43 research outputs found
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Too Much of Two Good Things: Explicating the Limited Complementarity Between Drivers of MNC Headquarters’ Absorptive Capacity
This study examines how multinational corporation (MNC) knowledge management mechanisms (systems, coordination and socialization) and international exposure affect MNC headquarters' absorptive capacity (AC). We build on Cohen and Levinthal's (Admin Sci Quart 35(1):128–152, 1990, https://doi.org/10.2307/2393553) under-researched trade-off between the inward- and outward-looking drivers of AC in the context of the MNC international knowledge transfer. First, we hypothesize that knowledge management mechanisms (the inward-looking driver) and international exposure (the outward-looking driver) directly influence headquarters' AC. Our findings from a sample of 106 Brazilian and Portuguese MNC headquarters support this view. Second, because "not-invented-here" syndrome and distance can affect knowledge flows from subsidiaries, we develop a hypothesis on the trade-off between AC's inward- and outward-looking drivers. We observe that their impact on the AC of MNC headquarters is diminished for high levels of coordination mechanisms and international exposure. Hence, coordination mechanisms become less effective to absorb subsidiary knowledge as the MNC increases its international footprint. We also conclude that the headquarters of highly internationalized MNCs can regard socialization mechanisms as facilitators of the absorption of knowledge generated by subsidiaries
Atuação das multinacionais brasileiras e portuguesas nos mercados da CPLP
info:eu-repo/semantics/publishedVersio
Telocytes and putative stem cells in the lungs: electron microscopy, electron tomography and laser scanning microscopy
This study describes a novel type of interstitial (stromal) cell — telocytes (TCs) — in the human and mouse respiratory tree (terminal and respiratory bronchioles, as well as alveolar ducts). TCs have recently been described in pleura, epicardium, myocardium, endocardium, intestine, uterus, pancreas, mammary gland, etc. (see www.telocytes.com). TCs are cells with specific prolongations called telopodes (Tp), frequently two to three per cell. Tp are very long prolongations (tens up to hundreds of μm) built of alternating thin segments known as podomers (≤ 200 nm, below the resolving power of light microscope) and dilated segments called podoms, which accommodate mitochondria, rough endoplasmic reticulum and caveolae. Tp ramify dichotomously, making a 3-dimensional network with complex homo- and heterocellular junctions. Confocal microscopy reveals that TCs are c-kit- and CD34-positive. Tp release shed vesicles or exosomes, sending macromolecular signals to neighboring cells and eventually modifying their transcriptional activity. At bronchoalveolar junctions, TCs have been observed in close association with putative stem cells (SCs) in the subepithelial stroma. SCs are recognized by their ultrastructure and Sca-1 positivity. Tp surround SCs, forming complex TC-SC niches (TC-SCNs). Electron tomography allows the identification of bridging nanostructures, which connect Tp with SCs. In conclusion, this study shows the presence of TCs in lungs and identifies a TC-SC tandem in subepithelial niches of the bronchiolar tree. In TC-SCNs, the synergy of TCs and SCs may be based on nanocontacts and shed vesicles
The great screen anomaly—a new frontier in product discovery through functional metagenomics
Functional metagenomics, the study of the collective genome of a microbial community by expressing it in a foreign host, is an emerging field in biotechnology. Over the past years, the possibility of novel product discovery through metagenomics has developed rapidly. Thus, metagenomics has been heralded as a promising mining strategy of resources for the biotechnological and pharmaceutical industry. However, in spite of innovative work in the field of functional genomics in recent years, yields from function-based metagenomics studies still fall short of producing significant amounts of new products that are valuable for biotechnological processes. Thus, a new set of strategies is required with respect to fostering gene expression in comparison to the traditional work. These new strategies should address a major issue, that is, how to successfully express a set of unknown genes of unknown origin in a foreign host in high throughput. This article is an opinionating review of functional metagenomic screening of natural microbial communities, with a focus on the optimization of new product discovery. It first summarizes current major bottlenecks in functional metagenomics and then provides an overview of the general metagenomic assessment strategies, with a focus on the challenges that are met in the screening for, and selection of, target genes in metagenomic libraries. To identify possible screening limitations, strategies to achieve optimal gene expression are reviewed, examining the molecular events all the way from the transcription level through to the secretion of the target gene product
Near-infrared low-level laser stimulation of telocytes from human myometrium.
Telocytes (TCs) are a brand-new cell type frequently observed in the interstitial space of many organs (see www.telocytes.com ). TCs are defined by very long (tens of micrometers) and slender prolongations named telopodes. At their level, dilations-called podoms (~300 nm), alternate with podomers (80-100 nm). TCs were identified in a myometrial interstitial cell culture based on morphological criteria and by CD34 and PDGF receptor alpha (PDGFRα) immunopositivity. However, the mechanism(s) of telopodes formation and/or elongation and ramification is not known. We report here the low-level laser stimulation (LLLS) using a 1,064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (with an output power of 60 mW) of the telopodal lateral extension (TLE) growth in cell culture. LLLS of TCs determines a higher growth rate of TLE in pregnant myometrium primary cultures (10.3 ± 1.0 μm/min) compared to nonpregnant ones (6.6 ± 0.9 μm/min). Acute exposure (30 min) of TCs from pregnant myometrium to 1 μM mibefradil, a selective inhibitor of T-type calcium channels, determines a significant reduction in the LLLS TLE growth rate (5.7 ± 0.8 μm/min) compared to LLLS per se in same type of samples. Meanwhile, chronic exposure (24 h) completely abolishes the LLLS TLE growth in both nonpregnant and pregnant myometria. The initial direction of TLE growth was modified by LLLS, the angle of deviation being more accentuated in TCs from human pregnant myometrium than in TCs from nonpregnant myometrium. In conclusion, TCs from pregnant myometrium are more susceptible of reacting to LLLS than those from nonpregnant myometrium. Therefore, some implications are emerging for low-level laser therapy (LLLT) in uterine regenerative medicine