1,237 research outputs found

    Incremento de la productividad a través del Mapeo de Flujo de Valor (VSM) en una empresa metalmecánica

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    Actualmente las empresas manufactureras son objeto de cambios y transformaciones. Resultado de la competencia por mantener o mejorar su posición en el mercado, recurren a una variada gama de estrategias para aumentar su presencia y aumentar sus ventas, por ello es necesario dar un giro a la manera tradicional de operar de las empresas y optimizar los procesos productivos eliminando desperdicios que se generan en el mismo, los cuales afectan a los indicadores de producción, así como las ventajas que estos puedan tener. En el presente estudio se busca optimizar el proceso de elaboración de sillas de la empresa Fametal y eliminar desperdicios desde la perspectiva de la producción esbelta, que contemplan los conceptos de valor agregado en actividades y recursos. Para la determinación de los problemas del proceso y los desperdicios se ha hecho uso fundamental del VSM, el mismo que al ser aplicado muestra un análisis integral del proceso productivo,permitiendo proponer mejoras necesarias y un plan de acción para tal efecto

    Public profiles, private parties: Digital Ethnography, Ethics and Research in the context of Web 2.0

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    The Role of Mesotocin on Social Bonding in Pinyon Jays

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    The neuropeptide oxytocin influences mammalian social bonding by facilitating the building and maintenance of parental, sexual, and same‐sex social relationships. However, we do not know whether the function of the avian homologue mesotocin is evolutionarily conserved across birds. While it does influence avian prosocial behavior, mesotocin\u27s role in avian social bonding remains unclear. Here, we investigated whether mesotocin regulates the formation and maintenance of same‐sex social bonding in pinyon jays (Gymnorhinus cyanocephalus), a member of the crow family. We formed squads of four individually housed birds. In the first, “pair‐formation” phase of the experiment, we repeatedly placed pairs of birds from within the squad together in a cage for short periods of time. Prior to entering the cage, we intranasally administered one of three hormone solutions to both members of the pair: mesotocin, oxytocin antagonist, or saline. Pairs received repeated sessions with administration of the same hormone. In the second, “pair‐maintenance” phase of the experiment, all four members of the squad were placed together in a large cage, and no hormones were administered. For both phases, we measured the physical proximity between pairs as our proxy for social bonding. We found that, compared with saline, administering mesotocin or oxytocin antagonist did not result in different proximities in either the pair‐formation or pair‐maintenance phase of the experiment. Therefore, at the dosages and time frames used here, exogenously introduced mesotocin did not influence same‐sex social bond formation or maintenance. Like oxytocin in mammals, mesotocin regulates avian prosocial behavior; however, unlike oxytocin, we do not have evidence that mesotocin regulates social bonds in birds

    Cyclin D1 repressor domain mediates proliferation and survival in prostate cancer.

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    Regulation of the androgen receptor (AR) is critical to prostate cancer (PCa) development; therefore, AR is the first line therapeutic target for disseminated tumors. Cell cycle-dependent accumulation of cyclin D1 negatively modulates the transcriptional regulation of AR through discrete, CDK4-independent mechanisms. The transcriptional corepressor function of cyclin D1 resides within a defined motif termed repressor domain (RD), and it was hypothesized that this motif could be utilized as a platform to develop new strategies for blocking AR function. Here, we demonstrate that expression of the RD peptide is sufficient to disrupt AR transcriptional activation of multiple, prostate-specific AR target genes. Importantly, these actions are sufficient to specifically inhibit S-phase progression in AR-positive PCa cells, but not in AR-negative cells or tested AR-positive cells of other lineages. As expected, impaired cell cycle progression resulted in a suppression of cell doubling. Additionally, cell death was observed in AR-positive cells that maintain androgen dependence and in a subset of castrate-resistant PCa cells, dependent on Akt activation status. Lastly, the ability of RD to cooperate with existing hormone therapies was examined, which revealed that RD enhanced the cellular response to an AR antagonist. Together, these data demonstrate that RD is sufficient to disrupt AR-dependent transcriptional and proliferative responses in PCa, and can enhance efficacy of AR antagonists, thus establishing the impetus for development of RD-based mimetics

    Incommensurate magnetism near quantum criticality in CeNiAsO

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    Two phase transitions in the tetragonal strongly correlated electron system CeNiAsO were probed by neutron scattering and zero field muon spin rotation. For T<TN1T <T_{N1} = 8.7(3) K, a second order phase transition yields an incommensurate spin density wave with wave vector k=(0.44(4),0,0)\textbf{k} = (0.44(4), 0, 0). For T<TN2T < T_{N2} = 7.6(3) K, we find co-planar commensurate order with a moment of 0.37(5) μB0.37(5)~\mu_B, reduced to 30%30 \% of the saturation moment of the ±12|\pm\frac{1}{2}\rangle Kramers doublet ground state, which we establish by inelastic neutron scattering. Muon spin rotation in CeNiAs1xPxO\rm CeNiAs_{1-x}P_xO shows the commensurate order only exists for x \le 0.1 so the transition at xcx_c = 0.4(1) is from an incommensurate longitudinal spin density wave to a paramagnetic Fermi liquid

    Rebuttal to Hasan and Pedraza in comments and controversies: "Improving the reliability of manual and automated methods for hippocampal and amygdala volume measurements"

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    Here we address the critiques offered by Hasan and Pedraza to our recently published manuscript comparing the performance of two automated segmentation programs, FSL/FIRST and FreeSurfer (Morey R, Petty C, Xu Y, Pannu Hayes J, Wagner H, Lewis D, LaBar K, Styner M, McCarthy G. (2009): A comparison of automated segmentation and manual tracing for quantifying of hippocampal and amygdala volumes. Neuroimage 45:855-866). We provide an assessment and discussion of their specific critiques. Hasan and Pedraza bring up some important points concerning our omission of sample demographic features and inclusion of left and right hemisphere volumes as independent measures in correlational analyses. We present additional data on demographic attributes of our sample and correlations analyzed separately on left and right hemispheres of the amygdala and hippocampus. While their commentary aids the reader to more critically asses our study, it falls short of substantiating that our omissions ought to lead readers to significantly revise their interpretations. Further research will help to disentangle the advantages and limitations of the various freely-available automated segmentation software packages

    Integrated cross-domain object storage in working memory: Evidence from a verbal-spatial memory task

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    Working-memory theories often include domain-specific verbal and visual stores (e.g., the phonological and visuospatial buffers of Baddeley, 1986), and some also posit more general stores thought to be capable of holding verbal or visuospatial materials (Baddeley, 2000; Cowan, 2005). However, it is currently unclear which type of store is primarily responsible for maintaining objects that include components from multiple domains. In these studies, a spatial array of letters was followed by a single probe identical to an item in the array or differing systematically in spatial location, letter identity, or their combination. Concurrent verbal rehearsal suppression impaired memory in each of these trial types in a task that required participants to remember verbal-spatial binding, but did not impair memory for spatial locations if the task did not require verbal-spatial binding for a correct response. Thus, spatial information might be stored differently when it must be bound to verbal information. This suggests that a cross-domain store such as the episodic buffer of Baddeley (2000) or the focus of attention of Cowan (2001) might be used for integrated object storage, rather than the maintenance of associations between features stored in separate domain-specific buffers

    WoMMBAT: A user interface for hierarchical Bayesian estimation of working memory capacity

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    The change detection paradigm has become an important tool for researchers studying working memory. Change detection is especially useful for studying visual working memory, because recall paradigms are difficult to employ in the visual modality. Pashler (Perception & Psychophysics, 44, 369–378, 1988) and Cowan (Behavioral and Brain Sciences, 24, 87–114, 2001) suggested formulas for estimating working memory capacity from change detection data. Although these formulas have become widely used, Morey (Journal of Mathematical Psychology, 55, 8–24, 2011) showed that the formulas suffer from a number of issues, including inefficient use of information, bias, volatility, uninterpretable parameter estimates, and violation of ANOVA assumptions. Morey presented a hierarchical Bayesian extension of Pashler’s and Cowan’s basic models that mitigates these issues. Here, we present WoMMBAT (Working Memory Modeling using Bayesian Analysis Techniques) software for fitting Morey’s model to data. WoMMBAT has a graphical user interface, is freely available, and is cross-platform, running on Windows, Linux, and Mac operating systems
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