Regulation of shoot growth, root development and manganese allocation in wheat ( Triticum aestivum ) genotypes by light intensity

The objective of this study was to assess effects of different light intensities on shoot growth, root development and allocation of root-borne solutes via the transpiration stream to various shoot parts of young wheat plants (Triticum aestivum L.). Hydroponic culture allowed direct access to the roots and shoots throughout the experiment. Under low light intensity (100μmol photons m−2s−1), shoot growth was restricted, less (but larger) leaves were produced at the main shoot and only a few tillers became visible as compared to plants under high light intensity (380μmol photons m−2s−1). The root system was indirectly also affected by the illumination of the aerial parts. A larger number of shorter roots were produced under high light leading to a denser root system, while only a small number of longer roots were present under low light. The distribution of 54Mn (xylem-mobile, but essentially phloem-immobile in wheat) from the roots to the shoot lead to the conclusion that light regime strongly influences the distribution of root-borne solutes within the shoots. Labels introduced into the roots may allow a deeper insight into the transfer of solutes from the root system to the various shoot parts under different light regime

Evaluating the Potential of Design for Additive Manufacturing Heuristic Cards to Stimulate Novel Product Redesigns

Abstract Additive manufacturing (AM) affords those who wield it correctly the benefits of shape, material, hierarchical, and functional complexity. However, many engineers and designers lack the training and experience necessary to take full advantage of these benefits. They require training, tools, and methods to assist them in gaining the enhanced design freedom made possible by additive manufacturing. This work, which is an extension of the authors’ previous work, explores if design heuristics for AM, presented in a card-based format, are an effective mechanism for helping designers achieve the design freedoms enabled by AM. The effectiveness of these design heuristic cards is demonstrated in an experiment with 27 product design students, by showing that there is an increase in the number of unique capabilities of AM being utilized, an increase in the AM novelty, and an increase in the AM flexibility of the generated concepts, when given access to the cards. Additionally, similar to the previous work, an increase in the number of interpreted heuristics and AM modifications present in the participants’ designs when they are provided with the heuristic cards is shown. Comparisons are also made between 8-heuristic and 29-heuristic experiments, but no conclusive statements regarding these comparisons can be drawn. Further user studies are planned to confirm the efficacy of this format at enhancing the design freedoms achieved in group and team design scenarios

Panicle Angle is an Important Factor in Tef Lodging Tolerance.

Tef [Eragrostis tef (Zucc.) Trotter] is an important crop in the Horn of Africa, particularly in Ethiopia, where it is a staple food for over 60 million people. However, the productivity of tef remains extremely low in part due to its susceptibility to lodging. Lodging is the displacement of the plant from the upright position, and it is exacerbated by rain, wind and the application of fertilizer. In order to address the issue of global food security, especially in the Horn of Africa, greater insight into the causes of tef lodging is needed. In this study, we combine modeling and biomechanical measurements to compare the properties relating to lodging tolerance in high yielding, improved tef genotypes, and lower yielding natural landraces. Our results indicate that the angle of the panicle contributes to the likelihood of lodging in tef. Varieties with compact panicles and reduced height had increased lodging resistance compared to the other varieties. By comparing different varieties, we found that overall, the landraces of tef lodged less than improved varieties. We constructed a model of stem bending and found that panicle angle was an important determinant of the amount of lodging. The findings from this study provide key information to those involved in tef improvement, especially those interested in lodging tolerance

Tef (Eragrostis tef) Variety ‘Tesfa’

 አህፅሮት ጤፍ በኢትዮጵያ ከሚመረቱ የብርዕና አገዳ ሰብሎች ዋናው ሲሆን በየዓመቱ ቁጥር ከ6.5 ሚሊዮን የማያንስ አርሶ አደር ያመርተዋል፡፡ ይህም አጠቃላይ በብርዕና አገዳ ሰብሎች ከሚሸፈነው ማሳ 30% ድርሻ አለው፡፡ ይሁን እንጂ ከሌሎች ሰብሎች ጋር ሲነፃፀር ምርታማነቱ አነስተኛ ነው፡፡ ለዚህም ምክንያቱ በከፊል አርሶ አደሩ ያልተሻሻሉ የአካባቢ ዝርያዎችን በመጠቀሙና፣ የሰብሉ ተፈጥሯዊ የመጋሸብ ባህሪ ናቸው፡፡  የዚህ ጥናት ዓላማ በተለየ ምርምር አሰራር የተገኘን የጤፍ ዝርያን በመፈተሸ የተሻለ ምርት፤ የአገዳ ጥንካሬን አንዲሁም የዘር ቀለም ያለውና በአርሶ አደሩ ተመራጭ ዝርያ ማፍለቅ ነበር፡፡ በጥናቱ በቅርቡ የተለቀቀ አንድ ዝርያና አንድ የአካባቢ ዝርያን ጨምሮ 10 የተለያዩ የጤፍ አይነቴዎችን በማካተት በስድስት ወካይ ጤፍ አብቃይ ቦታዎች ላይ ተፈትሸው ተስፋ (ደዘ-ክሮስ-457) ተብሎ የተሰየመውና የተለያዩ የጤፍ አይነቴዎች ተዳቅለው የተገኘው ዝርያ ከሌሎች ማወዳደሪያ ተፈታሽ ዝርያዎች የተሻለ ውጤት በማስመዝገቡ በብሄራዊ የዝርያ አፅዳቂ ኮሚቴ ተገምግሞ ለምርት እንዲለቀቅ ተወስኗል፡፡ ይህ ዝርያ ከሌሎች ዝርያዎች በንፅፅር መጋሸብን በመቋቋሙ፤ የተሻለ ምርት በመስጠቱ በአርሶአደሩ ተፈላጊ ከመሆኑም በሻገር ከዝርያው ባህሪ የተነሳ ለመስኖ እርሻና በሰብል መድረሻ ጊዜ የማጨጃ የእርሻ መሳሪያ መጠቀም ያስችላል፡፡ Abstract Tef [Eragrostis tef (Zucc.) Trotter] is extensively cultivated cereal crop in Ethiopia where it is annually grown by about 6.5 million smallholder farmers on about 30% of the total area allocated to cereal crops.However, the productivity of tef is very low compared to other cereals mainly due to lack of high yielding and lodging tolerant cultivars. The objective of this study was to evaluate the performance of the recently released tef variety called Tesfaand to provide unique morphological and agronomic descriptions of this new variety. Ten genotypes which were derived from three independent crosses and bred for at least eight generations plus a local and standard check varieties were tested at six tef growing sites in Ethiopia (namely, Adet, Chafe Donsa,DebreZeit black soil, DebreZeit light soil,Ginchiand Holetta) using RandomizedCompleteBlock Design with three replications. The study found that Tesfa(DZ-Cr-457 RIL-181) which was obtained from a cross between kinde (a semi-dwarf mutant line developed at the University of Bern, Switzerland) and Kay Murri(a landrace) outperformed other genotypes and approved for release by the Ethiopian National Variety Release Committee in March 2017.The main advantages of Tesfa over other tested lines were its higher grain yield and higher lodging tolerance. In addition, Tesfa possesses unique properties for which high acceptance by growers is expected. These are its compact panicle, lack of shattering, and thick and strong culm which makes it potentially cultivated under irrigation and also mechanically harvested

Sex-biased parental care and sexual size dimorphism in a provisioning arthropod

The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests. To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest. We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight. Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species

Technology generation to dissemination:lessons learned from the tef improvement project

Indigenous crops also known as orphan crops are key contributors to food security, which is becoming increasingly vulnerable with the current trend of population growth and climate change. They have the major advantage that they fit well into the general socio-economic and ecological context of developing world agriculture. However, most indigenous crops did not benefit from the Green Revolution, which dramatically increased the yield of major crops such as wheat and rice. Here, we describe the Tef Improvement Project, which employs both conventional- and molecular-breeding techniques to improve tef\u2014an orphan crop important to the food security in the Horn of Africa, a region of the world with recurring devastating famines. We have established an efficient pipeline to bring improved tef lines from the laboratory to the farmers of Ethiopia. Of critical importance to the long-term success of this project is the cooperation among participants in Ethiopia and Switzerland, including donors, policy makers, research institutions, and farmers. Together, European and African scientists have developed a pipeline using breeding and genomic tools to improve the orphan crop tef and bring new cultivars to the farmers in Ethiopia. We highlight a new variety, Tesfa, developed in this pipeline and possessing a novel and desirable combination of traits. Tesfa\u2019s recent approval for release illustrates the success of the project and marks a milestone as it is the first variety (of many in the pipeline) to be released

Differential expression of mRNA variants Egr1-sv and Egr1-lv during endurance exercise and normobaric hypoxia

Sowohl für körperliche Belastung als auch für Umwelteinflüsse wie zum Beispiel Hypoxie ist ein Einfluss auf das Immunsystem bekannt. So wird die körperliche Belastung wird schon seit längerer Zeit als Modell zur Untersuchung der entzündlichen Reaktion verwendet (Shek et al., 1998). In dieser Studie führen wir einen Vergleich der Immunmodulation bei Ausdauerbelastung einerseits und Hypoxie andererseits durch. Frühere Untersuchungen intrazellulärer Prozesse, die diese bedingen, zeigten, dass der Transkriptionsfaktor EGR1 auf verschiedenen Wegen das Immunsystem beeinflusst. Auch der durch freie Radikale bedingte oxidative Stress scheint in diesem Zusammenhang eine große Rolle zu spielen. Da diese Radikale wiederum die Expression von EGR1 induzieren, liegt die Vermutung einer Assoziation beider Faktoren auch in vivo nahe. Ein erst seit kurzem bekannter Aspekt des Transkriptionsfaktors EGR1 ist die Existenz zweier mRNA-Varianten: Egr1-sv und Egr1-lv. Wir überprüfen, ob im peripheren Blut unter Belastung eine differenzielle Regulation dieser Varianten stattfindet, ob ein Unterschied zwischen der Egr1-Expression bei Ausdauerbelastung und Hypoxieexposition besteht und ob Antioxidantien über eine Reduktion freier Radikale die Reaktion auf Hypoxie beeinflussen. Dafür untersuchen wir drei Probandengruppen. Sieben trainierte Ausdauerathleten bei einem Halbmarathonwettkampf, sieben nicht höhenangepasste Freiwillige, die 23 Stunden in einer normobaren Hypoxiekammer verbrachten, und sechs Probanden, die sich im Rahmen einer Cross-over-Studie mit placebokontrollierter Antioxidantienbehandlung vier Stunden unter normobarer Hypoxie aufhielten. Bei diesen Gruppen zeigen sich deutliche Unterschiede in der Reaktion der beiden mRNA-Varianten. Während Egr1-lv sich praktisch nicht verändert, wird für Egr1-sv als erstem Transkriptionsfaktor eine differenzielle Regulation durch Hypoxie und Ausdauerbelastung beobachtet. Bei den Teilnehmern des Halbmarathons wurden ausser Egr1 noch verschiedene Belastungsparameter bestimmt. Sowohl der Anstieg von Noradrenalin und CKMB als auch der definitionsgemäß pathologisch erhöhte Quotient aus CKMB und CK stehen im Einklang mit der bekannten Literatur. Es besteht eine signifikante Korrelation von Noradrenalin und der Expression von Egr.1 sv, während CKMB und Egr1-sv nicht korrelieren. Die beobachtete Verschiebungen des Blutbilds zu Neutrophilie und Leukopenie durch eine Halbmarathonbelastung stimmt ebenfalls mit der aktuellen Literatur überein. Für die Probanden der Cross-Over-Studie zeigt sich sowohl für die Peroxidkonzentration als auch für die Egr1-Expression ein signifikantes Absinken der Werte in der Placebogruppe im Vergleich zur Verumgruppe, was auf einen direkten Zusammenhang zwischen dem zellulären Reduktions-Oxidations-System und EGR1 hindeutet. Die vorliegende Arbeit bestätigt manche Vermutungen bezüglich der Reaktion des Organismus und speziell des Immunsystems auf Belastung. Für die Zukunft ergeben sich aus den gewonnenen Erkenntnissen interessante Fragen, deren Beantwortung zum besseren Verständnis der immunologischen Reaktion auf verschiedene Belastungsarten führen und die Rolle des EGR1 bei diesen Prozessen weiter aufklären wird. Auf den klinischen Alltag angewandt könnte dieses Wissen neue Impulse geben für die Behandlung der akuten Höhenkrankheit, immunologischer Erkrankungen sowie die Entwicklung neuer Trainingskonzepte in Kombination mit zeitlich begrenzten Höhenexpositionen.For physical exertion as well as for environmental influences as for example hypoxia an influence onto the immune system is well-known. Physical exertion has been used as a model for inflammatory reactions for quite some time (Shek et al., 1998). In this study we conduct a comparison of the immune modulation during endurance exercise versus during hypoxia. Earlier analyses of intracellular processes associated with this modulation have shown that the transcription factor EGR1 influences the immune system in various ways. Oxidative stress caused by free radicals appears to be of importance in this context. Since the radicals in return induce the expression of EGR1 it is likely that these two factors are also associated in vivo. A only recently known feature of the transcription factor EGR1 is the existence of two mRNA variants: Egr1-sv and Egr1-lv. We test whether there is a differential regulation of these variants in the peripheral blood, whether there is a difference between the Egr1 expression during endurance exercise and hypoxia and whether antioxidants influence the response to hypoxia via reduction of free radicals. For this we tested three groups of subjects. Seven trained endurance athletes at a competitive half marathon, seven non-acclimatized volunteers who spent 23 hours in a normobaric hypoxic chamber and six subjects who spent four hours in normobaric hypoxia in the setting of a placebo controlled crossover study of treatment with antioxidants. In these groups there are marked differences in the response of the two mRNA variants. While Egr1-lv virtually does not change, in Egr1-sv we could show a differential regulation by hypoxia and endurance exercise for the first time in a transcription factor. Other than Egr1 other parameters of stress were determined in the participants of the half marathon. The increase in norepinephrine and CKMB as well as the ratio of CKMB and CK within the pathological range are consistent with the current literature. There is a significant correlation of norepinephrine and the expression of Egr1-sv while CKMB and Egr1-sv do not correlate. We can also see a shift of the blood count towards neutrophilia and leukopenia that is consistent with the literature. For the subjects of the cross over study there is a significant decrease of peroxides as well as of expression of Egr1 in the placebo compared to the treatment group which points towards a connection of the cellular oxidation system and EGR1. The study at hand confirms some assumptions regarding the organism’s response to exertional stress, particularly regarding immunity. For the future interesting questions arise from these findings, the answers to which will increase the understanding of the immune response to different stressors and the part EGR1 is playing in this process. In clinical practice this knowledge could give new impulses in the treatment of altitude sickness and immunologic diseases as well as in the development of new training concepts using time limited exposures to altitude

Design Heuristics for Additive Manufacturing

Additive manufacturing (AM), colloquially known as 3D printing, has gained prominence over the last 15 years and has moved out of the laboratory and into the industrial product stream, becoming a viable manufacturing option. It has come to fascinate designers and the public alike due to its unique capabilities when compared to conventional manufacturing. These are, namely: shape, material, hierarchical, and functional complexity. Both novice and experienced designers have the desire to enhance their designs with AM, but they need assistance in learning to take advantage of these new capabilities and breaking out of their conventional manufacturing mindset in the early-phases of the design process. As only limited methods aimed at addressing this need exist, this thesis proposes to develop a set of Design Heuristics for Additive Manufacturing (DHAM) that focus on transferring early design phase-relevant AM-process independent knowledge and capabilities to both novice and experienced designers. First, 18 characteristics for early-phase Design for AM (DfAM) methods are synthesized from literature, which later guide the derivation and validation process. Then, a set of 25 DHAM are derived from a pool of 275 AM artifacts gathered from literature, industry, the media, and hobby websites. These 25 DHAM are divisible into eight thematic categories: part consolidation, customization, information communication, materials, material distribution, embed-enclose, lightweight, and reconfiguration. Another literature investigation indicates that the delivery format of the DHAM should be multi-modal and consist of a combination of text, images, abstract and concrete examples, and physical objects in order to aid understanding, design by analogy, and creativity. As such, accompanying cards and objects are developed. The cards contain a mix of text and visual examples, and one object that physically represents the heuristic is designed for each DHAM. It is found that the current standard for the validation of early-phase DfAM methods is not in alignment with good design research practice, so a four-phase validation procedure is proposed. The four phases are verification, controlled validation, workshop/project validation, and comparison to other methods. This procedure is used to validate the DHAM and its delivery format. First, in the verification phase, the DHAM are applied to two case studies to demonstrate their feasibility. Second, the controlled validation phase is conducted. Four controlled user studies are conducted to (1) validate the DHAM; (2) validate the DHAM cards in an individual design scenario; (3) validate the DHAM cards in a team design scenario; and (4) validate the DHAM objects. In each of these user studies, novice designers complete one of two redesign tasks. In Study (1), it is shown that the DHAM stimulate the inclusion of more AM concepts in the generated designs and cause users to make more AM-relevant modifications to their designs. Next, in Study (2), in addition to confirming the findings of Study (1), the cards are shown to stimulate the inclusion of more of the unique capabilities of AM in the designs and increase AM-novelty and AM-flexibility, while leaving the quantity of concepts produced by the participants unaffected. Then, in Study (3), in addition to the previous findings, the cards are found to increase both general novelty and variety among the teams. Finally, Study (4) demonstrates that the objects in concert with the cards produce the same effects seen when only the cards are used. However, when comparing the variety of Studies (3) and (4), one finds that the variety of concepts generated is higher when the participants have access to both the cards and objects. Following the novice user studies, the third phase of the validation procedure is conducted, workshop/project validation. This phase is completed by conducting three industry workshops with a total of 19 participants at three different companies. During each three-hour workshop, the participants apply the DHAM to their chosen product in an ideation session. Following the ideation session, they provide verbal feedback on the DHAM and rate the ability of the DHAM to fulfill the 18 criteria for early design-phase DfAM methods. All three companies react positively to the DHAM, particularly the objects, and they see the DHAM not only as a good ideation tool, but also as a way to teach AM novices about AM. However, they would like more examples to be included and more information about how to take the next steps regarding the various AM possibilities presented by the DHAM. Based on the ratings provided by the workshop participants, the DHAM fulfill 16 of the 18 criteria for early-phase DfAM methods. The DHAM score low on the ability to communicate information about the restrictions of AM (expected) and on being AM-process and material independent (unexpected). Finally, the DHAM are compared to other methods by comparing them to the most similar pre-existing method, Design Principles for AM developed by Perez (2018). They are found to induce similar effects, but the DHAM are more comprehensive and focused on the opportunities afforded by AM. Based on the evidence gathered through the validation procedure, the DHAM are found to fulfill their stated goal of transferring early design phase-relevant AM-process independent knowledge and capabilities to both novice and experienced designers. Thus, the contributions of this work are six-fold. First, the community consensus on the requirements for early design phase DfAM methods is determined. Second, the community’s knowledge about delivery format and modalities for early-phase DfAM methods is summarized and reviewed. Third, 25 DHAM, along with accompanying cards and objects, which are focused on the needs of designers in the early phases of the design process are proposed. Fourth, the ability of the DHAM are to stimulate the inclusion of AM concepts and their positive effect on creativity in a variety of novice and expert design scenarios is shown. Fifth, appropriate use-case scenarios for the DHAM are determined. Finally, a basis for validating early-phase DfAM methods and evaluating their ability to stimulate the inclusion of AM concepts and their effect on creativity is proposed. Future work should include determining the cause of the low rating from industry regarding process and material independence and directly comparing the DHAM to other early-phase DfAM methods in controlled user studies