707 research outputs found
Vergleich genetisch diverser Brokkoli-Populationssorten mit einer F1-Hybride unter ökologischen Anbaubedingungen
Field trials were conducted for three years on an organic farm in England to assess the performance and yield variability of two synthetic sprouting broccoli populations with 4 or 8 parents respectively, along with the original landrace mother plants and a commercial F1 hybrid variety as control (Santée). In terms of total yield, Santée outperformed the other entries, but for some other traits, e.g. heading time and number of sprouts, Santée was comparable with the mean of one or more of the genetically diverse entries. Analysis of yield variability over time showed mixed results. With regard to total yield and total sprout number, variability was higher in the F1 hybrid than in the genetically diverse populations, but for other parameters such as average sprout weight and time to maturity, patterns were less clear. Using broccoli populations in commercial production will depend on acceptability of within-population variability of phenotypic traits, especially maturation time
Utilizing UV and Visible Sensors on Micro Satellites to Demonstrate Target Acquisition and Tracking
The Distributed Sensing Experiment (DSE) program is a technology demonstration of target acquisition, tracking, and three-dimensional track development using a constellation of three micro satellites. DSE will demonstrate how micro satellites, working singly and as a group, can observe test-missile boost and ballistic-flight events. The overarching program objective is to demonstrate a means of fusing measurements from multiple sensors into a composite track. To perform this demonstration, each DSE micro satellite will acquire and track a target, determine a two-dimensional direction and movement rate for each, communicate observations to other DSE satellites, determine a three-dimensional target position and velocity, and relay this information to ground systems. A key design parameter of the program is incorporating commercial off-the-shelf (COTS) hardware and software to reduce risk and control costs, while maintaining performance. Having completed a successful Critical Design Review, the program is currently in fabrication, integration, and test phase. The constellation of satellites is scheduled for launch in CY2009. This paper describes the status and capabilities of the UV and visible sensor payloads, as well as the algorithms and software being developed to achieve the DSE mission
Proteomic responses to elevated ocean temperature in ovaries of the ascidian \u3cem\u3eCiona intestinalis\u3c/em\u3e
Ciona intestinalis, a common sea squirt, exhibits lower reproductive success at the upper extreme of the water temperatures it experiences in coastal New England. In order to understand the changes in protein expression associated with elevated temperatures, and possible response to global temperature change, we reared C. intestinalis from embryos to adults at 18°C (a temperature at which they reproduce normally at our collection site in Rhode Island) and 22°C (the upper end of the local temperature range). We then dissected ovaries from animals at each temperature, extracted protein, and measured proteomic levels using shotgun mass spectrometry (LC-MS/MS). 1532 proteins were detected at a 1% false discovery rate present in both temperature groups by our LC-MS/MS method. 62 of those proteins are considered up- or down-regulated according to our statistical criteria. Principal component analysis shows a clear distinction in protein expression pattern between the control (18°C) group and high temperature (22°C) group. Similar to previous studies, cytoskeletal and chaperone proteins are upregulated in the high temperature group. Unexpectedly, we find evidence that proteolysis is downregulated at the higher temperature. We propose a working model for the high temperature response in C. intestinalis ovaries whereby increased temperature induces upregulation of signal transduction pathways involving PTPN11 and CrkL, and activating coordinated changes in the proteome especially in large lipid transport proteins, cellular stress responses, cytoskeleton, and downregulation of energy metabolism
What is the impact of Apps in medical education? A study of CAPSULE, a case-based learning App
Introduction - Mobile applications (Apps) are popular in medical education; yet, the actual benefits for students are yet to be formally researched. Clinical And Professional Studies Unique Learning Environment (CAPSULE) is an App created by Brighton and Sussex Medical School. The App provides 650 cases offered to students in their final two years of the undergraduate programme. The App performed consistently well in student feedback, and therefore, a study into the educational benefits of the App was constructed.
Methods - A cross-sectional study was performed following two years of use by students to investigate the relationship between App usage and decile ranking.
Results - The study found that the students who completed more cases tended to score higher per case (p value=0.0037). The study also found a trend between having higher case scores and being part of a stronger decile (p value=0.019).
Conclusions - Greater App usage was linked with performing better in the App itself and this was further associated with being in a stronger decile rank. From a user perspective, the data generated from the App could help with identifying students who are underperforming or help students to recognise areas on which they need to focus
Patterns of predation and meat-eating by chacma baboons in an Afromontane environment
Meat-eating among non-human primates has been well documented but its prevalence among Afromontane baboons is understudied. In this study we report the predatory and meat-eating behaviours of a habituated group of gray-footed chacma baboons (Papio ursinus griseipes) living in an Afromontane environment in South Africa. We calculated a vertebrate-eating rate of 1 every 78.5 hours, increasing to 58.1 hours when unsuccessful predation attempts were included. A key food source was young antelopes, particularly bushbuck (Tragelaphus scriptus), which were consumed once every 115 observation hours. Similar to other baboon research sites, predations seemed mostly opportunistic, adult males regularly scrounged and monopolised prey, there was no evidence they used an active kill bite, and active sharing was absent. This is the first baboon study to report predation of rock python (Python sebae) eggs and likely scavenging of a leopard (Panthera pardus) kill (bushbuck) cached in a tree. We also describe several scramble kleptoparasitism events, tolerating active defence from antelope parents, and the baboons inhibiting public information about predations. In the latter case, baboons with meat often hid beyond the periphery of the group, reducing the likelihood of scrounging by competitors. This often led to prey carcasses being discarded without being fully exploited and potentially providing resources to scavengers. We also highlight the absence of encounters with numerous species, suggesting the baboons are a key component of several species’ landscapes of fear. Given these findings it seems likely that their ecological role in the Soutpansberg has been undervalued, and such conclusions may also hold for other baboon populations
Weeds in organic fertility-building leys:aspects of species richness and weed management
Legume-based leys (perennial sod crops) are an important component of fertility management in organic rotations in many parts of Europe. Despite their importance, however, relatively little is known about how these leys affect weed communities or how the specific composition of leys may contribute to weed management. To determine whether the choice of plant species in the ley affects weeds, we conducted replicated field trials at six locations in the UK over 24 months, measuring weed cover and biomass in plots sown with monocultures of 12 legume and 4 grass species and in plots sown with a mixture of 10 legume species and 4 grass species. Additionally, we monitored weed communities in leys on 21 organic farms across the UK either sown with a mixture of the project species or the farmers? own species mix. In total, 63 weed species were found on the farms, with the annuals Stellaria media, Sonchus arvensis, and Veronica persica being the most frequent species in the first year after establishment of the ley, while Stellaria media and the two perennials Ranunculus repens and Taraxacum officinale dominated the weed spectrum in the second year. Our study shows that organic leys constitute an important element of farm biodiversity. In both replicated and on-farm trials, weed cover and species richness were significantly lower in the second than in the first year, owing to lower presence of annual weeds in year two. In monocultures, meadow pea (Lathyrus pratensis) was a poor competitor against weeds, and a significant increase in the proportion of weed biomass was observed over time, due to poor recovery of meadow pea after mowing. For red clover (Trifolium pratense), we observed the lowest proportion of weed biomass in total biomass among the tested legume species. Crop biomass and weed biomass were negatively correlated across species. Residuals from the linear regression between crop biomass and weed biomass indicated that at similar levels of crop biomass, grasses had lower weed levels than legumes. We conclude that choice of crop species is an important tool for weed management in leys.authorsversionPeer reviewe
- …