bluuebunny/crossref_metadata_2025 huggingface dataset:
Oscillatory stability assessment of microgrid in autonomous operation with uncertainties
Authors: Krismanto Awan Uji , Mithulananthan Nadarajah , Kamwa Innocent
Published: December 2017

One of the main challenges of the microgrid (MG) operation in autonomous mode is the uncertain output due to the fluctuating nature of renewable energy resources (RES). This study investigates the effects of RES uncertainties to the oscillatory stability of a hybrid MG in islanded operation. A comprehensive model of Wind Energy Conversion System (WECS), a two‐stage Photovoltaic (PV) and bio‐‐diesel engine (BDE) based distributed generation (DG) units are considered to capture a complete dynamic response of the hybrid MG. Trajectories and distribution of damping ratios and oscillatory frequencies of the critical modes were thoroughly investigated through Monte Carlo simulation considering wind speed and solar irradiance uncertainties. From the probabilistic study, it was observed that the presence of RES variations results in a dynamic change of power‐sharing strategies and introduce an adverse effect on small signal stability. Uncertain condition of wind speed brings more deterioration in system damping than solar irradiation variation. From time domain simulation, it was confirmed that at higher wind speed, damping on the critical modes reduced. As a consequence, the hybrid MG experienced more oscillatory conditions and even lead to unstable situation at high wind speed conditions. While with solar irradiance change, the investigated MG system can maintain its stable operation.
Modal analysis of a grid‐connected DFIG‐based WT considering multi‐timescale control interactions
Authors: Wan Minhui , Hu Jiabing
Published: December 2017

In a grid‐connected doubly fed induction generator (DFIG)‐based wind turbine system, the multi‐timescale control loops of DFIGs work together to keep the output active/reactive power tracking their references. In weak AC grid condition where the grid impedance cannot be neglected, interactions among those control loops are very strong. This study presents a modal analysis of the system containing a DFIG. The DFIG model for analysis considers multi‐timescale control and its interactions. The effect of bandwidths of rotor speed control, phase‐locked loop, DC‐link voltage control and rotor current control on system stability is presented. Interactions among those control loops are explored. The analysis results indicate that the interactions among multi‐timescale control are strong and will have an effect on the stability and the dynamics of the DFIG system under weak AC grid condition.
Implementation and value of power hardware in the loop testing bed for wind turbines integrated into grid
Authors: Luo Kui , Shi Wenhui , Tang Haiyan
Published: December 2017

Wind power providing grid support is an interesting topic for the power grid stable operation, due to the large‐scale power electronics devices integrated, advanced simulation and experiment methods are required to deal with the complexity. This study presents a power hardware in the loop (PHIL) testing bed implementation method for wind turbines grid integration. The components (emulated physical wind turbine, real‐time simulator and power interface) and the configuration of the testing bed are listed from the view point of power flow and signal flow. Stability, accuracy, and safety considerations for the implementation of wind turbine PHIL testing bed are proposed, in order to accurately emulate the system and wind turbine behaviours. Inertial control strategies of wind turbines are validated, and simulation results show the value of PHIL simulation testing bed, which can be a useful tool for testing and evaluation of the electromechanical transient dynamic interaction between wind turbine/wind power plant with advanced functions and power system.
Complementary metal‐SU8‐graphene method for making integrated graphene nanocircuits
Authors: Al‐Mumen Haider , Li Wen
Published: December 2017

This work reports a complementary metal‐SU8‐graphene (MSG) method for constructing integrated graphene nanocircuits with excellent air and temperature stability. In this approach, electron beam (e‐beam) lithography was first used to selectively pattern micro/nanoscale meshes on pristine graphene to form p‐type regions. Then SU‐8 thin films were spun and e‐beam patterned to convert the target region of p‐type graphene into n‐type. The SU‐8 was utilised as a doping source and an encapsulating layer for n‐type graphene. To demonstrate the proposed MSG method, a graphene‐based voltage inverter is constructed by complementary doping p‐ and n‐type field effect transistors on a single graphene sheet. The electronic and thermal characteristics of the fabricated device were also studied.
Far-infrared photometry of OJ 287 with the Herschel Space Observatory
Authors: Kidger Mark , Zola Staszek , Valtonen Mauri , Lähteenmäki Anne , Järvelä Emilia , Tornikoski Merja , Tammi Joni , Liakos Alexis , Poyner Gary
Published: December 2017

Context. The blazar OJ 287 has shown a ≈12 year quasi-periodicity over more than a century, in addition to the common properties of violent variability in all frequency ranges. It is the strongest known candidate to have a binary singularity in its central engine.

Aim. We aim to better understand the different emission components by searching for correlated variability in the flux over four decades of frequency measurements.

Methods. We combined data at frequencies from the millimetric to the visible to characterise the multifrequency light curve in April and May 2010. This includes the only photometric observations of OJ 287 made with the Herschel Space Observatory: five epochs of data obtained over 33 days at 250, 350, and 500 μm with Herschel-SPIRE.

Results. Although we find that the variability at 37 GHz on timescales of a few weeks correlates with the visible to near-IR spectral energy distribution, there is a small degree of reddening in the continuum at lower flux levels that is revealed by the decreasing rate of decline in the light curve at lower frequencies. However, we see no clear evidence that a rapid flare detected in the light curve during our monitoring in the visible to near-IR light curve is seen either in the Herschel data or at 37 GHz, suggesting a low-frequency cut-off in the spectrum of such flares.

Conclusions.We see only marginal evidence of variability in the observations with Herschel over a month, although this may be principally due to the poor sampling. The spectral energy distribution between 37 GHz and the visible can be characterised by two components of approximately constant spectral index: a visible to far-IR component of spectral index α = −0.95, and a far-IR to millimetric spectral index of α = −0.43. There is no evidence of an excess of emission that would be consistent with the 60 μmdust bump found in many active galactic nuclei.
Uniform convergence of penalized time-inhomogeneous Markov processes
Authors: Champagnat Nicolas , Villemonais Denis
Published: December 2017

We provide a general criterion ensuring the exponential contraction of Feynman–Kac semi-groups of penalized processes. This criterion applies to time-inhomogeneous Markov processes with absorption and killing through penalization. We also give the asymptotic behavior of the expected penalization and provide results of convergence in total variation of the process penalized up to infinite time. For exponential convergence of penalized semi-groups with bounded penalization, a converse result is obtained, showing that our criterion is sharp in this case. Several cases are studied: we first show how our criterion can be simply checked for processes with bounded penalization, and we then study in detail more delicate examples, including one-dimensional diffusion processes conditioned not to hit 0 and penalized birth and death processes evolving in a quenched random environment.
Evaluation klinikinterner Suizidrisikostufen für den stationären Bereich: Validitäts- und Reliabilitätsprüfung
Authors: Macagnino Sandro , Steinert Tilman , Uhlmann Carmen
Published: December 2017

Ziel der Studie Untersuchung klinikinterner Suizidrisikostufen hinsichtlich ihrer Validität und Reliabilität.

Methodik Evaluationsstudie mit 163 Patienten. Prüfung der Interraterreliabilität sowie der inneren Kriteriumsvalidität und der Konstruktvalidität.

Ergebnisse Es konnte eine gute Interraterreliabilität und Validität der Suizidrisikostufen festgestellt werden, störungsspezifische Subgruppen zeigten deutliche Unterschiede.

Schlussfolgerung Die klinikinternen Suizidrisikostufen könnten aufgrund ihrer guten Validität und Reliabilität einen wichtigen Beitrag zur Beurteilung von Suizidalität bei stationär-psychiatrischen Patienten leisten.
Viktimisierung im Erwachsenenalter von Personen mit Psychiatrieerfahrung
Authors: Krumm Silvia , Checchia Carmen , Kilian Reinhold , Becker Thomas
Published: December 2017

Hintergrund Eine psychische Erkrankung erhöht das Risiko einer Viktimisierung im Erwachsenenalter. Das Thema wird in der psychiatrischen Versorgung und Forschung in Deutschland allerdings kaum thematisiert bzw. untersucht.

Methode Systematische Literaturübersicht zu Prävalenzen von Viktimisierung im Erwachsenenalter. Vorstellung und Einordnung von Risikofaktoren in theoretische Konzepte sowie von Befunden zu Offenlegung.

Ergebnisse Internationale Befunde belegen übereinstimmend ein hohes Viktimisierungsrisiko im Vergleich zur Allgemeinbevölkerung. Zentrale Risikofaktoren sind Psychopathologie, Alkohol- bzw. Substanzkonsum, eigene Gewalttätigkeit, frühere Gewalterfahrungen und soziale Faktoren. Gewalterfahrungen werden unzureichend offengelegt.

Diskussion Präventive und interventive Maßnahmen müssen auf individueller, versorgungsbezogener und gesellschaftlicher Ebene ansetzen. Forschungsbedarf besteht hinsichtlich repräsentativer Prävalenzdaten für Deutschland, der Offenlegung und des professionellen Umgangs mit Gewalterfahrungen, hinsichtlich situativer und interaktiver Gewaltdynamik sowie der Bedeutung soziokultureller Gewaltnormen.
Das Management von Patienten mit Peniskarzinom – Neue Aspekte in der Therapie einer seltenen Tumorentität
Authors: Roiner M. , Maurer O. , Lebentrau S. , Gilfrich C. , Schäfer C. , Haberl C. , Brookman-May S. , Burger M. , May M. , Hakenberg O.
Published: December 2017

Einige Prinzipien der primären Therapie des Peniskarzinoms haben sich in den letzten Jahrzehnten grundlegend verändert: Galt aufgrund der Aggressivität des Tumors bei der Penisteilamputation vor 15 Jahren noch ein tumorfreier Sicherheitsabstand von 2 cm als obligat, so gilt heute, dass weitgehender Organerhalt Priorität hat und minimale tumorfreie Schnittränder ausreichend sind. Es besteht somit der Grundsatz: So viel Organerhalt wie möglich, so viel Radikalität wie nötig. Auch hat sich zunehmend die Erkenntnis durchgesetzt, dass Patienten mit begrenzter regionär-lymphogener Metastasierung heilbar sein können, allerdings nur bei Durchführung einer multimodalen Therapie bestehend aus einer radikalen inguinalen Lymphadenektomie und nachfolgenden adjuvanten Chemotherapie. Bei Patienten mit fixierten inguinalen Lymphknotenmetastasen konnte hingegen die neoadjuvante Chemotherapie etabliert werden.

Trotz der verbesserten Therapieoptionen bleiben die funktionellen und onkologischen Ergebnisse bei der Behandlung des Peniskarzinoms vielfach enttäuschend. Die Möglichkeiten des Organerhalts mittels rekonstruktiver operativer Techniken verbessern zwar die Lebensqualität der Langzeitüberlebenden erheblich, doch weniger als 25 % der Patienten mit Lymphknotenmetastasierung überleben ihre Tumorerkrankung. Von großer Bedeutung ist die chirurgische Lymphknotendiagnostik bei klinisch unauffälligen Lymphknoten ab dem Tumorstadium T1b, da hier eine okkulte Mikrometastasierung in bis zu 25 % der Fälle vorliegen kann. Die minimal-invasive Sentinel-Lymphknoten-Biopsie ist ein durchaus sinnvoller Weg, diese Patienten zu diagnostizieren, ohne gleich die Morbidität einer primär radikalen Lymphadenektomie hervorzurufen. Ein zunehmendes Verständnis der zugrundeliegenden Tumorbiologie, insbesondere Erkenntnisse zum Humanen-Papillomavirus- und Epidermal-Growth-Factor-Receptor-Status, brachten zuletzt erfolgversprechende klinische Studien auf den Weg; zudem wird gegenwärtig die gezielte Immuntherapie mittels Immun-Checkpoint-Inhibitoren bei therapierefraktärem Peniskarzinom geprüft.

In diesem Review werden die aktuellen Aspekte des therapeutischen Managements von Peniskarzinom-Patienten zusammengefasst.
A double-reprocessing high-level disinfection protocol does not eliminate positive cultures from the elevators of duodenoscopes
Authors: Rex Douglas , Sieber Marnie , Lehman Glen , Webb Douglas , Schmitt Bryan , Kressel Amy , Bang Ji , Easler Jeffery , McHenry Lee , El-Hajj Ihab , Fogel Evan , Watkins James , Sherman Stuart
Published: December 2017

Background and study aim Duodenoscopes have been the source of serious infection, despite correct performance of high-level disinfection (HLD). This study aimed to observe the impact of performing HLD twice on the rate of positive cultures from duodenoscope elevators.

Methods We performed double HLD (DHLD; i. e. complete manual cleaning followed by automated reprocessing, with the entire process repeated) and then randomly cultured the elevators of our duodenoscopes on about 30 % of occasions.

Results DHLD was associated with positive elevator cultures for any microorganism in 9.4 % of cases, with a 0.8 % rate of known pathogens (627 cultures) between May 2015 and February 2016. After February 2016, and in association with changing the precleaning fluid, as well as use of a new FDA-recommended cleaning brush, the rate of positive cultures for any microorganism after DHLD was 4.8 % and 0.2 % for known pathogens (420 cultures). In a third phase, characterized by a change in personnel performing DHLD and retirement of a duodenoscope with a high rate of positive cultures, the rate of positive cultures for any microorganism was 4.9 % (783 cultures) and the rate of positive culture for known pathogens was 0.3 %. To our knowledge, no duodenoscope transmission of infection occurred during the study interval.

Conclusions DHLD resulted in a low rate of positive cultures for known pathogens and for organisms of low pathogenic potential, but did not eliminate these, from duodenoscope elevators. Additional improvements in HLD protocols and/or duodenoscope design are needed.
Piperacillin/Tazobactam-Lieferengpass: Zentrale Restriktion und Alternativempfehlungen als effektive Antibiotic-Stewardship-Maßnahme an einem Klinikum der Maximalversorgung
Authors: Kessel Johanna , Dolff Barbara , Wichelhaus Thomas , Keiner Nils , Hogardt Michael , Reinheimer Claudia , Wieters Imke , Harder Sebastian , Kempf Volkhard , Stephan Christoph ,   für das Antibiotic-Stewardship-Team (UKF)
Published: December 2017

Hintergrund Arzneimittel-Lieferengpässe stellen ein zunehmendes Problem dar, wie z. B. im Fall des Breitspektrum-Antibiotikums Piperacillin/Tazobactam (PIP/TAZ) in 2016/2017. Die Effektivität eines aktiven Ausfallmanagements am Universitätsklinikum Frankfurt (UKF) soll bewertet werden.

Methode Das Antibiotic-Stewardship (ABS) -Team des UKF beschloss klinikumsweit den restriktiven Einsatz von PIP/TAZ und empfahl alternative Antibiotikatherapien im Zeitraum des Lieferengpasses. Die Konsequenzen dieser Intervention auf Antibiotikaeinsatz und Kosten wurden retrospektiv untersucht.

Ergebnisse Über 12 Wochen wurde der Verbrauch von PIP/TAZ um durchschnittlich 71 % reduziert. Im Interventionszeitraum wurde PIP/TAZ vorwiegend zur Behandlung nosokomialer Pneumonien (62 %) und Fieber in der Neutropenie bei Kindern (12 %) eingesetzt, andere Indikationen lagen bei jeweils < 10 %. Der Verbrauch der Alternativsubstanzen stieg prozentual an (Ceftazidim + 229 %, Imipenem/Cilastatin + 18 %, Meropenem + 27 %, Ceftriaxon + 26 %, Levofloxacin + 11 %, Ciprofloxacin + 14 %, Ampicillin/Sulbactam + 83 %), insgesamt sank der Antibiotikaverbrauch jedoch um 5,8 % (Kostenersparnis: 13 %), bei moderat ansteigenden Personalkosten (+ 4300,- €). Die Rate nachgewiesener Blutstrominfektionen mit resistenten Bakterien und Clostridium difficile-Toxinnachweise im Stuhl waren nicht signifikant erhöht, verglichen mit Zeiträumen direkt vor und nach Intervention sowie ein Jahr zuvor.

Schlussfolgerung Lieferengpässe untergraben die Ziele des Antibiotic-Stewardship durch erzwungenen Einsatz von Breitspektrum-Antibiotika, bedrohen potenziell die Patientensicherheit und erfordern ein Ausfallmanagement nach mikrobiologisch-infektiologisch sinnvollen Kriterien. Bei moderat erhöhtem Personalaufwand können Antibiotic-Stewardship-Maßnahmen erfolgreich beitragen, Mehrkosten für Arzneimittel zu vermeiden.
Potential terahertz radiation by mode conversion from two-color laser to surface plasma waves
Authors: Pan K. Q. , Jiang S. E. , Li S. W. , Yang D. , Li Z. C. , Guo L. , Zheng C. Y. , Zhang B. H. , He X. T.
Published: December 2017

A potential terahertz (THz) radiation source generated by mode conversion from laser to surface plasma waves (SPWs) is proposed. The radiation is produced by a two-color laser interaction with a grating. It is shown that the frequency of the THz radiation can be precisely controlled by the frequency difference of the two-color laser. Two-dimensional (2D) particle-in-cell (PIC) simulations are used to verify this mechanism and the results show that the amplitude of the THz electric field increases nonlinearly with the amplitude of the laser electric field, which theoretically means, before the mechanism fails, the intensity of the radiated THz radiation may reach to a pretty high level as long as the driven laser is intense enough. For our simulations, the intensity of the THz radiation is even more than 10% of the laser. Besides, further analysis shows this mechanism also can be used to generate electromagnetic radiation with many other required frequencies by modifying the period of the grating.
Finite-size corrections in simulation of dipolar fluids
Authors: Belloni Luc , Puibasset Joël
Published: December 2017

Monte Carlo simulations of dipolar fluids are performed at different numbers of particles N = 100-4000. For each size of the cubic cell, the non-spherically symmetric pair distribution function g(r,Ω) is accumulated in terms of projections gmnl(r) onto rotational invariants. The observed N dependence is in very good agreement with the theoretical predictions for the finite-size corrections of different origins: the explicit corrections due to the absence of fluctuations in the number of particles within the canonical simulation and the implicit corrections due to the coupling between the environment around a given particle and that around its images in the neighboring cells. The latter dominates in fluids of strong dipolar coupling characterized by low compressibility and high dielectric constant. The ability to clean with great precision the simulation data from these corrections combined with the use of very powerful anisotropic integral equation techniques means that exact correlation functions both in real and Fourier spaces, Kirkwood-Buff integrals, and bridge functions can be derived from box sizes as small as N ≈ 100, even with existing long-range tails. In the presence of dielectric discontinuity with the external medium surrounding the central box and its replica within the Ewald treatment of the Coulombic interactions, the 1/N dependence of the gmnl(r) is shown to disagree with the, yet well-accepted, prediction of the literature.
Microwave absorption through the martensitic and Curie transitions in Ni45Cr5Mn37In13
Authors: Pandey Sudip , Vyzulin Sergey , Quetz Abdiel , Aryal Anil , Dubenko Igor , Granovsky Alexander , Stadler Shane , Ali Naushad
Published: December 2017

We have investigated the electron spin resonance (ESR) of the Ni45Cr5Mn37In13 Heusler alloy near the structural and magnetic phase transition temperatures. Ni45Cr5Mn37In13 is characterized by a first order magnetostructural (martensitic) transition (MST) with magneto-responsive properties such as magnetoresistance, Hall and magnetocaloric effects, etc., in the vicinity of the MST. Since the details and origins of these behaviors are not well understood, we used a technique beyond magnetometry, i.e., “microwave absorption”, to reveal new information. ESR studies of Ni45Cr5Mn37In13 shows that this compound is characterized by wide absorption spectra at temperatures greater than 250 K that depend on the angle of the magnetic field relative to the normal to the sample plate (α) and temperature (T). Two local maxima at about 5 and 6 kOe were detected for α close to zero degrees near the martensitic transition and Curie temperatures. The absorption spectra are discussed along with the results of the structural and magnetic studies.
Stability of CTL immunity pathogen dynamics model with capsids and distributed delay
Authors: Elaiw A. M. , AlShamrani N. H. , Alofi A. S.
Published: December 2017

In this paper, a pathogen dynamics model with capsids and saturated incidence has been proposed and analyzed. Cytotoxic T Lymphocyte (CTL) immune response and two distributed time delays have been incorporated into the model. The nonnegativity and boundedness of the solutions of the proposed model have been shown. Two threshold parameters which fully determine the existence and stability of the three steady states of the model have been computed. Using the method of Lyapunov function, the global stability of the steady states of the model has been established. The theoretical results have been confirmed by numerical simulations.
Effect of external magnetic field on locking range of spintronic feedback nano oscillator
Authors: Singh Hanuman , Konishi K. , Bose A. , Bhuktare S. , Miwa S. , Fukushima A. , Yakushiji K. , Yuasa S. , Kubota H. , Suzuki Y. , Tulapurkar A. A.
Published: December 2017

In this work we have studied the effect of external applied magnetic field on the locking range of spintronic feedback nano oscillator. Injection locking of spintronic feedback nano oscillator at integer and fractional multiple of its auto oscillation frequency was demonstrated recently. Here we show that the locking range increases with increasing external magnetic field. We also show synchronization of spintronic feedback nano oscillator at integer (n=1,2,3) multiples of auto oscillation frequency and side band peaks at higher external magnetic field values. We have verified experimental results with macro-spin simulation using similar conditions as used for the experimental study.
The effect of TM doping on the superconducting properties of ZrNi2-xTMxGa (TM = Cu, Co) Heusler compounds
Authors: Basaula Dharma Raj , Brock Jeffrey , Khan Mahmud
Published: December 2017

We have explored the structural and superconducting properties of ZrNi2-xTMxGa (TM = Cu, Co) Heusler compounds via x-ray diffraction, scanning electron mi croscopy, electrical resistivity, dc magnetization and ac susceptibility measurements. All samples crystallized in the cubic L21 structure at room temperature. For x ≤ 0.25, all the ZrNi2-xCuxGa compounds showed superconducting properties and a decrease in TC with increasing Cu concentration. The dc magnetization data suggested type-II superconductivity for all the Cu-doped compounds. Contrary to the ZrNi2-xCuxGa compounds, no superconductivity was observed in the ZrNi2-xCoxGa compounds. Substitution of Ni by a small concentration of Co destroyed superconductivity in the Co-doped compounds. The experimental results are discussed and possible explanations are provided.
The engineering power of microfluidics delivers platforms to study the human microbiome
Authors: Cockbill Louisa
Published: December 2017

Microfluidic devices have high spatial and temporal resolution with a number of platforms that enable observation of microbes on a single cell scale.
Microstructure and properties of Cu–Mg alloy treated by internal oxidation
Authors: Guo Xiuhua , Zhou Yanjun , Song Kexing , Wang Xu , Liang Shuhua
Published: December 2017

A Cu–0.24Mg alloy bar was treated by internal oxidation using Cu2O as an oxidiser at 1123–1273 K for 10 h. The thermodynamic diagram for oxidation of a Cu–Mg alloy was confirmed by the critical oxygen pressure. The results show that the thickness of the MgO/Cu layer and the electrical conductivity of the Cu–0.24Mg alloy increase with increasing internal oxidation temperature, whereas the average hardness of the MgO/Cu layer initially increases and subsequently decreases. Examination of the microstructure of the MgO/Cu layer revealed that Mg precipitation in the form of MgO particles and their uniform dispersion in the Cu matrix were the primary reasons for increases in the comprehensive properties of the Cu–Mg alloy treated by internal oxidation.
Development of novel CoCu0.5FeNiVTix (x = 0, 0.5, 1, 1.5, 2) high-entropy alloys
Authors: Ye Haimei , Zhan Yongzhong , Nie Na
Published: December 2017

CoCu0.5FeNiVTi x ( x = 0, 0.5, 1, 1.5, 2) high-entropy alloys (HEAs) were prepared using vacuum arc melting. The microstructures, crystal structures, hardness, compressive properties and wear resistances of the alloys were studied. The alloys always contained face-centred cubic (FCC) and body-centred cubic (BCC) solid solution regardless of the increase in Ti content. The microstructure of alloys exhibited typical dendritic characteristics, which were more and more unapparent with the increase in the Ti content. The alloys with a high content of Ti had a high compressive strength and low ductility. Owing to the formation of nano-precipitates and BCC as the major phase, the CoCu0.5FeNiVTi1 alloy exhibited the highest compressive strength of 2747 MPa and a plastic strain limit of 7.4%. As the content of Ti was increased, the wear resistance of CoCu0.5FeNiVTi x alloys displayed a rapid increase and reached the highest value when x = 1, and finally decreased. Because of the large volume fraction of BCC, the CoCu0.5FeNiVTi1 alloy exhibited high hardness so exhibiting the best wear resistance. Adhesive wear and abrasive wear dominated the wear behaviour of CoCu0.5FeNiVTi x alloys during sliding against SUJ2 steel.
Sequential actions of phosphatidylinositol phosphates regulate phagosome-lysosome fusion
Authors: Jeschke Andreas , Haas Albert
Published: December 2017

Phagosomes mature into phagolysosomes by sequential fusion with early endosomes, late endosomes, and lysosomes. Phagosome-with-lysosome fusion (PLF) results in the delivery of lysosomal hydrolases into phagosomes and in digestion of the cargo. The machinery that drives PLF has been little investigated. Using a cell-free system, we recently identified the phosphoinositide lipids (PIPs) phosphatidylinositol 3-phosphate (PI(3)P) and phosphatidylinositol 4-phosphate (PI(4)P) as regulators of PLF. We now report the identification and the PIP requirements of four distinct subreactions of PLF. Our data show that (i) PI(3)P and PI(4)P are dispensable for the disassembly and activation of (phago)lysosomal soluble N-ethylmaleimide-sensitive factor attachment protein receptors, that (ii) PI(3)P is required only after the tethering step, and that (iii) PI(4)P is required during and after tethering. Moreover, our data indicate that PI(4)P is needed to anchor Arl8 (Arf-like GTPase 8) and its effector homotypic fusion/vacuole protein sorting complex (HOPS) to (phago)lysosome membranes, whereas PI(3)P is required for membrane association of HOPS only. Our study provides a first link between PIPs and established regulators of membrane fusion in late endocytic trafficking.
Mps1 promotes chromosome meiotic chromosome biorientation through Dam1
Authors: Meyer Régis E. , Brown Jamin , Beck Lindsay , Dawson Dean S.
Published: December 2017

In budding yeast meiosis, homologous chromosomes become linked by chiasmata and then move back and forth on the spindle until they are bioriented, with the kinetochores of the partners attached to microtubules from opposite spindle poles. Certain mutations in the conserved kinase, Mps1, result in catastrophic meiotic segregation errors but mild mitotic defects. We tested whether Dam1, a known substrate of Mps1, was necessary for its critical meiotic role. We found that kinetochore–microtubule attachments are established even when Dam1 is not phosphorylated by Mps1, but that Mps1 phosphorylation of Dam1 sustains those connections. But the meiotic defects when Dam1 is not phosphorylated are not nearly as catastrophic as when Mps1 is inactivated. The results demonstrate that one meiotic role of Mps1 is to stabilize connections that have been established between kinetochores and microtubles by phosphorylating Dam1.
Potassium-regulated distal tubule WNK bodies are kidney-specific WNK1 dependent
Authors: Boyd-Shiwarski Cary R. , Shiwarski Daniel J. , Roy Ankita , Namboodiri Hima N. , Nkashama Lubika J. , Xie Jian , McClain Kara L. , Marciszyn Allison , Kleyman Thomas R. , Tan Roderick J. , Stolz Donna B. , Puthenveedu Manojkumar A. , Huang Chou-Long , Subramanya Arohan R.
Published: December 2017

With-no-lysine (WNK) kinases coordinate volume and potassium homeostasis by regulating renal tubular electrolyte transport. In the distal convoluted tubule (DCT), potassium imbalance causes WNK signaling complexes to concentrate into large discrete foci, which we call “WNK bodies.” Although these structures have been reported previously, the mechanisms that drive their assembly remain obscure. Here, we show that kidney-specific WNK1 (KS-WNK1), a truncated kinase-defective WNK1 isoform that is highly expressed in the DCT, is critical for WNK body formation. While morphologically distinct WNK bodies were evident in the distal tubules of mice subjected to dietary potassium loading and restriction, KS-WNK1 knockout mice were deficient in these structures under identical conditions. Combining in vivo observations in kidney with reconstitution studies in cell culture, we found that WNK bodies are dynamic membraneless foci that are distinct from conventional organelles, colocalize with the ribosomal protein L22, and cluster the WNK signaling pathway. The formation of WNK bodies requires an evolutionarily conserved cysteine-rich hydrophobic motif harbored within a unique N-terminal exon of KS-WNK1. We propose that WNK bodies are not pathological aggregates, but rather are KS-WNK1–dependent microdomains of the DCT cytosol that modulate WNK signaling during physiological shifts in potassium balance.
Why Should I Believe Your Applied Economics?
Authors: Swinton Scott M
Published: December 2017

In an era of rising skepticism about science, this article explores what agricultural and applied economists can do to advance knowledge. If knowledge is what is believed by the preponderance of a community, then the key to advancing knowledge is to build substantive arguments—ones that are persuasive. To evaluate the substantiveness of an argument, this article develops a framework based on validity, topic, and audience. Applying that framework to two highly‐cited articles, this article concludes that validity is a necessary condition for a substantive argument, but relevance (of topic to audience) is the sufficient condition. Applied economists are well‐positioned to build compelling, objective arguments by fitting appropriate theory and methods to relevant, important topics.
Invasive Insular Sampling in Pediatric Epilepsy: A Single-Institution Experience
Authors: Tomycz Luke D , Hale Andrew T , Haider Ali S , Clarke Dave F , Lee Mark R
Published: December 2017

BACKGROUND

It has been increasingly recognized that the insular cortex plays an important role in frontotemporal-parietal epilepsy in children. The insula, however, cannot be properly interrogated with conventional subdural grids, and its anatomy makes it difficult to implicate the insula with semiology or noninvasive modalities. Frame-based, stereotactic placement of insular depth electrodes for direct extraoperative monitoring is a relatively low-risk maneuver that allows for conclusive interrogation of this region, and, in select cases, can easily be replaced with a laser applicator for minimally invasive treatment via thermoablation.

OBJECTIVE

To describe the largest reported series of pediatric patients with refractory epilepsy undergoing insular depth electrode placement.

METHODS

We used current procedural terminology billing records to identify cases of depth electrode insertion performed at our institution. Clinical information from patients undergoing invasive insular sampling was then retrospectively collected.

RESULTS

Seventy-four insular depth electrodes were placed in 49 patients for extraoperative, inpatient monitoring. The decision to place insular depth electrodes was determined by a multidisciplinary epilepsy team. In 65.3% of cases, direct invasive sampling implicated the insula in seizure onset and prompted either thermoablation or surgical resection of some portion of the insula. There were no serious adverse effects or complications associated with the placement of insular depth electrodes.

CONCLUSION

Given the low morbidity of insular depth electrode insertion and the high proportion of patients who exhibited insular involvement, it is worth considering whether insular depth electrodes should be part of the standard presurgical evaluation in children with treatment-refractory frontotemporal-parietal epilepsy.
Proposed Performance-Based Metrics for the Future Funding of Graduate Medical Education: Starting the Conversation
Authors: Caverzagie Kelly J. , Lane Susan W. , Sharma Niraj , Donnelly John , Jaeger Jeffrey R. , Laird-Fick Heather , Moriarty John P. , Moyer Darilyn V. , Wallach Sara L. , Wardrop Richard M. , Steinmann Alwin F.
Published: December 2017

Graduate medical education (GME) in the United States is financed by contributions from both federal and state entities that total over $15 billion annually. Within institutions, these funds are distributed with limited transparency to achieve ill-defined outcomes. To address this, the Institute of Medicine convened a committee on the governance and financing of GME to recommend finance reform that would promote a physician training system that meets society’s current and future needs. The resulting report provided several recommendations regarding the oversight and mechanisms of GME funding, including implementation of performance-based GME payments, but did not provide specific details about the content and development of metrics for these payments. To initiate a national conversation about performance-based GME funding, the authors asked: What should GME be held accountable for in exchange for public funding? In answer to this question, the authors propose 17 potential performance-based metrics for GME funding that could inform future funding decisions. Eight of the metrics are described as exemplars to add context and to help readers obtain a deeper understanding of the inherent complexities of performance-based GME funding. The authors also describe considerations and precautions for metric implementation.
Clozapine and Norclozapine Concentrations in Paired Human Plasma and Serum Samples
Authors: Handley Simon A. , Silk Stuart W. , Fisher Danielle S. , Subramaniam Krithika , Flanagan Robert J.
Published: December 2017

Background:

Plasma and serum are often used interchangeably for therapeutic drug monitoring (TDM) purposes, and concentrations of some drugs are reported to be lower in serum than in plasma when collected into blood collection tubes containing a gel separator. TDM is recommended for clozapine, although few studies have compared concentrations between plasma and serum. Therefore, we investigated the comparability of dipotassium ethylenediaminetetraacetic acid human plasma and serum from blood collection tubes containing a gel separator for the measurement of clozapine and norclozapine.

Methods:

Whole blood from patients (N = 93) prescribed clozapine was collected into a polypropylene Vacuette dipotassium ethylenediaminetetraacetic acid–containing blood collection tube (Greiner Bio-One), and a polypropylene Vacuette serum separator blood collection tube (Greiner Bio-One) containing a clotting activator (silica particles) and a polymer gel.

Results:

Mean clozapine concentrations were significantly (P ≤ 0.05) lower in serum (0.37 mg/L) than in plasma (0.39 mg/L), as were concentrations of norclozapine (0.17 and 0.18 mg/L, respectively). Bland–Altman plots indicated mean serum clozapine and norclozapine were 0.018 mg/L (5.3%) and 0.004 mg/L (3.6%), respectively, lower in serum than plasma.

Conclusions:

Despite the finding that clozapine and norclozapine were significantly higher in plasma than in serum when obtained from blood collected into Vacuette serum separator collection tubes, this difference is insignificant in the clinical interpretation of clozapine and norclozapine TDM results.
Simulation Training Facilitates Physical Therapists' Self-efficacy in the Intensive Care Unit
Authors: Silberman Nicki J. , Mintz Sarah B. , Zych Natalie , Bloch Naomi , Tal Eric R. , Rios Lorena
Published: December 2017

Purpose:

Physical therapists (PTs) perform early mobilization in the intensive care unit (ICU), but specialized knowledge, skills, and behaviors for ICU clinical practice pose unique challenges. High-fidelity human simulation (HFHS) training prepares medical professionals for ICU practice, but evidence on HFHS training for PTs is limited. The purpose was to develop and evaluate an HFHS-based training program focused on improving PTs' self-efficacy for ICU clinical practice.

Methods:

Six PTs participated in 3 immersive HFHS experiences, each including a simulation and group debriefing. All participants completed self-efficacy surveys pre- and posttraining. A focus group was conducted to gather participant perspectives on the learning experience.

Results:

Significant improvements in 3 self-efficacy categories occurred: performing a chart review, understanding precautions/medications, and implementing early mobilization. Qualitative analysis of the focus group revealed 4 themes: simulation facilitates positive reinforcement and confidence building; collaborative learning in a safe environment promotes skill acquisition, teamwork in training improves clinical collaboration; and simulation provides effective orientation to complex line management. The small sample size and unknown psychometric properties of the self-efficacy scale limit these results.

Conclusions:

The HFHS program facilitated PTs' teamwork, collaboration, and self-efficacy for ICU clinical practice. Further investigation is recommended to evaluate the efficacy of HFHS as a training tool to enhance PT practice in the ICU.
Making Wise Choices in Health Provision
Authors: Ellen Moriah E. , Horowitz Einav
Published: December 2017

Overuse of health services drives up costs while affecting quality of care. It can also harm patients physically and psychologically through invoking duplicate testing, unnecessary procedures, and psychological stress. The purpose of this study was to understand nurses' perceptions of health care overuse. Nurses perceived that physicians' main considerations when ordering tests are to get additional data to strengthen the diagnosis and “just to be safe.” Fear of litigation and patients' desires were important factors. Implementing interventions to reduce overuse will create a more efficient and effective system.
Preventing Falls and Fall-Related Injuries in State Veterans Homes
Authors: Zubkoff Lisa , Neily Julia , Quigley Patricia , Delanko Valarie , Young-Xu Yinong , Boar Shoshana , Mills Peter D.
Published: December 2017

This article reports on improved processes and outcomes from a virtual breakthrough series quality improvement collaborative to reduce preventable falls and fall-related injuries in 23 State Veterans Homes. Participating teams implemented 24 interventions (process changes); the most common was the postfall huddle. Teams reduced falls and fall-related injuries. This project highlights the importance of leadership support, interdisciplinary team involvement, and collaboration as essential components of fall prevention work.
Behavioural tuning in a tropical amphibian along an altitudinal gradient
Authors: Meenderink Sebastiaan W. F. , Quiñones Patricia M. , Narins Peter M.
Published: December 2017

Males of the coqui treefrog,Eleutherodactylus coqui, produce a distinct two-note ‘co-qui' advertisement call from sunset to midnight throughout most of the year. Previous work established that both the spectrotemporal aspects of the call and the frequency of highest inner-ear sensitivity change with altitude above sea level. These variations are such that the frequency of the emitted co-note closely matches the frequency to which the inner ear is most sensitive. Given this parallel variation, we expected that the call-evoked behavioural response of male coqui treefrogs would also show an altitude dependence, and hypothesized that males would produce their most robust acoustical territorial response to advertisement calls that match calls from their own altitude. We tested this hypothesis in the field by studying the vocal response behaviour of coquis to playbacks of synthetic, altitude-dependent conspecific calls, and indeed found that the most robust vocal responses were obtained using stimuli closely matching the calls from the same altitude.
Biomimetic wall-shaped adhesive microstructure for shear-induced attachment: the effects of pulling angle and preliminary displacement
Authors: Kim Jae-Kang , Varenberg Michael
Published: December 2017

To date, a handful of different gecko-like adhesives inspired by spatula-shaped attachment hairs have been suggested based on wedge and flap geometry of contact elements. However, while these surface designs have been shown to have directionality in adhesion, high friction, long lifetime and the ability to work in vacuum, an experimental verification of the very basic concept of the pulling angle effect has not yet been reported. To close this gap, here we use wall-shaped adhesive microstructures of three different flap heights to systematically study the effect of pulling angle on the normal and tangential components of the pull-off force tested at different preliminary tangential displacements. In accord with the prediction of the Kendall model for the normal component of peeling force, there is an optimal normal force that is required to detach the wall-shaped adhesive microstructure. The optimum is obtained at about half the distance needed to initiate sliding and at pulling angles that range within 60–90°, which suggests that the wall-shaped microstructure can tolerate relatively large inaccuracies in the loading direction. The increase of the attachment force with increasing flap height is found to correlate with the flap thickness, which decreased with increasing flap height.
The role of astrocytes in amyloid production and Alzheimer's disease
Authors: Frost Georgia R. , Li Yue-Ming
Published: December 2017

Alzheimer's disease (AD) is marked by the presence of extracellular amyloid beta (Aβ) plaques, intracellular neurofibrillary tangles (NFTs) and gliosis, activated glial cells, in the brain. It is thought that Aβ plaques trigger NFT formation, neuronal cell death, neuroinflammation and gliosis and, ultimately, cognitive impairment. There are increased numbers of reactive astrocytes in AD, which surround amyloid plaques and secrete proinflammatory factors and can phagocytize and break down Aβ. It was thought that neuronal cells were the major source of Aβ. However, mounting evidence suggests that astrocytes may play an additional role in AD by secreting significant quantities of Aβ and contributing to overall amyloid burden in the brain. Astrocytes are the most numerous cell type in the brain, and therefore even minor quantities of amyloid secretion from individual astrocytes could prove to be substantial when taken across the whole brain. Reactive astrocytes have increased levels of the three necessary components for Aβ production: amyloid precursor protein, β-secretase (BACE1) and γ-secretase. The identification of environmental factors, such as neuroinflammation, that promote astrocytic Aβ production, could redefine how we think about developing therapeutics for AD.
Transition from fractional to classical Stokes–Einstein behaviour in simple fluids
Authors: Coglitore Diego , Edwardson Stuart P. , Macko Peter , Patterson Eann A. , Whelan Maurice
Published: December 2017

An optical technique for tracking single particles has been used to evaluate the particle diameter at which diffusion transitions from molecular behaviour described by the fractional Stokes–Einstein relationship to particle behaviour described by the classical Stokes–Einstein relationship. The results confirm a prior prediction from molecular dynamic simulations that there is a particle size at which transition occurs and show it is inversely dependent on concentration and viscosity but independent of particle density. For concentrations in the range 5 × 10
−3
to 5 × 10
−6
 mg ml
−1
and viscosities from 0.8 to 150 mPa s, the transition was found to occur in the diameter range 150–300 nm.
Adsorption and photocatalysis for methyl orange and Cd removal from wastewater using TiO
2
/sewage sludge-based activated carbon nanocomposites
Authors: Rashed M. Nageeb , Eltaher M. A. , Abdou A. N. A.
Published: December 2017

Nanocomposite TiO
2
/ASS (TiO
2
nanoparticle coated sewage sludge-based activated carbon) was synthesized by the sol-gel method. The changes in surface properties of the TiO
2
/ASS nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence. The prepared TiO
2
/ASS nanocomposite was applied for simultaneous removal of methyl orange dye (MO) and Cd
2+
from bi-pollutant solution. The factors influencing photocatalysis (TiO
2
 : ASS ratios, initial pollutant concentrations, solution pH, nanocomposite dosage and UV irradiation time) were investigated. The results revealed that high removal efficiency of methyl orange dye (MO) and Cd
2+
from bi-pollutant solution was achieved with TiO
2
/ASS at a ratio (1 : 2). The obtained results revealed that degradation of MO dye on the TiO
2
/ASS nanocomposite was facilitated by surface adsorption and photocatalytic processes. The coupled photocatalysis and adsorption shown by TiO
2
/ASS nanocomposite resulted in faster and higher degradation of MO as compared to MO removal by ASS adsorbent. The removal efficiency of MO by ASS adsorbent and TiO
2
/ASS (1 : 2) nanocomposite at optimum pH value 7 were 74.14 and 94.28%, respectively, while for Cd
2+
it was more than 90%. The experimental results fitted well with the second-order kinetic reaction.
Multiple scaling behaviour and nonlinear traits in music scores
Authors: González-Espinoza Alfredo , Larralde Hernán , Martínez-Mekler Gustavo , Müller Markus
Published: December 2017

We present a statistical analysis of music scores from different composers using detrended fluctuation analysis (DFA). We find different fluctuation profiles that correspond to distinct autocorrelation structures of the musical pieces. Further, we reveal evidence for the presence of nonlinear autocorrelations by estimating the DFA of the magnitude series, a result validated by a corresponding study of appropriate surrogate data. The amount and the character of nonlinear correlations vary from one composer to another. Finally, we performed a simple experiment in order to evaluate the pleasantness of the musical surrogate pieces in comparison with the original music and find that nonlinear correlations could play an important role in the aesthetic perception of a musical piece.