An Investigation of the Effects of Quantum Dot Nanoparticles on Photopolymer Resin for Use in PolyJet Direct 3D Printing

The addition of quantum dot (QD) nanoparticles to additive manufacturing (AM) media provides the opportunity to create artifacts with complex geometry that also have unique optical characteristics. However, the addition of nanoparticles can significantly alter the rheology of a material and make it difficult to process in an AM context. In this study, quantum dots were added to a photopolymer resin in varying mass ratios to photopolymer, and their effects on the viscosity, surface tension, and jetting ability of the suspension were investigated. Results show that printability was not significantly affected by the presence of quantum dots in mass concentrations less than or equal to 0.5%. The nanosuspensions were deposited via inkjet to demonstrate the feasibility of creating optically-unique artifacts.Mechanical Engineerin

Survival of the fittest: explanations for gadoid imbalance in heavily fished seas

1. Anthropogenic activities have caused the degradation of the world's ecosystems, accelerating the loss of biodiversity. In marine ecosystems, fishing has had strong impacts on fish populations and their habitats; however, not all species have responded equally to fishing pressure. 2. Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and whiting (Merlangius merlangus) are of high commercial value throughout the North Atlantic. Despite having relatively similar life cycles, the state of stocks of these three species varies enormously, with whiting faring better than cod. Within the Firth of Clyde (south‐west Scotland), this imbalance is especially accentuated, where small whiting now make up the greater proportion of the biomass. 3. In this study, cod, haddock, and whiting recruitment to coastal areas, growth, and bait attraction were explored within a marine protected area (MPA) in the Firth of Clyde. Over the course of the summers of 2013 and 2014, whiting and haddock arrived at coastal areas earlier than cod, and grew more quickly. Cod were on average the smallest gadoid observed, and whiting the largest. Whiting also had more predominant scavenging behaviour. 4. These results, in combination with other life‐history traits, indicate that whiting may be at a competitive advantage over cod, and this may partly explain the imbalance of gadoids in the Firth of Clyde. This study highlights the importance of considering life‐history differences in multi‐species fisheries management, and how appropriately managed MPAs could help to restore fish population and assemblage structure

Implications of climate mitigation for future agricultural production

Climate change is projected to negatively impact biophysical agricultural productivity in much of the world. Actions taken to reduce greenhouse gas emissions and mitigate future climate changes, are thus of central importance for agricultural production. Climate impacts are, however, not unidirectional; some crops in some regions (primarily higher latitudes) are projected to benefit, particularly if increased atmospheric carbon dioxide is assumed to strongly increase crop productivity at large spatial and temporal scales. Climate mitigation measures that are implemented by reducing atmospheric carbon dioxide concentrations lead to reductions both in the strength of climate change and in the benefits of carbon dioxide fertilization. Consequently, analysis of the effects of climate mitigation on agricultural productivity must address not only regions for which mitigation is likely to reduce or even reverse climate damages. There are also regions that are likely to see increased crop yields due to climate change, which may lose these added potentials under mitigation action. Comparing data from the most comprehensive archive of crop yield projections publicly available, we find that climate mitigation leads to overall benefits from avoided damages at the global scale and especially in many regions that are already at risk of food insecurity today. Ignoring controversial carbon dioxide fertilization effects on crop productivity, we find that for the median projection aggressive mitigation could eliminate ~81% of the negative impacts of climate change on biophysical agricultural productivity globally by the end of the century. In this case, the benefits of mitigation typically extend well into temperate regions, but vary by crop and underlying climate model projections. Should large benefits to crop yields from carbon dioxide fertilization be realized, the effects of mitigation become much more mixed, though still positive globally and beneficial in many food insecure countries

Human Clostridium difficile infection caused by a livestock-associated PCR ribotype 237 strain in Western Australia

Introduction: Clostridium difficile infection (CDI) is a significant gastrointestinal disease in the developed world and increasingly recognised as a zoonotic infection. In North America and Europe, the PCR ribotype (RT) 078 strain of C. difficile is commonly found in production animals and as a cause of disease in humans although proof of transmission from animals is lacking. This strain is absent in Australian livestock. We report a case of human CDI caused by a strain of C. difficile belonging to known Australian livestock-associated RT 237. Case presentation: A young male was admitted for multiple trauma following a motor vehicle accident and placed on piperacillin/tazobactam for pneumonia. After 4 days of treatment, he developed symptoms of CDI, which was confirmed in the laboratory. His symptoms resolved after 6 days of intravenous metronidazole. The strain of C. difficile isolated was identified as RT 237, an unusual RT previously found in with several Western Australia piggeries. Conclusion: This case of CDI caused by an unusual livestock-associated C. difficile RT 237 supports the hypothesis of zoonotic transmission. The case highlights the potential of livestock to act as reservoir for C. difficile and the need for continued surveillance of CDI in both human and animal populations

Vulnerability to bullying in children with a history of specific speech and language difficulties

This is an electronic version of an article published in Lindsay, Geoff and Dockrell, Julie and Mackie, Clare (2008) Vulnerability to bullying in children with a history of specific speech and language difficulties. European Journal of Special Needs Education, 23 (1). pp. 1-16. European Journal of Special Needs Education is available online at: http://www.informaworld.com/10.1080/0885625070179120

Robust tests for a linear trend with an application to equity indices

In this paper we develop a testing procedure for the presence of a deterministic linear trend in a univariate time series which is robust to whether the series is I(0) or I(1) and requires no knowledge of the form of weak dependence present in the data. Our approach is motivated by the testing procedures of Vogelsang [1998, Econometrica, vol 66, p123–148] and Bunzel and Vogelsang [2005, Journal of Business and Economic Statistics, vol 23, p381–394], but utilises an auxiliary unit root test to switch between critical values in the exact I(1) and I(0) environments, rather than using this unit root test to scale the test statistic as is done in the aforementioned procedures. We show that our proposed tests have uniformly greater local asymptotic power than the tests of Vogelsang (1998) and Bunzel and Vogelsang (2005) when the error process is exact I(1), identical local asymptotic when the error process is I(0), and have better overall local asymptotic power when the error process is near I(1). Our proposed tests also display superior finite sample power to the tests of Vogelsang (1998) and Bunzel and Vogelsang (2005) and are competitive in finite samples with tests designed to be optimal in both the exact I(1) and I(0) environments. We apply our test procedures to a number of equity indices and find that these series appear to have a significant upward deterministic trend, yet are also highly persistent about this long run growth path

CD56 regulates human NK cell cytotoxicity through Pyk2

Human natural killer (NK) cells are defined as CD5

An evaluation of injurious falls and Fall-Risk-Increasing-Drug (FRID) prescribing in ambulatory care in older adults

Background: Falls are a major public health problem affecting millions of older adults each year. Little is known about FRID prescribing behaviors after injurious falls occur. The primary objective of this study was to investigate whether an injurious fall is associated with being prescribed a new FRID. Methods: We conducted a cross-sectional analysis using data from the National Ambulatory Medical Care Survey (2016). We included visits from patients age ≥ 65 years and classified visits based on presence of an injurious fall. The outcome of interest was prescription of new FRID between those with and without an injurious fall. Multivariable logistic regression weighted for sampling and adjusted for demographics, health history and other medications was used. Age and Alzheimer’s disease were examined as potential effect measure modifiers. Odds ratios and 95% confidence intervals were reported. Bayes factor upper bounds were also reported to quantify whether the data were better predicted by the null hypothesis or the alternative hypothesis. Results: The sample included 239,016,482 ambulatory care visits. 5,095,734 (2.1%) of the visits were related to an injurious fall. An injurious fall was associated with a non-statistically significant increase in odds of at least one new FRID prescription: adjusted OR = 1.6 (95% CI 0.6, 4.0). However, there was non-statistically significant evidence that the association depended on patient age, with OR = 2.6 (95% CI 0.9, 7.4) for ages 65–74 versus OR = 0.4 (95% CI 0.1, 1.6) for ages ≥ 75. In addition to age, Alzheimer’s disease was also identified as a statistically significant effect measure modifier, but stratum specific estimates were not determined due to small sample sizes. Conclusions: Ambulatory care visits involving an injurious fall showed a non-statistically significant increase in odds of generating a new FRID prescription, but this association may depend on age

Evaluating the effectiveness of management measures on skates in a changing world

Global declines in elasmobranchs have been observed. Conservation measures such as area closures and fisheries prohibitions have been put in place to support the recovery of vulnerable species. However, the effectiveness of such measures is rarely evaluated in the context of other factors that may affect population abundance. This study investigates the effectiveness of management measures using 1) General additive mixed model derivative changes, taking into account environmental factors that may affect population stochasticity and 2) an age-structured density dependent population dynamic model. The Raja undulata (undulate ray) 2009 targeted fisheries prohibition was used as a case study. Potential beneficial responses on sympatric species Raja clavata (thornback ray) were modelled. A significant increase in abundance was observed in both IUCN red list species during the ban. Surface seawater temperature had a marginal effect on the abundance of both species. The prohibition was in place for an insufficient length of time for long lasting effects to be detected on skate length. The population dynamic model indicated that the increase in abundance was only possible when combining the fisheries ban with increased juvenile discard survival. Our results indicate that species conservation measures may not only have positive effects on the species in question, but also on species with a niche overlap. Nonetheless, due to ongoing fishing for other species, the full potential of fisheries prohibitions may not be realised. For real benefits to be assessed, evaluation of bans should take place once a steady state is observed