932 resultados para McAllister, L.W.
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Parasites and pathogens are ubiquitous and act as an important selection pressure on animals. Here, drawing primarily on our own research, mostly on insects, we illustrate how host-parasite interactions have played a role in the evolution of a range of phenomena, including animal coloration, social behavior, foraging ecology, sexual selection, and life-history tradeoffs, as well as how variation in host behavior and ecology can drive variation in parasitism risk and host allocation of resources to immunity and other antiparasite defenses. We conclude by identifying key areas for future study.
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The breast cancer susceptibility gene BRCA1 encodes a protein implicated in the cellular response to DNA damage, with postulated roles in homologous recombination as well as transcriptional regulation. To identify downstream target genes, we established cell lines with tightly regulated inducible expression of BRCA1. High-density oligonucleotide arrays were used to analyze gene expression profiles at various times following BRCA1 induction. A major BRCA1 target is the DNA damage-responsive gene GADD45. Induction of BRCA1 triggers apoptosis through activation of c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK), a signaling pathway potentially linked to GADD45 gene family members. The p53-independent induction of GADD45 by BRCA1 and its activation of JNK/SAPK suggest a pathway for BRCA1-induced apoptosis.
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Patterns of glycosylation are important in cancer, but the molecular mechanisms that drive changes are often poorly understood. The androgen receptor drives prostate cancer (PCa) development and progression to lethal metastatic castration-resistant disease. Here we used RNA-Seq coupled with bioinformatic analyses of androgen-receptor (AR) binding sites and clinical PCa expression array data to identify ST6GalNAc1 as a direct and rapidly activated target gene of the AR in PCa cells. ST6GalNAc1 encodes a sialytransferase that catalyses formation of the cancer-associated sialyl-Tn antigen (sTn), which we find is also induced by androgen exposure. Androgens induce expression of a novel splice variant of the ST6GalNAc1 protein in PCa cells. This splice variant encodes a shorter protein isoform that is still fully functional as a sialyltransferase and able to induce expression of the sTn-antigen. Surprisingly, given its high expression in tumours, stable expression of ST6GalNAc1 in PCa cells reduced formation of stable tumours in mice, reduced cell adhesion and induced a switch towards a more mesenchymal-like cell phenotype in vitro. ST6GalNAc1 has a dynamic expression pattern in clinical datasets, beingsignificantly up-regulated in primary prostate carcinoma but relatively down-regulated in established metastatic tissue. ST6GalNAc1 is frequently upregulated concurrently with another important glycosylation enzyme GCNT1 previously associated with prostate cancer progression and implicated in Sialyl Lewis X antigen synthesis. Together our data establishes an androgen-dependent mechanism for sTn antigen expression in PCa, and are consistent with a general role for the androgen receptor in driving important coordinate changes to the glycoproteome during PCa progression.
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Histone deacetylases (HDACs) are enzymes involved in transcriptional repression. We aimed to examine the significance of HDAC1 and HDAC2 gene expression in the prediction of recurrence and survival in 156 patients with hepatocellular carcinoma (HCC) among a South East Asian population who underwent curative surgical resection in Singapore. We found that HDAC1 and HDAC2 were upregulated in the majority of HCC tissues. The presence of HDAC1 in tumor tissues was correlated with poor tumor differentiation. Notably, HDAC1 expression in adjacent non-tumor hepatic tissues was correlated with the presence of satellite nodules and multiple lesions, suggesting that HDAC1 upregulation within the field of HCC may contribute to tumor spread. Using competing risk regression analysis, we found that increased cancer-specific mortality was significantly associated with HDAC2 expression. Mortality was also increased with high HDAC1 expression. In the liver cancer cell lines, HEP3B, HEPG2, PLC5, and a colorectal cancer cell line, HCT116, the combined knockdown of HDAC1 and HDAC2 increased cell death and reduced cell proliferation as well as colony formation. In contrast, knockdown of either HDAC1 or HDAC2 alone had minimal effects on cell death and proliferation. Taken together, our study suggests that both HDAC1 and HDAC2 exert pro-survival effects in HCC cells, and the combination of isoform-specific HDAC inhibitors against both HDACs may be effective in targeting HCC to reduce mortality.
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This chapter discusses that the theoretical studies, using both atomistic and phenomenological approaches, have made clear predictions about the existence and behaviour of ferroelectric (FE) vortices. Effective Hamiltonians can be implemented within both Monte Carlo (MC) and molecular dynamics (MD) simulations. In contrast to the effective Hamiltonian method, which is atomistic in nature, the phase field method employs a continuum approach, in which the polarization field is the order parameter. Properties of FE nanostructures are largely governed by the existence of a depolarization field, which is much stronger than the demagnetization field in magnetic nanosystems. The topological patterns seen in rare earth manganites are often referred to as vortices and yet this claim never seems to be explicitly justified. By inspection, the form of a vortex structure is such that there is a continuous rotation in the orientation of dipole vectors around the singularity at the centre of the vortex.
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Concert program for An Operatic Triptych August 18, 20, 1971
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Many rural-based farm and food businesses are relatively small but successful companies. They face severe constraints in terms of finance, marketing and distribution. However, marketing food by mail order presents the opportunity for these firms to gain access to national or even international markets. The achievement of commercial success requires that these companies become marketing oriented. Thus, the critical issue for these firms is to identify the needs of existing or potential customers. The objectives of the paper are to establish a profile of the characteristics, behaviour and attitudes of mail order customers.
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This study aims to examine the relationship between the personality attributes of Internet users and their leisure activities. A questionnaire survey was undertaken which revealed that most Internet users are single males aged between 21-30 belonging to the lower income groups, employed in information technology or related fields. The personality attributes of the sample showed a tendency towards a mixed locus control category. The survey indicated that the preferred leisure activities of this population group are reading, collecting and computer-based activities. However, ‘movement’ and collecting were the only leisure activities to show a significant correlation with the users’ personality attributes.
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Purpose: In recent years, there has been a big increase in the use of ethical attributes as marketing appeals. This paper examines consumers’ willingness to pay for three selected ethical attributes, namely ‘Organic’, ‘Recyclable Packaging’ and ‘Fairtrade’ in monetary terms. Design/Methodology/Approach: A modified choice-based experimental design with manipulation of the key constructs was used to estimate the mean value of how much consumers are willing to pay for the selected attributes attached to a box of premium chocolates. The results are based on the responses of a total of 208 consumers. Findings: Of the three attributes, ‘Recyclable Packaging’ has the strongest influence on the purchase decision, although this attribute generates the least additional value. The aggregated result shows that although consumers are willing to pay more for the product with ethical attributes than the one that is without, still around a half of them are not willing to pay more. In terms of demographics, the results show no significant differences between the two genders or different age groups in their willingness to pay for ethical attributes. As might be expected, willingness to pay was correlated with the level of consciousness of the ethical attributes. Originality/Value: The findings of this study help management to think practically about the value consumers willing to pay for the selected attributes. The results show a significant synergy in a combination of ethical attributes in products.
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Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder associated with premutation alleles of the fragile X mental retardation 1 (FMR1) gene. Approximately 40% of older male premutation carriers, and a smaller proportion of females, are affected by FXTAS; due to the lower penetrance the characterization of the disorder in females is much less detailed. Core clinical features of FXTAS include intention tremor, cerebellar gait ataxia and frequently parkinsonism, autonomic dysfunction and cognitive deficits progressing to dementia in up to 50% of males. In this study, we report the clinical, molecular and neuropathological findings of eight female premutation carriers. Significantly, four of these women had dementia; of the four, three had FXTAS plus dementia. Post-mortem examination showed the presence of intranuclear inclusions in all eight cases, which included one asymptomatic premutation carrier who died from cancer. Among the four subjects with dementia, three had sufficient number of cortical amyloid plaques and neurofibrillary tangles to make Alzheimer's disease a highly likely cause of dementia and a fourth case had dementia with cortical Lewy bodies. Dementia appears to be more common than originally reported in females with FXTAS. Although further studies are required, our observation suggests that in a portion of FXTAS cases there is Alzheimer pathology and perhaps a synergistic effect on the progression of the disease may occur.
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A solution adpoted in gvSIG for Coordinate Reference Systems (CRS) management is shown, like importing form several databases, to the new definition, as well as handing conversion and transformation operations between different CRSs, in particular for ED50 to ETRS89 transition
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El objetivo del presente trabajo es formular, mediante una profunda revisión documental, bibliográfica y empírica, una fundamentación teórica sobre si existe o no incidencia de las prácticas de recursos humanos sobre el bienestar laboral de los empleados, y el que grado en que esta se presenta sobre aspecto como el engagement y la satisfacción laboral. Se realizó la revisión de múltiples estudios empíricos que aportaran evidencia sobre la relación que se presenta entre las principales prácticas de recursos humanos – provisión de personal, formación y desarrollo, promoción de personal, evaluación de desempeño, compensación y pago, y balance trabajo-familia – y el bienestar laboral, representado en el engagement y satisfacción en el trabajo de los empleados. Los resultados de este trabajo indican la existencia de una relación e incidencia de las prácticas de recursos humanos, el bienestar laboral, el engagement y la satisfacción laboral. De igual forma se encontró que estas relaciones son principalmente de carácter positivo, lo cual indica que las organizaciones que desarrollan este tipo de prácticas en su interior, fomentan tanto el desarrollo y la presencia de bienestar laboral en sus empleados, como su perdurabilidad.
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La Federación Nacional de Cafeteros fue fundada en el año 1927 con el objetivo de elevar el nivel de vida de los caficultores y dar a conocer la calidad del café Colombiano en el mundo. Parte del trabajo de la federación ha sido el posicionamiento a nivel mundial del café Colombiano, para lo cual ha utilizado varias campañas publicitarias entre las cuales se destaca la creación en el año 1959 del icono Juan Valdez con su mula Conchita. Así mismo, en noviembre del año 2002 la Federación Nacional de Cafeteros creó la empresa Procafecol S.A. con el objetivo de generar negocios de valor agregado para los cafeteros y desarrollar las actividades empresariales bajo la marca Juan Valdez Café. En el año 2005 Procafecol S.A. inició el proceso de expansión internacional, para el año 2013 la compañía reportaba utilidades alrededor de los cuatro mil millones de pesos colombianos y excelentes cifras de expansión. Sin embargo, desde la apertura de la primera tienda Juan Valdez en el año 2002 la marca generaba pérdidas, que alcanzaron aproximadamente diecinueve mil millones de pesos colombianos en el año 2012. (Procafecol S.A., 2013) Teniendo en cuenta que es necesario tener herramientas que permitan generar estrategias desde la dirección y gerencia para asegurar la perdurabilidad en las empresas, adscrito al GIPE (Grupo de Investigación en Perdurabilidad Empresarial), se realizó este estudio de caso como parte de la línea de investigación de Realidad empresarial. Con el fin de analizar el caso de Procafecol S.A. y su marca Juan Valdez, e ilustrar el resurgimiento de la compañía después de 9 años de presentar pérdidas en el ejercicio financiero. (Escuela de administración Universidad del Rosario, 2013)
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San francisco es uno de las ciudades mas importantes a nivel mundial en temas de tecnología y comunicación digital . Alberca empresas de gran relevancia en estos campo tales como Goolge, Youtube , Jupiter entre otras. Esta misión empresarial fue de gran importancia para aprender de manera directa como estas organización perciben el mundo a través de la comunicación digital y la tecnología.