88 research outputs found
Strategies for sustainable pearl millet hybrid breeding in West Africa
Pearl millet [Pennisetum glaucum (L.) R. Br.] is grown by >90 million subsistence farmers, mostly in the drylands of Sub-Saharan Africa and India for human consumption and provides additionally fodder and building material. It is commonly grown in regions with 300 500 mm of precipitation, low soil phosphorus levels, and temperatures of >42°C), like its center of origin in West Africa (WA). Pearl millet is a highly heterozygous, diploid (2n = 2x = 14) C4 plant species with outcrossing rates of >70%. Yield levels increased largely in India and the US, while they almost stagnated in WA. Challenging, highly variable environments and a weak seed sector are largely contributing to these differences. To suggest a way forward this thesis was meant to guide heterotic group development for sustainable WA pearl millet breeding. The specific objectives were to (I) facilitate efficient use of pearl millet gene bank accessions, (II) identify diversity patterns, (III) validate the yield superiority and stability of pearl millet population hybrids over OPVs, (IV) derive a more comprehensive picture about combining ability patterns, and (V) develop a unified strategy for heterotic grouping and sustainable hybrid breeding.
A total of 81 accessions acquired from the pearl millet reference collection was evaluated for resistance to Striga hermonthica (Del.) Benth. in one artificially infested field in Niger. A subset of 74 accessions was characterized in 2009 in multi-environment trials (MET) under low-input and fertilized conditions. The general superiority of local check varieties compared to the genebank accessions highlighted the importance of local adaptation, possibly lost during the ex situ conservation and regeneration. Nevertheless, the development and preservation of germplasm collections are important to maintain the rich genetic diversity. The MET identified several accessions as sources for specific traits of interest and revealed an immense diversity but also strong admixture.
This admixture underlines the need to develop heterotic groups. Therefore, 17 WA open-pollinated varieties (OPVs) were crossed in a diallel mating design and tested together with their offspring in nine environments over two years in Niger and Senegal. Results from these MET verified large panmictic better parent heterosis (PBPH) effects with an average of 18% (147%) for panicle yield. A large G × E interaction variance was confirmed and it was not possible to define repeatable mega-environments. Importantly, yield stability was more pronounced in the population hybrids compared to their parental OPVs. Furthermore, a superior combining ability among selected OPVs from Niger vs. Senegal was revealed and the evaluated OPVs were clearly grouped by origin based on genetic information. Nevertheless, there was no significant relationship between genetic distance among OPVs and PBPH.
These and earlier studies showed a large diversity, sufficiently large heterosis effects and high yield stability in experimental pearl millet population and topcross hybrids, offering a great opportunity for a regionally coordinated hybrid breeding approach. Therefore, we suggested a unified strategy with a continuous output of different hybrid types, specifically tailored to WA. First, existing diversity and combining ability pattern information on western WA and eastern WA cultivars forming loose groups that combine well with each other should be used. Selected genotypes with high general combining ability (GCA) and per se performance from eastern and western WA, respectively, are promising founder populations. Initiating a reciprocal recurrent selection (RRS) program, possibly supported by modern breeding tools, will diverge the two groups further, while improving the inter-pool per se performance. RRS in combination with continuous diversification of both pools allows distinct female and male pool development, line development and introgression of a cytoplasmic male sterility system. Creating OPVs and population hybrids early and aiming for long-term development of topcross hybrids from improved OPVs and newly derived lines is possible alongside the heterotic pool development. Additionally, the RRS lays the foundation for possible future single-cross hybrid breeding programs. The suggested framework is highly ambitious and requires long-term commitment, vision and financial resources. Considering the flexibility regarding single steps and the possibility to develop different types of varieties at every stage of the pool diversification, it has the potential to enhance gains from selection and, with the continuous output of new high-yielding and stable cultivars, to improve the livelihood of WA subsistence farmers substantially.Perlhirse [Pennisetum glaucum (L.) R. Br.] wird von >90 Millionen Subsistenzbauern, vor allem in Subsahara-Afrika und Indien, für Nahrung angebaut und liefert Futter und Baumaterial. Es wird häufig in Regionen mit 300 - 500 mm Niederschlag, niedrigem Bodenphosphorgehalt und Temperaturen von >42°C angebaut, wie z.B. seiner Ursprungsregion Westafrika (WA). Perlhirse ist eine sehr heterozygote, diploide (2n = 2x = 14) C4-Pflanze mit Auskreuzungsraten von >70%. Die Erträge stiegen in Indien und den USA, während sie in WA fast stagnierten. Herausfordernde, sehr variable Umwelten und ein schwacher Saatgutsektor tragen weitgehend zu diesen Unterschieden bei. Daher soll diese Thesis die Entwicklung heterotischer Gruppen für eine nachhaltige WA Perlhirsezüchtung anleiten. Die spezifischen Ziele waren (I) effiziente Nutzung von Perlhirsesorten aus Genbanken zu erleichtern, (II) Diversitätsmuster zu identifizieren, (III) Ertragsüberlegenheit und Stabilität von Perlhirse-Populationshybriden gegenüber OPVs zu validieren, (IV) ein umfassenderes Bild über Kombinierfähigkeitsmuster zu erstellen und (V) eine einheitliche Strategie für die heterotische Gruppierung und nachhaltige Hybridzüchtung zu entwickeln.
Perlhirsesorten aus der Referenzsammlung wurden auf Striga hermonthica (Del.) Benth. Resistenz in einem künstlich infizierten Feld im Niger untersucht. Davon wurden 74 Genotypen in mehrortigen Versuchen (MET) in 2009 unter gering und regulär gedüngten Bedingungen charakterisiert. Die generelle Überlegenheit der lokalen Standards gegenüber den Genbank-Genotypen zeigt die Bedeutung der lokalen Anpassung, die möglicherweise durch die ex situ Erhaltung und Regeneration verloren ging. Dennoch sind die Entwicklung und Erhaltung von Keimplasma-Sammlungen wichtig, um die reiche genetische Vielfalt zu erhalten. Die MET identifizierten mehrere Genotypen als Quellen für bestimmte, relevante Merkmale und zeigten eine immense Vielfalt, aber auch starke Vermischung.
Diese Vermischung zeigt das Erfordernis, heterotische Gruppen zu entwickeln. Daher wurden 17 WA offen bestäubte Sorten (OPVs) in einem Diallel-Paarungsschema gekreuzt und mit ihren Nachkommen in neun Umwelten über zwei Jahre im Niger und Senegal getestet. Diese Ergebnisse verifizierten große panmiktische Heterosiseffekte relativ zum besseren Elter (PBPH) von durchschnittlichen 18% (1 47 %) beim Rispenertrag. Eine große G × E Interaktionsvarianz wurde bestätigt und es war nicht möglich wiederholbare Mega-Umwelten zu definieren. Wichtig ist, dass die Erträge der Populationshybriden im Vergleich zu ihren elterlichen OPVs stabiler waren. Darüber hinaus zeigte sich eine überlegene Kombinationsfähigkeit bestimmter OPVs aus Niger vs. Senegal und die evaluierten OPVs wurden auf Grundlage genetischer Informationen klar nach Herkunft gruppiert. Dennoch gab es keinen signifikanten Zusammenhang der genetischen Distanz zwischen den OPVs und PBPH.
Diese und frühere Studien zeigten eine große Diversität, ausreichend große Heterosis Effekte und eine hohe Ertragsstabilität in experimentellen Perlhirse Populations- und Topcross-Hybriden, was eine große Chance für einen regionalen Hybridzüchtungsansatz bietet. Daher schlugen wir eine einheitliche, speziell auf WA zugeschnittene Strategie mit kontinuierlicher Produktion verschiedener Hybridtypen vor. Zunächst sollten Informationen über die bestehende Vielfalt und die Kombinationsfähigkeitsmuster bei westlichen WA- und östlichen WA-Sorten, die lose Gruppen bilden und sich gut miteinander kombinieren lassen, genutzt werden. Ausgewählte Genotypen mit hoher allgemeiner Kombinationsfähigkeit (GCA) und Eigenleistungen aus Ost- und West-WA sind vielversprechende Gründerpopulationen. Die Initiierung eines Programms zur reziproken rekursiven Selektion (RRS), eventuell unterstützt durch moderne Züchtungsmethoden, wird die beiden Gruppen weiter divergieren und gleichzeitig die Eigenleistung je Genpools verbessern. RRS in Kombination mit einer kontinuierlichen Diversifizierung beider Pools ermöglicht die Entwicklung eines jeweils eindeutig weiblichen und männlichen Pools, Linienentwicklung und Introgression eines zytoplasmatischen männlichen Sterilitätssystems. Außerdem ist es möglich, OPVs und Populationshybride frühzeitig zu erzeugen und auf eine langfristige Entwicklung von Topcross-Hybriden aus verbesserten OPVs und neu entwickelten Linien hinzuarbeiten. Darüber hinaus legt das RRS den Grundstein für mögliche zukünftige Zweiweghybridzüchtungsprogramme. Der vorgeschlagene Rahmen ist sehr ehrgeizig und erfordert langfristiges Engagement, Voraussicht und finanzielle Ressourcen. In Anbetracht der Flexibilität der einzelnen Schritte und der Möglichkeit, in jeder Phase der Pooldiversifizierung verschiedene Sortentypen zu entwickeln, hat es das Potenzial, die Selektionserfolge zu steigern und mit der kontinuierlichen Produktion neuer ertragreicher und stabiler Sorten die Lebensgrundlage der Subsistenzlandwirte in WA erheblich zu verbessern
Architektur und Performativ : Das Fernsehbild der Freiheitsstatue am 11. September 2001
Wissenschaftliches Kolloquium vom 19. bis 22. April 2007 in Weimar an der Bauhaus-Universität zum Thema: ‚Die Realität des Imaginären. Architektur und das digitale Bild
Learning event patterns for gesture detection
Usability often plays a key role when software is brought to market, including clearly structured workows, the way of presenting information to the user, and, last but not least, how he interacts with the application. In this context, input devices as 3D cameras or (multi-)touch displays became omnipresent in order to define new intuitive ways of user interaction. State-of-the-art systems tightly couple application logic with separate gesture detection components for supported devices. Hard-coded rules or static models obtained by applying machine learning algorithms on many training
samples are used in order to robustly detect a pre defined set of gesture patterns. If possible at all, it becomes difficcult to extend these sets with new patterns or to modify existing ones difficult for both, application developers and end users. Further, adding gesture support for legacy software
or for additional devices becomes dificult with this hardwired approach. In previous research we demonstrated how the database community can contribute to this challenge by leveraging complex event processing on data streams to express gesture patterns. While this declarative approach
decouples application logic from gesture detection components, its major drawback was the non-intuitive definition of gesture queries. In this paper, we present an approach that is related to density-based clustering in order to find declarative gesture descriptions using only a few samples.
We demonstrate the algorithms on mining definitions for multi-dimensional gestures from the sensor data stream that is delivered by a Microsoft Kinect 3D camera, and provide a way for non-expert users to intuitively customize gesturecontrolled user interfaces even during runtime
Sparse Binary Compression: Towards Distributed Deep Learning with minimal Communication
Currently, progressively larger deep neural networks are trained on ever
growing data corpora. As this trend is only going to increase in the future,
distributed training schemes are becoming increasingly relevant. A major issue
in distributed training is the limited communication bandwidth between
contributing nodes or prohibitive communication cost in general. These
challenges become even more pressing, as the number of computation nodes
increases. To counteract this development we propose sparse binary compression
(SBC), a compression framework that allows for a drastic reduction of
communication cost for distributed training. SBC combines existing techniques
of communication delay and gradient sparsification with a novel binarization
method and optimal weight update encoding to push compression gains to new
limits. By doing so, our method also allows us to smoothly trade-off gradient
sparsity and temporal sparsity to adapt to the requirements of the learning
task. Our experiments show, that SBC can reduce the upstream communication on a
variety of convolutional and recurrent neural network architectures by more
than four orders of magnitude without significantly harming the convergence
speed in terms of forward-backward passes. For instance, we can train ResNet50
on ImageNet in the same number of iterations to the baseline accuracy, using
less bits or train it to a lower accuracy using less bits. In the latter case, the total upstream communication required
is cut from 125 terabytes to 3.35 gigabytes for every participating client
B2G4: A synthetic data pipeline for the integration of Blender models in Geant4 simulation toolkit
The correctness and precision of particle physics simulation software, such
as Geant4, is expected to yield results that closely align with real-world
observations or well-established theoretical predictions. Notably, the accuracy
of these simulated outcomes is contingent upon the software's capacity to
encapsulate detailed attributes, including its prowess in generating or
incorporating complex geometrical constructs. While the imperatives of
precision and accuracy are essential in these simulations, the need to manually
code highly detailed geometries emerges as a salient bottleneck in developing
software-driven physics simulations. This research proposes Blender-to-Geant4
(B2G4), a modular data workflow that utilizes Blender to create 3D scenes,
which can be exported as geometry input for Geant4. B2G4 offers a range of
tools to streamline the creation of simulation scenes with multiple complex
geometries and realistic material properties. Here, we demonstrate the use of
B2G4 in a muon scattering tomography application to image the interior of a
sealed steel structure. The modularity of B2G4 paves the way for the designed
scenes and tools to be embedded not only in Geant4, but in other scientific
applications or simulation software.Comment: submitted for review at the Muographers 2023 conference. Initial
version. 6 pages, 4 figure
Side Differences of Thigh Muscle Cross-Sectional Areas and Maximal Isometric Muscle Force in Bilateral Knees with the Same Radiographic Disease Stage, but Unilateral Frequent Pain – Data from the Osteoarthritis Initiative
Objective To determine whether anatomical thigh muscle cross-sectional areas (MCSAs) and strength differ between osteoarthritis (OA) knees with frequent pain compared with contra-lateral knees without pain, and to examine the correlation between MCSAs and strength in painful vs painless knees. Methods Forty-eight subjects (31 women; 17 men; age 45–78 years) were drawn from 4,796 Osteoarthritis Initiative (OAI) participants, in whom both knees displayed the same radiographic stage (KLG2 or 3), one with frequent pain (most days of the month within the past 12 months) and the contra-lateral one without pain. Axial MR images were used to determine MCSAs of extensors, flexors and adductors at 35% femoral length (distal to proximal) and in two adjacent 5 mm images. Maximal isometric extensor and flexor forces were used as provided from the OAI database. Results Painful knees showed 5.2% lower extensor MCSAs (P = 0.00003; paired t-test), and 7.8% lower maximal extensor muscle forces (P = 0.003) than contra-lateral painless knees. There were no significant differences in flexor forces, or flexor and adductor MCSAs (P > 0.39). Correlations between force and MCSAs were similar in painful and painless OA knees (0.44 < r < 0.66). Conclusions Knees with frequent pain demonstrate lower MCSAs and force of the quadriceps (but not of other thigh muscles) compared with contra-lateral knees without knee pain with the same radiographic stage. Frequent pain does not appear to affect the correlations between MCSAs and strength in OA knees. The findings suggest that quadriceps strengthening exercise may be useful in treating symptomatic knee OA
Real-time embedded reconstruction of dynamic objects for a 3D maritime situational awareness picture
Monitoring maritime infrastructures is an important part of maritime safety and security. To best assess the security status of these facilities, detailed information should be made available to stakeholders, such as port authorities, law enforcement agencies and emergency services in a concise
and easily understandable format. In this work, we propose
a novel real-time 3D reconstruction framework for enhancing
maritime situational awareness. We introduce and verify a
pipeline prototype for dynamic 3D reconstruction of maritime
objects using a static observer and stereoscopic cameras on an
GPU-accelerated embedded device. Our pipeline runs with approx. 6Hz
on a Nvidia Jetson Xavier AGX embedded system and is verified
using a simulated dataset of a harbor basin
Deep learning-based denoising streamed from mobile phones improves speech-in-noise understanding for hearing aid users
The hearing loss of almost half a billion people is commonly treated with
hearing aids. However, current hearing aids often do not work well in
real-world noisy environments. We present a deep learning based denoising
system that runs in real time on iPhone 7 and Samsung Galaxy S10 (25ms
algorithmic latency). The denoised audio is streamed to the hearing aid,
resulting in a total delay of around 75ms. In tests with hearing aid users
having moderate to severe hearing loss, our denoising system improves audio
across three tests: 1) listening for subjective audio ratings, 2) listening for
objective speech intelligibility, and 3) live conversations in a noisy
environment for subjective ratings. Subjective ratings increase by more than
40%, for both the listening test and the live conversation compared to a fitted
hearing aid as a baseline. Speech reception thresholds, measuring speech
understanding in noise, improve by 1.6 dB SRT. Ours is the first denoising
system that is implemented on a mobile device, streamed directly to users'
hearing aids using only a single channel as audio input while improving user
satisfaction on all tested aspects, including speech intelligibility. This
includes overall preference of the denoised and streamed signal over the
hearing aid, thereby accepting the higher latency for the significant
improvement in speech understanding
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