Multiscale Mechanobiology of Primary Cilia

Mechanosensation, the ability for cells to sense and respond to physical cues, is a ubiquitous process among living organisms and its dysfunction can lead to devastating diseases, including atherosclerosis, osteoporosis, and cancer. The primary cilium is a solitary, immotile organelle that projects from the surface of virtually every cell in the human body and can function as a mechanosensor across diverse biological contexts, deflecting in response to fluid flow, pressure, touch and vibration. It can detect urinary flow rate in the kidney, monitor bile flow in the liver, and distinguish the direction of nodal flow in embryos. In this thesis, we examined the interplay of biology and mechanics in the context of this multifunctional sensory organelle from the tissue to subcellular scale. In the first part of this work, we examined the cilium at the tissue level. Primary cilia are just beginning to be appreciated in bone with studies recently reporting loss of cilia results in defects in skeletal development and adaptation. We disrupted primary cilia in osteocytes, the principal mechanosensing cells in bone, and demonstrated that loss of primary cilia in osteocytes impairs load-induced bone formation. Over the course of our work with primary cilia, we also identified the need for more standardized imaging approaches to the cilium and presented an improvement to distinguishing proteins within the cilium from the rest of the cell. In the later part of this work, we examined the primary cilium at the subcellular level. While deflection is integral to the cilium's mechanosensory function, it remains poorly understood and characterized. Using a novel experimental and computational approach to capture and determine the mechanical properties of the cilium, we demonstrated cilium deflection can be mechanically and chemically modulated. We revealed a mechanism, acetylation, through which this mechanosensor can adapt and regulate overall cellular mechanosensing. By modifying our combined experimental and computational approach, we analyzed cilium deflection in vivo for the first time. Collectively, this work uncovers new insights across biological scales in the primary cilium as an extracellular nexus integrating mechanical stimuli and cellular signaling. Understanding the mechanisms driving cilium mechanosensing has broad reaching implications and unlocks the cilium's potential as a therapeutic target to treat impaired cellular mechanosensing critical to a multitude of diseases

CONCEPTS AND AWARENESS ABOUT SELF-HARM AND SUICIDAL THOUGHTS AMONG HIGH SCHOOL STUDENTS CURRENTLY

The article focuses on understanding concepts and awareness of suicidal thoughts and self – harm behaviors based on quantitative and qualitative data. The quantitative database will be taken from a survey of high school students living and studying in Ho Chi Minh City. The qualitative database is taken from in-depth interviews focusing on teachers, parents, and students. The article presents the main results of the research. First, focus on the research basis including subjects, objects, and research methodology. Second, include views on suicidal thoughts and self-harm from many different perspectives, manifestations and causes of these behaviors, the prevalence of self-harm/suicidal thoughts, and consequences. Third, conclude and propose some recommendations to minimize the problem

Numerical simulation of discharge plasma generation and nitriding the metals and alloys

This research provides the numerical simulation of the plasma generation in a hollow cathode as well as the diffusion of nitrogen atoms into the metal in the low-pressure glow discharge plasma. The characteristics of the gas discharge were obtained and the relation of the basic technological parameters and the structural and phase state of the nitrided material were defined. Authors provided the comparison of calculations with the experimental results of titanium nitriding by low-pressure glow discharge plasma in a hollow cathode

"Limb-body-Wall complex" et exposition anténatale à l’ alcool - à propos de deux cas

Le "Limb-Body-Wall complex" est une association malformative rare décrite pour la première fois en 1987 par Van Allen. Sa cause n'est pas encore connue à ce jour. L'hypothèse de l'existence de facteurs génétiques et environnementaux (alcool) associés à ces phénotypes a été évoquée dans la littérature. Nous décrivons deux phénotypes de cette association malformative complexe, diagnostiquée chez des nouveau-nés à terme. Les mères des deux propositus ont reconnu avoir consommé de l'alcool régulièrement durant leur grossesse. Il s'agit des premiers cas Congolais rapportés dans la littérature.Key words: Limb-body-Wall complexe, placento-crânienne, placento-abdominale, alcoo

Alliance Catering at Deakin: the Economics of University Cafeterias

University cafeterias are a common and crucial component of university life as they provide cheap and convenient meals for students. Ideally, university cafeterias should also be responsible for providing nutritious food at reasonable prices. In practice though, university cafeterias often provide less nutritious food and at high prices. One reason for why this may happen is that cafeterias are aware of their unique market power. For instance, students consider the opportunity and transportation costs in the price they are willing to pay for on-campus services. The costs of preparing meals at home or walking to the alternatives are high, as students may prefer to use the time for studying or socializing. Thus, for a variety of reasons, university cafeterias become more practical in their delivery of services by placing less concern on the health quality of products and the fairness of prices. In this paper, we study the market power of university cafeterias specifically due to a locational advantage by analysing the case of the Alliance Cafeteria operating in Buildings La and Lb at Deakin University’s Burwood campus in Melbourne. We begin by examining Alliance as a monopolistically competitive firm and assess how its location gives market power

Chemical composition and antibacterial activities of the ethanol extracts from the leaves and tubers of Amorphophallus pusillus

Amorphophallus pusillus is a rare species which is found only in Binh Chau-Phuoc Buu Nature Reserve. In this study, we determined 7 flavonoid compounds in tuber and leaf of A. pusillus, including of vitexin, orientin, vitexin 2?-O-glucoside, cyanidin 3-O-rutinoside, pelargonidin 3-O-glucoside, schaftoside, and peonidin 3-O-rutinoside via liquid chromatography-mass spectrometry (LC-MS). Furthermore, we have proved the antibacterial activities of ethanol extracts obtained from A. pusillus leaves and tubers in the first time. The data revealed that ethanol extracts could inhibit the growth of 6 tested microorganisms, such as Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enteritidis, Salmonella typhimurium, and Staphylococcus aureus. These data suggested the potential application of ethanol extracts isolated from this species as natural antimicrobial agents for treatment of infection caused by bacteria, especially in dermatologic and enteric infections

Nitriding of steel 40x with a high-intensity ion beam

The results of experimental and theoretical studies of the regularities and features of the modification of steel 40X with high-intensity beams of low-energy nitrogen ions are provided. The study of the effect of high-intensity, ultra-high-fluency implantation of low-energy nitrogen ions at temperatures of steel 40X samples in the range of 450-650 °C are presented. It is established, that the width of the nitrided layer, during 60 minutes, depends both on the temperature implantation regime and on the ion current density, the maximum depth of nitrogen penetration of 180 ?m was observed at a target treatment temperature of 500 °C. The results of numerical simulation agree with the experiments and allow predicting the structure of surface layers when the geometry of the system and parameters of a high-intensity low-energy beam of nitrogen ions change

Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence

Bis-(3 ',5 ') cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (K-d similar to 2 mu M). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence

Determinants Influencing Entrepreneurial Intention in Hanoi, Vietnam

This research employed survey data from 204 students between two groups of  economics and technical majors in Hanoi city for assessing the impact levels of determinants on entrepreneurial intention. The results show that a number of determinants including Need for achievement, Self-efficacy, and Instrumental readiness have positive impacts on student’s entrepreneurial intention. Besides, this study is also to create a basis for  comparative students among different economics and technical majors, work exoperience, and gender. These findings are the basis to recommend policies and solutions to promote entrepreneurship movement in Vietnam. Keywords: Entrepreneurial intention, need for achievement, self-efficacy, instrumental readiness. DOI: 10.7176/EJBM/12-15-10 Publication date:May 31st 2020