Unusual pegmatoid crystallisations in a nephelinite plug, near Round Lagoon, eastern Central Plateau, Tasmania

Pegmatoids in a Late Oligocene olivine nephelinite plug near Round Lagoon form a complex low-pressure fractionation suite. The host nephelinite contains meta-peridotite and meta-wehrlite mantle xenoliths and its composition (Mg# 0.63) may reflect both mantle and then limited fractionation. The pegmatoids range from ultramafic through mafic to feldspathic assemblages in a progressive, but discontinuous, fractionation sequence ~ olivine ~ sodalite ijolite, nepheline syenite ~ alkali syenite). Within this sequence, olivine and clinopyroxene compositions decrease in content, while clinopyroxene becomes increasingly Na- and Fe-rich to produce late stage aegirine-augite and aegirine. Nepheline is prominent in the sequence and crystallised over a wide temperature range from 10000 to <500°C. The presence of sodalite suggests volatile Cl-rich fluxing. Mg-rich spinel crystallised in assemblages, distinct from Fe- and Ti-rich oxides of the magnetite-ulvospinel series in later assemblages. The Round Lagoon low-pressure pegmatoids developed by fractionation in a narrow, vertical feeder rather than in broad lava ponds such as those noted in nephelinite flows at Inverell, New South Wales, and at La Madera, Argentina

Seasonality of Human Leptospirosis in Reunion Island (Indian Ocean) and Its Association with Meteorological Data

Background: Leptospirosis is a disease which occurs worldwide but particularly affects tropical areas. Transmission of the disease is dependent on its excretion by reservoir animals and the presence of moist environment which allows the survival of the bacteria. Methods and Findings: A retrospective study was undertaken to describe seasonal patterns of human leptospirosis cases reported by the Centre National de Re´fe´rences des Leptospiroses (CNRL, Pasteur Institute, Paris) between 1998 and 2008, to determine if there was an association between the occurrence of diagnosed cases and rainfall, temperature and global solar radiation (GSR). Meteorological data were recorded in the town of Saint-Beno?¿t (Me´te´o France ''Beaufonds-Miria'' station), located on the windward (East) coast. Time-series analysis was used to identify the variables that best described and predicted the occurrence of cases of leptospirosis on the island. Six hundred and thirteen cases were reported during the 11-year study period, and 359 cases (58.56%) were diagnosed between February and May. A significant correlation was identified between the number of cases in a given month and the associated cumulated rainfall as well as the mean monthly temperature recorded 2 months prior to diagnosis (r = 0.28 and r = 0.23 respectively). The predictive model includes the number of cases of leptospirosis recorded 1 month prior to diagnosis (b = 0.193), the cumulated monthly rainfall recorded 2 months prior to diagnosis (b = 0.145), the average monthly temperature recorded 0 month prior to diagnosis (b = 3.836), and the average monthly GSR recorded 0 month prior to diagnosis (b =21.293). Conclusions: Leptospirosis has a seasonal distribution in Reunion Island. Meteorological data can be used to predict the occurrence of the disease and our statistical model can help to implement seasonal prevention measures. (Résumé d'auteur

Chromatin-associated regulation of sorbitol synthesis in flower buds of peach

[EN] Key message PpeS6PDH gene is postulated to mediate sorbitol synthesis in flower buds of peach concomitantly with specific chromatin modifications. Abstract Perennial plants have evolved an adaptive mechanism involving protection of meristems within specialized structures named buds in order to survive low temperatures and water deprivation during winter. A seasonal period of dormancy further improves tolerance of buds to environmental stresses through specific mechanisms poorly known at the molecular level. We have shown that peach PpeS6PDH gene is down-regulated in flower buds after dormancy release, concomitantly with changes in the methylation level at specific lysine residues of histone H3 (H3K27 and H3K4) in the chromatin around the translation start site of the gene. PpeS6PDH encodes a NADPH-dependent sorbitol-6-phosphate dehydrogenase, the key enzyme for biosynthesis of sorbitol. Consistently, sorbitol accumulates in dormant buds showing higher PpeS6PDH expression. Moreover, PpeS6PDH gene expression is affected by cold and water deficit stress. Particularly, its expression is up-regulated by low temperature in buds and leaves, whereas desiccation treatment induces PpeS6PDH in buds and represses the gene in leaves. These data reveal the concurrent participation of chromatin modification mechanisms, transcriptional regulation of PpeS6PDH and sorbitol accumulation in flower buds of peach. In addition to its role as a major translocatable photosynthate in Rosaceae species, sorbitol is a widespread compatible solute and cryoprotectant, which suggests its participation in tolerance to environmental stresses in flower buds of peach.This work was funded by the Instituto Nacional de Investigacion y Tecnologia Agraria y Alimentaria (INIA)-FEDER (RF2013-00043-C02-02) and the Ministry of Science and Innovation of Spain (AGL2010-20595). AL was funded by a fellowship co-financed by the European Social Fund and the Instituto Valenciano de Investigaciones Agrarias (IVIA).Lloret, A.; Martinez Fuentes, A.; Agustí Fonfría, M.; Badenes, ML.; Rios, G. (2017). Chromatin-associated regulation of sorbitol synthesis in flower buds of peach. Plant Molecular Biology. 95(4-5):507-517. https://doi.org/10.1007/s11103-017-0669-6S507517954-5Andersen CL, Jensen JL, Ørntoft TF (2004) Normalization of real-time quantitative reverse transcription-PCR data: a model-based variance estimation approach to identify genes suited for normalization, applied to bladder and colon cancer data sets. Cancer Res 64:5245–5250. doi: 10.1158/0008-5472.CAN-04-0496Bai S, Saito T, Ito A et al (2016) Small RNA and PARE sequencing in flower bud reveal the involvement of sRNAs in endodormancy release of Japanese pear (Pyrus pyrifolia ‘Kosui’). BMC Genomics 17:230. doi: 10.1186/s12864-016-2514-8Bielenberg DG, Wang Y, Li Z et al (2008) Sequencing and annotation of the evergrowing locus in peach (Prunus persica [L.] Batsch) reveals a cluster of six MADS-box transcription factors as candidate genes for regulation of terminal bud formation. Tree Genet Genomes 4:495–507. doi: 10.1007/s11295-007-0126-9Bieleski RL (1969) Accumulation and translocation of sorbitol in apple phloem. Aust J Biol Sci 22:611–620. doi: 10.1071/BI9690611Bieleski RL (1982) Sugar alcohols. In: Loewus F, Tanner W (eds) Encyclopedia of plant physiology, new series 13A. Springer-Verlag, Berlin, pp 158–192Bortiri E, Oh SH, Gao FY, Potter D (2002) The phylogenetic utility of nucleotide sequences of sorbitol 6-phosphate dehydrogenase in Prunus (Rosaceae). Am J Bot 89:1697–1708. doi: 10.3732/ajb.89.10.1697Chouard P (1960) Vernalization and its relations to dormancy. Annu Rev Plant Physiol 11:191–238. doi: 10.1146/annurev.pp.11.060160.001203Conde D, Le Gac AL, Perales M et al (2017) Chilling-responsive DEMETER-LIKE DNA demethylase mediates in poplar bud break. Plant Cell Environ 40:2236–2249. doi: 10.1111/pce.13019Couvillon GA, Erez A (1985) Influence of prolonged exposure to chilling temperatures on bud break and heat requirement for bloom of several fruit species. J Amer Soc Hort Sci 110:47–50de la Fuente L, Conesa A, Lloret A, Badenes ML, Ríos G (2015) Genome-wide changes in histone H3 lysine 27 trimethylation associated with bud dormancy release in peach. Tree Genet Genomes 11:45. doi: 10.1007/s11295-015-0869-7Deng W, Buzas DM, Ying H et al (2013) Arabidopsis polycomb repressive complex 2 binding sites contain putative GAGA factor binding motifs within coding regions of genes. BMC Genomics 14:593. doi: 10.1186/1471-2164-14-593Escobar-Gutiérrez AJ, Gaudillère JP (1996) Distribution, metabolism and role of sorbitol in higher plants—A review. Agronomie 16:281–298. doi: 10.1051/agro:19960502Escobar-Gutiérrez AJ, Zipperlin B, Carbonne F, Moing A, Gaudillére JP (1998) Photosynthesis, carbon partitioning and metabolite content during drought stress in peach seedlings. Aust J Plant Physiol 25:197–205. doi: 10.1071/PP97121Eshghi S, Tafazoli E, Dokhani S, Rahemi M, Emam Y (2007) Changes in carbohydrate contents in shoot tips, leaves and roots of strawberry (Fragaria x ananassa Duch) during flower-bud differentiation. Sci Hortic 113:255–260. doi: 10.1016/j.scienta.2007.03.014Everard JD, Cantini C, Grumet R, Plummer J, Loescher WH (1997) Molecular cloning of mannose-6-phosphate reductase and its developmental expression in celery. Plant Physiol 113:1427–1435. doi: 10.1104/pp.113.4.1427Fennell A (2014) Genomics and functional genomics of winter low temperature tolerance in temperate fruit crops. Crit Rev Plant Sci 33:125–140. doi: 10.1080/07352689.2014.870410Figueroa CM, Iglesias AA (2010) Aldose-6-phosphate reductase from apple leaves: importance of the quaternary structure for enzyme activity. Biochimie 92:81–88. doi: 10.1016/j.biochi.2009.09.013Gao M, Tao R, Miura K, Dandekar AM, Sugiura A (2001) Transformation of Japanese persimmon (Diospyros kaki Thunb) with apple cDNA encoding NADP-dependent sorbitol-6-phosphate dehydrogenase. Plant Sci 160:837–845. doi: 10.1016/S0168-9452(00)00458-1Grant CR, ap Rees T (1981) Sorbitol metabolism by apple seedlings. Phytochemistry 20:1505–1511. doi: 10.1016/S0031-9422(00)98521-2Hartman MD, Figueroa CM, Arias DG, Iglesias AA (2017) Inhibition of recombinant aldose-6-phosphate reductase from peach leaves by hexose-phosphates, inorganic phosphate and oxidants. Plant Cell Physiol 58:145–155. doi: 10.1093/pcp/pcw180Horvath DP, Anderson JV, Chao WS, Foley ME (2003) Knowing when to grow: signals regulating bud dormancy. Trends Plant Sci 8:534–540. doi: 10.1016/j.tplants.2003.09.013Horvath DP, Sung S, Kim D, Chao W, Anderson J (2010) Characterization, expression and function of DORMANCY ASSOCIATED MADS-BOX genes from leafy spurge. Plant Mol Biol 73:169–179. doi: 10.1007/s11103-009-9596-5Hussain S, Niu Q, Yang F, Hussain N, Teng Y (2015) The possible role of chilling in floral and vegetative bud dormancy release in Pyrus pyrifolia. Biol Plant 59:726–734. doi: 10.1007/s10535-015-0547-5Hyndman D, Baumanb DR, Herediac VV, Penning TM (2003) The aldo-keto reductase superfamily homepage. Chem Biol Interact 143–144:621–631. doi: 10.1016/S0009-2797(02)00193-XIto A, Sakamoto D, Moriguchi T (2012) Carbohydrate metabolism and its possible roles in endodormancy transition in Japanese pear. Sci Hortic 144:187–194. doi: 10.1016/j.scienta.2012.07.009Ito A, Sugiura T, Sakamoto D, Moriguchi T (2013) Effects of dormancy progression and low-temperature response on changes in the sorbitol concentration in xylem sap of Japanese pear during winter season. Tree Physiol 33:398–408. doi: 10.1093/treephys/tpt021Jung S, Bassett C, Bielenberg DG et al (2015) A standard nomenclature for gene designation in the Rosaceae. Tree Genet Genomes 11:108. doi: 10.1007/s11295-015-0931-5Kanayama Y, Mori H, Imaseki H, Yamaki S (1992) Nucleotide sequence of a cDNA encoding NADP-sorbitol-6-phosphate dehydrogenase from apple. Plant Physiol 100:1607–1608Kanayama Y, Watanabe M, Moriguchi R, Deguchi M, Kanahama K, Yamaki S (2006) Effects of low temperature and abscisic acid on the expression of the sorbitol-6-phosphate dehydrogenase gene in apple leaves. J Japan Soc Hort Sci 75:20–25. doi: 10.2503/jjshs.75.20Kumar G, Rattan UK, Singh AK (2016a) Chilling-mediated DNA methylation changes during dormancy and its release reveal the importance of epigenetic regulation during winter dormancy in apple (Malus x domestica Borkh). PLoS ONE 11:e0149934. doi: 10.1371/journal.pone.0149934Kumar S, Stecher G, Tamura K (2016b) MEGA7: molecular evolutionary genetics analysis version 70 for bigger datasets. Mol Biol Evol 33:1870–1874. doi: 10.1093/molbev/msw054Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227:680–685. doi: 10.1038/227680a0Larkin MA, Blackshields G, Brown NP et al (2007) Clustal W and Clustal X version 2.0. Bioinformatics 23:2947–2948. doi: 10.1093/bioinformatics/btm404Leida C, Terol J, Martí G et al (2010) Identification of genes associated with bud dormancy release in Prunus persica by suppression subtractive hybridization. Tree Physiol 30:655–666. doi: 10.1093/treephys/tpq008Leida C, Conesa A, Llácer G, Badenes ML, Ríos G (2012) Histone modifications and expression of DAM6 gene in peach are modulated during bud dormancy release in a cultivar-dependent manner. New Phytol 193:67–80. doi: 10.1111/j.1469-8137.2011.03863.xLiang D, Cui M, Wu S, Ma F-W (2012) Genomic structure, sub-cellular localization, and promoter analysis of the gene encoding sorbitol-6-phosphate dehydrogenase from apple. Plant Mol Biol Rep 30:904–914. doi: 10.1007/s11105-011-0409-zLiu D, Ni J, Wu R, Teng Y (2013) High temperature alters sorbitol metabolism in Pyrus pyrifolia leaves and fruit flesh during late stages of fruit enlargement. J Am Soc Hortic Sci 138:443–451Lloret A, Conejero A, Leida C et al (2017) Dual regulation of water retention and cell growth by a stress-associated protein (SAP) gene in Prunus. Sci Rep 7:332. doi: 10.1038/s41598-017-00471-7Lo Bianco R, Rieger M, Sung S-JS (2000) Effect of drought on sorbitol and sucrose metabolism in sinks and sources of peach. Physiol Plant 108:71–78. doi: 10.1034/j.1399-3054.2000.108001071.xLoescher WH (1987) Physiology and metabolism of sugar alcohols in higher-plants. Physiol Plant 70:553–557. doi: 10.1111/j.1399-3054.1987.tb02857.xLoescher WH, Marlow GC, Kennedy RA (1982) Sorbitol metabolism and sink-source interconversions in developing apple leaves. Plant Physiol 70:335–339. doi: 10.1104/pp.70.2.335Marquat C, Vandamme M, Gendraud M, Pétel G (1999) Dormancy in vegetative buds of peach: relation between carbohydrate absorption potentials and carbohydrate concentration in the bud during dormancy and its release. Sci Hortic 79:151–162. doi: 10.1016/S0304-4238(98)00203-9Niu Q, Li J, Cai D et al (2016) Dormancy-associated MADS-box genes and microRNAs jointly control dormancy transition in pear (Pyrus pyrifolia white pear group) flower bud. J Exp Bot 67:239–257. doi: 10.1093/jxb/erv454Pfaffl MW, Tichopad A, Prgomet C, Neuvians TP (2004) Determination of stable housekeeping genes, differentially regulated target genes and sample integrity: BestKeeper—excel-based tool using pair-wise correlations. Biotechnol Lett 26:509–515. doi: 10.1023/B:BILE.0000019559.84305.47Ríos G, Leida C, Conejero A, Badenes ML (2014) Epigenetic regulation of bud dormancy events in perennial plants. Front Plant Sci 5:247. doi: 10.3389/fpls.2014.00247Saito T, Bai S, Imai T, Ito A, Nakajima I, Moriguchi T (2015) Histone modification and signalling cascade of the dormancy-associated MADS-box gene, PpMADS13-1, in Japanese pear (Pyrus pyrifolia) during endodormancy. Plant Cell Environ 38:1157–1166. doi: 10.1111/pce.12469Santamaría ME, Hasbún R, Valera MJ et al (2009) Acetylated H4 histone and genomic DNA methylation patterns during bud set and bud burst in Castanea sativa. J Plant Physiol 166:1360–1369. doi: 10.1016/j.jplph.2009.02.014Shen B, Hohmann S, Jensen RG, Bohnert HJ (1999) Roles of sugar alcohols in osmotic stress adaptation replacement of glycerol by mannitol and sorbitol in yeast. Plant Physiol 121:45–52. doi: 10.1104/pp.121.1.45Sheveleva EV, Marquez S, Chmara W, Zegeer A, Jensen RG, Bohnert HJ (1998) Sorbitol-6-phosphate dehydrogenase expression in transgenic tobacco high amounts of sorbitol lead to necrotic lesions. Plant Physiol 117:831–839. doi: 10.1104/pp.117.3.831Silver N, Best S, Jian J, Thein SL (2006) Selection of housekeeping genes for gene expression studies in human reticulocytes using real-time PCR. BMC Mol Biol 7:33. doi: 10.1186/1471-2199-7-33Talavera G, Castresana J (2007) Improvement of phylogenies after removing divergent and ambiguously aligned blocks from protein sequence alignments. Syst Biol 56:564–577. doi: 10.1080/10635150701472164Tao R, Uratsu SL, Dandekar AM (1995) Sorbitol synthesis in transgenic tobacco with apple cDNA encoding NADP-dependent sorbitol-6-phosphate dehydrogenase. Plant Cell Physiol 36:525–532. doi: 10.1093/oxfordjournals.pcp.a078789Teo G, Suzuki Y, Uratsu SL et al (2006) Silencing leaf sorbitol synthesis alters long-distance partitioning and apple fruit quality. Proc Natl Acad Sci USA 103:18842–18847. doi: 10.1073/pnas.0605873103Trotel P, Bouchereau A, Niogret MF, Larher F (1996) The fate of osmo-accumulated proline in leaf discs of Rape (Brassica napus L) incubated in a medium of low osmolarity. Plant Sci 118:31–45. doi: 10.1016/0168-9452(96)04422-6Verde I, Abbott AG, Scalabrin S et al (2013) The high-quality draft genome of peach (Prunus persica) identifies unique patterns of genetic diversity, domestication and genome evolution. Nat Genet 45:487–494. doi: 10.1038/ng.2586Webb KL, Burley JWA (1962) Sorbitol translocation in apple. Science 137:766. doi: 10.1126/science.137.3532.766Wisniewski M, Norelli J, Artlip T (2015) Overexpression of a peach CBF gene in apple: a model for understanding the integration of growth, dormancy, and cold hardiness in woody plants. Front Plant Sci 6:85. doi: 10.3389/fpls.2015.00085Yadav R, Prasad R (2014) Identification and functional characterization of sorbitol-6-phosphate dehydrogenase protein from rice and structural elucidation by in silico approach. Planta 240:223–238. doi: 10.1007/s00425-014-2076-

Metformin and the gastrointestinal tract

Metformin is an effective agent with a good safety profile that is widely used as a first-line treatment for type 2 diabetes, yet its mechanisms of action and variability in terms of efficacy and side effects remain poorly understood. Although the liver is recognised as a major site of metformin pharmacodynamics, recent evidence also implicates the gut as an important site of action. Metformin has a number of actions within the gut. It increases intestinal glucose uptake and lactate production, increases GLP-1 concentrations and the bile acid pool within the intestine, and alters the microbiome. A novel delayed-release preparation of metformin has recently been shown to improve glycaemic control to a similar extent to immediate-release metformin, but with less systemic exposure. We believe that metformin response and tolerance is intrinsically linked with the gut. This review examines the passage of metformin through the gut, and how this can affect the efficacy of metformin treatment in the individual, and contribute to the side effects associated with metformin intolerance

Expert consensus document: The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of prebiotics

In December 2016, a panel of experts in microbiology, nutrition and clinical research was convened by the International Scientific Association for Probiotics and Prebiotics to review the definition and scope of prebiotics. Consistent with the original embodiment of prebiotics, but aware of the latest scientific and clinical developments, the panel updated the definition of a prebiotic: a substrate that is selectively utilized by host microorganisms conferring a health benefit. This definition expands the concept of prebiotics to possibly include non-carbohydrate substances, applications to body sites other than the gastrointestinal tract, and diverse categories other than food. The requirement for selective microbiota-mediated mechanisms was retained. Beneficial health effects must be documented for a substance to be considered a prebiotic. The consensus definition applies also to prebiotics for use by animals, in which microbiota-focused strategies to maintain health and prevent disease is as relevant as for humans. Ultimately, the goal of this Consensus Statement is to engender appropriate use of the term ‘prebiotic’ by relevant stakeholders so that consistency and clarity can be achieved in research reports, product marketing and regulatory oversight of the category. To this end, we have reviewed several aspects of prebiotic science including its development, health benefits and legislation

Ecological drivers of plant diversity patterns in remnants coastal sand dune ecosystems along the northern Adriatic coastline

Coastal sand dunes represent one of the most fragile ecosystems in the Mediterranean basin. These habitats naturally suffer the action of several limiting factors such as sand burial, marine aerosol and low soil fertility; on the other hand, they often host species of high conservation value. Over the last decades, they have also experienced a high level of biological invasion. In this study, we sampled psammophilous vegetation in two sites in the northern Adriatic coast belonging to the Natura 2000 network to describe diversity patterns and to identify the main ecological drivers of species diversity. Plant species richness and their abundance were assessed in each plot. Differences in species composition for native and alien species were compared via PERMANOVA analysis. Species complementarity was explored by partitioning beta diversity in its spatial components (richness and replacement). A Generalized Linear Model was also computed to assess the main environmental factors that may promote invasiveness in these ecosystems. For the investigated area, our results highlight the strong differentiation in community composition both in alien and native species: in particular alien species showed on average a lower complementarity among habitats compared to native species. Specifically, communities seem to be more diversified when larger spatial scales were considered. Beta diversity in both groups appears to be more dominated by the richness component with respect to the replacement component. Furthermore, in these habitats, the occurrence of alien species was shown to be related to geomorphological predictors more than climatic variables