982 resultados para CANDIDATES
Resumo:
Matrix sublimation has demonstrated to be a powerful approach for high-resolution matrix-assisted laser desorption ionization (MALDI) imaging of lipids, providing very homogeneous solvent-free deposition. This work presents a comprehensive study aiming to evaluate current and novel matrix candidates for high spatial resolution MALDI imaging mass spectrometry of lipids from tissue section after deposition by sublimation. For this purpose, 12 matrices including 2,5-dihydroxybenzoic acid (DHB), sinapinic acid (SA), α-cyano-4-hydroxycinnamic acid (CHCA), 2,6-dihydroxyacetphenone (DHA), 2',4',6'-trihydroxyacetophenone (THAP), 3-hydroxypicolinic acid (3-HPA), 1,8-bis(dimethylamino)naphthalene (DMAN), 1,8,9-anthracentriol (DIT), 1,5-diaminonapthalene (DAN), p-nitroaniline (NIT), 9-aminoacridine (9-AA), and 2-mercaptobenzothiazole (MBT) were investigated for lipid detection efficiency in both positive and negative ionization modes, matrix interferences, and stability under vacuum. For the most relevant matrices, ion maps of the different lipid species were obtained from tissue sections at high spatial resolution and the detected peaks were characterized by matrix-assisted laser desorption ionization time-of-flight/time-of-flight (MALDI-TOF/TOF) mass spectrometry. First proposed for imaging mass spectrometry (IMS) after sublimation, DAN has demonstrated to be of high efficiency providing rich lipid signatures in both positive and negative polarities with high vacuum stability and sub-20 μm resolution capacity. Ion images from adult mouse brain were generated with a 10 μm scanning resolution. Furthermore, ion images from adult mouse brain and whole-body fish tissue sections were also acquired in both polarity modes from the same tissue section at 100 μm spatial resolution. Sublimation of DAN represents an interesting approach to improve information with respect to currently employed matrices providing a deeper analysis of the lipidome by IMS.
Resumo:
98% of patients who have undergone a gastric bypass for treating severe obesity develop multiple micronutrient deficits. However, prior to surgery, it isn't rare to find nutrient deficiencies. Indeed, the dietary intakes of surgery candidates are often unbalanced, lacking in variety especially in high vitamin and mineral nutrients. We present the preliminary results concerning the qualitative and quantitative analysis in a group of patients waiting for a gastric bypass. The recommended daily amounts in vitamin B9, vitamin D and iron are insufficient in the majority of the patients. The correction of nutritional intakes is advisable, even before the surgery, in order to reduce the risks of developing biological deficiencies.
Resumo:
Notwithstanding the functional role that the aggregates of some amyloidogenic proteins can play in different organisms, protein aggregation plays a pivotal role in the pathogenesis of a large number of human diseases. One of such diseases is Alzheimer"s disease (AD), where the overproduction and aggregation of the β-amyloid peptide (Aβ) are regarded as early critical factors. Another protein that seems to occupy a prominent position within the complex pathological network of AD is the enzyme acetylcholinesterase (AChE), with classical and non-classical activities involved at the late (cholinergic deficit) and early (Aβ aggregation) phases of the disease. Dual inhibitors of Aβ aggregation and AChE are thus emerging as promising multi-target agents with potential to efficiently modify the natural course of AD. In the initial phases of the drug discovery process of such compounds, in vitro evaluation of the inhibition of Aβ aggregation is rather troublesome, as it is very sensitive to experimental assay conditions, and requires expensive synthetic Aβ peptides, which makes cost-prohibitive the screening of large compound libraries. Herein, we review recently developed multi-target anti-Alzheimer compounds that exhibit both Aβ aggregation and AChE inhibitory activities, and, in some cases also additional valuable activities such as BACE-1 inhibition or antioxidant properties. We also discuss the development of simplified in vivo methods for the rapid, simple, reliable, unexpensive, and high-throughput amenable screening of Aβ aggregation inhibitors that rely on the overexpression of Aβ42 alone or fused with reporter proteins in Escherichia coli.
Resumo:
To evaluate the efficacy of endorectal Magnetic Resonance Imaging (MRI) and Magnetic Resonance Spetroscopic Imaging (MRSI) combined with total prostate-specific antigen (tPSA) and free prostate-specific antigen (fPSA) in selecting candidates for biopsy. Subjects and Methods: 246 patients with elevated tPSA (median: 7.81 ng/ml) underwent endorectal MRI and MRSI before Transrectal Ultrasound (TRUS) biopsy (10 peripheral + 2 central cores); patients with positive biopsies were treated with radical intention; those with negative biopsies were followed up and underwent MRSI before each additional biopsy if tPSA rose persistently. Mean follow-up: 27.6 months. We compared MRI, MRSI, tPSA, and fPSA with histopathology by sextant and determined the association between the Gleason score and MRI and MRSI. We determined the most accurate combination to detect prostate cancer (PCa) using receiver operating curves; we estimated the odds ratios (OR) and calculated sensitivity, specificity, and positive and negative predictive values. Results: No difference in tPSA was found between patients with and without PCa (p = 0.551). In the peripheral zone, the risk of PCa increased with MRSI grade; patients with high-grade MRSI had the greatest risk of PCa over time (OR = 328.6); the model including MRI, MRSI, tPSA, and fPSA was more accurate (Area under Curve: AUC = 95.7%) than MRI alone (AUC = 85.1%) or fPSA alone (AUC = 78.1%), but not than MRSI alone (94.5%). In the transitional zone, the model was less accurate (AUC = 84.4%). The association (p = 0.005) between MRSI and Gleason score was significant in both zones. Conclusions: MRSI is useful in patients with elevated tPSA. High-grade MRSI lesions call for repeated biopsies. Men with negative MRSI may forgo further biopsies because a significantly high Gleason lesion is very unlikely
Resumo:
Diplomityön tavoitteena oli sopivimman yritysostokohteen valitseminen useiden kilpailijoiden joukosta puunkäsittelykoneiden toimittajalle. Ensin esiteltiin Suomen metsäteollisuus sekä sen osaamistarpeista noussut metsäklusteri pääosin kohdeyrityksen näkökulmasta. Seuraavaksi annettiin kuva yrityksen tuotteista, kilpailijoista ja asiakkaista. Yritysostoprosessi kuvattiin sekä esille tuotiin yleiset motiivit ja kriittiset menestystekijät. Lisäksi kuvattiin kilpailijoiden ja liiketoimintaympäristön analysointi yrityksen menestyksen edellytyksenä. Puuntyöstökoneiden markkinat segmentoitiin ja analysoitiin vuodesta 1990 aina tähän päivään asti, jotta löydettäisiin kehityskelpoiset osa-alueet eli alueet, joissa yrityksen markkinaosuutta voitaisiin kasvattaa. Kandidaattien ominaisuuksia verrattiin yritysoston motiiveihin. Yritysten tuotteet sekä maantieteellinen sijainti pisteytettiin, jotta sopivimmat yritykset nousisivat esille. Kolme yritystä valittiin syvällisempään tarkasteluun. Yritysten tuotteita, taloudellista asemaa ja globaalia verkostoa vertailtiin keskenään muiden tekijöiden, kuten maailmantalouden ohessa. Taloudellisesti vakaa ja teknisesti monipuolinen yritys kohtasi yritysoston motiivit parhaiten. Kohteen positiivisia puolia olivat sijainti, tuotteet ja palvelut. Lisäksi, yritys sopii ostajan strategiaan sekä auttaa kohtaamaan asiakkaiden nykyiset ja tulevat tarpeet.
Resumo:
We report optical spectroscopic observations of a sample of 6 low-galactic latitude microquasar candidates selected by cross-identification of X-ray and radio point source catalogs for |b|<5 degrees. Two objects resulted to be of clear extragalactic origin, as an obvious cosmologic redshift has been measured from their emission lines. For the rest, none exhibits a clear stellar-like spectrum as would be expected for genuine Galactic microquasars. Their featureless spectra are consistent with being extragalactic in origin although two of them could be also highly reddened stars. The apparent non-confirmation of our candidates suggests that the population of persistent microquasar systems in the Galaxy is more rare than previously believed. If none of them is galactic, the upper limit to the space density of new Cygnus X-3-like microquasars within 15 kpc would be 1.1\times10^{-12} per cubic pc. A similar upper limit for new LS 5039-like systems within 4 kpc is estimated to be 5.6\times10^{-11} per cubic pc.
Resumo:
In an attempt to increase the number of known microquasars, Paredes et al. (2002) have presented a long-term project focused on the search for new objects of this type. They performed a cross-identification between X-ray and radio catalogs under very restrictive selection criteria for sources with |b|<5 degrees, and obtained a sample of 13 radio-emitting X-ray sources. Follow-up observations of 6 of these sources with the VLA provided accurate coordinates, which were used to discover optical counterparts for all of them. We have observed these six sources with the EVN and MERLIN at 5 GHz. Five of the six objects have been detected and imaged, presenting different morphologies: one source has a two-sided jet, three sources have one-sided jets, and one source is compact. With all the presently available information, we conclude that two of the sources are promising microquasar candidates in our Galaxy.
Resumo:
Notwithstanding the functional role that the aggregates of some amyloidogenic proteins can play in different organisms, protein aggregation plays a pivotal role in the pathogenesis of a large number of human diseases. One of such diseases is Alzheimer"s disease (AD), where the overproduction and aggregation of the β-amyloid peptide (Aβ) are regarded as early critical factors. Another protein that seems to occupy a prominent position within the complex pathological network of AD is the enzyme acetylcholinesterase (AChE), with classical and non-classical activities involved at the late (cholinergic deficit) and early (Aβ aggregation) phases of the disease. Dual inhibitors of Aβ aggregation and AChE are thus emerging as promising multi-target agents with potential to efficiently modify the natural course of AD. In the initial phases of the drug discovery process of such compounds, in vitro evaluation of the inhibition of Aβ aggregation is rather troublesome, as it is very sensitive to experimental assay conditions, and requires expensive synthetic Aβ peptides, which makes cost-prohibitive the screening of large compound libraries. Herein, we review recently developed multi-target anti-Alzheimer compounds that exhibit both Aβ aggregation and AChE inhibitory activities, and, in some cases also additional valuable activities such as BACE-1 inhibition or antioxidant properties. We also discuss the development of simplified in vivo methods for the rapid, simple, reliable, unexpensive, and high-throughput amenable screening of Aβ aggregation inhibitors that rely on the overexpression of Aβ42 alone or fused with reporter proteins in Escherichia coli.
Resumo:
Par Zhong Zhen li, surnom Zhi an, de Pu tao ; avertissement par Cai Guang hua, surnom Ling an, de Nan cheng. Publié en 1820.
Resumo:
In this study, teacher candidates’ experiences, perceptions, and knowledge of multicultural education at 2 Ontario universities were used determine to the effectiveness of their teacher education programs in preparing them to teach in multicultural classrooms. The research also strived to highlight the most effective practices in these programs that contributed to the preparation of teacher candidates for employment in culturally, racially, and ethnically diverse classrooms in Ontario. A questionnaire and interviews were used to determine the effectiveness of the program in preparing them to teach in diverse classrooms. The findings revealed the need for a greater emphasis of multicultural education in teacher education programs at these universities. The data showed that teacher candidates were most critical of the courses and the delivery of the curriculum in relation to multicultural education. Teacher candidates were also concerned with the lack of multicultural education in their practicum placements. In addition, teacher candidates indicated in the questionnaire that they felt competent adapting instruction to the needs of students in multicultural classrooms. However, the results obtained from the interviews were more varied. The interviews highlighted that teacher candidates were hesitant about teaching in culturally diverse classrooms and less likely to state that they were prepared for these teaching environments. As well, many teacher candidates believed their peers were not prepared for multicultural issues. Teacher candidates believed the program could be improved in many ways including specific instruction across all classes, more diverse practicum experiences, guest speakers, case studies, and the creation of new courses that specifically address multicultural education.
Resumo:
The poverty rate in Ontario affects approximately 1 in 6 children. Consequently, many classrooms in the province include students who come from poverty, and teachers are faced with the challenge of providing an equitable education to students who come from economically diverse backgrounds. Because student poverty in our education system is so prevalent, this challenge exists also for teacher candidates who enter the education system and complete their practicums in classrooms that often include students from impoverished backgrounds. This project examined issues of poverty and education and developed a workshop to assist teacher candidates to develop knowledge in this area. The project combined existing pedagogical approaches with participants’ recommendations and developed a workshop that could be delivered to Faculty of Education students. The workshop addresses poverty, the relationship between poverty and education, student academic achievement and well-being, and the relationship between school and home. The goal and hope of the workshop is that teacher candidates will be better prepared when working in economically diverse school environments.
Resumo:
This study used narrative inquiry to shed light on the identity development of teacher candidates who experienced mental health issues during teacher education programs. The study sought to examine (a) stories that teacher candidates tell about being in a teacher education program while experiencing mental health issues; (b) identity development of teachers who have experienced mental health issues; and (c) how narratives of teacher candidates and beginning teachers challenge stereotyping and stigmatization. Through discussion and letter correspondence, the participants and I shared stories that represented our lived experiences. The study explored our stories using the 3 commonplaces of temporality, sociality, and place from a theoretical framework of narrative inquiry. Four themes emerged from the data analysis: the stigmatization of mental health issues; dealing with conflict; the need for a safe and supportive environment; and the complexity of mental health issues. This study contributes to the literature by exploring the lived experiences of teacher candidates and beginning teachers with mental health issues. The narratives inform teacher education programs, the teaching profession, and the mental health field.
Resumo:
The aim of this thesis is to explore the relationship between imagery, technology, and remote adult Aboriginal teacher candidates through the computer software Elluminate Live. It focuses on the implications that the role imagery plays in third generation distance education with these learners and the new media associated therein. The thesis honours the Medicine Wheel teachings and is presented within this cyclical framework that reflects Indigenous philosophies and belief systems. In accordance, Sharing Circle as methodology is used to keep the research culturally grounded, and tenets of narrative inquiry further support the study. Results indicate there are strong connections to curricula enhanced with imagery—most notably a spiritual connection. Findings also reveal that identity associated to geographical location is significant, as are supportive networks. Third generation distance education, such as Elluminate Live, needs to be addressed before Aboriginal communities open the doors to all it encompasses, and although previous literature peers into various elements, this study delves into why the graphical interface resonates with members of these communities. Of utmost importance is the insight this thesis lends to the pedagogy that may possibly evoke a transformative learning process contributing to the success rate of Aboriginal learners and benefit Aboriginal communities as a whole.
Resumo:
In this study, teacher candidates’ perception of their concurrent education program at two Ontario universities were examined, with specific emphasis on how the programs utilized practicum placements, to determine the effectiveness in preparing teacher candidates to teach. This research also strived to uncover the best ways to optimize concurrent teacher education through practicum placements. A questionnaire and interviews were used to uncover teacher candidates’ perceptions at one teacher education program that used full integration of practicum and one that used minimal integration of practicum. The findings revealed that teacher candidates were generally more satisfied with the overall program when there was full integration of practicum. There were statistically significant differences found between the two concurrent programs with regard to practicum time and preparedness and context of the practicum and a highly significant difference found for theory-practice divide. There was also a statistically significant difference (p < .05) observed between the teacher candidates at each university in terms of their beliefs about the need for improvement of their program. Some of the improvements that participants believed could be made to their respective programs included having (a) exceptional mentor teachers and teacher educators, (b) longer placements with a balance of observation and practicum teaching, (c) clear expectations and evaluations of practicum placement, and (d) more distinct connections between theory and practice made within the programs.