2,514 research outputs found
Technological catch-up and strategic technology partnering in developing countries
This paper examines the trends in strategic technology partnering (STP) by firms from developing countries over the period 1980-94. The evidence shows that a small group of countries, namely the Asian NICs and Eastern Europe dominate STP activity. We also examine differences in organisational modes and how these have evolved over time, suggesting an increasing similarity between the NICs and Triad firms. Although it has been argued that these trends demonstrate the technological and economic falling behind of most developing countries, we suggest that it may also represent fundamental differences in the economic structure of these countries and the normal process of structural upgrading with development.research and development ;
Severity of cardiomyopathy associated with adenine nucleotide translocator-1 deficiency correlates with mtDNA haplogroup
Mutations of both nuclear and mitochondrial DNA (mtDNA)-encoded mitochondrial proteins can cause cardiomyopathy associated with mitochondrial dysfunction. Hence, the cardiac phenotype of nuclear DNA mitochondrial mutations might be modulated by mtDNA variation. We studied a 13-generation Mennonite pedigree with autosomal recessive myopathy and cardiomyopathy due to an SLC25A4 frameshift null mutation (c.523delC, p.Q175RfsX38), which codes for the heart-muscle isoform of the adenine nucleotide translocator-1. Ten homozygous null (adenine nucleotide translocator-1(-/-)) patients monitored over a median of 6 years had a phenotype of progressive myocardial thickening, hyperalaninemia, lactic acidosis, exercise intolerance, and persistent adrenergic activation. Electrocardiography and echocardiography with velocity vector imaging revealed abnormal contractile mechanics, myocardial repolarization abnormalities, and impaired left ventricular relaxation. End-stage heart disease was characterized by massive, symmetric, concentric cardiac hypertrophy; widespread cardiomyocyte degeneration; overabundant and structurally abnormal mitochondria; extensive subendocardial interstitial fibrosis; and marked hypertrophy of arteriolar smooth muscle. Substantial variability in the progression and severity of heart disease segregated with maternal lineage, and sequencing of mtDNA from five maternal lineages revealed two major European haplogroups, U and H. Patients with the haplogroup U mtDNAs had more rapid and severe cardiomyopathy than those with haplogroup H
Relaxation lifetimes of plasmonically enhanced hybrid gold-carbon nanotubes systems
Recently, we introduced a novel hybridization route for carbon nanotubes using
gold nanoparticles, whose close proximity neatly enhances their radiative
emission. Here we investigate the mechanisms behind the enhancement by
monitoring the de-excitation dynamics of our π-hybrids through two-color pump-
probe time-resolved spectroscopy. The de-excitation process reveals a fast
component and a slow component. We find that the presence of gold prominently
affects the fast processes, indicating a stronger influence of the gold
nanoparticle on the intra-band non-radiative relaxation than on the inter-band
recombination of the single-walled carbon nanotube. By evaluating the de-
excitation times, we estimate the balance between near-field pumping and the
faster metal-induced de-excitation contributions, proving the enhanced pumping
to be the leading mechanism
Beginning of the End of Cost Competitiveness in CEE Countries - Analysis of Dependence between Labor Costs and Internationalization of the Region
In order to exemplify the above econometric model I carried out empirical analysis of the companies listed on the Warsaw Stock Exchange, identifying the companies for which efficiency-seeking is the main internationalization motive. The analysis of internationalization of 26 companies during the years 1990-2010 clearly shows that a significant part of investments is located outside the territory of Poland, in the countries with lower labor costs. This fact confirms that CEE countries will gradually become less and less attractive in terms of costs not only for MNEs from developed countries but also for the companies originating from transition economies.Głównym celem artykułu jest weryfikacja, czy niski poziom kosztów pracy w Europie Środkowej i Wschodniej będący do tej pory jednym z czynników wpływających na konkurencyjność tego regionu pozostanie nim w dłuższej perspektywie czasowej. W pracy na podstawie próby wszystkich państw UE zbadano zależność pomiędzy poziomem internacjonalizacji (stan odpływu BIZ per capita) a kosztami pracy w sektorze przedsiębiorstw i GNP per capita. Analiza regresji potwierdziła istnienie zależności pomiędzy wyżej wymienionymi czynnikami. Oznacza to, że stopniowy wzrost kosztów pracy w państwach Europy Środkowej i Wschodniej prowadził będzie do stopniowego odpływu BIZ z tego regionu do państw bardziej konkurencyjnych kosztowo. W celu egzemplifikacji powyższych zależności w pracy dodatkowo przedstawiono analizę inwestycji zagranicznych polskich spółek notowanych na GPW, z których to 26 dokonało inwwestycji zagranicznych o wyraźnych motywach związanych z obniżeniem kosztów produkcji. Fakt ten potwierdza powolny spadek konkurencyjności kosztowej polskiej gospodarki, tym samym zmusza do poszukiwania nowych rozwiązań instytucjonalnych mogących utrzymać konkurencyjność polskiej gospodarki w długim okresie
Open radial artery harvesting better preserves endothelial function compared to the endoscopic approach
OBJECTIVES: Both the open and endovascular techniques are commonly used for harvesting the radial artery (ORAH and ERAH, respectively), and yet, very little is known about the effects of these 2 techniques on endothelial integrity and function of the radial artery (RA). The aim of this study was to assess the endothelial integrity and function of RA harvested using the 2 approaches. METHODS: Two independent surgical teams working in the same institution routinely use the RA for coronary artery bypass grafting exclusively employing either ORAH or ERAH. Thirty-nine consecutive patients were enrolled in this comparative study. Endothelial function after ORAH or ERAH was assessed by using the wire myograph system. The integrity of the RA endothelium was evaluated by immunohistochemical staining for erythroblast transformation specific-related gene. RESULTS: The vasodilation in response to acetylcholine was significantly higher in RA harvested with ORAH (P ≤ 0.001 versus ERAH). Endothelial integrity was not different between the 2 groups. CONCLUSIONS: ORAH is associated with a significantly higher endothelium-dependent vasodilation. Further investigation on the potential implications of these findings in terms of graft spasm and patency as well as clinical outcomes are needed
Spasmogenic Effects of the Proteasome Inhibitor Carfilzomib on Coronary Resistance, Vascular Tone and Reactivity
Background: Carfilzomib (CFZ) is a new proteasome inhibitor used for the treatment of multiple myeloma. Besides
heart failure, angina and myocardial ischemia occurred following administration of CFZ, which is not contraindicated
in patients with recent myocardial infarction/unstable angina excluded from the safety trials.
Aimof Study: To test the effects of CFZ (10−9 to 10−7 mol/L) on vascular tone and reactivity in the isolated rabbit
heart and aorta.
Methods and Results: CFZ administered by bolus injection to the isolated heart increased coronary perfusion pressure
(CPP) at all tested concentrations and mildly raised left ventricular pressure and heart rate, only at the
highest concentration. Addition of CFZ directly into the organ bath increased the basal tone of isolated aortic
strips with contraction plateau reached after 10 min. This spasmogenic effect doubled following ablation of the
endothelium. Pretreatment with CFZ amplified the vasospastic action exerted by KCl, noradrenaline (NA) and angiotensin
II (A) on aortic strips, and impaired vasodilation following administration of nitroglycerin (NTG) and
nifedipine (NFP) on the contraction plateau induced by KCl, NA and A. Aortic strips pretreatedwith CFZ exhibited
impaired relaxation, as compared to untreated strips, following administration of acetylcholine (Ach), an endothelium-
dependent vasodilating agent, on the plateau of NA contraction (p b 0.05).
Conclusions: CFZ increased CPP, resting vasoconstricting tone and the spasmogenic effect of different agents.
Preincubation with CFZ decreased the anti-spasmogenic activity of NTG and NFP, as well as reduced by over
50% the vasodilating effect of Ach, suggesting that CFZ can impair vasodilation via an endothelium dependent
mechanism. Further studies are warranted to establish its clinical safety in patients with known CAD and prior
history of coronary spasm
Noninvasive Molecular Imaging of Disease Activity in Atherosclerosis.
Major focus has been placed on the identification of vulnerable plaques as a means of improving the prediction of myocardial infarction. However, this strategy has recently been questioned on the basis that the majority of these individual coronary lesions do not in fact go on to cause clinical events. Attention is, therefore, shifting to alternative imaging modalities that might provide a more complete pan-coronary assessment of the atherosclerotic disease process. These include markers of disease activity with the potential to discriminate between patients with stable burnt-out disease that is no longer metabolically active and those with active atheroma, faster disease progression, and increased risk of infarction. This review will examine how novel molecular imaging approaches can provide such assessments, focusing on inflammation and microcalcification activity, the importance of these processes to coronary atherosclerosis, and the advantages and challenges posed by these techniques.M.R.D and D.E.N are supported by the British Heart Foundation (CH/09/002 to D.E.N., FS/14/78/31020 to M.R.D). M.R.D is the recipient of the Sir Jules Thorn Biomedical Research Award 2015 (M.R.D.) E.A. research is supported by R01HL 114805 and R01HL 109506.This is the final version of the article. It first appeared from Lippincott, Williams & Wilkins via http://dx.doi.org/10.1161/CIRCRESAHA.116.30797
Learning Interpretable Anatomical Features Through Deep Generative Models: Application to Cardiac Remodeling
Alterations in the geometry and function of the heart define well-established causes of cardiovascular disease. However, current approaches to the diagnosis of cardiovascular diseases often rely on subjective human assessment as well as manual analysis of medical images. Both factors limit the sensitivity in quantifying complex structural and functional phenotypes. Deep learning approaches have recently achieved success for tasks such as classification or segmentation of medical images, but lack interpretability in the feature extraction and decision processes, limiting their value in clinical diagnosis. In this work, we propose a 3D convolutional generative model for automatic classification of images from patients with cardiac diseases associated with structural remodeling. The model leverages interpretable task-specific anatomic patterns learned from 3D segmentations. It further allows to visualise and quantify the learned pathology-specific remodeling patterns in the original input space of the images. This approach yields high accuracy in the categorization of healthy and hypertrophic cardiomyopathy subjects when tested on unseen MR images from our own multi-centre dataset (100%) as well on the ACDC MICCAI 2017 dataset (90%). We believe that the proposed deep learning approach is a promising step towards the development of interpretable classifiers for the medical imaging domain, which may help clinicians to improve diagnostic accuracy and enhance patient risk-stratification
Ultrasensitivity of the Bacillus subtilis sporulation decision
Starving Bacillus subtilis cells execute a gene expression program
resulting in the formation of stress-resistant spores. Sporulation
master regulator, Spo0A, is activated by a phosphorelay and controls
the expression of a multitude of genes, including the forespore-
specific sigma factor σF and the mother cell-specific sigma
factor σE. Identification of the system-level mechanism of the sporulation
decision is hindered by a lack of direct control over Spo0A
activity. This limitation can be overcome by using a synthetic system
in which Spo0A activation is controlled by inducing expression
of phosphorelay kinase KinA. This induction results in a switch-like
increase in the number of sporulating cells at a threshold of KinA.
Using a combination of mathematical modeling and single-cell microscopy,
we investigate the origin and physiological significance
of this ultrasensitive threshold. The results indicate that the phosphorelay
is unable to achieve a sufficiently fast and ultrasensitive
response via its positive feedback architecture, suggesting that the
sporulation decision is made downstream. In contrast, activation
of σF in the forespore and of σE in the mother cell compartments
occurs via a cascade of coherent feed-forward loops, and thereby
can produce fast and ultrasensitive responses as a result of KinA
induction. Unlike σF activation, σE activation in the mother cell
compartment only occurs above the KinA threshold, resulting in
completion of sporulation. Thus, ultrasensitive σE activation explains
the KinA threshold for sporulation induction. We therefore infer
that under uncertain conditions, cells initiate sporulation but postpone
making the sporulation decision to average stochastic fluctuations
and to achieve a robust population response
Digitalized service multinationals and international business theory
Banalieva and Dhanaraj argue that digital service multinationals (DSMNCs) possess a new category of firm-specific advantage (FSA), the network advantage, and that, contrary to extant theory, they use networks as a mode of governance. I review the business models used by DSMNCs, compare them to non-digital ones, and explore what we can learn about them from extant IB theory. I conclude that network advantages are not a new category of FSAs, that networks are not a mode of governance, and that their use by DSMNCs is well explained by extant theory
- …
