The effect of reinfection and mixed Trypanosoma cruzi infections on disease progression in mice

The progression of Chagas disease (CD) varies significantly from host to host and is affected by multiple factors. In particular, mixed strain infections and reinfections have the potential to exacerbate disease progression subsequently affecting clinical management of patients with CD. Consequently, an associated reduction in therapeutic intervention and poor prognosis may occur due to this exacerbated disease state. This study investigated the effects of mixed strain infections and reinfection with Trypanosoma cruzi in mice, using two isolates from different discrete typing units, TcI (C8 clone 1) and TcIV (10R26). There were no significant differences in mortality rate, body weight or body condition among mice infected with either C8 clone 1, 10R26, or a mixture of both isolates. However, the parasite was found in a significantly greater number of host organs in mice infected with a mixture of isolates, and the histopathological response to infection was significantly greater in mice infected with C8 clone 1 alone, and C8 clone 1 + 10R26 mixed infections than in mice infected with 10R26 alone. To investigate the effects of reinfection, mice received either a double exposure to C8 clone 1; a double exposure to 10R26; exposure to C8 clone 1 followed by 10R26; or exposure to 10R26 followed by C8 done 1. Compared to single infection groups, mortality was significantly increased, while survival time, body weight and body condition were all significantly decreased across all reinfection groups, with no significant differences among these groups. The mortality rate over all reinfection groups was 63.6%, compared to 0% in single infection groups, however there was no evidence of a greater histopathological response to infection. These results suggest firstly, that the C8 clone 1 isolate is more virulent than the 10R26 isolate, and secondly, that a more disseminated infection may occur with a mixture of isolates than with single isolates, although there is no evidence that mixed infections have a greater pathological effect. By contrast, reinfections do have major effects on host survivability and thus disease outcome. This confirms previous research demonstrating spontaneous deaths following reinfection, a phenomenon that to our knowledge has only been reported once before

<em>Ab initio</em> thermodynamic model of Cu₂ZnSnS₄

Thin-film solar cells based on the semiconductor Cu2ZnSnS4 (CZTS) are a promising candidate for terawatt-scale renewable energy generation. While CZTS is composed of earth abundant and non-toxic elements, arranged in the kesterite crystal structure, there is a synthetic challenge to produce high-quality stoichiometric materials over large areas. We calculate the thermodynamic potentials of CZTS and its elemental and binary components based on energetic and vibrational data computed using density functional theory. These chemical potentials are combined to produce a thermodynamic model for the stability of CZTS under arbitrary temperatures and pressures, which provide insights into the materials chemistry. CZTS was shown to be thermodynamically stable with respect to its component elements and their major binary phases binaries under modest partial pressures of sulfur and temperatures below 1100 K. Under near-vacuum conditions with sulfur partial pressures below 1 Pa decomposition into binaries including solid SnS becomes favourable, with a strongly temperature-dependent stability window

Leionema lamprophyllum subsp. fractum (Rutaceae); a new and highly restricted taxon from the Hunter Valley of New South Wales

A new subspecies of Leionema lamprophyllum, formerly included in L. lamprophyllum subsp. obovatum F.M.Anderson, is here described as new. Currently known from fewer than 50 individuals, the new subsp. is highly restricted and warrants a conservation risk code of at least Endangered. An illustration of the new taxon, notes on its distribution and habitat, and a key to all four subspecies of L. lamprophyllum are also provided

The online world of the future: Safe, productive, and creative

A safer online world is required to attain higher levels of productivity and creativity. We offer a view of a future state of the online world that places safety, productivity, and creativity above all else. The online world envisaged for 2030 is safe (i.e., users communicate with accuracy and enduring confidence), productive (i.e., users make timely decisions that have an ongoing global effect), and creative (i.e., users can connect seemingly unrelated information online). The proposed view differs from other views of the future online world that are anchored around technology solutions, confrontation, deception, and personal or commercial gain. The following seven conditions characterize the proposed view of the online world: i) global-scale autonomous learning systems; ii) humans co-working with machines; iii) human factors that are authentic and transferrable; iv) global scale whole-brain communities; v) foundational knowledge that is authentic and transferrable; vi) timely productive communication; and vii) continuous technological adaptation. These conditions are expected to enable new social-behavioural, socio-technical, and organizational interaction models

Chemical telemetry of OH observed to measure interstellar magnetic fields

We present models for the chemistry in gas moving towards the ionization front of an HII region. When it is far from the ionization front, the gas is highly depleted of elements more massive than helium. However, as it approaches the ionization front, ices are destroyed and species formed on the grain surfaces are injected into the gas phase. Photodissociation removes gas phase molecular species as the gas flows towards the ionization front. We identify models for which the OH column densities are comparable to those measured in observations undertaken to study the magnetic fields in star forming regions and give results for the column densities of other species that should be abundant if the observed OH arises through a combination of the liberation of H2O from surfaces and photodissociation. They include CH3OH, H2CO, and H2S. Observations of these other species may help establish the nature of the OH spatial distribution in the clouds, which is important for the interpretation of the magnetic field results.Comment: 11 pages, 2 figures, accepted by Astrophysics and Space Scienc

Spin echo small angle neutron scattering using a continuously pumped He-3 neutron polarisation analyser

We present a new instrument for spin echo small angle neutron scattering (SESANS) developed at the Low Energy Neutron Source at Indiana University. A description of the various instrument components is given along with the performance of these components. At the heart of the instrument are a series of resistive coils to encode the neutron trajectory into the neutron polarisation. These are shown to work well over a broad range of neutron wavelengths. Neutron polarisation analysis is accomplished using a continuously operating neutron spin filter polarised by Rb spin-exchange optical pumping of 3He. We describe the performance of the analyser along with a study of the 3He polarisation stability and its implications for SESANS measurements. Scattering from silica Stöber particles is investigated and agrees with samples run on similar instruments

Step-type and step-density influences on CO adsorption probed by reflection absorption infrared spectroscopy (RAIRS) using a curved Pt(111) surface

Catalysis and Surface Chemistr

Site-specific reactivity of molecules with surface defects-the case of H-2 dissociation on Pt

Catalysis and Surface Chemistr

Developing an innovation engine to make Canada a global leader in cybersecurity

An engine designed to convert innovation into a country’s global leadership position in a specific product market is examined in this article, using Canada and cybersecurity as an example. Five entities are core to the innovation engine: an ecosystem, a project community, an external community, a platform, and a corporation. The ecosystem is the focus of innovation in firm-specific factors that determine outcomes in global competition; the project community is the focus of innovation in research and development; and the external community is the focus of innovation in resources produced and used by economic actors that operate outside of the focal product market. Strategic intent, governance, resource flows, and organizational agreements bind the five entities together. Operating the innovation engine in Canada is expected to improve the level and quality of prosperity, security, and capacity of Canadians, increase the number of Canadian-based companies that successfully compete globally in cybersecurity product markets, and better protect Canada’s critical infrastructure. Researchers interested in learning how to create, implement, improve, and grow innovation engines will find this article interesting. The article will also be of interest to senior management teams in industry and government, chief information and technology officers, social and policy analysts, academics, and individual citizens who wish to learn how to secure cyberspace

The anti-NGF antibody muMab 911 both prevents and reverses pain behaviour and subchondral osteoclast numbers in a rat model of osteoarthritis pain

Objective: Nerve growth factor (NGF) has a pivotal role in peripheral hyperalgesia and inflammation; anti-NGF antibodies attenuate pain responses in inflammatory pain models, and in people with osteoarthritis (OA) or low back pain. The aim of this study was to characterise the peripheral mechanisms contributing to the analgesic effects of anti-NGF antibody treatment in an established model of joint pain, which mimics key clinical features of OA. Design: Effects of preventative vs therapeutic treatment with an anti-NGF antibody (monoclonal antibody 911: muMab 911 (10 mg/kg, s.c.)) on pain behaviour (weight bearing asymmetry and hindpaw withdrawal thresholds (PWT)), cartilage damage, synovitis and numbers of subchondral osteoclasts were investigated in the monosodium iodoacetate (MIA) model. Potential direct effects of NGF on receptor activator of nuclear factor kappa-B ligand (RANKL) mediated osteoclastogenesis were investigated in cultured human osteoclasts. Results: Intra-articular MIA injection resulted in significant pain behaviour, cartilage damage, synovitis and increased numbers of subchondral osteoclasts. Both preventative and therapeutic treatment with muMab 911 significantly prevented, or reversed, MIA-induced pain behaviour, but did not alter cartilage or synovial pathology quantified at the end of the treatment period. NGF did not facilitate RANKL driven osteoclast differentiation in vitro, but preventative or therapeutic muMab 911 reduced numbers of TRAP positive osteoclasts in the subchondral bone. Conclusions: We demonstrate that anti-NGF antibody treatment attenuates OA pain behaviour despite permitting cartilage damage and synovitis. Indirec