On the correspondence of external rays under renormalization

Let $P$ be a monic polynomial of degree $D \geq 3$ whose filled Julia set $K_P$ has a non-degenerate periodic component $K$ of period $k \geq 1$ and renormalization degree $2 \leq d<D$. Let $I=I_K$ denote the set of angles $\theta$ on the circle ${\mathbb T}={\mathbb R}/{\mathbb Z}$ for which the (smooth or broken) external ray $R^P_\theta$ for $P$ accumulates on $\partial K$. We prove the following: $\bullet$ $I$ is a compact set of Hausdorff dimension $<1$ and there is an essentially unique degree $1$ monotone map $\Pi: I \to {\mathbb T}$ which semiconjugates $\theta \mapsto D^k \theta$ (mod 1) on $I$ to $\theta \mapsto d \theta$ (mod 1) on $\mathbb T$. $\bullet$ Any hybrid conjugacy $\varphi$ between a renormalization of $P^{\circ k}$ on a neighborhood of $K$ and a monic degree $d$ polynomial $Q$ induces a semiconjugacy $\Pi: I \to {\mathbb T}$ with the property that for every $\theta \in I$ the external ray $R^P_\theta$ has the same accumulation set as the curve $\varphi^{-1}(R^Q_{\Pi(\theta)})$. In particular, $R^P_\theta$ lands at $z \in \partial K$ if and only if $R^Q_{\Pi(\theta)}$ lands at $\varphi(z) \in \partial K_Q$. $\bullet$ The ray correspondence established by the above result is finite-to-one. In fact, the cardinality of each fiber of $\Pi$ is $\leq D-d+2$, and the inequality is strict when the component $K$ has period $k=1$. Using a new type of quasiconformal surgery we construct a class of examples with $k=1$ for which the upper bound $D-d+1$ is realized and the set $I$ has isolated points.Comment: 43 pages, 9 figure

AmpliTaq DNA polymerase, FS dye-terminator sequencing: Analysis of peak height patterns

Taq DNA polymerases in which the phenylalanine is substituted by a tyrosine at position 667 (Taq F667Y) are members of a new class of DNA polymerases that incorporate chain-terminating dideoxyribonucleoside triphosphates (ddNTPs) much more efficiently than the wild-type Taq DNA polymerase. Improved incorporation of ddNTPs into DNA during cycle sequencing using AmpliTaq DNA polymerase, FS (Taq-FS, a member of the Taq F667Y family), and dye-labeled primers results in nearly uniform peak heights in the sequencing trace. This is not the case when dye-labeled ddNTPs are used in Taq-FS cycle sequencing reactions. While the rate of dye-terminator incorporation is more efficient with Taq-FS, the peak pattern is still highly variable and different from that produced by the wild-type enzyme. We have systematically examined pairs of sequence-tagged sites that vary at only a single nucleotide to determine how base changes influence the peak heights of neighboring bases in sequencing traces generated by the Taq-FS dye-terminator chemistry. In 31 of 64 possible 3-base windows (48%), we find that the peak height of a particular base can be predicted by knowing just one or two bases 5\u27 to the base in question. We have also compared and contrasted the peak patterns produced by the Taq-FS enzyme with those previously identified for the wild-type enzyme. Establishing the patterns in peak heights within local sequence contexts can improve the accuracy of base-calling and the identification of polymorphisms/mutations when using the Taq-FS dye-terminator cycle-sequencing chemistry

Derailment risk and dynamics of railway vehicles in curved tracks: Analysis of the effect of failed fasteners

[EN] The effect of the fastener s failure in a railway track on the dynamic forces produced in the wheel-rail contact is studied using the simulation software VAMPIRE to assess the derailment risk of two different vehicles in two curves with distinct characteristics. First, a 3D-FEM model of a real track is constructed, paying special attention to fasteners, and calibrated with displacement data obtained experimentally during a train passage. This numerical model is subsequently used to determine the track vertical and lateral stiffness. This study evidences that although the track can practically lose its lateral stiffness as a consequence of the failure of 7 consecutive fasteners, the vehicle stability would not be necessarily compromised in the flawed zone. Moreover, the results reveal that the uncompensated acceleration and the distance along which the fasteners are failed play an important role in the dynamic behavior of the vehicle-track system, influencing strongly the risk of derailmentMorales-Ivorra, S.; Real Herráiz, JI.; Hernández Gracia, C.; Montalbán-Domingo, L. (2016). Derailment risk and dynamics of railway vehicles in curved tracks: Analysis of the effect of failed fasteners. Journal of Modern Transportation. 24(1):38-47. doi:10.1007/s40534-015-0093-zS3847241Iwnicki S (2006) Handbook of railway vehicle dynamics.CRC Press, Boca RatónJin XS, Wen ZF, Wang KY, Zhou ZR, Liu QY, Li CH (2006) Three-dimensional train-track model for study of rail corrugation. J Sound Vib 293:830–855Jin X, Wen Z, Xiao X (2007) A numerical method for prediction of curved rail wear. Multibody Sys Dyn 18:531–557Li W, Xiao G, Wen Z, Xiao X, Jin X (2011) Plastic deformation of curved rail at rail weld caused by train-track dynamic interaction. Wear 271:311–318Jin X, Wen Z (2008) Effect of discrete track support by sleepers on rail corrugation at a curved track. J Sound Vib 315:279–300Di Gialleonardo E, Bruni S, True H (2014) Analysis of the nonlinear dynamics of a 2-axle freight wagon in curves. Veh Syst Dyn 52(1):125–141Wang K, Liu P (2012) Lateral stability analysis of heavy-haul vehicle on curved track based on wheel/rail coupled dynamics. J Transp Technol 2:150–157Kurzeck B, Hecht M (2010) Dynamic simulation of friction-induced vibrations in a light railway bogie while curving compared with measurement results. Veh Syst Dyn 48:121–138Chen P, Gao L, Hao J (2007) Simulation study on parameters influencing wheel/rail wear in railway curve. China Railway Science 5Sun Y, Cole C, Boyd P (2011) A numerical method using VAMPIRE modelling for prediction of turnout curve wheel-rail wear. Wear 271(1–2):482–491Brabie D (2007) On derailment-worthiness in railway vehicle design. Analysis of vehicle features influencing derailment processes and consequences, PhD Thesis, Royal Institute of Technology, StockholmMatsumoto A, Sato Y, Ohno H, Shimizu M, Kurihara J, Saitou T, Michitsuji Y, Matsui R, Tanimoto M, Mizuno M (2014) Actual states of wheel/rail contact forces and friction on sharp curves—continuous monitoring from in-service trains and numerical simulations. Wear 314:189–197Wang L, Huang A, Liu G (2013) Analysis on curve negotiation ability of the rail vehicle based on SIMPACK. Adv Mater Res 721:551–555Eom BG, Lee H (2010) Assessment of running safety of railway vehicles using multibody dynamics. Int J Precis Eng Manuf 11(2):315–320Zhou L, Shen Z (2013) Dynamic analysis of a high-speed train operating on a curved track with failed fasteners. J Zhejiang Univ Sci A 14(6):447–458Xiao X, Jin X, Wen Z (2007) Effect of disabled fastening systems and ballast on vehicle derailment. J Vib Acoust 129:217–229Shi W, Cai C (2011) Influence of slab track fastener failure on track dynamic performance. In: Advances in environmental vibration-proceedings of the 5th international symposium on environmental vibration, Chengdu, pp 686–692Xiao X, Jin X, Deng Y, Zhou Z (2008) Effect of curved track support failure on vehicle derailment. Veh Syst Dyn 46(11):1029–1059Zakeri J, Fakhari M, Mirfattahi B (2012) Lateral resistance of railway track with frictional sleepers. Proc Inst Civ Eng Transp 165(2):151–155Gibert X, Patel V, Chellappa R (2015) Robust fastener detection for autonomous visual railway track inspection. In: IEEE Winter Conference on Applications of Computer Vision, Waikoloa Beach Hawai, pp 694–701Thompson D, Hemsworth B, Vincent N (1996) Experimental validation of the TWINS prediction program for rolling noise, part 1: description of the model and method. J Sound Vib 193(1):123–135Zakeri JA (2012) Lateral resistance of railway track. In: Perpinya DX (ed) Reliability and safety in railway. InTech Europe, Rijeka, pp 357–374Kernes RG, Edwards JR, Dersh MS, Lange DA, Barkan CP (2011) Investigation of the dynamic frictional properties of a concrete crosstie rail seat and pad and its effect on rail seat deterioration (RSD). Transportation Research Board 91st annual meeting. Railtec, Chicago, IllinoisCarrascal-Vaquero I (2006) Optimization and analysis of the behavior of fastener systems for Spanish high-speed railways. PhD Thesis, University of Cantabria, Santander (In Spanish)Sany J (1996) Another look at the single wheel derailment criteria. In: Proceedings of the IEEE/ASME Joint Railroad Conference, pp 17–22Koo J, Oh H (2014) A new derailment coefficient considering dynamic and geometrical effects of a single wheelset. J Mech Sci Technol 28(9):3483–3498UIC-Leaflet-518 (2009) Testing and approval of railway vehicles from the point of view of their dynamic behaviour-safety-track fatigue-ride quality. Railway Technical Publications, ParisUNE-EN14363:2007 (2007) Railway applications—testing for the acceptance of running characteristics of railway vehicles—testing of running behaviour and stationary tests. AENOR, Madri

Monocyte dysfunction in decompensated cirrhosis is mediated by the prostaglandin E2-EP4 pathway

Background & Aims: Infection is a major problem in advanced liver disease secondary to monocyte dysfunction. Elevated prostaglandin (PG)E2 is a mediator of monocyte dysfunction in cirrhosis; thus, we examined PGE2 signalling in outpatients with ascites and in patients hospitalised with acute decompensation to identify potential therapeutic targets aimed at improving monocyte dysfunction. Methods: Using samples from 11 outpatients with ascites and 28 patients hospitalised with decompensated cirrhosis, we assayed plasma levels of PGE2 and lipopolysaccharide (LPS); performed quantitative real-time PCR on monocytes; and examined peripheral blood monocyte function. We performed western blotting and immunohistochemistry for PG biosynthetic machinery expression in liver tissue. Finally, we investigated the effect of PGE2 antagonists in whole blood using polychromatic flow cytometry and cytokine production. Results: We show that hepatic production of PGE2 via the cyclo-oxygenase 1–microsomal PGE synthase 1 pathway, and circulating monocytes contributes to increased plasma PGE2 in decompensated cirrhosis. Transjugular intrahepatic sampling did not reveal whether hepatic or monocytic production was larger. Blood monocyte numbers increased, whereas individual monocyte function decreased as patients progressed from outpatients with ascites to patients hospitalised with acute decompensation, as assessed by Human Leukocyte Antigen (HLA)–DR isotype expression and tumour necrosis factor alpha and IL6 production. PGE2 mediated this dysfunction via its EP4 receptor. Conclusions: PGE2 mediates monocyte dysfunction in decompensated cirrhosis via its EP4 receptor and dysfunction was worse in hospitalised patients compared with outpatients with ascites. Our study identifies a potential drug target and therapeutic opportunity in these outpatients with ascites to reverse this process to prevent infection and hospital admission. Lay summary: Patients with decompensated cirrhosis (jaundice, fluid build-up, confusion, and vomiting blood) have high infection rates that lead to high mortality rates. A white blood cell subset, monocytes, function poorly in these patients, which is a key factor underlying their sensitivity to infection. We show that monocyte dysfunction in decompensated cirrhosis is mediated by a lipid hormone in the blood, prostaglandin E2, which is present at elevated levels, via its EP4 pathway. This dysfunction worsens when patients are hospitalised with complications of cirrhosis compared with those in the outpatients setting, which supports the EP4 pathway as a potential therapeutic target for patients to prevent infection and hospitalisation

Salmonella Pathogenesis and Processing of Secreted Effectors by Caspase-3

The enteric pathogen Salmonella enterica serovar Typhimurium causes food poisoning resulting in gastroenteritis. The S. Typhimurium effector Salmonella invasion protein A (SipA) promotes gastroenteritis by functional motifs that trigger either mechanisms of inflammation or bacterial entry. During infection of intestinal epithelial cells, SipA was found to be responsible for the early activation of caspase-3, an enzyme that is required for SipA cleavage at a specific recognition motif that divided the protein into its two functional domains and activated SipA in a manner necessary for pathogenicity. Other caspase-3 cleavage sites identified in S. Typhimurium appeared to be restricted to secreted effector proteins, which indicates that this may be a general strategy used by this pathogen for processing of its secreted effectors

Use of quercetin in animal feed : effects on the P-gp expression and pharmacokinetics of orally administrated enrofloxacin in chicken

Modulation of P-glycoprotein (P-gp, encoded by Mdr1) by xenobiotics plays central role in pharmacokinetics of various drugs. Quercetin has a potential to modulate P-gp in rodents, however, its effects on P-gp modulation in chicken are still unclear. Herein, study reports role of quercetin in modulation of P-gp expression and subsequent effects on the pharmacokinetics of enrofloxacin in broilers. Results show that P-gp expression was increased in a dose-dependent manner following exposure to quercetin in Caco-2 cells and tissues of chicken. Absorption rate constant and apparent permeability coefficient of rhodamine 123 were decreased, reflecting efflux function of P-gp in chicken intestine increased by quercetin. Quercetin altered pharmacokinetic of enrofloxacin by decreasing area under curve, peak concentration, and time to reach peak concentration and by increasing clearance rate. Molecular docking shows quercetin can form favorable interactions with binding pocket of chicken xenobiotic receptor (CXR). Results provide convincing evidence that quercetin induced P-gp expression in tissues by possible interaction with CXR, and consequently reducing bioavailability of orally administered enrofloxacin through restricting its intestinal absorption and liver/kidney clearance in broilers. The results can be further extended to guide reasonable use of quercetin to avoid drug-feed interaction occurred with co-administered enrofloxacin or other similar antimicrobials.Peer reviewedFinal Published versio

Merozoite surface protein-3α is a reliable marker for population genetic analysis of Plasmodium vivax

BACKGROUND: The knowledge on population structure of the parasite isolates has contributed greatly to understanding the dynamics of the disease transmission for designing and evaluating malaria vaccines as well as for drug applications. msp-1 and msp-3α genes have been used as a genetic marker in population studies of Plasmodium vivax isolates. In this study, msp-3α was compared and assessed with msp-1 marker in order to find whether msp-3α is a reliable genetic marker for P. vivax population studies. METHODS: This comparative study was designed and carried out as the first assessment of diversity in Pvmsp-3α gene by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in the 50 northern and 94 southern P. vivax isolates from Iran, which had been analysed before for msp-1 gene. RESULTS: Three allele size as, Type A (1.8 kb), Type B (1.5 kb) and Type C (1.2 kb) have been detected among both northern and southern isolates based on PCR results. Type C (70%) and Type A (68.7%) were the predominant fragments among northern and southern parasites, respectively. 99 distinct Pvmsp-3α fragments defined by the size were detected in the 94 southern samples by PCR analysis. However, no mixed genotype infections have been detected among northern isolates. Based on restriction pattern from digestion with Hha I and Alu I 12 and 49 distinct allelic variants have been detected among 50 northern and 94 southern isolates. However, based on msp-1 gene, 30 distinct variants identified in all 146-sequenced Iranian P. vivax isolate. CONCLUSION: The results suggested that PCR-RFLP on msp-3α gene is an adequate, applicable and easily used technique for molecular epidemiology studies of P. vivax isolates without the need for further sequencing analysis

Seawater air-conditioning and ammonia district cooling: A solution for warm coastal regions

The world switching to more sustainable energy sources to curb CO2 emissions and haul climate change. One sector expected to see rapid growth in energy consumption is the cooling sector due to population growth and climate change. A sustainable solution for cooling needs in coastal areas that are not often addressed is seawater air-conditioning, which pumps cold water from the deep sea to the shore and uses it for cooling. The main challenge for this technology is to distribute the cooling service. This paper proposes using pressurized ammonia to distribute the cooling services provided by SWAC plants. Results show that ammonia district cooling allows SWAC to significantly increase its load demand and lower cooling costs. Ammonia district cooling could be the missing piece for implementing seawater air-conditioning due to its potential to increase the cooling load of district cooling systems