bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of different orthodontic retention protocols on the periodontal health of mandibular incisors
Authors: Rody W. J. , Elmaraghy S. , McNeight A. M. , Chamberlain C. A. , Antal D. , Dolce C. , Wheeler T. T. , McGorray S. P. , Shaddox L. M.
Published: September 2016

Structured Abstract

Objectives

To test the following two hypotheses: 1) different types of retainers result in distinct levels of biomarkers in gingival crevicular fluid (GCF) and 2) the retainer bonded to all mandibular anterior teeth induces more detrimental outcomes to the periodontium.

Setting and Sample Population

The Department of Orthodontics at the University of Florida. The population consisted of individuals in the retention phase of orthodontic treatment.

Material and Methods

This was a cross‐sectional study that enrolled 36 individuals. Subjects in group 1 had retainers bonded to the mandibular canines only. Group 2 consisted of individuals having retainers bonded to all mandibular anterior teeth. Group 3 included patients using mandibular removable retainers. After clinical examination, GCF was collected from the mandibular incisor and biomarker levels were compared between the groups.

Results

Plaque accumulation and gingivitis differed significantly among groups, with the highest median values in group 2 subjects. Pairwise comparison of the groups with respect to gingivitis showed significant differences between groups 1 and 2. Significant differences among groups were detected for RANKL, OPG, OPN, M‐CSF, MMP‐3, and MMP‐9. The ratio RANKL/OPG was significantly higher in group 2 subjects, with pairwise comparisons indicating that groups 1 and 2 differed from group 3.

Conclusion

An association was found between orthodontic retention groups and GCF biomarker levels, which should be further explored in longitudinal studies. The presence of retainers bonded to all anterior teeth seems to increase plaque accumulation and gingivitis.
The Roots of Patriotism Across Political Contexts
Authors: Wolak Jennifer , Dawkins Ryan
Published: September 2016

Why do some Americans feel more patriotic than others? We argue that feelings of national pride are reinforced by cues from people's political and social environments. When Americans reside in contexts that align with their values, traits, and civic orientations, they are more likely to express pride in their country. We consider both civic and ethnic pathways to patriotism. We expect that minorities and those who particularly value political equality will feel increasingly patriotic as the racial and ethnic diversity of their state climbs. For those who see politics through a partisan lens, we expect that environments defined by political competition will enhance feelings of national pride. We test our theory using data from the 2012 American National Election Studies (ANES). We find that Americans are more likely to say that they feel love for their country when they reside in political contexts congruent with their values and approach to citizenship.
The effects of canthaxanthin on porcine oocyte maturation and embryo development in vitro after parthenogenetic activation and somatic cell nuclear transfer
Authors: Taweechaipaisankul A , Jin JX , Lee S , Kim GA , Lee BC
Published: September 2016

Contents

The objective of this study was to examine the effects of canthaxanthin (Cx) treatment during in vitro maturation (IVM) of porcine oocytes on embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT), on intracellular glutathione (GSH) and reactive oxygen species (ROS) levels in mature oocytes, and on gene expression in both PA‐ and SCNT‐derived blastocysts. To determine the optimal effective concentration of Cx, porcine oocytes were cultured in IVM medium supplemented with various concentrations (0, 20, 40 and 80 μM) of Cx for 22 hr. Compared to other groups, supplementation with 40 μM Cx significantly improved blastocyst formation rates after PA (p < .05), but no significant differences were observed among groups in total blastocyst cell numbers. Subsequently, oocytes were cultured in IVM medium supplemented with or without 40 μM Cx. Oocytes treated with 40 μM Cx showed significantly increased cleavage and blastocyst formation rates after SCNT compared to the control group (p < .05). Moreover, significantly increased intracellular GSH and reduced ROS levels were observed in the Cx‐treated group (p < .05). In addition, both PA‐ and SCNT‐derived blastocysts from the 40 μM Cx‐treated group showed significantly increased mRNA expression of Bcl2 and Oct4 and decreased Caspase3 expression level (p < .05), when compared with the control group. PA‐derived blastocysts from the 40 μM Cx‐treated group also exhibited significantly decreased expression of Bax (p < .05). Our results demonstrated that treatment with 40 μM Cx during IVM improves the developmental competence of PA and SCNT embryos. Improvement of embryo development by Cx is most likely due to increased intracellular GSH synthesis, which reduces ROS levels in oocytes, and it may also positively regulate apoptosis‐ and development‐related genes.
Writing the travelling self: travel and life‐writing in Peter Mundy's (1597–1667) Itinerarium Mundii
Authors: Johanna Holmberg Eva
Published: September 2016

This article explores the manuscript travel journal of the seventeenth century merchant adventurer Peter Mundy (d. 1667), seeking for instances of life writing amidst the hybrid forms of his textual and visual production of more than five hundred folios. It will argue that Mundy's manuscript travel journal Itinerarium Mundii, was not just a strategically selfconcealing or ‘fashioning’ text. It formed part of a life long process of accounting, editing, recording, and re‐writing, where Mundy sought not just to hide his own opinions and person, as has been sometimes claimed, but also recorded memorable events and travels, making sense of a lifetime of travels both for himself and his interested friends. This will not just provide a new perspective on Peter Mundy, but, it is hoped, encourages scholars to widen the scope of studies of early modern travel writing by opening them up for inquiries into the ways in which travelers and their ‘selves’ were embedded in, represented, and recorded in similar texts.
Low transplantability of 0 blood group and highly sensitized candidates in the Portuguese kidney allocation algorithm: quantifying an old problem in search of new solutions
Authors: Tafulo S. , Malheiro J. , Dias L. , Mendes C. , Osório E. , Martins L. S. , Santos J. , Pedroso S. , Almeida M. , Castro‐Henriques A.
Published: September 2016

The impact of patient's biological differences in waiting time for kidney transplantation is well known and has been a subject of extensive debate and struggle in transplantation community. Our purpose was to evaluate patient's access to kidney transplantation in Portugal, regarding their degree of allosensitization and blood type. A retrospective cohort study including 1020 candidates for kidney transplantation between 01 January 2010 and 31 December 2011 in transplant unit Centro Hospitalar do Porto was performed. The deceased donor organ offer by blood type decreased with the calculated panel reactive antibody (cPRA) increase for A and B blood groups candidates, while in 0 blood group candidates, a significant reduction in organ offer was only observable in hypersensitized (HS) ones. As a consequence, the median waiting time was also significantly higher in 0 blood group patients, when compared to the remaining groups. However, waiting time increased extensively with cPRA regardless blood type, especially HS patients with increases of 368%, 632%, 486%, and 140% for blood groups A, B, AB, and 0, respectively, when compared to each blood group global median waiting time. Our study shows that important measures need to be undertaken in order to mitigate the huge disadvantage that HS and 0 blood type patients naturally have.
Newly synthesized and recycling pools of the apical protein gp135 do not occupy the same compartments
Authors: Stoops Emily H. , Hull Michael , Caplan Michael J.
Published: September 2016

Polarized epithelial cells sort newly synthesized and recycling plasma membrane proteins into distinct trafficking pathways directed to either the apical or basolateral membrane domains. While the trans‐Golgi network is a well‐established site of protein sorting, increasing evidence indicates a key role for endosomes in the initial trafficking of newly synthesized proteins. Both basolateral and apical proteins have been shown to traverse endosomes en route to the plasma membrane. In particular, apical proteins traffic through either subapical early or recycling endosomes. Here we use the SNAP tag system to analyze the trafficking of the apical protein gp135, also known as podocalyxin. We show that newly synthesized gp135 traverses the apical recycling endosome, but not the apical early endosomes (AEEs). In contrast, post‐endocytic gp135 is delivered to the AEE before recycling back to the apical membrane. The pathways pursued by the newly synthesized and recycling gp135 populations do not detectably intersect, demonstrating that the biosynthetic and post‐endocytic pools of this protein are subjected to distinct sorting processes.
Waging peace: militarising pacifism in Central Africa and the problem of geography, 1962
Authors: Hodder Jake
Published: September 2016

Despite the discipline having undergone a ‘peace turn’ in recent years, the history of the peace movement itself remains curiously under explored by geographers. This paper retraces the World Peace Brigade and its collaboration with the Northern Rhodesian independence movement in 1962. I argue that the Brigade offers geographers important insights into how ideas of peace have been circulated, adapted and even resisted. The paper suggests that geography poses a distinct conceptual problem for peace movements, which must simultaneously operate beyond conventional forms of territorial politics while remaining sufficiently flexible in the political arena for their strength and relevance. In Central Africa this meant the Brigade developed two, ultimately incompatible, conceptions of peace: an internationalist one that stressed world community, and a local one that adapted pacifism for nationalist movements. I suggest this case study has two implications for peace research in geography. First, it encourages us to remain attentive to the big stories of peace and, specifically, the way in which the peace movement has been a historically important conduit for a range of internationalist ideas. Second, the histories of waging peace (peace armies, civil disobedience, etc.) allow us to critically interrogate the co‐constitutive geographies of violence and nonviolence while retaining peace as a distinct category around which to promote political engagement.
ANALYSIS AND ENHANCEMENT OF THE DENOISING DEPTH DATA USING KINECT THROUGH ITERATIVE TECHNIQUE
Authors: Karbasi Mostafa , Bilal Sara , Aghababaeyan Reza , Rad Abdolvahab Ehsani , Bhatti Zeeshan , Shah Asadullah
Published: September 2016

Since the release of Kinect by Microsoft, the, accuracy and stability of Kinect data-such as depth map, has been essential and important element of research and data analysis. In order to develop efficient means of analyzing and using the kinnect data, researchers require high quality of depth data during the preprocessing step, which is very crucial for accurate results. One of the most important concerns of researchers is to eliminate image noise and convert image and video to the best quality. In this paper, different types of the noise for Kinect are analyzed and a unique technique is used, to reduce the background noise based on distance between Kinect devise and the user. Whereas, for shadow removal, the iterative method is used to eliminate the shadow casted by the Kinect. A 3D depth image is obtained as a result with good quality and accuracy. Further, the results of this present study reveal that the image background is eliminated completely and the 3D image quality in depth map has been enhanced.
Long‐chain acyl‐CoA synthetase 6 regulates lipid synthesis and mitochondrial oxidative capacity in human and rat skeletal muscle
Authors: Teodoro Bruno G. , Sampaio Igor H. , Bomfim Lucas H. M. , Queiroz André L. , Silveira Leonardo R. , Souza Anderson O. , Fernandes Anna M. A. P. , Eberlin Marcos N. , Huang Tai‐Yu , Zheng Donghai , Neufer P. Darrell , Cortright Ronald N. , Alberici Luciane C.
Published: September 2016

Key points

Long‐chain acyl‐CoA synthetase 6 (ACSL6) mRNA is present in human and rat skeletal muscle, and is modulated by nutritional status: exercise and fasting decrease ACSL6 mRNA, whereas acute lipid ingestion increase its expression.

ACSL6 genic inhibition in rat primary myotubes decreased lipid accumulation, as well as activated the higher mitochondrial oxidative capacity programme and fatty acid oxidation through the AMPK/PGC1‐α pathway.

ACSL6 overexpression in human primary myotubes increased phospholipid species and decreased oxidative metabolism.

Long‐chain acyl‐CoA synthetases (ACSL 1 to 6) are key enzymes regulating the partitioning of acyl‐CoA species toward different metabolic fates such as lipid synthesis or β‐oxidation. Despite our understanding of ecotopic lipid accumulation in skeletal muscle being associated with metabolic diseases such as obesity and type II diabetes, the role of specific ACSL isoforms in lipid synthesis remains unclear. In the present study, we describe for the first time the presence of ACSL6 mRNA in human skeletal muscle and the role that ACSL6 plays in lipid synthesis in both rodent and human skeletal muscle. ACSL6 mRNA was observed to be up‐regulated by acute high‐fat meal ingestion in both rodents and humans. In rats, we also demonstrated that fasting and chronic aerobic training negatively modulated the ACSL6 mRNA and other genes of lipid synthesis. Similar results were obtained following ACSL6 knockdown in rat myotubes, which was associated with a decreased accumulation of TAGs and lipid droplets. Under the same knockdown condition, we further demonstrate an increase in fatty acid content, p‐AMPK, mitochondrial content, mitochondrial respiratory rates and palmitate oxidation. These results were associated with increased PGC‐1α, UCP2 and UCP3 mRNA and decreased reactive oxygen species production. In human myotubes, ACSL6 overexpression reduced palmitate oxidation and PGC‐1α mRNA. In conclusion, ACSL6 drives acyl‐CoA toward lipid synthesis and its downregulation improves mitochondrial biogenesis, respiratory capacity and lipid oxidation. These outcomes are associated with the activation of the AMPK/PGC1‐α pathway.
Hydrodynamic Measurements Throughout a Flat Plate Multi-Row Film Cooling Array With Inclined Holes
Authors: Natsui Greg , Voet Michael T. , Little Zachary , Fernandez Erik , Kapat Jay , Dees Jason E.
Published: September 2016

Particle image velocimetry and particle scattering measurements are taken over a flat multi-row film cooled surface. The effect of coolant mass flow (characterized by blowing ratio, momentum flux ratio or velocity ratio) is investigated. The array investigated has 8 rows containing 52 holes of 3.8 mm diameter with inclination angles of 20° and hole length-to-diameter ratios of 11.2. The lateral and streamwise pitches are 7.5 times the diameter. The holes are in a staggered arrangement.

PIV measurements are taken with CO2 as coolant injecting into an air primary stream. Two streamwise aligned planes are measured; a centerline plane and a plane spaced laterally half a diameter from centerline. The PIV results provide a quantitative view of the flow over eight rows of injection as well as the recovery region. Images are acquired at 8 Hz and have a spatial resolution of 10.3 interrogation windows per hole diameter. The tunnel has low freestream turbulence (1%) and is low speed, so the primary turbulence production mechanism is shearing. As a result, the M = 0.45 blowing ratio case shows higher levels of turbulent kinetic energy compared with the M = 1.05 blowing ratio case. Uncertainty in the PIV measurements is estimated via the correlation statistics method.
Experimental Study of a Low-NOx Lean Direct Injection Combustor Design
Authors: Ahmed Abdelallah , Haseman Jacob , Tambe Samir , Jeng San-Mou
Published: September 2016

An experimental investigation was undertaken to develop a lean direct injection (LDI) combustor concept. The LDI concept consisted of a 9-point fuel injection system setup in a 3×3 array, where each point is made of a fuel nozzle fitted into a counter-rotating radial-radial swirler. Each swirler consisted of an inner, primary swirler, and an outer, secondary swirler, with opposite flow rotation. The experimental investigation consisted of atmospheric combustion and lean blow-out (LBO) tests, and high pressure combustion. All tests utilized a pressure drop of 4% across the swirlers. Parameters tested included variable swirler strengths and fuel nozzle injection depth. Fuel staging was employed on all configurations.

Two swirlers, with swirl numbers (SN) of 0.64 and 1.07, were used in the swirler array, with the baseline configuration consisting entirely of the low-SN swirlers, and configurations 2 and 3 utilizing 1 and 3, respectively, of the high-SN swirlers. Configuration 2 has the high-SN swirler at the center, whereas Configuration 3 uses three high-SN swirlers in the center row. From the atmospheric tests, flame stability and lean blowout occurred at lower equivalence ratios for configuration 2 and 3, indicating that the presence of the high-swirl swirler improved flame anchoring. Two different nozzle insertion depths were tested, with a deep insertion depth providing partial prefilming on the venturi, and a shallow insertion depth with no pre-filming. Partial pre-filming greatly aided in fuel/air mixing and produced a shorter, blue flame, which was stable, and had lower LBO limit as compared to full direct injection (shallow insertion), which resulted in more unstable, longer, yellow flames.

Emission measurements were conducted at high pressures using water cooled sampling probe, and a gas analyzer system to measure the emission indices of NOx and CO. The results showed that this LDI design produced emissions values comparable to those produced by current lean premixed prevaporized (LPP) combustor designs, well below current ICAO standards.
Water-Mist-Cooled Heat Sink for Autonomous Air-Cooling System (AACS) of More Electric Aircraft (MEA)
Authors: Murata Akira , Saito Hiroshi , Okita Yoji
Published: September 2016

The More Electric Aircraft (MEA) is a system architecture concept for the aircraft that reduces fuel consumption and environmental load while improving safety, reliability, and maintainability. MEA architecture replaces some of the conventional hydraulic and/or mechanical control system with electric motor-driven system, integrates system power management into the aircraft/engine controls, and optimizes the aircraft geometry by flexibly arranging the accessory devices. The primary challenge to realize the MEA concept is how to manage the heat from these additional power electronic devices. The authors’ group proposed novel cooling system, the Autonomous Air-Cooling System (AACS) which cools the power electronics of the motor devices distributed in the aircraft. In AACS, each power electronic device (e.g. motor controller) is air-cooled by heat sinks connected to compact blowers. This system is very simple and efficient since it re-uses the cabin air and needs no additional coolant.

One of the key technologies which realize AACS is an efficient heat sink. In this study, at first the performance evaluation targeting a single-aisle 180-seater aircraft was performed. In the analysis, a plate-fin heat sink was adopted, and the pressure loss and heat transfer was estimated by using empirical correlations. In the analysis, the value of heat generation was assumed from power demand for each operation condition, and the required mass flow rate of cooling air was calculated so as for the enclosure temperature of the power electronics to be 80°C which was the allowable maximum temperature of the motor controller. The effect of the fin geometry on the cooling performance was also examined by varying the geometric parameters (fin height, thickness, and spacing). In order to further enhance the cooling performance without increasing the pressure loss, the water-mist injection to the cooling air flow was adopted and its effect was analytically confirmed. In addition, the effectiveness of the water-mist injection on the cooling performance was verified by performing experiments for a plate-fin heat sink manufactured by a wire electric discharge method.
Adjoint-Based Unsteady Aerodynamic Optimization of a Transonic Turbine Stage
Authors: Ma Can , Su Xinrong , Yuan Xin
Published: September 2016

Unsteady blade row interactions considerably affect the performance of turbomachinery consisting of multiple blade rows. However, most aerodynamic optimizations of turbomachinery are based on mixing-plane steady flow simulations which cannot account for the unsteady effects of blade row interactions. In this work, the rotor of a two-dimensional transonic turbine stage is optimized using an in-house unsteady aerodynamic optimization system that allows for a more accurate modeling of the unsteady flow features occurring in multi-row turbomachinery configurations. The gradients of the objective function and constraint to the design variables are efficiently calculated with the discrete adjoint method. In the developed adjoint-based unsteady aerodynamic optimization system, the unsteady Reynolds-Averaged Navier-Stokes equations are solved using the harmonic balance method with an in-house code. The adjoint equations are derived by hand from the discrete form of the unsteady flow equations. The present results demonstrate the efficiency and capability of the unsteady aerodynamic optimization system for turbomachinery with multiple blade rows.
Visualizations of Flow Structures in the Rotor Passage of an Axial Compressor at the Onset of Stall
Authors: Chen Huang , Li Yuanchao , Tan David , Katz Joseph
Published: September 2016

Flow visualizations and stereoscopic PIV (SPIV) measurements are carried out to study the flow phenomena developing in the rotor passage of an axial compressor at the onset of stall. Experiments have been performed in the JHU optically index-matched facility, using acrylic blades and liquid that have the same optical refractive index. The blade geometries are based on the first one and a half stages of the Low Speed Axial Compressor (LSAC) facility at NASA Glenn. The SPIV measurements provide detailed snapshots and ensemble statistics on the flow in a series of meridional planes. Data recorded in closely spaced planes enable us to obtain ensemble averaged 3D vorticity distributions. High speed imaging of cavitation, performed at low pressure, is used to qualitatively visualize the vortical structures within the rotor passage. The observations are performed just above and at stall conditions. At pre-stall condition, shortly after it rolled up, the tip leakage vortex (TLV) breaks up into widely distributed intermittent vortical structures. In particular, interaction of the backward tip leakage flow with the nearly opposite direction main passage flow under (radially inward) it results in periodic generation of large scale vortices that extend upstream, from the suction side (SS) of one blade to the pressure side (PS) or even near the leading edge of the next blade. When these structures penetrate to the next passage, they trigger formation of a similar phenomenon there, initiating a process that sustains itself. Once they form, these vortices rotate with the blade, indicating little through flow in the tip region. The 3D velocity and vorticity distributions confirm the presence of these large flow structures at the transition between the high circumferential velocity region below the TLV center and the main flow deeper in the passage. Further reduction in flow rate into the stall range caused a rapid increase in the number and scale of these vortices, demonstrating that their formation and proliferation plays a key role in the onset of stall.
Analysis of Multiaxial Fatigue Evaluation in Engine Components Using an Improved Multiaxial Fatigue Life Model
Authors: Zhang Cheng-cheng , Ren Yuan , Gao Jing-yun , Li Ying , Yang Kun
Published: September 2016

Current design methodologies for LCF/HCF of aero engine components are based on traditional uniaxial stress/strain methods like strain-life (ε-N), stress-life (S-N) and Goodman / Haigh diagram approaches, often applied with a wide safe factors to account for uncertainties in the understanding of multiaxial loading and other effects. With constantly striving to improve the performance and life of gas turbine engines, there is a need to increase accuracy of life prediction and reduce maintenance cost. Some multiaxial fatigue methods like Manson-McKnight, Sines, Smith-Watson-Topper etc. were developed to convert the multiaxial stresses into an equivalent uniaxial stress. This conversion simply provides the treatment of both the mean stress, the stress amplitude and directions. However, critical locations in engine components often experience significant multiaxial non-proportional loading conditions, such as blades and LP/HP shafts are subjected to HCF loading associated with mixed bending and torsional vibration modes. In this paper, the use of a new multiaxial fatigue life model was explored in the prediction of multiaxial fatigue behavior in aeronautic materials and structural steel. This new life model is based on the multiaxial S-N curve and an improved multiaxial high-cycle fatigue criterion which validated before by authors. The applied range of this new multiaxial fatigue life model were also compared with other models. Several groups of solid and hollow specimens with different ductile materials were conducted and evaluated under multiaxial loading cases. The predictions based on the proposed model give a better statistical result than other models.
On the Application of a Harmonic Balance Method With a Volume Source Cooling Model to the Simulation of a Film-Cooled Turbine Stage
Authors: Becker Kai , Ashcroft Graham , Weber Anton , Rochhausen Stefan , Rodriguez Jose , Schmid Gregor
Published: September 2016

The application of Reduced Order Models (ROMs) in the simulation of complex, time-dependent flows in turbomachines provides a means to significantly reduce the cost, both in terms of preprocessing and computational overhead, of numerical simulations. In this work the development and combination of two ROMs for the simulation of the unsteady, time-periodic flow and heat transfer in a film-cooled turbine are presented. For the simulation of the unsteady flow an alternating frequency/time domain Harmonic Balance (HB) method is applied. To allow the efficient preprocessing and simulation of film-cooled blades a second, volume source based, ROM is incorporated into the underlying nonlinear solver of the HB method. Through the application of the volume source model the time consuming and error prone resolution and specification of individual cooling holes is no longer necessary. To validate the newly implemented volume source model a number of simple academic test cases are presented and analyzed in detail. Following the basic validation of the cooling model the approach is combined with the HB method to simulate the unsteady flow in the first one and half stages of a high-pressure turbine.
Evaluation of the Cycle Averaged Performances of a Pulsed Detonation Engine Based on Thermodynamic Cycle Computations
Authors: Cuciumita Cleopatra Florentina , Cuciuc Tudor , Porumbel Ionut
Published: September 2016

The paper presents a numerical algorithm for the theoretical calculation of the thermodynamic cycle of a pulsed detonation based engine, based on the Zeldovich – von Neumann – Doring detonation model, together with the algorithm employed to perform them, and a numerical application. The results are compared to numerical data obtained for the Chapman – Jouguet detonation thermodynamic parameters using the NASA – Glenn Chemical Equilibrium Program CEA2. As a reference, the thermodynamic cycle of a Brayton engine operating under the same conditions of compressor pressure ratio and fuel mass flow rate is computed and included in the paper. It is found that the CEA2 detonation model predicts a very low engine thermodynamic efficiency, while the ZND model yields a higher efficiency of the detonation based engine with respect to the Brayton cycle engine. The specific work of the detonation engine is higher than the Brayton engine, but the power remains lower.
Influence of Rotor Tip Flow Field Mis-Prediction on Rotating Disturbance Near Surge in a High Speed Multistage Compressor
Authors: Schreiber Johannes , Ottavy Xavier , Ngo Boum Ghislaine , Gourdain Nicolas
Published: September 2016

In this work, unsteady numerical results and high-frequency measurements are investigated from nominal to loaded operating points with the objective to contribute to the understanding of pre-stall rotating disturbances. A 3.5 stages high speed axial multistage compressor is investigated on a 2 MW test rig in the laboratory of fluid mechanics (LMFA) at Ecole Centrale de Lyon, France. The compressor has been built by Snecma, and is representative of modern high-pressure rear blocks of a modern aircraft engine. The unsteady numerical results predict a rotating disturbance in the tip flow field of the rotor 2 at the loaded operating point. It causes a frequency which is not a multiple of the periodicity of the compressor, and is rotating at about 72% of the shaft speed. The mesh independency of this disturbance is ensured. The analysis of the circumferential and axial propagation of the disturbance reveals a rotating instability like phenomenon. Most characteristic is the very important periodic oscillation of the tip leakage vortex trajectory, leading to a modulation of the leakage flow in the neighboring tip gap. The influence of the neighboring blade rows is investigated by filtering their unsteady contribution by means of mixing planes up and/or downstream of the rotor 2. In either case, the rotating disturbance is found to be still present. There are no traces of this rotating disturbance in the high-frequency measurements investigated at a near surge operating point. A spike like stall inception and almost instantaneous surge inception is identified. The mis-prediction of the tip region flow field in the rotors 2 and 3 is believed to cause the mis-prediction of the pre-stall disturbance.
Computational Study of the Effect of Inlet Velocity Profile and Rib Orientation on Heat Transfer in Rotating Ribbed Radial Turbine Cooling Passages
Authors: Pearce Robert , Ireland Peter , McGilvray Matthew , Romero Eduardo
Published: September 2016

This study investigates the effect of inlet velocity profiles and rib orientations on the Nusselt number distribution within ribbed radial turbine cooling passages representative of systems used in current engines. A triple-pass serpentine passage is investigated, which includes rib turbulators angled at 45° and 180° bends. The first two passes are radially outward and inward respectively and both have an aspect ratio of 1:4, with the third pass radially outward with an aspect ratio of 1:2. Multiple inlet velocity profiles are studied in RANS CFD simulations under both stationary and rotating conditions. The rotating simulations have Reynolds, Rotation and Buoyancy numbers representative of a passage within a HP turbine blade of a gas turbine engine. The flow structure and Nusselt number distributions are discussed in detail with the inlet velocity profile found to have a very large influence in the first pass under both stationary and rotating conditions, with smaller differences observed in the later passes. The rib orientation in the second pass was also investigated, with simulations of reversed and non-reversed rib orientation compared. Improved heat transfer characteristics were found in simulations where the ribs were orientated in the same direction for all three passages. These simulations are compared to experimental results in order to explain previous discrepancies found between experimental and CFD data from an experimental setup with complex inlet geometry.
Large-Eddy Simulation Investigation of Impact of Roughness on Flow in a Low-Pressure Turbine
Authors: Joo Jongwook , Medic Gorazd , Sharma Om
Published: September 2016

Surface roughness can make boundary-layers separate in diffusing flow. Most roughness Reynolds Averaged Navier Stokes (RANS) models which change the boundary conditions to model the roughness effects cannot predict this phenomenon. In this study, Large-Eddy Simulation (LES) is performed to predict the roughness induced separation and investigate the flow physics to improve our understanding of the underlying phenomena.

Flow over a roughened low-pressure turbine airfoil was simulated by LES with WALE subgrid-scale model [15]. The roughness is modeled as regularly placed roughness elements with a similar equivalent roughness height following Schlichting [1]. The roughness elements are gridded in a body-fitted and multi-block structured way.

Over a range of Reynolds number, the LES correctly predicted the behavior — with the flow separation occurring only at the high Reynolds number. Analysis revealed that surface drag and boundary layer thickness increase as Reynolds number increases, which is opposite to the conventional smooth wall boundary-layer behavior. In the end, the thickened boundary layer undergoes separation in the diffusing section.

RANS simulations are also conducted with a roughness model — over a smooth airfoil grid — and without a roughness model — by using the same rough airfoil grid. In all cases, no separation was observed. The boundary layer thickness predicted with RANS is thinner than those of LES, suggesting that models that only modify surface stress at the boundary do not properly capture the flow physics over the rough surface of an airfoil.
Big brown bats (Eptesicus fuscus) reveal diverse strategies for sonar target tracking in clutter
Authors: Mao Beatrice , Aytekin Murat , Wilkinson Gerald S. , Moss Cynthia F.
Published: September 2016

Bats actively adjust the acoustic features of their sonar calls to control echo information specific to a given task and environment. A previous study investigated how bats adapted their echolocation behavior when tracking a moving target in the presence of a stationary distracter at different distances and angular offsets. The use of only one distracter, however, left open the possibility that a bat could reduce the interference of the distracter by turning its head. Here, bats tracked a moving target in the presence of one or two symmetrically placed distracters to investigate adaptive echolocation behavior in a situation where vocalizing off-axis would result in increased interference from distracter echoes. Both bats reduced bandwidth and duration but increased sweep rate in more challenging distracter conditions, and surprisingly, made more head turns in the two-distracter condition compared to one, but only when distracters were placed at large angular offsets. However, for most variables examined, subjects showed distinct strategies to reduce clutter interference, either by (1) changing spectral or temporal features of their calls, or (2) producing large numbers of sonar sound groups and consistent head-turning behavior. The results suggest that individual bats can use different strategies for target tracking in cluttered environments.
How conifers adapt to the cold
Authors: Hancock Angela M.
Published: September 2016

Highly diverged conifer species share many genetic signals of adaptation to local climate conditions
The apo-structure of the leucine sensor Sestrin2 is still elusive
Authors: Saxton Robert A. , Knockenhauer Kevin E. , Schwartz Thomas U. , Sabatini David M.
Published: September 2016

The unliganded Sestrin2 structure awaits discovery.
Paper of note in
Science Translational Medicine
Authors: Ferrarelli Leslie K.
Published: September 2016

This week’s article describes how targeting a chemokine receptor on T cells may be therapeutic in patients with autoimmune-related type 1 diabetes.
HDAC inhibitors in solid tumors and blood cancers
Authors: Ferrarelli Leslie K.
Published: September 2016

Strategies using HDAC inhibitors—and overcoming resistance to them—may improve clinical outcome for some cancer patients.
Evaluation of Propranolol Effect on Experimental Acute and Chronic Toxoplasmosis Using Quantitative PCR
Authors: Montazeri Mahbobeh , Ebrahimzadeh Mohammad Ali , Ahmadpour Ehsan , Sharif Mehdi , Sarvi Shahabeddin , Daryani Ahmad
Published: September 2016

Current therapies against toxoplasmosis are limited, and drugs have significant side effects and low efficacies. We evaluated the potential anti-
Toxoplasma
activity of propranolol at a dose of 2 or 3 mg/kg of body weight/day
in vivo
in the acute and chronic phases. Propranolol as a cell membrane-stabilizing agent is a suitable drug for inhibiting the entrance of
Toxoplasma gondii
tachyzoites into cells. The acute-phase assay was performed using propranolol, pyrimethamine, and propranolol plus pyrimethamine before (pretreatment) and after (posttreatment) intraperitoneal challenge with 1 × 10
3
tachyzoites of the virulent
T. gondii
strain RH in BALB/c mice. Also, in the chronic phase, treatment was performed 12 h before intraperitoneal challenge with 1 × 10
6
tachyzoites of the virulent strain RH of
T. gondii
in rats. One week (in the acute phase) and 2 months (in the chronic phase) after postinfection, tissues were isolated and DNA was extracted. Subsequently, parasite load was calculated using quantitative PCR (qPCR). In the acute phase, in both groups, significant anti-
Toxoplasma
activity was observed using propranolol (
P
< 0.001). Propranolol in the pretreatment group showed higher anti-
Toxoplasma
activity than propranolol in posttreatment in brain tissues, displaying therapeutic efficiency on toxoplasmosis. Also, propranolol combined with pyrimethamine reduced the parasite load as well as significantly increased survival of mice in the pretreatment group. In the chronic phase, anti-
Toxoplasma
activity and decreased parasite load in tissues were observed with propranolol. In conclusion, the presented results demonstrate that propranolol, as an orally available drug, is effective at low doses against acute and latent murine toxoplasmosis, and the efficiency of the drug is increased when it is used in combination therapy with pyrimethamine.
Antiviral Activity of Bictegravir (GS-9883), a Novel Potent HIV-1 Integrase Strand Transfer Inhibitor with an Improved Resistance Profile
Authors: Tsiang Manuel , Jones Gregg S. , Goldsmith Joshua , Mulato Andrew , Hansen Derek , Kan Elaine , Tsai Luong , Bam Rujuta A. , Stepan George , Stray Kirsten M. , Niedziela-Majka Anita , Yant Stephen R. , Yu Helen , Kukolj George , Cihlar Tomas , Lazerwith Scott E. , White Kirsten L. , Jin Haolun
Published: September 2016

Bictegravir (BIC; GS-9883), a novel, potent, once-daily, unboosted inhibitor of HIV-1 integrase (IN), specifically targets IN strand transfer activity (50% inhibitory concentration [IC50] of 7.5 ± 0.3 nM) and HIV-1 integration in cells. BIC exhibits potent and selectivein vitroantiretroviral activity in both T-cell lines and primary human T lymphocytes, with 50% effective concentrations ranging from 1.5 to 2.4 nM and selectivity indices up to 8,700 relative to cytotoxicity. BIC exhibits synergisticin vitroantiviral effects in pairwise combinations with tenofovir alafenamide, emtricitabine, or darunavir and maintains potent antiviral activity against HIV-1 variants resistant to other classes of antiretrovirals. BIC displayed anin vitroresistance profile that was markedly improved compared to the integrase strand transfer inhibitors (INSTIs) raltegravir (RAL) and elvitegravir (EVG), and comparable to that of dolutegravir (DTG), against nine INSTI-resistant site-directed HIV-1 mutants. BIC displayed statistically improved antiviral activity relative to EVG, RAL, and DTG against a panel of 47 patient-derived HIV-1 isolates with high-level INSTI resistance; 13 of 47 tested isolates exhibited >2-fold lower resistance to BIC than DTG. In dose-escalation experiments conductedin vitro, BIC and DTG exhibited higher barriers to resistance than EVG, selecting for HIV-1 variants with reduced phenotypic susceptibility at days 71, 87, and 20, respectively. A recombinant virus with the BIC-selected M50I/R263K dual mutations in IN exhibited only 2.8-fold reduced susceptibility to BIC compared to wild-type virus. All BIC-selected variants exhibited low to intermediate levels of cross-resistance to RAL, DTG, and EVG (<8-fold) but remained susceptible to other classes of antiretrovirals. A high barrier toin vitroresistance emergence for both BIC and DTG was also observed in viral breakthrough studies in the presence of constant clinically relevant drug concentrations. The overall virologic profile of BIC supports its ongoing clinical investigation in combination with other antiretroviral agents for both treatment-naive and -experienced HIV-infected patients.
Potent Antiedematous and Protective Effects of Ciprofloxacin in Pulmonary Ricinosis
Authors: Gal Yoav , Sapoznikov Anita , Falach Reut , Ehrlich Sharon , Aftalion Moshe , Sabo Tamar , Kronman Chanoch
Published: September 2016

The plant toxin ricin is considered a biological threat agent of concern and is most toxic when inhaled. Pulmonary exposure to a lethal dose of ricin can be redressed by treatment with antiricin antibodies; however, late antitoxin intervention is of limited efficacy. This limitation is associated with overt lung damage, clinically manifested as severe pulmonary inflammation, which develops over time. Increased evidence indicates that ciprofloxacin, a broad-spectrum antimicrobial agent, possesses immunomodulatory properties. Here we demonstrate that while antiricin antibody administration at late hours after intranasal exposure to ricin confers limited protection to mice, highly efficient protection can be achieved by adding ciprofloxacin to the antibody treatment. We further demonstrate that parameters associated with lung injury, in particular, pulmonary proinflammatory cytokine production, neutrophil migration, and edema, are sharply reduced in ricin-intoxicated mice that were treated with ciprofloxacin. The presented data highlight the potential clinical application of ciprofloxacin as a beneficial immunomodulatory agent in the course of ricin intoxication.
Genetic Characterization of a
bla
VEB-2
-Carrying Plasmid in Vibrio parahaemolyticus
Authors: Li Ruichao , Ye Lianwei , Zheng Zhiwei , Chan Edward Wai Chi , Chen Sheng
Published: September 2016

This report describes the first detection of a
bla
VEB-2
gene in a
Vibrio parahaemolyticus
strain isolated from a shrimp sample. The
bla
VEB-2
gene was carried on a novel Inc-type plasmid that was likely to have originated from aquatic organisms, as indicated by a comparison with other known genetic elements in the GenBank database. However, the plasmid contains resistance elements usually harbored by members of the family
Enterobacteriaceae
, suggesting that gene transfer events occurred and contributed to the formation of this multidrug resistance-encoding plasmid.
The Phosphotransfer Protein CD1492 Represses Sporulation Initiation in Clostridium difficile
Authors: Childress Kevin O. , Edwards Adrianne N. , Nawrocki Kathryn L. , Anderson Sarah E. , Woods Emily C. , McBride Shonna M.
Published: September 2016

The formation of spores is critical for the survival of
Clostridium difficile
outside the host gastrointestinal tract. Persistence of
C. difficile
spores greatly contributes to the spread of
C. difficile
infection (CDI), and the resistance of spores to antimicrobials facilitates the relapse of infection. Despite the importance of sporulation to
C. difficile
pathogenesis, the molecular mechanisms controlling spore formation are not well understood. The initiation of sporulation is known to be regulated through activation of the conserved transcription factor Spo0A. Multiple regulators influence Spo0A activation in other species; however, many of these factors are not conserved in
C. difficile
and few novel factors have been identified. Here, we investigated the function of a protein, CD1492, that is annotated as a kinase and was originally proposed to promote sporulation by directly phosphorylating Spo0A. We found that deletion of
CD1492
resulted in increased sporulation, indicating that CD1492 is a negative regulator of sporulation. Accordingly, we observed increased transcription of Spo0A-dependent genes in the
CD1492
mutant. Deletion of CD1492 also resulted in decreased toxin production
in vitro
and in decreased virulence in the hamster model of CDI. Further, the
CD1492
mutant demonstrated effects on gene expression that are not associated with Spo0A activation, including lower
sigD
and
rstA
transcription, suggesting that this protein interacts with factors other than Spo0A. Altogether, the data indicate that CD1492 negatively affects sporulation and positively influences motility and virulence. These results provide further evidence that
C. difficile
sporulation is regulated differently from that of other endospore-forming species.
Transcriptional Responses of Escherichia coli to a Small-Molecule Inhibitor of LolCDE, an Essential Component of the Lipoprotein Transport Pathway
Authors: Lorenz Christian , Dougherty Thomas J. , Lory Stephen
Published: September 2016

In Gram-negative bacteria, a dedicated machinery consisting of LolABCDE components targets lipoproteins to the outer membrane. We used a previously identified small-molecule inhibitor of the LolCDE complex of
Escherichia coli
to assess the global transcriptional consequences of interference with lipoprotein transport. Exposure of
E. coli
to the LolCDE inhibitor at concentrations leading to minimal and significant growth inhibition, followed by transcriptome sequencing, identified a small group of genes whose transcript levels were decreased and a larger group whose mRNA levels increased 10- to 100-fold compared to those of untreated cells. The majority of the genes whose mRNA concentrations were reduced were part of the flagellar assembly pathway, which contains an essential lipoprotein component. Most of the genes whose transcript levels were elevated encode proteins involved in selected cell stress pathways. Many of these genes are involved with envelope stress responses induced by the mislocalization of outer membrane lipoproteins. Although several of the genes whose RNAs were induced have previously been shown to be associated with the general perturbation of the cell envelope by antibiotics, a small subset was affected only by LolCDE inhibition. Findings from this work suggest that the efficiency of the Lol system function may be coupled to a specific monitoring system, which could be exploited in the development of reporter constructs suitable for use for screening for additional inhibitors of lipoprotein trafficking.

IMPORTANCE
Inhibition of the lipoprotein transport pathway leads to
E. coli
death and subsequent lysis. Early significant changes in the levels of RNA for a subset of genes identified to be associated with some periplasmic and envelope stress responses were observed. Together these findings suggest that disruption of this key pathway can have a severe impact on balanced outer membrane synthesis sufficient to affect viability.