1,065 research outputs found
Ontogeny and Season Constrain the Production of Herbivore-Inducible Plant Volatiles in the Field
Herbivores may induce plants to produce an array of volatile organic compounds (herbivore-induced plant volatiles, or HIPVs) after damage, and some natural enemies of herbivores are attracted by those HIPVs. The production of HIPVs by the undomesticated species Datura wrightii was quantified in response to damage by its natural community of herbivores or the plant hormone methyl jasmonate (MeJA) over plant's 6-month growing season. Patterns of HIPV production were compared to the seasonal abundance of D. wrightii's two most abundant herbivores, the chrysomelid beetle Lema daturaphila and the mirid bug Tupiocoris notatus, and their shared generalist predator, the lygaeid bug Geocoris pallens. HIPV production was especially high in the spring, when plants were growing vegetatively, but HIPV production declined after plants began to flower and produce fruit, and these volatiles no longer were inducible by September. The composition of the HIPV blends also changed seasonally. HIPV production and composition were partially restored by "rejuvenating" plants back to the vegetative growth stage independently of season by cutting them back and allowing them to resprout and regrow vegetatively. HIPV production of D. wrightii in the field is limited to the earlier ontogenetic stages of growth, despite the fact that both herbivores and their shared natural enemy inhabited plants throughout the full season. The adaptive value of HIPV production in D. wrightii may be constrained by plant ontogeny to the vegetative stages of plant growth
CHEMICAL CONSPICUOUSNESS OF AN HERBIVORE TO ITS NATURAL ENEMY: EFFECT OF FEEDING SITE SELECTION
An Instagram is worth a thousand words:An industry panel session at ALIA Information Online 2013
The Domination Number of Grids
In this paper, we conclude the calculation of the domination number of all
grid graphs. Indeed, we prove Chang's conjecture saying that for
every , .Comment: 12 pages, 4 figure
Overcoming the roadblocks to cardiac cell therapy using tissue engineering
Transplantations of various stem cells or their progeny have repeatedly improved cardiac performance in animal models of myocardial injury; however, the benefits observed in clinical trials have been generally less consistent. Some of the recognized challenges are poor engraftment of implanted cells and, in the case of human cardiomyocytes, functional immaturity and lack of electrical integration, leading to limited contribution to the heartâs contractile activity and increased arrhythmogenic risks. Advances in tissue and genetic engineering techniques are expected to improve the survival and integration of transplanted cells, and to support structural, functional, and bioenergetic recovery of the recipient hearts. Specifically, application of a prefabricated cardiac tissue patch to prevent dilation and to improve pumping efficiency of the infarcted heart offers a promising strategy for making stem cell therapy a clinical reality.
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Developmental characteristics of atrioventricular node reentry (AVNRT) in children, adolescents and adults
Herbivore-mediated negative frequency-dependent selection underlies a trichome dimorphism in nature
Authors are grateful for funding provided by an NSF GRFP to J.K.G. (2015195769) and DEBâ1353970 to L.F.D.Negative frequencyâdependent selection (NFDS) has been shown to maintain polymorphism in a diverse array of traits. The action of NFDS has been confirmed through modeling, experimental approaches, and genetic analyses. In this study, we investigated NFDS in the wild using morphâfrequency changes spanning a 20âyear period from over 30 dimorphic populations of Datura wrightii. In these populations, plants either possess glandular (sticky) or nonâglandular (velvety) trichomes, and the ratio of these morphs varies substantially among populations. Our method provided evidence that NFDS, rather than drift or migration, is the primary force maintaining this dimorphism. Most populations that were initially dimorphic remained dimorphic, and the overall mean and variance in morph frequency did not change over time. Furthermore, morphâfrequency differences were not related to geographic distances. Together, these results indicate that neither directional selection, drift, or migration played a substantial role in determining morph frequencies. However, as predicted by negative frequencyâdependent selection, we found that the rare morph tended to increase in frequency, leading to a negative relationship between the change in the frequency of the sticky morph and its initial frequency. In addition, we found that morphâfrequency change over time was significantly correlated with the damage inflicted by two herbivores: Lema daturaphila and Tupiochoris notatus. The latter is a specialist on the sticky morph and damage by this herbivore was greatest when the sticky morph was common. The reverse was true for L. daturaphila, such that damage increased with the frequency of the velvety morph. These findings suggest that these herbivores contribute to balancing selection on the observed trichome dimorphism.Publisher PDFPeer reviewe
ORGANIC AGRICULTURE - rural development measures aimed at organic production of vegetables, fruits and grapes
EkoloĆĄka poljoprivredna proizvodnja se u Hrvatskoj provodi od 2001. godine. Do sada je financirana iz nacionalnih izvora, poĆĄtujuÄi pri tome pravila koja vrijede na nivou EU. Ista se pravila ekoloĆĄke proizvodnje nastavljaju, dok su se uvjeti i obveze za ostvarenje potpore neznatno promijenili. Zbog nezagaÄene prirode, tla, zraka i vode, ekoloĆĄko povrÄarstvo, voÄarstvo i vinogradarstvo predstavljaju ogroman potencijal za razvoj.Organic agricultural production has been implemented in Croatia in 2001. So far it was financed from national resources, while complying with the rules that apply on the EU level at the same time. Although the same rules of organic production continue to apply, the terms and conditions to receive financial aid have slightly changed.
Organic vegetables, fruits and grapes have a considerable potential to develop further due to unpolluted soil, air, water and environment in general
Brief Communication: CATALYST - a multi-regional stakeholder think tank for fostering capacity development in disaster risk reduction and climate change adaptation
Abstract. This brief communication presents the work and objectives of the CATALYST project on "Capacity Development for Hazard Risk Reduction and Adaptation" funded by the European Commission (October 2011âSeptember 2013). CATALYST set up a multi-regional think tank covering four regions (Central America and the Caribbean, East and West Africa, the European Mediterranean, and South and Southeast Asia), intending to strengthen capacity development for stakeholders involved in disaster risk reduction (DRR) and climate change adaptation, in the context of natural hazards. This communication concludes with a selection of recommendations for capacity development in DRR and climate change adaptation from the perspective of governance issues
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