bluuebunny/crossref_metadata_2025 huggingface dataset:
Lightweight authentication scheme for smart grid using Merkle hash tree and lossless compression hybrid method
Authors: Tohidi Hamed , Vakili Vahid Tabataba
Published: September 2018

In order to make efficient use of the benefits of smart grid, meeting the security objectives of the network seems an essential requirement. Implementation of authentication protocols on the communication among the nodes of the network plays an important role in achieving the security objectives. In this study, a lightweight authentication scheme is presented for the connection between the neighbourhood area network gateway and the control centre in the smart grid. In the proposed scheme, a lossless compression algorithm, as well as Merkel hash tree, is used to compress the data prior to cryptography. Due to the fact that large amounts of data are compressed in the compression process and then Merkel tree is applied on them, confidentiality of the data against cryptanalysis attacks has increased considerably. Security analysis of the proposed scheme indicates that the objectives of confidentiality, data integrity, and availability have been fully achieved, and the process of authentication and counteraction to the replay attack has been successfully applied. In addition, making use of the compression algorithm, as well as one time pad cryptography system, tends to reduce the computational, communication, and storage costs of the proposed scheme compared to previous scheme.
Sampled‐data based quantisation control for T–S fuzzy switched systems with actuator failures dependent on an improved Lyapunov functional method
Authors: Zhao Jianrong , Liu Wei , Zhuang Guangming , Chu Yuming , Li Yongmin
Published: September 2018

Sampled‐data based quantisation control for Takagi–Sugeno (T–S) fuzzy switched systems with actuator failures under asynchronous switching is studied. By the T–S fuzzy model, sampled‐data based asynchronous control is extended into switched non‐linear systems. An improved functional method is introduced. Applying this method, improved Lyapunov functionals are constructed. These functionals are mode dependent and piecewise continuous; not every term of these functionals is required to be positive definite; sampling states at both sides of sampling intervals are introduced into these functionals. More useful information with respect to system states is reflected in constructing functionals. Combining these functionals with the averaged dwell time technique, stabilisation conditions are relaxed, and improved exponential stabilisation criteria are obtained with less conservatism. In addition, variation ranges of membership functions are taken into account to reduce conservatism. Then, a sampled‐data based fuzzy quantisation controller is designed. Simulation examples are given to illustrate the effectiveness of the proposed results.
Complex transfer function‐based sequence domain impedance model of doubly fed induction generator
Authors: Chen Liang , Nian Heng , Xu Yunyang
Published: September 2018

The impedance‐based analysis is widely used to study stability problem between wind turbine system and grid network. Stationary sequence domain impedance has advantages over synchronous dq domain impedance due to its easy measurement in practical application. However, there is frequency coupling effect in sequence domain impedance, and a 2×2 impedance matrix is needed which makes the system be multiple‐input–multiple‐output system, which makes stability study and controller tuning much more complex compared with single‐input–single‐output (SISO) system. In this study, impedance model of doubly fed induction generator (DFIG) in sequence domain considering frequency coupling effect is derived based on the complex vector modelling method, which can obtain the straightforward block diagram representation of DFIG impedance. On the basis of the proposed model, the interaction of DFIG and different kinds of grid impedances are studied. Gershgorin theorem is applied to study the fidelity of SISO impedance model in stability analysis. Finally, the proposed impedance‐based analysis is verified through simulation.
Quantification of bed-load transport over dunes
Authors: Lockwood Kenneth , Grover Patrick , Ferreira da Silva Ana Maria
Published: September 2018

There is disagreement in the literature as to whether a shear stress-based approach can be used to accurately predict sediment transport over dunes. This study aims to address this disagreement. To this end, use is made of an experiment involving the study of naturally formed, fully developed dunes produced in a laboratory flume. The bed shear stress is estimated through a combination of velocity, Reynolds stress measurements, and results of a CFD RANS rough wall model. The validity of using Bagnold’s equation to predict the bed-load rate is subsequently analyzed. In contrast to what has been previously suggested by some authors, it is found from the present experiment that the bed-load rate correlates well with the bed shear stress, and that Bagnold’s equation yields realistic values of the bed-load rate over the stoss side of the dune downstream of the reattachment point. This work also highlights the difficulties in reliably estimating the bed shear stress in complex flows. Such difficulties are overcome in this paper through a combination of flow velocity measurements and modeled results.
Spillway blockage caused by large wood in reservoirs
Authors: Furlan Paloma , Pfister Michael , Matos Jorge , Schleiss Anton J.
Published: September 2018

Large wood (LW) elements are often transported by rivers into reservoirs during heavy rainfall events. Large wood has important environmental attributes that benefit the diversification of riverine ecosystems. There are several studies dealing with the transport and behaviour of LW inside streams. However, during flood events, LW tends to create jams or blockages at diverse hydraulic structures inside streams, creating significant problems such as discharge limitations and increased water levels. Even though knowledge on the effect of LW at bridges in rivers with relatively high flow velocities starts to be available, the latter is hardly applicable for reservoir approach flow conditions. Understanding LW blockage processes at a reservoir spillway is essential regarding the safety evaluation of a dam and the surrounding areas. The geomorphologic benefits of wood for stream restoration depends also on our present ability to manage jams and the risk they imply for civil structures when blocked. Therefore, series of systematic laboratory experiments were conducted to analyse blockage of floating stems at an ogee crested spillway equipped with piers. Different LW characteristics were represented in a physical model with cylindrical stems. Results associate the size of stem groups to blockage probabilities and the effect blockages can have on the discharge capacity of a spillway.
The influence of large wood and rootwad on flow patterns and bed morphology in a moving bed channel
Authors: Chen Su-Chin , Liang Min-Chih , Tfwala Samkele
Published: September 2018

Studying large wood in river channels can help gain insight on their form and processes. Over the preceding decade, laboratory and field experiments have been used to explain wood dynamics, flow patterns and sediment transport. Moreover, field experiments are sparse, while laboratory experiments have focused mostly on fixed bed to capture their entrainment. To enhance our scientific understanding on logs of different morphology, this study designed an experimental flume to investigate the effects of log presence on flow and bed topography in a moving bed channel. Two log configurations were used, with and without rootwad. Wood pieces had a length of 0.2 m, diameter 0.05 m and a density of approximately 760 kg/m3. Rootwad were simulated by joining 0.06 m wood pieces, having a diameter of 0.02 m to the base of the log pieces at an angle of 30°. The experiments were carried out in a 4 m long flume, 0.6 m width and 0.6 m deep, and having a slope of 0.001. The experimental bed zone was paved with uniform sand, d50 = 0.750 mm, of 0.1 m thickness. Flow in the channel was set such that it was below the critical flow for wood entrainment, and it ranged between 0.0015 to 0.005 m3/s. Three different orientations of the log were considered, namely parallel, oblique and transverse to flow. Bed evolution was monitored using a camera and a laser mounted on a moving motor frame. This research shows that log orientation and the presence of rootwad dictate bed elevation changes and stability of single wood pieces. In addition, the contrast of morphological changes caused by the presence of abundant wood in a moving bed is crucial in determining large wood appropriate for river restoration. Our study provokes fascinating questions for future investigations.
Analysis for Underwater Sound on Natural River Habitat
Authors: Gu Jung-Eun , Jung Sang Hwa , Kang Joongu , Woo Hyoseop
Published: September 2018

A riffle-pool structure is a representative physical structure of bed in rivers. The change in the physical parameter of the habitat could lead to changes in the sound environment of rivers, which are expressed by underwater acoustics. This change in underwater sound affects fish habitat. In this study, the changes of underwater acoustics were analyzed according to the change of pool-riffle sequence in a natural river. And the correlation between underwater acoustics and hydraulic characteristics was investigated. The survey for underwater acoustics was performed in the Namdae stream where is in Gangwon province. This stream belongs to the Han River basin and the river length is 39.01 km and the catchment area is 127.56 km2. The Namdae stream is a river that accounts for more than 70% of salmon returning to South Korea. The spawning salmon will return to this area around November after growing in the Bering Sea. It is important to manage the fish habitat in this river so there is a lot of research on the enhancement of fish habitat. Hydraulic characteristics were changed by the river bed structure. In this study, we investigated the relationship between underwater acoustic characteristics and hydraulic factors such as riverbed material, flow rate and water depth of each habitat type at 12 sites. The characteristics of underwater acoustic differed relative to different hydraulic factors of the two habitats, which is riffle and pool. The sound pressure level of riffles was relatively higher than that of the pools due to bed materials, shallow depth and high water velocity of riffles. In the future, it is considered that the underwater sound can be utilized as a parameter to evaluate the physical habitat environment of the river.
Direct field observations of massive bedload and debris-flow depositions in open check dams
Authors: Piton Guillaume , Fontaine Firmin , Bellot Hervé , Liébault Frédéric , Bel Coraline , Recking Alain , Hugerot Thérèse
Published: September 2018

Sediment detention basins, also called SABO dams, are key facilities in flood protection systems of mountain catchments, specifically in torrents prone to massive bedload transport or debris flows. A better understanding of the processes generating sediment trapping is required to optimize their functioning. Two monitoring stations have been implemented in the French Alps on two torrents: the Manival (Saint-Nazaire-Les-Eymes) and the Claret (Saint-Julien-Mont-Denis). Time-lapse photos show an event depositing 10,000 m3of debris flow in a basin in less than six minutes and several events partially filling the other basin with gravel, impairing its capacity to store debris flows later. After a presentation of the catchments, this paper qualitatively analyzes the dynamics of the depositions. It highlights and stresses the consistency and differences between bedload and debris-flow deposition. Overall, despite clear differences of geomorphic activity, deposits tend to fill the trap basins just enough to enable the sediment transport continuity reestablishment through the basin. The open check dams thus play a role only provided that this continuity precondition is completed. These observations enhance our comprehension of massive sediment trapping in torrents and our capacity to better adjust trap maintenance and design to the objective sought in each site.
Scouring due to submerged sills
Authors: Dudill Ashley , Vasquez Jose , Mclean Dave
Published: September 2018

As the construction of infrastructure in and around a river channel modifies the flow and sediment transport characteristics, prediction of scour depths is an integral part of engineering design. Whilst there are a substantial number of predictive equations available to estimate the scour resulting from bridge piers, other types of structures have been less examined. This paper reports on flume experiments and numerical modelling to examine the role of submerged sills in the development of scour. Sills can be utilised in a channel to control bed stability, influence mixing dynamics or dictate water levels. Additionally, sills can occur due to infrastructure including riprap-covered pipeline crossings. The majority of previous work on sills has been undertaken on unsubmerged or partially submerged sills. The only experimental work on submerged sills is restricted to a range of conditions not applicable to pipeline crossings in large sand-bed rivers. This paper presents experiments, using artificial light-weight sediment (crushed walnut shell), undertaken with a fixed flow depth but a range of velocities and sill heights, all of which are in the surface flow regime. Hydrodynamic numerical simulations were run for the same conditions to gain insight into the corresponding flow structure.
Measurement and control of high suspended sediment concentration during the Kurobe River sediment flushing with submersible type SMDP
Authors: Sumi Tetsuya , Morita Saichiro , Komiya Hideaki
Published: September 2018

In the Kurobe River, coordinated sediment flushing and sediment sluicing of Dashidaira and Unazuki dams have been executed since 2001. From the view point of the comprehensive sediment management in the sediment routing system, monitoring of quantity and quality of sediment transport during these events in rivers and reservoirs is very important. This paper shows the results of continuous measurement of high suspended sediment concentration during sediment flushing and sluicing operation of Unazuki dam in 2015 and 2016. These data have been obtained by submergible type of Suspended Sediment Concentration Measuring System with Differential Pressure Transmitter (hereinafter we call ‘submergible type SMDP’), which is designed to be placed underwater. Measured data have good correlation with manual sampling and effectively utilized to control gate operation by real-time basis during the most critical timing producing extreme high concentration just before free flow starts for sediment flushing.
Fish behavior and fish guidance at hydropower intake screens for fish downstream passage
Authors: Geiger Franz , Cuchet Mathilde , Rutschmann Peter
Published: September 2018

Fish behaviour investigations under controlled laboratory conditions but nature like environment were conducted to clarify the efficiency of inclined and horizontal screen planes for fish protection and fish downstream passage at hydropower plants concerning different potamodromous species and various sizes. The dependency on the underlying geometric and hydraulic parameters was investigated and comprehensive models were deduced to describe these relations. Adequate geometric and hydraulic design could achieve high levels of fish protection and downstream passage efficiency, even for small fish, weak swimmers and riverbed/bottom oriented species. The results imply good transferability and accordance with field observations at large scale facilities and can provide valuable information for facility design.
Towards an establishment of a rating curve for suspended sediment transport by means of ADCP measurements
Authors: Rüther Nils , Aleixo Rui , Guerrero Massimo , Sørås Sigurd , Stokseth Siri
Published: September 2018

This study presents a series of acoustic current Doppler profiler (ADCP) measurements, which are converted into suspended load concentrations (SSC). Depending on the particle size distribution (PSD), the sound backscatter and its attenuation are used to determine a theoretical minimal and physical upper limit of the SSC. The SSC are displayed over time and compared with the evolution of the water level during the same time interval. The present study shows that it is possible to have continuous measurements of SSC and water level with a horizontally installed two beam equipped ADCP and discusses the potential of such a continuing times series measurement for application in hydraulic engineering and research. However, the presented data set shows also that the calibration and the filtering of the raw data has to be improved and that further investigations are needed. After data verification, it will be possible to calculate the yearly sediment load and investigate physical behaviour of SSC concentration as a function of water level and discharge.
The spillway design for the dam’s height over 300 meters
Authors: Yao Weiwei , Chen Yuansheng , Ma Xiaoyi , Li Xiaobin
Published: September 2018

According the current hydropower development plan in China, numbers of hydraulic power plants with height over 300 meters will be built in the western region of China. These hydraulic power plants would be in crucial situation with the problems of high water head, huge discharge and narrow riverbed. Spillway is the most common structure in power plant which is used to drainage and flood release. According to the previous research, the velocity would be reaching to 55 m/s and the discharge can reach to 300 m3/s.m during spillway operation in the dam height over 300 m. The high velocity and discharge in the spillway may have the problems such as atomization nearby, slides on the side slope and river bank, Vibration on the pier, hydraulic jump, cavitation and the negative pressure on the spill way surface. All these problems may cause great disasters for both project and society. This paper proposes a novel method for flood release on high water head spillway which is named Rumei hydropower spillway located in the western region of China. This paper has following components: Determining the type and the layout of the spillway through the perspectives of air entrainment, flow jet angle and water energy dissipation in flushing pond structure. The physical hydraulic model has been used to evaluate spillway design effects.
Coupled method for the numerical simulation of 1D shallow water and Exner transport equations in channels with variable cross-section
Authors: Martínez-Aranda Sergio , Murillo Javier , García-Navarro Pilar
Published: September 2018

This work is focused on the a numerical finite volume scheme for the resulting coupled shallow water-Exner system in 1D applications with arbitrary geometry. The mathematical expression modeling the the hydrodynamic and morphodynamic components of the physical phenomenon are treated to deal with cross-section shape variations and empirical solid discharge estimations. The resulting coupled system of equations can be rewritten as a nonconservative hyperbolic system with three moving waves and one stationary wave to account for the source terms discretization. But, even for the simplest solid transport models as the Grass law, to find a linearized Jacobian matrix of the system can be a challenge if one considers arbitrary shape channels. Moreover, the bottom channel slope variations depends on the erosion-deposition mechanism considered to update the channel cross-section profile. In this paper a numerical finite volume scheme is proposed, based on an augmented Roe solver (first order accurate in time and space) and dealing with solid transport flux variations caused by the channel geometry changes. Channel crosssection variations lead to the appearance of a new solid flux source term which should be discretized properly. Comparison of the numerical results for several analytical and experimental cases demonstrate the effectiveness, exact wellbalanceness and accuracy of the scheme.
Velocity field and drag force measurements of a cube and a hemisphere mounted on an artificial bed surface roughness
Authors: Nardone Paride , Koll Katinka
Published: September 2018

Quantification of the resistance in complex roughness situations, when both bed surface and form roughnesses contribute to the total resistance, as well as partitioning of the two contributions is still unsolved. Studies about form resistance of single elements focused on obstacles mounted on smooth bed surfaces, and only few considered a rough bed surface. In order to define an approach for shear stress partitioning in open channel flows, the effect of flow conditions, the geometrical characteristics of the obstacle, and the effect of the bed surface need to be studied. This paper contributes to the topic presenting results of experiments investigating the flow field around a cube and a hemisphere mounted on a bed surface with wake interference roughness. The velocity field and the drag force exerted on the obstacles were measured with a 3D Laser Doppler Anemometer and a drag force sensor, respectively. The double averaging methodology (DAM) was applied to define the characteristic region influenced by the cube and the hemisphere, and to analyse the streamwise velocities. DAM was developed for canopy flow, thus, the methodology needed to be adapted for isolated obstacle situations. A dependency of the drag coefficient on the relative submergence is observed and analysed.
Experimental study of riverbank protection with bio-engineering techniques
Authors: Posi Sara , Montabonnet Lucas , Recking Alain , Evette André , Bellot Hervé , Ousset Frédéric , Ravanat Xavier , Piton Guillaume , Solari Luca
Published: September 2018

River management implies in many situation to control the river bank stability. Bio-engineering techniques are used as an alternative to rip-rap. These techniques are not new but a renewed interest was observed during the last decade. However the design of such bank protection is still largely based an expert evaluation of each situation, and we still crudely lack a real state of the art, based on mechanistic consideration of forces exerted by the river. We present the results of preliminary flume experiments aiming to study the resistance of river bank protections using bio-engineering techniques. The final applied objectives will be to propose a framework for a good use of such technique, accounting for the river morphodynamics context.
LES mesh resolution requirements for particledriven gravity currents
Authors: Pelmard Joë , Friedrich Heide , Norris Stuart
Published: September 2018

In this study we investigate the influence of grid resolution on a near-wall resolved LES model of a lock-exchange particle-driven gravity current. The simulations are performed using the finite volume Boussinesq code SnS with a Smagorinsky turbulence model for a buoyant Reynolds number of 60,000 on 4 grid sizes. According to previous studies, two-point correlations are most appropriate to estimate LES resolution. With the largest scales of the flow being resolved by more than 20 cells, well-resolved LES is obtained for grid resolutions of 1925×62×125 and finer. In addition, in order to apply the turbulence model correctly, we show that the velocity power spectrum densities provide useful information for the maximum cell size. The ratio of the subgrid scale viscosity to the molecular viscosity and the subgrid scale shear-stress to the resolved Reynolds stress show good convergence with grid refinement. The ratios vSGS / <0.3 above the current and τSGS (u'v')ave < 0.05 inside the mixing layer, are chosen as threshold values, based on our evaluation study.
Experiments on turbulence and near bank vorticities in an open channel sharp bend
Authors: Farhadi Alireza , Sindelar Christine , Tritthart Michael , Habersack Helmut
Published: September 2018

Turbulence has a significant influence on fluvial processes. Especially in the sharp bends of geometrically complex natural streams, the interaction of turbulence and flow three-dimensionalities is considerable. Here, generation and evolution of streamwise vorticity in an open channel bend is assessed by means of term-by-term experimental investigations. As a result, corresponding mechanisms are shown and analysed. In addition, based on the homogeneity term of vorticity equation, the applicability of a widely used simplified equation of streamwise vorticity is discussed. The presented comparison reaffirms the inadequacy of the equation in order to estimate near bank vorticities.
Numerical simulation of 2D real large scale floods on GPU: the Ebro River
Authors: Echeverribar Isabel , Morales-Hernández Mario , Brufau Pilar , García-Navarro Pilar
Published: September 2018

Modern flood risk management and mitigation plans incorporate the presence of numerical models that are able to assess the response of the system and to help in the decision-making processes. The shallow water system of equations (SWE) is widely used to model free surface flow evolution in river flooding. Although 1D models are usually adopted when simulating long rivers due to their computational efficiency, 2D models approximate better the behaviour in floodplains of meandering rivers using a fine mesh which implies unaffordable computations in real-world applications. However, the advances on parallelization methods accelerate computation making 2D models competitive. In particular, GPU technology offers important speed-ups which allow fast simulations of large scale scenarios. In this work, an example of the scope of this technology is presented. Several past flood events have been modelled using GPU. The physical domain (middle part of the Ebro River in Spain) has a extent of 477 km2, which gives rise to a large computational grid. The steps followed to carry out the numerical simulation are detailed, as well as the comparison between numerical results and observed flooded areas reaching coincidences up to 87.25 % and speed enhancements of 1-h of simulation time for 1-day flood event. These results lead to the feasible application of this numerical model in real-time simulation tools with accurate and fast predictions useful for flood management.
Drag determination of an array of square cylinders subjected to shear flow in a compound channel
Authors: Gymnopoulos Miltiadis , Prinos Panayotis , Alves Elsa , ML Ferreira Rui
Published: September 2018

Overbank flow in rivers threatens integrity of built elements located in the floodplain. Elements of infrastructure close to the interface between main channel and floodplain are subjected to complex hydrodynamic actions resulting from the obstruction of the shear flow that develops in that interface. In the current paper, the drag forces and the drag coefficient of building-like structures positioned in the interface are investigated. The experimental setup in Laboratorio Nacional de Engenharia Civil (LNEC) involves the placement of an array of square cylinders on the floodplain of a straight compound channel, next to the interface with the main channel. Three-component instantaneous-velocity recordings were performed by means of Acoustic Doppler Velocimetry (ADV) within the boundaries of a considered fluid-control volume encompassing the array, while uniform-flow conditions were established in the channel. The equation of momentum conservation was applied in its integral form in the fluid control-volume towards estimation of the time-averaged drag force at a certain elevation from the floodplain. The drag coefficient is estimated accounting for the typical shear layer at the main-channel/floodplain interface and is compared with coefficients strictly valid for isolated cylinders.
Hydraulic function of the kasumi levee system on the Kurobe Alluvial Fan of the 19th century
Authors: SENOO Hiroshi , ISHIKAWA Tadaharu
Published: September 2018

Kasumi levees are a type of discontinuous levee system that was used in early-modern times of Japan, but few records remain of the hydraulic design of the levee construction. Results of numerical flow simulation are presented for the hydraulic functioning of the Kasumi levee system along the Kurobe River that flows on a steep alluvial fan. Historical records from the 19th century to the present were used to simulate the flow through a levee system.. The computational results suggest that the flood control strategy was such that old river paths were utilized for temporary floodways and a portion of this diverted flow was returned to the main river channel through funnel-shaped levee openings located along the middle reach to prevent inundation of the alluvial fan.
Monitoring and analysis of lowland river discharge
Authors: (Ton) Hoitink A.J.F.
Published: September 2018

In single-thread channels with a sloping bed and quasi-steady con- ditions, river discharge can often directly be inferred from the water level using a rating curve. Challenges occur when the bed slope becomes negligibly small, or when the discharge becomes highly dynamic such as in the case of tides. This paper discusses recent work on monitoring and analysis of river discharge dynamics under such complicating circumstances. In lowland rivers, backwater has an effect on water levels that extends over a large region for smaller bed slopes. Results from a rainfall-runoff model and discharge measurements in the Mahakam catchment show that when a rating curve is developed in a backwater effected river, it essentially filters the backwater effects out of the discharge series. In coastal lowland plains, marine impacts cannot be ignored. Tidal waves may propagate hundreds of kilometers inland and interact with the river discharge. Acoustic Doppler current profilers are increasingly being employed for discharge monitoring in lowland rivers. A recently developed error model shows that the acoustic range needs to extend beyond the distance from the river bank where the depth mean flow velocity exceeds the cross-section averaged velocity.
Endoskopische Sinuschirurgie: Checkliste hilft Problemfälle
vorab zu entdecken
Authors: Scheckenbach Kathrin
Published: September 2018

Error M et al. Single-Blinded Prospective Implementation of a Preoperative
Imaging Checklist for Endoscopic Sinus Surgery. Otolaryngol Head Neck Surg 2018;
158: 177–180

Amerikanische HNO-Ärzt/innen untersuchten, ob die Einführung einer
präoperativen radiologischen Checkliste die Identifizierung von kritischen
Variationen in der Anatomie der Nasennebenhöhlen bei Patienten verbessert,
die sich einer endoskopischen Sinuschirurgie unterziehen.
Beratung zur Kontrazeption zwischen den Geburten
Authors: Wenderlein J. Matthias
Published: September 2018

Über eine unzureichende kontrazeptive Beratung nach der Geburt – vor allem für jüngere Frauen – wurde 2017 aus den USA berichtet 1. 43 % der Befragten gaben an, ungenügende Informationen zur Verhütung nach der Geburt erhalten zu haben. Über die Hälfte bemängelte, sie seien zu wenig über eine günstige Zeitspanne bis zur nächsten Schwangerschaft beraten worden. Hebammen haben die Chance, die Informationslücke zu schließen. Denn Frauenärzte allein werden dies nicht bewältigen können.
Die minimal-invasive Cochlea-Implantation – Chirurgische Machbarkeit und erste klinische Erfahrungen
Authors: Di Martino Ercole F.N. , v. Hesberg Jakob W.G. , Chatzakos Alkiviades , Megerle Michael , Hinder Raffael
Published: September 2018

Hintergrund: In den vergangenen Jahren wurden die Indikationen zur Cochleaimplantation ausgeweitet und gleichzeitig schonendere operative Vorgehensweisen
entwickelt.

Methoden und Patienten: Das hier vorgestellte und von uns entwickelte Verfahren kombiniert eine verkürzte retroauriculäre Hautinzision von 25 mm Länge mit
einer Reduzierung der Mastoidbohrung, der konsequenten Nutzung des Rundfensterzugangs und der Bohrung einer temporalen Implantatmulde (sog. Bremer Zugang). In
der vorliegenden Arbeit werden erste Erfahrungen und Ergebnisse mit einem minimal-invasiven Vorgehen (MiCI) bei n = 31Patienten im Alter zwischen 9–79 Jahren
berichtet.

Ergebnisse: Es gelang die Länge des retroauriculären Hautschnitts auf im Mittel 29,7 mm, die Fläche der Mastoidbohrung auf 20mm2 und die
Verweildauer um 0,55 Tage zu reduzieren. Es zeigte sich eine signifikante Lernkurve bei der Verkürzung der OP-Zeiten (p < 0.03). Die Frequenz und Art der
Komplikationen entsprach der eines konventionellen Vorgehens.

Schlußfolgerung: Die minimal-invasive Cochleaimplantation ist eine zuverlässige und sichere Methode zur Implantatversorgung.
Neuroprotective Efficacy of Clitoria Ternacea Root Extract on Hippocampal CA3 Neurons – A Quantitative Study in Mice
Authors: Hemamalini Shetty , Rao Muddanna
Published: September 2018

Clitoria ternatea is a vigorous, herbaceous perennial legume that belongs to the Fabaceae family. All parts of the plant are used in the preparations of Ayurvedic drugs. It is an astringent, an aphrodisiac, a rejuvenator, and a brain tonic. It also has anti-inflammatory, analgesic, and antipyretic properties. Baidyanath Shankapushpi, which contains extracts of herbs such as C. ternatea, Bacopa monnieri, Withania somnifera and Asparagus racemosus, is clinically administered for memory improvement, blood purification and to improve digestion. However, its neuroprotective effect has not been reported so far. In the present study, the neuroprotective effect of C. ternatea root (CTR) extract on hippocampal CA3 neurons was investigated. Three-month-old albino mice were divided into four groups. Group I was the normal control, group II was the saline control, group III was the stress group, and group IV was the stress + CTR-treated group. Group-III mice were stressed in a wire mesh restrainer for 6 hours/day for 6 weeks. Grou-IV mice were also stressed like group III, but received CTR extract orally throughout the stress period. After 6 weeks, their brain was removed, and their hippocampi were dissected and processed for Golgi staining. The hippocampal neurons were traced using a camera lucida focused at 400x magnification. The Sholl concentric circle method was used to quantify the dendrites. The results showed a decrease in the number of dendritic branching points and of dendritic intersections in the stressed group. On the other hand, there was an increase in the number of dendritic branching points and of dendritic intersections of hippocampal CA3 neurons in group IV, which was subjected to restraint stress and was treated with the CTR extract. The results showed that the oral administration of CTR significantly increased the dendritic branching points and the dendritic intersections of hippocampal CA3 neurons.
Mentale Begriffe und Theory of Mind bei Vorschulkindern mit und ohne spezifische Sprachentwicklungsstörung
Authors: Jester Melanie
Published: September 2018

Der Erwerb mentaler Begriffe verläuft bei Kindern mit normaler Sprachentwicklung (nSE) phasenhaft und parallel zu ihrer Theory of Mind (ToM)-Entwicklung, die zentral für soziale Interaktion ist. Ziel der Studie war es, die Spontansprache von deutschsprachigen Vorschulkindern mit und ohne spezifische Sprachentwicklungsstörung (SSES) auf ihren Gebrauch mentaler Begriffe zu analysieren und auf mögliche Zusammenhänge mit ihrem ToM-Verständnis zu untersuchen. Das ToM-Verständnis von jeweils 22 Kindern mit und ohne SSES wurde getestet und die Spontansprache auf mentale Begriffe untersucht. Kinder mit SSES schnitten schlechter bei ToM-Aufgaben ab und verwendeten weniger mentale Begriffe als Kinder mit nSE. Es gab eine signifikante partielle Korrelation zwischen ToM-Leistungen und dem Gebrauch mentaler Begriffe bei Kindern mit nSE, aber nicht bei Kindern mit SSES. Im Vergleich zur gleichaltrigen Kontrollgruppe scheinen Kinder mit SSES in ihrer ToM-Entwicklung verzögert zu sein.
Assessment and optimization of collective variables for protein conformational landscape: GB1 β-hairpin as a case study
Authors: Ahalawat Navjeet , Mondal Jagannath
Published: September 2018

Collective variables (CVs), when chosen judiciously, can play an important role in recognizing rate-limiting processes and rare events in any biomolecular systems. However, high dimensionality and inherent complexities associated with such biochemical systems render the identification of an optimal CV a challenging task, which in turn precludes the elucidation of an underlying conformational landscape in sufficient details. In this context, a relevant model system is presented by a 16-residue β-hairpin of GB1 protein. Despite being the target of numerous theoretical and computational studies for understanding the protein folding, the set of CVs optimally characterizing the conformational landscape of the β-hairpin of GB1 protein has remained elusive, resulting in a lack of consensus on its folding mechanism. Here we address this by proposing a pair of optimal CVs which can resolve the underlying free energy landscape of the GB1 hairpin quite efficiently. Expressed as a linear combination of a number of traditional CVs, the optimal CV for this system is derived by employing the recently introduced time-structured independent component analysis approach on a large number of independent unbiased simulations. By projecting the replica-exchange simulated trajectories along these pair of optimized CVs, the resulting free energy landscape of this system is able to resolve four distinct well-separated metastable states encompassing the extensive ensembles of folded, unfolded, and molten globule states. Importantly, the optimized CVs were found to be capable of automatically recovering a novel partial helical state of this protein, without needing to explicitly invoke helicity as a constituent CV. Furthermore, a quantitative sensitivity analysis of each constituent in the optimized CV provided key insights on the relative contributions of the constituent CVs in the overall free energy landscapes. Finally, the kinetic pathways connecting these metastable states, constructed using a Markov state model, provide an optimum description of the underlying folding mechanism of the peptide. Taken together, this work offers a quantitatively robust approach toward comprehensive mapping of the underlying folding landscape of a quintessential model system along its optimized CV.
The cankers of Exocarpos cupressiformis Labill
Authors: Scurfield G
Published: September 2018

The morphology and anatomy of cankers formed on Exocarpos cupressiformis
Labill. are described. The pathogen is fungal, though it is uncertain whether one
or more species of fungus is involved. The cankers consist of a woody framework of
lignified, pitted, and distorted fibre tracheids and occasional vessel elements, the
pathogen developing in "nests" within this framework. "Witches' brooms" formed
on the cankers develop reaction wood. The reaction wood fibres have tannins deposited
within their lumina and in the terminal lamellae of "gelatinous" layers. Enhancement
of tannin deposition in the wood and bark of cankered trees is one of the main effects
of infection. The water-soluble and methanol-soluble extractives in the heartwood
of an infected tree were approximately double the amounts in the heartwood of a healthy
tree of comparable size.
The structure of eucalypt mycorrhizas
Authors: Chilvers GA , Pryor LD
Published: September 2018

All Eucalyptus species examined are capable of forming ectotrophic mycorrhizas
in association with suitable fungi. The phenomenon is widespread but the intensity
of infection varies according to the environment in which they occur, mycorrhizas being
most common in leached soils which accumulate organlc materlal in or above the surface
layers. The general structure and behaviour of these infected roots is similar to that
described for Fagus sylvatica.
Eucalypt mycorrhizas are compared with ontogenetically equivalent uninfected
rootlets, revealing differences in anatomical structure which are assigned to two categories.
These are quantitative differences in which certain aspects of mycorrhizal structure
differ from the typical structure found in uninfected roots yet approximate to certain
extreme expressions of uninfected root anatomy, and qualitative differences where
infected and uninfected roots possess quite distinct characteristics. In the former category,
suppression of root hair formation and reduction of meristematic and root cap
tissues in mycorrhizal axes appear to be generalized changes of the kind which result
from slow growth through an unfavourable environment, so that it is not clear whether
the invading fungus induces or merely perpetuates the state found in mycorrhizas. In
the latter category, radial elongation of epidermal cells and pronounced thickening of
cell walls in the inner cortex are shown to be specific changes induced only by fungal
infection.
Mycorrhizal morphology may be simulated by uninfected roots treated with
high concentrations of naphthaleneacetic acid. Such treatment also induces some
generalized anatomical changes similar to those found in mycorrhizas, but fails to
bring about the specific changes characteristic of fungal infection. The importance of
applying anatomical criteria to studies on morphogenic compounds is discussed.
Growth of heath vegetation. II. The seasonal growth of a heath on ground-water Podzol at Wilson's Promontory, Victoria
Authors: Groves RH
Published: September 2018

The seasonal growth of a heath on a ground-water podzol in southern Victoria
is presented. Seasonal changes in the dry weight of standing vegetation, dry weight
of surface roots, and soil moisture were followed. Three phases of growth are obvious.
The first phase, shoot growth in late spring-early summer, may be the result of a
redistribution of metabolites.
During the second phase, a significant increase in the dry weight of tops may
occur; this presumably leads to an increase in evapotranspiration and a decrease in soil
moisture. Death of some roots then occurs, followed by abscission of older leaves and
death of weaker plants. Any increase in the biomass of tops is thus cancelled in this
heath ecosystem.
With reduction in leaf area, evapotranspiration decreases and soil moisture
increases. In this third phase in late summer, the root weight increases to approximately
that of the previous winter.
Thus the ecosystem maintains a fluctuating equilibrium in root-top biomass
from year to year.
Towards incorporation of potassium into the disaggregation model for determination of soil-specific threshold electrolyte concentration
Authors: Dang A. , Bennett J. M. , Marchuk A. , Marchuk S. , Biggs A. J. W. , Raine S. R.
Published: September 2018

Use of non-traditional irrigation sources will increase with industry water demand, with many industry wastewaters (e.g. agri-industry processes such as milk factories, piggeries, wineries and abattoirs) containing appreciable potassium (K), which is known to result in soil structural decline if the concentration is sufficient. The threshold electrolyte concentration (CTH) is generally understood to represent the electrolyte concentration (directly proportional to electrical conductivity) at which a soil will remain stable when subjected to a solution of given sodium adsorption ratio, without limiting dispersion. However, current approaches to determine CTH do not incorporate K. Hence, this work seeks to investigate incorporation of K into the disaggregation model for CTH and validate this against equivalent sodium (Na) systems using an ionicity approach. A single generalised coefficient of equivalence for K relative to Na did not appropriately describe the system changes; this coefficient was specific to a soil and appeared to vary with the percolating electrolyte concentration. Incorporation of K into the disaggregation model, although not accurate with a universal coefficient of equivalence for K, was considered reasonable where no other approach could be used. This conclusion was drawn on the basis that the model would produce a conservative CTH under such circumstances, which would not cause undue degradation to the soil environment.
The effect of polypropylene, polyvinyl-alcohol, carbon and glass fibres on geopolymers properties
Authors: Rashad Alaa M.
Published: September 2018

Recently, the inclusion of different types of fibres into geopolymers, as reinforcement, has amplified due to the rapid increase in geopolymers developments. In spite of geopolymers have prospective properties such as low carbon footprint, low consumption of energy, good compressive strength, resistance to fire, resistance to flame, resistance to corrosion and good durability, they undergo from low tensile strength and flexural strength. To avoid these shortages, different types of fibres could be incorporated into geopolymers to enhance their toughness, tensile strength and ductility. The current survey aims to review the effect of different types of fibres named polypropylene (PP), polyvinyl alcohol (PVA), carbon and glass fibres on the fresh and hardened properties of geopolymers.
The Ability of Forensic Psychiatric Patients with Substance Use Disorder to Learn Neurofeedback
Authors: Fielenbach Sandra , Donkers Franc C.L. , Spreen Marinus , Bogaerts Stefan
Published: September 2018

Despite the increasing use of neurofeedback in clinical psychology, it is rarely used in forensic psychiatric settings. This study investigated whether forensic psychiatric patients ( n = 19) diagnosed with substance use disorder were able to learn to control EEG-activity based on a sensorimotor rhythm/theta neurofeedback protocol. Criteria for qualifying patients as responders were established and scores on impulsivity measures and changes in level of craving over time were assessed. Results indicated that one in five patients was able to consistently change the targeted frequency bands. All patients improved on self-reported impulsivity measures and levels of craving, but only levels of craving were associated with responding to neurofeedback treatment. Patients were more able to up-train the sensorimotor rhythm magnitude than to down-train theta magnitude. Although these results are encouraging for some forensic patients, it is important to assess which patients will respond positively to the training and which will not. This requires more research.
Detailed Sonographic Anatomy of Dorsal Hand Augmentation With Hyaluronic Acid and Calcium Hydroxyapatite Fillers
Authors: Kim Jong Seo
Published: September 2018

Background

Volume restoration using filler in the dorsum of the hand is a simple and effective procedure to improve wrinkles and hide veins and tendons. Currently, calcium-hydroxyapatite (CaHA) filler is the only FDA-accepted material to use in the hand dorsum. However, it is not easy to inject due to swelling and redness. In addition, hand anatomy through sonography is wrongly described in Plastic and Reconstructive Surgery® Journal. Through incorrect marking in sonographic hand anatomy, physicians will conduct erroneous procedures and surgeries.

Objectives

CaHA filler and hyaluronic acid (HA) filler were both injected into the hand to compare intra-individually the effect of each filler. Through this study, the author introduced detailed and refined sonographic anatomy. Overall, the author identified the correct injection method and depth.

Methods

In this prospective, intra-individual, comparative study, patients were injected 1 cc of CaHA filler to the left hand and 3 cc (36 mg) of microphasic hyaluronic acid to the right. Outcomes were assessed by Merz hand grading scale, skin bio-parameters, dermascopic finding, and Global Aesthetic Improvement Scale (GAIS) with follow-up at 3, 6, 9, and 12 months.

Results

The average GAIS score improved in both hands and generally maintained over the course of the study. There was significantly more bruising and swelling in the CaHA-injected hands compared with the HA-injected hands. The skin roughness and appearance improved in both sets of hands on dermascope. The average Trans-Epidermal-Water-Loss decreased and the average Stratum Corneum Hydration increased in HA-injected hands. The biopsy study showed that the HA particles lasted for 9 months.

Conclusions

The author reestablished sonographic anatomy. Veins and tendons became less apparent after injections.

Level of Evidence: 2