Investigation on rotating ailerons

The effectiveness of rotating ailerons in a subsonic flow is theoretically studied to evaluate their capability in comparison to conventional ailerons. The analysis is based on the cortex lattice approach of Byelotserkovskii (1965) for different wing planforms of small and large aspect ratios. The rolling moment coefficient obtained with the rotating ailerons with a span equal to 22% of the wing span is higher than that for the conventional ailerons of almost double the span. The effectiveness of the rotating ailerons decreases with reduction in the wing aspect ratio, although it is possible to reduce the aileron size for required rolling capabilit

Investigating the Effect of Allostery on Downstream Biology of the Epidermal Growth Factor Receptor

The Epidermal Growth Factor Receptor (EGFR) is a member of the receptor tyrosine kinase (RTK) family of human proteins with a critical role in transducing diverse extracellular chemical information to initiate multiple cellular signaling cascade in the cell that are essential for normal cell development. Aberrant activation of this receptor via mutation or overexpression misregulates this flow of information and is implicated in a multiple human carcinoma. Thus, understanding the molecular mechanisms by which chemical information is encoded and decoded in EGFR is imperative both from a basic cell biology and therapeutic standpoint. In this thesis consisting of four chapters, I describe my graduate work studying the structure of a portion of EGFR called the juxtamembrane segment (JM) and investigating its role in modulating and controlling the downstream biology of the receptor. Chapter 1: This chapter provides an introduction, overview and in-depth discussion of the literature pertaining to the critical role of JM in modulating EGFR biology through its manifold functions in kinase activation, allosterically encoding structural changes in the various domains of EGFR, and its interactions with diverse intracellular components. Chapter 2: In this chapter I describe my work utilizing a chemical biology tool called Bipartite Tetracysteine Display to study to the structure of the JM of a constitutively active variant of EGFR, namely EGFRvIII that is implicated in most cases of Glioblastoma Multiforme. Through my studies I illustrate how the assembly of unique structures within the JM segment of this oncogenic receptor supports the constitutive activity of this protein. Chapter 3: In this chapter I describe my work utilizing tools in chemical biology, biochemistry and cell biology to demonstrate that the assembly of discrete coiled coil structures within the JM segment of EGFR is necessary and sufficient for controlling the path of endocytic trafficking of the receptor and its intracellular lifetime. Furthermore, I demonstrate how the assembly of these discrete JM structures also predicts kinase-independent effects of oncogenic EGFR mutations (implicated in Non-Small Cell Lung Cancer) and clinically relevant tyrosine kinase inhibitors that promote efficient, lysosome-based EGFR degradation. Chapter 4: This chapter describes preliminary experiments that were performed on two projects that were initiated in the early and later parts of Ph.D. research. The first project seeks to investigate the role of receptor multimerization on the JM structure of EGFR. The second ongoing project seeks to investigate the effect of JM structure on the interactome of WT and oncogenic EGFR using APEX2-based proximity labeling and mass spectrometry. For both projects, I discuss my rationale, experimental design and preliminary results and provide my thoughts for future directions

An Efficient Data Aggregation Algorithm for Cluster-based Sensor Network

Data aggregation in wireless sensor networks eliminates redundancy to improve bandwidth utilization and energy-efficiency of sensor nodes. One node, called the cluster leader, collects data from surrounding nodes and then sends the summarized information to upstream nodes. In this paper, we propose an algorithm to select a cluster leader that will perform data aggregation in a partially connected sensor network. The algorithm reduces the traffic flow inside the network by adaptively selecting the shortest route for packet routing to the cluster leader. We also describe a simulation framework for functional analysis of WSN applications taking our proposed algorithm as an exampl

Validation study of LQAS-2 in Uttar Pradesh behavior change management project

India’s Uttar Pradesh Behavior Change Management project studied the potential of community mobilization through Self Help Groups (SHGs) to improve healthy behaviors that may have a direct bearing on maternal, newborn, and child health outcomes. Multiple rounds of Lot Quality Assurance Sampling (LQAS) surveys were undertaken to monitor project activities and take corrective measures to improve project indicators. The surveys also evaluated the diffusion of health messages in the project area. The LQAS-2 validation study aimed to examine the accuracy of LQAS-2 data and understand the process of administering the LQAS. The study, which documented the process of survey administration, accuracy of data, and effects of mentor support, used two approaches: a validation survey among a subsample of women who participated in LQAS-2, and observation of the sampled interviews during the LQAS-2 survey. The following programmatic recommendations were made: A longer training of the interviewers is necessary. Prolonged mentor support should be replaced by limited mentoring, but better mentor training is necessary so individuals can properly interview even without mentoring support

A comparison of software platforms for Wireless Sensor Networks: MANTIS, TinyOS and ZigBee

Wireless sensor networks are characterized by very tight code size and power constraints, and by a lack of well-established standard software development platforms such as Posix. In this paper, we present a comparative study between a few fairly different such platforms, namely MANTIS, TinyOS and ZigBee, when considering them from the application developer's perspective, i.e. by focusing mostly on functional aspects, rather than on performance or code size. In other words, we compare both the tasking model used by these platforms and the API libraries they offer. Sensor network applications are basically event based, so most of the software platforms are also built on considering event handling mechanism, however some use a more traditional thread based model. In this paper, we consider implementations of a simple generic application in MAN- TIS, TinyOS and the Ember ZigBee development framework, with the goal of depicting major differences between these platforms, and suggesting a programming style aimed at maximizing portability between them

Entrepreneurship against the tide : Business performance of women entrepreneurs in a constrained environment. A survey in Bangladesh

Stimulating women’s entrepreneurship is widely seen as a vital way of enhancing their family livelihoods especially in developing countries. The enhancement of their family livelihoods is dependent on their business performance. The literature has focused on entrepreneurial orientation (EO) and social capital (social ties and networks) leveraging business performance. This however can be hampered in a constrained context, defined as a home based, resource scarce, socially confining and business wise threat-to-disrupt environment where women entrepreneurs (in developing countries) execute their businesses. This thesis enters into this debate offering a view on a specific developing country, Bangladesh. The main objective of this thesis is to explore the influence of EO and social capital on business performance of women entrepreneurs in a constrained environment and their contribution to family livelihoods. Empirical study is conducted based on the survey data collected from 292 women entrepreneurs in Bangladesh in 2015. The exploratory factor analyses show that innovativeness and pro-activeness jointly and risk-taking are the two dimensions of EO in the case of women entrepreneurs engaged in the handicraft business in Bangladesh. The results obtained from hierarchical multiple regression analyses suggest that the EO dimensions positively relate to business performance, but barriers in the social environment (for example, socio-cultural norms and customs) correlate negatively on it. In contrast, barriers in the business environment positively relate to business performance, suggesting that apparently, when being faced with risk, entrepreneurial women transform barriers into opportunities. Our findings from multiple regression models show that network size negatively relates to business performance of women entrepreneurs in Bangladesh. Also, the findings show that the number of bonding ties correlates negatively with business performance of Bangladeshi women entrepreneurs, while the number of bridging and linking ties are not significant. Based on in-depth analysis, our study offers an interesting new insight that a particular number of bonding ties of women entrepreneurs in Bangladesh relates positively with their business performance and beyond that, this relates negatively. Possibly Bangladeshi women entrepreneurs’ too extensive ties with family and relatives may create over-embeddedness in their network. Based on a multiple regression model, the study also shows that the number of strong ties is negatively related to business performance. In fact, this suggests that women entrepreneurs’ strong bonding- and bridging ties are not beneficial for their business performance in a traditional culture such as the Bangladeshi one. The results of a structural equation model suggest that financial capital and education level are antecedents positively influencing innovative- and pro-active EO of Bangladeshi women entrepreneurs, whereas their risk-taking EO is positively related to financial capital only. Next to women entrepreneurs’ EO, financial capital, business experience and business training drive their business performance. However, the findings suggest that among all drivers EO largely leverages their business performance in such a context. Furthermore, the study finds that women’s business performance in this context relates positively to their families’ livelihood. Apparently, the study suggests that Bangladeshi women’s EO, via its large positive impact on business performance, is at the root of their contribution to family livelihood. The findings of this study will help in decision making of policy makers and development partners or organizations (e.g. NGOs) who work for women’s entrepreneurship development in constrained conditions in developing countries.</p

Contraceptive use dynamics in India: A prospective cohort study of modern reversible contraceptive users

This report highlights the contraceptive use dynamics among 2,699 married women in India who began using one of four reversible contraceptive methods over one year. Women aged 15-49 were enrolled into the study from Odisha and Haryana states within one month of starting their reversible method—interval intrauterine device (IUD), postpartum IUD (PPIUD), injectable contraceptive, or oral contraceptive pill (OCP)—and were interviewed at four time points: at enrollment into the study, and three, six, and 12 months after enrollment. Study findings include the quality of care received at the time of method adoption, experience and management of side effects, reasons for discontinuation of the enrollment method, dynamics of contraceptive use after one year, changes in fertility preferences, and the method-specific experiences related to contraceptive use and pregnancy over the course of the study. The findings from this study will be useful to program designers, policymakers, and health care professionals in delivering voluntary family planning services in India