A Study of the Stochastic Behavior of Durable Goods Consumption

The author of this thesis examines the stochastic behavior of durables consumption in the rational expectations/permanent income hypothesis framework. The testing in this paper parallels the studies conducted by other researchers, who basing their work mainly on quarterly data rejected the frictionless rational expectations/permanent income hypothesis. The distinctive feature of this thesis is that the models are examined using monthly instead of quarterly data. The results of the estimation are compared to the results based on quarterly data. The results show that estimates obtained using monthly data seem to be more consistent with the frictionless rational expectations/permanent income hypothesis than the estimates from quarterly data. Then, by using two subsets of the monthly data representing the first and the last twelve years of a 37 year period, the models are reexamined to explore the possibility of change in the stochastic behavior of personal expenditures on durable goods over time. This results suggest a change in influence of liquidity constraints on the time series behavior of durable goods consumption over the last four decades

Evidence for Horizontal Gene Transfer of Anaerobic Carbon Monoxide Dehydrogenases

Carbon monoxide (CO) is commonly known as a toxic gas, yet both cultivation studies and emerging genome sequences of bacteria and archaea establish that CO is a widely utilized microbial growth substrate. In this study, we determined the prevalence of anaerobic carbon monoxide dehydrogenases ([Ni,Fe]-CODHs) in currently available genomic sequence databases. Currently, 185 out of 2887, or 6% of sequenced bacterial and archaeal genomes possess at least one gene encoding [Ni,Fe]-CODH, the key enzyme for anaerobic CO utilization. Many genomes encode multiple copies of [Ni,Fe]-CODH genes whose functions and regulation are correlated with their associated gene clusters. The phylogenetic analysis of this extended protein family revealed six distinct clades; many clades consisted of [Ni,Fe]-CODHs that were encoded by microbes from disparate phylogenetic lineages, based on 16S rRNA sequences, and widely ranging physiology. To more clearly define if the branching patterns observed in the [Ni,Fe]-CODH trees are due to functional conservation vs. evolutionary lineage, the genomic context of the [Ni,Fe]-CODH gene clusters was examined, and superimposed on the phylogenetic trees. On the whole, there was a correlation between genomic contexts and the tree topology, but several functionally similar [Ni,Fe]-CODHs were found in different clades. In addition, some distantly related organisms have similar [Ni,Fe]-CODH genes. Thermosinus carboxydivorans was used to observe horizontal gene transfer (HGT) of [Ni,Fe]-CODH gene clusters by applying Kullback–Leibler divergence analysis methods. Divergent tetranucleotide frequency and codon usage showed that the gene cluster of T. carboxydivorans that encodes a [Ni,Fe]-CODH and an energy-converting hydrogenase is dissimilar to its whole genome but is similar to the genome of the phylogenetically distant Firmicute, Carboxydothermus hydrogenoformans. These results imply that T carboxydivorans acquired this gene cluster via HGT from a relative of C. hydrogenoformans

Observation of time quasicrystal and its transition to superfluid time crystal

We report experimental realization of a quantum time quasicrystal, and its transformation to a quantum time crystal. We study Bose-Einstein condensation of magnons, associated with coherent spin precession, created in a flexible trap in superfluid $^3$He-B. Under a periodic drive with an oscillating magnetic field, the coherent spin precession is stabilized at a frequency smaller than that of the drive, demonstrating spontaneous breaking of discrete time translation symmetry. The induced precession frequency is incommensurate with the drive, and hence the obtained state is a time quasicrystal. When the drive is turned off, the self-sustained coherent precession lives a macroscopically-long time, now representing a time crystal with broken symmetry with respect to continuous time translations. Additionally, the magnon condensate manifests spin superfluidity, justifying calling the obtained state a time supersolid or a time super-crystal

Dissimilatory sulfate reduction in the archaeon ‘Candidatus Vulcanisaeta moutnovskia’ sheds light on the evolution of sulfur metabolism

Dissimilatory sulfate reduction (DSR)—an important reaction in the biogeochemical sulfur cycle—has been dated to the Palaeoarchaean using geological evidence, but its evolutionary history is poorly understood. Several lineages of bacteria carry out DSR, but in archaea only Archaeoglobus, which acquired DSR genes from bacteria, has been proven to catalyse this reaction. We investigated substantial rates of sulfate reduction in acidic hyperthermal terrestrial springs of the Kamchatka Peninsula and attributed DSR in this environment to Crenarchaeota in the Vulcanisaeta genus. Community profiling, coupled with radioisotope and growth experiments and proteomics, confirmed DSR by ‘Candidatus Vulcanisaeta moutnovskia’, which has all of the required genes. Other cultivated Thermoproteaceae were briefly reported to use sulfate for respiration but we were unable to detect DSR in these isolates. Phylogenetic studies suggest that DSR is rare in archaea and that it originated in Vulcanisaeta, independent of Archaeoglobus, by separate acquisition of qmoABC genes phylogenetically related to bacterial hdrA genes.This work was supported by the Russian Science Foundation (grant number 17-74-30025) and in part by the grant from the Russian Ministry of Science and Higher Education (to N.A.C., A.V.L., E.N.F., M.L.M., A.Y.M., N.V.P. and E.A.B.-O.). Sequencing of PCR amplicons was performed using the scientific equipment of the core research facility ‘Bioengineering’ by T. Kolganova. The proteomics analysis was performed at the Proteomics Facility of the Spanish National Center for Biotechnology (CNB-CSIC), which belongs to ProteoRed, PRB2-ISCIII, supported by grant PT13/0001 (to S.C., M.C.M. and M.F.). P.N.G. acknowledges funding from the UK Biotechnology and Biological Sciences Research Council (BBSRC) within the ERA NET-IB2 programme, grant number ERA-IB-14-030 and the European Union Horizon 2020 Research and Innovation programme (Blue Growth: Unlocking the Potential of Seas and Oceans) under grant agreement number 634486, as well as support from the Centre for Environmental Biotechnology project, part funded by the European Regional Development Fund (ERDF) through the Welsh Government, and support from the Centre of Environmental Biotechnology. D.Y.S. was supported by the SIAM/Gravitation Program (Dutch Ministry of Education, Culture and Science; grant 24002002) and RFBR grant 19-04-00401. F.L.S. and S.N. acknowledge support from the Wiener Wissenschafts, Forschungs- und Technologiefonds (Austria) through the grant VRG15-007. F.L.S. gratefully acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation programme (grant agreement 803768). I.A.C.P. acknowledges support from the Fundação para a Ciência e Tecnologia (Portugal) through grant PTDC/BIA-BQM/29118/2017 and R&D unit MOSTMICRO-ITQB (UIDB/04612/2020 and UIDP/04612/2020)

Genome analyses of the carboxydotrophic sulfate-reducers Desulfotomaculum nigrificans and Desulfotomaculum carboxydivorans and reclassification of Desulfotomaculum caboxydivorans as a later synonym of Desulfotomaculum nigrificans

Desulfotomaculum nigrificans and D. carboxydivorans are moderately thermophilic members of the polyphyletic spore-forming genus Desulfotomaculum in the family Peptococcaceae. They are phylogenetically very closely related and belong to 'subgroup a' of the Desulfotomaculum cluster 1. D. nigrificans and D. carboxydivorans have a similar growth substrate spectrum; they can grow with glucose and fructose as electron donors in the presence of sulfate. Additionally, both species are able to ferment fructose, although fermentation of glucose is only reported for D. carboxydivorans. D. nigrificans is able to grow with 20% carbon monoxide (CO) coupled to sulfate reduction, while D. carboxydivorans can grow at 100% CO with and without sulfate. Hydrogen is produced during growth with CO by D. carboxydivorans. Here we present a summary of the features of D. nigrificans and D. carboxydivorans together with the description of the complete genome sequencing and annotation of both strains. Moreover, we compared the genomes of both strains to reveal their differences. This comparison led us to propose a reclassification of D. carboxydivorans as a later heterotypic synonym of D. nigrificans.We would like to gratefully acknowledge the help of Christine Munk and Megan Lu for finishing the genome sequence (both at JGI). The work conducted by the U.S. Department of Energy Joint Genome Institute is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, and was also supported by grants CW-TOP 700.55.343 and ALW 819.02.014 of the Netherlands Science Foundation (NWO) and grant 323009 of the European Research Council

Genomic analysis of Caldithrix abyssi, the thermophilic anaerobic bacterium of the novel bacterial phylum Calditrichaeota

The genome of Caldithrix abyssi, the first cultivated representative of a phylum-level bacterial lineage, was sequenced within the framework of Genomic Encyclopedia of Bacteria and Archaea (GEBA) project. The genomic analysis revealed mechanisms allowing this anaerobic bacterium to ferment peptides or to implement nitrate reduction with acetate or molecular hydrogen as electron donors. The genome encoded five different [NiFe]- and [FeFe]-hydrogenases, one of which, group 1 [NiFe]-hydrogenase, is presumably involved in lithoheterotrophic growth, three other produce H2 during fermentation, and one is apparently bidirectional. The ability to reduce nitrate is determined by a nitrate reductase of the Nap family, while nitrite reduction to ammonia is presumably catalyzed by an octaheme cytochrome c nitrite reductase εHao. The genome contained genes of respiratory polysulfide/thiosulfate reductase, however, elemental sulfur and thiosulfate were not used as the electron acceptors for anaerobic respiration with acetate or H2, probably due to the lack of the gene of the maturation protein. Nevertheless, elemental sulfur and thiosulfate stimulated growth on fermentable substrates (peptides), being reduced to sulfide, most probably through the action of the cytoplasmic sulfide dehydrogenase and/or NAD(P)-dependent [NiFe]-hydrogenase (sulfhydrogenase) encoded by the genome. Surprisingly, the genome of this anaerobic microorganism encoded all genes for cytochrome c oxidase, however, its maturation machinery seems to be non-operational due to genomic rearrangements of supplementary genes. Despite the fact that sugars were not among the substrates reported when C. abyssi was first described, our genomic analysis revealed multiple genes of glycoside hydrolases, and some of them were predicted to be secreted. This finding aided in bringing out four carbohydrates that supported the growth of C. abyssi: starch, cellobiose, glucomannan and xyloglucan. The genomic analysis demonstrated the ability of C. abyssi to synthesize nucleotides and most amino acids and vitamins. Finally, the genomic sequence allowed us to perform a phylogenomic analysis, based on 38 protein sequences, which confirmed the deep branching of this lineage and justified the proposal of a novel phylum Calditrichaeota.The work conducted by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility, is supported under Contract No. DE-AC02-05CH11231. OS and MSG were supported by the Russian Science Foundation (RSF, grant 14-24-00155). EB-O and SG were supported by the RSF grant 14-24-00165. IK, NC, AL, and MM were supported by the Russian Foundation for Basic Research grant 14-04-00503.http://www.frontiersin.orgam2017Biochemistr

Affine Currency Pricing Model with Regime Switching

Abstract Recent emprical studies show that, while uncovered interest parity fails at short horizons, there is more support for UIP at longer horizons. In this paper I show how these different results for UIP can be explained with a single model. The propsed model is a discrete-time affine stochastic discount factor model that allows for switching in mean and variance of the pricing kernel. Estimates of the model show that it can reproduce complex dynamics observed in the data

PCR-Based Identification of Hyperthermophilic Archaea of the Family Thermococcaceae

A method for rapid detection and identification of hyperthermophilic archaea of the family Thermococcaceae based on PCR amplification of 16S rRNA gene fragments with primers TcPc 173F (5′-TCCCCCATAGGYCTGRGGTACTGGAAGGTC-3′) and TcPc 589R (5′-GCCGTGRGATTTCGCCAGGGACTTACGGGC-3′) was developed and used for identification of new isolates

Identification of a Novel Class of Membrane-Bound [NiFe]-Hydrogenases in Thermococcus onnurineus NA1 by In Silico Analysis▿ †

In silico analysis of group 4 [NiFe]-hydrogenases from a hyperthermophilic archaeon, Thermococcus onnurineus NA1, revealed a novel tripartite gene cluster consisting of dehydrogenase-hydrogenase-cation/proton antiporter subunits, which may be classified as the new subgroup 4b of [NiFe]-hydrogenases-based on sequence motifs

Complete Genome Sequence of the Hyperthermophilic Archaeon Thermococcus sp Strain AM4, Capable of Organotrophic Growth and Growth at the Expense of Hydrogenogenic or Sulfidogenic Oxidation of Carbon Monoxide

International audienceAnalysis of the complete genome of Thermococcus sp. strain AM4, which was the first lithotrophic Thermococcales isolate described and the first archaeal isolate to exhibit a capacity for hydrogenogenic carboxydotrophy, reveals a proximity with Thermococcus gammatolerans, corresponding to close but distinct species that differ significantly in their lithotrophic capacities