Accumulation of carbohydrates and pungent principles in characteristic seed and set grown onion varieties (Allium cepa L.)

The profile of carbohydrates of onions (Allium cepa L.), mainly consisting of fructooligosaccharides (FOS), has a strong impact on digestibility, processability and storability. This study focused on the accumulation of FOS and pungent principles in onions during bulb maturation. Different onion varieties were grown from both, seedsand sets. Total FOS concentrations in onions of cv. ‘Sturon’ were higher when grown from sets than from seeds throughout the entire maturation period, reaching final levels of 75.7 ± 2.2 and 61.8 ± 11.8 g/L FOS, respectively. Higher levels in set grown onions might be due to their earlier emergence, thus resulting in an extended photosynthetically active period (+12% total sunshine hours). However, seed grown, so-called dehydrator onions (cv. ‘Stardust’) had significantly higher FOS contents than set grown cv. ‘Sturon’ onions at all sampling points (final FOS level: 129.3 ± 16.6 g/L), indicating cultivar-dependant accumulation. Furthermore, dehydrator onions accumulated FOS with highest molecular weight and a unique FOS distribution, allowing clear discrimination of such dehydrator cultivars. Besides carbohydrates, pungency as indicated by pyruvic acid levels was shown to be determined by sulphurous fertilization and its timing

Globally invariant metabolism but density-diversity mismatch in springtails.

Soil life supports the functioning and biodiversity of terrestrial ecosystems. Springtails (Collembola) are among the most abundant soil arthropods regulating soil fertility and flow of energy through above- and belowground food webs. However, the global distribution of springtail diversity and density, and how these relate to energy fluxes remains unknown. Here, using a global dataset representing 2470 sites, we estimate the total soil springtail biomass at 27.5 megatons carbon, which is threefold higher than wild terrestrial vertebrates, and record peak densities up to 2 million individuals per square meter in the tundra. Despite a 20-fold biomass difference between the tundra and the tropics, springtail energy use (community metabolism) remains similar across the latitudinal gradient, owing to the changes in temperature with latitude. Neither springtail density nor community metabolism is predicted by local species richness, which is high in the tropics, but comparably high in some temperate forests and even tundra. Changes in springtail activity may emerge from latitudinal gradients in temperature, predation and resource limitation in soil communities. Contrasting relationships of biomass, diversity and activity of springtail communities with temperature suggest that climate warming will alter fundamental soil biodiversity metrics in different directions, potentially restructuring terrestrial food webs and affecting soil functioning

Aspect processing across languages: A visual world eye-tracking study

The study employed a combination of a picture selection task and Visual World eye-tracking to investigate the processing of grammatical aspect (perfective vs. imperfective) in three languages: Russian, Spanish and English. In order to probe into the cognitive representations triggered by the aspectual forms we contrasted visual representations of dierent temporal portions of telic events—a snapshot of the process stage (ongoing event) and a snapshot of the immediate aftermath of the event/the result state (completed event). In all three languages, the gaze patterns and o ine responses revealed a strong preference for representations of ongoing events in the imperfective condition. This confirms that the imperfective forms in all the three languages draw attention to the in-progress portion of a telic event. In the perfective condition, however, we found robust dierences. Russian uses verbal prefixes to mark perfective aspect, and our results suggest that perfective telic verbs in Russian strongly highlight the result state of an event. In Spanish, the perfective past tense form (Preterite) also highlights event completion, but to a lesser extent than in Russian—in line with its less restrictive semantics in not requiring an inherent boundary. In contrast to Russian and Spanish, English speakers did not show a preference for representations of completed events in the perfective (Simple Past) condition. This suggests that the English Simple Past form does not encode a preferential cognitive salience for either the activity portion of an event or its result state, and lends support to the analysis of the English Simple Past as a non-aspectual tense form

Fine-grained time course of verb aspect processing

Sentence processing is known to be highly incremental. Speakers make incremental commitments as the sentence unfolds, dynamically updating their representations based on the smallest pieces of information from the incoming speech stream. Less is known about linguistic processing on the sub-word level, especially with regard to abstract grammatical information. This study employs the Visual World Paradigm to investigate the processing of grammatical aspect by Russian-speaking adults (n = 124). Aspectual information is encoded relatively early within the Russian verb which makes this an ideal testing ground to investigate the incrementality of grammatical processing on the sub-word level. Participants showed preference for pictures of ongoing events when they heard sentences involving Imperfective verbs, and for pictures of completed events when they heard sentences involving Perfective verbs. Crucially, the analysis of the participants’ eye-movements showed that they exhibited preference for the target picture already before they heard the end of the verb. Moreover, the latency of this effect depended on where the aspectual information was encoded within the verb. These results indicate that the processing and integration of grammatical aspect information can happen rapidly and incrementally on a fine-grained wordinternal level. Methodologically, the study draws together a set of analytical techniques which can be fruitfully applied to the analysis of effect latencies in a wide range of studies within the Visual World eye-tracking paradigm

Temporal Information and Event Bounding Across Languages: Evidence from Visual World EyeTracking

We explore the typological question of what the interpretation of grammatical perfectivity is, and how it connects to the related aktionsartal notion of boundedness/telicity on the one hand, and the tense category Past on the other. We report on a comparative experimental paradigm of past tense accomplishment sentences in Russian, Spanish and English respectively, in which we use an online visual world paradigm -- comparing looks to an ongoing representation (OE) with a result state representation (CE) -- to track the triggering of entailments of culmination during auditory processing. In all three languages, the results revealed at-ceiling preference for OE in the imperfective condition both in the offline task and the online gaze patterns. In the perfective condition, we found robust differences. In Russian, the choice of the result state (CE) picture in the offline task was at ceiling (95 %); for Spanish it was high, but not quite at ceiling (83 %); in English there was no statistical preference for the CE picture in the Simple Past condition (54 %, not significantly different from chance, p=0.39). Analysis of the participants' online gaze patterns yielded parallel results. Our results for English suggest that even on telic predicates, the simple past form does not obligatorily enforce a completed-event interpretation, contrary to previous assumptions in the literature (Smith 1995)

The invasion biology of tomato begomoviruses in Costa Rica reveals neutral synergism that may lead to increased disease pressure and economic loss

Since the late 1980s, tomato production in Costa Rica has been affected by diseases caused by whitefly-transmitted begomoviruses. The first was tomato yellow mottle virus (ToYMoV), a locally evolved New World (NW) bipartite begomovirus associated with the tomato yellow mottle disease (ToYMoD). In the late 1990s, the invasive NW bipartite tomato leaf curl Sinaloa virus (ToLCSiV) was detected in Costa Rica and has become established and associated with ToYMoD. Finally, the invasive Old World (OW) monopartite tomato yellow leaf curl virus (TYLCV) was detected in Costa Rica in 2012 and has also become established and is causing tomato yellow leaf curl disease (TYLCD). In the present study, we investigated the invasion biology of these tomato-infecting begomoviruses in Costa Rica in terms of (i) their biological and genetic properties and (ii) disease symptoms and viral DNA accumulation in tomato plants having single and mixed infections. We first generated infectious DNA-A and DNA-B clones and agroinoculation systems for ToYMoV and ToLCSiV isolates recovered from archival ToYMoD samples collected in Costa Rica in 1990 and 2002, respectively. Tomato plants agroinoculated with the infectious clones of both viruses developed ToYMoD symptoms, completing Koch’s postulates for ToYMoV, and showing that ToLCSiV also causes this disease. However, pseudorecombinants formed between the DNA components of these viruses were not infectious, which is consistent with independent evolution in different lineages and limits genetic interactions. Furthermore, ToYMoV is well-adapted to tomato, has a narrow host range and is mechanically transmissible. The DNA-A component has a recombination event in the hot spot area and induced a symptomless infection in agroinoculated Nicotiana benthamiana and tomato plants. Tomato plants co-infected with two or all three viruses developed more severe symptoms compared with plants infected with each virus alone. Symptoms induced by the NW bipartite ToYMoV and ToLCSiV appeared earlier (~7 d post-inoculation [dpi]) than those induced by TYLCV (~10 dpi), but TYLCD symptoms became predominant in single and mixed infections by 14 dpi. Viral DNA accumulation was quantified by qPCR and generally revealed a neutral synergistic interaction in which the viruses co-existed in mixed infections. A transient reduction in accumulation of ToYMoV and ToLCSiV was detected in mixed infections at 7 dpi, whereas TYLCV accumulation was not affected in mixed infections and was uniform among treatments and time points. Together our results suggest that this neutral synergistic interaction will lead to increased begomovirus disease severity in Costa Rica. We discuss this in terms of begomovirus invasion biology and disease management.Universidad de Costa Rica/[735-B9-470]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Agroalimentarias::Facultad de Ciencias Agroalimentarias::Escuela de Tecnología de AlimentosUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA