64 research outputs found
Altered Regional and Circuit Resting-State Activity Associated with Unilateral Hearing Loss
The deprivation of sensory input after hearing damage results in functional reorganization of the brain including cross-modal plasticity in the sensory cortex and changes in cognitive processing. However, it remains unclear whether partial deprivation from unilateral auditory loss (UHL) would similarly affect the neural circuitry of cognitive processes in addition to the functional organization of sensory cortex. Here, we used resting-state functional magnetic resonance imaging to investigate intrinsic activity in 34 participants with UHL from acoustic neuroma in comparison with 22 matched normal controls. In sensory regions, we found decreased regional homogeneity (ReHo) in the bilateral calcarine cortices in UHL. However, there was an increase of ReHo in the right anterior insular cortex (rAI), the key node of cognitive control network (CCN) and multimodal sensory integration, as well as in the left parahippocampal cortex (lPHC), a key node in the default mode network (DMN). Moreover, seed-based restingāstate functional connectivity analysis showed an enhanced relationship between rAI and several key regions of the DMN. Meanwhile, lPHC showed more negative relationship with components in the CCN and greater positive relationship in the DMN. Such reorganizations of functional connectivity within the DMN and between the DMN and CCN were confirmed by a graph theory analysis. These results suggest that unilateral sensory input damage not only alters the activity of the sensory areas but also reshapes the regional and circuit functional organization of the cognitive control network
Population genetic structure of the deepāsea mussel Bathymodiolus platifrons (Bivalvia: Mytilidae) in the Northwest Pacific
Ā© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Evolutionary Applications 11 (2018): 1915-1930, doi:10.1111/eva.12696.Studying population genetics of deepāsea animals helps us understand their history of habitat colonization and population divergence. Here, we report a population genetic study of the deepāsea mussel Bathymodiolus platifrons (Bivalvia: Mytilidae) widely distributed in chemosynthesisābased ecosystems in the Northwest Pacific. Three mitochondrial genes (i.e., atp6, cox1, and nad4) and 6,398 genomewide single nucleotide polymorphisms (SNPs) were obtained from 110 individuals from four hydrothermal vents and two methane seeps. When using the three mitochondrial genes, nearly no genetic differentiation was detected for B. platifrons in the Northwest Pacific. Nevertheless, when using SNP datasets, all individuals in the South China Sea (SCS) and three individuals in Sagami Bay (SB) together formed one genetic cluster that was distinct from the remaining individuals. Such genetic divergence indicated a genetic barrier to gene flow between the SCS and the open Northwest Pacific, resulting in the coāoccurrence of two cryptic semiāisolated lineages. When using 125 outlier SNPs identified focusing on individuals in the Okinawa Trough (OT) and SB, a minor genetic subdivision was detected between individuals in the southern OT (SāOT) and those in the middle OT (MāOT) and SB. This result indicated that, although under the influence of the Kuroshio Current and the North Pacific Intermediate Water, subtle geographic barriers may exist between the SāOT and the MāOT. Introgression analyses based on these outlier SNPs revealed that Hatoma Knoll in the SāOT represents a possible contact zone for individuals in the OTāSB region. Furthermore, migration dynamic analyses uncovered stronger gene flow from Daiāyon Yonaguni Knoll in the SāOT to the other local populations, compared to the reverse directions. Taken together, the present study offered novel perspectives on the genetic connectivity of B. platifrons mussels, revealing the potential interaction of ocean currents and geographic barriers with adaption and reproductive isolation in shaping their migration patterns and genetic differentiation in the Northwest Pacific.General Research Fund Grant Number: HKBU12302917;
Hong Kong Baptist University Grant Number: 15ā1012āP0
Fermentation Products of Paenibacillus bovis sp. nov. BD3526 Alleviates the Symptoms of Type 2 Diabetes Mellitus in GK Rats
Gut microbiota is closely related to type 2 diabetes mellitus (T2DM). The gut microbiota of patients with T2DM is significantly different from that of healthy subjects in terms of bacterial composition and diversity. Here, we used the fermentation products of Paenibacillus bovis sp. nov. BD3526 to study the disease progression of T2DM in Goto-kakisaki (GK) rats. We found that the symptoms in GK rats fed the fermentation products of BD3526 were significantly improved. The 16S rRNA sequencing showed that the fermentation products of BD3526 had strong effects on the gut microbiota by increasing the content of Akkermansia. In addition, the interaction of the genus in the gut of the BD3526 group also significantly changed. Additional cytokine detection revealed that the fermentation products of BD3526 can reduce the inflammatory factors in the intestinal mucus of GK rats and thereby inhibit the inflammatory response and ameliorate the symptoms of T2DM
Discovery of TIGIT inhibitors based on DEL and machine learning
Drug discovery has entered a new period of vigorous development with advanced technologies such as DNA-encoded library (DEL) and artificial intelligence (AI). The previous DEL-AI combination has been successfully applied in the drug discovery of classical kinase and receptor targets mainly based on the known scaffold. So far, there is no report of the DEL-AI combination on inhibitors targeting protein-protein interaction, including those undruggable targets with few or unknown active scaffolds. Here, we applied DEL technology on the T cell immunoglobulin and ITIM domain (TIGIT) target, resulting in the unique hit compound 1 (IC50 = 20.7Ā Ī¼M). Based on the screening data from DEL and hit derivatives a1-a34, a machine learning (ML) modeling process was established to address the challenge of poor sample distribution uniformity, which is also frequently encountered in DEL screening on new targets. In the end, the established ML model achieved a satisfactory hit rate of about 75% for derivatives in a high-scored area
Lactobacillus acidophilus JCM 1132 Strain and Its Mutant with Different Bacteriocin-Producing Behaviour Have Various In Situ Effects on the Gut Microbiota of Healthy Mice
peer-reviewedThe production of bacteriocin is considered to be a probiotic trait of lactic acid bacteria (LAB).
However, not all strains of LAB harbour bacteriocin genes, even within the same species. Moreover,
the effects of bacteriocins on the host gut microbiota and on host physiological indicators are rarely
studied. This study evaluated the effects of the bacteriocin-producing Lactobacillus acidophilus strain
JCM1132 and its non-producing spontaneous mutant, L. acidophilus CCFM720, on the physiological
statuses and gut microbiota of healthy mice. Mice that received the bacteriocin-producing strain
JCM1132 exhibited reduced water and food intake. Furthermore, the administration of these strains
induced significant changes in the compositional abundance of faecal microbiota at the phylum
and genus levels, and some of these changes were more pronounced after one week of withdrawal.
The effects of CCFM720 treatment on the gut microbiota seemed to favour the prevention of metabolic
diseases to some extent. However, individuals that received JCM1132 treatment exhibited weaker
inflammatory responses than those that received CCFM720 treatment. Our results indicate that
treatment with bacteriocin-producing or non-producing strains can have different effects on the host.
Accordingly, this trait should be considered in the applications of LAB
Compositions of experimental major elements in the mantle transition zone
The starting materials are two carbonated basalt compositions with CO2 concentrations of 2.5 wt% (PC-a) and 5.0 wt% (PC-b), respectively. The partial melting experimental were conducted at the Laboratory for the Study of the Earth's Deep Interior (SEDI-Lab), China University of Geosciences (Wuhan), using 10/5 and 18/12 cell assemblages combined with a 1000-ton Walker-type multi-anvil press. The experimental pressure and temperature conditions are 13-20 GPa and 1300-1600 oC, respectively. Five phases were observed in the run products: garnet, clinopyroxene, stishovite, magnesite, and quench melt. The chemical compositions of phases were examined by an electron probe micro-analyzer (EPMA, JXA-8100) at the Key Laboratory of Submarine Geosciences, State Oceanic Administration. The accelerating voltage, beam size, and beam current were 15 kV, 5.0ā10.0 Ī¼m and 10 nA, respectively. Count times were 10s for each of the measured element and 5s for the background. Standard materials were diopside for Si, rutile for Ti, pyrope for Al, Cr2O3 for Cr, CaSiO3 for Ca, Mg2SiO4 for Mg, Fe2O3 for Fe, MnSiO3 for Mn, NiO for Ni, jadeite for Na, K-feldspar for K, and Ca5P3F for P. The relative uncertainties were ~5% for elements of less than 1 wt%, ~1% for elements of ~1ā5 wt%, and less than 0.5% for elements of greater than 5 wt%
High-pressure experiments of phase compositions in subducted ophicarbonate
Ophicarbonate is an important type of hydrothermally altered ultramafic rock that occurs in spreading centers and trenches, and in the interface between a subducting slab and the overlying mantle wedge. High-pressure experiments were performed at 10-15 GPa and 700-1100 oC to investigate the phase relations of subducted ophicarbonate. Ten samples were recovered after the experiments. In the recovered experimental charges, hydrous phases include phases A, D, and E; anhydrous minerals include clinopyroxene, orthopyroxene, garnet, magnesite, and olivine/wadsleyite. Phase compositions in the recovered charges were analyzed with an electron probe micro-analyzer (EPMA, JXA-8100), installed at the Key Laboratory of Submarine Geosciences, State Oceanic Administration. The accelerating voltage, beam current and beam size were 15 kv, 20 nA and 1-2 Ī¼m, respectively, for minerals, and 15 kv,10 nA and 5-30 Ī¼m, respectively, for quench phases. Count times were 10s for each of the measured element and 5s for the background. Standard materials were diopside for SiO2, MgO and CaO, jadeite for Na2O, K-feldspar for K2O, hematite for FeO, pyrope for Al2O3, NiO for NiO, apatite (Ca5P3F) for P2O5, rutile for TiO2, and eskolaite (Cr2O3) for Cr2O3
Grossular Exsolution at Pyrope Dislocation: New Evidence for the Ultradeep Origin of Dabie Orogenic Peridotite
Exsolution and dislocation microstructures are an important basis to decipher the conditions of metamorphic deformation and evolution processes of its host minerals and rocks. The grossular-rich exsolution in pyrope-rich garnet grains of Bixiling orogenic crustal cumulative peridotite, Dabie orogen, China, was studied by electron backscatter diffraction (EBSD), conventional and high-resolution transmission electron microscopy (TEM/HRTEM) and electron-microprobe analysis (EMPA). Our results indicate that the precursor pyrope-rich host grains had undergone plastic deformation and developed numerous dislocation microstructures before the grossular precipitated. When the pressure and/or temperature decreased during the exhumation of subducted slab, the grossular-rich lamellae exsolved and precipitated at the dislocation structures of host and inherited their shapes. EBSD and TEM analyses show that the crystallographic orientation of exsolution is controlled by, and coherent with, the host grain. These exsolution textures and the chemical composition of precursor garnet correspond to a balance pressure–temperature (P–T) condition of >6 GPa and >850 °C based on the previous thermodynamic models, which indicates that the origin depth of the Bixiling garnet peridotite should be more than 200 km
Lower crustal delamination and evolution of continental crust
It has been suggested that during collision events leading to crustal thickening and
formation of eclogite, or through underplating and fractionation of basaltic magma at the
base of the crust, the mafic/ultramafic root of the continental crust will become denser than
the underlying upper mantle. This density instability will lead to delamination that occurs
during continental collision and drives lower crust recycling into the mantle. Lower crustal
delamination has been proposed to explain the dilemma that the primary mantle additions
into the crust are principally basaltic, whereas the present-day continental crust has an
intermediate bulk composition.
Eu, Sr and transition metals (Cr, Ni, Co, V, Sc and Ti) are enriched in mafic granulites
and eclogites. As a result, delamination of lower crust will reduce abundances of these
elements as well as Eu/Eu* and ratios of Sr and transition metals to Nd in the continental
crust. Correspondingly, SiO_2 increases. Therefore, Eu, Sr and transition metals can be used
together to test the consistency of a geochemical model of lower crustal delamination.
The seismic consequence of delamination will be evident in lower seismic velocities due
to the loss of high-velocity mafic root, while geologically, delamination is expected to
produce crustal exhumation followed by extension and formation of basins and leads to a lack
of substantial mountain roots.
Our estimates of the total crust composition in central East China show a more evolved
character compared to models of Rudnick and Fountain (1995) and Taylor and McLennan
(1985, 1995) and are characterized by a prominent negative Eu anomaly (Eu/Eu* = 0.80),
higher SiO_2 (61.8%), and lower Sr/Nd (~10) as well as lower Sr/Nd, Cr/Nd, Ni/Nd, Co/Nd, V/Nd and Ti/Nd ratios. This, together with slower crustal velocities and remarkably
thin crustal thicknesses (34km) for the paleozoic-Mesozoic Qinling-Dabie orogenic belt, leads
to the suggestion that lower crustal delamination played an important role in modification of
the East China crust. Mass balance modeling further suggests that eclogite from the Dabie-Sulu
ultrahigh pressure metamorphic belt is the most likely candidate as the delaminated
material, and that a cumulative 37~82km thick eclogitic lower crust is required to have been
delaminated in order to explain the relative Eu, Sr and transition metal deficits in the crust of
central East China. Delamination of eclogites can also explain the significantly higher than
eclogite Poisson's ratio in the present Dabie lower crust and upper mantle and lack of eclogite
in Cenozoic xenolith populations of the lower crust and upper mantle in East China.
As an analogue, xenolith and geophysical evidences from the Sierra Nevada batholith
indicate existence of a ~70km mafic-ultramafic eclogite facies root in Mid-Miocene, which
complements the ~30km granitic intrusion as cumulates/residues. Delamination of the thick
eclogitic root has also been proposed to explain the very thin crust of 30~40km currently in
the southern Sierra Nevada, which is mainly granitic, as indicated by Vp=6.0~6.3km s^(-1), and is underlain by a peridotitic upper mantle, as revealed by younger Late Miocene
xenoliths. Therefore, delamination of eclogite is a common and important process for
evolution of continental crust and crust-mantle interaction
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