New method for lubricating wind turbine pitch gears using embedded micro-nozzles

Josep Farré-Lladós,Lars G. Westerberg,Jasmina Casals-Terré 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

The increase of power generated by wind turbines has increased the stresses applied in all of its components, thereby causing premature failures. Particularly, pitch and yaw gears suffer from excessive wear mainly caused by inappropriate lubrication. This paper presents a novel method to automatically lubricate the wind turbine pitch gear during operation. A micro-nozzle to inject fresh grease continuously between the teeth in contact was designed, manufactured, and installed in a test bench of a 2 MW wind turbine pitch system. The test bench was used to characterize the fatigue behavior of the gear surface using conventional wind turbine greases under real cyclic loads. Measurements of wear evolution in a pitch gear with and without micro-nozzle show a decrease of 70 % of the wear coefficient after 2×10 4 cycles.

Lacticaseibacillus casei AMBR2 Restores Airway Epithelial Integrity in Chronic Rhinosinusitis With Nasal Polyps

Martens Katleen,De Boeck Ilke,Jokicevic Katarina,Kiekens Filip,Farré Ricard,Vanderveken Olivier M.,Seys Sven F.,Lebeer Sarah,Hellings Peter W.,Steelant Brecht 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.4

Purpose A defective epithelial barrier has been demonstrated in chronic rhinosinusitis with nasal polyps (CRSwNP). Lactobacilli are shown to restore epithelial barrier defects in gastrointestinal disorders, but their effect on the airway epithelial barrier is unknown. In this study, hence, we evaluated whether the nasopharyngeal isolates Lacticaseibacillus casei AMBR2 and Latilactobacillus sakei AMBR8 could restore nasal epithelial barrier integrity in CRSwNP. Methods Ex vivo trans-epithelial tissue resistance and fluorescein isothiocyanate-dextran 4 kDa (FD4) permeability of nasal mucosal explants were measured. The relative abundance of lactobacilli in the maxillary sinus of CRSwNP patients was analyzed by amplicon sequencing of the V4 region of the 16S rRNA gene. The effect of spray-dried L. casei AMBR2 and L. sakei AMBR8 on epithelial integrity was investigated in vitro in primary nasal epithelial cells (pNECs) from healthy controls and patients with CRSwNP as well as in vivo in a murine model of interleukin (IL)-4 induced barrier dysfunction. The activation of Toll-like receptor 2 (TLR2) was explored in vitro by using polyclonal antibodies. Results Patients with CRSwNP had a defective epithelial barrier which positively correlated with the relative abundance of lactobacilli-specific amplicons in the maxillary sinus. L. casei AMBR2, but not L. sakei AMBR8, increased the trans-epithelial electrical resistance (TEER) of pNECs from CRSwNP patients in a time-dependent manner. Treatment of epithelial cells with L. casei AMBR2 promoted the tight junction proteins occludin and zonula occludens-1 reorganization. Furthermore, L. casei AMBR2 prevented IL-4-induced nasal permeability in vivo and in vitro. Finally, the beneficial effect of L. casei AMBR2 on nasal epithelial cells in vitro was TLR2-dependent as blocking TLR2 receptors prevented the increase in TEER. Conclusions A defective epithelial barrier in CRSwNP may be associated with a decrease in relative abundance of lactobacilli-specific amplicons. L. casei AMBR2 would restore nasal epithelial integrity and can be a novel therapeutic strategy for CRSwNP.

Evolution of gene regulation in ruminants differs between evolutionary breakpoint regions and homologous synteny blocks

Farré,, Marta,Kim, Jaebum,Proskuryakova, Anastasia A.,Zhang, Yang,Kulemzina, Anastasia I.,Li, Qiye,Zhou, Yang,Xiong, Yingqi,Johnson, Jennifer L.,Perelman, Polina L.,Johnson, Warren E.,Warren, We Cold Spring Harbor Laboratory Press 2019 Genome research Vol.29 No.4

<P>The role of chromosome rearrangements in driving evolution has been a long-standing question of evolutionary biology. Here we focused on ruminants as a model to assess how rearrangements may have contributed to the evolution of gene regulation. Using reconstructed ancestral karyotypes of Cetartiodactyls, Ruminants, Pecorans, and Bovids, we traced patterns of gross chromosome changes. We found that the lineage leading to the ruminant ancestor after the split from other cetartiodactyls was characterized by mostly intrachromosomal changes, whereas the lineage leading to the pecoran ancestor (including all livestock ruminants) included multiple interchromosomal changes. We observed that the liver cell putative enhancers in the ruminant evolutionary breakpoint regions are highly enriched for DNA sequences under selective constraint acting on lineage-specific transposable elements (TEs) and a set of 25 specific transcription factor (TF) binding motifs associated with recently active TEs. Coupled with gene expression data, we found that genes near ruminant breakpoint regions exhibit more divergent expression profiles among species, particularly in cattle, which is consistent with the phylogenetic origin of these breakpoint regions. This divergence was significantly greater in genes with enhancers that contain at least one of the 25 specific TF binding motifs and located near bovidae-to-cattle lineage breakpoint regions. Taken together, by combining ancestral karyotype reconstructions with analysis of <I>cis</I> regulatory element and gene expression evolution, our work demonstrated that lineage-specific regulatory elements colocalized with gross chromosome rearrangements may have provided valuable functional modifications that helped to shape ruminant evolution.</P>

THE PROBABILISTIC METHOD MEETS GO

Farr, Graham Korean Mathematical Society 2017 대한수학회지 Vol.54 No.4

Go is an ancient game of great complexity and has a huge following in East Asia. It is also very rich mathematically, and can be played on any graph, although it is usually played on a square lattice. As with any game, one of the most fundamental problems is to determine the number of legal positions, or the probability that a random position is legal. A random Go position is generated using a model previously studied by the author, with each vertex being independently Black, White or Uncoloured with probabilities q, q, 1 - 2q respectively. In this paper we consider the probability of legality for two scenarios. Firstly, for an $N{\times}N$ square lattice graph, we show that, with $q=cN^{-{\alpha}}$ and c and ${\alpha}$ constant, as $N{\rightarrow}{\infty}$ the limiting probability of legality is 0, exp($-2c^5$), and 1 according as ${\alpha}$ < 2/5, ${\alpha}=2/5$ and ${\alpha}$ > 2/5 respectively. On the way, we investigate the behaviour of the number of captured chains (or chromons). Secondly, for a random graph on n vertices with edge probability p generated according to the classical $Gilbert-Erd{\ddot{o}}s-R{\acute{e}}nyi$ model ${\mathcal{G}}$(n; p), we classify the main situations according to their asymptotic almost sure legality or illegality. Our results draw on a variety of probabilistic and enumerative methods including linearity of expectation, second moment method, factorial moments, polyomino enumeration, giant components in random graphs, and typicality of random structures. We conclude with suggestions for further work.

THE PROBABILISTIC METHOD MEETS GO

Graham Farr 대한수학회 2017 대한수학회지 Vol.54 No.4

Go is an ancient game of great complexity and has a huge following in East Asia. It is also very rich mathematically, and can be played on any graph, although it is usually played on a square lattice. As with any game, one of the most fundamental problems is to determine the number of legal positions, or the probability that a random position is legal. A random Go position is generated using a model previously studied by the author, with each vertex being independently Black, White or Uncoloured with probabilities $q,q,1-2q$ respectively. In this paper we consider the probability of legality for two scenarios. Firstly, for an $N\times N$ square lattice graph, we show that, with $q=cN^{-\alpha}$ and $c$ and $\alpha$ constant, as $N\rightarrow\infty$ the limiting probability of legality is 0, $\exp(-2c^5)$, and 1 according as $\alpha<2/5$, $\alpha=2/5$ and $\alpha>2/5$ respectively. On the way, we investigate the behaviour of the number of captured chains (or chromons). Secondly, for a random graph on $n$ vertices with edge probability $p$ generated according to the classical Gilbert-Erd\H{o}s-R\'enyi model $\mathcal{G}(n;p)$, we classify the main situations according to their asymptotic almost sure legality or illegality. Our results draw on a variety of probabilistic and enumerative methods including linearity of expectation, second moment method, factorial moments, polyomino enumeration, giant components in random graphs, and typicality of random structures. We conclude with suggestions for further work.

Skeletal Senescence with Aging and Type 2 Diabetes

Joshua Nicholas Farr 대한내분비학회 2023 Endocrinology and metabolism Vol.38 No.3

Osteoporosis and type 2 diabetes (T2D) are common diseases that often coexist. While both of these diseases are associated withpoor bone quality and increased fracture risk, their pathogenesis of increased fracture risk differs and is multifactorial. Mounting evidence now indicates that key fundamental mechanisms that are central to both aging and energy metabolism exist. Importantly, thesemechanisms represent potentially modifiable therapeutic targets for interventions that could prevent or alleviate multiple complications of osteoporosis and T2D, including poor bone quality. One such mechanism that has gained increasing momentum is senescence, which is a cell fate that contributes to multiple chronic diseases. Accumulating evidence has established that numerous boneresident cell types become susceptible to cellular senescence with old age. Recent work also demonstrates that T2D causes the premature accumulation of senescent osteocytes during young adulthood, at least in mice, although it remains to be seen which otherbone-resident cell types become senescent with T2D. Given that therapeutically removing senescent cells can alleviate age-relatedbone loss and T2D-induced metabolic dysfunction, it will be important in future studies to rigorously test whether interventions thateliminate senescent cells can also alleviate skeletal dysfunction in context of T2D, as it does with aging.

Unusual Rhizoidal Development in Bangia (Bangiales, Rhodophyta) -Another Form of Vegetative Reproduction?

Boedeker, Christian,Farr, Tracy J.,Nelson, Wendy A. The Korean Society of Phycology 2007 ALGAE Vol.22 No.1

The gametophytic filaments of two genetically distinct taxa of Bangia from New Zealand showed unusual rhizoidal development in comparative culture experiments. In the past Bangia has been reported to possess simple, colourless rhizoids that extend from the basal cells of the unbranched filaments, whereas in this study the rhizoids observed became pigmented and multicellular. A reversal of growth direction occurred and filamentous extensions developed from the rhizoids under some culture conditions. These extensions were either prostrate or resembled new gametophytic filaments. This is the first report for filamentous members of the Bangiales of the development of such stolon-like rhizoids, apparently serving as a form of vegetative reproduction.

Reconstruction and evolutionary history of eutherian chromosomes

Kim, Jaebum,Farré,, Marta,Auvil, Loretta,Capitanu, Boris,Larkin, Denis M.,Ma, Jian,Lewin, Harris A. National Academy of Sciences 2017 Proceedings of the National Academy of Sciences Vol.114 No.27

<P>Whole-genome assemblies of 19 placental mammals and two outgroup species were used to reconstruct the order and orientation of syntenic fragments in chromosomes of the eutherian ancestor and six other descendant ancestors leading to human. For ancestral chromosome reconstructions, we developed an algorithm (DESCHRAMBLER) that probabilistically determines the adjacencies of syntenic fragments using chromosome-scale and fragmented genome assemblies. The reconstructed chromosomes of the eutherian, boreoeutherian, and euarchontoglires ancestor each included >80% of the entire length of the human genome, whereas reconstructed chromosomes of the most recent common ancestor of simians, catarrhini, great apes, and humans and chimpanzees included >90% of human genome sequence. These high-coverage reconstructions permitted reliable identification of chromosomal rearrangements over similar to 105 My of eutherian evolution. Orangutan was found to have eight chromosomes that were completely conserved in homologous sequence order and orientation with the eutherian ancestor, the largest number for any species. Ruminant artiodactyls had the highest frequency of intrachromosomal rearrangements, and interchromosomal rearrangements dominated in murid rodents. A total of 162 chromosomal breakpoints in evolution of the eutherian ancestral genome to the human genome were identified; however, the rate of rearrangements was significantly lower (0.80/My) during the first similar to 60 My of eutherian evolution, then increased to greater than 2.0/My along the five primate lineages studied. Our results significantly expand knowledge of eutherian genome evolution and will facilitate greater understanding of the role of chromosome rearrangements in adaptation, speciation, and the etiology of inherited and spontaneously occurring diseases.</P>

Chylous ascites following robotic lymph node dissection on a patient with metastatic cervical carcinoma

Enrique Soto,Carlos Soto,Farr R. Nezhat,Herbert F. Gretz,Linus Chuang 대한부인종양학회 2011 Journal of Gynecologic Oncology Vol.22 No.1

Chylous ascites is an uncommon postoperative complication of gynecological surgery. We report a case of chylous ascites following a robotic lymph node dissection for a cervical carcinoma. A 38-year-old woman with IB2 cervical adenocarcinoma with a palpable 3 cm left external iliac lymph node was taken to the operating room for robotic-assisted laparoscopic pelvic and para-aortic lymph node dissection. Patient was discharged on postoperative day 2 after an apparent uncomplicated procedure. The patient was readmitted the hospital on postoperative day 9 with abdominal distention and a CT-scan revealed free fluid in the abdomen and pelvis. A paracentesis demonstrated milky-fluid with an elevated concentration of triglycerides, confirming the diagnosis of chylous ascites. She recovered well with conservative measures. The risk of postoperative chylous ascites following lymph node dissection is still present despite the utilization of new technologies such as the da Vinci robot.

Solution Structure of a Prion Protein: Implications for Infectivity

He Liu,Shauna Farr-Jones,Nikolai Ulyanov,Manuel Llinas,Susan Marqusee,Fred E. Cohen,Stanley B. Prusiner,Thomas L. James 한국자기공명학회 1998 Journal of the Korean Magnetic Resonance Society Vol.2 No.2

Prions cause neurodegenerative diseases in animals and humans. The scrapie prion protein (PrPSc) is the major – possibly only – component of the infectious prion and is generated from the cellular isoform (PrPC) by a conformational change. Limited proteolysis of PrPSc produces a polypeptide comprised primarily of residues 90 to 231, which retains infectivity. The three-dimensional structure of rPrP(90-231), a recombinant protein resembling PrPC with the Syrian hamster (SHa) sequence, was solved using multidimensional NMR. Low-resolution structures of rPrP(90-231), synthetic peptides up to 56 residues, a longer (29-231, full-length) protein with SHa sequence, and a shorter (121-231) protein with the mouse sequence have been previously reported. We report here further structure refinement of rPrP(90-231) and dynamic features of the protein. Consideration of these features in the context of published data suggests regions of conformational heterogeneity, structural elements involved in the PrPC  PrPSc transformation, and possible structural features related to a species barrier to transmission of prion diseases 영어논문