Volatile components and key odorants of fennel (Foeniculum vulgare Mill.) and thyme (Thymus vulgaris L.) oil extracts obtained by simultaneous distillation-extraction and supercritical fluid extraction

Volatile oil extracts of fennel seeds (Foeniculum vulgare Mill.) and thyme leaves (Thymus vulgaris L.) were obtained by simultaneous distillation-extraction (SDE) and supercritical fluid extraction (SFE) and analyzed by gas chromatography-mass spectrometry (GC-MS). In general, fennel oil extracted by SDE and SFE showed similar compositions, with trans-anethole, estragole, and fenchone as the main components. In contrast, thymol and p-cymene, the most abundant compounds in thyme leaves, showed big differences, with generally higher amounts of monoterpenes obtained by SDE. However, in this case, the differences between the extracts were higher. Key odorants of fennel seeds determined by gas chromatography-olfactometry (GC-O) showed similar patterns when applying SDE and SFE. trans-Anethole (anise, licorice), estragole (anise, licorice, sweet), fenchone (mint, camphor, warm), and 1-octen-3-ol (mushroom) were the most intense odor compounds detected in fennel extracts. Thymol and carvacrol, with oregano, thyme, and spicy notes, were identified as key compounds contributing to the aroma of thyme leaves.     

Human gene expression as a tool to determine horticultural maturity in a bioactive plant (Echinacea purpurea L. Moench)

A phenological study was conducted to determine the impact of harvest maturity on the immune-modulating properties of Echinacea purpurea. The aerial parts of this plant were collected during seven stages of development and were assayed for a common botanical marker for this species, cichoric acid. Plants of selected development stages were also assayed for total polysaccharides and compared for their immune-modulating effects on the THP-1 monocyte/macrophage cell line by means of a gene expression study. Although the concentration of cichoric acid did not change significantly during the course of the study, stage 1 (advanced vegetative) had the highest concentration of total polysaccharides and exhibited the most potent induction activity on immune-modulating cytokines such as interferon-gamma and tumor necrosis factor-alpha. These findings suggest that the use of gene expression may be an effective tool not only to standardize botanical extracts but also to optimize harvest time.     

Blind inlets: conservation practices to reduce herbicide losses from closed depressional areas

Purpose

In a 6-year study, we investigated the effectiveness of blind inlets as a conservation practice in reducing pesticide losses compared to tile risers from two closed farmed depressional areas (potholes) in the US Midwest under a 4-year cropping rotation.

Materials and methods

In two adjacent potholes within the same farm and having similar soils, a conventional tile riser and blind inlet were installed. Each draining practice could be operated independent of each other in order to drain and monitor each depression with either practice. Sampling events (runoff events) were collected from the potholes from 2008 to 2013 using autosamplers. The samples were analyzed for atrazine, metolachlor, 2,4-D, glyphosate, and deethylatrazine.

Results and discussion

The results of this study demonstrated that the blind inlet reduced analyzed pesticide losses; however, the level of reduction was compound dependent: atrazine (57 %), 2,4-D (58 %), metolachlor (53 %), and glyphosate (11 %).

Conclusions

Results from this study corroborate previous research findings that blind inlets are an effective conservation practice to reduce discharge and pollutants, including pesticides from farmed pothole surface runoff in the US Midwest.

     

Geomorphological significance of lichen colonization in a present snow hollow: Hoya del Cuchillar de las Navajas, Sierra de Gredos (Spain)

This paper discusses the results of a lichenometrical and geomorphological study of one of the few remaining active snow hollows in the central region of the Iberian Peninsula. The study area, located on a glacial shoulder, is called Hoya del Cuchillar de las Navajas. A protalus rampart occurs at the base of the hollow. Our studies, conducted between 1992 and 1998, were designed to determine the geomorphological characteristics of Hoya, the mobility of the deposits, and the characteristics of the snow cover. These data formed the basis for a study of the lichen colonization on the blocks and on the wall surrounding the snow hollow. All of the lichen species found were analyzed according to their abundance, distribution and the extent of their surface cover. Measurements of the diameter of the thalli of the species Rhizocarpon geographicum were also obtained. Thalli of this species were found to require a mean snow-free growing season of at least 95 days (13.5 weeks) per year. Maximum mean thallus diameters indicate that the protalus rampart was formed during the Little Ice Age and became inactive 130 years ago.     

Profiling essential genes in human mammary cells by multiplex RNAi screening

By virtue of their accumulated genetic alterations, tumor cells may acquire vulnerabilities that create opportunities for therapeutic intervention. We have devised a massively parallel strategy for screening short hairpin RNA (shRNA) collections for stable loss-of-function phenotypes. We assayed from 6000 to 20,000 shRNAs simultaneously to identify genes important for the proliferation and survival of five cell lines derived from human mammary tissue. Lethal shRNAs common to these cell lines targeted many known cell-cycle regulatory networks. Cell line-specific sensitivities to suppression of protein complexes and biological pathways also emerged, and these could be validated by RNA interference (RNAi) and pharmacologically. These studies establish a practical platform for genome-scale screening of complex phenotypes in mammalian cells and demonstrate that RNAi can be used to expose genotype-specific sensitivities.     

Stability of retrieved memory: inverse correlation with trace dominance

In memory consolidation, the memory trace stabilizes and becomes resistant to certain amnesic agents. The textbook account is that for any memorized item, consolidation starts and ends just once. However, evidence has accumulated that upon activation in retrieval, the trace may reconsolidate. Whereas some authors reported transient renewed susceptibility of retrieved memories to consolidation blockers, others could not detect it. Here, we report that in both conditioned taste aversion in the rat and fear conditioning in the medaka fish, the stability of retrieved memory is inversely correlated with the control of behavior by that memory. This result may explain some conflicting findings on reconsolidation of activated memories.     

Biscrolling nanotube sheets and functional guests into yarns

Multifunctional applications of textiles have been limited by the inability to spin important materials into yarns. Generically applicable methods are demonstrated for producing weavable yarns comprising up to 95 weight percent of otherwise unspinnable particulate or nanofiber powders that remain highly functional. Scrolled 50-nanometer-thick carbon nanotube sheets confine these powders in the galleries of irregular scroll sacks whose observed complex structures are related to twist-dependent extension of Archimedean spirals, Fermat spirals, or spiral pairs into scrolls. The strength and electronic connectivity of a small weight fraction of scrolled carbon nanotube sheet enables yarn weaving, sewing, knotting, braiding, and charge collection. This technology is used to make yarns of superconductors, lithium-ion battery materials, graphene ribbons, catalytic nanofibers for fuel cells, and titanium dioxide for photocatalysis.     

The genome of the diatom Thalassiosira pseudonana: ecology, evolution, and metabolism

Diatoms are unicellular algae with plastids acquired by secondary endosymbiosis. They are responsible for approximately 20% of global carbon fixation. We report the 34 million-base pair draft nuclear genome of the marine diatom Thalassiosira pseudonana and its 129 thousand-base pair plastid and 44 thousand-base pair mitochondrial genomes. Sequence and optical restriction mapping revealed 24 diploid nuclear chromosomes. We identified novel genes for silicic acid transport and formation of silica-based cell walls, high-affinity iron uptake, biosynthetic enzymes for several types of polyunsaturated fatty acids, use of a range of nitrogenous compounds, and a complete urea cycle, all attributes that allow diatoms to prosper in aquatic environments.