Design and Synthesis of Fluorescent Silica Nanoparticle Conjugates for Metal Ion Sensing Applications

A novel series of fluorescent nanoparticle conjugates were designed and synthesized for the selective turn-off sensing of low concentrations of Cu2+ ion (nM-μM) in 2:1 ethanol:10 mM HEPES (pH 7). Silica nanoparticles (~250 nm) were modified with heterobifunctional polyethylene glycol (PEG) linkers and a third generation PAMAM dendron to function as chelator for Cu2+ ions. The organic dye fluorescein isothiocyanate (FITC) was subsequently conjugated to the dendron to act as a fluorescent sensitizer for the nanoparticle that is quenched upon the binding of Cu2+. Fluorescent nanoparticle conjugates using third and fourth generation PAMAM dendrimers (SNP-G3-FITC and SNP-G4-FITC) were synthesized for comparison. The dendron conjugate (SNP-PEG8-G3S-FITC) was determined to have a higher dynamic range (0.10-1.99 μM Cu2+) than the dendrimer counterparts (0.02 -0.30 μM Cu2+). A follow- up series of sensors were designed and synthesized using FITC-conjugated silica nanoparticles for use in characterization of the surface using Fluorescence Resonance Energy Transfer (FRET). These conjugates provide examples of an attractive modular framework for other fluorescent nanoparticles to be synthesized and tailored to analytes of interest. Silica nanoparticle conjugates can be readily synthesized using known reactions, easily isolated from reaction solutions, and they remain undetectable in fluorescent experiments

Creation of the selection list for the Experiment Scheduling Program (ESP)

The efforts to develop a procedure to construct selection groups to augment the Experiment Scheduling Program (ESP) are summarized. Included is a User's Guide and a sample scenario to guide in the use of the software system that implements the developed procedures

Teacher Regenesis: Supporting Teacher Resiliency Through Wellness

Previous studies demonstrate that weight loss has many benefits, but research has yet to focus on how a physically healthy lifestyle is beneficial to teachers in our schools. Although past research has provided insight into how emotional and occupational wellness impacts stress, job burnout, and self-efficacy, few studies focus on how the physical aspect of wellness plays a role in the teacher’s ability to create a classroom that is healthy, and most importantly, effective. This research study was conducted as a phenomenological study of six White female urban school teachers who have transitioned from obesity to wellness. A qualitative research framework was adopted to answer five research questions: (1) how do teachers define obesity? (2) How do teachers define wellness? (3) How do teachers describe their teaching behaviors as it relates to obesity? (4) How do teachers describe their teaching behaviors as it relates to wellness? And (5) how do teachers describe their transition from obesity to wellness in the school environment? Results of this study yielded the following themes related to the experience of the six white female urban school teachers: (1) the teachers had varying definitions of obesity that reflect the stigma attached to obesity in our country, while the teachers definitions of wellness reflect an understanding of its synergistic nature, with a heavy focus on physical and emotional wellness; (2) due to the stigma attached to obesity and the social consequences of obesity, the teachers have become hyper-aware of the comments and judgments made about obese people, leading to mental and emotional consequences that impact behavior inside the school environment, their self-esteem, and their self-efficacy; (3) by transitioning from obesity to wellness, the teachers experienced Teacher Regenesis, in which energy and confidence gained from physical activity is diffused into other areas of their lives. The success experienced in physical exercise and weight loss also allows for an infusion of healthy wellness behaviors in other areas of their lives; and (4) the transition period from obesity to wellness was influenced by both stressors and resources that were available to them inside the school environment

Optimal Partitions in Additively Separable Hedonic Games

We conduct a computational analysis of fair and optimal partitions in additively separable hedonic games. We show that, for strict preferences, a Pareto optimal partition can be found in polynomial time while verifying whether a given partition is Pareto optimal is coNP-complete, even when preferences are symmetric and strict. Moreover, computing a partition with maximum egalitarian or utilitarian social welfare or one which is both Pareto optimal and individually rational is NP-hard. We also prove that checking whether there exists a partition which is both Pareto optimal and envy-free is $\Sigma_{2}^{p}$-complete. Even though an envy-free partition and a Nash stable partition are both guaranteed to exist for symmetric preferences, checking whether there exists a partition which is both envy-free and Nash stable is NP-complete.Comment: 11 pages; A preliminary version of this work was invited for presentation in the session `Cooperative Games and Combinatorial Optimization' at the 24th European Conference on Operational Research (EURO 2010) in Lisbo

White Male Privilege: An Intersectional Deconstruction

This research saliently deconstructs the philosophical writing of a white, privileged male by five diverse academic peers by using a methodology of deconstruction to analyze the initial author\u27s writing. Their reflects on his nascent perspectives address the stages of racism, mea culpa, the relationship between privilege, oppression, and classism, a feminist perspective, binary, and intersectionality. Further analysis connote for the need to deconstruct privilege in a literary context and to develop an autoethnography to fully delve into privilege beyond a superficial and neglectful narrative

Designing the blood supply chain: How much, how and where?

BACKGROUND: The blood supply chain network can take many forms in different settings, depending on local factors such as geography, politics, costs, etc.; however, many developed countries are moving towards centralized facilities. The goal for all blood distribution networks, regardless of design, remains the same: to satisfy demand at minimal cost and minimal wastage.STUDY DESIGN AND METHODS: Mathematically, the blood supply system design can be viewed as a location-allocation problem, where the aim is to find the optimal location of facilities and to assign hospitals to them to minimize total system cost. However, most location-allocation models in the blood supply chain modeling literature omit important aspects of the problem, such as selecting amongst differing methods of collection and production. In this paper, we present a location-allocation model that takes these factors into account to support strategic decision-making at different levels of centralization. RESULTS: Our approach is illustrated by a case study (Colombia) to redesign the national blood supply chain under a range of realistic travel time limitations. For each scenario, an optimal supply chain configuration is obtained, together with optimal collection and production strategies. We show that the total costs for the most centralized scenario are around 40% of the costs for the least centralized scenario.CONCLUSION: Centralized systems are more efficient than decentralized systems. However, the latter may be preferred for political or geographical reasons. Our model allows decision-makers to redesign the supply network per local circumstances, and determine optimal collection and production strategies that minimize total costs