1,212 research outputs found
Insights on nitrate respiration by Shewanella
Shewanellae are well known for their ability to utilize a number of electron acceptors and are therefore considered to have important roles in element cycling in the environment, such as nitrogen cycling through dissimilatory nitrate reduction to ammonia (DNRA) and denitrification. Possessing two periplasmic nitrate reductase systems (NAP-α and NAP-β) is a special trait of the Shewanella genus, and both enzymes are likely to provide selective advantage to the host. This review relates the current knowledge and aspects of the nitrate respiration system of Shewanella. Specifically, the potential physiological functions and regulation mechanisms of the duo-NAP system are discussed in addition to the evolution of anaerobic respiration systems of Shewanella
The relationship between Cho/NAA and glioma metabolism: implementation for margin delineation of cerebral gliomas
BACKGROUND: The marginal delineation of gliomas cannot be defined by conventional imaging due to their infiltrative growth pattern. Here we investigate the relationship between changes in glioma metabolism by proton magnetic resonance spectroscopic imaging ((1)H-MRSI) and histopathological findings in order to determine an optimal threshold value of choline/N-acetyl-aspartate (Cho/NAA) that can be used to define the extent of glioma spread. METHOD: Eighteen patients with different grades of glioma were examined using (1)H-MRSI. Needle biopsies were performed under the guidance of neuronavigation prior to craniotomy. Intraoperative magnetic resonance imaging (MRI) was performed to evaluate the accuracy of sampling. Haematoxylin and eosin, and immunohistochemical staining with IDH1, MIB-1, p53, CD34 and glial fibrillary acidic protein (GFAP) antibodies were performed on all samples. Logistic regression analysis was used to determine the relationship between Cho/NAA and MIB-1, p53, CD34, and the degree of tumour infiltration. The clinical threshold ratio distinguishing tumour tissue in high-grade (grades III and IV) glioma (HGG) and low-grade (grade II) glioma (LGG) was calculated. RESULTS: In HGG, higher Cho/NAA ratios were associated with a greater probability of higher MIB-1 counts, stronger CD34 expression, and tumour infiltration. Ratio threshold values of 0.5, 1.0, 1.5 and 2.0 appeared to predict the specimens containing the tumour with respective probabilities of 0.38, 0.60, 0.79, 0.90 in HGG and 0.16, 0.39, 0.67, 0.87 in LGG. CONCLUSIONS: HGG and LGG exhibit different spectroscopic patterns. Using (1)H-MRSI to guide the extent of resection has the potential to improve the clinical outcome of glioma surgery
Sistem Pengendali Kecepatan Motor Dc Pada Lift Barang Menggunakan Kontroler Pid Berbasis Atmega 2560
Lift barang adalah angkutan transportasi vertikal digunakan untuk memindahkan barang. Lift ini sangat khusus fungsinya untuk barang saja, lift ini hampir sama dengan lift penumpang namun ada sedikit perbedaan dalam sistem keamanannya. Lift barang yang sekarang memang sudah otomatis tetapi hanya pada gedung bertingkat tinggi. Untuk minimarket atau home industry yang memiliki struktur bangunan 2 lantai, banyak dijumpai masih menggunakan pengkatrolan secara manual oleh tenaga manusia untuk memindahkan barang. Hal ini cukup tidak efisien. Pada penelitian ini telah dirancang sistem pengaturan kecepatan motor DC pada lift barang menggunakan kontoler PID dengan kontruksi sistem yang sederhana. Digunakan Kontroler PID untuk mengurangi kesalahan, sehingga putaran motor dapat sesuai dengan kecepatan yang diinginkan. Dengan bantuan kontroler PID maka lift barang mampu bergerak dengan aman dan halus. Pada skripsi ini digunakan metode Ziegler-Nichols tunning 2. Dalam pembuatannya digunakan Arduino Mega 2560, rotary encoder Autonic E40H8 500-6-L-5, limit switch, dan motor DC. Berdasarkan data respons sistem yang diperoleh dari pengujian dengan menggunakan metode kedua Ziegler-Nichols, maka parameter kontroler PID dapat ditentukan dengan gain Kp = 7.71, Ki = 7.035 dan Kd = 2.113.Kata Kunci— Lift barang, Pengendalian Kecepatan, PID, Arduino Mega 2560
SPA-SVC: Self-supervised Pitch Augmentation for Singing Voice Conversion
Diffusion-based singing voice conversion (SVC) models have shown better
synthesis quality compared to traditional methods. However, in cross-domain SVC
scenarios, where there is a significant disparity in pitch between the source
and target voice domains, the models tend to generate audios with hoarseness,
posing challenges in achieving high-quality vocal outputs. Therefore, in this
paper, we propose a Self-supervised Pitch Augmentation method for Singing Voice
Conversion (SPA-SVC), which can enhance the voice quality in SVC tasks without
requiring additional data or increasing model parameters. We innovatively
introduce a cycle pitch shifting training strategy and Structural Similarity
Index (SSIM) loss into our SVC model, effectively enhancing its performance.
Experimental results on the public singing datasets M4Singer indicate that our
proposed method significantly improves model performance in both general SVC
scenarios and particularly in cross-domain SVC scenarios.Comment: Accepted by Interspeech 202
Expanding anaerobic alkane metabolism in the domain of Archaea
Methanogenesis and anaerobic methane oxidation through methyl-coenzyme M reductase (MCR) as a key enzyme have been suggested to be basal pathways of archaea1. How widespread MCR-based alkane metabolism is among archaea, where it occurs and how it evolved remain elusive. Here, we performed a global survey of MCR-encoding genomes based on metagenomic data from various environments. Eleven high-quality mcr-containing metagenomic-assembled genomes were obtained belonging to the Archaeoglobi in the Euryarchaeota, Hadesarchaeota and different TACK superphylum archaea, including the Nezhaarchaeota, Korarchaeota and Verstraetearchaeota. Archaeoglobi WYZ-LMO1 and WYZ-LMO3 and Korarchaeota WYZ-LMO9 encode both the (reverse) methanogenesis and the dissimilatory sulfate reduction pathway, suggesting that they have the genomic potential to couple both pathways in individual organisms. The Hadesarchaeota WYZ-LMO4–6 and Archaeoglobi JdFR-42 encode highly divergent MCRs, enzymes that may enable them to thrive on non-methane alkanes. The occurrence of mcr genes in different archaeal phyla indicates that MCR-based alkane metabolism is common in the domain of Archaea
Endocrine Characteristics and Regulatory Mechanism of Follicular Development and Ovulation Failure in Mammalian Ovary
In mammals, the follicular development and following ovulation are regulated by reproductive hormones, while polycystic ovary syndrome (PCOS) is an endocrine disorder syndrome with reproductive dysfunction and abnormal glucose metabolism in most PCOS women. Its characteristics are hyperandrogenism, ovarian dysfunction, and the exclusion of other androgen excess or related diseases. Its clinical characteristics are large antral follicle pool from which to recruit and persistent anovulation. The incidence of PCOS in women of childbearing age ranged from 4 to 12%. About one-third of infertility cases had no ovulation, and 90% of them had PCOS. Therefore, further studying the regulatory mechanism of follicular hyperrecruitment and anovulation can provide theoretical basis for exploring the pathogenesis of PCOS and guiding clinical treatment, especially for protecting female fertility and preventing the occurrence of metabolic disorder syndrome. The present article will review the progress in endocrine characteristics and regulatory mechanism of follicular development and ovulation failure in the mammalian ovary
A Value-Consistent Method for Downscaling SMAP Passive Soil Moisture With MODIS Products Using Self-Adaptive Window
Many remote sensing soil moisture (SM) products have been developed with global coverage. However, most of them
are derived from passive microwave observations with very coarse resolution, greatly constraining the applications at regional scales. To increase the spatial resolution, a downscaling method is developed to downscale the 36-km Soil Moisture Active Passive L3 SM (SMAP SM) product to 1 km using the Moderate Resolution Imaging Spectroradiometer (MODIS) products (8-d land surface temperature, LST, and 16-d normalized difference vegetation index, NDVI). In this method, a linking model is first established between SM and LST and NDVI, and a self-adaptive window method is applied with the use of the geographically weighted regression (GWR) method to obtain an optimal local regression. Then, the uncertainty of the linking model, expressed as the regression residual, is redistributed to fine-resolution pixels to analyze the consistency before and after downscaling. The method was applied to the Iberian Peninsula to produce the 8-d downscaled SM product in 2016. The downscaled SM was validated with the in-situ SM network (REMEDHUS). A good agreement was found between the two data sets, with a correlation coefficient (R) of 0.87 and an unbiased root-mean-squared error (ubRMSE) of 0.043 m3/m3 at a network level. At station level, the R is larger than 0.6 for all the REMEDHUS stations, with an ubRMSE smaller than 0.06 m3/m3. The evaluation indicates the
good potential of the proposed method in the SM downscaling, which achieves a robust consistency and provides rich spatial
information while maintaining good accuracy.National Natural Science Foundation of China
Strategic Program of the Institute of Mountain Hazards and Environment, Chinese Academy of Sciences (CAS)
Youth Innovation Promotion Association
Spanish Ministry of Science, Innovation and Universities
State Research Agency (AEI)
European Regional Development Fund under ProjectThe authors would like to thank the National Aeronautics and Space Administration (NASA, https://www.nasa.gov) for the provision of SMAP soil moisture product and MODIS products
Enrichment of a microbial community performing anaerobic oxidation of methane in a continuous high-pressure bioreactor
<p>Abstract</p> <p>Background</p> <p>Anaerobic oxidation of methane coupled to sulphate reduction (SR-AOM) prevents more than 90% of the oceanic methane emission to the atmosphere. In a previous study, we demonstrated that the high methane pressure (1, 4.5, and 8 MPa) stimulated <it>in vitro </it>SR-AOM activity. However, the information on the effect of high-pressure on the microbial community structure and architecture was still lacking.</p> <p>Results</p> <p>In this study we analysed the long-term enrichment (286 days) of this microbial community, which was mediating SR-AOM in a continuous high-pressure bioreactor. 99.7% of the total biovolume represented cells in the form of small aggregates (diameter less then 15 μm). An increase of the total biovolume was observed (2.5 times). After 286 days, the ANME-2 (anaerobic methanotrophic archaea subgroup 2) and SRB (sulphate reducing bacteria) increased with a factor 12.5 and 8.4, respectively.</p> <p>Conclusion</p> <p>This paper reports a net biomass growth of communities involved in SR-AOM, incubated at high-pressure.</p
Editorial: Ecology, Metabolism and Evolution of Archaea-Perspectives From Proceedings of the International Workshop on Geo-Omics of Archaea
To facilitate global efforts in addressing fundamental questions related to the biology of archaea, an international consortium of experts organized the International Workshop on Geo-Omics of Archaea (IWGOA), with the overarching themes of Ecology/Biogeochemistry, Metabolism, and Evolution. The IWGOA was held in Shenzhen, China, from October 25th to 27th, 2019. The meeting was attended by more than 200 attendees from China, Japan, USA, Australia, Germany, and France. Some of the most exciting oral and poster presentations made at the IWGOA are celebrated in this Research Topic Figure 1. The 21 manuscripts herein span different aspects of archaeal biology in both extreme and “non-extreme” environments in both marine and terrestrial settings and use a variety of approaches—community ecology, environmental lipidomics and genomics, organismal biology, and nucleic acid biochemistry—embodying diverse research thrusts that makes archaeal biology so exciting. At the same time, the manuscripts include over 100 authors from Asia, North America, and Europe, realizing our goal to engage a global audience in the biology of archaea
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