Description de Falklandia gen.n. de I'Ocean Austral et définition des Lysianassoidea uristidiens (Crustacea, Amphipoda)

The revision of the antarctic–subantarctic species Orchomenopsis reducta Schellenberg, 1931, has led to its attribution to a new, highly apomorphic genus: Falklandia gen.n. A new definition of the uristid group is given and Falklandia with 36 other lysianassoid genera are attributed to this supposedly monophyletic group.     

Cyanide-Resistant Root Respiration and Tap Root Formation in Two Subspecies of Hypochaeris radicata

Root respiration of the tap root forming species Hypochaeris radicata L. was measured during tap root formation. A comparison was made of two subspecies: H. radicata L. ssp. radicata L., a subspecies from relatively rich soils, and H. radicata L. ssp. ericetorum Van Soest, a subspecies from poor acidic soils. Root respiration was high and to a large extent inhibited by hydroxamic acid (SHAM) before the start of the tap root formation, indicating a high activity of an alternative non-phosphorylative electron transport chain. The rate of root respiration was much lower and less sensitive to SHAM when a considerable tap root was present. However, root respiration was also cyanide-resistant when a tap root was present, indicating that the alternative pathway was still present. A decreased rate of root respiration coincided with an increase of the content of storage carbohydrates, mainly in the tap root. The level of reducing sugars was constant throughout the experimental period, and it was concluded that the activity of the alternative oxidative pathway was significant in oxidation of sugars that could not be utilized for purposes like energy production, the formation of intermediates for growth or for storage. Root respiration decreased after the formation of a tap root. This decrease could neither be attributed to a gradual disappearance of the alternative chain, nor to a decreased level of reducing sugars. No differences in respiratory metabolism between the two subspecies have been observed, suggesting that a high activity of the alternative oxidative pathway is not significant in adaptation of the present two subspecies to relatively nutrient-rich or poor soils.     

The Influence of Texting Language on Grammar and Executive Functions in Primary School Children

When sending text messages on their mobile phone to friends, children often use a special type of register, which is called textese. This register allows the omission of words and the use of textisms: instances of non-standard written language such as 4ever (forever). Previous studies have shown that textese has a positive effect on children’s literacy abilities. In addition, it is possible that children’s grammar system is affected by textese as well, as grammar rules are often transgressed in this register. Therefore, the main aim of this study was to investigate whether the use of textese influences children’s grammar performance, and whether this effect is specific to grammar or language in general. Additionally, studies have not yet investigated the influence of textese on children’s cognitive abilities. Consequently, the secondary aim of this study was to find out whether textese affects children’s executive functions. To investigate this, 55 children between 10 and 13 years old were tested on a receptive vocabulary and grammar performance (sentence repetition) task and various tasks measuring executive functioning. In addition, text messages were elicited and the number of omissions and textisms in children’s messages were calculated. Regression analyses showed that omissions were a significant predictor of children’s grammar performance after various other variables were controlled for: the more words children omitted in their text messages, the better their performance on the grammar task. Although textisms correlated (marginally) significantly with vocabulary, grammar and selective attention scores and omissions marginally significantly with vocabulary scores, no other significant effects were obtained for measures of textese in the regression analyses: neither for the language outcomes, nor for the executive function tasks. Hence, our results show that textese is positively related to children’s grammar performance. On the other hand, use of textese does not affect—positively nor negatively—children’s executive functions.     

Productivity-diversity relationships for plants, bryophytes, lichens, and polypore fungi in six northern forest landscapes

We investigated the relationship between site productivity and diversity of vascular plants, bryophytes, lichens, and polypore fungi in forests based on species richness data in 0.25 ha forest plots (grain size), selected from six 150–200 ha study areas (focus), and spanning over a latitudinal distance of 1350 km (extent) in Norway. We 1) searched for prevailing productivity-diversity relationships (PDRs), 2) compared PDRs among taxonomic groups and species found in different micro-habitats, and 3) investigated the effect of increasing plot (grain) size on PDRs. Using vegetation types as a surrogate for site productivity, we found a general pattern of increasing species richness with site productivity. On average total species richness doubled with a ten-fold increase in productivity. Lichens PDRs stood out as less pronounced and more variable than for other species groups investigated. PDRs of species associated with downed logs tended to level off at high-productive sites, a pattern interpreted as an effect of disturbance. Increasing the grain size >10-fold did not change the proportional difference in species richness between sites with high and low productivity.