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Biology subjects

Ali, M. A. S.

Publications and source records attributed to Ali, M. A. S..

4 recordsLinked to original sources

ArtSeg: Rapid Artifact Segmentation and Removal in Brightfield Cell Microscopy Images

Brightfield cell microscopy is a foundational tool in life sciences. The acquired images are prone to contain visual artifacts that hinder downstream analysis, and automatically removing them is therefore of great practical interest. Deep convolutional neural networks are state-of-the-art for image segmentation, but require pixel-level annotations, which are time-consuming to produce. Here, we propose ScoreCAM-U-Net, a pipeline to segment artifactual regions in brightfield images with limited user input. The model is trained using only image-level labels, so the process is faster by orders of magnitude compared to pixel-level annotation, but without substantially sacrificing the segmentation performance. We confirm that artifacts indeed exist with different shapes and sizes in three different brightfield microscopy image datasets, and distort downstream analyses such as nuclei segmentation, morphometry and fluorescence intensity quantification. We then demonstrate that our automated artifact removal ameliorates this problem. Such rapid cleaning of acquired images using the power of deep learning models is likely to become a standard step for all large scale microscopy experiments.

bioinformatics↗

Live-cell microscopy or fluorescence anisotropy with budded baculoviruses - which way to go with measuring ligand binding to M4 muscarinic receptors?

M4 muscarinic receptor is a G protein-coupled receptor that has been associated with alcohol and cocaine abuse, Alzheimers disease and schizophrenia which makes it an interesting drug target. For many G protein-coupled receptors, the development of high-affinity fluorescence ligands has expanded the options for high throughput screening of drug candidates and serve as useful tools in fundamental receptor research. So far, the lack of suitable fluorescence ligands has limited studying M4 receptor ligand binding. Here, we explored the possibilities of using fluorescence-based methods for studying binding affinity and kinetics to M4 receptor of both labeled and unlabeled ligands. We used two TAMRA-labeled fluorescence ligands, UR-MK342 and UR-CG072, for assay development. Using budded baculovirus particles as M4 receptor preparation and fluorescence anisotropy method, we determined the affinities and binding kinetics of both fluorescence ligands. The fluorescence ligands could also be used as reported probes for determining binding affinities of a set of unlabeled ligands. Based on these results, we took a step further towards a more natural signaling system and developed a method using live CHO-K1-hM4R cells and automated fluorescence microscopy suitable for routine determination of unlabeled ligand affinities. For quantitative image analysis, we developed random forest and deep learning-based pipelines for cell segmentation. The pipelines were integrated into the user-friendly open-source Aparecium software. Both developed methods were suitable for measuring fluorescence ligand saturation binding, association and dissociation kinetics as well as for screening binding affinities of unlabeled ligands. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/473643v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@17dfac6org.highwire.dtl.DTLVardef@1db1760org.highwire.dtl.DTLVardef@dba2a0org.highwire.dtl.DTLVardef@191f149_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

Molecular Phylogenetic Analysis of 16S rRNA Sequences Identified Two lineages of H. pylori Strains Detected from Different Regions in Sudan Suggestive of Differential Evolution

BackgroundH. pylori is ubiquitous among humans, and one of the best studied examples of an intimate association between bacteria and humans. Under several diverse socio-demographic factors in Sudan, a continuous increase in the prevalence rate of H. pylori infection has been noticed which represents a major public health challenge. In this study, we analyzed the molecular evolution of H. pylori Strains detected from different ethnic and regions of Sudan using 16S rRNA gene and phylogenetic approach. Materials and methodsA total of 75 gastric biopsies taken from patients who had been referred for endoscopy from different regions of Sudan. The DNA extraction was done by using the guanidine chloride method. Two sets of primers (universal and specific for H. pylori) were used to amplify the 16S ribosomal gene. Sanger sequencing was performed; then Blast these sequences with those available in the NCBI nucleotide database. The evolutionary aspects were analyzed using a MEGA7 software. ResultMolecular detection of H. pylori has shown that 28 (37.33%) of patients were positive for H. pylori. Bivariate analysis has found no significant differences exhibited across sociodemographic, endoscopy series and H. pylori infection. Nucleotide variations were found at five nucleotide positions (positions 219, 305, 578, 741 and 763-764) and one insertion mutation (750_InsC_751) was present in sixty-seven percent (7/12) of our strains. The phylogenetic tree diverged into two lineages. ConclusionThe phylogenetic analysis of 16S rRNA sequences identified two lineages of H. pylori strains detected from different regions in Sudan. Sex mutations were detected in regions of the 16S rRNA not closely associated with either tetracycline or tRNA binding sites. 66.67% of them were located in the central domain of 16S rRNA. Studying the effect of these mutations on the functions of 16S rRNA molecules in protein synthesis and antibiotic resistance is of great importance.

microbiology↗

Evaluation of 21 Brassica microgreens growth and nutritional profile grown under different red, blue and green LEDs combination

Microgreens are rich functional crops with valuable nutritional elements that have health benefits when used as food supplants. Growth characterization, nutritional composition profile of 21 varieties representing 5 species of the Brassica genus as microgreens were assessed under light-emitting diodes (LEDs) conditions. Microgreens were grown under four different LEDs ratios (%) (R80:B20, R20:B80, R70:G10:B20, and R20:G10:B70). Results indicated that supplemental lighting with green LEDs (R70:G10:B20) enhanced vegetative growth and morphology, while blue LEDs (R20:B80) increased the mineral composition and vitamins content. Interestingly, combining the nutritional content with the growth yield to define the optimal LEDs setup, we found that the best lighting to promote the microgreen growth was supplying the green LEDs combination (R70:G10:B20). Remarkably, under this proper conditions, Kohlrabi purple, Cabbage red, Broccoli, Kale Tucsan, Komatsuna red, Tatsoi, and Cabbage green had the highest growth and nutritional content profile as microgreens which being a health-promoting in a diet support strategy required for the human health under certain isolated of limited food conditions.

plant biology↗