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Preliminary prediction of individual response to electroconvulsive therapy using whole-brain functional magnetic resonance imaging data.
Electroconvulsive therapy (ECT) works rapidly and has been widely used to treat depressive disorders (DEP). However, identifying biomarkers predictive of response to ECT remains a priority to individually tailor treatment and understand treatment mechanisms. This study used a connectome-based predictive modeling (CPM) approach in 122 patients with DEP to determine if pre-ECT whole-brain functional connectivity (FC) predicts depressive rating changes and remission status after ECT (47 of 122 total subjects or 38.5% of sample), and whether pre-ECT and longitudinal changes (pre/post-ECT) in regional brain network biomarkers are associated with treatment-related changes in depression ratings. Results show the networks with the best predictive performance of ECT response were negative (anti-correlated) FC networks, which predict the post-ECT depression severity (continuous measure) with a 76.23% accuracy for remission prediction. FC networks with the greatest predictive power were concentrated in the prefrontal and temporal cortices and subcortical nuclei, and include the inferior frontal (IFG), superior frontal (SFG), superior temporal (STG), inferior temporal gyri (ITG), basal ganglia (BG), and thalamus (Tha). Several of these brain regions were also identified as nodes in the FC networks that show significant change pre-/post-ECT, but these networks were not related to treatment response. This study design has limitations regarding the longitudinal design and the absence of a control group that limit the causal inference regarding mechanism of post-treatment status. Though predictive biomarkers remained below the threshold of those recommended for potential translation, the analysis methods and results demonstrate the promise and generalizability of biomarkers for advancing personalized treatment strategies
Single cell fluorescence imaging of glycan uptake by intestinal bacteria
Microbes in the intestines of mammals degrade dietary glycans for energy and growth. The pathways required for polysaccharide utilization are functionally diverse; moreover, they are unequally dispersed between bacterial genomes. Hence, assigning metabolic phenotypes to genotypes remains a challenge in microbiome research. Here we demonstrate that glycan uptake in gut bacteria can be visualized with fluorescent glycan conjugates (FGCs) using epifluorescence microscopy. Yeast α-mannan and rhamnogalacturonan-II, two structurally distinct glycans from the cell walls of yeast and plants, respectively, were fluorescently labeled and fed to Bacteroides thetaiotaomicron VPI-5482. Wild-type cells rapidly consumed the FGCs and became fluorescent; whereas, strains that had deleted pathways for glycan degradation and transport were non-fluorescent. Uptake of FGCs, therefore, is direct evidence of genetic function and provides a direct method to assess specific glycan metabolism in intestinal bacteria at the single cell level.</p
The Advanced LIGO Photon Calibrators
The two interferometers of the Laser Interferometry Gravitaional-wave
Observatory (LIGO) recently detected gravitational waves from the mergers of
binary black hole systems. Accurate calibration of the output of these
detectors was crucial for the observation of these events, and the extraction
of parameters of the sources. The principal tools used to calibrate the
responses of the second-generation (Advanced) LIGO detectors to gravitational
waves are systems based on radiation pressure and referred to as Photon
Calibrators. These systems, which were completely redesigned for Advanced LIGO,
include several significant upgrades that enable them to meet the calibration
requirements of second-generation gravitational wave detectors in the new era
of gravitational-wave astronomy. We report on the design, implementation, and
operation of these Advanced LIGO Photon Calibrators that are currently
providing fiducial displacements on the order of
m/ with accuracy and precision of better than 1 %.Comment: 14 pages, 19 figure
Dietary pectic glycans are degraded by coordinated enzyme pathways in human colonic Bacteroides.
The major nutrients available to human colonic Bacteroides species are glycans, exemplified by pectins, a network of covalently linked plant cell wall polysaccharides containing galacturonic acid (GalA). Metabolism of complex carbohydrates by the Bacteroides genus is orchestrated by polysaccharide utilization loci (PULs). In Bacteroides thetaiotaomicron, a human colonic bacterium, the PULs activated by different pectin domains have been identified; however, the mechanism by which these loci contribute to the degradation of these GalA-containing polysaccharides is poorly understood. Here we show that each PUL orchestrates the metabolism of specific pectin molecules, recruiting enzymes from two previously unknown glycoside hydrolase families. The apparatus that depolymerizes the backbone of rhamnogalacturonan-I is particularly complex. This system contains several glycoside hydrolases that trim the remnants of other pectin domains attached to rhamnogalacturonan-I, and nine enzymes that contribute to the degradation of the backbone that makes up a rhamnose-GalA repeating unit. The catalytic properties of the pectin-degrading enzymes are optimized to protect the glycan cues that activate the specific PULs ensuring a continuous supply of inducing molecules throughout growth. The contribution of Bacteroides spp. to metabolism of the pectic network is illustrated by cross-feeding between organisms.This work was supported in part by an Advanced Grant from the European Research Council (Grant No. 322820) awarded to H.J.G. and B.H. supporting A.S.L., D.N., A.C. and N.T., a Wellcome Trust Senior Investigator Award to H.J.G. (grant No. WT097907MA) that supported J.B. and E.C.L. a European Union Seventh Framework Initial Training Network Programme entitled the “WallTraC project” (Grant Agreement number 263916) awarded to M-C.R. and H.J.G, which supported X.Z. and J.S. The Biotechnology and Biological Research Council project ‘Ricefuel’ (grant numbers BB/K020358/1) awarded to H.J.G. supported A.L
Evaluation of the red seaweed Mazzaella japonica as a feed additive for beef cattle
Supplementing ruminant diets with macroalgae is gaining interest globally because bromoform-containing seaweeds (e.g., Asparagopsis spp.) have been shown to be highly effective enteric methane (CH4) inhibitors. Some alternative seaweeds decrease in vitro CH4 production, but few have been evaluated in animals. This study examined the effects of including the red seaweed Mazzaella japonica in the diet of beef cattle on dry matter intake (DMI), rumen fermentation, digestibility, nitrogen (N) utilization, and enteric CH4 production. Six ruminally cannulated, mature beef heifers (824 ± 47.1 kg) were used in a double 3 × 3 Latin square with 35-d periods. The basal diet consisted of 52% barley silage, 44% barley straw, and 4% vitamin and mineral supplement [dry matter (DM) basis]. The treatments were (DM basis): 0% (control), 1%, and 2% M. japonica. The DMI increased quadratically (P = 0.025) with the inclusion of M. japonica, such that the DMI of heifers consuming 1% was greater (P < 0.05) than that of control heifers. The apparent total-tract digestibility of DM decreased linearly (P = 0.002) with the inclusion of M. japonica, but there were no treatment differences in the digestibility of organic matter, crude protein (CP), neutral detergent fiber, or starch. The level of M. japonica linearly (P < 0.001) increased the N intake of the heifers. Fecal N excretion linearly increased (P = 0.020) with M. japonica, but there were no differences in total urinary N excretion, N fractions (allantoin, uric acid), total purine derivatives, microbial purine derivatives absorbed, microbial N flow, or retained N. There were no treatment effects on rumen pH or total volatile fatty acids (VFAs); however, adding M. japonica to the diet quadratically (P = 0.023) decreased the proportion of acetate, whereas 1% inclusion decreased the acetate proportion. Methane production (g/day) decreased quadratically (P = 0.037), such that the heifers receiving 2% M. japonica produced 9.2% less CH4 than control animals; however, CH4 yield (g/kg DMI) did not differ among treatments. We conclude that supplementing a forage-based diet with up to 2% M. japonica failed to lower the enteric CH4 yield of beef heifers. M. japonica can be used in diets to help meet the CP requirements of cattle, but inclusion rates may be limited by high inorganic matter proportions. When comprising up to 2% of the diet, M. japonica cannot be recommended as a CH4 inhibitor for beef cattle fed on high-forage diets
Comparative analysis of macroalgae supplementation on the rumen microbial community: Asparagopsis taxiformis inhibits major ruminal methanogenic, fibrolytic, and volatile fatty acid-producing microbes in vitro
Seaweeds have received a great deal of attention recently for their potential as methane-suppressing feed additives in ruminants. To date, Asparagopsis taxiformis has proven a potent enteric methane inhibitor, but it is a priority to identify local seaweed varieties that hold similar properties. It is essential that any methane inhibitor does not compromise the function of the rumen microbiome. In this study, we conducted an in vitro experiment using the RUSITEC system to evaluate the impact of three red seaweeds, A. taxiformis, Palmaria mollis, and Mazzaella japonica, on rumen prokaryotic communities. 16S rRNA sequencing showed that A. taxiformis had a profound effect on the microbiome, particularly on methanogens. Weighted Unifrac distances showed significant separation of A. taxiformis samples from the control and other seaweeds (p < 0.05). Neither P. mollis nor M. japonica had a substantial effect on the microbiome (p > 0.05). A. taxiformis reduced the abundance of all major archaeal species (p < 0.05), leading to an almost total disappearance of the methanogens. Prominent fiber-degrading and volatile fatty acid (VFA)-producing bacteria including Fibrobacter and Ruminococcus were also inhibited by A. taxiformis (p < 0.05), as were other genera involved in propionate production. The relative abundance of several other bacteria including Prevotella, Bifidobacterium, Succinivibrio, Ruminobacter, and unclassified Lachnospiraceae were increased by A. taxiformis suggesting that the rumen microbiome adapted to an initial perturbation. Our study provides baseline knowledge of microbial dynamics in response to seaweed feeding over an extended period and suggests that feeding A. taxiformis to cattle to reduce methane may directly, or indirectly, inhibit important fiber-degrading and VFA-producing bacteria
Comparative variation within the genome of Campylobacter jejuni NCTC 11168 in human and murine hosts
Sherpa Romeo green journal. Open access, distributed under the terms of the Creative Commons Attibution License.Campylobacteriosis incited by
C. jejuni
is a significant enteric disease of human beings. A person working with two reference
strains of
C. jejuni
National Collection of Type Cultures (NCTC) 11168 developed symptoms of severe enteritis including
bloody diarrhea. The worker was determined to be infected by
C. jejuni
. In excess of 50 isolates were recovered from the
worker’s stool. All of the recovered isolates and the two reference strains were indistinguishable from each other based on
comparative genomic fingerprint subtyping. Whole genome sequence analysis indicated that the worker was infected with
a
C. jejuni
NCTC 11168 obtained from the American Type Culture Collection; this strain (NCTC 11168-GSv) is the genome
sequence reference. After passage through the human host, major genetic changes including indel mutations within twelve
contingency loci conferring phase variations were detected in the genome of
C. jejuni
. Specific and robust single nucleotide
polymorphism (SNP) changes in the human host were also observed in two loci (Cj0144c, Cj1564). In mice inoculated with
an isolate of
C. jejuni
NCTC 11168-GSv from the infected person, the isolate underwent further genetic variation. At nine loci,
mutations specific to inoculated mice including five SNP changes were observed. The two predominant SNPs observed in
the human host reverted in mice. Genetic variations occurring in the genome of
C. jejuni
in mice corresponded to increased
densities of
C. jejuni
cells associated with cecal mucosa. In conclusion,
C. jejuni
NCTC 11168-GSv was found to be highly
virulent in a human being inciting severe enteritis. Host-specific mutations in the person with enteritis occurred/were
selected for in the genome of
C. jejuni
, and many were not maintained in mice. Information obtained in the current study
provides new information on host-specific genetic adaptation by
C. jejuni
.Ye
Identification of novel enzymes to enhance the ruminal digestion of barley straw
Crude enzyme extracts typically contain a broad spectrum of enzyme activities, most of which are redundant to those naturally produced by the rumen microbiome. Identification of enzyme activities that are synergistic to those produced by the rumen microbiome could enable formulation of enzyme cocktails that improve fiber digestion in ruminants. Compared to untreated barley straw, Viscozyme® increased gas production, dry matter digestion (P<0.01) and volatile fatty acid production (P<0.001) in ruminal batch cultures. Fractionation of Viscozyme® by Blue Native PAGE and analyses using a microassay and mass-spectrometry revealed a GH74 endoglucanase, GH71 α-1,3-glucanase, GH5 mannanase, GH7 cellobiohydrolase, GH28 pectinase, and esterases from Viscozyme® contributed to enhanced saccharification of barley straw by rumen mix enzymes. Grouping of these identified activities with their carbohydrate active enzymes (CAZy) counterparts enabled selection of similar CAZymes for downstream production and screening. Mining of these specific activities from other biological systems could lead to high value enzyme formulations for ruminants
The Advanced LIGO photon calibrators
The two interferometers of the Laser Interferometry Gravitational-wave Observatory (LIGO) recently detected gravitational waves from the mergers of binary black hole systems. Accurate calibration of the output of these detectors was crucial for the observation of these events and the extraction of parameters of the sources. The principal tools used to calibrate the responses of the second-generation (Advanced) LIGO detectors to gravitational waves are systems based on radiation pressure and referred to as photon calibrators. These systems, which were completely redesigned for Advanced LIGO, include several significant upgrades that enable them to meet the calibration requirements of second-generation gravitational wave detectors in the new era of gravitational-wave astronomy. We report on the design, implementation, and operation of these Advanced LIGO photon calibrators that are currently providing fiducial displacements on the order of 10-18m/Hz with accuracy and precision of better than 1%
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