WRA-Net: Wide Receptive Field Attention Network for Motion Deblurring in Crop and Weed Image.

Automatically segmenting crops and weeds in the image input from cameras accurately is essential in various agricultural technology fields, such as herbicide spraying by farming robots based on crop and weed segmentation information. However, crop and weed images taken with a camera have motion blur due to various causes (e.g., vibration or shaking of a camera on farming robots, shaking of crops and weeds), which reduces the accuracy of crop and weed segmentation. Therefore, robust crop and weed segmentation for motion-blurred images is essential. However, previous crop and weed segmentation studies were performed without considering motion-blurred images. To solve this problem, this study proposed a new motion-blur image restoration method based on a wide receptive field attention network (WRA-Net), based on which we investigated improving crop and weed segmentation accuracy in motion-blurred images. WRA-Net comprises a main block called a lite wide receptive field attention residual block, which comprises modified depthwise separable convolutional blocks, an attention gate, and a learnable skip connection. We conducted experiments using the proposed method with 3 open databases: BoniRob, crop/weed field image, and rice seedling and weed datasets. According to the results, the crop and weed segmentation accuracy based on mean intersection over union was 0.7444, 0.7741, and 0.7149, respectively, demonstrating that this method outperformed the state-of-the-art methods.

Activation of multiple transcriptional regulators by growth restriction in Pseudomonas aeruginosa.

Growth restriction by antibiotics is a common feature that pathogenic bacteria must overcome for survival. The struggle of bacteria to escape from growth restriction eventually results in development of antibiotic-resistance through the expression of a set of genes. Here we found that some physiologically important transcriptional regulators of Pseudomonas aeruginosa including QscR, a quorum sensing (QS) receptor, SoxR, a superoxide sensor-regulator, and AntR, a regulator of anthranilate-related secondary metabolism, are activated by various growth-restricted conditions. We generated the growth-restricted conditions by various methods, such as overexpression of PA2537 and treatment with antibiotics or disinfectants. The overexpression of PA2537, encoding an acyltransferase homologue, tightly restricted the growth of P. aeruginosa and significantly activated QscR during the growth restriction. Similarly, treatments with gentamycin, tetracycline, and ethanol also activated QscR near their minimal inhibitory concentrations (MICs). Some non-QS regulators, such as AntR and SoxR, were also activated near the MICs in the same conditions. However, LasR and PqsR, other QS receptors of P. aeruginosa, were not activated, suggesting that only a specific set of transcriptional regulators is activated by growth restriction. Since paraquat, a super-oxide generator, significantly activated QscR and AntR, we suggest that the oxidative stress generated by growth restriction may be partly involved in this phenomenon.

AntR-mediated bidirectional activation of antA and antR, anthranilate degradative genes in Pseudomonas aeruginosa.

Bidirectional activation of transcription is a peculiar regulation mode of gene expression. In this study, we show that genes involved in the metabolism of anthranilate, a precursor of biosynthesis of tryptophan and Pseudomonas quinolone signal (PQS) are regulated by this bidirectional activation of transcription. Anthranilate is degraded by anthranilate dioxygenase complex encoded by antABC operon, and AntR, a LysR-type regulator encoded by antR activates the transcription of antABC operon in the presence of anthranilate. In P. aeruginosa, antABC and antR are divergently located and AntR binds to the intergenic region between antA and antR to activate the antABC transcription. In this study, we determined the transcriptional start site of the antA promoter (antA(p)) and AntR-responsive elements (AREs) in P. aeruginosa. The upstream deletion analysis of antA(p) and in vitro gel shift assay with purified AntR showed that there are two AREs at -194 to -148 and -88 to -47 regions. We also found that AntR activates antR promoter (antR(p)) in the opposite direction and both AREs are important in the bidirectional activation of antA(p) and antR(p). Two AREs have different binding affinities to AntR and the strength of transcriptional activation was dramatically asymmetric depending on the direction. We suggest that the different affinities of two AREs may explain the asymmetry of the bidirectional activation by AntR.

Interspecies signaling through QscR, a quorum receptor of Pseudomonas aeruginosa.

The QS machinery of Pseudomonas aeruginosa, an opportunistic human pathogen, consists of three acyl-homoserine lactone (acyl-HSL) signaling systems, LasR-I, RhlR-I, and QscR. QscR, known as an orphan receptor and a repressor of other QS systems, operates its own regulon using N-3-oxododecanoyl HSL (3OC12), which is synthesized by LasI, as its signal. In this study, we addressed the role of QscR in interspecies communication. We found that QscR auto-activates its own transcription in the presence of 3OC12. In a single population of P. aeruginosa, where 3OC12 is the sole signal available for QscR, the QscR regulon is activated by 3OC12 produced by the LasI-R system. However, the broad signal specificity of QscR allowed it to respond to a non-P. aeruginosa signal, such as N-decanoyl HSL (C10) and N-3-hydroxydecanoyl HSL (3OHC10), which preferentially activated QscR to LasR. The signal extracts from Pseudomonas fluorescens and Burkholeria vietnamiensis also preferentially activated QscR. These non-P. aeruginosa signals activated QscR more strongly than 3OC12, the authentic P. aeruginosa signal. Since a variety of acyl-HSLs are produced in the multi-species habitat of nature, our study provides a clue for the particular situation that allows QscR to secede from the conventional QS cascade in mixed microbial community.

Growth phase-differential quorum sensing regulation of anthranilate metabolism in Pseudomonas aeruginosa.

Pseudomonas quinolone signal (PQS) plays a role in the regulation of virulence genes and it is intertwined in the las/rhl quorum sensing (QS) circuits of Pseudomonas aeruginosa. PQS is synthesized from anthranilate by pqsA-D and pqsH whose expression is influenced by the las/rhl systems. Since anthranilate can be degraded by functions of antABC and catBCA, PQS synthesis might be regulated by the balance between the expression of the pqsA-D/phnAB, pqsH, antABC, and catBCA gene loci. antA and catA are repressed by LasR during log phase and activated by RhlR in late stationary phase, whereas pqsA-E/phnAB is activated by LasR in log phase and repressed by RhlR. QscR represses both but each repression occurs in a different growth phase. This growth phase-differential regulation appears to be accomplished by the antagonistic interplay of LasR, RhlR, and QscR, mediated by two intermediate regulators, AntR and PqsR, and their cofactors, anthranilate and PQS, where the expressions of antR and pqsR and the production of anthranilate and PQS are growth phase-differentially regulated by QS systems. Especially, the anthranilate level increases in an RhlR-dependent manner at late stationary phase. From these results, we suggest that RhlR and LasR regulate the anthranilate metabolism in a mutually antagonistic and growth phase-differential manner by affecting both the expressions and activities of AntR and PqsR, and that QscR also phase-differentially represses both LasR and RhlR functions in this regulation.

A Case of Urethral Metastasis from Sigmoid Colon Cancer Diagnostically and Prognostically Indicated by F-18 FDG PET/CT.

Urethral metastasis from colorectal cancer is rare and is known to have a poor prognosis. A 72-year-old man with a history of colectomy and colostomy due to sigmoid colon cancer was admitted to the emergency room with bowel distension, rectal bleeding and urinary symptoms. Computed tomography of the abdominopelvis showed sigmoid colon cancer with multiple metastases involving the liver. Positron emission tomography with F-18 fluorodeoxyglucose (FDG) showed multiple hypermetabolic foci in the liver, penis and pubic bone, which otherwise could not be diagnosed. The lesions revealed no improvement with chemotherapy and urological surgery on follow-up F-18 FDG PET/CT. We present a case of urethral metastasis of sigmoid colon cancer diagnostically and prognostically indicated by F-18 FDG PET/CT.

In vitro and in vivo test of PEG/PCL-based hydrogel scaffold for cell delivery application.

Biodegradable elastic hydrogel scaffolds based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(epsilon-caprolactone) (PCL) were fabricated and investigated as a delivery vehicle of rabbit chondrocytes for the formation of neocartilage. The diacrylated forms of PEG and PCL were used as building blocks to prepare a series of hydrogel scaffolds with different block compositions and, thus, different physico-chemical properties. The porous hydrogel scaffolds were prepared by using the salt leaching method that is generally used for the creation of porous scaffolds, and their in vitro cell interactions were examined using chondrocytes. The hydrogel scaffold with a relatively high PEG content showed better cell growth for chondrocytes, while the scaffold with a relatively low PEG content showed lower chondrogenic differentiation. It was observed that different kinds of scaffolds and rabbit chondrocytes were shown to have different swelling ratios in the scaffold for effective cell growth and tissue regeneration. RT-PCR results for the resultant cartilage tissue revealed that a PEG-PCL ratio of 14 to 6 scaffold was optimal for cartilage tissue formation in terms of collagen Type II, aggrecan, SOX9, and COMP gene expression. In addition, the hydrogel scaffold with a PEG-PCL ratio of 14 to 6 showed faster formation of new cartilage than those shown by other scaffolds.