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The Influence of Tillage Frequency on Crop Productivity in Sub-Tropical to Semi-Arid Climates
MH Crawford,K Bell,S Kodur,YP Dang 한국작물학회 2018 Journal of crop science and biotechnology Vol.21 No.1
Strategic tillage (ST), an occasional tillage in a continuous no-till (NT) farming system, is already being utilized by many landholders in the Northern Grains Region (NGR) of Australia to control weeds. But the impact on productivity (yield), both short- and long-term, has been largely under investigated. This study focused on yield data from 14 on-farm ST in NT experiments from 2012 to 2014 (3 years/4 seasons) and the comparison of the re-interpreted results of a long-term (27 years) tillage experiment. This study explored production impacts of tillage on long-term NT systems over the short and longer term. Results from tillage-frequency studies across the NGR demonstrated that overall grain yield was not significantly impacted. A long-term tillage trial at Biloela showed wheat (Triticum aestivum) and sorghum (Sorghum bicolor) grain yields were similar across no till, stubble mulch and reduced tillage treatments, these in turn were all significantly higher than aggressive tillage without stubble retention treatments. Dealing with increased herbicide resistance often associated with reduced tillage and no-till systems poses a real time issue with landholders in the NGR. This analysis of historical yield data together with the more recent strategic tillage data can aid in selecting the appropriate soil management option by providing tillage impacts on yield.
Fully implantable, battery-free wireless optoelectronic devices for spinal optogenetics :
Samineni, Vijay K.,Yoon, Jangyeol,Crawford, Kaitlyn E.,Jeong, Yu Ra,McKenzie, Kajanna C,Shin, Gunchul,Xie, Zhaoqian,Sundaram, Saranya S.,Li, Yuhang,Yang, Min Young,Kim, Jeonghyun,Wu, Di,Xue, Yeguang,F Ovid Technologies (Wolters Kluwer) - Lippincott Wi 2017 Pain Vol.158 No.11
<P>The advent of optogenetic tools has allowed unprecedented insights into the organization of neuronal networks. Although recently developed technologies have enabled implementation of optogenetics for studies of brain function in freely moving, untethered animals, wireless powering and device durability pose challenges in studies of spinal cord circuits where dynamic, multidimensional motions against hard and soft surrounding tissues can lead to device degradation. We demonstrate here a fully implantable optoelectronic device powered by near-field wireless communication technology, with a thin and flexible open architecture that provides excellent mechanical durability, robust sealing against biofluid penetration and fidelity in wireless activation, thereby allowing for long-term optical stimulation of the spinal cord without constraint on the natural behaviors of the animals. The system consists of a double-layer, rectangular-shaped magnetic coil antenna connected to a microscale inorganic light-emitting diode (m-ILED) on a thin, flexible probe that can be implanted just above the dura of the mouse spinal cord for effective stimulation of light-sensitive proteins expressed in neurons in the dorsal horn. Wireless optogenetic activation of TRPV1-ChR2 afferents with spinal m-ILEDs causes nocifensive behaviors and robust real-time place aversion with sustained operation in animals over periods of several weeks to months. The relatively low-cost electronics required for control of the systems, together with the biocompatibility and robust operation of these devices will allow broad application of optogenetics in future studies of spinal circuits, as well as various peripheral targets, in awake, freely moving and untethered animals, where existing approaches have limited utility.</P>
OBSERVATIONAL STUDIES OF MAGNETICALLY ACTIVE STARS
BUDDlNG E.,ALLEN D.,CRAWFORD D. L.,JONES K. M.,SLEE O. B.,ZEILIK M. The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1
Multi-wavelength observing has been particularly fruitful in cool star research. There have been some well-observed examples, eg AB Dor, though ambiguity remains. This raises issues of data information content and model parameter determinacy, which are examined firstly in an optical context. We then widen the discussion to show how multi-site and multi-wavelength data can be combined to point to better constrained models. Particular cases, involving near-simultaneous radiometry and photometry, are discussed to clarify such modelling.
The burden of typhoid fever in low- and middle-income countries: A meta-regression approach
Antilló,n, Marina,Warren, Joshua L.,Crawford, Forrest W.,Weinberger, Daniel M.,Kü,rü,m, Esra,Pak, Gi Deok,Marks, Florian,Pitzer, Virginia E. Public Library of Science 2017 PLoS neglected tropical diseases Vol.11 No.3
<▼1><P><B>Background</B></P><P>Upcoming vaccination efforts against typhoid fever require an assessment of the baseline burden of disease in countries at risk. There are no typhoid incidence data from most low- and middle-income countries (LMICs), so model-based estimates offer insights for decision-makers in the absence of readily available data.</P><P><B>Methods</B></P><P>We developed a mixed-effects model fit to data from 32 population-based studies of typhoid incidence in 22 locations in 14 countries. We tested the contribution of economic and environmental indices for predicting typhoid incidence using a stochastic search variable selection algorithm. We performed out-of-sample validation to assess the predictive performance of the model.</P><P><B>Results</B></P><P>We estimated that 17.8 million cases of typhoid fever occur each year in LMICs (95% credible interval: 6.9–48.4 million). Central Africa was predicted to experience the highest incidence of typhoid, followed by select countries in Central, South, and Southeast Asia. Incidence typically peaked in the 2–4 year old age group. Models incorporating widely available economic and environmental indicators were found to describe incidence better than null models.</P><P><B>Conclusions</B></P><P>Recent estimates of typhoid burden may under-estimate the number of cases and magnitude of uncertainty in typhoid incidence. Our analysis permits prediction of overall as well as age-specific incidence of typhoid fever in LMICs, and incorporates uncertainty around the model structure and estimates of the predictors. Future studies are needed to further validate and refine model predictions and better understand year-to-year variation in cases.</P></▼1><▼2><P><B>Author summary</B></P><P>Typhoid fever is a bacterial enteric infection that continues to pose a considerable burden to the 5.5 billion people living in low- and middle-income countries (LMICs). We developed and validated a model incorporating widely available indicators of economic and social development and the environment to estimate the burden of typhoid fever across LMICs. Our analysis uses all available data to estimate the incidence of typhoid in key age groups, which is important for the design and implementation of optimal vaccination strategies, and it identifies regions of the world that have the most uncertainty in typhoid incidence. Across all LMICs, we estimated that the expected number of typhoid fever cases per year is 17.8 million (95% CI: 6.9–48.4 million). We also present the probability that incidence surpasses the criteria for low, medium, high, and very high incidence in each country, which could help guide policy in the face of uncertainty.</P></▼2>
Stability of the Broad-line Region Geometry and Dynamics in Arp 151 Over Seven Years
Pancoast, A.,Barth, A. J.,Horne, K.,Treu, T.,Brewer, B. J.,Bennert, V. N.,Canalizo, G.,Gates, E. L.,Li, W.,Malkan, M. A.,Sand, D.,Schmidt, T.,Valenti, S.,Woo, J.-H.,Clubb, K. I.,Cooper, M. C.,Crawford American Astronomical Society 2018 The Astrophysical journal Vol.856 No.2
<P>The Seyfert 1 galaxy Arp 151 was monitored as part of three reverberation mapping campaigns spanning 2008-2015. We present modeling of these velocity-resolved reverberation mapping data sets using a geometric and dynamical model for the broad-line region (BLR). By modeling each of the three data sets independently, we infer the evolution of the BLR structure in Arp 151 over a total of 7 yr and constrain the systematic uncertainties in nonvarying parameters such as the black hole mass. We find that the BLR geometry of a thick disk viewed close to face-on is stable over this time, although the size of the BLR grows by a factor of similar to 2. The dynamics of the BLR are dominated by inflow, and the inferred black hole mass is consistent for the three data sets, despite the increase in BLR size. Combining the inference for the three data sets yields a black hole mass and statistical uncertainty of log(10)(M-BH/M-circle dot) = 6.82(-0.09)(+0.09) with a standard deviation in individual measurements of 0.13 dex.</P>