385 research outputs found
A GeoSocial Intelligence Framework for Studying & Promoting Resilience to Seasonal Flooding in Jakarta, Indonesia
PetaJakarta.org is a web-based platform developed to harness the power of social media to gather, sort, and
display information about flooding for Jakarta residents in real time. The platform runs on the open source software
CogniCity—an OSS platform developed by the SMART Infrastructure Facility, University of Wollongong—which
allows data to be collected and disseminated by community members through their location-enabled mobile
devices. The project uses a GeoSocial Intelligence Framework to approach the complexity of Jakarta’s entangled
hydraulic, hydrological and meteorological systems and thereby converts the noise of social media into knowledge
about urban infrastructure and situational conditions related to flooding and inundation.
In this paper, PetaJakarta.org co-directors Dr Tomas Holderness, Geomatics Research Fellow at the SMART
Infrastructure Facility, Dr Etienne Turpin, Vice-Chancellor’s Postdoctoral Research Fellow at the SMART Infrastructure
Facility, and Dr Rohan Wickramasuriyam, GIS Research Fellow at the SMART Infrastructure Facility, will discuss
their GeoSocial Intelligence Framework as it applies to their current research in Jakarta. They will also present their
preliminary findings from their 2014 Twitter #DataGrant, which has allowed them to develop a correlative analysis
between historic social media information, the Jakarta government’s flood maps, and the infrastructure used to
manage critical flood emergencies. Finally, they will speculate on several future applications of the CogniCity OSS
and suggest how it might be developed to further promote an integrated civic co-management platform with the
support of business, industry, government and community organizations
An Evaluation of Spatial Network Modeling To Aid Sanitation Planning In Informal Settlements Using Crowd-Sourced Data
Limited water and sanitation infrastructure in rapidly
urbanising informal settlements can present significant health and
environmental risks to the populations of developing nations. Where
formal piped networks are not available, road-based sewage treatmenttransportation
options have been cited as a viable alternative. However,
little research has been undertaken to evaluate the long-term operational
costs of such systems. In this paper we present an evaluation of network
modelling, as a novel method to evaluate the costs of road-based sewage
treatment-transport options. Such analysis is made possible using crowdsourced,
open geospatial data sets that allow us to examine costs based
on different spatio-topological network configurations. It is envisaged
that engineers could use such a tool as part of the sanitation planning
process, to evaluate sanitation network implementation options. This
study provides an evaluation of the methods using a case study from the
Kibera settlement in Kenya
Polysaccharides Isolated from Açaí Fruit Induce Innate Immune Responses
The Açaí (Acai) fruit is a popular nutritional supplement that purportedly enhances immune system function. These anecdotal claims are supported by limited studies describing immune responses to the Acai polyphenol fraction. Previously, we characterized γδ T cell responses to both polyphenol and polysaccharide fractions from several plant-derived nutritional supplements. Similar polyphenol and polysaccharide fractions are found in Acai fruit. Thus, we hypothesized that one or both of these fractions could activate γδ T cells. Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures. To characterize the immune response to Acai polysaccharides, we fractionated the crude polysaccharide preparation and tested these fractions for activity in human PBMC cultures. The largest Acai polysaccharides were the most active in vitro as indicated by activation of myeloid and γδ T cells. When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production. These results define innate immune responses induced by the polysaccharide component of Acai and have implications for the treatment of asthma and infectious disease
Why do large shareholders adopt a short-term versus a long-term investment horizon in different firms?
I ask why the same large shareholders have different investment horizons. Using data for 1998–2013, I examine four fundamental firm policies for their potential influence on blockholders’ investments with different time horizons. The panel ordinary least squares, difference‐in‐difference (using the Sarbanes‐Oxley Act), logistic, and dynamic generalized method of moments regression analyses reveal that blockholders adopt a short‐term horizon in smaller firms with a less independent board, high leverage, and high dividends while the same blockholders keep their investments longer in firms with a more independent board and low dividends. Under various economic conditions, different firm characteristics gain importance in blockholders’ decision on short‐term versus long‐term investments
Truth, trust, and civic duty:Cultural factors in citizens' perceptions of mobile phone apps and social media in disasters
This study investigates how citizens perceive the role of mobile phone apps specifically designed for disaster communication, and how these perceptions may differ from perceived roles and functions of social media in disaster-related tasks/situations. Focusing on trust in authorities and technology use, results suggest that social media use not only fosters trust via shared narratives and collective sense-making but may also improve trust relationships through local authorities assuming the function of a trustworthy information provider. In disaster apps usage, trust between citizens and authorities is generated through perceptions of shared responsibility rather than shared narratives. Apps were seen as mechanisms that reveal authorities' general willingness to share control, which may help overcome citizens' perceptions that they are distrusted by authorities.</p
A Low-Mass Planet with a Possible Sub-Stellar-Mass Host in Microlensing Event MOA-2007-BLG-192
We report the detection of an extrasolar planet of mass ratio q ~ 2 x 10^(-4)
in microlensing event MOA-2007-BLG-192. The best fit microlensing model shows
both the microlensing parallax and finite source effects, and these can be
combined to obtain the lens masses of M = 0.060 (+0.028 -0.021) M_sun for the
primary and m = 3.3 (+4.9 -1.6) M_earth for the planet. However, the
observational coverage of the planetary deviation is sparse and incomplete, and
the radius of the source was estimated without the benefit of a source star
color measurement. As a result, the 2-sigma limits on the mass ratio and finite
source measurements are weak. Nevertheless, the microlensing parallax signal
clearly favors a sub-stellar mass planetary host, and the measurement of finite
source effects in the light curve supports this conclusion. Adaptive optics
images taken with the Very Large Telescope (VLT) NACO instrument are consistent
with a lens star that is either a brown dwarf or a star at the bottom of the
main sequence. Follow-up VLT and/or Hubble Space Telescope (HST) observations
will either confirm that the primary is a brown dwarf or detect the low-mass
lens star and enable a precise determination of its mass. In either case, the
lens star, MOA-2007-BLG-192L, is the lowest mass primary known to have a
companion with a planetary mass ratio, and the planet, MOA-2007-BLG-192Lb, is
probably the lowest mass exoplanet found to date, aside from the lowest mass
pulsar planet.Comment: Accepted for publication in the Astrophysical Journal. Scheduled for
the Sept. 1, 2008 issu
Risk-shifting Through Issuer Liability and Corporate Monitoring
This article explores how issuer liability re-allocates fraud risk and how risk allocation may reduce the incidence of fraud. In the US, the apparent absence of individual liability of officeholders and insufficient monitoring by insurers under-mine the potential deterrent effect of securities litigation. The underlying reasons why both mechanisms remain ineffective are collective action problems under the prevailing dispersed ownership structure, which eliminates the incentives to moni-tor set by issuer liability. This article suggests that issuer liability could potentially have a stronger deterrent effect when it shifts risk to individuals or entities holding a larger financial stake. Thus, it would enlist large shareholders in monitoring in much of Europe. The same risk-shifting effect also has implications for the debate about the relationship between securities litigation and creditor interests. Credi-tors’ claims should not be given precedence over claims of defrauded investors (e.g., because of the capital maintenance principle), since bearing some of the fraud risk will more strongly incentivise large creditors, such as banks, to monitor the firm in jurisdictions where corporate debt is relatively concentrated
Multiple agency perspective, family control, and private information abuse in an emerging economy
Using a comprehensive sample of listed companies in Hong Kong this paper investigates how family control affects private information abuses and firm performance in emerging economies. We combine research on stock market microstructure with more recent studies of multiple agency perspectives and argue that family ownership and control over the board increases the risk of private information abuse. This, in turn, has a negative impact on stock market performance. Family control is associated with an incentive to distort information disclosure to minority shareholders and obtain private benefits of control. However, the multiple agency roles of controlling families may have different governance properties in terms of investors’ perceptions of private information abuse. These findings contribute to our understanding of the conflicting evidence on the governance role of family control within a multiple agency perspectiv
Nasal Acai Polysaccharides Potentiate Innate Immunity to Protect against Pulmonary Francisella tularensis and Burkholderia pseudomallei Infections
Pulmonary Francisella tularensis and Burkholderia pseudomallei infections are highly lethal in untreated patients, and current antibiotic regimens are not always effective. Activating the innate immune system provides an alternative means of treating infection and can also complement antibiotic therapies. Several natural agonists were screened for their ability to enhance host resistance to infection, and polysaccharides derived from the Acai berry (Acai PS) were found to have potent abilities as an immunotherapeutic to treat F. tularensis and B. pseudomallei infections. In vitro, Acai PS impaired replication of Francisella in primary human macrophages co-cultured with autologous NK cells via augmentation of NK cell IFN-γ. Furthermore, Acai PS administered nasally before or after infection protected mice against type A F. tularensis aerosol challenge with survival rates up to 80%, and protection was still observed, albeit reduced, when mice were treated two days post-infection. Nasal Acai PS administration augmented intracellular expression of IFN-γ by NK cells in the lungs of F. tularensis-infected mice, and neutralization of IFN-γ ablated the protective effect of Acai PS. Likewise, nasal Acai PS treatment conferred protection against pulmonary infection with B. pseudomallei strain 1026b. Acai PS dramatically reduced the replication of B. pseudomallei in the lung and blocked bacterial dissemination to the spleen and liver. Nasal administration of Acai PS enhanced IFN-γ responses by NK and γδ T cells in the lungs, while neutralization of IFN-γ totally abrogated the protective effect of Acai PS against pulmonary B. pseudomallei infection. Collectively, these results demonstrate Acai PS is a potent innate immune agonist that can resolve F. tularensis and B. pseudomallei infections, suggesting this innate immune agonist has broad-spectrum activity against virulent intracellular pathogens
Loss of Sialic Acid Binding Domain Redirects Protein σ1 to Enhance M Cell-Directed Vaccination
Ovalbumin (OVA) genetically fused to protein sigma 1 (pσ1) results in tolerance to both OVA and pσ1. Pσ1 binds in a multi-step fashion, involving both protein- and carbohydrate-based receptors. To assess the relative pσ1 components responsible for inducing tolerance and the importance of its sialic binding domain (SABD) for immunization, modified OVA-pσ1, termed OVA-pσ1(short), was deleted of its SABD, but with its M cell targeting moiety intact, and was found to be immunostimulatory and enhanced CD4+ and CD8+ T cell proliferation. When used to nasally immunize mice given with and without cholera toxin (CT) adjuvant, elevated SIgA and serum IgG responses were induced, and OVA-pσ1(s) was more efficient for immunization than native OVA+CT. The immune antibodies (Abs) were derived from elevated Ab-forming cells in the upper respiratory tissues and submaxillary glands and were supported by mixed Th cell responses. Thus, these studies show that pσ1(s) can be fused to vaccines to effectively elicit improved SIgA responses
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