Spontaneous dural tear leading to intracranial hypotension and tonsillar herniation in Marfan syndrome: a case report

Background  

We describe the case of a 38 year old male with Marfan syndrome who presented with orthostatic headaches and seizures.     

An anthraquinone from the roots of Digitalis davisiana

A new anthraquinone, 1-hydroxy-2-hydroxymethyl-8-methoxyanthraquinone, was isolated from the root of Digitalis davisiana.     

Soil inoculation of lodgepole pine seedlings alters root-associated fungal communities but does not improve seedling performance in beetle-killed pine stands

Extensive tree mortality in forests can change the community composition of soil fungi altering seedling establishment, a process critical to forest restoration. Disturbances that result in the loss of ectomycorrhizal fungi, in particular, may impede the establishment of tree species reliant on these symbionts for their survival. Inoculation of seedlings with soil from intact forests may improve the establishment of seedlings in such disturbances but the method has rarely been tested in the field. Here, we assess whether soil inoculation improves lodgepole pine (Pinus contorta var. latifolia) seedling performance in conspecific stands with high levels of tree mortality caused by a mountain pine beetle (Dendroctonus ponderosae) outbreak and whether underlying soil type modifies inoculation effects. We first inoculated seedlings in a growth chamber with small amounts of soils (5% volume) originating from either intact (<10%) or “beetle-killed” (>70% pine basal area killed) conspecific stands or added no soil inoculum and, after 4 months, transplanted them into 15 beetle-killed stands. After two growing seasons, root-associated fungal communities of seedlings receiving inoculum from intact stands differed in composition from those receiving inoculum from beetle-killed stands or no inoculum. However, inoculation had no effect on seedling survival, height, or biomass. Site properties, including soil texture and the resident fungal community composition, overwhelmed the effect of soil inoculation on seedling performance. Seedling survival and shoot mass was higher in sandy than loamy soils. Restoration to improve seedling performance in beetle-killed stands should consider stand-level treatments as soil inoculation at the level evaluated was ineffective.     

NaCl stress inhibits maltose fermentation by Saccharomyces cerevisiae

While fermentation of 20 g glucose l^–1 by Saccharomyces cerevisiae was not impaired by high NaCl concentrations, fermentation of 20 g maltose l^–1 was significantly decreased by 0.7 M NaCl, and completely inhibited with 1.4 M NaCl. No glycerol was produced in response to the salt stress when yeast cells were fermenting maltose. Active maltose transport, and not intracellular hydrolysis, was the metabolic step severely impaired by the NaCl stress.     

A host monoterpene influences Ips typographus (Coleoptera: Curculionidae,Scolytinae) responses to its aggregation pheromone

1 Host tree terpenes can influence attraction of conifer‐infesting bark beetles to their aggregation pheromones, and both synergistic and inhibitory effects have been reported. 2 We tested a gradient of ratios of (–)‐α‐pinene, the predominant monoterpene in Norway spruce, to the pheromone of Ips typographus, a major pest of Norway spruce. 3 Attraction of I. typographus increased as the release rate of (–)‐α‐pinene increased. The two highest (–)‐α‐pinene : pheromone ratios (526 : 1 and 2595 : 1) attracted twice as many I. typographus as pheromone alone, whereas low to intermediate ratios (56 : 1, 274 : 1) did not differ from pheromone alone. 4 Our results are in agreement with a proposed model, which suggests that bark beetles display unique response profiles to host terpenes depending on the physiological condition of the host trees that they typically colonize. Ips typographus, which is an aggressive species capable of colonizing and killing healthy trees, showed an increased attraction to monoterpene : pheromone ratios, and this may be high enough to inhibit attraction of less aggressive beetle species typically colonizing dead, dying or stressed trees. 5 Attraction of associates of I. typographus was also modified by (–)‐α‐pinene. Ips duplicatus, a competitor of I. typographus, showed increased attraction to the pheromone of I. typographus across all concentrations of (–)‐α‐pinene.     

Molecular substitution rate increases in myrmecophilous lycaenid butterflies (Lepidoptera)

Pellissier, L., Litsios, G., Guisan, A. & Alvarez, N. (2012). Molecular substitution rate increases in myrmecophilous lycaenid butterflies (Lepidoptera). —Zoologica Scripta, 41, 651–658. Is species diversification driven by neutral‐ or niche‐based processes? Butterflies of the Lycaenidae family have developed mutualistic interactions with ants. This biotic requirement increased the spatial fragmentation of populations of lower effective population size (Ne) compared with autonomous species. The nearly neutral theory predicts that species with smaller Ne should fix more mutations because of the increased strength of drift. Taking into account the phylogenetic relatedness among species, this study shows that species with a stronger dependence on ants displayed more intra‐specific Single Nucleotide Polymorphisms compared with species with low or no myrmecophily. This phenomenon can cause more pronounced genetic differentiation between populations and could ultimately promote speciation in a similar manner as on physical islands. The large species diversity observed in this family could be the consequence of this neutral process enhancing the diversification of lineages.     

Dye-coupling between term pregnant human myometrial cells before labor: Carboxyfluorescein versus lucifer yellow

Term pregnant human myometrial cells in whole mounts were microinjected by pressure with the fluorescent probes Lucifer Yellow and carboxyfluorescein. Tissues obtained from acute and elective sections displayed weak dye-coupling when injected with Lucifer Yellow. Injection of carboxyfluorescein into cells from the elective sections resulted in a more extensive dye-coupling than that observed with Lucifer Yellow. These results indicate that term pregnant human myometrial cells are metabolically coupled before labor and carboxyfluorescein is superior to Lucifer Yellow in detecting the coupling.