Dynamics of the Gut Microbiota in Children Receiving Selective or Total Gut Decontamination Treatment during Hematopoietic Stem Cell Transplantation

Bloodstream infections and graft-versus-host disease are common complications after hematopoietic stem cell transplantation (HSCT) procedures, associated with the gut microbiota that acts as a reservoir for opportunistic pathogens. Selective gut decontamination (SGD) and total gut decontamination (TGD) during HSCT have been associated with a decreased risk of developing these complications after transplantation. However, because studies have shown conflicting results, the use of these treatments remains subject of debate. In addition, their impact on the gut microbiota is not well studied. The aim of this study was to elucidate the dynamics of the microbiota during and after TGD and to compare these with the dynamics of SGD. In this prospective, observational, single center study fecal samples were longitudinally collected from 19 children eligible for allogenic HSCT (TGD, n=12; SGD, n=7), weekly during hospital admission and monthly after discharge. In addition, fecal samples were collected from 3 family stem cell donors. Fecal microbiota structure of patients and donors was determined by 16S rRNA gene amplicon sequencing. Microbiota richness and diversity markedly decreased during SGD and TGD and gradually increased after cessation of decontamination treatment. During SGD, gut microbiota composition was relatively stable and dominated by Bacteroides, whereas it showed high inter- and intraindividual variation and low Bacteroides abundance during TGD. In some children TGD allowed the genera Enterococcus and Streptococcus to thrive during treatment. A gut microbiota dominated by Bacteroides was associated with increased predicted activity of several metabolic processes. Comparing the microbiota of recipients and their donors indicated that receiving an SCT did not alter the patient's microbiota to become more similar to that of its donor. Overall, our findings indicate that SGD and TGD affect gut microbiota structure in a treatment-specific manner. Whether these treatments affect clinical outcomes via interference with the gut microbiota needs to be further elucidated. (C) 2019 American Society for Blood and Marrow Transplantation.Peer reviewe

Surprisingly Simple Spectra

The large N limit of the anomalous dimensions of operators in ${\cal N}=4$ super Yang-Mills theory described by restricted Schur polynomials, are studied. We focus on operators labeled by Young diagrams that have two columns (both long) so that the classical dimension of these operators is O(N). At large N these two column operators mix with each other but are decoupled from operators with $n\ne 2$ columns. The planar approximation does not capture the large N dynamics. For operators built with 2, 3 or 4 impurities the dilatation operator is explicitly evaluated. In all three cases, in a certain limit, the dilatation operator is a lattice version of a second derivative, with the lattice emerging from the Young diagram itself. The one loop dilatation operator is diagonalized numerically. All eigenvalues are an integer multiple of $8g_{YM}^2$ and there are interesting degeneracies in the spectrum. The spectrum we obtain for the one loop anomalous dimension operator is reproduced by a collection of harmonic oscillators. This equivalence to harmonic oscillators generalizes giant graviton results known for the BPS sector and further implies that the Hamiltonian defined by the one loop large $N$ dilatation operator is integrable. This is an example of an integrable dilatation operator, obtained by summing both planar and non-planar diagrams.Comment: 34 page

Antikke samfunn i krig og fred

Festskrift til Johan Henrik SchreinerDenne boken er er festskrift ril professor Johan Henrik Schreiner i forbindelse med hans 70-årsdag. Den består av en samling artikler 0111 krig, konflikt og fredsslurninger i antikken. Krigen er alle tings mor, kunne det hete da, og mens verdenslitteraturen ofte fører sin stamtavle tilbake ril Homer og hans beskrivelse av Trojanerkrigen, fører hisroriefaget sin tilbake til Herodots og Thukydides' verker om perserkrigene og Peloponneserkrigen. Fascinasjonen for greske bystaters borger- og krigerkollekriv og store generaler som Alexander og Caesar har dessuten holdt seg godt i to tusen år. Denne boken vil forhåpentligvis bidra til videre interesse. Her vil man finne belyst mange sider ved antikke samfunns forhold til krig - både svært omdiskuterte og nye, lite omtalte. Bidragene strekker seg fra Assyrerriker ved jernalderens begynnelse til det seinantikke Romerriket. Artiklene er ført i pennen av antikkhistorikere, arkeologer og klassiskfilologer ved norske og danske universitet. De er skrevet også med tanke på et alminnelig inreressert publikum og bør kunne interessere både leg og lærd

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Population Genetics and Comparative Genetics of CLDN1, a Gene Involved in Hepatitis C Virus Entry

The claudin-1 gene (CLDN1) is a member of a family of genes that encodes proteins found in tight junctions and it has recently been implicated as one of several receptors for late stage binding of hepatitis C virus (HCV). Exploration of the population genetics of this gene could be informative, especially in the investigation of a possible genetic contribution to HCV infection. Comparison to a highly similar gene, claudin-7 (CLDN7) could provide insight into the recent molecular evolution of CLDN1. Mean interspecies conservation score was 0.11 (SD 0.28) for CLDN1 and 0.31 (SD 0.43) for CLDN7. Re-sequence analysis was performed across all exons and evolutionarily conserved regions in CLDN1 (13 kb in total) and CLDN7 (2 kb in total) in 204 chromosomes drawn from the SNP500Cancer resource of four self-described ethnic groups in the US. For CLDN1, 133 SNPs were identified as well as 8 indels and an AC repeat length polymorphism. For CLDN7, 5 SNPs were identified. Assessment of nucleotide diversity (including Fst, θ and π statistics) did not show evidence for recent positive or negative selection in either gene. The pattern of linkage disequilibrium was determined for each group and there is substantial difference for common SNPS (>5%) between populations as well as genes, further supporting the absence of signatures of recent selection