886 resultados para the process of becoming an entrepreneur


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The impact of health promotion programs is related to both program effectiveness and the extent to which the program is implemented among the target population. The purpose of this dissertation was to describe the development and evaluation of a school-based program diffusion intervention designed to increase the rate of dissemination and adoption of the Child and Adolescent Trial for Cardiovascular Health, or CATCH program (recently renamed the Coordinated Approach to Child Health). ^ The first study described the process by which schools across the state of Texas spontaneously began to adopt the CATCH program after it was tested and proven effective in a multi-site randomized efficacy trial. A survey of teachers and administrator representatives of all schools on record that purchased the CATCH program, but were not involved in the efficacy trial, was used to find out who brought CATCH into the schools, how they garnered support for its adoption, why they decided to adopt the program, and what was involved in deciding to adopt. ^ The second study described how the Intervention Mapping framework guided the planning, development and implementation of a program for the diffusion of CATCH. An iterative process was used to integrate theory, literature, the experience of project staff and data from the target population into a meaningful set of program determinants and performance objectives. Proximal program objectives were specified and translated into both media and interpersonal communication strategies for program diffusion. ^ The third study assessed the effectiveness of the diffusion program in a case-comparison design. Three of the twenty Education Service Center regions in Texas were chosen, selected based on similar demographic criteria, and were followed for adoption of the CATCH curriculum. One of these regions received the full media and interpersonal channel intervention; a second received a reduced media-only intervention, and a third received no intervention. Results suggested the use of the interpersonal channels with media follow-up is an effective means to facilitate program dissemination and adoption. The media-alone condition was not effective in facilitating program adoption. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The importance of IGF-1/IGF-1R signaling is evident in human cancers including breast, colon, prostate, and lung which have been shown to overexpress IGF-1. Also, serum levels of IGF-1 have been identified as a risk factor for these cancers. IGF-1 has been primarily shown to mediate its mitogenic effects through signaling pathways such as MAPK and PI3K/Akt. In this regard, BK5.IGF-1 transgenic mice were generated and these mice displayed hyperplasia and hyperkeratosis in the epidermis. In addition, these mice were also found to have elevated MAPK, PI3K, and Akt activities. Furthermore, overexpression of IGF-1 in epidermis can act as a tumor promoter. BK5.IGF-1 transgenic mice developed papillomas after initiation with DMBA without further treatment with a tumor promoter such as TPA. Previous data has also shown that inhibition of the PI3K/Akt signaling pathway by the inhibitor LY294002 was able to reduce the number of tumors formed by IGF-1 mediated tumor promotion. The current studies presented demonstrate that Akt may be the critical effector molecule in IGF-1/IGF-1R mediated tumor promotion. We have found that inhibition of PI3K/Akt by LY294002 inhibits cell cycle components, particularly those associated with G1 to S phase transition including Cyclin D1, Cyclin E, E2F1, and E2F4, that are elevated in epidermis of BK5.IGF-1 transgenic mice. We have also demonstrated that Akt activation may be a central theme in early tumor promotion. In this regard, treatment with diverse tumor promoters such as TPA, okadaic acid, chrysarobin, and UVB was shown to activate epidermal Akt and its downstream signaling pathways after a single treatment. Furthermore, overexpression of Akt targeted to the basal cells of the epidermis led to hyperplasia and increased labeling index as determined by BrdU staining. These mice also had constitutively elevated levels of cell cycle components, particularly Cyclin D1, Cyclin E, E2F1, E2F4, and Mdm-2. These mice developed skin tumors following initiation with DMBA and were hypersensitive to the tumor promoting effects of TPA. Collectively, these studies provide evidence that Akt activation plays an important role in the process of mouse skin tumor promotion. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

An in-depth treatise on the process of film editing, featuring 16 original interviews from renowned editors. These editors share insight and anecdotes about the daily joys and difficulties of their careers (and the professional principles they subscribe to), as well as the creative, interpersonal, and technical challenges they constantly face. Discussion of the “MTV influence” behind modern film editing is offered, and this influence is explored in filmmaking history. Advice and inspiration is also shared for the benefit of future film editors; Hollywood editors tell their own stories about how they thrived in a notoriously-difficult field, and what it would take for an aspiring editor to do the same.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The protein p53 binding protein one (53BP1) was discovered in a yeast two-hybrid screen that used the DNA binding domain of p53 as bait. Cloning of full-length 53BP1 showed that this protein contains several protein domains which help make up the protein, which include two tandem BRCT domains and a amino-terminal serine/glutamine cluster domain (SCD). These are two protein domains are often seen in factors that are involved in the cellular response to DNA damage and control of cell cycle checkpoints and we hypothesize that 53BP1 is involved in the cellular response to DNA damage. In support of this hypothesis we observe that 53BP1 is phosphorylated and undergoes a dramatic nuclear re-localization in response to DNA damaging agents. 53BP1 also interacts with several factors that are important in the cellular response to DNA damage, such as the BRCA1 tumor suppressor, ATM and Rad3 related (ATR), and the phosphorylated version of the histone variant H2AX. Mice deficient in 53BP1 display increased sensitivity ionizing radiation (IR), a DNA damaging agent that introduces DNA double strand breaks (DSBs). In addition, 53BP1-deficient mice do not properly undergo the process of class switch recombination (CSR). We also observe that when a defect in 53BP1 is combined with a defect in p53; the resulting mice have an increased rate of formation of spontaneous tumors, notably the formation of B and T lineage lymphomas. The T lineage tumors arise by two distinct mechanisms: one driven by defects in cell cycle regulation and a second driven by defects in the ability to repair DNA DSBs. The B lineage tumors arise by the inability to repair DNA damage and over-expression of the oncogene c-myc. ^ With these observations, we conclude that not only does 53BP1 function in the cellular response to DNA damage, but it also works in concert with p53 to suppress tumor formation. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Purpose. Understanding siblings' experiences after a major childhood burn injury was the purpose of this mixed method, qualitative dominant study. The following research questions guided this project: How do siblings describe the impact of a major childhood burn injury experience? How do sibling relationship factors of warmth/closeness, relative status/power, conflict, and rivalry further clarify their relationship and their experience after a major burn injury? ^ Methods. A mixed method, qualitative dominant, design was implemented to understand the sibling experiences in a family with a child suffering from a major burn injury. Informants were selected from patients with childhood burn injuries attending the reconstructive clinic at a Gulf coast children's specialty hospital. The qualitative portion used the life story method, a narrative process, to portray the long-term impact on sibling relationships. A "case" represents a family unit and could be composed of one or multiple family members. Participants from 22 cases (N = 40 participants) were interviewed. Interviews were conducted in person and via telephone. The quantitative portion, or the embedded part of this mixed method design, used the Sibling Relationship Questionnaire Revised (SRQ-R) to conduct an additional structured interview and acquire scoring data. It was postulated that the SRQ-R would provide another perspective on the sibling experience and expand the qualitative data analysis. Thematic analysis was implemented on the qualitative interview data including the qualitative data from the interviews structured on the SRQ-R. Additionally, scores on the SRQ-R were tabulated to further describe the cases. ^ Results. The overall thematic pattern for the sibling relationship in families having a child with a major burn injury was that of normalization. Areas of normalization as well as the process of adjustment were the major themes. Areas of normalization were found in play and other activities, in school and work, and in family relations with their siblings and their parents. The process of adjustment in the sibling relationship was described as varied, involved school and work re-entry, and might even change their life perspective. Further analysis included an examination of the cases in which more than one person were interviewed and completed the SRQ-R. Participants from five ( n = 11) of six cases (n = 14), scored above 3.0 on the five-point scale on the Warmth/Closeness construct, indicating they perceived the sibling relationship as close. Five participants scored high on the Conflict construct and four participants scored high on the Rivalry construct. Finally, Relative Status/Power was low or negative in the six cases (n = 13). ^ Conclusions/implications. These findings suggest the importance of returning to normalcy for many of the families and the significance of sibling relationships on the process. Some of these families were able to use this major life event in a positive way to promote normalization. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Candida albicans is the most common opportunistic fungal pathogen of humans. The balance between commensal and pathogenic C. albicans is maintained largely by phagocytes of the innate immune system. Analysis of transcriptional changes after macrophage phagocytosis indicates the C. albicans response is broadly similar to starvation, including up-regulation of alternate carbon metabolism. Systems known and suspected to be part of acetate/acetyl-CoA metabolism were also up-regulated, importantly the ACH and ACS genes, which manage acetate/acetyl-CoA interconversion, and the nine-member ATO gene family, thought to participate in transmembrane acetate transport and also linked to the process of environmental alkalinization. ^ Studies into the roles of Ach, Acs1 and Acs2 function in alternate carbon metabolism revealed a substantial role for Acs2 and lesser, but distinct roles, for Ach and Acs1. Deletion mutants were made in C. albicans and were phenotypically evaluated both in vitro and in vivo. Loss of Ach function resulted in mild growth defects on ethanol and acetate and no significant attenuation in virulence in a disseminated mouse model of infection. While loss of Acs1 did not produce any significant phenotypes, loss of Acs2 greatly impaired growth on multiple carbon sources, including glucose, ethanol and acetate. We also concluded that ACS1 and ACS2 likely comprise an essential gene pair. Expression analyses indicated that ACS2 is the predominant form under most growth conditions. ^ ATO gene function had been linked to the process of environmental alkalinization, an ammonium-mediated phenomenon described here first in C. albicans. During growth in glucose-poor, amino acid-rich conditions C. albicans can rapidly change its extracellular pH. This process was glucose-repressible and was accompanied by hyphal formation and changes in colony morphology. We showed that introduction of the ATO1G53D point mutant to C. albicans blocked alkalinization, as did over-expression of C. albicans ATO2, the only C. albicans ATO gene to lack the conserved N-terminal domain. A screen for alkalinization-deficient mutants revealed that ACH1 is essential for alkalinization. However, addition of acetate to the media restored alkalinization to the ach1 mutant. We proposed a model of ATO function in which Atos regulated the cellular co-export of ammonium and acetate. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The prevalence of obesity has continued to rise over the last several decades in the United States lending to overall increases in risk for chronic diseases including many types of cancer. In contrast, reduction in energy consumption via calorie restriction (CR) has been shown to be a potent inhibitor of carcinogenesis across a broad range of species and tumor types. Previous data has demonstrated differential signaling through Akt and mTOR via the IGF-1R and other growth factor receptors across the diet-induced obesity (DIO)/CR spectrum. Furthermore, mTORC1 is known to be regulated directly via nutrient availability, supporting its role in the link between epithelial carcinogenesis and diet-induced obesity. In an effort to better understand the importance of mTORC1 in the context of both positive and negative energy balance during epithelial carcinogenesis, we have employed the use of specific pharmacological inhibitors, rapamycin (mTORC1 inhibitor) and metformin (AMPK activator) to target mTORC1 or various components of this pathway during skin tumor promotion. Two-stage skin carcinogenesis studies demonstrated that mTORC1 inhibition via rapamycin, metformin or combination treatments greatly inhibited skin tumor development in normal, overweight and obese mice. Furthermore, mechanisms by which these chemopreventive agents may be exerting their anti-tumor effects were explored. In addition, the effect of these compounds on the epidermal proliferative response was analyzed and drastic decreases in epidermal hyperproliferation and hyperplasia were found. Rapamycin also inhibited dermal inflammatory cell infiltration in a dose-dependent manner. Both compounds also blocked or attenuated TPA-induced signaling through epidermal mTORC1 as well as several downstream targets. In addition, inhibition of this pathway by metformin appeared to be, at least in part, dependent on AMPK activation in the skin. Overall, the data indicate that pharmacological strategies targeting this pathway offset the tumor-enhancing effects of DIO and may serve as possible CR mimetics. They suggest that mTORC1 contributes significantly to the process of skin tumor promotion, specifically during dietary energy balance effects. Exploiting the mechanistic information underlying dietary energy balance responsive pathways will help translate decades of research into effective strategies for prevention of epithelial carcinogenesis.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Akt (also known as protein kinase B) serves a central regulator in PI3K/Akt signaling pathways to regulate numerous physiological functions including cell proliferation, survival and metabolism. Akt activation requires the binding of Akt to phospholipid PIP3 on the plasma membrane and subsequent phosphorylation of Akt by its kinases. Growth factor-mediated membrane recruitment of Akt is a crucial step for Akt activation. However, the mechanism of Akt membrane translocation is unclear. Protein ubiquitination is a significant posttranslational modification that controls many biological functions such as protein trafficking and signaling activation. Therefore, we hypothesize that ubiquitination may be involved in Akt signaling activation. We have demonstrated that Akt could be conjugated with non-proteolytic K63-linked ubiquitination by TRAF6 ubiquitin E3 ligase. This modification on Akt was required for membrane recruitment, phosphorylation and activation of Akt in response to growth factor stimulation. The human cancer-associated Akt E17K mutant exhibited an increase in K63-linked ubiquitination, which contributes to the enrichment of membrane recruitment and phosphorylation of Akt. Thus, we conclude that K63-linked ubiquitination is a critical step for oncogenic Akt activation and also involved in human cancer development. Notably, the process of protein ubiquitination can be reversed by deubiquitinating enzymes (DUBs), which play a critical role to terminate signaling activation induced by ubiquitination. To further investigate how ubiquitination cycles regulate Akt activation, we have identified that CYLD as a DUB for Akt, and CYLD inhibited growth factor-induced ubiquitination and activation of Akt. Under serum-depletion condition, CYLD interacts with Akt and keep Akt under inactive state by directly removing K63-linked ubiquitination of Akt. CYLD disassociates with Akt upon growth factor stimulation, thereby allowing E3 ligases to induce ubiquitination and activation of Akt. We also demonstrated that CYLD deficiency promoted cancer cell proliferation, survival, glucose metabolism and human prostate cancer development. Therefore, we conclude that CYLD plays a critical role for negatively regulating Akt signaling activation through deubiquitination of Akt. In summary, this study delineated the important mechanism of cycles of ubiquitination and deubiquitination of Akt in regulating membrane translocation and activation of Akt, and TRAF6 and CYLD as central switches for these processes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Like other simple retroviruses the murine sarcoma virus ts110 (MuSVts110) displays an inefficient mode of genome splicing. But, unlike the splicing phenotypic of other retroviruses, the splicing event effected upon the transcript of MuSVts110 is temperature sensitive. Previous work in this laboratory has established that the conditionally defective nature of MuSVts110 RNA splicing is mediated in cis by features in the viral transcript. Here we show that the 5$\sp\prime$ splice site of the MuSVts110 transcript acts as a point of control of the overall splicing efficiency at both permissive and nonpermissive temperatures for splicing. We strengthened and simultaneously weakened the nucleotide structure of the 5$\sp\prime$ splice site in an attempt to elucidate the differential effects each of the two known critical splicing components which interact with the 5$\sp\prime$ splice site have on the overall efficiency of intron excision. We found that a transversion of the sixth nucleotide, resulting in the formation of a near-consensus 5$\sp\prime$ splice site, dramatically increased the overall efficiency of MuSVts110 RNA splicing and abrogated the thermosensitive nature of this splicing event. Various secondary mutations within this original transversion mutant, designed to selectively decrease specific splicing component interactions, lead to recovery of inefficient and thermosensitive splicing. We have further shown that a sequence of 415 nucleotides lying in the downstream exon of the viral RNA and hypothesized to act as an element in the temperature-dependent inhibition of splicing displays a functional redundancy throughout its length; loss and/or replacement of any one sequence of 100 nucleotides within this sequence does not, with one exception detailed below, diminish the degree to which MuSVts110 RNA is inhibited to splice at the restrictive temperature. One specific deletion, though, fortuitously juxtaposed and activated cryptic consensus splicing signals for the excision of a cryptic intron within the downstream exon and markedly potentiated--across a newly defined cryptic exon--the splicing event effected upon the upstream, native intron. We have exploited this mutant of MuSVts110 to further an understanding of the process of exon definition and intron definition and show that the polypyrimidine tract and consensus 3$\sp\prime$ splice site, as well as the 5$\sp\prime$ splice site, within the intron at the 3$\sp\prime$ flank of the defined exon are required for the exon's definition; implying that definition of the downstream intron is required for the in vivo definition of the proximal, upstream exon. Finally; we have shown, through the construction of heterologous mutants of MuSVts110 employing a foreign 3$\sp\prime$ end-forming sequence, that efficiency of transcript splicing can be increased--to a degree which abrogates its thermosensitive nature--in direct proportion to increasing proximity of the 3$\sp\prime$ end-forming signal to the terminal 3$\sp\prime$ splice site. ^

Relevância:

100.00% 100.00%

Publicador:

Resumo:

El turismo rural ha sido incorporado por pequeños establecimientos agropecuarios del partido de Cnel. Suárez, provincia de Buenos Aires, Argentina, como actividad alternativa para mejorar la calidad de vida de sus miembros y superar situaciones de crisis agravadas por la marginalidad productiva del SO bonaerense, región a la que pertenecen. Bajo el programa Cambio Rural del INTA (Instituto Nacional de Tecnología Agropecuaria) conforman el Grupo 'Cortaderas II', junto a otros emprendedores interesados en valorar el medio rural. Han avanzado en el proceso de reconocimiento de su identidad y puesta en valor de recursos específicos con anclaje en el territorio. Esta identidad comienza a apreciarse internamente, a raíz de la dinámica grupal lograda y la incipiente articulación con otros actores para la construcción de un partenariado público y privado que genere sinergias y contribuya al desarrollo sustentable del territorio. Sin embargo, aún no es claramente percibida por el turista, cada vez más exigente. Por lo tanto, el presente trabajo persigue proponer indicadores para evaluar el desempeño de un Sistema de Gestión de Calidad con enfoque territorial que, adaptando el modelo europeo 'Marca de Calidad Territorial', sustente una estrategia comercial de diferenciación del servicio y simultáneamente, mida el progreso hacia una mejor calidad de vida y fortalecimiento de vínculos con la cultura local y el entorno físico-natural en el marco del desarrollo sustentable. La investigación se plantea para la micro escala, ya que se trata de un estudio de caso, relevándose información primaria mediante observación directa y entrevistas semi-estructuradas, complementada con información secundaria diagnóstica utilizada por INTA. Las características del grupo y su dinámica de funcionamiento bajo el programa Cambio Rural revelan que es posible adoptar un proceso de certificación participativa propuesto para cuatro pilares de la calidad: de Bienes y Servicios, Institucional, Social y Ambiental. El modelo se integra con indicadores de evaluación de desempeño, agrupados en áreas clave para cada una de las dimensiones de la sustentabilidad, que contemplan el paisaje y la gestión de los recursos naturales; el impacto económico de la actividad, la calidad de la oferta y satisfacción del turista; así como las relaciones sociales internas y los vínculos con otros actores del territorio. Principalmente se encontraron fortalezas en la búsqueda de partenariados y debilidades en aspectos de comunicación y promoción. Se considera que este sistema de herramientas de gestión sustentable permitiría superar las dificultades de una certificación individual, pudiendo aplicarse a emprendimientos con otra ubicación geográfica

Relevância:

100.00% 100.00%

Publicador:

Resumo:

El turismo rural ha sido incorporado por pequeños establecimientos agropecuarios del partido de Cnel. Suárez, provincia de Buenos Aires, Argentina, como actividad alternativa para mejorar la calidad de vida de sus miembros y superar situaciones de crisis agravadas por la marginalidad productiva del SO bonaerense, región a la que pertenecen. Bajo el programa Cambio Rural del INTA (Instituto Nacional de Tecnología Agropecuaria) conforman el Grupo 'Cortaderas II', junto a otros emprendedores interesados en valorar el medio rural. Han avanzado en el proceso de reconocimiento de su identidad y puesta en valor de recursos específicos con anclaje en el territorio. Esta identidad comienza a apreciarse internamente, a raíz de la dinámica grupal lograda y la incipiente articulación con otros actores para la construcción de un partenariado público y privado que genere sinergias y contribuya al desarrollo sustentable del territorio. Sin embargo, aún no es claramente percibida por el turista, cada vez más exigente. Por lo tanto, el presente trabajo persigue proponer indicadores para evaluar el desempeño de un Sistema de Gestión de Calidad con enfoque territorial que, adaptando el modelo europeo 'Marca de Calidad Territorial', sustente una estrategia comercial de diferenciación del servicio y simultáneamente, mida el progreso hacia una mejor calidad de vida y fortalecimiento de vínculos con la cultura local y el entorno físico-natural en el marco del desarrollo sustentable. La investigación se plantea para la micro escala, ya que se trata de un estudio de caso, relevándose información primaria mediante observación directa y entrevistas semi-estructuradas, complementada con información secundaria diagnóstica utilizada por INTA. Las características del grupo y su dinámica de funcionamiento bajo el programa Cambio Rural revelan que es posible adoptar un proceso de certificación participativa propuesto para cuatro pilares de la calidad: de Bienes y Servicios, Institucional, Social y Ambiental. El modelo se integra con indicadores de evaluación de desempeño, agrupados en áreas clave para cada una de las dimensiones de la sustentabilidad, que contemplan el paisaje y la gestión de los recursos naturales; el impacto económico de la actividad, la calidad de la oferta y satisfacción del turista; así como las relaciones sociales internas y los vínculos con otros actores del territorio. Principalmente se encontraron fortalezas en la búsqueda de partenariados y debilidades en aspectos de comunicación y promoción. Se considera que este sistema de herramientas de gestión sustentable permitiría superar las dificultades de una certificación individual, pudiendo aplicarse a emprendimientos con otra ubicación geográfica

Relevância:

100.00% 100.00%

Publicador:

Resumo:

El turismo rural ha sido incorporado por pequeños establecimientos agropecuarios del partido de Cnel. Suárez, provincia de Buenos Aires, Argentina, como actividad alternativa para mejorar la calidad de vida de sus miembros y superar situaciones de crisis agravadas por la marginalidad productiva del SO bonaerense, región a la que pertenecen. Bajo el programa Cambio Rural del INTA (Instituto Nacional de Tecnología Agropecuaria) conforman el Grupo 'Cortaderas II', junto a otros emprendedores interesados en valorar el medio rural. Han avanzado en el proceso de reconocimiento de su identidad y puesta en valor de recursos específicos con anclaje en el territorio. Esta identidad comienza a apreciarse internamente, a raíz de la dinámica grupal lograda y la incipiente articulación con otros actores para la construcción de un partenariado público y privado que genere sinergias y contribuya al desarrollo sustentable del territorio. Sin embargo, aún no es claramente percibida por el turista, cada vez más exigente. Por lo tanto, el presente trabajo persigue proponer indicadores para evaluar el desempeño de un Sistema de Gestión de Calidad con enfoque territorial que, adaptando el modelo europeo 'Marca de Calidad Territorial', sustente una estrategia comercial de diferenciación del servicio y simultáneamente, mida el progreso hacia una mejor calidad de vida y fortalecimiento de vínculos con la cultura local y el entorno físico-natural en el marco del desarrollo sustentable. La investigación se plantea para la micro escala, ya que se trata de un estudio de caso, relevándose información primaria mediante observación directa y entrevistas semi-estructuradas, complementada con información secundaria diagnóstica utilizada por INTA. Las características del grupo y su dinámica de funcionamiento bajo el programa Cambio Rural revelan que es posible adoptar un proceso de certificación participativa propuesto para cuatro pilares de la calidad: de Bienes y Servicios, Institucional, Social y Ambiental. El modelo se integra con indicadores de evaluación de desempeño, agrupados en áreas clave para cada una de las dimensiones de la sustentabilidad, que contemplan el paisaje y la gestión de los recursos naturales; el impacto económico de la actividad, la calidad de la oferta y satisfacción del turista; así como las relaciones sociales internas y los vínculos con otros actores del territorio. Principalmente se encontraron fortalezas en la búsqueda de partenariados y debilidades en aspectos de comunicación y promoción. Se considera que este sistema de herramientas de gestión sustentable permitiría superar las dificultades de una certificación individual, pudiendo aplicarse a emprendimientos con otra ubicación geográfica

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Although there are numerous examples of large-scale commercial microbial synthesis routes for organic bioproducts, few studies have addressed the obvious potential for microbial systems to produce inorganic functional biomaterials at scale. Here we address this by focusing on the production of nano-scale biomagnetite particles by the Fe(III)-reducing bacterium Geobacter sulfurreducens, which was scaled-up successfully from lab-scale to pilot plant-scale production, whilst maintaining the surface reactivity and magnetic properties which make this material well suited to commercial exploitation. At the largest scale tested, the bacterium was grown in a 50 L bioreactor, harvested and then inoculated into a buffer solution containing Fe(III)-oxyhydroxide and an electron donor and mediator, which promoted the formation of magnetite in under 24 hours. This procedure was capable of producing up to 120 g biomagnetite. The particle size distribution was maintained between 10 and 15 nm during scale-up of this second step from 10 ml to 10 L, with conserved magnetic properties and surface reactivity; the latter demonstrated by the reduction of Cr(VI). The process presented provides an environmentally benign route to magnetite production and serves as an alternative to harsher synthetic techniques, with the clear potential to be used to produce kg to tonne quantities.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The United States imposed trade sanctions against the military regime in Myanmar in July 2003. The import ban damaged the garment industry in particular. This industry exported nearly half of its products to the United States, and more than eighty percent of United States imports from Myanmar had been clothes. The garment industry was probably the main target of the sanctions. Nevertheless, the impact on the garment industry and its workers has not been accurately evaluated or closely examined. The purpose of this paper is to evaluate the impact of the sanctions and to further understand the present situation. This is done using several sources of information, including the author's field and questionnaire surveys. This paper also describes the process of selection and polarization underway in the garment industry, an industry that now has more severe competition fueled by the sanctions. Through such a process, the impact was inflicted disproportionately on small and medium-sized domestic firms and their workers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Green innovation, which enables us to extract energy from food crops, caused a food shortage in 2008. Countries suffering severe damage started to reconsider their agricultural policy with the aim of becoming more autonomous. The food price hike of the time looks like a reversal of the celebrated Singer-Prebisch thesis proposed in the 1950s. This paper examines the consequences of this trend on the comparative advantages and development strategies of developing countries. For that purpose, first, trends and short-run fluctuations in the prices of fuel and bio-energy crops are investigated. It is shown that the price series of fuels and the crops are synchronized only after the fuel extracting technology came into effect. Second, the reversal of the Singer-Prebisch thesis is underpinned by the generic form of an endogenous growth model developed by Rebelo (1991). It is shown that as an economy grows, appreciation of the non-reproducible, such as mineral resources and raw labor, over the reproducible, such as capital goods, is the norm rather than an anomaly. Third, the consequences of the food price hike and underlying capital accumulation on the development strategies of labor-abundant and low-income countries are explored. It is concluded that the impact of the food price hikes on the alteration of a development strategy is only incremental, without reinforcement from raw-labor-saving innovation. A case study of inventions by JUKI Corporation, a world-leader in the sewing machine market exemplifies the fact that, of all the major inventions the company have made, raw-labor-saving inventions have not dominated, although JUKI's machines are sold to one of the most raw-labor-intensive industries.