97 research outputs found
Structural studies of cytidine repressor and catabolite activator protein
No full textThe Escherichia Coli Catabolite Activator Protein (CAP) activates DNA transcription at more than a hundred promoters. Cytidine Repressor (CytR), in conjunction with two CAP dimers, acts as a repressor of DNA transcription at the deoP2 promoter. In the first part of this work, we describe a method by which a (CAP)[subscript] 2-CytR-DNA complex can be prepared for structural studies. In the second part of this project, we describe the crystallization of what was initially
intended to be a (CAP)[subscript] 2-DNA complex in order to study the effects of two CAP dimers on transcription at an artificially constructed promoter containing tandem CAP binding sites. Upon structure determination of the crystal, we observed that while there was no DNA present, the protein had bound multiple Co[superscript]2+ and SO2−/4 ligands. We provide an analysis of the crystal structure and present a possible explanation for the absence of DNA in the structure.M.S.Includes bibliographical referencesby Ramya Rangesh Ra
Knot theory addendum
No full textAt Right Angles met up with author Ramya to discuss her article on Knot Theory. Over coffee at Starbucks, Ramya adeptly made sense of a tangled bunch of wool which I had carried with me to try and see if Knot Theory could help me untangle the web
Water mass classification using band ratios
No full textThe Hudson River plume has been the topic of consideration and observation in order to try and understand the physical, chemical and biological behavior of the plume which is a key component of the oceanography of the Mid-Atlantic Bight (MAB) region off the east coast of the United States. One approach towards understanding the chlorophyll production for the plume would be to make use of satellite data to measure the optical ocean color properties of these waters. In this direction classifying the water masses of the Hudson River plume according to these optical properties would be an interesting method of analyzing the satellite data for the purpose of understanding and identifying the physical and biological changes and the correlation between them in this region.
The first step is to design and implement a water mass classification algorithm in the LaTTE (Lagrangian Transport and Transformation Experiment) region of the MAB. It takes about 1-2 weeks for the nutrients from the freshwater from the Hudson Estuary to be dissipated and mixed with the open ocean. This classification algorithm is developed using ocean color data from the Sea viewing WIde Field of view Sensor (SeaWiFS). The algorithm is validated by overlaying ship salinity tracks on the classified water masses to show that salinity values change at the boundaries of the classified regions, due to the mixing and export of freshwater across the shelf.
We analyze global Sea Surface Temperature (SST) data collected over the years 1995-2005 for summer and winter in order to find coastal estuarine ecosystems that may display similar behavior as the Hudson River Estuary. Looking at the seasonal variation in this data, we observe that the regions of MAB and the East Asian coast are found to have strikingly similar seasonal behavior.
This leads into the third and the last step of the process which involves applying the water mass classification algorithm to ocean color data from eastern coastal Asia. It is observed that the algorithm well in the seas of Okhotsk, Japan and East China where it is able to identify plume water and non river water.M.S.Includes bibliographical references (p. 86-92)
Sentiment analysis of big data with intensity analysis by rule engine, 2015
No full textThe use of social media is an emerging way for the public to express their views on companies and other organizations. The success of these entities can depend on a positive presence on social media, leading to an increasing interest in understanding public opinion expressed there. This thesis presents a method for gathering and storing a large number of social media posts, analyzing the sentiments expressed, and further classifying the specific emotions conveyed. The social media platform Twitter was used as a source of millions of publicly viewable posts. The big data software tools Twitter4j, Apache Hadoop, and Apache Hive were used to gather and store these posts. These were then classified as communicating a positive, negative, or neutral sentiment through the technique of sentiment analysis, performed using the tool Lingpipe. To further identify the particular emotions expressed in the Tweet, a rule engine, specifically the DROOLS software, was used
Study of health franchises in resource limited settings
No full textThesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 62-64).Billions of dollars are spent to develop drugs for infectious diseases in developing countries. How will these drugs along with clinical services be delivered to the patients who currently do not have access to them? Health franchises have been around since early 1990s, creating networks of shops and clinics that provide specialized care to low income individuals. This thesis attempts to understand the underlying mechanisms of successful health franchises. Two cases are taken into consideration, CFWshops in Kenya and Mi Farmacita Nacional (MFN) in Mexico. Both are pharmaceutical shops with small clinics attached to them. The two cases were examined through a framework derived from successful commercial franchises and franchise theory. The elements that were addressed include operational structure, marketing strategy, product and service offerings, monitoring of businesses, and financial structure. CFWshops and MFN had some stark differences in how they addressed each of these elements. Unlike typical commercial franchises, health franchises aim to provide social benefits to the population. This goal requires franchises to not only create a business strategy to be financially sustainable and take advantage of networks, but also show health improvements in the community. The success of a health franchise is dependent on the health impacts it provides because its mission is not to generate a profit for the stakeholders but rather the value added to the customer by providing access that was not there before.(cont.) The comparative case analysis suggests several key recommendations. Health innovations in resource limited settings should create networks with other public and private health groups to leverage existing knowledge and best practices. This reduces cost and time of learning and allows businesses to utilize existing channels to provide access for drugs and services to individuals who currently are not receiving them.by Ramya Sankar.S.M.in Technology and Polic
Not Available
No full textNot AvailableClimate change (CC) is the present challenge to mankind, which has direct effect on agriculture. There are various strategies developed to face climate change in agriculture. Crop diversification is one among the best strategies, in which oilseeds
fits very well since they are climate resilient crops by their true nature. Oilseed crops such sunflower, castor, safflower, sesame and niger take the advantage of elevated CO2 with increase in both quality and quantity. Nevertheless, climate change will
restrict resource availability and alter conditions that are vital to oilseed crop growth and yield, thus instigating environmentally induced shifts in phenotypes. Understanding this phenotypic plasticity is essential to predict and manage climate change impact
on current and future oilseed crops. Breeding for phenotypic plasticity in traits other than seed or oil yield will potentially provide resilience under increasingly unpredictable environmental conditions. Major changes in breeding and management
programs may be required for achieving these interconnected goals.Not Availabl
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