Abiotic methane synthesis and serpentinization in olivine-hosted fluid inclusions

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Proceedings of the National Academy of Sciences.of the United States of America 116(36), (2019): 17666-17672. doi:10.1073/pnas.1907871116.The conditions of methane (CH4) formation in olivine-hosted secondary fluid inclusions and their prevalence in peridotite and gabbroic rocks from a wide range of geological settings were assessed using confocal Raman spectroscopy, optical and scanning electron microscopy, electron microprobe analysis, and thermodynamic modeling. Detailed examination of 160 samples from ultraslow- to fast-spreading midocean ridges, subduction zones, and ophiolites revealed that hydrogen (H2) and CH4 formation linked to serpentinization within olivine-hosted secondary fluid inclusions is a widespread process. Fluid inclusion contents are dominated by serpentine, brucite, and magnetite, as well as CH4(g) and H2(g) in varying proportions, consistent with serpentinization under strongly reducing, closed-system conditions. Thermodynamic constraints indicate that aqueous fluids entering the upper mantle or lower oceanic crust are trapped in olivine as secondary fluid inclusions at temperatures higher than ∼400 °C. When temperatures decrease below ∼340 °C, serpentinization of olivine lining the walls of the fluid inclusions leads to a near-quantitative consumption of trapped liquid H2O. The generation of molecular H2 through precipitation of Fe(III)-rich daughter minerals results in conditions that are conducive to the reduction of inorganic carbon and the formation of CH4. Once formed, CH4(g) and H2(g) can be stored over geological timescales until extracted by dissolution or fracturing of the olivine host. Fluid inclusions represent a widespread and significant source of abiotic CH4 and H2 in submarine and subaerial vent systems on Earth, and possibly elsewhere in the solar system.We are indebted to J. Eckert for his support with FE-EMPA; to K. Aquinho and E. Codillo for providing samples from Zambales; to K. Aquinho for Raman analysis of some of the samples from Zambales and Mt. Dent; to H. Dick for providing access to his thin section collection; to the curators of the IODP core repositories for providing access to Ocean Drilling Program (ODP) and Integrated Ocean Drilling Program (IODP) samples; and to the captains and crews of the many cruises without whom the collection of these samples would not have been possible. Reviews by Peter Kelemen and an anonymous referee greatly improved this manuscript. This study is supported with funds provided by the National Science Foundation (NSF-OCE Award 1634032 to F.K. and J.S.S.).2020-02-1

A chromosomal analysis of Nepa cinerea Linnaeus, 1758 and Ranatra linearis (Linnaeus, 1758) (Heteroptera, Nepidae)

An account is given of the karyotypes and male meiosis of the Water Scorpion Nepa cinerea Linnaeus, 1758 and the Water Stick Insect Ranatra linearis (Linnaeus, 1758) (Heteroptera, Nepomorpha, Nepidae). A number of different approaches and techniques were tried: the employment of both male and female gonads and mid-guts as the sources of chromosomes, squash and air-drying methods for chromosome preparations, C-banding and fluorescence in situ hybridization (FISH) for chromosome study. We found that N. cinerea had a karyotype comprising 14 pairs of autosomes and a multiple sex chromosome system, which is X1X2X3X4Y (♂) / X1X1X2X2X3X3X4X4 (♀), whereas R. linearis had a karyotype comprising 19 pairs of autosomes and a multiple sex chromosome system X1X2X3X4Y (♂) / X1X1X2X2X3X3X4X4 (♀). In both N. cinerea and R. linearis, the autosomes formed chiasmate bivalents in spermatogenesis, and the sex chromosome univalents divided during the first meiotic division and segregated during the second one suggesting thus a post-reductional type of behaviour. These results confirm and amplify those of Steopoe (1925, 1927, 1931, 1932) but are inconsistent with those of other researchers. C-banding appeared helpful in pairing up the autosomes for karyotype assembly; however in R. linearis the chromosomes were much more uniform in size and general appearance than in N. cinerea. FISH for 18S ribosomal DNA (major rDNA) revealed hybridization signals on two of the five sex chromosomes in N. cinerea. In R. linearis, rDNA location was less obvious than in N. cinerea; however it is suggested to be similar. We have detected the presence of the canonical “insect” (TTAGG)n telomeric repeat in chromosomes of these species. This is the first application of C-banding and FISH in the family Nepidae.Copyright Robert B. Angus et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.NHM Repositor

Monte Carlo simulation of a sputtering hollow-cathode discharge for laser applications

We report on a kinetic model that computes the electron behaviour in a hollow cathode discharge. It is a part of the PLASIMO toolkit and is based on a Monte-Carlo technique. The model is tested by varying the input parameters and by comparing the output with the output obtained by the freeware Boltzmann equation solver BOLSIG+. The results show that the Monte-Carlo model gives reliable information about the behavior of the electrons in the discharge. The Monte-Carlo module is applied to the case of a hollow cathode discharge for laser applications. Analysis of the output data and its adequateness is done. Future developments of the model are discussed

Monte Carlo simulation of electron kinetics in a hollow cathode discharge

A kinetic model is reported computing the electron behavior in a hollow cathode discharge based on the Monte Carlo technique. It is a part of the PLASIMO modelling toolkit. The model allows the electrons to be closely followed while they travel and undergo collisions in the discharge. The Monte Carlo modulewas applied to the case of a HCD used as an excitation medium of atoms obtained by laser ablation. Results are obtained on the electron energy distribution function and the mean electron energy under typical discharge conditions. The output data and future development of the model and its applications are analyzed and discussed

Comparative cytogenetic study of three Macrolophus species (Heteroptera, Miridae.)

Macrolophus pygmaeus (Rambur, 1839) (Insecta, Heteroptera, Miridae) is a predator of key vegetable crop pests applied as a biocontrol agent in the Mediterranean region. M. pygmaeus and M. melanotoma (A. Costa, 1853) are cryptic species with great morphological similarity which results in their misidentification and negative consequences for the conservation of their populations on greenhouse and outdoor crops. In order to find out specific markers for their separation we studied the karyotype, male meiosis and heterochromatin composition of these species and additionally of a third species (as a reference one), M. costalis Fieber, 1858. We demonstrate here that all the three species share achiasmate male meiosis and sex chromosome pre-reduction. On the other hand, the species differ in karyotype, with 2n=28 (26+XY) in M. pygmaeus, 2n=27 (24+X1X2Y) in M. costalis, and 2n=34 (32+XY) in M. melanotoma, and heterochromatin distribution and composition. In addition, the species differ in sperm morphology: sperm cells of M. costalis are significantly longer with longer head and tail than those of M. melanotoma and M. pygmaeus, whereas sperm cells of M. melanotoma have a longer tail than those of M. pygmaeus. All these characters can be used as markers to identify the species, in particular the cryptic species M. melanotoma and M. pygmaeus.This study has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO) (Project AGL2011-24349), and by a travel grant from the University of Lleida - Fundació “La Caixa” to Dr Grozeva. The chromosome analysis was performed using microscope Axio Scope A1 – Carl Zeiss Microscopy upgraded by the project WETLANET (FP7 CSA – SUPPORT ACTION, GA 229802). We thank cordially Prof. Dr V. Kuznetsova for the valuable advices to improve the manuscrip

Genome-wide linkage analysis of 972 bipolar pedigrees using single-nucleotide polymorphisms.

Because of the high costs associated with ascertainment of families, most linkage studies of Bipolar I disorder (BPI) have used relatively small samples. Moreover, the genetic information content reported in most studies has been less than 0.6. Although microsatellite markers spaced every 10 cM typically extract most of the genetic information content for larger multiplex families, they can be less informative for smaller pedigrees especially for affected sib pair kindreds. For these reasons we collaborated to pool family resources and carried out higher density genotyping. Approximately 1100 pedigrees of European ancestry were initially selected for study and were genotyped by the Center for Inherited Disease Research using the Illumina Linkage Panel 12 set of 6090 single-nucleotide polymorphisms. Of the ~1100 families, 972 were informative for further analyses, and mean information content was 0.86 after pruning for linkage disequilibrium. The 972 kindreds include 2284 cases of BPI disorder, 498 individuals with bipolar II disorder (BPII) and 702 subjects with recurrent major depression. Three affection status models (ASMs) were considered: ASM1 (BPI and schizoaffective disorder, BP cases (SABP) only), ASM2 (ASM1 cases plus BPII) and ASM3 (ASM2 cases plus recurrent major depression). Both parametric and non-parametric linkage methods were carried out. The strongest findings occurred at 6q21 (non-parametric pairs LOD 3.4 for rs1046943 at 119 cM) and 9q21 (non-parametric pairs logarithm of odds (LOD) 3.4 for rs722642 at 78 cM) using only BPI and schizoaffective (SA), BP cases. Both results met genome-wide significant criteria, although neither was significant after correction for multiple analyses. We also inspected parametric scores for the larger multiplex families to identify possible rare susceptibility loci. In this analysis, we observed 59 parametric LODs of 2 or greater, many of which are likely to be close to maximum possible scores. Although some linkage findings may be false positives, the results could help prioritize the search for rare variants using whole exome or genome sequencing

Identification of tomato accessions as source of new genes for improving heat tolerance: from controlled experiments to field

Background: Due to global warming, the search for new sources for heat tolerance and the identification of genes involved in this process has become an important challenge as of today. The main objective of the current research was to verify whether the heat tolerance determined in controlled greenhouse experiments could be a good predictor of the agronomic performance in field cultivation under climatic high temperature stress. Results: Tomato accessions were grown in greenhouse under three temperature regimes: control (T1), moderate (T2) and extreme heat stress (T3). Reproductive traits (flower and fruit number and fruit set) were used to define heat tolerance. In a first screening, heat tolerance was evaluated in 219 tomato accessions. A total of 51 accessions were identified as being potentially heat tolerant. Among those, 28 accessions, together with 10 accessions from Italy (7) and Bulgaria (3), selected for their heat tolerance in the field in parallel experiments, were re-evaluated at three temperature treatments. Sixteen tomato accessions showed a significant heat tolerance at T3, including five wild species, two traditional cultivars and four commercial varieties, one accession from Bulgaria and four from Italy. The 15 most promising accessions for heat tolerance were assayed in field trials in Italy and Bulgaria, confirming the good performance of most of them at high temperatures. Finally, a differential gene expression analysis in pre-anthesis (ovary) and post-anthesis (developing fruit) under heat stress among pairs of contrasting genotypes (tolerant and sensitive from traditional and modern groups) showed that the major differential responses were produced in post-anthesis fruit. The response of the sensitive genotypes included the induction of HSP genes, whereas the tolerant genotype response included the induction of genes involved in the regulation of hormones or enzymes such as abscisic acid and transferases. Conclusions: The high temperature tolerance of fifteen tomato accessions observed in controlled greenhouse experiments were confirmed in agronomic field experiments providing new sources of heat tolerance that could be incorporated into breeding programs. A DEG analysis showed the complex response of tomato to heat and deciphered the different mechanisms activated in sensitive and tolerant tomato accessions under heat stress

Identification of tomato accessions as source of new genes for improving heat tolerance: from controlled experiments to field

Background: Due to global warming, the search for new sources for heat tolerance and the identification of genes involved in this process has become an important challenge as of today. The main objective of the current research was to verify whether the heat tolerance determined in controlled greenhouse experiments could be a good predictor of the agronomic performance in field cultivation under climatic high temperature stress. Results: Tomato accessions were grown in greenhouse under three temperature regimes: control (T1), moderate (T2) and extreme heat stress (T3). Reproductive traits (flower and fruit number and fruit set) were used to define heat tolerance. In a first screening, heat tolerance was evaluated in 219 tomato accessions. A total of 51 accessions were identified as being potentially heat tolerant. Among those, 28 accessions, together with 10 accessions from Italy (7) and Bulgaria (3), selected for their heat tolerance in the field in parallel experiments, were re-evaluated at three temperature treatments. Sixteen tomato accessions showed a significant heat tolerance at T3, including five wild species, two traditional cultivars and four commercial varieties, one accession from Bulgaria and four from Italy. The 15 most promising accessions for heat tolerance were assayed in field trials in Italy and Bulgaria, confirming the good performance of most of them at high temperatures. Finally, a differential gene expression analysis in pre-anthesis (ovary) and post-anthesis (developing fruit) under heat stress among pairs of contrasting genotypes (tolerant and sensitive from traditional and modern groups) showed that the major differential responses were produced in post-anthesis fruit. The response of the sensitive genotypes included the induction of HSP genes, whereas the tolerant genotype response included the induction of genes involved in the regulation of hormones or enzymes such as abscisic acid and transferases. Conclusions: The high temperature tolerance of fifteen tomato accessions observed in controlled greenhouse experiments were confirmed in agronomic field experiments providing new sources of heat tolerance that could be incorporated into breeding programs. A DEG analysis showed the complex response of tomato to heat and deciphered the different mechanisms activated in sensitive and tolerant tomato accessions under heat stress

Copy number variation in bipolar disorder.

Large (>100 kb), rare (500 kb) CNVs in BD compared with SZ, most notably for deletions >1 Mb (P=9 × 10(-4))

IAPT/IOPB chromosome data 16

[EN] Inula helenioides DC., I. langeana Beck, I. maletii Maire, I. montana L., I. oculus-christi L., I. salicina L. (Asteraceae)