2,972 research outputs found
Industry Career Guide: Construction
This paper is a career guide on the Philippine construction industry. It provides a general overview into the nature and role of construction in the context of the general macroeconomy, highlights its employment-generating capacity and manpower development prospects, and gives jobseekers and other interested parties a peek into the industry’s likely direction in terms of performance and labor market interface within the next short run cycle
Histone Monoubiquitination in Chromatin Remodelling: Focus on the Histone H2B Interactome and Cancer.
Chromatin remodelling is a major mechanism by which cells control fundamental processes including gene expression, the DNA damage response (DDR) and ensuring the genomic plasticity required by stem cells to enable differentiation. The post-translational modification of histone H2B resulting in addition of a single ubiquitin, in humans at lysine 120 (K120; H2Bub1) and in yeast at K123, has key roles in transcriptional elongation associated with the RNA polymerase II-associated factor 1 complex (PAF1C) and in the DDR. H2Bub1 itself has been described as having tumour suppressive roles and a number of cancer-related proteins and/or complexes are recognised as part of the H2Bub1 interactome. These include the RING finger E3 ubiquitin ligases RNF20, RNF40 and BRCA1, the guardian of the genome p53, the PAF1C member CDC73, subunits of the switch/sucrose non-fermenting (SWI/SNF) chromatin remodelling complex and histone methyltransferase complexes DOT1L and COMPASS, as well as multiple deubiquitinases including USP22 and USP44. While globally depleted in many primary human malignancies, including breast, lung and colorectal cancer, H2Bub1 is selectively enriched at the coding region of certain highly expressed genes, including at p53 target genes in response to DNA damage, functioning to exercise transcriptional control of these loci. This review draws together extensive literature to cement a significant role for H2Bub1 in a range of human malignancies and discusses the interplay between key cancer-related proteins and H2Bub1-associated chromatin remodelling
Differential Induction of Long-Term Potentiation in the Horizontal versus Columnar Superficial Connections to Layer II Cells of the Entorhinal Cortex
The entorhinal cortex (EC) is a nodal and independent mnemonic element of the medial temporal lobe memory circuit as it forms a bidirectional interface between the neocortex and hippocampus. Within the EC, intra- and inter-lamellar associational connections occur via horizontal and columnar projections, respectively. We undertook a comparative study of these two inputs as they converge upon EC layer II cells using whole-cell patch techniques in an adult rat EC horizontal slice preparation in which the deepest layers (V-VI) had been dissected out. Electrical stimulation of layers I and III during GABA blockade allowed us to study excitatory synaptic properties and plasticity in the horizontal and columnar fibre systems, respectively. Both pathways exhibited AMPA- and NMDA-receptor mediated transmission and both exhibited long-term potentiation (LTP) after high-frequency (tetanic) stimulation. LTP in the horizontal, but not in the columnar pathway, was blocked by NMDA receptor antagonism. Intriguingly, LTP in both appeared to be mediated by post synaptic increases in Ca2+ that may be coupled to differing second messenger pathways. Thus, the superficial excitatory horizontal and columnar associative pathways to layer II have divergent mechanisms for LTP which may endow the EC with even more complex and dynamic processing characteristics than previously thought
The Algebro-Geometric Solutions for the Ruijsenaars-Toda Hierarchy
We provide a detailed treatment of Ruijsenaars-Toda (RT) hierarchy with
special emphasis on its the theta function representation of all
algebro-geometric solutions. The basic tools involve hyperelliptic curve
associated with the Burchnall-Chaundy polynomial, Dubrovin-type
equations for auxiliary divisors and associated trace formulas. With the help
of a foundamental meromorphic function , Baker-Akhiezer vector on
, the complex-valued algebro-geometric solutions of RT hierarchy
are derived.Comment: 49 pages. arXiv admin note: substantial text overlap with
arXiv:nlin/0702058, arXiv:nlin/0611055 by other author
PARP Inhibitors Display Differential Efficacy in Models of BRCA Mutant High-Grade Serous Ovarian Cancer
Several poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors are now in clinical use for tumours with defects in BReast CAncer genes BRCA1 or BRCA2 that result in deficient homologous recombination repair (HRR). Use of olaparib, niraparib or rucaparib for the treatment of high-grade serous ovarian cancer, including in the maintenance setting, has extended both progression free and overall survival for women with this malignancy. While different PARP inhibitors (PARPis) are mechanistically similar, differences are apparent in their chemical structures, toxicity profiles, PARP trapping abilities and polypharmacological landscapes. We have treated ovarian cancer cell line models of known BRCA status, including the paired cell lines PEO1 and PEO4, and UWB1.289 and UWB1.289+BRCA1, with five PARPis (olaparib, niraparib, rucaparib, talazoparib and veliparib) and observed differences between PARPis in both cell viability and cell survival. A cell line model of acquired resistance to veliparib showed increased resistance to the other four PARPis tested, suggesting that acquired resistance to one PARPi may not be able to be rescued by another. Lastly, as a proof of principle, HRR proficient ovarian cancer cells were sensitised to PARPis by depletion of BRCA1. In the future, guidelines will need to emerge to assist clinicians in matching specific PARPis to specific patients and tumours.</jats:p
Three-Dimensional Modelling of Ovarian Cancer: From Cell Lines to Organoids for Discovery and Personalized Medicine
Ovarian cancer has the highest mortality of all of the gynecological malignancies. There are several distinct histotypes of this malignancy characterized by specific molecular events and clinical behavior. These histotypes have differing responses to platinum-based drugs that have been the mainstay of therapy for ovarian cancer for decades. For histotypes that initially respond to a chemotherapeutic regime of carboplatin and paclitaxel such as high-grade serous ovarian cancer, the development of chemoresistance is common and underpins incurable disease. Recent discoveries have led to the clinical use of PARP (poly ADP ribose polymerase) inhibitors for ovarian cancers defective in homologous recombination repair, as well as the anti-angiogenic bevacizumab. While predictive molecular testing involving identification of a genomic scar and/or the presence of germline or somatic BRCA1 or BRCA2 mutation are in clinical use to inform the likely success of a PARP inhibitor, no similar tests are available to identify women likely to respond to bevacizumab. Functional tests to predict patient response to any drug are, in fact, essentially absent from clinical care. New drugs are needed to treat ovarian cancer. In this review, we discuss applications to address the currently unmet need of developing physiologically relevant in vitro and ex vivo models of ovarian cancer for fundamental discovery science, and personalized medicine approaches. Traditional two-dimensional (2D) in vitro cell culture of ovarian cancer lacks critical cell-to-cell interactions afforded by culture in three-dimensions. Additionally, modelling interactions with the tumor microenvironment, including the surface of organs in the peritoneal cavity that support metastatic growth of ovarian cancer, will improve the power of these models. Being able to reliably grow primary tumoroid cultures of ovarian cancer will improve the ability to recapitulate tumor heterogeneity. Three-dimensional (3D) modelling systems, from cell lines to organoid or tumoroid cultures, represent enhanced starting points from which improved translational outcomes for women with ovarian cancer will emerge.</jats:p
Bioinspired design of a landing system with soft shock absorbers for autonomous aerial robots
© 2018 Wiley Periodicals Inc. One of the main challenges for autonomous aerial robots is to land safely on a target position on varied surface structures in real-world applications. Most of current aerial robots (especially multirotors) use only rigid landing gears, which limit the adaptability to environments and can cause damage to the sensitive cameras and other electronics onboard. This paper presents a bioinpsired landing system for autonomous aerial robots, built on the inspire–abstract–implement design paradigm and an additive manufacturing process for soft thermoplastic materials. This novel landing system consists of 3D printable Sarrus shock absorbers and soft landing pads which are integrated with an one-degree-of-freedom actuation mechanism. Both designs of the Sarrus shock absorber and the soft landing pad are analyzed via finite element analysis, and are characterized with dynamic mechanical measurements. The landing system with 3D printed soft components is characterized by completing landing tests on flat, convex, and concave steel structures and grassy field in a total of 60 times at different speeds between 1 and 2 m/s. The adaptability and shock absorption capacity of the proposed landing system is then evaluated and benchmarked against rigid legs. It reveals that the system is able to adapt to varied surface structures and reduce impact force by 540N at maximum. The bioinspired landing strategy presented in this paper opens a promising avenue in Aerial Biorobotics, where a cross-disciplinary approach in vehicle control and navigation is combined with soft technologies, enabled with adaptive morphology
Development of an in vitro periodontal biofilm model for assessing antimicrobial and host modulatory effects of bioactive molecules
Background:
Inflammation within the oral cavity occurs due to dysregulation between microbial biofilms and the host response. Understanding how different oral hygiene products influence inflammatory properties is important for the development of new products. Therefore, creation of a robust host-pathogen biofilm platform capable of evaluating novel oral healthcare compounds is an attractive option. We therefore devised a multi-species biofilm co-culture model to evaluate the naturally derived polyphenol resveratrol (RSV) and gold standard chlorhexidine (CHX) with respect to anti-biofilm and anti-inflammatory properties.<p></p>
Methods:
An in vitro multi-species biofilm containing <i>S. mitis, F. nucleatum, P. Gingivalis</i> and <i>A. Actinomycetemcomitans</i> was created to represent a disease-associated biofilm and the oral epithelial cell in OKF6-TERT2. Cytotoxicity studies were performed using RSV and CHX. Multi-species biofilms were either treated with either molecule, or alternatively epithelial cells were treated with these prior to biofilm co-culture. Biofilm composition was evaluated and inflammatory responses quantified at a transcriptional and protein level.<p></p>
Results:
CHX was toxic to epithelial cells and multi-species biofilms at concentrations ranging from 0.01-0.2%. RSV did not effect multi-species biofilm composition, but was toxic to epithelial cells at concentrations greater than 0.01%. In co-culture, CHX-treated biofilms resulted in down regulation of the inflammatory chemokine IL-8 at both mRNA and protein level. RSV-treated epithelial cells in co-culture were down-regulated in the release of IL-8 protein, but not mRNA.<p></p>
Conclusions:
CHX possesses potent bactericidal properties, which may impact downstream inflammatory mediators. RSV does not appear to have bactericidal properties against multi-species biofilms, however it did appear to supress epithelial cells from releasing inflammatory mediators. This study demonstrates the potential to understand the mechanisms by which different oral hygiene products may influence gingival inflammation, thereby validating the use of a biofilm co-culture model.<p></p>
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