76 research outputs found
Optimizing Social Media in Humanitarian Crisis Responses
The social media boom has brought about a new age of communications and connectedness in our world. Just as the advent of televised news brought more attention to humanitarianism, social media has the capability to alter how humanitarian responses are viewed, coordinated, and executed. However, despite the vast potential of social media, humanitarian actors have been hesitant to fully incorporate it within their modus operandi. This essay explores the reasons for their skepticism and looks at cases where social media was put to good use during humanitarian crises. Using that information, we will argue that several measures can be taken to improve social media use in humanitarian responses: the creation of a social media data aggregation website, the inclusion of local actors in forming communications strategies, and the continued research of social media data trends in humanitarian crises. These measures would facilitate advocacy, aid distribution, and the ability to carry out the humanitarian imperative more effectively
Evaluation of Soybean Varieties Resistant to Soybean Cyst Nematode
Use of resistant soybean varieties is a very effective strategy for managing soybean cyst nematode (SCN), and numerous SCN-resistant soybean varieties are available for Iowa soybean growers. Each year, public and private SCN-resistant soybean varieties are evaluated in SCN-infested fields in Iowa by Iowa State University personnel. The research described in this report was performed to assess the agronomic performance of SCNresistant soybean varieties and to determine the effects of the varieties on SCN numbers or population densities
Increase in Soybean Cyst Nematode Virulence and Reproduction on Resistant Soybean Varieties in Iowa From 2001 to 2015 and the Effects on Soybean Yields
Management of the soybean cyst nematode (SCN) relies heavily on use of SCN-resistant soybean varieties to limit nematode reproduction and minimize yield loss. For Iowa, almost all SCNresistant soybean varieties contain SCN resistance genes from a breeding line named Plant Introduction (PI) 88788. Iowa State University conducts experiments to evaluate numerous SCNresistant and three to four SCN-susceptible soybean varieties in up to nine field experiments across Iowa each year. Data on SCN population density, virulence (SCN race and HG type), soybean yield, precipitation, and growing degree days frommore than 25,000 fourrow plots in field experiments conducted from 2001 to 2015 were analyzed to determine how these factors affected SCN reproduction and yield. SCN population densities were positively correlated with temperatures and negatively associated with precipitation during the growing seasons, indicating that SCN reproduction was greatest in hot, dry years. Over the years, virulence of SCN populations on PI 88788 increased in the fields in which the experiments were conducted, resulting in increased end-of-season SCN population densities and reduced yields of SCN-resistant soybean varieties with the PI 88788 source of resistance. These results indicate that soybean yield loss caused by SCN on resistant varieties with the common PI 88788 source of resistance likely will increase as virulence of SCN populations increases unless new sources of resistance become widely available and used in the future
Evaluation of Soybean Varieties Resistant to Soybean Cyst Nematode
Use of resistant soybean varieties is a very effective strategy for managing soybean cyst nematode (SCN), and numerous SCN-resistant soybean varieties are available for Iowa soybean growers. Each year, public and private SCN-resistant soybean varieties are evaluated in SCN-infested fields in Iowa by Iowa State University personnel. The research described in this report was performed to assess the agronomic performance of SCNresistant soybean varieties and to determine the effects of the varieties on SCN numbers or population densities
An end-to-end convolutional selective autoencoder approach to Soybean Cyst Nematode eggs detection
This paper proposes a novel selective autoencoder approach within the
framework of deep convolutional networks. The crux of the idea is to train a
deep convolutional autoencoder to suppress undesired parts of an image frame
while allowing the desired parts resulting in efficient object detection. The
efficacy of the framework is demonstrated on a critical plant science problem.
In the United States, approximately $1 billion is lost per annum due to a
nematode infection on soybean plants. Currently, plant-pathologists rely on
labor-intensive and time-consuming identification of Soybean Cyst Nematode
(SCN) eggs in soil samples via manual microscopy. The proposed framework
attempts to significantly expedite the process by using a series of manually
labeled microscopic images for training followed by automated high-throughput
egg detection. The problem is particularly difficult due to the presence of a
large population of non-egg particles (disturbances) in the image frames that
are very similar to SCN eggs in shape, pose and illumination. Therefore, the
selective autoencoder is trained to learn unique features related to the
invariant shapes and sizes of the SCN eggs without handcrafting. After that, a
composite non-maximum suppression and differencing is applied at the
post-processing stage.Comment: A 10 pages, 8 figures International Conference on Machine
Leaning(ICML) Submissio
Effects of Clariva Complete Beans Seed Treatment on Heterodera glycines Reproduction and Soybean Yield in Iowa
In recent years, nematode-protectant seed treatments have become available to supplement resistant soybean cultivars to manage soybean cyst nematode (Heterodera glycines; SCN). Twenty-seven small-plot and 18 strip-trial experiments were conducted comparing the effects of Clariva Complete Beans (CCB) and CruiserMaxx Advanced plus Vibrance (CMV) on SCN reproduction and soybean yield on a moderately resistant (2014) and resistant (2015 to 2016) soybean cultivar. Yield data were collected, and an SCN reproductive factor was calculated by dividing final (at harvest) SCN egg population densities by initial (at planting) population densities from soil samples collected in each small plot or sampled area in the strip trials. Relative to the CMV treatment, CCB significantly decreased SCN reproductive factor in two small-plot experiments (one each in 2014 and 2015) but not in any of the strip trials in any year. Soybean yields were significantly greater with CCB versus CMV in 5 of the 18 strip trials but not in any of the small-plot experiments, even when there were significant decreases in SCN reproduction. For unknown reasons, CCB significantly decreased yields in two small-plot experiments and at one strip-trial location. In summary, the effects of CCB seed treatment on SCN reproduction and soybean yields were variable in the years that these experiments were conducted in Iowa
Fluorescent T7 display phages obtained by translational frameshift
Lytic phages form a powerful platform for the display of large cDNA libraries and offer the possibility to screen for interactions with almost any substrate. To visualize these interactions directly by fluorescence microscopy, we constructed fluorescent T7 phages by exploiting the flexibility of phages to incorporate modified versions of its capsid protein. By applying translational frameshift sequences, helper plasmids were constructed that expressed a fixed ratio of both wild-type capsid protein (gp10) and capsid protein fused to enhanced yellow fluorescent protein (EYFP). The frameshift sequences were inserted between the 3′ end of the capsid gene and the sequence encoding EYFP. Fluorescent fusion proteins are only formed when the ribosome makes a −1 shift in reading frame during translation. Using standard fluorescence microscopy, we could sensitively monitor the enrichment of specific binders in a cDNA library displayed on fluorescent T7 phages. The perspectives of fluorescent display phages in the fast emerging field of single molecule detection and sorting technologies are discussed
Bladesense – a novel approach for measuring dynamic helicopter rotor blade deformation
Technologies that allow accurate measurement of rotorblade dynamics can impact almost all areas of the rotorcraft sector; ranging from maintenance all the way to blade design. The BladeSense project initiated in 2016 aims to take a step in developing and demonstrating such a capability using novel fibre optic sensors that allow direct shape measurement. In this article the authors summarise key project activities in modelling and simulation, instrumentation development and ground testing. The engineering approach and associated challenges and achievements in each of these disciplines are discussed albeit briefly. This ranges from the use of computational aerodynamics and structural modelling to predict blade dynamics to the development of direct fibre optic shape sensing that allows measurements above 1kHz over numerous positions on the blade. Moreover, the development of the prototype onboard system that overcomes the challenge of transferring data between the rotating main rotor to the fixed fuselage frames is also discussed
CANDELS: The progenitors of compact quiescent galaxies at z~2
We combine high-resolution HST/WFC3 images with multi-wavelength photometry
to track the evolution of structure and activity of massive (log(M*) > 10)
galaxies at redshifts z = 1.4 - 3 in two fields of the Cosmic Assembly
Near-infrared Deep Extragalactic Legacy Survey (CANDELS). We detect compact,
star-forming galaxies (cSFGs) whose number densities, masses, sizes, and star
formation rates qualify them as likely progenitors of compact, quiescent,
massive galaxies (cQGs) at z = 1.5 - 3. At z > 2 most cSFGs have specific
star-formation rates (sSFR = 10^-9 yr^-1) half that of typical, massive SFGs at
the same epoch, and host X-ray luminous AGN 30 times (~30%) more frequently.
These properties suggest that cSFGs are formed by gas-rich processes (mergers
or disk-instabilities) that induce a compact starburst and feed an AGN, which,
in turn, quench the star formation on dynamical timescales (few 10^8 yr). The
cSFGs are continuously being formed at z = 2 - 3 and fade to cQGs by z = 1.5.
After this epoch, cSFGs are rare, thereby truncating the formation of new cQGs.
Meanwhile, down to z = 1, existing cQGs continue to enlarge to match local QGs
in size, while less-gas-rich mergers and other secular mechanisms shepherd
(larger) SFGs as later arrivals to the red sequence. In summary, we propose two
evolutionary scenarios of QG formation: an early (z > 2), fast-formation path
of rapidly-quenched cSFGs that evolve into cQGs that later enlarge within the
quiescent phase, and a slow, late-arrival (z < 2) path for SFGs to form QGs
without passing through a compact state.Comment: Submitted to the Astrophysical Journal Letters, 6 pages, 4 figure
An Observed Link between Active Galactic Nuclei and Violent Disk Instabilities in High-Redshift Galaxies
We provide evidence for a correlation between the presence of giant clumps
and the occurrence of active galactic nuclei (AGN) in disk galaxies. Giant
clumps of 10^8-9 Msun arise from violent gravitational instability in gas-rich
galaxies, and it has been proposed that this instability could feed
supermassive black holes (BH). We use emission line diagnostics to compare a
sample of 14 clumpy (unstable) disks and a sample of 13 smoother (stable) disks
at redshift z~0.7. The majority of clumpy disks in our sample have a high
probability of containing AGN. Their [OIII] emission line is strongly excited,
inconsistent with low-metallicity star formation alone. [NeIII] excitation is
also higher. Stable disks rarely have such properties. Stacking ultra sensitive
Chandra observations (4 Ms) reveals an X-ray excess in clumpy galaxies, which
cannot be solely due to star formation and confirms the presence of AGN. The
clumpy galaxies in our intermediate-redshift sample have properties typical of
gas-rich disk galaxies rather than mergers, being in particular on the Main
Sequence of star formation. This suggests that our findings apply to the
physically-similar and numerous gas-rich unstable disks at z>1. Using the
observed [OIII] and X-ray luminosities, we conservatively estimate that AGN
hosted by clumpy disks have typical bolometric luminosities of the order of a
few 10^43 erg/s, BH growth rates ~10^-2 Msun/yr, and that these AGN are
substantially obscured in X-rays. This moderate-luminosity mode could be
sufficient to provide a large fraction of today's BH mass over a couple of Gyr
given that our observations suggest a high duty cycle (>10%), accretion bursts
with higher luminosities being possible over shorter phases. The observed
evolution of disk instabilities with mass and redshift could explain the
simultaneous downsizing of star formation and of BH growth.Comment: ApJ in pres
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