868 research outputs found

    Effects of expression of mammalian G alpha and hybrid mammalian-yeast G alpha proteins on the yeast pheromone response signal transduction pathway

    Get PDF
    Scg1, the product of the Saccharomyces cerevisiae SCG1 (also called GPA1) gene, is homologous to the alpha subunits of G proteins involved in signal transduction in mammalian cells. Scg1 negatively controls the pheromone response pathway in haploid cells. Either pheromonal activation or an scg1 null mutation relieves the negative control and leads to an arrest of cell growth in the G1 phase of the cell cycle. Expression of rat G alpha s was previously shown to complement the growth defect of scg1 null mutants while not allowing mating. We have extended this analysis to examine the effects of the short form of G alpha s (which lacks 15 amino acids present in the long form), G alpha i2, G alpha o, and Scg1-mammalian G alpha hybrids. In addition, we have found that constructs able to complement scg1 are also able to inhibit the response to pheromone and mating when expressed in a wild-type SCG1 strain. Overexpression of Scg1 has a similar inhibitory effect. These results are consistent with a model proposed for the action of Scg1 as the alpha component of a heterotrimeric G protein in which the beta gamma component (Ste4/Ste18) activates the pheromone response after dissociation from Scg1. They suggest that the G alpha constructs able to complement scg1 can interact with beta gamma to prevent activation of the pathway but are unable to interact with pheromone receptors to activate the pathway

    ACTIVE: Towards Highly Transferable 3D Physical Camouflage for Universal and Robust Vehicle Evasion

    Full text link
    Adversarial camouflage has garnered attention for its ability to attack object detectors from any viewpoint by covering the entire object's surface. However, universality and robustness in existing methods often fall short as the transferability aspect is often overlooked, thus restricting their application only to a specific target with limited performance. To address these challenges, we present Adversarial Camouflage for Transferable and Intensive Vehicle Evasion (ACTIVE), a state-of-the-art physical camouflage attack framework designed to generate universal and robust adversarial camouflage capable of concealing any 3D vehicle from detectors. Our framework incorporates innovative techniques to enhance universality and robustness, including a refined texture rendering that enables common texture application to different vehicles without being constrained to a specific texture map, a novel stealth loss that renders the vehicle undetectable, and a smooth and camouflage loss to enhance the naturalness of the adversarial camouflage. Our extensive experiments on 15 different models show that ACTIVE consistently outperforms existing works on various public detectors, including the latest YOLOv7. Notably, our universality evaluations reveal promising transferability to other vehicle classes, tasks (segmentation models), and the real world, not just other vehicles.Comment: Accepted for ICCV 2023. Main Paper with Supplementary Material. Project Page: https://islab-ai.github.io/active-iccv2023

    Leadership Succession Planning: An Examination of Sole Proprietor Estate Surveying and Valuation Firms in Lagos Metropolis, Nigeria

    Get PDF
    This paper reports the results from a survey of 38 small sole- proprietor estate surveying and valuation firms in Lagos, Nigeria. A 45% questionnaire retrieval rate was achieved while CEOs/owners of estate surveying and valuation firms were interviewed. Descriptive statistics were used to analyze the respondents‟ general characteristics as well as their attitude toward business succession planning. The study found that sole-proprietor firm owners desired that their firms outlive them through transferring of the firms‟ businesses to their next generation. However, majority of these sole proprietors‟ next generation were not keen on pursuing real estate business related courses in their undergraduate days in view of their exposure to modern technology and the influence of peers. Also, the study found that the owners of these firms have not, as a matter of policy, planned for their succession because of the cultural and attitudinal beliefs and values, which forbid thoughts about death or incapacitation about a living soul. As a result, the study indicated that only 5% of sole proprietor estate surveying and valuation firms in this category have continued to the second generation in the study area. This outcome has serious implications for small professional service businesses‟ economic and job creation potential for Nigeria

    miRNA regulation of cytotoxic effects in mouse Sertoli cells exposed to nonylphenol

    Get PDF
    Background: It is known that some environmental chemicals affect the human endocrine system. The harmful effects of endocrine disrupting chemical (EDC) nonylphenol (NP) have been studied since the 1980s. It is known that NP adversely affects physiological functions by mimicking the natural hormone 17 beta-estradiol. In the present study, we analyzed the expression of miRNAs and their target genes in mouse Sertoli TM4 cells to better understand the regulatory roles of miRNAs on Sertoli cells after NP exposure. Methods: Mouse TM4 Sertoli cells were treated with NP for 3 or 24 h, and global gene and miRNA expression were analyzed using Agilent mouse whole genome and mouse miRNA v13 arrays. Results: We identified genes that were > 2-fold differentially expressed in NP-treated cells and control cells (P < 0.05) and analyzed their functions through Gene Ontology analysis. We also identified miRNAs that were differentially expressed in NP-treated and control cells. Of the 186 miRNAs the expression of which differed between NP-treated and control cells, 59 and 147 miRNAs exhibited 1.3-fold increased or decreased expression at 3 and 24 h, respectively. Network analysis of deregulated miRNAs suggested that Ppara may regulate the expression of certain miRNAs, including miR-378, miR-125a-3p miR-20a, miR-203, and miR-101a, after exposure to NP. Additionally, comprehensive analysis of predicted target genes for miRNAs showed that the expression of genes with roles in cell proliferation, the cell cycle, and cell death were regulated by miRNA in NP-treated TM4 cells. Levels of expression of the miRNAs miR-135a* and miR-199a-5p were validated by qRT-PCR. Finally, miR-135a* target gene analysis suggests that the generation of reactive oxygen species (ROS) following exposure to NP exposure may be mediated by miR-135a* through regulation of the Wnt/beta-catenin signaling pathway. Conclusions: Collectively, these data help to determine NP's actions on mouse TM4 Sertoli cells and increase our understanding of the molecular mechanisms underlying the adverse effects of xenoestrogens on the reproductive system.This work was supported an Eco-Technopia 21 project grant from the Ministry of Environment (Development of Decision Method of Chromosomal Abnormality in Reproductive System by Toxic Substances at the Korea Institute of Toxicology)

    Chemoenzymatic Synthesis of Glycosylated Macrolactam Analogues of the Macrolide Antibiotic YC‐17

    Full text link
    YC‐17 is a 12‐membered ring macrolide antibiotic produced from Streptomyces venezuelae ATCC 15439 and is composed of the polyketide macrolactone 10‐deoxymethynolide appended with D‐desosamine. In order to develop structurally diverse macrolactam analogues of YC‐17 with improved therapeutic potential, a combined approach involving chemical synthesis and engineered cell‐based biotransformation was employed. Eight new antibacterial macrolactam analogues of YC‐17 were generated by supplying a novel chemically synthesized macrolactam aglycone to S. venezuelae mutants harboring plasmids capable of synthesizing several unnatural sugars for subsequent glycosylation. Some YC‐17 macrolactam analogues were active against erythromycin‐resistant bacterial pathogens and displayed improved metabolic stability in vitro. The enhanced therapeutic potential demonstrated by these glycosylated macrolactam analogues reveals the unique potential of chemoenzymatic synthesis in antibiotic drug discovery and development.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113147/1/adsc_201500250_sm_miscellaneous_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113147/2/2697_ftp.pd

    Lupus Myocarditis Presenting as Acute Congestive Heart Failure: A Case Report

    Get PDF
    A young woman who had a delivery history 3 months previously presented with dyspnea and orthopnea. Initial findings of physical examination, chest radiography, and echocardiogram showed typical congestive heart failure with severe left ventricular (LV) dysfunction. At first, we considered peripartum cardiomyopathy because she had given birth to a baby 3 months previously. However, even though we massively tried conventional drug therapy for 10 days, the patient still remained with refractory heart failure. We performed additional laboratory studies such as complement level and autoantibodies, of which the results supported systemic lupus erythematosus. We could make the diagnosis of acute lupus myocarditis and treated her with corticosteroid. The symptoms were dramatically disappeared and LV function also improved

    Primary Biliary Lymphoma Mimicking Cholangiocarcinoma: A Characteristic Feature of Discrepant CT and Direct Cholangiography Findings

    Get PDF
    Primary non-Hodgkin's lymphoma arising from the bile duct is extremely rare and the reported imaging features do not differ from those of cholangiocarcinoma of the bile duct. We report a case of a patient with extranodal marginal zone B-cell lymphoma of mucosa associated lymphoid tissue (MALT), who presented with obstructive jaundice and describe the distinctive radiologic features that may suggest the correct preoperative diagnosis of primary lymphoma of the bile duct. Primary MALT lymphoma of the extrahepatic bile duct should be considered in the differential diagnosis when there is a mismatch in imaging findings on computed tomography or magnetic resonance imaging and cholangiography
    corecore