Effectiveness Of International Non-Governmental Organizations’ Response Operations During Public Health Emergency: Lessons Learned From The 2014 Ebola Outbreak In Sierra Leone

International Nongovernmental Organizations (INGOs) have played critical roles in improving the quality of primary health care in ordinary time and, indeed, responding to epidemic crises in developing countries. Due to a lack of empirical research for effectiveness of their responding activities, the legitimacy and accountability of nonprofits’ engagement in the health crisis as a critical responder is doubted. This paper aims to examine the effectiveness of INGOs in a context of managing a fatal epidemic outbreak of Ebola in Sierra Leone during May-November, 2014; building healthcare infrastructures, providing medical supplies, educating local residents, and training response staffs. The analysis results show that development of healthcare infrastructures and provision of medical supplies have been significantly effective in terms of decreasing the severity of the crisis in chiefdoms. The findings imply that policy tools, which allow INGOs to enter to the field in a timely manner, can improve the effectiveness of INGOs’ responses in current and future epidemic outbreaks in developing countries where people suffer from a lack of health infrastructures