900 resultados para Stadium of development
Resumo:
Programmed cell death in the form of apoptosis involves a network of metabolic events and may be triggered by a variety of stimuli in distinct cells. The nervous system contains several neuron and glial cell types, and developmental events are strongly dependent on selective cell interactions. Retinal explants have been used as a model to investigate apoptosis in nervous tissue. This preparation maintains the structural complexity and cell interactions similar to the retina in situ, and contains cells in all stages of development. We review the finding of nuclear exclusion of several transcription factors during apoptosis in retinal cells. The data reviewed in this paper suggest a link between apoptosis and a failure in the nucleo-cytoplasmic partition of transcription factors. It is argued that the nuclear exclusion of transcription factors may be an integral component of apoptosis both in the nervous system and in other types of cells and tissues.
Resumo:
Most adult tissues retain a reservoir of self-renewing, multipotent stem cells that can generate differentiated tissue components. Until recently, the brain was thought to be an exception to this rule and for many years the pervasive dogma of neurobiology relegated neurogenesis to the embryonic and earlier postnatal stages of development. The discovery of constant neuronal replacement in the adult brain has changed the way we think about neurological diseases and about the exploration of new strategies for brain repair. In this review we will explore the potential of adult neural stem cells and we will present some of our own work on this subject. We will also discuss the possibility that adult neurogenesis and neuronal replacement may also play a role in therapies aimed at restoring impaired brain function. A better understanding of the various aspects of spontaneous neuronal replacement may also be used to increase the success of procedures with cell therapies.
Resumo:
There is currently little empirical knowledge regarding the construction of a musician’s identity and social class. With a theoretical framework based on Bourdieu’s (1984) distinction theory, Bronfenbrenner’s (1979) theory of ecological systems, and the identity theories of Erikson (1950; 1968) and Marcia (1966), a survey called the Musician’s Social Background and Identity Questionnaire (MSBIQ) is developed to test three research hypotheses related to the construction of a musician’s identity, social class and ecological systems of development. The MSBIQ is administered to the music students at Sibelius Academy of the University of Arts Helsinki and Helsinki Metropolia University of Applied Sciences, representing the ’highbrow’ and the ’middlebrow’ samples in the field of music education in Finland. Acquired responses (N = 253) are analyzed and compared with quantitative methods including Pearson’s chi-square test, factor analysis and an adjusted analysis of variance (ANOVA). The study revealed that (1) the music students at Sibelius Academy and Metropolia construct their subjective musician’s identity differently, but (2) social class does not affect this identity construction process significantly. In turn, (3) the ecological systems of development, especially the individual’s residential location, do significantly affect the construction of a musician’s identity, as well as the age at which one starts to play one’s first musical instrument. Furthermore, a novel finding related to the structure of a musician’s identity was the tripartite model of musical identity consisting of the three dimensions of a musician’s identity: (I) ’the subjective dimension of a musician’s identity’, (II) ’the occupational dimension of a musician’s identity’ and, (III) ’the conservative-liberal dimension of a musician’s identity’. According to this finding, a musician’s identity is not a uniform, coherent entity, but a structure consisting of different elements continuously working in parallel within different dimensions. The results and limitations related to the study are discussed, as well as the objectives related to future studies using the MSBIQ to research the identity construction and social backgrounds of a musician or other performing artists.
Resumo:
The regulatory function of α1B-adrenoceptors in mammalian heart homeostasis is controversial. The objective of the present study was to characterize the expression/activity of key proteins implicated in cardiac calcium handling (Na+/K+-ATPase and Ca2+-ATPases) and growth (ERK1/2, JNK1/2 and p38) in mice with cardiac-selective overexpression of constitutively active mutant α1B-adrenoceptor (CAMα1B-AR), which present a mild cardiac hypertrophy phenotype. Immunoblot assays showed that myocardial plasma membrane Ca2+-ATPase (PMCA) expression was increased by 30% in CAMα1B-AR mice (N = 6, P < 0.05), although there was no change in sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2) expression. Moreover, total Ca2+-ATPase activity was not modified, but a significant increase in the activity of the thapsigargin-resistant (PMCA) to thapsigargin-sensitive (SERCA) ratio was detected. Neither Na+/K+-ATPase activity nor the expression of α1 and α2 subunit isoforms was changed in CAMα1B-AR mouse hearts. Moreover, immunoblot assays did not provide evidence for an enhanced activation of the three mitogen-activated protein kinases studied in this stage of hypertrophy. Therefore, these findings indicate that chronic cardiac α1B-AR activation in vivo led to mild hypertrophy devoid of significant signs of adaptive modifications concerning primary intracellular calcium control and growth-related proteins, suggesting a minor pathophysiological role of this adrenergic receptor in mouse heart at this stage of development.
Resumo:
Personalized pharmacogenomics aims to use individual genotypes to direct medical treatment. Unfortunately, the loci relevant for the pharmacokinetics and especially the pharmacodynamics of most drugs are still unknown. Moreover, we still do not understand the role that individual genotypes play in modulating the pathogenesis, the clinical course and the susceptibility to drugs of human diseases which, although appearing homogeneous on the surface, may vary from patient to patient. To try to deal with this situation, it has been proposed to use interpopulational variability as a reference for drug development and prescription, leading to the development of "race-targeted drugs". Given the present limitations of genomic knowledge and of the tools needed to fully implement it today, some investigators have proposed to use racial criteria as a palliative measure until personalized pharmacogenomics is fully developed. This was the rationale for the FDA approval of BiDil for treatment of heart failure in African Americans. I will evaluate the efficacy and safety of racial pharmacogenomics here and conclude that it fails on both counts. Next I shall review the perspectives and the predicted rate of development of clinical genomic studies. The conclusion is that "next-generation" genomic sequencing is advancing at a tremendous rate and that true personalized pharmacogenomics, based on individual genotyping, should soon become a clinical reality.
Resumo:
Meconium aspiration syndrome causes respiratory failure after birth and in vivo monitoring of pulmonary edema is difficult. The objective of the present study was to assess hemodynamic changes and edema measured by transcardiopulmonary thermodilution in low weight newborn piglets. Additionally, the effect of early administration of sildenafil (2 mg/kg vo, 30 min after meconium aspiration) on this critical parameter was determined in the meconium aspiration syndrome model. Thirty-eight mechanically ventilated anesthetized male piglets (Sus scrofa domestica) aged 12 to 72 h (1660 ± 192 g) received diluted fresh human meconium in the airway in order to evoke pulmonary hypertension (PHT). Extravascular lung water was measured in vivo with a PiCCO monitor and ex vivo by the gravimetric method, resulting in an overestimate of 3.5 ± 2.3 mL compared to the first measurement. A significant PHT of 15 Torr above basal pressure was observed, similar to that of severely affected humans, leading to an increase in ventilatory support. The vascular permeability index increased 57%, suggesting altered alveolocapillary membrane permeability. Histology revealed tissue vessel congestion and nonspecific chemical pneumonitis. A group of animals received sildenafil, which prevented the development of PHT and lung edema, as evaluated by in vivo monitoring. In summary, the transcardiopulmonary thermodilution method is a reliable tool for monitoring critical newborn changes, offering the opportunity to experimentally explore putative therapeutics in vivo. Sildenafil could be employed to prevent PHT and edema if used in the first stages of development of the disease.
Resumo:
It is well known that the risk of development of gastric cancer (GC) in Helicobacter pylori-infected patients depends on several factors. Thus, the aim of this study was to investigate the effect of proinflammatory cytokine gene polymorphisms for IL-1β, IL-1RN and TNF-α on the development of GC in a Brazilian population. A total of 202 biopsies obtained from Brazilian patients with chronic gastritis and GC were included in the study. Infection with H. pylori cagA+ was determined by the polymerase chain reaction (PCR) as previously described. IL-1β, IL-1RN and TNF-α polymorphism genotyping was performed by restriction fragment length polymorphism PCR. Associations between gene polymorphisms, clinical diseases and virulence markers were evaluated using either the χ² test or the Fisher exact test. Our results demonstrated that the IL-1β -511 C/C and IL-1β -511 C/T alleles were associated with chronic gastritis in H. pylori-positive patients (P = 0.04 and P = 0.05, respectively) and the IL-1β -511 C/C genotype was associated with GC (P = 0.03). The frequency of IL-1RN alleles from patients with chronic gastritis and GC indicated that there was no difference between the genotypes of the groups studied. Similar results were found for TNF-α -308 gene polymorphisms. Our results indicate that the IL-1β -511 C/C and C/T gene polymorphisms are associated with chronic gastritis and GC development in H. pylori-infected individuals.
Resumo:
Alfa Laval Aalborg Oy designs and manufactures waste heat recovery systems utilizing extended surfaces. The waste heat recovery boiler considered in this thesis is a water-tube boiler where exhaust gas is used as the convective heat transfer medium and water or steam flowing inside the tubes is subject to cross-flow. This thesis aims to contribute to the design of waste heat recovery boiler unit by developing a numerical model of the H-type finned tube bundle currently used by Alfa Laval Aalborg Oy to evaluate the gas-side heat transfer performance. The main objective is to identify weaknesses and potential areas of development in the current H-type finned tube design. In addition, numerical simulations for a total of 15 cases with varying geometric parameters are conducted to investigate the heat transfer and pressure drop performance dependent on H-type fin geometry. The investigated geometric parameters include fin width and height, fin spacing, and fin thickness. Comparison between single and double tube type configuration is also conducted. Based on the simulation results, the local heat transfer and flow behaviour of the H-type finned tube is presented including boundary layer development between the fins, the formation of recirculation zone behind the tubes, and the local variations of flow velocity and temperature within the tube bundle and on the fin surface. Moreover, an evaluation of the effects of various fin parameters on heat transfer and pressure drop performance of H-type finned tube bundle has been provided. It was concluded that from the studied parameters fin spacing and fin width had the most significant effect on tube bundle performance and the effect of fin thickness was the least important. Furthermore, the results suggested that the heat transfer performance would increase due to enhanced turbulence if the current double tube configuration is replaced with single tube configuration, but further investigation and experimental measurements are required in order to validate the results.
Resumo:
Beetroot leaves (Beta vulgaris L.) are commonly cut off and discarded before using its bulb due to lack of knowledge of how to use them. Aiming at using these leaves, in the present study, in natura and dehydrated beetroot leaves were chemically characterized in terms of fatty acid composition, proximate composition, minerals, total phenolic compounds (TPC), and antioxidant activity by DPPH in different stages (60, 80, and 100 days) of development. The beetroot leaves showed significant levels of protein and lipids in all developmental stages, and all proximate composition nutrients decreased during these maturation stages; the highest content was observed at 60 days. The Fe content decreased during the developmental stages (from 342.75 to 246.30 mg.kg-1), while the content of K increased (from 13,367.64 to 20,784.90 mg.kg-1). With regard to to fatty acid composition, linolenic acid was present in the greatest quantity, and it increase up to 2.58 mg.g-1 (in natura) and 40.11 mg.g-1 (dehydrated) at 100 days of development. The n-6/n-3 ratios were low in all stages. The TPC and antioxidant activity by DPPH changed during the developmental stages. The TPC was highest in the 100-day dehydrated leaves (15.27±0.12 mg GAE.g-1 FW), and the 50% inhibition of DPPH (IC50 89.52 µg.mL-1) were better in the 60-day in natura leaves. This study shows that all developmental stages produced satisfactory results, and therefore, these leaves can be reused as food. The antioxidant activity and the chemical constituents, mainly the ω-3fatty acid, increased during the stages of development.
Resumo:
Seeds of Magnolia ovata were dried to different water contents to assess the viability and transcript abundance of genes related to seed development, cell cycle, cytoskeleton and desiccation tolerance.The expression of development, cell cycle and cytoskeleton relative genes (ABI3, CDC2-like and ACT2) alone could not explain the germination behaviour of M. ovata seeds in relation to drying damage. Irrespective of their initial water content, the seeds performed in the same way during the initial period of germination and the deleterious effects of desiccation only occurred in later stages. Expression of PKABA1, sHSP17.5 and 2-Cys-PRX did not show a relationship with desiccation. However, the expression patterns of PKABA1 and sHSP17.5 suggested the participation of these genes in protective mechanisms during the imbibition of M. ovata seeds.
Resumo:
In Brazil, although the coffee plantations are predominantly grown under full sunlight, the use of agroforestry systems can lead to socioeconomic advantages, thus providing a favorable environment to the crop by promoting its sustainability as well as environmental preservation. However, there is a lack of information on physiological quality of the coffee seeds produced under different levels of solar radiation. Within this context, the objective of this study was to evaluate the influence of different levels of solar radiation and maturation stages on the physiological quality of coffee (Coffea arabica L.) seeds, cv. Acaiá Cerrado MG-1474. Three levels of solar radiation (plants grown under full sunlight; under plastic screens of 35% shading; and under plastic screens of 50% shading) and three maturation stages (cherry, greenish-yellow and green) were assessed. Physiological quality of seeds was assessed by using germination test, first count of germination, abnormal seedlings, dead seeds, and seedlings with open cotyledonary leaves. Electrophoretic analysis of isoenzymes catalase, esterase, superoxide dismutase and peroxidase was also performed. With the evolution of development the coffee seeds presents increases on physiological quality, and at its beginning the seeds show improvements on quality with the reduction of solar radiation.
Resumo:
This study examines a new kind of public reporting, called integrated reporting as a form of a firm’s interaction with stakeholders. The study concerned issues such as how the studied organization defined its stakeholders and how this definition evolved during the transition period from 2009 to 2013, how has the integrated reporting of the organization evolved as an instrument of interaction with stakeholders over the transition period, and how the organization reported its value creation according to the international integrated reporting framework in the final, full-featured report. In examining the theory, the study used a qualitative analysis method that allowed deriving conceptual tools necessary to carry out the study. This study is based on the material of the five integrated reports written in Russian from a subsidiary of a Russian public company. The subsidiary carried out the transition to an integrated reporting for the five years from 2009 to 2013. A comparative qualitative method was used in reviewing the empirical material. During the research, an active cooperation of the organization with key stakeholders was revealed, which occurred during the whole period of development of integrated reporting. As a result, integrated reports were produced in cooperation with various key stakeholders, allowing balancing the financial and non-financial information in the reports. The study found that during the transition period, integrated reports gradually changed in the direction of greater clarity and ease of access to perception, consistency of presentation and materiality. The integrated reporting of the organization began reflect the basic requirements of the international integrated reporting framework regarding the content elements and guiding principles. Thus, the organization’s reports began including features of financial and non-financial reporting and connecting the three aspects of the organization's activities: economic, environmental and social. This study reveals the importance of identifying key stakeholders and their influence on the creation of organizational value. The new form of reporting suits better the requirements of modern organizations to interact with their stakeholder groups. The integrated reporting, which reflects the principles of the international integrated reporting framework, is an active resource for companies to communicate with stakeholders and a platform of transmission the necessary information on the creation of value in the long term.
Resumo:
The global economic crisis has created an opportunity to rethink macroeconomics for development. Such rethinking is both necessary and desirable. It is essential to redefine macroeconomic objectives so that the emphasis is on fostering employment creation and supporting economic growth instead of the focus on price stability alone. It is just as important to rethink macroeconomic policies which cannot simply be used for the management of inflation and the elimination of macroeconomic imbalances, since fiscal and monetary policies are powerful and versatile instruments in the pursuit of development objectives. In doing so, it is essential to the overcome the constraints embedded in orthodox economic thinking and recognize the constraints implicit in the politics of ideology and interests.
Resumo:
This study discusses the importance of government intervention for companies and the expansion of national innovation systems. The purpose of the study is to examine the impact which the U.S. Embassy in Helsinki can have on Finnish businesses through their business support programs and events. The embassy has shifted focus in recent years with the creation of an innovation center and increased business services. The study has sub-objectives to discover the critical factors for producing impact, host and home based factor interaction, and effects produced by these initiatives. The theoretical background of the study consists of literature relating to the concepts of national innovation systems and government intervention. The empirical research conduct for this study is based on interviews with experts from the environment surrounding the U.S. Embassy in Helsinki, Finland and participation in embassy events. The data was collected between March 2014 and September 2015. Seven interviews were conducted; five with representatives of the U.S. Embassy and two with related organizations. Thematic analysis was used to categorize and interpret interview and observation data. The use of an impact radar was implemented as a basis for analysis. This study finds that the internationalization of national innovation systems provides interesting opportunities and challenges for national governments. The opportunity to provide services to foreign companies by an embassy in a stable environment opens the possibility to create positive notice and relations with the host country. The increased connections and inputs to the national innovation system of the home country have the potential to increase knowledge absorption and create positive growth. The most effective way for governments to encourage businesses is to create incentives and reduce barriers. The services are best aimed at small to medium sized companies in the early stages of development. The findings of this report suggest that the most critical factors for producing impact on companies are the ability to disseminate information effectively, the ability to create a positive image of the country, the ability to foster effective networks between the two countries, and the ability to facilitate the internationalization of companies. In the best cases, the embassy is able to create incentives to internationalize to the United States and reduce barriers which are encountered by companies. Future research is necessary to fully understand the impact of business services provided by an embassy can have on the political and economic relations of countries, and on particular industry sectors. The institutional setting provided by the embassy’s focus on business relations provides a rich environment for further study in a number of areas.
Resumo:
In this paper, I review recent developments in global political economy and political economy of development that have captured inter alia the attention of agrarian political economists. I do so through the periscope of two recent publications by Fred pearce, Great Britain's leading eco journalist and an edited volume by Tony Allann, Martin Keulertz, Suvi Sojamo and Jeroen Warner, scholars trained in different disciplines and based at various universities in the UK, the netherlands, and Finland. The account of the pace, places, and perpetrators, procedures, and problems of this particular agrarian model provides fodder for the further development of a locus classicus on what is happening to the land question in this current moment under the capitalist order, a shorthand for which is 'water and land grab'.