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Marker-Free Isolation and Enrichment of Rare Cell Types Including Tumor Initiating Cells through Contactless DielectrophoresisShafiee, Hadi 09 December 2010 (has links)
Microfluidics has found numerous applications ranging from the life sciences industries for pharmaceuticals and biomedicine (drug design, delivery and detection, diagnostic devices) to industrial applications of combinational synthesis (such as rapid analysis and high throughput screening). Among all these, one of the intriguing exploitation of microfluidics or micro total analysis systems (µTAS) is the separation of circulating tumor cells (CTCs) from body fluids. Cancer cells spread from the initial site of a tumor by first invading the surrounding tissue, then by entering the blood or lymph vessels, and finally by crossing the vessel wall to exit the vasculature into distal organs. The September 2006 issue of the Journal of the National Cancer Institute (NCI) states: "The war on cancer was declared 40 years ago and cancer is still here," and "Technologies that capture enemy CTCs for further interrogation might prove useful in the war on cancer." CTCs cannot only become a new marker for cancer prognosis, but their detection can also be a valid new parameter for diagnosing cancer early, for monitoring disease progression and relapse, and for optimizing therapy.
This research established a new method to manipulate rare cell types based on their electrical signatures using dielectrophoresis (DEP) without having direct contact between the electrodes and the sample, known as contactless dielectrophoresis (cDEP). DEP is the motion of a particle in a suspending medium due to its polarization in the presence of a non-uniform electric field. cDEP relies upon reservoirs filled with highly conductive fluid to act as electrodes and provide the necessary electric field. These reservoirs are placed adjacent to the main microfluidic channel and are separated from the sample by a thin barrier of a dielectric material as is shown in Figure 1h. The application of a high-frequency electric field to the electrode reservoirs causes their capacitive coupling to the main channel and an electric field is induced across the sample fluid. Similar to traditional DEP, cDEP exploits the varying geometry of the electrodes to create spatial non-uniformities in the electric field. However, by utilizing reservoirs filled with a highly conductive solution, rather than a separate thin film array, the electrode structures employed by cDEP can be fabricated in the same step as the rest of the device; hence the process is conducive to mass production.
We demonstrated the ability to isolate human leukemia cancer cells (THP-1) cells from a heterogeneous mixture of live and dead cells using cDEP with more than 99% selectivity and 95% removal efficiency. Through numerical and experimental investigations, new generation of cDEP devices have been designed and tested to detect and isolate THP-1 cells from spiked blood samples with high selectivity and cell capture efficiency. Our experimental observations, using prototype devices, indicate that breast cancer cell lines at their different stages (MCF-7, MCF-10, and MDA-MB231) have unique electrical. Furthermore, through collaborations at the Wake Forest Comprehensive Center, we demonstrated that prostate tumor initiating cells (TICs) exhibit unique electrical signatures and DEP responses and cDEP technology can be exploited to isolate and enrich TICs for further genetic pathways investigations. / Ph. D.
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I'm the Smart Kid: Adult Attitudes and Perceptions about Enrichment and Special EducationMisitzis, Yannos Dimitrios 17 May 2019 (has links)
Within the educational community, there is a growing shift towards the development of essential skills, emphasizing process-skills over mastery of content. This shift is mirrored in the rapid changes in workplace-related technology, outpacing the creativity and flexibility of current graduates. Makerspaces and related technology education approaches have been increasingly implemented to offer students opportunities for developing these desired skills. Parallel to this effort, students who receive special education services but access the general education curriculum continue to lag behind the general education population in high-stakes testing, graduation-rates, and long-term employment outcomes. Remediation-based services often preclude students receiving services from exposure to technology- or other enrichment-based educational opportunities. The initial phase of this exploratory case study focused on the impacts of a technology-based enrichment club on a small group of special education learners. Through this proof-of-concept study, it became apparent that adult participants across stakeholder groups were showing evidence of transformative learning through their experiences with the club. The follow-up study, therefore, focused on changes in adult perceptions and/or practices resulting from these experiences, as evidenced through the Nerstrom Transformative Learning Model (2014). Following exposure, interviews were conducted with participating cosponsors, school-based educational leaders, and guest presenters from technical fields. These interviews were analyzed for both commonly identified and group-specific themes. Results suggest that experiences with the club challenged various assumptions held by participants, often leading to new perspectives on special education practices and students who receive services. These results suggest that potential shifts are a function of how many established perspective-based obstacles these challenged and reformed assumptions can address. Recommendations for future research include replication, extension beyond a club setting, and further exploration of identified themes, as well as investigating the deeper implications of obstacles to transformative learning. / Doctor of Education / Within the educational community, there is a growing shift towards the development of essential skills, emphasizing process-skills over mastery of content. This shift is mirrored in the rapid changes in workplace-related technology, outpacing the creativity and flexibility of current graduates. Makerspaces and related technology education approaches have been increasingly implemented to offer students opportunities for developing these desired skills. Parallel to this effort, students who receive special education services but access the general education curriculum continue to lag behind the general education population in high-stakes testing, graduation-rates, and long-term employment outcomes. Remediation-based services often preclude students receiving services from exposure to technology- or other enrichment-based educational opportunities. The initial phase of this exploratory case study focused on the impacts of a technology-based enrichment club on a small group of special education learners. Through this proof-of-concept study, it became apparent that adult participants across stakeholder groups were showing evidence of transformative learning through their experiences with the club. The follow-up study, therefore, focused on changes in adult perceptions and/or practices resulting from these experiences, as evidenced through the Nerstrom Transformative Learning Model (2014). Following exposure, interviews were conducted with participating cosponsors, school-based educational leaders, and guest presenters from technical fields. These interviews were analyzed for both commonly identified and group-specific themes. Results suggest that experiences with the club challenged various assumptions held by participants, often leading to new perspectives on special education practices and students who receive services. These results suggest that potential shifts are a function of how many established perspective-based obstacles these challenged and reformed assumptions can address. Recommendations for future research include replication, extension beyond a club setting, and further exploration of identified themes, as well as investigating the deeper implications of obstacles to transformative learning.
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Lab on a chip rare cell isolation platform with dielectrophoretic smart sample focusing, automated whole cell tracking analysis script, and a bioinspired on-chip electroactive polymer micropumpAnders, Lisa Mae 18 July 2014 (has links)
Dielectrophoresis (DEP), an electrokinetic force, is the motion of a polarizable particle in a non-uniform electric field. Contactless DEP (cDEP) is a recently developed cell sorting and isolation technique that uses the DEP force by capacitavely coupling the electrodes across the channel. The cDEP platform sorts cells based on intrinsic biophysical properties, is inexpensive, maintains a sterile environment by using disposable chips, is a rapid process with minimal sample preparation, and allows for immediate downstream recovery. This platform is highly competitive compared to other cell sorting techniques and is one of the only platforms to sort cells based on phenotype, allowing for the isolation of unique cell populations not possible in other systems.
The original purpose of this work was to determine differences in the bioelectrical fingerprint between several critical cancer types. Results demonstrate a difference between Tumor Initiating Cells, Multiple Drug Resistant Cells, and their bulk populations for experiments conducted on three prostate cancer cell lines and treated and untreated MOSE cells. However, three significant issues confounded these experiments and challenged the use of the cDEP platform. The purpose of this work then became the development of solutions to these barriers and presenting a more commercializable cDEP platform.
An improved analysis script was first developed that performs whole cell detection and cell tracking with an accuracy of 93.5%. Second, a loading system for doing smart sample handling, specifically cell focusing, was developed using a new in-house system and validated. Experimental results validated the model and showed that cells were successfully focused into a tight band in the middle of the channel. Finally, a proof of concept for an on-chip micropump is presented and achieved 4.5% in-plane deformation. When bonded over a microchannel, fluid flow was induced and measured.
These solutions present a stronger, more versatile cDEP platform and make for a more competitive commercial product. However, these solutions are not just limited to the cDEP platform and may be applicable to multitudes of other microfluidic devices and applications. / Master of Science
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Wild Tigers in Captivity: A Study of the Effects of the Captive Environment on Tiger BehaviorPitsko, Leigh Elizabeth 22 May 2003 (has links)
Humans maintain wild animals in zoological parks for the purposes of education,conservation, research, and recreation. However, abnormal behaviors may develop in animals housed in human-made environments, if those environments do not allow them to carry out their natural behaviors (such as swimming, climbing, stalking, and predation). Captive environments in zoological parks often do not provide for natural behaviors due to spatial constraints and negative public reaction. Tigers (Panthera tigris) present a difficult case; they have large home ranges in the wild and natural predatory hunting behaviors that are difficult to provide for in captivity.
As the numbers of wild tigers decline, captive breeding programs have become a major focus of the zoo community, which magnifies the importance of research on tiger husbandry. A body of research exists on small felids, but little, if any, has focused on tigers. This thesis presents an analysis of the effects of the captive environment on the behaviors of 18 captive Bengal and Siberian tigers in four zoological parks in Virginia and Pennsylvania. Certain animal characteristics (such as subspecies, and age) were also related to behavior. Several characteristics of the captive environment had statistically significant effects on stereotypic and exploratory behaviors of tigers: shade availability, the presence of a body of water, cage size, the presence of a conspecific, vegetation, environmental enrichment, and substrate type. There were significant differences in the behaviors of the two subspecies studied, but the reason for the differences are unclear.
The results of this study showed clearly that tigers kept in more natural and complex enclosures performed less stereotypic pacing (unnatural behavior), and more exploratory (natural) behaviors than those housed in less natural enclosures. Reducing the stress level in captive tigers will enhance the animals' overall physical and psychological well being, which will in turn increase the success of captive breeding programs. These results suggest that captive tigers should be housed in large enclosures containing natural substrate and vegetation, water pools, ample shade, a variety of resting locations, and a variety of enrichment items. / Master of Science
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Bezdůvodné obohacení ze srovnávacího pohledu / Unjustified Enrichment in the Comparative PerspectivePetrov, Jan January 2015 (has links)
strana 259 Unjustified Enrichment in the Comparative Perspective Abstract The aim of the thesis is the legal research of important results concerning unjustified en- richment that have been attained in foreign jurisprudence and judicial opinions, especially within the German legal family, and their comparative application to all provisions of the New Czech Civil Code ("NCC") regulating unjustified enrichment, including their rela- tion to other parts of civil law. The thesis thus draws extensively from Austrian and Ger- man jurisprudence and case law, from the Draft Common Frame of Reference, from Swiss law and from comparative literature; further legal orders are also mentioned and a refined translation of relevant foreign provisions is included in the appendix. The thesis does not include a mere description, but rather follows the interests of Czech law and aims to make a contribution to Czech jurisprudence and application the of law. Accord- ingly, the thesis is also founded on complete research of the Czech Supreme Court case law made in and after 2010. The thesis comes to a number of conclusions (summarized in the itemized resumé) which may be deemed for original from the point of view of the Czech legal discourse. These conclusions corroborate the hypothesis that the Czech law of unjustified...
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An evaluation of the worth of a partial withdrawal enrichment program for gifted children based on Maker's curriculum principlesWilliams, E. Marion, n/a January 1986 (has links)
As a means of addressing observed inadequacies in school
curricula, the Catholic Special Education and Guidance Service, Brisbane Catholic Education Office in 1980 established a partial
withdrawal centre for counsellor-selected gifted children.
The Learning Enrichment Centre (L.E.C.) aimed to -
1) meet the needs of enrolled gifted students by -
a) providing appropriate learning experiences; and
b) providing an administrative arrangement (partial withdrawal)
which afforded them the opportunity to interact
with like minds;
2) meet the needs of the system by -
a) developing and evaluating units of work for gifted
students;
b) conducting workshops, seminars and in-service days for
teachers.
In 1984 the L.E.C. curriculum was designed and implemented in
accordance with Maker's model of curriculum modification for gifted
students (Maker, 1982). This model outlines a set of principles which
Maker claims, recognize the characteristics and needs of gifted
students and guide the development of a qualitatively different
curriculum. In making decisions about design and implementation of
Maker's curriculum modifications, factors related to the setting, the
teachers and the students were considered.
The overall purpose of the Study was to assist teachers in making
rational decisions about future L.E.C. provision. In particular the
Study was to collect information on the worth of the program - its
relative strengths and weaknesses - and the influence on the curriculum
of the administrative arrangement.
The program was evaluated by ascertaining levels of satisfaction
typically expressed by the students.
Of secondary concern was whether the organisational arrangement
of partial withdrawal had inhibited or enhanced the program's
intentions. It was acknowledged that unfavourable attitudes of
parents, classroom teachers or peers could conceivably alter students'
receptivity of the program.
In Term 4, two parallel questionnaires, one addressing the
L.E.C., the other the regular classroom, were administered to the
students. By comparing responses on matching items, levels of
satisfaction with the L.E.C. curriculum were determined. Selected
items on the L.E.C. instrument were further to reveal how students
felt about the administrative provision and whether classroom teachers
and peers were perceived to be supportive.
Subsequent to program completion, a questionnaire was mailed to
parents bo ascertain their support for the program by asking them how
their child's emotional behaviour had changed as a result of LEC
attendance. Also they were to indicate whether they preferred that
enrichment occur in the regular classroom or partial withdrawal
setting.
To confirm the students' impressions of classroom teacher support
and interest, parents were requested to comment on their understanding
of it.
Student responses indicated that they found their LEC experiences
to be particularly interesting and enjoyable, and the LEC teachers to
be kind, helpful, friendly and fair. These perceptions differed
significantly from their perceptions of school. Elements of the Maker
model which were consistently most valued by the group were the
Process modifications, 'Freedom of Choice' and 'Higher Levels of
Thinking'.
Parents proved to be supportive of the LEC program.
Although some would have preferred classroom enrichment
to partial withdrawal, they felt that schools could not
currently provide it.
It was the students' viewpoint that interactions
with peers and classroom teachers were not adversely affected
by their LEC participation. Classroom teachers were seen
to be generally supportive and interested - a perception
incidentally not shared by parents and LEC teachers.
Perceived positive attitudes towards their LEC involvement
most likely enhanced student satisfaction with the program.
The evaluation unequivocally indicated that the
LEC program based on Maker's model appealed to the students.
Though withdrawal from class possibly contributed to program
satisfaction, the level of satisfaction was very high
and could not be attributed solely to hidden curriculum
efects (the organisational arrangement).
The Study concluded that use of the Maker model
as a guide for developing LEC curricula should continue
but that parent and classroom teacher attitudes towards
the administrative arrangement should be regularly monitored
as they appeared to have the potential to enhance or
reduce students' receptivity of the program.
As a result of Study, various procedures for the
conduct of future evaluations were recommended.
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Enrichissement nutritionnel de l’huile d’olive : entre tradition et innovation / Olive oil nutritional enrichment : from tradition to innovationVeillet, Sébastien 29 June 2010 (has links)
L’huile d’olive est un produit ancestral largement reconnu pour ses effets bénéfiques sur la santé humaine. Sa technique de fabrication a beaucoup évolué au cours des siècles, notamment ces dernières années avec l’automatisation croissante des chaînes de production. La première partie de ce manuscrit fait le bilan de ces différentes évolutions, puis la seconde partie détaille l’impact de chacune des étapes de fabrication sur la composition nutritionnelle de l’huile. Nous avons ainsi étudié l’influence du broyage, des séparations liquide-liquide et solide-liquide. L’optimisation de ces étapes permet l’obtention d’une huile enrichit de façon endogène puisque tous les nutriments étaient présents dans l’olive. En complément nous avons également développé des méthodes d’enrichissement exogène de l’huile. Dans ce cas des molécules bioactives issues de plantes ou de légumes sont ajoutées à l’huile d’olive. Afin de limiter les étapes d’extraction et de bannir l’utilisation de solvants organiques, l’huile est utilisée en tant que solvant d’extraction et l’enrichissement se fait de façon directe dans l’huile. Pour accélérer des cinétiques d’extraction qui pourraient être très longues, nous avons utilisé des ultrasons. Les résultats obtenus sont très encourageants et ils permettent d’imaginer un élargissement de la gamme de produits oléicoles disponibles / Olive oil is an ancestral product widely known for its benefic effects on human health. Its processing has changed a lot through centuries, especially these past few years with the increasing automation of the production lines. The first part of this manuscript describes these evolutions while the second part gives details on the influence of each processing step on the nutritional composition of the olive oil. We have studied the influence of the crushing systems, liquid-liquid and solid-liquid separations. The optimization of each of these steps allows the endogenous enrichment of the oil with nutrients extracted from the olive fruit. Then, we have also developed exogenous olive oil enrichment methods by bioactive compounds issued from plants and vegetables. In order to restrain the number of extraction steps and avoid the use of petroleum solvents, the olive oil is used as the extraction solvent so the enrichment is directly performed in the oil. To accelerate extraction kinetics that could be very long we developed ultrasound accelerated extraction techniques. The results obtained in this work are very promising and extensions of olive oil available product ranges are possible
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Der strafrechtliche Schutz gegen ungerechtfertigte Vermögensverschiebungen in England und Wales im Vergleich mit dem deutschen Strafrecht /Och, Frank. January 2004 (has links) (PDF)
Univ., Diss.-2003--Würzburg, 2002.
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Global functional association network inference and crosstalk analysis for pathway annotationOgris, Christoph January 2017 (has links)
Cell functions are steered by complex interactions of gene products, like forming a temporary or stable complex, altering gene expression or catalyzing a reaction. Mapping these interactions is the key in understanding biological processes and therefore is the focus of numerous experiments and studies. Small-scale experiments deliver high quality data but lack coverage whereas high-throughput techniques cover thousands of interactions but can be error-prone. Unfortunately all of these approaches can only focus on one type of interaction at the time. This makes experimental mapping of the genome-wide network a cost and time intensive procedure. However, to overcome these problems, different computational approaches have been suggested that integrate multiple data sets and/or different evidence types. This widens the stringent definition of an interaction and introduces a more general term - functional association. FunCoup is a database for genome-wide functional association networks of Homo sapiens and 16 model organisms. FunCoup distinguishes between five different functional associations: co-membership in a protein complex, physical interaction, participation in the same signaling cascade, participation in the same metabolic process and for prokaryotic species, co-occurrence in the same operon. For each class, FunCoup applies naive Bayesian integration of ten different evidence types of data, to predict novel interactions. It further uses orthologs to transfer interaction evidence between species. This considerably increases coverage, and allows inference of comprehensive networks even for not well studied organisms. BinoX is a novel method for pathway analysis and determining the relation between gene sets, using functional association networks. Traditionally, pathway annotation has been done using gene overlap only, but these methods only get a small part of the whole picture. Placing the gene sets in context of a network provides additional evidence for pathway analysis, revealing a global picture based on the whole genome. PathwAX is a web server based on the BinoX algorithm. A user can input a gene set and get online network crosstalk based pathway annotation. PathwAX uses the FunCoup networks and 280 pre-defined pathways. Most runs take just a few seconds and the results are summarized in an interactive chart the user can manipulate to gain further insights of the gene set's pathway associations. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.</p>
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Enrichment at the claimant's expense : attribution rules in unjust enrichmentBall, Eli Byron Stuart January 2014 (has links)
This thesis presents an account of attribution in unjust enrichment. Attribution refers to how and when two parties – a claimant and a defendant – are relevantly connected to each other for unjust enrichment purposes. It is reflected in the familiar expression that a defendant be 'enriched at the claimant's expense'. This thesis presents a structured account of attribution, consisting of two requirements: first, the identification of an enrichment to the defendant and a loss to the claimant; and, secondly, the identification of a connection between that enrichment and that loss. These two requirements must be kept separate from other considerations often subsumed within the expression 'enrichment at the claimant's expense' which in truth have nothing to do with attribution, and which instead qualify unjust enrichment liability for reasons that should be analysed in their own terms. The structure of attribution so presented fits a normative account of unjust enrichment based upon each party's exchange capacities. A defendant is enriched when he receives something that he has not paid for under prevailing market conditions, while a claimant suffers a loss when he loses the opportunity to charge for something under the same conditions. A counterfactual test – asking whether enrichment and loss arise 'but for' each other – provides the best generalisation for testing whether enrichment and loss are connected, thereby satisfying the requirements of attribution in unjust enrichment. The law is stated as at 15 March 2014.
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