7,524 research outputs found
Operational Capabilities: The Secret Ingredient
We develop a theoretical definition of operational capabilities, based on the strategic
management and operations management literature, and differentiate this construct from
the related constructs of resources and operational practices, drawing upon the resourcebased view of the firm as our foundation. We illustrate the key features of operational capabilities using the illustration of a restaurant kitchen. Because the traits of operational capabilities are distinct, they create a barrier to imitation, making them a potential source of competitive advantage. However, operational capabilities are particularly challenging to measure, because they emerge gradually and are tacit, embedded, and manifested differently across firms. In solving this measurement conundrum, we draw upon similar situations experienced by Schein (2004) and Eisenhardt and Martin (2000) in operationalizing organizational culture and dynamic capabilities. A taxonomy of six emergent operational capabilities is developed: operational improvement, operational innovation, operational customization, operational cooperation, operational responsiveness, and operational reconfiguration. A set of measurement scales is developed, in order to measure each of the operational capabilities, and validated using two different datasets. This allows replication of the psychometric properties of the multi-item scales and helps to ensure the validity of the resulting measures
INVESTIGATING THE ROLE OF THE P63 ISOFORM ΔNP63 IN LUNG STEM CELL POPULATIONS AND LUNG CANCER
Cell of origin studies have determined separate populations of lung progenitor cells that give rise to lung adenocarcinoma and squamous cell carcinoma. ΔNp63 is known to regulate lung development but its role in lung cancer progression remains unclear. We utilized a ΔNp63-specific conditional knockout mouse model to determine ΔNp63’s role in lung progenitor cells and lung cancer. In vivo and in vitro experiments revealed a role for ΔNp63 in maintaining lung progenitor cells. ChIP-seq results indicate that deletion of ΔNp63 results in robust loss of enhancer histone marks at cell identity genes for lung progenitor populations of basal cells and AT2 cells. Analysis of ΔNp63-regulated pathways uncovered that ΔNp63 regulates cell-type-specific genes as well as common genes for basal cells and AT2 cells. Our experiments using a deactivated cas9 system showed that co-targeting of ΔNp63 and the enhancer activator p300 to p63 binding motifs significantly enhanced the transcription of ΔNp63-regulated genes, indicating that ΔNp63 directly regulates enhancer region activity. These novel findings suggest that ΔNp63 acts as a master regulator of transcriptional and epigenetic networks in lung progenitor cells whose oncogenic characteristics are essential to the initiation and progression of lung cancer
Establishment of an isotope dilution LC-MS/MS method revealing kinetics and distribution of co-occurring mycotoxins in rats
An isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with a fast sample preparation using homemade clean-up cartridges was developed for simultaneous determination of co-occurring mycotoxins exemplified with aflatoxin B1 (AFB1) and T-2 toxin (T-2) in representative biomatrices of rat plasma, heart, liver, kidney, spleen, lung and brain in a total run time of 7 min. The established approach using stable internal standards of [C-13(17)]-AFB1 and [C-13(24)]-T-2 was extensively validated by determining the specificity, linearity (R-2 >= 0.9990), sensitivity (lower limit of quantitation at 0.05 ng mL(-1)), accuracy (70.9-107.7%), precision (RSD = 70.8%). Based on this methodological advance, the subsequent kinetics and tissue distribution after oral administration of 0.5 mg kg(-1) b.w. of both AFB1 and T-2 in rats were thoroughly studied. As revealed, both AFB1 and T-2 were rapidly eliminated with the half-life time (t(1/2)) in plasma of 8.44 +/- 4.02 h and 8.12 +/- 4.05 h, respectively. Moreover, AFB1 accumulated in all organs where the highest concentration was observed in liver (1.34 mu g kg(-1)), followed by kidney (0.76 mu g kg(-1)). Notably, only low levels of T-2 were observed in spleen (0.70 mu g kg(-1)) and in liver (0.15 mu g kg(-1)). The achieved data as supporting evidence would substantially promote the practical application of the proposed LC-MS/MS method for in vivo toxicokinetics and toxicity studies of co-occurring mycotoxins imitating natural incidence in rat system
The Relationship Between Information and Communication Technologies and Country Governance: An Exploratory Study
In this exploratory study we investigate the relationship between information and communication technologies (ICTs) and country-level governance. We include in our framework the five factors of ICTs: access, quality, affordability, applications and institutional efficiency & sustainability. Governance indicators include voice and accountability, political stability and absence of violence, government effectiveness, regulatory quality, rule of law, and control of corruption. Using secondary data on ICTs and governance indicators for countries from the World Bank, and controlling for the wealth effect, our main multivariate result indicates that ICTs—with the exception of the institutional efficiency and sustainability factor—have a positive relationship with governance indicators. ICTs therefore, have the potential to promote good governance. We also find that accessibility is the most important ICTs’ factor to enhance governance. Our results are useful in shaping policy decisions involving the nature and extent of investment in ICT infrastructure at the country level
The Relationship Between Information and Communication Technologies and the Delivery of Public Health: A Country-level Study
We empirically investigate the relationship between information and communication technologies (ICTs) and the delivery of country-level public health. Our underlying hypothesis is that ICTs can improve the efficiency and effectiveness of public health delivery mechanisms. In our framework, we include the ICT factors of accessibility, quality, affordability, applications, and institutional efficiency and sustainability. The public health delivery is represented by the changes in the indicators of immunization coverage, TB infection, sanitation, undernourishment, life expectancy, mortality rate, and health care expenses. Results indicate in most cases ICT factors have a significant correlation to a country’s delivery of public health over and above a country’s income level. The “Accessibility” ICT factor contributes to improved delivery for nearly all of the public health indicators. This is followed by “ICT Applications.” Increased ICTs usage leads to increased health care expenditure. Our findings are useful at the country level for informing policy decisions regarding the nature and extent of investment in ICT infrastructure for the delivery of public health. We do caution that merely investing in more ICTs does not imply an automatic improvement in public health. Rather, ICTs have the potential to improve the delivery process
Dual-Gated Volumetric Modulated Arc Therapy
BACKGROUND: Gated Volumetric Modulated Arc Therapy (VMAT) is an emerging radiation therapy modality for treatment of tumors affected by respiratory motion. However, gating significantly prolongs the treatment time, as delivery is only activated during a single respiratory phase. To enhance the efficiency of gated VMAT delivery, a novel dual-gated VMAT (DG-VMAT) technique, in which delivery is executed at both exhale and inhale phases in a given arc rotation, is developed and experimentally evaluated.
METHODS: Arc delivery at two phases is realized by sequentially interleaving control points consisting of MUs, MLC sequences, and angles of VMAT plans generated at the exhale and inhale phases. Dual-gated delivery is initiated when a respiration gating signal enters the exhale window; when the exhale delivery concludes, the beam turns off and the gantry rolls back to the starting position for the inhale window. The process is then repeated until both inhale and exhale arcs are fully delivered. DG-VMAT plan delivery accuracy was assessed using a pinpoint chamber and diode array phantom undergoing programmed motion.
RESULTS: DG-VMAT delivery was experimentally implemented through custom XML scripting in Varian's TrueBeam™ STx Developer Mode. Relative to single gated delivery at exhale, the treatment time was improved by 95.5% for a sinusoidal breathing pattern. The pinpoint chamber dose measurement agreed with the calculated dose within 0.7%. For the DG-VMAT delivery, 97.5% of the diode array measurements passed the 3%/3 mm gamma criterion.
CONCLUSIONS: The feasibility of DG-VMAT delivery scheme has been experimentally demonstrated for the first time. By leveraging the stability and natural pauses that occur at end-inspiration and end-exhalation, DG-VMAT provides a practical method for enhancing gated delivery efficiency by up to a factor of two
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