bluuebunny/crossref_metadata_2025 huggingface dataset:
A simple non-equilibrium bedload transport equation for the formation of dune in a shallowwater flow over an erodible bed
Authors: Cañada-Pereira Pablo , Bohorquez Patricio
Published: September 2018

In this work, we consider the long-standing problem of capturing dune formation in an erodible-bed channel at subcritical speed by using a reduced order model of depth-averaged equations. The pioneering study by Reynolds [1] showed that the standard Saint-Venant-Exner equations are unconditionally stable at subcritical Froude number. Hence, the use of depthaveraged flow equations, which are commonly used by the hydraulic community, prevents the formation of bedforms as dunes. Recently, Cañada-Pereira & Bohorquez [2] have proposed a simple sediment transport formulation able to capture the formation of dune when coupled with the Saint-Venant equations. We replace the standard Exner equation with a non-equilibrium sediment transport equation that includes the following necessary ingredients: first, a phase shift in the particle entrainment rate; second, a particle diffusivity and an eddy viscosity. Subsequently, we solve the linear stability problem of an erodiblebed channel and show that the neutral curve properly captures the bed instability both in subcritical regime (i.e. dune) and supercritical flow (i.e. antidune and roll wave). Finally, we corroborate the capabilities of the model by means of non-linear numerical simulations which reproduce the growth of dune and antidune in agreement with experiments.
A hydro-morphodynamic model integrating extended sediment particle size distribution and flocculation processes for better simulating hydro-sedimentary fluxes
Authors: Lepesqueur Jeremy , Hostache Renaud , Martinez-Carreras Núria , Manceau Luc , Delus Claire , Losson Benoit , Montarges-Pelletier Emmanuelle , Hissler Christophe
Published: September 2018

Many studies focusing on suspended sediment transport modelling in river systems only consider one class of sediment grain size. Rather recently, the SISYPHE sediment transport model has integrated sand-mud mixture transport processes using two classes of sediment. However, this new modelling framework still suffers from limitations, and increasing the number of sediment classes would arguably improve sediment transport and therefore riverbed evolution simulations. Moreover, current sediment transport models do not simulate sediment particle aggregation and disaggregation processes while these can play an important role in sediment transport. Integrating these new concepts would then contribute to significant improvements to river bed morphodynamics and sediment transport modelling. In this study, we further develop the SISYPHE model by extending the sediment particle size distribution to ten classes and integrating flocculation processes (coupling with the flocculation FLOCMOD model). The preliminary results we present in this paper are based on a large-scale flood event, which occurred in river Orne, north-eastern France. We clearly show that the proposed developments of SYSIPHE improves qualitatively and quantitatively the predictions of sediment transport and riverbed morphodynamics.
Numerical shockwave anomalies in the resolu- tion of the Shallow Water Equations with bed variations
Authors: Navas-Montilla Adrian , Murillo Javier
Published: September 2018

The presence of numerical shockwave anomalies appearing in the resolution of hyperbolic systems of conservation laws is a well-known problem in the scientific community. The most common anomalies are the carbuncle and the slowly-moving shock anomaly. They have been studied for decades in the framework of Euler equations, but only a few authors have considered such problems for the Shallow Water Equations (SWE). In this work, the SWE are considered and the aforementioned anomalies are studied. They arise in presence of hydraulic jumps, which are transcritical shockwaves mathematically modelled as a pure discontinuity. When solving numerically such discontinuities, an unphysical intermediate state appears and gives rise to a spurious spike in the momentum. This is observed in the numerical solution as a spike in the discharge appearing in the cell containing the jump. The presence of the spurious spike in the discharge has been taken for granted by the scientific community and has even become a feature of the solution. Even though it does not disturb the rest of the solution in steady cases, it produces an undesirable shedding of spurious oscillations downstream when considering transient events. We show how it is possible to define a coherent spike reduction technique that reduces the magnitude of this anomaly and ensures convergence to the exact solution with mesh refinement. Concerning the carbuncle, which may also appear in presence of strong hydraulic jumps, a combination of Riemann solvers is proposed to circumvent it. Also, it will be shown how there is still room from improvement when treating anomalies in moving hydraulic jumps over variable topography.
A Well-balanced Finite Volume Scheme for Shallow Water Equations with Porosity: Application to Modelling Flow through Rigid Vegetation
Authors: Le Minh H. , Dubos Virgile , Oukacine Marina , Goutal Nicole
Published: September 2018

Strong interactions exist between flow dynamics and vegetation in open-channel. Depth-averaged shallow water equations can be used for such a study. However, explicit representation of vegetation can lead to very high resolution of the mesh since the vegetation is often modelled as vertical cylinders. Our work aims to study the ability of a single porosity-based shallow water model for these applications. More attention on flux and source terms discretizations are required in order to archive the well-balancing and shock capturing properties. We present a new Godunov-type finite volume scheme based on a simple-wave approximation and compare it with some other methods in the literature. A first application with experimental data was performed.
Experimental study of the surface oscillations induced by a shallow flow past a lateral cavity
Authors: Engelen L. , Creëlle S. , Schindfessel L. , De Mulder T.
Published: September 2018

The present work presents an experimental study in which resonant surface oscillations inside a lateral cavity are reconstructed, often denoted as se- iching, which are excited by a shallow main stream flowing past the horizontal basin. Firstly, the flow configurations that trigger transverse and/or longitu- dinal seiching are studied using pressure measurements in the corners of the cavity, which shows that a transitional Froude number exists, approximately 0.63, at which the dominant seiching mode changes from transverse to longi- tudinal seiching. For both types of resonant conditions, the surface shape is analyzed in detail using a three-dimensional particle tracking velocimetry (3D- PTV) setup. Based upon floating seeding particles, the 3D surface is recon- structed with a superior spatial resolution compared to traditional measurement techniques, which confirms the multimodal aspect of the surface oscillations.
Turbulence structure of non-uniform rough open channel flow
Authors: Williams Priscilla , Roussinova Vesselina , Balachandar Ram
Published: September 2018

This paper focuses on the turbulence structure in a non-uniform, gradually varied, sub-critical open channel flow (OCF) on a rough bed. The flow field is analysed under accelerating, near-uniform and decelerating conditions. Information for the flow and turbulence parameters was obtained at multiple sections and planes using two different techniques: two-component laser Doppler velocimetry (LDV) and particle image velocimetry (PIV). Different outer region velocity scaling methods were explored for evaluation of the local friction velocity. Analysis of the mean velocity profiles showed that the overlap layer exists for all flow cases. The outer layer of the decelerated velocity profile was strongly affected by the pressure gradient, where a large wake was noted. Due to the prevailing nature of the experimental setup it was found that the time-averaged flow quantities do not attained equilibrium conditions and the flow is spatially heterogeneous. The roughness generally increases the friction velocity and its effect was stronger than the effect of the pressure gradient. It was found that for the decelerated flow section over a rough bed, the mean flow and turbulence intensities were affected throughout the flow depth. The flow features presented in this study can be used to develop a model for simulating flow over a block ramp. The effect of the non-uniformity and roughness on turbulence intensities and Reynolds shear stresses was further investigated.
Impact of flow variability and sediment characteristics on channel width evolution
Authors: Vargas-Luna Andrés , Crosato Alessandra , Byishimo Protogene , Uijttewaal Wim
Published: September 2018

Alluvial rivers are shaped by sequences of water flows excavating their channels. Observations show that besides the magnitude, also the frequency and duration of streamflow oscillations might be important for the river channel formation. In addition, the river morphology appears influenced also by both size and degree of uniformity of the sediment. Nevertheless, many morphodynamic studies still represent the flow regime with a single value of the discharge, often corresponding to the bankfull condition, and the sediment with its median grain size. This work investigates the effects of streamflow variability and sediment characteristics on channel width formation, analysing the evolution of experimental streams with different sediments and discharge hydrographs. Results show that the formative condition of the channel width is not the geometric bankfull flow but a rather frequent peak flow. Remarkably different channel configurations arise from different sediment characteristics in the laboratory, where sediment non-uniformity produces more stable banks.
Bar dynamics and sediment transport pulses in gravel-bed channels
Authors: Dhont Blaise , Ancey Christophe , Bohorquez Patricio
Published: September 2018

Mountain rivers exhibit sediment transport rate fluctuations that often cover more than two orders of magnitude. Bedform migration is often cited as the key process that causes giant fluctuations in the sediment transport rate. To quantify the effect of bedform migration on transport rate, we ran laboratory experiments in a 19-m long 60-cm wide flume with well-sorted gravel bed. At the flume inlet, the water discharge and the particle flux were kept constant. Experiments were conducted over long times (typically > 500 h). Sediment transport rate was monitored at the flume outlet using accelerometers. Bed topography was scanned at high spatial resolution using a laser sheet. Water depth was measured using ultrasonic probes mounted on an automated rolling carriage. We observed that, under steady state experimental conditions, bed morphology played a key part in the generation of bedload transport fluctuations. The bars migrated downstream intermittently, producing the most important pulses. When the bar position was stable for a few hours, additional pulses resulted from sediment transfer from pool to pool, in the form of sediment waves (bedload sheets). Thus, in our experiments, alternate bars formed a two-entity system (bar + pool) with two distinctive functions: the bars contributed to fix and stabilize the bed whereas the pools were the preferential zones of short-term storage and transfer of sediment.
Multiple analysis approach for the design of the labyrinth spillway on the Nam Teng river, Myanmar: Concept design - CFD - physical model
Authors: Bigillon Françoise , Løvoll Aslak , Venås Bård
Published: September 2018

This paper presents the results of a combined approach - concept design, Computational Fluid Dynamics (CFD) simulations and physical model test - to design a spillway on the Nam Teng River in Myanmar. The spillway includes a 140 m wide labyrinth weir which ensures that the PMF flow QPMF=6800 m3/s passes with a maximum head of 5.5 m. The width required to pass PMF flow for a conventional ogee shaped weir is ca. 200m. The design of the spillway is based on design recommendations for labyrinth weirs from Tullis [1] and USBR guidelines to design the chute, stilling basin and outfall channel that leads the flood flow back to the river. The CFD simulations helped to improve the flow condition at the entrance and towards the labyrinth weir by altering the approach channel. The physical model tests confirmed the capacity of the labyrinth weir, investigated blockage risk due to floating debris. The design modifications made based on the physical model tests have increased the hydraulic performance and safety of the spillway and made the construction cheaper and simpler (less excavation and civil work).
Flood Management at Narrow River Mouth
Authors: Seleem Omar , Kadota Akihiro , Aziz Pratiwi
Published: September 2018

Hiji River is characterized by many tributaries, low bed gradient, and narrow river mouth. Due to these characteristics, several floods occurred in the past. The narrow river mouth is the main reason of flood occurrence in Hiji River. The current study is focusing on the rainfall event which caused massive damage in 2004. The purpose of the current study is to update the existing hazardous map and compare the simulation results obtained from International River Interface Cooperative (iRIC) with the measured data to calibrate the model. The simulation was carried out using Nays2DH within the measured data record from Japan Ministry of Land, Infrastructure, and Transport. The analysis result was compared with the inundated areas and almost have the same results.
Application of a 3-D CFD model to investigate flood-related engineering problems
Authors: Munoz Daniel Horna , Constantinescu George
Published: September 2018

The paper discusses the application of a fully 3-D, non-hydrostatic, RANS model with deformable free-surface capabilities to several main types of flood-related engineering problems. The model is found to accurately simulate the dam break flow developing in a 900 open channel bend for which detailed validation data from a laboratory experiment are available. First practical application deals with mitigation of flooding extent via implementation of flood protection structures such as floodwalls. Numerical results show that the floodwalls effectively protect the critical regions situated in the vicinity of the river and the reduction of the flooded area with respect to the case when floodwalls are not present is about the same at high-flow conditions and at low-flow conditions. The second application deals with prediction of flow structure around a location containing a bridge whose deck becomes submerged as the flood wave passes the bridge location. The final application considers the effects of a sudden dam break failure for a dam situated upstream of the Iowa City, USA.
Study of dam break flow interaction with urban settlements over a sloping channel
Authors: Stamataki Ioanna , Zang Jun , Buldakov Eugeny , Kjeldsen Thomas , Stagonas Dimitris
Published: September 2018

This paper describes a dam break experiment on a sloped channel, carried out in a hydraulic flume at UCL for the purpose of computer model validations of extreme events, such as flash floods. An elevated reservoir was situated upstream followed by a 1/20 slope leading up to a flat floodplain. Plexiglas blocks were positioned on the floodplain constituting different urban settlements and creating different obstructions to the flow. The flume was instrumented along its length measuring the change in water depth in the reservoir; the water depth time histories in various locations; the flow patterns and flood front velocity; and lastly the pressure and load on the buildings. The experiments were repeated for different urban settlements, flood intensities (two different initial water depths in the reservoir) and roughness layers along the slope, representative of a vegetated and a non-vegetated hill. In the present study, the experimental results were described qualitatively and compared with theoretical processes and 2D numerical results obtained using OpenFOAM's RAS turbulent model. Water depth, velocity and load measurements were analysed for different cases and it was found that while the 2D model provided a good fit on the slope, the flows generated around the building were more complex 3D formations which lead to inaccuracies. All experiments were repeated multiple times to ensure repeatability and thus the procedure was validated successfully providing a complete dataset that can be used for the validation of computational models for extreme events.
Flood forecasting using a coupled hydrological and hydraulic model (based on FVM) and highresolution meteorological model
Authors: Sanz-Ramos Marcos , Amengual Arnau , Bladé Ernest , Romero Romu , Roux Hélène
Published: September 2018

A forecasting systems based on the coupling of meteorological, hydrologic, hydraulic and risk models is used to minimize the risks associated to water scarcity and flooding. The fulfilment of such complex forecasting chains can allow obtaining information of the most plausible scenarios of water and risk management up to 96 hours ahead. In the present work, flood forecasting was carried out for different events in the upper La Muga basin (including the reservoir), within the European project “Flood Risk Assessment and Management in the Pyrenees” (http://pgriepm. eu/). The main purpose of the project was to develop a method to optimize the management of flood scenarios in order to minimize the flood risk while maximizing the water resources. The good fit of all the models, obtaining the forecasting rainfall and converting the overland flow in water levels in the reservoir, can give tools and important information to the authorities or dam managers for suitable management during the extreme rainfall and flood events.
Sediment pulses and extreme events: Assessing the effect of storm characteristics on propagation dynamics
Authors: Castro-Bolinaga Celso , Diplas Panayiotis , Bodnar Robert
Published: September 2018

The objective of this research is to assess the effect that extreme hydrologic events have on the propagation of sediment pulses in river corridors. These sediment-flow hazards are associated with large amounts of loose material suddenly deposited in rivers by the action of external factors or processes of natural or anthropogenic origin, including landslides, debris flows from tributaries, dam removal projects, and mining-related activities. Their occurrence is associated with severe channel aggradation and degradation, floodplain deposition, damage of infrastructure, and impairment of riparian and aquatic ecosystems. Given that the intensity of rainfall events have been significantly enhanced due to the influence of various human activities, sediment pulses are expected to become more common, with a more pronounced downstream impact as such climatic changes directly affect the magnitude, duration, and frequency of flows in riverine environments. Herein, numerical simulations were performed to characterize the propagation of a fine-grained sediment pulse for the 10-, 100-, and 500-yr storms. Results indicate that magnitude, frequency, and duration of the storms primarily influence the temporal variation of the total sediment discharge. In particular, these storm characteristics have a marked impact on the relationship between pre- and post-pulse conditions in the river channel, the dissipation of the pulse peak discharge, and the travel time of the pulse apex.
Vaginale Beckenendlagegeburt – immer noch eine Option?
Authors: Tschan Bianca , Klein Olivia
Published: September 2018

Um der neonatalen Morbidität und Mortalität entgegenzuwirken, tendieren einige bisher veröffentlichte Studienresultate zur systematischen Schnittentbindung bei einem Kind in Beckenendlage (BEL). Insbesondere stieg die Sectiorate nach Veröffentlichung der Term Breech Trial (TBT) von Hannah et al. (2000) eklatant an, obwohl Jahre später die Ergebnisse aufgrund methodischer Mängel relativiert wurden. Trotz aller neuen Evidenzen ist die Sectiorate bei betroffenen Schwangeren noch erschreckend hoch.
Baden, Feuchtigkeitspflege und Pflege des Windelbereichs
Authors: Dachs Claudia , Busmann Ulla , Merk Hans F.
Published: September 2018

Die Hautpflege bei Neugeborenen und Säuglingen ist ein wichtiges Thema in der Beratung junger Eltern. Angewandte Pflegeroutinen basieren oft auf Traditionen und Erfahrungen. So hat sich eine Vielfalt an Empfehlungen herausgebildet, die Eltern bisweilen überfordert. Auf Basis wissenschaftlicher Untersuchungen von Pflegeroutinen lassen sich Empfehlungen abgeben. Teil 2 der Artikelserie beleuchtet, worauf beim Baden, bei der Feuchtigkeitspflege und bei der Pflege des Windelbereichs zu achten ist.
Synthesis of Aryl-Substituted 3,3a,4,5-Tetrahydropyrrolo[1,2-a] quinolin-1(2H)-ones and 2,3,4,4a,5,6-Hexahydro-1H-pyrido[1,2-a]quinolin-1-ones
Authors: Bunce Richard , Watts Field
Published: September 2018

A new route to the title benzo-fused angular tricyclic amides 3,3a,4,5-tetrahydropyrrolo- and 2,3,4,4a,5,6-hexahydro-1H-pyrido[1,2-a]quinolin-1-ones is reported from 1-(tert-butyl) 6-ethyl 3-oxohexanedioate and 1-(tert-butyl) 7-ethyl 3-oxoheptanedioate. Alkylation of these β-keto diesters with a series of 2-nitrobenzyl bromides followed by acid hydrolysis and decarboxylation gives ethyl 6-(2-nitrophenyl)-4-oxohexanoates and ethyl 7-(2-nitrophenyl)-5-oxoheptanoates, respectively. Reductive amination under hydrogenation conditions followed by ester hydrolysis and condensative ring closure affords the final lactam products. The reactions proceed cleanly and only two chromatographic purifications are required.
Epidemiological and Clinical Features of Diaper Dermatitis in Infants at the Yaounde Gynaeco-Obstetric and Pediatric Hospital, Cameroon
Authors: Chiabi Andreas , Ngamgo Kamdem Jenny Christelle , Nkoro Anita Grâce , Siyou Hippolyte , Mah Evelyn , Nguefack Félicitée Dongmo , Nguefack Seraphin , Angwafo Fru
Published: September 2018

Diaper dermatitis is defined as an inflammatory reaction localized on the skin that is usually covered by the diaper (genitals, buttocks, and anus). The aim of this study was to determine the prevalence of diaper dermatitis and to describe the clinical presentation and practices related to hygiene in infants with diaper rash at the Yaounde Gynaeco-Obstetric and Pediatric hospital. It was a descriptive cross-sectional study undertaken in 1,004 mother–children pairs. Data were collected using structured questionnaires during face-to-face interviews with the parents. The prevalence of diaper dermatitis was 18.4%, and infants were aged 7 days to 24 months with a mean age of 5.91 months. The most represented age group was 0 to 6 months (67.6%). Infants living in urban areas (59.5%), of unemployed mothers or guardians (30.3%), and those of mothers living as a couple (75.1%) were most represented in our study sample. The majority of infants used both disposable and reusable diapers (48.6%). In addition, 72.7% mothers used palm kernel oil, and 27.3% rubbed other ointments before changing the baby's diapers. The most frequent clinical form was the chaffing form (48.1%). Healthcare personnel should inform, educate, and communicate with mothers on body hygiene of their babies to avoid this disorder, which can cause severe discomfort and sometimes lead to complications.
Aktuelle Aspekte der Lungentransplantation
Authors: von Samson-Himmelstjerna Patrick
Published: September 2018

Seit der ersten Lungentransplantation im Jahr 1963 ist diese Operation zu einer erfolgreichen und etablierten Therapie für Patienten mit Lungenversagen geworden. Obwohl die Sterblichkeitsraten im Vergleich zu anderen Organtransplantationen höher sind, wurden dank Verbesserungen in den Bereichen Technik, Organkonservierung, Immunsuppression und Antibiotika sowie diagnostischer Mittel und Therapie gegen Abstoßung bemerkenswerte Fortschritte erzielt.
Feedback enhanced entanglement in a spin-1/2 XY dimer model permeated by a transverse magnetic field
Authors: Wang Jin , Sutter Thomas , Landman Magnolia , Seblini Zahra
Published: September 2018

This paper studies the ability of feedback control to reduce the effect of decoherence and enhance entanglement in an interacting spin-1/2 XY dimer model in the presence of a transverse magnetic field. The system reaches an improved steady state entanglement when feedback is present. The influence of the strength of the external B field is found for optimized steady state entanglement. The time-dependent entanglement evolution of the system is also studied. One potential application of this scheme is to raise the maximum operating temperature of spin entangled systems.
Distribution, habitat, morphological diversity and genetic interrelations of native
Authors: Lawn R. J. , Cottrell A.
Published: September 2018

A 2-week road trip was made through the Pilbara region to collect seed of native Vigna species. Thirty-two new accessions were collected, all of which were within what can be broadly described as the V. lanceolata Benth. complex. All 32 accessions were amphicarpic, rhizomatous, trailing or vining perennials. The largest and most widely distributed group of 21 accessions belonged to the Silverleaf morphotype and a further nine accessions belonged to the Central morphotype. Two accessions from the Karratha region were of a recently described diminutive species, V. triodiophila. The Silverleaf accessions were all collected from grassy woodlands on river levees and alluvial floodplains. The Central accessions were collected from a more diverse range of habitats, albeit again mostly in wetter or ‘run-on’ parts of the landscape. Measurements of selected traits on a subset of accessions grown for seed increase in Townsville indicated that the Pilbara Silverleaf and Central accessions were comparable with accessions of these morphotypes from elsewhere in northern Australia. Healthy, viable F1 hybrids were readily obtained from crosses between accessions from all three Vigna groups collected from the Pilbara, indicating that all belong to same primary gene pool. This includes V. triodiophila, notwithstanding its taxonomy. Healthy, viable and fertile F1 hybrids were also obtained between the Pilbara accessions of both the Silverleaf and Central morphotypes and respective accessions of these morphotypes from elsewhere in northern Australia. The F1 hybrids between V. triodiophila and both the Silverleaf and the Central accessions exhibited near-normal plant phenotype in terms of the size of their vegetative and reproductive structures, indicating that the diminutive size of V. triodiophila is a recessive trait. The most plausible explanation is that V. triodiophila is a dwarf variant of the Central morphotype, which it most closely resembles apart from its size. The fact that the F1 hybrids between V. triodiophila and two Pilbara Central accessions were fully self-fertile supports that conclusion, while the recovery of dwarf segregants from small numbers of F2 and backcross progeny from one of the crosses indicates that the dwarf trait may involve just a single gene. These 32 new accessions extend the range of climatic and edaphic environments, especially at the harsher end, from which accessions of V. lanceolata have been collected and seeds conserved.
Effective distance between nested Margulis tubes
Authors: Futer David , Purcell Jessica , Schleimer Saul
Published: September 2018

We give sharp, effective bounds on the distance between tori of fixed injectivity radius inside a Margulis tube in a hyperbolic

3
3

–manifold.
Varieties of mixing
Authors: Akin Ethan , Wiseman Jim
Published: September 2018

We consider extensions of the notion of topological transitivity for a dynamical system

(
X
,
f
)

(X,f)

. In addition to chain transitivity, we define strong chain transitivity and vague transitivity. Associated with each, there is a notion of mixing, defined by transitivity of the product system

(
X
×
X
,
f
×
f
)

(X \times X, f \times f)

. These extend the concept of weak mixing which is associated with topological transitivity. Using the barrier functions of Fathi and Pageault, we obtain for each of these extended notions a dichotomy result in which a transitive system of each type either satisfies the corresponding mixing condition or else factors into an appropriate type of equicontinuous minimal system. The classical dichotomy result for minimal systems follows when it is shown that a minimal system is weak mixing if and only if it is vague mixing.
On the size of 𝑝-adic Whittaker functions
Authors: Assing Edgar
Published: September 2018

In this paper we tackle a question raised by N. Templier and A. Saha concerning the size of Whittaker new vectors appearing in infinite-dimensional representations of

GL

2

\textrm {GL}_2

over nonarchimedean fields. We derive precise bounds for such functions in all possible situations. Our main tool is the

p
p

-adic method of stationary phase.
Better hospital context increases success of care pathway implementation on achieving greater teamwork: a multicenter study on STEMI care
Authors: Aeyels Daan , Bruyneel Luk , Seys Deborah , Sinnaeve Peter R , Sermeus Walter , Panella Massimiliano , Vanhaecht Kris
Published: September 2018

Objective

To evaluate whether hospital context influences the effect of care pathway implementation on teamwork processes and output in STEMI care.

Design

A multicenter pre–post intervention study.

Setting

Eleven acute hospitals.

Participants

Cardiologists-in-chief, nurse managers, quality staff, quality managers and program managers reported on hospital context. Teamwork was rated by professional groups (medical doctors, nurses, allied health professionals, other) in the following departments: emergency room, catheterization lab, coronary care unit, cardiology ward and rehabilitation.

Intervention

Care pathway covering in-hospital care from emergency services to rehabilitation.

Main outcome measures

Hospital context was measured by the five dimensions of the Model for Understanding Success in Quality: microsystem, quality improvement team, quality improvement support, high-level organization, external environment. Teamwork process measures reflected teamwork between professional groups within departments and teamwork between departments. Teamwork output was measured through the level of organized care. Two-level regression analysis accounted for clustering of respondents within hospitals and assessed the influence of hospital context on the impact of care pathway implementation on teamwork.

Results

Care pathway implementation significantly improved teamwork processes both between professional groups (P < 0.001) and between departments (P < 0.001). Teamwork output also improved (P < 0.001). The effect of care pathway implementation on teamwork was more pronounced when the quality improvement team and quality improvement support and capacity were more positively reported on.

Conclusions

Hospitals can leverage the effect of quality improvement interventions such as care pathways by evaluating and improving aspects of hospital context.
EX-PRESS Ab Externo Revision With a 41-G Needle
Authors: Cutolo Carlo A. , Bonzano Chiara , Bagnis Alessandro , Scotto Riccardo , Traverso Carlo E.
Published: September 2018

The EX-PRESS Glaucoma Filtration Device is a stainless steel, nonvalved filtration device that channels aqueous humor through a secure lumen to a half-thickness scleral flap, creating a subconjunctival filtration bleb. Elevated postoperative intraocular pressure may indicate occlusion of the device lumen or episcleral fibrosis, and it is essential to reestablish the flow in a timely manner to prevent bleb formation failure. We report the successful use of an extendible 41-G subretinal injection needle to rapidly restore device patency when the conventional bleb revision was not effective.
Mesenchymal stem cell exosomes as a cell-free therapy for nerve injury–induced pain in rats
Authors: Shiue Sheng-Jie , Rau Ruey-Horng , Shiue Han-Shiang , Hung Yi-Wei , Li Zhi-Xiang , Yang Kuender D. , Cheng Jen-Kun
Published: September 2018

Nerve injury–induced neuropathic pain is difficult to treat. In this study, we used exosomes derived from human umbilical cord mesenchymal stem cell (UCMSC) as a cell-free therapy for nerve injury–induced pain in rats. Isolated UCMSC exosomes range in size from 30 to 160 nm and contain CD63, HSP60, and CD81 exosome markers. After L5/6 spinal nerve ligation surgery, single intrathecal injection of exosomes reversed nerve ligation–induced mechanical and thermal hypersensitivities of right hindpaw of rats at initial and well-developed pain stages. Moreover, continuous intrathecal infusion of exosomes achieved excellent preventive and reversal effects for nerve ligation–induced pain. In immunofluorescent study, lots of Exo-green-labelled exosomes could be found majorly in the ipsilateral L5 spinal dorsal horn, dorsal root ganglion, and peripheral axons, suggesting the homing ability of UCMSC exosomes. They also appeared in the central terminals or cell bodies of IB4+, CGRP+, and NF200+ sensory neurons. In addition, exosome treatment suppressed nerve ligation–induced upregulation of c-Fos, CNPase, GFAP, and Iba1. All these data suggest that the analgesic effects of exosomes may involve their actions on neuron and glial cells. Exosomes also inhibited the level of TNF-α and IL-1β, while enhanced the level of IL-10, brain-derived neurotrophic factor, and glial cell line–derived neurotrophic factor in the ipsilateral L5/6 dorsal root ganglion of nerve-ligated rats, indicating anti-inflammatory and proneurotrophic abilities. Protein analysis revealed the content of vascular endothelial growth factor C, angiopoietin-2, and fibroblast growth factor-2 in the exosomes. In summary, intrathecal infusion of exosomes from UCMSCs may be considered as a novel therapeutic approach for nerve injury–induced pain.
Effects of Thermomechanical Stimulation During Intravenous Catheter Insertion in Adults
Authors: Redfern Roberta E. , Micham Jennifer , Sievert Deana , Chen John T.
Published: September 2018

This was an open-label, randomized clinical trial comparing the effects of thermomechanical stimulation (Buzzy) versus no intervention in 105 adults undergoing intravenous (IV) catheter insertion before elective orthopedic surgical procedures. A visual analog scale was used to measure pain; satisfaction questionnaires were administered after IV catheter insertion. There was no significant difference in the mean pain score between the experimental (n = 49) and control (n = 56) groups (2.52 vs 2.43, P = .86). Subjects who reported higher preprocedure anxiety benefited most from the test intervention. It was determined that the application of cold and vibration is not universally effective for pain prevention during IV catheter insertion or for improvement in patient satisfaction in preoperative care.
Brief Intervention on Nurses’ Knowledge and Behavior Regarding Smoking Cessation
Authors: Hughes Jennifer , Smith Lynette S. , Garrett-Wright Dawn
Published: September 2018

Nurses receive little training on smoking cessation education delivery in their nursing curricula and practice settings. A brief intervention to assess nurses' knowledge and behavior regarding smoking cessation education found increases in knowledge and intended behavior. In their practice setting, nurses maintained their knowledge long term; however, nurses did not change their behavior to match their intentions of increasing the delivery of smoking cessation education.
Pancreatectomy With Arterial Resection for Pancreatic Adenocarcinoma: How Can It Be Done Safely and With Which Outcomes?
Authors: Bachellier Philippe , Addeo Pietro , Faitot François , Nappo Gennaro , Dufour Patrick
Published: September 2018

Objective:

This study assesses the safety and outcomes of the largest cohort of pancreatectomy with arterial resection (P-AR).

Background:

A high postoperative mortality rate and uncertain oncologic benefits have limited the use of P-AR for locally advanced pancreatic adenocarcinoma.

Methods:

We retrospectively reviewed a prospectively maintained database of patients who underwent P-AR between January 1990 and November 2017. Univariate and multivariate Cox analyses were used to assess prognostic factors for survival.

Results:

There were 118 consecutive resections (51 pancreaticoduodenectomies, 18 total pancreatectomies, and 49 distal splenopancreatectomies). Resected arterial segments included the coeliac trunk (50), hepatic artery (29), superior mesenteric artery (35), and other segments (4). The overall mortality and morbidity were 5.1% and 41.5%, respectively. There were 84 (75.4%) patients who received neoadjuvant chemotherapy, 105 (89%) simultaneous venous resections, and 101 (85.5%) arterial reconstructions. The rates of R0 resection and pathologic invasion of venous and arterial walls were 52.4%, 74.2%, and 58%, respectively. The overall survival was 59%, 13%, and 11.8% at 1, 3, and 5 years, respectively. The median overall survival after resection was 13.70 months (CI 95%:11–18.5 mo). In multivariate analysis, R0 resection (HR: 0.60; 95% CI: 0.38–0.96; P = 0.01) and venous invasion (HR: 1.67; 95% CI: 1.01–2.63; P = 0.04) were independent prognostic factors.

Conclusion:

In a specialized setting, P-AR for locally advanced pancreatic adenocarcinoma can be performed safely with limited mortality and morbidity. Negative resection margin and the absence of associated venous invasion might predict favorable long-term outcomes.
Neurological and Ophthalmological Manifestations of Varicella Zoster Virus
Authors: Kedar Sachin , Jayagopal Lakshman N. , Berger Joseph R.
Published: September 2018

Background:

Approximately 1 million new cases of herpes zoster (HZ) occur in the United States annually, including 10%–20% with herpes zoster ophthalmicus (HZO). Postherpetic neuralgia, a debilitating pain syndrome occurs in 30% HZ, whereas 50% HZO develop ophthalmic complications. Diplopia from cranial nerve palsy occurs in less than 30% HZO, whereas optic neuropathy is seen in less than 1% HZO. We reviewed recent developments in the diagnosis, treatment, and prevention of HZ as well as neurological and ophthalmological complications of relevance to the neuro-ophthalmologist.

Evidence Acquisition:

We searched the English language literature on Pubmed and Google scholar for articles relevant to the various sections of this review.

Results:

Antiviral treatment should be initiated within 48–72 hours of onset of HZ and HZO to decrease pain and reduce complications. We recommend neuroimaging in all patients with neuro-ophthalmic manifestations such as diplopia and acute vision loss. Diagnostic confirmation using polymerase chain reaction and serology on paired serum and cerebrospinal fluid samples should be obtained in those with neurological signs and symptoms or abnormal imaging. Patients with neurological and/or retinal varicella zoster virus (VZV) infection should be treated promptly with intravenous acyclovir. Patients with isolated optic neuropathy or cranial nerve palsy can be managed with oral antivirals. The prognosis for visual recovery is good for patients with isolated optic neuropathy and excellent for patients with isolated ocular motor cranial nerve palsy.

Conclusions:

HZ produces a spectrum of potentially blinding and life-threatening complications that adversely affect quality of life and increase health care costs. Individuals at risk for HZ, such as the elderly and immunocompromised, should be encouraged to receive the highly effective VZV vaccine to prevent HZ and its complications.
Robert Aubrey Hinde CBE. 26 October 1923—23 December 2016
Authors: Bateson Patrick , Stevenson-Hinde Joan , Clutton-Brock Tim
Published: September 2018

Robert Hinde led the study of animal behaviour for much of his long working life, drawing on his expertise in zoology and ethology to build bridges with psychology, psychiatry and the social sciences. He pioneered the application of a quantitative scientific approach to observations of behaviour, making important contributions to understanding underlying mechanisms, behavioural development and the dynamics of relationships between individuals. His influence on the field of animal behaviour was deep and pervasive, he was held in exceptionally high regard by others and his students and their students occupy many key positions in behavioural studies today. He went on to develop a science of personal relationships in humans, ranging from child development to the nature of aggression. Robert's dedication to research was combined with a commitment to promoting peace, including key roles in the Pugwash Conferences in Science and World Affairs. In retirement, he applied his ethological perspective to writing on the origins of religion and morality, the bases of war, and our culture of greed. Throughout his academic life he was a devoted member of St John's College, Cambridge—serving as teaching fellow, tutor and eventually Master.
James Francis Tait. 1 December 1925—2 February 2014
Authors: Vinson Gavin P. , Coghlan John P.
Published: September 2018

James F. Tait FRS, with his wife Sylvia A. S. Tait FRS, made an indelible contribution to life science and medicine with the isolation and characterization of aldosterone, the most potent mineralocorticoid hormone produced by the mammalian adrenal cortex.

Trained as a physicist, Tait turned to endocrinology during his first academic appointment at the Medical School of the Middlesex Hospital in London, where he met Sylvia. Their collaboration resulted in this major achievement within five years of his appointment, and they were both elected to fellowships of the Royal Society in 1959, when James was just 34.

Shortly afterwards the Taits moved to the Worcester Foundation for Experimental Biology in Massachusetts, where he virtually created the study of hormone dynamics, using sophisticated techniques involving isotopically labelled hormone infusions. Many of his most highly cited papers stem from this period.

In 1970 the Taits returned to the Middlesex Hospital, when he was appointed to the Joel Chair of Physics as Applied to Medicine. Here they continued studies on aldosterone and other adrenal steroids, using animal cell models.

He continued to be active after retiring in 1982, and published a history of aldosterone in 2009. As a hobby he made a magnificent photographic record of the churches and abbeys of Yorkshire.

Although, initially, recognition of aldosterone's clinical significance was slow, today it is thought that 10% of the incidence of essential hypertension is attributable to excess aldosterone. Aldactone, the earliest aldosterone antagonist, as well as more recently developed blockers, have proved effective in congestive heart failure. Sixty years after its discovery, aldosterone remains a rich and dynamic research field.
An Artificial Intelligence Workflow for Defining Host-Pathogen Interactions
Authors: Fisch Daniel H , Yakimovich Artur , Clough Barbara , Wright Joseph , Bunyan Monique , Howell Michael , Mercer Jason , Frickel Eva-Maria
Published: September 2018

For image-based infection biology, accurate unbiased quantification of host-pathogen interactions is essential, yet often performed manually or using limited enumeration employing simple image analysis algorithms based on image segmentation. Host protein recruitment to pathogens is often refractory to accurate automated assessment due to its heterogeneous nature. An intuitive intelligent image analysis program to assess host protein recruitment within general cellular pathogen defense is lacking. We present HRMAn (Host Response to Microbe Analysis), an open-source image analysis platform based on machine learning algorithms and deep learning. We show that HRMAn has the capability to learn phenotypes from the data, without relying on researcher-based assumptions. Using Toxoplasma gondii and Salmonella typhimurium we demonstrate HRMAn’s capacity to recognize, classify and quantify pathogen killing, replication and cellular defense responses.
Viewing pictures triggers rapid morphological enlargement in the human visual cortex
Authors: Månsson K.N.T. , Cortes D.S. , Manzouri A. , Hau S. , Fischer H.
Published: September 2018

Brain morphology change over the course of weeks, days, and hours, and can be detected by non-invasive structural magnetic resonance imaging. Rapid morphological changes at scanning has yet not been investigated. In a randomized within-group study, high-resolution anatomical images were acquired during passive viewing of pictures or a fixation cross. Forty-seven individuals gray matter volume and cortical thickness were investigated, and both measures increased in the visual cortex while viewing pictures relative to a fixation cross. Thus, brain morphology enlargements were detected in less than 263 seconds. Neuroplasticity is a far more dynamic process than previously shown, suggesting that individuals’ current mental state affects indices of brain morphology. This needs to be taken into account in future morphology studies and in everyday clinical practice.
Specific detection of cell-free DNA derived from intestinal epithelial cells using methylation patterns
Authors: Lehmann-Werman Roni , Zick Aviad , Paweletz Cloud , Welch Marisa , Hubert Ayala , Maoz Miriam , Davidy Tal , Magenheim Judith , Piyanzin Sheina , Neiman Daniel , Moss Joshua , Golan Hadar , Israeli Eran , Fischer Matan , Segal Eran , Grompe Markus , Pikarsky Alon , Golan Talia , Glaser Benjamin , Shemer Ruth , Wolpin Brian , Dor Yuval
Published: September 2018

Epithelial cells of the intestine undergo rapid turnover and are thought to be cleared via stool. Disruption of tissue architecture, as occurs in colorectal cancer (CRC), results in the release of material from dying intestinal epithelial cells to blood. This phenomenon could be utilized for diagnosis and monitoring of intestinal diseases, if circulating cell-free DNA (cfDNA) derived from intestinal cells could be specifically identified. Here we describe two genomic loci that are unmethylated specifically in intestinal epithelial cells, allowing for sensitive and specific detection of DNA derived from such cells. As expected, intestinal DNA is found in stool, but not in plasma, of healthy individuals. Patients with inflammatory bowel disease (IBD) have minimal amounts of intestinal cfDNA in the plasma, whereas patients with advanced CRC show a strong signal. The intestinal markers are not elevated in plasma samples from patients with pancreatic ductal adenocarcinoma (PDAC), and a combination of intestine- and pancreas-specific markers allowed for robust differentiation between plasma cfDNA derived from CRC and PDAC patients. Intestinal DNA markers provide a mutation-independent tool for monitoring intestinal dynamics in health and disease.
Organ-specific propensity drives patterns of gene expression evolution
Authors: Fukushima Kenji , Pollock David D.
Published: September 2018

The origins of multicellular physiology are tied to evolution of gene expression. Genes can shift expression as organisms evolve, but how ancestral expression influences altered descendant expression is not well understood. To examine this, we amalgamated 1,903 RNA-seq datasets from 182 research projects, including 6 organs in 21 vertebrate species. Quality control eliminated project-specific biases, and expression shifts were reconstructed using gene-family-wise phylogenetic Ornstein–Uhlenbeck models. Expression shifts following gene duplication result in more drastic changes in expression properties than shifts without gene duplication. The expression properties were tightly coupled with protein evolutionary rate, depending on whether and how gene duplication occurred. Fluxes in expression patterns among organs were nonrandom, forming modular connections which were reshaped by gene duplication. Thus, if expression shifted, ancestral expression in some organs induces a strong propensity for expression in particular organs in descendants. This supports a major role for what might be termed “preadaptive” pathways of gene expression evolution.