1,483 research outputs found
Provision of local bus services in Japan: focusing on the roles for local governments and nonprofit organisations
Japan’s bus deregulation program (coach and local) was carried out in February 2002. Its main point was to loosen or eliminate Demand-Supply Balancing (Jukyu-Chosei.) This regulation was a licensing system and functioned as entry/exit regulation. It defended incumbents (approximately 360 operators) and did not let potential entrants respond to increasing demand for some services. It also forced the incumbents to cross-subsidise noncommercial services. In other words, the incumbents were allowed to enjoy a situation of local monopoly but forced to maintain non-commercial services. Although five years have passed since the deregulation, we have not seen major changes in the structure of the local bus market, as there have been few entrants. On the other hand, the incumbents are apt to abandon non-commercial services, because they now have freedom of exit and cross-subsidisation is no longer sustainable. The supply of commercial services can be left to the market mechanism, but the problem is who is in charge of maintaining noncommercial but indispensable services, especially in rural areas. This is why the deregulation has had impact on the transport policy by local governments. In fact, local governments all over Japan have been more involved in policies for public transport. But many of them are now facing a budget deficit and need to cut expenditures, including subsidies for bus services. Thus, nonprofit organisations (NPOs) are also expected to play a crucial role in the local transport market, like community transport in England. Some NPOs have been founded by the inhabitants and have tried to form a partnership with bus operators, local governments, shops, hospitals and so on in their local communities. The aim of this paper is to analyse the roles for NPOs in the local bus market, in comparison with those for local government. First, we describe the Japanese local bus market before and after the deregulation. Secondly, we consider the roles for local governments and NPOs in the local bus market. Next, we analyse some pioneering cases. In conclusion, we give a future prospect of local bus service provision in Japan, from the viewpoint of partnerships among local governments, private operators and NPOs.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne
Simulating Dynamical Features of Escape Panic
One of the most disastrous forms of collective human behaviour is the kind of
crowd stampede induced by panic, often leading to fatalities as people are
crushed or trampled. Sometimes this behaviour is triggered in life-threatening
situations such as fires in crowded buildings; at other times, stampedes can
arise from the rush for seats or seemingly without causes. Tragic examples
within recent months include the panics in Harare, Zimbabwe, and at the
Roskilde rock concert in Denmark. Although engineers are finding ways to
alleviate the scale of such disasters, their frequency seems to be increasing
with the number and size of mass events. Yet, systematic studies of panic
behaviour, and quantitative theories capable of predicting such crowd dynamics,
are rare. Here we show that simulations based on a model of pedestrian
behaviour can provide valuable insights into the mechanisms of and
preconditions for panic and jamming by incoordination. Our results suggest
practical ways of minimising the harmful consequences of such events and the
existence of an optimal escape strategy, corresponding to a suitable mixture of
individualistic and collective behaviour.Comment: For related information see http://angel.elte.hu/~panic,
http://www.helbing.org, http://angel.elte.hu/~fij, and
http://angel.elte.hu/~vicse
Coherent motion of stereocilia assures the concerted gating of hair-cell transduction channels
The hair cell's mechanoreceptive organelle, the hair bundle, is highly
sensitive because its transduction channels open over a very narrow range of
displacements. The synchronous gating of transduction channels also underlies
the active hair-bundle motility that amplifies and tunes responsiveness. The
extent to which the gating of independent transduction channels is coordinated
depends on how tightly individual stereocilia are constrained to move as a
unit. Using dual-beam interferometry in the bullfrog's sacculus, we found that
thermal movements of stereocilia located as far apart as a bundle's opposite
edges display high coherence and negligible phase lag. Because the mechanical
degrees of freedom of stereocilia are strongly constrained, a force applied
anywhere in the hair bundle deflects the structure as a unit. This feature
assures the concerted gating of transduction channels that maximizes the
sensitivity of mechanoelectrical transduction and enhances the hair bundle's
capacity to amplify its inputs.Comment: 24 pages, including 6 figures, published in 200
A suite of web applications to streamline the interdisciplinary collaboration in secondary data analyses
BACKGROUND: We describe a system of web applications designed to streamline the interdisciplinary collaboration in outcomes research. DESCRIPTION: The outcomes research process can be described as a set of three interrelated phases: design and selection of data sources, analysis, and output. Each of these phases has inherent challenges that can be addressed by a group of five web applications developed by our group. QuestForm allows for the formulation of relevant and well-structured outcomes research questions; Research Manager facilitates the project management and electronic file exchange among researchers; Analysis Charts facilitate the communication of complex statistical techniques to clinicians with varying previous levels of statistical knowledge; Literature Matrices improve the efficiency of literature reviews. An outcomes research question is used to illustrate the use of the system. CONCLUSIONS: The system presents an alternative to streamline the interdisciplinary collaboration of clinicians, statisticians, programmers, and graduate students
Identification and validation of oncologic miRNA biomarkers for Luminal A-like breast cancer
Introduction: Breast cancer is a common disease with distinct tumor subtypes phenotypically characterized by ER and HER2/neu receptor status. MiRNAs play regulatory roles in tumor initiation and progression, and altered miRNA expression has been demonstrated in a variety of cancer states presenting the potential for exploitation as cancer biomarkers. Blood provides an excellent medium for biomarker discovery. This study investigated systemic miRNAs differentially expressed in Luminal A-like (ER+PR+HER2/neu-) breast cancer and their effectiveness as oncologic biomarkers in the clinical setting. Methods: Blood samples were prospectively collected from patients with Luminal A-like breast cancer (n=54) and controls (n=56). RNA was extracted, reverse transcribed and subjected to microarray analysis (n=10 Luminal A-like; n=10 Control). Differentially expressed miRNAs were identified by artificial neural network (ANN) data-mining algorithms. Expression of specific miRNAs was validated by RQ-PCR (n=44 Luminal A; n=46 Control) and potential relationships between circulating miRNA levels and clinicopathological features of breast cancer were investigated. Results: Microarray analysis identified 76 differentially expressed miRNAs. ANN revealed 10 miRNAs for further analysis ( miR-19b, miR-29a, miR-93, miR-181a, miR-182, miR-223, miR-301a, miR-423-5p, miR-486-5 and miR-652 ). The biomarker potential of 4 miRNAs ( miR-29a, miR-181a , miR-223 and miR-652 ) was confirmed by RQ-PCR, with significantly reduced expression in blood of women with Luminal A-like breast tumors compared to healthy controls (p=0.001, 0.004, 0.009 and 0.004 respectively). Binary logistic regression confirmed that combination of 3 of these miRNAs ( miR-29a, miR-181a and miR-652 ) could reliably differentiate between cancers and controls with an AUC of 0.80. Conclusion: This study provides insight into the underlying molecular portrait of Luminal A-like breast cancer subtype. From an initial 76 miRNAs, 4 were validated with altered expression in the blood of women with Luminal A-like breast cancer. The expression profiles of these 3 miRNAs, in combination with mammography, has potential to facilitate accurate subtype- specific breast tumor detection
Different Prey Resources Suggest Little Competition Between Non-Native Frogs and Insectivorous Birds Despite Isotopic Niche Overlap
Non-native amphibians often compete with native amphibians in their introduced range, but their competitive effects on other vertebrates are less well known. The Puerto Rican coqui frog (Eleutherodactylus coqui) has colonized the island of Hawaii, and has been hypothesized to compete with insectivorous birds and bats. To address if the coqui could compete with these vertebrates, we used stable isotope analyses to compare the trophic position and isotopic niche overlap between the coqui, three insectivorous bird species, and the Hawaiian hoary bat. Coquis shared similar trophic position to Hawaii amakihi, Japanese white-eye, and red-billed leiothrix. Coquis were about 3 ‰ less enriched in δ15N than the Hawaiian hoary bat, suggesting the bats feed at a higher trophic level than coquis. Analyses of potential diet sources between coquis and each of the three bird species indicate that there was more dietary overlap between bird species than any of the birds and the coqui. Results suggest that Acari, Amphipoda, and Blattodea made up \u3e90% of coqui diet, while Araneae made up only 2% of coqui diet, but approximately 25% of amakihi and white-eye diet. The three bird species shared similar proportions of Lepidoptera larvae, which were ~25% of their diet. Results suggest that coquis share few food resources with insectivorous birds, but occupy a similar trophic position, which could indicate weak competition. However, resource competition may not be the only way coquis impact insectivorous birds, and future research should examine whether coqui invasions are associated with changes in bird abundance
Hypoxia induces dilated cardiomyopathy in the chick embryo: mechanism, intervention, and long-term consequences
Background: Intrauterine growth restriction is associated with an increased future risk for developing cardiovascular diseases. Hypoxia in utero is a common clinical cause of fetal growth restriction. We have previously shown that chronic hypoxia alters cardiovascular development in chick embryos. The aim of this study was to further characterize cardiac disease in hypoxic chick embryos. Methods: Chick embryos were exposed to hypoxia and cardiac structure was examined by histological methods one day prior to hatching (E20) and at adulthood. Cardiac function was assessed in vivo by echocardiography and ex vivo by contractility measurements in isolated heart muscle bundles and isolated cardiomyocytes. Chick embryos were exposed to vascular endothelial growth factor (VEGF) and its scavenger soluble VEGF receptor-1 (sFlt-1) to investigate the potential role of this hypoxia-regulated cytokine. Principal Findings: Growth restricted hypoxic chick embryos showed cardiomyopathy as evidenced by left ventricular (LV) dilatation, reduced ventricular wall mass and increased apoptosis. Hypoxic hearts displayed pump dysfunction with decreased LV ejection fractions, accompanied by signs of diastolic dysfunction. Cardiomyopathy caused by hypoxia persisted into adulthood. Hypoxic embryonic hearts showed increases in VEGF expression. Systemic administration of rhVEGF165 to normoxic chick embryos resulted in LV dilatation and a dose-dependent loss of LV wall mass. Lowering VEGF levels in hypoxic embryonic chick hearts by systemic administration of sFlt-1 yielded an almost complete normalization of the phenotype. Conclusions/Significance: Our data show that hypoxia causes a decreased cardiac performance and cardiomyopathy in chick embryos, involving a significant VEGF-mediated component. This cardiomyopathy persists into adulthood
Variability in Basal Melting Beneath Pine Island Ice Shelf on Weekly to Monthly Timescales
Ocean-driven basal melting of Amundsen Sea ice shelves has triggered acceleration, thinning,
and grounding line retreat on many West Antarctic outlet glaciers. Here we present the first year-long
(2014) record of basal melt rate at sub-weekly resolution from a location on the outer Pine Island Ice Shelf.
Adjustment of the upper thermocline to local wind forced variability in the vertical Ekman velocity is the
dominant control on basal melting at weekly to monthly timescales. Atmosphere-ice-ocean surface heat
fluxes or changes in advection of modified Circumpolar Deep Water play no discernible role at these
timescales. We propose that during other years, a deepening of the thermocline in Pine Island Bay driven by
longer timescale processes may have suppressed the impact of local wind forcing on high-frequency
upper thermocline height variability and basal melting. This highlights the complex interplay between the
different processes and their timescales that set the basal melt rate beneath Pine Island Ice Shelf
Use of the lambda Red recombinase system to rapidly generate mutants in Pseudomonas aeruginosa
<p>Abstract</p> <p>Background</p> <p>The Red recombinase system of bacteriophage lambda has been used to inactivate chromosomal genes in various bacteria and fungi. The procedure consists of electroporating a polymerase chain reaction (PCR) fragment that was obtained with a 1- or 3-step PCR protocol and that carries an antibiotic cassette flanked by a region homologous to the target locus into a strain that expresses the lambda Red recombination system.</p> <p>Results</p> <p>This system has been modified for use in <it>Pseudomonas aeruginosa</it>. Chromosomal DNA deletions of single genes were generated using 3-step PCR products containing flanking regions 400–600 nucleotides (nt) in length that are homologous to the target sequence. A 1-step PCR product with a homologous extension flanking region of only 100 nt was in some cases sufficient to obtain the desired mutant. We further showed that the <it>P. aeruginosa </it>strain PA14 non-redundant transposon library can be used in conjunction with the lambda Red technique to rapidly generate large chromosomal deletions or transfer mutated genes into various PA14 isogenic mutants to create multi-locus knockout mutants.</p> <p>Conclusion</p> <p>The lambda Red-based technique can be used efficiently to generate mutants in <it>P. aeruginosa</it>. The main advantage of this procedure is its rapidity as mutants can be easily obtained in less than a week if the 3-step PCR procedure is used, or in less than three days if the mutation needs to be transferred from one strain to another.</p
Lectin-like bacteriocins from pseudomonas spp. utilise D-rhamnose containing lipopolysaccharide as a cellular receptor
Lectin-like bacteriocins consist of tandem monocot mannose-binding domains and display a genus-specific killing activity. Here we show that pyocin L1, a novel member of this family from Pseudomonas aeruginosa, targets susceptible strains of this species through recognition of the common polysaccharide antigen (CPA) of P. aeruginosa lipopolysaccharide that is predominantly a homopolymer of d-rhamnose. Structural and biophysical analyses show that recognition of CPA occurs through the C-terminal carbohydrate-binding domain of pyocin L1 and that this interaction is a prerequisite for bactericidal activity. Further to this, we show that the previously described lectin-like bacteriocin putidacin L1 shows a similar carbohydrate-binding specificity, indicating that oligosaccharides containing d-rhamnose and not d-mannose, as was previously thought, are the physiologically relevant ligands for this group of bacteriocins. The widespread inclusion of d-rhamnose in the lipopolysaccharide of members of the genus Pseudomonas explains the unusual genus-specific activity of the lectin-like bacteriocins
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