56 research outputs found

    Corn Yield Response to Water Availability

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    Drought-tolerant technologies have become popular in hybrids for low-yielding corn environments across central and western Kansas and are marketed for their ability to produce higher grain yields with less water. The objective of this study was to compare water use, yield, and water use efficiency (WUE) of two types of drought-tolerant (DT) corn hybrids and a high-yielding non-DT hybrid. Water use and yield of two DT and one non-DT, high-yielding hybrid were compared in both dryland and irrigated situations. The average yield for the irrigated corn was 217 bu/a, and the average was 127 bu/a in dryland, representing a yield increase of 90 bu/a. The irrigated corn received a total of 10 in. more water than the dryland corn over the course of the growing season, resulting in 9 bu for each additional inch of water use averaged across the three hybrids. The irrigated corn used a mean of 20.85 in. of water, and the dryland corn used a mean of 11.66 in. of water. The WUE was 10.71 bu/in. and 10.43 bu/in. for dryland and irrigated corn, respectively. Although hybrid yields differed in the irrigated environment, water use and WUE were similar for all hybrids in both dryland and irrigated environments. One DT hybrid exhibited more stable yields across dryland and irrigated environments compared with the other DT hybrid and the non-DT hybrid

    Grain Sorghum Yield Response to Water Availability

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    Yield effects of irrigation on sorghum and corn were compared, focusing only on the grain sorghum phase. Average water use for irrigation was 22 in., and dryland sorghum used 17 in. Average yields based on 12.5% grain moisture for dryland and irrigated sorghum were similar, with 138 bu/a for the irrigated and 142 bu/a for the dryland environment. Irrigated sorghum yields were similar, but in dryland, the Pioneer 84G62 hybrid yielded 149 bu/a, a 10 bu/a increase over Pioneer 84Y50 and DKS 53-67 hybrids, which yielded 139 bu/a and 138 bu/a, respectively. Although there was a difference in the yield between the hybrids on the dryland block, there were no significant differences between water use and water use efficiency (WUE)

    Grain Sorghum Yield Response to Water Availability

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    Yield effects of irrigation on sorghum and corn were compared, but this report is merely focused on the sorghum phase of the crop rotation. Mean yield for irrigated sorghum was 168 bu/a, whereas dryland yield was 145 bu/a. The latter represents a yield improvement of 24 bu/a, an increase of approximately 2 bu/a per unit (in.) of water applied (considering a total of 11 in. of water applied in the irrigation block). The irrigated sorghum used a mean of 7.8 in. more water than the dryland, which suggests that the dryland sorghum consumed 3.4 in. more water from the soil profile than the irrigated sorghum (this value assumes no water losses due to runoff or deep percolation and is calculated from total precipitation and irrigation as well as changes in profile water status). Water use efficiency, or WUE, was calculated as the ratio of yield to water use. A trend for superior WUE of 6.5 bu/in. was documented under dryland conditions, compared with 5.6 bu/in. for irrigated sorghum

    Grain Sorghum Response to Water Supply and Environment

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    Three grain sorghum hybrids were selected to compare under different water supply scenarios across Kansas. The environments ranged from dryland in western Kansas to dryland and irrigated in central and eastern Kansas. The three hybrids that were selected represent different sorghum genotypes used commercially. Looking at two situations from higher and lower yielding environments, hybrids 1 and 3 had different strategies to attain final yields. In the higher yielding environment, both grain harvest index (HI, expressed as the dry weight ratio of grain yield to plant biomass at maturity) and biomass were maximized for hybrid 1 and hybrid 2. In the lower yielding environment, their yields were similar, but hybrid 1 produced less biomass and had a greater HI. Hybrid 3 exhibited the opposite scenario in that environment: greater biomass production and smaller HI. Following these outcomes, grain sorghum hybrids use multiple strategies to produce grain yield in each environment. In high yielding environments though, plants need to maximize both biomass and efficiency in partitioning to grain

    The epidemiology of injuries across the weight-training sports

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    Background: Weight-training sports, including weightlifting, powerlifting, bodybuilding, strongman, Highland Games, and CrossFit, are weight-training sports that have separate divisions for males and females of a variety of ages, competitive standards, and bodyweight classes. These sports may be considered dangerous because of the heavy loads commonly used in training and competition. Objectives: Our objective was to systematically review the injury epidemiology of these weight-training sports, and, where possible, gain some insight into whether this may be affected by age, sex, competitive standard, and bodyweight class. Methods: We performed an electronic search using PubMed, SPORTDiscus, CINAHL, and Embase for injury epidemiology studies involving competitive athletes in these weight-training sports. Eligible studies included peer-reviewed journal articles only, with no limit placed on date or language of publication. We assessed the risk of bias in all studies using an adaption of the musculoskeletal injury review method. Results: Only five of the 20 eligible studies had a risk of bias score ≥75 %, meaning the risk of bias in these five studies was considered low. While 14 of the studies had sample sizes >100 participants, only four studies utilized a prospective design. Bodybuilding had the lowest injury rates (0.12–0.7 injuries per lifter per year; 0.24–1 injury per 1000 h), with strongman (4.5–6.1 injuries per 1000 h) and Highland Games (7.5 injuries per 1000 h) reporting the highest rates. The shoulder, lower back, knee, elbow, and wrist/hand were generally the most commonly injured anatomical locations; strains, tendinitis, and sprains were the most common injury type. Very few significant differences in any of the injury outcomes were observed as a function of age, sex, competitive standard, or bodyweight class. Conclusion: While the majority of the research we reviewed utilized retrospective designs, the weight-training sports appear to have relatively low rates of injury compared with common team sports. Future weight-training sport injury epidemiology research needs to be improved, particularly in terms of the use of prospective designs, diagnosis of injury, and changes in risk exposure

    The techno-ecological practice as the politics of ontological coalitions

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    The paper focuses on the art projects aimed at visualizing (grasping) the physical or biological phenomena through interfaces and / or installations designed specifically for such purpose. Such works often mirror the post-­digital condition of our time where the digital technologies constitute the common background for everyday activities, no longer having the allure of "new" and "exciting" (Berry, Dieter et al., 2015). In this process, both the networked technologies of wireless communication and the act of crossing the boundaries between the digital and the physical play the crucial role as the post-­digital networked imagery increasingly becomes directly connected to the physical environment. I would like to ponder on the questions of processuality and relationality involved in such instances where the complexity of the hybrid works of art clearly transgresses the paradigm of representationalism (Thrift, 2008;; Anderson and Harrison, 2010;; Kember and Zylinska, 2012). The particular attention is given to the fact that such artworks bond different ontological realms (discursive, physical, digital) and different agents (human and non-­human, carbon-­based and software-­based) forging “ontological coalitions” (Malafouris, 2013). Throughout the article the mutlirealist and relational perspective is offered, inspired by the propositions of Gilbert Simondon and Etienne Souriau. Based on the research project supported by National Science Centre Poland ("The aesthetics of post-­digital imagery: between new materialism and object-­oriented philosophy", 2016/21/B/HS2/00746)

    The influence of speed and size on avian terrestrial locomotor biomechanics: predicting locomotion in extinct theropod dinosaurs

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    How extinct, non-avian theropod dinosaurs moved is a subject of considerable interest and controversy. A better understanding of non-avian theropod locomotion can be achieved by better understanding terrestrial locomotor biomechanics in their modern descendants, birds. Despite much research on the subject, avian terrestrial locomotion remains little explored in regards to how kinematic and kinetic factors vary together with speed and body size. Here, terrestrial locomotion was investigated in twelve species of ground-dwelling bird, spanning a 1,780-fold range in body mass, across almost their entire speed range. Particular attention was devoted to the ground reaction force (GRF), the force that the feet exert upon the ground. Comparable data for the only other extant obligate, striding biped, humans, were also collected and studied. In birds, all kinematic and kinetic parameters examined changed continuously with increasing speed, while in humans all but one of those same parameters changed abruptly at the walk-run transition. This result supports previous studies that show birds to have a highly continuous locomotor repertoire compared to humans, where discrete ‘walking’ and ‘running’ gaits are not easily distinguished based on kinematic patterns alone. The influences of speed and body size on kinematic and kinetic factors in birds are developed into a set of predictive relationships that may be applied to extinct, non-avian theropods. The resulting predictive model is able to explain 79–93% of the observed variation in kinematics and 69–83% of the observed variation in GRFs, and also performs well in extrapolation tests. However, this study also found that the location of the whole-body centre of mass may exert an important influence on the nature of the GRF, and hence some caution is warranted, in lieu of further investigation
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