2,879 research outputs found
SIFTER search: a web server for accurate phylogeny-based protein function prediction.
We are awash in proteins discovered through high-throughput sequencing projects. As only a minuscule fraction of these have been experimentally characterized, computational methods are widely used for automated annotation. Here, we introduce a user-friendly web interface for accurate protein function prediction using the SIFTER algorithm. SIFTER is a state-of-the-art sequence-based gene molecular function prediction algorithm that uses a statistical model of function evolution to incorporate annotations throughout the phylogenetic tree. Due to the resources needed by the SIFTER algorithm, running SIFTER locally is not trivial for most users, especially for large-scale problems. The SIFTER web server thus provides access to precomputed predictions on 16 863 537 proteins from 232 403 species. Users can explore SIFTER predictions with queries for proteins, species, functions, and homologs of sequences not in the precomputed prediction set. The SIFTER web server is accessible at http://sifter.berkeley.edu/ and the source code can be downloaded
Design of a Ka-band MW-level high efficiency gyroklystron for accelerators
Design of a three-cavity Ka-band MW-level gyroklystron operated at the fundamental TE02 mode is presented in this paper. The initial design of the magnetron injection gun (MIG) and interaction circuit has been completed by using the PIC (Particle in cell) code MAGIC. The PIC simulation shows this gyroklystron can deliver an output power of more than 1.5 MW with a gain of > 35 dB at 36 GHz. The achieved efficiency exceeds 40 % when driven by a 95 kV, 45 A beam. The optimized MIG has a transverse velocity spread of less than 2.5% when the velocity ratio is around 1.3
A Hierarchical Method for Removal of Baseline Drift from Biomedical Signals: Application in ECG Analysis
Noise can compromise the extraction of some fundamental and important features from biomedical signals and hence prohibit accurate analysis of these signals. Baseline wander in electrocardiogram (ECG) signals is one such example, which can be caused by factors such as respiration, variations in electrode impedance, and excessive body movements. Unless baseline wander is effectively removed, the accuracy of any feature extracted from the ECG, such as timing and duration of the ST-segment, is compromised. This paper approaches this filtering task from a novel standpoint by assuming that the ECG baseline wander comes from an independent and unknown source. The technique utilizes a hierarchical method including a blind source separation (BSS) step, in particular independent component analysis, to eliminate the effect of the baseline wander. We examine the specifics of the components causing the baseline wander and the factors that affect the separation process. Experimental results reveal the superiority of the proposed algorithm in removing the baseline wander
Feasibility and efficacy of a multicomponent exercise medicine programme in patients with pancreatic cancer undergoing neoadjuvant therapy (the EXPAN trial): Study protocol of a dual-centre, two-armed phase I randomised controlled trial
Introduction Exercise is emerging as a therapy in oncology for its physical and psychosocial benefits and potential effects on chemotherapy tolerability and efficacy. However, evidence from randomised controlled trials (RCTs) supporting exercise in patients with borderline resectable or locally advanced pancreatic cancer (PanCa) undergoing neoadjuvant therapy (NAT) are lacking. Methods and analysis The EXPAN trial is a dual-centre, two-armed, phase I RCT. Forty patients with borderline resectable or locally advanced PanCa undergoing NAT will be randomised equally to an exercise intervention group (individualised exercise+standard NAT) or a usual care control group (standard NAT). The exercise intervention will be supervised and consist of moderate to vigorous intensity resistance and aerobic-based training undertaken two times a week for 45-60 min per session for a maximum period of 6 months. The primary outcome is feasibility. Secondary outcomes are patient-related and treatment-related endpoints, objectively measured physical function, body composition, psychological health and quality of life. Assessments will be conducted at baseline, prior to potential alteration of treatment (∼4 months postbaseline), at completion of the intervention (maximum 6 months postbaseline) and 3-month and 6-month postintervention (maximum 9 and 12 months postbaseline). Ethics and dissemination The EXPAN trial has been approved by Edith Cowan University (reference no.: 2020-02011-LUO), Sir Charles Gairdner Hospital (reference no.: RGS 03956) and St John of God Subiaco Hospital (reference no.: 1726). The study results will be presented at national/international conferences and submitted for publications in peer-reviewed journals. Trial registration number ACTRN12620001081909
In Vitro Colony Assays for Characterizing Tri-potent Progenitor Cells Isolated from the Adult Murine Pancreas
Stem and progenitor cells from the adult pancreas could be a potential source of therapeutic beta-like cells for treating patients with type 1 diabetes. However, it is still unknown whether stem and progenitor cells exist in the adult pancreas. Research strategies using cre-lox lineage-tracing in adult mice have yielded results that either support or refute the idea that beta cells can be generated from the ducts, the presumed location where adult pancreatic progenitors may reside. These in vivo cre-lox lineage-tracing methods, however, cannot answer the questions of self-renewal and multi-lineage differentiation-two criteria necessary to define a stem cell. To begin addressing this technical gap, we devised 3-dimensional colony assays for pancreatic progenitors. Soon after our initial publication, other laboratories independently developed a similar, but not identical, method called the organoid assay. Compared to the organoid assay, our method employs methylcellulose, which forms viscous solutions that allow the inclusion of extracellular matrix proteins at low concentrations. The methylcellulose-containing assays permit easier detection and analyses of progenitor cells at the single-cell level, which are critical when progenitors constitute a small sub-population, as is the case for many adult organ stem cells. Together, results from several laboratories demonstrate in vitro self-renewal and multi-lineage differentiation of pancreatic progenitor-like cells from mice. The current protocols describe two methylcellulose-based colony assays to characterize mouse pancreatic progenitors; one contains a commercial preparation of murine extracellular matrix proteins and the other an artificial extracellular matrix protein known as a laminin hydrogel. The techniques shown here are 1) dissociation of the pancreas and sorting of CD133(+)Sox9/EGFP(+) ductal cells from adult mice, 2) single cell manipulation of the sorted cells, 3) single colony analyses using microfluidic qRT-PCR and whole-mount immunostaining, and 4) dissociation of primary colonies into single-cell suspensions and re-plating into secondary colony assays to assess self-renewal or differentiation
Risk of Cancer After Diagnosis of Cardiovascular Disease
BACKGROUND: Cardiovascular disease (CVD) and cancer share several risk factors. Although preclinical models show that various types of CVD can accelerate cancer progression, clinical studies have not determined the impact of atherosclerosis on cancer risk.
OBJECTIVES: The objective of this study was to determine whether CVD, especially atherosclerotic CVD, is independently associated with incident cancer.
METHODS: Using IBM MarketScan claims data from over 130 million individuals, 27 million cancer-free subjects with a minimum of 36 months of follow-up data were identified. Individuals were stratified by presence or absence of CVD, time-varying analysis with multivariable adjustment for cardiovascular risk factors was performed, and cumulative risk of cancer was calculated. Additional analyses were performed according to CVD type (atherosclerotic vs nonatherosclerotic) and cancer subtype.
RESULTS: Among 27,195,088 individuals, those with CVD were 13% more likely to develop cancer than those without CVD (HR: 1.13; 95% CI: 1.12-1.13). Results were more pronounced for individuals with atherosclerotic CVD (aCVD), who had a higher risk of cancer than those without CVD (HR: 1.20; 95% CI: 1.19-1.21). aCVD also conferred a higher risk of cancer compared with those with nonatherosclerotic CVD (HR: 1.11; 95% CI: 1.11-1.12). Cancer subtype analyses showed specific associations of aCVD with several malignancies, including lung, bladder, liver, colon, and other hematologic cancers.
CONCLUSIONS: Individuals with CVD have an increased risk of developing cancer compared with those without CVD. This association may be driven in part by the relationship of atherosclerosis with specific cancer subtypes, which persists after controlling for conventional risk factors
Successional change in species composition alters climate sensitivity of grassland productivity.
Succession theory predicts altered sensitivity of ecosystem functions to disturbance (i.e., climate change) due to the temporal shift in plant community composition. However, empirical evidence in global change experiments is lacking to support this prediction. Here, we present findings from an 8-year long-term global change experiment with warming and altered precipitation manipulation (double and halved amount). First, we observed a temporal shift in species composition over 8 years, resulting in a transition from an annual C3 -dominant plant community to a perennial C4 -dominant plant community. This successional transition was independent of any experimental treatments. During the successional transition, the response of aboveground net primary productivity (ANPP) to precipitation addition magnified from neutral to +45.3%, while the response to halved precipitation attenuated substantially from -17.6% to neutral. However, warming did not affect ANPP in either state. The findings further reveal that the time-dependent climate sensitivity may be regulated by successional change in species composition, highlighting the importance of vegetation dynamics in regulating the response of ecosystem productivity to precipitation change
Stromal senescence establishes an immunosuppressive microenvironment that drives tumorigenesis
Age is a significant risk factor for the development of cancer. However, the mechanisms that drive age-related increases in cancer remain poorly understood. To determine if senescent stromal cells influence tumorigenesis, we develop a mouse model that mimics the aged skin microenvironment. Using this model, here we find that senescent stromal cells are sufficient to drive localized increases in suppressive myeloid cells that contributed to tumour promotion. Further, we find that the stromal-derived senescence-associated secretory phenotype factor interleukin-6 orchestrates both increases in suppressive myeloid cells and their ability to inhibit anti-tumour T-cell responses. Significantly, in aged, cancer-free individuals, we find similar increases in immune cells that also localize near senescent stromal cells. This work provides evidence that the accumulation of senescent stromal cells is sufficient to establish a tumour-permissive, chronic inflammatory microenvironment that can shelter incipient tumour cells, thus allowing them to proliferate and progress unabated by the immune system
Loss-of-function mutations in Lysyl-tRNA synthetase cause various leukoencephalopathy phenotypes
Objective: To expand the clinical spectrum of lysyl-tRNA synthetase (KARS) gene–related diseases, which so far includes Charcot-Marie-Tooth disease, congenital visual impairment and microcephaly, and nonsyndromic hearing impairment.
Methods: Whole-exome sequencing was performed on index patients from 4 unrelated families with leukoencephalopathy. Candidate pathogenic variants and their cosegregation were confirmed by Sanger sequencing. Effects of mutations on KARS protein function were examined by aminoacylation assays and yeast complementation assays.
Results: Common clinical features of the patients in this study included impaired cognitive ability, seizure, hypotonia, ataxia, and abnormal brain imaging, suggesting that the CNS involvement is the main clinical presentation. Six previously unreported and 1 known KARS mutations were identified and cosegregated in these families. Two patients are compound heterozygous for missense mutations, 1 patient is homozygous for a missense mutation, and 1 patient harbored an insertion mutation and a missense mutation. Functional and structural analyses revealed that these mutations impair aminoacylation activity of lysyl-tRNA synthetase, indicating that de- fective KARS function is responsible for the phenotypes in these individuals.
Conclusions: Our results demonstrate that patients with loss-of-function KARS mutations can manifest CNS disorders, thus broadening the phenotypic spectrum associated with KARS-related disease
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