Identification of a cosmid clone containing the Neurospora crassa lys-5 and un-4 genes, isolation of a partial lys-5 cDNA and associated chromosome walking.

The un-4 gene of Neurospora crassa was cloned to determine the limits of a chromosome walk on linkage group VI (LGVI) and to allow analysis of un loci on LGVI. Subsequent analysis identified the lys-5 locus on the same cosmid clone as un-4. We have isolated and sequenced a partial lys-5 cDNA clone and initiated a chromosome walk from the lys-5, un-4 cosmid clone

SHIP COLLISION RISK ASSESSMENT MODEL FOR QINZHOU PORT BASED ON EVENT SEQUENCE DIAGRAM

Qinzhou Port is one of the most important ports in the “Beibu Gulf” of China. It is also the main hub port of the "21st century maritime silk road" strategy. Based on a basic collision risk assessment approach, an Event Sequence Diagram (ESD) model that explains the four-stage collision avoidance decision-making procedure is proposed from the perspectives of perception, cognition, decision, and execution. Using the historical data derived from collision accident reports from the Qinzhou Port waters from 2013 to 2017, as well as the data elicited from expert knowledge, a quantitative evaluation of probability distributions of different collision failure modes is performed. The results are also compared with relevant results from other types of navigation waters to analyse collision risk level of Qinzhou waters. At the same time, the main failures paths of collision avoidance decision making are identified. The proposed model can provide with an overall collision risk picture from a macro perspective

Macrophage VLDL Receptor Promotes PAFAH Secretion in Mother’s Milk and Suppresses Systemic Inflammation in Nursing Neonates

Mother’s milk is widely accepted as nutritious and protective to the newborn mammals by providing not only macronutrients but also immune-defensive factors. However, the mechanisms accounting for these benefits are not fully understood. Here we show that maternal very-low-density-lipoprotein receptor (VLDLR) deletion in mice causes the production of defective milk containing diminished level of platelet-activating factor acetylhydrolase (PAFAH). As a consequence, the nursing neonates suffer from alopecia, anemia and growth retardation owing to elevated levels of pro-inflammatory platelet-activating factors (PAFs). VLDLR deletion significantly impairs the expression of phospholipase A2 group 7 (Pla2g7) in macrophages, which decreases PAFAH secretion. Exogenous oral supplementation of neonates with PAFAH effectively rescues the toxicity. These findings not only reveal a novel role of VLDLR in suppressing inflammation by maintaining macrophage PAFAH secretion, but also identify the maternal VLDLR as a key genetic program that ensures milk quality and protects the newborns.Chemistry and Chemical Biolog

View-Disentangled Transformer for Brain Lesion Detection

Deep neural networks (DNNs) have been widely adopted in brain lesion detection and segmentation. However, locating small lesions in 2D MRI slices is challenging, and requires to balance between the granularity of 3D context aggregation and the computational complexity. In this paper, we propose a novel view-disentangled transformer to enhance the extraction of MRI features for more accurate tumour detection. First, the proposed transformer harvests long-range correlation among different positions in a 3D brain scan. Second, the transformer models a stack of slice features as multiple 2D views and enhance these features view-by-view, which approximately achieves the 3D correlation computing in an efficient way. Third, we deploy the proposed transformer module in a transformer backbone, which can effectively detect the 2D regions surrounding brain lesions. The experimental results show that our proposed view-disentangled transformer performs well for brain lesion detection on a challenging brain MRI dataset.Comment: International Symposium on Biomedical Imaging (ISBI) 2022, code: https://github.com/lhaof/ISBI-VDForme

Orexin Regulates Bone Remodeling via a Dominant Positive Central Action and a Subordinate Negative Peripheral Action

SummaryOrexin neuropeptides promote arousal, appetite, reward, and energy expenditure. However, whether orexin affects bone mass accrual is unknown. Here, we show that orexin functions centrally through orexin receptor 2 (OX2R) in the brain to enhance bone formation. OX2R null mice exhibit low bone mass owing to elevated circulating leptin, whereas central administration of an OX2R-selective agonist augments bone mass. Conversely, orexin also functions peripherally through orexin receptor 1 (OX1R) in the bone to suppress bone formation. OX1R null mice exhibit high bone mass owing to a differentiation shift from marrow adipocyte to osteoblast that results from higher osseous ghrelin expression. The central action is dominant because bone mass is reduced in orexin null and OX1R2R double null mice but enhanced in orexin-overexpressing transgenic mice. These findings reveal orexin as a critical rheostat of skeletal homeostasis that exerts a yin-yang dual regulation and highlight orexin as a therapeutic target for osteoporosis

Biphasic and Dosage-Dependent Regulation of Osteoclastogenesis by β-Catenin

Wnt/β-catenin signaling is a critical regulator of skeletal physiology. However, previous studies have mainly focused on its roles in osteoblasts, while its specific function in osteoclasts is unknown. This is a clinically important question because neutralizing antibodies against Wnt antagonists are promising new drugs for bone diseases. Here, we show that in osteoclastogenesis, β-catenin is induced during the macrophage colony-stimulating factor (M-CSF)-mediated quiescence-to-proliferation switch but suppressed during the RANKL-mediated proliferation-to-differentiation switch. Genetically, β-catenin deletion blocks osteoclast precursor proliferation, while β-catenin constitutive activation sustains proliferation but prevents osteoclast differentiation, both causing osteopetrosis. In contrast, β-catenin heterozygosity enhances osteoclast differentiation, causing osteoporosis. Biochemically, Wnt activation attenuates whereas Wnt inhibition stimulates osteoclastogenesis. Mechanistically, β-catenin activation increases GATA2/Evi1 expression but abolishes RANKL-induced c-Jun phosphorylation. Therefore, β-catenin exerts a pivotal biphasic and dosage-dependent regulation of osteoclastogenesis. Importantly, these findings suggest that Wnt activation is a more effective treatment for skeletal fragility than previously recognized that confers dual anabolic and anti-catabolic benefits

A Mismatch-Tolerant Reverse Transcription Loop-Mediated Isothermal Amplification Method and Its Application on Simultaneous Detection of All Four Serotype of Dengue Viruses

Loop-mediated isothermal amplification (LAMP) has been widely used in the detection of pathogens causing infectious diseases. However, mismatches between primers (especially in the 3′-end) and templates significantly reduced the amplification efficiency of LAMP, and limited its application to genetically diverse viruses. Here, we reported a novel mismatch-tolerant LAMP assay and its application in the detection of dengue viruses (DENV). The novel method features the addition of as little as 0.15 U of high-fidelity DNA polymerase to the standard 25 μl LAMP reaction mixture. This amount was sufficient to remove the mismatched bases at the 3′-end of primers, thereby resulting in excellent tolerance for various mismatches occurring at the 3′-end of the LAMP primers during amplification. This novel LAMP assay has a markedly improved amplification efficiency especially for the mutants forming mismatches with internal primers (FIP/BIP) and loop primers (FLP/BLP). The reaction time of the novel method was about 5.6–22.6 min faster than the conventional LAMP method regardless of the presence or absence of mismatches between primers and templates. Using the novel method, we improved a previously established pan-serotype assay for DENV, and demonstrated greater sensitivity for detection of four DENV serotypes than the previous one. The limit of detection (LOD) of the novel assay was 74, 252, 78, and 35 virus RNA copies per reaction for DENV-1, DENV-2, DENV-3, and DENV-4, respectively. Among 153 clinical samples from patients with suspected DENV infection, the novel assay detected 94.8% samples being DENV positive, higher than that detected by the commercial NS1 antigen assay (92.2%), laboratory-based RT-PCR method (78.4%), and the conventional RT-LAMP assay (86.9%). Furthermore, the novel RT-LAMP assay has been developed into a visual determination method by adding colorimetric dyes. Because of its simplicity, all LAMP-based diagnostic assays may be easily updated to the newly improved version. The novel mismatch-tolerant LAMP method represents a simple, sensitive and promising approach for molecular diagnosis of highly variable viruses, and it is especially suited for application in resource-limited settings