1,101 research outputs found
Evaluating Logistics Capabilities on Firm Performance of the Photonics Industry in Taiwan
This study empirically examined the impact of logistics capabilities on firm performance in the photonics industry. Structural equating modelling (SEM) was employed to test the research hypotheses with the use of data collected from a survey of 221 photonics manufacturing firms in Taiwan. Three dimensions were identified based on a factor analysis, including warehousing capability, information technology capability, and transportation capability. The research findings indicated that logistics capabilities positively influence firm performance. Information technology capability was found to be the most important logistics capability in the photonics industry, followed by warehousing capability, and transportation capability. There is also a discussion of the theoretical and managerial implications for the photonics industry
NADH oxidation drives respiratory Na+ transport in mitochondria from Yarrowia lipolytica
It is generally assumed that respiratory complexes exclusively use protons to energize the inner mitochondrial membrane. Here we show that oxidation of NADH by submitochondrial particles (SMPs) from the yeast Yarrowia lipolytica is coupled to protonophore-resistant Na+ uptake, indicating that a redox-driven, primary Na+ pump is operative in the inner mitochondrial membrane. By purification and reconstitution into proteoliposomes, a respiratory NADH dehydrogenase was identified which coupled NADH-dependent reduction of ubiquinone (1.4μmolmin−1mg−1) to Na+ translocation (2.0μmolmin−1mg−1). NADH-driven Na+ transport was sensitive towards rotenone, a specific inhibitor of complex I. We conclude that mitochondria from Y. lipolytica contain a NADH-driven Na+ pump and propose that it represents the complex I of the respiratory chain. Our study indicates that energy conversion by mitochondria does not exclusively rely on the proton motive force but may benefit from the electrochemical Na+ gradient established by complex
Retroperitoneal hemorrhage caused by enoxaparin-induced spontaneous lumbar artery bleeding and treated by transcatheter arterial embolization: a case report
Lumbar artery bleeding with retroperitoneal hematoma is an uncommon life-threatening complication secondary to enoxaparin use. We present a case of 73-year-old Chinese woman with acute retroperitoneal hemorrhage one month following hip surgery, due to enoxaparine. Enoxaparin induced hemorrhage caused by spontaneous rupture of lumbar artery was suspected and treated successfully by transcatheter arterial embolization
On the Efficiency of An Election Game of Two or More Parties: How Bad Can It Be?
We extend our previous work on two-party election competition [Lin, Lu & Chen
2021] to the setting of three or more parties. An election campaign among two
or more parties is viewed as a game of two or more players. Each of them has
its own candidates as the pure strategies to play. People, as voters, comprise
supporters for each party, and a candidate brings utility for the the
supporters of each party. Each player nominates exactly one of its candidates
to compete against the other party's. A candidate is assumed to win the
election with higher odds if it brings more utility for all the people. The
payoff of each player is the expected utility its supporters get. The game is
egoistic if every candidate benefits her party's supporters more than any
candidate from the competing party does. In this work, we first argue that the
election game always has a pure Nash equilibrium when the winner is chosen by
the hardmax function, while there exist game instances in the three-party
election game such that no pure Nash equilibrium exists even the game is
egoistic. Next, we propose two sufficient conditions for the egoistic election
game to have a pure Nash equilibrium. Based on these conditions, we propose a
fixed-parameter tractable algorithm to compute a pure Nash equilibrium of the
egoistic election game. Finally, perhaps surprisingly, we show that the price
of anarchy of the egoistic election game is upper bounded by the number of
parties. Our findings suggest that the election becomes unpredictable when more
than two parties are involved and, moreover, the social welfare deteriorates
with the number of participating parties in terms of possibly increasing price
of anarchy. This work alternatively explains why the two-party system is
prevalent in democratic countries
Noninvasive technique for measurement of heartbeat regularity in zebrafish (Danio rerio) embryos
<p>Abstract</p> <p>Background</p> <p>Zebrafish (<it>Danio rerio</it>), due to its optical accessibility and similarity to human, has emerged as model organism for cardiac research. Although various methods have been developed to assess cardiac functions in zebrafish embryos, there lacks a method to assess heartbeat regularity in blood vessels. Heartbeat regularity is an important parameter for cardiac function and is associated with cardiotoxicity in human being. Using stereomicroscope and digital video camera, we have developed a simple, noninvasive method to measure the heart rate and heartbeat regularity in peripheral blood vessels. Anesthetized embryos were mounted laterally in agarose on a slide and the caudal blood circulation of zebrafish embryo was video-recorded under stereomicroscope and the data was analyzed by custom-made software. The heart rate was determined by digital motion analysis and power spectral analysis through extraction of frequency characteristics of the cardiac rhythm. The heartbeat regularity, defined as the rhythmicity index, was determined by short-time Fourier Transform analysis.</p> <p>Results</p> <p>The heart rate measured by this noninvasive method in zebrafish embryos at 52 hour post-fertilization was similar to that determined by direct visual counting of ventricle beating (<it>p </it>> 0.05). In addition, the method was validated by a known cardiotoxic drug, terfenadine, which affects heartbeat regularity in humans and induces bradycardia and atrioventricular blockage in zebrafish. A significant decrease in heart rate was found by our method in treated embryos (<it>p </it>< 0.01). Moreover, there was a significant increase of the rhythmicity index (p < 0.01), which was supported by an increase in beat-to-beat interval variability (<it>p </it>< 0.01) of treated embryos as shown by Poincare plot.</p> <p>Conclusion</p> <p>The data support and validate this rapid, simple, noninvasive method, which includes video image analysis and frequency analysis. This method is capable of measuring the heart rate and heartbeat regularity simultaneously via the analysis of caudal blood flow in zebrafish embryos. With the advantages of rapid sample preparation procedures, automatic image analysis and data analysis, this method can potentially be applied to cardiotoxicity screening assay.</p
Precision Medicine for Frontotemporal Dementia
Frontotemporal dementia (FTD) is a common young-onset dementia presenting with heterogeneous and distinct syndromes. It is characterized by progressive deficits in behavior, language, and executive function. The disease may exhibit similar characteristics to many psychiatric disorders owing to its prominent behavioral features. The concept of precision medicine has recently emerged, and it involves neurodegenerative disease treatment that is personalized to match an individual's specific pattern of neuroimaging, neuropathology, and genetic variability. In this paper, the pathophysiology underlying FTD, which is characterized by the selective degeneration of the frontal and temporal cortices, is reviewed. We also discuss recent advancements in FTD research from the perspectives of clinical, imaging, molecular characterizations, and treatment. This review focuses on the approach of precision medicine to manage the clinical and biological complexities of FTD
Carbon monoxide may enhance bile secretion by increasing glutathione excretion and Mrp2 expression in rats
AbstractBackgroundNitric oxide (NO) donors have been reported to induce choleresis via an increased excretion of glutathione. The effects of another gas molecule, carbon monoxide (CO), on bile formation are, however, inconsistent among previous reports. We investigated the sequential changes of bile output and the biliary contents in rats with or without CO supplementation to elucidate the mechanism of CO on bile excretion.MethodsDichloromethane (DCM) was gastrically fed to male Sprague–Dawley rats to yield CO by liver biotransformation. The rats were divided into DCM-treated (n = 7), DCM plus L-NAME-treated (n = 6), and corn oil-treated-(n = 8) groups. Bile samples were collected hourly to examine the flow rate and bile content. Serum levels of nitrite and nitrate 4 hours after DCM supplementation with or without NO synthase (NOS) inhibition were measured by capillary electrophoresis. The expression of hepatic inducible NOS was evaluated by Western blotting 6 hours after DCM administration.ResultsLevels of carboxyhemoglobin rose to around 10% at 4 hours after DCM supplementation and were maintained until the end of the experiments. Bile flow increased after DCM supplementation and was associated with a concomitant increase of biliary glutathione and higher hepatic multidrug resistance-associated protein 2 (Mrp2) expression. Hepatic inducible NOS expression and serum nitrate/nitrite levels were also increased. Treatment with an NOS inhibitor (L-NAME) abolished the CO-induced glutathione excretion and choleresis, but not Mrp2 expression.ConclusionThe present study demonstrated that CO enhanced biliary output in conjunction with NO by increasing the biliary excretion of glutathione. The increment in biliary glutathione was associated with an increased expression of hepatic Mrp2
In vitro-binding of the natural siderophore enantiomers pyochelin and enantiopyochelin to their AraC-type regulators PchR in Pseudomonas
The enantiomeric siderophores pyochelin and enantiopyochelin of Pseudomonas aeruginosa and Pseudomonas protegens promote growth under iron limitation and activate transcription of their biosynthesis and uptake genes via the AraC-type regulator PchR. Here we investigated siderophore binding to PchR in vitro using fluorescence spectroscopy. A fusion of the N-terminal domain of P. aeruginosa PchR with maltose binding protein (MBP-PchR′PAO) bound iron-loaded (ferri-) pyochelin with an affinity (Kd) of 41±5μM. By contrast, no binding occurred with ferri-enantiopyochelin. Stereospecificity of a similar fusion protein of the P. protegens PchR (MBP-PchR′CHA0) was less pronounced. The Kd's of MBP-PchR′CHA0 for ferri-enantiopyochelin and ferri-pyochelin were 24±5 and 40±7μM, respectively. None of the proteins interacted with the iron-free siderophore enantiomers, suggesting that transcriptional activation by PchR occurs only when the respective siderophore actively procures iron to the cel
- …