Impedance based cell culture platform for nanotechnology based drug formulations

Bennet, Devasier Gachon Univ. 2013 국내박사

Advancement in bio-nanotechnology has expanded our ability to design new regeneration applications in the field of photo-oxidative therapeutics. Light incidence morbidity and mortality of human eye and skin diseases have continued to rise. Continuous exposure causes photo-oxidative damages, degenerative disorders including retinopathies retinitis pigmentosa, computer vision syndrome, premature aging, and skin diseases and disorders. All together the radiation-induced photo-oxidative mechanism has mediated by reactive oxygen species (ROS). Surplus production of free radicals activates various diseases including vascular dysfunction and damage to cellular macromolecules and nucleic acid. Targeting ROS is therefore an important strategy for protection. While the early stages of the disease can often be cured by appropriate therapy, it will allow patients to improve their quality of life. However, the potential role of this early stage of degenerative process is neither well understood nor explored. For this reason the treatment of light toxicity remains challenge in optometry and dermatological intervention. In other side continuous monitoring cellular responce is very difficult with existing methods. Understanding their importance is a prerequisite to develop more sensitive and real-time analytical tools to rectify existing drawbacks. The objective of this thesis work is to development of analytical tool and newer approach of biomedically important targeted towards eye and skin. In our present research developed an analytical tool, which unprecedented and real-time in vitro light setup was established using a bioimpedance system to measure the cell photo-oxidative damage and protective effect of various drugs. This thesis is based on the following chapters. Chapter 1 provides the general description about research and developments for phototoxicity-oxidative damages in eye and skin cells, especially highlighting the retinal and skin damage existing in the literature. Also addressing the virtual need in research and developments for therapeutics, and exploring analytical platform. Chapter 2 is an experimental report demonstrating the cellular behavior and real-time evaluation of light-induced stress in retinal cells. Also, the different color light-induced effects on the response of cells that exposed to protective drugs were studied. Finally, the effects of agmatine and resveratrol on light-induced damage and its underlying photo-oxidative and protective mechanisms were monitored, and its helps to rescue damaged cells. Chapter 3 describes an analytical tool, which unprecedented, simple and real-time in vitro light setup was established using a bioimpedance system to measure the skin cell photo-oxidative damage and protective effect of quercetin-loaded PLGA nanoparticle. Also the phyto-medicine applications to protect against skin cell photo-damage. The continuous real-time evaluations of photo-damage and photo-protective effect of phyto-compounds on skin cells were studied. Chapter 4 deals with targeting oxidative stress with inhibiting or boosting the endogenous levels of antioxidants effect in the treatment of oxidative-stress-related diseases. It describe permeation enhanced nanoparticle for enhanced transdermal delivery. Also describes the dual drug-loaded nanoparticles incorporated swelling-induced scaffold film for controlled transdermal drug-delivery system to prevent first-pass metabolism. Chapter 5 provides the overall concluding remarks and future perspectives about the different phenotypic skin cell (human dermal fibroblast cells and human epidermal keratinocyte cells) response to light radiation and to elucidate mechanism of melanoma regeneration applications.

Identity preservation & traceability: The state of the art - from a grain perspective (status of agricultural quality systems / traceability / certification systems)

Bennet, Gregory Scott Iowa State University 2008 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

A descriptive paper on the state of identity preservation and traceability (IPT) as it relates domestically and internationally to food safety and economics. While not exhaustive, it is illustrative of trends. Identity preservation and traceability (IPT) are not new concepts; however, the growth of public and business interest and concerns regarding them has grown tremendously during the past decade due to many events, which has resulted in these concepts joining together within a single concept (with the same title). This paper, while attempting to be thorough, will highlight the major systems of IPT from a US business perspective. Before and during the research of this study many companies and organizations have been created, bought out, or simply gone out of business. Government and non-government organizations have changed regulations and how they have adapted to current world events. Thus the state of IPT will be a sampling of the major players that are in existence during the research. Several of the examples of IPT programs will be of situations that affect the US grain industry, however, other examples will be provided. Scope of this work; to provide an introduction to, and summary of, identity preservation and traceability (IPT) systems and programs presently available, develop a conceptual model of IPT at the farmer level, and interpretation of the overall art. The purpose of this research is to provide a sampling of government, industry, and company approaches towards identity preservation and traceability (IPT) systems from the 1990s to early 2007. From this the audience should gain a better understanding of the complexity of IPT systems, rules that it functions under, how IPT is shaped and modified; primary, support, and ancillary components, and the diverse reasons why IPT is critical for food safety and the market. The format of this work starts with IPT history followed by the theory, design, and general components of IPT, examples of IPT programs and standards, examples of auditing and laboratory firms, chapters that discuss domestic/foreign policy and advisory groups, software providers, process facilitators, food recalls/insurance, cost-benefit spreadsheet that focuses on farm level IP for comparison, farmer IP questionnaire, interpretation, conclusion, and appendixes, related products guide, glossary, directory of resources, and works cited.

Self-efficacy and perceptions of community: How they relate to new teachers' commitment

Bennet, Paula University of Virginia 2010 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Far too many teachers leave the profession in the early years of their career. This study explores the relationships between self-efficacy, perception of school support, commitment. Fifty teachers one year out of a Master's in Teaching program were surveyed using self-report questionnaires. Using descriptive analysis, correlational analysis, and stepwise regression I found that self-efficacy was a predictor in professional commitment whereas, perception of school support was predictive of commitment at the school level. Findings indicate that the teachers with higher levels of self-efficacy were more committed to teaching in general whereas, those perceiving greater support were more inclined to return to their schools. Perceptions of care and support at the school level were not related to stronger self-efficacy. There was a decline in self-efficacy declines from graduation to one year after teaching. Teachers who graduate with more positive self-efficacy beliefs were less inclined to be committed to their schools.

Political institutions, interest group competition and investment strategy: International and domestic applications to electric utilities

Zelner, Bennet Andrew University of California, Berkeley 2001 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This dissertation examines how the strength of a firm's “interest group competitors”—rival interest groups with which the firm has a distributive or allocative conflict, such as the consumers of its products or the suppliers of substitute products—interacts with the political and regulatory institutions that define the “rules of the game” to affect the firm's investment choices. It contributes to the growing body of research on politics and firm strategy by suggesting that the manner in which such institutions shape a firm's investment decision is not uniform, but rather depends on the strength of its interest group competitors. When the firm faces strong political competitors, “responsive” institutions that fail to limit the discretion of political actors confront the firm with the risk from unfavorable distributive or allocative policies. The expectation of adverse treatment leads the firm to pursue “defensive” strategies, of which reduced investment is one form. In contrast, when the firm faces weak interest group competitors, it anticipates favorable treatment by political actors. In this case, responsive institutions facilitate the promulgation of favorable policies toward the firm, and lead the firm to pursue an “opportunistic” strategy characterized by increased investment. The dissertation applies these arguments to the investment strategies of firms engaged in the generation of electricity. It contains two empirical applications, both of which feature the political influence of the business consumers of electricity, as measured by the ratio of business to total consumption of electricity (the “B/T ratio”). The first application is a cross-national econometric analysis of the investment choices of up to 78 countries during the period 1970–1994. The econometric model relates country-level measure of institutional responsiveness and the B/T ratio, as well as other relevant influences, to a country's growth rate of generating capacity. The second application examines how differences in US state-level regulatory selection methods and partisan unity, together with a state's B/T ratio, influence the planned investment strategies of US investor-owned electric utilities during the period 1990–1996. This analysis complements the cross-national analysis by focusing exclusively on private sector firms, and also identifying the effects of specific political institutional attributes rather than aggregate measures of institutional attributes. Both of the empirical analyses are generally supportive of the hypotheses.

A Framework for Signal Decomposition with Applications to Solar Energy Generation

Meyers, Bennet E Stanford University ProQuest Dissertations & These 2023 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

My research has been focused on two major areas: (1) optimization as a methodology for signal decomposition and (2) developing useful, practical methods for solar power data science. This dissertation is a synthesis of these areas of research.I present a generalized framework for decomposing time series signal into components, which is motivated by challenges in the analysis of photo-voltaic (PV) data. The industry standard approach uses PV output time series plus additional time series measuring local weather conditions (e.g., irradiance, temperature, and wind speed) and system configuration/modeling parameters (e.g., location, mounting, and orientation). However, it can be very difficult (sometimes impossible) to gather all this data. And so, we propose performing PV performance analysis using only PV output time series, through the application of signal decomposition.Chapters 2 through 6 are based on [73], in which we consider the well-studied problem of decomposing a vector time series signal into components with different characteristics, such as smooth, periodic, nonnegative, or sparse. We describe a simple and general framework in which the components are defined by loss functions (which include constraints), and the signal decomposition is carried out by minimizing the sum of losses of the components (subject to the constraints). When each loss function is the negative log-likelihood of a density for the signal component, this framework coincides with maximum a posteriori probability (MAP) estimation; but it also includes many other interesting cases. Summarizing and clarifying prior results, we give two distributed optimization methods for computing the decomposition, which find the optimal decomposition when the component class loss functions are convex, and are good heuristics when they are not. Both methods require only themasked proximal operator of each of the component loss functions, a generalization of the well-known proximal operator that handles missing entries in its argument. Both methods are distributed, i.e., handle each component separately. We derive tractable methods for evaluating the masked proximal operators of some loss functions that, to our knowledge, have not appeared in the literature. Chapter 6 is concerned with numerical examples from three different domains.Chapter 7 is based on [69]. In this chapter, we provide a methodology for estimating the losses due to soiling for PV systems. We focus this work on estimating the losses from historical power production data that are unlabeled, i.e. power measurements with time stamps, but no other information such as site configuration or meteorological data. We present a validation of this approach on a small fleet of typical rooftop PV systems. The proposed method differs from prior work in that the construction of a performance index is not required to analyze soiling loss. This approach is appropriate for analyzing the soiling losses in field production data from fleets of distributed rooftop systems and is highly automatic, allowing for scaling to large fleets of heterogeneous PV systems.Chapter 8 is based on [74]. In this chapter, we provide a methodology for estimating the losses due to shade in power generation data sets produced by real-world PV systems. We focus this work on estimating shade loss from data that are unlabeled, i.e. power measurements with time stamps but no other information such as site configuration or meteorological data. This approach enables, for the first time, the analysis of data generated by small scale, distributed PV systems, which do not have the data quality or richness of large, utility-scale PV systems or research-grade installations.

Toward a science of individual differences in vision: An investigation of motion perception and oculomotor pursuit

Wilmer, Jeremy Bennet Harvard University 2006 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The study of individual differences in vision has much to offer both basic science and the science of group differences. For example, research on individual differences in color vision has taught us about basic functional mechanisms and their underlying genetics while also informing us about color blindness and its differing prevalence between males and females. Despite such utility, individual differences in vision are rarely studied. This dissertation seeks to demonstrate by example the value, to both basic science and the science of differences between groups, of studying individual differences in vision. In paper one, we show evidence for two independent visual motion processing deficits in developmental dyslexia, each associated with a different reading deficit. A consideration of individual differences in this study allows us to establish that these deficits are independent, while providing evidence that our two motion processing measures may rely upon independently varying processes in normal populations as well. In paper two, we report independent associations between individual differences in two types of motion processing and two periods of oculomotor pursuit. There is a clear transition between these two associations at the time of the initial saccade, evidence that the motion signals driving presaccadic pursuit differ from those driving postsaccadic pursuit. This study both informs us about the nature of signals driving smooth pursuit and provides a useful point of departure for clinical investigations involving smooth pursuit. In paper three, we demonstrate a sex difference favoring males in precision of smooth pursuit eye movements, which could underlie male advantages seen in gross visuomotor performance. This sex difference is independent of the associations reported in paper two, and we show evidence that the difference is likely to be one of internal monitoring of eye movement commands, or efference copy. Given extensive knowledge of factors that differentially affect development of men and women, the further investigation of this sex difference could aid our understanding of the development of oculomotor function. We propose that a healthy science of individual differences in vision could lead to insights applicable to both basic science and the science of group differences.