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The role of hydrogen sulfide in doxorubicin-induced drug resistance in hepatocellular carcinoma cells
No full textDoxorubicin is one of the most common chemical agents used in the treatment of cancers.
Doxorubicin-treated cancer cells often develop drug resistance due to alterations in the
trafficking and metabolism of the drug, which severely limits the drug’s effectiveness. This is
seen at especially high rates in human hepatocellular carcinoma (HCC), the most common form
of liver cancer. H2S is an important gasotransmitter and is involved in a variety of cellular
functions and pathophysiologic processes. The role of H2S in drug resistance in cancer cells is
still unclear. In this study, by using a human hepatocellular carcinoma cell line (HepG2), we
found that NaHS (an H2S donor) was able to reduce cancer cell viability and colony formation in
a doxorubicin dose dependent manner, while H2S alone did not show any effect. The expression
of H2S-generating enzyme cystathionine gamma-lyase (CSE) but not cystathionine beta-synthase
(CBS) was reduced by doxorubicin treatment. In addition, H2S promoted cellular retention of
doxorubicin in HepG2 cells, possibly by suppressing the expression of ABCA1 and ABCG8, two
drug efflux proteins. LXRα acts as a transcription factor for ABCA1 and ABCG8, however our
findings showed that H2S had no effect on the protein expression and S-sulfhydration of LXRα,
suggesting LXRα is not involved in H2S-regulated expressions of ABCA1 and ABCG8. In
comparison with the parental cells, CSE expression was also reduced in doxorubicin-resistant
cells. Exogenously applied NaHS reversed the drug resistance in doxorubicin-resistant cells. In
conclusion, our study provides a novel solution for reversing drug resistance by targeting H2S
signaling
Teaching practice between ostension and proximity: the case of a seasoned physical education teacher in clinical didactics
No full textThis study aims, within a clinical didactics framework, to
identify the crucial role of “proxemics” (Hall, 1966, 1973), as a major
driver of the non-verbal interaction within the teaching-learning process
in Physical Education (PE) and the relationship that it maintains with
ostension. We proceeded with a double analysis (quantitative and
qualitative) case study of a Physical Education teacher‟s in situ practice
in order to identify this singularity (Terrisse, 2000). Results show a
significant dependence between the use of didactic distance types
(Forest, 2006) and ostension types (Salin, 2002) utilized in his teaching
practice. As a result, we noticed that “distance” is intimately related to
different types of ostension and has a major role, as an implicit form of
interaction, in the regulation and the management of didactic situations
Étude exploratoire des formes de dépendances marginales, de leurs impacts et des besoins parmi les personnes concernées : enjeux de l'intervention sociale
No full textCe mémoire de maîtrise en service social vise à explorer l’expérience vécue des
dépendances marginales, des impacts et des besoins des personnes concernées. Le
concept de dépendance marginale est ici élaboré pour tenir compte des différentes
formes de dépendances comportementales, non basées sur la consommation de
substances, qui demeurent sujettes à la controverse dans la littérature et parmi les
praticiens de divers domaines. Par leur non reconnaissance officielle, les dépendances
comportementales sont rarement prises en compte par les cliniciens et dans les
traitements et se situent donc à la marge des services de traitement financés.
À partir de la perspective du travail social, et par l’intermédiaire de la méthode
qualitative et des approches biopsychosociale, narrative, phénoménologique et de l’outil
de Potter-Efron (2004), douze entrevues semi-dirigées ont été réalisées auprès d’adultes
en mesure de partager leurs expériences personnelles et professionnelles au sujet de
l’expérience vécue de la toxicomanie, de l’addiction et des dépendances marginales chez
soi-même et /ou dans son environnement social. Les résultats des entrevues ont été
soumis à une analyse de contenu.
Les principaux résultats de la recherche révèlent que vivre soi-même avec une
ou plusieurs dépendances marginales, ou vivre auprès de personnes aux prises avec une
addiction ou une dépendance aux substances, engendre le stress, le trauma, les abus de
types variés et la désintégration relationnelle et familiale. La famille d’origine, la famille
de progéniture et les relations intimes sont particulièrement affectées par les addictions
et les dépendances marginales de toutes sortes. Ce sont des malaises familiaux et il y a
un grand besoin d’intervenir auprès des membres de la famille, en plus du client.
Pour réduire les écarts dans les services, il faut d’abord résoudre les formalités
d’accès aux services et les problèmes systémiques, afin qu’il soit facile d’accéder à des
services abordables et offertes à toutes les personnes qui en ont besoin. Pour intervenir,
les travailleurs sociaux doivent se doter d’une approche éclectique, pluraliste (du Plessis,
2014) et adopter une vision plus englobante et inclusive qui tient compte des aspects
personnels et sociaux de la personne, et s’assurer d’engager l’individu et son réseau dans
le traitement de ces problèmes, en leur donnant l’espace de s’exprimer, car ils sont les
experts de leur souffrance.Maîtrise en Service Socia
The effects of body region, season and external arsenic application on hair cortisol concentration
No full textHair cortisol analysis has been used to quantify hormone levels in circulation in several mammal species. Hair remains stable for decades or centuries, allowing researchers to use archived hair samples to investigate hormone levels that span long time periods. However, several studies have found that intra-individual variability, driven by the body region from which a sample is derived, confounds measurements of systemic glucocorticoid hormone concentrations. In addition, the external application of chemical agents to hair can remove or concentrate molecules of interest. These may preclude the use of samples that have been collected opportunistically and/or those that have been housed in museum collections. Using a captive population of Vancouver Island marmots (Marmota vancouverensis), we found a strong effect of body region on the concentration of cortisol within hair, as well as an effect of season. Using a collection of American mink (Neovison vison) pelts, we found that application of the preservative arsenic in the form of a soap does not cause a signifi- cant decrease in cortisol. The marmot results suggest that intra-individual variability is not stable through time. The reason for these seasonal effects is not clear and further study is necessary. Researchers using samples from an unknown body region should exercise caution in interpreting their results. The mink results suggest that samples held in museum collec- tions can be used to quantify cortisol, even when arsenic preservation is suspected
A clinical didactics analysis of the use of proxemics forms in the teaching-learning process of sports and physical education setting: a case study in Tunisia
Get PDFThis paper aims to explore the link between teacher’s use of
proxemics and the “link to body” and its impact on teaching act through
the analysis of the teaching practice of one Physical Education (PE)
teacher named (E). Relying on a clinical didactic methodology based on
a “case study” (Terrisse, 2003; Ben Jomaa, Chihi, Sghaier, Mami &
Kpazaï, 2017), two types of data were collected. The observation and the
video recording of two PE sessions (gymnastics and volleyball) allows to
obtain quantitative data in terms of the amount of proxemics types
(Hall, 1966) used by the teacher in each teaching session. To collect the
qualitative data, different types of interviews (already-there, post-stroke,
ante and post session) were conducted with the same teacher in different
research temporalities. As a result, the triangulation of these two types
of data (Huberman & Miles & De Backer, 1991) shows an obvious
correlation between the use of proxemics types and the link to body
(Jourdan, 2006). When he gets close, especially in gymnastics setting, he
maintains an intimate link to the body through touching and
manipulating liberally student’s body parts. When he stays distant, he sometimes shows a narcissistic aspect by showing off his corporal skills
in terms of his unconscious “impossible to support”, although he
sometimes manifests a distant and repulsive link to body when he faces
a paucity of knowledge especially in volleyball
Dynamic modelling of catalytic SO2 converter in a sulfuric acid plant of an industrial smelter
Get PDFIn industrial nickel and copper production, sulfur dioxide (SO2) is generated from the
combustion of sulfide ores. With increasingly tightened regulations on SO2 emissions, a sulfuric
acid plant has become a crucial part of industrial smelters. It converts environmentally harmful
SO2, which is generated in smelter furnaces, roasters, and Cu-reactors, into commercially
beneficial sulfuric acid. This method is recognized as one of the most effective ways to ensure
that smelters are able to satisfy the SO2 emission regulations.
A sulfuric acid plant is primarily comprised of a central catalytic SO2 converter, SO3 (sulfur
trioxide) absorption towers and a series of interconnected heat exchangers. The catalytic SO2
converter is the key component and the focus of this research. Both steady-state and dynamic
models of the converter are developed in this thesis.
A steady-state model of the converter is established in accordance with steady-state
mass and energy balances. The developed model provides an explicit relation between SO2
conversion ratio and gas temperature, which is denoted as the heat-up path of the converter.
By combining the heat-up path with the equilibrium curve of the SO2 oxidation reaction, an
equilibrium state for every converter stage can be obtained. Using the developed steady-state
model, simulations are performed to investigate the effect of inlet SO2 molar fraction and gas
temperature on the equilibrium conversion ratio.
In an industrial SO2 converter, the SO2 concentration and conversion ratio out of each
bed are important variables but are not measured in real time. To monitor these unmeasured
variables in industrial operations, a soft sensor is proposed by combining the derived steadystate
model with dynamic data analysis. The obtained soft sensor provides a real-time
estimation of outlet SO2 concentration and the conversion ratio from measured temperatures.
For synchronization between the inlet SO2 concentration and outlet temperature, a first-order
exponential data filter is applied to the feed SO2 data. With the filtered signal being used,
the proposed soft sensors give a satisfactory estimation of both outlet SO2 concentration and
conversion ratio in the converter stages.
Dynamic modelling is carried out using two different model forms: ordinary differential
equation (ODE) and partial differential equation (PDE) models. The ODE model is obtained by
applying dynamic mass and energy conservation to the SO2 converter. The resulting model can
be used in industrial applications and describes the converter performance even if information
of reaction kinetics is not available. A good fit with collected industrial data verifies the validity
of the developed ODE model. The effect of process input variables is studied using simulations
with the ODE model.
Dynamic modelling is performed by implementing mass and energy balances on both fluid
and solid-phase gas flows. The proposed two-phase dynamic model, which takes the PDE
form, is able to generate detailed profiles of the SO2 converter within time and space. With the
estimated parameters, this two-phase dynamic model generates a good fit between the simulated
and measured outlet temperatures. Based on the PDE model, simulations are run to investigate
the detailed mechanistic performance of the converter. The detailed PDE model provides useful
explanation of, and prediction for the converter behaviour
A phenomenological view at the stigmatization of visibly tattooed individuals in the workplace
Get PDFThis thesis explores the world of the visibly tattooed individual from their own
vantage point, particularly in the work environment and whether, as well as how, tattoos
have affected their career prospects in terms of being hired and promoted. Accordingly, I
will examine how an image or symbol that is visible on the skin can have different
perceptions by management and how it is perceived by, and effects, those with visible
tattoos in the workplace. My goal is to ensure that non-tattooed individuals are able to
understand that tattoos are more than just ink on the skin to be judged, particularly by
those holding power in the workplace. From the standpoint of a heavily, visibly tattooed
mothers, women and students I have a firsthand view of the difficulty society places on
visibly tattooed people. Utilizing field research via a qualitative approach, I conducted
and analyzed thirteen interviews. Utilizing interviews this enabled me to capture the
experiences of participants whether management at a workplace, or visibly tattooed
employees. Results indicate that tattoos have recently become more accepted to a certain
degree, dependent on several factors, including the fine line between an individual who
has a few visible tattoos and others who have what I have labelled ‘body projects.’ I
conclude that stigma and judgment in the workplace are very much alive for tattooed
individuals and will continue to affect their job prospects in the short-term
Concerning the politicization of climate science: epistemic dependency, trust in expert testimony, and determining What We Ought to Believe
No full textBelief in climate change does not divide into a simple dichotomy of (good) believers and (evil)
nonbelievers. An unclear view of skepticism arises when the differences between empirical and
normative claims are revealed. Developing responsible beliefs on matters of which we possess
no expertise requires reliable expert testimony. However, trust and objectivity are integral factors
for belief in expert consensus. A reduction in public opinion regarding the reliability of climate
science, due to politicization, enables the dismissal anthropogenic climate change.
Understanding politicization from both Pielke and Douglas clarifies a negative role that politics
can play in the doing of science. The risks that politicization pose, mistrust for one, do not
undermine the necessary role of values in science. The role of values within scientific enquiry
must be restricted and acknowledged for trustworthy science to be produced, and for scientific
findings regarding climate change to be accepted by nonexperts, including policymakers
(Spine title: NGF INDUCES CHANGES IN GENE EXPRESSION) (Thesis format: Monograph)
No full textOver sixty years ago, nerve growth factor (NGF) was originally discovered as a
neurotrophic factor essential for the survival of sensory and sympathetic neurons during
development. However, recent studies in patients with chronic pain indicate elevated
levels of NGF in their sera and within injured and inflamed tissues. Abnormal
neurotrophin action has been suggested to have an effect on acute and chronic pain, and
in the development of degenerative diseases such as Alzheimer’s, neuropathy, and
cancer. NGF signals through two different types of receptors: TrkA and p75. These
signals can be disrupted by the presence of small molecules inhibitors such as PD90780,
ALE-0450, and PQC 083 by specifically binding to NGF. The binding by these
molecules antagonizes the action of NGF from binding to its receptors, therefore blocking
its signalling pathways. This could have a potential application in pain control and
treatment of degenerative diseases. More recently, pain therapy has focused on selective
NGF inhibition.
The aim of this study was to utilize gene expression analysis to investigate the intricate
results of signalling in NGF treated cells compared to cells treated with both NGF and NGF
inhibitors. A better understanding of genetic networks may contribute to the identification
of novel drug targets, and more sensitive diagnostic strategies.
In this research, peak time expression for Egr-1 in NGF treated cells was evaluated. Also,
Egr-1 gene expression was assessed in NGF treated cells using semi-quantitative RT-PCR.
This may provide a better way to identify new drugs through the examination of cell
signalling response. Moreover, these findings will be helpful as a model for in vivo
applications